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Marstrand-Joergensen MR, Laurell GL, Herrmann S, Nasser A, Johansen A, Lund A, Andersen TL, Knudsen GM, Pinborg LH. Assessment of cerebral drug occupancy in humans using a single PET-scan: A [ 11C]UCB-J PET study. Eur J Nucl Med Mol Imaging 2024:10.1007/s00259-024-06759-x. [PMID: 38758370 DOI: 10.1007/s00259-024-06759-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 05/07/2024] [Indexed: 05/18/2024]
Abstract
PURPOSE Here, we evaluate a PET displacement model with a Single-step and Numerical solution in healthy individuals using the synaptic vesicle glycoprotein (SV2A) PET-tracer [11C]UCB-J and the anti-seizure medication levetiracetam (LEV). We aimed to (1) validate the displacement model by comparing the brain LEV-SV2A occupancy from a single PET scan with the occupancy derived from two PET scans and the Lassen plot and (2) determine the plasma LEV concentration-SV2A occupancy curve in healthy individuals. METHODS Eleven healthy individuals (five females, mean age 35.5 [range: 25-47] years) underwent two 120-min [11C]UCB-J PET scans where an LEV dose (5-30 mg/kg) was administered intravenously halfway through the first PET scan to partially displace radioligand binding to SV2A. Five individuals were scanned twice on the same day; the remaining six were scanned once on two separate days, receiving two identical LEV doses. Arterial blood samples were acquired to determine the arterial input function and plasma LEV concentrations. Using the displacement model, the SV2A-LEV target engagement was calculated and compared with the Lassen plot method. The resulting data were fitted with a single-site binding model. RESULTS SV2A occupancies and VND estimates derived from the displacement model were not significantly different from the Lassen plot (p = 0.55 and 0.13, respectively). The coefficient of variation was 14.6% vs. 17.3% for the Numerical and the Single-step solution in Bland-Altman comparisons with the Lassen plot. The average half maximal inhibitory concentration (IC50), as estimated from the area under the curve of the plasma LEV concentration, was 12.5 µg/mL (95% CI: 5-25) for the Single-Step solution, 11.8 µg/mL (95% CI: 4-25) for the Numerical solution, and 6.3 µg/mL (95% CI: 0.08-21) for the Lassen plot. Constraining Emax to 100% did not significantly improve model fits. CONCLUSION Plasma LEV concentration vs. SV2A occupancy can be determined in humans using a single PET scan displacement model. The average concentration of the three computed IC50 values ranges between 6.3 and 12.5 µg/mL. The next step is to use the displacement model to evaluate LEV occupancy and corresponding plasma concentrations in relation to treatment efficacy. CLINICAL TRIAL REGISTRATION NCT05450822. Retrospectively registered 5 July 2022 https://clinicaltrials.gov/ct2/results? term=NCT05450822&Search=Search.
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Affiliation(s)
- Maja R Marstrand-Joergensen
- Epilepsy Clinic, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, Copenhagen O, 2100, Denmark
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Rigshospitalet, Building 8057, Blegdamsvej 9, Copenhagen, 8057, DK-2100, Denmark
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, 2100, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gjertrud L Laurell
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Rigshospitalet, Building 8057, Blegdamsvej 9, Copenhagen, 8057, DK-2100, Denmark
- Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Susan Herrmann
- Department of Clinical Biochemistry, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Arafat Nasser
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Rigshospitalet, Building 8057, Blegdamsvej 9, Copenhagen, 8057, DK-2100, Denmark
| | - Annette Johansen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Rigshospitalet, Building 8057, Blegdamsvej 9, Copenhagen, 8057, DK-2100, Denmark
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, 2100, Denmark
| | - Anton Lund
- Department of Neuroanaesthesiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, 2100, Denmark
| | - Thomas L Andersen
- Department of Clinical Physiology & Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, 2100, Denmark
- Department of Clinical Medicine, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Rigshospitalet, Building 8057, Blegdamsvej 9, Copenhagen, 8057, DK-2100, Denmark
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, 2100, Denmark
- Department of Clinical Medicine, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Lars H Pinborg
- Epilepsy Clinic, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, Copenhagen O, 2100, Denmark.
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Rigshospitalet, Building 8057, Blegdamsvej 9, Copenhagen, 8057, DK-2100, Denmark.
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, 2100, Denmark.
- Department of Clinical Medicine, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark.
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Hobbs NZ, Papoutsi M, Delva A, Kinnunen KM, Nakajima M, Van Laere K, Vandenberghe W, Herath P, Scahill RI. Neuroimaging to Facilitate Clinical Trials in Huntington's Disease: Current Opinion from the EHDN Imaging Working Group. J Huntingtons Dis 2024:JHD240016. [PMID: 38788082 DOI: 10.3233/jhd-240016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
Neuroimaging is increasingly being included in clinical trials of Huntington's disease (HD) for a wide range of purposes from participant selection and safety monitoring, through to demonstration of disease modification. Selection of the appropriate modality and associated analysis tools requires careful consideration. On behalf of the EHDN Imaging Working Group, we present current opinion on the utility and future prospects for inclusion of neuroimaging in HD trials. Covering the key imaging modalities of structural-, functional- and diffusion- MRI, perfusion imaging, positron emission tomography, magnetic resonance spectroscopy, and magnetoencephalography, we address how neuroimaging can be used in HD trials to: 1) Aid patient selection, enrichment, stratification, and safety monitoring; 2) Demonstrate biodistribution, target engagement, and pharmacodynamics; 3) Provide evidence for disease modification; and 4) Understand brain re-organization following therapy. We also present the challenges of translating research methodology into clinical trial settings, including equipment requirements and cost, standardization of acquisition and analysis, patient burden and invasiveness, and interpretation of results. We conclude, that with appropriate consideration of modality, study design and analysis, imaging has huge potential to facilitate effective clinical trials in HD.
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Affiliation(s)
- Nicola Z Hobbs
- HD Research Centre, UCL Institute of Neurology, UCL, London, UK
| | - Marina Papoutsi
- HD Research Centre, UCL Institute of Neurology, UCL, London, UK
- IXICO plc, London, UK
| | - Aline Delva
- Department of Neurosciences, KU Leuven, Belgium
- Department of Neurology, University Hospitals Leuven, Belgium
| | | | | | - Koen Van Laere
- Department of Imaging and Pathology, Nuclear Medicine and Molecular Imaging, KU Leuven, Belgium
- Division of Nuclear Medicine, University Hospitals Leuven, Belgium
| | - Wim Vandenberghe
- Department of Neurosciences, KU Leuven, Belgium
- Department of Neurology, University Hospitals Leuven, Belgium
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Wang HE, Triebkorn P, Breyton M, Dollomaja B, Lemarechal JD, Petkoski S, Sorrentino P, Depannemaecker D, Hashemi M, Jirsa VK. Virtual brain twins: from basic neuroscience to clinical use. Natl Sci Rev 2024; 11:nwae079. [PMID: 38698901 PMCID: PMC11065363 DOI: 10.1093/nsr/nwae079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 05/05/2024] Open
Abstract
Virtual brain twins are personalized, generative and adaptive brain models based on data from an individual's brain for scientific and clinical use. After a description of the key elements of virtual brain twins, we present the standard model for personalized whole-brain network models. The personalization is accomplished using a subject's brain imaging data by three means: (1) assemble cortical and subcortical areas in the subject-specific brain space; (2) directly map connectivity into the brain models, which can be generalized to other parameters; and (3) estimate relevant parameters through model inversion, typically using probabilistic machine learning. We present the use of personalized whole-brain network models in healthy ageing and five clinical diseases: epilepsy, Alzheimer's disease, multiple sclerosis, Parkinson's disease and psychiatric disorders. Specifically, we introduce spatial masks for relevant parameters and demonstrate their use based on the physiological and pathophysiological hypotheses. Finally, we pinpoint the key challenges and future directions.
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Affiliation(s)
- Huifang E Wang
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Paul Triebkorn
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Martin Breyton
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
- Service de Pharmacologie Clinique et Pharmacosurveillance, AP–HM, Marseille, 13005, France
| | - Borana Dollomaja
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Jean-Didier Lemarechal
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Spase Petkoski
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Pierpaolo Sorrentino
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Damien Depannemaecker
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Meysam Hashemi
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
| | - Viktor K Jirsa
- Aix Marseille Université, Institut National de la Santé et de la Recherche Médicale, Institut de Neurosciences des Systèmes (INS) UMR1106; Marseille 13005, France
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Bavarsad MS, Grinberg LT. SV2A PET imaging in human neurodegenerative diseases. Front Aging Neurosci 2024; 16:1380561. [PMID: 38699560 PMCID: PMC11064927 DOI: 10.3389/fnagi.2024.1380561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 03/20/2024] [Indexed: 05/05/2024] Open
Abstract
This manuscript presents a thorough review of synaptic vesicle glycoprotein 2A (SV2A) as a biomarker for synaptic integrity using Positron Emission Tomography (PET) in neurodegenerative diseases. Synaptic pathology, characterized by synaptic loss, has been linked to various brain diseases. Therefore, there is a need for a minimally invasive approach to measuring synaptic density in living human patients. Several radiotracers targeting synaptic vesicle protein 2A (SV2A) have been created and effectively adapted for use in human subjects through PET scans. SV2A is an integral glycoprotein found in the membranes of synaptic vesicles in all synaptic terminals and is widely distributed throughout the brain. The review delves into the development of SV2A-specific PET radiotracers, highlighting their advancements and limitations in neurodegenerative diseases. Among these tracers, 11C-UCB-J is the most used so far. We summarize and discuss an increasing body of research that compares measurements of synaptic density using SV2A PET with other established indicators of neurodegenerative diseases, including cognitive performance and radiological findings, thus providing a comprehensive analysis of SV2A's effectiveness and reliability as a diagnostic tool in contrast to traditional markers. Although the literature overall suggests the promise of SV2A as a diagnostic and therapeutic monitoring tool, uncertainties persist regarding the superiority of SV2A as a biomarker compared to other available markers. The review also underscores the paucity of studies characterizing SV2A distribution and loss in human brain tissue from patients with neurodegenerative diseases, emphasizing the need to generate quantitative neuropathological maps of SV2A density in cases with neurodegenerative diseases to fully harness the potential of SV2A PET imaging in clinical settings. We conclude by outlining future research directions, stressing the importance of integrating SV2A PET imaging with other biomarkers and clinical assessments and the need for longitudinal studies to track SV2A changes throughout neurodegenerative disease progression, which could lead to breakthroughs in early diagnosis and the evaluation of new treatments.
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Affiliation(s)
| | - Lea T. Grinberg
- Memory and Aging Center, Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
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Oliva HNP, Prudente TP, Nunes EJ, Cosgrove KP, Radhakrishnan R, Potenza MN, Angarita GA. Substance use and spine density: a systematic review and meta-analysis of preclinical studies. Mol Psychiatry 2024:10.1038/s41380-024-02519-3. [PMID: 38561468 DOI: 10.1038/s41380-024-02519-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 02/28/2024] [Accepted: 03/04/2024] [Indexed: 04/04/2024]
Abstract
The elucidation of synaptic density changes provides valuable insights into the underlying brain mechanisms of substance use. In preclinical studies, synaptic density markers, like spine density, are altered by substances of abuse (e.g., alcohol, amphetamine, cannabis, cocaine, opioids, nicotine). These changes could be linked to phenomena including behavioral sensitization and drug self-administration in rodents. However, studies have produced heterogeneous results for spine density across substances and brain regions. Identifying patterns will inform translational studies given tools that now exist to measure in vivo synaptic density in humans. We performed a meta-analysis of preclinical studies to identify consistent findings across studies. PubMed, ScienceDirect, Scopus, and EBSCO were searched between September 2022 and September 2023, based on a protocol (PROSPERO: CRD42022354006). We screened 6083 publications and included 70 for meta-analysis. The meta-analysis revealed drug-specific patterns in spine density changes. Hippocampal spine density increased after amphetamine. Amphetamine, cocaine, and nicotine increased spine density in the nucleus accumbens. Alcohol and amphetamine increased, and cannabis reduced, spine density in the prefrontal cortex. There was no convergence of findings for morphine's effects. The effects of cocaine on the prefrontal cortex presented contrasting results compared to human studies, warranting further investigation. Publication bias was small for alcohol or morphine and substantial for the other substances. Heterogeneity was moderate-to-high across all substances. Nonetheless, these findings inform current translational efforts examining spine density in humans with substance use disorders.
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Affiliation(s)
- Henrique Nunes Pereira Oliva
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, USA
| | - Tiago Paiva Prudente
- Faculdade de Medicina, Universidade Federal de Goiás (UFG), Goiânia, Goiás, Brazil
| | - Eric J Nunes
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Yale Tobacco Center of Regulatory Science, Yale University School of Medicine, New Haven, CT, USA
| | - Kelly P Cosgrove
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Rajiv Radhakrishnan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Marc N Potenza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, USA
- Child Study Center, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University, New Haven, CT, USA
- Connecticut Council on Problem Gambling, Wethersfield, CT, USA
- Wu Tsai Institute, Yale University, New Haven, CT, USA
| | - Gustavo A Angarita
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, USA.
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Onwordi EC, Whitehurst T, Shatalina E, Mansur A, Arumuham A, Osugo M, Marques TR, Jauhar S, Gupta S, Mehrotra R, Rabiner EA, Gunn RN, Natesan S, Howes OD. Synaptic Terminal Density Early in the Course of Schizophrenia: An In Vivo UCB-J Positron Emission Tomographic Imaging Study of SV2A. Biol Psychiatry 2024; 95:639-646. [PMID: 37330164 PMCID: PMC10923626 DOI: 10.1016/j.biopsych.2023.05.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND The synaptic hypothesis is an influential theory of the pathoetiology of schizophrenia (SCZ), which is supported by the finding that there is lower uptake of the synaptic terminal density marker [11C]UCB-J in patients with chronic SCZ than in control participants. However, it is unclear whether these differences are present early in the illness. To address this, we investigated [11C]UCB-J volume of distribution (VT) in antipsychotic-naïve/free patients with SCZ who were recruited from first-episode services compared with healthy volunteers. METHODS Forty-two volunteers (SCZ n = 21, healthy volunteers n = 21) underwent [11C]UCB-J positron emission tomography to index [11C]UCB-J VT and distribution volume ratio in the anterior cingulate, frontal, and dorsolateral prefrontal cortices; the temporal, parietal and occipital lobes; and the hippocampus, thalamus, and amygdala. Symptom severity was assessed in the SCZ group using the Positive and Negative Syndrome Scale. RESULTS We found no significant effects of group on [11C]UCB-J VT or distribution volume ratio in most regions of interest (effect sizes from d = 0.0-0.7, p > .05), with two exceptions: we found lower distribution volume ratio in the temporal lobe (d = 0.7, uncorrected p < .05) and lower VT/fp in the anterior cingulate cortex in patients (d = 0.7, uncorrected p < .05). The Positive and Negative Syndrome Scale total score was negatively associated with [11C]UCB-J VT in the hippocampus in the SCZ group (r = -0.48, p = .03). CONCLUSIONS These findings indicate that large differences in synaptic terminal density are not present early in SCZ, although there may be more subtle effects. When taken together with previous evidence of lower [11C]UCB-J VT in patients with chronic illness, this may indicate synaptic density changes during the course of SCZ.
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Affiliation(s)
- Ellis Chika Onwordi
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom; Centre for Psychiatry and Mental Health, Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom.
| | - Thomas Whitehurst
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Ekaterina Shatalina
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Ayla Mansur
- Department of Brain Sciences, Imperial College London, The Commonwealth Building, Hammersmith Hospital, London, United Kingdom; Invicro, Burlington Danes Building, London, United Kingdom
| | - Atheeshaan Arumuham
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Martin Osugo
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Tiago Reis Marques
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Sameer Jauhar
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Susham Gupta
- Early Detection and Early Intervention, East London National Health Service Foundation Trust, London, United Kingdom
| | - Ravi Mehrotra
- Early Intervention in Psychosis Team, West Middlesex University Hospital, West London National Health Service Trust, Isleworth, London, United Kingdom
| | - Eugenii A Rabiner
- Invicro, Burlington Danes Building, London, United Kingdom; Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Roger N Gunn
- Department of Brain Sciences, Imperial College London, The Commonwealth Building, Hammersmith Hospital, London, United Kingdom; Invicro, Burlington Danes Building, London, United Kingdom
| | - Sridhar Natesan
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Oliver D Howes
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom; Psychiatric Imaging Group, Medical Research Council, London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.
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Martin SL, Uribe C, Strafella AP. PET imaging of synaptic density in Parkinsonian disorders. J Neurosci Res 2024; 102:e25253. [PMID: 37814917 DOI: 10.1002/jnr.25253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/31/2023] [Accepted: 09/21/2023] [Indexed: 10/11/2023]
Abstract
Synaptic dysfunction and altered synaptic pruning are present in people with Parkinsonian disorders. Dopamine loss and alpha-synuclein accumulation, two hallmarks of Parkinson's disease (PD) pathology, contribute to synaptic dysfunction and reduced synaptic density in PD. Atypical Parkinsonian disorders are likely to have unique spatiotemporal patterns of synaptic density, differentiating them from PD. Therefore, quantification of synaptic density has the potential to support diagnoses, monitor disease progression, and treatment efficacy. Novel radiotracers for positron emission tomography which target the presynaptic vesicle protein SV2A have been developed to quantify presynaptic density. The radiotracers have successfully investigated synaptic density in preclinical models of PD and people with Parkinsonian disorders. Therefore, this review will summarize the preclinical and clinical utilization of SV2A radiotracers in people with Parkinsonian disorders. We will evaluate how SV2A abundance is associated with other imaging modalities and the considerations for interpreting SV2A in Parkinsonian pathology.
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Affiliation(s)
- Sarah L Martin
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Carme Uribe
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Unitat de Psicologia Medica, Departament de Medicina, Institute of Neuroscience, Universitat de Barcelona, Barcelona, Spain
| | - Antonio P Strafella
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Edmond J. Safra Parkinson Disease Program, Neurology Division, Toronto Western Hospital & Krembil Brain Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
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Toyonaga T, Khattar N, Wu Y, Lu Y, Naganawa M, Gallezot JD, Matuskey D, Mecca AP, Pittman B, Dias M, Nabulsi NB, Finnema SJ, Chen MK, Arnsten A, Radhakrishnan R, Skosnik PD, D'Souza DC, Esterlis I, Huang Y, van Dyck CH, Carson RE. The regional pattern of age-related synaptic loss in the human brain differs from gray matter volume loss: in vivo PET measurement with [ 11C]UCB-J. Eur J Nucl Med Mol Imaging 2024; 51:1012-1022. [PMID: 37955791 DOI: 10.1007/s00259-023-06487-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 10/21/2023] [Indexed: 11/14/2023]
Abstract
PURPOSE Aging is a major societal concern due to age-related functional losses. Synapses are crucial components of neural circuits, and synaptic density could be a sensitive biomarker to evaluate brain function. [11C]UCB-J is a positron emission tomography (PET) ligand targeting synaptic vesicle glycoprotein 2A (SV2A), which can be used to evaluate brain synaptic density in vivo. METHODS We evaluated age-related changes in gray matter synaptic density, volume, and blood flow using [11C]UCB-J PET and magnetic resonance imaging (MRI) in a wide age range of 80 cognitive normal subjects (21-83 years old). Partial volume correction was applied to the PET data. RESULTS Significant age-related decreases were found in 13, two, and nine brain regions for volume, synaptic density, and blood flow, respectively. The prefrontal cortex showed the largest volume decline (4.9% reduction per decade: RPD), while the synaptic density loss was largest in the caudate (3.6% RPD) and medial occipital cortex (3.4% RPD). The reductions in caudate are consistent with previous SV2A PET studies and likely reflect that caudate is the site of nerve terminals for multiple major tracts that undergo substantial age-related neurodegeneration. There was a non-significant negative relationship between volume and synaptic density reductions in 16 gray matter regions. CONCLUSION MRI and [11]C-UCB-J PET showed age-related decreases of gray matter volume, synaptic density, and blood flow; however, the regional patterns of the reductions in volume and SV2A binding were different. Those patterns suggest that MR-based measures of GM volume may not be directly representative of synaptic density.
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Affiliation(s)
- Takuya Toyonaga
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA.
| | - Nikkita Khattar
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Yanjun Wu
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Yihuan Lu
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Mika Naganawa
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Jean-Dominique Gallezot
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - David Matuskey
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Adam P Mecca
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, CT, USA
| | - Brian Pittman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Mark Dias
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Nabeel B Nabulsi
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Sjoerd J Finnema
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Ming-Kai Chen
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Amy Arnsten
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychology, Yale University School of Medicine, New Haven, CT, USA
| | - Rajiv Radhakrishnan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Patrick D Skosnik
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Bouvé College of Health Sciences, Northeastern University Schools of Nursing & Pharmacy/Pharmaceutical Sciences, Boston, MA, USA
| | - Deepak Cyril D'Souza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Irina Esterlis
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Yiyun Huang
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Christopher H van Dyck
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Richard E Carson
- PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, 06520, USA
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9
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Betzel R, Puxeddu MG, Seguin C, Bazinet V, Luppi A, Podschun A, Singleton SP, Faskowitz J, Parakkattu V, Misic B, Markett S, Kuceyeski A, Parkes L. Controlling the human connectome with spatially diffuse input signals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.581006. [PMID: 38463980 PMCID: PMC10925126 DOI: 10.1101/2024.02.27.581006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
The human brain is never at "rest"; its activity is constantly fluctuating over time, transitioning from one brain state-a whole-brain pattern of activity-to another. Network control theory offers a framework for understanding the effort - energy - associated with these transitions. One branch of control theory that is especially useful in this context is "optimal control", in which input signals are used to selectively drive the brain into a target state. Typically, these inputs are introduced independently to the nodes of the network (each input signal is associated with exactly one node). Though convenient, this input strategy ignores the continuity of cerebral cortex - geometrically, each region is connected to its spatial neighbors, allowing control signals, both exogenous and endogenous, to spread from their foci to nearby regions. Additionally, the spatial specificity of brain stimulation techniques is limited, such that the effects of a perturbation are measurable in tissue surrounding the stimulation site. Here, we adapt the network control model so that input signals have a spatial extent that decays exponentially from the input site. We show that this more realistic strategy takes advantage of spatial dependencies in structural connectivity and activity to reduce the energy (effort) associated with brain state transitions. We further leverage these dependencies to explore near-optimal control strategies such that, on a per-transition basis, the number of input signals required for a given control task is reduced, in some cases by two orders of magnitude. This approximation yields network-wide maps of input site density, which we compare to an existing database of functional, metabolic, genetic, and neurochemical maps, finding a close correspondence. Ultimately, not only do we propose a more efficient framework that is also more adherent to well-established brain organizational principles, but we also posit neurobiologically grounded bases for optimal control.
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Affiliation(s)
- Richard Betzel
- Department of Psychological and Brain Sciences, Indiana University, Bloomington IN 47401
- Cognitive Science Program, Indiana University, Bloomington IN 47401
- Program in Neuroscience, Indiana University, Bloomington IN 47401
| | - Maria Grazia Puxeddu
- Department of Psychological and Brain Sciences, Indiana University, Bloomington IN 47401
| | - Caio Seguin
- Department of Psychological and Brain Sciences, Indiana University, Bloomington IN 47401
| | - Vincent Bazinet
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Andrea Luppi
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | | | | | - Joshua Faskowitz
- Department of Psychological and Brain Sciences, Indiana University, Bloomington IN 47401
| | - Vibin Parakkattu
- Department of Psychological and Brain Sciences, Indiana University, Bloomington IN 47401
- Cognitive Science Program, Indiana University, Bloomington IN 47401
| | - Bratislav Misic
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | | | - Amy Kuceyeski
- Department of Radiology, Weill Cornell Medicine, New York, NY
- Department of Computational Biology, Cornell University, Ithaca, NY
| | - Linden Parkes
- Department of Psychiatry, Brain Health Institute, Rutgers University, Piscataway, NJ, USA
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10
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DiFilippo A, Jonaitis E, Makuch R, Gambetti B, Fleming V, Ennis G, Barnhart T, Engle J, Bendlin B, Johnson S, Handen B, Krinsky-McHale S, Hartley S, Christian B. Measurement of synaptic density in Down syndrome using PET imaging: a pilot study. Sci Rep 2024; 14:4676. [PMID: 38409349 PMCID: PMC10897336 DOI: 10.1038/s41598-024-54669-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/15/2024] [Indexed: 02/28/2024] Open
Abstract
Down syndrome (DS) is the most prevalent genetic cause of intellectual disability, resulting from trisomy 21. Recently, positron emission tomography (PET) imaging has been used to image synapses in vivo. The motivation for this pilot study was to investigate whether synaptic density in low functioning adults with DS can be evaluated using the PET radiotracer [11C]UCB-J. Data were acquired from low functioning adults with DS (n = 4) and older neurotypical (NT) adults (n = 37). Motion during the scans required the use of a 10-minute acquisition window for the calculation of synaptic density using SUVR50-60,CS which was determined to be a suitable approximation for specific binding in this analysis using dynamic data from the NT group. Of the regions analyzed a large effect was observed when comparing DS and NT hippocampus and cerebral cortex synaptic density as well as hippocampus and cerebellum volumes. In this pilot study, PET imaging of [11C]UCB-J was successfully completed and synaptic density measured in low functioning DS adults. This work provides the basis for studies where synaptic density may be compared between larger groups of NT adults and adults with DS who have varying degrees of baseline cognitive status.
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Affiliation(s)
- Alexandra DiFilippo
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.
| | - Erin Jonaitis
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Renee Makuch
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Brianna Gambetti
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Victoria Fleming
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Gilda Ennis
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Todd Barnhart
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Jonathan Engle
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Barbara Bendlin
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Sterling Johnson
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Benjamin Handen
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sharon Krinsky-McHale
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Sigan Hartley
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
| | - Bradley Christian
- Madison School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
- University of Wisconsin-Madison Waisman Center, Madison, WI, USA
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11
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d’Orchymont F, Narvaez A, Raymond R, Sachdev P, Charil A, Krause S, Vasdev N. In vitro evaluation of PET radiotracers for imaging synaptic density, the acetylcholine transporter, AMPA-tarp-γ8 and muscarinic M4 receptors in Alzheimer's disease. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2024; 14:1-12. [PMID: 38500748 PMCID: PMC10944377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 02/04/2024] [Indexed: 03/20/2024]
Abstract
Several therapeutics and biomarkers that target Alzheimer's disease (AD) are under development. Our clinical positron emission tomography (PET) research programs are interested in six radiopharmaceuticals to image patients with AD and related dementias, specifically [11C]UCB-J and [18F]SynVesT-1 for synaptic vesicle glycoprotein 2A as a marker of synaptic density, two vesicular acetylcholine transporter PET radiotracers: [18F]FEOBV and [18F]VAT, as well as the transmembrane AMPA receptor regulatory protein (TARP)-γ8 tracer, [18F]JNJ-64511070, and the muscarinic acetylcholine receptor (mAChR) M4 tracer [11C]MK-6884. The goal of this study was to compare all six radiotracers (labeled with tritium or 18F) by measuring their density variability in pathologically diagnosed cases of AD, mild cognitive impairment (MCI) and normal healthy volunteer (NHV) human brains, using thin-section in vitro autoradiography (ARG). Region of interest analysis was used to quantify radioligand binding density and determine whether the radioligands provide a signal-to-noise ratio optimal for showing changes in binding. Our preliminary study confirmed that all six radiotracers show specific binding in MCI and AD. An expected decrease in their respective target density in human AD hippocampus tissues compared to NHV was observed with [3H]UCB-J, [3H]SynVesT-1, [3H]JNJ-64511070, and [3H]MK-6884. This preliminary study will be used to guide human PET imaging of SV2A, TARP-γ8 and the mAChR M4 subtype for imaging in AD and related dementias.
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Affiliation(s)
- Faustine d’Orchymont
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
| | - Andrea Narvaez
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
- Enigma Biomedical Group, Inc.Toronto, ON, Canada
| | - Roger Raymond
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
| | | | | | | | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
- Department of Psychiatry, University of TorontoToronto, ON, Canada
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12
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Vanderlinden G, Carron C, Vandenberghe R, Vandenbulcke M, Van Laere K. In vivo PET of synaptic density as potential diagnostic marker for cognitive disorders: prospective comparison with current imaging markers for neuronal dysfunction and relation to symptomatology - study protocol. BMC Med Imaging 2024; 24:41. [PMID: 38347458 PMCID: PMC10860316 DOI: 10.1186/s12880-024-01224-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 02/05/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND 18F-FDG brain PET is clinically used for differential diagnosis in cognitive dysfunction of unclear etiology and for exclusion of a neurodegenerative cause in patients with cognitive impairment in late-life psychiatric disorders. 18F-FDG PET measures regional glucose metabolism, which represents a combination of neuronal/synaptic activity but also astrocytic activity and neuroinflammation. Recently, imaging of synaptic vesicle protein 2 A (SV2A) has become available and was shown to be a proxy of synaptic density. This prospective study will investigate the use of 18F-SynVesT-1 for imaging SV2A and its discriminative power for differential diagnosis in cognitive disorders in a head-to-head comparison to 18F-FDG PET. In addition, simultaneous PET/MR allows an evaluation of contributing factors and the additional value of advanced MRI imaging to FDG/SV2A PET imaging will be investigated. In this work, the study design and protocol are depicted. METHODS In this prospective, multimodal imaging study, 110 patients with uncertain diagnosis of cognitive impairment who are referred for 18F-FDG PET brain imaging in their diagnostic work-up in a tertiary memory clinic will be recruited. In addition, 40 healthy volunteers (HV) between 18 and 85 years (M/F) will be included. All study participants will undergo simultaneous 18F-SynVesT-1 PET/MR and an extensive neuropsychological evaluation. Amyloid status will be measured by PET using 18FNAV4694, in HV above 50 years of age. Structural T1-weighted and T2-weighted fluid-attenuated inversion recovery MR images, triple-tagging arterial spin labeling (ASL) and resting-state functional MRI (rs-fMRI) will be obtained. The study has been registered on ClinicalTrials.gov (NCT05384353) and is approved by the local Research Ethics Committee. DISCUSSION The main endpoint of the study will be the comparison of the diagnostic accuracy between 18F-SynVesT-1 and 18F-FDG PET in cognitive disorders with uncertain etiology and in exclusion of a neurodegenerative cause in patients with cognitive impairment in late-life psychiatric disorders. The strength of the relationship between cognition and imaging data will be assessed, as well as the potential incremental diagnostic value of including MR volumetry, ASL perfusion and rs-fMRI.
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Affiliation(s)
- Greet Vanderlinden
- Nuclear Medicine and Molecular Imaging, Imaging and Pathology, KU Leuven, Leuven, Belgium.
| | - Charles Carron
- Nuclear Medicine and Molecular Imaging, Imaging and Pathology, KU Leuven, Leuven, Belgium
- Division of Nuclear Medicine, University Hospitals UZ Leuven, Leuven, Belgium
| | - Rik Vandenberghe
- Department of Neurology, University Hospitals UZ Leuven, Leuven, Belgium
- Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Mathieu Vandenbulcke
- Research Group Psychiatry, KU Leuven, Leuven, Belgium
- Department of Old-Age Psychiatry, University Hospitals UZ Leuven, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Imaging and Pathology, KU Leuven, Leuven, Belgium
- Division of Nuclear Medicine, University Hospitals UZ Leuven, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
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13
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Visser M, O'Brien JT, Mak E. In vivo imaging of synaptic density in neurodegenerative disorders with positron emission tomography: A systematic review. Ageing Res Rev 2024; 94:102197. [PMID: 38266660 DOI: 10.1016/j.arr.2024.102197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/09/2024] [Accepted: 01/12/2024] [Indexed: 01/26/2024]
Abstract
Positron emission tomography (PET) with radiotracers that bind to synaptic vesicle glycoprotein 2 A (SV2A) enables quantification of synaptic density in the living human brain. Assessing the regional distribution and severity of synaptic density loss will contribute to our understanding of the pathological processes that precede atrophy in neurodegeneration. In this systematic review, we provide a discussion of in vivo SV2A PET imaging research for quantitative assessment of synaptic density in various dementia conditions: amnestic Mild Cognitive Impairment and Alzheimer's disease, Frontotemporal dementia, Progressive supranuclear palsy and Corticobasal degeneration, Parkinson's disease and Dementia with Lewy bodies, Huntington's disease, and Spinocerebellar Ataxia. We discuss the main findings concerning group differences and clinical-cognitive correlations, and explore relations between SV2A PET and other markers of pathology. Additionally, we touch upon synaptic density in healthy ageing and outcomes of radiotracer validation studies. Studies were identified on PubMed and Embase between 2018 and 2023; last searched on the 3rd of July 2023. A total of 36 studies were included, comprising 5 on normal ageing, 21 clinical studies, and 10 validation studies. Extracted study characteristics were participant details, methodological aspects, and critical findings. In summary, the small but growing literature on in vivo SV2A PET has revealed different spatial patterns of synaptic density loss among various neurodegenerative disorders that correlate with cognitive functioning, supporting the potential role of SV2A PET imaging for differential diagnosis. SV2A PET imaging shows tremendous capability to provide novel insights into the aetiology of neurodegenerative disorders and great promise as a biomarker for synaptic density reduction. Novel directions for future synaptic density research are proposed, including (a) longitudinal imaging in larger patient cohorts of preclinical dementias, (b) multi-modal mapping of synaptic density loss onto other pathological processes, and (c) monitoring therapeutic responses and assessing drug efficacy in clinical trials.
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Affiliation(s)
- Malouke Visser
- Department of Psychiatry, School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, United Kingdom; Neuropsychology and Rehabilitation Psychology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - John T O'Brien
- Department of Psychiatry, School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, United Kingdom
| | - Elijah Mak
- Department of Psychiatry, School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, United Kingdom.
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14
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van Dyck CH, Mecca AP, O'Dell RS, Bartlett HH, Diepenbrock NG, Huang Y, Hamby ME, Grundman M, Catalano SM, Caggiano AO, Carson RE. A pilot study to evaluate the effect of CT1812 treatment on synaptic density and other biomarkers in Alzheimer's disease. Alzheimers Res Ther 2024; 16:20. [PMID: 38273408 PMCID: PMC10809445 DOI: 10.1186/s13195-024-01382-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 01/01/2024] [Indexed: 01/27/2024]
Abstract
BACKGROUND Effective, disease-modifying therapeutics for the treatment of Alzheimer's disease (AD) remain a large unmet need. Extensive evidence suggests that amyloid beta (Aβ) is central to AD pathophysiology, and Aβ oligomers are among the most toxic forms of Aβ. CT1812 is a novel brain penetrant sigma-2 receptor ligand that interferes with the binding of Aβ oligomers to neurons. Preclinical studies of CT1812 have demonstrated its ability to displace Aβ oligomers from neurons, restore synapses in cell cultures, and improve cognitive measures in mouse models of AD. CT1812 was found to be generally safe and well tolerated in a placebo-controlled phase 1 clinical trial in healthy volunteers and phase 1a/2 clinical trials in patients with mild to moderate dementia due to AD. The unique objective of this study was to incorporate synaptic positron emission tomography (PET) imaging as an outcome measure for CT1812 in AD patients. METHODS The present phase 1/2 study was a randomized, double-blind, placebo-controlled, parallel-group trial conducted in 23 participants with mild to moderate dementia due to AD to primarily evaluate the safety of CT1812 and secondarily its pharmacodynamic effects. Participants received either placebo or 100 mg or 300 mg per day of oral CT1812 for 24 weeks. Pharmacodynamic effects were assessed using the exploratory efficacy endpoints synaptic vesicle glycoprotein 2A (SV2A) PET, fluorodeoxyglucose (FDG) PET, volumetric MRI, cognitive clinical measures, as well as cerebrospinal fluid (CSF) biomarkers of AD pathology and synaptic degeneration. RESULTS No treatment differences relative to placebo were observed in the change from baseline at 24 weeks in either SV2A or FDG PET signal, the cognitive clinical rating scales, or in CSF biomarkers. Composite region volumetric MRI revealed a trend towards tissue preservation in participants treated with either dose of CT1812, and nominally significant differences with both doses of CT1812 compared to placebo were found in the pericentral, prefrontal, and hippocampal cortices. CT1812 was safe and well tolerated. CONCLUSIONS The safety findings of this 24-week study and the observed changes on volumetric MRI with CT1812 support its further clinical development. TRIAL REGISTRATION The clinical trial described in this manuscript is registered at clinicaltrials.gov (NCT03493282).
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Affiliation(s)
- Christopher H van Dyck
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
| | - Adam P Mecca
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Ryan S O'Dell
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Hugh H Bartlett
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Nina G Diepenbrock
- Alzheimer's Disease Research Unit, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Mary E Hamby
- Cognition Therapeutics Inc., Pittsburgh, PA, USA
| | - Michael Grundman
- Global R&D Partners, LLC, San Diego, CA, USA
- Department of Neurosciences, University of California, San Diego, USA
| | | | | | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
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15
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Fang L, Zhang B, Li B, Zhang X, Zhou X, Yang J, Li A, Shi X, Liu Y, Kreissl M, D'Ascenzo N, Xiao P, Xie Q. Development and evaluation of a new high-TOF-resolution all-digital brain PET system. Phys Med Biol 2024; 69:025019. [PMID: 38100841 DOI: 10.1088/1361-6560/ad164d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 12/15/2023] [Indexed: 12/17/2023]
Abstract
Objective.Time-of-flight (TOF) capability and high sensitivity are essential for brain-dedicated positron emission tomography (PET) imaging, as they improve the contrast and the signal-to-noise ratio (SNR) enabling a precise localization of functional mechanisms in the different brain regions.Approach.We present a new brain PET system with transverse and axial field-of-view (FOV) of 320 mm and 255 mm, respectively. The system head is an array of 6 × 6 detection elements, each consisting of a 3.9 × 3.9 × 20 mm3lutetium-yttrium oxyorthosilicate crystal coupled with a 3.93 × 3.93 mm2SiPM. The SiPMs analog signals are individually digitized using the multi-voltage threshold (MVT) technology, employing a 1:1:1 coupling configuration.Main results.The brain PET system exhibits a TOF resolution of 249 ps at 5.3 kBq ml-1, an average sensitivity of 22.1 cps kBq-1, and a noise equivalent count rate (NECR) peak of 150.9 kcps at 8.36 kBq ml-1. Furthermore, the mini-Derenzo phantom study demonstrated the system's ability to distinguish rods with a diameter of 2.0 mm. Moreover, incorporating the TOF reconstruction algorithm in an image quality phantom study optimizes the background variability, resulting in reductions ranging from 44% (37 mm) to 75% (10 mm) with comparable contrast. In the human brain imaging study, the SNR improved by a factor of 1.7 with the inclusion of TOF, increasing from 27.07 to 46.05. Time-dynamic human brain imaging was performed, showing the distinctive traits of cortex and thalamus uptake, as well as of the arterial and venous flow with 2 s per time frame.Significance.The system exhibited a good TOF capability, which is coupled with the high sensitivity and count rate performance based on the MVT digital sampling technique. The developed TOF-enabled brain PET system opens the possibility of precise kinetic brain PET imaging, towards new quantitative predictive brain diagnostics.
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Affiliation(s)
- Lei Fang
- Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Bo Zhang
- Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Bingxuan Li
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui, People's Republic of China
| | - Xiangsong Zhang
- Department of Nuclear Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Xiaoyun Zhou
- Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Jigang Yang
- Department of Nuclear Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Ang Li
- Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Xinchong Shi
- Department of Nuclear Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Yuqing Liu
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui, People's Republic of China
| | - Michael Kreissl
- Division of Nuclear Medicine, Deprtment of Radiology and Nuclear Medicine, University Hospital Magdeburg, Otto-von-Guericke University, Magdeburg, Germany
- Research Campus STIMULATE, Otto-von-Guericke University, Magdeburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Nicola D'Ascenzo
- Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- Department of Innovation in Engineering and Physics, Istituto Neurologico Mediterraneo NEUROMED I.R.C.C.S., Pozzilli, Italy
| | - Peng Xiao
- Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Qingguo Xie
- Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- Department of Innovation in Engineering and Physics, Istituto Neurologico Mediterraneo NEUROMED I.R.C.C.S., Pozzilli, Italy
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16
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Silva-Rudberg JA, Salardini E, O'Dell RS, Chen MK, Ra J, Georgelos JK, Morehouse MR, Melino KP, Varma P, Toyonaga T, Nabulsi NB, Huang Y, Carson RE, van Dyck CH, Mecca AP. Assessment of Gray Matter Microstructure and Synaptic Density in Alzheimer's Disease: A Multimodal Imaging Study With DTI and SV2A PET. Am J Geriatr Psychiatry 2024; 32:17-28. [PMID: 37673749 PMCID: PMC10840732 DOI: 10.1016/j.jagp.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/19/2023] [Accepted: 08/05/2023] [Indexed: 09/08/2023]
Abstract
OBJECTIVE Multimodal imaging techniques have furthered our understanding of how different aspects of Alzheimer's disease (AD) pathology relate to one another. Diffusion tensor imaging (DTI) measures such as mean diffusivity (MD) may be a surrogate measure of the changes in gray matter structure associated with AD. Positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A) has been used to quantify synaptic loss, which is the major pathological correlate of cognitive impairment in AD. In this study, we investigated the relationship between gray matter microstructure and synaptic density. METHODS DTI was used to measure MD and [11C]UCB-J PET to measure synaptic density in 33 amyloid-positive participants with AD and 17 amyloid-negative cognitively normal (CN) participants aged 50-83. Univariate regression analyses were used to assess the association between synaptic density and MD in both the AD and CN groups. RESULTS Hippocampal MD was inversely associated with hippocampal synaptic density in participants with AD (r = -0.55, p <0.001, df = 31) but not CN (r = 0.13, p = 0.62, df = 15). Exploratory analyses across other regions known to be affected in AD suggested widespread inverse associations between synaptic density and MD in the AD group. CONCLUSION In the setting of AD, an increase in gray matter MD is inversely associated with synaptic density. These co-occurring changes may suggest a link between synaptic loss and gray matter microstructural changes in AD. Imaging studies of gray matter microstructure and synaptic density may allow important insights into AD-related neuropathology.
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Affiliation(s)
- Jason A Silva-Rudberg
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT.
| | - Elaheh Salardini
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Ryan S O'Dell
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Jocelyn Ra
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Jamie K Georgelos
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Mackenzie R Morehouse
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Kaitlyn P Melino
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT
| | - Pradeep Varma
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging (M-KC, PV, TT, NBN, YH, REC), Yale University School of Medicine, New Haven, CT
| | - Christopher H van Dyck
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Neuroscience (CHvD), Yale University School of Medicine, New Haven, CT; Department of Neurology (CHvD), Yale University School of Medicine, New Haven, CT
| | - Adam P Mecca
- Alzheimer's Disease Research Unit (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT; Department of Psychiatry (JAS-R, ES, RSO, JR, JKG, MRM, KPM, CHvD, APM), Yale University School of Medicine, New Haven, CT.
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17
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Ozolmez N, Silindir-Gunay M, Volkan-Salanci B. An overview: Radiotracers and nano-radiopharmaceuticals for diagnosis of Parkinson's disease. Appl Radiat Isot 2024; 203:111110. [PMID: 37989065 DOI: 10.1016/j.apradiso.2023.111110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/23/2023]
Abstract
Parkinson's disease (PD) is a widespread progressive neurodegenerative disease. Clinical diagnosis approaches are insufficient to provide an early and accurate diagnosis before a substantial of loss of dopaminergic neurons. PET and SPECT can be used for accurate and early diagnosis of PD by using target-specific radiotracers. Additionally, the importance of BBB penetrating targeted nanosystems has increased in recent years. This article reviews targeted radiopharmaceuticals used in clinics and novel nanocarriers for research purposes of PD imaging.
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Affiliation(s)
- Nur Ozolmez
- Hacettepe University, Faculty of Pharmacy, Department of Radiopharmacy, Ankara, Turkey.
| | - Mine Silindir-Gunay
- Hacettepe University, Faculty of Pharmacy, Department of Radiopharmacy, Ankara, Turkey.
| | - Bilge Volkan-Salanci
- Hacettepe University, Faculty of Medicine, Department of Nuclear Medicine, Ankara, Turkey.
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18
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Li A, Yang B, Naganawa M, Fontaine K, Toyonaga T, Carson RE, Tang J. Dose reduction in dynamic synaptic vesicle glycoprotein 2A PET imaging using artificial neural networks. Phys Med Biol 2023; 68:245006. [PMID: 37857316 PMCID: PMC10739622 DOI: 10.1088/1361-6560/ad0535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/02/2023] [Accepted: 10/19/2023] [Indexed: 10/21/2023]
Abstract
Objective. Reducing dose in positron emission tomography (PET) imaging increases noise in reconstructed dynamic frames, which inevitably results in higher noise and possible bias in subsequently estimated images of kinetic parameters than those estimated in the standard dose case. We report the development of a spatiotemporal denoising technique for reduced-count dynamic frames through integrating a cascade artificial neural network (ANN) with the highly constrained back-projection (HYPR) scheme to improve low-dose parametric imaging.Approach. We implemented and assessed the proposed method using imaging data acquired with11C-UCB-J, a PET radioligand bound to synaptic vesicle glycoprotein 2A (SV2A) in the human brain. The patch-based ANN was trained with a reduced-count frame and its full-count correspondence of a subject and was used in cascade to process dynamic frames of other subjects to further take advantage of its denoising capability. The HYPR strategy was then applied to the spatial ANN processed image frames to make use of the temporal information from the entire dynamic scan.Main results. In all the testing subjects including healthy volunteers and Parkinson's disease patients, the proposed method reduced more noise while introducing minimal bias in dynamic frames and the resulting parametric images, as compared with conventional denoising methods.Significance. Achieving 80% noise reduction with a bias of -2% in dynamic frames, which translates into 75% and 70% of noise reduction in the tracer uptake (bias, -2%) and distribution volume (bias, -5%) images, the proposed ANN+HYPR technique demonstrates the denoising capability equivalent to a 11-fold dose increase for dynamic SV2A PET imaging with11C-UCB-J.
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Affiliation(s)
- Andi Li
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States of America
| | - Bao Yang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China
| | - Mika Naganawa
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Kathryn Fontaine
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Takuya Toyonaga
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Richard E Carson
- Positron Emission Tomography Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America
| | - Jing Tang
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States of America
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19
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Bazinet V, Hansen JY, Misic B. Towards a biologically annotated brain connectome. Nat Rev Neurosci 2023; 24:747-760. [PMID: 37848663 DOI: 10.1038/s41583-023-00752-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2023] [Indexed: 10/19/2023]
Abstract
The brain is a network of interleaved neural circuits. In modern connectomics, brain connectivity is typically encoded as a network of nodes and edges, abstracting away the rich biological detail of local neuronal populations. Yet biological annotations for network nodes - such as gene expression, cytoarchitecture, neurotransmitter receptors or intrinsic dynamics - can be readily measured and overlaid on network models. Here we review how connectomes can be represented and analysed as annotated networks. Annotated connectomes allow us to reconceptualize architectural features of networks and to relate the connection patterns of brain regions to their underlying biology. Emerging work demonstrates that annotated connectomes help to make more veridical models of brain network formation, neural dynamics and disease propagation. Finally, annotations can be used to infer entirely new inter-regional relationships and to construct new types of network that complement existing connectome representations. In summary, biologically annotated connectomes offer a compelling way to study neural wiring in concert with local biological features.
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Affiliation(s)
- Vincent Bazinet
- Montréal Neurological Institute, McGill University, Montréal, Quebec, Canada
| | - Justine Y Hansen
- Montréal Neurological Institute, McGill University, Montréal, Quebec, Canada
| | - Bratislav Misic
- Montréal Neurological Institute, McGill University, Montréal, Quebec, Canada.
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20
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Asch RH, Naganawa M, Nabulsi N, Huan Y, Esterlis I, Carson RE. Evaluating infusion methods and simplified quantification of synaptic density in vivo with [ 11C]UCB-J and [ 18F]SynVesT-1 PET. J Cereb Blood Flow Metab 2023; 43:2120-2129. [PMID: 37669455 PMCID: PMC10925870 DOI: 10.1177/0271678x231200423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/04/2023] [Accepted: 08/13/2023] [Indexed: 09/07/2023]
Abstract
For some positron emission tomography studies, radiotracer is administered as bolus plus continuous infusion (B/I) to achieve a state of equilibrium. This approach can reduce scanning time and simplify data analysis; however, the method must be validated and optimized for each tracer. This study aimed to validate a B/I method for in vivo quantification of synaptic density using radiotracers which target the synaptic vesicle glycoprotein 2 A: [11C]UCB-J and [18F]SynVesT-1. Observed mean standardized uptake values (SUV) in target tissue relative to that in plasma (CT/CP) or a reference tissue (SUVR-1) were calculated for 30-minute intervals across 120 or 150-minute dynamic scans and compared against one-tissue compartment (1TC) model estimates of volume of distribution (VT) and binding potential (BPND), respectively. We were unable to reliably achieve a state of equilibrium with [11C]UCB-J, and all 30-minute windows yielded overly large bias and/or variability for CT/CP and SUVR-1. With [18F]SynVesT-1, a 30-minute scan 90-120 minutes post-injection yielded CT/CP and SUVR-1 values that estimated their respective kinetic parameter with sufficient accuracy and precision (within 7± 6%) . This B/I approach allows a clinically feasible scan at equilibrium with potentially better accuracy than a static scan SUVR following a bolus injection.
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Affiliation(s)
- Ruth H Asch
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Yiyun Huan
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Irina Esterlis
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- U.S. Department of Veteran Affairs National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, West Haven, CT, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
- Department of Biomedical Engineering, Yale School of Medicine, New Haven, CT, USA
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21
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Matheson GJ, Ge L, Zhang M, Sun B, Tu Y, Zanderigo F, Forsberg Morèn A, Ogden RT. Parametric and non-parametric Poisson regression for modelling of the arterial input function in positron emission tomography. EJNMMI Phys 2023; 10:72. [PMID: 37987874 PMCID: PMC10663416 DOI: 10.1186/s40658-023-00591-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 11/06/2023] [Indexed: 11/22/2023] Open
Abstract
Full quantification of Positron Emission Tomography (PET) requires an arterial input function (AIF) for measurement of certain targets, or using particular radiotracers, or for the quantification of specific outcome measures. The AIF represents the measurement of radiotracer concentrations in the arterial blood plasma over the course of the PET examination. Measurement of the AIF is prone to error as it is a composite measure created from the combination of multiple measurements of different samples with different equipment, each of which can be sources of measurement error. Moreover, its measurement requires a high degree of temporal granularity for early time points, which necessitates a compromise between quality and quantity of recorded samples. For these reasons, it is often desirable to fit models to this data in order to improve its quality before using it for quantification of radiotracer binding in the tissue. The raw observations of radioactivity in arterial blood and plasma samples are derived from radioactive decay, which is measured as a number of recorded counts. Count data have several specific properties, including the fact that they cannot be negative as well as a particular mean-variance relationship. Poisson regression is the most principled modelling strategy for working with count data, as it both incorporates and exploits these properties. However, no previous studies to our knowledge have taken this approach, despite the advantages of greater efficiency and accuracy which result from using the appropriate distributional assumptions. Here, we implement a Poisson regression modelling approach for the AIF as proof-of-concept of its application. We applied both parametric and non-parametric models for the input function curve. We show that a negative binomial distribution is a more appropriate error distribution for handling overdispersion. Furthermore, we extend this approach to a hierarchical non-parametric model which is shown to be highly resilient to missing data. We thus demonstrate that Poisson regression is both feasible and effective when applied to AIF data, and propose that this is a promising strategy for modelling blood count data for PET in future.
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Affiliation(s)
- Granville J Matheson
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA.
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA.
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, NY, 10032, USA.
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, 171 76, Sweden.
| | - Liner Ge
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
| | - Mengyu Zhang
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
- Department of Biostatistics and Data Science, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Bingyu Sun
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Yuqi Tu
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
| | - Francesca Zanderigo
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Anton Forsberg Morèn
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, 171 76, Sweden
| | - R Todd Ogden
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, NY, 10032, USA
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22
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Hou J, Xiao Q, Zhou M, Xiao L, Yuan M, Zhong N, Long J, Luo T, Hu S, Dong H. Lower synaptic density associated with gaming disorder: an 18F-SynVesT-1 PET imaging study. Gen Psychiatr 2023; 36:e101112. [PMID: 37829163 PMCID: PMC10565144 DOI: 10.1136/gpsych-2023-101112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/31/2023] [Indexed: 10/14/2023] Open
Abstract
Background Internet gaming disorder (IGD) is an ideal model to study the mechanisms underlying synaptic deficits in addiction as it eliminates the confounding effects of substance use. Synaptic loss and deficits are hypothesised to underlie the enduring maladaptive behaviours and impaired cognitive function that contribute to IGD. Aims This study aimed to determine whether subjects with IGD have lower synaptic density than control subjects and the relationship between synaptic density and IGD severity. Methods Eighteen unmedicated subjects diagnosed with current IGD according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria and 16 demographically matched healthy controls (HCs) participated in the study and underwent 18F-labelled difluoro-analogue of UCB-J (18F-SynVesT-1) positron emission tomography scans to assess the density of synaptic vesicle glycoprotein 2A (SV2A). The Internet Gaming Disorder Scale-Short Form (IGDS9-SF), Hamilton Rating Scale for Depression (HAMD), Hamilton Anxiety Rating Scale (HAMA), Barratt Impulsiveness Scale Version 11 (BIS-11), Stroop Colour-Word Test (SCWT), stop-signal paradigms and N-back tasks were administered to all subjects. Results Patients with IGD had significantly higher scores on the IGDS9-SF, HAMD, HAMA and BIS-11 than HCs. HCs performed better on the two-back and SCWT tests as well as in terms of stop-signal reaction times (SSRTs) in the stop-signal paradigms than patients with IGD. Lower uptake was found in the bilateral putamen, right pregenual anterior cingulate cortex and Rolandic operculum of patients with IGD compared with HCs. Furthermore, in the IGD group, IGDS9-SF scores and daily gaming hours were negatively correlated with the standardised uptake value ratios of 18F-SynVesT-1 in the bilateral putamen. Longer SSRTs were significantly associated with lower SV2A density in the right pregenual anterior cingulate cortex and right Rolandic operculum. Conclusions The in vivo results in this study suggest that lower synaptic density contributes to the severity and impairments in inhibitory control of IGD. These findings may provide further incentive to evaluate interventions that restore synaptic transmission and plasticity to treat IGD.
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Affiliation(s)
- Jiale Hou
- Department of Nuclear Medicine, Central South University, Changsha, Hunan, China
| | - Qian Xiao
- Mental Health Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ming Zhou
- Department of Nuclear Medicine, Central South University, Changsha, Hunan, China
| | - Ling Xiao
- Department of Nuclear Medicine, Central South University, Changsha, Hunan, China
| | - Ming Yuan
- Department of Applied Psychology, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Na Zhong
- Department of Substance Use and Addictive Behaviors Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiang Long
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Internal Medicine, Yale University, New Haven, Connecticut, USA
| | - Tao Luo
- Department of Psychology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Shuo Hu
- Department of Nuclear Medicine, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders (Xiangya), Changsha, Hunan, China
| | - Huixi Dong
- Mental Health Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
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23
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Johansen A, Armand S, Plavén-Sigray P, Nasser A, Ozenne B, Petersen IN, Keller SH, Madsen J, Beliveau V, Møller K, Vassilieva A, Langley C, Svarer C, Stenbæk DS, Sahakian BJ, Knudsen GM. Effects of escitalopram on synaptic density in the healthy human brain: a randomized controlled trial. Mol Psychiatry 2023; 28:4272-4279. [PMID: 37814129 PMCID: PMC10827655 DOI: 10.1038/s41380-023-02285-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are widely used for treating neuropsychiatric disorders. However, the exact mechanism of action and why effects can take several weeks to manifest is not clear. The hypothesis of neuroplasticity is supported by preclinical studies, but the evidence in humans is limited. Here, we investigate the effects of the SSRI escitalopram on presynaptic density as a proxy for synaptic plasticity. In a double-blind placebo-controlled study (NCT04239339), 32 healthy participants with no history of psychiatric or cognitive disorders were randomized to receive daily oral dosing of either 20 mg escitalopram (n = 17) or a placebo (n = 15). After an intervention period of 3-5 weeks, participants underwent a [11C]UCB-J PET scan (29 with full arterial input function) to quantify synaptic vesicle glycoprotein 2A (SV2A) density in the hippocampus and the neocortex. Whereas we find no statistically significant group difference in SV2A binding after an average of 29 (range: 24-38) days of intervention, our secondary analyses show a time-dependent effect of escitalopram on cerebral SV2A binding with positive associations between [11C]UCB-J binding and duration of escitalopram intervention. Our findings suggest that brain synaptic plasticity evolves over 3-5 weeks in healthy humans following daily intake of escitalopram. This is the first in vivo evidence to support the hypothesis of neuroplasticity as a mechanism of action for SSRIs in humans and it offers a plausible biological explanation for the delayed treatment response commonly observed in patients treated with SSRIs. While replication is warranted, these results have important implications for the design of future clinical studies investigating the neurobiological effects of SSRIs.
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Affiliation(s)
- Annette Johansen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sophia Armand
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Psychology, Faculty of Social Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Arafat Nasser
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Brice Ozenne
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Public Health, Section of Biostatistics, University of Copenhagen, Copenhagen, Denmark
| | - Ida N Petersen
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Sune H Keller
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Jacob Madsen
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Vincent Beliveau
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Kirsten Møller
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Neuroanaesthesiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Alexandra Vassilieva
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Neuroanaesthesiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | | | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Dea S Stenbæk
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Psychology, Faculty of Social Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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24
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Shafiei G, Fulcher BD, Voytek B, Satterthwaite TD, Baillet S, Misic B. Neurophysiological signatures of cortical micro-architecture. Nat Commun 2023; 14:6000. [PMID: 37752115 PMCID: PMC10522715 DOI: 10.1038/s41467-023-41689-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023] Open
Abstract
Systematic spatial variation in micro-architecture is observed across the cortex. These micro-architectural gradients are reflected in neural activity, which can be captured by neurophysiological time-series. How spontaneous neurophysiological dynamics are organized across the cortex and how they arise from heterogeneous cortical micro-architecture remains unknown. Here we extensively profile regional neurophysiological dynamics across the human brain by estimating over 6800 time-series features from the resting state magnetoencephalography (MEG) signal. We then map regional time-series profiles to a comprehensive multi-modal, multi-scale atlas of cortical micro-architecture, including microstructure, metabolism, neurotransmitter receptors, cell types and laminar differentiation. We find that the dominant axis of neurophysiological dynamics reflects characteristics of power spectrum density and linear correlation structure of the signal, emphasizing the importance of conventional features of electromagnetic dynamics while identifying additional informative features that have traditionally received less attention. Moreover, spatial variation in neurophysiological dynamics is co-localized with multiple micro-architectural features, including gene expression gradients, intracortical myelin, neurotransmitter receptors and transporters, and oxygen and glucose metabolism. Collectively, this work opens new avenues for studying the anatomical basis of neural activity.
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Affiliation(s)
- Golia Shafiei
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, Canada
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ben D Fulcher
- School of Physics, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Bradley Voytek
- Department of Cognitive Science, Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA
| | - Theodore D Satterthwaite
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sylvain Baillet
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, Canada
| | - Bratislav Misic
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, Canada.
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Laurell GL, Plavén-Sigray P, Johansen A, Raval NR, Nasser A, Aabye Madsen C, Madsen J, Hansen HD, Donovan LL, Knudsen GM, Lammertsma AA, Ogden RT, Svarer C, Schain M. Kinetic models for estimating occupancy from single-scan PET displacement studies. J Cereb Blood Flow Metab 2023; 43:1544-1556. [PMID: 37070382 PMCID: PMC10414003 DOI: 10.1177/0271678x231168591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/01/2023] [Accepted: 03/05/2023] [Indexed: 04/19/2023]
Abstract
The traditional design of PET target engagement studies is based on a baseline scan and one or more scans after drug administration. We here evaluate an alternative design in which the drug is administered during an on-going scan (i.e., a displacement study). This approach results both in lower radiation exposure and lower costs. Existing kinetic models assume steady state. This condition is not present during a drug displacement and consequently, our aim here was to develop kinetic models for analysing PET displacement data. We modified existing compartment models to accommodate a time-variant increase in occupancy following the pharmacological in-scan intervention. Since this implies the use of differential equations that cannot be solved analytically, we developed instead one approximate and one numerical solution. Through simulations, we show that if the occupancy is relatively high, it can be estimated without bias and with good accuracy. The models were applied to PET data from six pigs where [11C]UCB-J was displaced by intravenous brivaracetam. The dose-occupancy relationship estimated from these scans showed good agreement with occupancies calculated with Lassen plot applied to baseline-block scans of two pigs. In summary, the proposed models provide a framework to determine target occupancy from a single displacement scan.
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Affiliation(s)
- Gjertrud Louise Laurell
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | | | - Annette Johansen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Nakul Ravi Raval
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Arafat Nasser
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Clara Aabye Madsen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Jacob Madsen
- Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University, Copenhagen, Denmark
| | - Hanne Demant Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Lene Lundgaard Donovan
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Adriaan A Lammertsma
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - R Todd Ogden
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Molecular Imaging and Neuropathology Division, The New York State Psychiatric Institute, New York, USA
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, USA
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
- Antaros Medical, Mölndal, Sweden
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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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Delva A, Van Laere K, Vandenberghe W. Longitudinal Imaging of Regional Brain Volumes, SV2A, and Glucose Metabolism In Huntington's Disease. Mov Disord 2023; 38:1515-1526. [PMID: 37382295 DOI: 10.1002/mds.29501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/03/2023] [Accepted: 05/18/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Development of disease-modifying treatments for Huntington's disease (HD) could be aided by the use of imaging biomarkers of disease progression. Positron emission tomography (PET) with 11 C-UCB-J, a radioligand for the brain-wide presynaptic marker synaptic vesicle protein 2A (SV2A), detects more widespread brain changes in early HD than volumetric magnetic resonance imaging (MRI) and 18 F-fludeoxyglucose (18 F-FDG) PET, but longitudinal 11 C-UCB-J PET data have not been reported. The aim of this study was to compare the sensitivity of 11 C-UCB-J PET, 18 F-FDG PET, and volumetric MRI for detection of longitudinal changes in early HD. METHODS Seventeen HD mutation carriers (six premanifest and 11 early manifest) and 13 healthy controls underwent 11 C-UCB-J PET, 18 F-FDG PET, and volumetric MRI at baseline (BL) and after 21.4 ± 2.7 months (Y2). Within-group and between-group longitudinal clinical and imaging changes were assessed. RESULTS The HD group showed significant 2-year worsening of Unified Huntington's Disease Rating Scale motor scores. There was significant longitudinal volume loss within the HD group in caudate (-4.5% ± 3.8%), putamen (-3.6% ± 3.5%), pallidum (-3.0% ± 2.7%), and frontal cortex (-2.0% ± 2.1%) (all P < 0.001). Within the HD group there was longitudinal loss of putaminal SV2A binding (6.4% ± 8.8%, P = 0.01) and putaminal glucose metabolism (-2.8% ± 4.4%, P = 0.008), but these changes were not significant after correction for multiple comparisons. Premanifest subjects at BL only had significantly lower SV2A binding than controls in basal ganglia structures, but at Y2 additionally had significant SV2A loss in frontal and parietal cortex, indicating spread of SV2A loss from subcortical to cortical regions. CONCLUSIONS Volumetric MRI may be more sensitive than 11 C-UCB-J PET and 18 F-FDG PET for detection of 2-year brain changes in early HD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Aline Delva
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Van Laere
- Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
- Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Wim Vandenberghe
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
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28
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O'Dell RS, Higgins-Chen A, Gupta D, Chen MK, Naganawa M, Toyonaga T, Lu Y, Ni G, Chupak A, Zhao W, Salardini E, Nabulsi NB, Huang Y, Arnsten AFT, Carson RE, van Dyck CH, Mecca AP. Principal component analysis of synaptic density measured with [ 11C]UCB-J PET in early Alzheimer's disease. Neuroimage Clin 2023; 39:103457. [PMID: 37422964 PMCID: PMC10338149 DOI: 10.1016/j.nicl.2023.103457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 05/01/2023] [Accepted: 06/19/2023] [Indexed: 07/11/2023]
Abstract
BACKGROUND Synaptic loss is considered an early pathological event and major structural correlate of cognitive impairment in Alzheimer's disease (AD). We used principal component analysis (PCA) to identify regional patterns of covariance in synaptic density using [11C]UCB-J PET and assessed the association between principal components (PC) subject scores with cognitive performance. METHODS [11C]UCB-J binding was measured in 45 amyloid + participants with AD and 19 amyloid- cognitively normal participants aged 55-85. A validated neuropsychological battery assessed performance across five cognitive domains. PCA was applied to the pooled sample using distribution volume ratios (DVR) standardized (z-scored) by region from 42 bilateral regions of interest (ROI). RESULTS Parallel analysis determined three significant PCs explaining 70.2% of the total variance. PC1 was characterized by positive loadings with similar contributions across the majority of ROIs. PC2 was characterized by positive and negative loadings with strongest contributions from subcortical and parietooccipital cortical regions, respectively, while PC3 was characterized by positive and negative loadings with strongest contributions from rostral and caudal cortical regions, respectively. Within the AD group, PC1 subject scores were positively correlated with performance across all cognitive domains (Pearson r = 0.24-0.40, P = 0.06-0.006), PC2 subject scores were inversely correlated with age (Pearson r = -0.45, P = 0.002) and PC3 subject scores were significantly correlated with CDR-sb (Pearson r = 0.46, P = 0.04). No significant correlations were observed between cognitive performance and PC subject scores in CN participants. CONCLUSIONS This data-driven approach defined specific spatial patterns of synaptic density correlated with unique participant characteristics within the AD group. Our findings reinforce synaptic density as a robust biomarker of disease presence and severity in the early stages of AD.
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Affiliation(s)
- Ryan S O'Dell
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA.
| | - Albert Higgins-Chen
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA; Pain Research, Informatics, Multi-morbidities, and Education Center, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Dhruva Gupta
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520, USA
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520, USA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520, USA
| | - Yihuan Lu
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520, USA
| | - Gessica Ni
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA
| | - Anna Chupak
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA
| | - Wenzhen Zhao
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA
| | - Elaheh Salardini
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520, USA
| | - Amy F T Arnsten
- Department of Neuroscience, Yale University School of Medicine, P.O. Box 208001, New Haven, CT 06520, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, P.O. Box 208048, New Haven, CT 06520, USA
| | - Christopher H van Dyck
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA; Department of Neuroscience, Yale University School of Medicine, P.O. Box 208001, New Haven, CT 06520, USA; Department of Neurology, Yale University School of Medicine, P.O. Box 208018, New Haven, CT 06520, USA
| | - Adam P Mecca
- Alzheimer's Disease Research Unit, Yale University School of Medicine, One Church Street, 8(th) Floor, New Haven, CT 06510, USA; Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA.
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29
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Yu Y, Akif A, Herman P, Cao M, Rothman DL, Carson RE, Agarwal D, Evans AC, Hyder F. A 3D atlas of functional human brain energetic connectome based on neuropil distribution. Cereb Cortex 2023; 33:3996-4012. [PMID: 36104858 PMCID: PMC10068297 DOI: 10.1093/cercor/bhac322] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
The human brain is energetically expensive, yet the key factors governing its heterogeneous energy distributions across cortical regions to support its diversity of functions remain unexplored. Here, we built up a 3D digital cortical energy atlas based on the energetic costs of all neuropil activities into a high-resolution stereological map of the human cortex with cellular and synaptic densities derived, respectively, from ex vivo histological staining and in vivo PET imaging. The atlas was validated with PET-measured glucose oxidation at the voxel level. A 3D cortical activity map was calculated to predict the heterogeneous activity rates across all cortical regions, which revealed that resting brain is indeed active with heterogeneous neuronal activity rates averaging around 1.2 Hz, comprising around 70% of the glucose oxidation of the cortex. Additionally, synaptic density dominates spatial patterns of energetics, suggesting that the cortical energetics rely heavily on the distribution of synaptic connections. Recent evidence from functional imaging studies suggests that some cortical areas act as hubs (i.e., interconnecting distinct and functionally active regions). An inverse allometric relationship was observed between hub metabolic rates versus hub volumes. Hubs with smaller volumes have higher synapse density, metabolic rate, and activity rates compared to nonhubs. The open-source BrainEnergyAtlas provides a granular framework for exploring revealing design principles in energy-constrained human cortical circuits across multiple spatial scales.
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Affiliation(s)
- Yuguo Yu
- Shanghai Artificial Intelligence Laboratory, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Research Institute of Intelligent and Complex Systems, Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai 200032, China
| | - Adil Akif
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
| | - Peter Herman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- Magnetic Resonance Research Center, Yale University, New Haven, CT 06520, USA
| | - Miao Cao
- Shanghai Artificial Intelligence Laboratory, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Research Institute of Intelligent and Complex Systems, Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai 200032, China
| | - Douglas L Rothman
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- Magnetic Resonance Research Center, Yale University, New Haven, CT 06520, USA
| | - Richard E Carson
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- PET Center, Yale University, New Haven, CT 06520, USA
| | - Divyansh Agarwal
- Department of Surgery, MGH, Harvard University, Boston, MA 02114, USA
| | - Alan C Evans
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 0G4, Canada
| | - Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- Magnetic Resonance Research Center, Yale University, New Haven, CT 06520, USA
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30
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Fang XT, Volpi T, Holmes SE, Esterlis I, Carson RE, Worhunsky PD. Linking resting-state network fluctuations with systems of coherent synaptic density: A multimodal fMRI and 11C-UCB-J PET study. Front Hum Neurosci 2023; 17:1124254. [PMID: 36908710 PMCID: PMC9995441 DOI: 10.3389/fnhum.2023.1124254] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/31/2023] [Indexed: 02/25/2023] Open
Abstract
Introduction: Resting-state network (RSN) connectivity is a widely used measure of the brain's functional organization in health and disease; however, little is known regarding the underlying neurophysiology of RSNs. The aim of the current study was to investigate associations between RSN connectivity and synaptic density assessed using the synaptic vesicle glycoprotein 2A radioligand 11C-UCB-J PET. Methods: Independent component analyses (ICA) were performed on resting-state fMRI and PET data from 34 healthy adult participants (16F, mean age: 46 ± 15 years) to identify a priori RSNs of interest (default-mode, right frontoparietal executive-control, salience, and sensorimotor networks) and select sources of 11C-UCB-J variability (medial prefrontal, striatal, and medial parietal). Pairwise correlations were performed to examine potential intermodal associations between the fractional amplitude of low-frequency fluctuations (fALFF) of RSNs and subject loadings of 11C-UCB-J source networks both locally and along known anatomical and functional pathways. Results: Greater medial prefrontal synaptic density was associated with greater fALFF of the anterior default-mode, posterior default-mode, and executive-control networks. Greater striatal synaptic density was associated with greater fALFF of the anterior default-mode and salience networks. Post-hoc mediation analyses exploring relationships between aging, synaptic density, and RSN activity revealed a significant indirect effect of greater age on fALFF of the anterior default-mode network mediated by the medial prefrontal 11C-UCB-J source. Discussion: RSN functional connectivity may be linked to synaptic architecture through multiple local and circuit-based associations. Findings regarding healthy aging, lower prefrontal synaptic density, and lower default-mode activity provide initial evidence of a neurophysiological link between RSN activity and local synaptic density, which may have relevance in neurodegenerative and psychiatric disorders.
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Affiliation(s)
- Xiaotian T. Fang
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States
| | - Tommaso Volpi
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States
| | - Sophie E. Holmes
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States
| | - Irina Esterlis
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States
- Department of Psychology, Yale University, New Haven, CT, United States
| | - Richard E. Carson
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States
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31
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Singh P, Singh D, Srivastava P, Mishra G, Tiwari AK. Evaluation of advanced, pathophysiologic new targets for imaging of CNS. Drug Dev Res 2023; 84:484-513. [PMID: 36779375 DOI: 10.1002/ddr.22040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/12/2022] [Accepted: 12/31/2022] [Indexed: 02/14/2023]
Abstract
The inadequate information about the in vivo pathological, physiological, and neurological impairments, as well as the absence of in vivo tools for assessing brain penetrance and the efficiency of newly designed drugs, has hampered the development of new techniques for the treatment for variety of new central nervous system (CNS) diseases. The searching sites such as Science Direct and PubMed were used to find out the numerous distinct tracers across 16 CNS targets including tau, synaptic vesicle glycoprotein, the adenosine 2A receptor, the phosphodiesterase enzyme PDE10A, and the purinoceptor, among others. Among the most encouraging are [18 F]FIMX for mGluR imaging, [11 C]Martinostat for Histone deacetylase, [18 F]MNI-444 for adenosine 2A imaging, [11 C]ER176 for translocator protein, and [18 F]MK-6240 for tau imaging. We also reviewed the findings for each tracer's features and potential for application in CNS pathophysiology and therapeutic evaluation investigations, including target specificity, binding efficacy, and pharmacokinetic factors. This review aims to present a current evaluation of modern positron emission tomography tracers for CNS targets, with a focus on recent advances for targets that have newly emerged for imaging in humans.
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Affiliation(s)
- Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Deepika Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Pooja Srivastava
- Division of Cyclotron and Radiopharmaceuticals Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Gauri Mishra
- Department of Zoology, Swami Shraddhananad College, University of Delhi, Alipur, Delhi, India
| | - Anjani K Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
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32
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Hoenig MC, Drzezga A. Clear-headed into old age: Resilience and resistance against brain aging-A PET imaging perspective. J Neurochem 2023; 164:325-345. [PMID: 35226362 DOI: 10.1111/jnc.15598] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 11/28/2022]
Abstract
With the advances in modern medicine and the adaptation towards healthier lifestyles, the average life expectancy has doubled since the 1930s, with individuals born in the millennium years now carrying an estimated life expectancy of around 100 years. And even though many individuals around the globe manage to age successfully, the prevalence of aging-associated neurodegenerative diseases such as sporadic Alzheimer's disease has never been as high as nowadays. The prevalence of Alzheimer's disease is anticipated to triple by 2050, increasing the societal and economic burden tremendously. Despite all efforts, there is still no available treatment defeating the accelerated aging process as seen in this disease. Yet, given the advances in neuroimaging techniques that are discussed in the current Review article, such as in positron emission tomography (PET) or magnetic resonance imaging (MRI), pivotal insights into the heterogenous effects of aging-associated processes and the contribution of distinct lifestyle and risk factors already have and are still being gathered. In particular, the concepts of resilience (i.e. coping with brain pathology) and resistance (i.e. avoiding brain pathology) have more recently been discussed as they relate to mechanisms that are associated with the prolongation and/or even stop of the progressive brain aging process. Better understanding of the underlying mechanisms of resilience and resistance may one day, hopefully, support the identification of defeating mechanism against accelerating aging.
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Affiliation(s)
- Merle C Hoenig
- Research Center Juelich, Institute for Neuroscience and Medicine II, Molecular Organization of the Brain, Juelich, Germany.,Department of Nuclear Medicine, Faculty of Medicine, University Hospital Cologne, Cologne, Germany
| | - Alexander Drzezga
- Research Center Juelich, Institute for Neuroscience and Medicine II, Molecular Organization of the Brain, Juelich, Germany.,Department of Nuclear Medicine, Faculty of Medicine, University Hospital Cologne, Cologne, Germany.,German Center for Neurodegenerative Diseases, Bonn/Cologne, Germany
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33
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Lopresti BJ, Royse SK, Mathis CA, Tollefson SA, Narendran R. Beyond monoamines: I. Novel targets and radiotracers for Positron emission tomography imaging in psychiatric disorders. J Neurochem 2023; 164:364-400. [PMID: 35536762 DOI: 10.1111/jnc.15615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
Abstract
With the emergence of positron emission tomography (PET) in the late 1970s, psychiatry had access to a tool capable of non-invasive assessment of human brain function. Early applications in psychiatry focused on identifying characteristic brain blood flow and metabolic derangements using radiotracers such as [15 O]H2 O and [18 F]FDG. Despite the success of these techniques, it became apparent that more specific probes were needed to understand the neurochemical bases of psychiatric disorders. The first neurochemical PET imaging probes targeted sites of action of neuroleptic (dopamine D2 receptors) and psychoactive (serotonin receptors) drugs. Based on the centrality of monoamine dysfunction in psychiatric disorders and the measured success of monoamine-enhancing drugs in treating them, the next 30 years witnessed the development of an armamentarium of PET radiopharmaceuticals and imaging methodologies for studying monoamines. Continued development of monoamine-enhancing drugs over this time however was less successful, realizing only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely paralleled drug development priorities resulting in the development of new PET imaging agents for non-monoamine targets. Part one of this review will briefly survey novel PET imaging targets with relevance to the field of psychiatry, which include the metabotropic glutamate receptor type 5 (mGluR5), purinergic P2 X7 receptor, type 1 cannabinoid receptor (CB1 ), phosphodiesterase 10A (PDE10A), and describe radiotracers developed for these and other targets that have matured to human subject investigations. Current limitations of the targets and techniques will also be discussed.
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Affiliation(s)
- Brian J Lopresti
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah K Royse
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Chester A Mathis
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Savannah A Tollefson
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rajesh Narendran
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Departments of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Shafiei G, Fulcher BD, Voytek B, Satterthwaite TD, Baillet S, Misic B. Neurophysiological signatures of cortical micro-architecture. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.23.525101. [PMID: 36747831 PMCID: PMC9900796 DOI: 10.1101/2023.01.23.525101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Systematic spatial variation in micro-architecture is observed across the cortex. These micro-architectural gradients are reflected in neural activity, which can be captured by neurophysiological time-series. How spontaneous neurophysiological dynamics are organized across the cortex and how they arise from heterogeneous cortical micro-architecture remains unknown. Here we extensively profile regional neurophysiological dynamics across the human brain by estimating over 6 800 timeseries features from the resting state magnetoencephalography (MEG) signal. We then map regional time-series profiles to a comprehensive multi-modal, multi-scale atlas of cortical micro-architecture, including microstructure, metabolism, neurotransmitter receptors, cell types and laminar differentiation. We find that the dominant axis of neurophysiological dynamics reflects characteristics of power spectrum density and linear correlation structure of the signal, emphasizing the importance of conventional features of electromagnetic dynamics while identifying additional informative features that have traditionally received less attention. Moreover, spatial variation in neurophysiological dynamics is colocalized with multiple micro-architectural features, including genomic gradients, intracortical myelin, neurotransmitter receptors and transporters, and oxygen and glucose metabolism. Collectively, this work opens new avenues for studying the anatomical basis of neural activity.
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Affiliation(s)
- Golia Shafiei
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, Canada
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ben D. Fulcher
- School of Physics, The University of Sydney, NSW 2006, Australia
| | - Bradley Voytek
- Department of Cognitive Science, Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA
| | - Theodore D. Satterthwaite
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sylvain Baillet
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, Canada
| | - Bratislav Misic
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, Canada
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Botermans W, Koole M, Van Laere K, Savidge JR, Kemp JA, Sunaert S, Duffy MM, Ramael S, Cesura AM, D’Ostilio K, Gossen D, Madsen TM, Lodeweyckx T, de Hoon J. SDI-118, a novel procognitive SV2A modulator: First-in-human randomized controlled trial including PET/fMRI assessment of target engagement. Front Pharmacol 2023; 13:1066447. [PMID: 36733374 PMCID: PMC9887116 DOI: 10.3389/fphar.2022.1066447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/19/2022] [Indexed: 01/18/2023] Open
Abstract
Background: Current treatments for progressive neurodegenerative disorders characterized by cognitive impairment either have limited efficacy or are lacking altogether. SDI-118 is a small molecule which modulates the activity of synaptic vesicle glycoprotein 2A (SV2A) in the brain and shows cognitive enhancing effects in a range of animal models of cognitive deficit. Methods: This first-in-human study evaluated safety, tolerability, and pharmacokinetics/pharmacodynamics of SDI-118 in single ascending oral doses up to 80 mg administered to 32 healthy male subjects. Brain target occupancy was measured in eight subjects using positron emission tomography with PET-ligand [11C]-UCB-J. Food effect was assessed in seven subjects. Mood state was regularly evaluated using standardized questionnaires, and resting state fMRI data were analyzed as exploratory objectives. Key Results: At all doses tested, SDI-118 was well tolerated and appeared safe. Adverse events were mainly dizziness, hypersomnia, and somnolence. All were mild in intensity and increased in frequency with increasing administered dose. No dose-limiting adverse reactions were observed at any dose. SDI-118 displayed a linear pharmacokinetic profile with no significant food effect. Brain penetration and target engagement were demonstrated by a dose-proportional SV2A occupancy. Conclusion: Single oral doses of SDI-118 up to 80 mg were very well tolerated in healthy male subjects. Dose-proportional SV2A occupancy in the brain was demonstrated with brain imaging. Adverse effects in humans mainly occurred in higher dose ranges, with high occupancy levels, and were all mild and self-limiting. These data support further clinical exploration of the compound in patients with cognitive disorders. Clinical Trial Registration: https://clinicaltrials.gov/, identifier NCT05486195.
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Affiliation(s)
- Wouter Botermans
- Center for Clinical Pharmacology, University Hospital Leuven, Leuven, Belgium,*Correspondence: Wouter Botermans,
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Imaging and Pathology, KU Leuven and University Hospital Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Imaging and Pathology, KU Leuven and University Hospital Leuven, Leuven, Belgium
| | - Jonathan R. Savidge
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven Brain Institute, KU Leuven, Radiology, University Hospital Leuven, Leuven, Belgium
| | - John A. Kemp
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven Brain Institute, KU Leuven, Radiology, University Hospital Leuven, Leuven, Belgium
| | - Stefan Sunaert
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven Brain Institute, KU Leuven, Radiology, University Hospital Leuven, Leuven, Belgium
| | - Maeve M. Duffy
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven Brain Institute, KU Leuven, Radiology, University Hospital Leuven, Leuven, Belgium
| | - Steven Ramael
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven Brain Institute, KU Leuven, Radiology, University Hospital Leuven, Leuven, Belgium
| | - Andrea M. Cesura
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven Brain Institute, KU Leuven, Radiology, University Hospital Leuven, Leuven, Belgium
| | | | | | - Torsten M. Madsen
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven Brain Institute, KU Leuven, Radiology, University Hospital Leuven, Leuven, Belgium
| | - Thomas Lodeweyckx
- Center for Clinical Pharmacology, University Hospital Leuven, Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospital Leuven, Leuven, Belgium
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Kitamura T, Shijo M, Yokoi M, Maruyama T, Osaki M, Nakamura U, Arakawa S. Stroke-like lesions confined to the cerebellum in MELAS and a possible association with neuronal hyperexcitability. J Neurol 2023; 270:565-568. [PMID: 36152051 DOI: 10.1007/s00415-022-11397-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 09/07/2022] [Accepted: 09/19/2022] [Indexed: 01/07/2023]
Affiliation(s)
- Taisuke Kitamura
- Department of Cerebrovascular Medicine and Neurology, Steel Memorial Yawata Hospital, Kitakyushu, Japan.
| | - Masahiro Shijo
- Department of Internal Medicine, Fukuoka Dental College Medical and Dental Hospital, Fukuoka, Japan
| | - Mio Yokoi
- Department of Cerebrovascular Medicine and Neurology, Steel Memorial Yawata Hospital, Kitakyushu, Japan
| | - Takako Maruyama
- Department of Cerebrovascular Medicine and Neurology, Steel Memorial Yawata Hospital, Kitakyushu, Japan
| | - Masato Osaki
- Department of Cerebrovascular Medicine and Neurology, Steel Memorial Yawata Hospital, Kitakyushu, Japan
| | - Udai Nakamura
- Diabetes Center, Steel Memorial Yawata Hospital, Kitakyushu, Japan
| | - Shuji Arakawa
- Department of Cerebrovascular Medicine and Neurology, Steel Memorial Yawata Hospital, Kitakyushu, Japan
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Howes OD, Cummings C, Chapman GE, Shatalina E. Neuroimaging in schizophrenia: an overview of findings and their implications for synaptic changes. Neuropsychopharmacology 2023; 48:151-167. [PMID: 36056106 PMCID: PMC9700830 DOI: 10.1038/s41386-022-01426-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022]
Abstract
Over the last five decades, a large body of evidence has accrued for structural and metabolic brain alterations in schizophrenia. Here we provide an overview of these findings, focusing on measures that have traditionally been thought to reflect synaptic spine density or synaptic activity and that are relevant for understanding if there is lower synaptic density in the disorder. We conducted literature searches to identify meta-analyses or other relevant studies in patients with chronic or first-episode schizophrenia, or in people at high genetic or clinical risk for psychosis. We identified 18 meta-analyses including over 50,000 subjects in total, covering: structural MRI measures of gyrification index, grey matter volume, grey matter density and cortical thickness, neurite orientation dispersion and density imaging, PET imaging of regional glucose metabolism and magnetic resonance spectroscopy measures of N-acetylaspartate. We also review preclinical evidence on the relationship between ex vivo synaptic measures and structural MRI imaging, and PET imaging of synaptic protein 2A (SV2A). These studies show that schizophrenia is associated with lower grey matter volumes and cortical thickness, accelerated grey matter loss over time, abnormal gyrification patterns, and lower regional SV2A levels and metabolic markers in comparison to controls (effect sizes from ~ -0.11 to -1.0). Key regions affected include frontal, anterior cingulate and temporal cortices and the hippocampi. We identify several limitations for the interpretation of these findings in terms of understanding synaptic alterations. Nevertheless, taken with post-mortem findings, they suggest that schizophrenia is associated with lower synaptic density in some brain regions. However, there are several gaps in evidence, in particular whether SV2A findings generalise to other cohorts.
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Affiliation(s)
- Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK.
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
- South London and Maudsley NHS Foundation Trust, London, UK.
| | - Connor Cummings
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Clare Hall (College), University of Cambridge, Cambridge, UK
| | - George E Chapman
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- South London and Maudsley NHS Foundation Trust, London, UK
| | - Ekaterina Shatalina
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK
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Michiels L, Thijs L, Mertens N, Coremans M, Vandenbulcke M, Verheyden G, Koole M, Van Laere K, Lemmens R. Longitudinal Synaptic Density PET with 11 C-UCB-J 6 Months After Ischemic Stroke. Ann Neurol 2022; 93:911-921. [PMID: 36585914 DOI: 10.1002/ana.26593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/30/2022] [Accepted: 12/28/2022] [Indexed: 01/01/2023]
Abstract
OBJECTIVE The purpose of this study was to explore longitudinal changes in synaptic density after ischemic stroke in vivo with synaptic vesicle protein 2A (SV2A) positron emission tomography (PET). METHODS We recruited patients with an ischemic stroke to undergo 11 C-UCB-J PET/MR within the first month and 6 months after the stroke. We investigated longitudinal changes of partial volume corrected 11 C-UCB-J standardized uptake value ratio (SUVR; relative to centrum semiovale) within the ischemic lesion, peri-ischemic area and unaffected ipsilesional and contralesional grey matter. We also explored crossed cerebellar diaschisis at 6 months. Additionally, we defined brain regions potentially influencing upper limb motor recovery after stroke and studied 11 C-UCB-J SUVR evolution in comparison to baseline. RESULTS In 13 patients (age = 67 ± 15 years) we observed decreasing 11 C-UCB-J SUVR in the ischemic lesion (ΔSUVR = -1.0, p = 0.001) and peri-ischemic area (ΔSUVR = -0.31, p = 0.02) at 6 months after stroke compared to baseline. Crossed cerebellar diaschisis as measured with 11 C-UCB-J SUVR was present in 11 of 13 (85%) patients at 6 months. The 11 C-UCB-J SUVR did not augment in ipsilesional or contralesional brain regions associated with motor recovery. On the contrary, there was an overall trend of declining 11 C-UCB-J SUVR in these brain regions, reaching statistical significance only in the nonlesioned part of the ipsilesional supplementary motor area (ΔSUVR = -0.83, p = 0.046). INTERPRETATION At 6 months after stroke, synaptic density further declined in the ischemic lesion and peri-ischemic area compared to baseline. Brain regions previously demonstrated to be associated with motor recovery after stroke did not show increases in synaptic density. ANN NEUROL 2023.
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Affiliation(s)
- Laura Michiels
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven, Belgium.,Department of Neurology, University Hospitals Leuven, Leuven, Belgium.,Leuven Brain Institute, Leuven, Belgium
| | - Liselot Thijs
- Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Nathalie Mertens
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Marjan Coremans
- Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Mathieu Vandenbulcke
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, Leuven, Belgium.,Department of Geriatric Psychiatry, University Psychiatric Centre, Leuven, Belgium
| | - Geert Verheyden
- Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- Leuven Brain Institute, Leuven, Belgium.,Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Department of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Robin Lemmens
- Department of Neurosciences, KU Leuven, Leuven, Belgium.,Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven, Belgium.,Department of Neurology, University Hospitals Leuven, Leuven, Belgium.,Leuven Brain Institute, Leuven, Belgium
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Mecca AP, O'Dell RS, Sharp ES, Banks ER, Bartlett HH, Zhao W, Lipior S, Diepenbrock NG, Chen M, Naganawa M, Toyonaga T, Nabulsi NB, Vander Wyk BC, Arnsten AFT, Huang Y, Carson RE, van Dyck CH. Synaptic density and cognitive performance in Alzheimer's disease: A PET imaging study with [ 11 C]UCB-J. Alzheimers Dement 2022; 18:2527-2536. [PMID: 35174954 PMCID: PMC9381645 DOI: 10.1002/alz.12582] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/23/2021] [Accepted: 12/12/2021] [Indexed: 01/31/2023]
Abstract
INTRODUCTION For 30 years synapse loss has been referred to as the major pathological correlate of cognitive impairment in Alzheimer's disease (AD). However, this statement is based on remarkably few patients studied by autopsy or biopsy. With the recent advent of synaptic vesicle glycoprotein 2A (SV2A) positron emission tomography (PET) imaging, we have begun to evaluate the consequences of synaptic alterations in vivo. METHODS We examined the relationship between synaptic density measured by [11 C]UCB-J PET and neuropsychological test performance in 45 participants with early AD. RESULTS Global synaptic density showed a significant positive association with global cognition and performance on five individual cognitive domains in participants with early AD. Synaptic density was a stronger predictor of cognitive performance than gray matter volume. CONCLUSION These results confirm neuropathologic studies demonstrating a significant association between synaptic density and cognitive performance, and suggest that this correlation extends to the early stages of AD.
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Affiliation(s)
- Adam P. Mecca
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Ryan S. O'Dell
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Emily S. Sharp
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
| | - Emmie R. Banks
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Hugh H. Bartlett
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Wenzhen Zhao
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Sylwia Lipior
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Nina G. Diepenbrock
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
| | - Ming‐Kai Chen
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | - Mika Naganawa
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | - Nabeel B. Nabulsi
- Department of Radiology and Biomedical ImagingYale University School of MedicineNew HavenConnecticutUSA
| | | | - Amy F. T. Arnsten
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of NeuroscienceYale University School of MedicineNew HavenConnecticutUSA
| | - Yiyun Huang
- Program on AgingYale University School of MedicineNew HavenConnecticutUSA
| | - Richard E. Carson
- Program on AgingYale University School of MedicineNew HavenConnecticutUSA
| | - Christopher H. van Dyck
- Alzheimer's Disease Research UnitYale University School of MedicineNew HavenConnecticutUSA
- Department of PsychiatryYale University School of MedicineNew HavenConnecticutUSA
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
- Department of NeuroscienceYale University School of MedicineNew HavenConnecticutUSA
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Akkermans J, Zajicek F, Miranda A, Adhikari MH, Bertoglio D. Identification of pre-synaptic density networks using [ 11C]UCB-J PET imaging and ICA in mice. Neuroimage 2022; 264:119771. [PMID: 36436710 DOI: 10.1016/j.neuroimage.2022.119771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/28/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Synaptic vesicle glycoprotein 2A (SV2A) is a vesicle glycoprotein involved in neurotransmitter release. SV2A is located on the pre-synaptic terminals of neurons and visualized using the radioligand [11C]UCB-J and positron emission tomography (PET) imaging. Thus, SV2A PET imaging can provide a proxy for pre-synaptic density in health and disease. This study aims to apply independent component analysis (ICA) to SV2A PET data acquired in mice to identify pre-synaptic density networks (pSDNs), explore how ageing affects these pSDNs, and determine the impact of a neurological disorder on these networks. METHODS We used [11C]UCB-J PET imaging data (n = 135) available at different ages (3, 7, 10, and 16 months) in wild-type (WT) C57BL/6J mice and in diseased mice (mouse model of Huntington's disease, HD) with reported synaptic deficits. First, ICA was performed on a healthy dataset after it was split into two equal-sized samples (n = 36 each) and the analysis was repeated 50 times in different partitions. We tested different model orders (8, 12, and 16) and identified the pSDNs. Next, we investigated the effect of age on the loading weights of the identified pSDNs. Additionally, the identified pSDNs were compared to those of diseased mice to assess the impact of disease on each pSDNs. RESULTS Model order 12 resulted in the preferred choice to provide six reliable and reproducible independent components (ICs) as supported by the cluster-quality index (IQ) and regression coefficients (β) values. Temporal analysis showed age-related statistically significant changes on the loading weights in four ICs. ICA in an HD model revealed a statistically significant disease-related effect on the loading weights in several pSDNs in line with the progression of the disease. CONCLUSION This study validated the use of ICA on SV2A PET data acquired with [11C]UCB-J for the identification of cerebral pre-synaptic density networks in mice in a rigorous and reproducible manner. Furthermore, we showed that different pSDNs change with age and are affected in a disease condition. These findings highlight the potential value of ICA in understanding pre-synaptic density networks in the mouse brain.
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Affiliation(s)
- Jordy Akkermans
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Belgium
| | - Franziska Zajicek
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Belgium
| | | | - Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Belgium; Bio-Imaging Lab, University of Antwerp, Belgium.
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Naganawa M, Gallezot JD, Finnema SJ, Maguire RP, Mercier J, Nabulsi NB, Kervyn S, Henry S, Nicolas JM, Huang Y, Chen MK, Hannestad J, Klitgaard H, Stockis A, Carson RE. Drug characteristics derived from kinetic modeling: combined 11C-UCB-J human PET imaging with levetiracetam and brivaracetam occupancy of SV2A. EJNMMI Res 2022; 12:71. [PMID: 36346513 PMCID: PMC9643320 DOI: 10.1186/s13550-022-00944-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/24/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Antiepileptic drugs, levetiracetam (LEV) and brivaracetam (BRV), bind to synaptic vesicle glycoprotein 2A (SV2A). In their anti-seizure activity, speed of brain entry may be an important factor. BRV showed faster entry into the human and non-human primate brain, based on more rapid displacement of SV2A tracer 11C-UCB-J. To extract additional information from previous human studies, we developed a nonlinear model that accounted for drug entry into the brain and binding to SV2A using brain 11C-UCB-J positron emission tomography (PET) data and the time-varying plasma drug concentration, to assess the kinetic parameter K1 (brain entry rate) of the drugs. METHOD Displacement (LEV or BRV p.i. 60 min post-tracer injection) and post-dose scans were conducted in five healthy subjects. Blood samples were collected for measurement of drug concentration and the tracer arterial input function. Fitting of nonlinear differential equations was applied simultaneously to time-activity curves (TACs) from displacement and post-dose scans to estimate 5 parameters: K1 (drug), K1(11C-UCB-J, displacement), K1(11C-UCB-J, post-dose), free fraction of 11C-UCB-J in brain (fND(11C-UCB-J)), and distribution volume of 11C-UCB-J (VT(UCB-J)). Other parameters (KD(drug), KD(11C-UCB-J), fP(drug), fP(11C-UCB-J, displacement), fP(11C-UCB-J, post-dose), fND(drug), koff(drug), koff(11C-UCB-J)) were fixed to literature or measured values. RESULTS The proposed model described well the TACs in all subjects; however, estimates of drug K1 were unstable in comparison with 11C-UCB-J K1 estimation. To provide a conservative estimate of the relative speed of brain entry for BRV vs. LEV, we determined a lower bound on the ratio BRV K1/LEV K1, by finding the lowest BRV K1 or highest LEV K1 that were statistically consistent with the data. Specifically, we used the F test to compare the residual sum of squares with fixed BRV K1 to that with floating BRV K1 to obtain the lowest possible BRV K1; the same analysis was performed to find the highest LEV K1. The lower bound of the ratio BRV K1/LEV K1 was ~ 7. CONCLUSIONS Under appropriate conditions, this advanced nonlinear model can directly estimate entry rates of drugs into tissue by analysis of PET TACs. Using a conservative statistical cutoff, BRV enters the brain at least sevenfold faster than LEV.
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Affiliation(s)
- Mika Naganawa
- Yale University School of Medicine, 801 Howard Ave, PO Box 208048, New Haven, CT, USA.
| | | | - Sjoerd J Finnema
- Yale University School of Medicine, 801 Howard Ave, PO Box 208048, New Haven, CT, USA
| | | | | | - Nabeel B Nabulsi
- Yale University School of Medicine, 801 Howard Ave, PO Box 208048, New Haven, CT, USA
| | | | - Shannan Henry
- Yale University School of Medicine, 801 Howard Ave, PO Box 208048, New Haven, CT, USA
| | | | - Yiyun Huang
- Yale University School of Medicine, 801 Howard Ave, PO Box 208048, New Haven, CT, USA
| | - Ming-Kai Chen
- Yale University School of Medicine, 801 Howard Ave, PO Box 208048, New Haven, CT, USA
| | | | | | | | - Richard E Carson
- Yale University School of Medicine, 801 Howard Ave, PO Box 208048, New Haven, CT, USA
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Saunders TS, Gadd DA, Spires‐Jones TL, King D, Ritchie C, Muniz‐Terrera G. Associations between cerebrospinal fluid markers and cognition in ageing and dementia: A systematic review. Eur J Neurosci 2022; 56:5650-5713. [PMID: 35338546 PMCID: PMC9790745 DOI: 10.1111/ejn.15656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/08/2022] [Accepted: 03/13/2022] [Indexed: 12/30/2022]
Abstract
A biomarker associated with cognition in neurodegenerative dementias would aid in the early detection of disease progression, complement clinical staging and act as a surrogate endpoint in clinical trials. The current systematic review evaluates the association between cerebrospinal fluid protein markers of synapse loss and neuronal injury and cognition. We performed a systematic search which revealed 67 studies reporting an association between cerebrospinal fluid markers of interest and neuropsychological performance. Despite the substantial heterogeneity between studies, we found some evidence for an association between neurofilament-light and worse cognition in Alzheimer's diseases, frontotemporal dementia and typical cognitive ageing. Moreover, there was an association between cerebrospinal fluid neurogranin and cognition in those with an Alzheimer's-like cerebrospinal fluid biomarker profile. Some evidence was found for cerebrospinal fluid neuronal pentraxin-2 as a correlate of cognition across dementia syndromes. Due to the substantial heterogeneity of the field, no firm conclusions can be drawn from this review. Future research should focus on improving standardization and reporting as well as establishing the importance of novel markers such as neuronal pentraxin-2 and whether such markers can predict longitudinal cognitive decline.
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Affiliation(s)
- Tyler S. Saunders
- UK Dementia Research InstituteThe University of EdinburghEdinburghUK,Center for Discovery Brain SciencesThe University of EdinburghEdinburghUK,Center for Clinical Brain SciencesThe University of EdinburghEdinburghUK,Center for Dementia PreventionThe University of EdinburghEdinburghUK
| | - Danni A. Gadd
- Center for Genomic and Experimental Medicine, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Tara L. Spires‐Jones
- UK Dementia Research InstituteThe University of EdinburghEdinburghUK,Center for Discovery Brain SciencesThe University of EdinburghEdinburghUK
| | - Declan King
- UK Dementia Research InstituteThe University of EdinburghEdinburghUK,Center for Discovery Brain SciencesThe University of EdinburghEdinburghUK
| | - Craig Ritchie
- Center for Clinical Brain SciencesThe University of EdinburghEdinburghUK,Center for Dementia PreventionThe University of EdinburghEdinburghUK
| | - Graciela Muniz‐Terrera
- Center for Clinical Brain SciencesThe University of EdinburghEdinburghUK,Center for Dementia PreventionThe University of EdinburghEdinburghUK
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Hansen JY, Shafiei G, Markello RD, Smart K, Cox SML, Nørgaard M, Beliveau V, Wu Y, Gallezot JD, Aumont É, Servaes S, Scala SG, DuBois JM, Wainstein G, Bezgin G, Funck T, Schmitz TW, Spreng RN, Galovic M, Koepp MJ, Duncan JS, Coles JP, Fryer TD, Aigbirhio FI, McGinnity CJ, Hammers A, Soucy JP, Baillet S, Guimond S, Hietala J, Bedard MA, Leyton M, Kobayashi E, Rosa-Neto P, Ganz M, Knudsen GM, Palomero-Gallagher N, Shine JM, Carson RE, Tuominen L, Dagher A, Misic B. Mapping neurotransmitter systems to the structural and functional organization of the human neocortex. Nat Neurosci 2022; 25:1569-1581. [PMID: 36303070 PMCID: PMC9630096 DOI: 10.1038/s41593-022-01186-3] [Citation(s) in RCA: 93] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 09/20/2022] [Indexed: 01/13/2023]
Abstract
Neurotransmitter receptors support the propagation of signals in the human brain. How receptor systems are situated within macro-scale neuroanatomy and how they shape emergent function remain poorly understood, and there exists no comprehensive atlas of receptors. Here we collate positron emission tomography data from more than 1,200 healthy individuals to construct a whole-brain three-dimensional normative atlas of 19 receptors and transporters across nine different neurotransmitter systems. We found that receptor profiles align with structural connectivity and mediate function, including neurophysiological oscillatory dynamics and resting-state hemodynamic functional connectivity. Using the Neurosynth cognitive atlas, we uncovered a topographic gradient of overlapping receptor distributions that separates extrinsic and intrinsic psychological processes. Finally, we found both expected and novel associations between receptor distributions and cortical abnormality patterns across 13 disorders. We replicated all findings in an independently collected autoradiography dataset. This work demonstrates how chemoarchitecture shapes brain structure and function, providing a new direction for studying multi-scale brain organization.
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Affiliation(s)
- Justine Y Hansen
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Golia Shafiei
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Ross D Markello
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Kelly Smart
- Yale PET Center, Yale School of Medicine, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Sylvia M L Cox
- Department of Psychiatry, McGill University, Montréal, QC, Canada
| | - Martin Nørgaard
- Department of Psychology, Center for Reproducible Neuroscience, Stanford University, Stanford, CA, USA
- Neurobiology Research Unit, Cimbi & OpenNeuroPET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Vincent Beliveau
- Neurobiology Research Unit, Cimbi & OpenNeuroPET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Yanjun Wu
- Yale PET Center, Yale School of Medicine, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Jean-Dominique Gallezot
- Yale PET Center, Yale School of Medicine, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Étienne Aumont
- Cognitive Pharmacology Research Unit, UQAM, Montréal, QC, Canada
| | - Stijn Servaes
- McGill University Research Centre for Studies in Aging, Douglas Hospital, McGill University, Montréal, QC, Canada
| | | | | | | | - Gleb Bezgin
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- McGill University Research Centre for Studies in Aging, Douglas Hospital, McGill University, Montréal, QC, Canada
| | - Thomas Funck
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Taylor W Schmitz
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
| | - R Nathan Spreng
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Marian Galovic
- Department of Neurology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
- MRI Unit, Chalfont Centre for Epilepsy, Chalfont Saint Peter, UK
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
- MRI Unit, Chalfont Centre for Epilepsy, Chalfont Saint Peter, UK
| | - John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
- MRI Unit, Chalfont Centre for Epilepsy, Chalfont Saint Peter, UK
| | - Jonathan P Coles
- Department of Medicine, Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Tim D Fryer
- Department of Clinical Neurosciences, Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Franklin I Aigbirhio
- Department of Clinical Neurosciences, Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Colm J McGinnity
- King's College London and Guy's and St. Thomas' PET Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Alexander Hammers
- King's College London and Guy's and St. Thomas' PET Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Jean-Paul Soucy
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Sylvain Baillet
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Synthia Guimond
- Department of Psychiatry, Royal's Institute of Mental Health Research, University of Ottawa, Ottawa, ON, Canada
- Department of Psychoeducation and Psychology, University of Quebec in Outaouais, Gatineau, QC, Canada
| | - Jarmo Hietala
- Department of Psychiatry, University of Turku and Turku University Hospital, Turku, Finland
| | - Marc-André Bedard
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- Cognitive Pharmacology Research Unit, UQAM, Montréal, QC, Canada
| | - Marco Leyton
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- Department of Psychiatry, McGill University, Montréal, QC, Canada
| | - Eliane Kobayashi
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Pedro Rosa-Neto
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
- McGill University Research Centre for Studies in Aging, Douglas Hospital, McGill University, Montréal, QC, Canada
| | - Melanie Ganz
- Neurobiology Research Unit, Cimbi & OpenNeuroPET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Cimbi & OpenNeuroPET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Nicola Palomero-Gallagher
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
- C. and O. Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - James M Shine
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia
| | - Richard E Carson
- Yale PET Center, Yale School of Medicine, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Lauri Tuominen
- Department of Psychiatry, Royal's Institute of Mental Health Research, University of Ottawa, Ottawa, ON, Canada
| | - Alain Dagher
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Bratislav Misic
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada.
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Howes OD, Shatalina E. Integrating the Neurodevelopmental and Dopamine Hypotheses of Schizophrenia and the Role of Cortical Excitation-Inhibition Balance. Biol Psychiatry 2022; 92:501-513. [PMID: 36008036 DOI: 10.1016/j.biopsych.2022.06.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/16/2022] [Accepted: 06/04/2022] [Indexed: 12/23/2022]
Abstract
The neurodevelopmental and dopamine hypotheses are leading theories of the pathoetiology of schizophrenia, but they were developed in isolation. However, since they were originally proposed, there have been considerable advances in our understanding of the normal neurodevelopmental refinement of synapses and cortical excitation-inhibition (E/I) balance, as well as preclinical findings on the interrelationship between cortical and subcortical systems and new in vivo imaging and induced pluripotent stem cell evidence for lower synaptic density markers in patients with schizophrenia. Genetic advances show that schizophrenia is associated with variants linked to genes affecting GABA (gamma-aminobutyric acid) and glutamatergic signaling as well as neurodevelopmental processes. Moreover, in vivo studies on the effects of stress, particularly during later development, show that it leads to synaptic elimination. We review these lines of evidence as well as in vivo evidence for altered cortical E/I balance and dopaminergic dysfunction in schizophrenia. We discuss mechanisms through which frontal cortex circuitry may regulate striatal dopamine and consider how frontal E/I imbalance may cause dopaminergic dysregulation to result in psychotic symptoms. This integrated neurodevelopmental and dopamine hypothesis suggests that overpruning of synapses, potentially including glutamatergic inputs onto frontal cortical interneurons, disrupts the E/I balance and thus underlies cognitive and negative symptoms. It could also lead to disinhibition of excitatory projections from the frontal cortex and possibly other regions that regulate mesostriatal dopamine neurons, resulting in dopamine dysregulation and psychotic symptoms. Together, this explains a number of aspects of the epidemiology and clinical presentation of schizophrenia and identifies new targets for treatment and prevention.
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Affiliation(s)
- Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, United Kingdom; Department of Psychosis, Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
| | - Ekaterina Shatalina
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, United Kingdom
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Hansen JY, Shafiei G, Vogel JW, Smart K, Bearden CE, Hoogman M, Franke B, van Rooij D, Buitelaar J, McDonald CR, Sisodiya SM, Schmaal L, Veltman DJ, van den Heuvel OA, Stein DJ, van Erp TGM, Ching CRK, Andreassen OA, Hajek T, Opel N, Modinos G, Aleman A, van der Werf Y, Jahanshad N, Thomopoulos SI, Thompson PM, Carson RE, Dagher A, Misic B. Local molecular and global connectomic contributions to cross-disorder cortical abnormalities. Nat Commun 2022; 13:4682. [PMID: 35948562 PMCID: PMC9365855 DOI: 10.1038/s41467-022-32420-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 07/28/2022] [Indexed: 12/21/2022] Open
Abstract
Numerous brain disorders demonstrate structural brain abnormalities, which are thought to arise from molecular perturbations or connectome miswiring. The unique and shared contributions of these molecular and connectomic vulnerabilities to brain disorders remain unknown, and has yet to be studied in a single multi-disorder framework. Using MRI morphometry from the ENIGMA consortium, we construct maps of cortical abnormalities for thirteen neurodevelopmental, neurological, and psychiatric disorders from N = 21,000 participants and N = 26,000 controls, collected using a harmonised processing protocol. We systematically compare cortical maps to multiple micro-architectural measures, including gene expression, neurotransmitter density, metabolism, and myelination (molecular vulnerability), as well as global connectomic measures including number of connections, centrality, and connection diversity (connectomic vulnerability). We find a relationship between molecular vulnerability and white-matter architecture that drives cortical disorder profiles. Local attributes, particularly neurotransmitter receptor profiles, constitute the best predictors of both disorder-specific cortical morphology and cross-disorder similarity. Finally, we find that cross-disorder abnormalities are consistently subtended by a small subset of network epicentres in bilateral sensory-motor, inferior temporal lobe, precuneus, and superior parietal cortex. Collectively, our results highlight how local molecular attributes and global connectivity jointly shape cross-disorder cortical abnormalities.
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Affiliation(s)
- Justine Y Hansen
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Golia Shafiei
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Jacob W Vogel
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kelly Smart
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Carrie E Bearden
- Departments of Psychiatry and Biobehavioral Sciences and Psychology, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Martine Hoogman
- Departments of Psychiatry and Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Barbara Franke
- Departments of Psychiatry and Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Daan van Rooij
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Jan Buitelaar
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Carrie R McDonald
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Lianne Schmaal
- Centre for Youth Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Dick J Veltman
- Department of Psychiatry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Odile A van den Heuvel
- Department of Psychiatry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
- Department of Anatomy & Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Dan J Stein
- SA MRC Unit on Risk & Resilience in Mental Disorders, Dept of Psychiatry & Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Theo G M van Erp
- Clinical Translational Neuroscience Laboratory, Department of Psychiatry and Human Behavior, & Center for the Neurobiology of Leaning and Memory, University of California Irvine, 309 Qureshey Research Lab, Irvine, CA, USA
| | - Christopher R K Ching
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Ole A Andreassen
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Tomas Hajek
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Nils Opel
- Institute of Translational Psychiatry, University of Münster, Münster, Germany & Department of Psychiatry, Jena University Hospital/Friedrich-Schiller-University Jena, Jena, Germany
| | - Gemma Modinos
- Department of Psychosis Studies & MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - André Aleman
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, Groningen, The Netherlands
| | - Ysbrand van der Werf
- Department of Anatomy & Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Neda Jahanshad
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Sophia I Thomopoulos
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Paul M Thompson
- Keck School of Medicine, Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Alain Dagher
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Bratislav Misic
- McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada.
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46
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Healthy brain aging assessed with [ 18F]FDG and [ 11C]UCB-J PET. Nucl Med Biol 2022; 112-113:52-58. [PMID: 35820300 DOI: 10.1016/j.nucmedbio.2022.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/21/2022] [Accepted: 06/28/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND The average human lifespan has increased dramatically over the past century. However, molecular and physiological alterations of the healthy brain during aging remain incompletely understood. Generalized synaptic restructuring may contribute to healthy aging and the reduced metabolism observed in the aged brain. The aim of this study was to assess healthy brain aging using [18F]FDG as a measure of cerebral glucose consumption and [11C]UCB-J PET as an indicator of synaptic density. METHOD Using in vivo PET imaging and the novel synaptic-vesicle-glycoprotein 2A (SV2A) radioligand [11C]UCB-J alongside with the fluorodeoxyglucose radioligand [18F]FDG, we obtained SUVR-1 values for 14 pre-defined volume-of-interest brain regions defined on MRI T1 scans. Regional differences in relative [18F]FDG and [11C]UCB-J uptake were investigated using a voxel-wise approach. Finally, correlations between [11C]UCB-J, [18F]FDG PET, and age were examined. RESULTS We found widespread cortical reduction of synaptic density in a cohort of older HC subjects (N = 15) compared with young HC subjects (N = 11). However, no reduction persisted after partial volume correction and corrections for multiple comparison. Our study confirms previously reported synaptic stability during aging. Regional differences in relative [18F]FDG and [11C]UCB-J uptake were observed with up to 20 % higher [11C]UCB-J uptake in the amygdala and temporal lobe and up to 34 % higher glucose metabolism in thalamus, striatum, occipital, parietal and frontal cortex. CONCLUSION In vivo PET using [11C]UCB-J does not support declining synaptic density levels during aging. Thus, loss of synaptic density may be unrelated to aging and does not seem to be a sufficient explanation for the recognized reduction in brain metabolism during aging. Our study also demonstrates that the relationship between glucose consumption and synaptic density is not uniform throughout the human brain with implications for our understanding of neuroenergetics.
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Chou YH, Sundman M, Ton That V, Green J, Trapani C. Cortical excitability and plasticity in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis of transcranial magnetic stimulation studies. Ageing Res Rev 2022; 79:101660. [PMID: 35680080 DOI: 10.1016/j.arr.2022.101660] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 05/13/2022] [Accepted: 05/30/2022] [Indexed: 11/01/2022]
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique. When stimulation is applied over the primary motor cortex and coupled with electromyography measures, TMS can probe functions of cortical excitability and plasticity in vivo. The purpose of this meta-analysis is to evaluate the utility of TMS-derived measures for differentiating patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) from cognitively normal older adults (CN). METHODS Databases searched included PubMed, Embase, APA PsycInfo, Medline, and CINAHL Plus from inception to July 2021. RESULTS Sixty-one studies with a total of 2728 participants (1454 patients with AD, 163 patients with MCI, and 1111 CN) were included. Patients with AD showed significantly higher cortical excitability, lower cortical inhibition, and impaired cortical plasticity compared to the CN cohorts. Patients with MCI exhibited increased cortical excitability and reduced plasticity compared to the CN cohort. Additionally, lower cognitive performance was significantly associated with higher cortical excitability and lower inhibition. No seizure events due to TMS were reported, and the mild adverse response rate is approximately 3/1000 (i.e., 9/2728). CONCLUSIONS Findings of our meta-analysis demonstrate the potential of using TMS-derived cortical excitability and plasticity measures as diagnostic biomarkers and therapeutic targets for AD and MCI.
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Affiliation(s)
- Ying-Hui Chou
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, USA; Evelyn F McKnight Brain Institute, Arizona Center on Aging, and BIO5 Institute, University of Arizona, Tucson, USA.
| | - Mark Sundman
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, USA
| | - Viet Ton That
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, USA
| | - Jacob Green
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, USA
| | - Chrisopher Trapani
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, USA
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Carson RE, Naganawa M, Toyonaga T, Koohsari S, Yang Y, Chen MK, Matuskey D, Finnema SJ. Imaging of Synaptic Density in Neurodegenerative Disorders. J Nucl Med 2022; 63:60S-67S. [PMID: 35649655 DOI: 10.2967/jnumed.121.263201] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/10/2022] [Indexed: 02/07/2023] Open
Abstract
PET technology has produced many radiopharmaceuticals that target specific brain proteins and other measures of brain function. Recently, a new approach has emerged to image synaptic density by targeting the synaptic vesicle protein 2A (SV2A), an integral glycoprotein in the membrane of synaptic vesicles and widely distributed throughout the brain. Multiple SV2A ligands have been developed and translated to human use. The most successful of these to date is 11C-UCB-J, because of its high uptake, moderate metabolism, and effective quantification with a 1-tissue-compartment model. Further, since SV2A is the target of the antiepileptic drug levetiracetam, human blocking studies have characterized specific binding and potential reference regions. Regional brain SV2A levels were shown to correlate with those of synaptophysin, another commonly used marker of synaptic density, providing the basis for SV2A PET imaging to have broad utility across neuropathologic diseases. In this review, we highlight the development of SV2A tracers and the evaluation of quantification methods, including compartment modeling and simple tissue ratios. Mouse and rat models of neurodegenerative diseases have been studied with small-animal PET, providing validation by comparison to direct tissue measures. Next, we review human PET imaging results in multiple neurodegenerative disorders. Studies on Parkinson disease and Alzheimer disease have progressed most rapidly at multiple centers, with generally consistent results of patterns of SV2A or synaptic loss. In Alzheimer disease, the synaptic loss patterns differ from those of amyloid, tau, and 18F-FDG, although intertracer and interregional correlations have been found. Smaller studies have been reported in other disorders, including Lewy body dementia, frontotemporal dementia, Huntington disease, progressive supranuclear palsy, and corticobasal degeneration. In conclusion, PET imaging of SV2A has rapidly developed, and qualified radioligands are available. PET studies on humans indicate that SV2A loss might be specific to disease-associated brain regions and consistent with synaptic density loss. The recent availability of new 18F tracers, 18F-SynVesT-1 and 18F-SynVesT-2, will substantially broaden the application of SV2A PET. Future studies are needed in larger patient cohorts to establish the clinical value of SV2A PET and its potential for diagnosis and progression monitoring of neurodegenerative diseases, as well as efficacy assessment of disease-modifying therapies.
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Affiliation(s)
- Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut;
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Sheida Koohsari
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Yanghong Yang
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
| | - David Matuskey
- Department of Radiology and Biomedical Imaging, Yale Positron Emission Tomography Center, Yale University, New Haven, Connecticut
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut; and
| | - Sjoerd J Finnema
- Neuroscience Discovery Research, Translational Imaging, AbbVie, North Chicago, Illinois
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49
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Rossi R, Arjmand S, Bærentzen SL, Gjedde A, Landau AM. Synaptic Vesicle Glycoprotein 2A: Features and Functions. Front Neurosci 2022; 16:864514. [PMID: 35573314 PMCID: PMC9096842 DOI: 10.3389/fnins.2022.864514] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/05/2022] [Indexed: 01/05/2023] Open
Abstract
In recent years, the field of neuroimaging dramatically moved forward by means of the expeditious development of specific radioligands of novel targets. Among these targets, the synaptic vesicle glycoprotein 2A (SV2A) is a transmembrane protein of synaptic vesicles, present in all synaptic terminals, irrespective of neurotransmitter content. It is involved in key functions of neurons, focused on the regulation of neurotransmitter release. The ubiquitous expression in gray matter regions of the brain is the basis of its candidacy as a marker of synaptic density. Following the development of molecules derived from the structure of the anti-epileptic drug levetiracetam, which selectively binds to SV2A, several radiolabeled markers have been synthetized to allow the study of SV2A distribution with positron emission tomography (PET). These radioligands permit the evaluation of in vivo changes of SV2A distribution held to be a potential measure of synaptic density in physiological and pathological conditions. The use of SV2A as a biomarker of synaptic density raises important questions. Despite numerous studies over the last decades, the biological function and the expressional properties of SV2A remain poorly understood. Some functions of SV2A were claimed, but have not been fully elucidated. While the expression of SV2A is ubiquitous, stronger associations between SV2A and Υ amino butyric acid (GABA)-ergic rather than glutamatergic synapses were observed in some brain structures. A further issue is the unclear interaction between SV2A and its tracers, which reflects a need to clarify what really is detected with neuroimaging tools. Here, we summarize the current knowledge of the SV2A protein and we discuss uncertain aspects of SV2A biology and physiology. As SV2A expression is ubiquitous, but likely more strongly related to a certain type of neurotransmission in particular circumstances, a more extensive knowledge of the protein would greatly facilitate the analysis and interpretation of neuroimaging results by allowing the evaluation not only of an increase or decrease of the protein level, but also of the type of neurotransmission involved.
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Affiliation(s)
- Rachele Rossi
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Shokouh Arjmand
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Simone Larsen Bærentzen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Albert Gjedde
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Anne M Landau
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
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Rossano S, Toyonaga T, Bini J, Nabulsi N, Ropchan J, Cai Z, Huang Y, Carson RE. Feasibility of imaging synaptic density in the human spinal cord using [ 11C]UCB-J PET. EJNMMI Phys 2022; 9:32. [PMID: 35503134 PMCID: PMC9065222 DOI: 10.1186/s40658-022-00464-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 04/20/2022] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Neuronal damage and synapse loss in the spinal cord (SC) have been implicated in spinal cord injury (SCI) and neurodegenerative disorders such as Amyotrophic Lateral Sclerosis (ALS). Current standards of diagnosis for SCI include CT or MRI imaging to evaluate injury severity. The current study explores the use of PET imaging with [11C]UCB-J, which targets the synaptic vesicle protein 2A (SV2A), in the human spinal cord, as a way to visualize synaptic density and integrity in vivo. RESULTS First, simulations of baseline and blocking [11C]UCB-J HRRT scans were performed, based on SC dimensions and SV2A distribution to predict VT, VND, and VS values. Next, human baseline and blocking [11C]UCB-J HRRT images were used to estimate these values in the cervical SC (cSC). Simulation results had excellent agreement with observed values of VT, VND, and VS from the real human data, with baseline VT, VND, and VS of 3.07, 2.15, and 0.92 mL/cm3, respectively, with a BPND of 0.43. Lastly, we explored full SC imaging with whole-body images. Using automated SC regions of interest (ROIs) for the full SC, cSC, and thoracic SC (tSC), the distribution volume ratio (DVR) was estimated using the brain gray matter as a reference region to evaluate SC SV2A density relative to the brain. In full body imaging, DVR values of full SC, cSC, and tSC were 0.115, 0.145, and 0.112, respectively. Therefore, measured [11C]UCB-J uptake, and thus SV2A density, is much lower in the SC than in the brain. CONCLUSIONS The results presented here provide evidence for the feasibility of SV2A PET imaging in the human SC, however, specific binding of [11C]UCB-J is low. Ongoing and future work include further classification of SV2A distribution in the SC as well as exploring higher-affinity PET radioligands for SC imaging.
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Affiliation(s)
- Samantha Rossano
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA.
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA
| | - Jason Bini
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA
| | - Zhengxin Cai
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale PET Center, Yale School of Medicine, P.O. Box 208048, New Haven, CT, 06520, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
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