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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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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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Endepols H, Anglada-Huguet M, Mandelkow E, Neumaier B, Mandelkow EM, Drzezga A. Fragmentation of functional resting state brain networks in a transgenic mouse model of tau pathology: A metabolic connectivity study using [ 18F]FDG-PET. Exp Neurol 2024; 372:114632. [PMID: 38052272 DOI: 10.1016/j.expneurol.2023.114632] [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: 08/24/2023] [Revised: 11/07/2023] [Accepted: 11/29/2023] [Indexed: 12/07/2023]
Abstract
In a previous study, regional reductions in cerebral glucose metabolism have been demonstrated in the tauopathy mouse model rTg4510 (Endepols et al., 2022). Notably, glucose hypometabolism was present in some brain regions without co-localized synaptic degeneration measured with [18F]UCB-H. We hypothesized that in those regions hypometabolism may reflect reduced functional connectivity rather than synaptic damage. To test this hypothesis, we performed seed-based metabolic connectivity analyses using [18F]FDG-PET data in this mouse model. Eight rTg4510 mice at the age of seven months and 8 non-transgenic littermates were injected intraperitoneally with 11.1 ± 0.8 MBq [18F]FDG and spent a 35-min uptake period awake in single cages. Subsequently, they were anesthetized and measured in a small animal PET scanner for 30 min. Three seed-based connectivity analyses were performed per group. Seeds were selected for apparent mismatch between [18F]FDG and [18F]UCB-H. A seed was placed either in the medial orbitofrontal cortex, dorsal hippocampus or dorsal thalamus, and correlated with all other voxels of the brain across animals. In the control group, the emerging correlative pattern was strongly overlapping for all three seed locations, indicating a uniform fronto-thalamo-hippocampal resting state network. In contrast, rTg4510 mice showed three distinct networks with minimal overlap. Frontal and thalamic networks were greatly diminished. The hippocampus, however, formed a new network with the whole parietal cortex. We conclude that resting-state functional networks are fragmented in the brain of rTg4510 mice. Thus, hypometabolism can be explained by reduced functional connectivity of brain areas devoid of tau-related pathology, such as the thalamus.
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Affiliation(s)
- Heike Endepols
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute of Radiochemistry and Experimental Molecular Imaging, Cologne, Germany; Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, Jülich 52428, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Nuclear Medicine, Cologne, Germany
| | | | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn-Cologne, Germany; Department Neurodegenerative Diseases & Gerontopsychiatry, University Hospital Bonn, Germany
| | - Bernd Neumaier
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute of Radiochemistry and Experimental Molecular Imaging, Cologne, Germany; Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen-Straße, Jülich 52428, Germany.
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn-Cologne, Germany; Department Neurodegenerative Diseases & Gerontopsychiatry, University Hospital Bonn, Germany
| | - Alexander Drzezga
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Nuclear Medicine, Cologne, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn-Cologne, Germany; Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Molecular Organization of the Brain (INM-2), Wilhelm-Johnen-Straße, Jülich 52428, Germany
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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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Jin SO, Mérida I, Stavropoulos I, Elwes RDC, Lam T, Guedj E, Girard N, Costes N, Hammers A. Characterisation of a novel [ 18F]FDG brain PET database and combination with a second database for optimising detection of focal abnormalities, using focal cortical dysplasia as an example. EJNMMI Res 2023; 13:98. [PMID: 37964137 PMCID: PMC10645721 DOI: 10.1186/s13550-023-01023-z] [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: 03/10/2023] [Accepted: 07/26/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Brain [18F]FDG PET is used clinically mainly in the presurgical evaluation for epilepsy surgery and in the differential diagnosis of neurodegenerative disorders. While scans are usually interpreted visually on an individual basis, comparison against normative cohorts allows statistical assessment of abnormalities and potentially higher sensitivity for detecting abnormalities. Little work has been done on out-of-sample databases (acquired differently to the patient data). Combination of different databases would potentially allow better power and discrimination. We fully characterised an unpublished healthy control brain [18F]FDG PET database (Marseille, n = 60, ages 21-78 years) and compared it to another publicly available database (MRXFDG, n = 37, ages 23-65 years). We measured and then harmonised spatial resolution and global values. A collection of patient scans (n = 34, 13-48 years) with histologically confirmed focal cortical dysplasias (FCDs) obtained on three generations of scanners was used to estimate abnormality detection rates using standard software (statistical parametric mapping, SPM12). RESULTS Regional SUVs showed similar patterns, but global values and resolutions were different as expected. Detection rates for the FCDs were 50% for comparison with the Marseille database and 53% for MRXFDG. Simply combining both databases worsened the detection rate to 41%. After harmonisation of spatial resolution, using a full factorial design matrix to accommodate global differences, and leaving out controls older than 60 years, we achieved detection rates of up to 71% for both databases combined. Detection rates were similar across the three scanner types used for patients, and high for patients whose MRI had been normal (n = 10/11). CONCLUSIONS As expected, global and regional data characteristics are database specific. However, our work shows the value of increasing database size and suggests ways in which database differences can be overcome. This may inform analysis via traditional statistics or machine learning, and clinical implementation.
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Affiliation(s)
- Sameer Omer Jin
- Faculty of Life Sciences and Medicine, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- King's College London & Guy's and St Thomas' PET Centre, London, UK
| | - Inés Mérida
- Centre d'Etude et de Recherche Multimodale et Pluridisciplinaire en Imagerie du Vivant (CERMEP), Lyon, France
| | - Ioannis Stavropoulos
- Department of Clinical Neurophysiology, King's College Hospital, London, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Robert D C Elwes
- Department of Clinical Neurophysiology, King's College Hospital, London, UK
| | - Tanya Lam
- Children's Neuroscience Centre, Evelina London Children's Hospital, Guy's and St Thomas' NHS Trust, London, UK
| | - Eric Guedj
- Nuclear Medicine Department, APHM, CNRS, Centrale Marseille, Institut Fresnel, Timone Hospital, CERIMED, Aix Marseille University, Marseille, France
| | - Nadine Girard
- Department of Neuroradiology, APHM, CRMBM, UMR CNRS 7339, Timone Hospital, Aix Marseille University, Marseille, France
| | - Nicolas Costes
- Centre d'Etude et de Recherche Multimodale et Pluridisciplinaire en Imagerie du Vivant (CERMEP), Lyon, France
| | - Alexander Hammers
- Faculty of Life Sciences and Medicine, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
- King's College London & Guy's and St Thomas' PET Centre, London, UK.
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Van Cauwenberge MGA, Delva A, Vande Casteele T, Laroy M, Radwan A, Vansteelandt K, Van den Stock J, Bouckaert F, Van Laere K, Emsell L, Vandenberghe W, Vandenbulcke M. Mild Motor Signs in Healthy Aging Are Associated with Lower Synaptic Density in the Brain. Mov Disord 2023; 38:1786-1794. [PMID: 37574924 DOI: 10.1002/mds.29570] [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: 04/18/2023] [Revised: 06/17/2023] [Accepted: 07/17/2023] [Indexed: 08/15/2023] Open
Abstract
OBJECTIVE To investigate whether mild motor signs (MMS) in old age correlate with synaptic density in the brain. BACKGROUND Normal aging is associated with a decline in movement quality and quantity, commonly termed "mild parkinsonian signs" or more recently MMS. Whether MMS stem from global brain aging or pathology within motor circuits remains unresolved. The synaptic vesicle glycoprotein 2A positron emission tomography (PET) ligand 11 C-UCB-J allows the investigation of brain-motor associations at the synaptic level in vivo. METHOD Fifty-eight healthy older adults (≥50 years) were included from two monocentric control cohorts. Brain magnetic resonance imaging and 11 C-UCB-J PET data were available in 54 participants. 11 C-UCB-J PET binding was quantified by standardized uptake value ratio (SUVR) values in grey matter (GM) volumes of interest (VOIs): caudate, putamen, globus pallidus, substantia nigra, thalamus, cerebellum, and the frontal, parietal, temporal, and occipital cortex. Multiple linear regression analyses were performed with Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III score measuring MMS as the dependent variable and mean SUVR values in each VOI as the independent variable with age, Fazekas score (white matter lesion [WML] load), VOI and cohort as covariates. RESULTS Participants (68 ± 7.5 years; 52% female) had an average MDS-UPDRS part III score of 3.3 ± 2.8. The MDS-UPDRS part III score was inversely associated with synaptic density, independently of WML load or GM volume, in the caudate, substantia nigra, thalamus, cerebellum, and parietal, occipital, temporal cortex. Cohen's f2 showed moderate effect sizes for subcortical (range, 0.30-0.35), cortical (0.28-0.35) and cerebellar VOIs (0.31). CONCLUSION MMS in healthy aging are associated with lower synaptic density throughout the brain. © 2023 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Margot G A Van Cauwenberge
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Aline Delva
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
- Department of Neurosciences, Laboratory for Parkinson Research, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Thomas Vande Casteele
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Geriatric Psychiatry, University Psychiatric Center KU Leuven, Leuven, Belgium
| | - Maarten Laroy
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Ahmed Radwan
- Department of Imaging and Pathology, Translational MRI, KU Leuven, Leuven, Belgium
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Kristof Vansteelandt
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Jan Van den Stock
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Geriatric Psychiatry, University Psychiatric Center KU Leuven, Leuven, Belgium
| | - Filip Bouckaert
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Geriatric Psychiatry, University Psychiatric Center KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
- Department of Imaging and Pathology, Nuclear Medicine and Molecular Imaging, KU Leuven, Leuven, Belgium
| | - Louise Emsell
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Geriatric Psychiatry, University Psychiatric Center KU Leuven, Leuven, Belgium
- Department of Imaging and Pathology, Translational MRI, KU Leuven, Leuven, Belgium
| | - Wim Vandenberghe
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
- Department of Neurosciences, Laboratory for Parkinson Research, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Mathieu Vandenbulcke
- Department of Neurosciences, Neuropsychiatry, Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Geriatric Psychiatry, University Psychiatric Center 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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8
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Xiong M, Roshanbin S, Sehlin D, Hansen HD, Knudsen GM, Rokka J, Eriksson J, Syvänen S. Synaptic density in aging mice measured by [ 18F]SynVesT-1 PET. Neuroimage 2023:120230. [PMID: 37355199 DOI: 10.1016/j.neuroimage.2023.120230] [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: 12/03/2022] [Revised: 05/03/2023] [Accepted: 06/14/2023] [Indexed: 06/26/2023] Open
Abstract
Synaptic alterations in certain brain structures are related to cognitive decline in neurodegeneration and in aging. Synaptic loss in many neurodegenerative diseases can be visualized by positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A). However, the use of SV2A PET for studying synaptic changes during aging is not particularly explored. Thus, in the present study, PET ligand [18F]SynVesT-1, which binds to SV2A, was used to investigate synaptic density at different ages in healthy mice. Wild type C57BL/6 mice divided into three age groups (4-5 months (n = 7), 12-14 months (n = 11), 17-19 months (n = 7)) were PET scanned with [18F]SynVesT-1. Brain retention of [18F]SynVesT-1 expressed as the volume of distribution (VIDIF) was calculated using an image-derived input function. Estimates of VIDIF were derived using either a one-tissue compartment model (1TCM), a two-tissue compartment model (2TCM), or the Logan plot with blood input to find the best-fit model for [18F]SynVesT-1. After the PET scans, tissue sections were immunostained for the detection of SV2A and neuronal markers. We found that [18F]SynVesT-1 data acquired 60 min post intravenously injection and analyzed with 1TCM described the brain pharmacokinetics of the radioligand in mice well. [18F]SynVesT-1 brain retention was lower in the oldest group of mice, indicating a decrease in synaptic density in this age group. However, no gradual age-dependent decrease in synaptic density at a region-specific level was observed. Immunostaining indicated that SV2A expression and neuron numbers were similar across all three age groups. In general, these data obtained in healthy aging mice are consistent with previous findings in humans where synaptic density appeared stable during aging up to a certain age, after which a small decrease is observed.
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Affiliation(s)
- Mengfei Xiong
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Sahar Roshanbin
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Dag Sehlin
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Hanne D Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Johanna Rokka
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Jonas Eriksson
- PET Centre, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Medicinal Chemistry, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Stina Syvänen
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
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