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Fu H, Rong J, Chen Z, Zhou J, Collier T, Liang SH. Positron Emission Tomography (PET) Imaging Tracers for Serotonin Receptors. J Med Chem 2022; 65:10755-10808. [PMID: 35939391 DOI: 10.1021/acs.jmedchem.2c00633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) and 5-HT receptors (5-HTRs) have crucial roles in various neuropsychiatric disorders and neurodegenerative diseases, making them attractive diagnostic and therapeutic targets. Positron emission tomography (PET) is a noninvasive nuclear molecular imaging technique and is an essential tool in clinical diagnosis and drug discovery. In this context, numerous PET ligands have been developed for "visualizing" 5-HTRs in the brain and translated into human use to study disease mechanisms and/or support drug development. Herein, we present a comprehensive repertoire of 5-HTR PET ligands by focusing on their chemotypes and performance in PET imaging studies. Furthermore, this Perspective summarizes recent 5-HTR-focused drug discovery, including biased agonists and allosteric modulators, which would stimulate the development of more potent and subtype-selective 5-HTR PET ligands and thus further our understanding of 5-HTR biology.
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Affiliation(s)
- Hualong Fu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jian Rong
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Zhen Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Thomas Collier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
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Spies M, Nasser A, Ozenne B, Jensen PS, Knudsen GM, Fisher PM. Common HTR2A variants and 5-HTTLPR are not associated with human in vivo serotonin 2A receptor levels. Hum Brain Mapp 2020; 41:4518-4528. [PMID: 32697408 PMCID: PMC7555071 DOI: 10.1002/hbm.25138] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 05/08/2020] [Accepted: 06/16/2020] [Indexed: 12/22/2022] Open
Abstract
The serotonin 2A receptor (5‐HT2AR) is implicated in the pathophysiology and treatment of various psychiatric disorders. [18F]altanserin and [11C]Cimbi‐36 positron emission tomography (PET) allow for high‐resolution imaging of 5‐HT2AR in the living human brain. Cerebral 5‐HT2AR binding is strongly genetically determined, though the impact of specific variants is poorly understood. Candidate gene studies suggest that HTR2A single nucleotide polymorphisms including rs6311/rs6313, rs6314, and rs7997012 may influence risk for psychiatric disorders and mediate treatment response. Although known to impact in vitro expression of 5‐HT2AR or other serotonin (5‐HT) proteins, their effect on human in vivo brain 5‐HT2AR binding has as of yet been insufficiently studied. We thus assessed the extent to which these variants and the commonly studied 5‐HTTLPR predict neocortex in vivo 5‐HT2AR binding in healthy adult humans. We used linear regression analyses and likelihood ratio tests in 197 subjects scanned with [18F]altanserin or [11C]Cimbi‐36 PET. Although we observed genotype group differences in 5‐HT2AR binding of up to ~10%, no genetic variants were statistically significantly predictive of 5‐HT2AR binding in what is the largest human in vivo 5‐HT2AR imaging genetics study to date. Thus, in vitro and post mortem results suggesting effects on 5‐HT2AR expression did not carry over to the in vivo setting. To any extent these variants might affect clinical risk, our findings do not support that 5‐HT2AR binding mediates such effects. Our observations indicate that these individual variants do not significantly contribute to genetic load on human in vivo 5‐HT2AR binding.
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Affiliation(s)
- Marie Spies
- Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.,Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Arafat Nasser
- Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - Brice Ozenne
- Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.,Department of Public Health, Section of Biostatistics, University of Copenhagen, Copenhagen, Denmark
| | - Peter S Jensen
- Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark
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Reduced serotonin receptors and transporters in normal aging adults: a meta-analysis of PET and SPECT imaging studies. Neurobiol Aging 2019; 80:1-10. [PMID: 31055162 DOI: 10.1016/j.neurobiolaging.2019.03.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 03/18/2019] [Accepted: 03/31/2019] [Indexed: 12/31/2022]
Abstract
Alterations in serotonin (5-HT) function have been hypothesized to underlie a range of physiological, emotional, and cognitive changes in older age. Here, we conducted a quantitative synthesis and comparison of the effects of age on 5-HT receptors and transporters from cross-sectional positron emission tomography and single-photon emission computed tomography imaging studies. Random-effects meta-analyses of 31 studies including 1087 healthy adults yielded large negative effects of age in 5-HT-2A receptors (largest in global cortex), moderate negative effects of age in 5-HT transporters (largest in thalamus), and small negative effects of age in 5-HT-1A receptors (largest in parietal cortex). Presynaptic 5-HT-1A autoreceptors in raphe/midbrain, however, were preserved across adulthood. Adult age differences were significantly larger in 5-HT-2A receptors compared with 5-HT-1A receptors. A meta-regression showed that 5-HT target, radionuclide, and publication year significantly moderated the age effects. The findings overall identify reduced serotonergic signal transmission in healthy aging. The evidence for the relative preservation of 5-HT-1A compared with 5-HT-2A receptors may partially explain psychological age differences, such as why older adults use more emotion-focused rather than problem-focused coping strategies.
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Zhang R, Bi Y, Niu W, Huang X, Chen S, Li X, Wu X, Cao Y, Yang F, Wang L, Li W, Xu Y, He L, Yu T, He G. Association study of 5-HT1A, 5-HT2A polymorphisms with schizophrenia and major depressive disorder in the Han Chinese population. Neurosci Lett 2016; 635:39-43. [PMID: 27756686 DOI: 10.1016/j.neulet.2016.10.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 10/03/2016] [Accepted: 10/11/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Rui Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Yan Bi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Weibo Niu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Xiaoye Huang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Shiqing Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Xingwang Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Xi Wu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Yanfei Cao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Fengping Yang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Lu Wang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Weidong Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Yifeng Xu
- Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Lin He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China
| | - Tao Yu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China.
| | - Guang He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China; Shanghai Key Laboratory of Psychiatric Disorders, Shanghai Mental Health Center, 600 South Wan Ping Road, Shanghai 200030, China.
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Rong Y, Vernaleken I, Winz OH, Goedicke A, Mottaghy FM, Kops ER. Simulation-based partial volume correction for dopaminergic PET imaging: Impact of segmentation accuracy. Z Med Phys 2014; 25:230-42. [PMID: 25172832 DOI: 10.1016/j.zemedi.2014.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 08/05/2014] [Accepted: 08/05/2014] [Indexed: 11/16/2022]
Abstract
AIM Partial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in (18)F-FDOPA brain-PET, with a special focus on the accuracy degradation introduced by various MR-based segmentation approaches. METHODS Four PVC algorithms (M-PVC; MG-PVC; mMG-PVC; and R-PVC) were analyzed on simulated (18)F-FDOPA brain-PET images. MR image segmentation was carried out using FSL (FMRIB Software Library) and SPM (Statistical Parametric Mapping) packages, including additional adaptation for subcortical regions (SPML). Different PVC and segmentation combinations were compared with respect to deviations in regional activity values and time-activity curves (TACs) of the occipital cortex (OCC), caudate nucleus (CN), and putamen (PUT). Additionally, the PVC impact on the determination of the influx constant (Ki) was assessed. RESULTS Main differences between tissue-maps returned by three segmentation algorithms were found in the subcortical region, especially at PUT. Average misclassification errors in combination with volume reduction was found to be lowest for SPML (PUT < 30%) and highest for FSL (PUT > 70%). Accurate recovery of activity data at OCC is achieved by M-PVC (apparent recovery coefficient varies between 0.99 and 1.10). The other three evaluated PVC algorithms have demonstrated to be more suitable for subcortical regions with MG-PVC and mMG-PVC being less prone to the largest tissue misclassification error simulated in this study. Except for M-PVC, quantification accuracy of Ki for CN and PUT was clearly improved by PVC. CONCLUSIONS The regional activity value of PUT was appreciably overcorrected by most of the PVC approaches employing FSL or SPM segmentation, revealing the importance of accurate MR image segmentation for the presented PVC framework. The selection of a PVC approach should be adapted to the anatomical structure of interest. Caution is recommended in subsequent interpretation of Ki values. The possible different change of activity concentrations due to PVC in both target and reference regions tends to alter the corresponding TACs, introducing bias to Ki determination. The accuracy of quantitative analysis was improved by PVC but at the expense of precision reduction, indicating the potential impropriety of applying the presented framework for group comparison studies.
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Affiliation(s)
- Ye Rong
- Department of Nuclear Medicine, University Hospital Aachen, Aachen, Germany
| | - Ingo Vernaleken
- Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital Aachen, Aachen, Germany
| | - Oliver H Winz
- Department of Nuclear Medicine, University Hospital Aachen, Aachen, Germany
| | - Andreas Goedicke
- Department of Nuclear Medicine, University Hospital Aachen, Aachen, Germany; Philips Research Laboratories, High Tech Campus, Eindhoven, The Netherlands
| | - Felix M Mottaghy
- Department of Nuclear Medicine, University Hospital Aachen, Aachen, Germany; Department of Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Elena Rota Kops
- Institute of Neuroscience and Medicine-4, Forschungszentrum Jülich, Jülich, Germany
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Martín A, Szczupak B, Gómez-Vallejo V, Plaza S, Padró D, Cano A, Llop J. PET imaging of serotoninergic neurotransmission with [(11)C]DASB and [(18)F]altanserin after focal cerebral ischemia in rats. J Cereb Blood Flow Metab 2013; 33:1967-75. [PMID: 23982048 PMCID: PMC3851906 DOI: 10.1038/jcbfm.2013.156] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 08/02/2013] [Accepted: 08/05/2013] [Indexed: 11/09/2022]
Abstract
The use of selective serotonin reuptake inhibitors has shown functional improvement after stroke. Despite this, the role of serotoninergic neurotransmission after cerebral ischemia evolution and its involvement in functional recovery processes are still largely unknown. For this purpose, we performed in parallel in vivo magnetic resonance imaging and positron emission tomography (PET) with [(11)C]DASB and [(18)F]altanserin at 1, 3, 7, 14, 21, and 28 days after middle cerebral artery occlusion (MCAO) in rats. In the ischemic territory, PET with [(11)C]DASB and [(18)F]altanserin showed a dramatic decline in serotonin transporter (SERT) and 5-HT2A binding potential in the cortex and striatum after cerebral ischemia. Interestingly, a slight increase in [(11)C]DASB binding was observed from days 7 to 21 followed by the uppermost binding at day 28 in the ipsilateral midbrain. In contrast, no changes were observed in the contralateral hemisphere by using both radiotracers. Likewise, both functional and behavior testing showed major impaired outcome at day 1 after ischemia onset followed by a recovery of the sensorimotor function and dexterity from day 21 to day 28 after cerebral ischemia. Taken together, these results might evidence that SERT changes in the midbrain could have a key role in the functional recovery process after cerebral ischemia.
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Affiliation(s)
- Abraham Martín
- Molecular Imaging Unit, CIC biomaGUNE, San Sebastian, Spain
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Hornboll B, Macoveanu J, Rowe J, Elliott R, Paulson OB, Siebner HR, Knudsen GM. Acute serotonin 2A receptor blocking alters the processing of fearful faces in the orbitofrontal cortex and amygdala. J Psychopharmacol 2013; 27:903-14. [PMID: 23824248 PMCID: PMC4606977 DOI: 10.1177/0269881113494106] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The serotonin 2A (5-HT2A) receptor has been implicated in neural-processing of emotionally salient information. To elucidate its role in processing of fear and anger, healthy individuals were studied with functional magnetic resonance imaging (fMRI) after 5-HT2A receptor blockade, while judging the gender of neutral, fearful and angry faces. METHODS 5-HT2A receptors were blocked with ketanserin to a variable degree across subjects by adjusting the time between ketanserin-infusion and onset of the fMRI protocol. Neocortical 5-HT2A receptor binding in terms of the binding potential (BPp ) was assessed prior to fMRI with (18)F-altanserin positron emission tomography (PET) and subsequently integrated in the fMRI data analysis. Also functional connectivity analysis was employed to evaluate the effect of ketanserin blocking on connectivity. RESULTS Compared to a control session, 5-HT2A receptor blockade reduced the neural response to fearful faces in the medial orbitofrontal cortex (OFC), independently of 5-HT2A receptor occupancy or neocortical 5-HT2A receptor BPp . The medial OFC also showed increased functional coupling with the left amygdala during processing of fearful faces depending on the amount of blocked 5-HT2A receptors. CONCLUSIONS 5-HT2A receptor mediated signaling increases the sensitivity of the OFC to fearful facial expressions and regulates the strength of a negative feedback signal from the OFC to amygdala during processing of fearful faces.
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Affiliation(s)
- Bettina Hornboll
- Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
,Center for Integrated Molecular Imaging (Cimbi), Copenhagen, Denmark
| | - Julian Macoveanu
- Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
,Center for Integrated Molecular Imaging (Cimbi), Copenhagen, Denmark
| | - James Rowe
- Center for Integrated Molecular Imaging (Cimbi), Copenhagen, Denmark
,Cambridge University Department of Clinical Neurosciences, Cambridge, United Kingdom
| | - Rebecca Elliott
- Neuroscience & Psychiatry Unit, University of Manchester, Manchester, United Kingdom
| | - Olaf B. Paulson
- Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
,Center for Integrated Molecular Imaging (Cimbi), Copenhagen, Denmark
,Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Hartwig R. Siebner
- Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
,Center for Integrated Molecular Imaging (Cimbi), Copenhagen, Denmark
| | - Gitte M. Knudsen
- Center for Integrated Molecular Imaging (Cimbi), Copenhagen, Denmark
,Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
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Macoveanu J, Hornboll B, Elliott R, Erritzoe D, Paulson OB, Siebner H, Knudsen GM, Rowe JB. Serotonin 2A receptors, citalopram and tryptophan-depletion: a multimodal imaging study of their interactions during response inhibition. Neuropsychopharmacology 2013; 38:996-1005. [PMID: 23303045 PMCID: PMC3629389 DOI: 10.1038/npp.2012.264] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Poor behavioral inhibition is a common feature of neurological and psychiatric disorders. Successful inhibition of a prepotent response in 'NoGo' paradigms requires the integrity of both the inferior frontal gyrus (IFG) and the serotonergic system. We investigated individual differences in serotonergic regulation of response inhibition. In 24 healthy adults, we used (18)F-altanserin positron emission tomography to assess cerebral 5-HT2A receptors, which have been related to impulsivity. We then investigated the impact of two acute manipulations of brain serotonin levels on behavioral and neural correlates of inhibition using intravenous citalopram and acute tryptophan depletion during functional magnetic resonance imaging. We adapted the NoGo paradigm to isolate effects on inhibition per se as opposed to other aspects of the NoGo paradigm. Successful NoGo inhibition was associated with greater activation of the right IFG compared to control trials with alternative responses, indicating that the IFG is activated with inhibition in NoGo trials rather than other aspects of invoked cognitive control. Activation of the left IFG during NoGo trials was greater with citalopram than acute tryptophan depletion. Moreover, with the NoGo-type of response inhibition, the right IFG displayed an interaction between the type of serotonergic challenge and neocortical 5-HT2A receptor binding. Specifically, acute tryptophan depletion (ATD) produced a relatively larger NoGo response in the right IFG in subjects with low 5-HT2A BPP but reduced the NoGo response in those with high 5-HT2A BPP. These links between serotonergic function and response inhibition in healthy subjects may help to interpret serotonergic abnormalities underlying impulsivity in neuropsychiatric disorders.
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Affiliation(s)
- Julian Macoveanu
- Danish Research Centre for MR, Copenhagen University Hospital, Hvidovre, Denmark,Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark
| | - Bettina Hornboll
- Danish Research Centre for MR, Copenhagen University Hospital, Hvidovre, Denmark,Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark
| | - Rebecca Elliott
- Neuroscience and Psychiatry Unit, University of Manchester, Manchester, UK
| | - David Erritzoe
- Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark,Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Olaf B Paulson
- Danish Research Centre for MR, Copenhagen University Hospital, Hvidovre, Denmark,Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark,Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Hartwig Siebner
- Danish Research Centre for MR, Copenhagen University Hospital, Hvidovre, Denmark,Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark
| | - Gitte M Knudsen
- Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark,Neurobiology Research Unit, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - James B Rowe
- Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark,Cambridge University Department of Clinical Neurosciences, Cambridge, UK,Cambridge University Department of Clinical Neurosciences, Herchel-Smith Building for Brain and Mind Sciences, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK. Tel: +44 1223 273 630, Fax: +44 1223 359 062, E-mail:
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Elmenhorst D, Kroll T, Matusch A, Bauer A. Sleep deprivation increases cerebral serotonin 2A receptor binding in humans. Sleep 2012. [PMID: 23204604 DOI: 10.5665/sleep.2230] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
STUDY OBJECTIVES Serotonin and its cerebral receptors play an important role in sleep-wake regulation. The aim of the current study is to investigate the effect of 24-h total sleep deprivation on the apparent serotonin 2A receptor (5-HT(2A)R) binding capacity in the human brain to test the hypothesis that sleep deprivation induces global molecular alterations in the cortical serotonergic receptor system. DESIGN Volunteers were tested twice with the subtype-selective radiotracer [(18)F]altanserin and positron emission tomography (PET) for imaging of 5-HT(2A)Rs at baseline and after 24 h of sleep deprivation. [(18)F]Altanserin binding potentials were analyzed in 13 neocortical regions of interest. The efficacy of sleep deprivation was assessed by questionnaires, waking electroencephalography, and cognitive performance measurements. SETTING Sleep laboratory and neuroimaging center. PATIENTS OR PARTICIPANTS Eighteen healthy volunteers. INTERVENTIONS Sleep deprivation. MEASUREMENTS AND RESULTS A total of 24 hours of sleep deprivation led to a 9.6% increase of [(18)F]altanserin binding on neocortical 5-HT(2A) receptors. Significant region-specific increases were found in the medial inferior frontal gyrus, insula, and anterior cingulate, parietal, sensomotoric, and ventrolateral prefrontal cortices. CONCLUSIONS This study demonstrates that a single night of total sleep deprivation causes significant increases of 5-HT(2A)R binding potentials in a variety of cortical regions although the increase declines as sleep deprivation continued. It provides in vivo evidence that total sleep deprivation induces adaptive processes in the serotonergic system of the human brain.
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Affiliation(s)
- David Elmenhorst
- Institute of Neuroscience and Medicine, INM-2, Forschungszentrum Jüulich, Jüulich, Germany.
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Talbot PS, Slifstein M, Hwang DR, Huang Y, Scher E, Abi-Dargham A, Laruelle M. Extended characterisation of the serotonin 2A (5-HT2A) receptor-selective PET radiotracer 11C-MDL100907 in humans: quantitative analysis, test-retest reproducibility, and vulnerability to endogenous 5-HT tone. Neuroimage 2011; 59:271-85. [PMID: 21782029 DOI: 10.1016/j.neuroimage.2011.07.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 06/29/2011] [Accepted: 07/01/2011] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Scanning properties and analytic methodology of the 5-HT2A receptor-selective positron emission tomography (PET) tracer 11C-MDL100907 have been partially characterised in previous reports. We present an extended characterisation in healthy human subjects. METHODS 64 11C-MDL100907 PET scans with metabolite-corrected arterial input function were performed in 39 healthy adults (18-55 years). 12 subjects were scanned twice (duration 150 min) to provide data on plasma analysis, model order estimation, and stability and test-retest characteristics of outcome measures. All other scans were 90 min duration. 3 subjects completed scanning at baseline and following 5-HT2A receptor antagonist medication (risperidone or ciproheptadine) to provide definitive data on the suitability of the cerebellum as reference region. 10 subjects were scanned under reduced 5-HT and control conditions using rapid tryptophan depletion to investigate vulnerability to competition with endogenous 5-HT. 13 subjects were scanned as controls in clinical protocols. Pooled data were used to analyse the relationship between tracer injected mass and receptor occupancy, and age-related decline in 5-HT2A receptors. RESULTS Optimum analytic method was a 2-tissue compartment model with arterial input function. However, basis function implementation of SRTM may be suitable for measuring between-group differences non-invasively and warrants further investigation. Scan duration of 90 min achieved stable outcome measures in all cortical regions except orbitofrontal which required 120 min. Binding potential (BPP and BPND) test-retest variability was very good (7-11%) in neocortical regions other than orbitofrontal, and moderately good (14-20%) in orbitofrontal cortex and medial temporal lobe. Saturation occupancy of 5-HT2A receptors by risperidone validates the use of the cerebellum as a region devoid of specific binding for the purposes of PET. We advocate a mass limit of 4.6 μg to remain below 5% receptor occupancy. 11C-MDL100907 specific binding is not vulnerable to competition with endogenous 5-HT in humans. Paradoxical decreases in BPND were found in right prefrontal cortex following reduced 5-HT, possibly representing receptor internalisation. Mean age-related decline in brain 5-HT2A receptors was 14.0±5.0% per decade, and higher in prefrontal regions. CONCLUSIONS Our data confirm and extend support for 11C-MDL100907 as a PET tracer with very favourable properties for quantifying 5-HT2A receptors in the human brain.
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Affiliation(s)
- Peter S Talbot
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY 10032, USA.
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Paterson LM, Kornum BR, Nutt DJ, Pike VW, Knudsen GM. 5-HT radioligands for human brain imaging with PET and SPECT. Med Res Rev 2011; 33:54-111. [PMID: 21674551 DOI: 10.1002/med.20245] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The serotonergic system plays a key modulatory role in the brain and is the target for many drug treatments for brain disorders either through reuptake blockade or via interactions at the 14 subtypes of 5-HT receptors. This review provides the history and current status of radioligands used for positron emission tomography (PET) and single photon emission computerized tomography (SPECT) imaging of human brain serotonin (5-HT) receptors, the 5-HT transporter (SERT), and 5-HT synthesis rate. Currently available radioligands for in vivo brain imaging of the 5-HT system in humans include antagonists for the 5-HT(1A), 5-HT(1B), 5-HT(2A), and 5-HT(4) receptors, and for SERT. Here we describe the evolution of these radioligands, along with the attempts made to develop radioligands for additional serotonergic targets. We describe the properties needed for a radioligand to become successful and the main caveats. The success of a PET or SPECT radioligand can ultimately be assessed by its frequency of use, its utility in humans, and the number of research sites using it relative to its invention date, and so these aspects are also covered. In conclusion, the development of PET and SPECT radioligands to image serotonergic targets is of high interest, and successful evaluation in humans is leading to invaluable insight into normal and abnormal brain function, emphasizing the need for continued development of both SPECT and PET radioligands for human brain imaging.
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Affiliation(s)
- Louise M Paterson
- Neuropsychopharmacology Unit, Division of Experimental Medicine, Imperial College London, Burlington Danes Building, Du Cane Road, London, United Kingdom
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A nonlinear relationship between cerebral serotonin transporter and 5-HT(2A) receptor binding: an in vivo molecular imaging study in humans. J Neurosci 2010; 30:3391-7. [PMID: 20203198 DOI: 10.1523/jneurosci.2852-09.2010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Serotonergic neurotransmission is involved in the regulation of physiological functions such as mood, sleep, memory, and appetite. Within the serotonin transmitter system, both the postsynaptically located serotonin 2A (5-HT(2A)) receptor and the presynaptic serotonin transporter (SERT) are sensitive to chronic changes in cerebral 5-HT levels. Additionally, experimental studies suggest that alterations in either the 5-HT(2A) receptor or SERT level can affect the protein level of the counterpart. The aim of this study was to explore the covariation between cerebral 5-HT(2A) receptor and SERT in vivo in the same healthy human subjects. Fifty-six healthy human subjects with a mean age of 36 +/- 19 years were investigated. The SERT binding was imaged with [(11)C]3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl)-benzonitrile (DASB) and 5-HT(2A) receptor binding with [(18)F]altanserin using positron emission tomography. Within each individual, a regional intercorrelation for the various brain regions was seen with both markers, most notably for 5-HT(2A) receptor binding. An inverted U-shaped relationship between the 5-HT(2A) receptor and the SERT binding was identified. The observed regional intercorrelation for both the 5-HT(2A) receptor and the SERT cerebral binding suggests that, within the single individual, each marker has a set point adjusted through a common regulator. A quadratic relationship between the two markers is consistent with data from experimental studies of the effect on SERT and 5-HT(2A) receptor binding of chronic changes in 5-HT levels. That is, the observed association between the 5-HT(2A) receptor and SERT binding could be driven by the projection output from the raphe nuclei, but other explanations are also at hand.
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