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Hahn A, Reed MB, Murgaš M, Vraka C, Klug S, Schmidt C, Godbersen GM, Eggerstorfer B, Gomola D, Silberbauer LR, Nics L, Philippe C, Hacker M, Lanzenberger R. Dynamics of human serotonin synthesis differentially link to reward anticipation and feedback. Mol Psychiatry 2024:10.1038/s41380-024-02696-1. [PMID: 39179904 DOI: 10.1038/s41380-024-02696-1] [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: 02/09/2024] [Revised: 07/26/2024] [Accepted: 08/12/2024] [Indexed: 08/26/2024]
Abstract
Serotonin (5-HT) plays an essential role in reward processing, however, the possibilities to investigate 5-HT action in humans during emotional stimulation are particularly limited. Here we demonstrate the feasibility of assessing reward-specific dynamics in 5-HT synthesis using functional PET (fPET), combining its molecular specificity with the high temporal resolution of blood oxygen level dependent (BOLD) fMRI. Sixteen healthy volunteers underwent simultaneous fPET/fMRI with the radioligand [11C]AMT, a substrate for tryptophan hydroxylase. During the scan, participants completed the monetary incentive delay task and arterial blood samples were acquired for quantifying 5-HT synthesis rates. BOLD fMRI was recorded as a proxy of neuronal activation, allowing differentiation of reward anticipation and feedback. Monetary gain and loss resulted in substantial increases in 5-HT synthesis in the ventral striatum (VStr, +21% from baseline) and the anterior insula (+41%). In the VStr, task-specific 5-HT synthesis was further correlated with BOLD signal changes during reward feedback (ρ = -0.65), but not anticipation. Conversely, 5-HT synthesis in the anterior insula correlated with BOLD reward anticipation (ρ = -0.61), but not feedback. In sum, we provide a robust tool to identify task-induced changes in 5-HT action in humans, linking the dynamics of 5-HT synthesis to distinct phases of reward processing in a regionally specific manner. Given the relevance of altered reward processing in psychiatric disorders such as addiction, depression and schizophrenia, our approach offers a tailored assessment of impaired 5-HT signaling during cognitive and emotional processing.
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Affiliation(s)
- Andreas Hahn
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria.
| | - Murray B Reed
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - Matej Murgaš
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - Chrysoula Vraka
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Sebastian Klug
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - Clemens Schmidt
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - Godber M Godbersen
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - Benjamin Eggerstorfer
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - David Gomola
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - Leo R Silberbauer
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria
| | - Lukas Nics
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Cécile Philippe
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria.
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2
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Erritzoe D, Godlewska BR, Rizzo G, Searle GE, Agnorelli C, Lewis Y, Ashok AH, Colasanti A, Boura I, Farrell C, Parfitt H, Howes O, Passchier J, Gunn RN, Politis M, Nutt DJ, Cowen PJ, Knudsen GM, Rabiner EA. Brain Serotonin Release Is Reduced in Patients With Depression: A [ 11C]Cimbi-36 Positron Emission Tomography Study With a d-Amphetamine Challenge. Biol Psychiatry 2022:S0006-3223(22)01704-8. [PMID: 36635177 DOI: 10.1016/j.biopsych.2022.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/03/2022] [Accepted: 10/21/2022] [Indexed: 01/14/2023]
Abstract
BACKGROUND The serotonin hypothesis of depression proposes that diminished serotonergic (5-HT) neurotransmission is causal in the pathophysiology of the disorder. Although the hypothesis is over 50 years old, there is no firm in vivo evidence for diminished 5-HT neurotransmission. We recently demonstrated that the 5-HT2A receptor agonist positron emission tomography (PET) radioligand [11C]Cimbi-36 is sensitive to increases in extracellular 5-HT induced by an acute d-amphetamine challenge. Here we applied [11C]Cimbi-36 PET to compare brain 5-HT release capacity in patients experiencing a major depressive episode (MDE) to that of healthy control subjects (HCs) without depression. METHODS Seventeen antidepressant-free patients with MDE (3 female/14 male, mean age 44 ± 13 years, Hamilton Depression Rating Scale score 21 ± 4 [range 16-30]) and 20 HCs (3 female/17 male, mean age 32 ± 9 years) underwent 90-minute dynamic [11C]Cimbi-36 PET before and 3 hours after a 0.5-mg/kg oral dose of d-amphetamine. Frontal cortex (main region of interest) 5-HT2A receptor nondisplaceable binding was calculated from kinetic analysis using the multilinear analysis-1 approach with the cerebellum as the reference region. RESULTS Following d-amphetamine administration, frontal nondisplaceable binding potential (BPND) was significantly reduced in the HC group (1.04 ± 0.31 vs. 0.87 ± 0.24, p < .001) but not in the MDE group (0.97 ± 0.25 vs. 0.92 ± 0.22, not significant). ΔBPND of the MDE group was significantly lower than that of the HC group (HC: 15% ± 14% vs. MDE: 6.5% ± 20%, p = .041). CONCLUSIONS This first direct assessment of 5-HT release capacity in people with depression provides clear evidence for dysfunctional serotonergic neurotransmission in depression by demonstrating reduced 5-HT release capacity in patients experiencing an MDE.
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Affiliation(s)
- David Erritzoe
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, United Kingdom.
| | - Beata R Godlewska
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | | | | | - Claudio Agnorelli
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, United Kingdom; Department of Molecular Medicine, University of Siena, Siena, Italy
| | | | - Abhishekh H Ashok
- Department of Psychosis Studies, King's College London, London, United Kingdom; Department of Radiology, University of Cambridge & Addenbrooke's Hospital, Cambridge, United Kingdom
| | | | - Iro Boura
- Parkinson Foundation Centre of Excellence, King's College London, London, United Kingdom
| | - Chloe Farrell
- Parkinson Foundation Centre of Excellence, King's College London, London, United Kingdom
| | - Hollie Parfitt
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Oliver Howes
- Department of Psychosis Studies, King's College London, London, United Kingdom
| | | | | | - Marios Politis
- Neurodegeneration Imaging Group, University of Exeter, Exeter, United Kingdom
| | - David J Nutt
- Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Philip J Cowen
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Gitte M Knudsen
- Neurobiology Research Unit, University Hospital Rigshospitalet and Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Eugenii A Rabiner
- Invicro, London, United Kingdom; Department of Neuroimaging, King's College London, London, United Kingdom
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3
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Cervenka S, Frick A, Bodén R, Lubberink M. Application of positron emission tomography in psychiatry-methodological developments and future directions. Transl Psychiatry 2022; 12:248. [PMID: 35701411 PMCID: PMC9198063 DOI: 10.1038/s41398-022-01990-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 05/20/2022] [Accepted: 05/25/2022] [Indexed: 11/09/2022] Open
Abstract
Mental disorders represent an increasing source of disability and high costs for societies globally. Molecular imaging techniques such as positron emission tomography (PET) represent powerful tools with the potential to advance knowledge regarding disease mechanisms, allowing the development of new treatment approaches. Thus far, most PET research on pathophysiology in psychiatric disorders has focused on the monoaminergic neurotransmission systems, and although a series of discoveries have been made, the results have not led to any material changes in clinical practice. We outline areas of methodological development that can address some of the important obstacles to fruitful progress. First, we point towards new radioligands and targets that can lead to the identification of processes upstream, or parallel to disturbances in monoaminergic systems. Second, we describe the development of new methods of PET data quantification and PET systems that may facilitate research in psychiatric populations. Third, we review the application of multimodal imaging that can link molecular imaging data to other aspects of brain function, thus deepening our understanding of disease processes. Fourth, we highlight the need to develop imaging study protocols to include longitudinal and interventional paradigms, as well as frameworks to assess dimensional symptoms such that the field can move beyond cross-sectional studies within current diagnostic boundaries. Particular effort should be paid to include also the most severely ill patients. Finally, we discuss the importance of harmonizing data collection and promoting data sharing to reach the desired sample sizes needed to fully capture the phenotype of psychiatric conditions.
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Affiliation(s)
- Simon Cervenka
- Department of Medical Sciences, Psychiatry, Uppsala University, Uppsala, Sweden. .,Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.
| | - Andreas Frick
- grid.8993.b0000 0004 1936 9457Department of Medical Sciences, Psychiatry, Uppsala University, Uppsala, Sweden
| | - Robert Bodén
- grid.8993.b0000 0004 1936 9457Department of Medical Sciences, Psychiatry, Uppsala University, Uppsala, Sweden
| | - Mark Lubberink
- grid.8993.b0000 0004 1936 9457Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
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4
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Ghosh KK, Padmanabhan P, Yang CT, Ng DCE, Palanivel M, Mishra S, Halldin C, Gulyás B. Positron emission tomographic imaging in drug discovery. Drug Discov Today 2021; 27:280-291. [PMID: 34332093 DOI: 10.1016/j.drudis.2021.07.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/07/2021] [Accepted: 07/23/2021] [Indexed: 01/02/2023]
Abstract
Positron emission tomography (PET) is an extensively used nuclear functional imaging technique, especially for central nervous system (CNS) and oncological disorders. Currently, drug development is a lengthy and costly pursuit. Imaging with PET radiotracers could be an effective way to hasten drug discovery and advancement, because it facilitates the monitoring of key facets, such as receptor occupancy quantification, drug biodistribution, pharmacokinetic (PK) analyses, validation of target engagement, treatment monitoring, and measurement of neurotransmitter concentrations. These parameters demand careful analyses for the robust appraisal of newly formulated drugs during preclinical and clinical trials. In this review, we discuss the usage of PET imaging in radiopharmaceutical development; drug development approaches with PET imaging; and PET developments in oncological and cardiac drug discovery.
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Affiliation(s)
- Krishna Kanta Ghosh
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
| | - Parasuraman Padmanabhan
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore.
| | - Chang-Tong Yang
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Department of Nuclear Medicine and Molecular Imaging, Radiological Sciences Division, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - David Chee Eng Ng
- Department of Nuclear Medicine and Molecular Imaging, Radiological Sciences Division, Singapore General Hospital, Outram Road, Singapore 169608, Singapore; Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Mathangi Palanivel
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
| | - Sachin Mishra
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore
| | - Christer Halldin
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institute and Stockholm County Council, SE-171 76 Stockholm, Sweden
| | - Balázs Gulyás
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore; Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore; Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institute and Stockholm County Council, SE-171 76 Stockholm, Sweden
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5
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Colom M, Vidal B, Fieux S, Redoute J, Costes N, Lavenne F, Mérida I, Irace Z, Iecker T, Bouillot C, Billard T, Newman-Tancredi A, Zimmer L. [ 18F]F13640, a 5-HT 1A Receptor Radiopharmaceutical Sensitive to Brain Serotonin Fluctuations. Front Neurosci 2021; 15:622423. [PMID: 33762906 PMCID: PMC7982540 DOI: 10.3389/fnins.2021.622423] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/17/2021] [Indexed: 12/30/2022] Open
Abstract
Introduction Serotonin is involved in a variety of physiological functions and brain disorders. In this context, efforts have been made to investigate the in vivo fluctuations of this neurotransmitter using positron emission tomography (PET) imaging paradigms. Since serotonin is a full agonist, it binds preferentially to G-protein coupled receptors. In contrast, antagonist PET ligands additionally interact with uncoupled receptors. This could explain the lack of sensitivity to serotonin fluctuations of current 5-HT1A radiopharmaceuticals which are mainly antagonists and suggests that agonist radiotracers would be more appropriate to measure changes in neurotransmitter release. The present study evaluated the sensitivity to endogenous serotonin release of a recently developed, selective 5-HT1A receptor PET radiopharmaceutical, the agonist [18F]F13640 (a.k.a. befiradol or NLX-112). Materials and Methods Four cats each underwent three PET scans with [18F]F13640, i.e., a control PET scan of 90 min, a PET scan preceded 30 min before by an intravenous injection 1 mg/kg of d-fenfluramine, a serotonin releaser (blocking challenge), and a PET scan comprising the intravenous injection of 1 mg/kg of d-fenfluramine 30 min after the radiotracer injection (displacement challenge). Data were analyzed with regions of interest and voxel-based approaches. A lp-ntPET model approach was implemented to determine the dynamic of serotonin release during the challenge study. Results D-fenfluramine pretreatment elicited a massive inhibition of [18F]F13640 labeling in regions known to express 5-HT1A receptors, e.g., raphe nuclei, hippocampus, thalamus, anterior cingulate cortex, caudate putamen, occipital, frontal and parietal cortices, and gray matter of cerebellum. Administration of d-fenfluramine during PET acquisition indicates changes in occupancy from 10% (thalamus) to 31% (gray matter of cerebellum) even though the dissociation rate of [18F]F13640 over the 90 min acquisition time was modest. The lp-ntPET simulation succeeded in differentiating the control and challenge conditions. Conclusion The present findings demonstrate that labeling of 5-HT1A receptors with [18F]F13640 is sensitive to serotonin concentration fluctuations in vivo. Although the data underline the need to perform longer PET scan to ensure accurate measure of displacement, they support clinical development of [18F]F13640 as a tool to explore experimental paradigms involving physiological or pathological (neurological or neuropsychiatric pathologies) fluctuations of extracellular serotonin.
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Affiliation(s)
- Matthieu Colom
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France.,Hospices Civils de Lyon, Lyon, France
| | - Benjamin Vidal
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Sylvain Fieux
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | | | | | | | | | | | | | | | | | | | - Luc Zimmer
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France.,Hospices Civils de Lyon, Lyon, France.,CERMEP-Imagerie du Vivant, Bron, France.,Institut National des Sciences et Techniques Nucléaires, Gif-sur-Yvette, France
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6
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Abstract
Positron emission tomography (PET) is a non-invasive imaging technology employed to describe metabolic, physiological, and biochemical processes in vivo. These include receptor availability, metabolic changes, neurotransmitter release, and alterations of gene expression in the brain. Since the introduction of dedicated small-animal PET systems along with the development of many novel PET imaging probes, the number of PET studies using rats and mice in basic biomedical research tremendously increased over the last decade. This article reviews challenges and advances of quantitative rodent brain imaging to make the readers aware of its physical limitations, as well as to inspire them for its potential applications in preclinical research. In the first section, we briefly discuss the limitations of small-animal PET systems in terms of spatial resolution and sensitivity and point to possible improvements in detector development. In addition, different acquisition and post-processing methods used in rodent PET studies are summarized. We further discuss factors influencing the test-retest variability in small-animal PET studies, e.g., different receptor quantification methodologies which have been mainly translated from human to rodent receptor studies to determine the binding potential and changes of receptor availability and radioligand affinity. We further review different kinetic modeling approaches to obtain quantitative binding data in rodents and PET studies focusing on the quantification of endogenous neurotransmitter release using pharmacological interventions. While several studies have focused on the dopamine system due to the availability of several PET tracers which are sensitive to dopamine release, other neurotransmitter systems have become more and more into focus and are described in this review, as well. We further provide an overview of latest genome engineering technologies, including the CRISPR/Cas9 and DREADD systems that may advance our understanding of brain disorders and function and how imaging has been successfully applied to animal models of human brain disorders. Finally, we review the strengths and opportunities of simultaneous PET/magnetic resonance imaging systems to study drug-receptor interactions and challenges for the translation of PET results from bench to bedside.
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7
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Hansen HD, Lindberg U, Ozenne B, Fisher PM, Johansen A, Svarer C, Keller SH, Hansen AE, Knudsen GM. Visual stimuli induce serotonin release in occipital cortex: A simultaneous positron emission tomography/magnetic resonance imaging study. Hum Brain Mapp 2020; 41:4753-4763. [PMID: 32813903 PMCID: PMC7555083 DOI: 10.1002/hbm.25156] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 06/25/2020] [Accepted: 07/21/2020] [Indexed: 12/27/2022] Open
Abstract
Endogenous serotonin (5-HT) release can be measured noninvasively using positron emission tomography (PET) imaging in combination with certain serotonergic radiotracers. This allows us to investigate effects of pharmacological and nonpharmacological interventions on brain 5-HT levels in living humans. Here, we study the neural responses to a visual stimulus using simultaneous PET/MRI. In a cross-over design, 11 healthy individuals were PET/MRI scanned with the 5-HT1B receptor radioligand [11 C]AZ10419369, which is sensitive to changes in endogenous 5-HT. During the last part of the scan, participants either viewed autobiographical images with positive valence (n = 11) or kept their eyes closed (n = 7). The visual stimuli increased cerebral blood flow (CBF) in the occipital cortex, as measured with pseudo-continuous arterial spin labeling. Simultaneously, we found decreased 5-HT1B receptor binding in the occipital cortex (-3.6 ± 3.6%), indicating synaptic 5-HT release. Using a linear regression model, we found that the change in 5-HT1B receptor binding was significantly negatively associated with change in CBF in the occipital cortex (p = .004). For the first time, we here demonstrate how cerebral 5-HT levels change in response to nonpharmacological stimuli in humans, as measured with PET. Our findings more directly support a link between 5-HT signaling and visual processing and/or visual attention.
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Affiliation(s)
- Hanne Demant Hansen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Massachusetts, Massachusetts
| | - Ulrich Lindberg
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Brice Ozenne
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Public Health, Section of Biostatistics, University of Copenhagen, Copenhagen K, Denmark
| | - Patrick MacDonald Fisher
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Annette Johansen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus Svarer
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Sune Høgild Keller
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Adam Espe Hansen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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8
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Baldassarri SR, Park E, Finnema SJ, Planeta B, Nabulsi N, Najafzadeh S, Ropchan J, Huang Y, Hannestad J, Maloney K, Bhagwagar Z, Carson RE. Inverse changes in raphe and cortical 5-HT 1B receptor availability after acute tryptophan depletion in healthy human subjects. Synapse 2020; 74:e22159. [PMID: 32324935 DOI: 10.1002/syn.22159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/08/2020] [Accepted: 04/19/2020] [Indexed: 11/07/2022]
Abstract
Serotonergic neurotransmission plays a key role in the pathophysiology and treatment of various neuropsychiatric diseases. The purpose of this study was to investigate changes in serotonergic neurotransmission after acute tryptophan depletion (ATD) using positron emission tomography (PET) with [11 C]P943, a 5-HT1B receptor radioligand previously shown to be sensitive to changes in 5-HT. Five healthy subjects were scanned on a high resolution PET scanner twice on the same day, before and approximately 5 hours after ingesting capsules containing an amino acid mixture that lacks tryptophan. For each scan, emission data were acquired for 120 min after intravenous bolus injection of [11 C]P943. Binding potential (BPND ) values were estimated from parametric images using the second version of the multilinear reference tissue model (MRTM2, t* = 20 min) with cerebellar grey matter used as a reference region. The change in [11 C]P943 binding (ΔBPND , %) was calculated as (BPND,post - BPND,pre )/(BPND,pre ) × 100, and correlation analysis was performed to measure linear associations of ΔBPND between raphe and other regions of interest (ROIs). ΔBPND ranged from -6% to 45% in the raphe, with positive values indicating reduced competition from 5-HT. In cortical regions, ΔBPND ranged from -28% to 7%. While these changes did not reach significance, there were significant negative correlations of ΔBPND of the raphe with those of cerebral cortical regions and the thalamus (e.g., r = -.96, p = .011 for average cortex). These findings support the hypothesis that raphe serotonin is a critical modulator of cortical serotonin release via projecting neurons in healthy human subjects.
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Affiliation(s)
- Stephen R Baldassarri
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Eunkyung Park
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA.,Division of Nuclear Medicine, Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Sjoerd J Finnema
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA
| | - Beata Planeta
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA
| | - Soheila Najafzadeh
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA
| | - Jonas Hannestad
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Kathleen Maloney
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Zubin Bhagwagar
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, PET Center, Yale School of Medicine, New Haven, CT, USA
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Serotonin release measured in the human brain: a PET study with [ 11C]CIMBI-36 and d-amphetamine challenge. Neuropsychopharmacology 2020; 45:804-810. [PMID: 31715617 PMCID: PMC7075951 DOI: 10.1038/s41386-019-0567-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/25/2019] [Accepted: 10/17/2019] [Indexed: 12/25/2022]
Abstract
Positron emission tomography (PET) enables non-invasive estimation of neurotransmitter fluctuations in the living human brain. While these methods have been applied to dopamine and some other transmitters, estimation of 5-hydroxytryptamine (5-HT; Serotonin) release has proved to be challenging. Here we demonstrate the utility of the novel 5-HT2A receptor agonist radioligand, [11C]CIMBI-36, and a d-amphetamine challenge to evaluate synaptic 5-HT changes in the living human brain. Seventeen healthy male volunteers received [11C]CIMBI-36 PET scans before and 3 h after an oral dose of d-amphetamine (0.5 mg/kg). Dynamic PET data were acquired over 90 min, and the total volume of distribution (VT) in the frontal cortex and the cerebellum derived from a kinetic analysis using MA1. The frontal cortex binding potential (BPNDfrontal) was calculated as (VTfrontal/VTcerebellum) - 1. ∆BPNDfrontal = 1 - (BPNDfrontal post-dose/BPNDfrontal baseline) was used as an index of 5-HT release. Statistical inference was tested by means of a paired Students t-test evaluating a reduction in post-amphetamine [11C]CIMBI-36 BPNDfrontal. Following d-amphetamine administration, [11C]CIMBI-36 BPNDfrontal was reduced by 14 ± 13% (p = 0.002). Similar effects were observed in other cortical regions examined in an exploratory analysis. [11C]CIMBI-36 binding is sensitive to synaptic serotonin release in the human brain, and when combined with a d-amphetamine challenge, the evaluation of the human brain serotonin system in neuropsychiatric disorders, such as major depression and Parkinson's disease is enabled.
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McCluskey SP, Plisson C, Rabiner EA, Howes O. Advances in CNS PET: the state-of-the-art for new imaging targets for pathophysiology and drug development. Eur J Nucl Med Mol Imaging 2020; 47:451-489. [PMID: 31541283 PMCID: PMC6974496 DOI: 10.1007/s00259-019-04488-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/15/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE A limit on developing new treatments for a number of central nervous system (CNS) disorders has been the inadequate understanding of the in vivo pathophysiology underlying neurological and psychiatric disorders and the lack of in vivo tools to determine brain penetrance, target engagement, and relevant molecular activity of novel drugs. Molecular neuroimaging provides the tools to address this. This article aims to provide a state-of-the-art review of new PET tracers for CNS targets, focusing on developments in the last 5 years for targets recently available for in-human imaging. METHODS We provide an overview of the criteria used to evaluate PET tracers. We then used the National Institute of Mental Health Research Priorities list to identify the key CNS targets. We conducted a PubMed search (search period 1st of January 2013 to 31st of December 2018), which yielded 40 new PET tracers across 16 CNS targets which met our selectivity criteria. For each tracer, we summarised the evidence of its properties and potential for use in studies of CNS pathophysiology and drug evaluation, including its target selectivity and affinity, inter and intra-subject variability, and pharmacokinetic parameters. We also consider its potential limitations and missing characterisation data, but not specific applications in drug development. Where multiple tracers were present for a target, we provide a comparison of their properties. RESULTS AND CONCLUSIONS Our review shows that multiple new tracers have been developed for proteinopathy targets, particularly tau, as well as the purinoceptor P2X7, phosphodiesterase enzyme PDE10A, and synaptic vesicle glycoprotein 2A (SV2A), amongst others. Some of the most promising of these include 18F-MK-6240 for tau imaging, 11C-UCB-J for imaging SV2A, 11C-CURB and 11C-MK-3168 for characterisation of fatty acid amide hydrolase, 18F-FIMX for metabotropic glutamate receptor 1, and 18F-MNI-444 for imaging adenosine 2A. Our review also identifies recurrent issues within the field. Many of the tracers discussed lack in vivo blocking data, reducing confidence in selectivity. Additionally, late-stage identification of substantial off-target sites for multiple tracers highlights incomplete pre-clinical characterisation prior to translation, as well as human disease state studies carried out without confirmation of test-retest reproducibility.
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Affiliation(s)
- Stuart P McCluskey
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK.
| | - Christophe Plisson
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Eugenii A Rabiner
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Oliver Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK
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Yang KC, Stepanov V, Amini N, Martinsson S, Takano A, Bundgaard C, Bang-Andersen B, Sanchez C, Halldin C, Farde L, Finnema SJ. Effect of clinically relevant doses of vortioxetine and citalopram on serotonergic PET markers in the nonhuman primate brain. Neuropsychopharmacology 2019; 44:1706-1713. [PMID: 31216565 PMCID: PMC6784989 DOI: 10.1038/s41386-019-0442-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/04/2019] [Accepted: 06/11/2019] [Indexed: 12/18/2022]
Abstract
Vortioxetine is a multimodal antidepressant approved for treatment of major depressive disorder. Preclinical studies have demonstrated that the mechanism of action of vortioxetine might be different from selective serotonin reuptake inhibitors (SSRIs), including larger serotonin (5-HT) release and direct modulation of several 5-HT receptors. In the current positron emission tomography (PET) study, we evaluated the mechanism of action of vortioxetine by comparing its effect to the SSRI citalopram on the binding of [11C]AZ10419369 to the 5-HT1B receptor in the nonhuman primate brain. Initially, the 5-HT transporter (5-HTT) binding of vortioxetine was determined by [11C]MADAM PET measurements before and after administration of vortioxetine (0.1-3.0 mg/kg) and data were used to confirm clinically relevant dosing in subsequent PET measurements with [11C]AZ10419369. The 5-HT1B receptor binding was significantly decreased after 0.3 mg/kg of citalopram in the dorsal raphe nucleus (5%), as well as after 0.3 mg/kg of vortioxetine in six brain regions (~25%) or 1.0 mg/kg of vortioxetine in all 12 examined regions (~48%). Moreover, there was no effect of 1.0 mg/kg of vortioxetine on the binding of [11C]Cimbi-36 to the 5-HT2A receptor, which has comparable sensitivity to 5-HT release as [11C]AZ10419369 binding. In conclusion, at clinically relevant doses, vortioxetine induced larger reductions in [11C]AZ10419369 binding than citalopram. These observations suggest that vortioxetine binds to the 5-HT1B receptor at clinically relevant doses. Future studies are warranted to evaluate the role of the 5-HT1B receptor in the therapeutic effects of vortioxetine and as a potential target for the development of novel antidepressant drugs.
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Affiliation(s)
- Kai-Chun Yang
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.
| | - Vladimir Stepanov
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Nahid Amini
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Stefan Martinsson
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Akihiro Takano
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | | | | | | | - Christer Halldin
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Lars Farde
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden ,0000 0004 1937 0626grid.4714.6Personalized Health Care and Biomarkers, AstraZeneca PET Science Center at Karolinska Institutet, Stockholm, Sweden
| | - Sjoerd J. Finnema
- 0000 0004 1937 0626grid.4714.6Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden ,0000000419368710grid.47100.32Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT USA
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Liu Z, Zeng Z, Wu C, Liu H. Tropisetron inhibits sepsis by repressing hyper-inflammation and regulating the cardiac action potential in rat models. Biomed Pharmacother 2019; 110:380-388. [PMID: 30529771 DOI: 10.1016/j.biopha.2018.11.142] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/22/2018] [Accepted: 11/28/2018] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE The objective of the present investigation was to explore the possible effect of the 5-HT3 receptor antagonist tropisetron on the expression levels of the inflammatory factors interleukin 6 (IL-6), creatine kinase isoenzyme (CK-MB), soluble growth stimulating gene 2 protein (sST2) and immunoglobulin E (IgE), as well as the cardiac action potential in septic rats. METHODS The cecal ligation and perforation (CLP) method was utilized to construct abdominal infarction in rats. A total of 68 male adult Sprague Dawley rats were used, including 40 for assessing survival and 28 for detecting the expression levels of IL-6 and IgE, myocardial injury, cardiac dysfunction and the cardiac action potential. These 28 rats were divided into the sham (6 rats), sham + Tropisetron (6 rats), CLP (8 rats) and CLP + Tropisetron (8 rats) groups. Twenty-four hours after establishment of the sepsis rat model, immunohistochemistry was used to analyze 5-HT3 receptor protein expression, and enzyme-linked immunosorbent assay (ELISA) was employed to monitor the serum levels of IL-6, CKMB, sST2 and IgE. Furthermore, the structure of the myocardium in various groups was examined by H&E staining. RESULTS The levels of IL-6, CK-MB, sST2 and IgE in the sepsis group were significantly higher than those of the sham group (P < 0.01). Furthermore, the heart rate in the sepsis group was lower than that of the sham group (P < 0.01), and the time of atrial ventricular action potential in the sepsis group was longer than that of the sham group (P < 0.05). In addition, immunohistochemical analyses showed that the area, intensity and index of 5-HT3 receptor in the sepsis group were significantly lower than those of the sham group (P < 0.01). Importantly, the 5-HT3 receptor antagonist Tropisetron exhibited significant inhibitory effects IL-6, CK-MB, sST2 and IgE expression levels, and inductive effects on atrial ventricular action potential in the sepsis group. CONCLUSIONS Sepsis leads to systemic inflammatory reaction, resulting in myocardial injury, structural changes and immune imbalance. The inhibitory effect of tropisetron on inflammation, and the regulatory inflammatory disorder by the efferent vagus nerve may be one of the important mechanisms leading to cardiac electrophysiological changes in sepsis.
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Affiliation(s)
- Zhengjiang Liu
- Department of Cardiology, the Six Affiliated Hospital of Guangzhou Medical University/ Qingyuan People's Hospital, Qingyuan 511500, China.
| | - Zhiheng Zeng
- Department of Cardiology, the First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, China
| | - Changdong Wu
- NO.1 Deppartment of ICU, the People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi 830000, China
| | - Hua Liu
- Department of Cardiology, the Six Affiliated Hospital of Guangzhou Medical University/ Qingyuan People's Hospital, Qingyuan 511500, China
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