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Gärde M, Matheson GJ, Varnäs K, Svenningsson P, Hedman-Lagerlöf E, Lundberg J, Farde L, Tiger M. Altered Serotonin 1B Receptor Binding After Escitalopram for Depression Is Correlated With Treatment Effect. Int J Neuropsychopharmacol 2024; 27:pyae021. [PMID: 38695786 PMCID: PMC11119883 DOI: 10.1093/ijnp/pyae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 05/01/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Major depressive disorder (MDD) is commonly treated with selective serotonin reuptake inhibitors (SSRIs). SSRIs inhibit the serotonin transporter (5-HTT), but the downstream antidepressant mechanism of action of these drugs is poorly understood. The serotonin 1B (5-HT1B) receptor is functionally linked to 5-HTT and 5-HT1B receptor binding and 5-HT1B receptor mRNA is reduced in the raphe nuclei after SSRI administration in primates and rodents, respectively. The effect of SSRI treatment on 5-HT1B receptor binding in patients with MDD has not been examined previously. This positron emission tomography (PET) study aimed to quantify brain 5-HT1B receptor binding changes in vivo after SSRI treatment for MDD in relation to treatment effect. METHODS Eight unmedicated patients with moderate to severe MDD underwent PET with the 5-HT1B receptor radioligand [11C]AZ10419369 before and after 3 to 4 weeks of treatment with the SSRI escitalopram 10 mg daily. Depression severity was assessed at time of PET and after 6 to 7 weeks of treatment with the Montgomery-Åsberg Depression Rating Scale. RESULTS We observed a significant reduction in [11C]AZ10419369 binding in a dorsal brainstem (DBS) region containing the median and dorsal raphe nuclei after escitalopram treatment (P = .036). Change in DBS [11C]AZ10419369 binding correlated with Montgomery-Åsberg Depression Rating Scale reduction after 3-4 (r = 0.78, P = .021) and 6-7 (r = 0.94, P < .001) weeks' treatment. CONCLUSIONS Our findings align with the previously reported reduction of 5-HT1B receptor binding in the raphe nuclei after SSRI administration and support future studies testing change in DBS 5-HT1B receptor binding as an SSRI treatment response marker.
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Affiliation(s)
- M Gärde
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - G J Matheson
- Department of Psychiatry, Columbia University, New York, USA
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - K Varnäs
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - P Svenningsson
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - E Hedman-Lagerlöf
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - J Lundberg
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - L Farde
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - M Tiger
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
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2
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Tiger M, Gärde M, Tateno A, Matheson GJ, Sakayori T, Nogami T, Moriya H, Varnäs K, Arakawa R, Okubo Y. A positron emission tomography study of the serotonin1B receptor effect of electroconvulsive therapy for severe major depressive episodes. J Affect Disord 2021; 294:645-651. [PMID: 34332365 DOI: 10.1016/j.jad.2021.07.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 01/17/2023]
Abstract
BACKGROUND Electroconvulsive therapy (ECT) is an effective treatment for depressive disorders, although its molecular mechanism of action is unknown. The serotonin 1B (5-HT1B) receptor is a potential target for treatment of depression and low 5-HT1B receptor binding in limbic regions has been reported in previous positron emission tomography (PET) studies of depression. METHODS The objective of this longitudinal PET study was to examine the effect of ECT for depression on 5-HT1B receptor binding. Fifteen hospitalized patients with major depressive episodes were examined with PET and the 5-HT1B receptor selective radioligand [11C]AZ10419369, before and after ECT. Fifteen controls matched for age and sex were examined. Limbic regions with previously reported low 5-HT1B receptor binding in depression and a dorsal brain stem region were selected. RESULTS Thirteen patients completed the study according to protocol. Eleven out of thirteen patients responded to ECT. 5-HT1B receptor binding in hippocampus increased with 30 % after ECT (p=0.021). Using linear mixed effects modelling, we observed increases in 5-HT1B receptor binding following ECT with a moderate to large effect size, which did not differ significantly between regions. In an exploratory analysis, strong correlations between changes in 5-HT1B receptor binding and agitation scores on the Hamilton Depression Rating Scale after ECT were observed. LIMITATIONS Albeit representative of a PET study, the sample size is still small and there are potential confounding effects of medication. CONCLUSIONS Increased 5-HT1B receptor binding was observed following ECT for depression, corresponding to previous findings of increased 5-HT1B receptor binding in hippocampus after rapid acting ketamine for treatment resistant depression.
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Affiliation(s)
- Mikael Tiger
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Sweden.; Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
| | - Martin Gärde
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Sweden
| | - Amane Tateno
- Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Granville J Matheson
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Sweden
| | - Takeshi Sakayori
- Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Tsuyoshi Nogami
- Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Hiroki Moriya
- Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Katarina Varnäs
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Sweden
| | - Ryosuke Arakawa
- Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Yoshiro Okubo
- Department of Neuropsychiatry, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
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3
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The Modulatory Role of Serotonin on Human Impulsive Aggression. Biol Psychiatry 2021; 90:447-457. [PMID: 34266672 DOI: 10.1016/j.biopsych.2021.05.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/29/2021] [Accepted: 05/16/2021] [Indexed: 12/15/2022]
Abstract
The hypothesis of chronically low brain serotonin levels as pathophysiologically linked to impulsive aggression has been around for several decades. Whereas the theory was initially based on indirect methods to probe serotonin function, our understanding of the neural mechanisms involved in impulsive aggression has progressed with recent advances in neuroimaging. The review integrates evidence based on data from several neuroimaging domains in humans. In vivo molecular neuroimaging findings demonstrate associations between impulsive aggression and high serotonin 1B and serotonin 4 receptor binding, high serotonin transporter levels, and low monoamine oxidase A levels, suggesting that low interstitial serotonin levels are a neurobiological risk factor for impulsive aggressive behavior. Imaging genetics suggests that serotonergic-related genetic polymorphisms associate with antisocial behavior, and some evidence indicates that the low-expressing monoamine oxidase A genotype specifically predisposes to impulsive aggression, which may be mediated by effects on corticolimbic function. Interventions that (presumably) alter serotonin levels have effects on brain activity within brain regions involved in impulsive aggression, notably the amygdala, dorsal striatum, anterior cingulate, insula, and prefrontal cortex. Based on these findings, we propose a model for the modulatory role of serotonin in impulsive aggression. Future studies should ensure that clinical features unique for impulsive aggression are appropriately assessed, and we propose investigations of knowledge gaps that can help confirm, refute, or modify our proposed model of impulsive aggression.
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4
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Jørgensen LM, Henriksen T, Mardosiene S, Keller SH, Stenbæk DS, Hansen HD, Jespersen B, Thomsen C, Weikop P, Svarer C, Knudsen GM. Parkinson patients have a presynaptic serotonergic deficit: A dynamic deep brain stimulation PET study. J Cereb Blood Flow Metab 2021; 41:1954-1963. [PMID: 33461410 PMCID: PMC8327106 DOI: 10.1177/0271678x20982389] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Patients with Parkinson's disease (PD) often suffer from non-motor symptoms, which may be caused by serotonergic dysfunction. Apart from alleviating the motor symptoms, Deep Brain Stimulation (DBS) in the subthalamic nucleus (STN) may also influence non-motor symptoms. The aim of this study is to investigate how turning DBS off affects the serotonergic system. We here exploit a novel functional PET neuroimaging methodology to evaluate the preservation of serotonergic neurons and capacity to release serotonin. We measured cerebral 5-HT1BR binding in 13 DBS-STN treated PD patients, at baseline and after turning DBS off. Ten age-matched volunteers served as controls. Clinical measures of motor symptoms were assessed under the two conditions and correlated to the PET measures of the static and dynamic integrity of the serotonergic system. PD patients exhibited a significant loss of frontal and parietal 5-HT1BR, and the loss was significantly correlated to motor symptom severity. We saw a corresponding release of serotonin, but only in brain regions with preserved 5-HT1BR, suggesting the presence of a presynaptic serotonergic deficit. Our study demonstrates that DBS-STN dynamically regulates the serotonin system in PD, and that preservation of serotonergic functions may be predictive of DBS-STN effects.
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Affiliation(s)
- Louise M Jørgensen
- Neurobiology Research Unit, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Tove Henriksen
- Department of Neurology, Bispebjerg Hospital, Copenhagen, Denmark
| | | | - Sune H Keller
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Dea S Stenbæk
- Neurobiology Research Unit, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Hanne D Hansen
- Neurobiology Research Unit, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Bo Jespersen
- Department of Neurosurgery, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Thomsen
- Department of Radiology, Rigshospitalet, University of Copenhagen, Denmark.,Research Center for Advanced Imaging, Zealand University Hospital, Roskilde, Denmark
| | - Pia Weikop
- Center for Basic and Translational Neuroscience, Nedergaard Laboratory, Division of Glial Disease and Therapeutics, University of Copenhagen, Copenhagen, Denmark
| | - Claus Svarer
- Neurobiology Research Unit, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Department of Neurology, Rigshospitalet, Copenhagen, Denmark.,Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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5
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Lindberg A, Arakawa R, Nogami T, Nag S, Schou M, Elmore CS, Farde L, Pike VW, Halldin C. Potential for imaging the high-affinity state of the 5-HT 1B receptor: a comparison of three PET radioligands with differing intrinsic activity. EJNMMI Res 2019; 9:100. [PMID: 31754940 PMCID: PMC6872687 DOI: 10.1186/s13550-019-0570-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 11/01/2019] [Indexed: 11/19/2022] Open
Abstract
Background Over the last decade, a few radioligands have been developed for PET imaging of brain 5-HT1B receptors. The 5-HT1B receptor is a G-protein-coupled receptor (GPCR) that exists in two different agonist affinity states. An agonist ligand is expected to be more sensitive towards competition from another agonist, such as endogenous 5-HT, than an antagonist ligand. It is of interest to know whether the intrinsic activity of a PET radioligand for the 5-HT1B receptor impacts on its ability to detect changes in endogenous synaptic 5-HT density. Three high-affinity 11C-labeled 5-HT1B PET radioligands with differing intrinsic activity were applied to PET measurements in cynomolgus monkey to evaluate their sensitivity to be displaced within the brain by endogenous 5-HT. For these experiments, fenfluramine was pre-administered at two different doses (1.0 and 5.0 mg/kg, i.v.) to induce synaptic 5-HT release. Results A dose-dependent response to fenfluramine was detected for all three radioligands. At the highest dose of fenfluramine (5.0 mg/kg, i.v.), reductions in specific binding in the occipital cortex increased with radioligand agonist efficacy, reaching 61% for [11C]3. The most antagonistic radioligand showed the lowest reduction in specific binding. Conclusions Three 5-HT1B PET radioligands were identified with differing intrinsic activity that could be used in imaging high- and low-affinity states of 5-HT1B receptors using PET. From this limited study, radioligand sensitivity to endogenous 5-HT appears to depend on agonist efficacy. More extensive studies are required to substantiate this suggestion.
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Affiliation(s)
- Anton Lindberg
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176, Stockholm, Sweden. .,Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892-1003, USA.
| | - Ryosuke Arakawa
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176, Stockholm, Sweden
| | - Tsuyoshi Nogami
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176, Stockholm, Sweden
| | - Sangram Nag
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176, Stockholm, Sweden
| | - Magnus Schou
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176, Stockholm, Sweden.,PET Science Centre, Precision Medicine and Genomics, R&D, AstraZeneca, SE-17176, Stockholm, Sweden
| | - Charles S Elmore
- Isotope Chemistry, Early Chemical Development, Pharmaceutical Sciences R&D, AstraZeneca, SE-43250, Göteborg, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176, Stockholm, Sweden.,PET Science Centre, Precision Medicine and Genomics, R&D, AstraZeneca, SE-17176, Stockholm, Sweden
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892-1003, USA
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176, Stockholm, Sweden
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6
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Lindberg A, Lu S, Nag S, Schou M, Liow JS, Zoghbi SS, Frankland MP, Gladding RL, Morse CL, Takano A, Amini N, Elmore CS, Lee YS, Innis RB, Halldin C, Pike VW. Synthesis and evaluation of two new candidate high-affinity full agonist PET radioligands for imaging 5-HT 1B receptors. Nucl Med Biol 2019; 70:1-13. [PMID: 30811975 DOI: 10.1016/j.nucmedbio.2019.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/17/2019] [Accepted: 01/21/2019] [Indexed: 11/17/2022]
Abstract
INTRODUCTION The serotonin 1B receptor subtype is of interest in the pathophysiology and treatment of depression, anxiety, and migraine. Over recent years 5-HT1B receptor binding in human brain has been examined with PET using radioligands that are partial but not full agonists. To explore how the intrinsic activity of a PET radioligand may affect imaging performance, two high-affinity full 5-HT1B receptor agonists (AZ11136118, 4; and AZ11895987, 5) were selected from a large compound library and radiolabeled for PET examination in non-human primates. METHODS [11C]4 was obtained through Pd(0)-mediated insertion of [11C]carbon monoxide between prepared iodoarene and homochiral amine precursors. [11C]5 was obtained through N-11C-methylation of N-desmethyl precursor 6 with [11C]methyl triflate. [11C]4 and [11C]5 were studied with PET in rhesus or cynomolgus monkey. [11C]4 was studied with PET in mice and rats to measure brain uptake and specific binding. Ex-vivo experiments in rats were performed to identify whether there were radiometabolites in brain. Physiochemical parameters for [11C]4 (pKa, logD and conformational energetics) were evaluated. RESULTS Both [11C]4 and [11C]5 were successfully produced in high radiochemical purity and in adequate amounts for PET experiments. After intravenous injection of [11C]4, brain radioactivity peaked at a low level (0.2 SUV). Pretreatment with tariquidar, an inhibitor of the brain P-gp efflux transporter, increased brain exposure four-fold whereas pretreatment with a high pharmacological dose of the 5-HT1B antagonist, AR-A000002, had no effect on the binding. Ex-vivo experiments in rats showed no radiometabolites entering brain. [11C]5 also failed to enter monkey brain under baseline conditions. CONCLUSIONS [11C]4 and [11C]5 show too low brain uptake and specific binding to be useful PET radioligands. Low brain uptake is partly ascribed to efflux transporter action as well as unfavorable conformations.
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Affiliation(s)
- Anton Lindberg
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden; Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA.
| | - Shuiyu Lu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Sangram Nag
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Magnus Schou
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden; PET Science Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, SE-17176 Stockholm, Sweden
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Michael P Frankland
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Robert L Gladding
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Nahid Amini
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Charles S Elmore
- Isotope Chemistry, Early Chemical Development, Pharmaceutical Sciences, IMED Biotech Unit, AstraZeneca, SE-43250 Göteborg, Sweden
| | - Yong Sok Lee
- Center for Molecular Modeling, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892-5624, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-17176 Stockholm, Sweden
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1003, USA
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7
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Yang KC, Takano A, Halldin C, Farde L, Finnema SJ. Serotonin concentration enhancers at clinically relevant doses reduce [ 11C]AZ10419369 binding to the 5-HT 1B receptors in the nonhuman primate brain. Transl Psychiatry 2018; 8:132. [PMID: 30013068 PMCID: PMC6048172 DOI: 10.1038/s41398-018-0178-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/14/2018] [Accepted: 04/03/2018] [Indexed: 12/25/2022] Open
Abstract
The serotonin (5-HT) system plays an important role in the pathophysiology and treatment of several major psychiatric disorders. Currently, no suitable positron emission tomography (PET) imaging paradigm is available to assess 5-HT release in the living human brain. [11C]AZ10419369 binds to 5-HT1B receptors and is one of the most 5-HT-sensitive radioligands available. This study applied 5-HT concentration enhancers which can be safely studied in humans, and examined their effect on [11C]AZ10419369 binding at clinically relevant doses, including amphetamine (1 mg/kg), 3,4-methylenedioxymethamphetamine (MDMA; 1 mg/kg) or 5-hydroxy-L-tryptophan (5-HTP; 5 mg/kg). Twenty-six PET measurements (14 for amphetamine, 6 for MDMA and 6 for 5-HTP) using a bolus and constant infusion protocol were performed in four cynomolgus monkeys before or after drug administration. Binding potential (BPND) values were determined with the equilibrium method (integral interval: 63-123 min) using cerebellum as the reference region. BPND values were significantly decreased in several examined brain regions after administration of amphetamine (range: 19-31%), MDMA (16-25%) or 5-HTP (13-31%). Reductions in [11C]AZ10419369 binding were greater in striatum than cortical regions after administration of 5-HTP, while no prominent regional differences were found for amphetamine and MDMA. In conclusion, [11C]AZ10419369 binding is sensitive to changes in 5-HT concentration induced by amphetamine, MDMA or 5-HTP. The robust changes in BPND, following pretreatment drugs administered at clinically relevant doses, indicate that the applied PET imaging paradigms hold promise to be successfully used in future human studies.
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Affiliation(s)
- Kai-Chun Yang
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Personalized Health Care and Biomarkers, AstraZeneca PET Science Center at Karolinska Institutet, Stockholm, Sweden
| | - Sjoerd J Finnema
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
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8
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Jørgensen LM, Weikop P, Svarer C, Feng L, Keller SH, Knudsen GM. Cerebral serotonin release correlates with [ 11C]AZ10419369 PET measures of 5-HT 1B receptor binding in the pig brain. J Cereb Blood Flow Metab 2018; 38:1243-1252. [PMID: 28685616 PMCID: PMC6434452 DOI: 10.1177/0271678x17719390] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/26/2017] [Accepted: 05/21/2017] [Indexed: 11/17/2022]
Abstract
Positron emission tomography (PET) can, when used with appropriate radioligands, non-invasively capture temporal and spatial information about acute changes in brain neurotransmitter systems. We here evaluate the 5-HT1B receptor partial agonist PET radioligand, [11C]AZ10419369, for its sensitivity to detect changes in endogenous cerebral serotonin levels, as induced by different pharmacological challenges. To enable a direct translation of PET imaging data to changes in brain serotonin levels, we compared the [11C]AZ10419369 PET signal in the pig brain to simultaneous measurements of extracellular serotonin levels with microdialysis after various acute interventions (saline, escitalopram, fenfluramine). The interventions increased the cerebral extracellular serotonin levels to two to six times baseline, with fenfluramine being the most potent pharmacological enhancer of serotonin release. The interventions induced a varying degree of decline in [11C]AZ10419369 binding in the brain, consistent with the occupancy competition model. The observed correlation between changes in the extracellular serotonin level in the pig brain and the 5-HT1B receptor occupancy indicates that [11C]AZ10419369 binding is sensitive to changes in endogenous serotonin levels to a degree equivalent to that reported of [11C]raclopride to dopamine, a much used approach to detect in vivo change in cerebral dopamine.
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Affiliation(s)
- Louise M Jørgensen
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences,
University of Copenhagen, Copenhagen, Denmark
| | - Pia Weikop
- Department of Neuroscience and
Pharmacology, The Laboratory of Neuropsychiatry, University of Copenhagen,
Copenhagen, Denmark
- Psychiatric Centre Copenhagen,
University of Copenhagen, Copenhagen, Denmark
| | - Claus Svarer
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
| | - Ling Feng
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
| | - Sune H Keller
- Department of Clinical Physiology,
Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen,
Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit,
Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences,
University of Copenhagen, Copenhagen, Denmark
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9
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da Cunha-Bang S, Fisher PM, Hjordt LV, Perfalk E, Beliveau V, Holst K, Knudsen GM. Men with high serotonin 1B receptor binding respond to provocations with heightened amygdala reactivity. Neuroimage 2018; 166:79-85. [DOI: 10.1016/j.neuroimage.2017.10.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/12/2017] [Accepted: 10/16/2017] [Indexed: 10/18/2022] Open
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10
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Lindberg A, Nag S, Schou M, Takano A, Matsumoto J, Amini N, Elmore CS, Farde L, Pike VW, Halldin C. [ 11C]AZ10419096 - a full antagonist PET radioligand for imaging brain 5-HT 1B receptors. Nucl Med Biol 2017; 54:34-40. [PMID: 28950161 DOI: 10.1016/j.nucmedbio.2017.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/05/2017] [Accepted: 07/14/2017] [Indexed: 10/19/2022]
Abstract
INTRODUCTION The serotonergic system is widely present in all regions of the central nervous system (CNS) and plays a key modulatory role in many of its functions. Positron emission tomography (PET) is used to study several serotonin receptors in CNS in vivo. The G-protein coupled receptor 5-HT1B is mostly present in the occipital cortex and in midbrain and is linked to several psychiatric disorders. There is evidence that agonist PET radioligands for neuroreceptors are more sensitive to endogenous neurotransmitters than antagonists. Our previously developed 5-HT1B receptor PET radioligand, [11C]AZ10419369, is now considered a partial agonist. In this work we are aiming to develop a full antagonist PET radioligand for imaging brain 5-HT1B receptors, and evaluate its sensitivity to increased endogenous serotonin concentration. MATERIALS [11C]AZ10419096 was synthesized by rapid methylation of the prepared corresponding N-desmethyl precursor with [11C]methyl triflate. Five PET measurements were performed in cynomolgus monkeys, consisting of two at baseline, one after treatment of a monkey with a 5-HT1B antagonist, AR-A000002, and two in which fenfluramine was administered during scanning to induce endogenous serotonin release. RESULTS AND DISCUSSION [11C]AZ10419096 was synthesized in high yield and purity within 30 min, including purification, formulation and sterile filtration. The baseline PET measurements demonstrated [11C]AZ10419096 to have favorable radioligand characteristics, including high specific binding in brain regions that have high 5-HT1B density, such as occipital cortex and globus pallidus, as well as subsequent rapid elimination from brain and a minor abundance of lipophilic radiometabolites in plasma. AR-A00002 completely blocked radioligand receptor-specific binding. Fenfluramine produced a distinct displacement of radioligand consistent with an expected increase of synaptic endogenous serotonin concentration. CONCLUSIONS [11C]AZ10419096, a full 5-HT1B antagonist PET radioligand, demonstrates high specific binding in monkey brain that is sensitive to competition from a known 5-HT1B antagonist as well as to putatively increased endogenous serotonin levels.
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Affiliation(s)
- Anton Lindberg
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden.
| | - Sangram Nag
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden
| | - Magnus Schou
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden; AstraZeneca, Personalised Healthcare and Biomarkers, AstraZeneca PET Science Centre, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden
| | - Junya Matsumoto
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden
| | - Nahid Amini
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden
| | - Charles S Elmore
- Isotope chemistry, Early Chemical Development, Pharmaceutical Sciences Innovative Medicines and Early Development, AstraZeneca, Mölndal, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden; AstraZeneca, Personalised Healthcare and Biomarkers, AstraZeneca PET Science Centre, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden
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da Cunha-Bang S, Hjordt LV, Dam VH, Stenbæk DS, Sestoft D, Knudsen GM. Anterior cingulate serotonin 1B receptor binding is associated with emotional response inhibition. J Psychiatr Res 2017; 92:199-204. [PMID: 28502766 DOI: 10.1016/j.jpsychires.2017.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 05/02/2017] [Accepted: 05/05/2017] [Indexed: 01/10/2023]
Abstract
Serotonin has a well-established role in emotional processing and is a key neurotransmitter in impulsive aggression, presumably by facilitating response inhibition and regulating subcortical reactivity to aversive stimuli. In this study 44 men, of whom 19 were violent offenders and 25 were non-offender controls, completed an emotional Go/NoGo task requiring inhibition of prepotent motor responses to emotional facial expressions. We also measured cerebral serotonin 1B receptor (5-HT1BR) binding with [11C]AZ10419369 positron emission tomography within regions of the frontal cortex. We hypothesized that 5-HT1BR would be positively associated with false alarms (failures to inhibit nogo responses) in the context of aversive (angry and fearful) facial expressions. Across groups, we found that frontal cortex 5-HT1BR binding was positively correlated with false alarms when angry faces were go stimuli and neutral faces were nogo stimuli (p = 0.05, corrected alpha = 0.0125), but not with false alarms for non-emotional stimuli (failures to inhibit geometric figures). A posthoc analysis revealed the strongest association in anterior cingulate cortex (p = 0.006). In summary, 5-HT1BRs in the anterior cingulate are involved in withholding a prepotent response in the context of angry faces. Our findings suggest that serotonin modulates response inhibition in the context of certain emotional stimuli.
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Affiliation(s)
- Sofi da Cunha-Bang
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100, Denmark
| | - Liv Vadskjær Hjordt
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Vibeke Høyrup Dam
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Dea Siggaard Stenbæk
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100, Denmark
| | - Dorte Sestoft
- Ministry of Justice, Clinic of Forensic Psychiatry, Blegdamsvej 6B, DK-2200 Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.
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Serotonin 1B Receptor Binding Is Associated With Trait Anger and Level of Psychopathy in Violent Offenders. Biol Psychiatry 2017; 82:267-274. [PMID: 27108021 DOI: 10.1016/j.biopsych.2016.02.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/18/2016] [Accepted: 02/26/2016] [Indexed: 12/30/2022]
Abstract
BACKGROUND The involvement of serotonin in aggression has traditionally been attributed to impaired prefrontal serotonergic inhibitory control of emotional reactions to provocations in antisocial individuals. However, it is unclear which specific serotonergic receptors are involved in the effects. A large body of preclinical research supports a specific role of serotonin 1B receptors (5-HT1BRs) in aggression and impulsivity, but this has never been evaluated in humans. METHODS Nineteen incarcerated violent offenders and 24 healthy control nonoffenders were included and examined with positron emission tomography, using the radioligand [11C]AZ10419369 for quantification of cerebral 5-HT1BR binding in three regions of interest: the anterior cingulate cortex, orbitofrontal cortex, and striatum. RESULTS Group status significantly moderated the association between striatal 5-HT1BRs and trait anger (difference in slopes, pcorrected = .04). In the violent offender group, striatal 5-HT1BR binding was positively correlated with self-reported trait anger (p = .0004), trait psychopathy (p = .008), and level of psychopathy according to the Psychopathy Checklist-Revised (p = .02). We found no group differences in 5-HT1BR binding. CONCLUSIONS Our data demonstrate for the first time in humans a specific involvement of 5-HT1BR binding in anger and psychopathy. 5-HT1BRs putatively represent a molecular target for development of pharmacologic antiaggressive treatments.
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Yang KC, Stepanov V, Martinsson S, Ettrup A, Takano A, Knudsen GM, Halldin C, Farde L, Finnema SJ. Fenfluramine Reduces [11C]Cimbi-36 Binding to the 5-HT2A Receptor in the Nonhuman Primate Brain. Int J Neuropsychopharmacol 2017; 20:683-691. [PMID: 28911007 PMCID: PMC5581490 DOI: 10.1093/ijnp/pyx051] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/18/2017] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND [11C]Cimbi-36 is a serotonin 2A receptor agonist positron emission tomography radioligand that has recently been examined in humans. The binding of agonist radioligand is expected to be more sensitive to endogenous neurotransmitter concentrations than antagonist radioligands. In the current study, we compared the effect of serotonin releaser fenfluramine on the binding of [11C]Cimbi-36, [11C]MDL 100907 (a serotonin 2A receptor antagonist radioligand), and [11C]AZ10419369 (a serotonin 1B receptor partial agonist radioligand with established serotonin sensitivity) in the monkey brain. METHODS Eighteen positron emission tomography measurements, 6 for each radioligand, were performed in 3 rhesus monkeys before or after administration of 5.0 mg/kg fenfluramine. Binding potential values were determined with the simplified reference tissue model using cerebellum as the reference region. RESULTS Fenfluramine significantly decreased [11C]Cimbi-36 (26-62%) and [11C]AZ10419369 (35-58%) binding potential values in most regions (P < 0.05). Fenfluramine-induced decreases in [11C]MDL 100907 binding potential were 8% to 30% and statistically significant in 3 regions. Decreases in [11C]Cimbi-36 binding potential were larger than for [11C]AZ10419369 in neocortical and limbic regions (~35%) but smaller in striatum and thalamus (~40%). Decreases in [11C]Cimbi-36 binding potential were 0.9 to 2.8 times larger than for [11C]MDL 100907, and the fraction of serotonin 2A receptor in the high-affinity state was estimated as 54% in the neocortex. CONCLUSIONS The serotonin sensitivity of serotonin 2A receptor agonist radioligand [11C]Cimbi-36 was higher than for antagonist radioligand [11C]MDL 100907. The serotonin sensitivity of [11C]Cimbi-36 was similar to [11C]AZ10419369, which is one of the most sensitive radioligands. [11C]Cimbi-36 is a promising radioligand to examine serotonin release in the primate brain.
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Affiliation(s)
- Kai-Chun Yang
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde).,Correspondence: Kai-Chun Yang, MD, Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, Building R5:02, SE-171 76 Stockholm, Sweden ()
| | - Vladimir Stepanov
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
| | - Stefan Martinsson
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
| | - Anders Ettrup
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
| | - Akihiro Takano
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
| | - Gitte M Knudsen
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
| | - Christer Halldin
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
| | - Lars Farde
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
| | - Sjoerd J Finnema
- Karolinska Institutet and Stockholm County Council, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Yang and Stepanov, Mr Martinsson, and Drs Takano, Halldin, Farde, and Finnema); Rigshospitalet, Center for Integrated Molecular Brain Imaging, Copenhagen, Denmark and University of Copenhagen, Faculty of Health and Medicine Sciences, Copenhagen, Denmark (Drs Ettrup and Knudsen); AstraZeneca, PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm, Sweden (Dr Farde)
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Deen M, Hansen HD, Hougaard A, da Cunha-Bang S, Nørgaard M, Svarer C, Keller SH, Thomsen C, Ashina M, Knudsen GM. Low 5-HT 1B receptor binding in the migraine brain: A PET study. Cephalalgia 2017; 38:519-527. [PMID: 28730894 DOI: 10.1177/0333102417698708] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Background The pathophysiology of migraine may involve dysfunction of serotonergic signaling. In particular, the 5-HT1B receptor is considered a key player due to the efficacy of 5-HT1B receptor agonists for treatment of migraine attacks. Aim To examine the cerebral 5-HT1B receptor binding in interictal migraine patients without aura compared to controls. Methods Eighteen migraine patients, who had been migraine free for >48 hours, and 16 controls were scanned after injection of the 5-HT1B receptor specific radioligand [11C]AZ10419369 for quantification of cerebral 5-HT1B receptor binding. Patients who reported migraine <48 hours after the PET examination were excluded from the final analysis. We defined seven brain regions involved in pain modulation as regions of interest and applied a latent variable model (LVM) to assess the group effect on binding across these regions. Results Our data support a model wherein group status predicts the latent variable ( p = 0.038), with migraine patients having lower 5-HT1B receptor binding across regions compared to controls. Further, in a whole-brain voxel-based analysis, time since last migraine attack correlated positively with 5-HT1B receptor binding in the dorsal raphe and in the midbrain. Conclusion We report here for the first time that migraine patients have low 5-HT1B receptor binding in pain modulating regions, reflecting decreased receptor density. This is either a primary constitutive trait of the migraine brain or secondary to repeated exposure to migraine attacks. We also provide indirect support for the dorsal raphe 5-HT1B receptors being temporarily downregulated during the migraine attack, presumably in response to higher cerebral serotonin levels in the ictal phase.
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Affiliation(s)
- Marie Deen
- 1 Danish Headache Center and Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,3 Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hanne D Hansen
- 2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark
| | - Anders Hougaard
- 1 Danish Headache Center and Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark
| | - Sofi da Cunha-Bang
- 2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,3 Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Nørgaard
- 2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark
| | - Claus Svarer
- 2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark
| | - Sune H Keller
- 4 Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Carsten Thomsen
- 5 Department of Radiology, Rigshospitalet, Copenhagen, Denmark
| | - Messoud Ashina
- 1 Danish Headache Center and Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,3 Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gitte M Knudsen
- 2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,3 Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Abstract
The discovery and development of central nervous system (CNS) drugs is an extremely challenging process requiring large resources, timelines, and associated costs. The high risk of failure leads to high levels of risk. Over the past couple of decades PET imaging has become a central component of the CNS drug-development process, enabling decision-making in phase I studies, where early discharge of risk provides increased confidence to progress a candidate to more costly later phase testing at the right dose level or alternatively to kill a compound through failure to meet key criteria. The so called "3 pillars" of drug survival, namely; tissue exposure, target engagement, and pharmacologic activity, are particularly well suited for evaluation by PET imaging. This review introduces the process of CNS drug development before considering how PET imaging of the "3 pillars" has advanced to provide valuable tools for decision-making on the critical path of CNS drug development. Finally, we review the advances in PET science of biomarker development and analysis that enable sophisticated drug-development studies in man.
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Affiliation(s)
- Roger N Gunn
- Imanova Ltd, London, United Kingdom; Division of Brain Sciences, Imperial College London, London, United Kingdom; Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom.
| | - Eugenii A Rabiner
- Imanova Ltd, London, United Kingdom; Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, United Kingdom
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Slifstein M, Abi-Dargham A. Recent Developments in Molecular Brain Imaging of Neuropsychiatric Disorders. Semin Nucl Med 2016; 47:54-63. [PMID: 27987558 DOI: 10.1053/j.semnuclmed.2016.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Molecular imaging with PET or SPECT has been an important research tool in psychiatry for as long as these modalities have been available. Here, we discuss two areas of neuroimaging relevant to current psychiatry research. The first is the use of imaging to study neurotransmission. We discuss the use of pharmacologic probes to induce changes in levels of neurotransmitters that can be inferred through their effects on outcome measures of imaging experiments, from their historical origins focusing on dopamine transmission through recent developments involving serotonin, GABA, and glutamate. Next, we examine imaging of neuroinflammation in the context of psychiatry. Imaging markers of neuroinflammation have been studied extensively in other areas of brain research, but they have more recently attracted interest in psychiatry research, based on accumulating evidence that there may be an inflammatory component to some psychiatric conditions. Furthermore, new probes are under development that would allow unprecedented insights into cellular processes. In summary, molecular imaging would continue to offer great potential as a unique tool to further our understanding of brain function in health and disease.
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Affiliation(s)
- Mark Slifstein
- Department of Psychiatry, Columbia University Medical Center, New York, NY; New York State Psychiatric Institute, New York, NY; Department of Psychiatry, Stony Brook University, New York, NY.
| | - Anissa Abi-Dargham
- Department of Psychiatry, Columbia University Medical Center, New York, NY; Department of Radiology, Columbia University Medical Center, New York, NY; New York State Psychiatric Institute, New York, NY; Department of Psychiatry, Stony Brook University, New York, NY
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Tiger M, Farde L, Rück C, Varrone A, Forsberg A, Lindefors N, Halldin C, Lundberg J. Low serotonin1B receptor binding potential in the anterior cingulate cortex in drug-free patients with recurrent major depressive disorder. Psychiatry Res Neuroimaging 2016; 253:36-42. [PMID: 27269199 DOI: 10.1016/j.pscychresns.2016.04.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 12/17/2022]
Abstract
The pathophysiology of major depressive disorder (MDD) is not fully understood and the diagnosis is largely based on history and clinical examination. So far, several lines of preclinical data and a single imaging study implicate a role for the serotonin1B (5-HT1B) receptor subtype. We sought to study 5-HT1B receptor binding in brain regions of reported relevance in patients with MDD. Subjects were examined at the Karolinska Institutet PET centre using positron emission tomography (PET) and the 5-HT1B receptor selective radioligand [(11)C]AZ10419369. Ten drug-free patients with recurrent MDD and ten control subjects matched for age and sex were examined. The main outcome measure was [(11)C]AZ10419369 binding in brain regions of reported relevance in the pathophysiology of MDD. The [(11)C]AZ10419369 binding potential was significantly lower in the MDD group compared with the healthy control group in the anterior cingulate cortex (20% between-group difference), the subgenual prefrontal cortex (17% between-group difference), and in the hippocampus (32% between-group difference). The low anterior cingulate [(11)C]AZ10419369 binding potential in patients with recurrent MDD positions 5-HT1B receptor binding in this region as a putative biomarker for MDD and corroborate a role of the anterior cingulate cortex and associated areas in the pathophysiology of recurrent MDD.
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Affiliation(s)
- Mikael Tiger
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden.
| | - Lars Farde
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden; AstraZeneca, Translational Science Center, Karolinska Institutet, 171 76 Stockholm, Sweden
| | - Christian Rück
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Andrea Varrone
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Anton Forsberg
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Nils Lindefors
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Christer Halldin
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Johan Lundberg
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
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Deen M, Christensen CE, Hougaard A, Hansen HD, Knudsen GM, Ashina M. Serotonergic mechanisms in the migraine brain - a systematic review. Cephalalgia 2016; 37:251-264. [PMID: 27013238 DOI: 10.1177/0333102416640501] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background Migraine is one of the most common and disabling of all medical conditions, affecting 16% of the general population, causing huge socioeconomic costs globally. Current available treatment options are inadequate. Serotonin is a key molecule in the neurobiology of migraine, but the exact role of brain serotonergic mechanisms remains a matter of controversy. Methods We systematically searched PubMed for studies investigating the serotonergic system in the migraine brain by either molecular neuroimaging or electrophysiological methods. Results The literature search resulted in 59 papers, of which 13 were eligible for review. The reviewed papers collectively support the notion that migraine patients have alterations in serotonergic neurotransmission. Most likely, migraine patients have a low cerebral serotonin level between attacks, which elevates during a migraine attack. Conclusion This review suggests that novel methods of investigating the serotonergic system in the migraine brain are warranted. Uncovering the serotonergic mechanisms in migraine pathophysiology could prove useful for the development of future migraine drugs.
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Affiliation(s)
- Marie Deen
- 1 Danish Headache Center, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,3 Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Casper Emil Christensen
- 1 Danish Headache Center, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark
| | - Anders Hougaard
- 1 Danish Headache Center, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark
| | - Hanne Demant Hansen
- 2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark
| | - Gitte Moos Knudsen
- 2 Neurobiology Research Unit and Center for Experimental Medicine Neuropharmacology, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,3 Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Messoud Ashina
- 1 Danish Headache Center, Department of Neurology, The Neuroscience Centre, Rigshospitalet, Denmark.,3 Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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Finnema SJ, Halldin C, Bang-Andersen B, Bundgaard C, Farde L. Serotonin transporter occupancy by escitalopram and citalopram in the non-human primate brain: a [(11)C]MADAM PET study. Psychopharmacology (Berl) 2015; 232:4159-67. [PMID: 25980484 DOI: 10.1007/s00213-015-3961-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/05/2015] [Indexed: 11/29/2022]
Abstract
RATIONALE A number of serotonin receptor positron emission tomography (PET) radioligands have been shown to be sensitive to changes in extracellular serotonin concentration, in a generalization of the well-known dopamine competition model. High doses of selective serotonin reuptake inhibitors (SSRIs) decrease serotonin receptor availability in monkey brain, consistent with increased serotonin concentrations. However, two recent studies on healthy human subjects, using a single, lower and clinically relevant SSRI dose, showed increased cortical serotonin receptor radioligand binding, suggesting potential decreases in serotonin concentration in projection regions when initiating treatment. OBJECTIVES The cross-species differential SSRI effect may be partly explained by serotonin transporter (SERT) occupancy in monkey brain being higher than is clinically relevant. We here determine SERT occupancy after single doses of escitalopram or citalopram by conducting PET measurements with [(11)C]MADAM in monkeys. Relationships between dose, plasma concentration and SERT occupancy were estimated by one-site binding analyses. Binding affinity was expressed as dose (ID50) or plasma concentration (K i) where 50 % SERT occupancy was achieved. RESULTS Estimated ID50 and K i values were 0.020 mg/kg and 9.6 nmol/L for escitalopram and 0.059 mg/kg and 9.7 nmol/L for citalopram, respectively. Obtained K i values are comparable to values reported in humans. CONCLUSIONS Escitalopram or citalopram doses nearly saturated SERT in previous monkey studies which examined serotonin sensitivity of receptor radioligands. PET-measured cross-species differential effects of SSRI on cortical serotonin concentration may thus be related to SSRI dose. Future monkey studies using SSRI doses inducing clinically relevant SERT occupancy may further illuminate the delayed onset of SSRI therapeutic effects.
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Affiliation(s)
- Sjoerd J Finnema
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Building R5:02, SE-17176, Stockholm, Sweden. .,Department of Diagnostic Radiology, Yale University, New Haven, CT, USA.
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Building R5:02, SE-17176, Stockholm, Sweden
| | | | | | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Karolinska University Hospital, Building R5:02, SE-17176, Stockholm, Sweden.,AstraZeneca, Translational Science Center at Karolinska Institutet, Stockholm, Sweden
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Sensitivity of [(11)C]ORM-13070 to increased extracellular noradrenaline in the CNS - a PET study in human subjects. Psychopharmacology (Berl) 2015; 232:4169-78. [PMID: 25918111 DOI: 10.1007/s00213-015-3941-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/14/2015] [Indexed: 10/23/2022]
Abstract
RATIONALE No validated methods have been available for studying brain noradrenergic neurotransmission in vivo in humans. Positron emission tomography (PET) radiotracers are widely used in clinical drug development targeted to brain receptors and can also in some cases be employed to monitor extracellular (synaptic) neurotransmitter concentrations. OBJECTIVES The objective of this study is to test the sensitivity of [(11)C]ORM-13070 uptake to increased concentrations of extracellular (synaptic) noradrenaline in the human brain. METHODS Eight subjects underwent a control PET scan with [(11)C]ORM-13070, a subtype-selective α2C-adrenoceptor antagonist radioligand, and two PET scans after two different noradrenaline challenges, i.e. during ketamine infusion and after a dose of atomoxetine combined with cold stimulation. Tracer uptake in the caudate nucleus and putamen was described with AUC values in scan time windows of 10-20 and 5-30 min post injection and quantified with the ratio method. Voxel-based analysis was performed with average bound per free (B/F) ratio images. RESULTS Both noradrenaline challenges were consistently associated with 10-20 % (p < 0.05) reductions in tracer uptake in the dorsal striatum, as determined with region-of-interest-based analysis. Voxel-based analysis revealed significant reductions in B/F ratios in the dorsal striatum, in the brain stem and in several cortical areas. Reductions of 24 and 23 % were detected in the peak putamen clusters with ketamine and atomoxetine + cold, respectively. CONCLUSION Direct experimental support was gained for the suitability of [(11)C]ORM-13070 for imaging of brain noradrenergic neurotransmission.
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Finnema SJ, Hughes ZA, Haaparanta-Solin M, Stepanov V, Nakao R, Varnäs K, Varrone A, Arponen E, Marjamäki P, Pohjanoksa K, Vuorilehto L, Babalola PA, Solin O, Grimwood S, Sallinen J, Farde L, Scheinin M, Halldin C. Amphetamine decreases α2C-adrenoceptor binding of [11C]ORM-13070: a PET study in the primate brain. Int J Neuropsychopharmacol 2015; 18:pyu081. [PMID: 25522417 PMCID: PMC4360244 DOI: 10.1093/ijnp/pyu081] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The neurotransmitter norepinephrine has been implicated in psychiatric and neurodegenerative disorders. Examination of synaptic norepinephrine concentrations in the living brain may be possible with positron emission tomography (PET), but has been hampered by the lack of suitable radioligands. METHODS We explored the use of the novel α2C-adrenoceptor antagonist PET tracer [(11)C]ORM-13070 for measurement of amphetamine-induced changes in synaptic norepinephrine. The effect of amphetamine on [(11)C]ORM-13070 binding was evaluated ex vivo in rat brain sections and in vivo with PET imaging in monkeys. RESULTS Microdialysis experiments confirmed amphetamine-induced elevations in rat striatal norepinephrine and dopamine concentrations. Regional [(11)C]ORM-13070 receptor binding was high in the striatum and low in the cerebellum. After injection of [(11)C]ORM-13070 in rats, mean striatal specific binding ratios, determined using cerebellum as a reference region, were 1.4±0.3 after vehicle pretreatment and 1.2±0.2 after amphetamine administration (0.3mg/kg, subcutaneous). Injection of [(11)C]ORM-13070 in non-human primates resulted in mean striatal binding potential (BP ND) estimates of 0.65±0.12 at baseline. Intravenous administration of amphetamine (0.5 and 1.0mg/kg, i.v.) reduced BP ND values by 31-50%. Amphetamine (0.3mg/kg, subcutaneous) increased extracellular norepinephrine (by 400%) and dopamine (by 270%) in rat striata. CONCLUSIONS Together, these results indicate that [(11)C]ORM-13070 may be a useful tool for evaluation of synaptic norepinephrine concentrations in vivo. Future studies are required to further understand a potential contribution of dopamine to the amphetamine-induced effect.
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Affiliation(s)
- Sjoerd J Finnema
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm, Sweden (Drs Finnema, Stepanov, Nakao, Varnäs, Varrone, Farde, and Halldin); Pfizer, Neuroscience Research Unit, Cambridge, MA (Drs Hughes, Babalola, and Grimwood); University of Turku, Turku PET Centre, Turku, Finland (Drs Haaparanta-Solin, Arponen, Marjamäki, and Solin); University of Turku, Department of Pharmacology, Drug Development and Therapeutics, and Turku University Hospital, Unit of Clinical Pharmacology, Turku, Finland (Drs Pohjanoksa, Vuorilehto, and Scheinin); Orion Corporation, Orion Pharma, Research and Development, Turku, Finland (Dr Sallinen); AstraZeneca, Translational Science Center at Karolinska Institutet, Stockholm, Sweden (Dr Farde)
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Finnema SJ, Scheinin M, Shahid M, Lehto J, Borroni E, Bang-Andersen B, Sallinen J, Wong E, Farde L, Halldin C, Grimwood S. Application of cross-species PET imaging to assess neurotransmitter release in brain. Psychopharmacology (Berl) 2015; 232:4129-57. [PMID: 25921033 PMCID: PMC4600473 DOI: 10.1007/s00213-015-3938-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/09/2015] [Indexed: 01/03/2023]
Abstract
RATIONALE This review attempts to summarize the current status in relation to the use of positron emission tomography (PET) imaging in the assessment of synaptic concentrations of endogenous mediators in the living brain. OBJECTIVES Although PET radioligands are now available for more than 40 CNS targets, at the initiation of the Innovative Medicines Initiative (IMI) "Novel Methods leading to New Medications in Depression and Schizophrenia" (NEWMEDS) in 2009, PET radioligands sensitive to an endogenous neurotransmitter were only validated for dopamine. NEWMEDS work-package 5, "Cross-species and neurochemical imaging (PET) methods for drug discovery", commenced with a focus on developing methods enabling assessment of changes in extracellular concentrations of serotonin and noradrenaline in the brain. RESULTS Sharing the workload across institutions, we utilized in vitro techniques with cells and tissues, in vivo receptor binding and microdialysis techniques in rodents, and in vivo PET imaging in non-human primates and humans. Here, we discuss these efforts and review other recently published reports on the use of radioligands to assess changes in endogenous levels of dopamine, serotonin, noradrenaline, γ-aminobutyric acid, glutamate, acetylcholine, and opioid peptides. The emphasis is on assessment of the availability of appropriate translational tools (PET radioligands, pharmacological challenge agents) and on studies in non-human primates and human subjects, as well as current challenges and future directions. CONCLUSIONS PET imaging directed at investigating changes in endogenous neurochemicals, including the work done in NEWMEDS, have highlighted an opportunity to further extend the capability and application of this technology in drug development.
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Affiliation(s)
- Sjoerd J. Finnema
- />Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, Sweden
| | - Mika Scheinin
- />Department of Pharmacology, Drug Development and Therapeutics, University of Turku, Turku, Finland , />Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - Mohammed Shahid
- />Research and Development, Orion Corporation, Orion Pharma, Turku, Finland
| | - Jussi Lehto
- />Department of Pharmacology, Drug Development and Therapeutics, University of Turku, Turku, Finland
| | - Edilio Borroni
- />Neuroscience Department, Hoffman-La Roche, Basel, Switzerland
| | | | - Jukka Sallinen
- />Research and Development, Orion Corporation, Orion Pharma, Turku, Finland
| | - Erik Wong
- />Neuroscience Innovative Medicine Unit, AstraZeneca, Wilmington, DE USA
| | - Lars Farde
- />Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, Sweden , />Translational Science Center at Karolinska Institutet, AstraZeneca, Stockholm, Sweden
| | - Christer Halldin
- />Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska Institutet, Stockholm, Sweden
| | - Sarah Grimwood
- Neuroscience Research Unit, Pfizer Inc, Cambridge, MA, USA. .,, 610 Main Street, Cambridge, MA, 02139, USA.
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Nord M, Cselenyi Z, Forsberg A, Rosenqvist G, Tiger M, Lundberg J, Varrone A, Farde L. Distinct regional age effects on [11C]AZ10419369 binding to 5-HT1B receptors in the human brain. Neuroimage 2014; 103:303-308. [PMID: 25255943 DOI: 10.1016/j.neuroimage.2014.09.040] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 08/21/2014] [Accepted: 09/15/2014] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Age-related changes in the serotonin system have been described, and proposed to be associated with behavioral changes observed particularly in the elderly population. The 5-HT1B receptor is thought to have a regulatory role in a number of physiological functions, and has been implicated in several age-related diseases. The purpose of the present study was to examine if the availability of 5-HT1B receptors is decreasing with age in healthy subjects. METHODS Data from five previous studies were reanalyzed and pooled, generating data from fifty-one healthy subjects, age 20 to 70, that had been examined with positron emission tomography (PET) and the 5-HT1B specific radioligand [11C]AZ10419369 at baseline conditions. The binding potential (BPND) in cortical and subcortical areas was calculated using the simplified reference tissue model (SRTM). After correction for partial volume effects (PVEc), the correlation between age and regional BPND was examined. RESULTS A statistically significant negative correlation between age and BPND was obtained for neocortical regions and the ventral striatum (VST). The average reduction in BPND per decade was 8% in cortex and 4% in VST. The BPND in the caudate nucleus and the putamen was mainly unaffected by age. CONCLUSION The 5-HT1B receptor availability decreases by age in cortical regions, whereas it remains stable in the caudate nucleus and putamen. By consequence, age-matching of control subjects will be necessary in future clinical studies.
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Affiliation(s)
- Magdalena Nord
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden.
| | - Zsolt Cselenyi
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden; AstraZeneca Translational Science Center, Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Anton Forsberg
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Göran Rosenqvist
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Mikael Tiger
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Johan Lundberg
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Andrea Varrone
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden
| | - Lars Farde
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden; AstraZeneca Translational Science Center, Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm, Sweden
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Tiger M, Rück C, Forsberg A, Varrone A, Lindefors N, Halldin C, Farde L, Lundberg J. Reduced 5-HT(1B) receptor binding in the dorsal brain stem after cognitive behavioural therapy of major depressive disorder. Psychiatry Res 2014; 223:164-70. [PMID: 24916155 DOI: 10.1016/j.pscychresns.2014.05.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 05/08/2014] [Accepted: 05/19/2014] [Indexed: 12/15/2022]
Abstract
Major depression is a significant contributor to the global burden of disease, and its pathophysiology is largely unknown. The serotonin hypothesis is, however, the model with most supporting data, although the details are only worked out to some extent. Recent clinical imaging measurements indeed imply a role in major depressive disorder (MDD) for the inhibitory serotonin autoreceptor 5-hydroxytryptamine1B (5-HT1B). The aim of the current study was to examine 5-HT1B receptor binding in the brain of MDD patients before and after psychotherapy. Ten patients with an ongoing untreated moderate depressive episode were examined with positron emission tomography (PET) and the 5-HT1B receptor selective radioligand [(11)C]AZ10419369, before and after treatment with internet-based cognitive behavioural therapy. All of the patients examined responded to treatment, and 70% were in remission by the time of the second PET measurement. A statistically significant 33% reduction of binding potential (BPND) was found in the dorsal brain stem (DBS) after treatment. No other significant changes in BPND were found. The DBS contains the raphe nuclei, which regulate the serotonin system. This study gives support for the importance of serotonin and the 5-HT1B receptor in the biological response to psychological treatment of MDD.
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Affiliation(s)
- Mikael Tiger
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden.
| | - Christian Rück
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Anton Forsberg
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Andrea Varrone
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Nils Lindefors
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
| | - Johan Lundberg
- Department of Clinical Neuroscience, Karolinska Institutet, Centrum för psykiatriforskning, R5:0, Karolinska Universitetssjukhuset i Solna, 171 76 Stockholm, Sweden
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Positron emission tomography imaging of 5-hydroxytryptamine1B receptors in Parkinson's disease. Neurobiol Aging 2014; 35:867-75. [DOI: 10.1016/j.neurobiolaging.2013.08.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 08/12/2013] [Accepted: 08/23/2013] [Indexed: 12/24/2022]
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Yamanaka H, Yokoyama C, Mizuma H, Kurai S, Finnema SJ, Halldin C, Doi H, Onoe H. A possible mechanism of the nucleus accumbens and ventral pallidum 5-HT1B receptors underlying the antidepressant action of ketamine: a PET study with macaques. Transl Psychiatry 2014; 4:e342. [PMID: 24399045 PMCID: PMC3905222 DOI: 10.1038/tp.2013.112] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 10/29/2013] [Indexed: 12/19/2022] Open
Abstract
Ketamine is a unique anesthetic reagent known to produce various psychotic symptoms. Ketamine has recently been reported to elicit a long-lasting antidepressant effect in patients with major depression. Although recent studies provide insight into the molecular mechanisms of the effects of ketamine, the antidepressant mechanism has not been fully elucidated. To understand the involvement of the brain serotonergic system in the actions of ketamine, we performed a positron emission tomography (PET) study on non-human primates. Four rhesus monkeys underwent PET studies with two serotonin (5-HT)-related PET radioligands, [(11)C]AZ10419369 and [(11)C]DASB, which are highly selective for the 5-HT1B receptor and serotonin transporter (SERT), respectively. Voxel-based analysis using standardized brain images revealed that ketamine administration significantly increased 5-HT1B receptor binding in the nucleus accumbens and ventral pallidum, whereas it significantly reduced SERT binding in these brain regions. Fenfluramine, a 5-HT releaser, significantly decreased 5-HT1B receptor binding, but no additional effect was observed when it was administered with ketamine. Furthermore, pretreatment with 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(f)quinoxaline (NBQX), a potent antagonist of the glutamate α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor, blocked the action of ketamine on the 5-HT1B receptor but not SERT binding. This indicates the involvement of AMPA receptor activation in ketamine-induced alterations of 5-HT1B receptor binding. Because NBQX is known to block the antidepressant effect of ketamine in rodents, alterations in the serotonergic neurotransmission, particularly upregulation of postsynaptic 5-HT1B receptors in the nucleus accumbens and ventral pallidum may be critically involved in the antidepressant action of ketamine.
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Affiliation(s)
- H Yamanaka
- Bio-Function Imaging Team, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan
| | - C Yokoyama
- Bio-Function Imaging Team, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan
| | - H Mizuma
- Bio-Function Imaging Team, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan
| | - S Kurai
- Labelling Chemistry Team, Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan
| | - S J Finnema
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, Stockholm, Sweden
| | - C Halldin
- Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, Stockholm, Sweden
| | - H Doi
- Labelling Chemistry Team, Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan
| | - H Onoe
- Bio-Function Imaging Team, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan,Bio-Function Imaging Team, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan. E-mail:
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Characterization of [11C]Cimbi-36 as an agonist PET radioligand for the 5-HT2A and 5-HT2C receptors in the nonhuman primate brain. Neuroimage 2014; 84:342-53. [DOI: 10.1016/j.neuroimage.2013.08.035] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/12/2013] [Accepted: 08/15/2013] [Indexed: 11/18/2022] Open
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Hargreaves RJ, Rabiner EA. Translational PET imaging research. Neurobiol Dis 2013; 61:32-8. [PMID: 24055214 DOI: 10.1016/j.nbd.2013.08.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 08/07/2013] [Accepted: 08/14/2013] [Indexed: 10/26/2022] Open
Abstract
The goal of any early central nervous system (CNS) drug development program is always to test the mechanism and not the molecule in order to support additional research investments in late phase clinical trials. Confirmation that drugs reach their targets using translational positron emission tomography (PET) imaging markers of engagement is central to successful clinical proof-of-concept testing and has become an important feature of most neuropsychiatric drug development programs. CNS PET imaging can also play an important role in the clinical investigation of the neuropharmacological basis of psychiatric disease and the optimization of drug therapy.
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Affiliation(s)
- Richard J Hargreaves
- Merck and Co, WP-42-212, 770, Sumneytown Pike, PO Box 4, West Point, PA19486, USA.
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Test–retest reliability of [11C]AZ10419369 binding to 5-HT1B receptors in human brain. Eur J Nucl Med Mol Imaging 2013; 41:301-7. [DOI: 10.1007/s00259-013-2529-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 07/25/2013] [Indexed: 10/26/2022]
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30
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Morris ED, Kim SJ, Sullivan JM, Wang S, Normandin MD, Constantinescu CC, Cosgrove KP. Creating dynamic images of short-lived dopamine fluctuations with lp-ntPET: dopamine movies of cigarette smoking. J Vis Exp 2013. [PMID: 23963311 PMCID: PMC4046621 DOI: 10.3791/50358] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We describe experimental and statistical steps for creating dopamine movies of the brain from dynamic PET data. The movies represent minute-to-minute fluctuations of dopamine induced by smoking a cigarette. The smoker is imaged during a natural smoking experience while other possible confounding effects (such as head motion, expectation, novelty, or aversion to smoking repeatedly) are minimized. We present the details of our unique analysis. Conventional methods for PET analysis estimate time-invariant kinetic model parameters which cannot capture short-term fluctuations in neurotransmitter release. Our analysis - yielding a dopamine movie - is based on our work with kinetic models and other decomposition techniques that allow for time-varying parameters 1-7. This aspect of the analysis - temporal-variation - is key to our work. Because our model is also linear in parameters, it is practical, computationally, to apply at the voxel level. The analysis technique is comprised of five main steps: pre-processing, modeling, statistical comparison, masking and visualization. Preprocessing is applied to the PET data with a unique 'HYPR' spatial filter 8 that reduces spatial noise but preserves critical temporal information. Modeling identifies the time-varying function that best describes the dopamine effect on 11C-raclopride uptake. The statistical step compares the fit of our (lp-ntPET) model 7 to a conventional model 9. Masking restricts treatment to those voxels best described by the new model. Visualization maps the dopamine function at each voxel to a color scale and produces a dopamine movie. Interim results and sample dopamine movies of cigarette smoking are presented.
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Effect of a single dose of escitalopram on serotonin concentration in the non-human and human primate brain. Int J Neuropsychopharmacol 2013; 16:1577-86. [PMID: 23351590 DOI: 10.1017/s1461145712001617] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed for treatment of psychiatric disorders. The exact mechanism underlying the clinical effects of SSRIs remains unclear, although increased synaptic serotonin concentrations have been hypothesized to be an initial step. [¹¹C]AZ10419369 is a novel 5-HT(1B) receptor selective radioligand, which is sensitive to changes in endogenous serotonin concentrations. To assess whether a single dose of the SSRI escitalopram affects endogenous serotonin concentrations in serotonergic projection areas and in the raphe nuclei (RN), three cynomolgus monkeys and nine human subjects underwent PET examinations with [¹¹C]AZ10419369 at baseline conditions and after escitalopram administration. In monkeys, the binding potential (BP(ND)) was significantly lower post dose compared to baseline in dorsolateral prefrontal cortex, occipital cortex, thalamus, midbrain and RN (p < 0.05). In humans, the BP(ND) tended to decrease in RN post dose (p = 0.08). In all serotonergic projection areas, the BP(ND) was conversely higher post dose compared to baseline. The increase was significant in a combined region of all projection areas (p = 0.01) and in occipital and temporal cortex (p < 0.05). SSRIs are generally assumed to elevate endogenous serotonin concentrations in projection areas, evoking the antidepressant effect. In the present study, a single, clinically relevant, dose of escitalopram was found to decrease serotonin concentrations in serotonergic projection areas in humans. Hypothetically, desensitization of inhibitory serotonergic autoreceptors will cause the serotonin concentration in projection areas to increase over time with chronic administration. Thus, the findings in the present study might aid in understanding the mechanism of SSRIs' delayed onset of clinical effect.
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Tuominen L, Salo J, Hirvonen J, Någren K, Laine P, Melartin T, Isometsä E, Viikari J, Cloninger CR, Raitakari O, Hietala J, Keltikangas-Järvinen L. Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort. Psychol Med 2013; 43:881-894. [PMID: 22850434 DOI: 10.1017/s003329171200164x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension 'harm avoidance' (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT) density in vivo with positron emission tomography (PET) in healthy individuals with high or low HA scores using an 'oversampling' study design. Method Subjects consistently in either upper or lower quartiles for the HA trait were selected from a population-based cohort in Finland (n = 2075) with pre-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high- and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BPND) in high- and low-HA groups estimated with PET and [11C]N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine ([11C]MADAM). In secondary analyses, 5-HTT BPND was correlated with other TCI dimensions. RESULTS 5-HTT BPND did not differ between high- and low-HA groups in the midbrain or any other brain region. This result remained the same even after adjusting for other relevant TCI dimensions. Higher 5-HTT BPND in the raphe nucleus predicted higher scores in 'self-directedness'. CONCLUSIONS This study does not support an association between the temperament dimension HA and serotonin transporter density in healthy subjects. However, we found a link between high serotonin transporter density and high 'self-directedness' (ability to adapt and control one's behaviour to fit situations in accord with chosen goals and values). We suggest that biological factors are more important in explaining variability in character than previously thought.
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Affiliation(s)
- L Tuominen
- Department of Psychiatry, University of Turku, Turku, Finland
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Fisher PM, Hariri AR. Identifying serotonergic mechanisms underlying the corticolimbic response to threat in humans. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120192. [PMID: 23440464 DOI: 10.1098/rstb.2012.0192] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A corticolimbic circuit including the amygdala and medial prefrontal cortex (mPFC) plays an important role in regulating sensitivity to threat, which is heightened in mood and anxiety disorders. Serotonin is a potent neuromodulator of this circuit; however, specific serotonergic mechanisms mediating these effects are not fully understood. Recent studies have evaluated molecular mechanisms mediating the effects of serotonin signalling on corticolimbic circuit function using a multi-modal neuroimaging strategy incorporating positron emission tomography and blood oxygen level-dependent functional magnetic resonance imaging. This multi-modal neuroimaging strategy can be integrated with additional techniques including imaging genetics and pharmacological challenge paradigms to more clearly understand how serotonin signalling modulates neural pathways underlying sensitivity to threat. Integrating these methodological approaches offers novel opportunities to identify mechanisms through which serotonin signalling contributes to differences in brain function and behaviour, which in turn can illuminate factors that confer risk for illness and inform the development of more effective treatment strategies.
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Affiliation(s)
- Patrick M Fisher
- Center for Integrated Molecular Brain Imaging, University of Copenhagen, Copenhagen 2100, Denmark.
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Fisher PM, Hariri AR. Linking variability in brain chemistry and circuit function through multimodal human neuroimaging. GENES BRAIN AND BEHAVIOR 2012; 11:633-42. [PMID: 22443230 DOI: 10.1111/j.1601-183x.2012.00786.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Identifying neurobiological mechanisms mediating the emergence of individual differences in behavior is critical for advancing our understanding of relative risk for psychopathology. Neuroreceptor positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) can be used to assay in vivo regional brain chemistry and function, respectively. Typically, these neuroimaging modalities are implemented independently despite the capacity for integrated data sets to offer unique insight into molecular mechanisms associated with brain function. Through examples from the serotonin and dopamine system and its effects on threat- and reward-related brain function, we review evidence for how such a multimodal neuroimaging strategy can be successfully implemented. Furthermore, we discuss how multimodal PET-fMRI can be integrated with techniques such as imaging genetics, pharmacological challenge paradigms and gene-environment interaction models to more completely map biological pathways mediating individual differences in behavior and related risk for psychopathology and inform the development of novel therapeutic targets.
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Affiliation(s)
- P M Fisher
- Center for Integrated Molecular Brain Imaging, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
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Finnema SJ, Varrone A, Hwang TJ, Halldin C, Farde L. Confirmation of fenfluramine effect on 5-HT(1B) receptor binding of [(11)C]AZ10419369 using an equilibrium approach. J Cereb Blood Flow Metab 2012; 32:685-95. [PMID: 22167236 PMCID: PMC3318146 DOI: 10.1038/jcbfm.2011.172] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Assessment of serotonin release in the living brain with positron emission tomography (PET) may have been hampered by the lack of suitable radioligands. We previously reported that fenfluramine caused a dose-dependent reduction in specific binding in monkeys using a classical displacement paradigm with bolus administration of [(11)C]AZ10419369. The aim of this study was to confirm our previous findings using an equilibrium approach in monkey. A total of 24 PET measurements were conducted using a bolus infusion protocol of [(11)C]AZ10419369 in three cynomolgus monkeys. Initial PET measurements were performed to assess suitable K(bol) values. The fenfluramine effect on [(11)C]AZ10419369 binding was evaluated in a displacement and pretreatment paradigm. The effect of fenfluramine on [(11)C]AZ10419369 binding potential (BP(ND)) was dose-dependent in the displacement paradigm and confirmed in the pretreatment paradigm. After pretreatment administration of fenfluramine (5.0 mg/kg), the mean BP(ND) of the occipital cortex decreased by 39%, from 1.38±0.04 to 0.84±0.09. This study confirms that the new 5-HT(1B) receptor radioligand [(11)C]AZ10419369 is sensitive to fenfluramine-induced changes in endogenous serotonin levels in vivo. The more advanced methodology is suitable for exploring the sensitivity limit to serotonin release as measured using [(11)C]AZ10419369 and PET.
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Affiliation(s)
- Sjoerd J Finnema
- Psychiatry Section, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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Abstract
The results of imaging studies have played an important role in the formulation of hypotheses regarding the etiology of psychosis and schizophrenia, as well as in our understanding of the mechanisms of action of antipsychotics. Since this volume is primarily directed to molecular aspects of psychosis and antipsychotics, only the results of molecular imaging techniques addressing these topics will be discussed here.One of the most consistent findings of molecular imaging studies in schizophrenia is an increased uptake of DOPA in the striatum, which may be interpreted as an increased synthesis of L-DOPA. Also, several studies reported an increased release of dopamine induced by amphetamine in schizophrenia patients. These findings played an important role in reformulating the dopamine hypothesis of schizophrenia. To study the roles of the neurotransmitters γ-aminobutyric acid (GABA) and glutamate in schizophrenia, SPECT as well as MR spectroscopy have been used. The results of preliminary SPECT studies are consistent with the hypothesis of NMDA receptor dysfunction in schizophrenia. Regarding the GABA deficit hypothesis of schizophrenia, imaging results are inconsistent. No changes in serotonin transporters were demonstrated in imaging studies in schizophrenia, but studies of several serotonin receptors showed conflicting results. The lack of selective radiotracers for muscarinic receptors may have hampered examination of this system in schizophrenia as well as its role in the induction of side effects of antipsychotics. Interestingly, preliminary molecular imaging studies on the cannabinoid-1 receptor and on neuroinflammatory processes in schizophrenia have recently been published. Finally, a substantial number of PET/SPECT studies have examined the occupancy of receptors by antipsychotics and an increasing number of studies is now focusing on the effects of these drugs using techniques like spectroscopy and pharmacological MRI.
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Measuring Dopamine Synaptic Transmission with Molecular Imaging and Pharmacological Challenges: The State of the Art. MOLECULAR IMAGING IN THE CLINICAL NEUROSCIENCES 2012. [DOI: 10.1007/7657_2012_45] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Murrough JW, Czermak C, Henry S, Nabulsi N, Gallezot JD, Gueorguieva R, Planeta-Wilson B, Krystal JH, Neumaier JF, Huang Y, Ding YS, Carson RE, Neumeister A. The effect of early trauma exposure on serotonin type 1B receptor expression revealed by reduced selective radioligand binding. ACTA ACUST UNITED AC 2011; 68:892-900. [PMID: 21893657 DOI: 10.1001/archgenpsychiatry.2011.91] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
CONTEXT Serotonergic dysfunction is implicated in the pathogenesis of posttraumatic stress disorder (PTSD), and recent animal models suggest that disturbances in serotonin type 1B receptor function, in particular, may contribute to chronic anxiety. However, the specific role of the serotonin type 1B receptor has not been studied in patients with PTSD. OBJECTIVE To investigate in vivo serotonin type 1B receptor expression in individuals with PTSD, trauma-exposed control participants without PTSD (TC), and healthy (non-trauma-exposed) control participants (HC) using positron emission tomography and the recently developed serotonin type 1B receptor selective radiotracer [(11)C]P943. DESIGN Cross-sectional positron emission tomography study under resting conditions. SETTING Academic and Veterans Affairs medical centers. PARTICIPANTS Ninety-six individuals in 3 study groups: PTSD (n = 49), TC (n = 20), and HC (n = 27). Main Outcome Measure Regional [(11)C]P943 binding potential (BP(ND)) values in an a priori-defined limbic corticostriatal circuit investigated using multivariate analysis of variance and multiple regression analysis. RESULTS A history of severe trauma exposure in the PTSD and TC groups was associated with marked reductions in [(11)C]P943 BP(ND) in the caudate, the amygdala, and the anterior cingulate cortex. Participant age at first trauma exposure was strongly associated with low [(11)C]P943 BP(ND). Developmentally earlier trauma exposure also was associated with greater PTSD symptom severity and major depression comorbidity. CONCLUSIONS These data suggest an enduring effect of trauma history on brain function and the phenotype of PTSD. The association of early age at first trauma and more pronounced neurobiological and behavioral alterations in PTSD suggests a developmental component in the cause of PTSD.
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Affiliation(s)
- James W Murrough
- Mood and Anxiety Disorders Program, Department of Psychiatry, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, USA.
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Quednow BB, Treyer V, Hasler F, Dörig N, Wyss MT, Burger C, Rentsch KM, Westera G, Schubiger PA, Buck A, Vollenweider FX. Assessment of serotonin release capacity in the human brain using dexfenfluramine challenge and [18F]altanserin positron emission tomography. Neuroimage 2011; 59:3922-32. [PMID: 21996132 DOI: 10.1016/j.neuroimage.2011.09.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 09/12/2011] [Accepted: 09/19/2011] [Indexed: 10/17/2022] Open
Abstract
Although alterations of serotonin (5-HT) system functioning have been proposed for a variety of psychiatric disorders, a direct method quantitatively assessing 5-HT release capacity in the living human brain is still lacking. Therefore, we evaluated a novel method to assess 5-HT release capacity in vivo using dexfenfluramine challenge and [(18)F]altanserin positron emission tomography (PET). Thirteen healthy male subjects received placebo and single oral doses of 40 mg (n = 6) or 60 mg (n = 7) of the potent 5-HT releaser dexfenfluramine separated by an interval of 14 days. Three further subjects received placebo on both days. Two hours after placebo/drug administration, 250 MBq of the 5-HT(2A) receptor selective PET-radiotracer [(18)F]altanserin was administered intravenously as a 30s bolus. Dynamic PET data were subsequently acquired over 90 min. Moreover, arterial blood samples were drawn for measurement of total activity and metabolite correction of the input function. Dexfenfluramine as well as cortisol and prolactin plasma concentration-time profiles was quantitatively determined. Tracer distribution volumes for five volumes-of-interest (prefrontal and occipital cortex, insula, thalamus, caudatum) were calculated by the Logan plot and a 2-tissue compartment model. Dexfenfluramine dose-dependently decreased the total distribution volume of [(18)F]altanserin in cortical regions independent of the PET modeling approach. Cortisol and prolactin plasma concentrations were dose-dependently increased by dexfenfluramine. The decrease in cortical [(18)F]altanserin receptor binding under dexfenfluramine was correlated with the increase of plasma prolactin. These data suggest that the combination of a dexfenfluramine-induced 5-HT release and subsequent assessment of 5-HT(2A) receptor availability with [(18)F]altanserin PET is suitable to measure cortical 5-HT release capacity in the human brain.
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Affiliation(s)
- Boris B Quednow
- Clinic of Affective Disorders and General Psychiatry, University Hospital of Psychiatry, Zurich, Switzerland.
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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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Ridler K, Plisson C, Rabiner EA, Gunn RN, Easwaramoorthy B, Abi-Dargham A, Laruelle M, Slifstein M. Characterization of in vivo pharmacological properties and sensitivity to endogenous serotonin of [11C] P943: A positron emission tomography study in Papio anubis. Synapse 2011; 65:1119-27. [DOI: 10.1002/syn.20946] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 04/21/2011] [Indexed: 11/08/2022]
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Cosgrove KP, Kloczynski T, Nabulsi N, Weinzimmer D, Lin SF, Staley JK, Bhagwagar Z, Carson RE. Assessing the sensitivity of [¹¹C]p943, a novel 5-HT1B radioligand, to endogenous serotonin release. Synapse 2011; 65:1113-7. [PMID: 21484884 DOI: 10.1002/syn.20942] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 04/03/2011] [Indexed: 11/09/2022]
Abstract
The main objective of the current study was to determine the sensitivity of the positron emission tomography (PET) radioligand [¹¹C]P943 to fenfluramine-induced changes in endogenous 5-HT in nonhuman primate brain. Fenfluramine-induced changes in 5-HT(1B) occupancy were compared to those obtained by self-block with unlabeled P943. Two baboons and 1 rhesus monkey were given preblocking or displacing doses of fenfluramine (1-5 mg/kg) or preblocking doses of unlabeled P943 (0.2 mg/kg) and imaged with [¹¹C]P943 PET. Receptor occupancy by the low dose of fenfluramine (1 mg/kg) in the baboons was 25 and 29% and by the high dose of fenfluramine (5 mg/kg) in the rhesus macaque was 42%. Receptor occupancy by P943 (0.2 mg/kg) was 68 and 86% in the baboons. PET imaging of 5-HT(1B) receptors with [¹¹C]P943 may be a useful approach for measuring changes in endogenous 5-HT in the living human brain.
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Affiliation(s)
- Kelly P Cosgrove
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut, USA.
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Development of a PET radioligand for the central 5-HT1B receptor: radiosynthesis and characterization in cynomolgus monkeys of eight radiolabeled compounds. Nucl Med Biol 2011; 38:261-72. [DOI: 10.1016/j.nucmedbio.2010.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 08/17/2010] [Accepted: 08/24/2010] [Indexed: 11/30/2022]
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Varnäs K, Nyberg S, Karlsson P, Pierson ME, Kågedal M, Cselényi Z, McCarthy D, Xiao A, Zhang M, Halldin C, Farde L. Dose-dependent binding of AZD3783 to brain 5-HT1B receptors in non-human primates and human subjects: a positron emission tomography study with [11C]AZ10419369. Psychopharmacology (Berl) 2011; 213:533-45. [PMID: 21234549 DOI: 10.1007/s00213-011-2165-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 01/02/2011] [Indexed: 12/22/2022]
Abstract
RATIONALE The serotonin 5-HT(1B) receptor is a potential target for the pharmacologic treatment of depression. Positron emission tomography (PET) determination of 5-HT(1B) receptor occupancy with drug candidates targeting this receptor in non-human primate and human subjects may facilitate translation of research from animal models and guide dose selection for clinical studies. AZD3783 is a recently developed, orally bioavailable 5-HT(1B) receptor antagonist with potential antidepressant properties. OBJECTIVES To determine the relationship between plasma concentration of AZD3783 and occupancy at primate brain 5-HT(1B) receptors using PET and the radioligand [(11)C]AZ10419369. METHODS PET studies with [(11)C]AZ10419369 were performed in three non-human primates at baseline and after intravenous injection of AZD3783. Subsequently, PET measurements were undertaken in six human subjects at baseline and after administration of different single oral doses of AZD3783 (1-40 mg). RESULTS After administration in non-human primates and human subjects, AZD3783 reduced regional [(11)C]AZ10419369 binding in a dose-dependent and saturable manner. The AZD3783 plasma concentration required for 50% receptor occupancy (K (i,plasma)) for monkeys was 25 and 27 nmol/L in occipital cortex and striatum, respectively. Corresponding estimates for human occipital cortex and ventral striatum were 24 and 18 nmol/L, respectively. CONCLUSIONS The potential antidepressant AZD3783 binds in a saturable manner to brain 5-HT(1B) receptors with a similar in vivo affinity for human and monkey receptors. [(11)C]AZ10419369 can be successfully used to determine occupancy at brain 5-HT(1B) receptors in vivo and constitutes a useful tool for dose selection in clinical studies with 5-HT(1B) receptor compounds.
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Affiliation(s)
- Katarina Varnäs
- Karolinska Institutet, Department of Clinical Neuroscience, Karolinska University Hospital, Stockholm, Sweden.
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Abstract
Molecular in vivo neuroimaging techniques can be used to measure regional changes in endogenous neurotransmitters, evoked by challenges that alter synaptic neurotransmitter concentration. This technique has most successfully been applied to the study of endogenous dopamine release using positron emission tomography, but has not yet been adequately extended to other neurotransmitter systems. This review focuses on how the technique has been applied to the study of the 5-hydroxytryptamine (5-HT) system. The principles behind visualising fluctuations in neurotransmitters are introduced, with reference to the dopaminergic system. Studies that aim to image acute, endogenous 5-HT release or depletion at 5-HT receptor targets are summarised, with particular attention to studies in humans. Radiotracers targeting the 5-HT(1A), 5-HT(2A), and 5-HT(4) receptors and the serotonin reuptake transporter have been explored for their sensitivity to 5-HT fluctuations, but with mixed outcomes; tracers for these targets cannot reliably image endogenous 5-HT in humans. Shortcomings in our basic knowledge of the mechanisms underlying changes in binding potential are addressed, and suggestions are made as to how the selection of targets, radiotracers, challenge paradigms, and experimental design might be optimised to improve our chances of successfully imaging endogenous neurotransmitters in the future.
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