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Weidenauer A, Sauerzopf U, Bauer M, Bum C, Diendorfer C, Dajic I, Bartova L, Kastner A, Bamminger K, Nics L, Philippe C, Hacker M, Rujescu D, Wadsak W, Praschak-Rieder N, Willeit M. Amphetamine-Induced Dopamine Release Predicts 1-Year Outcome in First-Episode Psychosis: A Naturalistic Observation. Schizophr Bull 2024:sbae111. [PMID: 39137162 DOI: 10.1093/schbul/sbae111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
BACKGROUND AND HYPOTHESIS The dopamine theory of schizophrenia suggests that antipsychotics alleviate symptoms by blocking dopamine D2/3 receptors, yet a significant subset of patients does not respond adequately to treatment. To investigate potential predictors, we evaluated d-amphetamine-induced dopamine release and 1-year clinical outcomes in 21 antipsychotic-naive patients with first-episode schizophrenia. STUDY DESIGN Twenty-one antipsychotic-naive patients (6 female) underwent dopamine D2/3 receptor radioligand [11C]-(+)-PHNO positron emission tomography. For estimating dopamine release, scans were performed with and without d-amphetamine pretreatment. The Positive and Negative Syndrome Scale was performed at regular intervals over 1 year while receiving treatment in a naturalistic setting (Clinical Trial Registry: EUDRACT 2010-019586-29). STUDY RESULTS A group analysis revealed no significant differences in d-amphetamine-induced dopamine release between patients with or without clinically significant improvement. However, d-amphetamine-induced dopamine release in ventral striatum was significantly associated with reductions in positive symptoms (r = 0.54, P = .04; uncorrected P-values); release in globus pallidus correlated with a decrease in PANSS negative (r = 0.58, P = .02), general (r = 0.53, P = .04), and total symptom scores (r = 0.063, P = .01). Higher dopamine release in substantia nigra/ventral tegmental area predicted larger reductions in general symptoms (r = 0.51, P = .05). Post-amphetamine binding in putamen correlated positively with negative symptom scores at baseline (r = 0.66, P = .005) and throughout all follow-up visits. CONCLUSIONS These exploratory results support a relationship between d-amphetamine-induced dopamine release and the severity and persistence of symptoms during the first year of psychosis.
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Affiliation(s)
- Ana Weidenauer
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
- Douglas Research Centre, Clinical and Translational Sciences Lab, Montreal, Quebec, Canada
- Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Ulrich Sauerzopf
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Martin Bauer
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
- Psychosocial Services in Vienna, Vienna, Austria
| | - Carina Bum
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Cornelia Diendorfer
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Irena Dajic
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Lucie Bartova
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Alina Kastner
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Karsten Bamminger
- Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Austria
| | - Lukas Nics
- Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Austria
| | - Cecile Philippe
- Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Austria
| | - Dan Rujescu
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Wadsak
- Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Austria
- Center for Biomarker Research in Medicine CBmed, Graz, Austria
| | - Nicole Praschak-Rieder
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Matthäus Willeit
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
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Hart XM, Spangemacher M, Uchida H, Gründer G. Update Lessons from Positron Emission Tomography Imaging Part I: A Systematic Critical Review on Therapeutic Plasma Concentrations of Antipsychotics. Ther Drug Monit 2024; 46:16-32. [PMID: 38018857 DOI: 10.1097/ftd.0000000000001131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 06/06/2023] [Indexed: 11/30/2023]
Abstract
BACKGROUND Positron emission tomography (PET) and single photon emission tomography (SPECT) of molecular drug targets (neuroreceptors and transporters) provide essential information for therapeutic drug monitoring-guided antipsychotic drug therapy. The optimal therapeutic windows for D 2 antagonists and partial agonists, as well as their proposed target ranges, are discussed based on an up-to-date literature search. METHODS This part I of II presents an overview of molecular neuroimaging studies in humans and primates involving the target engagement of amisulpride, haloperidol, clozapine, aripiprazole, olanzapine, quetiapine, risperidone, cariprazine, and ziprasidone. The systemic review particularly focused on dopamine D 2 -like and 5-HT 2A receptors. Target concentration ranges were estimated based on receptor occupancy ranges that relate to clinical effects or side effects (ie, extrapyramidal side effects). In addition, findings for other relevant receptor systems were included to further enrich the discussion. RESULTS The reported reference ranges for aripiprazole and clozapine align closely with findings from PET studies. Conversely, for haloperidol, risperidone, and olanzapine, the PET studies indicate that a lowering of the previously published upper limits would be necessary to decrease the risk of extrapyramidal side effect. CONCLUSIONS Molecular neuroimaging studies serve as a strong tool for defining target ranges for antipsychotic drug treatment and directing therapeutic drug monitoring.
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Affiliation(s)
- Xenia M Hart
- Central Institute of Mental Health, Department of Molecular Neuroimaging, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Moritz Spangemacher
- Central Institute of Mental Health, Department of Molecular Neuroimaging, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- Central Institute of Mental Health, Department of Psychiatry, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; and
| | - Hiroyuki Uchida
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Gerhard Gründer
- Central Institute of Mental Health, Department of Molecular Neuroimaging, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
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de Bartolomeis A, Ciccarelli M, De Simone G, Mazza B, Barone A, Vellucci L. Canonical and Non-Canonical Antipsychotics' Dopamine-Related Mechanisms of Present and Next Generation Molecules: A Systematic Review on Translational Highlights for Treatment Response and Treatment-Resistant Schizophrenia. Int J Mol Sci 2023; 24:ijms24065945. [PMID: 36983018 PMCID: PMC10051989 DOI: 10.3390/ijms24065945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Schizophrenia is a severe psychiatric illness affecting almost 25 million people worldwide and is conceptualized as a disorder of synaptic plasticity and brain connectivity. Antipsychotics are the primary pharmacological treatment after more than sixty years after their introduction in therapy. Two findings hold true for all presently available antipsychotics. First, all antipsychotics occupy the dopamine D2 receptor (D2R) as an antagonist or partial agonist, even if with different affinity; second, D2R occupancy is the necessary and probably the sufficient mechanism for antipsychotic effect despite the complexity of antipsychotics' receptor profile. D2R occupancy is followed by coincident or divergent intracellular mechanisms, implying the contribution of cAMP regulation, β-arrestin recruitment, and phospholipase A activation, to quote some of the mechanisms considered canonical. However, in recent years, novel mechanisms related to dopamine function beyond or together with D2R occupancy have emerged. Among these potentially non-canonical mechanisms, the role of Na2+ channels at the dopamine at the presynaptic site, dopamine transporter (DAT) involvement as the main regulator of dopamine concentration at synaptic clefts, and the putative role of antipsychotics as chaperones for intracellular D2R sequestration, should be included. These mechanisms expand the fundamental role of dopamine in schizophrenia therapy and may have relevance to considering putatively new strategies for treatment-resistant schizophrenia (TRS), an extremely severe condition epidemiologically relevant and affecting almost 30% of schizophrenia patients. Here, we performed a critical evaluation of the role of antipsychotics in synaptic plasticity, focusing on their canonical and non-canonical mechanisms of action relevant to the treatment of schizophrenia and their subsequent implication for the pathophysiology and potential therapy of TRS.
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Affiliation(s)
- Andrea de Bartolomeis
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Mariateresa Ciccarelli
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Giuseppe De Simone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Benedetta Mazza
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Annarita Barone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
| | - Licia Vellucci
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment-Resistant Psychosis, Department of Neuroscience, Reproductive Sciences and Dentistry, University Medical School of Naples "Federico II", 80131 Naples, Italy
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de Bartolomeis A, Vellucci L, Barone A, Manchia M, De Luca V, Iasevoli F, Correll CU. Clozapine's multiple cellular mechanisms: What do we know after more than fifty years? A systematic review and critical assessment of translational mechanisms relevant for innovative strategies in treatment-resistant schizophrenia. Pharmacol Ther 2022; 236:108236. [PMID: 35764175 DOI: 10.1016/j.pharmthera.2022.108236] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/21/2022] [Accepted: 06/21/2022] [Indexed: 12/21/2022]
Abstract
Almost fifty years after its first introduction into clinical care, clozapine remains the only evidence-based pharmacological option for treatment-resistant schizophrenia (TRS), which affects approximately 30% of patients with schizophrenia. Despite the long-time experience with clozapine, the specific mechanism of action (MOA) responsible for its superior efficacy among antipsychotics is still elusive, both at the receptor and intracellular signaling level. This systematic review is aimed at critically assessing the role and specific relevance of clozapine's multimodal actions, dissecting those mechanisms that under a translational perspective could shed light on molecular targets worth to be considered for further innovative antipsychotic development. In vivo and in vitro preclinical findings, supported by innovative techniques and methods, together with pharmacogenomic and in vivo functional studies, point to multiple and possibly overlapping MOAs. To better explore this crucial issue, the specific affinity for 5-HT2R, D1R, α2c, and muscarinic receptors, the relatively low occupancy at dopamine D2R, the interaction with receptor dimers, as well as the potential confounder effects resulting in biased ligand action, and lastly, the role of the moiety responsible for lipophilic and alkaline features of clozapine are highlighted. Finally, the role of transcription and protein changes at the synaptic level, and the possibility that clozapine can directly impact synaptic architecture are addressed. Although clozapine's exact MOAs that contribute to its unique efficacy and some of its severe adverse effects have not been fully understood, relevant information can be gleaned from recent mechanistic understandings that may help design much needed additional therapeutic strategies for TRS.
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Affiliation(s)
- Andrea de Bartolomeis
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy.
| | - Licia Vellucci
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy
| | - Annarita Barone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy
| | - Mirko Manchia
- Section of Psychiatry, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy; Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Felice Iasevoli
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy
| | - Christoph U Correll
- The Zucker Hillside Hospital, Department of Psychiatry, Northwell Health, Glen Oaks, NY, USA; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Department of Psychiatry and Molecular Medicine, Hempstead, NY, USA; Charité Universitätsmedizin Berlin, Department of Child and Adolescent Psychiatry, Berlin, Germany
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Mazhar F, Battini V, Pozzi M, Invernizzi E, Mosini G, Gringeri M, Capuano A, Scavone C, Radice S, Clementi E, Carnovale C. Hyponatremia Following Antipsychotic Treatment: In Silico Pharmacodynamics Analysis of Spontaneous Reports From the US Food and Drug Administration Adverse Event Reporting System Database and an Updated Systematic Review. Int J Neuropsychopharmacol 2021; 24:477-489. [PMID: 33575781 PMCID: PMC8278799 DOI: 10.1093/ijnp/pyab005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 01/14/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Hyponatremia associated with antipsychotic drugs is a rare but potentially life-threatening adverse drug reaction; the underlying pharmacological mechanism has not yet been explained. METHODS We investigated the relationship between pharmacological targets of antipsychotic drugs and the occurrence of hyponatremia by conducting a nested case-control study using the Food and Drug Administration Adverse Event Reporting System database. Multiple logistic regression was used to determine the associations between antipsychotics receptor occupancy and hyponatremia. We also performed a systematic review of clinical studies on this association. RESULTS Of 139 816 reports involving at least 1 antipsychotic, 1.1% reported hyponatremia. Olanzapine was the most frequently suspected drug (27%). A significant positive association was found between dopamine D3, D4, and hyponatremia, while adrenergic α 1, serotonin 5-HT1A, and 5-HT2A receptor occupancies were negatively associated. A multivariable stepwise regression model showed that dopamine D3 (adj. odds ratio = 1.21; 95% CI = 1.09-1.34; P < .05) predicted the risk for hyponatremia (P < .05), while serotonin 5-HT2A occupancy (Adj. odds ratio = 0.78; 95% CI = 0.68-0.90; P < .01) exhibited a protective effect against hyponatremia. Among the 11 studies included in the systematic review, incidence rates of hyponatremia diverged between 0.003% and 86%, whereas the odds of developing hyponatremia from effect studies ranged between 0.83 and 3.47. CONCLUSIONS Antipsychotic drugs having a combined modest occupancy for D3 and 5-HT2A receptors and higher levels of D3 receptor occupancy correspond to different degrees of risk for hyponatremia. Based on the few, relatively large-scale available studies, atypical antipsychotics have a more attenuated risk profile for hyponatremia.
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Affiliation(s)
- Faizan Mazhar
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
| | - Vera Battini
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
| | - Marco Pozzi
- Scientific Institute, IRCCS E. Medea, Bosisio Parini, Italy
| | - Elena Invernizzi
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
| | - Giulia Mosini
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
| | - Michele Gringeri
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
| | - Annalisa Capuano
- Section of Pharmacology “L. Donatelli,” Department of Experimental Medicine, Campania Regional Centre for Pharmacovigilance and Pharmacoepidemiology, University of Campania “Luigi Vanvitelli,”Naples, Italy
| | - Cristina Scavone
- Section of Pharmacology “L. Donatelli,” Department of Experimental Medicine, Campania Regional Centre for Pharmacovigilance and Pharmacoepidemiology, University of Campania “Luigi Vanvitelli,”Naples, Italy
| | - Sonia Radice
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
| | - Emilio Clementi
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
- Scientific Institute, IRCCS E. Medea, Bosisio Parini, Italy
| | - Carla Carnovale
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences L. Sacco, “Luigi Sacco” University Hospital, Università di Milano, Milan, Italy
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Imaging synaptic dopamine availability in individuals at clinical high-risk for psychosis: a [ 11C]-(+)-PHNO PET with methylphenidate challenge study. Mol Psychiatry 2021; 26:2504-2513. [PMID: 33154566 DOI: 10.1038/s41380-020-00934-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/14/2020] [Accepted: 10/22/2020] [Indexed: 02/02/2023]
Abstract
Patients at clinical high-risk (CHR) for psychosis show elevations in [18F]DOPA uptake, an estimate of dopamine (DA) synthesis capacity, in the striatum predictive of conversion to schizophrenia. Intrasynaptic DA levels can be inferred from imaging the change in radiotracer binding at D2 receptors due to a pharmacological challenge. Here, we used methylphenidate, a DA reuptake inhibitor, and [11C]-(+)-PHNO, to measure synaptic DA availability in CHR both in striatal and extra-striatal brain regions. Fourteen unmedicated, nonsubstance using CHR individuals and 14 matched control subjects participated in the study. Subjects underwent two [11C]-(+)-PHNO scans, one at baseline and one following administration of a single oral dose (60 mg) of methylphenidate. [11C]-(+)-PHNO BPND, the binding potential relative to the nondisplaceable compartment, was derived using the simplified reference tissue model with cerebellum as reference tissue. The percent change in BPND between scans, ΔBPND, was computed as an index of synaptic DA availability, and group comparisons were performed with a linear mixed model. An overall trend was found for greater synaptic DA availability (∆BPND) in CHR than controls (p = 0.06). This was driven entirely by ∆BPND in ventral striatum (-34 ± 14% in CHR, -20 ± 12% in HC; p = 0.023). There were no significant group differences in any other brain region. There were no significant differences in DA transmission in any striatal region between converters and nonconverters, although this finding is limited by the small sample size (N = 2). There was a strong and negative correlation between ΔBPND in VST and severity of negative symptoms at baseline in the CHR group (r = -0.66, p < 0.01). We show abnormally increased DA availability in the VST in CHR and an inverse relationship with negative symptoms. Our results suggest a potential early role for mesolimbic dopamine overactivity in CHR. Longitudinal studies are needed to ascertain the significance of the differential topography observed here with the [18F]DOPA literature.
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Abstract
Tardive dyskinesia (TD) is a delayed and potentially irreversible motor complication following chronic exposure to centrally acting dopamine receptor antagonists, mainly of the class of antipsychotics drugs. New generations of antipsychotic drugs reduced its mean prevalence to 20%, but it continues to mar the drug experience and social integration in a significant fraction of patients. The underlying molecular cascade remains elusive, explaining in part why TD management is so often difficult. Protocol variations between experimental laboratories and inter-species differences in the biological response to antipsychotic drugs have added layers of complexity. The traditional dopamine D2 receptor supersensitivity hypothesis was revisited in an experimental nonhuman primate model. Findings in the striatum revealed a strong upregulation of D3, not D2, receptors specific to dyskinetic animals, and indirect evidence suggestive of a link between overactivation of glycogen synthase kinase-3β signaling and TD. New effective vesicular monoamine transporter type 2 inhibitors alleviating TD have been approved in the USA. They were integrated to an emerging stepwise treatment algorithm for troublesome TD, which also includes consideration for changes in the current antipsychotic drug regimen and recognition of potentially aggravating factors such as anticholinergic co-medications. These advances may benefit TD.
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Girgis RR, Forbes A, Abi-Dargham A, Slifstein M. A positron emission tomography occupancy study of brexpiprazole at dopamine D 2 and D 3 and serotonin 5-HT 1A and 5-HT 2A receptors, and serotonin reuptake transporters in subjects with schizophrenia. Neuropsychopharmacology 2020; 45:786-792. [PMID: 31847007 PMCID: PMC7075883 DOI: 10.1038/s41386-019-0590-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/20/2019] [Accepted: 12/05/2019] [Indexed: 11/09/2022]
Abstract
The objective of this study (NCT01854944) was to assess D2/D3, 5-HT1A, 5-HT2A and serotonin transporter (SERT) occupancies of brexpiprazole in adult subjects with schizophrenia in order to identify the in vivo pharmacologic profile that may be relevant to the antipsychotic, antidepressant, and side effect profiles of the drug. Subjects were grouped into three independent cohorts of four subjects each. All subjects underwent positron emission tomography (PET) scans with two different radiotracers at baseline prior to brexpiprazole administration, and again on Day 10 after daily doses of either 4 mg (Cohorts 1 and 2), or 1 mg (Cohort 3). Cohort 1 received scans with [11C]-(+)-PHNO to measure D2 and D3 receptor occupancy and [11C]CUMI101 to measure 5-HT1A occupancy; Cohort 2 received [11C]MDL100907 for 5-HT2A occupancy and [11C]DASB for SERT occupancy; Cohort 3 underwent scanning with [11C]-(+)-PHNO and [11C]MDL100907. Five female and seven male subjects, aged 42 ± 8 years (range, 28-55 years), participated in this study. Dose dependency was observed at D2 receptors, with occupancies reaching 64 ± 8% (mean +/- SD) following 1 mg/day and 80 ± 12% following 4 mg/day. D3 receptor availability increased following 1 mg brexpiprazole treatment and did not change with 4 mg. Robust and dose-related occupancy was also observed at 5-HT2A receptors. Negligible occupancy (<5%) was observed at 5-HT1A and SERT at 4 mg/day. In summary, brexpiprazole demonstrated in vivo binding to D2 receptors and 5-HT2A receptors at steady state after 10 days of daily administration in a dose dependent manner, while binding to D3, 5-HT1A receptors and SERT was not detectable with the radiotracers used for these targets. This pharmacologic profile is consistent with the observed antipsychotic and antidepressant effects.
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Affiliation(s)
- Ragy R Girgis
- New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, USA.
| | - Andy Forbes
- Otsuka Pharmaceutical Development & Commercialization Inc., Princeton, NJ, USA
| | - Anissa Abi-Dargham
- Department of Psychiatry, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Mark Slifstein
- Department of Psychiatry, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
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Caravaggio F, Worhunsky P, Graff-Guerrero A, Matuskey D. Further in vivo characterization of [ 11 C]-(+)-PHNO uptake into a retina-like region of interest in humans. Synapse 2019; 74:e22135. [PMID: 31553807 DOI: 10.1002/syn.22135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/20/2019] [Indexed: 11/12/2022]
Abstract
The neurotransmitter dopamine is present in the retina and is involved in several modulatory functions. Unlike in rodents, dopamine D3 receptors are expressed in the retina of humans. Recently, uptake of the D3 receptor-preferring radiotracer [11 C]-(+)-PHNO has been observed in a retina-like region of interest (ROI) in humans. Here, we attempted to quantify [11 C]-(+)-PHNO uptake into this ROI using an independent sample, employing an extended scan acquisition time (120 min) and arterial kinetic modeling. Data from 14 healthy controls were analyzed (Mean Age: 38.41 ± 9.55, 3 female), 8 of which provided arterial line input function data (Mean Age: 41.07 ± 7.82, 3 female). Using Ichise's multilinear analysis (MA1) method, it was possible to quantify the volume of distribution (VT ) of [11 C]-(+)-PHNO in this retina-like region (Mean VT = 13.56 ± 3.52; Mean χ2 = 2.08 ± 2.20). Notably, the shape of the time activity curve resembled closely that of the globus pallidus. Moreover, the VT values in the retina correlated well with binding potential (BPND ) values calculated using the simplified reference tissue model (Mean BPND = 2.11 ± .94; Mean χ2 = 5.76 ± 2.56), employing the cerebellum as the reference region (r = .76, r2 = .58). In summary, we provide evidence that the in vivo uptake of [11 C]-(+)-PHNO into a retina-like ROI in humans can be quantified using both arterial blood sampling (VT ) and simplified reference tissue methods (BPND ).
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Affiliation(s)
- Fernando Caravaggio
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Patrick Worhunsky
- Department of Psychiatry, Yale University, New Haven, Connecticut, USA
| | - Ariel Graff-Guerrero
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - David Matuskey
- Department of Psychiatry, Yale University, New Haven, Connecticut, USA.,PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA.,Department of Neurology, Yale University, New Haven, Connecticut, USA
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Caravaggio F, Iwata Y, Kim J, Shah P, Gerretsen P, Remington G, Graff-Guerrero A. What proportion of striatal D2 receptors are occupied by endogenous dopamine at baseline? A meta-analysis with implications for understanding antipsychotic occupancy. Neuropharmacology 2019; 163:107591. [PMID: 30940535 DOI: 10.1016/j.neuropharm.2019.03.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 11/30/2022]
Abstract
Using molecular imaging techniques - positron emission tomography (PET) and single-photon emission computed tomography (SPECT) - in conjunction with an acute dopamine depletion challenge (alpha-methyl-para-tyrosine) it is possible to estimate endogenous dopamine levels occupying striatal dopamine D2 receptors (D2R) in humans in vivo. However, it is unclear what proportion of striatal D2R are occupied by endogenous dopamine under normal conditions. This is important since it has been suggested that in schizophrenia there may be a substantial proportion of striatal D2R which are occupied by endogenous dopamine and not accessible by therapeutic doses of antipsychotics. In order to clarify these issues, we conducted a meta-analysis of dopamine depletion studies using substituted benzamide radiotracers in healthy persons. This meta-analysis suggests that anywhere from 8 to 21% (weighted average 11%) of striatal D2R may be occupied by endogenous dopamine at baseline. Using these estimates, we propose an updated occupancy model and tentatively suggest that antipsychotics inhibit a smaller proportion of the total pool of striatal D2R in vivo than previously acknowledged. This article is part of the issue entitled 'Special Issue on Antipsychotics'.
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Affiliation(s)
- Fernando Caravaggio
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.
| | - Yusuke Iwata
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Julia Kim
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 1 Kings College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Parita Shah
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 1 Kings College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Philip Gerretsen
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 1 Kings College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Gary Remington
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 1 Kings College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Ariel Graff-Guerrero
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 1 Kings College Circle, Toronto, Ontario, M5S 1A8, Canada
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11
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Hernandez G, Mahmoudi S, Cyr M, Diaz J, Blanchet PJ, Lévesque D. Tardive dyskinesia is associated with altered putamen Akt/GSK‐3β signaling in nonhuman primates. Mov Disord 2019; 34:717-726. [DOI: 10.1002/mds.27630] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 12/22/2018] [Accepted: 01/07/2019] [Indexed: 12/19/2022] Open
Affiliation(s)
| | - Souha Mahmoudi
- Faculté de PharmacieUniversité de Montréal Montréal Quebec Canada
| | - Michel Cyr
- Groupe de Recherche en Signalisation Moléculaire, Dép. de Biologie MédicaleUniversité du Québec à Trois‐Rivières Trois‐Rivières Quebec Canada
| | - Jorge Diaz
- INSERM U894, Centre de Psychiatrie et NeurosciencesUniversité Paris Descartes Paris France
| | - Pierre J. Blanchet
- Dép. de Stomatologie, Faculté de Médecine DentaireUniversité de Montréal Montréal Quebec Canada
| | - Daniel Lévesque
- Faculté de PharmacieUniversité de Montréal Montréal Quebec Canada
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12
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Caravaggio F, Scifo E, Sibille EL, Hernandez-Da Mota SE, Gerretsen P, Remington G, Graff-Guerrero A. Expression of dopamine D2 and D3 receptors in the human retina revealed by positron emission tomography and targeted mass spectrometry. Exp Eye Res 2018; 175:32-41. [PMID: 29883636 DOI: 10.1016/j.exer.2018.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/24/2018] [Accepted: 06/04/2018] [Indexed: 11/26/2022]
Abstract
Dopamine D2 receptors (D2R) are expressed in the human retina and play an important role in the modulation of neural responses to light-adaptation. However, it is unknown whether dopamine D3 receptors (D3R) are expressed in the human retina. Using positron emission tomography (PET), we have observed significant uptake of the D3R-preferring agonist radiotracer [11C]-(+)-PHNO into the retina of humans in vivo. This led us to examine whether [11C]-(+)-PHNO binding in the retina was quantifiable using reference tissue methods and if D3R are expressed in human post-mortem retinal tissue. [11C]-(+)-PHNO data from 49 healthy controls (mean age: 39.96 ± 14.36; 16 female) and 12 antipsychotic-naïve patients with schizophrenia (mean age: 25.75 ± 6.25; 4 female) were analyzed. We observed no differences in [11C]-(+)-PHNO binding in the retina between first-episode, drug-naïve patients with schizophrenia and healthy controls. Post-mortem retinal tissues from four healthy persons (mean age: 59.75 ± 9.11; 2 female) and four patients with schizophrenia (mean age: 54 ± 17.11; 2 female) were analyzed using a targeted mass spectrometry technique: parallel reaction monitoring (PRM) analysis. Using targeted mass spectrometry, we confirmed that D3R are expressed in human retinal tissue ex vivo. Notably, there was far greater expression of D2R relative to D3R in the healthy human retina (∼12:1). Moreover, PRM analysis revealed reduced D2R, but not D3R, expression in the retinas of non-first episode patients with schizophrenia compared to healthy controls. We confirm that D3R are expressed in the human retina. Future studies are needed to determine what proportion of the [11C]-(+)-PHNO signal in the human retina in vivo is due to binding to D3R versus D2R. Knowledge that both D2R and D3R are expressed in the human retina, and potentially quantifiable in vivo using [11C]-(+)-PHNO, poses new research avenues for better understanding the role of retinal dopamine in human vision. This work may have important implications for elucidating pathophysiological and antipsychotic induced visual deficits in schizophrenia.
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Affiliation(s)
- Fernando Caravaggio
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.
| | - Enzo Scifo
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Molecular and Cellular Cognition Lab, German Center for Neurodegenerative Diseases(DZNE), Bonn, Germany
| | - Etienne L Sibille
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Pharmacology and Toxicology, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | | | - Philip Gerretsen
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Gary Remington
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Ariel Graff-Guerrero
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
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13
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Tateno A, Sakayori T, Kim WC, Honjo K, Nakayama H, Arakawa R, Okubo Y. Comparison of Dopamine D3 and D2 Receptor Occupancies by a Single Dose of Blonanserin in Healthy Subjects: A Positron Emission Tomography Study With [11C]-(+)-PHNO. Int J Neuropsychopharmacol 2018; 21:522-527. [PMID: 29346639 PMCID: PMC6007421 DOI: 10.1093/ijnp/pyy004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 01/10/2018] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Blockade of D3 receptor, a member of the dopamine D2-like receptor family, has been suggested as a possible medication for schizophrenia. Blonanserin has high affinity in vitro for D3 as well as D2 receptors. We investigated whether a single dose of 12 mg blonanserin, which was within the daily clinical dose range (i.e., 8-24 mg) for the treatment of schizophrenia, occupies D3 as well as D2 receptors in healthy subjects. METHODS Six healthy males (mean 35.7±7.6 years) received 2 positron emission tomography scans, the first prior to taking blonanserin, and the second 2 hours after the administration of a single dose of 12 mg blonanserin. Dopamine receptor occupancies by blonanserin were evaluated by [11C]-(+)-PHNO. RESULTS Occupancy of each region by 12 mg blonanserin was: caudate (range 64.3%-81.5%; mean±SD, 74.3±5.6%), putamen (range 60.4%-84.3%; mean±SD, 73.3%±8.2%), ventral striatum (range 40.1%-88.2%; mean±SD, 60.8%±17.1%), globus pallidus (range 65.8%-87.6%; mean±SD, 75.7%±8.6%), and substantia nigra (range 56.0%-88.7%; mean±SD, 72.4%±11.0%). Correlation analysis between plasma concentration of blonanserin and receptor occupancy in D2-rich (caudate and putamen) and D3-rich (globus pallidus and substantia nigra) regions showed that EC50 for D2-rich region was 0.39 ng/mL (r=0.43) and EC50 for D3-rich region was 0.40 ng/mL (r=0.79). CONCLUSIONS A single dose of 12 mg blonanserin occupied D3 receptor to the same degree as D2 receptor in vivo. Our results were consistent with previous studies that reported that some of the pharmacological effect of blonanserin is mediated via D3 receptor antagonism.
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Affiliation(s)
- Amane Tateno
- Department of Neuropsychiatry, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Takeshi Sakayori
- Department of Neuropsychiatry, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Woo-chan Kim
- Department of Neuropsychiatry, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Kazuyoshi Honjo
- Clinical Imaging Center for Healthcare, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Haruo Nakayama
- Healthcare Solutions Division, Advanced Medical Services Department, Healthcare Business Unit, Hitachi, Ltd., Taito-ku, Tokyo, Japan
| | - Ryosuke Arakawa
- Department of Neuropsychiatry, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Yoshiro Okubo
- Department of Neuropsychiatry, Nippon Medical School, Bunkyo-ku, Tokyo, Japan,Correspondence: Yoshiro Okubo, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113–8602, Japan ()
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14
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Caravaggio F, Ku Chung J, Plitman E, Boileau I, Gerretsen P, Kim J, Iwata Y, Patel R, Chakravarty MM, Remington G, Graff-Guerrero A. The relationship between subcortical brain volume and striatal dopamine D 2/3 receptor availability in healthy humans assessed with [ 11 C]-raclopride and [ 11 C]-(+)-PHNO PET. Hum Brain Mapp 2017; 38:5519-5534. [PMID: 28752565 DOI: 10.1002/hbm.23744] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/21/2017] [Accepted: 07/16/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Abnormalities in dopamine (DA) and brain morphology are observed in several neuropsychiatric disorders. However, it is not fully understood how these abnormalities may relate to one another. For such in vivo findings to be used as biomarkers for neuropsychiatric disease, it must be understood how variability in DA relates to brain structure under healthy conditions. We explored how the availability of striatal DA D2/3 receptors (D2/3 R) is related to the volume of subcortical brain structures in a sample of healthy humans. Differences in D2/3 R availability measured with an antagonist radiotracer ([11 C]-raclopride) versus an agonist radiotracer ([11 C]-(+)-PHNO) were examined. METHODS Data from 62 subjects scanned with [11 C]-raclopride (mean age = 38.98 ± 14.45; 23 female) and 68 subjects scanned with [11 C]-(+)-PHNO (mean age = 38.54 ± 14.59; 25 female) were used. Subcortical volumes were extracted from T1-weighted images using the Multiple Automatically Generated Templates (MAGeT-Brain) algorithm. Partial correlations were used controlling for age, gender, and total brain volume. RESULTS For [11 C]-(+)-PHNO, ventral caudate volumes were positively correlated with BPND in the dorsal caudate and globus pallidus (GP). Ventral striatum (VS) volumes were positively correlated with BPND in the VS. With [11 C]-raclopride, BPND in the VS was negatively correlated with subiculum volume of the hippocampus. Moreover, BPND in the GP was negatively correlated with the volume of the lateral posterior nucleus of the thalamus. CONCLUSION Findings are purely exploratory and presented corrected and uncorrected for multiple comparisons. We hope they will help inform the interpretation of future PET studies where concurrent changes in D2/3 R and brain morphology are observed. Hum Brain Mapp 38:5519-5534, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Fernando Caravaggio
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.,Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Jun Ku Chung
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Eric Plitman
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Isabelle Boileau
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.,Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Philip Gerretsen
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.,Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Julia Kim
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Yusuke Iwata
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.,Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Raihaan Patel
- Department of Biological & Biomedical Engineering, McGill University, Montreal, Quebec, H4H 1R3, Canada.,Cerebral Imaging Centre, Douglas Mental Health Institute, McGill University, Montreal, Quebec, H4H 1R3, Canada
| | - M Mallar Chakravarty
- Department of Biological & Biomedical Engineering, McGill University, Montreal, Quebec, H4H 1R3, Canada.,Cerebral Imaging Centre, Douglas Mental Health Institute, McGill University, Montreal, Quebec, H4H 1R3, Canada.,Department of Psychiatry, McGill University, Montreal, Quebec, H4H 1R3, Canada
| | - Gary Remington
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.,Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Ariel Graff-Guerrero
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.,Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
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15
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Sokoloff P, Le Foll B. The dopamine D3 receptor, a quarter century later. Eur J Neurosci 2016; 45:2-19. [DOI: 10.1111/ejn.13390] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/23/2016] [Accepted: 08/28/2016] [Indexed: 12/16/2022]
Affiliation(s)
| | - Bernard Le Foll
- Centre for Addiction and Mental Health; Toronto ON Canada
- University of Toronto; Toronto ON Canada
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16
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Girgis RR, Slifstein M, D'Souza D, Lee Y, Periclou A, Ghahramani P, Laszlovszky I, Durgam S, Adham N, Nabulsi N, Huang Y, Carson RE, Kiss B, Kapás M, Abi-Dargham A, Rakhit A. Preferential binding to dopamine D3 over D2 receptors by cariprazine in patients with schizophrenia using PET with the D3/D2 receptor ligand [(11)C]-(+)-PHNO. Psychopharmacology (Berl) 2016; 233:3503-12. [PMID: 27525990 PMCID: PMC5035321 DOI: 10.1007/s00213-016-4382-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 07/10/2016] [Indexed: 01/01/2023]
Abstract
RATIONALE Second-generation antipsychotics occupy dopamine D2 receptors and act as antagonists or partial agonists at these receptors. While these drugs alleviate positive symptoms in patients with schizophrenia, they are less effective for treating cognitive deficits and negative symptoms. Dopamine D3 receptors are highly expressed in areas of the brain thought to play a role in the regulation of motivation and reward-related behavior. Consequently, the dopamine D3 receptor has become a target for treating negative symptoms in combination with D2 antagonism to treat positive symptoms in patients with schizophrenia. OBJECTIVE The purpose of this study was to determine the cariprazine receptor occupancies in brain for D2 and D3 receptors in patients with schizophrenia. METHODS Using [(11)C]-(+)-PHNO as a radioligand, positron emission tomography (PET) scans were performed in eight patients at baseline and postdose on days 1, 4, and 15. Plasma and cerebrospinal fluid (CSF) samples were analyzed for cariprazine concentrations. RESULTS A monotonic dose-occupancy relationship was observed for both receptor types. After 2 weeks of treatment, near complete (∼100 %) occupancies were observed for both receptors at a dose of 12 mg/day. At the lowest cariprazine dose (1 mg/day), mean D3 and D2 receptor occupancies were 76 and 45 %, respectively, suggesting selectivity for D3 over D2 receptors at low doses. An exposure-response analysis found a ∼3-fold difference in EC50 (D3 = 3.84 nM and D2 = 13.03 nM) in plasma after 2 weeks of dosing. CONCLUSION This PET imaging study in patients with schizophrenia demonstrated that cariprazine is a D3-preferring dual D3/D2 receptor partial agonist.
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Affiliation(s)
- Ragy R Girgis
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University, 1051 Riverside Drive Unit 31, New York, NY, 10032, USA.
- New York State Psychiatric Institute (NYSPI), Columbia University Medical Center, New York, NY, USA.
| | - Mark Slifstein
- New York State Psychiatric Institute (NYSPI), Columbia University Medical Center, New York, NY, USA
| | - Deepak D'Souza
- Clinical Neuroscience Research Unit (CNRU), Yale School of Medicine, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, Yale PET Center, New Haven, CT, USA
| | - Yih Lee
- Forest Research Institute, Jersey City, NJ, USA
- Pharmaceutical Product Development, LLC, Richmond, VA, 23230, USA
| | | | | | | | | | - Nika Adham
- Forest Research Institute, Jersey City, NJ, USA
| | - Nabeel Nabulsi
- Department of Psychiatry, Yale University School of Medicine, Yale PET Center, New Haven, CT, USA
| | - Yiyun Huang
- Department of Psychiatry, Yale University School of Medicine, Yale PET Center, New Haven, CT, USA
| | - Richard E Carson
- Department of Psychiatry, Yale University School of Medicine, Yale PET Center, New Haven, CT, USA
| | - Béla Kiss
- Gedeon Richter Plc., Budapest, Hungary
| | | | - Anissa Abi-Dargham
- New York State Psychiatric Institute (NYSPI), Columbia University Medical Center, New York, NY, USA
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17
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Caravaggio F, Chung JK, Gerretsen P, Fervaha G, Nakajima S, Plitman E, Iwata Y, Wilson A, Graff-Guerrero A. Exploring the relationship between social attachment and dopamine D 2/3 receptor availability in the brains of healthy humans using [ 11C]-(+)-PHNO. Soc Neurosci 2016; 12:163-173. [PMID: 26873034 DOI: 10.1080/17470919.2016.1152997] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Differences in striatal dopamine (DA) function may be related to differences in the degree of social attachment to others. Using positron emission tomography (PET), socially detached persons demonstrate reduced DA D2/3 receptor (D2/3R) availability in the striatum. However, previous PET studies have only used antagonist radiotracers for D2/3R and have not specifically examined regions of interest (ROIs) such as the ventral striatum (VS). In 32 healthy persons, we investigated the relationship between self-reported attachment and DA D2/3R availability in striatal and extrastriatal ROIs as measured using the agonist radiotracer [11C]-(+)-PHNO. Surprisingly, more social attachment-as measured by the attachment subscale of the temperament and character inventory-was related to less [11C]-(+)-PHNO binding in the VS (r(30) = -.43, p = .01). This relationship held in a subsample who also completed the detachment subscale of the Karolinska Scales of Personality (r(10) = .62, p = .03). However, no relationships were observed with BPND in the dorsal striatum or D3R-specific ROIs. One potential explanation for these findings is that persons who are more socially detached have less endogenous DA occupying D2/3R in the VS. This interpretation warrants investigation by future research. These findings may help us better understand the neurochemical basis of attachment.
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Affiliation(s)
- Fernando Caravaggio
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8
| | - Jun Ku Chung
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8
| | - Philip Gerretsen
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8.,c Department of Psychiatry , University of Toronto , Toronto , Ontario , Canada M5T 1R8
| | - Gagan Fervaha
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8
| | - Shinichiro Nakajima
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,c Department of Psychiatry , University of Toronto , Toronto , Ontario , Canada M5T 1R8
| | - Eric Plitman
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8
| | - Yusuke Iwata
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8
| | - Alan Wilson
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8.,c Department of Psychiatry , University of Toronto , Toronto , Ontario , Canada M5T 1R8
| | - Ariel Graff-Guerrero
- a Research Imaging Centre, Centre for Addiction and Mental Health , Toronto , Ontario , Canada M5T 1R8.,b Institute of Medical Science, University of Toronto , Toronto , Ontario , Canada M5S 1A8.,c Department of Psychiatry , University of Toronto , Toronto , Ontario , Canada M5T 1R8
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18
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Matuskey D, Worhunksy P, Correa E, Pittman B, Gallezot JD, Nabulsi N, Ropchan J, Sreeram V, Gudepu R, Gaiser E, Cosgrove K, Ding YS, Potenza MN, Huang Y, Malison RT, Carson RE. Age-related changes in binding of the D2/3 receptor radioligand [(11)C](+)PHNO in healthy volunteers. Neuroimage 2016; 130:241-247. [PMID: 26876475 DOI: 10.1016/j.neuroimage.2016.02.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 01/06/2016] [Accepted: 02/04/2016] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE Previous imaging studies with positron emission tomography (PET) have reliably demonstrated an age-associated decline in the dopamine system. Most of these studies have focused on the densities of dopamine receptor subtypes D2/3R (D2R family) in the striatum using antagonist radiotracers that are largely nonselective for D2R vs. D3R subtypes. Therefore, less is known about any possible age effects in D3-rich extrastriatal areas such as the substantia nigra/ventral tegmental area (SN/VTA) and hypothalamus. This study sought to investigate whether the receptor availability measured with [(11)C](+)PHNO, a D3R-preferring agonist radiotracer, also declines with age. METHODS Forty-two healthy control subjects (9 females, 33 males; age range 19-55 years) were scanned with [(11)C](+)PHNO using a High Resolution Research Tomograph (HRRT). Parametric images were computed using the simplified reference tissue model (SRTM2) with cerebellum as the reference region. Binding potentials (BPND) were calculated for the amygdala, caudate, hypothalamus, pallidum, putamen, SN/VTA, thalamus, and ventral striatum and then confirmed at the voxel level with whole-brain parametric images. RESULTS Regional [(11)C](+)PHNO BPND displayed a negative correlation between receptor availability and age in the caudate (r=-0.56, corrected p=0.0008) and putamen (r=-0.45, corrected p=0.02) in healthy subjects (respectively 8% and 5% lower per decade). No significant correlations with age were found between age and other regions (including the hypothalamus and SN/VTA). Secondary whole-brain voxel-wise analysis confirmed these ROI findings of negative associations and further identified a positive correlation in midbrain (SN/VTA) regions. CONCLUSION In accordance with previous studies, the striatum (an area rich in D2R) is associated with age-related declines of the dopamine system. We did not initially find evidence of changes with age in the SN/VTA and hypothalamus, areas previously found to have a predominantly D3R signal as measured with [(11)C](+)PHNO. A secondary analysis did find a significant positive correlation in midbrain (SN/VTA) regions, indicating that there may be differential effects of aging, whereby D2R receptor availability decreases with age while D3R availability stays unchanged or is increased.
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Affiliation(s)
- David Matuskey
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA; Department of Psychiatry, Yale University, New Haven, CT, USA.
| | - Patrick Worhunksy
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Elizabeth Correa
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Brian Pittman
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | | | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Venkatesh Sreeram
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Rohit Gudepu
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Edward Gaiser
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA; Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Kelly Cosgrove
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA; Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Yu-Shin Ding
- Department of Radiology, New York University School of Medicine, New York, NY, USA; Department of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - Marc N Potenza
- Department of Psychiatry, Yale University, New Haven, CT, USA; Department of Neurobiology, Yale University, New Haven, CT, USA; Department ofChild Study Center, Yale University, New Haven, CT, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | | | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
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19
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Lemercier CE, Schulz SB, Heidmann KE, Kovács R, Gerevich Z. Dopamine D3 Receptors Inhibit Hippocampal Gamma Oscillations by Disturbing CA3 Pyramidal Cell Firing Synchrony. Front Pharmacol 2016; 6:297. [PMID: 26779018 PMCID: PMC4702013 DOI: 10.3389/fphar.2015.00297] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/03/2015] [Indexed: 11/13/2022] Open
Abstract
Cortical gamma oscillations are associated with cognitive processes and are altered in several neuropsychiatric conditions such as schizophrenia and Alzheimer’s disease. Since dopamine D3 receptors are possible targets in treatment of these conditions, it is of great importance to understand their role in modulation of gamma oscillations. The effect of D3 receptors on gamma oscillations and the underlying cellular mechanisms were investigated by extracellular local field potential and simultaneous intracellular sharp micro-electrode recordings in the CA3 region of the hippocampus in vitro. D3 receptors decreased the power and broadened the bandwidth of gamma oscillations induced by acetylcholine or kainate. Blockade of the D3 receptors resulted in faster synchronization of the oscillations, suggesting that endogenous dopamine in the hippocampus slows down the dynamics of gamma oscillations by activation of D3 receptors. Investigating the underlying cellular mechanisms for these effects showed that D3 receptor activation decreased the rate of action potentials (APs) during gamma oscillations and reduced the precision of the AP phase coupling to the gamma cycle in CA3 pyramidal cells. The results may offer an explanation how selective activation of D3 receptors may impair cognition and how, in converse, D3 antagonists may exert pro-cognitive and antipsychotic effects.
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Affiliation(s)
- Clément E Lemercier
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin Berlin, Germany
| | - Steffen B Schulz
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin Berlin, Germany
| | - Karin E Heidmann
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin Berlin, Germany
| | - Richard Kovács
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin Berlin, Germany
| | - Zoltan Gerevich
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin Berlin, Germany
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20
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Occupancy of Dopamine D3 and D2 Receptors by Buspirone: A [11C]-(+)-PHNO PET Study in Humans. Neuropsychopharmacology 2016; 41:529-37. [PMID: 26089182 PMCID: PMC5130128 DOI: 10.1038/npp.2015.177] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 06/08/2015] [Accepted: 06/10/2015] [Indexed: 11/08/2022]
Abstract
There is considerable interest in blocking the dopamine D3 receptor (DRD3) versus the D2 receptor (DRD2) to treat drug addiction. However, there are currently no selective DRD3 antagonists available in the clinic. The anxiolytic drug buspirone has been proposed as a potential strategy as findings suggest that this drug has high in vitro affinity for DRD3, binds to DRD3 in brain of living non-human primate, and also disrupts psychostimulant self-administration in preclinical models. No study has explored the occupancy of DRD3 by buspirone in humans. Here, we used positron emission tomography (PET) and the D3-preferring probe, [(11)C]-(+)-PHNO, to test the hypothesis that buspirone will occupy (decreases [(11)C]-(+)-PHNO binding) the DRD3 more readily than the DRD2. Eight healthy participants underwent [(11)C]-(+)-PHNO scans after single oral dose administration of placebo and 30, 60, and 120 mg of buspirone in a single-blind within-subjects design. [(11)C]-(+)-PHNO binding in DRD2- and DRD3-rich areas was decreased by the highest (60-120 mg), but not the lowest (30 mg), doses of buspirone. The maximal occupancy obtained was ~25% in both areas. Plasma levels of prolactin (a DRD2 marker) correlated with percentage occupancy after orally administered buspirone. Self-reported dizziness and drowsiness increased after buspirone but that did not correlate with receptor occupancy in any region. Overall, the modest occupancy of DRD2 and DRD3 even at high acute doses of buspirone, yielding high levels of metabolites, suggests that buspirone may not be a good drug to preferentially block DRD3 in humans.
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21
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Nakajima S, Caravaggio F, Boileau I, Chung JK, Plitman E, Gerretsen P, Wilson AA, Houle S, Mamo DC, Graff-Guerrero A. Lack of age-dependent decrease in dopamine D3 receptor availability: a [(11)C]-(+)-PHNO and [(11)C]-raclopride positron emission tomography study. J Cereb Blood Flow Metab 2015; 35:1812-8. [PMID: 26058690 PMCID: PMC4635236 DOI: 10.1038/jcbfm.2015.129] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 03/17/2015] [Accepted: 04/23/2015] [Indexed: 02/05/2023]
Abstract
Positron emission tomography with antagonist radiotracers has showed that striatal dopamine D2/3 receptor (D2/3R) availability decreases with age. However, no study has specifically assessed whether D2/3R availability decreases with age in healthy persons as measured with agonist radiotracers. Moreover, it is unknown whether D3R availability changes with age in healthy humans. Thus, we explored the relationship between age and D2/3R availability in healthy humans using the D3 receptor (D3R)-preferential agonist radiotracer [(11)C]-(+)-PHNO (n=72, mean±s.d. age=40±15, range=18 to 73) and the antagonist [(11)C]-Raclopride (n=70, mean±s.d. age =40±14, range=18 to 73) (both, n=33). The contribution of D3R to the [(11)C]-(+)-PHNO signal varies across regions of interest; the substantia nigra and hypothalamus represent D3R-specific regions, the ventral pallidum, globus pallidus, and ventral striatum represent D2/3R-mixed regions, and the caudate and putamen represent D2 receptor (D2R)-specific regions. With [(11)C]-(+)-PHNO, a negative correlation was observed between age and nondisplaceable binding potential (BPND) in the caudate (r(70)=-0.32, P=0.005). No correlations were observed in the other regions. With [(11)C]-Raclopride, negative correlations were observed between age and BPND in the caudate (r(68)=-0.50, P<0.001), putamen (r(68)=-0.41, P<0.001), and ventral striatum (r(68)=-0.43, P<0.001). In conclusion, in contrast with the age-dependent decrease in D2R availability, these findings suggest that D3R availability does not change with age.
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Affiliation(s)
- Shinichiro Nakajima
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo, Japan
| | - Fernando Caravaggio
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Isabelle Boileau
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
| | - Jun K Chung
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Eric Plitman
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Philip Gerretsen
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Alan A Wilson
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
| | - Sylvain Houle
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
| | - David C Mamo
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, University of Malta, Valletta, Malta
| | - Ariel Graff-Guerrero
- Multimodal Imaging Group-Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, Ontario, Canada
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22
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Girgis RR, Xu X, Gil RB, Hackett E, Ojeil N, Lieberman JA, Slifstein M, Abi-Dargham A. Antipsychotic binding to the dopamine-3 receptor in humans: A PET study with [(11)C]-(+)-PHNO. Schizophr Res 2015; 168:373-6. [PMID: 26190300 PMCID: PMC4591174 DOI: 10.1016/j.schres.2015.06.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 06/25/2015] [Accepted: 06/29/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND All currently available antipsychotic medications bind to both the dopamine-2 (D2) and dopamine-3 (D3) receptors in vitro. However, there is conflicting evidence from in vivo studies about whether or not antipsychotic medications bind to the D3 receptor (D3R). The purpose of this study was to determine whether acute doses of risperidone bind to the D3R in humans. METHODS We performed PET scans on an mCT scanner with [(11)C]-(+)-PHNO injected as a bolus, before and after a 2mg oral dose of risperidone in five medication free subjects with schizophrenia. The subjects were scanned for 120min and underwent an MRI scan for region of interest delineation and coregistration. Cerebellum was used as a reference region. Simplified reference tissue modeling (SRTM) was used to calculate BPND. RESULTS We observed binding to the D3R receptor by risperidone as evidenced by observable occupancy in regions in which the [(11)C]-(+)-PHNO signal is almost exclusively from the D3R (i.e., substantia nigra/ventral tegmental area). Using a regression model to estimate D2R:D3R selectivity, we observed a D2R:D3R selectivity of 2.1 for risperidone. CONCLUSION Our preliminary results provide further support that acute doses of antipsychotic medications bind to the D3R and provide additional support for the further development of this receptor as a treatment target in schizophrenia.
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Affiliation(s)
- Ragy R. Girgis
- Corresponding author, Tel. +1 646 774 5553; fax: +1 212 568 6171.
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23
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Baba S, Enomoto T, Horisawa T, Hashimoto T, Ono M. Blonanserin extensively occupies rat dopamine D3 receptors at antipsychotic dose range. J Pharmacol Sci 2015; 127:326-31. [PMID: 25837930 DOI: 10.1016/j.jphs.2015.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 01/04/2015] [Accepted: 01/22/2015] [Indexed: 12/14/2022] Open
Abstract
Antagonism of the dopamine D3 receptor has been hypothesized to be beneficial for schizophrenia cognitive deficits, negative symptoms and extrapyramidal symptoms. However, recent animal and human studies have shown that most antipsychotics do not occupy D3 receptors in vivo, despite their considerable binding affinity for this receptor in vitro. In the present study, we investigated the D3 receptor binding of blonanserin, a dopamine D2/D3 and serotonin 5-HT2A receptors antagonist, in vitro and in vivo. Blonanserin showed the most potent binding affinity for human D3 receptors among the tested atypical antipsychotics (risperidone, olanzapine and aripiprazole). Our GTPγS-binding assay demonstrated that blonanserin acts as a potent full antagonist for human D3 receptors. All test-drugs exhibited antipsychotic-like efficacy in methamphetamine-induced hyperactivity in rats. Treatment with blonanserin at its effective dose blocked the binding of [(3)H]-(+)-PHNO, a D2/D3 receptor radiotracer, both in the D2 receptor-rich region (striatum) and the D3 receptor-rich region (cerebellum lobes 9 and 10). On the other hand, the occupancies of other test-drugs for D3 receptors were relatively low. In conclusion, we have shown that blonanserin, but not other tested antipsychotics, extensively occupies D3 receptors in vivo in rats.
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Affiliation(s)
- Satoko Baba
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
| | - Takeshi Enomoto
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan.
| | - Tomoko Horisawa
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
| | - Takashi Hashimoto
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
| | - Michiko Ono
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
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24
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Cosgrove KP, Esterlis I, Sandiego C, Petrulli R, Morris ED. Imaging Tobacco Smoking with PET and SPECT. Curr Top Behav Neurosci 2015; 24:1-17. [PMID: 25638332 DOI: 10.1007/978-3-319-13482-6_1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Receptor imaging, including positron emission computed tomography (PET) and single photon emission computed tomography (SPECT), provides a way to measure chemicals of interest, such as receptors, and neurotransmitter fluctuations, in the living human brain. Imaging the neurochemical mechanisms involved in the maintenance and recovery from tobacco smoking has provided insights into critical smoking related brain adaptations. Nicotine, the primary addictive chemical in tobacco smoke, enters the brain, activates beta2-nicotinic acetylcholine receptors (β2*-nAChRs) and, like most drugs of abuse, elicits dopamine (DA) release in the ventral striatum. Both β2*-nAChRs and DA signaling are critical neurosubstrates underlying tobacco smoking behaviors and dependence and have been studied extensively with PET and SPECT brain imaging. We review the imaging literature on these topics and describe how brain imaging has helped inform the treatment of tobacco smoking.
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Affiliation(s)
- Kelly P Cosgrove
- Department of Psychiatry, Yale University School of Medicine, 2 Church Street South, Suite 511, New Haven, CT, 06519, USA,
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25
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Abstract
Dopamine D3 receptor (D3R) antagonists may be effective medications for multiple substance use disorders (SUDs). However, no selective D3R antagonists are currently available for clinical testing. Buspirone, originally characterized as a 5-HT1A partial agonist and used as an anxiolytic, also binds to D3R and D4R with high affinity, with lower affinity to D2R, and interferes with cocaine reward. Here we used PET with [11C]PHNO (D3R-preferring radioligand), [11C]raclopride (D2R/D3R radioligand) and [11C]NNC-112 (D1R radioligand) to measure occupancy of oral and parenteral buspirone in the primate brain. Intramuscular buspirone (0.19 and 0.5 mg/kg) blocked both [11C]PHNO and [11C]raclopride binding to striatum, exhibiting high occupancy (50-85%) at 15 min and rapid wash-out over 2-6 h. In contrast, oral buspirone (3 mg/kg) significantly blocked [11C]PHNO binding in D3-rich regions (globus pallidum and midbrain) at 3 h, but had minimal effects on [11C]raclopride binding (28-37% at 1 h and 10% at 3 h). Buspirone did not block [11C]NNC-112. Our findings provide evidence that i.m. buspirone blocks D3R and D2R, whereas oral buspirone is more selective towards D3R blockade in vivo, consistent with extensive first pass metabolism and supporting the hypothesis that its metabolites (5- and 6'-hydroxybuspirone) merit evaluation for treating SUDs. They also indicate that for oral buspirone to achieve greater than 80% sustained D3R occupancy, as might be needed to treat addiction, higher doses (at least three-fold) than those used to treat anxiety (maximal 60 mg) will be required. Nonetheless, based on previous clinical studies, these doses would be safe and well tolerated.
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26
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Mahmoudi S, Lévesque D, Blanchet PJ. Upregulation of dopamine D3, not D2, receptors correlates with tardive dyskinesia in a primate model. Mov Disord 2014; 29:1125-33. [PMID: 24838395 DOI: 10.1002/mds.25909] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/24/2014] [Accepted: 04/08/2014] [Indexed: 11/12/2022] Open
Abstract
Tardive dyskinesia (TD) is a delayed and potentially irreversible motor complication arising in patients chronically exposed to centrally active dopamine D2 receptor antagonists, including antipsychotic drugs and metoclopramide. The classical dopamine D2 receptor supersensitivity hypothesis in TD, which stemmed from rodent studies, lacks strong support in humans. To investigate the neurochemical basis of TD, we chronically exposed adult capuchin monkeys to haloperidol (median, 18.5 months; n = 11) or clozapine (median, 6 months; n = 6). Six unmedicated animals were used as controls. Five haloperidol-treated animals developed mild TD movements, and no TD was observed in the clozapine group. Using receptor autoradiography, we measured striatal dopamine D1, D2, and D3 receptor levels. We also examined the D3 receptor/preprotachykinin messenger RNA (mRNA) co-expression, and quantified preproenkephalin mRNA levels, in striatal sections. Unlike clozapine, haloperidol strongly induced dopamine D3 receptor binding sites in the anterior caudate-putamen, particularly in TD animals, and binding levels positively correlated with TD intensity. Interestingly, the D3 receptor upregulation was observed in striatonigral neurons. In contrast, D2 receptor binding was comparable to controls, and dopamine D1 receptor binding was reduced in the anterior putamen. Enkephalin mRNA widely increased in all animals, but to a greater extent in TD-free animals. These results suggest for the first time that upregulated striatal D3 receptors correlate with TD in nonhuman primates, adding new insights to the dopamine receptor supersensitivity hypothesis. The D3 receptor could provide a novel target for drug intervention in human TD.
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Affiliation(s)
- Souha Mahmoudi
- Faculty of Pharmacy, Universite de Montreal, Montreal, Quebec, Canada
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27
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Gallezot JD, Zheng MQ, Lim K, Lin SF, Labaree D, Matuskey D, Huang Y, Ding YS, Carson RE, Malison RT. Parametric Imaging and Test-Retest Variability of ¹¹C-(+)-PHNO Binding to D₂/D₃ Dopamine Receptors in Humans on the High-Resolution Research Tomograph PET Scanner. J Nucl Med 2014; 55:960-6. [PMID: 24732151 DOI: 10.2967/jnumed.113.132928] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 01/21/2014] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED (11)C-(+)-4-propyl-9-hydroxynaphthoxazine ((11)C-(+)-PHNO) is an agonist radioligand for imaging dopamine D2 and D3 receptors in the human brain with PET. In this study we evaluated the reproducibility of (11)C-(+)-PHNO binding parameters using a within-day design and assessed parametric imaging methods. METHODS Repeated studies were performed in 8 subjects, with simultaneous measurement of the arterial input function and plasma free fraction. Two (11)C-(+)-PHNO scans for the same subject were separated by 5.4 ± 0.7 h. After compartment models were evaluated, (11)C-(+)-PHNO volumes of distribution (V(T)) and binding potentials relative to the concentration of tracer in plasma (BP(P)), nondisplaceable tracer in tissue (BP(ND)), and free tracer in tissue (BP(F)) were quantified using the multilinear analysis MA1 method, with the cerebellum as the reference region. Parametric images of BP(ND) were also computed using the simplified reference tissue model (SRTM) and SRTM2. RESULTS The test-retest variability of (11)C-(+)-PHNO BP(ND) was 9% in D2-rich regions (caudate and putamen). Among D3-rich regions, variability was low in the pallidum (6%) but higher in substantia nigra (19%), thalamus (14%), and hypothalamus (21%). No significant mass carry-over effect was observed in D3-rich regions, although a trend in BP(ND) was present in the substantia nigra (-14% ± 15%). Because of the relatively fast kinetics, low-noise BP(ND) parametric images were obtained with both SRTM and SRTM2 without spatial smoothing. CONCLUSION (11)C-(+)-PHNO can be used to compute low-noise parametric images in both D2- and D3-rich regions in humans.
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Affiliation(s)
- Jean-Dominique Gallezot
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Ming-Qiang Zheng
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Keunpoong Lim
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Shu-fei Lin
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - David Labaree
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - David Matuskey
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut; and
| | - Yiyun Huang
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Yu-Shin Ding
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut Department of Radiology and Psychiatry, New York University School of Medicine, New York, New York
| | - Richard E Carson
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Robert T Malison
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut; and
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28
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Gallezot JD, Kloczynski T, Weinzimmer D, Labaree D, Zheng MQ, Lim K, Rabiner EA, Ridler K, Pittman B, Huang Y, Carson RE, Morris ED, Cosgrove KP. Imaging nicotine- and amphetamine-induced dopamine release in rhesus monkeys with [(11)C]PHNO vs [(11)C]raclopride PET. Neuropsychopharmacology 2014; 39:866-74. [PMID: 24220025 PMCID: PMC3924521 DOI: 10.1038/npp.2013.286] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 07/15/2013] [Accepted: 07/16/2013] [Indexed: 11/09/2022]
Abstract
The radiotracer [(11)C]PHNO may have advantages over other dopamine (DA) D2/D3 receptor ligands because, as an agonist, it measures high-affinity, functionally active D2/D3 receptors, whereas the traditionally used radiotracer [(11)C]raclopride measures both high- and low-affinity receptors. Our aim was to take advantage of the strength of [(11)C]PHNO for measuring the small DA signal induced by nicotine, which has been difficult to measure in preclinical and clinical neuroimaging studies. Nicotine- and amphetamine-induced DA release in non-human primates was measured with [(11)C]PHNO and [(11)C]raclopride positron emission tomography (PET) imaging. Seven adult rhesus monkeys were imaged on a FOCUS 220 PET scanner after injection of a bolus of [(11)C]PHNO or [(11)C]raclopride in three conditions: baseline; preinjection of nicotine (0.1 mg/kg bolus+0.08 mg/kg infusion over 30 min); preinjection of amphetamine (0.4 mg/kg, 5 min before radiotracer injection). DA release was measured as change in binding potential (BPND). Nicotine significantly decreased BPND in the caudate (7 ± 8%), the nucleus accumbens (10 ± 7%), and in the globus pallidus (13 ± 15%) measured with [(11)C]PHNO, but did not significantly decrease BPND in the putamen or the substantia nigra or in any region when measured with [(11)C]raclopride. Amphetamine significantly reduced BPND in all regions with both radiotracers. In the striatum, larger amphetamine-induced changes were detected with [(11)C]PHNO compared with [(11)C]raclopride (52-64% vs 33-35%, respectively). We confirmed that [(11)C]PHNO is more sensitive than [(11)C]raclopride to nicotine- and amphetamine-induced DA release. [(11)C]PHNO PET may be more sensitive to measuring tobacco smoking-induced DA release in human tobacco smokers.
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Affiliation(s)
- Jean-Dominique Gallezot
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - Tracy Kloczynski
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - David Weinzimmer
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - David Labaree
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - Ming-Qiang Zheng
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - Keunpoong Lim
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA
| | | | | | - Brian Pittman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Yiyun Huang
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - Richard E Carson
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA,Department of Biomedical Engineering, Yale University School of Medicine, New Haven, CT, USA
| | - Evan D Morris
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA,Department of Biomedical Engineering, Yale University School of Medicine, New Haven, CT, USA
| | - Kelly P Cosgrove
- Department of Diagnostic Radiology, Yale PET Center, Yale University School of Medicine, New Haven, CT, USA,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA,Department of Psychiatry, Yale University School of Medicine, 2 Church Street South, Suite 511, New Haven, CT 06519, USA, Tel: +1 203 737 6969, E-mail:
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Le Foll B, Collo G, Rabiner EA, Boileau I, Merlo Pich E, Sokoloff P. Dopamine D3 receptor ligands for drug addiction treatment: update on recent findings. PROGRESS IN BRAIN RESEARCH 2014; 211:255-75. [PMID: 24968784 DOI: 10.1016/b978-0-444-63425-2.00011-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The dopamine D3 receptor is located in the limbic area and apparently mediates selective effects on motivation to take drugs and drug-seeking behaviors, so that there has been considerable interest on the possible use of D3 receptor ligands to treat drug addiction. However, only recently selective tools allowing studying this receptor have been developed. This chapter presents an overview of findings that were presented at a symposium on the conference Dopamine 2013 in Sardinia in May 2013. Novel neurobiological findings indicate that drugs of abuse can lead to significant structural plasticity in rodent brain and that this is dependent on the availability of functional dopamine D3 autoreceptor, whose activation increased phosphorylation in the ERK pathway and in the Akt/mTORC1 pathway indicating the parallel engagement of a series of intracellular signaling pathways all involved in cell growth and survival. Preclinical findings using animal models of drug-seeking behaviors confirm that D3 antagonists have a promising profile to treat drug addiction across drugs of abuse type. Imaging the D3 is now feasible in human subjects. Notably, the development of (+)-4-propyl-9-hydroxynaphthoxazine ligand used in positron emission tomography (PET) studies in humans allows to measure D3 and D2 receptors based on the area of the brain under study. This PET ligand has been used to confirm up-regulation of D3 sites in psychostimulant users and to reveal that tobacco smoking produces elevation of dopamine at the level of D3 sites. There are now novel antagonists being developed, but also old drugs such as buspirone, that are available to test the D3 hypothesis in humans. The first results of clinical investigations are now being provided. Overall, those recent findings support further exploration of D3 ligands to treat drug addiction.
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Affiliation(s)
- Bernard Le Foll
- Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Alcohol Research and Treatment Clinic, Addiction Medicine Services, Ambulatory Care and Structured Treatments, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Family and Community Medicine, Pharmacology and Toxicology, Psychiatry, Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.
| | - Ginetta Collo
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Eugenii A Rabiner
- Imanova, Centre for Imaging Sciences, London, UK; Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College, London, UK
| | - Isabelle Boileau
- Addiction Imaging Research Group, Centre for Addiction and Mental Health, Toronto, ON, Canada
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Acutely administered antipsychotic drugs are highly selective for dopamine D2 over D3 receptors. Pharmacol Res 2013; 70:66-71. [DOI: 10.1016/j.phrs.2013.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 01/04/2013] [Accepted: 01/06/2013] [Indexed: 11/20/2022]
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Tóth M, Varrone A, Steiger C, Laszlovszky I, Horváth A, Kiss B, Gyertyán I, Adham N, Halldin C, Gulyás B. Brain uptake and distribution of the dopamine D3 /D2 receptor partial agonist [11 C]cariprazine: an in vivo positron emission tomography study in nonhuman primates. Synapse 2013; 67:258-64. [PMID: 23238770 DOI: 10.1002/syn.21631] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 12/05/2012] [Accepted: 12/07/2012] [Indexed: 12/11/2022]
Abstract
Cariprazine is a dopamine D(3)/D(2) receptor partial agonist antipsychotic candidate, which binds with high affinity to dopamine D(3) and D(2) receptors (with ∼10-fold higher in vitro affinity to D(3) vs. D(2) receptors) and with moderate affinity to 5-HT(1A) receptors. The main objective of the present molecular imaging investigation was to evaluate the uptake and reversible binding of 11-C labeled cariprazine in the nonhuman primate brain, in relation to the known distributions of dopamine D(2) and D(3) receptors. We examined the brains of two cynomolgus monkeys at baseline condition as well as during a pharmacological blocking condition, using unlabeled cariprazine or raclopride as blockers before injection of [(11) C]cariprazine. Of the total injected radioactivity, ∼7% entered the brain and ∼3-4% remained in the brain after 90 min, indicating good blood brain barrier penetration and slow washout. It was possible to block cariprazine binding with unlabeled cariprazine and raclopride indicating that [(11) C]cariprazine binds to dopamine D(3)/D(2) receptors. Nondisplaceable binding potential (BPND) measurements, using a simplified reference tissue model and cerebellum as the reference region, yielded values of ∼1.5 and 0.3 in the striatum and thalamus, respectively. Striatum BPND values were reduced by 80 and 85% following pretreatment with 0.1 mg/kg IV injection of unlabeled cariprazine and 1 mg/kg IV injection of unlabeled raclopride, respectively. The data confirm that cariprazine, a novel antipsychotic drug candidate, enters the nonhuman primate brain readily and binds to dopamine D(3)/D(2) receptors. Furthermore, in PET imaging [(11) C]cariprazine can effectively visualize dopamine D(3)/D(2) receptors in the nonhuman primate brain.
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Affiliation(s)
- Miklós Tóth
- Karolinska Institutet, Department of Clinical Neuroscience, Centrum for Psychiatry Research, S-171 76, Stockholm, Sweden.
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Gross G, Drescher K. The role of dopamine D(3) receptors in antipsychotic activity and cognitive functions. Handb Exp Pharmacol 2013:167-210. [PMID: 23027416 DOI: 10.1007/978-3-642-25758-2_7] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Dopamine D(3) receptors have a pre- and postsynaptic localization in brain stem nuclei, limbic parts of the striatum, and cortex. Their widespread influence on dopamine release, on dopaminergic function, and on several other neurotransmitters makes them attractive targets for therapeutic intervention. The signaling pathways of D(3) receptors are distinct from those of other members of the D(2)-like receptor family. There is increasing evidence that D(3) receptors can form heteromers with dopamine D(1), D(2), and probably other G-protein-coupled receptors. The functional consequences remain to be characterized in more detail but might open new interesting pharmacological insight and opportunities. In terms of behavioral function, D(3) receptors are involved in cognitive, social, and motor functions, as well as in filtering and sensitization processes. Although the role of D(3) receptor blockade for alleviating positive symptoms is still unsettled, selective D(3) receptor antagonism has therapeutic features for schizophrenia and beyond as demonstrated by several animal models: improved cognitive function, emotional processing, executive function, flexibility, and social behavior. D(3) receptor antagonism seems to contribute to atypicality of clinically used antipsychotics by reducing extrapyramidal motor symptoms; has no direct influence on prolactin release; and does not cause anhedonia, weight gain, or metabolic dysfunctions. Unfortunately, clinical data with new, selective D(3) antagonists are still incomplete; their cognitive effects have only been communicated in part. In vitro, virtually all clinically used antipsychotics are not D(2)-selective but also have affinity for D(3) receptors. The exact D(3) receptor occupancies achieved in patients, particularly in cortical areas, are largely unknown, mainly because only nonselective or agonist PET tracers are currently available. It is unlikely that a degree of D(3) receptor antagonism optimal for antipsychotic and cognitive function can be achieved with existing antipsychotics. Therefore, selective D(3) antagonism represents a promising mechanism still to be fully exploited for the treatment of schizophrenia, cognitive deficits in schizophrenia, and comorbid conditions such as substance abuse.
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Affiliation(s)
- Gerhard Gross
- Abbott, Neuroscience Research, Ludwigshafen, Germany.
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Dopamine D3 receptor antagonism—still a therapeutic option for the treatment of schizophrenia. Naunyn Schmiedebergs Arch Pharmacol 2012; 386:155-66. [DOI: 10.1007/s00210-012-0806-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/19/2012] [Indexed: 10/27/2022]
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Direct and indirect interactions of the dopamine D₃ receptor with glutamate pathways: implications for the treatment of schizophrenia. Naunyn Schmiedebergs Arch Pharmacol 2012; 386:107-24. [PMID: 23001156 PMCID: PMC3558669 DOI: 10.1007/s00210-012-0797-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 09/03/2012] [Indexed: 12/24/2022]
Abstract
This article, based on original data as well as on previously reported preclinical and clinical data that are reviewed, describes direct and indirect interactions of the D(3) receptor with N-methyl-D-aspartate receptor (NMDA) signaling and their functional consequences and therapeutic implications for schizophrenia. D(3) receptor immunoreactivity at ultrastructural level with electron microscopy was identified at presumably glutamatergic, asymmetric synapses of the medium-sized spiny neurons of the nucleus accumbens. This finding supports the existence of a direct interaction of the D(3) receptor with glutamate, in line with previously described interactions with NMDA signaling involving Ca(2+)/calmodulin-dependent protein kinase II at post-synaptic densities (Liu et al. 2009). Indirect interactions of the D(3) receptor with glutamate could involve a negative control exerted by the D(3) receptor on mesocortical dopamine neurons and the complex regulation of the glutamatergic pyramidal cells by dopamine in the prefrontal cortex. This could be exemplified here by the regulation of pyramidal cell activity in conditions of chronic NMDA receptor blockade with dizocilpine (MK-801). BP897, a D(3) receptor-selective partial agonist, reversed the dysregulation of cortical c-fos mRNA expression and pyramidal cell hyperexcitability, as measured by paired-pulse electrophysiology. At the behavioral level, blockade of the D(3) receptor, by known D(3) receptor antagonists or the novel D(3) receptor-selective antagonist F17141, produces antipsychotic-like effects in reversing hyperactivity and social interaction deficits induced by NMDA receptor blockade by MK-801 in mice. The glutamate-D(3) receptor interactions described here offer a conceptual framework for developing new D(3) receptor-selective drugs, which may appear as an original, efficacious, and safe way to potentially indirectly target glutamate in schizophrenia.
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Eisenstein SA, Koller JM, Piccirillo M, Kim A, Antenor-Dorsey JAV, Videen TO, Snyder AZ, Karimi M, Moerlein SM, Black KJ, Perlmutter JS, Hershey T. Characterization of extrastriatal D2 in vivo specific binding of [¹⁸F](N-methyl)benperidol using PET. Synapse 2012; 66:770-80. [PMID: 22535514 DOI: 10.1002/syn.21566] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 04/16/2012] [Accepted: 04/17/2012] [Indexed: 12/25/2022]
Abstract
PET imaging studies of the role of the dopamine D2 receptor family in movement and neuropsychiatric disorders are limited by the use of radioligands that have near-equal affinities for D2 and D3 receptor subtypes and are susceptible to competition with endogenous dopamine. By contrast, the radioligand [¹⁸F]N-methylbenperidol ([¹⁸F]NMB) has high selectivity and affinity for the D2 receptor subtype (D2R) and is not sensitive to endogenous dopamine. Although [¹⁸F]NMB has high binding levels in striatum, its utility for measuring D2R in extrastriatal regions is unknown. A composite MR-PET image was constructed across 14 healthy adult participants representing average NMB uptake 60 to 120 min after [¹⁸F]NMB injection. Regional peak radioactivity was identified using a peak-finding algorithm. FreeSurfer and manual tracing identified a priori regions of interest (ROI) on each individual's MR image and tissue activity curves were extracted from coregistered PET images. [¹⁸F]NMB binding potentials (BP(ND) s) were calculated using the Logan graphical method with cerebellum as reference region. In eight unique participants, extrastriatal BP(ND) estimates were compared between Logan graphical methods and a three-compartment kinetic tracer model. Radioactivity and BP(ND) levels were highest in striatum, lower in extrastriatal subcortical regions, and lowest in cortical regions relative to cerebellum. Age negatively correlated with striatal BP(ND) s. BP(ND) estimates for extrastriatal ROIs were highly correlated across kinetic and graphical methods. Our findings indicate that PET with [¹⁸F]NMB measures specific binding in extrastriatal regions, making it a viable radioligand to study extrastriatal D2R levels in healthy and diseased states.
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Affiliation(s)
- Sarah A Eisenstein
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
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Matthews PM, Rabiner EA, Passchier J, Gunn RN. Positron emission tomography molecular imaging for drug development. Br J Clin Pharmacol 2012; 73:175-86. [PMID: 21838787 DOI: 10.1111/j.1365-2125.2011.04085.x] [Citation(s) in RCA: 231] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Human in vivo molecular imaging with positron emission tomography (PET) enables a new kind of 'precision pharmacology', able to address questions central to drug development. Biodistribution studies with drug molecules carrying positron-emitting radioisotopes can test whether a new chemical entity reaches a target tissue compartment (such as the brain) in sufficient amounts to be pharmacologically active. Competition studies, using a radioligand that binds to the target of therapeutic interest with adequate specificity, enable direct assessment of the relationship between drug plasma concentration and target occupancy. Tailored radiotracers can be used to measure relative rates of biological processes, while radioligands specific for tissue markers expected to change with treatment can provide specific pharmacodynamic information. Integrated application of PET and magnetic resonance imaging (MRI) methods allows molecular interactions to be related directly to anatomical or physiological changes in a tissue. Applications of imaging in early drug development can suggest approaches to patient stratification for a personalized medicine able to deliver higher value from a drug after approval. Although imaging experimental medicine adds complexity to early drug development and costs per patient are high, appropriate use can increase returns on R and D investment by improving early decision making to reduce new drug attrition in later stages. We urge that the potential value of a translational molecular imaging strategy be considered routinely and at the earliest stages of new drug development.
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Affiliation(s)
- Paul M Matthews
- GSK Clinical Imaging Centre, GlaxoSmithKline Research and Development Ltd, Hammersmith Hospital, London, UK.
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Mizrahi R, Agid O, Borlido C, Suridjan I, Rusjan P, Houle S, Remington G, Wilson AA, Kapur S. Effects of antipsychotics on D3 receptors: a clinical PET study in first episode antipsychotic naive patients with schizophrenia using [11C]-(+)-PHNO. Schizophr Res 2011; 131:63-8. [PMID: 21684721 DOI: 10.1016/j.schres.2011.05.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 04/26/2011] [Accepted: 05/04/2011] [Indexed: 01/23/2023]
Abstract
Most antipsychotics are thought to have an effect on D(2) and D(3) receptors, although their D(3), versus D(2) binding has not been clearly established in vivo in humans. However, the development of [(11)C]-(+)-PHNO now permits the differentiation of antipsychotic activity on these two receptor subtypes. In this study we examined the effects of antipsychotics on D(2) and D(3) receptors by comparing [(11)C]-(+)-PHNO in D(2)-rich (caudate, CAU and putamen, PUT), mixed (ventral striatum) and D(3)-rich (globus-pallidus, GP and substantia nigra, SN) regions before and after the initiation of antipsychotic medication. The investigation therefore represents a longitudinal within-subject follow-up design wherein antipsychotic-naive patients with schizophrenia spectrum disorders were first scanned in a drug-naïve state and then again after ~2.5 weeks of antipsychotic treatment (risperidone or olanzapine). Binding potential (non displaceable or BP(ND)) was obtained to derive estimates of drug occupancy in the identified brain regions. Antipsychotic treatment was associated with the expected occupancies in the D(2)-rich regions; unexpectedly though, patients showed a higher, rather than the expected lower, [(11)C]-(+)-PHNO BP(ND) in the GP and SN despite simultaneous evidence for ongoing D(2) blockade in the other regions (CAU and PUT). In conclusion, patients treated with atypical antipsychotics demonstrated no evidence of D(3) receptor occupancy, but instead possible D(3) up-regulation following short-term treatment. The present findings add to a very limited body of evidence related to D(3) binding in vivo. [(11)C]-(+)-PHNO offer new opportunities for exploring the potential therapeutic significance of the D(3) receptor in schizophrenia and the action of antipsychotics.
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Affiliation(s)
- Romina Mizrahi
- PET Centre, Centre for Addiction and Mental Health, Toronto, Canada.
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