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Higa GSV, Viana FJC, Francis-Oliveira J, Cruvinel E, Franchin TS, Marcourakis T, Ulrich H, De Pasquale R. Serotonergic neuromodulation of synaptic plasticity. Neuropharmacology 2024; 257:110036. [PMID: 38876308 DOI: 10.1016/j.neuropharm.2024.110036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/15/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024]
Abstract
Synaptic plasticity constitutes a fundamental process in the reorganization of neural networks that underlie memory, cognition, emotional responses, and behavioral planning. At the core of this phenomenon lie Hebbian mechanisms, wherein frequent synaptic stimulation induces long-term potentiation (LTP), while less activation leads to long-term depression (LTD). The synaptic reorganization of neuronal networks is regulated by serotonin (5-HT), a neuromodulator capable of modify synaptic plasticity to appropriately respond to mental and behavioral states, such as alertness, attention, concentration, motivation, and mood. Lately, understanding the serotonergic Neuromodulation of synaptic plasticity has become imperative for unraveling its impact on cognitive, emotional, and behavioral functions. Through a comparative analysis across three main forebrain structures-the hippocampus, amygdala, and prefrontal cortex, this review discusses the actions of 5-HT on synaptic plasticity, offering insights into its role as a neuromodulator involved in emotional and cognitive functions. By distinguishing between plastic and metaplastic effects, we provide a comprehensive overview about the mechanisms of 5-HT neuromodulation of synaptic plasticity and associated functions across different brain regions.
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Affiliation(s)
- Guilherme Shigueto Vilar Higa
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil; Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Felipe José Costa Viana
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - José Francis-Oliveira
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Emily Cruvinel
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Thainá Soares Franchin
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Tania Marcourakis
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Henning Ulrich
- Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Roberto De Pasquale
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil.
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2
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Kossatz E, Diez-Alarcia R, Gaitonde SA, Ramon-Duaso C, Stepniewski TM, Aranda-Garcia D, Muneta-Arrate I, Tepaz E, Saen-Oon S, Soliva R, Shahraki A, Moreira D, Brea J, Loza MI, de la Torre R, Kolb P, Bouvier M, Meana JJ, Robledo P, Selent J. G protein-specific mechanisms in the serotonin 5-HT 2A receptor regulate psychosis-related effects and memory deficits. Nat Commun 2024; 15:4307. [PMID: 38811567 PMCID: PMC11137019 DOI: 10.1038/s41467-024-48196-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 04/23/2024] [Indexed: 05/31/2024] Open
Abstract
G protein-coupled receptors (GPCRs) are sophisticated signaling machines able to simultaneously elicit multiple intracellular signaling pathways upon activation. Complete (in)activation of all pathways can be counterproductive for specific therapeutic applications. This is the case for the serotonin 2 A receptor (5-HT2AR), a prominent target for the treatment of schizophrenia. In this study, we elucidate the complex 5-HT2AR coupling signature in response to different signaling probes, and its physiological consequences by combining computational modeling, in vitro and in vivo experiments with human postmortem brain studies. We show how chemical modification of the endogenous agonist serotonin dramatically impacts the G protein coupling profile of the 5-HT2AR and the associated behavioral responses. Importantly, among these responses, we demonstrate that memory deficits are regulated by Gαq protein activation, whereas psychosis-related behavior is modulated through Gαi1 stimulation. These findings emphasize the complexity of GPCR pharmacology and physiology and open the path to designing improved therapeutics for the treatment of stchizophrenia.
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Affiliation(s)
- Elk Kossatz
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Research Institute, Barcelona, Spain
| | - Rebeca Diez-Alarcia
- Department of Pharmacology, University of the Basque Country/Euskal Herriko Unibertsitatea, Leioa, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Madrid, Spain
- Instituto de Investigación Sanitaria Biobizkaia, Barakaldo, Bizkaia, Spain
| | - Supriya A Gaitonde
- Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, H3T 1J4, Canada
| | - Carla Ramon-Duaso
- Cell-type mechanisms in normal and pathological behaviour Research Group, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain
| | - Tomasz Maciej Stepniewski
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute, Barcelona, Spain
- InterAx Biotech AG, PARK InnovAARE, 5234, Villigen, Switzerland
| | - David Aranda-Garcia
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute, Barcelona, Spain
- Department of Medicine and Life Sciences, Pompeu Fabra University, Barcelona, Spain
| | - Itziar Muneta-Arrate
- Department of Pharmacology, University of the Basque Country/Euskal Herriko Unibertsitatea, Leioa, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Madrid, Spain
| | - Elodie Tepaz
- Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, H3T 1J4, Canada
| | - Suwipa Saen-Oon
- NBD NOSTRUM BIODISCOVERY, Av. de Josep Tarradellas, 8-10, 3-2, 08029, Barcelona, Spain
| | - Robert Soliva
- NBD NOSTRUM BIODISCOVERY, Av. de Josep Tarradellas, 8-10, 3-2, 08029, Barcelona, Spain
| | - Aida Shahraki
- Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 8, Marburg, 35037, Germany
| | - David Moreira
- Innopharma Drug Screening and Pharmacogenomics Platform. BioFarma research group. Center for Research in Molecular Medicine and Chronic Diseases (CiMUS). Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela, Santiago de Compostela, Spain
- Health Research Institute of Santiago de Compostela (IDIS), University Hospital of Santiago de Compostela (SERGAS), Trav. Choupana s/n, 15706, Santiago de Compostela, Spain
| | - Jose Brea
- Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 8, Marburg, 35037, Germany
- Innopharma Drug Screening and Pharmacogenomics Platform. BioFarma research group. Center for Research in Molecular Medicine and Chronic Diseases (CiMUS). Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Maria Isabel Loza
- Innopharma Drug Screening and Pharmacogenomics Platform. BioFarma research group. Center for Research in Molecular Medicine and Chronic Diseases (CiMUS). Department of Pharmacology, Pharmacy and Pharmaceutical Technology, University of Santiago de Compostela, Santiago de Compostela, Spain
- Health Research Institute of Santiago de Compostela (IDIS), University Hospital of Santiago de Compostela (SERGAS), Trav. Choupana s/n, 15706, Santiago de Compostela, Spain
| | - Rafael de la Torre
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Research Institute, Barcelona, Spain
| | - Peter Kolb
- Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 8, Marburg, 35037, Germany
| | - Michel Bouvier
- Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, H3T 1J4, Canada
| | - J Javier Meana
- Department of Pharmacology, University of the Basque Country/Euskal Herriko Unibertsitatea, Leioa, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Madrid, Spain
- Instituto de Investigación Sanitaria Biobizkaia, Barakaldo, Bizkaia, Spain
| | - Patricia Robledo
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Research Institute, Barcelona, Spain.
| | - Jana Selent
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute, Barcelona, Spain.
- Department of Medicine and Life Sciences, Pompeu Fabra University, Barcelona, Spain.
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3
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Holze F, Singh N, Liechti ME, D'Souza DC. Serotonergic Psychedelics: A Comparative Review of Efficacy, Safety, Pharmacokinetics, and Binding Profile. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024; 9:472-489. [PMID: 38301886 DOI: 10.1016/j.bpsc.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 12/27/2023] [Accepted: 01/22/2024] [Indexed: 02/03/2024]
Abstract
Psychedelic compounds, including psilocybin, LSD (lysergic acid diethylamide), DMT (N,N -dimethyltryptamine), and 5-MeO-DMT (5-methoxy-N,N-dimethyltryptamine), all of which are serotonin 2A receptor agonists, are being investigated as potential treatments. This review aims to summarize the current clinical research on these 4 compounds and mescaline to guide future research. Their mechanism(s) of action, pharmacokinetics, pharmacodynamics, efficacy, and safety were reviewed. While evidence for therapeutic indications, with the exception of psilocybin for depression, is still relatively scarce, we noted no differences in psychedelic effects beyond effect duration. Therefore, it remains unclear whether different receptor profiles contribute to the therapeutic potential of these compounds. More research is needed to differentiate these compounds in order to inform which compounds might be best for different therapeutic uses.
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Affiliation(s)
- Friederike Holze
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland; Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
| | - Nirmal Singh
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut; Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, Connecticut
| | - Matthias E Liechti
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland; Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Deepak Cyril D'Souza
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut; Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, Connecticut; VA Connecticut Healthcare System, West Haven, Connecticut.
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4
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Gao H, Liu X, Xie L, Tan B, Su R. Modulation of DOM-Induced Head-Twitch Response by mGluR2 Agonist/Inverse Agonist is Associated with 5-HT 2AR-Mediated G s Signaling Pathway. Neurochem Res 2024; 49:636-648. [PMID: 37989895 DOI: 10.1007/s11064-023-04055-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 10/18/2023] [Accepted: 10/21/2023] [Indexed: 11/23/2023]
Abstract
Hallucinogenic 5-HT2A receptor (5-HT2AR) agonists-induced head-twitch response (HTR) is regulated by Gs signaling pathway. Formation of heterodimers between 5-HT2AR and metabotropic glutamate mGlu2 receptor (mGluR2) is essential for the hallucinogenic 5-HT2AR agonist-induced HTR. In order to investigate the effects of mGluR2 agonists and inverse agonists on hallucinogenic 5-HT2AR agonists DOM-induced HTR, C57BL/6 mice were pretreated with mGluR2 agonists (LY379268, LY354740, LY404039) or the inverse agonist LY341495, and the HTR was manually counted after administering DOM immediately. IP-One (IP1) HTRF assay and cAMP assay were performed to evaluate the effect of LY341495 or LY354740 on DOM-induced Gq and Gs activation in Human Embryonic Kidney-293 (HEK-293) T-type cells co-expressing 5-HT2AR and mGluR2. The results showed that DOM-induced HTR in mice was dose-dependently inhibited by LY379268, LY354740, and LY404039, while it was dose-dependently enhanced by LY341495. Moreover, LY341495 reversed the inhibitory effect of LY354740 on DOM-induced HTR. In HEK-293T cells co-expressing 5-HT2AR and mGluR2, DOM-induced cAMP level was decreased by LY354740 and increased by LY341495, but DOM-induced IP1 level was not regulated by LY354740 or LY341495. The regulation of DOM-induced HTR by mGluR2 agonists and inverse agonists is closely related to 5-HT2AR-mediated Gs signaling pathway. In HEK-293T cells co-expressing 5-HT2AR and mGluR2 A677S/A681P/A685G mutant (mGluR2 3 A mutant), DOM-induced cAMP level was not regulated by LY354740, but was significantly enhanced by LY341495. The 5-HT2AR/mGluR2 heterodimers is critical for DOM-induced HTR and cAMP level, both of which are inhibited by mGluR2 agonists and enhanced by mGluR2 inverse agonists.
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Affiliation(s)
- Huan Gao
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, China
- School of Pharmacy, Yantai University, Yantai, China
| | - Xiaoqian Liu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, China
| | - Lulu Xie
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, China
| | - Bo Tan
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, China.
| | - Ruibin Su
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, China.
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5
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Hatzipantelis CJ, Olson DE. The Effects of Psychedelics on Neuronal Physiology. Annu Rev Physiol 2024; 86:27-47. [PMID: 37931171 PMCID: PMC10922499 DOI: 10.1146/annurev-physiol-042022-020923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Psychedelics are quite unique among drugs that impact the central nervous system, as a single administration of a psychedelic can both rapidly alter subjective experience in profound ways and produce sustained effects on circuits relevant to mood, fear, reward, and cognitive flexibility. These remarkable properties are a direct result of psychedelics interacting with several key neuroreceptors distributed across the brain. Stimulation of these receptors activates a variety of signaling cascades that ultimately culminate in changes in neuronal structure and function. Here, we describe the effects of psychedelics on neuronal physiology, highlighting their acute effects on serotonergic and glutamatergic neurotransmission as well as their long-lasting effects on structural and functional neuroplasticity in the cortex. We propose that the neurobiological changes leading to the acute and sustained effects of psychedelics might be distinct, which could provide opportunities for engineering compounds with optimized safety and efficacy profiles.
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Affiliation(s)
- Cassandra J Hatzipantelis
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, California, USA;
- Department of Chemistry, University of California, Davis, Davis, California, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, California, USA
| | - David E Olson
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, California, USA;
- Department of Chemistry, University of California, Davis, Davis, California, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, California, USA
- Center for Neuroscience, University of California, Davis, Davis, California, USA
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6
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Duan W, Cao D, Wang S, Cheng J. Serotonin 2A Receptor (5-HT 2AR) Agonists: Psychedelics and Non-Hallucinogenic Analogues as Emerging Antidepressants. Chem Rev 2024; 124:124-163. [PMID: 38033123 DOI: 10.1021/acs.chemrev.3c00375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Psychedelics make up a group of psychoactive compounds that induce hallucinogenic effects by activating the serotonin 2A receptor (5-HT2AR). Clinical trials have demonstrated the traditional psychedelic substances like psilocybin as a class of rapid-acting and long-lasting antidepressants. However, there is a pressing need for rationally designed 5-HT2AR agonists that possess optimal pharmacological profiles in order to fully reveal the therapeutic potential of these agonists and identify safer drug candidates devoid of hallucinogenic effects. This Perspective provides an overview of the structure-activity relationships of existing 5-HT2AR agonists based on their chemical classifications and discusses recent advancements in understanding their molecular pharmacology at a structural level. The encouraging clinical outcomes of psychedelics in depression treatment have sparked drug discovery endeavors aimed at developing novel 5-HT2AR agonists with improved subtype selectivity and signaling bias properties, which could serve as safer and potentially nonhallucinogenic antidepressants. These efforts can be significantly expedited through the utilization of structure-based methods and functional selectivity-directed screening.
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Affiliation(s)
- Wenwen Duan
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Dongmei Cao
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Sheng Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Jianjun Cheng
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
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7
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Luppi AI, Girn M, Rosas FE, Timmermann C, Roseman L, Erritzoe D, Nutt DJ, Stamatakis EA, Spreng RN, Xing L, Huttner WB, Carhart-Harris RL. A role for the serotonin 2A receptor in the expansion and functioning of human transmodal cortex. Brain 2024; 147:56-80. [PMID: 37703310 DOI: 10.1093/brain/awad311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 09/15/2023] Open
Abstract
Integrating independent but converging lines of research on brain function and neurodevelopment across scales, this article proposes that serotonin 2A receptor (5-HT2AR) signalling is an evolutionary and developmental driver and potent modulator of the macroscale functional organization of the human cerebral cortex. A wealth of evidence indicates that the anatomical and functional organization of the cortex follows a unimodal-to-transmodal gradient. Situated at the apex of this processing hierarchy-where it plays a central role in the integrative processes underpinning complex, human-defining cognition-the transmodal cortex has disproportionately expanded across human development and evolution. Notably, the adult human transmodal cortex is especially rich in 5-HT2AR expression and recent evidence suggests that, during early brain development, 5-HT2AR signalling on neural progenitor cells stimulates their proliferation-a critical process for evolutionarily-relevant cortical expansion. Drawing on multimodal neuroimaging and cross-species investigations, we argue that, by contributing to the expansion of the human cortex and being prevalent at the apex of its hierarchy in the adult brain, 5-HT2AR signalling plays a major role in both human cortical expansion and functioning. Owing to its unique excitatory and downstream cellular effects, neuronal 5-HT2AR agonism promotes neuroplasticity, learning and cognitive and psychological flexibility in a context-(hyper)sensitive manner with therapeutic potential. Overall, we delineate a dual role of 5-HT2ARs in enabling both the expansion and modulation of the human transmodal cortex.
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Affiliation(s)
- Andrea I Luppi
- Department of Clinical Neurosciences and Division of Anaesthesia, University of Cambridge, Cambridge, CB2 0QQ, UK
- Leverhulme Centre for the Future of Intelligence, University of Cambridge, Cambridge, CB2 1SB, UK
- The Alan Turing Institute, London, NW1 2DB, UK
| | - Manesh Girn
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, H3A 2B4, Canada
- Psychedelics Division-Neuroscape, Department of Neurology, University of California SanFrancisco, San Francisco, CA 94158, USA
| | - Fernando E Rosas
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
- Data Science Institute, Imperial College London, London, SW7 2AZ, UK
- Centre for Complexity Science, Imperial College London, London, SW7 2AZ, UK
| | - Christopher Timmermann
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - Leor Roseman
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - David Erritzoe
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - David J Nutt
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - Emmanuel A Stamatakis
- Department of Clinical Neurosciences and Division of Anaesthesia, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - R Nathan Spreng
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, H3A 2B4, Canada
| | - Lei Xing
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, 01307, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, 01307, Germany
| | - Robin L Carhart-Harris
- Psychedelics Division-Neuroscape, Department of Neurology, University of California SanFrancisco, San Francisco, CA 94158, USA
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
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8
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Gumpper RH, Roth BL. Psychedelics: preclinical insights provide directions for future research. Neuropsychopharmacology 2024; 49:119-127. [PMID: 36932180 PMCID: PMC10700551 DOI: 10.1038/s41386-023-01567-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/30/2023] [Accepted: 02/28/2023] [Indexed: 03/19/2023]
Abstract
Recently, psychedelics have emerged as promising therapeutics for numerous neuropsychiatric disorders. While their potential in the clinic has yet to be fully elucidated, understanding their molecular and biological mechanisms is imperative as these compounds are becoming widely used both in therapeutic and recreational contexts. This review examines the current understanding of basic biology, pharmacology, and structural biology in an attempt to reveal both the knowns and unknowns within the field.
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Affiliation(s)
- Ryan H Gumpper
- Department of Pharmacology, UNC School of Medicine, Chapel Hill, NC, 27514, USA
| | - Bryan L Roth
- Department of Pharmacology, UNC School of Medicine, Chapel Hill, NC, 27514, USA.
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9
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Wallach J, Cao AB, Calkins MM, Heim AJ, Lanham JK, Bonniwell EM, Hennessey JJ, Bock HA, Anderson EI, Sherwood AM, Morris H, de Klein R, Klein AK, Cuccurazzu B, Gamrat J, Fannana T, Zauhar R, Halberstadt AL, McCorvy JD. Identification of 5-HT 2A receptor signaling pathways associated with psychedelic potential. Nat Commun 2023; 14:8221. [PMID: 38102107 PMCID: PMC10724237 DOI: 10.1038/s41467-023-44016-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023] Open
Abstract
Serotonergic psychedelics possess considerable therapeutic potential. Although 5-HT2A receptor activation mediates psychedelic effects, prototypical psychedelics activate both 5-HT2A-Gq/11 and β-arrestin2 transducers, making their respective roles unclear. To elucidate this, we develop a series of 5-HT2A-selective ligands with varying Gq efficacies, including β-arrestin-biased ligands. We show that 5-HT2A-Gq but not 5-HT2A-β-arrestin2 recruitment efficacy predicts psychedelic potential, assessed using head-twitch response (HTR) magnitude in male mice. We further show that disrupting Gq-PLC signaling attenuates the HTR and a threshold level of Gq activation is required to induce psychedelic-like effects, consistent with the fact that certain 5-HT2A partial agonists (e.g., lisuride) are non-psychedelic. Understanding the role of 5-HT2A Gq-efficacy in psychedelic-like psychopharmacology permits rational development of non-psychedelic 5-HT2A agonists. We also demonstrate that β-arrestin-biased 5-HT2A receptor agonists block psychedelic effects and induce receptor downregulation and tachyphylaxis. Overall, 5-HT2A receptor Gq-signaling can be fine-tuned to generate ligands distinct from classical psychedelics.
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Affiliation(s)
- Jason Wallach
- Department of Pharmaceutical Sciences, Saint Joseph's University, Philadelphia, PA, 19104, USA.
| | - Andrew B Cao
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Maggie M Calkins
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Andrew J Heim
- Department of Chemistry, Saint Joseph's University, Philadelphia, PA, 19104, USA
- Chemical Computing Group ULC, 910-1010 Sherbrooke W, Montréal, QC, H3A 2R7, Canada
| | - Janelle K Lanham
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Emma M Bonniwell
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Joseph J Hennessey
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Hailey A Bock
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Emilie I Anderson
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | | | - Hamilton Morris
- Department of Pharmaceutical Sciences, Saint Joseph's University, Philadelphia, PA, 19104, USA
| | - Robbin de Klein
- Research Service, VA San Diego Healthcare System, San Diego, CA, 92161, USA
| | - Adam K Klein
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
- Gilgamesh Pharmaceuticals, New York, NY, 10003, USA
| | - Bruna Cuccurazzu
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - James Gamrat
- Department of Pharmaceutical Sciences, Saint Joseph's University, Philadelphia, PA, 19104, USA
| | - Tilka Fannana
- Department of Pharmaceutical Sciences, Saint Joseph's University, Philadelphia, PA, 19104, USA
| | - Randy Zauhar
- Department of Chemistry, Saint Joseph's University, Philadelphia, PA, 19104, USA
- Artemis Discovery, LLC, Suite 300, 709 N 2nd Street, Philadelphia, PA, 19123, USA
| | - Adam L Halberstadt
- Research Service, VA San Diego Healthcare System, San Diego, CA, 92161, USA.
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA.
- Center for Psychedelic Research, University of California San Diego, La Jolla, CA, 92093, USA.
| | - John D McCorvy
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
- Cancer Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
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10
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Custodio RJP, Ortiz DM, Lee HJ, Sayson LV, Kim M, Lee YS, Kim KM, Cheong JH, Kim HJ. Serotonin 2C receptors are also important in head-twitch responses in male mice. Psychopharmacology (Berl) 2023:10.1007/s00213-023-06482-9. [PMID: 37882810 DOI: 10.1007/s00213-023-06482-9] [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] [Received: 06/08/2023] [Accepted: 10/05/2023] [Indexed: 10/27/2023]
Abstract
RATIONALE Serotonergic psychedelics exert their effects via their high affinity for serotonin (5-HT) receptors, particularly through activating 5-HT2A receptors (5-HT2AR), employing the frontal cortex-dependent head-twitch response (HTR). Although universally believed to be so, studies have not yet fully ascertained whether 5-HT2AR activation is the sole initiator of these psychedelic effects. This is because not all 5-HT2AR agonists exhibit similar pharmacologic properties. OBJECTIVE This study aims to identify and discriminate the roles of 5-HT2AR and 5-HT2CR in the HTR induced by Methallylescaline (MAL) and 4-Methyl-2,5,β-trimethoxyphenethylamine (BOD) in male mice. Also, an analysis of their potential neurotoxic properties was evaluated. METHODS Male mice treated with MAL and BOD were evaluated in different behavioral paradigms targeting HTR and neurotoxicity effects. Drug affinity, pharmacological blocking, and molecular analysis were also conducted to support the behavioral findings. The HTR induced by DOI has been extensively characterized in male mice, making it a good positive control for this study, specifically for comparing the pharmacological effects of our test compounds. RESULTS The activation of 5-HT2CR, alone or in concert with 5-HT2AR, produces a comparable degree of HTRs (at a dose of 1 mg·kg-1), with divergent 5-HT2CR- and 5-HT2AR-Gqα11-mediated signaling and enhanced neurotoxic properties (at a dose of 30 mg·kg-1) coupled with activated pro-inflammatory cytokines. These findings show these compounds' potential psychedelic and neurotoxic effects in male mice. CONCLUSION These findings showed that while 5-HT2AR is the main initiator of HTR, the 5-HT2CR also has a distinct property that renders it effective in inducing HTR in male mice.
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Affiliation(s)
- Raly James Perez Custodio
- Networking Group Aging, Department of Ergonomics, Leibniz Research Centre for Working Environment and Human Factors - IfADo, Ardeystrasse 67, Dortmund, 44139, Germany.
| | - Darlene Mae Ortiz
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Hyun Jun Lee
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Leandro Val Sayson
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Mikyung Kim
- Department of Chemistry & Life Science, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Yong Sup Lee
- Medicinal Chemistry Laboratory, Department of Pharmacy & Department of Life and Nanopharmaceutical Sciences, College of Pharmacy, Kyung Hee University, 26 Kyungheedae-ro, Seoul, 02447, Republic of Korea
| | - Kyeong-Man Kim
- Department of Pharmacology, College of Pharmacy, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea
| | - Jae Hoon Cheong
- Institute for New Drug Development, College of Pharmacy, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeollabuk-do, 54896, Republic of Korea.
| | - Hee Jin Kim
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea.
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11
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Zhu H, Liu X, Wang X, Li Y, Ma F, Tan B, Zhou P, Fu F, Su R. Gβγ subunit inhibitor decreases DOM-induced head twitch response via the PLCβ/IP3/Ca 2+/ERK and cAMP signaling pathways. Eur J Pharmacol 2023; 957:176038. [PMID: 37657742 DOI: 10.1016/j.ejphar.2023.176038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 08/17/2023] [Accepted: 08/30/2023] [Indexed: 09/03/2023]
Abstract
AIMS (-)-2,5-dimethoxy-4-methylamphetamine (DOM) induces the head-twitch response (HTR) primarily by activating the serotonin 5-hydroxytryptamine 2A receptor (5-HT2A receptor) in mice. However, the mechanisms underlying 5-HT2A receptor activation and the HTR remain elusive. Gβγ subunits are a potential treatment target in numerous diseases. The present study investigated the mechanism whereby Gβγ subunits influence DOM-induced HTR. MAIN METHODS The effects of the Gβγ inhibitor 3',4',5',6'-tetrahydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one (gallein) and antagonistic peptide βARKct (β-adrenergic receptor kinase C-terminal fragment) on DOM-induced HTR were studied via an HTR test. The activation of the phospholipase C β (PLCβ)/inositol triphosphate (IP3)/calcium (Ca2+) signaling pathway and extracellular signal-regulated kinase (ERK) following Gβγ subunit inhibition was detected by western blotting, Homogeneous Time-Resolved Fluorescence (HTRF) inositol phosphate (IP1) assay and Fluorometric Imaging Plate Reader (FLIPR) calcium 6 assay. The Gβγ subunit-mediated regulation of cyclic adenosine monophosphate (cAMP) was assessed via a GloSensor™ cAMP assay. KEY FINDINGS The Gβγ subunit inhibitors gallein and βARKct reduced DOM-induced HTR in C57BL/6J mice. Like the 5-HT2A receptor-selective antagonist (R)-[2,3-di(methoxy)phenyl]-[1-[2-(4-fluorophenyl)ethyl]piperidin-4-yl]methanol (M100907), gallein inhibited PLCβ phosphorylation (pPLCβ), IP1 production, Ca2+ transients, ERK1/2 phosphorylation (pERK1/2) and cAMP accumulation induced by DOM in human embryonic kidney (HEK) 293T cells stably or transiently transfected with the human 5-HT2A receptor. Moreover, PLCβ protein inhibitor 1-[6-[[(8R,9S,13S,14S,17S)-3-methoxy-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthren-17-yl]amino]hexyl]pyrrole-2,5-dione (U73122) (10 nmol/mouse), intracellular Ca2+ blocker 6-[6-[6-[5-acetamido-4,6-dihydroxy-2-(sulfooxymethyl)oxan-3-yl]oxy-2-carboxy-4-hydroxy-5-sulfooxyoxan-3-yl]oxy-2-(hydroxymethyl)-5-(sulfoamino)-4-sulfooxyoxan-3-yl]oxy-3,4-dihydroxy-5-sulfooxyoxane-2-carboxylic acid (heparin) (5 nmol/mouse), L-type Ca2+ channel blocker 3-O-(2-methoxyethyl) 5-O-propan-2-yl 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate (nimodipine) (4 mg/kg), mitogen extracellular regulating kinase 1/2 (MEK1/2) inhibitor (Z)-3-amino-3-(4-aminophenyl)sulfanyl-2-[2-(trifluoromethyl)phenyl]prop-2-enenitrile (SL327) (30 mg/kg), and Gαs protein selective antagonist 4,4',4″,4‴-(Carbonylbis-(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakisbenzene-1,3-disulfonic acid (NF449) (10 nmol/mouse) reduced DOM-induced HTR in C57BL/6J mice. SIGNIFICANCE The Gβγ subunits potentially mediate the HTR after 5-HT2A receptor activation via the PLCβ/IP3/Ca2+/ERK1/2 and cAMP signaling pathways. Inhibitors targeting the Gβγ subunits potentially inhibit the hallucinogenic effects of 5-HT2A receptor agonists.
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Affiliation(s)
- Huili Zhu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China; School of Pharmacy, Yantai University, Yantai, 264005, China
| | - Xiaoqian Liu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Xiaoxuan Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Yulei Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Fang Ma
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Bo Tan
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Peilan Zhou
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China.
| | - Fenghua Fu
- School of Pharmacy, Yantai University, Yantai, 264005, China
| | - Ruibin Su
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China.
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12
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Wallach J, Cao AB, Calkins MM, Heim AJ, Lanham JK, Bonniwell EM, Hennessey JJ, Bock HA, Anderson EI, Sherwood AM, Morris H, de Klein R, Klein AK, Cuccurazzu B, Gamrat J, Fannana T, Zauhar R, Halberstadt AL, McCorvy JD. Identification of 5-HT 2A Receptor Signaling Pathways Responsible for Psychedelic Potential. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.29.551106. [PMID: 37577474 PMCID: PMC10418054 DOI: 10.1101/2023.07.29.551106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Serotonergic psychedelics possess considerable therapeutic potential. Although 5-HT2A receptor activation mediates psychedelic effects, prototypical psychedelics activate both 5-HT2A-Gq/11 and β-arrestin2 signaling, making their respective roles unclear. To elucidate this, we developed a series of 5-HT2A-selective ligands with varying Gq efficacies, including β-arrestin-biased ligands. We show that 5-HT2A-Gq but not 5-HT2A-β-arrestin2 efficacy predicts psychedelic potential, assessed using head-twitch response (HTR) magnitude in male mice. We further show that disrupting Gq-PLC signaling attenuates the HTR and a threshold level of Gq activation is required to induce psychedelic-like effects, consistent with the fact that certain 5-HT2A partial agonists (e.g., lisuride) are non-psychedelic. Understanding the role of 5-HT2A-Gq efficacy in psychedelic-like psychopharmacology permits rational development of non-psychedelic 5-HT2A agonists. We also demonstrate that β-arrestin-biased 5-HT2A receptor agonists induce receptor downregulation and tachyphylaxis, and have an anti-psychotic-like behavioral profile. Overall, 5-HT2A receptor signaling can be fine-tuned to generate ligands with properties distinct from classical psychedelics.
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Affiliation(s)
- Jason Wallach
- Department of Pharmaceutical Sciences, Saint Joseph’s University, Philadelphia, Pennsylvania 19104, United States
| | - Andrew B. Cao
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Maggie M. Calkins
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Andrew J. Heim
- Department of Chemistry, Saint Joseph’s University, Philadelphia, Pennsylvania 19104, United States
| | - Janelle K. Lanham
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Emma M. Bonniwell
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Joseph J. Hennessey
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Hailey A. Bock
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Emilie I. Anderson
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | | | - Hamilton Morris
- Department of Pharmaceutical Sciences, Saint Joseph’s University, Philadelphia, Pennsylvania 19104, United States
| | - Robbin de Klein
- Research Service, VA San Diego Healthcare System, San Diego, California 92161, United States
| | - Adam K. Klein
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093, United States
| | - Bruna Cuccurazzu
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093, United States
| | - James Gamrat
- Department of Pharmaceutical Sciences, Saint Joseph’s University, Philadelphia, Pennsylvania 19104, United States
| | - Tilka Fannana
- Department of Pharmaceutical Sciences, Saint Joseph’s University, Philadelphia, Pennsylvania 19104, United States
| | - Randy Zauhar
- Department of Chemistry, Saint Joseph’s University, Philadelphia, Pennsylvania 19104, United States
| | - Adam L. Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093, United States
- Research Service, VA San Diego Healthcare System, San Diego, California 92161, United States
| | - John D. McCorvy
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
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13
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Abstract
Over the past decade, psychedelic compounds have emerged as potentially transformative therapeutics for a variety of intractable neuropsychiatric conditions. However, historically most of the basic science has utilized these compounds as probes to interrogate various endogenous neurotransmitter systems-mainly the serotonin 5-HT2A receptor. With the renewed interest in utilizing these compounds as therapeutics and the explosion in clinical trials, psychedelics have been purported to treat many neuropsychiatric disorders, including depression, cluster headaches, migraines, anxiety, and obsessive-compulsive disorder. It is therefore imperative to understand the biology and pharmacology behind their therapeutic mechanisms as well as expose any potential pitfalls in their widespread use as treatments. This review covers the latest advances in understanding the biological mechanisms, the newest efforts in drug discovery, and potential pitfalls when it comes to utilizing this class of compounds as emerging therapeutics.
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Affiliation(s)
- Bryan L Roth
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill
| | - Ryan H Gumpper
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill
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14
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Domanegg K, Sommer WH, Meinhardt MW. Psychedelic Targeting of Metabotropic Glutamate Receptor 2 and Its Implications for the Treatment of Alcoholism. Cells 2023; 12:963. [PMID: 36980303 PMCID: PMC10047550 DOI: 10.3390/cells12060963] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Alcohol abuse is a leading risk factor for the public health burden worldwide. Approved pharmacotherapies have demonstrated limited effectiveness over the last few decades in treating alcohol use disorders (AUD). New therapeutic approaches are therefore urgently needed. Historical and recent clinical trials using psychedelics in conjunction with psychotherapy demonstrated encouraging results in reducing heavy drinking in AUD patients, with psilocybin being the most promising candidate. While psychedelics are known to induce changes in gene expression and neuroplasticity, we still lack crucial information about how this specifically counteracts the alterations that occur in neuronal circuits throughout the course of addiction. This review synthesizes well-established knowledge from addiction research about pathophysiological mechanisms related to the metabotropic glutamate receptor 2 (mGlu2), with findings and theories on how mGlu2 connects to the major signaling pathways induced by psychedelics via serotonin 2A receptors (2AR). We provide literature evidence that mGlu2 and 2AR are able to regulate each other's downstream signaling pathways, either through monovalent crosstalk or through the formation of a 2AR-mGlu2 heteromer, and highlight epigenetic mechanisms by which 2ARs can modulate mGlu2 expression. Lastly, we discuss how these pathways might be targeted therapeutically to restore mGlu2 function in AUD patients, thereby reducing the propensity to relapse.
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Affiliation(s)
- Kevin Domanegg
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 69115 Heidelberg, Germany
| | - Wolfgang H. Sommer
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 69115 Heidelberg, Germany
- Bethanien Hospital for Psychiatry, Psychosomatics, and Psychotherapy Greifswald, 17489 Greifswald, Germany
| | - Marcus W. Meinhardt
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 69115 Heidelberg, Germany
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 69115 Heidelberg, Germany
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15
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Wulff AB, Nichols CD, Thompson SM. Preclinical perspectives on the mechanisms underlying the therapeutic actions of psilocybin in psychiatric disorders. Neuropharmacology 2023; 231:109504. [PMID: 36921889 DOI: 10.1016/j.neuropharm.2023.109504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/14/2023] [Accepted: 03/11/2023] [Indexed: 03/14/2023]
Abstract
Psychedelic compounds have shown extraordinary potential in treating a wide range of neuropsychiatric disorders. Psilocybin, for example, has now been shown in several clinical trials to induce a rapid (within days) and persistent (3-12 months) improvement in human treatment-resistant depression and other neuropsychiatric conditions. Here we review the preclinical models and experimental approaches that have been used to study the neurobiological actions of psychedelic drugs. We further summarize the insights these studies have provided into the possible mechanisms underlying the induction of their therapeutic actions, including the receptors to which psychedelics bind and the second messenger signaling cascades that they activate. We also discuss potential biological processes that psychedelics may alter to produce the lasting amelioration of symptoms, including improvements in synaptic structure and function and suppression of inflammation. Improved mechanistic understanding of psychedelic drug actions will aid in the advancement of these promising new medicines.
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Affiliation(s)
- Andreas B Wulff
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Charles D Nichols
- Department of Pharmacology and Experimental Therapeutics, LSU Health Sciences Center, New Orleans, LA, 70112, USA
| | - Scott M Thompson
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA; Department of Psychiatry, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
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16
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Glatfelter GC, Pottie E, Partilla JS, Sherwood AM, Kaylo K, Pham DNK, Naeem M, Sammeta VR, DeBoer S, Golen JA, Hulley EB, Stove CP, Chadeayne AR, Manke DR, Baumann MH. Structure-Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice. ACS Pharmacol Transl Sci 2022; 5:1181-1196. [PMID: 36407948 PMCID: PMC9667540 DOI: 10.1021/acsptsci.2c00177] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Indexed: 11/06/2022]
Abstract
4-Phosphoryloxy-N,N-dimethyltryptamine (psilocybin) is a naturally occurring tertiary amine found in many mushroom species. Psilocybin is a prodrug for 4-hydroxy-N,N-dimethyltryptamine (psilocin), which induces psychedelic effects via agonist activity at the serotonin (5-HT) 2A receptor (5-HT2A). Several other 4-position ring-substituted tryptamines are present in psilocybin-containing mushrooms, including the secondary amine 4-phosphoryloxy-N-methyltryptamine (baeocystin) and the quaternary ammonium 4-phosphoryloxy-N,N,N-trimethyltryptamine (aeruginascin), but these compounds are not well studied. Here, we investigated the structure-activity relationships for psilocybin, baeocystin, and aeruginascin, as compared to their 4-acetoxy and 4-hydroxy analogues, using in vitro and in vivo methods. Broad receptor screening using radioligand binding assays in transfected cells revealed that secondary and tertiary tryptamines with either 4-acetoxy or 4-hydroxy substitutions display nanomolar affinity for most human 5-HT receptor subtypes tested, including the 5-HT2A and the serotonin 1A receptor (5-HT1A). The same compounds displayed affinity for 5-HT2A and 5-HT1A in mouse brain tissue in vitro and exhibited agonist efficacy in assays examining 5-HT2A-mediated calcium mobilization and β-arrestin 2 recruitment. In mouse experiments, only the tertiary amines psilocin, psilocybin, and 4-acetoxy-N,N-dimethyltryptamine (psilacetin) induced head twitch responses (ED50 0.11-0.29 mg/kg) indicative of psychedelic-like activity. Head twitches were blocked by 5-HT2A antagonist pretreatment, supporting 5-HT2A involvement. Both secondary and tertiary amines decreased body temperature and locomotor activity at higher doses, the effects of which were blocked by 5-HT1A antagonist pretreatment. Across all assays, the pharmacological effects of 4-acetoxy and 4-hydroxy compounds were similar, and these compounds were more potent than their 4-phosphoryloxy counterparts. Importantly, psilacetin appears to be a prodrug for psilocin that displays substantial serotonin receptor activities of its own.
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Affiliation(s)
- Grant C. Glatfelter
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
| | - Eline Pottie
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, 9000 Ghent, Belgium
| | - John S. Partilla
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
| | | | - Kristi Kaylo
- Usona
Institute, Madison, Wisconsin 53711, United States
| | - Duyen N. K. Pham
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Marilyn Naeem
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Vamshikrishna Reddy Sammeta
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Stacie DeBoer
- Department
of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - James A. Golen
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Elliott B. Hulley
- Department
of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Christophe P. Stove
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, 9000 Ghent, Belgium
| | | | - David R. Manke
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Michael H. Baumann
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
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17
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Kwan AC, Olson DE, Preller KH, Roth BL. The neural basis of psychedelic action. Nat Neurosci 2022; 25:1407-1419. [PMID: 36280799 PMCID: PMC9641582 DOI: 10.1038/s41593-022-01177-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 09/06/2022] [Indexed: 01/13/2023]
Abstract
Psychedelics are serotonin 2A receptor agonists that can lead to profound changes in perception, cognition and mood. In this review, we focus on the basic neurobiology underlying the action of psychedelic drugs. We first discuss chemistry, highlighting the diversity of psychoactive molecules and the principles that govern their potency and pharmacokinetics. We describe the roles of serotonin receptors and their downstream molecular signaling pathways, emphasizing key elements for drug discovery. We consider the impact of psychedelics on neuronal spiking dynamics in several cortical and subcortical regions, along with transcriptional changes and sustained effects on structural plasticity. Finally, we summarize neuroimaging results that pinpoint effects on association cortices and thalamocortical functional connectivity, which inform current theories of psychedelic action. By synthesizing knowledge across the chemical, molecular, neuronal, and network levels, we hope to provide an integrative perspective on the neural mechanisms responsible for the acute and enduring effects of psychedelics on behavior.
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Affiliation(s)
- Alex C. Kwan
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA,Correspondence: ; ; ;
| | - David E. Olson
- Department of Chemistry, University of California, Davis, Davis, CA, USA,Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, USA,Center for Neuroscience, University of California, Davis, Davis, CA, USA,Correspondence: ; ; ;
| | - Katrin H. Preller
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital, University of Zurich, Zurich, Switzerland.,Correspondence: ; ; ;
| | - Bryan L. Roth
- Department of Pharmacology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA.,Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.,Psychoactive Drug Screening Program, National Institute of Mental Health, School of Medicine, University of North Carolina, Chapel Hill, NC, USA.,Correspondence: ; ; ;
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18
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Liu X, Zhu H, Gao H, Tian X, Tan B, Su R. G s signaling pathway distinguishes hallucinogenic and nonhallucinogenic 5-HT 2AR agonists induced head twitch response in mice. Biochem Biophys Res Commun 2022; 598:20-25. [PMID: 35149433 DOI: 10.1016/j.bbrc.2022.01.113] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 01/28/2022] [Indexed: 11/21/2022]
Abstract
5- HT2A receptor is a member of the family A G-protein-coupled receptor. It is involved in many psychiatric disorders, such as depression, addiction and Parkinson's disease. 5-HT2AR targeted drugs play an important role in regulating cognition, memory, emotion and other physiological function by coupling G proteins, and their most notable function is stimulating the serotonergic hallucination. However, not all 5-HT2AR agonists exhibit hallucinogenic activity, such as lisuride. Molecular mechanisms of these different effects are not well illustrated. This study suggested that 5-HT2AR coupled both Gs and Gq protein under hallucinogenic agonists DOM and 25CN-NBOH stimulation, but nonhallucinogenic agonist lisuride and TBG only activates Gq signaling. Moreover, in head twitch response (HTR) model, we found that cAMP analogs 8-Bromo-cAMP and PDE4 inhibitor Rolipram could increase HTR, while Gs protein inhibitor Melittin could reduce HTR. Collectively, these results revealed that Gs signaling is a key signaling pathway that may distinguish hallucinogenic agonists and nonhallucinogenic agonists.
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Affiliation(s)
- Xiaoqian Liu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Huili Zhu
- School of Pharmacy, Yantai University, Yantai, 264005, China
| | - Huan Gao
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China; School of Pharmacy, Yantai University, Yantai, 264005, China
| | - Xiangyun Tian
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Bo Tan
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Ruibin Su
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China.
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Abstract
In addition to producing profound subjective effects following acute administration, psychedelic compounds can induce beneficial behavioral changes relevant to the treatment of neuropsychiatric disorders that last long after the compounds have been cleared from the body. One hypothesis with the potential to explain the remarkable enduring effects of psychedelics is related to their abilities to promote structural and functional neuroplasticity in the prefrontal cortex (PFC). A hallmark of many stress-related neuropsychiatric diseases, including depression, post-traumatic stress disorder (PTSD), and addiction, is the atrophy of neurons in the PFC. Psychedelics appear to be particularly effective catalysts for the growth of these key neurons, ultimately leading to restoration of synaptic connectivity in this critical brain region. Furthermore, evidence suggests that the hallucinogenic effects of psychedelics are not directly linked to their ability to promote structural and functional neuroplasticity. If we are to develop improved alternatives to psychedelics for treating neuropsychiatric diseases, we must fully characterize the molecular mechanisms that give rise to psychedelic-induced neuroplasticity. Here, I review our current understanding of the biochemical signaling pathways activated by psychedelics and related neuroplasticity-promoting molecules, with an emphasis on key unanswered questions.
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Affiliation(s)
- David E. Olson
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA,Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, 2700 Stockton Blvd, Suite 2102, Sacramento, CA 95817, USA,Center for Neuroscience, University of California, Davis, 1544 Newton Ct, Davis, CA 95618, USA,Corresponding Author: David E. Olson,
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Cao D, Yu J, Wang H, Luo Z, Liu X, He L, Qi J, Fan L, Tang L, Chen Z, Li J, Cheng J, Wang S. Structure-based discovery of nonhallucinogenic psychedelic analogs. Science 2022; 375:403-411. [PMID: 35084960 DOI: 10.1126/science.abl8615] [Citation(s) in RCA: 107] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Drugs that target the human serotonin 2A receptor (5-HT2AR) are used to treat neuropsychiatric diseases; however, many have hallucinogenic effects, hampering their use. Here, we present structures of 5-HT2AR complexed with the psychedelic drugs psilocin (the active metabolite of psilocybin) and d-lysergic acid diethylamide (LSD), as well as the endogenous neurotransmitter serotonin and the nonhallucinogenic psychedelic analog lisuride. Serotonin and psilocin display a second binding mode in addition to the canonical mode, which enabled the design of the psychedelic IHCH-7113 (a substructure of antipsychotic lumateperone) and several 5-HT2AR β-arrestin-biased agonists that displayed antidepressant-like activity in mice but without hallucinogenic effects. The 5-HT2AR complex structures presented herein and the resulting insights provide a solid foundation for the structure-based design of safe and effective nonhallucinogenic psychedelic analogs with therapeutic effects.
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Affiliation(s)
- Dongmei Cao
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jing Yu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Huan Wang
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Zhipu Luo
- Institute of Molecular Enzymology, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Xinyu Liu
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Licong He
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jianzhong Qi
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Luyu Fan
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Lingjie Tang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Zhangcheng Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jinsong Li
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jianjun Cheng
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Sheng Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
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21
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Slocum ST, DiBerto JF, Roth BL. Molecular insights into psychedelic drug action. J Neurochem 2021; 162:24-38. [PMID: 34797943 DOI: 10.1111/jnc.15540] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/11/2021] [Accepted: 11/11/2021] [Indexed: 12/14/2022]
Abstract
A confluence of factors has renewed interest in the scientific understanding and translational potential of psychedelic drugs such as lysergic acid diethylamide (LSD), mescaline, and psilocybin: the desire for additional approaches to mental health care, incremental progress in basic and clinical research, and the reconsideration and relaxation of existing drug policies. With the United States Food and Drug Administration's designation of psilocybin as a "Breakthrough Therapy" for treatment-resistant depression, a new path has been forged for the conveyance of psychedelics to the clinic. Essential to the further development of such applications, however, is a clearer understanding of how these drugs exert their effects at the molecular level. Here we review the current knowledge regarding the molecular details of psychedelic drug actions and suggest that these discoveries can facilitate new insights into their hallucinogenic and therapeutic mechanisms.
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Affiliation(s)
- Samuel T Slocum
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Jeffrey F DiBerto
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
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Banks MI, Zahid Z, Jones NT, Sultan ZW, Wenthur CJ. Catalysts for change: the cellular neurobiology of psychedelics. Mol Biol Cell 2021; 32:1135-1144. [PMID: 34043427 PMCID: PMC8351556 DOI: 10.1091/mbc.e20-05-0340] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/23/2021] [Accepted: 03/31/2021] [Indexed: 01/18/2023] Open
Abstract
The resurgence of interest in the therapeutic potential of psychedelics for treating psychiatric disorders has rekindled efforts to elucidate their mechanism of action. In this Perspective, we focus on the ability of psychedelics to promote neural plasticity, postulated to be central to their therapeutic activity. We begin with a brief overview of the history and behavioral effects of the classical psychedelics. We then summarize our current understanding of the cellular and subcellular mechanisms underlying these drugs' behavioral effects, their effects on neural plasticity, and the roles of stress and inflammation in the acute and long-term effects of psychedelics. The signaling pathways activated by psychedelics couple to numerous potential mechanisms for producing long-term structural changes in the brain, a complexity that has barely begun to be disentangled. This complexity is mirrored by that of the neural mechanisms underlying psychiatric disorders and the transformations of consciousness, mood, and behavior that psychedelics promote in health and disease. Thus, beyond changes in the brain, psychedelics catalyze changes in our understanding of the neural basis of psychiatric disorders, as well as consciousness and human behavior.
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Affiliation(s)
- Matthew I. Banks
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
- Neuroscience Training Program, University of Wisconsin–Madison, Madison, WI 53706
| | - Zarmeen Zahid
- Neuroscience Training Program, University of Wisconsin–Madison, Madison, WI 53706
| | - Nathan T. Jones
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin–Madison, Madison, WI 53706
| | - Ziyad W. Sultan
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
| | - Cody J. Wenthur
- Neuroscience Training Program, University of Wisconsin–Madison, Madison, WI 53706
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin–Madison, Madison, WI 53706
- School of Pharmacy, University of Wisconsin–Madison, Madison, WI 53705
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23
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Michaiel AM, Parker PRL, Niell CM. A Hallucinogenic Serotonin-2A Receptor Agonist Reduces Visual Response Gain and Alters Temporal Dynamics in Mouse V1. Cell Rep 2020; 26:3475-3483.e4. [PMID: 30917304 PMCID: PMC6559379 DOI: 10.1016/j.celrep.2019.02.104] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 11/06/2018] [Accepted: 02/22/2019] [Indexed: 11/19/2022] Open
Abstract
Sensory perception arises from the integration of externally and internally driven representations of the world. Disrupted balance of these representations can lead to perceptual deficits and hallucinations. The serotonin-2A receptor (5-HT2AR) is associated with such perceptual alterations, both in its role in schizophrenia and in the action of hallucinogenic drugs. Despite this powerful influence on perception, relatively little is known about how serotonergic hallucinogens influence sensory processing in the neocortex. Using widefield and two-photon calcium imaging and single-unit electrophysiology in awake mice, we find that administration of the hallucinogenic selective 5-HT2AR agonist DOI (2,5-dimethoxy-4-iodoamphetamine) leads to a net reduction in visual response amplitude and surround suppression in primary visual cortex, as well as disrupted temporal dynamics. However, basic retinotopic organization, tuning properties, and receptive field structure remain intact. Our results provide support for models of hallucinations in which reduced bottom-up sensory drive is a key factor leading to altered perception. Activation of serotonin-2A receptors (5-HT2ARs) is associated with hallucinations, but impacts on sensory processing are largely unknown. Michaiel et al. demonstrate that the 5-HT2AR agonist DOI strongly reduces sensory-evoked activity and disrupts temporal dynamics. These results support models of hallucinations that propose reduced bottom-up sensory drive.
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Affiliation(s)
- Angie M Michaiel
- Institute of Neuroscience and Department of Biology, University of Oregon, Eugene, OR 97403, USA
| | - Philip R L Parker
- Institute of Neuroscience and Department of Biology, University of Oregon, Eugene, OR 97403, USA
| | - Cristopher M Niell
- Institute of Neuroscience and Department of Biology, University of Oregon, Eugene, OR 97403, USA.
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24
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Canal CE. Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action. Handb Exp Pharmacol 2019; 252:227-260. [PMID: 29532180 PMCID: PMC6136989 DOI: 10.1007/164_2018_107] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent, well-controlled - albeit small-scale - clinical trials show that serotonergic psychedelics, including psilocybin and lysergic acid diethylamide, possess great promise for treating psychiatric disorders, including treatment-resistant depression. Additionally, fresh results from a deluge of clinical neuroimaging studies are unveiling the dynamic effects of serotonergic psychedelics on functional activity within, and connectivity across, discrete neural systems. These observations have led to testable hypotheses regarding neural processing mechanisms that contribute to psychedelic effects and therapeutic benefits. Despite these advances and a plethora of preclinical and clinical observations supporting a central role for brain serotonin 5-HT2A receptors in producing serotonergic psychedelic effects, lingering and new questions about mechanisms abound. These chiefly pertain to molecular neuropharmacology. This chapter is devoted to illuminating and discussing such questions in the context of preclinical experimental approaches for studying mechanisms of action of serotonergic psychedelics, classic and new.
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Affiliation(s)
- Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA, USA.
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25
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Abiero A, Botanas CJ, Sayson LV, Custodio RJ, de la Peña JB, Kim M, Lee HJ, Seo JW, Ryu IS, Chang CM, Yang JS, Lee YS, Jang CG, Kim HJ, Cheong JH. 5-Methoxy-α-methyltryptamine (5-MeO-AMT), a tryptamine derivative, induces head-twitch responses in mice through the activation of serotonin receptor 2a in the prefrontal cortex. Behav Brain Res 2019; 359:828-835. [DOI: 10.1016/j.bbr.2018.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/10/2018] [Accepted: 07/24/2018] [Indexed: 12/20/2022]
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26
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Dalwadi DA, Ozuna L, Harvey BH, Viljoen M, Schetz JA. Adverse Neuropsychiatric Events and Recreational Use of Efavirenz and Other HIV-1 Antiretroviral Drugs. Pharmacol Rev 2018; 70:684-711. [DOI: 10.1124/pr.117.013706] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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27
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Abstract
Because of the ethical and regulatory hurdles associated with human studies, much of what is known about the psychopharmacology of hallucinogens has been derived from animal models. However, developing reliable animal models has proven to be a challenging task due to the complexity and variability of hallucinogen effects in humans. This chapter focuses on three animal models that are frequently used to test the effects of hallucinogens on unconditioned behavior: head twitch response (HTR), prepulse inhibition of startle (PPI), and exploratory behavior. The HTR has demonstrated considerable utility in the neurochemical actions of hallucinogens. However, the latter two models have clearer conceptual bridges to human phenomenology. Consistent with the known mechanism of action of hallucinogens in humans, the behavioral effects of hallucinogens in rodents are mediated primarily by activation of 5-HT2A receptors. There is evidence, however, that other receptors may play secondary roles. The structure-activity relationships (SAR) of hallucinogens are reviewed in relation to each model, with a focus on the HTR in rats and mice.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA.
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Mark A Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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28
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The renaissance in psychedelic research: What do preclinical models have to offer. PROGRESS IN BRAIN RESEARCH 2018; 242:25-67. [DOI: 10.1016/bs.pbr.2018.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Abstract
The classic serotonergic hallucinogens, or psychedelics, have the ability to profoundly alter perception and behavior. These can include visual distortions, hallucinations, detachment from reality, and mystical experiences. Some psychedelics, like LSD, are able to produce these effects with remarkably low doses of drug. Others, like psilocybin, have recently been demonstrated to have significant clinical efficacy in the treatment of depression, anxiety, and addiction that persist for at least several months after only a single therapeutic session. How does this occur? Much work has recently been published from imaging studies showing that psychedelics alter brain network connectivity. They facilitate a disintegration of the default mode network, producing a hyperconnectivity between brain regions that allow centers that do not normally communicate with each other to do so. The immediate and acute effects on both behaviors and network connectivity are likely mediated by effector pathways downstream of serotonin 5-HT2A receptor activation. These acute molecular processes also influence gene expression changes, which likely influence synaptic plasticity and facilitate more long-term changes in brain neurochemistry ultimately underlying the therapeutic efficacy of a single administration to achieve long-lasting effects. In this review, we summarize what is currently known about the molecular genetic responses to psychedelics within the brain and discuss how gene expression changes may contribute to altered cellular physiology and behaviors.
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Abstract
The neuropsychological effects of naturally occurring psychoactive chemicals have been recognized for millennia. Hallucinogens, which include naturally occurring chemicals such as mescaline and psilocybin, as well as synthetic compounds, such as lysergic acid diethylamide (LSD), induce profound alterations of human consciousness, emotion, and cognition. The discovery of the hallucinogenic effects of LSD and the observations that LSD and the endogenous ligand serotonin share chemical and pharmacological profiles led to the suggestion that biogenic amines like serotonin were involved in the psychosis of mental disorders such as schizophrenia. Although they bind other G protein-coupled receptor (GPCR) subtypes, studies indicate that several effects of hallucinogens involve agonist activity at the serotonin 5-HT2A receptor. In this chapter, we review recent advances in understanding hallucinogen drug action through characterization of structure, neuroanatomical location, and function of the 5-HT2A receptor.
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Abstract
Lysergic acid diethylamide (LSD), described as a classical hallucinogen, began its journey from the middle of the last century following an accidental discovery. Since then, it was used as a popular and notorious substance of abuse in various parts of the world. Its beneficial role as an adjunct to psychotherapy was much unknown, until some 'benevolent' experiments were carried out over time to explore some of its potential uses. But, many of its effects were unclear and seemed to be a psychedelic enigma. In this review article, we have described the receptor pharmacology, mechanism of action, effects and adverse effects of LSD on the normal body system. We have also highlighted its addictive potentials and the chances of developing tolerance. We have assimilated some of the interesting therapeutic uses of this drug, such as an antianxiety agent, a creativity enhancer, a suggestibility enhancer, and a performance enhancer. We have also described LSD to be successfully used in drug and alcohol dependence, and as a part of psychedelic peak therapy in terminally ill patients. The relevant chronological history and literature in the light of present knowledge and scenarios have been discussed. Based on available evidence, LSD could be tried therapeutically in certain specific conditions under controlled settings. But as we mention, due to all the safety concerns, the use of this nonaddictive 'entheogen' in actual practice warrants a lot of expertise, caution, cooperation and ethical considerations.
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Affiliation(s)
- Saibal Das
- Department of Pharmacology, Christian Medical College, Vellore, 632002, India
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Dalwadi DA, Kim S, Amdani SM, Chen Z, Huang RQ, Schetz JA. Molecular mechanisms of serotonergic action of the HIV-1 antiretroviral efavirenz. Pharmacol Res 2016; 110:10-24. [PMID: 27157251 DOI: 10.1016/j.phrs.2016.04.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/14/2016] [Accepted: 04/28/2016] [Indexed: 02/04/2023]
Abstract
Efavirenz is highly effective at suppressing HIV-1, and the WHO guidelines list it as a component of the first-line antiretroviral (ARV) therapies for treatment-naïve patients. Though the pharmacological basis is unclear, efavirenz is commonly associated with a risk for neuropsychiatric adverse events (NPAEs) when taken at the prescribed dose. In many patients these NPAEs appear to subside after several weeks of treatment, though long-term studies show that in some patients the NPAEs persist. In a recent study focusing on the abuse potential of efavirenz, its receptor psychopharmacology was reported to include interactions with a number of established molecular targets for known drugs of abuse, and it displayed a prevailing behavioral profile in rodents resembling an LSD-like activity. In this report, we discovered interactions with additional serotonergic targets that may be associated with efavirenz-induced NPAEs. The most robust interactions were with 5-HT3A and 5-HT6 receptors, with more modest interactions noted for the 5-HT2B receptor and monoamine oxidase A. From a molecular mechanistic perspective, efavirenz acts as a 5-HT6 receptor inverse agonist of Gs-signaling, 5-HT2A and 5-HT2C antagonist of Gq-signaling, and a blocker of the 5-HT3A receptor currents. Efavirenz also completely or partially blocks agonist stimulation of the M1 and M3 muscarinic receptors, respectively. Schild analysis suggests that efavirenz competes for the same site on the 5-HT2A receptor as two known hallucinogenic partial agonists (±)-DOI and LSD. Prolonged exposure to efavirenz reduces 5-HT2A receptor density and responsiveness to 5-HT. Other ARVs such as zidovudine, nevirapine and emtricitabine did not share the same complex pharmacological profile as efavirenz, though some of them weakly interact with the 5-HT6 receptor or modestly block GABAA currents.
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Affiliation(s)
- Dhwanil A Dalwadi
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Seongcheol Kim
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Shahnawaz M Amdani
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Zhenglan Chen
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Ren-Qi Huang
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States; Institute for Healthy Aging, Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - John A Schetz
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States; Institute for Healthy Aging, Center for Neuroscience Discovery, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States.
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33
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Bogenschutz MP, Johnson MW. Classic hallucinogens in the treatment of addictions. Prog Neuropsychopharmacol Biol Psychiatry 2016; 64:250-8. [PMID: 25784600 DOI: 10.1016/j.pnpbp.2015.03.002] [Citation(s) in RCA: 134] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/05/2015] [Accepted: 03/07/2015] [Indexed: 01/09/2023]
Abstract
Addictive disorders are very common and have devastating individual and social consequences. Currently available treatment is moderately effective at best. After many years of neglect, there is renewed interest in potential clinical uses for classic hallucinogens in the treatment of addictions and other behavioral health conditions. In this paper we provide a comprehensive review of both historical and recent clinical research on the use of classic hallucinogens in the treatment of addiction, selectively review other relevant research concerning hallucinogens, and suggest directions for future research. Clinical trial data are very limited except for the use of LSD in the treatment of alcoholism, where a meta-analysis of controlled trials has demonstrated a consistent and clinically significant beneficial effect of high-dose LSD. Recent pilot studies of psilocybin-assisted treatment of nicotine and alcohol dependence had strikingly positive outcomes, but controlled trials will be necessary to evaluate the efficacy of these treatments. Although plausible biological mechanisms have been proposed, currently the strongest evidence is for the role of mystical or other meaningful experiences as mediators of therapeutic effects. Classic hallucinogens have an excellent record of safety in the context of clinical research. Given our limited understanding of the clinically relevant effects of classic hallucinogens, there is a wealth of opportunities for research that could contribute important new knowledge and potentially lead to valuable new treatments for addiction.
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Affiliation(s)
- Michael P Bogenschutz
- Department of Psychiatry and Behavioral Sciences, University of New Mexico Health Sciences Center, MSC11 6035, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA.
| | - Matthew W Johnson
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, USA.
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34
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Nocjar C, Alex KD, Sonneborn A, Abbas AI, Roth BL, Pehek EA. Serotonin-2C and -2a receptor co-expression on cells in the rat medial prefrontal cortex. Neuroscience 2015; 297:22-37. [PMID: 25818050 PMCID: PMC4595040 DOI: 10.1016/j.neuroscience.2015.03.050] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 03/20/2015] [Accepted: 03/20/2015] [Indexed: 11/28/2022]
Abstract
Neural function within the medial prefrontal cortex (mPFC) regulates normal cognition, attention and impulse control, implicating neuroregulatory abnormalities within this region in mental dysfunction related to schizophrenia, depression and drug abuse. Both serotonin-2A (5-HT2A) and -2C (5-HT2C) receptors are known to be important in neuropsychiatric drug action and are distributed throughout the mPFC. However, their interactive role in serotonergic cortical regulation is poorly understood. While the main signal transduction mechanism for both receptors is stimulation of phosphoinositide production, they can have opposite effects downstream. 5-HT2A versus 5-HT2C receptor activation oppositely regulates behavior and can oppositely affect neurochemical release within the mPFC. These distinct receptor effects could be caused by their differential cellular distribution within the cortex and/or other areas. It is known that both receptors are located on GABAergic and pyramidal cells within the mPFC, but it is not clear whether they are expressed on the same or different cells. The present work employed immunofluorescence with confocal microscopy to examine this in layers V-VI of the prelimbic mPFC. The majority of GABA cells in the deep prelimbic mPFC expressed 5-HT2C receptor immunoreactivity. Furthermore, most cells expressing 5-HT2C receptor immunoreactivity notably co-expressed 5-HT2A receptors. However, 27% of 5-HT2C receptor immunoreactive cells were not GABAergic, indicating that a population of prelimbic pyramidal projection cells could express the 5-HT2C receptor. Indeed, some cells with 5-HT2C and 5-HT2A receptor co-labeling had a pyramidal shape and were expressed in the typical layered fashion of pyramidal cells. This indirectly demonstrates that 5-HT2C and 5-HT2A receptors may be commonly co-expressed on GABAergic cells within the deep layers of the prelimbic mPFC and perhaps co-localized on a small population of local pyramidal projection cells. Thus a complex interplay of cortical 5-HT2A and 5-HT2C receptor mechanisms exists, which if altered, could modulate efferent brain systems implicated in mental illness.
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Affiliation(s)
- C Nocjar
- Louis Stokes Cleveland VA Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA; Department of Psychiatry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
| | - K D Alex
- Louis Stokes Cleveland VA Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA; Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
| | - A Sonneborn
- Louis Stokes Cleveland VA Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA.
| | - A I Abbas
- Department of Psychiatry, Columbia University, New York, NY 10032, USA; Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA.
| | - B L Roth
- Department of Pharmacology, University of North Carolina-Chapel Hill School of Medicine, 120 Mason Farm Road, 4072 Genetic Medicine Building, Campus Box 7365, Chapel Hill, NC 27599-7365, USA.
| | - E A Pehek
- Louis Stokes Cleveland VA Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA; Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Department of Psychiatry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
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Halberstadt AL. Recent advances in the neuropsychopharmacology of serotonergic hallucinogens. Behav Brain Res 2015; 277:99-120. [PMID: 25036425 PMCID: PMC4642895 DOI: 10.1016/j.bbr.2014.07.016] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 07/07/2014] [Accepted: 07/08/2014] [Indexed: 12/12/2022]
Abstract
Serotonergic hallucinogens, such as (+)-lysergic acid diethylamide, psilocybin, and mescaline, are somewhat enigmatic substances. Although these drugs are derived from multiple chemical families, they all produce remarkably similar effects in animals and humans, and they show cross-tolerance. This article reviews the evidence demonstrating the serotonin 5-HT2A receptor is the primary site of hallucinogen action. The 5-HT2A receptor is responsible for mediating the effects of hallucinogens in human subjects, as well as in animal behavioral paradigms such as drug discrimination, head twitch response, prepulse inhibition of startle, exploratory behavior, and interval timing. Many recent clinical trials have yielded important new findings regarding the psychopharmacology of these substances. Furthermore, the use of modern imaging and electrophysiological techniques is beginning to help unravel how hallucinogens work in the brain. Evidence is also emerging that hallucinogens may possess therapeutic efficacy.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States.
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Changes in intensity of serotonin syndrome caused by adverse interaction between monoamine oxidase inhibitors and serotonin reuptake blockers. Neuropsychopharmacology 2014; 39:1996-2007. [PMID: 24577320 PMCID: PMC4059910 DOI: 10.1038/npp.2014.49] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/15/2014] [Accepted: 02/17/2014] [Indexed: 11/08/2022]
Abstract
Drug interaction between inhibitors of monoamine oxidase (MAOIs) and selective serotonin (5-hydroxytryptamine, 5-HT) reuptake (SSRIs) induces serotonin syndrome, which is usually mild but occasionally severe in intensity. However, little is known about neural mechanisms responsible for the syndrome induction and intensification. In this study, we hypothesized that the syndrome induction and intensity utilize two different but inter-related mechanisms. Serotonin syndrome is elicited by excessive 5-HT in the brain (presynaptic mechanism), whereas syndrome intensity is attributed to neural circuits involving 5-HT2A and NMDA receptors (postsynaptic mechanism). To test this hypothesis, basal 5-HT efflux and postsynaptic circuits were pharmacologically altered in rats by once daily pretreatment of the MAOI clorgyline for 3, 6, or 13 days. Syndrome intensity was estimated by measuring 5-HT efflux, neuromuscular activity, and body-core temperature in response to challenge injection of clorgyline combined with the SSRI paroxetine. Results showed that the onset of serotonin syndrome is caused by 5-HT efflux exceeding 10-fold above baseline, confirming the presynaptic hypothesis. The neuromuscular and body-core temperature abnormalities, which were otherwise mild in drug-naive rats, were significantly intensified to a severe level in rats pretreated with daily clorgyline for 3 and 6 days but not in rats pretreated for 13 days. The intensified effect was blocked by M100907 and MK-801, suggesting that variation in syndrome intensity was mediated through a 5-HT2A and NMDA receptor-engaged circuit. Therefore, we concluded that pretreatments of MAOI pharmacologically alter the activity of postsynaptic circuits, which is responsible for changes in syndrome intensity.
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Manganese-enhanced magnetic resonance imaging reveals increased DOI-induced brain activity in a mouse model of schizophrenia. Proc Natl Acad Sci U S A 2014; 111:E2492-500. [PMID: 24889602 DOI: 10.1073/pnas.1323287111] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Maternal infection during pregnancy increases the risk for schizophrenia in offspring. In rodent models, maternal immune activation (MIA) yields offspring with schizophrenia-like behaviors. None of these behaviors are, however, specific to schizophrenia. The presence of hallucinations is a key diagnostic symptom of schizophrenia. In mice, this symptom can be defined as brain activation in the absence of external stimuli, which can be mimicked by administration of hallucinogens. We find that, compared with controls, adult MIA offspring display an increased stereotypical behavioral response to the hallucinogen 2,5-dimethoxy-4-iodoamphetamine (DOI), an agonist for serotonin receptor 2A (5-HT2AR). This may be explained by increased levels of 5-HT2AR and downstream signaling molecules in unstimulated MIA prefrontal cortex (PFC). Using manganese-enhanced magnetic resonance imaging to identify neuronal activation elicited by DOI administration, we find that, compared with controls, MIA offspring exhibit a greater manganese (Mn(2+)) accumulation in several brain areas, including the PFC, thalamus, and striatum. The parafascicular thalamic nucleus, which plays the role in the pathogenesis of hallucinations, is activated by DOI in MIA offspring only. Additionally, compared with controls, MIA offspring demonstrate higher DOI-induced expression of early growth response protein 1, cyclooxygenase-2, and brain-derived neurotrophic factor in the PFC. Chronic treatment with the 5-HT2AR antagonist ketanserin reduces DOI-induced head twitching in MIA offspring. Thus, the MIA mouse model can be successfully used to investigate activity induced by DOI in awake, behaving mice. Moreover, manganese-enhanced magnetic resonance imaging is a useful, noninvasive method for accurately measuring this type of activity.
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N-acetylcysteine modulates hallucinogenic 5-HT2A receptor agonist-mediated responses: Behavioral, molecular, and electrophysiological studies. Neuropharmacology 2014; 81:215-23. [DOI: 10.1016/j.neuropharm.2014.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 01/10/2014] [Accepted: 02/06/2014] [Indexed: 01/01/2023]
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Halberstadt AL, Geyer MA. Characterization of the head-twitch response induced by hallucinogens in mice: detection of the behavior based on the dynamics of head movement. Psychopharmacology (Berl) 2013; 227:727-39. [PMID: 23407781 PMCID: PMC3866102 DOI: 10.1007/s00213-013-3006-z] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 01/21/2013] [Indexed: 02/05/2023]
Abstract
RATIONALE The head-twitch response (HTR) is a rapid side-to-side rotational head movement that occurs in rats and mice after administration of serotonergic hallucinogens and other 5-HT2A agonists. The HTR is widely used as a behavioral assay for 5-HT2A activation and to probe for interactions between the 5-HT2A receptor and other transmitter systems. OBJECTIVE High-speed video recordings were used to analyze the head movement that occurs during head twitches in C57BL/6J mice. Experiments were also conducted in C57BL/6J mice to determine whether a head-mounted magnet and a magnetometer coil could be used to detect the HTR induced by serotonergic hallucinations based on the dynamics of the response. RESULTS Head movement during the HTR was highly rhythmic and occurred within a specific frequency range (mean head movement frequency of 90.3 Hz). Head twitches produced wave-like oscillations of magnetometer coil voltage that matched the frequency of head movement during the response. The magnetometer coil detected the HTR induced by the serotonergic hallucinogens 2,5-dimethoxy-4-iodoamphetamine (DOI; 0.25, 0.5, and 1.0 mg/kg, i.p.) and lysergic acid diethylamide (LSD; 0.05, 0.1, 0.2, and 0.4 mg/kg, i.p.) with extremely high sensitivity and specificity. Magnetometer coil recordings demonstrated that the non-hallucinogenic compounds (+)-amphetamine (2.5 and 5.0 mg/kg, i.p.) and lisuride (0.8, 1.6, and 3.2 mg/kg, i.p.) did not induce the HTR. CONCLUSIONS These studies confirm that a magnetometer coil can be used to detect the HTR induced by hallucinogens. The use of magnetometer-based HTR detection provides a high-throughput, semi-automated assay for this behavior, and offers several advantages over traditional assessment methods.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0804, USA.
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Support for 5-HT2C receptor functional selectivity in vivo utilizing structurally diverse, selective 5-HT2C receptor ligands and the 2,5-dimethoxy-4-iodoamphetamine elicited head-twitch response model. Neuropharmacology 2013; 70:112-21. [PMID: 23353901 DOI: 10.1016/j.neuropharm.2013.01.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 01/03/2013] [Accepted: 01/10/2013] [Indexed: 11/22/2022]
Abstract
There are seemingly conflicting data in the literature regarding the role of serotonin (5-HT) 5-HT2C receptors in the mouse head-twitch response (HTR) elicited by the hallucinogenic 5-HT2A/2B/2C receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI). Namely, both 5-HT2C receptor agonists and antagonists, regarding 5-HT2C receptor-mediated Gq-phospholipase C (PLC) signaling, reportedly attenuate the HTR response. The present experiments tested the hypothesis that both classes of 5-HT2C receptor compounds could attenuate the DOI-elicited-HTR in a single strain of mice, C57Bl/6J. The expected results were considered in accordance with ligand functional selectivity. Commercially-available 5-HT2C agonists (CP 809101, Ro 60-0175, WAY 161503, mCPP, and 1-methylpsilocin), novel 4-phenyl-2-N,N-dimethyl-aminotetralin (PAT)-type 5-HT2C agonists (with 5-HT2A/2B antagonist activity), and antagonists selective for 5-HT2A (M100907), 5-HT2C (SB-242084), and 5-HT2B/2C (SB-206553) receptors attenuated the DOI-elicited-HTR. In contrast, there were differential effects on locomotion across classes of compounds. The 5-HT2C agonists and M100907 decreased locomotion, SB-242084 increased locomotion, SB-206553 resulted in dose-dependent biphasic effects on locomotion, and the PATs did not alter locomotion. In vitro molecular pharmacology studies showed that 5-HT2C agonists potent for attenuating the DOI-elicited-HTR also reduced the efficacy of DOI to activate mouse 5-HT2C receptor-mediated PLC signaling in HEK cells. Although there were differences in affinities of a few compounds at mouse compared to human 5-HT2A or 5-HT2C receptors, all compounds tested retained their selectivity for either receptor, regardless of receptor species. Results indicate that 5-HT2C receptor agonists and antagonists attenuate the DOI-elicited-HTR in C57Bl/6J mice, and suggest that structurally diverse 5-HT2C ligands result in different 5-HT2C receptor signaling outcomes compared to DOI.
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Moreno JL, Holloway T, Umali A, Rayannavar V, Sealfon SC, González-Maeso J. Persistent effects of chronic clozapine on the cellular and behavioral responses to LSD in mice. Psychopharmacology (Berl) 2013; 225:217-26. [PMID: 22842765 PMCID: PMC3552490 DOI: 10.1007/s00213-012-2809-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 07/09/2012] [Indexed: 12/24/2022]
Abstract
RATIONALE In schizophrenia patients, optimal treatment with antipsychotics requires weeks to months of sustained drug therapy. However, single administration of antipsychotic drugs can reverse schizophrenia-like behavioral alterations in rodent models of psychosis. This raises questions about the physiological relevance of such antipsychotic-like activity. OBJECTIVE This study evaluates the effects of chronic treatment with clozapine on the cellular and behavioral responses induced by the hallucinogenic serotonin 5-HT(2A) receptor agonist lysergic acid diethylamide (LSD) as a mouse model of psychosis. METHOD Mice were treated chronically (21 days) with 25 mg/kg/day clozapine. Experiments were conducted 1, 7, 14, and 21 days after the last clozapine administration. [(3)H]Ketanserin binding and 5-HT ( 2A ) mRNA expression were determined in mouse somatosensory cortex. Head-twitch behavior, expression of c-fos, which is induced by all 5-HT(2A) agonists, and expression of egr-1 and egr-2, which are LSD-like specific, were assayed. RESULTS Head-twitch response was decreased and [(3)H]ketanserin binding was downregulated in 1, 7, and 14 days after chronic clozapine. 5-HT ( 2A ) mRNA was reduced 1 day after chronic clozapine. Induction of c-fos, but not egr-1 and egr-2, was rescued 7 days after chronic clozapine. These effects were not observed after short treatment (2 days) with clozapine or chronic haloperidol (1 mg/kg/day). CONCLUSION Our findings provide a murine model of chronic atypical antipsychotic drug action and suggest downregulation of the 5-HT(2A) receptor as a potential mechanism involved in these persistent therapeutic-like effects.
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Affiliation(s)
- José L. Moreno
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Terrell Holloway
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Adrienne Umali
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Vinayak Rayannavar
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Stuart C. Sealfon
- Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, USA. Center for Translational Systems Biology, Mount Sinai School of Medicine, New York, NY 10029, USA. Friedman Brain Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Javier González-Maeso
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA. Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, USA. Friedman Brain Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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Canal CE, Morgan D. Head-twitch response in rodents induced by the hallucinogen 2,5-dimethoxy-4-iodoamphetamine: a comprehensive history, a re-evaluation of mechanisms, and its utility as a model. Drug Test Anal 2012; 4:556-76. [PMID: 22517680 DOI: 10.1002/dta.1333] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/09/2012] [Accepted: 01/10/2012] [Indexed: 11/06/2022]
Abstract
Two primary animal models persist for assessing hallucinogenic potential of novel compounds and for examining the pharmacological and neurobiological substrates underlying the actions of classical hallucinogens, the two-lever drug discrimination procedure and the drug-induced head-twitch response (HTR) in rodents. The substituted amphetamine hallucinogen, serotonin 2 (5-HT(2) ) receptor agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI) has emerged as the most popular pharmacological tool used in HTR studies of hallucinogens. Synthesizing classic, recent, and relatively overlooked findings, addressing ostensibly conflicting observations, and considering contemporary theories in receptor and behavioural pharmacology, this review provides an up-to-date and comprehensive synopsis of DOI and the HTR model, from neural mechanisms to utility for understanding psychiatric diseases. Also presented is support for the argument that, although both the two-lever drug discrimination and the HTR models in rodents are useful for uncovering receptors, interacting proteins, intracellular signalling pathways, and neurochemical processes affected by DOI and related classical hallucinogens, results from both models suggest they are not reporting hallucinogenic experiences in animals.
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Affiliation(s)
- Clint E Canal
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA.
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Serotonin, but not N-methyltryptamines, activates the serotonin 2A receptor via a ß-arrestin2/Src/Akt signaling complex in vivo. J Neurosci 2010; 30:13513-24. [PMID: 20926677 DOI: 10.1523/jneurosci.1665-10.2010] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Hallucinogens mediate many of their psychoactive effects by activating serotonin 2A receptors (5-HT(2A)R). Although serotonin is the cognate endogenous neurotransmitter and is not considered hallucinogenic, metabolites of serotonin also have high affinity at 5-HT(2A)R and can induce hallucinations in humans. Here we report that serotonin differs from the psychoactive N-methyltryptamines by its ability to engage a β-arrestin2-mediated signaling cascade in the frontal cortex. Serotonin and 5-hydroxy-L-tryptophan (5-HTP) induce a head-twitch response in wild-type (WT) mice that is a behavioral proxy for 5-HT(2A)R activation. The response in β-arrestin2 knock-out (βarr2-KO) mice is greatly attenuated until the doses are elevated, at which point, βarr2-KO mice display a head-twitch response that can exceed that of WT mice. Direct administration of N-methyltryptamines also produces a greater response in βarr2-KO mice. Moreover, the inhibition of N-methyltransferase blocks 5-HTP-induced head twitches in βarr2-KO mice, indicating that N-methyltryptamines, rather than serotonin, primarily mediate this response. Biochemical studies demonstrate that serotonin stimulates Akt phosphorylation in the frontal cortex and in primary cortical neurons through the activation of a β-arrestin2/phosphoinositide 3-kinase/Src/Akt cascade, whereas N-methyltryptamines do not. Furthermore, disruption of any of the components of this cascade prevents 5-HTP-induced, but not N-methyltryptamine-induced, head twitches. We propose that there is a bifurcation of 5-HT(2A)R signaling that is neurotransmitter and β-arrestin2 dependent. This demonstration of agonist-directed 5-HT(2A)R signaling in vivo may significantly impact drug discovery efforts for the treatment of disorders wherein hallucinations are part of the etiology, such as schizophrenia, or manifest as side effects of treatment, such as depression.
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Enhanced function of prefrontal serotonin 5-HT(2) receptors in a rat model of psychiatric vulnerability. J Neurosci 2010; 30:12138-50. [PMID: 20826676 DOI: 10.1523/jneurosci.3245-10.2010] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Prefrontal serotonin 5-HT(2) receptors have been linked to the pathogenesis and treatment of affective disorders, yet their function in psychiatric vulnerability is not known. Here, we examine the effects of 5-HT(2) receptors in a rat model of psychiatric vulnerability using electrophysiology, gene expression, and behavior. Following the early stress of chronic maternal separation, we found that serotonin has atypical 5-HT(2) receptor-mediated excitatory effects in the adult prefrontal cortex that were blocked by the 5-HT(2A) receptor antagonist MDL 100907. In the absence of a serotonergic agonist, the intrinsic excitability of the prefrontal cortex was not enhanced relative to controls. Yet, in response to stimulation of 5-HT(2) receptors, adult animals with a history of early stress exhibit heightened prefrontal network activity in vitro, enhanced immediate early gene expression in vivo, and potentiated head shake behavior. These changes arise in the absence of any major alteration of prefrontal 5-HT(2A/C) mRNA expression or 5-HT(2) receptor binding. Our microarray results and quantitative PCR validation provide insight into the molecular changes that accompany such enhanced 5-HT(2) receptor function in adult animals following early stress. We observed persistent prefrontal transcriptome changes, with significant enrichment of genes involved in cellular developmental processes, regulation of signal transduction, and G-protein signaling. Specific genes regulated by early stress were validated in an independent cohort, and several altered genes were normalized by chronic blockade of 5-HT(2) receptors in adulthood. Together, our results demonstrate enhanced prefrontal 5-HT(2) receptor function and persistent alterations in prefrontal gene expression in a rat model of psychiatric vulnerability.
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Canal CE, Olaghere da Silva UB, Gresch PJ, Watt EE, Sanders-Bush E, Airey DC. The serotonin 2C receptor potently modulates the head-twitch response in mice induced by a phenethylamine hallucinogen. Psychopharmacology (Berl) 2010; 209:163-74. [PMID: 20165943 PMCID: PMC2868321 DOI: 10.1007/s00213-010-1784-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 01/18/2010] [Indexed: 12/25/2022]
Abstract
RATIONALE Hallucinogenic serotonin 2A (5-HT(2A)) receptor partial agonists, such as (+ or -)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI), induce a frontal cortex-dependent head-twitch response (HTR) in rodents, a behavioral proxy of a hallucinogenic response that is blocked by 5-HT(2A) receptor antagonists. In addition to 5-HT(2A) receptors, DOI and most other serotonin-like hallucinogens have high affinity and potency as partial agonists at 5-HT(2C) receptors. OBJECTIVES We tested for involvement of 5-HT(2C) receptors in the HTR induced by DOI. RESULTS Comparison of 5-HT(2C) receptor knockout and wild-type littermates revealed an approximately 50% reduction in DOI-induced HTR in knockout mice. Also, pretreatment with either the 5-HT(2C) receptor antagonist SB206553 or SB242084 eradicated a twofold difference in DOI-induced HTR between the standard inbred mouse strains C57BL/6J and DBA/2J, and decreased the DOI-induced HTR by at least 50% in both strains. None of several measures of 5-HT(2A) receptors in frontal cortex explained the strain difference, including 5-HT(2A) receptor density, Galpha(q) or Galpha(i/o) protein levels, phospholipase C activity, or DOI-induced expression of Egr1 and Egr2. 5-HT(2C) receptor density in the brains of C57BL/6J and DBA/2J was also equivalent, suggesting that 5-HT(2C) receptor-mediated intracellular signaling or other physiological modulators of the HTR may explain the strain difference in response to DOI. CONCLUSIONS We conclude that the HTR to DOI in mice is strongly modulated by 5-HT(2C) receptor activity. This novel finding invites reassessment of hallucinogenic mechanisms involving 5-HT(2) receptors.
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MESH Headings
- Aminopyridines/pharmacology
- Amphetamines/pharmacology
- Animals
- Autoradiography
- Behavior, Animal
- Binding Sites
- Blotting, Western
- Brain/drug effects
- Brain/metabolism
- Dose-Response Relationship, Drug
- Drug Partial Agonism
- Early Growth Response Protein 1/genetics
- Early Growth Response Protein 2/genetics
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Hallucinogens/pharmacology
- Head Movements/drug effects
- Indoles/pharmacology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Pyridines/pharmacology
- RNA, Messenger/metabolism
- Receptor, Serotonin, 5-HT2C/deficiency
- Receptor, Serotonin, 5-HT2C/drug effects
- Receptor, Serotonin, 5-HT2C/genetics
- Serotonin Antagonists/pharmacology
- Serotonin Receptor Agonists/pharmacology
- Species Specificity
- Type C Phospholipases/metabolism
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Halberstadt AL, Geyer MA. LSD but not lisuride disrupts prepulse inhibition in rats by activating the 5-HT(2A) receptor. Psychopharmacology (Berl) 2010; 208:179-89. [PMID: 19937319 PMCID: PMC2797624 DOI: 10.1007/s00213-009-1718-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Accepted: 10/27/2009] [Indexed: 11/27/2022]
Abstract
RATIONALE Compounds that activate the 5-HT(2A) receptor, such as lysergic acid diethylamide (LSD), act as hallucinogens in humans. One notable exception is the LSD congener lisuride, which does not have hallucinogenic effects in humans even though it is a potent 5-HT(2A) agonist. LSD and other hallucinogens have been shown to disrupt prepulse inhibition (PPI), an operational measure of sensorimotor gating, by activating 5-HT(2A) receptors in rats. OBJECTIVE We tested whether lisuride disrupts PPI in male Sprague-Dawley rats. Experiments were also conducted to identify the mechanism(s) responsible for the effect of lisuride on PPI and to compare the effects of lisuride to those of LSD. RESULTS Confirming a previous report, LSD (0.05, 0.1, and 0.2 mg/kg, s.c.) reduced PPI, and the effect of LSD was blocked by pretreatment with the selective 5-HT(2A) antagonist MDL 11,939. Administration of lisuride (0.0375, 0.075, and 0.15 mg/kg, s.c.) also reduced PPI. However, the PPI disruption induced by lisuride (0.075 mg/kg) was not blocked by pretreatment with MDL 11,939 or the selective 5-HT(1A) antagonist WAY-100635 but was prevented by pretreatment with the selective dopamine D(2)/D(3) receptor antagonist raclopride (0.1 mg/kg, s.c). CONCLUSIONS The effect of LSD on PPI is mediated by the 5-HT(2A) receptor, whereas activation of the 5-HT(2A) receptor does not appear to contribute to the effect of lisuride on PPI. These findings demonstrate that lisuride and LSD disrupt PPI via distinct receptor mechanisms and provide additional support for the classification of lisuride as a non-hallucinogenic 5-HT(2A) agonist.
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Affiliation(s)
- Adam L. Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093 USA
| | - Mark A. Geyer
- Department of Psychiatry-0804, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0804 USA
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Molinaro G, Traficante A, Riozzi B, Di Menna L, Curto M, Pallottino S, Nicoletti F, Bruno V, Battaglia G. Activation of mGlu2/3 Metabotropic Glutamate Receptors Negatively Regulates the Stimulation of Inositol Phospholipid Hydrolysis Mediated by 5-Hydroxytryptamine2A Serotonin Receptors in the Frontal Cortex of Living Mice. Mol Pharmacol 2009; 76:379-87. [DOI: 10.1124/mol.109.056580] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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48
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Mannoury La Cour C, Chaput C, Touzard M, Millan MJ. An immunocapture/scintillation proximity analysis of G alpha q/11 activation by native serotonin (5-HT)2A receptors in rat cortex: blockade by clozapine and mirtazapine. Synapse 2009; 63:95-105. [PMID: 19016481 DOI: 10.1002/syn.20587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Though transduction mechanisms recruited by heterologously expressed 5-HT(2A) receptors have been extensively studied, their interaction with specific subtypes of G-protein remains to be directly evaluated in cerebral tissue. Herein, as shown by an immunocapture/scintillation proximity analysis, 5-HT, the prototypical 5-HT(2A) agonist, DOI, and Ro60,0175 all enhanced [(35)S]GTPgammaS binding to G alpha q/11 in rat cortex with pEC(50) values of 6.22, 7.24 and 6.35, respectively. No activation of G o or G s/olf was seen at equivalent concentrations of DOI. Stimulation of G alpha q/11 by 5-HT (30 microM) and DOI (30 microM) was abolished by the selective 5-HT(2A) vs. 5-HT(2C)/5-HT(2B) antagonists, ketanserin (pK(B) values of 9.11 and 8.88, respectively) and MDL100,907 (9.82 and 9.68). By contrast, 5-HT-induced [(35)S]GTPgammaS binding to G alpha q/11 was only weakly inhibited by the preferential 5-HT(2C) receptor antagonists, RS102,221 (6.94) and SB242,084 (7.39), and the preferential 5-HT(2B) receptor antagonist, LY266,097 (6.66). The antipsychotic, clozapine, which had marked affinity for 5-HT(2A) receptors, blocked the recruitment of G alpha q/11 by 5-HT and DOI with pK(B) values of 8.54 and 8.14, respectively. Its actions were mimicked by the "atypical" antidepressant and 5-HT(2A) receptor antagonist, mirtazapine, which likewise blocked 5-HT and DOI-induced G alpha q/11 protein activation with pK(B) values of 7.90 and 7.76, respectively. In conclusion, by use of an immunocapture/scintillation proximity strategy, this study shows that native 5-HT(2A) receptors in rat frontal cortex specifically recruit G alpha q/11 and that this action is blocked by clozapine and mirtazapine. Quantification of 5-HT(2A) receptor-mediated G alpha q/11 activation in frontal cortex should prove instructive in characterizing the actions of diverse classes of psychotropic agent.
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Affiliation(s)
- C Mannoury La Cour
- Institut de Recherche Servier, Psychopharmacology Department, 125 Chemin de Ronde, 78290 Croissy sur Seine, France.
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Cussac D, Boutet-Robinet E, Ailhaud MC, Newman-Tancredi A, Martel JC, Danty N, Rauly-Lestienne I. Agonist-directed trafficking of signalling at serotonin 5-HT2A, 5-HT2B and 5-HT2C-VSV receptors mediated Gq/11 activation and calcium mobilisation in CHO cells. Eur J Pharmacol 2008; 594:32-8. [PMID: 18703043 DOI: 10.1016/j.ejphar.2008.07.040] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 07/04/2008] [Accepted: 07/22/2008] [Indexed: 10/21/2022]
Abstract
Several examples of agonist-directed trafficking of receptor signalling at 5-HT2A and 5-HT2C receptors have been reported that involve independent downstream transduction pathways. We now report the functional selectivity of a series of chemically diverse agonists at human (h)5-HT2A, h5-HT2B and h5-HT2C-VSV by examining two related responses, the upstream activation of Gq/11 proteins in comparison with its associated cascade of calcium mobilisation. At the h5-HT2A receptor, d-lysergic acid diethylamide (LSD) and the antiparkinsonian agents lisuride, bromocriptine and pergolide exhibit a higher potency for Gq/11 activation than calcium release in contrast with all the other tested ligands such as 5-HT, mCPP and BW723C86, that show an opposite preference of signalling pathway. Comparable observations are made at h5-HT2B and h5-HT2C-VSV receptors, suggesting a similar mechanism of functional selectivity for the three serotonin receptors. Interestingly, the non-hallucinogenic compound lisuride behaves as a partial agonist for both Gq/11 activation and calcium release at the three 5-HT2 receptors, in contrast with DOI, LSD, pergolide and bromocriptine, which are known to provoke hallucinations, and behave as more efficacious agonists. Hence, a functional selectivity for Gq/11 activation together with a threshold of efficacy at h5-HT2A (and possibly h5-HT2B and/or h5-HT2C-VSV) may contribute to hallucinogenic liability. Thus, our results extend the notion of agonist-directed trafficking of receptor signalling to all the 5-HT2-receptor family and indicate that measures of Gq/11 activation versus calcium release may be useful to identify more effective therapeutic drugs with limited side effects.
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Affiliation(s)
- Didier Cussac
- Department of Cellular and Molecular Biology, Centre de Recherche Pierre Fabre, 17 avenue Jean Moulin, F 81106 Castres Cedex, France.
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Ma Z, Zhang G, Jenney C, Krishnamoorthy S, Tao R. Characterization of serotonin-toxicity syndrome (toxidrome) elicited by 5-hydroxy-l-tryptophan in clorgyline-pretreated rats. Eur J Pharmacol 2008; 588:198-206. [PMID: 18499101 DOI: 10.1016/j.ejphar.2008.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 03/11/2008] [Accepted: 04/01/2008] [Indexed: 12/13/2022]
Abstract
Patients are at high risk of developing serotonin-toxicity syndrome (toxidrome) when they take multiple serotonergic drugs, particularly co-administered with monoamine oxidase inhibitors or 5-hydroxytryptamine (5-HT) reuptake blockers. The toxidrome can vary from mild to severe. The primary goal of the present study was to understand the relationship between behavioral signs and degrees of toxidrome induced by 5-hydroxy-l-tryptophan (5-HTP) in clorgylinized rats. The severity was obtained by scoring behavioral signs including head shakes, penile erection, forepaw treading, hind limb abduction, Straub tail and tremor. It was found that 5-HTP produced a dose-dependent increase in degrees of the toxidrome. Furthermore, correlation between the toxidrome and changes in body-core temperature (delta Tcor) was determined. There was hypothermia in the mild toxidrome (delta Tcor<-1 degrees C), high hyperthermia in the severe toxidrome (delta Tcor>+2 degrees C) and a small change in T(cor) in the moderate toxidrome (-1 degrees C<delta Tcor<+2 degrees C). Thus, delta Tcor in response to drugs can be used to estimate the severity of the toxidrome. The second attempt was to identify the receptors mediating those changes. 5-HT1A receptors were involved in the hypothermic response while 5-HT2A and NMDA receptors mediated head shakes, hyperthermia, forepaw treading and Straub tail. Lastly, antidotal effect of cyproheptadine and (+)-MK-801 was examined. Both drugs blocked hyperthermia and death. However, the effects on mortality became poor when the antidotes were injected 60 min after high hyperthermia had been induced. These findings demonstrate the importance of the time frame using antidotes in the treatment of the 5-HT toxidrome.
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Affiliation(s)
- Zhiyuan Ma
- Department of Basic Science, Florida Atlantic University, Boca Raton, FL 33431, USA
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