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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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Murray CH, Frohlich J, Haggarty CJ, Tare I, Lee R, de Wit H. Neural complexity is increased after low doses of LSD, but not moderate to high doses of oral THC or methamphetamine. Neuropsychopharmacology 2024; 49:1120-1128. [PMID: 38287172 PMCID: PMC11109226 DOI: 10.1038/s41386-024-01809-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/07/2024] [Accepted: 01/17/2024] [Indexed: 01/31/2024]
Abstract
Neural complexity correlates with one's level of consciousness. During coma, anesthesia, and sleep, complexity is reduced. During altered states, including after lysergic acid diethylamide (LSD), complexity is increased. In the present analysis, we examined whether low doses of LSD (13 and 26 µg) were sufficient to increase neural complexity in the absence of altered states of consciousness. In addition, neural complexity was assessed after doses of two other drugs that significantly altered consciousness and mood: delta-9-tetrahydrocannabinol (THC; 7.5 and 15 mg) and methamphetamine (MA; 10 and 20 mg). In three separate studies (N = 73; 21, LSD; 23, THC; 29, MA), healthy volunteers received placebo or drug in a within-subjects design over three laboratory visits. During anticipated peak drug effects, resting state electroencephalography (EEG) recorded Limpel-Ziv complexity and spectral power. LSD, but not THC or MA, dose-dependently increased neural complexity. LSD also reduced delta and theta power. THC reduced, and MA increased, alpha power, primarily in frontal regions. Neural complexity was not associated with any subjective drug effect; however, LSD-induced reductions in delta and theta were associated with elation, and THC-induced reductions in alpha were associated with altered states. These data inform relationships between neural complexity, spectral power, and subjective states, demonstrating that increased neural complexity is not necessary or sufficient for altered states of consciousness. Future studies should address whether greater complexity after low doses of LSD is related to cognitive, behavioral, or therapeutic outcomes, and further examine the role of alpha desynchronization in mediating altered states of consciousness.
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Affiliation(s)
- Conor H Murray
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA.
- Department of Psychiatry and Biobehavioral Sciences, University of Los Angeles, California, 760 Westwood Plaza, Los Angeles, CA, 90024, USA.
| | - Joel Frohlich
- Institute for Neuromodulation and Neurotechnology, University of Tübingen, Otfried-Müller-Straße 45, 72076, Tübingen, Germany
- Institute for Advanced Consciousness Studies, Santa Monica, California; 2811 Wilshire Blvd # 510, Santa Monica, CA, 90403, USA
| | - Connor J Haggarty
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Ilaria Tare
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
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Korkmaz ND, Cikrikcili U, Akan M, Yucesan E. Psychedelic therapy in depression and substance use disorders. Eur J Neurosci 2024. [PMID: 38773750 DOI: 10.1111/ejn.16421] [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: 02/15/2024] [Revised: 04/20/2024] [Accepted: 05/05/2024] [Indexed: 05/24/2024]
Abstract
Psychoactive substances obtained from botanicals have been applied for a wide variety of purposes in the rituals of different cultures for thousands of years. Classical psychedelics from N,N'-dimethyltryptamine, psilocybin, mescaline and various lysergamides cause specific alterations in perception, emotion and cognition by acting through serotonin 5-HT2A receptor activation. Lysergic acid diethylamide, the first famous breakthrough in the field, was discovered by chance by Albert Hoffman in the Zurich Sandoz laboratory in 1943, and studies on its psychoactive effects began to take place in the literature. Studies in this area were blocked after the legislation controlling the use and research of psychedelic drugs came into force in 1967, but since the 1990s, it has started to be a matter of scientific curiosity again by various research groups. In particular, with the crucial reports of psychotherapy-assisted psilocybin applications for life-threatening cancer-related anxiety and depression, a new avenues have been opened in the treatment of psychiatric diseases such as treatment-resistant depression and substance addictions. An increasing number of studies show that psychedelics have a very promising potential in the treatment of neuropsychiatric diseases where the desired efficiency cannot be achieved with conventional treatment methods. In this context, we discuss psychedelic therapy, encompassing its historical development, therapeutic applications and potential treatment effects-especially in depression, trauma disorders and substance use disorders-within the framework of ethical considerations.
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Affiliation(s)
- Nur Damla Korkmaz
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
- Graduate School of Health Sciences, Istanbul University, Istanbul, Turkey
- Department of Medical Biology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Ugur Cikrikcili
- Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University, Magdeburg, Germany
- Deutsche Zentrum für Neurodegenerative Erkrankungen (DZNE), Magdeburg, Germany
| | - Merve Akan
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Emrah Yucesan
- Institute of Neurological Sciences, Department of Neurogenetics, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Rogers SA, Heller EA, Corder G. Psilocybin-enhanced fear extinction linked to bidirectional modulation of cortical ensembles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.04.578811. [PMID: 38352491 PMCID: PMC10862786 DOI: 10.1101/2024.02.04.578811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
The serotonin 2 receptor (5HT2R) agonist psilocybin displays rapid and persistent therapeutic efficacy across neuropsychiatric disorders characterized by cognitive inflexibility. However, the impact of psilocybin on patterns of neural activity underlying sustained changes in behavioral flexibility has not been characterized. To test the hypothesis that psilocybin enhances behavioral flexibility by altering activity in cortical neural ensembles, we performed longitudinal single-cell calcium imaging in the retrosplenial cortex across a five-day trace fear learning and extinction assay. A single dose of psilocybin induced ensemble turnover between fear learning and extinction days while oppositely modulating activity in fear- and extinction- active neurons. The acute suppression of fear-active neurons and delayed recruitment of extinction-active neurons were predictive of psilocybin-enhanced fear extinction. A computational model revealed that acute inhibition of fear-active neurons by psilocybin is sufficient to explain its neural and behavioral effects days later. These results align with our hypothesis and introduce a new mechanism involving the suppression of fear-active populations in the retrosplenial cortex.
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Affiliation(s)
- Sophie A. Rogers
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elizabeth A. Heller
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gregory Corder
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Allen J, Dames SS, Foldi CJ, Shultz SR. Psychedelics for acquired brain injury: a review of molecular mechanisms and therapeutic potential. Mol Psychiatry 2024; 29:671-685. [PMID: 38177350 DOI: 10.1038/s41380-023-02360-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 11/24/2023] [Accepted: 12/01/2023] [Indexed: 01/06/2024]
Abstract
Acquired brain injury (ABI), such as traumatic brain injury and stroke, is a leading cause of disability worldwide, resulting in debilitating acute and chronic symptoms, as well as an increased risk of developing neurological and neurodegenerative disorders. These symptoms can stem from various neurophysiological insults, including neuroinflammation, oxidative stress, imbalances in neurotransmission, and impaired neuroplasticity. Despite advancements in medical technology and treatment interventions, managing ABI remains a significant challenge. Emerging evidence suggests that psychedelics may rapidly improve neurobehavioral outcomes in patients with various disorders that share physiological similarities with ABI. However, research specifically focussed on psychedelics for ABI is limited. This narrative literature review explores the neurochemical properties of psychedelics as a therapeutic intervention for ABI, with a focus on serotonin receptors, sigma-1 receptors, and neurotrophic signalling associated with neuroprotection, neuroplasticity, and neuroinflammation. The promotion of neuronal growth, cell survival, and anti-inflammatory properties exhibited by psychedelics strongly supports their potential benefit in managing ABI. Further research and translational efforts are required to elucidate their therapeutic mechanisms of action and to evaluate their effectiveness in treating the acute and chronic phases of ABI.
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Affiliation(s)
- Josh Allen
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Shannon S Dames
- Psychedelic-Assisted Therapy Post-Graduate Program, Health Sciences and Human Services, Vancouver Island University, Nanaimo, BC, Canada
| | - Claire J Foldi
- Department of Physiology, Monash University, Clayton, VIC, Australia
- Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.
- Centre for Trauma and Mental Health Research, Health Sciences and Human Services, Vancouver Island University, Nanaimo, BC, Canada.
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Yao H, Wang X, Chi J, Chen H, Liu Y, Yang J, Yu J, Ruan Y, Xiang X, Pi J, Xu JF. Exploring Novel Antidepressants Targeting G Protein-Coupled Receptors and Key Membrane Receptors Based on Molecular Structures. Molecules 2024; 29:964. [PMID: 38474476 DOI: 10.3390/molecules29050964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/29/2024] [Accepted: 02/09/2024] [Indexed: 03/14/2024] Open
Abstract
Major Depressive Disorder (MDD) is a complex mental disorder that involves alterations in signal transmission across multiple scales and structural abnormalities. The development of effective antidepressants (ADs) has been hindered by the dominance of monoamine hypothesis, resulting in slow progress. Traditional ADs have undesirable traits like delayed onset of action, limited efficacy, and severe side effects. Recently, two categories of fast-acting antidepressant compounds have surfaced, dissociative anesthetics S-ketamine and its metabolites, as well as psychedelics such as lysergic acid diethylamide (LSD). This has led to structural research and drug development of the receptors that they target. This review provides breakthroughs and achievements in the structure of depression-related receptors and novel ADs based on these. Cryo-electron microscopy (cryo-EM) has enabled researchers to identify the structures of membrane receptors, including the N-methyl-D-aspartate receptor (NMDAR) and the 5-hydroxytryptamine 2A (5-HT2A) receptor. These high-resolution structures can be used for the development of novel ADs using virtual drug screening (VDS). Moreover, the unique antidepressant effects of 5-HT1A receptors in various brain regions, and the pivotal roles of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and tyrosine kinase receptor 2 (TrkB) in regulating synaptic plasticity, emphasize their potential as therapeutic targets. Using structural information, a series of highly selective ADs were designed based on the different role of receptors in MDD. These molecules have the favorable characteristics of rapid onset and low adverse drug reactions. This review offers researchers guidance and a methodological framework for the structure-based design of ADs.
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Affiliation(s)
- Hanbo Yao
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Xiaodong Wang
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jiaxin Chi
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Haorong Chen
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Yilin Liu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jiayi Yang
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jiaqi Yu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Yongdui Ruan
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
| | - Xufu Xiang
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jiang Pi
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
| | - Jun-Fa Xu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan 523808, China
- Institute of Laboratory Medicine, School of Medical Technology, Guangdong Medical University, Dongguan 523808, China
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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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Šabanović M, Lazari A, Blanco-Pozo M, Tisca C, Tachrount M, Martins-Bach AB, Lerch JP, Walton ME, Bannerman DM. Lasting dynamic effects of the psychedelic 2,5-dimethoxy-4-iodoamphetamine ((±)-DOI) on cognitive flexibility. Mol Psychiatry 2024:10.1038/s41380-024-02439-2. [PMID: 38321122 DOI: 10.1038/s41380-024-02439-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/08/2024]
Abstract
Psychedelic drugs can aid fast and lasting remission from various neuropsychiatric disorders, though the underlying mechanisms remain unclear. Preclinical studies suggest serotonergic psychedelics enhance neuronal plasticity, but whether neuroplastic changes can also be seen at cognitive and behavioural levels is unexplored. Here we show that a single dose of the psychedelic 2,5-dimethoxy-4-iodoamphetamine ((±)-DOI) affects structural brain plasticity and cognitive flexibility in young adult mice beyond the acute drug experience. Using ex vivo magnetic resonance imaging, we show increased volumes of several sensory and association areas one day after systemic administration of 2 mgkg-1 (±)-DOI. We then demonstrate lasting effects of (±)-DOI on cognitive flexibility in a two-step probabilistic reversal learning task where 2 mgkg-1 (±)-DOI improved the rate of adaptation to a novel reversal in task structure occurring one-week post-treatment. Strikingly, (±)-DOI-treated mice started learning from reward omissions, a unique strategy not typically seen in mice in this task, suggesting heightened sensitivity to previously overlooked cues. Crucially, further experiments revealed that (±)-DOI's effects on cognitive flexibility were contingent on the timing between drug treatment and the novel reversal, as well as on the nature of the intervening experience. (±)-DOI's facilitation of both cognitive adaptation and novel thinking strategies may contribute to the clinical benefits of psychedelic-assisted therapy, particularly in cases of perseverative behaviours and a resistance to change seen in depression, anxiety, or addiction. Furthermore, our findings highlight the crucial role of time-dependent neuroplasticity and the influence of experiential factors in shaping the therapeutic potential of psychedelic interventions for impaired cognitive flexibility.
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Affiliation(s)
- Merima Šabanović
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK.
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA.
| | - Alberto Lazari
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Marta Blanco-Pozo
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Cristiana Tisca
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Mohamed Tachrount
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Aurea B Martins-Bach
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Jason P Lerch
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Mark E Walton
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK.
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK.
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK.
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Murphy RJ, Godfrey K, Shaw AD, Muthukumaraswamy S, Sumner RL. Modulation of long-term potentiation following microdoses of LSD captured by thalamo-cortical modelling in a randomised, controlled trial. BMC Neurosci 2024; 25:7. [PMID: 38317077 PMCID: PMC10845757 DOI: 10.1186/s12868-024-00844-5] [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: 10/13/2023] [Accepted: 01/10/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Microdosing psychedelics is a phenomenon with claimed cognitive benefits that are relatively untested clinically. Pre-clinically, psychedelics have demonstrated enhancing effects on neuroplasticity, which cannot be measured directly in humans, but may be indexed by non-invasive electroencephalography (EEG) paradigms. This study used a visual long-term potentiation (LTP) EEG paradigm to test the effects of microdosed lysergic acid diethylamide (LSD) on neural plasticity, both acutely while on the drug and cumulatively after microdosing every third day for six weeks. Healthy adult males (n = 80) completed the visual LTP paradigm at baseline, 2.5 h following a dose of 10 µg of LSD or inactive placebo, and 6 weeks later after taking 14 repeated microdoses. Visually induced LTP was used as indirect index of neural plasticity. Surface level event-related potential (ERPs) based analyses are presented alongside dynamic causal modelling of the source localised data using a generative thalamocortical model (TCM) of visual cortex to elucidate underlying synaptic circuitry. RESULTS Event-related potential (ERP) analyses of N1b and P2 components did not show evidence of changes in visually induced LTP by LSD either acutely or after 6 weeks of regular dosing. However modelling the complete timecourse of the ERP with the TCM demonstrated changes in laminar connectivity in primary visual cortex. This primarily included changes to self-gain and inhibitory input parameters acutely. Layer 2/3 to layer 5 excitatory connectivity was also different between LSD and placebo groups. After regular dosing only excitatory input from layer 2/3 into layer 5 and inhibitory input into layer 4 were different between groups. CONCLUSIONS Without modulation of the ERPs it is difficult to relate the findings to other studies visually inducing LTP. It also indicates the classic peak analysis may not be sensitive enough to demonstrate evidence for changes in LTP plasticity in humans at such low doses. The TCM provides a more sensitive approach to assessing changes to plasticity as differences in plasticity mediated laminar connectivity were found between the LSD and placebo groups. TRIAL REGISTRATION ANZCTR registration number ACTRN12621000436875; Registered 16/04/2021 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=381476 .
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Affiliation(s)
- Robin J Murphy
- School of Pharmacy, University of Auckland, Auckland, New Zealand.
| | - Kate Godfrey
- Centre for Psychedelic Research, Department of Psychiatry, Imperial College London, London, UK
| | | | | | - Rachael L Sumner
- School of Pharmacy, University of Auckland, Auckland, New Zealand
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10
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Heifets BD, Olson DE. Therapeutic mechanisms of psychedelics and entactogens. Neuropsychopharmacology 2024; 49:104-118. [PMID: 37488282 PMCID: PMC10700553 DOI: 10.1038/s41386-023-01666-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/26/2023]
Abstract
Recent clinical and preclinical evidence suggests that psychedelics and entactogens may produce both rapid and sustained therapeutic effects across several indications. Currently, there is a disconnect between how these compounds are used in the clinic and how they are studied in preclinical species, which has led to a gap in our mechanistic understanding of how these compounds might positively impact mental health. Human studies have emphasized extra-pharmacological factors that could modulate psychedelic-induced therapeutic responses including set, setting, and integration-factors that are poorly modelled in current animal experiments. In contrast, animal studies have focused on changes in neuronal activation and structural plasticity-outcomes that are challenging to measure in humans. Here, we describe several hypotheses that might explain how psychedelics rescue neuropsychiatric disease symptoms, and we propose ways to bridge the gap between human and rodent studies. Given the diverse pharmacological profiles of psychedelics and entactogens, we suggest that their rapid and sustained therapeutic mechanisms of action might best be described by the collection of circuits that they modulate rather than their actions at any single molecular target. Thus, approaches focusing on selective circuit modulation of behavioral phenotypes might prove more fruitful than target-based methods for identifying novel compounds with rapid and sustained therapeutic effects similar to psychedelics and entactogens.
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Affiliation(s)
- Boris D Heifets
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA.
| | - David E Olson
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA, 95616, USA.
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
- Center for Neuroscience, University of California, Davis, Davis, CA, 95618, USA.
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA.
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11
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Blumenfeld Z, Bera K, Castrén E, Lester HA. Antidepressants enter cells, organelles, and membranes. Neuropsychopharmacology 2024; 49:246-261. [PMID: 37783840 PMCID: PMC10700606 DOI: 10.1038/s41386-023-01725-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 10/04/2023]
Abstract
We begin by summarizing several examples of antidepressants whose therapeutic actions begin when they encounter their targets in the cytoplasm or in the lumen of an organelle. These actions contrast with the prevailing view that most neuropharmacological actions begin when drugs engage their therapeutic targets at extracellular binding sites of plasma membrane targets-ion channels, receptors, and transporters. We review the chemical, pharmacokinetic, and pharmacodynamic principles underlying the movements of drugs into subcellular compartments. We note the relationship between protonation-deprotonation events and membrane permeation of antidepressant drugs. The key properties relate to charge and hydrophobicity/lipid solubility, summarized by the parameters LogP, pKa, and LogDpH7.4. The classical metric, volume of distribution (Vd), is unusually large for some antidepressants and has both supracellular and subcellular components. A table gathers structures, LogP, PKa, LogDpH7.4, and Vd data and/or calculations for most antidepressants and antidepressant candidates. The subcellular components, which can now be measured in some cases, are dominated by membrane binding and by trapping in the lumen of acidic organelles. For common antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin/norepinephrine reuptake inhibitors (SNRIs), the target is assumed to be the eponymous reuptake transporter(s), although in fact the compartment of target engagement is unknown. We review special aspects of the pharmacokinetics of ketamine, ketamine metabolites, and other rapidly acting antidepressants (RAADs) including methoxetamine and scopolamine, psychedelics, and neurosteroids. Therefore, the reader can assess properties that markedly affect a drug's ability to enter or cross membranes-and therefore, to interact with target sites that face the cytoplasm, the lumen of organelles, or a membrane. In the current literature, mechanisms involving intracellular targets are termed "location-biased actions" or "inside-out pharmacology". Hopefully, these general terms will eventually acquire additional mechanistic details.
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Affiliation(s)
- Zack Blumenfeld
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Kallol Bera
- Department of Neurosciences and Howard Hughes Medical Institute, University of California at San Diego, La Jolla, CA, USA
| | - Eero Castrén
- Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Henry A Lester
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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12
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Kim J, He MJ, Widmann AK, Lee FS. The role of neurotrophic factors in novel, rapid psychiatric treatments. Neuropsychopharmacology 2024; 49:227-245. [PMID: 37673965 PMCID: PMC10700398 DOI: 10.1038/s41386-023-01717-x] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 07/11/2023] [Accepted: 07/26/2023] [Indexed: 09/08/2023]
Abstract
Neurotrophic factors are a family of growth factors that modulate cellular growth, survival, and differentiation. For many decades, it has been generally believed that a lack of neurotrophic support led to the decreased neuronal synaptic plasticity, death, and loss of non-neuronal supportive cells seen in neuropsychiatric disorders. Traditional psychiatric medications that lead to immediate increases in neurotransmitter levels at the synapse have been shown also to elevate synaptic neurotrophic levels over weeks, correlating with the time course of the therapeutic effects of these drugs. Recent advances in psychiatric treatments, such as ketamine and psychedelics, have shown a much faster onset of therapeutic effects (within minutes to hours). They have also been shown to lead to a rapid release of neurotrophins into the synapse. This has spurred a significant shift in understanding the role of neurotrophins and how the receptor tyrosine kinases that bind neurotrophins may work in concert with other signaling systems. In this review, this renewed understanding of synaptic receptor signaling interactions and the clinical implications of this mechanistic insight will be discussed within the larger context of the well-established roles of neurotrophic factors in psychiatric disorders and treatments.
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Affiliation(s)
- Jihye Kim
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Michelle J He
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Alina K Widmann
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Francis S Lee
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA.
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, 10065, USA.
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13
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Wojtas A. The possible place for psychedelics in pharmacotherapy of mental disorders. Pharmacol Rep 2023; 75:1313-1325. [PMID: 37934320 PMCID: PMC10661751 DOI: 10.1007/s43440-023-00550-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/17/2023] [Accepted: 10/17/2023] [Indexed: 11/08/2023]
Abstract
Since its emergence in the 1960s, the serotonergic theory of depression bore fruit in the discovery of a plethora of antidepressant drugs affecting the lives of millions of patients. While crucial in the history of drug development, recent studies undermine the effectiveness of currently used antidepressant drugs in comparison to placebo, emphasizing the long time it takes to initiate the therapeutic response and numerous adverse effects. Thus, the scope of contemporary pharmacological research shifts from drugs affecting the serotonin system to rapid-acting antidepressant drugs. The prototypical representative of the aforementioned class is ketamine, an NMDA receptor antagonist capable of alleviating the symptoms of depression shortly after the drug administration. This discovery led to a paradigm shift, focusing on amino-acidic neurotransmitters and growth factors. Alas, the drug is not perfect, as its therapeutic effect diminishes circa 2 weeks after administration. Furthermore, it is not devoid of some severe side effects. However, there seems to be another, more efficient, and safer way to target the glutamatergic system. Hallucinogenic agonists of the 5-HT2A receptor, commonly known as psychedelics, are nowadays being reconsidered in clinical practice, shedding their infamous 1970s stigma. More and more clinical studies prove their clinical efficacy and rapid onset after a single administration while bearing fewer side effects. This review focuses on the current state-of-the-art literature and most recent clinical studies concerning the use of psychedelic drugs in the treatment of mental disorders. Specifically, the antidepressant potential of LSD, psilocybin, DMT, and 5-MeO-DMT will be discussed, together with a brief summary of other possible applications.
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Affiliation(s)
- Adam Wojtas
- Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland.
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14
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Maćkowiak M. Psychedelics action and schizophrenia. Pharmacol Rep 2023; 75:1350-1361. [PMID: 37899392 PMCID: PMC10661800 DOI: 10.1007/s43440-023-00546-5] [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: 08/25/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 10/31/2023]
Abstract
Psychedelics are compounds acting by serotonin 5-hydroxytryptamine (5-HT)2A receptor activation and induce several behavioral responses. They are of special interest because of their positive effects on neuropsychiatric disorders (depression and posttraumatic stress disorder). However, several findings revealed that some psychedelic actions are similar to symptoms observed in schizophrenia (psychosis, sensorimotor gating impairments, attention, and working memory deficits) which might limit their clinical applications. Psychedelics activate some neurotransmitters, i.e., serotonergic, and glutamatergic, that are also impaired in schizophrenia. Therefore, the neurobiological background of psychedelics and schizophrenia is partially similar. Another important aspect to discuss is the perspective of using psychedelics in schizophrenia therapy. Postmortem studies showed a loss of synapses in schizophrenia, and the positive effects of psychedelics on neuroplasticity (synaptogenesis, neurogenesis, and neuritogenesis) might be essential in the context of schizophrenia therapy. However, because of psychedelics' psychotic action, the recommended doses of psychedelics in schizophrenia treatment are not established, and subpsychedelic dosing or microdosing are considered. Exploratory studies are needed to determine the tolerability of treatment and appropriate dosing regimen. Another therapeutic option is using non-hallucinogenic psychedelic analogs that also induce neuroplastic outcomes but do not have psychotogenic effects. Further preclinical and clinical studies are needed to recognize the potential effectiveness of 5-HT2A agonists in schizophrenia therapy.
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Affiliation(s)
- Marzena Maćkowiak
- Laboratory of Pharmacology and Brain Biostructure, Pharmacology Department, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
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15
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Kolasa M, Faron-Górecka A. Preclinical models of treatment-resistant depression: challenges and perspectives. Pharmacol Rep 2023; 75:1326-1340. [PMID: 37882914 PMCID: PMC10661811 DOI: 10.1007/s43440-023-00542-9] [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: 08/29/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/27/2023]
Abstract
Treatment-resistant depression (TRD) is a subgroup of major depressive disorder in which the use of classical antidepressant treatments fails to achieve satisfactory treatment results. Although there are various definitions and grading models for TRD, common criteria for assessing TRD have still not been established. However, a common feature of any TRD model is the lack of response to at least two attempts at antidepressant pharmacotherapy. The causes of TRD are not known; nevertheless, it is estimated that even 60% of TRD patients are so-called pseudo-TRD patients, in which multiple biological factors, e.g., gender, age, and hormonal disturbances are concomitant with depression and involved in antidepressant drug resistance. Whereas the phenomenon of TRD is a complex disorder difficult to diagnose and successfully treat, the search for new treatment strategies is a significant challenge of modern pharmacology. It seems that despite the complexity of the TRD phenomenon, some useful animal models of TRD meet the construct, the face, and the predictive validity criteria. Based on the literature and our own experiences, we will discuss the utility of animals exposed to the stress paradigm (chronic mild stress, CMS), and the Wistar Kyoto rat strain representing an endogenous model of TRD. In this review, we will focus on reviewing research on existing and novel therapies for TRD, including ketamine, deep brain stimulation (DBS), and psychedelic drugs in the context of preclinical studies in representative animal models of TRD.
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Affiliation(s)
- Magdalena Kolasa
- Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland
| | - Agata Faron-Górecka
- Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland.
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16
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Banushi B, Polito V. A Comprehensive Review of the Current Status of the Cellular Neurobiology of Psychedelics. BIOLOGY 2023; 12:1380. [PMID: 37997979 PMCID: PMC10669348 DOI: 10.3390/biology12111380] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
Psychedelic substances have gained significant attention in recent years for their potential therapeutic effects on various psychiatric disorders. This review delves into the intricate cellular neurobiology of psychedelics, emphasizing their potential therapeutic applications in addressing the global burden of mental illness. It focuses on contemporary research into the pharmacological and molecular mechanisms underlying these substances, particularly the role of 5-HT2A receptor signaling and the promotion of plasticity through the TrkB-BDNF pathway. The review also discusses how psychedelics affect various receptors and pathways and explores their potential as anti-inflammatory agents. Overall, this research represents a significant development in biomedical sciences with the potential to transform mental health treatments.
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Affiliation(s)
- Blerida Banushi
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Vince Polito
- School of Psychological Sciences, Macquarie University, Sydney, NSW 2109, Australia;
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17
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Tuck JR, Dunlap LE, Olson DE. Synthetic Strategies toward Lysergic Acid Diethylamide: Ergoline Synthesis via α-Arylation, Borrowing Hydrogen Alkylation, and C-H Insertion. J Org Chem 2023; 88:13712-13719. [PMID: 37697477 PMCID: PMC10591856 DOI: 10.1021/acs.joc.3c01363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Lysergic acid diethylamide (LSD), a semisynthetic ergoline alkaloid analogue and hallucinogen, is a potent psychoplastogen with promising therapeutic potential. While a variety of synthetic strategies for accessing ergoline alkaloids have emerged, the complexity of the tetracyclic ring system results in distinct challenges in preparing analogues with novel substitution patterns. Methods of modulating the hallucinogenic activity of LSD by functionalization at previously inaccessible positions are of continued interest, and efficient syntheses of the ergoline scaffold are integral toward this purpose. Here, we report novel C-C bond forming strategies for preparing the ergoline tetracyclic core, focusing on the relatively unexplored strategy of bridging the B- and D-ring systems last. Following cross-coupling to first join the A- and D-rings, we explored a variety of methods for establishing the C-ring, including intramolecular α-arylation, borrowing hydrogen alkylation, and rhodium-catalyzed C-H insertion. Our results led to a seven-step formal synthesis of LSD and the first methods for readily introducing substitution on the C-ring. These strategies are efficient for forming ergoline-like tetracyclic compounds and analogues, though they each face unique challenges associated with elaboration to ergoline natural products. Taken together, these studies provide important insights that will guide future synthetic strategies toward ergolines.
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Affiliation(s)
- Jeremy R. Tuck
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95616, USA
| | - Lee E. Dunlap
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95616, USA
| | - David E. Olson
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95616, USA
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
- Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA
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18
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Mallaroni P, Mason NL, Kloft L, Reckweg JT, van Oorsouw K, Ramaekers JG. Cortical structural differences following repeated ayahuasca use hold molecular signatures. Front Neurosci 2023; 17:1217079. [PMID: 37869513 PMCID: PMC10585114 DOI: 10.3389/fnins.2023.1217079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 09/21/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction Serotonergic psychedelics such as ayahuasca are reported to promote both structural and functional neural plasticity via partial 5-HT2A agonism. However, little is known about how these molecular mechanisms may extend to repeated psychedelic administration in humans, let alone neuroanatomy. While early evidence suggests localised changes to cortical thickness in long-term ayahuasca users, it is unknown how such findings may be reflected by large-scale anatomical brain networks comprising cytoarchitecturally complex regions. Methods Here, we examined the relationship between cortical gene expression markers of psychedelic action and brain morphometric change following repeated ayahuasca usage, using high-field 7 Tesla neuroimaging data derived from 24 members of an ayahuasca-using church (Santo Daime) and case-matched controls. Results Using a morphometric similarity network (MSN) analysis, repeated ayahuasca use was associated with a spatially distributed cortical patterning of both structural differentiation in sensorimotor areas and de-differentiation in transmodal areas. Cortical MSN remodelling was found to be spatially correlated with dysregulation of 5-HT2A gene expression as well as a broader set of genes encoding target receptors pertinent to ayahuasca's effects. Furthermore, these associations were similarly interrelated with altered gene expression of specific transcriptional factors and immediate early genes previously identified in preclinical assays as relevant to psychedelic-induced neuroplasticity. Conclusion Taken together, these findings provide preliminary evidence that the molecular mechanisms of psychedelic action may scale up to a macroscale level of brain organisation in vivo. Closer attention to the role of cortical transcriptomics in structural-functional coupling may help account for the behavioural differences observed in experienced psychedelic users.
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Affiliation(s)
- Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Natasha L. Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Lilian Kloft
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Johannes T. Reckweg
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Kim van Oorsouw
- Department of Forensic Psychology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Johannes G. Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
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19
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Sadee W. Ligand-Free Signaling of G-Protein-Coupled Receptors: Physiology, Pharmacology, and Genetics. Molecules 2023; 28:6375. [PMID: 37687205 PMCID: PMC10489045 DOI: 10.3390/molecules28176375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
G-protein-coupled receptors (GPCRs) are ubiquitous sensors and regulators of cellular functions. Each GPCR exists in complex aggregates with multiple resting and active conformations. Designed to detect weak stimuli, GPCRs can also activate spontaneously, resulting in basal ligand-free signaling. Agonists trigger a cascade of events leading to an activated agonist-receptor G-protein complex with high agonist affinity. However, the ensuing signaling process can further remodel the receptor complex to reduce agonist affinity, causing rapid ligand dissociation. The acutely activated ligand-free receptor can continue signaling, as proposed for rhodopsin and μ opioid receptors, resulting in robust receptor activation at low agonist occupancy with enhanced agonist potency. Continued receptor stimulation can further modify the receptor complex, regulating sustained ligand-free signaling-proposed to play a role in opioid dependence. Basal, acutely agonist-triggered, and sustained elevated ligand-free signaling could each have distinct functions, reflecting multi-state conformations of GPCRs. This review addresses basal and stimulus-activated ligand-free signaling, its regulation, genetic factors, and pharmacological implications, focusing on opioid and serotonin receptors, and the growth hormone secretagogue receptor (GHSR). The hypothesis is proposed that ligand-free signaling of 5-HT2A receptors mediate therapeutic effects of psychedelic drugs. Research avenues are suggested to close the gaps in our knowledge of ligand-free GPCR signaling.
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Affiliation(s)
- Wolfgang Sadee
- Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA;
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
- Aether Therapeutics Inc., Austin, TX 78756, USA
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20
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Robinson GI, Li D, Wang B, Zahoruiko Y, Gerasymchuk M, Hudson D, Kovalchuk O, Kovalchuk I. Anti-Inflammatory Effects of Serotonin Receptor and Transient Receptor Potential Channel Ligands in Human Small Intestinal Epithelial Cells. Curr Issues Mol Biol 2023; 45:6743-6774. [PMID: 37623246 PMCID: PMC10453699 DOI: 10.3390/cimb45080427] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 08/26/2023] Open
Abstract
Intestinal inflammation and dysbiosis can lead to inflammatory bowel diseases (IBD) and systemic inflammation, affecting multiple organs. Developing novel anti-inflammatory therapeutics is crucial for preventing IBD progression. Serotonin receptor type 2A (5-HT2A) ligands, including psilocybin (Psi), 4-Acetoxy-N,N-dimethyltryptamine (4-AcO-DMT), and ketanserin (Ket), along with transient receptor potential (TRP) channel ligands like capsaicin (Cap), curcumin (Cur), and eugenol (Eug), show promise as anti-inflammatory agents. In this study, we investigated the cytotoxic and anti-inflammatory effects of Psi, 4-AcO-DMT, Ket, Cap, Cur, and Eug on human small intestinal epithelial cells (HSEIC). HSEIC were exposed to tumor necrosis factor (TNF)-α and interferon (IFN)-γ for 24 h to induce an inflammatory response, followed by treatment with each compound at varying doses (0-800 μM) for 24 to 96 h. The cytotoxicity was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and protein expression by Western blot (WB) analysis. As single treatments, Psi (40 μM), Cur (0.5 μM), and Eug (50 μM) significantly reduced COX-2 levels without cytotoxic effects. When combined, Psi (40 μM) and Cur (0.5 μM) exhibited synergy, resulting in a substantial decrease in COX-2 protein levels (-28× fold change), although the reduction in IL-6 was less pronounced (-1.6× fold change). Psi (20 μM) and Eug (25 μM) demonstrated the most favorable outcomes, with significant decreases in COX-2 (-19× fold change) and IL-6 (-10× fold change) protein levels. Moreover, the combination of Psi and Eug did not induce cytotoxic effects in vitro at any tested doses. This study is the first to explore the anti-inflammatory potential of psilocybin and 4-AcO-DMT in the intestines while highlighting the potential for synergy between the 5-HT2A and TRP channel ligands, specifically Psi and Eug, in alleviating the TNF-α/IFN-γ-induced inflammatory response in HSEIC. Further investigations should evaluate if the Psi and Eug combination has the therapeutic potential to treat IBD in vivo.
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Affiliation(s)
- Gregory Ian Robinson
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; (G.I.R.); (M.G.)
| | - Dongping Li
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; (G.I.R.); (M.G.)
| | - Bo Wang
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; (G.I.R.); (M.G.)
| | - Yeva Zahoruiko
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; (G.I.R.); (M.G.)
| | - Marta Gerasymchuk
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; (G.I.R.); (M.G.)
| | - Darryl Hudson
- GoodCap Pharmaceuticals, Calgary, AB T2P 0R3, Canada
| | - Olga Kovalchuk
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; (G.I.R.); (M.G.)
| | - Igor Kovalchuk
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; (G.I.R.); (M.G.)
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21
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Jones N, Zahid Z, Grady SM, Sultan ZW, Zheng Z, Razidlo J, Banks MI, Wenthur CJ. Transient Elevation of Plasma Glucocorticoids Supports Psilocybin-Induced Anxiolysis in Mice. ACS Pharmacol Transl Sci 2023; 6:1221-1231. [PMID: 37588757 PMCID: PMC10425994 DOI: 10.1021/acsptsci.3c00123] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Indexed: 08/18/2023]
Abstract
While correlations between drug-induced cortisol elevation, self-reported anxiety, and treatment outcomes have been reported for human studies during psilocybin-assisted psychotherapy, the mechanistic relationship between psychedelic-associated alterations in plasma glucocorticoid responses and the time course of anxious responsiveness remains unclear. Using rodents, both time-bound manipulation of glucocorticoid concentrations and assessment of anxiety-like behaviors can be achieved. Here, 3 mg/kg IP psilocybin was found to have anxiolytic-like effects in C57BL/6 male mice at 4 h after treatment. These effects were not altered by pretreatment with a 5-HT2A antagonist but were blunted by pretreatment with a glucocorticoid receptor antagonist or suppression of psilocybin-induced corticosterone elevations. Anxiolytic-like effects were also observed at 4 h following treatment with the nonpsychedelic 5-HT2A agonist lisuride at a dose causing a similar increase in plasma glucocorticoids as that seen with psilocybin, as well as following stress-induced (via repeated injection) glucocorticoid release alone. Psilocybin's anxiolytic-like effects persisted at 7 days following administration. The long-term anxiolytic effects of psilocybin were lost when psilocybin was administered to animals with ongoing chronic elevations in plasma corticosterone concentrations. Overall, these experiments indicate that acute, resolvable psilocybin-induced glucocorticoid release drives the postacute anxiolytic-like effects of psilocybin in mice and that its long-term anxiolytic-like effects can be abolished in the presence of chronically elevated plasma glucocorticoid elevations.
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Affiliation(s)
- Nathan
T. Jones
- Molecular
and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Zarmeen Zahid
- Neuroscience
Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Sean M. Grady
- Department
of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ziyad W. Sultan
- Department
of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Zhen Zheng
- School
of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - John Razidlo
- Neuroscience
Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Matthew I. Banks
- Neuroscience
Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department
of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Transdisciplinary
Center for Research in Psychoactive Substances, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Cody J. Wenthur
- Molecular
and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Neuroscience
Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- School
of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Transdisciplinary
Center for Research in Psychoactive Substances, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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22
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Zhornitsky S, Oliva HNP, Jayne LA, Allsop ASA, Kaye AP, Potenza MN, Angarita GA. Changes in synaptic markers after administration of ketamine or psychedelics: a systematic scoping review. Front Psychiatry 2023; 14:1197890. [PMID: 37435405 PMCID: PMC10331617 DOI: 10.3389/fpsyt.2023.1197890] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/05/2023] [Indexed: 07/13/2023] Open
Abstract
Background Ketamine and psychedelics have abuse liability. They can also induce "transformative experiences" where individuals experience enhanced states of awareness. This enhanced awareness can lead to changes in preexisting behavioral patterns which could be beneficial in the treatment of substance use disorders (SUDs). Preclinical and clinical studies suggest that ketamine and psychedelics may alter markers associated with synaptic density, and that these changes may underlie effects such as sensitization, conditioned place preference, drug self-administration, and verbal memory performance. In this scoping review, we examined studies that measured synaptic markers in animals and humans after exposure to ketamine and/or psychedelics. Methods A systematic search was conducted following PRISMA guidelines, through PubMed, EBSCO, Scopus, and Web of Science, based on a published protocol (Open Science Framework, DOI: 10.17605/OSF.IO/43FQ9). Both in vivo and in vitro studies were included. Studies on the following synaptic markers were included: dendritic structural changes, PSD-95, synapsin-1, synaptophysin-1, synaptotagmin-1, and SV2A. Results Eighty-four studies were included in the final analyses. Seventy-one studies examined synaptic markers following ketamine treatment, nine examined psychedelics, and four examined both. Psychedelics included psilocybin/psilocin, lysergic acid diethylamide, N,N-dimethyltryptamine, 2,5-dimethoxy-4-iodoamphetamine, and ibogaine/noribogaine. Mixed findings regarding synaptic changes in the hippocampus and prefrontal cortex (PFC) have been reported when ketamine was administered in a single dose under basal conditions. Similar mixed findings were seen under basal conditions in studies that used repeated administration of ketamine. However, studies that examined animals during stressful conditions found that a single dose of ketamine counteracted stress-related reductions in synaptic markers in the hippocampus and PFC. Repeated administration of ketamine also counteracted stress effects in the hippocampus. Psychedelics generally increased synaptic markers, but results were more consistently positive for certain agents. Conclusion Ketamine and psychedelics can increase synaptic markers under certain conditions. Heterogeneous findings may relate to methodological differences, agents administered (or different formulations of the same agent), sex, and type of markers. Future studies could address seemingly mixed results by using meta-analytical approaches or study designs that more fully consider individual differences.
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Affiliation(s)
- Simon Zhornitsky
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, United States
| | - Henrique N. P. Oliva
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, United States
| | - Laura A. Jayne
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, United States
| | - Aza S. A. Allsop
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, United States
| | - Alfred P. Kaye
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
- Connecticut Mental Health Center, New Haven, CT, United States
- Clinical Neurosciences Division, VA National Center for PTSD, West Haven, CT, United States
| | - Marc N. Potenza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
- Connecticut Mental Health Center, New Haven, CT, United States
- Child Study Center, Yale University School of Medicine, New Haven, CT, United States
- Department of Neuroscience, Yale University, New Haven, CT, United States
- Connecticut Council on Problem Gambling, Hartford, CT, United States
- Wu Tsai Institute, Yale University, New Haven, CT, United States
| | - Gustavo A. Angarita
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
- Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, United States
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23
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Moliner R, Girych M, Brunello CA, Kovaleva V, Biojone C, Enkavi G, Antenucci L, Kot EF, Goncharuk SA, Kaurinkoski K, Kuutti M, Fred SM, Elsilä LV, Sakson S, Cannarozzo C, Diniz CRAF, Seiffert N, Rubiolo A, Haapaniemi H, Meshi E, Nagaeva E, Öhman T, Róg T, Kankuri E, Vilar M, Varjosalo M, Korpi ER, Permi P, Mineev KS, Saarma M, Vattulainen I, Casarotto PC, Castrén E. Psychedelics promote plasticity by directly binding to BDNF receptor TrkB. Nat Neurosci 2023; 26:1032-1041. [PMID: 37280397 PMCID: PMC10244169 DOI: 10.1038/s41593-023-01316-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 90.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 03/21/2023] [Indexed: 06/08/2023]
Abstract
Psychedelics produce fast and persistent antidepressant effects and induce neuroplasticity resembling the effects of clinically approved antidepressants. We recently reported that pharmacologically diverse antidepressants, including fluoxetine and ketamine, act by binding to TrkB, the receptor for BDNF. Here we show that lysergic acid diethylamide (LSD) and psilocin directly bind to TrkB with affinities 1,000-fold higher than those for other antidepressants, and that psychedelics and antidepressants bind to distinct but partially overlapping sites within the transmembrane domain of TrkB dimers. The effects of psychedelics on neurotrophic signaling, plasticity and antidepressant-like behavior in mice depend on TrkB binding and promotion of endogenous BDNF signaling but are independent of serotonin 2A receptor (5-HT2A) activation, whereas LSD-induced head twitching is dependent on 5-HT2A and independent of TrkB binding. Our data confirm TrkB as a common primary target for antidepressants and suggest that high-affinity TrkB positive allosteric modulators lacking 5-HT2A activity may retain the antidepressant potential of psychedelics without hallucinogenic effects.
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Affiliation(s)
- Rafael Moliner
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Mykhailo Girych
- Department of Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | | | - Vera Kovaleva
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Caroline Biojone
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
- Department of Biomedicine, Faculty of Health, Aarhus University, Aarhus, Denmark
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark
| | - Giray Enkavi
- Department of Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - Lina Antenucci
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Erik F Kot
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Sergey A Goncharuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Katja Kaurinkoski
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Mirjami Kuutti
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Senem M Fred
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Lauri V Elsilä
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Sven Sakson
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | | | - Cassiano R A F Diniz
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Nina Seiffert
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Anna Rubiolo
- Neuroscience, University of Trieste, Trieste, Italy
| | - Hele Haapaniemi
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Elsa Meshi
- Biomedical Sciences, Hellenic University of Thessaloniki, Thessaloniki, Greece
| | - Elina Nagaeva
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Tiina Öhman
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Tomasz Róg
- Department of Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
| | - Esko Kankuri
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Marçal Vilar
- Molecular Basis of Neurodegeneration Unit, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
| | - Markku Varjosalo
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Esa R Korpi
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Perttu Permi
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
- Structural and Quantitative Biology Research Program, Institute of Biotechnology, Instruct-HiLIFE, University of Helsinki, Helsinki, Finland
| | - Konstantin S Mineev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Mart Saarma
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Ilpo Vattulainen
- Department of Physics, Faculty of Science, University of Helsinki, Helsinki, Finland.
| | | | - Eero Castrén
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland.
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24
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Borsellino P, Krider RI, Chea D, Grinnell R, Vida TA. Ketamine and the Disinhibition Hypothesis: Neurotrophic Factor-Mediated Treatment of Depression. Pharmaceuticals (Basel) 2023; 16:ph16050742. [PMID: 37242525 DOI: 10.3390/ph16050742] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/05/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Ketamine is a promising alternative to traditional pharmacotherapies for major depressive disorder, treatment-resistant depression, and other psychiatric conditions that heavily contribute to the global disease burden. In contrast to the current standard of care medications for these disorders, ketamine offers rapid onset, enduring clinical efficacy, and unique therapeutic potential for use in acute, psychiatric emergencies. This narrative presents an alternative framework for understanding depression, as mounting evidence supports a neuronal atrophy and synaptic disconnection theory, rather than the prevailing monoamine depletion hypothesis. In this context, we describe ketamine, its enantiomers, and various metabolites in a range of mechanistic actions through multiple converging pathways, including N-methyl-D-aspartate receptor (NMDAR) inhibition and the enhancement of glutamatergic signaling. We describe the disinhibition hypothesis, which posits that ketamine's pharmacological action ultimately results in excitatory cortical disinhibition, causing the release of neurotrophic factors, the most important of which is brain-derived neurotrophic factor (BDNF). BDNF-mediated signaling along with vascular endothelial growth factor (VEGF) and insulin-like growth factor 1 (IGF-1) subsequently give rise to the repair of neuro-structural abnormalities in patients with depressive disorders. Ketamine's efficacious amelioration of treatment-resistant depression is revolutionizing psychiatric treatment and opening up fresh vistas for understanding the underlying causes of mental illness.
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Affiliation(s)
- Philip Borsellino
- Kirk Kerkorian School of Medicine at UNLV, 625 Shadow Lane, Las Vegas, NV 89106, USA
| | - Reese I Krider
- Kirk Kerkorian School of Medicine at UNLV, 625 Shadow Lane, Las Vegas, NV 89106, USA
| | - Deanna Chea
- Kirk Kerkorian School of Medicine at UNLV, 625 Shadow Lane, Las Vegas, NV 89106, USA
| | - Ryan Grinnell
- Kirk Kerkorian School of Medicine at UNLV, 625 Shadow Lane, Las Vegas, NV 89106, USA
| | - Thomas A Vida
- Kirk Kerkorian School of Medicine at UNLV, 625 Shadow Lane, Las Vegas, NV 89106, USA
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25
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VanderZwaag J, Halvorson T, Dolhan K, Šimončičová E, Ben-Azu B, Tremblay MÈ. The Missing Piece? A Case for Microglia's Prominent Role in the Therapeutic Action of Anesthetics, Ketamine, and Psychedelics. Neurochem Res 2023; 48:1129-1166. [PMID: 36327017 DOI: 10.1007/s11064-022-03772-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 08/25/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
Abstract
There is much excitement surrounding recent research of promising, mechanistically novel psychotherapeutics - psychedelic, anesthetic, and dissociative agents - as they have demonstrated surprising efficacy in treating central nervous system (CNS) disorders, such as mood disorders and addiction. However, the mechanisms by which these drugs provide such profound psychological benefits are still to be fully elucidated. Microglia, the CNS's resident innate immune cells, are emerging as a cellular target for psychiatric disorders because of their critical role in regulating neuroplasticity and the inflammatory environment of the brain. The following paper is a review of recent literature surrounding these neuropharmacological therapies and their demonstrated or hypothesized interactions with microglia. Through investigating the mechanism of action of psychedelics, such as psilocybin and lysergic acid diethylamide, ketamine, and propofol, we demonstrate a largely under-investigated role for microglia in much of the emerging research surrounding these pharmacological agents. Among others, we detail sigma-1 receptors, serotonergic and γ-aminobutyric acid signalling, and tryptophan metabolism as pathways through which these agents modulate microglial phagocytic activity and inflammatory mediator release, inducing their therapeutic effects. The current review includes a discussion on future directions in the field of microglial pharmacology and covers bidirectional implications of microglia and these novel pharmacological agents in aging and age-related disease, glial cell heterogeneity, and state-of-the-art methodologies in microglial research.
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Affiliation(s)
- Jared VanderZwaag
- Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Torin Halvorson
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Kira Dolhan
- Department of Psychology, University of Victoria, Vancouver, BC, Canada
- Department of Biology, University of Victoria, Vancouver, BC, Canada
| | - Eva Šimončičová
- Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Marie-Ève Tremblay
- Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada.
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
- Département de médecine moléculaire, Université Laval, Québec City, QC, Canada.
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada.
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada.
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada.
- Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada.
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26
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Lewis V, Bonniwell EM, Lanham JK, Ghaffari A, Sheshbaradaran H, Cao AB, Calkins MM, Bautista-Carro MA, Arsenault E, Telfer A, Taghavi-Abkuh FF, Malcolm NJ, El Sayegh F, Abizaid A, Schmid Y, Morton K, Halberstadt AL, Aguilar-Valles A, McCorvy JD. A non-hallucinogenic LSD analog with therapeutic potential for mood disorders. Cell Rep 2023; 42:112203. [PMID: 36884348 PMCID: PMC10112881 DOI: 10.1016/j.celrep.2023.112203] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/30/2022] [Accepted: 02/16/2023] [Indexed: 03/08/2023] Open
Abstract
Hallucinations limit widespread therapeutic use of psychedelics as rapidly acting antidepressants. Here we profiled the non-hallucinogenic lysergic acid diethylamide (LSD) analog 2-bromo-LSD (2-Br-LSD) at more than 33 aminergic G protein-coupled receptors (GPCRs). 2-Br-LSD shows partial agonism at several aminergic GPCRs, including 5-HT2A, and does not induce the head-twitch response (HTR) in mice, supporting its classification as a non-hallucinogenic 5-HT2A partial agonist. Unlike LSD, 2-Br-LSD lacks 5-HT2B agonism, an effect linked to cardiac valvulopathy. Additionally, 2-Br-LSD produces weak 5-HT2A β-arrestin recruitment and internalization in vitro and does not induce tolerance in vivo after repeated administration. 2-Br-LSD induces dendritogenesis and spinogenesis in cultured rat cortical neurons and increases active coping behavior in mice, an effect blocked by the 5-HT2A-selective antagonist volinanserin (M100907). 2-Br-LSD also reverses the behavioral effects of chronic stress. Overall, 2-Br-LSD has an improved pharmacological profile compared with LSD and may have profound therapeutic value for mood disorders and other indications.
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Affiliation(s)
- Vern Lewis
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Emma M Bonniwell
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Janelle K Lanham
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Abdi Ghaffari
- BetterLife Pharma Inc., Vancouver, BC V6H 1A6, Canada
| | | | - 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
| | | | - Emily Arsenault
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Andre Telfer
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada
| | | | - Nicholas J Malcolm
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Fatema El Sayegh
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Yasmin Schmid
- Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kathleen Morton
- Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Adam L Halberstadt
- Department of Psychiatry, 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.
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27
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Johnston JN, Kadriu B, Allen J, Gilbert JR, Henter ID, Zarate CA. Ketamine and serotonergic psychedelics: An update on the mechanisms and biosignatures underlying rapid-acting antidepressant treatment. Neuropharmacology 2023; 226:109422. [PMID: 36646310 PMCID: PMC9983360 DOI: 10.1016/j.neuropharm.2023.109422] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
The discovery of ketamine as a rapid-acting antidepressant spurred significant research to understand its underlying mechanisms of action and to identify other novel compounds that may act similarly. Serotonergic psychedelics (SPs) have shown initial promise in treating depression, though the challenge of conducting randomized controlled trials with SPs and the necessity of long-term clinical observation are important limitations. This review summarizes the similarities and differences between the psychoactive effects associated with both ketamine and SPs and the mechanisms of action of these compounds, with a focus on the monoaminergic, glutamatergic, gamma-aminobutyric acid (GABA)-ergic, opioid, and inflammatory systems. Both molecular and neuroimaging aspects are considered. While their main mechanisms of action differ-SPs increase serotonergic signaling while ketamine is a glutamatergic modulator-evidence suggests that the downstream mechanisms of action of both ketamine and SPs include mechanistic target of rapamycin complex 1 (mTORC1) signaling and downstream GABAA receptor activity. The similarities in downstream mechanisms may explain why ketamine, and potentially SPs, exert rapid-acting antidepressant effects. However, research on SPs is still in its infancy compared to the ongoing research that has been conducted with ketamine. For both therapeutics, issues with regulation and proper controls should be addressed before more widespread implementation. This article is part of the Special Issue on "Ketamine and its Metabolites".
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Affiliation(s)
- Jenessa N Johnston
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Bashkim Kadriu
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Josh Allen
- The Alfred Centre, Department of Neuroscience, Monash University, Melbourne, Victoria, Australia.
| | - Jessica R Gilbert
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Ioline D Henter
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Carlos A Zarate
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
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28
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Vargas MV, Dunlap LE, Dong C, Carter SJ, Tombari RJ, Jami SA, Cameron LP, Patel SD, Hennessey JJ, Saeger HN, McCorvy JD, Gray JA, Tian L, Olson DE. Psychedelics promote neuroplasticity through the activation of intracellular 5-HT2A receptors. Science 2023; 379:700-706. [PMID: 36795823 PMCID: PMC10108900 DOI: 10.1126/science.adf0435] [Citation(s) in RCA: 100] [Impact Index Per Article: 100.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/09/2023] [Indexed: 02/18/2023]
Abstract
Decreased dendritic spine density in the cortex is a hallmark of several neuropsychiatric diseases, and the ability to promote cortical neuron growth has been hypothesized to underlie the rapid and sustained therapeutic effects of psychedelics. Activation of 5-hydroxytryptamine (serotonin) 2A receptors (5-HT2ARs) is essential for psychedelic-induced cortical plasticity, but it is currently unclear why some 5-HT2AR agonists promote neuroplasticity, whereas others do not. We used molecular and genetic tools to demonstrate that intracellular 5-HT2ARs mediate the plasticity-promoting properties of psychedelics; these results explain why serotonin does not engage similar plasticity mechanisms. This work emphasizes the role of location bias in 5-HT2AR signaling, identifies intracellular 5-HT2ARs as a therapeutic target, and raises the intriguing possibility that serotonin might not be the endogenous ligand for intracellular 5-HT2ARs in the cortex.
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Affiliation(s)
- Maxemiliano V. Vargas
- Neuroscience Graduate Program, University of California, Davis; Davis, CA 95618, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
| | - Lee E. Dunlap
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Department of Chemistry, University of California, Davis; Davis, CA 95616, USA
| | - Chunyang Dong
- Biochemistry, Molecular, Cellular, and Developmental Biology Graduate Program, University of California, Davis; Davis, CA 95616, USA
| | - Samuel J. Carter
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Department of Chemistry, University of California, Davis; Davis, CA 95616, USA
| | - Robert J. Tombari
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Department of Chemistry, University of California, Davis; Davis, CA 95616, USA
| | - Shekib A. Jami
- Center for Neuroscience, University of California, Davis; Davis, CA 95618, USA
| | - Lindsay P. Cameron
- Neuroscience Graduate Program, University of California, Davis; Davis, CA 95618, USA
| | - Seona D. Patel
- Department of Chemistry, University of California, Davis; Davis, CA 95616, USA
| | - Joseph J. Hennessey
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin; Milwaukee, WI 53226, USA
| | - Hannah N. Saeger
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Pharmacology and Toxicology Graduate Program, University of California, Davis; Davis, CA 95616, USA
| | - John D. McCorvy
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin; Milwaukee, WI 53226, USA
| | - John A. Gray
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Center for Neuroscience, University of California, Davis; Davis, CA 95618, USA
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Lin Tian
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Center for Neuroscience, University of California, Davis; Davis, CA 95618, USA
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis; Sacramento, CA 95817, USA
| | - David E. Olson
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Department of Chemistry, University of California, Davis; Davis, CA 95616, USA
- Center for Neuroscience, University of California, Davis; Davis, CA 95618, USA
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis; Sacramento, CA 95817, USA
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29
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Cameron LP, Patel SD, Vargas MV, Barragan EV, Saeger HN, Warren HT, Chow WL, Gray JA, Olson DE. 5-HT2ARs Mediate Therapeutic Behavioral Effects of Psychedelic Tryptamines. ACS Chem Neurosci 2023; 14:351-358. [PMID: 36630260 PMCID: PMC9939288 DOI: 10.1021/acschemneuro.2c00718] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Psychedelic compounds have displayed antidepressant potential in both humans and rodents. Despite their promise, psychedelics can induce undesired effects that pose safety concerns and limit their clinical scalability. The rational development of optimized psychedelic-related medicines will require a full mechanistic understanding of how these molecules produce therapeutic effects. While the hallucinogenic properties of psychedelics are generally attributed to activation of serotonin 2A receptors (5-HT2ARs), it is currently unclear if these receptors also mediate their antidepressant effects as several nonhallucinogenic analogues of psychedelics with antidepressant-like properties have been developed. Moreover, many psychedelics exhibit promiscuous pharmacology, making it challenging to identify their primary therapeutic target(s). Here, we use a combination of pharmacological and genetic tools to demonstrate that activation of 5-HT2A receptors is essential for tryptamine-based psychedelics to produce antidepressant-like effects in rodents. Our results suggest that psychedelic tryptamines can induce hallucinogenic and therapeutic effects through activation of the same receptor.
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Affiliation(s)
- Lindsay P. Cameron
- Neuroscience Graduate Program, University of California, Davis, Davis, CA 95618, USA
| | - Seona D. Patel
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
| | - Maxemiliano V. Vargas
- Neuroscience Graduate Program, University of California, Davis, Davis, CA 95618, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
| | - Eden V. Barragan
- Neuroscience Graduate Program, University of California, Davis, Davis, CA 95618, USA
| | - Hannah N. Saeger
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Pharmacology and Toxicology Graduate Program, University of California, Davis, Davis, CA 95616, USA
| | - Hunter T. Warren
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
| | - Winston L. Chow
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
| | - John A. Gray
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - David E. Olson
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA 95618, USA
- Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
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Rucker JJ. Psilocybin therapy for depression. A good trip? J Ment Health 2023; 32:1-2. [PMID: 36913702 DOI: 10.1080/09638237.2023.2183492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
Affiliation(s)
- James J Rucker
- Department of Psychological Medicine, King's College London, London, United Kingdom of Great Britain and Northern Ireland
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Schizophrenia and psychedelic state: Dysconnection versus hyper-connection. A perspective on two different models of psychosis stemming from dysfunctional integration processes. Mol Psychiatry 2023; 28:59-67. [PMID: 35931756 DOI: 10.1038/s41380-022-01721-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 07/15/2022] [Accepted: 07/22/2022] [Indexed: 01/07/2023]
Abstract
Psychotic symptoms are a cross-sectional dimension affecting multiple diagnostic categories, despite schizophrenia represents the prototype of psychoses. Initially, dopamine was considered the most involved molecule in the neurobiology of schizophrenia. Over the next years, several biological factors were added to the discussion helping to constitute the concept of schizophrenia as a disease marked by a deficit of functional integration, contributing to the formulation of the Dysconnection Hypothesis in 1995. Nowadays the notion of dysconnection persists in the conceptualization of schizophrenia enriched by neuroimaging findings which corroborate the hypothesis. At the same time, in recent years, psychedelics received a lot of attention by the scientific community and astonishing findings emerged about the rearrangement of brain networks under the effect of these compounds. Specifically, a global decrease in functional connectivity was found, highlighting the disintegration of preserved and functional circuits and an increase of overall connectivity in the brain. The aim of this paper is to compare the biological bases of dysconnection in schizophrenia with the alterations of neuronal cyto-architecture induced by psychedelics and the consequent state of cerebral hyper-connection. These two models of psychosis, despite diametrically opposed, imply a substantial deficit of integration of neural signaling reached through two opposite paths.
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Calder AE, Hasler G. Towards an understanding of psychedelic-induced neuroplasticity. Neuropsychopharmacology 2023; 48:104-112. [PMID: 36123427 PMCID: PMC9700802 DOI: 10.1038/s41386-022-01389-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 12/20/2022]
Abstract
Classic psychedelics, such as LSD, psilocybin, and the DMT-containing beverage ayahuasca, show some potential to treat depression, anxiety, and addiction. Importantly, clinical improvements can last for months or years after treatment. It has been theorized that these long-term improvements arise because psychedelics rapidly and lastingly stimulate neuroplasticity. The focus of this review is on answering specific questions about the effects of psychedelics on neuroplasticity. Firstly, we review the evidence that psychedelics promote neuroplasticity and examine the cellular and molecular mechanisms behind the effects of different psychedelics on different aspects of neuroplasticity, including dendritogenesis, synaptogenesis, neurogenesis, and expression of plasticity-related genes (e.g., brain-derived neurotrophic factor and immediate early genes). We then examine where in the brain psychedelics promote neuroplasticity, particularly discussing the prefrontal cortex and hippocampus. We also examine what doses are required to produce this effect (e.g., hallucinogenic doses vs. "microdoses"), and how long purported changes in neuroplasticity last. Finally, we discuss the likely consequences of psychedelics' effects on neuroplasticity for both patients and healthy people, and we identify important research questions that would further scientific understanding of psychedelics' effects on neuroplasticity and its potential clinical applications.
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Affiliation(s)
- Abigail E. Calder
- grid.8534.a0000 0004 0478 1713University Center for Psychiatric Research, University of Fribourg, Fribourg, Switzerland
| | - Gregor Hasler
- University Center for Psychiatric Research, University of Fribourg, Fribourg, Switzerland.
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Urban MM, Stingl MR, Meinhardt MW. Mini-review: The neurobiology of treating substance use disorders with classical psychedelics. Front Neurosci 2023; 17:1156319. [PMID: 37139521 PMCID: PMC10149865 DOI: 10.3389/fnins.2023.1156319] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/23/2023] [Indexed: 05/05/2023] Open
Abstract
The potential of psychedelics to persistently treat substance use disorders is known since the 1960s. However, the biological mechanisms responsible for their therapeutic effects have not yet been fully elucidated. While it is known that serotonergic hallucinogens induce changes in gene expression and neuroplasticity, particularly in prefrontal regions, theories on how specifically this counteracts the alterations that occur in neuronal circuitry throughout the course of addiction are largely unknown. This narrative mini-review endeavors to synthesize well-established knowledge from addiction research with findings and theories regarding the neurobiological effects of psychedelics to give an overview of the potential mechanisms that underlie the treatment of substance use disorders with classical hallucinogenic compounds and point out gaps in the current understanding.
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Affiliation(s)
- Marvin M. Urban
- Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, United States
- *Correspondence: Marvin M. Urban,
| | - Moritz R. Stingl
- Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, United States
| | - Marcus W. Meinhardt
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
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Psychedelics and Neural Plasticity: Therapeutic Implications. J Neurosci 2022; 42:8439-8449. [PMID: 36351821 PMCID: PMC9665925 DOI: 10.1523/jneurosci.1121-22.2022] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Psychedelic drugs have reemerged as tools to treat several brain disorders. Cultural attitudes toward them are changing, and scientists are once again investigating the neural mechanisms through which these drugs impact brain function. The significance of this research direction is reflected by recent work, including work presented by these authors at the 2022 meeting of the Society for Neuroscience. As of 2022, there were hundreds of clinical trials recruiting participants for testing the therapeutic effects of psychedelics. Emerging evidence suggests that psychedelic drugs may exert some of their long-lasting therapeutic effects by inducing structural and functional neural plasticity. Herein, basic and clinical research attempting to elucidate the mechanisms of these compounds is showcased. Topics covered include psychedelic receptor binding sites, effects of psychedelics on gene expression, and on dendrites, and psychedelic effects on microcircuitry and brain-wide circuits. We describe unmet clinical needs and the current state of translation to the clinic for psychedelics, as well as other unanswered basic neuroscience questions addressable with future studies.
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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: 80] [Impact Index Per Article: 40.0] [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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Ketamine Pharmacodynamics Entangled: Reply. Anesthesiology 2022; 137:748-749. [PMID: 36095056 DOI: 10.1097/aln.0000000000004350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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37
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Dahan A, Henthorn TK. Editorial: Ketamine for treatment of acute and chronic pain: The relationship of mechanism and exposure to therapeutic outcome. FRONTIERS IN PAIN RESEARCH 2022; 3:991569. [PMID: 36081983 PMCID: PMC9445984 DOI: 10.3389/fpain.2022.991569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/01/2022] [Indexed: 11/14/2022] Open
Affiliation(s)
- Albert Dahan
- Department of Anesthesiology, Leiden University Medical Center, Leiden, Netherlands
- PainLess Foundation, Leiden, Netherlands
- *Correspondence: Albert Dahan
| | - Thomas K. Henthorn
- Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO, United States
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, United States
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38
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The role of serotonin neurotransmission in rapid antidepressant actions. Psychopharmacology (Berl) 2022; 239:1823-1838. [PMID: 35333951 DOI: 10.1007/s00213-022-06098-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 02/16/2022] [Indexed: 10/18/2022]
Abstract
RATIONALE Ketamine has rapid antidepressant effects that represent a significant advance in treating depression, but its poor safety and tolerability limit its clinical utility. Accreting evidence suggests that serotonergic neurotransmission participates in the rapid antidepressant effects of ketamine and hallucinogens. Thus, understanding how serotonin contributes to these effects may allow identification of novel rapid antidepressant mechanisms with improved tolerability. OBJECTIVE The goal of this paper is to understand how serotonergic mechanisms participate in rapid antidepressant mechanisms. METHODS We review the relevance of serotonergic neurotransmission for rapid antidepressant effects and evaluate the role of 5-HT1A, 5-HT1B, 5-HT2A, and 5-HT4 receptors in synaptic plasticity, BDNF signaling, and GSK-3β activity. Subsequently, we develop hypotheses on the relationship of these receptor systems to rapid antidepressant effects. RESULTS We found that 5-HT1A and 5-HT1B receptors may participate in ketamine's rapid antidepressant mechanisms, while agonists at 5-HT2A and 5-HT4 receptors may independently behave as rapid antidepressants. 5-HT1A, 5-HT2A, and 5-HT4 receptors increase synaptic plasticity in the cortex or hippocampus but do not consistently increase BDNF signaling. We found that 5-HT1A and 5-HT1B receptors may participate in rapid antidepressant mechanisms as a consequence of increased BDNF signaling, rather than a cause. 5-HT2A and 5-HT4 receptor agonists may increase BDNF signaling, but these relationships are tenuous and need more study. Finally, we found that ketamine and several serotonergic receptor systems may mechanistically converge on reduced GSK-3β activity. CONCLUSIONS We find it plausible that serotonergic neurotransmission participates in rapid antidepressant mechanisms by increasing synaptic plasticity, perhaps through GSK-3β inhibition.
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Sotille R, Singh H, Weisman A, Vida T. Unraveling the Mysteries of Mental Illness With Psilocybin. Cureus 2022; 14:e25414. [PMID: 35769681 PMCID: PMC9233936 DOI: 10.7759/cureus.25414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2022] [Indexed: 12/23/2022] Open
Abstract
Current medications have not been effective in reducing the prevalence of mental illness worldwide. The prevalence of illnesses such as treatment-resistant depression has increased despite the widespread use of a broad set of psychopharmaceuticals. Transcranial magnetic stimulation and ketamine therapy are making great strides in improving treatment-resistant depression outcomes but they have limitations. New psychotherapeutics are required that specifically target the underlying cellular pathologies leading to neuronal atrophy. This neuronal atrophy model is supplanting the long-held neurotransmitter deficit hypothesis to explain mental illness. Interest in psychedelics as therapeutic molecules to treat mental illness is experiencing a 21st-century reawakening that is on the cusp of a transformation. Psilocybin is a pro-drug, found in various naturally occurring mushrooms, that is dephosphorylated to produce psilocin, a classic tryptamine psychedelic functional as a 5-hydroxytryptamine 2A receptor agonist. We have focused this review to include studies in the last two years that suggest psilocybin promotes neuronal plasticity, which may lead to changes in brain network connectivity. Recent advancements in clinical trials using pure psilocybin in therapy suggest that it may effectively relieve the symptoms of depression in patients diagnosed with major depressive disorder and treatment-resistant depression. Sophisticated cellular and molecular experiments at the systems level have produced evidence that demonstrates psilocybin promotes neuritogenesis in the mouse brain - a mechanism that may address the root cause of depression at the cellular level. Finally, studies with psilocybin therapy for major depressive disorder suggest that this ancient molecule can promote functionally connected intrinsic networks in the human brain, resulting in durable improvements in the severity of depressive symptoms. Although further research is necessary, the prospect of using psilocybin for the treatment of mental illness is an enticing possibility.
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Affiliation(s)
- Robert Sotille
- Medical Education, Kirk Kerkorian School of Medicine at University of Nevada Las Vegas, Las Vegas, USA
| | - Herpreet Singh
- Medical Education, Kirk Kerkorian School of Medicine at University of Nevada Las Vegas, Las Vegas, USA
| | - Anne Weisman
- Medical Education, Kirk Kerkorian School of Medicine at University of Nevada Las Vegas, Las Vegas, USA
| | - Thomas Vida
- Medical Education, Kirk Kerkorian School of Medicine at University of Nevada Las Vegas, Las Vegas, USA
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40
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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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Kelley DP, Venable K, Destouni A, Billac G, Ebenezer P, Stadler K, Nichols C, Barker S, Francis J. Pharmahuasca and DMT Rescue ROS Production and Differentially Expressed Genes Observed after Predator and Psychosocial Stress: Relevance to Human PTSD. ACS Chem Neurosci 2022; 13:257-274. [PMID: 34990116 DOI: 10.1021/acschemneuro.1c00660] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is associated with cognitive deficits, oxidative stress, and inflammation. Animal models have recapitulated features of PTSD, but no comparative RNA sequencing analysis of differentially expressed genes (DEGs) in the brain between PTSD and animal models of traumatic stress has been carried out. We compared DEGs from the prefrontal cortex (PFC) of an established stress model to DEGs from the dorsolateral PFC (dlPFC) of humans. We observed a significant enrichment of rat DEGs in human PTSD and identified 20 overlapping DEGs, of which 17 (85%) are directionally concordant. N,N-dimethyltryptamine (DMT) is a known indirect antioxidant, anti-inflammatory, and neuroprotective compound with antidepressant and plasticity-facilitating effects. We tested the capacity of DMT, the monoamine oxidase inhibitor (MAOI) harmaline, and "pharmahuasca" (DMT + harmaline) to reduce reactive oxygen species (ROS) production and inflammatory gene expression and to modulate neuroplasticity-related gene expression in the model. We administered DMT (2 mg/kg IP), harmaline (1.5 mg/kg IP), pharmahuasca, or vehicle every other day for 5 days, following a 30 day stress regiment. We measured ROS production in the PFC and hippocampus (HC) by electron paramagnetic resonance spectroscopy and sequenced total mRNA in the PFC. We also performed in vitro assays to measure the affinity and efficacy of DMT and harmaline at 5HT2AR compared to 5-HT. DMT and pharmahuasca reduced ROS production in the PFC and HC, while harmaline had mixed effects. Treatments normalized 9, 12, and 14 overlapping DEGs, and pathway analysis implicated that genes were involved in ROS production, inflammation, growth factor signaling, neurotransmission, and neuroplasticity.
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Affiliation(s)
- D. Parker Kelley
- Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, United States
| | - Katy Venable
- Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, United States
| | - Aspasia Destouni
- Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, United States
| | - Gerald Billac
- Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States
| | - Philip Ebenezer
- Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, United States
| | - Krisztian Stadler
- Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, United States
| | - Charles Nichols
- Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States
| | - Steven Barker
- Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, United States
| | - Joseph Francis
- Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, United States
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Desouza LA, Benekareddy M, Fanibunda SE, Mohammad F, Janakiraman B, Ghai U, Gur T, Blendy JA, Vaidya VA. The Hallucinogenic Serotonin 2A Receptor Agonist, 2,5-Dimethoxy-4-Iodoamphetamine, Promotes cAMP Response Element Binding Protein-Dependent Gene Expression of Specific Plasticity-Associated Genes in the Rodent Neocortex. Front Mol Neurosci 2022; 14:790213. [PMID: 35002622 PMCID: PMC8739224 DOI: 10.3389/fnmol.2021.790213] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/26/2021] [Indexed: 12/27/2022] Open
Abstract
Psychedelic compounds that target the 5-HT2A receptor are reported to evoke psychoplastogenic effects, including enhanced dendritic arborization and synaptogenesis. Transcriptional regulation of neuronal plasticity-associated genes is implicated in the cytoarchitectural effects of serotonergic psychedelics, however, the transcription factors that drive this regulation are poorly elucidated. Here, we addressed the contribution of the transcription factor cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB) in the regulation of neuronal plasticity-associated genes by the hallucinogenic 5-HT2A receptor agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI). In vitro studies with rat cortical neurons indicated that DOI enhances the phosphorylation of CREB (pCREB) through mitogen-activated protein (MAP) kinase and calcium/calmodulin dependent kinase II (CaMKII) pathways, with both cascades contributing to the DOI-evoked upregulation of Arc, Bdnf1, Cebpb, and Egr2 expression, whilst the upregulation of Egr1 and cFos mRNA involved the MAP kinase and CaMKII pathway respectively. We observed a robust DOI-evoked increase in the expression of several neuronal plasticity-associated genes in the rat neocortex in vivo. This DOI-evoked upregulation of neuronal plasticity-associated genes was completely blocked by the 5-HT2A receptor antagonist MDL100,907 in vitro and was also abrogated in the neocortex of 5-HT2A receptor deficient mice. Further, 5-HT2A receptor stimulation enhanced pCREB enrichment at putative cAMP response element (CRE) binding sites in the Arc, Bdnf1, Cebpb, cFos, but not Egr1 and Egr2, promoters in the rodent neocortex. The DOI-mediated transcriptional induction of Arc, cFos and Cebpb was significantly attenuated in the neocortex of CREB deficient/knockout (CREBαδ KO) mice. Collectively, these results indicate that the hallucinogenic 5-HT2A receptor agonist DOI leads to a rapid transcriptional upregulation of several neuronal plasticity-associated genes, with a subset of them exhibiting a CREB-dependent regulation. Our findings raise the intriguing possibility that similar to slow-acting classical antidepressants, rapid-action serotonergic psychedelics that target the 5-HT2A receptor may also recruit the transcription factor CREB to enhance the expression of neuronal plasticity-associated genes in the neocortex, which could in turn contribute to the rapid psychoplastogenic changes evoked by these compounds.
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Affiliation(s)
- Lynette A Desouza
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Madhurima Benekareddy
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Sashaina E Fanibunda
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India.,Medical Research Centre, Kasturba Health Society, Mumbai, India
| | - Farhan Mohammad
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Balaganesh Janakiraman
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Utkarsha Ghai
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Tamar Gur
- Department of Psychiatry and Behavioral Health, The Ohio State University College of Medicine, Columbus, OH, United States
| | - Julie A Blendy
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Vidita A Vaidya
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
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van den Berg M, Magaraggia I, Schreiber R, Hillhouse TM, Porter JH. How to account for hallucinations in the interpretation of the antidepressant effects of psychedelics: a translational framework. Psychopharmacology (Berl) 2022; 239:1853-1879. [PMID: 35348806 PMCID: PMC9166823 DOI: 10.1007/s00213-022-06106-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 02/24/2022] [Indexed: 01/02/2023]
Abstract
RATIONALE Recent trials with psychedelics in major depressive disorder and treatment-resistant depression showed remarkable improvements in depressive symptoms that can last for up to several months after even a single administration. The lack of an appropriate placebo control group-as patients are often able to discriminate the subjective effects of the drug-and an incomplete understanding of the role of the hallucinogenic and mystical experience, hampers the interpretation of these therapeutic effects. OBJECTIVES To control for these factors, we developed a translational framework based on establishing pharmacokinetic/pharmacodynamic (PK/PD) relationships in rodents and humans for hallucinogenic (i.e., discriminative stimulus effects in rodents and humans; head twitch responses in rodents; questionnaires in humans) and therapeutic effects. For the latter, we selected the pattern separation and attentional set-shifting tasks as measures for cognitive flexibility because of their high translational value. We predict that these PK/PD analyses will lead to a more objective evaluation of improvements in patients compared to relying only on the currently used self-reported questionnaires. We hypothesize that-if the role of the hallucinogenic experience is not central in the antidepressant effects of psychedelics-the ED50's for the therapeutic effects will be significantly lower than for the hallucinogenic and mystical effects. CONCLUSION Our framework will help to inform future studies that aim at the elucidation of the mechanism(s) of action of psychedelics in depression, and the role of the acute subjective and/or hallucinogenic experience in their effects.
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Affiliation(s)
- Manon van den Berg
- Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands ,Faculty of Psychology and Neuroscience, Section Neuropsychology & Psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - Igor Magaraggia
- Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands ,Faculty of Psychology and Neuroscience, Section Neuropsychology & Psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - Rudy Schreiber
- Faculty of Psychology and Neuroscience, Section Neuropsychology & Psychopharmacology, Maastricht University, Maastricht, The Netherlands.
| | - Todd M. Hillhouse
- Department of Psychology, University of Wisconsin Green Bay, Green Bay, WI USA
| | - Joseph H. Porter
- Department of Psychology, Virginia Commonwealth University, Richmond, USA
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Kelly JR, Gillan CM, Prenderville J, Kelly C, Harkin A, Clarke G, O'Keane V. Psychedelic Therapy's Transdiagnostic Effects: A Research Domain Criteria (RDoC) Perspective. Front Psychiatry 2021; 12:800072. [PMID: 34975593 PMCID: PMC8718877 DOI: 10.3389/fpsyt.2021.800072] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 11/19/2021] [Indexed: 12/12/2022] Open
Abstract
Accumulating clinical evidence shows that psychedelic therapy, by synergistically combining psychopharmacology and psychological support, offers a promising transdiagnostic treatment strategy for a range of disorders with restricted and/or maladaptive habitual patterns of emotion, cognition and behavior, notably, depression (MDD), treatment resistant depression (TRD) and addiction disorders, but perhaps also anxiety disorders, obsessive-compulsive disorder (OCD), Post-Traumatic Stress Disorder (PTSD) and eating disorders. Despite the emergent transdiagnostic evidence, the specific clinical dimensions that psychedelics are efficacious for, and associated underlying neurobiological pathways, remain to be well-characterized. To this end, this review focuses on pre-clinical and clinical evidence of the acute and sustained therapeutic potential of psychedelic therapy in the context of a transdiagnostic dimensional systems framework. Focusing on the Research Domain Criteria (RDoC) as a template, we will describe the multimodal mechanisms underlying the transdiagnostic therapeutic effects of psychedelic therapy, traversing molecular, cellular and network levels. These levels will be mapped to the RDoC constructs of negative and positive valence systems, arousal regulation, social processing, cognitive and sensorimotor systems. In summarizing this literature and framing it transdiagnostically, we hope we can assist the field in moving toward a mechanistic understanding of how psychedelics work for patients and eventually toward a precise-personalized psychedelic therapy paradigm.
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Affiliation(s)
- John R. Kelly
- Department of Psychiatry, Trinity College, Dublin, Ireland
- Department of Psychiatry, Tallaght University Hospital, Dublin, Ireland
| | - Claire M. Gillan
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
- School of Psychology, Trinity College, Dublin, Ireland
- Global Brain Health Institute, Trinity College, Dublin, Ireland
| | - Jack Prenderville
- Transpharmation Ireland Ltd, Institute of Neuroscience, Trinity College, Dublin, Ireland
- Discipline of Physiology, School of Medicine, Trinity College, Dublin, Ireland
| | - Clare Kelly
- Department of Psychiatry, Trinity College, Dublin, Ireland
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
- School of Psychology, Trinity College, Dublin, Ireland
| | - Andrew Harkin
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
- School of Pharmacy and Pharmaceutical Sciences, Trinity College, Dublin, Ireland
| | - Gerard Clarke
- Department of Psychiatry and Neurobehavioral Science, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Veronica O'Keane
- Department of Psychiatry, Trinity College, Dublin, Ireland
- Department of Psychiatry, Tallaght University Hospital, Dublin, Ireland
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
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45
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Saeger HN, Olson DE. Psychedelic-inspired approaches for treating neurodegenerative disorders. J Neurochem 2021; 162:109-127. [PMID: 34816433 DOI: 10.1111/jnc.15544] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/19/2021] [Accepted: 11/21/2021] [Indexed: 12/21/2022]
Abstract
Psychedelics are increasingly being recognized for their potential to treat a wide range of brain disorders including depression, post-traumatic stress disorder (PTSD), and substance use disorder. Their broad therapeutic potential might result from an ability to rescue cortical atrophy common to many neuropsychiatric and neurodegenerative diseases by impacting neurotrophic factor gene expression, activating neuronal growth and survival mechanisms, and modulating the immune system. While the therapeutic potential of psychedelics has not yet been extended to neurodegenerative disorders, we provide evidence suggesting that approaches based on psychedelic science might prove useful for treating these diseases. The primary target of psychedelics, the 5-HT2A receptor, plays key roles in cortical neuron health and is dysregulated in Alzheimer's disease. Moreover, evidence suggests that psychedelics and related compounds could prove useful for treating the behavioral and psychological symptoms of dementia (BPSD). While more research is needed to probe the effects of psychedelics in models of neurodegenerative diseases, the robust effects of these compounds on structural and functional neuroplasticity and inflammation clearly warrant further investigation.
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Affiliation(s)
- Hannah N Saeger
- Pharmacology and Toxicology Graduate Group, University of California, Davis, Davis, California, USA
| | - David E Olson
- Department of Chemistry, University of California, Davis, Davis, California, USA.,Department of Biochemistry & 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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Lukasiewicz K, Baker JJ, Zuo Y, Lu J. Serotonergic Psychedelics in Neural Plasticity. Front Mol Neurosci 2021; 14:748359. [PMID: 34712118 PMCID: PMC8545892 DOI: 10.3389/fnmol.2021.748359] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/13/2021] [Indexed: 12/15/2022] Open
Abstract
Psychedelics, compounds that can induce dramatic changes in conscious experience, have been used by humans for centuries. Recent studies have shown that certain psychedelics can induce neural plasticity by promoting neurite growth and synapse formation. In this review, we focus on the role of classical serotonergic psychedelics in neural plasticity and discuss its implication for their therapeutic potentials.
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Affiliation(s)
- Kacper Lukasiewicz
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Jacob J Baker
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Yi Zuo
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Ju Lu
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
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47
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Vargas MV, Meyer R, Avanes AA, Rus M, Olson DE. Psychedelics and Other Psychoplastogens for Treating Mental Illness. Front Psychiatry 2021; 12:727117. [PMID: 34671279 PMCID: PMC8520991 DOI: 10.3389/fpsyt.2021.727117] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/06/2021] [Indexed: 12/28/2022] Open
Abstract
Psychedelics have inspired new hope for treating brain disorders, as they seem to be unlike any treatments currently available. Not only do they produce sustained therapeutic effects following a single administration, they also appear to have broad therapeutic potential, demonstrating efficacy for treating depression, post-traumatic stress disorder (PTSD), anxiety disorders, substance abuse disorder, and alcohol use disorder, among others. Psychedelics belong to a more general class of compounds known as psychoplastogens, which robustly promote structural and functional neural plasticity in key circuits relevant to brain health. Here we discuss the importance of structural plasticity in the treatment of neuropsychiatric diseases, as well as the evidence demonstrating that psychedelics are among the most effective chemical modulators of neural plasticity studied to date. Furthermore, we provide a theoretical framework with the potential to explain why psychedelic compounds produce long-lasting therapeutic effects across a wide range of brain disorders. Despite their promise as broadly efficacious neurotherapeutics, there are several issues associated with psychedelic-based medicines that drastically limit their clinical scalability. We discuss these challenges and how they might be overcome through the development of non-hallucinogenic psychoplastogens. The clinical use of psychedelics and other psychoplastogenic compounds marks a paradigm shift in neuropsychiatry toward therapeutic approaches relying on the selective modulation of neural circuits with small molecule drugs. Psychoplastogen research brings us one step closer to actually curing mental illness by rectifying the underlying pathophysiology of disorders like depression, moving beyond simply treating disease symptoms. However, determining how to most effectively deploy psychoplastogenic medicines at scale will be an important consideration as the field moves forward.
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Affiliation(s)
- Maxemiliano V. Vargas
- Neuroscience Graduate Program, University of California, Davis, Davis, CA, United States
| | - Retsina Meyer
- Delix Therapeutics, Inc., Concord, MA, United States
| | - Arabo A. Avanes
- Biochemistry, Molecular, Cellular, and Developmental Biology Graduate Program, University of California, Davis, Davis, CA, United States
| | - Mark Rus
- Delix Therapeutics, Inc., Concord, MA, United States
| | - David E. Olson
- Delix Therapeutics, Inc., Concord, MA, United States
- Department of Chemistry, University of California, Davis, Davis, CA, United States
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Sacramento, Sacramento, CA, United States
- Center for Neuroscience, University of California, Davis, Davis, CA, United States
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Aleksandrova LR, Phillips AG. Neuroplasticity as a convergent mechanism of ketamine and classical psychedelics. Trends Pharmacol Sci 2021; 42:929-942. [PMID: 34565579 DOI: 10.1016/j.tips.2021.08.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 12/20/2022]
Abstract
The emerging therapeutic efficacy of ketamine and classical psychedelics for depression has inspired tremendous interest in the underlying neurobiological mechanisms. We review preclinical and clinical evidence supporting neuroplasticity as a convergent downstream mechanism of action for these novel fast-acting antidepressants. Through their primary glutamate or serotonin receptor targets, ketamine and psychedelics [psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT)] induce synaptic, structural, and functional changes, particularly in pyramidal neurons in the prefrontal cortex. These include increased glutamate release, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) activation, brain-derived neurotrophic factor (BDNF) and mammalian target of rapamycin (mTOR)-mediated signaling, expression of synaptic proteins, and synaptogenesis. Such influences may facilitate adaptive rewiring of pathological neurocircuitry, thus providing a neuroplasticity-focused framework to explain the robust and sustained therapeutic effects of these compounds.
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Affiliation(s)
- Lily R Aleksandrova
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
| | - Anthony G Phillips
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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Peters J, Olson DE. Engineering Safer Psychedelics for Treating Addiction. Neurosci Insights 2021; 16:26331055211033847. [PMID: 34350400 PMCID: PMC8295933 DOI: 10.1177/26331055211033847] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 06/30/2021] [Indexed: 12/03/2022] Open
Abstract
Addiction is best described as a disorder of maladaptive neuroplasticity involving the simultaneous strengthening of reward circuitry that drives compulsive drug seeking and weakening of circuits involved in executive control over harmful behaviors. Psychedelics have shown great promise for treating addiction, with many people attributing their therapeutic effects to insights gained while under the influence of the drug. However, psychedelics are also potent psychoplastogens—molecules capable of rapidly re-wiring the adult brain. The advent of non-hallucinogenic psychoplastogens with anti-addictive properties raises the intriguing possibility that hallucinations might not be necessary for all therapeutic effects of psychedelic-based medicines, so long as the underlying pathological neural circuitry can be remedied. One of these non-hallucinogenic psychoplastogens, tabernanthalog (TBG), appears to have long-lasting therapeutic effects in preclinical models relevant to alcohol and opioid addiction. Here, we discuss the implications of these results for the development of addiction treatments, as well as the next steps for advancing TBG and related non-hallucinogenic psychoplastogens as addiction therapeutics.
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Affiliation(s)
- Jamie Peters
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA.,Department of Pharmacology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - David E Olson
- Department of Chemistry, University of California, Davis, Davis, CA, USA.,Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, USA.,Center for Neuroscience, University of California, Davis, Davis, CA, USA
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50
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Shao LX, Liao C, Gregg I, Davoudian PA, Savalia NK, Delagarza K, Kwan AC. Psilocybin induces rapid and persistent growth of dendritic spines in frontal cortex in vivo. Neuron 2021; 109:2535-2544.e4. [PMID: 34228959 DOI: 10.1016/j.neuron.2021.06.008] [Citation(s) in RCA: 192] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/16/2021] [Accepted: 06/07/2021] [Indexed: 12/18/2022]
Abstract
Psilocybin is a serotonergic psychedelic with untapped therapeutic potential. There are hints that the use of psychedelics can produce neural adaptations, although the extent and timescale of the impact in a mammalian brain are unknown. In this study, we used chronic two-photon microscopy to image longitudinally the apical dendritic spines of layer 5 pyramidal neurons in the mouse medial frontal cortex. We found that a single dose of psilocybin led to ∼10% increases in spine size and density, driven by an elevated spine formation rate. The structural remodeling occurred quickly within 24 h and was persistent 1 month later. Psilocybin also ameliorated stress-related behavioral deficit and elevated excitatory neurotransmission. Overall, the results demonstrate that psilocybin-evoked synaptic rewiring in the cortex is fast and enduring, potentially providing a structural trace for long-term integration of experiences and lasting beneficial actions.
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Affiliation(s)
- Ling-Xiao Shao
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Clara Liao
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Ian Gregg
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Pasha A Davoudian
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA; Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Neil K Savalia
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA; Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Kristina Delagarza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Alex C Kwan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06511, USA.
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