1
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McGriff SA, Hecker JC, Maitland AD, Partilla JS, Baumann MH, Glatfelter GC. Psychedelic-like effects induced by 2,5-dimethoxy-4-iodoamphetamine, lysergic acid diethylamide, and psilocybin in male and female C57BL/6J mice. Psychopharmacology (Berl) 2025:10.1007/s00213-025-06795-x. [PMID: 40381003 DOI: 10.1007/s00213-025-06795-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Accepted: 04/19/2025] [Indexed: 05/19/2025]
Abstract
RATIONALE The head twitch response (HTR) is a spontaneously occurring behavior in mice that is increased in frequency by serotonergic psychedelics. The mouse HTR is often used as a proxy for psychedelic-like drug effects, but limited information is available about sex differences in HTRs evoked by various classes of psychedelics (i.e., phenethylamines, lysergamides, tryptamines). OBJECTIVE AND METHODS To examine potential sex differences in responsiveness to structurally-distinct psychedelics, acute effects of subcutaneous 2,5-dimethoxy-4-iodo-amphetamine (DOI, 0.03-10 mg/kg), lysergic acid diethylamide (LSD, 0.003-1 mg/kg), and 4-phosphoryloxy-N,N-dimethyltryptamine (psilocybin, 0.03-10 mg/kg) on HTRs were compared in male and female C57BL/6J mice. For comparison, effects of the drugs on locomotor activity and body temperature were also determined. RESULTS Drug potencies for inducing HTRs were similar in males and females for all drugs, with only LSD exhibiting detectable differences due to increased maximal counts in females. Importantly, the maximum number of HTRs observed for all drugs was higher in females, with significant differences between sexes for DOI and LSD. Dose x sex interactions for the dose-response data were statistically significant for psilocybin and LSD, with females displaying more HTRs after the highest or peak doses of all drugs. The acute effects of drugs on locomotion and temperature varied by drug, but were similar in both sexes. CONCLUSIONS The present results overall show no substantial sex differences in the potencies to induce HTRs for DOI, LSD, and psilocybin in C57BL/6J mice. However, females uniformly displayed more HTRs at high doses administered across chemotypes. The results further suggest that commonly used doses of psychedelics induce comparable psychedelic-like effects in male and female C57BL/6J mice, but modest differences may emerge at high doses.
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Affiliation(s)
- Shelby A McGriff
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Jacquelin C Hecker
- Behavioral Neuroscience Research Branch, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Alexander D Maitland
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - John S Partilla
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Michael H Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Grant C Glatfelter
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA.
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Al-Imam A, Lora R, Motyka MA, Marletta E, Vezzaro M, Moczko J, Younus M, Michalak M. Opinion Mining of Erowid's Experience Reports on LSD and Psilocybin-Containing Mushrooms. Drug Saf 2025; 48:559-575. [PMID: 40032797 DOI: 10.1007/s40264-025-01530-z] [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] [Accepted: 02/13/2025] [Indexed: 03/05/2025]
Abstract
BACKGROUND Psychedelics are gaining attention for their therapeutic potential in modern and personalized medicine. Online forums such as Erowid provide valuable user insights, but analyses of these experiences using natural language processing (NLP) remain scarce. OBJECTIVE This study aims to utilize NLP, including sentiment and lexicon analysis, to examine user-generated experience reports on psilocybin-containing mushrooms and LSD from the Erowid forum. METHODS Data from 2188 Erowid users (1161 psilocybin mushrooms and 1027 LSD) was collected via automated web scraping with XPath, CSS selectors, and Selenium WebDriver. The dataset included report titles, substances, and demographics. Sentiment analysis utilized BERT, RoBERTa, and VADER models. Preprocessing involved tokenization, lemmatization, part-of-speech tagging, and stop-word filtering. Lexicon analysis identified themes through recurring n-grams, visualized using Python. RESULTS User demographics revealed comparable ages for psilocybin mushrooms (23.8 ± 0.9 years) and LSD users (20.0 ± 0.6 years), with a predominance of male users. The BERT model predominantly labeled experiences as negative (unfavorable), particularly for mushroom users (p = 0.001). VADER indicated more positive experiences for mushroom users (p < 0.001), while RoBERTa mainly classified experiences as negative or neutral. Significant gender differences were found only with VADER, where more male users expressed positive opinions about psilocybin mushrooms (74.09% versus 65.52%, p < 0.021). The VADER model yielded more polarized results, whereas RoBERTa's cautious classifications indicate its suitability for analyzing lengthy and complex psychedelic reports. Further, RoBERTa outperformed other transformer-based models, achieving the highest accuracy. Lexicon analysis revealed emotional, sensory, and temporal themes, with psilocybin reports emphasizing introspection and time dilation phenomenon, while LSD reports highlighted memory issues and cognitive disorientation. CONCLUSIONS Sentiment analysis showed that VADER produced more polarized results, while RoBERTa offered cautious classifications with the highest accuracy. Lexicon analysis revealed shared themes, with mushroom reports focusing on introspection and time dilation perception, while those of LSD emphasized cognitive disturbances. This study highlights the value of these analyses in understanding psychedelic experiences, informing harm reduction, and guiding policy-making.
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Affiliation(s)
- Ahmed Al-Imam
- Department of Computer Science and Statistics, Poznan University of Medical Sciences, 61-806, Poznan, Poland.
- Doctoral School, Poznan University of Medical Sciences, 61-806, Poznan, Poland.
- Department of Anatomy and Cellular Biology, College of Medicine, University of Baghdad, Baghdad, 10047, Iraq.
| | - Riccardo Lora
- Section of Pharmacology, Department of Diagnostics and Public Health, University of Verona, 37134, Verona, Italy
| | - Marek A Motyka
- Institute of Sociological Sciences, University of Rzeszow, 35-959, Rzeszów, Poland
| | - Erica Marletta
- Section of Pharmacology, Department of Diagnostics and Public Health, University of Verona, 37134, Verona, Italy
| | - Michele Vezzaro
- Section of Pharmacology, Department of Diagnostics and Public Health, University of Verona, 37134, Verona, Italy
| | - Jerzy Moczko
- Department of Computer Science and Statistics, Poznan University of Medical Sciences, 61-806, Poznan, Poland
| | - Manal Younus
- Iraqi Pharmacovigilance Centre, Ministry of Health, Baghdad, 10001, Iraq
- The Middle East Chapter, The International Society of Pharmacovigilance (ISoP), London, SW12 0HS, UK
- Council for International Organizations of Medical Sciences (CIOMS), 1218, Geneva, Switzerland
| | - Michal Michalak
- Department of Computer Science and Statistics, Poznan University of Medical Sciences, 61-806, Poznan, Poland
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3
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Floris G, Dabrowski KR, Zanda MT, Daws SE. Psilocybin reduces heroin seeking behavior and modulates inflammatory gene expression in the nucleus accumbens and prefrontal cortex of male rats. Mol Psychiatry 2025; 30:1801-1816. [PMID: 39433903 PMCID: PMC12015112 DOI: 10.1038/s41380-024-02788-y] [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: 12/01/2023] [Revised: 10/04/2024] [Accepted: 10/08/2024] [Indexed: 10/23/2024]
Abstract
Preclinical and human studies indicate psilocybin may reduce perseverant maladaptive behaviors, including nicotine and alcohol seeking. Such studies in the opioid field are lacking, though opioids are involved in >50% of overdose deaths. Psilocybin is an agonist at the serotonin 2A receptor (5-HT2AR), a well-documented target for modulation of drug seeking, and evidence suggests 5-HT2AR agonists may dampen motivation for opioids. We sought to investigate the therapeutic efficacy of psilocybin in mediating cessation of opioid use and maintenance of long-lasting abstinence from opioid seeking behavior in a rat model of heroin self-administration (SA). Psilocybin or 5-HT2AR antagonists ketanserin and volinanserin were administered systemically to rats prior to SA of 0.075 mg/kg/infusion of heroin, or relapse following forced abstinence. Psilocybin did not alter heroin taking, but a single exposure to 3.0 mg/kg psilocybin 4-24 h prior to a relapse test blunted cue-induced heroin seeking. Conversely, 5-HT2AR antagonists exacerbated heroin relapse. To begin to elucidate mechanisms of psilocybin, drug-naïve rats received psilocybin and/or ketanserin, and tissue was collected from the prefrontal cortex (PFC), a region critical for drug seeking and responsive to psilocybin, 24 h later for RNA-sequencing. 3.0 mg/kg psilocybin regulated ~2-fold more genes in the PFC than 1.0 mg/kg, including genes involved in the cytoskeleton and cytokine signaling. Ketanserin blocked >90% of psilocybin-regulated genes, including the IL-17a cytokine receptor, Il17ra. Psychedelic compounds have reported anti-inflammatory properties, and therefore we performed a gene expression array to measure chemokine/cytokine molecules in the PFC of animals that displayed psilocybin-mediated inhibition of heroin seeking. Psilocybin regulated 4 genes, including Il17a, and a subset of genes correlated with relapse behavior. Selective inhibition of PFC IL-17a was sufficient to reduce heroin relapse. We conclude that psilocybin reduces heroin relapse and highlight IL-17a signaling as a potential downstream pathway of psilocybin that also reduces heroin seeking.
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Affiliation(s)
- Gabriele Floris
- Center for Substance Abuse Research, Temple University, Philadelphia, PA, USA
- Department of Neural Sciences, Temple University, Philadelphia, PA, USA
| | - Konrad R Dabrowski
- Center for Substance Abuse Research, Temple University, Philadelphia, PA, USA
- Department of Biology, Temple University, Philadelphia, PA, USA
| | - Mary Tresa Zanda
- Center for Substance Abuse Research, Temple University, Philadelphia, PA, USA
- Department of Neural Sciences, Temple University, Philadelphia, PA, USA
| | - Stephanie E Daws
- Center for Substance Abuse Research, Temple University, Philadelphia, PA, USA.
- Department of Neural Sciences, Temple University, Philadelphia, PA, USA.
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4
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Low ZXB, Ng WS, Lim ESY, Goh BH, Kumari Y. The immunomodulatory effects of classical psychedelics: A systematic review of preclinical studies. Prog Neuropsychopharmacol Biol Psychiatry 2025; 136:111139. [PMID: 39251080 DOI: 10.1016/j.pnpbp.2024.111139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 08/27/2024] [Accepted: 09/06/2024] [Indexed: 09/11/2024]
Abstract
Emerging evidence suggests that classical psychedelics possess immunomodulatory and anti-inflammatory properties; however, these effects are yet to be well-established. This systematic review aims to provide a timely and comprehensive overview of the immunomodulatory effects of classical psychedelics in preclinical studies. A systematic search was conducted on six databases, including CINAHL, EMBASE, MEDLINE, PsychINFO, Scopus, and Web of Science. Eligible studies targeting classical psychedelics for evaluation of their effects on inflammatory markers and immunomodulation have been included for analysis. Data was extracted from 40 out of 2822 eligible articles, and their risk of bias was assessed using the Systematic Review Center for Laboratory Animal Experimentation (SYRCLE) tool and Quality Assessment Tool for In Vitro Studies (QUIN). Studies examined 2,5-dimethoxy-4-iodoamphetamine (DOI; n = 18); psilocybin (4-PO-DMT; n = 9); N,N-dimethyltryptamine (DMT; n = 8); lysergic acid diethylamide (LSD; n = 6); 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT; n = 3); psilocin (4-HO-DMT; n = 3); and mescaline (n = 2). In 36 studies where inflammatory cytokine levels were measured following psychedelic administration, a decrease in at least one inflammatory cytokine was observed in 29 studies. Immune cell activity was assessed in 10 studies and findings were mixed, with an equal number of studies (n = 5 out of 10) reporting either an increase or decrease in immune cell activity. Classical psychedelics were found to alleviate pre-existing inflammation but promote inflammation when administered under normal physiological conditions. This information is anticipated to inform future clinical trials, exploring classical psychedelics' potential to alleviate inflammation in various pathologies.
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Affiliation(s)
- Zhen Xuen Brandon Low
- Neurological Disorder and Aging (NDA) Research Group, Neuroscience Research Strength (NRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Selangor, Malaysia
| | - Wei Shen Ng
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Selangor, Malaysia
| | - Eugene Sheng Yao Lim
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Selangor, Malaysia
| | - Bey Hing Goh
- Sunway Biofunctional Molecules Discovery Centre, School of Medical and Life Sciences, Sunway University Malaysia, Bandar Sunway, 47500, Selangor Darul Ehsan, Malaysia; Biofunctional Molecule Exploratory Research Group, School of Pharmacy, Monash University Malaysia, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia; College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yatinesh Kumari
- Neurological Disorder and Aging (NDA) Research Group, Neuroscience Research Strength (NRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Selangor, Malaysia.
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5
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Alexander L, Anderson D, Baxter L, Claydon M, Rucker J, Robinson ESJ. Preclinical models for evaluating psychedelics in the treatment of major depressive disorder. Br J Pharmacol 2024. [PMID: 39467003 DOI: 10.1111/bph.17370] [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: 06/17/2024] [Revised: 09/13/2024] [Accepted: 09/16/2024] [Indexed: 10/30/2024] Open
Abstract
Psychedelic drugs have seen a resurgence in interest as a next generation of psychiatric medicines with potential as rapid-acting antidepressants (RAADs). Despite promising early clinical trials, the mechanisms which underlie the effects of psychedelics are poorly understood. For example, key questions such as whether antidepressant and psychedelic effects involve related or independent mechanisms are unresolved. Preclinical studies in relevant animal models are key to understanding the pharmacology of psychedelics and translating these findings to explain efficacy and safety in patients. Understanding the mechanisms of action associated with the behavioural effects of psychedelic drugs can also support the identification of novel drug targets and more effective treatments. Here we review the behavioural approaches currently used to quantify the psychedelic and antidepressant effects of psychedelic drugs. We discuss conceptual and methodological issues, the importance of using clinically relevant doses and the need to consider possible sex differences in preclinical psychedelic studies.
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Affiliation(s)
- Laith Alexander
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- South London and the Maudsley NHS Foundation Trust, London, UK
| | - Dasha Anderson
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
| | - Luke Baxter
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- South London and the Maudsley NHS Foundation Trust, London, UK
| | - Matthew Claydon
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
| | - James Rucker
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- South London and the Maudsley NHS Foundation Trust, London, UK
| | - Emma S J Robinson
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
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6
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Shadani S, Conn K, Andrews ZB, Foldi CJ. Potential Differences in Psychedelic Actions Based on Biological Sex. Endocrinology 2024; 165:bqae083. [PMID: 38980913 PMCID: PMC11259856 DOI: 10.1210/endocr/bqae083] [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: 05/23/2024] [Revised: 06/28/2024] [Accepted: 07/05/2024] [Indexed: 07/11/2024]
Abstract
The resurgence of interest in psychedelics as treatments for psychiatric disorders necessitates a better understanding of potential sex differences in response to these substances. Sex as a biological variable (SABV) has been historically neglected in medical research, posing limits to our understanding of treatment efficacy. Human studies have provided insights into the efficacy of psychedelics across various diagnoses and aspects of cognition, yet sex-specific effects remain unclear, making it difficult to draw strong conclusions about sex-dependent differences in response to psychedelic treatments. Compounding this further, animal studies used to understand biological mechanisms of psychedelics predominantly use one sex and present mixed neurobiological and behavioral outcomes. Studies that do include both sexes often do not investigate sex differences further, which may hinder the translation of findings to the clinic. In reviewing sex differences in responses to psychedelics, we will highlight the direct interaction between estrogen (the most extensively studied steroid hormone) and the serotonin system (central to the mechanism of action of psychedelics), and the potential that estrogen-serotonin interactions may influence the efficacy of psychedelics in female participants. Estrogen influences serotonin neurotransmission by affecting its synthesis and release, as well as modulating the sensitivity and responsiveness of serotonin receptor subtypes in the brain. This could potentially influence the efficacy of psychedelics in females by modifying their therapeutic efficacy across menstrual cycles and developmental stages. Investigating this interaction in the context of psychedelic research could aid in the advancement of therapeutic outcomes, especially for conditions with sex-specific prevalence.
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Affiliation(s)
- Sheida Shadani
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia
- Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Kyna Conn
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia
- Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Zane B Andrews
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia
- Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Claire J Foldi
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia
- Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
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7
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Floris G, Dabrowski KR, Zanda MT, Daws SE. Psilocybin reduces heroin seeking behavior and modulates inflammatory gene expression in the nucleus accumbens and prefrontal cortex of male rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596205. [PMID: 38854027 PMCID: PMC11160682 DOI: 10.1101/2024.05.28.596205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Preclinical and human studies indicate psilocybin may reduce perseverant maladaptive behaviors, including nicotine and alcohol seeking. Such studies in the opioid field are lacking, though opioids are involved in more >50% of overdose deaths. Psilocybin is an agonist at the serotonin 2A receptor (5-HT2AR), a well-documented target for modulation of drug seeking, and evidence suggests 5-HT2AR agonists may dampen motivation for opioids. We sought to investigate the therapeutic efficacy of psilocybin in mediating cessation of opioid use and maintenance of long-lasting abstinence from opioid seeking behavior in a rat model of heroin self-administration (SA). Psilocybin or 5-HT2AR antagonists ketanserin and volinanserin were administered systemically to rats prior to SA of 0.075 mg/kg/infusion of heroin, or relapse following forced abstinence. Psilocybin did not alter heroin taking, but a single exposure to 3.0 mg/kg psilocybin 4-24 hours prior to a relapse test blunted cue-induced heroin seeking. Conversely, 5-HT2AR antagonists exacerbated heroin relapse. To begin to elucidate mechanisms of psilocybin, drug-naïve rats received psilocybin and/or ketanserin, and tissue was collected from the prefrontal cortex (PFC), a region critical for drug seeking and responsive to psilocybin, 24 hours later for RNA-sequencing. 3.0 mg/kg psilocybin regulated ~2-fold more genes in the PFC than 1.0 mg/kg, including genes involved in the cytoskeleton and cytokine signaling. Ketanserin blocked >90% of psilocybin-regulated genes, including the IL-17a cytokine receptor, Il17ra. Psychedelic compounds have reported anti-inflammatory properties, and therefore we performed a gene expression array to measure chemokine/cytokine molecules in the PFC of animals that displayed psilocybin-mediated inhibition of heroin seeking. Psilocybin regulated 4 genes, including Il17a, and a subset of genes correlated with relapse behavior. Selective inhibition of PFC IL-17a was sufficient to reduce heroin relapse. We conclude that psilocybin reduces heroin relapse and highlight IL-17a signaling as a potential downstream pathway of psilocybin that also reduces heroin seeking.
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Affiliation(s)
- Gabriele Floris
- Center for Substance Abuse Research, Temple University, Philadelphia, PA USA
- Department of Neural Sciences, Temple University, Philadelphia, PA USA
| | - Konrad R Dabrowski
- Center for Substance Abuse Research, Temple University, Philadelphia, PA USA
- Department of Biology, Temple University, Philadelphia, PA USA
| | - Mary Tresa Zanda
- Center for Substance Abuse Research, Temple University, Philadelphia, PA USA
- Department of Neural Sciences, Temple University, Philadelphia, PA USA
| | - Stephanie E Daws
- Center for Substance Abuse Research, Temple University, Philadelphia, PA USA
- Department of Neural Sciences, Temple University, Philadelphia, PA USA
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8
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Jaster AM, González-Maeso J. Mechanisms and molecular targets surrounding the potential therapeutic effects of psychedelics. Mol Psychiatry 2023; 28:3595-3612. [PMID: 37759040 DOI: 10.1038/s41380-023-02274-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023]
Abstract
Psychedelics, also known as classical hallucinogens, have been investigated for decades due to their potential therapeutic effects in the treatment of neuropsychiatric and substance use disorders. The results from clinical trials have shown promise for the use of psychedelics to alleviate symptoms of depression and anxiety, as well as to promote substantial decreases in the use of nicotine and alcohol. While these studies provide compelling evidence for the powerful subjective experience and prolonged therapeutic adaptations, the underlying molecular reasons for these robust and clinically meaningful improvements are still poorly understood. Preclinical studies assessing the targets and circuitry of the post-acute effects of classical psychedelics are ongoing. Current literature is split between a serotonin 5-HT2A receptor (5-HT2AR)-dependent or -independent signaling pathway, as researchers are attempting to harness the mechanisms behind the sustained post-acute therapeutically relevant effects. A combination of molecular, behavioral, and genetic techniques in neuropharmacology has begun to show promise for elucidating these mechanisms. As the field progresses, increasing evidence points towards the importance of the subjective experience induced by psychedelic-assisted therapy, but without further cross validation between clinical and preclinical research, the why behind the experience and its translational validity may be lost.
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Affiliation(s)
- Alaina M Jaster
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
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9
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Saha S, González-Maeso J. The crosstalk between 5-HT 2AR and mGluR2 in schizophrenia. Neuropharmacology 2023; 230:109489. [PMID: 36889432 PMCID: PMC10103009 DOI: 10.1016/j.neuropharm.2023.109489] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/26/2023] [Accepted: 03/05/2023] [Indexed: 03/08/2023]
Abstract
Schizophrenia is a severe brain disorder that usually produces a lifetime of disability. First generation or typical antipsychotics such as haloperidol and second generation or atypical antipsychotics such as clozapine and risperidone remain the current standard for schizophrenia treatment. In some patients with schizophrenia, antipsychotics produce complete remission of positive symptoms, such as hallucinations and delusions. However, antipsychotic drugs are ineffective against cognitive deficits and indeed treated schizophrenia patients have small improvements or even deterioration in several cognitive domains. This underlines the need for novel and more efficient therapeutic targets for schizophrenia treatment. Serotonin and glutamate have been identified as key parts of two neurotransmitter systems involved in fundamental brain processes. Serotonin (or 5-hydroxytryptamine) 5-HT2A receptor (5-HT2AR) and metabotropic glutamate 2 receptor (mGluR2) are G protein-coupled receptors (GPCRs) that interact at epigenetic and functional levels. These two receptors can form GPCR heteromeric complexes through which their pharmacology, function and trafficking becomes affected. Here we review past and current research on the 5-HT2AR-mGluR2 heterocomplex and its potential implication in schizophrenia and antipsychotic drug action. This article is part of the Special Issue on "The receptor-receptor interaction as a new target for therapy".
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Affiliation(s)
- Somdatta Saha
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
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10
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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: 28] [Impact Index Per Article: 14.0] [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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Elsilä LV, Harkki J, Enberg E, Martti A, Linden AM, Korpi ER. Effects of acute lysergic acid diethylamide on intermittent ethanol and sucrose drinking and intracranial self-stimulation in C57BL/6 mice. J Psychopharmacol 2022; 36:860-874. [PMID: 35695174 PMCID: PMC9247434 DOI: 10.1177/02698811221104641] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Psychedelics, like lysergic acid diethylamide (LSD), are again being studied as potential therapies for many neuropsychiatric disorders, including addictions. At the same time, the acute effects of psychedelics on rewarding behaviours have been scarcely studied. AIMS The current study aimed to clarify if LSD decreases binge-like ethanol drinking in mice, and whether the observed acute effects on ethanol consumption are generalizable to a natural reinforcer, sucrose, and if the effects resulted from aversive or reward-attenuating effects caused by LSD. METHODS The effects of acute LSD were examined using 2-bottle choice intermittent ethanol (20%) and sucrose drinking (10%), discrete-trial current-intensity threshold method of intracranial self-stimulation and short-term feeding behaviour assay in C57BL/6 male mice. RESULTS The results showed that acute 0.1 mg/kg, but not 0.05 mg/kg, dose (i.p.) of LSD reduced 2-h intermittent ethanol drinking transiently without any prolonged effects. No effects were seen in intermittent 2-h sucrose drinking. The tested LSD doses had neither effect on the intracranial self-stimulation current-intensity thresholds, nor did LSD affect the threshold-lowering, or rewarding, effects of simultaneous amphetamine treatment. Furthermore, LSD had small, acute diminishing effects on 2-h food and water intake. CONCLUSIONS Based on these results, LSD decreases binge-like ethanol drinking in mice, but only acutely. This effect is not likely to stem from reward-attenuating effects but could be in part due to reduced consummatory behaviour.
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Affiliation(s)
- Lauri V Elsilä
- Lauri V Elsilä, Department of
Pharmacology, Faculty of Medicine, University of Helsinki, P.O. Box 63
(Haartmaninkatu 8), Biomedicum Helsinki, Helsinki FI-00014, Finland.
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Jaster AM, Elder H, Marsh SA, de la Fuente Revenga M, Negus SS, González-Maeso J. Effects of the 5-HT 2A receptor antagonist volinanserin on head-twitch response and intracranial self-stimulation depression induced by different structural classes of psychedelics in rodents. Psychopharmacology (Berl) 2022; 239:1665-1677. [PMID: 35233648 PMCID: PMC10055857 DOI: 10.1007/s00213-022-06092-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 02/13/2022] [Indexed: 01/26/2023]
Abstract
BACKGROUND Clinical studies suggest that psychedelics exert robust therapeutic benefits in a number of psychiatric conditions including substance use disorder. Preclinical studies focused on safety and efficacy of these compounds are necessary to determine the full range of psychedelics' effects. OBJECTIVES The present study explores the behavioral pharmacology of structurally distinct psychedelics in paradigms associated with serotonin 2A receptor (5-HT2AR) activation and behavioral disruption in two rodent models. Utilizing the selective 5-HT2AR antagonist volinanserin, we aimed to provide further pharmacological assessment of psychedelic effects in rodents. METHODS We compared volinanserin (0.0001-0.1 mg/kg) antagonism of the phenethylamine 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI, 1.0 mg/kg) and the ergoline lysergic acid diethylamide (LSD, 0.32 mg/kg) in preclinical assays predictive of hallucinations (head-twitch response or HTR in mice) and behavioral disruption (intracranial self-stimulation or ICSS in rats). Volinanserin antagonism of the phenethylamine mescaline, the tryptamine psilocybin, and the k-opioid receptor agonist salvinorin A was also evaluated in the rat ICSS assay. RESULTS Volinanserin had similar potency, effectiveness, and time-course to attenuate DOI-induced HTR in mice and ICSS depression in rats. Volinanserin completely blocked LSD-induced HTR in mice, but not LSD-induced ICSS depression in rats. Volinanserin also reversed ICSS depression by mescaline, but it was only partially effective to reduce the effects of psilocybin, and it exacerbated ICSS depression by salvinorin A. CONCLUSION Although hallucination-related HTR behavior induced by phenethylamine, ergoline, and tryptamine psychedelics appears to be 5-HT2AR-mediated, the receptor(s) responsible for behavioral disruptive effects may differ among these three structural classes.
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Affiliation(s)
- Alaina M Jaster
- Department of Physiology & Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Harrison Elder
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Samuel A Marsh
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Mario de la Fuente Revenga
- Department of Physiology & Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
- Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - S Stevens Negus
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
| | - Javier González-Maeso
- Department of Physiology & Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
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Psychedelics: Old trips, new destinations in psychopharmacology research. Psychopharmacology (Berl) 2022. [PMID: 35460341 DOI: 10.1007/s00213-022-06152-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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