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Glennon RA, Dukat M. 1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane (DOI): From an Obscure to Pivotal Member of the DOX Family of Serotonergic Psychedelic Agents - A Review. ACS Pharmacol Transl Sci 2024; 7:1722-1745. [PMID: 38898956 PMCID: PMC11184610 DOI: 10.1021/acsptsci.4c00157] [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: 03/19/2024] [Revised: 04/25/2024] [Accepted: 04/30/2024] [Indexed: 06/21/2024]
Abstract
1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane (DOI, or DOX where X = -I) was first synthesized in 1973 in a structure-activity study to explore the effect of various aryl substituents on the then newly identified, and subsequently controlled, hallucinogenic agent 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM, or DOX where X = -CH3). Over time, DOI was found to be a serotonin (5-HT) receptor agonist using various peripheral 5-HT receptor tissue assays and later, following the identification of multiple families of central 5-HT receptors, an agonist at 5-HT2 serotonin receptors in rat and, then, human brain. Today, classical hallucinogens, currently referred to as serotonergic psychedelic agents, are receiving considerable attention for their potential therapeutic application in various neuropsychiatric disorders including treatment-resistant depression. Here, we review, for the first time, the historical and current developments that led to DOI becoming a unique, perhaps a landmark, agent in 5-HT2 receptor research.
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Affiliation(s)
- Richard A. Glennon
- Department of Medicinal Chemistry
School of Pharmacy, Virginia Commonwealth
University, Richmond, Virginia 23298, United States
| | - Małgorzata Dukat
- Department of Medicinal Chemistry
School of Pharmacy, Virginia Commonwealth
University, Richmond, Virginia 23298, United States
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2
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Inserra A, Piot A, De Gregorio D, Gobbi G. Lysergic Acid Diethylamide (LSD) for the Treatment of Anxiety Disorders: Preclinical and Clinical Evidence. CNS Drugs 2023; 37:733-754. [PMID: 37603260 DOI: 10.1007/s40263-023-01008-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/19/2023] [Indexed: 08/22/2023]
Abstract
Anxiety disorders (ADs) represent the sixth leading cause of disability worldwide, resulting in a significant global economic burden. Over 50% of individuals with ADs do not respond to standard therapies, making the identification of more effective anxiolytic drugs an ongoing research priority. In this work, we review the preclinical literature concerning the effects of lysergic acid diethylamide (LSD) on anxiety-like behaviors in preclinical models, and the clinical literature on anxiolytic effects of LSD in healthy volunteers and patients with ADs. Preclinical and clinical findings show that even if LSD may exacerbate anxiety acutely (both in "microdoses" and "full doses"), it induces long-lasting anxiolytic effects. Only two randomized controlled trials combining LSD and psychotherapy have been performed in patients with ADs with and without life-threatening conditions, showing a good safety profile and persisting decreases in anxiety outcomes. The effect of LSD on anxiety may be mediated by serotonin receptors (5-HT1A/1B, 5-HT2A/2C, and 5-HT7) and/or transporter in brain networks and circuits (default mode network, cortico-striato-thalamo-cortical circuit, and prefrontal cortex-amygdala circuit), involved in the modulation of anxiety. It remains unclear whether LSD can be an efficacious treatment alone or only when combined with psychotherapy, and if "microdosing" may elicit the same sustained anxiolytic effects as the "full doses". Further randomized controlled trials with larger sample size cohorts of patients with ADs are required to clearly define the effective regimens, safety profile, efficacy, and feasibility of LSD for the treatment of ADs.
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Affiliation(s)
- Antonio Inserra
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Avenue des Pins Ouest, Montreal, QC, H3A 1A1, Canada
| | - Alexandre Piot
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Danilo De Gregorio
- Division of Neuroscience, Vita-Salute San Raffaele University, Milan, Italy
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Avenue des Pins Ouest, Montreal, QC, H3A 1A1, Canada.
- McGill University Health Center, Montreal, QC, Canada.
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3
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De Gregorio D, Popic J, Enns JP, Inserra A, Skalecka A, Markopoulos A, Posa L, Lopez-Canul M, Qianzi H, Lafferty CK, Britt JP, Comai S, Aguilar-Valles A, Sonenberg N, Gobbi G. Lysergic acid diethylamide (LSD) promotes social behavior through mTORC1 in the excitatory neurotransmission. Proc Natl Acad Sci U S A 2021; 118:e2020705118. [PMID: 33495318 PMCID: PMC7865169 DOI: 10.1073/pnas.2020705118] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Clinical studies have reported that the psychedelic lysergic acid diethylamide (LSD) enhances empathy and social behavior (SB) in humans, but its mechanism of action remains elusive. Using a multidisciplinary approach including in vivo electrophysiology, optogenetics, behavioral paradigms, and molecular biology, the effects of LSD on SB and glutamatergic neurotransmission in the medial prefrontal cortex (mPFC) were studied in male mice. Acute LSD (30 μg/kg) injection failed to increase SB. However, repeated LSD (30 μg/kg, once a day, for 7 days) administration promotes SB, without eliciting antidepressant/anxiolytic-like effects. Optogenetic inhibition of mPFC excitatory neurons dramatically inhibits social interaction and nullifies the prosocial effect of LSD. LSD potentiates the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and 5-HT2A, but not N-methyl-D-aspartate (NMDA) and 5-HT1A, synaptic responses in the mPFC and increases the phosphorylation of the serine-threonine protein kinases Akt and mTOR. In conditional knockout mice lacking Raptor (one of the structural components of the mTORC1 complex) in excitatory glutamatergic neurons (Raptorf/f:Camk2alpha-Cre), the prosocial effects of LSD and the potentiation of 5-HT2A/AMPA synaptic responses were nullified, demonstrating that LSD requires the integrity of mTORC1 in excitatory neurons to promote SB. Conversely, in knockout mice lacking Raptor in GABAergic neurons of the mPFC (Raptorf/f:Gad2-Cre), LSD promotes SB. These results indicate that LSD selectively enhances SB by potentiating mPFC excitatory transmission through 5-HT2A/AMPA receptors and mTOR signaling. The activation of 5-HT2A/AMPA/mTORC1 in the mPFC by psychedelic drugs should be explored for the treatment of mental diseases with SB impairments such as autism spectrum disorder and social anxiety disorder.
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Affiliation(s)
- Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1;
- Department of Biochemistry, McGill University, Montreal, QC, Canada, H3A 1A3
| | - Jelena Popic
- Department of Biochemistry, McGill University, Montreal, QC, Canada, H3A 1A3
| | - Justine P Enns
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1
| | - Antonio Inserra
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1
| | - Agnieszka Skalecka
- Department of Biochemistry, McGill University, Montreal, QC, Canada, H3A 1A3
| | - Athanasios Markopoulos
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1
| | - Luca Posa
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1
| | - Martha Lopez-Canul
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1
| | - He Qianzi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1
| | | | - Jonathan P Britt
- Department of Psychology, McGill University, Montreal, QC, Canada, H3A 1B1
| | - Stefano Comai
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1
- Division of Neuroscience, Vita Salute San Raffaele University, 20132 Milan, Italy
| | | | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC, Canada, H3A 1A3;
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada, H3A 1A1;
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada, K1S 5B6
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4
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Sherwood AM, Claveau R, Lancelotta R, Kaylo KW, Lenoch K. Synthesis and Characterization of 5-MeO-DMT Succinate for Clinical Use. ACS OMEGA 2020; 5:32067-32075. [PMID: 33344861 PMCID: PMC7745443 DOI: 10.1021/acsomega.0c05099] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/16/2020] [Indexed: 05/03/2023]
Abstract
To support clinical use, a multigram-scale process has been developed to provide 5-MeO-DMT, a psychedelic natural product found in the parotid gland secretions of the toad, Incilius alvarius. Several synthetic routes were initially explored, and the selected process featured an optimized Fischer indole reaction to 5-MeO-DMT freebase in high-yield, from which the 1:1 succinate salt was produced to provide 136 g of crystalline active pharmaceutical ingredient (API) with 99.86% peak area by high-performance liquid chromatography (HPLC) and a net yield of 49%. The report provides in-process monitoring, validated analytical methods, impurity formation and removal, and solid-state characterization of the API essential for subsequent clinical development.
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Affiliation(s)
| | - Romain Claveau
- Almac
Sciences, 20 Seagoe Industrial Estate, Craigavon BT63 5QD, United Kingdom
| | - Rafael Lancelotta
- Habituating
to Wholeness, 6500 W
13th Avenue, Lakewood, Colorado 80214, United States
| | - Kristi W. Kaylo
- Usona
Institute, 2800 Woods
Hollow Road, Madison, Wisconsin 53711, United States
| | - Kelsey Lenoch
- Usona
Institute, 2800 Woods
Hollow Road, Madison, Wisconsin 53711, United States
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Schindler EAD, Wallace RM, Sloshower JA, D'Souza DC. Neuroendocrine Associations Underlying the Persistent Therapeutic Effects of Classic Serotonergic Psychedelics. Front Pharmacol 2018; 9:177. [PMID: 29545753 PMCID: PMC5838010 DOI: 10.3389/fphar.2018.00177] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 02/16/2018] [Indexed: 12/12/2022] Open
Abstract
Recent reports on the effects of psychedelic-assisted therapies for mood disorders and addiction, as well as the effects of psychedelics in the treatment of cluster headache, have demonstrated promising therapeutic results. In addition, the beneficial effects appear to persist well after limited exposure to the drugs, making them particularly appealing as treatments for chronic neuropsychiatric and headache disorders. Understanding the basis of the long-lasting effects, however, will be critical for the continued use and development of this drug class. Several mechanisms, including biological and psychological ones, have been suggested to explain the long-lasting effects of psychedelics. Actions on the neuroendocrine system are some such mechanisms that warrant further investigation in the study of persisting psychedelic effects. In this report, we review certain structural and functional neuroendocrinological pathologies associated with neuropsychiatric disorders and cluster headache. We then review the effects that psychedelic drugs have on those systems and provide preliminary support for potential long-term effects. The circadian biology of cluster headache is of particular relevance in this area. We also discuss methodologic considerations for future investigations of neuroendocrine system involvement in the therapeutic benefits of psychedelic drugs.
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Affiliation(s)
- Emmanuelle A D Schindler
- Department of Neurology, Yale School of Medicine, New Haven, CT, United States.,Department of Neurology, VA Connecticut Healthcare System, West Haven, CT, United States
| | - Ryan M Wallace
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States
| | - Jordan A Sloshower
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States.,Department of Psychiatry, VA Connecticut Healthcare System, West Haven, CT, United States
| | - Deepak C D'Souza
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States.,Department of Psychiatry, VA Connecticut Healthcare System, West Haven, CT, United States
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6
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Abstract
Because of the ethical and regulatory hurdles associated with human studies, much of what is known about the psychopharmacology of hallucinogens has been derived from animal models. However, developing reliable animal models has proven to be a challenging task due to the complexity and variability of hallucinogen effects in humans. This chapter focuses on three animal models that are frequently used to test the effects of hallucinogens on unconditioned behavior: head twitch response (HTR), prepulse inhibition of startle (PPI), and exploratory behavior. The HTR has demonstrated considerable utility in the neurochemical actions of hallucinogens. However, the latter two models have clearer conceptual bridges to human phenomenology. Consistent with the known mechanism of action of hallucinogens in humans, the behavioral effects of hallucinogens in rodents are mediated primarily by activation of 5-HT2A receptors. There is evidence, however, that other receptors may play secondary roles. The structure-activity relationships (SAR) of hallucinogens are reviewed in relation to each model, with a focus on the HTR in rats and mice.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA.
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Mark A Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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Pokorny T, Preller KH, Kraehenmann R, Vollenweider FX. Modulatory effect of the 5-HT1A agonist buspirone and the mixed non-hallucinogenic 5-HT1A/2A agonist ergotamine on psilocybin-induced psychedelic experience. Eur Neuropsychopharmacol 2016; 26:756-66. [PMID: 26875114 DOI: 10.1016/j.euroneuro.2016.01.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/08/2015] [Accepted: 01/15/2016] [Indexed: 11/18/2022]
Abstract
The mixed serotonin (5-HT) 1A/2A/2B/2C/6/7 receptor agonist psilocybin dose-dependently induces an altered state of consciousness (ASC) that is characterized by changes in sensory perception, mood, thought, and the sense of self. The psychological effects of psilocybin are primarily mediated by 5-HT2A receptor activation. However, accumulating evidence suggests that 5-HT1A or an interaction between 5-HT1A and 5-HT2A receptors may contribute to the overall effects of psilocybin. Therefore, we used a double-blind, counterbalanced, within-subject design to investigate the modulatory effects of the partial 5-HT1A agonist buspirone (20mg p.o.) and the non-hallucinogenic 5-HT2A/1A agonist ergotamine (3mg p.o.) on psilocybin-induced (170 µg/kg p.o.) psychological effects in two groups (n=19, n=17) of healthy human subjects. Psychological effects were assessed using the Altered State of Consciousness (5D-ASC) rating scale. Buspirone significantly reduced the 5D-ASC main scale score for Visionary Restructuralization (VR) (p<0.001), which was mostly driven by a reduction of the VR item cluster scores for elementary and complex visual hallucinations. Further, buspirone also reduced the main scale score for Oceanic Boundlessness (OB) including derealisation and depersonalisation phenomena at a trend level (p=0.062), whereas ergotamine did not show any effects on the psilocybin-induced 5D-ASC main scale scores. The present finding demonstrates that buspirone exerts inhibitory effects on psilocybin-induced effects, presumably via 5-HT1A receptor activation, an interaction between 5-HT1A and 5-HT2A receptors, or both. The data suggest that the modulation of 5-HT1A receptor activity may be a useful target in the treatment of visual hallucinations in different psychiatric and neurological diseases.
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Affiliation(s)
- Thomas Pokorny
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland; Heffter Research Center Zurich, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Katrin H Preller
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland; Heffter Research Center Zurich, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Rainer Kraehenmann
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland; Heffter Research Center Zurich, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Franz X Vollenweider
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland; Heffter Research Center Zurich, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland.
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8
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Eshleman AJ, Forster MJ, Wolfrum KM, Johnson RA, Janowsky A, Gatch MB. Behavioral and neurochemical pharmacology of six psychoactive substituted phenethylamines: mouse locomotion, rat drug discrimination and in vitro receptor and transporter binding and function. Psychopharmacology (Berl) 2014; 231:875-88. [PMID: 24142203 PMCID: PMC3945162 DOI: 10.1007/s00213-013-3303-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 09/24/2013] [Indexed: 11/27/2022]
Abstract
RATIONALE Psychoactive-substituted phenethylamines 2,5-dimethoxy-4-chlorophenethylamine (2C-C); 2,5-dimethoxy-4-methylphenethylamine (2C-D); 2,5-dimethoxy-4-ethylphenethylamine (2C-E); 2,5-dimethoxy-4-iodophenethylamine (2C-I); 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2); and 2,5-dimethoxy-4-chloroamphetamine (DOC) are used recreationally and may have deleterious side effects. OBJECTIVES This study compares the behavioral effects and the mechanisms of action of these substituted phenethylamines with those of hallucinogens and a stimulant. METHODS The effects of these compounds on mouse locomotor activity and in rats trained to discriminate dimethyltryptamine, (-)-DOM, (+)-LSD, (±)-MDMA, and S(+)-methamphetamine were assessed. Binding and functional activity of the phenethylamines at 5-HT1A, 5-HT2A, 5-HT2C receptors and monoamine transporters were assessed using cells heterologously expressing these proteins. RESULTS The phenethylamines depressed mouse locomotor activity, although 2C-D and 2C-E stimulated activity at low doses. The phenethylamines except 2C-T-2 fully substituted for at least one hallucinogenic training compound, but none fully substituted for (+)-methamphetamine. At 5-HT1A receptors, only 2C-T-2 and 2C-I were partial-to-full very low potency agonists. In 5-HT2A arachidonic acid release assays, the phenethylamines were partial to full agonists except 2C-I which was an antagonist. All compounds were full agonists at 5-HT2A and 5-HT2C receptor inositol phosphate assays. Only 2C-I had moderate affinity for, and very low potency at, the serotonin transporter. CONCLUSIONS The discriminative stimulus effects of 2C-C, 2C-D, 2C-E, 2C-I, and DOC were similar to those of several hallucinogens, but not methamphetamine. Additionally, the substituted phenethylamines were full agonists at 5-HT2A and 5-HT2C receptors, but for 2C-T-2, this was not sufficient to produce hallucinogen-like discriminative stimulus effects. Additionally, the 5-HT2A inositol phosphate pathway may be important in 2C-I's psychoactive properties.
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Affiliation(s)
- Amy J Eshleman
- Research Service, Portland Veterans Affairs Medical Center, 3710 SW US Veterans Hospital Rd., Portland, OR, USA,
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9
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Halberstadt AL, Koedood L, Powell SB, Geyer MA. Differential contributions of serotonin receptors to the behavioral effects of indoleamine hallucinogens in mice. J Psychopharmacol 2011; 25:1548-61. [PMID: 21148021 PMCID: PMC3531560 DOI: 10.1177/0269881110388326] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Psilocin (4-hydroxy-N,N-dimethyltryptamine) is a hallucinogen that acts as an agonist at 5-HT(1A), 5-HT(2A), and 5-HT(2C) receptors. Psilocin is the active metabolite of psilocybin, a hallucinogen that is currently being investigated clinically as a potential therapeutic agent. In the present investigation, we used a combination of genetic and pharmacological approaches to identify the serotonin (5-HT) receptor subtypes responsible for mediating the effects of psilocin on head twitch response (HTR) and the behavioral pattern monitor (BPM) in C57BL/6J mice. We also compared the effects of psilocin with those of the putative 5-HT(2C) receptor-selective agonist 1-methylpsilocin and the hallucinogen and non-selective serotonin receptor agonist 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). Psilocin, 1-methylpsilocin, and 5-MeO-DMT induced the HTR, effects that were absent in mice lacking the 5-HT(2A) receptor gene. When tested in the BPM, psilocin decreased locomotor activity, holepoking, and time spent in the center of the chamber, effects that were blocked by the selective 5-HT(1A) antagonist WAY-100635 but were not altered by the selective 5-HT(2C) antagonist SB 242,084 or by 5-HT(2A) receptor gene deletion. 5-MeO-DMT produced similar effects when tested in the BPM, and the action of 5-MeO-DMT was significantly attenuated by WAY-100635. Psilocin and 5-MeO-DMT also decreased the linearity of locomotor paths, effects that were mediated by 5-HT(2C) and 5-HT(1A) receptors, respectively. In contrast to psilocin and 5-MeO-DMT, 1-methylpsilocin (0.6-9.6 mg/kg) was completely inactive in the BPM. These findings confirm that psilocin acts as an agonist at 5-HT(1A), 5-HT(2A), and 5-HT(2C) receptors in mice, whereas the behavioral effects of 1-methylpsilocin indicate that this compound is acting at 5-HT(2A) sites but is inactive at the 5-HT(1A) receptor. The fact that 1-methylpsilocin displays greater pharmacological selectivity than psilocin indicates that 1-methylpsilocin represents a potentially useful alternative to psilocybin for development as a potential therapeutic agent.
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Affiliation(s)
| | - Liselore Koedood
- Department of Psychiatry, University of California, La Jolla, CA, USA
| | - Susan B Powell
- Department of Psychiatry, University of California, La Jolla, CA, USA
| | - Mark A Geyer
- Department of Psychiatry, University of California, La Jolla, CA, USA
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10
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Halberstadt AL, Geyer MA. Multiple receptors contribute to the behavioral effects of indoleamine hallucinogens. Neuropharmacology 2011; 61:364-81. [PMID: 21256140 PMCID: PMC3110631 DOI: 10.1016/j.neuropharm.2011.01.017] [Citation(s) in RCA: 236] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Revised: 12/03/2010] [Accepted: 01/10/2011] [Indexed: 10/18/2022]
Abstract
Serotonergic hallucinogens produce profound changes in perception, mood, and cognition. These drugs include phenylalkylamines such as mescaline and 2,5-dimethoxy-4-methylamphetamine (DOM), and indoleamines such as (+)-lysergic acid diethylamide (LSD) and psilocybin. Despite their differences in chemical structure, the two classes of hallucinogens produce remarkably similar subjective effects in humans, and induce cross-tolerance. The phenylalkylamine hallucinogens are selective 5-HT(2) receptor agonists, whereas the indoleamines are relatively non-selective for serotonin (5-HT) receptors. There is extensive evidence, from both animal and human studies, that the characteristic effects of hallucinogens are mediated by interactions with the 5-HT(2A) receptor. Nevertheless, there is also evidence that interactions with other receptor sites contribute to the psychopharmacological and behavioral effects of the indoleamine hallucinogens. This article reviews the evidence demonstrating that the effects of indoleamine hallucinogens in a variety of animal behavioral paradigms are mediated by both 5-HT(2) and non-5-HT(2) receptors.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States.
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11
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12
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Krebs-Thomson K, Ruiz EM, Masten V, Buell M, Geyer MA. The roles of 5-HT1A and 5-HT2 receptors in the effects of 5-MeO-DMT on locomotor activity and prepulse inhibition in rats. Psychopharmacology (Berl) 2006; 189:319-29. [PMID: 17013638 DOI: 10.1007/s00213-006-0566-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Accepted: 08/13/2006] [Indexed: 12/01/2022]
Abstract
RATIONALE The hallucinogen 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is structurally similar to other indoleamine hallucinogens such as LSD. The present study examined the effects of 5-MeO-DMT in rats using the Behavioral Pattern Monitor (BPM), which enables analyses of patterns of locomotor activity and exploration, and the prepulse inhibition of startle (PPI) paradigm. OBJECTIVES A series of interaction studies using the serotonin (5-HT)(1A) antagonist WAY-100635 (1.0 mg/kg), the 5-HT(2A) antagonist M100907 (1.0 mg/kg), and the 5-HT(2C) antagonist SER-082 (0.5 mg/kg) were performed to assess the respective contributions of these receptors to the behavioral effects of 5-MeO-DMT (0.01, 0.1, and 1.0 mg/kg) in the BPM and PPI paradigms. RESULTS 5-MeO-DMT decreased locomotor activity, investigatory behavior, the time spent in the center of the BPM chamber, and disrupted PPI. All of these effects were antagonized by WAY-100635 pretreatment. M100907 pretreatment failed to attenuate any of these effects, while SER-082 pretreatment only antagonized the PPI disruption produced by 5-MeO-DMT. CONCLUSIONS While the prevailing view was that the activation of 5-HT(2) receptors is solely responsible for hallucinogenic drug effects, these results support a role for 5-HT(1A) receptors in the effects of the indoleamine hallucinogen 5-MeO-DMT on locomotor activity and PPI in rats.
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Affiliation(s)
- Kirsten Krebs-Thomson
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0804, USA
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13
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Koskinen T, Haapalinna A, Sirviö J. Alpha-adrenoceptor-mediated modulation of 5-HT2 receptor agonist induced impulsive responding in a 5-choice serial reaction time task. PHARMACOLOGY & TOXICOLOGY 2003; 92:214-25. [PMID: 12753409 DOI: 10.1034/j.1600-0773.2003.920504.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The activation of 5-HT2A receptors has been shown to enhance the probability of premature responding, regarded as a form of motor impulsive behaviour. At the behavioural level, the interaction of alpha-adrenoceptors and 5-HT2 receptors has been linked to head twitch behaviour, regarded as an experimental model of compulsive behaviour. The aim was to determine whether the probability of premature responding induced by an excess activation of 5-HT2A receptors can be modulated by the blockade of alpha1- or alpha2- adrenoceptors. In the experiments, the 5-choice serial reaction time task was used to measure attention and response control of the rats. The experiments assessed the effects of (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI) 0.1-0.2 mg/kg subcutaneously, a 5-HT2A/2C agonist, and prazosin, an alpha1-adrenoceptor antagonist, alone or in combination, on the performance of rats. In an additional experiment to examine the possible role of the alpha2-adrenoceptors, a potent, selective and specific alpha2-adrenoceptor antagonist, atipamezole, was given alone or in combination with DOI. Results showed that DOI increased the probability of premature responses, but it did not affect the choice accuracy. Prazosin (0.1 or 0.3 mg/kg, subcutaneously), given on its own had no effects on probability of responding prematurely, but prazosin (0.3 mg/kg.) was able to attenuate the DOI-induced responding. Atipamezole (0.1 mg/kg, s.c.) did not attenuate the effect of DOI on probability of premature responding. When given at lower doses, DOI (0.03 mg/kg) and atipamezole (0.03 mg/kg) synergistically increased the probability of premature responding, whereas a higher dose of atipamezole (0.3 mg/kg) on its own increased the probability of responding prematurely, but this effect was not additive to that of 0.1 mg/kg DOI. These data indicate that 5-HT2 receptor activation enhances impulsive responding and this effect can be diminished by the blockade of alpha1-adrenoceptors. Atipamezole, an alpha2-antagonist, enhances the probability of premature responding and shares the mechanism of action with the 5-HT2 agonist in this respect. These results provide evidence for an interaction between the serotonergic 5-HT2 receptors and alpha-adrenoceptors in the modulation of response control to the motor impulsivity type of behaviour (premature responding) in addition to that of compulsory behaviour (head shakes) found previously.
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MESH Headings
- Adrenergic alpha-Antagonists/pharmacology
- Animals
- Behavior, Animal/drug effects
- Discrimination, Psychological/drug effects
- Dose-Response Relationship, Drug
- Drug Synergism
- Imidazoles/pharmacology
- Impulsive Behavior/psychology
- Indophenol/administration & dosage
- Indophenol/analogs & derivatives
- Indophenol/pharmacology
- Male
- Prazosin/pharmacology
- Rats
- Rats, Wistar
- Receptor, Serotonin, 5-HT2A
- Receptor, Serotonin, 5-HT2C
- Receptors, Adrenergic, alpha/drug effects
- Receptors, Adrenergic, alpha/physiology
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/physiology
- Serial Learning/drug effects
- Serotonin Receptor Agonists/pharmacology
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Affiliation(s)
- Tiina Koskinen
- A I Virtanen Institute, University of Kuopio, Kuopio, Finland
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14
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Nichols CD, Garcia EE, Sanders-Bush E. Dynamic changes in prefrontal cortex gene expression following lysergic acid diethylamide administration. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2003; 111:182-8. [PMID: 12654518 DOI: 10.1016/s0169-328x(03)00029-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lysergic acid diethylamide (LSD) is a psychoactive drug that transiently alters human perception, behavior, and mood at extremely low doses. Certain aspects of the behavior elicited by acute doses of LSD closely resemble symptoms of mental disorders such as schizophrenia. Characterizing gene expression profiles after LSD will be important for understanding how it alters behavior, and will lead to novel insights into disorders, such as schizophrenia, whose behavioral symptoms resemble the temporary effects of hallucinogenic drugs. We previously identified a small collection of genes within the rat prefrontal cortex that respond to LSD. Many of the products of these genes are involved in the process of synaptic plasticity. In the current report, we present a detailed analysis of the expression of these genes within the brain using RNase protection analysis. We find that the gene response to LSD is quite dynamic. The expression of some genes increases rapidly and decreases rapidly, while other genes change more gradually. Dose-response studies show two classes of expression; gene expression maximally stimulated at lower doses, versus gene expression that continues to rise at the higher doses. The role of the 5-HT(1A) and 5-HT(2A) receptor in mediating the increases in gene expression was examined in a series of experiments using receptor specific antagonists. Most expression increases were due to activation of the 5-HT(2A) receptor, however expression of two genes had neither a 5-HT(1A) nor a 5-HT(2A) receptor component.
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MESH Headings
- Animals
- Carrier Proteins/genetics
- Dose-Response Relationship, Drug
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Genes, Immediate-Early/drug effects
- Genes, Immediate-Early/genetics
- Hallucinogens/pharmacology
- Homer Scaffolding Proteins
- Lysergic Acid Diethylamide/pharmacology
- Male
- NF-kappa B/genetics
- Nerve Tissue Proteins/genetics
- Neuronal Plasticity/drug effects
- Neuronal Plasticity/genetics
- Neurons/drug effects
- Neurons/metabolism
- Neuropeptides/genetics
- Prefrontal Cortex/drug effects
- Prefrontal Cortex/metabolism
- RNA/metabolism
- Rats
- Rats, Sprague-Dawley
- Reaction Time/drug effects
- Reaction Time/genetics
- Receptor, Serotonin, 5-HT2A
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/genetics
- Receptors, Serotonin/metabolism
- Receptors, Serotonin, 5-HT1
- Schizophrenia/genetics
- Schizophrenia/metabolism
- Schizophrenia/physiopathology
- Serotonin/metabolism
- Serotonin Antagonists/pharmacology
- Synaptic Transmission/drug effects
- Synaptic Transmission/genetics
- Transcription Factor RelA
- Up-Regulation/drug effects
- Up-Regulation/genetics
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Affiliation(s)
- Charles D Nichols
- Department of Pharmacology, Vanderbilt University School of Medicine, 8148 Medical Research Building Three, Nashville, TN 37232-8548, USA.
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15
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Knapp DJ, Sim-Selley LJ, Breese GR, Overstreet DH. Selective breeding of 5-HT(1A) receptor-mediated responses: application to emotion and receptor action. Pharmacol Biochem Behav 2000; 67:701-8. [PMID: 11166060 DOI: 10.1016/s0091-3057(00)00415-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rat lines that were selectively bred for high (high DPAT-sensitive, HDS) or low (low DPAT-sensitive, LDS) hypothermic responses to the specific 5-HT(1A) receptor agonist, 8-hydroxy-di-n-propylaminotetralin (8-OH-DPAT), differ in receptor binding and certain behaviors related to anxiety and depression. After reviewing this literature, the present communication summarizes new experiments designed to clarify and extend the nature of the pharmacological and biochemical differences between the lines. A challenge with the 5-HT(2) receptor agonist, DOI, produced similar degrees of head shakes and skin crawls in the HDS and LDS rats, suggesting similar sensitivity of 5-HT(2A) and 5-HT(2C) receptors. In contrast, DOI-induced flat body posture (FBP), which has been linked to 5-HT(1A) receptor stimulation, was observed more readily in the HDS rats. The HDS and LDS rats exhibited similar degrees of increase in 8-OH-DPAT-stimulated [35S]GTPgammaS binding in several brain regions. This result suggests that the dramatic differences in hypothermia in HDS and LDS rats cannot be related to 5-HT(1A) receptor-mediated action on G proteins. Overall, these findings indicate that the selective breeding for 5-HT(1A)-mediated hypothermia has been fairly selective, and that differences in emotionally relevant behaviors between these two rat lines can strongly be associated with an unidentified component of the 5-HT(1A) receptor signaling pathway.
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Affiliation(s)
- D J Knapp
- Bowles Center for Alcohol Studies and Department of Psychiatry, CB 7178, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
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16
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Abstract
We collected and reviewed studies in which neuropsychological tests were administered to users of LSD or other hallucinogens. Interpretation of the studies is limited by various confounding variables, such as subjects' premorbid cognitive and personality function and prior use of other substances. At present, the literature tentatively suggests that there are few, if any, long-term neuropsychological deficits attributable to hallucinogen use. To better resolve this issue, however, it will be important to study larger samples of chronic, frequent hallucinogen users who have not often used other types of drugs.
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Affiliation(s)
- J H Halpern
- Alcohol and Drug Abuse Research Center, McLean Hospital, Belmont, MA 02478, USA.
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17
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Roth BL, Willins DL, Kroeze WK. G protein-coupled receptor (GPCR) trafficking in the central nervous system: relevance for drugs of abuse. Drug Alcohol Depend 1998; 51:73-85. [PMID: 9716931 DOI: 10.1016/s0376-8716(98)00067-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- B L Roth
- Department of Psychiatry, Case Western Reserve University School of Medicine, Cleveland, OH 44106-4935, USA.
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18
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Knapp DJ, Overstreet DH, Crews FT. Brain 5-HT1A receptor autoradiography and hypothermic responses in rats bred for differences in 8-OH-DPAT sensitivity. Brain Res 1998; 782:1-10. [PMID: 9519243 DOI: 10.1016/s0006-8993(97)01127-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Three rat lines were selectively bred for high (HDS), random (RDS), or low (LDS) hypothermic responses to the specific 5-HT1A receptor agonist 8-OH-DPAT. Forty-five minutes after 8-OH-DPAT administration (0.5 mg/kg), body temperatures dropped 3-5 degrees C in HDS rats, yet this dose produced only about 1.2 degrees C and 0.7 degree C drops in RDS and LDS rats, respectively. To investigate the relationship of body temperature of 5-HT1A receptor binding sites, autoradiographic analyses of [3H]8-OH-DPAT binding to 5-HT1A receptors in brains of these rats were conducted. Significant differences in binding were found in specific limbic cortical projection sites, with the HDS line having the greatest density of sites. Body temperature responses correlated significantly with [3H]8-OH-DPAT receptor binding in only a few areas of frontal cortex. Binding in many other brain regions, including the anterior and posterior hypothalami (regions long associated with body temperature regulation) and the raphe showed no significant differences among the lines. [3H]Ketanserin binding to cortical 5-HT2 receptors did not differ among the lines, except in the cingulate and superficial frontal cortices where HDS exhibited higher binding. These data suggest that differences in 5-HT1A receptor number may contribute to the exaggerated hypothermic response to 8-OH-DPAT in HDS rats. These studies also suggest that genetic regulation of receptor density may be brain region specific which should encourage future studies of the mechanisms of 5-HT1A receptor activity in brain and the action of drugs affecting this receptor.
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Affiliation(s)
- D J Knapp
- Skipper Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7178, USA.
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19
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Frederick DL, Gillam MP, Lensing S, Paule MG. Acute effects of LSD on rhesus monkey operant test battery performance. Pharmacol Biochem Behav 1997; 57:633-41. [PMID: 9258988 DOI: 10.1016/s0091-3057(96)00469-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The acute effects of LSD were assessed in rhesus macaques using behavior in several complex tasks designed to model aspects of time estimation, short-term memory and attention, motivation, learning, and color and position discrimination. The end points monitored included percent task completed, response rate, and accuracy. LSD (0.0003-0.03 mg/kg intravenously) significantly decreased percent task completed and accuracy in the time estimation task at doses < or = 0.003 mg/kg, but did not significantly affect response rate in this task at any dose tested. Accuracy in the short-term memory task was significantly decreased at the highest dose tested (0.03 mg/kg), but no other end points were affected in this task. Response rate was decreased in both the motivation and learning tasks at doses (0.01 and 0.003 mg/kg, respectively) lower than those affecting other end points. In the color and position discrimination task, only response rate was affected (0.01 and 0.03 mg/kg). These data demonstrate that in rhesus monkeys, performance of tasks believed to depend on aspects of time estimation and motivation are more sensitive to the acute disruptive effects of LSD than are tasks thought to model learning, short-term memory, and color and position discrimination.
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Affiliation(s)
- D L Frederick
- Division of Neurotoxicology, National Center for Toxicological Research/FDA, Jefferson, AR 72079-9502, USA.
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20
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Antkiewicz-Michaluk L, Románska I, Vetulani J. Ca2+ channel blockade prevents lysergic acid diethylamide-induced changes in dopamine and serotonin metabolism. Eur J Pharmacol 1997; 332:9-14. [PMID: 9298920 DOI: 10.1016/s0014-2999(97)01025-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To investigate the effect of a single and multiple administration of lysergic acid diethylamide (LSD) on cerebral metabolism of dopamine and serotonin, male Wistar rats were treated with low and high doses (0.1 and 2.0 mg/kg i.p.) of LSD and the levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, 3-methoxytyramine, serotonin and 5-hydroxyindoleacetic acid were assayed by HPLC in the nucleus accumbens, striatum and frontal cortex. Some rats received nifedipine, 5 mg/kg i.p., before each injection of LSD to assess the effect of a Ca2+ channel blockade. High-dose LSD treatment (8 x 2 mg/kg per day) caused a strong stimulation of dopamine metabolism in the nucleus accumbens and striatum, and serotonin metabolism in the nucleus accumbens: the changes were observed 24 (but not 1 h) after the last dose. The changes induced by the low-dose treatment (8 x 0.1 mg/kg per day) had a different pattern, suggesting the release of dopamine from vesicles to cytoplasm. Co-administration of nifedipine completely prevented the LSD-induced biochemical changes. The results suggest that Ca2+ channel blocking agents may prevent development of some behavioral consequences of chronically used LSD.
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21
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Strassman RJ, Qualls CR, Berg LM. Differential tolerance to biological and subjective effects of four closely spaced doses of N,N-dimethyltryptamine in humans. Biol Psychiatry 1996; 39:784-95. [PMID: 8731519 DOI: 10.1016/0006-3223(95)00200-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Tolerance of the behavioral effects of the short-acting, endogenous hallucinogen, N,N-dimethyltryptamine (DMT) is seen inconsistently in animals, and has not been produced in humans. The nature and time course of responses to repetitive, closely spaced administrations of an hallucinogenic dose of DMT were characterized. Thirteen experienced hallucinogen users received intravenous 0.3 mg/kg DMT fumarate, or saline placebo, four times, at 30 min intervals, on 2 separate days, in a randomized, double-blind, design. Tolerance to "psychedelic" subjective effects did not occur according to either clinical interview or Hallucinogen Rating Scale scores. Adrenocorticotropic hormone (ACTH), prolactin, cortisol, and heart rate responses decreased with repeated DMT administration, although blood pressure did not. These data demonstrate the unique properties of DMT relative to other hallucinogens and underscore the differential regulation of the multiple processes mediating the effects of DMT.
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Affiliation(s)
- R J Strassman
- Department of Psychiatry, School of Medicine, University of New Mexico, Albuquerque, USA
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22
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Abstract
Changes in motor activity have long been used to characterize the effects of serotonergic manipulations. The prevailing view has been that serotonin typically inhibits motor output, often in reciprocity with catecholaminergic systems. Recent findings, however, indicate that the release of presynaptic serotonin by indirect agonists leads to a profound locomotor activation. Studies were performed in a behavioral pattern monitor (BPM). The BPM is an automated holeboard/activity apparatus measuring 30.5 x 61 cm, that allows detailed sequential analyses of both locomotor and investigatory behaviors. When tested under comparable conditions, direct agonists at both 5-HT1 and 5-HT2 receptors decrease locomotor activity in rats. With hallucinogenic 5-HT2 agonists, this effect is dependent upon the novelty of the test environment, indicating that these compounds increase the responsiveness of the animal to the threatening aspects of the novel environment. Indirect serotonin agonists, however, increase locomotor activity and decrease investigation of discrete stimuli in the environment. The activating effects of indirect agonists such as 3,4-methylenedioxy-methamphetamine (MDMA), para-chloroamphetamine (PCA), or alpha-ethyltryptamine are dependent upon the release of serotonin from presynaptic terminals and are mimicked by direct agonists at 5-HT1B receptors. Both behavioral analyses and studies with synthesis inhibitors and receptor antagonists clearly distinguish the MDMA-induced hyperactivity from that induced by amphetamine-like releasers of dopamine. Further supporting the relevance of 5-HT1B receptors to the activating effects of serotonin-releasing agents, MDMA exhibits reciprocal cross-tolerance with the 5-HT1B agonist RU 24969, but not with either 5-HT1A or 5-HT2 agonists or amphetamine. Thus, studies of locomotor and investigatory responses can be used to demonstrate and differentiate the effects of direct agonists at 5-HT1A, 5-HT1B, and 5-HT2 receptors as well as indirect serotonin agonists. The fact that the predominant effect of serotonin releasers is locomotor activation, apparently mediated via post-synaptic 5-HT1B receptors, suggests that some endogenous serotonergic systems may normally activate rather than suppress motor output.
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Affiliation(s)
- M A Geyer
- Department of Psychiatry, University of California at San Diego, La Jolla 92093-0804, USA
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