1
|
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] [MESH Headings] [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.
Collapse
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.
| |
Collapse
|
2
|
Miller VK, Broadie K. Experience-dependent serotonergic signaling in glia regulates targeted synapse elimination. PLoS Biol 2024; 22:e3002822. [PMID: 39352884 DOI: 10.1371/journal.pbio.3002822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 08/29/2024] [Indexed: 10/04/2024] Open
Abstract
The optimization of brain circuit connectivity based on initial environmental input occurs during critical periods characterized by sensory experience-dependent, temporally restricted, and transiently reversible synapse elimination. This precise, targeted synaptic pruning mechanism is mediated by glial phagocytosis. Serotonin signaling has prominent, foundational roles in the brain, but functions in glia, or in experience-dependent brain circuit synaptic connectivity remodeling, have been relatively unknown. Here, we discover that serotonergic signaling between glia is essential for olfactory experience-dependent synaptic glomerulus pruning restricted to a well-defined Drosophila critical period. We find that experience-dependent serotonin signaling is restricted to the critical period, with both (1) serotonin production and (2) 5-HT2A receptors specifically in glia, but not neurons, absolutely required for targeted synaptic glomerulus pruning. We discover that glial 5-HT2A receptor signaling limits the experience-dependent synaptic connectivity pruning in the critical period and that conditional reexpression of 5-HT2A receptors within adult glia reestablishes "critical period-like" experience-dependent synaptic glomerulus pruning at maturity. These results reveal an essential requirement for glial serotonergic signaling mediated by 5-HT2A receptors for experience-dependent synapse elimination.
Collapse
Affiliation(s)
- Vanessa Kay Miller
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, Tennessee, United States of America
| |
Collapse
|
3
|
Olson RJ, Bartlett L, Sonneborn A, Milton R, Bretton-Granatoor Z, Firdous A, Harris AZ, Abbas AI. Decoupling of cortical activity from behavioral state following administration of the classic psychedelic DOI. Neuropharmacology 2024; 257:110030. [PMID: 38851531 PMCID: PMC11260522 DOI: 10.1016/j.neuropharm.2024.110030] [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: 12/19/2023] [Revised: 05/02/2024] [Accepted: 06/04/2024] [Indexed: 06/10/2024]
Abstract
Administration or consumption of classic psychedelics (CPs) leads to profound changes in experience which are often described as highly novel and meaningful. They have shown substantial promise in treating depressive symptoms and may be therapeutic in other situations. Although research suggests that the therapeutic response is correlated with the intensity of the experience, the neural circuit basis for the alterations in experience caused by CPs requires further study. The medial prefrontal cortex (mPFC), where CPs have been shown to induce rapid, 5-HT2A receptor-dependent structural and neurophysiological changes, is believed to be a key site of action. To investigate the acute neural circuit changes induced by CPs, we recorded single neurons and local field potentials in the mPFC of freely behaving male mice after administration of the 5-HT2A/2C receptor-selective CP, 2,5-Dimethoxy-4-iodoamphetamine (DOI). We segregated recordings into active and rest periods in order to examine cortical activity during desynchronized (active) and synchronized (rest) states. We found that DOI induced a robust decrease in low frequency power when animals were at rest, attenuating the usual synchronization that occurs during less active behavioral states. DOI also increased broadband gamma power and suppressed activity in fast-spiking neurons in both active and rest periods. Together, these results suggest that the CP DOI induces persistent desynchronization in mPFC, including during rest when mPFC typically exhibits more synchronized activity. This shift in cortical dynamics may in part underlie the longer-lasting effects of CPs on plasticity, and may be critical to their therapeutic properties.
Collapse
Affiliation(s)
- Randall J Olson
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | - Lowell Bartlett
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | - Alex Sonneborn
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | - Russell Milton
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | | | - Ayesha Firdous
- Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10034, USA
| | - Alexander Z Harris
- Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10034, USA; Department of Psychiatry, Columbia University, New York, NY, 10034, USA
| | - Atheir I Abbas
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA; Department of Psychiatry, Oregon Health and Science University, Portland OR 97239, USA; VA Portland Health Care System, Portland OR, 97239, USA.
| |
Collapse
|
4
|
Miranda L. Antidepressant and anxiolytic effects of activating 5HT2A receptors in the anterior cingulate cortex and the theoretical mechanisms underlying them - A scoping review of available literature. Brain Res 2024; 1846:149226. [PMID: 39251056 DOI: 10.1016/j.brainres.2024.149226] [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: 07/15/2024] [Revised: 08/22/2024] [Accepted: 09/05/2024] [Indexed: 09/11/2024]
Abstract
Psychedelic drugs that activate the 5HT2A receptor have long been the target of extensive clinical research, particularly in models of psychiatric illness. The aim of this literature review was to investigate the therapeutic effects of 5HT2A receptor activation in the anterior cingulate cortex (ACC) and the respective mechanisms that underlie them. Based on the available research, I suggest that 5HT2A receptors in the ACC exert profound changes in excitatory neurotransmission and brain network connectivity in a way that reduces anxious preoccupation and obsessional thoughts, as well as promoting cognitive flexibility and long-lasting mood improvements in anhedonia. This is possibly due to a complex interplay with glutamate and gamma-butyric acid neurotransmission, particularly 5HT2A activation enhances α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor signalling, thus altering the ratio of AMPA to N-methyl-D-Aspartate (NMDA) activity in the ACC, which can dismantle previously established neuronal connections and aid the formation of new ones, an effect that may be beneficial for fear extinction and reversal learning. Psychedelics potentially change intra- and internetwork connectivity, strengthening connectivity from the dorsal ACC / Salience Network to the Default Mode Network (DMN) and Central Executive Network (CEN), which correlates with improvements in attentional shifting and anti-anhedonic effects. Additionally, they may decrease inhibitory influence of the DMN over the CEN which may reduce overevaluation of internal states and ameliorate cognitive deficits. Activation of ACC 5HT2A receptors also has important downstream effects on subcortical areas, including reducing amygdala reactivity to threatening stimuli and enhancing mesolimbic dopamine, respectively improving anxiety and the experience of natural rewards.
Collapse
|
5
|
Anderson TL, Keady JV, Songrady J, Tavakoli NS, Asadipooya A, Neeley RE, Turner JR, Ortinski PI. Distinct 5-HT receptor subtypes regulate claustrum excitability by serotonin and the psychedelic, DOI. Prog Neurobiol 2024; 240:102660. [PMID: 39218140 PMCID: PMC11444019 DOI: 10.1016/j.pneurobio.2024.102660] [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: 02/06/2024] [Revised: 07/03/2024] [Accepted: 08/25/2024] [Indexed: 09/04/2024]
Abstract
Recent evidence indicates that neuronal activity within the claustrum (CLA) may be central to cellular and behavioral responses to psychedelic hallucinogens. The CLA prominently innervates many cortical targets and displays exceptionally high levels of serotonin (5-HT) binding. However, the influence of serotonin receptors, prime targets of psychedelic drug action, on CLA activity remains unexplored. We characterize the CLA expression of all known 5-HT subtypes and contrast the effects of 5-HT and the psychedelic hallucinogen, 2,5-dimethoxy-4-iodoamphetamine (DOI), on excitability of cortical-projecting CLA neurons. We find that the CLA is particularly enriched with 5-HT2C receptors, expressed predominantly on glutamatergic neurons. Electrophysiological recordings from CLA neurons that project to the anterior cingulate cortex (ACC) indicate that application of 5-HT inhibits glutamate receptor-mediated excitatory postsynaptic currents (EPSCs). In contrast, application of DOI stimulates EPSCs. We find that the opposite effects of 5-HT and DOI on synaptic signaling can both be reversed by inhibition of the 5-HT2C, but not 5-HT2A, receptors. We identify specific 5-HT receptor subtypes as serotonergic regulators of the CLA excitability and argue against the canonical role of 5-HT2A in glutamatergic synapse response to psychedelics within the CLA-ACC circuit.
Collapse
Affiliation(s)
- Tanner L Anderson
- University of Kentucky, College of Medicine, Department of Neuroscience, Lexington, KY 40536, United States
| | - Jack V Keady
- University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, Lexington, KY 40536, United States
| | - Judy Songrady
- University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, Lexington, KY 40536, United States
| | - Navid S Tavakoli
- University of Kentucky, College of Medicine, Department of Neuroscience, Lexington, KY 40536, United States
| | - Artin Asadipooya
- University of Kentucky, College of Medicine, Department of Neuroscience, Lexington, KY 40536, United States
| | - Ryson E Neeley
- University of Kentucky, College of Medicine, Department of Neuroscience, Lexington, KY 40536, United States
| | - Jill R Turner
- University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, Lexington, KY 40536, United States
| | - Pavel I Ortinski
- University of Kentucky, College of Medicine, Department of Neuroscience, Lexington, KY 40536, United States.
| |
Collapse
|
6
|
Shahar O, Botvinnik A, Shwartz A, Lerer E, Golding P, Buko A, Hamid E, Kahn D, Guralnick M, Blakolmer K, Wolf G, Lotan A, Lerer L, Lerer B, Lifschytz T. Effect of chemically synthesized psilocybin and psychedelic mushroom extract on molecular and metabolic profiles in mouse brain. Mol Psychiatry 2024; 29:2059-2073. [PMID: 38378926 PMCID: PMC11408259 DOI: 10.1038/s41380-024-02477-w] [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: 07/06/2023] [Revised: 01/24/2024] [Accepted: 02/01/2024] [Indexed: 02/22/2024]
Abstract
Psilocybin, a naturally occurring, tryptamine alkaloid prodrug, is currently being investigated for the treatment of a range of psychiatric disorders. Preclinical reports suggest that the biological effects of psilocybin-containing mushroom extract or "full spectrum" (psychedelic) mushroom extract (PME), may differ from those of chemically synthesized psilocybin (PSIL). We compared the effects of PME to those of PSIL on the head twitch response (HTR), neuroplasticity-related synaptic proteins and frontal cortex metabolomic profiles in male C57Bl/6j mice. HTR measurement showed similar effects of PSIL and PME over 20 min. Brain specimens (frontal cortex, hippocampus, amygdala, striatum) were assayed for the synaptic proteins, GAP43, PSD95, synaptophysin and SV2A, using western blots. These proteins may serve as indicators of synaptic plasticity. Three days after treatment, there was minimal increase in synaptic proteins. After 11 days, PSIL and PME significantly increased GAP43 in the frontal cortex (p = 0.019; p = 0.039 respectively) and hippocampus (p = 0.015; p = 0.027) and synaptophysin in the hippocampus (p = 0.041; p = 0.05) and amygdala (p = 0.035; p = 0.004). PSIL increased SV2A in the amygdala (p = 0.036) and PME did so in the hippocampus (p = 0.014). In the striatum, synaptophysin was increased by PME only (p = 0.023). There were no significant effects of PSIL or PME on PSD95 in any brain area when these were analyzed separately. Nested analysis of variance (ANOVA) showed a significant increase in each of the 4 proteins over all brain areas for PME versus vehicle control, while significant PSIL effects were observed only in the hippocampus and amygdala and were limited to PSD95 and SV2A. Metabolomic analyses of the pre-frontal cortex were performed by untargeted polar metabolomics utilizing capillary electrophoresis - Fourier transform mass spectrometry (CE-FTMS) and showed a differential metabolic separation between PME and vehicle groups. The purines guanosine, hypoxanthine and inosine, associated with oxidative stress and energy production pathways, showed a progressive decline from VEH to PSIL to PME. In conclusion, our synaptic protein findings suggest that PME has a more potent and prolonged effect on synaptic plasticity than PSIL. Our metabolomics data support a gradient of effects from inert vehicle via chemical psilocybin to PME further supporting differential effects. Further studies are needed to confirm and extend these findings and to identify the molecules that may be responsible for the enhanced effects of PME as compared to psilocybin alone.
Collapse
Affiliation(s)
- Orr Shahar
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Alexander Botvinnik
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Amit Shwartz
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Elad Lerer
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
- Israel Institute for Biology, Nes Ziona, Israel
| | - Peretz Golding
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Alex Buko
- Human Metabolome Technologies, Boston, MA, USA
| | - Ethan Hamid
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Dani Kahn
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Miles Guralnick
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | | | - Gilly Wolf
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
- Achva Academic College, Beer Tuvia, Israel
| | - Amit Lotan
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Leonard Lerer
- Parow Entheobiosciences (ParowBio), Chicago, IL, USA
- Back of the Yards Algae Sciences (BYAS), Chicago, IL, USA
| | - Bernard Lerer
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel.
| | - Tzuri Lifschytz
- Biological Psychiatry Laboratory and Hadassah BrainLabs Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel.
| |
Collapse
|
7
|
Melo L, Beaupain MC, Ghanavati E, Kuo MF, Nitsche MA. Neurochemical mechanisms underlying serotonergic modulation of neuroplasticity in humans. Brain Stimul 2024; 17:421-430. [PMID: 38574852 DOI: 10.1016/j.brs.2024.04.001] [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: 06/06/2023] [Revised: 03/31/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND Studies in animals and humans have shown that cortical neuroplasticity can be modulated by increasing serotonin levels by administering selective serotonin reuptake inhibitors (SSRI). However, little is known about the mechanistic background, especially the contribution of intracortical inhibition and facilitation, which depend on gamma-aminobutyric acid (GABA) and glutamate. OBJECTIVE We aimed to explore the relevance of drivers of plasticity (glutamate- and GABA-dependent processes) for the effects of serotonin enhancement on tDCS-induced plasticity in healthy humans. METHODS A crossover, partially double-blinded, randomized, and sham-controlled study was conducted in 21 healthy right-handed individuals. In each of the 7 sessions, plasticity was induced via transcranial direct current stimulation (tDCS). Anodal, cathodal, and sham tDCS were applied to the left motor cortex under SSRI (20 mg/40 mg citalopram) or placebo. Short-interval cortical inhibition (SICI) and intracortical facilitation (ICF) were monitored by paired-pulse transcranial magnetic stimulation for 5-6 h after intervention. RESULTS Under placebo, anodal tDCS-induced LTP-like plasticity decreased SICI and increased ICF. In contrast, cathodal tDCS-elicited LTD-like plasticity induced the opposite effect. Under 20 mg and 40 mg citalopram, anodal tDCS did not affect SICI largely, while ICF was enhanced and prolonged. For cathodal tDCS, citalopram converted the increase of SICI and decrease of ICF into antagonistic effects, and this effect was dosage-dependent since it lasted longer under 40 mg when compared to 20 mg. CONCLUSION We speculate that the main effects of acute serotonergic enhancement on tDCS-induced plasticity, the increase and prolongation of LTP-like plasticity effects, involves mainly the glutamatergic system.
Collapse
Affiliation(s)
- Lorena Melo
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Marie C Beaupain
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany; Department of Psychology, Ruhr-University Bochum, Germany
| | - Elham Ghanavati
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany; Department of Psychology, Ruhr-University Bochum, Germany
| | - Min-Fang Kuo
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany.
| | - Michael A Nitsche
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany; Bielefeld University, University Hospital OWL, Protestant Hospital of Bethel Foundation, University Clinic of Psychiatry and Psychotherapy and University Clinic of Child and Adolescent Psychiatry and Psychotherapy, Germany; German Center for Mental Health (DZPG), Partner Site - Bochum/Marburg, Germany
| |
Collapse
|
8
|
Sekssaoui M, Bockaert J, Marin P, Bécamel C. Antidepressant-like effects of psychedelics in a chronic despair mouse model: is the 5-HT 2A receptor the unique player? Neuropsychopharmacology 2024; 49:747-756. [PMID: 38212441 PMCID: PMC10876623 DOI: 10.1038/s41386-024-01794-6] [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: 06/05/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/13/2024]
Abstract
Major depressive disorder (MDD) is one of the most disabling psychiatric disorders in the world. First-line treatments such as selective serotonin reuptake inhibitors (SSRIs) still have many limitations, including a resistance to treatment in 30% of patients and a delayed clinical benefit that is observed only after several weeks of treatment. Increasing clinical evidence indicates that the acute administration of psychedelic agonists of the serotonin 5-HT2A receptor (5-HT2AR), such as psilocybin, to patients with MDD induce fast antidepressant effects, which persist up to five weeks after the treatment. However, the involvement of the 5-HT2AR in these antidepressant effects remains controversial. Furthermore, whether the hallucinogenic properties of 5-HT2AR agonists are mandatory to their antidepressant activity is still an open question. Here, we addressed these issues by investigating the effect of two psychedelics of different chemical families, DOI and psilocybin, and a non-hallucinogenic 5-HT2AR agonist, lisuride, in a chronic despair mouse model exhibiting a robust depressive-like phenotype. We show that a single injection of each drug to wild type mice induces anxiolytic- and antidepressant-like effects in the novelty-suppressed feeding, sucrose preference and forced swim tests, which last up to 15 days. DOI and lisuride administration did not produce antidepressant-like effects in 5-HT2A-/- mice, whereas psilocybin was still effective. Moreover, neither 5-HT1AR blockade nor dopamine D1 or D2 receptor blockade affected the antidepressant-like effects of psilocybin in 5-HT2A-/- mice. Collectively, these findings indicate that 5-HT2AR agonists can produce antidepressant-like effects independently of hallucinogenic properties through mechanisms involving or not involving the receptor.
Collapse
Affiliation(s)
- Mehdi Sekssaoui
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, F-34094, Montpellier, France
| | - Joël Bockaert
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, F-34094, Montpellier, France
| | - Philippe Marin
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, F-34094, Montpellier, France
| | - Carine Bécamel
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, F-34094, Montpellier, France.
| |
Collapse
|
9
|
Flores-Gómez GD, Apam-Castillejos DJ, Juárez-Díaz I, Fuentes-Medel E, Díaz A, Tendilla-Beltrán H, Flores G. Aripiprazole attenuates the medial prefrontal cortex morphological and biochemical alterations in rats with neonatal ventral hippocampus lesion. J Chem Neuroanat 2023; 132:102316. [PMID: 37481172 DOI: 10.1016/j.jchemneu.2023.102316] [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: 06/11/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 07/24/2023]
Abstract
Schizophrenia is a neurodevelopmental disorder characterized by a loss of dendritic spines in the medial prefrontal cortex (mPFC). Multiple subclinical and clinical studies have evidenced the ability of antipsychotics to improve neuroplasticity. In this study, it was evaluated the effect of the atypical antipsychotic aripiprazole (ARI) on the behavioral and mPFC neuronal disturbances of rats with neonatal ventral hippocampus lesion (nVHL), which is a heuristic developmental model relevant to the study of schizophrenia. ARI attenuated open field hyperlocomotion in the rats with nVHL. Also, ARI ameliorated structural neuroplasticity disturbances of the mPFC layer 3 pyramidal cells, but not in the layer 5 neurons. These effects can be associated with the ARI capability of increasing brain-derived neurotrophic factor (BDNF) levels. Moreover, in the animals with nVHL, ARI attenuated the immunoreactivity for some oxidative stress-related molecules such as the nitric oxide synthase 2 (NOS-2), 3-nitrotyrosine (3-NT), and cyclooxygenase 2 (COX-2), as well as the reactive astrogliosis in the mPFC. These results contribute to current knowledge about the neurotrophic, anti-inflammatory, and antioxidant properties of antipsychotics which may be contributing to their clinical effects and envision promising therapeutic targets for the treatment of schizophrenia.
Collapse
Affiliation(s)
| | | | - Ismael Juárez-Díaz
- Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | - Estefania Fuentes-Medel
- Facultad de Ciencias Químicas (FCQ), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | - Alfonso Díaz
- Facultad de Ciencias Químicas (FCQ), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | - Hiram Tendilla-Beltrán
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | - Gonzalo Flores
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico.
| |
Collapse
|
10
|
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: 5] [Impact Index Per Article: 5.0] [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.
Collapse
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.
| |
Collapse
|
11
|
5-HT-dependent synaptic plasticity of the prefrontal cortex in postnatal development. Sci Rep 2022; 12:21015. [PMID: 36470912 PMCID: PMC9723183 DOI: 10.1038/s41598-022-23767-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/04/2022] [Indexed: 12/12/2022] Open
Abstract
Important functions of the prefrontal cortex (PFC) are established during early life, when neurons exhibit enhanced synaptic plasticity and synaptogenesis. This developmental stage drives the organization of cortical connectivity, responsible for establishing behavioral patterns. Serotonin (5-HT) emerges among the most significant factors that modulate brain activity during postnatal development. In the PFC, activated 5-HT receptors modify neuronal excitability and interact with intracellular signaling involved in synaptic modifications, thus suggesting that 5-HT might participate in early postnatal plasticity. To test this hypothesis, we employed intracellular electrophysiological recordings of PFC layer 5 neurons to study the modulatory effects of 5-HT on plasticity induced by theta-burst stimulation (TBS) in two postnatal periods of rats. Our results indicate that 5-HT is essential for TBS to result in synaptic changes during the third postnatal week, but not later. TBS coupled with 5-HT2A or 5-HT1A and 5-HT7 receptors stimulation leads to long-term depression (LTD). On the other hand, TBS and synergic activation of 5-HT1A, 5-HT2A, and 5-HT7 receptors lead to long-term potentiation (LTP). Finally, we also show that 5-HT dependent synaptic plasticity of the PFC is impaired in animals that are exposed to early-life chronic stress.
Collapse
|
12
|
Pędzich BD, Medrano M, Buckinx A, Smolders I, De Bundel D. Psychedelic-Induced Serotonin 2A Receptor Downregulation Does Not Predict Swim Stress Coping in Mice. Int J Mol Sci 2022; 23:ijms232315284. [PMID: 36499610 PMCID: PMC9736085 DOI: 10.3390/ijms232315284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/25/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Serotoninergic psychedelics such as psilocybin have been reported to elicit a long-lasting reduction in depressive symptoms. Although the main target for serotoninergic psychedelics, serotonin type 2A receptor (5-HT2A), has been established, the possible mechanism of the antidepressant action of psychedelics remains unknown. Using the mouse forced swim test model, we examined whether the administration of the synthetic serotoninergic psychedelic 2,5-dimethoxy-4-iodoamphetamine (DOI) would modulate 5-HT2A receptor levels in the medial prefrontal cortex (mPFC) and revert stress-induced changes in behavior. Mice subjected to swim stress developed a passive stress-coping strategy when tested in the forced swim test 6 days later. This change in behavior was not associated with the hypothesized increase in 5-HT2A receptor-dependent head twitch behaviors or consistent changes in 5-HT2A receptor levels in the mPFC. When DOI was administered 1 day before the forced swim test, a low dose (0.2 mg/kg i.p.) unexpectedly increased immobility while a high dose (2 mg/kg i.p.) had no significant effect on immobility. Nevertheless, DOI evoked a dose-dependent decrease in 5-HT2A levels in the mPFC of mice previously exposed to swim stress. Our findings do not support the hypothesis that the downregulation of 5-HT2A receptors in the mPFC contributes to the antidepressant-like properties of serotoninergic psychedelics.
Collapse
|
13
|
Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant. Biomolecules 2022; 12:biom12111618. [DOI: 10.3390/biom12111618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/27/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Ayahuasca is a psychoactive brew traditionally used in indigenous and religious rituals and ceremonies in South America for its therapeutic, psychedelic, and entheogenic effects. It is usually prepared by lengthy boiling of the leaves of the bush Psychotria viridis and the mashed stalks of the vine Banisteriopsis caapi in water. The former contains the classical psychedelic N,N-dimethyltryptamine (DMT), which is thought to be the main psychoactive alkaloid present in the brew. The latter serves as a source for β-carbolines, known for their monoamine oxidase-inhibiting (MAOI) properties. Recent preliminary research has provided encouraging results investigating ayahuasca’s therapeutic potential, especially regarding its antidepressant effects. On a molecular level, pre-clinical and clinical evidence points to a complex pharmacological profile conveyed by the brew, including modulation of serotoninergic, glutamatergic, dopaminergic, and endocannabinoid systems. Its substances also interact with the vesicular monoamine transporter (VMAT), trace amine-associated receptor 1 (TAAR1), and sigma-1 receptors. Furthermore, ayahuasca’s components also seem to modulate levels of inflammatory and neurotrophic factors beneficially. On a biological level, this translates into neuroprotective and neuroplastic effects. Here we review the current knowledge regarding these molecular interactions and how they relate to the possible antidepressant effects ayahuasca seems to produce.
Collapse
|
14
|
de Oliveira RP, de Andrade JS, Spina M, Chamon JV, Silva PHD, Werder AK, Ortolani D, Thomaz LDSC, Romariz S, Ribeiro DA, Longo BM, Spadari RC, Viana MDB, Melo-Thomas L, Céspedes IC, da Silva RCB. Clozapine prevented social interaction deficits and reduced c-Fos immunoreactivity expression in several brain areas of rats exposed to acute restraint stress. PLoS One 2022; 17:e0262728. [PMID: 35239670 PMCID: PMC8893644 DOI: 10.1371/journal.pone.0262728] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 01/04/2022] [Indexed: 11/21/2022] Open
Abstract
In the present study, we evaluate the effect of acute restraint stress (15 min) of male Wistar rats on social interaction measurements and c-Fos immunoreactivity (c-Fos-ir) expression, a marker of neuronal activity, in areas involved with the modulation of acute physical restraint in rats, i.e., the paraventricular nucleus of the hypothalamus (PVN), median raphe nucleus (MnR), medial prefrontal cortex (mPFC), cingulate prefrontal cortex (cPFC), nucleus accumbens (NaC), hippocampus (CA3), lateral septum (LS) and medial amygdala (MeA). We considered the hypothesis that restraint stress exposure could promote social withdrawal induced by the activation of the hypothalamic-pituitary-adrenocortical (HPA) axis, and increase c-Fos expression in these limbic forebrain areas investigated. In addition, we investigated whether pretreatment with the atypical antipsychotic clozapine (5 mg/kg; I.P.) could attenuate or block the effects of restraint on these responses. We found that restraint stress induced social withdrawal, and increased c-Fos-ir in these areas, demonstrating that a single 15 min session of physical restraint of rats effectively activated the HPA axis, representing an effective tool for the investigation of neuronal activity in brain regions sensitive to stress. Conversely, pretreatment with clozapine, prevented social withdrawal and reduced c-Fos expression. We suggest that treatment with clozapine exerted a preventive effect in the social interaction deficit, at least in part, by blocking the effect of restraint stress in brain regions that are known to regulate the HPA-axis, including the cerebral cortex, hippocampus, hypothalamus, septum and amygdala. Further experiments will be done to confirm this hypothesis.
Collapse
Affiliation(s)
| | - José Simões de Andrade
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | - Marianna Spina
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | - João Vítor Chamon
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | | | - Ana Keyla Werder
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | - Daniela Ortolani
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | | | - Simone Romariz
- Departamento de Fisiologia, Universidade Federal de São Paulo (UNIFESP/SP), São Paulo, Brazil
| | - Daniel Araki Ribeiro
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | - Beatriz Monteiro Longo
- Departamento de Fisiologia, Universidade Federal de São Paulo (UNIFESP/SP), São Paulo, Brazil
| | - Regina Célia Spadari
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | - Milena de Barros Viana
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
| | - Liana Melo-Thomas
- Behavioral Neuroscience, Experimental and Biological Psychology, Philipps-Universityof Marburg, Marburg, Germany
- Marburg Center for Mind, Brain, and Behavior (MCMBB), Marburg, Marburg, Germany
| | - Isabel Cristina Céspedes
- Departamento de Morfologia e Genética, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil
| | - Regina Cláudia Barbosa da Silva
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Santos (SP), Brazil
- Instituto de Neurociências e Comportamento (INeC), Ribeirão Preto, São Paulo, Brazil
| |
Collapse
|
15
|
Thomas CW, Blanco-Duque C, Bréant BJ, Goodwin GM, Sharp T, Bannerman DM, Vyazovskiy VV. Psilocin acutely alters sleep-wake architecture and cortical brain activity in laboratory mice. Transl Psychiatry 2022; 12:77. [PMID: 35197453 PMCID: PMC8866416 DOI: 10.1038/s41398-022-01846-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 01/03/2023] Open
Abstract
Serotonergic psychedelic drugs, such as psilocin (4-hydroxy-N,N-dimethyltryptamine), profoundly alter the quality of consciousness through mechanisms which are incompletely understood. Growing evidence suggests that a single psychedelic experience can positively impact long-term psychological well-being, with relevance for the treatment of psychiatric disorders, including depression. A prominent factor associated with psychiatric disorders is disturbed sleep, and the sleep-wake cycle is implicated in the homeostatic regulation of neuronal activity and synaptic plasticity. However, it remains largely unknown to what extent psychedelic agents directly affect sleep, in terms of both acute arousal and homeostatic sleep regulation. Here, chronic electrophysiological recordings were obtained in mice to track sleep-wake architecture and cortical activity after psilocin injection. Administration of psilocin led to delayed REM sleep onset and reduced NREM sleep maintenance for up to approximately 3 h after dosing, and the acute EEG response was associated primarily with an enhanced oscillation around 4 Hz. No long-term changes in sleep-wake quantity were found. When combined with sleep deprivation, psilocin did not alter the dynamics of homeostatic sleep rebound during the subsequent recovery period, as reflected in both sleep amount and EEG slow-wave activity. However, psilocin decreased the recovery rate of sleep slow-wave activity following sleep deprivation in the local field potentials of electrodes targeting the medial prefrontal and surrounding cortex. It is concluded that psilocin affects both global vigilance state control and local sleep homeostasis, an effect which may be relevant for its antidepressant efficacy.
Collapse
Affiliation(s)
- Christopher W. Thomas
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Cristina Blanco-Duque
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Benjamin J. Bréant
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Guy M. Goodwin
- grid.4991.50000 0004 1936 8948Department of Psychiatry, University of Oxford, Oxford, UK
| | - Trevor Sharp
- grid.4991.50000 0004 1936 8948Department of Pharmacology, University of Oxford, Oxford, UK
| | - David M. Bannerman
- grid.4991.50000 0004 1936 8948Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Vladyslav V. Vyazovskiy
- grid.4991.50000 0004 1936 8948Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| |
Collapse
|
16
|
Markopoulos A, Inserra A, De Gregorio D, Gobbi G. Evaluating the Potential Use of Serotonergic Psychedelics in Autism Spectrum Disorder. Front Pharmacol 2022; 12:749068. [PMID: 35177979 PMCID: PMC8846292 DOI: 10.3389/fphar.2021.749068] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 11/04/2021] [Indexed: 01/29/2023] Open
Abstract
Recent clinical and preclinical evidence points towards empathogenic and prosocial effects elicited by psychedelic compounds, notably the serotonin 5-HT2A agonists lysergic acid diethylamide (LSD), psilocybin, N,N-Dimethyltryptamine (DMT), and their derivatives. These findings suggest a therapeutic potential of psychedelic compounds for some of the behavioural traits associated with autism spectrum disorder (ASD), a neurodevelopmental condition characterized by atypical social behaviour. In this review, we highlight evidence suggesting that psychedelics may potentially ameliorate some of the behavioural atypicalities of ASD, including reduced social behaviour and highly co-occurring anxiety and depression. Next, we discuss dysregulated neurobiological systems in ASD and how they may underlie or potentially limit the therapeutic effects of psychedelics. These phenomena include: 1) synaptic function, 2) serotonergic signaling, 3) prefrontal cortex activity, and 4) thalamocortical signaling. Lastly, we discuss clinical studies from the 1960s and 70s that assessed the use of psychedelics in the treatment of children with ASD. We highlight the positive behavioural outcomes of these studies, including enhanced mood and social behaviour, as well as the adverse effects of these trials, including increases in aggressive behaviour and dissociative and psychotic states. Despite preliminary evidence, further studies are needed to determine whether the benefits of psychedelic treatment in ASD outweigh the risks associated with the use of these compounds in this population, and if the 5-HT2A receptor may represent a target for social-behavioural disorders.
Collapse
Affiliation(s)
- Athanasios Markopoulos
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Antonio Inserra
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada.,McGill University Health Centre, McGill University, Montreal, QC, Canada
| |
Collapse
|
17
|
Vollenweider FX, Smallridge JW. Classic Psychedelic Drugs: Update on Biological
Mechanisms. PHARMACOPSYCHIATRY 2022; 55:121-138. [PMID: 35079988 PMCID: PMC9110100 DOI: 10.1055/a-1721-2914] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Renewed interest in the effects of psychedelics in the treatment of psychiatric
disorders warrants a better understanding of the neurobiological mechanisms
underlying the effects of these substances. During the past two decades,
state-of-the-art studies of animals and humans have yielded new important
insights into the molecular, cellular, and systems-level actions of psychedelic
drugs. These efforts have revealed that psychedelics affect primarily
serotonergic receptor subtypes located in cortico-thalamic and cortico-cortical
feedback circuits of information processing. Psychedelic drugs modulate
excitatory-inhibitory balance in these circuits and can participate in
neuroplasticity within brain structures critical for the integration of
information relevant to sensation, cognition, emotions, and the narrative of
self. Neuroimaging studies showed that characteristic dimensions of the
psychedelic experience obtained through subjective questionnaires as well as
alterations in self-referential processing and emotion regulation obtained
through neuropsychological tasks are associated with distinct changes in brain
activity and connectivity patterns at multiple-system levels. These recent
results suggest that changes in self-experience, emotional processing, and
social cognition may contribute to the potential therapeutic effects of
psychedelics.
Collapse
Affiliation(s)
- Franz X. Vollenweider
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry,
Psychotherapy and Psychosomatics, University Hospital for Psychiatry Zurich,
Zurich, Switzerland
| | - John W. Smallridge
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry,
Psychotherapy and Psychosomatics, University Hospital for Psychiatry Zurich,
Zurich, Switzerland
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
5-HT Receptors and the Development of New Antidepressants. Int J Mol Sci 2021; 22:ijms22169015. [PMID: 34445721 PMCID: PMC8396477 DOI: 10.3390/ijms22169015] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 02/06/2023] Open
Abstract
Serotonin modulates several physiological and cognitive pathways throughout the human body that affect emotions, memory, sleep, and thermal regulation. The complex nature of the serotonergic system and interactions with other neurochemical systems indicate that the development of depression may be mediated by various pathomechanisms, the common denominator of which is undoubtedly the disturbed transmission in central 5-HT synapses. Therefore, the deliberate pharmacological modulation of serotonergic transmission in the brain seems to be one of the most appropriate strategies for the search for new antidepressants. As discussed in this review, the serotonergic system offers great potential for the development of new antidepressant therapies based on the combination of SERT inhibition with different pharmacological activity towards the 5-HT system. The aim of this article is to summarize the search for new antidepressants in recent years, focusing primarily on the possibility of benefiting from interactions with various 5-HT receptors in the pharmacotherapy of depression.
Collapse
|
20
|
Abstract
After participating in this activity, learners should be better able to:• Identify the effects of dysregulated opioid signalling in depression• Evaluate the use of opioid compounds and ketamine in patients with depression ABSTRACT: Major depressive disorder (MDD) remains one of the leading causes of disability and functional impairment worldwide. Current antidepressant therapeutics require weeks to months of treatment prior to the onset of clinical efficacy on depressed mood but remain ineffective in treating suicidal ideation and cognitive impairment. Moreover, 30%-40% of individuals fail to respond to currently available antidepressant medications. MDD is a heterogeneous disorder with an unknown etiology; novel strategies must be developed to treat MDD more effectively. Emerging evidence suggests that targeting one or more of the four opioid receptors-mu (MOR), kappa (KOR), delta (DOR), and the nociceptin/orphanin FQ receptor (NOP)-may yield effective therapeutics for stress-related psychiatric disorders. Furthermore, the effects of the rapidly acting antidepressant ketamine may involve opioid receptors. This review highlights dysregulated opioid signaling in depression, evaluates clinical trials with opioid compounds, and considers the role of opioid mechanisms in rapidly acting antidepressants.
Collapse
|
21
|
Banks MI, Zahid Z, Jones NT, Sultan ZW, Wenthur CJ. Catalysts for change: the cellular neurobiology of psychedelics. Mol Biol Cell 2021; 32:1135-1144. [PMID: 34043427 PMCID: PMC8351556 DOI: 10.1091/mbc.e20-05-0340] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/23/2021] [Accepted: 03/31/2021] [Indexed: 01/18/2023] Open
Abstract
The resurgence of interest in the therapeutic potential of psychedelics for treating psychiatric disorders has rekindled efforts to elucidate their mechanism of action. In this Perspective, we focus on the ability of psychedelics to promote neural plasticity, postulated to be central to their therapeutic activity. We begin with a brief overview of the history and behavioral effects of the classical psychedelics. We then summarize our current understanding of the cellular and subcellular mechanisms underlying these drugs' behavioral effects, their effects on neural plasticity, and the roles of stress and inflammation in the acute and long-term effects of psychedelics. The signaling pathways activated by psychedelics couple to numerous potential mechanisms for producing long-term structural changes in the brain, a complexity that has barely begun to be disentangled. This complexity is mirrored by that of the neural mechanisms underlying psychiatric disorders and the transformations of consciousness, mood, and behavior that psychedelics promote in health and disease. Thus, beyond changes in the brain, psychedelics catalyze changes in our understanding of the neural basis of psychiatric disorders, as well as consciousness and human behavior.
Collapse
Affiliation(s)
- Matthew I. Banks
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
- Neuroscience Training Program, University of Wisconsin–Madison, Madison, WI 53706
| | - Zarmeen Zahid
- Neuroscience Training Program, University of Wisconsin–Madison, Madison, WI 53706
| | - Nathan T. Jones
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin–Madison, Madison, WI 53706
| | - Ziyad W. Sultan
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706
| | - Cody J. Wenthur
- Neuroscience Training Program, University of Wisconsin–Madison, Madison, WI 53706
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin–Madison, Madison, WI 53706
- School of Pharmacy, University of Wisconsin–Madison, Madison, WI 53705
| |
Collapse
|
22
|
Magaraggia I, Kuiperes Z, Schreiber R. Improving cognitive functioning in major depressive disorder with psychedelics: A dimensional approach. Neurobiol Learn Mem 2021; 183:107467. [PMID: 34048913 DOI: 10.1016/j.nlm.2021.107467] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 05/06/2021] [Accepted: 05/23/2021] [Indexed: 12/28/2022]
Abstract
The high symptomatic and biological heterogeneity of major depressive disorder (MDD) makes it very difficult to find broadly efficacious treatments that work against all symptoms. Concentrating on single core symptoms that are biologically well understood might consist of a more viable approach. The Research Domain Criteria (RDoC) framework is a trans-diagnostic dimensional approach that focuses on symptoms and their underlying neurobiology. Evidence is accumulating that psychedelics may possess antidepressant activity, and this can potentially be explained through a multi-level (psychobiological, circuitry, (sub)cellular and molecular) analysis of the cognitive systems RDoC domain. Cognitive deficits, such as negative emotional processing and negativity bias, often lead to depressive rumination. Psychedelics can increase long-term cognitive flexibility, leading to normalization of negativity bias and reduction in rumination. We propose a theoretical model that explains how psychedelics can reduce the negativity bias in depressed patients. At the psychobiological level, we hypothesize that the negativity bias in MDD is due to impaired pattern separation and that psychedelics such as psilocybin help in depression because they enhance pattern separation and hence reduce negativity bias. Pattern separation is a mnemonic process that relies on adult hippocampal neurogenesis, where similar inputs are made more distinct, which is essential for optimal encoding of contextual information. Impairment in this process may underlie the negative cognitive bias in MDD by, for example, increased pattern separation of cues with a negative valence that can lead to excessive deliberation on aversive outcomes. On the (sub) cellular level, psychedelics stimulate hippocampal neurogenesis as well as synaptogenesis, spinogenesis and dendritogenesis in the prefrontal cortex. Together, these effects help restoring resilience to chronic stress and lead to modulation of the major connectivity hubs of the prefrontal cortex, hippocampus, and amygdala. Based on these observations, we propose a new translational framework to guide the development of a novel generation of therapeutics to treat the cognitive symptoms in MDD.
Collapse
Affiliation(s)
- Igor Magaraggia
- Faculty of Psychology and Neuroscience, Section Neuropsychology & Psychopharmacology, Maastricht University, Maastricht, the Netherlands
| | - Zilla Kuiperes
- Faculty of Health, Medicine and Life Sciences (FHML), the Netherlands
| | - Rudy Schreiber
- Faculty of Psychology and Neuroscience, Section Neuropsychology & Psychopharmacology, Maastricht University, Maastricht, the Netherlands.
| |
Collapse
|
23
|
Oña G, Bouso JC. Therapeutic Potential of Natural Psychoactive Drugs for Central Nervous System Disorders: A Perspective from Polypharmacology. Curr Med Chem 2021; 28:53-68. [PMID: 31830883 DOI: 10.2174/0929867326666191212103330] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 10/01/2019] [Accepted: 10/02/2019] [Indexed: 11/22/2022]
Abstract
In the drug development, the formation of highly selective ligands has been unsuccessful in the treatment of central nervous system disorders. Multi-target ligands, from the polypharmacology paradigm, are being proposed as treatments for these complex disorders, since they offer enhanced efficacy and a strong safety profile. Natural products are the best examples of multi-target compounds, so they are of high interest within this paradigm. Additionally, recent research on psychoactive drugs of natural origin, such as ayahuasca and cannabis, has demonstrated the promising therapeutic potential for the treatment of some psychiatric and neurological disorders. In this text, we describe how research on psychoactive drugs can be effectively combined with the polypharmacology paradigm, providing ayahuasca and cannabis research as examples. The advantages and disadvantages are also discussed.
Collapse
Affiliation(s)
- Genís Oña
- International Center for Ethnobotanical Education, Research and Service (ICEERS), Barcelona, Spain
| | - José Carlos Bouso
- International Center for Ethnobotanical Education, Research and Service (ICEERS), Barcelona, Spain
| |
Collapse
|
24
|
Révész D, Ona G, Rossi GN, Rocha JM, Dos Santos RG, Hallak JEC, Alcázar-Córcoles MÁ, Bouso JC. Cross-Sectional Associations Between Lifetime Use of Psychedelic Drugs and Psychometric Measures During the COVID-19 Confinement: A Transcultural Study. Front Psychiatry 2021; 12:687546. [PMID: 34220590 PMCID: PMC8242180 DOI: 10.3389/fpsyt.2021.687546] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/25/2021] [Indexed: 01/07/2023] Open
Abstract
Background: One of the main public health strategies adopted at the beginning of the COVID-19 pandemic consisted of implementing strict lockdowns to stop the transmission of the virus. Despite being an effective measure, the confinement and the associated social isolation create a stressful, potentially lengthy situations that has been proven to have several psychological consequences. Given the potential benefits that certain psychedelic drugs have shown for the treatment of psychological disorders, this study aimed to assess the impact of lifetime psychedelic drug use on mental health in relation to the first strict lockdown adopted by various countries (April-July 2020). Methods: Subjects completed an online survey that inquired about sociodemographic factors, activities, and lifestyle factors during confinement, as well as health and mental health related factors. Subjects were asked about their lifetime use of psychedelic drugs (MDMA, ayahuasca, psilocybin-containing mushrooms, LSD, peyote, San Pedro, Bufo alvarius or 5-MeO-DMT, and others), being classified as regular users (more than once per 6 months), occasional users, or non-users. The survey included psychometric tests used to assess psychological distress, peritraumatic stress, social support, psychopathological symptoms, and personality. Linear regressions were performed with psychedelic drug users as the independent variable and psychometric factors as the outcomes, while correcting for age, gender, language, religion, spirituality, and use of non-psychedelic drugs. Results: The study included 2,974 English, Portuguese, and Spanish speakers (497 regular users of psychedelic drugs, 606 occasional users, and 1,968 non-users). On average, respondents were 36 years old and 70% were female. Psychedelic drug users, especially regular ones, reported less psychological distress, less peritraumatic stress, and more social support. Regarding personality measures, psychedelic drug users scored higher on the novelty-seeking and self-transcendence scales, and lower on cooperativeness. Conclusion: Our findings showed that regular users of psychedelic drugs had less psychological stress and some personality differences when compared to occasional users and non-users. This suggests that either the use of psychedelics might be a protective factor itself or people with certain previous traits are more prone to frequently using psychedelic drugs. Future prospective longitudinal research should investigate the underlying processes observed in this study to develop consistent hypotheses.
Collapse
Affiliation(s)
- Dóra Révész
- Center of Research on Psychological and Somatic Disorders (CoRPS), Department of Medical and Clinical Psychology, Tilburg University, Tilburg, Netherlands
| | - Genís Ona
- ICEERS-International Center for Ethnobotanical Education, Research, and Service, Barcelona, Spain.,Medical Anthropology Research Center (MARC), Universitat Rovira i Virgili, Tarragona, Spain
| | - Giordano N Rossi
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Juliana M Rocha
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Rafael G Dos Santos
- ICEERS-International Center for Ethnobotanical Education, Research, and Service, Barcelona, Spain.,Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,National Institute of Science and Technology-Translational Medicine, São Paulo, Brazil
| | - Jaime E C Hallak
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,National Institute of Science and Technology-Translational Medicine, São Paulo, Brazil
| | - Miguel Á Alcázar-Córcoles
- Department of Biological and Health Psychology, School of Psychology, Autonomous University of Madrid (UAM), Madrid, Spain
| | - José C Bouso
- ICEERS-International Center for Ethnobotanical Education, Research, and Service, Barcelona, Spain.,Medical Anthropology Research Center (MARC), Universitat Rovira i Virgili, Tarragona, Spain.,Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| |
Collapse
|
25
|
Pak A, Chubykin AA. Cortical Tuning is Impaired After Perceptual Experience in Primary Visual Cortex of Serotonin Transporter-Deficient Mice. Cereb Cortex Commun 2020; 1:tgaa066. [PMID: 33134928 PMCID: PMC7575641 DOI: 10.1093/texcom/tgaa066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 08/27/2020] [Accepted: 09/06/2020] [Indexed: 11/16/2022] Open
Abstract
Serotonin (5-hydroxytryptamine) is crucial for the proper development of neuronal circuits early in life and their refinement throughout adulthood. Its signaling is tightly regulated by the serotonin transporter (SERT), alterations of which were implicated in various neurological and psychiatric disorders. Animal models lacking a functional SERT variant display diverse phenotypes, including increased anxiety, social communication deficits, and altered cortical development. However, it remains unclear how SERT disruption affects sensory processing and experience-dependent learning in adulthood. It has been previously shown that perceptual experience leads to the development of visual familiarity-evoked theta oscillations in mouse V1. Here, we discovered that familiarity-evoked theta oscillations were longer and less stimulus specific in SERT knockout (KO) compared with wild-type (WT) mice. Interestingly, while the overall visual response properties were similar in naive mice, orientation and spatial frequency processing were significantly impaired in SERT KO compared with WT or SERT heterozygous mice following perceptual experience. Our findings shed more light on the mechanism of familiarity-evoked oscillations and highlight the importance of serotonin signaling in perceptual learning.
Collapse
Affiliation(s)
- Alexandr Pak
- Department of Biological Sciences, Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Alexander A Chubykin
- Department of Biological Sciences, Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
26
|
Shin D, Cho KH, Joo K, Rhie DJ. Layer-specific serotonergic induction of long-term depression in the prefrontal cortex of rats. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:517-527. [PMID: 33093273 PMCID: PMC7585589 DOI: 10.4196/kjpp.2020.24.6.517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 09/29/2020] [Accepted: 10/04/2020] [Indexed: 11/15/2022]
Abstract
Layer 2/3 pyramidal neurons (L2/3 PyNs) of the cortex extend their basal dendrites near the soma and as apical dendritic tufts in layer 1, which mainly receive feedforward and feedback inputs, respectively. It is suggested that neuromodulators such as serotonin and acetylcholine may regulate the information flow between brain structures depending on the brain state. However, little is known about the dendritic compartment-specific induction of synaptic transmission in single PyNs. Here, we studied layer-specific serotonergic and cholinergic induction of long-term synaptic plasticity in L2/3 PyNs of the agranular insular cortex, a lateral component of the orbitofrontal cortex. Using FM1-43 dye unloading, we verified that local electrical stimulation to layers 1 (L1) and 3 (L3) activated axon terminals mostly located in L1 and perisomatic area (L2/3). Independent and AMPA receptor-mediated excitatory postsynaptic potential was evoked by local electrical stimulation of either L1 or L3. Application of serotonin (5-HT, 10 μM) induced activity-dependent long-term depression (LTD) in L2/3 but not in L1 inputs. LTD induced by 5-HT was blocked by the 5-HT2 receptor antagonist ketanserin, an NMDA receptor antagonist and by intracellular Ca2+ chelation. The 5-HT2 receptor agonist α-me-5-HT mimicked the LTD induced by 5-HT. However, the application of carbachol induced muscarinic receptor-dependent LTD in both inputs. The differential layer-specific induction of LTD by neuromodulators might play an important role in information processing mechanism of the prefrontal cortex.
Collapse
Affiliation(s)
- Dongchul Shin
- Department of Physiology, The Catholic University of Korea, Seoul 06591, Korea
| | - Kwang-Hyun Cho
- Department of Physiology, The Catholic University of Korea, Seoul 06591, Korea
| | - Kayoung Joo
- Department of Physiology, The Catholic University of Korea, Seoul 06591, Korea
| | - Duck-Joo Rhie
- Department of Physiology, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| |
Collapse
|
27
|
Potential safety, benefits, and influence of the placebo effect in microdosing psychedelic drugs: A systematic review. Neurosci Biobehav Rev 2020; 119:194-203. [PMID: 33031815 DOI: 10.1016/j.neubiorev.2020.09.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/24/2020] [Accepted: 09/25/2020] [Indexed: 02/08/2023]
Abstract
Microdosing psychedelic drugs-that is, taking sub-behavioral doses of lysergic acid diethylamide (LSD) or psilocybin-is a growing practice in Western societies. Taken mainly for creative or mood-enhancing purposes, thousands of users are increasingly being exposed to (micro)doses of psychedelic drugs. In this systematic review, we searched the available evidence from human studies, focusing our results in terms of three main axes: efficacy, safety, and the influence of the placebo effect in microdosing practices. While the available evidence has some strengths (e.g. large sample sizes, robust methodologies) there are also remarkable limitations (e.g. gender bias, heterogeneity of dosing schedules and drugs used). Highly contradictory results have been found, showing both the benefits and detriments of microdosing in terms of mood, creative processes, and energy, among other regards. This review provides a general overview of the methods and approaches used, which could be useful for improving future studies.
Collapse
|
28
|
Psychedelic drugs: neurobiology and potential for treatment of psychiatric disorders. Nat Rev Neurosci 2020; 21:611-624. [PMID: 32929261 DOI: 10.1038/s41583-020-0367-2] [Citation(s) in RCA: 212] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2020] [Indexed: 12/13/2022]
Abstract
Renewed interest in the use of psychedelics in the treatment of psychiatric disorders warrants a better understanding of the neurobiological mechanisms underlying the effects of these substances. After a hiatus of about 50 years, state-of-the art studies have recently begun to close important knowledge gaps by elucidating the mechanisms of action of psychedelics with regard to their effects on receptor subsystems, systems-level brain activity and connectivity, and cognitive and emotional processing. In addition, functional studies have shown that changes in self-experience, emotional processing and social cognition may contribute to the potential therapeutic effects of psychedelics. These discoveries provide a scientific road map for the investigation and application of psychedelic substances in psychiatry.
Collapse
|
29
|
Berthoux C, Hamieh AM, Rogliardo A, Doucet EL, Coudert C, Ango F, Grychowska K, Chaumont‐Dubel S, Zajdel P, Maldonado R, Bockaert J, Marin P, Bécamel C. Early 5-HT 6 receptor blockade prevents symptom onset in a model of adolescent cannabis abuse. EMBO Mol Med 2020; 12:e10605. [PMID: 32329240 PMCID: PMC7207164 DOI: 10.15252/emmm.201910605] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 03/05/2020] [Accepted: 03/10/2020] [Indexed: 01/05/2023] Open
Abstract
Cannabis abuse during adolescence confers an increased risk for developing later in life cognitive deficits reminiscent of those observed in schizophrenia, suggesting common pathological mechanisms that remain poorly characterized. In line with previous findings that revealed a role of 5-HT6 receptor-operated mTOR activation in cognitive deficits of rodent developmental models of schizophrenia, we show that chronic administration of ∆9-tetrahydrocannabinol (THC) to mice during adolescence induces a long-lasting activation of mTOR in prefrontal cortex (PFC), alterations of excitatory/inhibitory balance, intrinsic properties of layer V pyramidal neurons, and long-term depression, as well as cognitive deficits in adulthood. All are prevented by administrating a 5-HT6 receptor antagonist or rapamycin, during adolescence. In contrast, they are still present 2 weeks after the same treatments delivered at the adult stage. Collectively, these findings suggest a role of 5-HT6 receptor-operated mTOR signaling in abnormalities of cortical network wiring elicited by THC at a critical period of PFC maturation and highlight the potential of 5-HT6 receptor antagonists as early therapy to prevent cognitive symptom onset in adolescent cannabis abusers.
Collapse
Affiliation(s)
| | | | | | | | - Camille Coudert
- IGF, University of MontpellierCNRS, INSERMMontpellierFrance
- Department of Adult PsychiatryMontpellier University HospitalMontpellierFrance
| | - Fabrice Ango
- IGF, University of MontpellierCNRS, INSERMMontpellierFrance
| | - Katarzyna Grychowska
- Department of Medicinal ChemistryJagiellonian University Medical CollegeKrakówPoland
| | | | - Pawel Zajdel
- Department of Medicinal ChemistryJagiellonian University Medical CollegeKrakówPoland
| | - Rafael Maldonado
- Neuropharmacology LaboratoryDepartment of Experimental and Health SciencesPompeu Fabra UniversityBarcelonaSpain
| | - Joël Bockaert
- IGF, University of MontpellierCNRS, INSERMMontpellierFrance
| | - Philippe Marin
- IGF, University of MontpellierCNRS, INSERMMontpellierFrance
| | - Carine Bécamel
- IGF, University of MontpellierCNRS, INSERMMontpellierFrance
| |
Collapse
|
30
|
Carhart-Harris RL, Friston KJ. REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics. Pharmacol Rev 2019; 71:316-344. [PMID: 31221820 PMCID: PMC6588209 DOI: 10.1124/pr.118.017160] [Citation(s) in RCA: 373] [Impact Index Per Article: 74.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This paper formulates the action of psychedelics by integrating the free-energy principle and entropic brain hypothesis. We call this formulation relaxed beliefs under psychedelics (REBUS) and the anarchic brain, founded on the principle that-via their entropic effect on spontaneous cortical activity-psychedelics work to relax the precision of high-level priors or beliefs, thereby liberating bottom-up information flow, particularly via intrinsic sources such as the limbic system. We assemble evidence for this model and show how it can explain a broad range of phenomena associated with the psychedelic experience. With regard to their potential therapeutic use, we propose that psychedelics work to relax the precision weighting of pathologically overweighted priors underpinning various expressions of mental illness. We propose that this process entails an increased sensitization of high-level priors to bottom-up signaling (stemming from intrinsic sources), and that this heightened sensitivity enables the potential revision and deweighting of overweighted priors. We end by discussing further implications of the model, such as that psychedelics can bring about the revision of other heavily weighted high-level priors, not directly related to mental health, such as those underlying partisan and/or overly-confident political, religious, and/or philosophical perspectives. SIGNIFICANCE STATEMENT: Psychedelics are capturing interest, with efforts underway to bring psilocybin therapy to marketing authorisation and legal access within a decade, spearheaded by the findings of a series of phase 2 trials. In this climate, a compelling unified model of how psychedelics alter brain function to alter consciousness would have appeal. Towards this end, we have sought to integrate a leading model of global brain function, hierarchical predictive coding, with an often-cited model of the acute action of psychedelics, the entropic brain hypothesis. The resulting synthesis states that psychedelics work to relax high-level priors, sensitising them to liberated bottom-up information flow, which, with the right intention, care provision and context, can help guide and cultivate the revision of entrenched pathological priors.
Collapse
Affiliation(s)
- R L Carhart-Harris
- Centre for Psychedelic Research, Division of Brain Sciences, Imperial College London, London, United Kingdom (R.L.C.-H.); and Institute of Neurology, Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom (K.J.F.)
| | - K J Friston
- Centre for Psychedelic Research, Division of Brain Sciences, Imperial College London, London, United Kingdom (R.L.C.-H.); and Institute of Neurology, Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom (K.J.F.)
| |
Collapse
|
31
|
Scott G, Carhart-Harris RL. Psychedelics as a treatment for disorders of consciousness. Neurosci Conscious 2019; 2019:niz003. [PMID: 31024740 PMCID: PMC6475593 DOI: 10.1093/nc/niz003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 03/06/2019] [Accepted: 03/06/2019] [Indexed: 11/23/2022] Open
Abstract
Based on its ability to increase brain complexity, a seemingly reliable index of conscious level, we propose testing the capacity of the classic psychedelic, psilocybin, to increase conscious awareness in patients with disorders of consciousness. We also confront the considerable ethical and practical challenges this proposal must address, if this hypothesis is to be directly assessed.
Collapse
Affiliation(s)
- Gregory Scott
- Department of Medicine, The Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, 3rd Floor, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Robin L Carhart-Harris
- Department of Medicine, The Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, 3rd Floor, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
- Department of Medicine, Centre for Psychedelic Research, Division of Brain Sciences, Imperial College London, 5th Floor, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| |
Collapse
|