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PeerJ 2024Psilocybin and related tryptamines have come into the spotlight in recent years as potential therapeutics for depression. Research on the mechanisms of these effects has...
BACKGROUND
Psilocybin and related tryptamines have come into the spotlight in recent years as potential therapeutics for depression. Research on the mechanisms of these effects has historically focused on the direct effects of these drugs on neural processes. However, in addition to such neural effects, alterations in peripheral physiology may also contribute to their therapeutic effects. In particular, substantial support exists for a gut microbiome-mediated pathway for the antidepressant efficacy of other drug classes, but no prior studies have determined the effects of tryptamines on microbiota.
METHODS
To address this gap, in this preliminary study, male Long Evans rats were treated with varying dosages of oral psilocybin (0.2 or 2 mg/kg), norbaeocystin (0.25 or 2.52 mg/kg), or vehicle and their fecal samples were collected 1 week and 3 weeks after exposure for microbiome analysis using integrated 16S ribosomal DNA sequencing to determine gut microbiome composition.
RESULTS
We found that although treatment with neither psilocybin nor norbaeocystin significantly affected overall microbiome diversity, it did cause significant dose- and time-dependent changes in bacterial abundance at the phylum level, including increases in and , and decreases in .
CONCLUSION AND IMPLICATIONS
These preliminary findings support the idea that psilocybin and other tryptamines may act on the gut microbiome in a dose- and time-dependent manner, potentially identifying a novel peripheral mechanism for their antidepressant activity. The results from this preliminary study also suggest that norbaeocystin may warrant further investigation as a potential antidepressant, given the similarity of its effects to psilocybin.
Topics: Animals; Gastrointestinal Microbiome; Male; Rats, Long-Evans; Tryptamines; Rats; Feces; Psilocybin; Administration, Oral; Antidepressive Agents
PubMed: 38846751
DOI: 10.7717/peerj.17517 -
Acta Crystallographica. Section E,... May 2024The title compound, CHNO, is a hy-droxy-substituted mono-amine alkaloid, and the primary metabolite of the naturally occurring psychedelic compound psilocybin....
The title compound, CHNO, is a hy-droxy-substituted mono-amine alkaloid, and the primary metabolite of the naturally occurring psychedelic compound psilocybin. Crystalline forms of psilocin are known, but their characterization by single-crystal structure analysis is limited. Herein, two anhydrous polymorphic forms (I and II) of psilocin are described. The crystal structure of polymorphic Form I, in space group 2/, was first reported in 1974. Along with the redeterm-ination to modern standards and unambiguous location of the acidic H atom and variable-temperature single-crystal unit-cell determinations for Form I, the Form II polymorph of the title compound, which crystallizes in the monoclinic space group 2/, is described for the first time. The psilocin mol-ecules are present in both forms in their phenol-amine tautomeric forms (not resolved in the 1974 report). The mol-ecules in Forms I and II, however, feature different conformations of their ,-dimethyl ethyl-ene substituent, with the N-C-C-C link in Form I being and in Form II being , allowing the latter to bend back to the hydroxyl group of the same mol-ecule, leading to the formation of a strong intra-molecular O-H⋯N hydrogen bond between the hydroxyl moiety and ethyl-amino-nitro-gen group. In the extended structure of Form II, the mol-ecules form one-dimensional strands through N-H⋯O hydrogen bonds from the indole group to the oxygen atom of the hydroxyl moiety of an adjacent mol-ecule. Form II exhibits whole-mol-ecule disorder due to a pseudo-mirror operation, with an occupancy ratio of 0.689 (5):0.311 (5) for the two components. In contrast, Form I does not feature intra-molecular hydrogen bonds but forms a layered structure through inter-molecular N-H⋯O and O-H⋯N hydrogen bonds.
PubMed: 38845717
DOI: 10.1107/S2056989024004201 -
BioRxiv : the Preprint Server For... May 2024Psilocybin, ketamine, and MDMA are psychoactive compounds that exert behavioral effects with distinguishable but also overlapping features. The growing interest in using...
Psilocybin, ketamine, and MDMA are psychoactive compounds that exert behavioral effects with distinguishable but also overlapping features. The growing interest in using these compounds as therapeutics necessitates preclinical assays that can accurately screen psychedelics and related analogs. We posit that a promising approach may be to measure drug action on markers of neural plasticity in native brain tissues. We therefore developed a pipeline for drug classification using light sheet fluorescence microscopy of immediate early gene expression at cellular resolution followed by machine learning. We tested male and female mice with a panel of drugs, including psilocybin, ketamine, 5-MeO-DMT, 6-fluoro-DET, MDMA, acute fluoxetine, chronic fluoxetine, and vehicle. In one-versus-rest classification, the exact drug was identified with 67% accuracy, significantly above the chance level of 12.5%. In one-versus-one classifications, psilocybin was discriminated from 5-MeO-DMT, ketamine, MDMA, or acute fluoxetine with >95% accuracy. We used Shapley additive explanation to pinpoint the brain regions driving the machine learning predictions. Our results support a novel approach for screening psychoactive drugs with psychedelic properties.
PubMed: 38826215
DOI: 10.1101/2024.05.23.590306 -
The Primary Care Companion For CNS... May 2024The Psychiatric Consultation Service at Massachusetts General Hospital sees medical and surgical inpatients with comorbid psychiatric symptoms and conditions. During...
The Psychiatric Consultation Service at Massachusetts General Hospital sees medical and surgical inpatients with comorbid psychiatric symptoms and conditions. During their twice-weekly rounds, Dr Stern and other members of the Consultation Service discuss diagnosis and management of hospitalized patients with complex medical or surgical problems who also demonstrate psychiatric symptoms or conditions. These discussions have given rise to rounds repors that will prove useful for clinicians practicing at the interface of medicine and psychiatry. .
Topics: Humans; Psilocybin; Hallucinogens; Mental Disorders
PubMed: 38815272
DOI: 10.4088/PCC.23f03652 -
Clinical Case Reports Jun 2024Long-COVID syndrome lacks effective holistic treatment options. We present a case of a 41-year-old fully vaccinated female with Long-COVID syndrome who obtained...
KEY CLINICAL MESSAGE
Long-COVID syndrome lacks effective holistic treatment options. We present a case of a 41-year-old fully vaccinated female with Long-COVID syndrome who obtained significant symptomatic relief after self-medicating with psilocybin and MDMA.
ABSTRACT
Long-COVID, a syndrome persisting after the acute phase of coronavirus disease 2019 (COVID-19), lacks effective holistic treatment options. We present a case of a 41-year-old fully vaccinated female with Long-COVID syndrome who obtained significant symptomatic relief by self-prescribing psilocybin and MDMA. Future research is needed to assess safety and efficacy.
PubMed: 38813452
DOI: 10.1002/ccr3.8791 -
Journal of Neurophysiology Jul 2024Psilocybin is a serotonergic psychedelic believed to have therapeutic potential for neuropsychiatric conditions. Despite well-documented prevalence of perceptual...
Psilocybin is a serotonergic psychedelic believed to have therapeutic potential for neuropsychiatric conditions. Despite well-documented prevalence of perceptual alterations, hallucinations, and synesthesia associated with psychedelic experiences, little is known about how psilocybin affects sensory cortex or alters the activity of neurons in awake animals. To investigate, we conducted two-photon imaging experiments in auditory cortex of awake mice and collected video of free-roaming mouse behavior, both at baseline and during psilocybin treatment. In comparison with pre-dose neural activity, a 2 mg/kg ip dose of psilocybin initially increased the amplitude of neural responses to sound. Thirty minutes post-dose, behavioral activity and neural response amplitudes decreased, yet functional connectivity increased. In contrast, control mice given intraperitoneal saline injections showed no significant changes in either neural or behavioral activity across conditions. Notably, neuronal stimulus selectivity remained stable during psilocybin treatment, for both tonotopic cortical maps and single-cell pure-tone frequency tuning curves. Our results mirror similar findings regarding the effects of serotonergic psychedelics in visual cortex and suggest that psilocybin modulates the balance of intrinsic versus stimulus-driven influences on neural activity in auditory cortex. Recent studies have shown promising therapeutic potential for psychedelics in treating neuropsychiatric conditions. Musical experience during psilocybin-assisted therapy is predictive of treatment outcome, yet little is known about how psilocybin affects auditory processing. Here, we conducted two-photon imaging experiments in auditory cortex of awake mice that received a dose of psilocybin. Our results suggest that psilocybin modulates the roles of intrinsic neural activity versus stimulus-driven influences on auditory perception.
Topics: Animals; Auditory Cortex; Mice; Psilocybin; Hallucinogens; Male; Mice, Inbred C57BL; Neurons; Auditory Perception; Acoustic Stimulation
PubMed: 38810366
DOI: 10.1152/jn.00124.2024 -
Frontiers in Psychiatry 2024Intense interest surrounds current research on psychedelics, particularly regarding their potential in treating mental health disorders. Various studies suggest a link... (Review)
Review
Intense interest surrounds current research on psychedelics, particularly regarding their potential in treating mental health disorders. Various studies suggest a link between the subjective effects produced by psychedelics and their therapeutic efficacy. Neuroimaging evidence indicates an association of changes in brain functional connectivity with the subjective effects of psychedelics. We conducted a review focusing on psychedelics and brain functional connectivity. The review focused on four psychedelic drugs: ayahuasca, psilocybin and LSD, and the entactogen MDMA. We conducted searches in databases of MEDLINE, Embase, APA PsycInfo and Scopus from inception to Jun 2023 by keywords related to functional connectivity and psychedelics. Using the PRISMA framework, we selected 24 articles from an initial pool of 492 for analysis. This scoping review and analysis investigated the effects of psychedelics on subjective experiences and brain functional connectivity in healthy individuals. The studies quantified subjective effects through psychometric scales, revealing significant experiences of altered consciousness, mood elevation, and mystical experiences induced by psychedelics. Neuroimaging results indicated alterations in the functional connectivity of psychedelics, with consistent findings across substances of decreased connectivity within the default mode network and increased sensory and thalamocortical connectivity. Correlations between these neurophysiological changes and subjective experiences were noted, suggesting a brain network basis of the psychedelics' neuropsychological impact. While the result of the review provides a potential neural mechanism of the subjective effects of psychedelics, direct clinical evidence is needed to advance their clinical outcomes. Our research serves as a foundation for further exploration of the therapeutic potential of psychedelics.
PubMed: 38807690
DOI: 10.3389/fpsyt.2024.1386321 -
BioRxiv : the Preprint Server For... May 2024Intracellular calcium (Ca) is ubiquitous to cell signaling across all biology. While existing fluorescent sensors and reporters can detect activated cells with elevated...
Intracellular calcium (Ca) is ubiquitous to cell signaling across all biology. While existing fluorescent sensors and reporters can detect activated cells with elevated Ca levels, these approaches require implants to deliver light to deep tissue, precluding their noninvasive use in freely-behaving animals. Here we engineered an enzyme-catalyzed approach that rapidly and biochemically tags cells with elevated Ca in vivo. Ca-activated Split-TurboID (CaST) labels activated cells within 10 minutes with an exogenously-delivered biotin molecule. The enzymatic signal increases with Ca concentration and biotin labeling time, demonstrating that CaST is a time-gated integrator of total Ca activity. Furthermore, the CaST read-out can be performed immediately after activity labeling, in contrast to transcriptional reporters that require hours to produce signal. These capabilities allowed us to apply CaST to tag prefrontal cortex neurons activated by psilocybin, and to correlate the CaST signal with psilocybin-induced head-twitch responses in untethered mice.
PubMed: 38798353
DOI: 10.1101/2023.09.06.556431 -
Trials May 2024Symptoms of anxiety and depression are common in patients with terminal illness and multiple challenges exist with timely and effective care in this population. Several...
BACKGROUND
Symptoms of anxiety and depression are common in patients with terminal illness and multiple challenges exist with timely and effective care in this population. Several centres have reported that one dose of the serotonergic psychedelic psilocybin, combined with therapeutic support, improves these symptoms for up to 6 months in this patient group. Drawing upon related therapeutic mechanisms, 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy may have the potential to achieve similar, positive mental health outcomes in this group. Preliminary evidence also supports the tolerability of MDMA-assisted therapy for anxiety and depression in advanced-stage cancer.
METHODS
Up to 32 participants with advanced-stage cancer and associated depression and anxiety will be randomised in a 1:1 ratio into one of two blinded parallel treatment arms. The intervention group will receive 120 mg (+ 60 mg optional supplemental dose) MDMA-assisted therapy. The psychoactive control group will receive 20 mg oral (+ 10 mg optional supplemental dose) methylphenidate-assisted therapy. For each medication-assisted therapy session, participants will undergo two 90-min therapeutic support sessions in the week preceding, and one 90-min support session the day after the experimental session. A battery of measures (mood, anxiety, quality of life, mystical experience, spiritual wellbeing, attitudes towards death, personality traits, holistic health and wellbeing, connectedness, demoralisation, expectations, qualitative data and safety measures) will be assessed at baseline and through to the end of the protocol. Participants will be followed up until either 12 months post-randomisation or death, whichever occurs first.
DISCUSSION
This study will examine the effect of MDMA-assisted therapy on symptoms of anxiety and depression in advanced-stage cancer. Potential therapeutic implications include establishing the safety and effectiveness of a novel treatment that may relieve mental suffering in patients with life-threatening illness.
TRIAL REGISTRATION
Trial registered on Australian New Zealand Clinical Trials Registry.
REGISTRATION NUMBER
ACTRN12619001334190p. Date registered: 30/09/2019. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378153&showOriginal=true&isReview=true.
Topics: Humans; N-Methyl-3,4-methylenedioxyamphetamine; Neoplasms; Anxiety; Double-Blind Method; Randomized Controlled Trials as Topic; Affect; Hallucinogens; Treatment Outcome; Depression; Quality of Life; Methylphenidate; Time Factors; Male; Neoplasm Staging
PubMed: 38773523
DOI: 10.1186/s13063-024-08174-x -
ACS Chemical Neuroscience Jun 2024Results from randomized clinical trials of psilocybin in depressive disorders highlight the therapeutic potential of serotonergic psychedelic compounds in mental health...
Results from randomized clinical trials of psilocybin in depressive disorders highlight the therapeutic potential of serotonergic psychedelic compounds in mental health disorders. The synthetic 5-hydroxytryptamine 2A receptor agonist 4-hydroxy-,-diisopropyltryptamine (4-OH-DiPT) is structurally similar to psilocin but is reported to have a shorter duration (2-3 h) of psychedelic effects, suggesting the potential for psilocybin-like therapeutic activity with reduced clinical resource burden. Here, we describe the preclinical and translational characterization of RE104, a 4-OH-DiPT prodrug comprising a glutarate moiety designed to cleave rapidly in situ and thus provide reasonable bioavailability of the active drug. Plasma concentration of 4-HO-DiPT over time in PK experiments in rats was correlated with head-twitch intensity. The half-life of 4-OH-DiPT was 40 min after subcutaneous administration of RE104 in rats. In a forced swim test, a single dose of RE104 (1 mg/kg) significantly reduced mean immobility time at 1 week compared with vehicle ( < 0.001), confirming translational antidepressant potential. Taken together, these data with RE104 show that the glutarate ester can act as an efficient prodrug strategy for 4-HO-DiPT, a unique short-duration psychedelic with potential in depressive disorders.
Topics: Animals; Prodrugs; Hallucinogens; Male; Rats; Rats, Sprague-Dawley; Tryptamines; Antidepressive Agents
PubMed: 38758589
DOI: 10.1021/acschemneuro.4c00058