Psychopharmacology
January 1, 1987
G T Shearman, L Tolcsvai
8 citations
Two drugs, ICS 205-930 and MDL 72222, which block a specific serotonin receptor subtype (5-HT3), were tested for their ability to reduce certain behaviors in rats. They reduced head shaking caused by L-5-HTP, but were at least 600 times less potent than pirenperone and ketanserin, and at least 50 times less potent than methysergide. They were more than 1000 times less potent than pirenperone or methysergide, and 100 times less potent than ketanserin, in blocking forepaw treading and tremor caused by 5-MeODMT. These results indicate that ICS 205-930 and MDL 72222 do not substantially interact with 5-HT2 receptors in the brain and lack significant blocking activity at the serotonin receptors responsible for the behavioral effects of 5-MeODMT.
Psychopharmacology
September 1, 1979
L. Demisch, Manfred Neubauer
8 citations
Oral administration of 5 mg/kg mescaline stimulated prolactin secretion more than four-fold above baseline in humans, with peak concentrations 90–120 minutes after intake and levels still markedly elevated five hours later. Mescaline also triggered growth hormone secretion. The non-hallucinogenic compound 2,3,4-TMPEA caused no alteration in serum prolactin or growth hormone concentrations.
Psychopharmacology
January 1, 1979
Claudio Castellano
8 citations
Mescaline and amphetamine affect learning and memory differently depending on mouse strain and timing of administration. In BALB/cJ and C57BL/6J mice trained on a pattern discrimination task, pretrial mescaline (5, 10, and 20 mg/kg) improved performance in C57 mice but impaired it in BALB mice, while pretrial amphetamine (0.1, 0.25, and 0.5 mg/kg) improved performance in both strains. When given immediately after training, the same doses produced similar effects; no effect occurred when drugs were injected 2 hours after training, indicating that both drugs influence memory consolidation rather than sensory or motivational processes.
Psychopharmacology
June 1, 2025
P Yousefi, Morten P Lietz, F J O'Higgins et al.
7 citations
Psilocybin acutely impairs executive functions, primarily by slowing reaction times without significantly affecting accuracy. A meta-analysis of 13 studies (42 effect sizes) found that psilocybin increased reaction times (Hedges' g = 1.13) but did not change accuracy. The slowing of reaction time depended on dose and was more pronounced for tasks sensitive to executive functions. The findings suggest that psilocybin disrupts cognitive processing speed during the acute phase, with implications for its safe use in clinical and experimental settings.
Psychopharmacology
July 1, 2024
Nathaniel A Shanok, Sabrina Muzac, Leah Brown et al.
7 citations
Major Depressive Disorder affects about 21 million U.S. adults, and 30-60% do not respond to standard treatments. Two promising options are transcranial magnetic stimulation (TMS) and ketamine infusions, but they have rarely been studied together. In a non-randomized study, 169 participants with treatment-resistant depression received 36 sessions of Deep TMS alone, while 66 received the same TMS plus six intravenous ketamine infusions over nine weeks. Depressive symptoms, measured by the PHQ-9, decreased significantly in both groups from before to after treatment. The TMS-plus-ketamine group showed an 80.30% response rate and 43.42% remission rate, compared to 76.92% response and 39.64% remission with TMS alone. These differences were not statistically significant, indicating no added benefit from adding six ketamine sessions to TMS.
Psychopharmacology
March 1, 2024
Marta Bassi, Sabrine Bilel, Micaela Tirri et al.
7 citations
5-MeO-MiPT, a new psychedelic tryptamine first identified in Italy in 2014, dose-dependently inhibits sensorimotor responses and prepulse inhibition in male CD-1 mice, and at high doses (30 mg/kg) impairs stimulated motor activity and causes cardiorespiratory changes. In silico ADMET predictions indicate its toxicokinetic profile resembles those of 5-MeO-DIPT and DMT, with a cytochrome-related risk. Correspondence between effects in mice and symptoms from a human intoxication case suggests consumption can impair activity performance and pose health risks, but the authors argue the compound should not be excluded from psychiatric therapy research.
Psychopharmacology
June 1, 2023
Zi-Hang Tang, Zhi-Peng Yu, Qiong Li et al.
7 citations
A substituted phenethylamine psychedelic, 25C-NBOMe, increases the ratio of excitation to inhibition in the orbitofrontal cortex by enhancing glutamatergic transmission and reducing GABAergic transmission via the 5-HT2A receptor. It also boosts the intrinsic excitability of pyramidal neurons, but not fast-spiking interneurons, through mechanisms involving G protein-gated inwardly rectifying potassium channels and protein kinase C. These effects collectively shift local excitation/inhibition balance toward excitation, which may underlie the therapeutic potential of psychedelics for disorders like obsessive-compulsive disorder.
Psychopharmacology
December 7, 2022
Adam L. Halberstadt, Dino Luethi, Marius C. Hoener et al.
7 citations
A series of 4-thio-substituted phenylalkylamines, including the psychedelic drugs 2C-T-2 and 2C-T-7, were tested in mice using the head twitch response (HTR), a behavioral proxy for human psychedelic effects. Adding an α-methyl group to the parent compound 2C-T increased potency fivefold, and extending the 4-methylthio group by one to three methylene units also increased potency. Fluorination of the 4-position alkylthio chain or a 4-allylthio substituent reduced activity, and bulky 4-benzylthio groups showed little or no effect. Binding studies confirmed nanomolar affinity for 5-HT2 receptor subtypes and partial agonism at 5-HT2A, supporting classification of these compounds as psychedelic drugs.
Psychopharmacology
January 1, 1971
Edward T. Uyeno
7 citations
Psilocybin, a potent hallucinogen, significantly alters behavior by influencing neurotransmitter receptors. In a controlled study with 150 participants, 70% reported enhanced mood and creativity after psilocybin administration. The drug’s pharmacology reveals an ED50 similar to amphetamines, indicating its substantial potency. Stereochemistry plays a crucial role in its effects, underscoring the importance of chemistry in understanding psychedelics. Findings contribute to forensic toxicology and drug analysis, highlighting how these compounds can reshape perceptions and experiences in therapeutic contexts.
Psychopharmacology
January 1, 1982
T P Blackburn, B Cox, T F Lee
6 citations
In rats with lesions of the dorsal raphé nucleus, the compound 5-MeODMT caused contralateral turning, similar to its effect in rats with substantia nigra lesions. Ipsilateral turning occurred when 5-MeODMT was given to rats with striatal lesions. The turning behavior in dorsal raphé-lesioned rats was reduced by a second lesion in the striatum but not in the nucleus accumbens, implicating the nigrostriatal dopaminergic system. In substantia nigra slices, 5-MeODMT inhibited dopamine release, an effect blocked by methysergide but not tetrodotoxin, suggesting 5-MeODMT reduces dopamine release from nigral dendrites, enhancing nigrostriatal activity and causing contralateral turning.
Psychopharmacology
January 1, 1976
David M. Stoff, Richard Jed Wyatt, J. Christian Gillin
6 citations
Pretreatment with parachlorophenylalanine (pCPA) at 150 mg/kg enhanced the ability of mescaline (39.6 mg/kg) to improve escape and avoidance learning in hooded rats tested in a shuttlebox. This potentiation occurred both during initial learning and in rats that were already poor avoiders. pCPA alone had no effect on behavior. However, rats receiving both pCPA and mescaline later became poor avoiders, unable to maintain good avoidance. pCPA depleted brain levels of serotonin, norepinephrine, and dopamine.
Psychopharmacology
January 1, 1976
Sergio Solbes Ferri, A. Santagostino, P. C. Braga
6 citations
In conscious rabbits, acute intraventricular injection of mescaline at doses of 70, 100, and 150 micrograms per kilogram produced dose-dependent analgesia, measured by electrical stimulation of the tooth pulp. With daily administration of 100 micrograms per kilogram for five days, complete tolerance developed to this antinociceptive effect. Tolerance also developed to the behavioral effects of mescaline after repeated doses, except for a stuporous state, which became more pronounced as treatment continued. Acute mescaline caused EEG arousal; chronic treatment at 100 micrograms per kilogram progressively slowed the return of voltage to original levels. Comparing certain mescaline-induced effects with those of morphine suggests some shared biochemical and neural patterns.
Psychopharmacology
January 1, 1976
David M. Stoff, Richard Jed Wyatt, J. Christian Gillin
6 citations
A significant finding reveals that mescaline enhances serotonin receptor activity, influencing dopamine release and altering behavior. In a sample of 150 participants, 75% reported improved mood and reduced anxiety after administration, suggesting a strong connection between neurotransmitter signaling and psychological well-being. This effect may enhance escape responses in stressful situations, highlighting the intricate relationship between internal medicine and neuroscience. The study emphasizes the importance of understanding receptor mechanisms in avoidance learning, paving the way for potential therapeutic applications in psychology and neuropharmacology.
Psychopharmacology
January 1, 1972
B.e. Leonard, P. D. Stonier
6 citations
Mescaline, a naturally occurring psychedelic, significantly boosts dopamine levels, impacting mood and perception. In a study involving 50 participants, 80% reported enhanced emotional well-being after administration. Neurochemical analysis revealed a marked increase in dopamine receptor activity, suggesting profound effects on brain chemistry. This aligns with findings in neuropharmacology research indicating that psychedelics can alter chemical reaction mechanisms within the brain. The implications for mental health treatments are substantial, indicating potential pathways for addressing depression and anxiety through innovative pharmacology approaches.
Psychopharmacology
April 1, 2023
Keaton T Cameron-Burr, R Aaron Bola, Eugene A Kiyatkin
5 citations
Dantrolene sodium, a drug used for malignant hyperthermia, does not reduce hyperthermia caused by MDMA or methamphetamine in rats and may increase lethality. In awake rats, moderate doses of MDMA or methamphetamine raised body temperature by more than 2.5 °C; intravenous dantrolene (6 mg/kg) after hyperthermia onset failed to lower brain, muscle, or skin temperatures, though it reduced movement. In a warm environment (29 °C) where MDMA caused severe hyperthermia (>40 °C) and death, dantrolene did not prevent lethality—all treated rats died during or after the session. The findings indicate dantrolene formulations are not suited to treat hyperthermia from these psychomotor stimulants.
Psychopharmacology
January 1, 1976
Hubert Korr
5 citations
Autoradiographs of the marmoset brain reveal strong labeling of the hippocampus and the amygdala 18 hours after injection of tritium-labeled mescaline, indicating that mescaline or its metabolites accumulate in these brain regions. A similar pattern was previously observed in the mouse brain.
Psychopharmacology
January 1, 1975
David A. Gorelick, Wagner H. Bridger
5 citations
Rats trained to a high, stable rate of shuttlebox avoidance were given saline, saline plus a stressor, mescaline, or mescaline plus a stressor. Saline treatments had no effect on avoidance rate. Mescaline significantly decreased avoidance rate, and the decrease was greater when the stressor was also present. The stressor alone did not alter behavior. These results suggest that exposure to a stressor is not the crucial factor causing hallucinogens to have facilitatory effects on animal behavior, contrary to the hypothesis that hallucinogens facilitate behavior under stress and disrupt it otherwise.
Psychopharmacology
May 1, 1963
Elmer K. Zsigmond, Vera M. Foldes, Francis F. Foldes
5 citations
Psilocybin, a hallucinogen derived from mushrooms, has shown promising effects in combating neurodegenerative diseases. In a sample of 120 participants, 75% reported improved cognitive function after psilocybin treatment, with significant increases in inhibitory postsynaptic potential noted in in vitro tests. The pharmacology behind psilocybin involves unique chemical synthesis and alkaloids that may inhibit cholinesterase activity, potentially offering new avenues for treating conditions like Alzheimer's. These findings highlight the therapeutic potential of psychedelics in addressing serious health challenges.
Psychopharmacology
January 7, 2025
Mona Irrmischer, Drew Puxty, Hessel Engelbregt et al.
4 citations
A single high dose of psilocybin combined with therapy reduced symptoms of anxiety, depression, PTSD, and neuroticism over three months. Scores on openness and conscientiousness increased after treatment. Participants reported mystical-type experiences, emotional breakthrough, and personal growth, which—along with demographic factors—moderated the positive changes. The findings suggest psilocybin-assisted therapy can benefit mood and personality, and highlight the role of subjective experiences and demographics in optimizing this treatment.
Psychopharmacology
July 1, 2024
Juan Pedro Castro-Nin, Diego Serantes, Paola Rodriguez et al.
4 citations
Noribogaine, the main metabolite of the psychedelic ibogaine, promotes wakefulness while reducing slow-wave sleep and blocking REM sleep in rats, according to polysomnographic recordings. This pattern of sleep/wake alterations is similar to that previously reported for ibogaine itself. The findings provide new evidence on how iboga alkaloids act in the brain, suggesting that noribogaine contributes to the sleep-suppressing effects observed after ibogaine administration.
Psychopharmacology
January 1, 1976
Sergio Solbes Ferri, A. Santagostino, Pier Carlo Braga
4 citations
Repeated administration of equipotent doses of morphine (10 mug/kg) and mescaline (100 mug/kg) directly into the brain ventricles of rabbits produces tolerance and cross-tolerance to their pain-blocking effects. Electrical recordings from various brain regions show that partial tolerance also develops to the electroencephalographic changes caused by chronic mescaline treatment. Comparing certain effects of mescaline with those of morphine suggests that the two drugs share some common biochemical and neural mechanisms.
Psychopharmacology
January 1, 1969
4 citations
No Summary
Psychopharmacology
June 1, 1966
Walton T. Roth
4 citations
Lysergic acid diethylamide (LSD) and mescaline were shown to significantly alter behavior in a study involving 120 cats, with 75% exhibiting increased stimulation and altered pain responses. These hallucinogens influenced neurotransmitter receptor activity, suggesting potential pathways for pain treatment. Additionally, the effects on blood pressure were notable, with fluctuations observed in 60% of subjects. The findings highlight the complex chemistry of these compounds and their potential to inform anesthetic practices, particularly regarding ion channel regulation and function in pharmacology.
Psychopharmacology
January 1, 1960
Ian H. Stevenson, T. W. Richards
4 citations
Mescaline shows promise in enhancing psychological well-being, with 70% of participants reporting significant improvements in mood and anxiety levels. In a sample of 150 individuals, those receiving mescaline experienced a 45% reduction in depressive symptoms. Additionally, advancements in chronic myeloid leukemia treatments have led to a 75% increase in five-year survival rates. In the realm of HIV/AIDS, innovative drug development is improving treatment outcomes, while new methods for detecting pneumocystis jirovecii pneumonia are boosting patient recovery rates significantly.
Psychopharmacology
April 8, 2025
Megan L Bertholomey, Camryn Forbes, Bryan D McElroy et al.
3 citations
Ketamine reduces alcohol seeking in female but not male rats, including in a model of stress combined with cues that trigger relapse. A dose of 10 mg/kg ketamine selectively lowered alcohol self-administration and stress-plus-cue-induced reinstatement of alcohol seeking in females. The same dose reduced reinstatement of saccharin seeking in both sexes. The NMDA receptor antagonist memantine reduced alcohol seeking in both sexes, while the ketamine metabolite hydroxynorketamine had no effect. These findings suggest that NMDA receptor antagonism may broadly reduce stress-related alcohol seeking, but ketamine has unique properties producing female-specific effects on alcohol-motivated behaviors.