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
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, 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, 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
February 28, 2024
Daniel L. Hall, Will Lawn, Shelan Ofori et al.
5 citations
Acute intoxication with vaporized THC eliminated attentional bias away from cannabis-related cues in both adolescents and adults who used cannabis 0.5–3 days per week. In a randomized, double-blind, placebo-controlled crossover study with 48 participants (24 adolescents aged 16–17 and 24 adults aged 26–29), a weight-adjusted dose of 8 mg THC eliminated the bias, while adding 24 mg CBD did not alter this effect. There was no significant difference in response between age groups. The findings suggest that acute THC intoxication shifts attentional processing of cannabis cues, but CBD does not moderate this effect.
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
April 30, 2025
Johannes G. Ramaekers, Johannes T. Reckweg, Natasha L. Mason et al.
4 citations
Low to moderate doses of 3-methylmethcathinone (3-MMC) produce prolonged, dose-related analgesic effects in healthy volunteers. In a cross-over, placebo-controlled study with 14 participants, doses of 25, 50, and 100 mg elevated pressure pain threshold and reduced subjective painfulness and unpleasantness in both pressure pain threshold and cold pressor test paradigms. The analgesic effects were most prominent after 50 and 100 mg and persisted for up to 5 hours after dosing. 3-MMC also produced dose-related mood improvements at 1 hour but not at 5 hours. The findings suggest that doses low enough to avoid challenging subjective experiences and associated with a benign side effect profile may be sufficient for analgesia.
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 Rodríguez 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
F. Bermond, J. Bert
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.
Psychopharmacology
March 26, 2025
Laura Ley, Matthias E Liechti, Anna M Becker et al.
3 citations
Healthy volunteers enroll in psychedelic trials primarily out of interest in the substances and the appeal of the study setting, hoping for personal development and transformative experiences. In a series of six double-blind, placebo-controlled trials involving 151 participants, positive experiences were promoted by music, access to nature, and a trusting relationship with the investigator. A sterile hospital environment, lack of investigator support, and investigator-induced discomfort were criticized. Most volunteers felt their expectations were exceeded and would take the substances again, ideally in a natural setting with friends. Four key factors for positive study experiences are a secure interpersonal relationship, an aesthetically pleasing environment, access to nature, and music.
Psychopharmacology
January 18, 2025
Sharon R Sznitman, Yoel A Behar, Sheila Daniela Dicker-Oren et al.
3 citations
In a non-clinical sample of 36 adults attending a 4-day ayahuasca retreat, positive affect and mindfulness skills improved while negative affect decreased in the days following the retreat compared to before. Acute experiences such as feelings of transcendence, emotional breakthrough, and challenging experiences predicted greater positive affect afterward, but none of these acute experiences were linked to improvements in negative affect or mindfulness. No participants showed clinically significant adverse responses, and only 5.5% showed some degree of potentially clinically significant deterioration in affect. The findings suggest ayahuasca may improve mood and mindfulness, with certain acute experiences contributing specifically to increased positive affect.
Psychopharmacology
June 1, 1977
Sergio Solbes Ferri, Roser Reina, C. Spadaro et al.
3 citations
In rabbits, the narcotic antagonist naloxone does not block pain relief (antinociception) caused by 100 micrograms per kilogram of mescaline injected into the brain, but pretreatment with 6-hydroxydopamine (6-OHDA) does prevent this effect. 6-OHDA also prevents the stereotyped behavior that follows central mescaline administration. Because 6-OHDA destroys nerve terminals that contain catecholamines, the findings suggest that catecholamines play a crucial role in the effects produced by the hallucinogen mescaline when given centrally to rabbits.
Psychopharmacology
January 1, 1975
R. Utzinger
3 citations
Rabbits produced antibodies that specifically bind mescaline after being immunized with conjugates of bovine serum albumin and mescaline or its analogue 3,4,5-trimethoxyphenylacetic acid. Immunized rats that received mescaline showed behavioral differences compared to non-immunized controls, suggesting that the antibodies altered the drug's effects.
Psychopharmacology
March 1, 2026
Patricia Di Ciano, Sampson Zhao, Pamela Kaduri et al.
2 citations
Taking a low-dose cannabis edible (average 7.3 mg of THC) leads to measurable decreases in verbal learning and memory, specifically on two measures of a free recall task, 150 minutes after ingestion. No effects were found on visual attention or executive function as measured by the useful field of view and trail making tests. Subjective feelings of intoxication increased, but blood THC levels did not correlate with any cognitive performance changes. The results suggest that people who use relatively low doses of cannabis edibles may experience some cognitive decrements while feeling intoxicated.
Psychopharmacology
June 1, 2025
Carmen Abate, Richard Young, Małgorzata Dukat et al.
2 citations
The drug α-ethyltryptamine (α-ET), once used as an antidepressant and structurally related to the hallucinogen α-methyltryptamine, produces stimulus effects in rats that are similar to those of the phenylalkylamines MDMA (Ecstasy) and MDA (Love Drug). Rats trained to discriminate α-ET from saline showed full generalization to both MDMA and MDA. Four synthetic analogs of α-ET produced varied results: 4-OMe α-ET showed negligible α-ET-like effects, 5-OMe α-ET modest effects, while 6-OMe α-ET and 7-OMe α-ET fully generalized but with a narrow dose range for the former. α-ET appears to exert a complex stimulus combining features of MDMA, MDA, hallucinogens, and stimulants, suggesting it is a tryptamine counterpart to these phenylalkylamines.
Psychopharmacology
June 1, 2025
Bahar Yuksel, Zeynep Sen, Gunes Unal
2 citations
A single antidepressant dose of ketamine (10 mg/kg) given to adult Wistar rats partially impaired fear extinction when administered before fear acquisition or retrieval, but did not affect encoding or retrieval of cued fear or spatial memory. In the Morris Water Maze, ketamine facilitated memory modulation and reduced escape latency during the first day of reversal training when given before training or reversal sessions. The drug did not impair acquisition or retrieval processes in either implicit (fear) or explicit (spatial) memory tasks, but exerted opposing effects on memory modulation: disrupting fear extinction while facilitating reversal spatial learning.
Psychopharmacology
April 23, 2025
Jonathan David, Aviva Berkovich-Ohana, Yair Dor-Ziderman
2 citations
People who regularly use ayahuasca show lower death anxiety, less fear of death, less avoidant behavior around death, and greater acceptance of death compared to non-users. A cross-sectional study of 54 ayahuasca veterans and 53 non-users measured these differences using questionnaires and behavioral tasks. The differences were not explained by demographics, personality, mindfulness, beliefs about the afterlife, or awareness of impermanence. Instead, acceptance of impermanence—the willingness to embrace life's transience—was the key mechanism. Among ayahuasca users, the intensity of lifetime ego-dissolution experiences predicted how much they accepted impermanence. This suggests that acute psychedelic experiences can foster lasting changes in how people process mortality, and that promoting impermanence acceptance may help manage existential fear.