2026-04-17T04:33:07Zhttps://recercat.cat/oai/request

oai:recercat.cat:2072/4813532025-05-08T16:31:05Zcom_2072_98col_2072_378192

00925njm 22002777a 4500 dc Valle, Marta author Maqueda, Ana Elda author Rabella, Mireia author Rodríguez-Pujadas, Aina author Antonijoan Arbós, Rosa Ma (Rosa María) author Romero, Sergio author Alonso, Joan Francesc author Mañanas, Miquel Àngel author Barker, Steven author Friedlander, Pablo author Feilding, Amanda author Riba, Jordi author Universitat Autònoma de Barcelona. Departament de Farmacologia, de Terapèutica i de Toxicologia author 2016 Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus β-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT receptor, the molecular target of classical psychedelics, this has not been tested experimentally. Here we wished to study the contribution of the 5-HT receptor to the neurophysiological and psychological effects of ayahuasca in humans. We measured drug-induced changes in spontaneous brain oscillations and subjective effects in a double-blind randomized placebo-controlled study involving the oral administration of ayahuasca (0.75 mg DMT/kg body weight) and the 5-HT antagonist ketanserin (40 mg). Twelve healthy, experienced psychedelic users (5 females) participated in four experimental sessions in which they received the following drug combinations: placebo+placebo, placebo+ayahuasca, ketanserin+placebo and ketanserin+ayahuasca. Ayahuasca induced EEG power decreases in the delta, theta and alpha frequency bands. Current density in alpha-band oscillations in parietal and occipital cortex was inversely correlated with the intensity of visual imagery induced by ayahuasca. Pretreatment with ketanserin inhibited neurophysiological modifications, reduced the correlation between alpha and visual effects, and attenuated the intensity of the subjective experience. These findings suggest that despite the chemical complexity of ayahuasca, 5-HT activation plays a key role in the neurophysiological and visual effects of ayahuasca in humans. Ayahuasca Human Ketanserin Neurophysiological effects Serotonin-(2A) receptor Subjective effects Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans