title: Acute Biphasic Effects of Ayahuasca.
abstract: Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.
authors.affiliation: Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Eduardo Ekman
authors.initials: EE
authors.lastname: Schenberg
authors.affiliation: Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Santo André, Brazil.
authors.forename: João Felipe Morel
authors.initials: JF
authors.lastname: Alexandre
authors.affiliation: Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Filev
authors.affiliation: Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Santo André, Brazil.
authors.forename: Andre Mascioli
authors.initials: AM
authors.lastname: Cravo
authors.affiliation: Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Santo André, Brazil.
authors.forename: João Ricardo
authors.initials: JR
authors.lastname: Sato
authors.affiliation: Schools of Pharmacy and Psychology, University of Auckland, Auckland, New Zealand.
authors.forename: Suresh D
authors.initials: SD
authors.lastname: Muthukumaraswamy
authors.affiliation: Departamento de Análises Clinicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Maurício
authors.initials: M
authors.lastname: Yonamine
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, United States of America.
authors.forename: Marian
authors.initials: M
authors.lastname: Waguespack
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, United States of America.
authors.forename: Izabela
authors.initials: I
authors.lastname: Lomnicka
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, United States of America.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Barker
authors.affiliation: Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Dartiu Xavier
authors.initials: DX
authors.lastname: da Silveira
mesh_terms: D000328:Adult; D031581:Banisteriopsis / Q000737:chemistry*; D001921:Brain / Q000187:drug effects / Q000502:physiology; D058256:Brain Waves / Q000187:drug effects; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D011594:Psychometrics; D055815:Young Adult
chemical_list: D010936:Plant Extracts