Acute Biphasic Effects of Ayahuasca

PLoS One. 2015 Sep 30;10(9):e0137202. doi: 10.1371/journal.pone.0137202. eCollection 2015.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Banisteriopsis / chemistry*
  • Brain / drug effects
  • Brain / physiology
  • Brain Waves / drug effects
  • Electroencephalography
  • Female
  • Humans
  • Male
  • Middle Aged
  • Plant Extracts / chemistry*
  • Plant Extracts / pharmacology*
  • Psychometrics
  • Young Adult

Substances

  • Plant Extracts

Grant support

This work was supported by Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP) grants 2011/11341-8 (EES), 2012/07699-7 (DXS), 2014/07540-3 (EES) and 2015/13536-1 (DXS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.