Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans: a functional neuroimaging study using low-resolution electromagnetic tomography

This re-analysis of a double-blind, placebo-controlled clinical study (n=18) investigated the effects of ayahuasca (60mg DMT/70kg) on brain electrical activity with low-resolution electromagnetic tomography. They found a decrease in the delta, alpha-2, and beta-1 frequency rhythms over the temporo-parieto-occipital junction, and a decrease in theta rhythm in the temporomedial and frontomedial cortices.

Abstract of Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans

Introduction: Ayahuasca, a South American psychotropic plant tea obtained from Banisteriopsis caapi and Psychotria viridis, combines monoamine oxidase-inhibiting beta-carboline alkaloids with N,N-dimethyltryptamine (DMT), a psychedelic agent showing 5-HT(2A) agonist activity. In a clinical research setting, ayahuasca has demonstrated a combined stimulatory and psychedelic effect profile, as measured by subjective effect self-assessment instruments and dose-dependent changes in spontaneous brain electrical activity, which parallel the time course of subjective effects.

Methods: In the present study, the spatial distribution of ayahuasca-induced changes in brain electrical activity was investigated by means of low-resolution electromagnetic tomography (LORETA). Electroencephalography recordings were obtained from 18 volunteers after the administration of a dose of encapsulated freeze-dried ayahuasca containing 0.85 mg DMT/kg body weight and placebo. The intracerebral power density distribution was computed with LORETA from spectrally analyzed data, and subjective effects were measured by means of the Hallucinogen Rating Scale (HRS).

Results: Statistically significant differences compared to placebo were observed for LORETA power 60 and 90 min after dosing, together with increases in all six scales of the HRS. Ayahuasca decreased power density in the alpha-2, delta, theta and beta-1 frequency bands. Power decreases in the delta, alpha-2 and beta-1 bands were found predominantly over the temporo-parieto-occipital junction, whereas theta power was reduced in the temporomedial cortex and in frontomedial regions.

Discussion: The present results suggest the involvement of unimodal and heteromodal association cortex and limbic structures in the psychological effects elicited by ayahuasca.”

Authors: Jordi Riba, Peter Anderer, Francesc Jané, Bernd Saletu & Manel J. Barbanoj

Summary of Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans

The psychoactive plant tea known as ayahuasca has been used in the Upper Amazon since pre-Columbian times for religious and medicinal purposes. It has recently become popular in the United States and several European countries.

Botanical research has shown that the main ingredient of ayahuasca is the woody vine Banisteriopsis caapi (Malpighiaceae), which contains ß-carboline alkaloids, mainly harmine and tetrahydroharmine, and to a lesser extent harmaline and traces of harmol and harmalol.

Ayahuasca contains DMT from P. viridis and ß-carboline alkaloids from B. caapi, which prevents the extensive gut and liver first-pass effect on DMT, allowing it to reach the systemic circulation and the CNS unaltered.

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Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans: a functional neuroimaging study using low-resolution electromagnetic tomography

https://doi.org/10.1159/000077946

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Cite this paper (APA)

Riba, J., Anderer, P., Jané, F., Saletu, B., & Barbanoj, M. J. (2004). Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans: a functional neuroimaging study using low-resolution electromagnetic tomography. Neuropsychobiology50(1), 89-101.

Study details

Compounds studied
Ayahuasca

Topics studied
Neuroscience Healthy Subjects

Study characteristics
Original Re-analysis Placebo-Controlled Double-Blind Within-Subject Randomized

Participants
18 Humans

Authors

Authors associated with this publication with profiles on Blossom

Jordi Riba
Jordi Riba (1968 - 2020†) was a pioneering ayahuasca researcher who dedicated over two decades of work to the field. His work focussed on the pharmacokinetics and pharmacodynamics of ayahuasca, including alkaloid disposition, and electroencephalography, and neuroimaging measures of acute ayahuasca effects. He also conducted several studies on centrally-acting drugs on the acute and long-term effects of psychedelics, psychostimulants, cannabinoids, sedatives, and kappa-opioid receptor agonists. His later work moved towards investigating the neural and psychological mechanisms that could underlie the beneficial effects of ayahuasca in the treatment of various psychiatric conditions.

Institutes

Institutes associated with this publication

Hospital de Sant Pau
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Compound Details

The psychedelics given at which dose and how many times

Ayahuasca 56 mg | 1x

Linked Research Papers

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Topographic pharmaco-EEG mapping of the effects of the South American psychoactive beverage ayahuasca in healthy volunteers
This double-blind, crossover, placebo-controlled clinical study (n=18) investigated the effects of ayahuasca (42-60mg DMT/70kg) on temporal brain activity in healthy volunteers and found an absolute power decrease in all frequency bands measured with EEG, which paralleled the time course of its subjective effects.

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