Effects of ayahuasca on sensory and sensorimotor gating in humans as measured by P50 suppression and prepulse inhibition of the startle reflex, respectively
Jordi Riba, Antoni Rodrı́guez-fornells, Manel J. Barbanoj
Psychopharmacology December 1, 2002 DOI: 10.1007/s00213-002-1237-5 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Double-blind, cross-over balanced design Peer reviewed |
|---|---|
| Sample size | 18 |
| Population | Healthy volunteers with prior experience of psychedelic drug use |
| Intervention | Ayahuasca |
| Dose | 0.6 mg and 0.85 mg DMT/kg body weight |
| Duration | Recordings at 1.5 h and 2 h after drug intake |
| Topics | Ayahuasca Psilocybin Serotonin |
| Keywords | Prepulse inhibition Sensory gating Moro reflex Hallucinogen Agonist Startle response Pharmacology Anesthesia |
| Citations | 71 |
| Key points | Ayahuasca produced dose-dependent reductions in P50 suppression (sensory gating) but no significant effects on prepulse inhibition of startle (sensorimotor gating). |
Abstract
RationaleAyahuasca, a South American psychotropic plant tea, combines the psychedelic agent and 5-HT(2A/2C) agonist N, N-dimethyltryptamine (DMT) with beta-carboline alkaloids showing monoamine oxidase-inhibiting properties. Current human research with psychedelics and entactogens has explored the possibility that drugs displaying agonist activity at the 5-HT(2A/2C) sites temporally disrupt inhibitory neural mechanisms thought to intervene in the normal filtering of information. Suppression of the P50 auditory evoked potential (AEP) and prepulse inhibition of startle (PPI) are considered operational measures of sensory (P50 suppression) and sensorimotor (PPI) gating. Contrary to findings in lower animals, unexpected increases in sensorimotor gating have been found in humans following the administration of the serotonergic psychedelic psilocybin and the serotonin releaser 3,4-methylenedioxymethamphetamine (MDMA). In addition, to our knowledge P50 suppression has not been assessed previously in humans following the administration of a 5-HT(2A/2C) agonist.ObjectivesTo assess the effects of the acute administration of ayahuasca on P50 suppression and PPI in humans, in order to evaluate the drug's modulatory actions on these measures of sensory and sensorimotor gating.MethodsEighteen healthy volunteers with prior experience of psychedelic drug use participated in a clinical trial in which placebo or ayahuasca doses (0.6 mg and 0.85 mg DMT/kg body weight) were administered according to a double-blind, cross-over balanced design. P50 and startle reflex (pulse-alone and 60 ms, 120 ms, 240 ms and 2000 ms prepulse-to-pulse intervals) recordings were undertaken at 1.5 h and 2 h after drug intake, respectively.ResultsAyahuasca produced diverging effects on each of the two gating measures evaluated. Whereas significant dose-dependent reductions of P50 suppression were observed after ayahuasca, no significant effects were found on the startle response, its habituation rate, or on PPI at any of the prepulse-to-pulse intervals studied.ConclusionThe present findings indicate, at the doses tested, a decremental effect of ayahuasca on sensory gating, as measured by P50 suppression, and no distinct effects on sensorimotor gating, as measured by PPI.
Comparable studies
Other randomized controlled trials on ayahuasca, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial Patients with treatment-resistant depression | 2018 | Randomized controlled trial | n = 29 |
| Human Pharmacology of Ayahuasca: Subjective and Cardiovascular Effects, Monoamine Metabolite Excretion, and Pharmacokinetics Volunteers with prior experience in the use of psychedelics | 2003 | Double-blind placebo-controlled clinical trial | n = 18 |
| Subjective effects and tolerability of the South American psychoactive beverage Ayahuasca in healthy volunteers Healthy male volunteers with prior experience using ayahuasca | 2001 | Single-blind crossover placebo-controlled clinical trial | n = 6 |
| Increased frontal and paralimbic activation following ayahuasca, the pan-amazonian inebriant Male volunteers with prior experience in the use of psychedelics | 2006 | Randomized controlled trial | n = 15 |
| Human brain effects of DMT assessed via EEG-fMRI. Healthy volunteers | 2023 | Within-subjects, placebo-controlled design | n = 20 |
Citations in the library
Cited by 42
- Acute Effects of Lysergic Acid Diethylamide in Healthy Subjects Biological Psychiatry November 29, 2014
- Clinical investigations of the therapeutic potential of ayahuasca: rationale and regulatory challenges. Pharmacology & Therapeutics May 1, 2004
- Looking for the Self: Phenomenology, Neurophysiology and Philosophical Significance of Drug-induced Ego Dissolution Frontiers in Human Neuroscience May 23, 2017
- Hallucinogens and dissociative agents naturally growing in the United States. Pharmacology & Therapeutics May 1, 2004
- Ayahuasca enhances creative divergent thinking while decreasing conventional convergent thinking Psychopharmacology July 19, 2016
and 37 more in the library
Cites 12
- Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action Neuroreport December 1, 1998
- The Standardized Psychometric Assessment of Altered States of Consciousness (ASCs) in Humans Pharmacopsychiatry July 1, 1998
- Dose-Response Study of N,N-Dimethyltryptamine in Humans Archives of General Psychiatry February 1, 1994
- Monoamine oxidase inhibitors in South American hallucinogenic plants: Tryptamine and β-carboline constituents of Ayahuasca Journal of Ethnopharmacology April 1, 1984
- Subjective effects and tolerability of the South American psychoactive beverage Ayahuasca in healthy volunteers Psychopharmacology February 22, 2001
and 7 more in the library