Increased frontal and paralimbic activation following ayahuasca, the pan-amazonian inebriant
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Ayahuasca is a South American psychoactive plant tea which contains the serotonergic psychedelic N,N-dimethyltryptamine (DMT) and monoamine-oxidase inhibitors that render DMT orally active. Previous investigations with ayahuasca have highlighted a psychotropic effect profile characterized by enhanced introspective attention, with individuals reporting altered somatic perceptions and intense emotional modifications, frequently accompanied by visual imagery. Despite recent advances in the study of ayahuasca pharmacology, the neural correlates of acute ayahuasca intoxication remain largely unknown.
To investigate the effects of ayahuasca administration on regional cerebral blood flow.
Fifteen male volunteers with prior experience in the use of psychedelics received a single oral dose of encapsulated freeze-dried ayahuasca equivalent to 1.0 mg DMT/kg body weight and a placebo in a randomized double-blind clinical trial. Regional cerebral blood flow was measured 100–110 min after drug administration by means of single photon emission tomography (SPECT).
Ayahuasca administration led to significant activation of frontal and paralimbic brain regions. Increased blood perfusion was observed bilaterally in the anterior insula, with greater intensity in the right hemisphere, and in the anterior cingulate/frontomedial cortex of the right hemisphere, areas previously implicated in somatic awareness, subjective feeling states, and emotional arousal. Additional increases were observed in the left amygdala/parahippocampal gyrus, a structure also involved in emotional arousal.
The present results suggest that ayahuasca interacts with neural systems that are central to interoception and emotional processing and point to a modulatory role of serotonergic neurotransmission in these processes.
KeywordsAyahuasca Dimethyltryptamine Psychedelics SPECT Regional cerebral blood flow Human
- Anonymous (2000) Ayahuasca: from the Amazon to the urban jungles. In: The world geopolitics of drugs 1998/1999. Observatoire géopolitique des drogues, Paris, pp 103–107Google Scholar
- Damasio AR (2003) Looking for Spinoza: joy, sorrow, and the feeling brain. Harcourt, Orlando, FLGoogle Scholar
- Dobkin de Rios M (1984) Visionary vine: hallucinogenic healing in the Peruvian Amazon. Waveland, Prospect Heights, ILGoogle Scholar
- Gouzoulis-Mayfrank E, Schreckenberger M, Sabri O, Arning C, Thelen B, Spitzer M, Kovar KA, Hermle L, Büll U, Sass H (1999) Neurometabolic effects of psilocybin, 3,4-methylenedioxyethylamphetamine (MDE) and d-methamphetamine in healthy volunteers. A double-blind, placebo-controlled PET study with [18F]FDG. Neuropsychopharmacology 20:565–581CrossRefPubMedGoogle Scholar
- Greenhouse L (2005) Supreme court to hear case of dispute over religious group’s use of banned drug. The New York Times (April 19), p 15Google Scholar
- Hermle L, Fünfgeld M, Oepen G, Botsch H, Borchardt D, Gouzoulis E, Fehrenbach RA, Spitzer M (1992) Mescaline-induced psychopathological, neuropsychological, and neurometabolic effects in normal subjects: experimental psychosis as a tool for psychiatric research. Biol Psychiatry 32:976–991CrossRefPubMedGoogle Scholar
- Kotler S (2005) Psychedelics in rehab. Psychology Today (Mar/Apr)Google Scholar
- Labate B, Araújo W (2002) O Uso Ritual da Ayahuasca. Mercado de Letras, Sao PauloGoogle Scholar
- Melton L (2004) Dream drug or demon brew. New Sci 182(2453):42–43Google Scholar
- Reichel-Dolmatoff G (1990) The cultural context of an aboriginal hallucinogen: Banisteriopsis caapi. In: Furst P (ed) Flesh of the Gods: the ritual use of hallucinogens. Waveland, Prospect Heights, IL, pp 84–113Google Scholar
- Salak K (2004) The vision seekers. The New York Times (September 12)Google Scholar
- Schultes RE, Hofmann A (1980) The botany and chemistry of hallucinogens. Thomas, Springfield, ILGoogle Scholar
- Schultes RE, Hofmann A (1987) Plants of the gods: origins of hallucinogenic use. A. van der Marck Editions, New YorkGoogle Scholar
- Spruce R (1908) Notes of a botanist on the Amazon and Andes. Macmillan, LondonGoogle Scholar
- Villavicencio M (1858) Geografía de la República del Ecudador. Craighead, New YorkGoogle Scholar