Timmermann, Christopher, Roseman, Leor, Haridas, Sharad, Rosas, Fernando E, Luan, Lisa, Kettner, Hannes, Martell, Jonny, Erritzoe, David, Tagliazucchi, Enzo, Pallavicini, Carla, Girn, Manesh, Alamia, Andrea, Leech, Robert, Nutt, David J and Carhart-Harris, Robin L (2023) Human brain effects of DMT assessed via EEG-fMRI. Proc Natl Acad Sci U S A, 120. e2218949120 1-12. ISSN 0027-8424

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Abstract

Psychedelics have attracted medical interest, but their effects on human brain function are incompletely understood. In a comprehensive, within-subjects, placebo-controlled design, we acquired multimodal neuroimaging [i.e., EEG-fMRI (electroencephalography-functional MRI)] data to assess the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT) on brain function in 20 healthy volunteers. Simultaneous EEG-fMRI was acquired prior to, during, and after a bolus IV administration of 20 mg DMT, and, separately, placebo. At dosages consistent with the present study, DMT, a serotonin 2A receptor (5-HT2AR) agonist, induces a deeply immersive and radically altered state of consciousness. DMT is thus a useful research tool for probing the neural correlates of conscious experience. Here, fMRI results revealed robust increases in global functional connectivity (GFC), network disintegration and desegregation, and a compression of the principal cortical gradient under DMT. GFC × subjective intensity maps correlated with independent positron emission tomography (PET)-derived 5-HT2AR maps, and both overlapped with meta-analytical data implying human-specific psychological functions. Changes in major EEG-measured neurophysiological properties correlated with specific changes in various fMRI metrics, enriching our understanding of the neural basis of DMT's effects. The present findings advance on previous work by confirming a predominant action of DMT-and likely other 5-HT2AR agonist psychedelics-on the brain's transmodal association pole, i.e., the neurodevelopmentally and evolutionarily recent cortex that is associated with species-specific psychological advancements, and high expression of 5-HT2A receptors.

Item Type:	Article
Keywords:	ayahuasca, consciousness, dimethyltryptamine, psychedelics, serotonin, Humans, N,N-Dimethyltryptamine, Hallucinogens, Magnetic Resonance Imaging, Brain, Electroencephalography
Schools and Departments:	School of Engineering and Informatics > Informatics
SWORD Depositor:	Mx Elements Account
Depositing User:	Mx Elements Account
Date Deposited:	29 Mar 2023 11:11
Last Modified:	29 Mar 2023 11:15
URI:	http://sro.sussex.ac.uk/id/eprint/111500

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