Spectral signatures of serotonergic psychedelics and glutamatergic dissociatives

Publication date: Available online 24 June 2019Source: NeuroImageAuthor(s): Carla Pallavicini, Martina G. Vilas, Mirta Villarreal, Federico Zamberlan, Suresh Muthukumaraswamy, David Nutt, Robin Carhart-Harris, Enzo TagliazucchiAbstractClassic serotonergic psychedelics are remarkable for their capacity to induce reversible alterations in consciousness of the self and the surroundings, mediated by agonism at serotonin 5-HT2A receptors. The subjective effects elicited by dissociative drugs acting as N-methyl-D-aspartate (NMDA) antagonists (e.g. ketamine and phencyclidine) overlap in certain domains with those of serotonergic psychedelics, suggesting some potential similarities in the brain activity patterns induced by both classes of drugs, despite different pharmacological mechanisms of action. We investigated source-localized magnetoencephalography recordings to determine the frequency-specific changes in oscillatory activity and long-range functional coupling that are common to two serotonergic compounds (lysergic acid diethylamide [LSD] and psilocybin) and the NMDA-antagonist ketamine. Administration of the three drugs resulted in widespread and broadband spectral power reductions. We established their similarity by using different pairs of compounds to train and subsequently evaluate multivariate machine learning classifiers. After applying the same methodology to functional connectivity values, we observed a pattern of occipital, parietal and frontal decreases in the low a...

Source: NeuroImage - June 24, 2019 Category: Neuroscience Source Type: research