Dynamical exploration of the repertoire of brain networks at rest is modulated by psilocybin

Authors: Louis-David Lord, PaulExpert, SelenAtasoy, LeorRoseman, KristinaRapuano, RenaudLambiotte, David J.Nutt, GustavoDeco, Robin L.Carhart-Harris, Morten L.Kringelbach, Joana Cabral

Abstract

Growing evidence from the dynamical analysis of functional neuroimaging data suggests that brain function can be understood as the exploration of a repertoire of metastable connectivity patterns (‘functional brain networks’), which potentially underlie different mental processes.

The present study characterizes how the brain’s dynamical exploration of resting-state networks is rapidly modulated by intravenous infusion of psilocybin, a tryptamine psychedelic found in “magic mushrooms”. We employed a data-driven approach to characterize recurrent functional connectivity patterns by focusing on the leading eigenvector of BOLD phase coherence at single-TR resolution. Recurrent BOLD phase-locking patterns (PL states) were assessed and statistically compared pre- and post-infusion of psilocybin in terms of their probability of occurrence and transition profiles. Results were validated using a placebo session.

Recurrent BOLD PL states revealed high spatial overlap with canonical resting-state networks. Notably, a PL state forming a frontoparietal subsystem was strongly destabilized after psilocybin injection, with a concomitant increase in the probability of occurrence of another PL state characterized by global BOLD phase coherence. These findings provide evidence of network-specific neuromodulation by psilocybin and represent one of the first attempts at bridging molecular pharmacodynamics and whole-brain network dynamics.