Global brain connectivity (GBC), network-based statistic (NBS) and graph analysis demonstrate wide-spread psilocybin-induced connectivity alterations on a whole-brain level
Recent studies demonstrated psilocybin’s brain-wide influence on resting-state functional connectivity in humans [Next, we assessed psilocybin’s effects with regions-of-interest (ROI)-based functional connectivity analyses, namely NBS and graph analysis. In comparison to GBC, which quantifies voxel-wise average connectivity strength to To further characterize psilocybin-induced alterations in brain network organization on a whole-brain level, we performed graph analysis. Upon the administration of psilocybin, we found an increase in small-world propensity (SWP) characterizing the optimal small-world organization present in healthy brains (The local graph metrics strength (sum of connections for a given node) and participation index (ratio of intermodule strength to the total nodal strength), illustrated for regions with at least four significant connections within the NBS network in the table in Fig. In summary, our different analytical approaches (GBC, NBS, and graph analysis) for resting-state FC data provide converging evidence for wide-spread psilocybin-induced connectivity alterations with a large cortical cluster with reduced connectivity and a well-localized hyperconnected circuit that includes the serotonergic key region DRN and the hypothalamus.