Effective connectivity of the human claustrum: Triple networks, subcortical circuits, and psychedelic modulation
bioRxiv (Cold Spring Harbor Laboratory) September 12, 2025 Navid Shams Masjedi, Adeel Razi preprint
The claustrum, a brain region with extensive connections to both cortical and subcortical areas, may help synchronize brain networks. Psychedelics like psilocybin appear to disrupt this synchrony by altering claustral signaling. Using brain scans from the Human Connectome Project and PsiConnect datasets, this work provides the first in vivo description of how the claustrum communicates with key brain networks in humans, both at rest and under psilocybin. The claustrum showed widespread bidirectional connections and a strong inhibitory influence on target regions. Psilocybin increased this inhibition on cortical networks while reducing it on subcortical areas, partly linked to subjective psychedelic effects, supporting a role for claustro-cortical inhibition in regulating network synchrony.