Effective connectivity changes in LSD-induced altered states of consciousness in humans.
Proc Natl Acad Sci U S A January 28, 2019 Katrin H. Preller, Adeel Razi, Peter Zeidman et al. 303 citations
LSD alters communication within brain pathways that filter sensory information, according to a brain imaging study. Using a double-blind, placebo-controlled design with 25 healthy participants, researchers found that LSD increased signaling from the thalamus to the posterior cingulate cortex—an effect dependent on serotonin 2A receptor activation—and decreased signaling from the ventral striatum to the thalamus independently of those receptors. These changes in directed connectivity within cortico-striato-thalamo-cortical loops support the thalamic filter model of psychedelic action, which proposes that psychedelics disrupt the gating of sensory information to the cortex. The findings advance understanding of how psychedelics alter consciousness and may inform development of new therapeutics.