Psilocybin, a classic psychedelic, increases dendritic spine density in frontal cortical neurons and facilitates fear extinction after chronic restraint stress in mice, demonstrating its effects in a translationally relevant animal model. Prior studies had largely examined stress-naive animals, so these findings show that psilocybin can promote neural plasticity and behavioral recovery even after chronic stress.
Psilocybin, a classic psychedelic, alters the activity of specific inhibitory neurons in the mouse medial frontal cortex. It reduces firing of somatostatin-expressing interneurons while increasing activity of parvalbumin-expressing interneurons. This cell type-specific response depends on the 5-HT1A receptor on somatostatin interneurons, and contributes to the drug's long-term behavioral effects. The findings reveal that psilocybin changes cortical inhibition in a targeted manner, highlighting a mechanism beyond the commonly studied pyramidal cells.