Psilocin, a serotonergic psychedelic, alters sleep architecture and cortical activity in mice. Acute administration delays REM sleep onset, reduces NREM sleep maintenance for about three hours, and enhances a 4 Hz EEG oscillation. No long-term changes in sleep-wake quantity occur. Psilocin does not affect the overall homeostatic sleep rebound after sleep deprivation, but it slows the recovery of slow-wave activity in the medial prefrontal and surrounding cortex. These findings suggest psilocin influences both global vigilance state control and local sleep homeostasis, which may relate to its antidepressant effects.
Psychedelics like 5-MeO-DMT induce a dissociated state of arousal that combines features of waking and sleep. In freely moving adult male mice, the drug produced sleep-like slow waves in the cortex alongside marked pupil dilation, even while animals were awake and moving. REM sleep was strongly suppressed, similar to the effect of conventional antidepressants. This mixed brain state may explain psychedelic effects such as dream-like hallucinations and reopening of the critical period for plasticity.