Psilocybin: the relationship between head twitch response, locomotor activity, 5-HT2A ex vivo receptor occupancy and plasma and brain levels of psilocin

This study examines the effects of psilocybin, a psychedelic compound, on head twitches, locomotor activity, 5-HT2A receptor occupancy, and levels of psilocin in mice.

Psilocybin increased the number of head twitches and decreased locomotor activity, with a higher dose resulting in less time spent in the central zone of the arena. Frontal cortical 5-HT2A receptor occupancy increased with increasing dose of psilocybin. There was a correlation between plasma and brain levels of psilocin and ex vivo receptor occupancy.

The study suggests that rigorous characterization of psychedelics may be useful in the discovery and screening of therapeutics targeting the 5-HT2A receptor.