Psilocybin rapidly grows and prunes brain connections in mice, even without the psychedelic response.

Psilocybin rebuilt mouse brain connections even in mice that showed no trip. The healing and the high may be separable.

In a UC Santa Cruz-led study, psilocybin made mouse brains sprout and mature new dendritic spines, the docking points of connections, while clearing out some old ones, and the changes lasted a month. They appeared even without the head-twitch that marks the psychedelic response. If depression is a brain stuck in old routes, this is a way to repave them.

• What it could changeA plasticity drug without the psychedelic experience could reach patients who can't or won't take a trip.
• How it touches todayHuman scans already show psilocybin loosening the default mode network, the brain's self-talk circuit.
• Our futureTreating the mind could become less about chemical levels and more about rebuilding its roads.

• In mice, psilocybin rapidly increased dendritic-spine formation and maturation while eliminating some preexisting connections; these effects persisted for a month.medicalxpress +1
• Human imaging found that psilocybin produced pronounced desynchronization across cortical networks, strongest in the default mode network, with some changes lasting beyond the acute experience.pmc +1
• The mouse study reported that structural plasticity could occur without the head-twitch response, supporting research into plasticity-promoting treatments with fewer psychedelic effects.medicalxpress