Repeated low doses of psilocybin increase resilience to stress, lower compulsive actions, and strengthen cortical connections to the paraventricular thalamic nucleus in rats
January 5, 2023 Kat F. Kiilerich, Joe Lorenz, Malthe B. Scharff et al. 5 citations preprint
Repeated low doses of psilocybin, a serotonergic psychedelic drug, were given to rats in a regimen that mimics human microdosing. The rats tolerated the doses well, showing no signs of anhedonia, anxiety, or altered movement. The treatment did not downregulate or desensitize the 5-HT2A receptor. It did impart resilience against stress from repeated injections and reduced self-grooming frequency, a proxy for compulsive actions. Additionally, it increased 5-HT7 receptor expression and synaptic density in the paraventricular nucleus of the thalamus. These findings support anecdotal reports of benefits from psilocybin microdosing and suggest a possible physiological mechanism.