 The study found that psilocybin reduced the increase in freezing time induced by auditory cued fear conditioning at 24 hours, 6th day, and 7th day after administration in mice. Psilocybin also rescued the decrease in hippocampal dendritic complexity and spine density, as well as the protein levels of brain-derived neurotrophic factor, BDNF, and mechanistic target of rapamycin, MTOR, induced by fear conditioning. The study suggests that psilocybin may be a useful adjunct to exposure-based therapies for PTSD and other mental disorders characterized by failure of fear extinction, as it facilitates rapid and sustained fear extinction through promoting hippocampal neuroplasticity. This article was authored by Njidu, Yunfeng Li, Shangting Zhao, and others.