Psilocybin facilitates fear extinction in mice by promoting hippocampal neuroplasticity.
Chinese medical journal December 20, 2023 Yingjie Du, Yunfeng Li, Xiangting Zhao et al. 71 citations
A single dose of psilocybin (2.5 mg/kg) given to mice before extinction training reduced freezing time—a measure of fear—24 hours, 6 days, and 7 days later, indicating rapid and sustained facilitation of fear extinction. Psilocybin also reversed fear-conditioning-induced decreases in hippocampal dendritic complexity, spine density, levels of BDNF and mTOR proteins, and numbers of DCX- and BrdU-positive cells (markers of neurogenesis). These findings suggest psilocybin promotes hippocampal neuroplasticity, which may partially underlie its ability to enhance fear extinction. The authors propose psilocybin could be a useful adjunct to exposure-based therapies for PTSD and other disorders involving impaired fear extinction.