State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
2 papers in the library · 124 citations · publishing 2023-2024
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.
A single dose of psilocybin produces rapid and sustained antidepressant-like effects in both healthy mice and mice exposed to chronic corticosterone, a model of stress. Psilocybin reversed stress-induced reductions in neuroplasticity within the prefrontal cortex and hippocampus, increasing dendritic branching, spine density, and levels of synaptic proteins (p-GluA1, PSD95, synapsin-1) and activating the BDNF-mTOR signaling pathway. It also promoted neurogenesis, as indicated by more DCX-positive cells. These findings suggest that psilocybin's antidepressant action is linked to its ability to enhance structural and molecular neuroplasticity.