Effects of psilocybin and chronic mild stress on microglial activation in rat spinal cord: an ex vivo analysis
Pharmacological Reports January 20, 2026 Piotr Olejnik, Katarzyna Kamińska, Krystyna Gołembiowska et al.
Psilocybin, a classic serotonergic psychedelic, has antidepressant, anxiolytic, anti-inflammatory, and analgesic properties, but its effects on microglial activation in the central nervous system are not well understood. In a study using adult male Wistar Han rats, spinal cords from animals subjected to chronic mild stress (CMS) and treated with two doses of psilocybin (0.6 mg/kg) showed significantly higher levels of the microglial activation marker Arg1 and the cytokines TNF-α and IL-10 compared to control rats given psilocybin. iNOS levels showed a non-significant increasing trend. The findings suggest that CMS activates the immune system and microglia non-specifically despite psilocybin administration.