Psilocybin restores behavior and 5-HT2A signaling while reducing microglial density after chronic traumatic brain injury in rats.
Cell reports. Medicine June 12, 2026 Josh Allen, Bianca Jupp, Tamara L Baker et al.
One year after a fluid-percussion traumatic brain injury, male rats showed persistent sensorimotor, learning, memory, and affective deficits; reduced serotonin 2A receptor binding; and microglial changes in the medial prefrontal cortex, including decreased process branching and enlarged soma size. A single dose of psilocybin (1 mg/kg) improved sensorimotor function, restored serotonin 2A receptor binding, and reduced microglial cell counts. These results suggest psilocybin has therapeutic potential for chronic traumatic brain injury and support further investigation of psychedelic treatments.