EFFECTS OF PSILOCYBIN ON NEURONAL ACTIVITY AND STEM CELL PROLIFERATION IN THE MOUSE BRAIN

Psilocybin, a classical serotonergic psychedelic, has been reported to have therapeutic effects in several psychiatric disorders, which are associated with serotonin receptor-mediated changes in brain activity and neural plasticity. However, its underlying neuronal mechanisms remain unclear. Recent fMRI studies in humans and animals have shown that psilocybin alters brain activity in the cortex and claustrum. Accordingly, we hypothesized that psilocybin modulates neuronal circuits within the cortex and claustrum. In this study, we examined the effect of psilocybin on neuronal activity and intrinsic excitability in a region-, cortical layer-, and cell type-specific manner. Our results show that psilocybin increases c-Fos expression in most sensory cortices and the claustrum. We next investigated psilocybin-induced changes in intrinsic electrophysiological properties in the cortex. Our results suggest that psilocybin alters neuronal excitability in a region- and cell type-specific manner. In addition, to assess the potential impact of psilocybin on stem cell proliferation, EdU analysis was performed in the brain areas known as neural stem cell niches . Overall, this study provides experimental evidence for the potential of psilocybin in neuronal activity and stem cell proliferation in the mouse brain.