Acanthopanax Senticosus extract improve brain injury induced by simulated spatial radiation in mice via gut microbiota-brain communication

Complex space environments, including microgravity and radiation, affect the body's central nervous system, endocrine system, circulatory system, reproductive system. Especially, radiation-induced aberration in the neuronal integrity and cognitive functions are well known. AndAcanthopanax senticosus has a positive effect on nervous system diseases. Adult mice were irradiated by $ ^{60}$Co -γ $\gamma$ray at 4 Gy to simulate spatial radiation, and Acanthopanax senticosus extract was administrated to the mice. Behavioral experiments, pathological experiments, and transmission electron microscopy showed that Acanthopanax senticosus extract improve the learning and memory ability and increased hippocampal neurons in irradiated mice. In addition, we observed that Acanthopanax senticosus extract improved the impairment of colonic structure of irradiated mice, increased the expression of tight junction proteins, and decreased inflammation levels, which might regulated the disordered intestinal microbiota. Meanwhile, we found a correlation between brain and colon in the changes of neurotransmitters associated with learning and memory and Acanthopanax senticosus extract increased the mRNA expression of BDNF in irradiated mice. The 16srRNA results showed that the bacteria associated with these neurotransmitters also changed at the genus level and were significantly correlated. These results indicated that Acanthopanax senticosus extract improved radiation-induced memory and cognitive impairment can be linked to gut microbiota through neurotransmitters. Key words: Acanthopanax senticosus extract, Radiation, Learning and memory, Gut microbiota, Neurotransmitters gut-brain-axis