The Mechanism Of Kai-Xin-San On Cognition Deficit Induced By Simulated Spaceflight Environment In Rats

We aimed at using behavioral tests to study the influence of simulated spaceflight environment on cognition deficit and cognition improvement of Kai-Xin-San (KXS) water extract and its mechanism in rats.SD rats, tail suspension, separation, isolation and circadian rhythms change were used to establish model. Reward conditioning test and Morris water maze(MWM) test were used to measure cognitive function after 14days and 28days of simulated spaceflight environment. SD rats were randomly divided into six groups:the control group, the model group, the model+ Huperzine A group, the model+KXS 2g/kg group, the model+KXS 4g/kg group, the model+KXS 8g/kg group. Reward test and Morris Water maze test were used to observe the effects of KXS on cognitive function induced by simulated spaceflight environment. The content of serum Cortisone and ACTH were analysed using ELISA assay to evaluate HPA function. Mkp1, p38MAPK, JNK, ERK1/2 mRNA expression levels were determined with qRT-PCR. CREB and BDNF protein expression were determined with Western blot.The experimental results showed that simulated compound astronautic environment could induce serious cognitive function deficit, and the cognitive function deficit was more stable in 28d. Nose pokes were significantly reduced in 28d model groups. Escape latency and total distance were significantly increased in the 28d model group. Moreover, the cognitive state of rats in 28d is more stable than 14d.KXS(2 g/kg,4 g/kg,8 g/kg) treatment groups could increase nose pokes, reduce escape latency and total distance and increase swimmed less in the target quadrant and performed fewer crossing numbers significantly compared with 28d model group. KXS could reduce model group serum corticosterone, ACTH levels to resume HPA axis normal and the expression of p38MAPK and increase the expression of CREB and BDNF in hippocampus to promote the growth of neurons.This study acquires innovative achievements with model establishment and improving mechanism of Kai-Xin-San on cognition deficit induced by simulated spaceflight environment in rats. And hope to play a certain help and protect the cognitive function of astronauts effectively. Also bring broad prospects for educational brain development of traditional Chinese medicine.