An Experimental Study Of The Effect Of Chronic Forced Swimming Exercise To Whole Brain Radiation Induced Cognitive Dysfunction And Related Mechanism

Objective：To explore whether chronic forced swimming could improvewhole brain radiation induced cognitive dysfunction and related mechanism.Methods：Thirty-nine male Sprague-Dawley rat at age one month wererandomized into sham groups（C）,sham swimming groups（C-S）,radiationgroups（R）,radiation swimming groups（R-S）,radiation groups were givena signal dose of20Gy whole-brain radiation,swimming groups performed15min/d,5d/w swimming training.Behavioral tests were performed3monthsafter radiation in the order of open field,Morris water maze（the placenavigation and spatial probe test）and Western-blot tests.Results：In the place navigation test of Morris water maze,shamswimming groups showed significantly shorter latency than sham groups onday2,sham groups showed significantly shorter latency than radiation groupson day2,radiation swimming groups showed significantly shorter latencythan radiation groups on day2（all p<0.05）.In the open field test, totallatency of the place navigation test, the spatial probe test of Morris watermaze showed no significant difference among the four groups（all p>0.05）.Western-blot， the expressions of BDNF and downstream signalmolecules,including P-ERK、P-CREB,were markedly reduced by radiation(p<0.05),but this reductions following radiation were attenuated by chronic forced swimming.Conclusion：chronic forced swimming could up-regulate the expressionsof BDNF and downstream signal molecules P-ERK、 P-CREB inhippocampus,thereby improve the capacity of learning-memory.It shows themolecular mechanism of this process partially.