| Object Cognitive impairment is a common complication after stroke,and exercise is an effective rehabilitation method to promote the recovery of motor and cognitive function after stroke.In this study,we observed the effects of exercise on activities and cognition after treadmill training,and explored its mechanism to provide guidance for the treatment of patients with cognitive impairment after stroke.Method Sixty male SD rats were randomly divided into 6 groups: treadmill group I(ME1),treadmill group Ⅱ(ME2),treadmill group Ⅲ(ME3),sham-operated treadmill group(SE),model group(M)and sham-operated group(S),with 10 rats in each group.The model of middle cerebral artery occlusion(MCAO)was made in ME group and M group by thread embolism method.Three days after surgery,the rats of the ME group and SE group were trained on treadmill training for 15 days.The speed of ME1 group was 8m/min.the speed of ME2 group was 12m/min and ME3 group was 15min/min.Each group exercises for 30 minutes every day.We used open-field experiment and new objects recognition test to evaluate the cognitive function,anxiety degree and activity ability of rats in each group on the 7th or 15th day after interevention.Then,the ischemic brain tissue was taken,and the number and morphological changes of cortical nerve cells were observed by Nissl staining.The Neu N,BDNF,SynapsinⅠ and CYFIP1 in cortex were determined by immunofluorescence staining and immunohistochemistry staining,The expression of BDNF,SynapsinⅠ and CYFIP1 in rat serum was measured by ELISA,and the relative expression levels of BDNF,SynapsinⅠ and CYFIP1 mrna in cortex were analyzed by real-time fluorescence quantitative PCR(q Rt-PCR).Result1 After modeling,all rats in the model group showed symptoms of weight loss and nerve function damage.In group S,the rats were in good mental state,quick in response,smooth and colorful in hair.The mental state of M group rats is poor,the reaction is slow,and the hair is yellow and dry;In ME group,the mental state of rats was half,the reaction was slightly poor,and the hair was not smooth.Behavioral results showed that compared with S group,the times of crossing grid in open field experiment(P<0.0001),the activity time in central area obviously decreased(P<0.0001),and the cognitive index decreased in new object recognition experiment(P<0.001).Compared with m group,ME group increased the times of crossing(P<0.01),the activity time of central area(P<0.05)and cognitive index(P<0.05),among which ME2 increased most significantly among the three groups(P<0.05).2 Nissl staining showed that the number of Nissl bodies in the frontal cortex of M group decreased significantly(P<0.0001)compared with S group,and the number of Nissl bodies in ME group increased significantly(P<0.001)compared with M group.3 qRt-PCR results showed that the relative expression of BDNF in cortex of M group was significantly higher than that of S group(P<0.0001),while the m RNA expressions of SynapsinⅠ and CYFIP1 were significantly lower(P<0.01).Treadmill training could increase the relative expression level of three m RNA(P<0.05),and the relative expression level of genes in ME2 group increased most obviously(P<0.01)4 Immunofluorescence and immunohistochemical staining showed that Neu N and BDNF in cortex of M group were significantly higher than those of S group(P<0.05),while SynapsinⅠ and CYFIP1 were significantly lower(P<0.05).The expression of these four factors in cortex of ME group was significantly higher than that of M group(P<0.05),and the increasing trend was consistent with the results of q Rt-PCR.5 The results of Elisa showed that the expression of BDNF increased(P<0.001),while the expressions of CYFIP1 and CYFIP1 decreased(P<0.01).Treadmill training could promote the secretion of BDNF,SynapsinⅠ and CYFIP 1 and increase the serum concentration,among which the serum concentration of moderate intensity treadmill training group increased most significantly(P<0.05).Conclusion Cerebral ischemia can cause cognitive impairment in rats,and treadmill training with different intensity can alleviate nerve injury and improve cognitive function.The mechanism may be related to promoting the expression of BDNF,SynapsinⅠ and CYFIP1,increasing neurogenesis and synaptic plasticity,and moderate intensity exercise training has the most significant improvement on cognitive function. |
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