| Background:Cognitive dysfunction after stroke is one of the most common manifestations.More and more studies show that cognitive dysfunction will affect the overall rehabilitation of patients,seriously reduce the quality of life and rehabilitation efficacy.Previous studies have confirmed that electro-acupuncture(EA)and motor therapy can improve the limb function of affected side,accelerate neuron repair and promote inflammation absorption.?However,there are few reports on the mechanism of electro-acupuncture combined with exercise therapy to improve learning and memory function.Objective:To observe the effects of electro-acupuncture combined with wheel running on learning and memory in rats with cerebral ischemia-reperfusion injury and the expression of brain-derived growth factor(BDNF)in hippocampus.and explore the possible mechanism of learning and memory in rats with cerebral ischemia-reperfusion from macro-behavioral and molecular cellular biology levels,and to provide new ideas and clinical theoretical basis for the rehabilitation treatment of cerebrovascular diseases.Methods:120 SD rats(male,clean grade)were selected and screened by water maze test.According to random number table method,the rats were divided into control group,model group,electro-acupuncture group,Running wheel group and combined group.MCAO rat model was established by occluding the middle artery of rats with thread embolism.The model was successfully established by water maze and neurobehavioral experiments.After 2 hours of cerebral ischemia,withdrawal of the thread was the model of cerebral ischemia-reperfusion.according to the different intervening time after reperfusion,each group was divided into three subgroups: 3d,7d and 14 d,Six rats were selected in each group at each time point.The control group and the model group did not receive any t r e a t m e n t.T h e e l e c t r o-a c u p u n c t u r e g r o u p a n d t h e combined group began to perform electro-acupuncture treatment after 1 day of operation.Shenting and Baihui were selected as the acupoints,and the two acupoints were punctured with 1 inch filiform needle.The needle handle was connected to the same type of electro-acupuncture instrument after getting Qi by the method of flat reinforcing and reducing.The density wave was selected,and the frequency was set at 18 Hz,and the rat's quiet tolerance was appropriate(1-2m A)for each treatment.The treatment lasted for 20 minutes and 15 minutes.The treatment was carried out in the afternoon,once a day.Every time the same person's needling operation was prescribed;the running wheel group and the combined group started free running wheel training on the first day after operation,and the number of running wheel circles per day was automatically recorded by the system device.Each subgroup was treated continuously for 3,7and 14 days.At each time point after the end of treatment,the experiment was carried out and the samples were taken.At each time point,the degree ofneurological impairment in each group was observed by longa scoring method.Morris water maze test was used to test the learning and memory ability of rats at each time point.After the escape latency of rats was completed on the 14 th day,the number of times of rats crossing the platform was recorded.The rats in each group were sacrificed after 3,7 and 14 days of treatment.The pathological changes of hippocampus in each group were detected by HE staining,and the expression of BDNF protein in CA1 region of hippocampus was detected by immunohistochemistry.Results:1.Neurological deficit scores were scored at four time points of intervention 1,3,7 and 14 days after model establishment.The results were as follows: the longa scores of rats in the control group were all 0 points at four time points after operation;the longa scores of rats in the model group were higher than those in the normal group at all time points,with statistical significance(p < 0.01);and the scores of the intervention groups at 1,3 days after intervention were all higher than those in the normal group(p < 0.01).Compared with the model group,the scores of the model group were significantly higher than those of the three intervention groups on the 7th and14 th day of intervention(P < 0.05).Compared with the running wheel group and the electro-acupuncture group,the neurological deficit scores of the combined group were significantly lower than those of the running wheel group and the electro-acupuncture group,and the difference was statistically significant(P <0.05).2.Morris water maze experiment results showed that: with the extension of time and the increase of the number of experiments,the learning ability of rats in each group was gradually improved,the environment of water maze was more familiar,the activities of underwater quadrants were more frequent,the escape latency was gradually shortened,and the number of crossing platforms increased.At 3 days after operation,compared with the control group,the escape latency of the other four groups was significantly prolonged(P < 0.05).Compared with the model group,the escape latency of the electro-acupuncture group,the runningwheel group and the combination group was shorter and the difference was statistically significant(P < 0.05).At 7 days and 14 days after operation,the escape latency of each group continued to shorten.Compared with the control group,the model group,the electro-acupuncture group and the escape latency of the combined group were shorter.Compared with the model group,the time spent in the electro-acupuncture group,the running wheel group and the combined group was shorter and the difference was statistically significant.Compared with the electro-acupuncture group and the running wheel group,the time spent in the combined group was shorter,and the difference was statistically significant.Compared with the electro-acupuncture group and the running wheel group,the time spent in the combined group was shorter and the difference was statistically significant.There was no significant difference between the electro-acupuncture group and the running wheel group(P > 0.05).On the 14 th day,the rats were subjected to a space search experiment,and the number of times they crossed the original platform in 120 seconds was recorded.The results showed that compared with the control group,the time spent in the model group,electro-acupuncture group and running wheel group was longer and the difference was statistically significant(P < 0.05).There was no significant difference between the control group and the combined group.Compared with the model group,the time spent in the electro-acupuncture group,the running wheel group and the combined group was significantly shorter and worse.The difference was statistically significant(P < 0.05),compared with electro-acupuncture group and running wheel group.3.At each time point,the hippocampus structure of the control group was normal and the cells were arranged tightly.On the 3rd day after cerebral ischemia and reperfusion,edema,cell loosening,different size,abnormal shape and disordered arrangement of nerve cells in the ischemic center were observed in the brain tissues of model group,electro-acupuncture group,running wheel group and combination group;on the 7th day,vacuole and pull-net changes were observed in the brain tissues,nucleoli disappeared,number of neurons decreased,and residual cells had no complete structure.The pathological changes of ischemic brain tissue in electro-acupuncture group,runner group and combined group were significantly alleviated,vacuole-like structure was reduced,neuron loss was alleviated,and the combined group had the least degree of pathological damage.4.After cerebral ischemia-reperfusion,the positive expression of BDNF was not found in the brain tissue of the control group.The expression of BDNF in the cerebral ischemic side of the model group and the three intervention groups was strong.The positive expression of BDNF in the model group and the treatment group reached its peak on 3d,began to decrease on 7d,and continued to decrease on 14d(P < 0.01);Compared with the model group,at 3d,7d and 14 d,the three intervention groups were in the cerebral ischemic area.Compared with the acupuncture group and the treadmill group,the expression of BDNF in the combined group increased and the response increased on the 3rd,7th and 14 th days(P < 0.05).Conclusion:1.Both electro-acupuncture and running wheel training can improve motor nerve function and learning and memory ability of rats after cerebral ischemia.2.Electro-acupuncture combined with running wheel training can promote the repair of damaged neurons in ischemic area of MCAO rats,alleviate the infarction of cerebral ischemia-reperfusion injury,and improve the learning and memory function of MCAO rats.3.Both electro-acupuncture and running wheel training can increase the expression of BDNF in hippocampus,which may trigger the endogenous brain protection mechanism by up-regulating the expression of BDNF induced by cerebral ischemia-reperfusion injury.4.Electro-acupuncture combined with running wheel training can improve the learning and memory function of rats,alleviate the pathological damage of brain tissue in ischemic area,and improve the symptoms of neurological deficits,and the combined effect of the two is significantly better than that of theirseparate treatment. |
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