| Objective:The object of this study is to explore the mechanism of electroacupuncture on DU20 and DU24 acupoints on the improvement of spatial learning and memory of rats with MCAO/R,which possibly by regulating purinergic receptor of P2X7 which to influence synaptic plasticity.Method:110 Sprague-Dawley male rats were used in this study among which 92 rats were performed MCAO/R by thread embolism method and another 18 rats were only vascular separation as a sham group.According to the Zea-longa neurological behavior scores and the results of infarct volume by MRI,Finally 72 rats with MCAO/R and cognitive impairment were randomly divided into 4 groups:the model group(n=18),the electro-acupuncture group(n=18),the agonist group(n=18)and the electro-acupuncture agonist group(n=18).After model establishment,rats in the electro-acupuncture group received electroacupuncture intervention on DU20 and DU24 acupoints for 30 minutes with 2/20mA for 7 days.Zea-longa score was used to test neurobehavior of rats at 1st day,3rd day and 7th day post-intervention.Barnes maze was used to record the spatial learning and memory of rats from 3rd day to 7th day post-intervention.MRI was used to calculate the volume of cerebral infarction of rats.P2X7R and SYN expression were detected by immunofluorescence.Ultrastructure of synaptic was detected by transmission electron microscope.The expression of P2X7R and SYN were detected by western blot.Results:1.Zea-longa neuroethology score:There was no neurological deficit in the sham operation group.There was no significant difference between model groups before intervention(P>0.05);on the 7th day after intervention,there was significant difference between the electro-acupuncture group.the model group and the electro-acupuncture agonist group(P<0.01);there was significant difference between the model group and the agonist group(P<0.01);there was significant difference between the electro-acupuncture agonist group and the agonist group(P<0.01).2.Learning and memory function:In Barnes maze,compared with the sham operation group,the average escape latency and the average number of times to enter the wrong hole significantly increased in the model group(P<0.001),when compared with the model group,the average escape latency and the average number of times to enter the wrong hole significantly decreased in the electro-acupuncture group(P<0.001),when compared with the model group,the average escape latency and the average number of times to enter the wrong hole significantly increased in the agonist group(P<0.001),when compared with the agonist group,the average escape latency and the average number of times to enter the wrong hole significantly decreased in the electro-acupuncture agonist group(P<0.001).when compared with the electro-acupuncture agonist group,the average escape latency and the average number of times to enter the wrong hole significantly decreased in the electro-acupuncture group(P<0.001).At the 3rd,4th,5th,6th and 7th days of each time point,the escape latency of the model group was significantly longer than that of the sham-operated group,and the number of times to enter the wrong hole was significantly increased(P<0.001).the escape latency of the electro-acupuncture group was significantly decreased than that of the model group,and the number of times to enter the wrong hole was significantly reduced(P<0.001).The escape latency of the agonist group was significantly longer than that of the electro-acupuncture agonist group,and the number of times to enter the wrong hole was significantly increased(P<0.001).when compared with the model group,the escape latency and the number of times to enter the wrong hole significantly increased in the agonist group(P<0.001).when compared with the electro-acupuncture agonist group,the escape latency and the number of times to enter the wrong hole significantly decreased in the electro-acupuncture group(P<0.001).3.volume of cerebral infraction:There were no infarction lesions in the sham operation group.There were no significant difference in model group?the electro-acupuncture group?agonist group and the electro-acupuncture agonist group before electro-acupuncture treatment(P>0.05).Compared with the model group,the volume of cerebral infarction in electro-acupuncture group significantly decreased(P<0.001);Compared with the model group,the volume of cerebral infarction in agonist group significantly increased(P<0.001);Compared with the electro-acupuncture agonist group,the volume of cerebral infarction in agonist group significantly increased(P<0.001);Compared with the electro-acupuncture agonist group,the volume of cerebral infarction in electro-acupuncture group significantly decreased(P<0.001)after electro-acupuncture intervention for 7 days.4.The expression of P2X7R and SYN in the peri-infarct hippocampal CA1:P2X7R+/SYN+ cells were observed in all five groups.P2X7R+/SYN+ cells in the hippocampal CA1 region of the sham operation group were larger and more densely rounded.The cell structure was more complete and neatly arranged.Compared with electro-acupuncture group and electro-acupuncture agonist group,the model group and the agonist group were more scattered in cell arrangement,with irregular cell morphology and incomplete structural defect.5.The synaptic ultrastructure in the peri-infarct hippocampal CA1:The synaptic structure in the sham-operation group is complete and clear,the number of synapses is large,and the synaptic vesicles are abundant and of the same size.Compared with model group,the number of synapses in the electro-acupuncture group was increased(P<0.001);Compared with model group,the number of synapses in the agonist group was decreased(P<0.01);Compared with electro-acupuncture agonist group,the number of synapses in the electro-acupuncture group was increased(P<0.01);Compared with electro-acupuncture agonist group,the number of synapses in the agonist group was decreased(P<0.01);In the model group and the agonist group,the synaptic structure was dissolved,the synaptic vesicles were sparse and destroyed and the synaptic boundary was blurred.The electro-acupuncture group and the electro-acupuncture agonist group had a clearer synaptic structure,reduced synaptic gap fusion with more synapses and synaptic vesicles.6.The expression of P2X7R and SYN by molecular biological detection:The expression of P2X7R in the sham-operation group was the lowest,and the expression of P2X7R in the model group was higher than that in the sham operation group(P<0.01).Compared with the model group,the expression level of P2X7R in the electro-acupuncture group was significantly decreased(P<0.05);Compared with the model group,the expression level of P2X7R in the agonist group was significantly increased(P<0.05);Compared with electro-acupuncture agonist group,the expression level of P2X7R in the agonist group was significantly increased(P<0.05);Compared with electro-acupuncture agonist group,the expression level of P2X7R in the electro-acupuncture group was significantly decreased(P<0.05).The expression of SYN in the sham-operation group was the highest.Compared with sham-operated group,the expression of SYN was lower in model group was decreased(P<0.05).Compared with the model group,the expression level of SYN in the electro-acupuncture group was significantly increased(P<0.05);Compared with the model group,the expression level of SYN in the agonist group was significantly decreased(P<0.05);Compared with electro-acupuncture agonist group,the expression level of SYN in the agonist group was significantly decreased(P<0.001);Compared with electro-acupuncture agonist group,the expression level of SYN in the electro-acupuncture group was significantly increased(P<0.001).Conclusion:Electro-acupuncture at Baihui and Shenting points may promote the expression of synaptic vesicle protein,synaptophysin SYN,improve synaptic ultrastructure and promote synaptic plasticity,improving the ability of learning-memory in rats after cerebral ischemia reperfusion injury by inhibiting the expression of P2X7R in the left hippocampal CA1 region. |
PDF Full Text Request