Effects Of Electroacupuncture On Motor Function And Expression Of GAP-43,MAP-2 And Sema3C In The Contralateral Cerebral Cortex Of Mcao Rats And Investigation Of Their Relationship

Objectives:To investigate the effects of electroacupuncture on motor function and expression of GAP-43,MAP-2 and Sema3C on the contralateral cerebral cortex in rats with unilateral focal cerebral infarction,and to explore its relationship with the recovery of motor function and neural plasticity in rats.Methods:A total of 120 male SD rats were randomly divided into sham-operated group A（12 rats）,model groupand and EA group.The model group and EA group were randomly divided into 3d,7d,14d,and 28d.In four subgroups（n=12）,the right middle cerebral artery occlusion（MCAO）rat model was prepared by Longa modified thread embolism,and the bilateral“Quchi”and“Zusanli”acupunctures were taken from the electroacupuncture group.Each group was assessed on the 3th,7th,14th,and 28th time points respectively.Rats were evaluated for neurological deficits and scores for the wrong step,and 6 rats were selected for each group at 3d,7d,14d,28d.After fixed with 4%paraformaldehyde,the brain tissue was taken for Nissl staining,HE staining to observe the changes of cell morphology of the contralateral cortical neurons.Immunohistochemistry was used to detect the contralateral cerebral cortex GAP-43,MAP-2,Sema3C.The expression changes were observed in the fresh brains of the rats.The relative gene expressions of GAP-43,MAP-2 and Sema3C proteins in the contralateral cerebral cortex were observed by Quantitative Real-time（QT-PCR）.Results:（1）Compared with the model group,the neurological deficit score in electroacupuncture groups were no diffiences after 3d（P>0.05）,With prolongation of treatment,neurologic deficit score decreased gradually.Compared with the model group,the neurological deficit score in EA groups was statistically significant at the 7^th,14^thh and 28^thh day after operation（P<0.05）.（2）Hematoxylin-eosin staining showed that the cortical neurons in the contralateral side of the model group were mildly swollen and the nucleus shrunk slightly.The cells in the EA group were slightly swollen and structurally intact compared to the model group.The cell morphology was basically observed 7 days after the operation.After normalization,the blue staining of nuclei was deeper than that of the model group.With the prolongation of treatment time,the number of contralateral cortical cells in the infarct was increased,the cells were full,and the morphology and location of the nucleus were normal in the electroacupuncture group compared with the model group.Nissl staining showed a blue-purple staining after Nissl body staining.On the3rd day after the operation,the model group showed slight swelling and deformation of the contralateral neuronal cell body,and the perinuclear Nissl body swelling.The model group 7 days after,some Nissl bodies dissolved slightly,the coloring became lighter,the EA group and the model group were compared,the infarct contralateral the cortical Nissl body was slightly reduced,and the neurons were slightly swollen.At 14 days after surgery,the electroacupuncture group had darker staining of cytoplasm in the neurons of the model group and increased Nissl bodies;at 28 days after surgery,the EA group Compared with model group neurons Full,dense arrangement,Nigeria’s small lanes are patchy distribution.Compared with Nissl staining and HE staining,the neuron size,morphology,synapses and other aspects were more clearly and completely shown,which could better reflect the pathological changes of the cerebral cortex in the contralateral hemisphere.（3）Compared with the sham-operated group,the expression of GAP-43 and MAP-2 increased significantly at the 14th day in the model group（P<0.05）.Compared with the model group,the expression quantity of GAP-43,MAP-2 and Sema3C of the electroacupuncture group was not statistically significant（P>0.05）.The GAP-43 and MAP-2 positive cells in electroacupuncture group expressed significantly higher than that in model group at 7d and 14d after operation（P<0.05）.However,the expression of Sema3C positive cells of EA group is less than the model group,and the difference was statistically significant（P<0.05）.The expression of GAP-43 and MAP-2 positive cells of EA group is continued to increase on the 7th and 14th day after operation（P<0.05）.Compared with the3d group at EA group,the number of Sema3C positive cells on the 7th,14th,and28th day continued to decrease,showing a significant difference（P<0.05）.（4）The QT-PCR results showed that there was no significant difference in the expression of GAP-43 and MAP-2 positive cells in EA group compared with model group at 3d after operation（P>0.05）.At 7d,14d,and 28d after operation,the expression of GAP-43 mRNA and MAP-2 mRNA increased significantly in the EA group and non-EA group（P<0.05）.Nevertheless,compared with the model group at the same time point,the decrease of Sema3CmRNA expression in EA group was statistically significant（P<0.05）.The expression of GAP-43and MAP-2 positive cells of EA group is continued to increase on the 7th and14th day after operation（P<0.05）.Compared with the 3d group in the model group,there was no significant difference in the expression of GAP-43mRNA and MAP-2 mRNA at 28d（P>0.05）.In the EA group,the expression of GAP-43mRNA and MAP-2mRNA increased significantly at 7d and 14d compared to 3d（P<0.05）.Compared with 3d after operation in EA group,the expression of Sema3C mRNA decreased significantly at 28 days（P<0.05）.Conclusion:（1）In the observation of HE and Nissl staining,the contralateral cortical neurons in MCAO rats were also damaged.When observing the morphological and structural changes of neurons,Nissl staining had certain advantages over HE staining.（2）EA group can promote the remodeling of contralateral cerebral cortical nerve pathways in MCAO rats,achieve partial functional compensation,and improve motor function in rats.The mechanism may be related to up-regulation of GAP-43,MAP-2 expression in the contralateral cerebral infarct,and down-regulation of Sema3C expression,reducing the inhibitory effect of Sema3C on axon regeneration.