RESUMO
ObjectiveTo explore the possible mechanism of Tongdu Xingshen needling method （通督醒神针刺法） on post-stroke cognitive impairment. MethodsSD rats were randomly divided into a normal group （n=12）， a sham surgery group （n=12）， a model group （n=12）， and a electroacupuncture group （n=13）. The rats in the model group and electroacupuncture group were subjected to the wire bolus method to establish the rats model with learning memory impairment after cerebral ischaemia-reperfusion. After successful modelling， the rats in the electroacupuncture group were given electroacupuncture interventions at “Shenting （GV 24）” and “Baihui （GV 20）” once a day for 30 minutes for 14 days. The other three groups did not receive other interventions but grasp. A 5-day localisation navigation experiment was conducted on the 9th day of intervention， and a spatial exploration experiment was conducted on the 14th day of intervention to evaluate the learning and memory abilities of the rats. After the spatial exploration experiment， hippocampal tissues were taken from each group of rats， and the changes in the volume of cerebral infarction were observed by TTC staining； the changes in the morphology of pyramidal neurons and the density of dendritic spines in the CA1 area of the hippocampus were observed by Golgi staining； protein immunoblotting was used to detect the relative protein expression of the subunits of the α-amino-3-carboxy-5-methylisoxazole-4-propionic acid （AMPA） receptor including glutamate receptor 1 （GluR1）， glutamate receptor 2 （GluR2）， glutamate receptor 3 （GluR3） and auxiliary proteins TARPγ2， TARPγ8 in hippocampal tissues of rats in each group； the real-time fluorescence quantitative PCR was used to detect GluR1， GluR2， GluR3 mRNA levels in the hippocampal tissues of rats. ResultsIn the localisation navigation experiment， compared with the normal group and sham surgery group， the escape latency and total distance of rats in the model group were significantly extended （P＜0.05） at day 1， 2， 3， 4， and 5； and the escape latency and total distance of rats in the electroacupuncture group tended to be significantly shorter than those in the model group （P＜0.05）. In the spatial exploration experiment， compared with the normal group and the sham surgery group， the number of rats crossing the platform in the model group was significantly reduced （P＜0.05）， and the number of crossings of the platform in the electroacupuncture group increased significantly （P＜0.05）. The results of TTC staining showed that the volume of cerebral infarction increased clearly in the model group compared with the sham surgery group （P＜0.05）， and apparently decreased in the electroacupuncture group compared with the model group （P＜0.05）. Golgi staining showed that the number of dendritic branches of pyramidal neurons and dendritic spines in hippocampal CA1 region significantly decreased in the model group compared with the normal group and the sham surgery group （P＜0.05）. The number of dendritic branches of pyramidal neurons and the density of dendritic spines in hippocampal CA1 region significantly increased in the electroacupuncture group compared with the model group （P＜0.05）. The protein relative expression levels of GluR1， GluR2， GluR3， TARPγ2 and TARPγ8， and the mRNA levels of GluR1， GluR2 and GluR3 in hippocampus decreased in the model group compared with the normal group and the sham surgery group （P＜0.05）. The protein relative expression levels of GluR1， GluR2， GluR3， TARPγ2 and TARPγ8， and the mRNA levels of GluR1， GluR2 and GluR3 in hippocampus increased in the electroacupuncture group compared with model group （P＜0.05）. ConclusionThe Tongdu Xingshen needling method can improve learning memory impairment after cerebral ischaemia-reperfusion， which may be related to up-regulation of the expression of AMPA receptor and their auxiliary protein TARP， and promoting the synaptic plasticity of hippocampal tissues.