电针“百会”“神庭”对血管性痴呆大鼠学习记忆能力和海马突触结构与相关蛋白表达水平的影响

目的 观察电针“百会”“神庭”对血管性痴呆（vascular dementia，VD）大鼠学习和记忆功能的影响，并从突触结构及突触相关蛋白表达水平的角度揭示其作用机制。方法 将35只雄性SD大鼠随机分为假手术组、模型组、电针穴位组、电针非穴位组和奥拉西坦组，每组7只。采用改良双侧颈动脉结扎模型，电针穴位组大鼠选择“百会”“神庭”两穴治疗，电针非穴位组大鼠选择固定非穴位刺激，每次电针30 min，每日1次，连续干预14 d；奥拉西坦组大鼠选择腹腔注射奥拉西坦，50 mg/kg，每日1次，连续14 d。采用Morris水迷宫检测各组大鼠学习和空间记忆能力；透射电子显微镜观察各组大鼠海马CA1区突触结构；Western blot检测各组大鼠海马突触后致密蛋白95（postsynaptic density protein 95， PSD95）、GluA1、GluN2B和磷酸化GluN2B蛋白表达水平。结果 与假手术组比较，模型组大鼠学习期逃避潜伏时间延长，测试期跨越平台次数减少，目标象限停留时间显著缩短，大脑质量显著增加，海马CA1区突触结构数明显减少，海马PSD95、GluA1、GluN2B和磷酸化GluN2B蛋白表达水平均显著降低，差异均有统计学意义（P＜0.05）；与模型组比较，电针穴位组大鼠的学习期逃避潜伏时间缩短，测试期跨越平台次数增加，目标象限停留时间延长，大脑质量降低，CA1区突触结构数增多，海马PSD95、GluA1、GluN2B和磷酸化GluN2B蛋白表达水平增加，差异均有统计学意义（P＜0.05）。结论 电针“百会”“神庭”能改善VD大鼠的学习记忆功能，改变海马突触结构，分子机制可能和增加突触蛋白PSD95、GluA1和GluN2B的蛋白表达水平相关。

Effect of Electroacupuncture at Baihui and Shenting on Learning and Memory, Hippocampal Synaptic Structure, and Expression of Related Proteins in Rats with Vascular Dementia

Objective To investigate the effect of electroacupuncture at Baihui (GV20) and Shenting (GV24) on learning and memory in rats with vascular dementia (VD) and its mechanism of action from the perspective of synaptic structure and expression of synaptic-associated proteins. Methods A total of 35 male Sprague-Dawley rats were randomly divided into sham-operation group, model group, acupoint electroacupuncture group, non-acupoint electroacupuncture group, and oxiracetam group, with 7 rats in each group. After a model of VD was established by modified ligation of both carotid arteries, the rats in the acupoint electroacupuncture group were given electroacupuncture at Baihui and Shenting, and those in the non-acupoint electroacupuncture group were given non-acupoint fixed stimulation, 30 minutes each time, once a day for 14 consecutive days; the rats in the oxiracetam group were given intraperitoneal injection of 50 mg/kg oxiracetam, once a day for 14 consecutive days. The Morris water maze test was used to evaluate learning and spatial memory; a transmission electron microscope was used to observe the synaptic structure of the hippocampal CA1 region; Western blot was used to measure the protein expression levels of postsynaptic density-95 (PSD95), GluA1, GluN2B, and phosphorylated GluN2B (p-GluN2B) in the hippocampus of the rats in each group. Results Compared with the sham-operation group, the model group had a significant increase in escape latency in learning phase, a significant reduction in the number of platform crossings in testing phase, a significantly shorter retention time in target quadrant, a significant increase in brain weight, a significant reduction in the synaptic structure of the hippocampal CA1 region, and significant reductions in the protein expression levels of PSD95, GluA1, GluN2B, and p-GluN2B (P<0.05). Compared with the model group, the acupoint electroacupuncture group had a significant reduction in escape latency in learning phase, a significant increase in the number of platform crossings in testing phase, a significantly longer retention time in target quadrant, a significant reduction in brain weight, a significant increase in the synaptic structure of the hippocampal CA1 region, and significant increases in the protein expression levels of PSD95, GluA1, GluN2B, and p-GluN2B (P<0.05). Conclusion Electroacupuncture at Baihui and Shenting can improve the learning and memory function of VD rats and change the synaptic structure of the hippocampus, and its molecular mechanism may be associated with the increases in the protein expression levels of the synaptic proteins PSD95, GluA1, and GluN2B.