电针神庭、百会对脑缺血再灌注大鼠学习记忆能力和LIM激酶1磷酸化的影响

摘要

Objective To investigate the effect of electroacupuncture (EA) at Shenting (DU24) and Baihui (DU20) acupoints on hippo-campal synaptic plasticity and learning and memory function, and its possible mechanism in rats with cerebral ischemia-reperfusion. Meth-ods Thirty-two male adult Sprague-Dawley rats were randomly divided into sham group (n=8), model group (n=8), electroacupuncture (EA) group (n=8) and non-acupoint group (n=8). The model group, EA group and non-acupoint group were performed with left middle cerebral artery occlusion (MCAO). The EA group received electroacupuncture at Shenting and Baihui, while the non-acupoint group received elec-troacupuncture at two fixed non-acupoints from bilateral ribs, for fourteen days. Then they were tested with Morris Water Maze test, and their synaptic structure of hippocampal neurons was observed with transmission electron microscope. The level of total LIM-domain contain-ing protein kinase 1 (T-LIMK1) and LIM-domain containing protein kinase 1 phosphorylation (p-LIMK1) were detected with Western blot-ting. Results Compared with the sham group, the latency increased (t>6.789, P<0.01) and the frequence crossing platform decreased (t=8.695, P<0.001) in the model group, while the number of synapse in hippocampal neurons decreased, and the level of T-LIMK1 (t=7.568, P<0.01) and p-LIMK1 (t=8.874, P<0.001) decreased. Compared with the model group, the latency decreased (t>4.938, P<0.01) and the fre-quence crossing platform increased (t=-7.891, P<0.001) in the EA group, while the number of synapses increased, and the level of T-LIMK1 (t=-6.473, P<0.01) and p-LIMK1 (t=-6.579, P<0.01) increased. There was no significant difference between the the non-acu-point group and the model group in all the indices (P>0.05). Conclusion Electroacupuncture at Shenting and Baihui can improve the ability of learning and memory in rats with cerebral ischemia-reperfusion, which may relate with the increase of LIMK1 phosphorylation and hippo-campal synaptic plasticity.%目的：探讨电针神庭、百会穴对脑缺血再灌注大鼠海马突触可塑性和学习记忆能力的影响，及其可能的机制。方法雄性Sprague-Dawley大鼠32只，随机分为假手术组、模型组、电针组、非穴组，每组8只。模型组、电针组、非穴组采用线栓法制备大鼠脑缺血120 min再灌注模型。电针组电针神庭、百会14 d，非穴组电针大鼠双侧胁下非经非穴14 d。采用Morris水迷宫检测学习记忆能力；电镜观察海马区突触形态；Western blotting检测海马LIM激酶1及其磷酸化水平。结果与假手术组比较，模型组大鼠逃避潜伏期明显增加(t>6.789, P<0.01)，穿越平台次数显著减少(t=8.695, P<0.001)，突触数减少，LIM激酶1总蛋白(t=7.568, P<0.01)及磷酸化水平下降(t=8.874, P<0.001)；与模型组比较，电针组大鼠平均逃避潜伏期明显减少(t>4.938, P<0.01)，穿越平台次数显著增多(t=-7.891, P<0.001)，突触数量增多，LIM激酶1总蛋白(t=-6.473, P<0.01)及磷酸化水平上升(t=-6.579, P<0.01)。非穴组各项指标与模型组比较无显著性差异(P>0.05)。结论电针神庭、百会穴可以改善脑缺血再灌注大鼠学习记忆能力，可能与LIM激酶1磷酸化水平升高进而改善突触可塑性有关。