艾灸对缺氧缺血性脑病新生小鼠学习记忆的影响

Effect of moxibustion on learning and memory in neonatal hypoxic-ischemia encephalopathy mice

目的:观察艾灸对缺氧缺血性脑病(HIE)新生小鼠脑组织磷酸化钙调蛋白依赖性蛋白激酶Ⅱα(pCaMKⅡα)、神经元核抗原(NeuN)表达和学习记忆的影响,探讨艾灸的作用机制。方法:将出生7 d的ICR小鼠随机分为假手术组、模型组和艾灸组。采用右颈总动脉结扎联合缺氧的方法制备新生HIE动物模型。艾灸组小鼠于"大椎"处施行温和灸,35 min/次,1次/d,连续3 d。采用大体和切片观察小鼠脑组织病理变化;免疫荧光染色法检测小鼠脑组织缺血半暗带区pCaMKⅡα和NeuN表达;Morris水迷宫检测小鼠学习记忆能力。结果:假手术组小鼠脑组织未见梗死灶,脑组织pCaMKⅡα、NeuN表达较多,寻找平台的潜伏期较短;与假手术组比较,模型组小鼠右侧脑半球可见梗死灶,脑组织pCaMKⅡα、NeuN表达明显减少(P<0.01),寻找平台的潜伏期明显延长(P<0.01);与模型组比较,艾灸组小鼠右侧脑半球可见小面积梗死灶,脑组织pCaMKⅡα、NeuN表达明显增多(P<0.01),寻找平台的潜伏期显著缩短(P<0.01)。结论:艾灸可改善HIE新生小鼠的学习记忆能力,其机制可能与减轻脑组织损伤、增加脑神经元中pCaMKⅡα表达有关。

Objective To observe the effect of moxibustion on the expression of phosphorylated calcium/calmodulin-dependent protein kinase Ⅱα(pCaMKⅡα) and neuronal nuclei(NeuN) and the ability of learning and memory in the neonatal mice model of hypoxic-ischemia encephalopathy(HIE), so as to explore its mechanism underlying improvement of learning and memory. Methods ICR mice(aged 7 days) were randomly divided into sham operation, model and moxibustion groups. HIE model was induced by ligation of the right common carotid artery combined with hypoxia in a closed transparent chamber. Mice in the moxibustion group were treated with gentle moxibustion at "Dazhui"(GV14) for 35 min, once daily for 3 consecutive days. The pathological changes of brain tissues were observed with the naked eyes and under microscope after H.E. staining, respectively. The expressions of pCaMKⅡα and NeuN in the ischemic penumbra were examined by immunofluorescent staining, and the learning and memory ablility was tested with Morris maze. Results No infarcts were found in the brain tissue of the mice in the sham operation group. Compared with the sham operation group, mice in the model group had infarcts and the expression of pCaMKⅡα and NeuN in the ischemic penumbra was significantly reduced(P<0.01), and the latency to find a platform was significantly prolonged in Morris maze test(P<0.01). After moxibustion, in comparison with the model group showed that, small areas of infarction were seen in the right hemisphere of the moxibustion group, and the expressions of pCaMKⅡα, NeuN increased significantly(P<0.01), and the latency to find a platform was significantly shortened(P<0.01). Conclusion Moxibustion can improve the ability of learning and memory in the neonatal mice with HIE, which might be related to alleviating brain injury and increasing the expression of pCaMKⅡα in neurons of ischemic brain tissues.