Effect Of Preventive Electroacupuncture Intervention On Brain Aβ Deposition And Neuronal Apoptosis In Rapidly Aging Model Mice

Objective:To observe the effect of preventive intervention by electro-acupuncture therapy on behavior change, deposition of A(3and apoptosis in the brain of senescence accelerated mouse prone8(SAMP8), so as to explore the preventive treatment effect on AD by electro-acupuncture.Methods:305-month old SAMP8mice were selected and randomly divided into model group, restrained group and electro-acupuncture group, and10SAMR1mice of the same age were enrolled as normal control group. The electro-acupuncture group mice were treated with preventive electro-acupuncture intervention. Baihui(DU20) and Yintang (EX-HN3) were chosen as the treatment acu-points. Electricity stimulation was used after needles were punctured into acu-points. Dilatational wave was applied and the frequency was2/100Hz, electric current intensity was0.2-0.4mA. The retaining time of each treatment was20min, and all the mice was treated once every other day,3times a week, and12times was considered as a course, totally3courses were needed. The restrained group mice were given restraining of the same intensity and time with the electro-acupuncture group. Morris Water Maze was used to test the behavioral changes before electro-acupuncture intervention and after each course of treatment, so as to analysis the effect on learning and memory ability of SAMP8mice by preventive electro-acupuncture intervention. After behavioral test, all the mice were anesthetized and then perfused with paraformaldehyde through aorta abdominalis. Brain tissues that contained hippocampus and parietal cortex were chosen to make slices. Immunohistochemical staining was applied to observe the expression of Aβ in hippocampus and parietal cortex, positive cells of A(3expression of neurons in each group were recorded. Tunnel staining method was applied to observe the apoptosis of neurons in the hippocampus, positive apoptosis of neurons ratio and the value of optical density were recorded.Results:1Results of behavioral test After3courses of preventive intervention of electro-acupuncture, compared with SAMR1group, the mice of model group displayed obvious learning and memory impairment in Morris Maze Test, having the following concrete manifestations:the escape latency was obviously extended in place navigation test and the retaining time was obviously shortened in spatial probe test (P<0.05). The escape latency of electro-acupuncture group was obviously shortened compared with model group and restrained group (P<0.05), and had no obvious difference when compared with control group (P>0.05); The retaining time of electro-acupuncture group was obviously extended when compared with model group and restrained group (P<0.05), and had no obvious difference compared with control group (P>0.05).2Results of pathological test By Immunohistochemistry staining method, the expression of Aβwas observed in hippocampus and parietal lobe. Positive cells in model group were largely increased, and most of them were moderate, parts of them were strong positive expressed. In control group, there were little positive cells and they were scattered, and most of them were weakly positive and moderately positive, no strongly positive cells were seen. The number of positive cells of restrained group were between control group and model group with little strong positive cells. The quantity of positive cells in electro-acupuncture group was less than restrained group. By Tunnel staining method, the apoptosis positive ratio of neurons was the lowest in four groups, and that of the model group was the highest, it had obvious difference when compared with each other (P<0.05). The apoptosis positive ratio of electro-acupuncture group was larger than that of control group, however, it was smaller than that of model and control group. The optical density value of apoptosis of model group was the largest, and the restrained group was the second, they were both higher than control group. The optical density value of electro-acupuncture group was significantly lower than that of model group, and it had obvious difference when compared with each other (P<0.05).Conclusions:1Behavioral test indicated that SAMP8mice manifested learning and memory impairment at8-month old, went into the period of obvious aging. After the preventive intervention of electro-acupuncture, the8-month old mice didn’t have obvious learning and memory injury, which illustrated that preventive intervention of electro-acupuncture had the effect of improving the learning and memory ability of SAMP8mice.2Pathological test indicated that there were lots of A β deposition in neurons of hippocampus and parietal cortex, as well as apoptosis in the hippocampus of8-month old SAMP8. After preventive intervention of electro-acupuncture, the deposition of A β was reduced, and the apoptosis was alleviated. So we could conclude that preventive intervention of electro-acupuncture had the effect of delaying process of accelerated aging.