| Objective: Alzheimer’s disease(AD)is a neurodegenerative disease characterized by typical memory loss and learning difficulties.The main clinical manifestations are progressive memory cognitive disorders,behavioral abnormalities and personality behavior changes.In recent years,the research on AD is endless,but the pathogenesis of ad is not fully described.In order to explore the improvement of learning and memory of AD mice by low-frequency electroacupuncture,this experiment observed the improvement of learning and memory of AD mice by low-frequency electroacupuncture at Baihui and Shenshu points,and explored its potential therapeutic mechanism,so as to provide certain scientific basis for clinical electroacupuncture prevention and treatment of AD.Methods: Twenty four five-month old SAMP8 mice were randomly divided into three groups: model group,electroacupuncture group and sham electroacupuncture group,8 in each group,and 8 samr1 mice of the same age as the control group.The electroacupuncture group was treated with low-frequency electroacupuncture,and the acupoint location was selected according to the atlas of acupoint location of common experimental animals designated by the experimental acupuncture branch of Chinese Acupuncture Association.Baihui Point is inclined to stab 2mm forward and Shenshu Point is inclined to stab 3-4 mm inboard.Thepositive and negative poles of electroacupuncture are respectively connected to Baihui and Shenshu(Shenshu Point is stimulated alternately on both sides).Connect g6805 ii electroacupuncture instrument after the injection of needle,select continuous wave,frequency 2Hz,and keep the needle for 20 min.Once a day,6 days for a course of treatment,after each course of treatment to rest a day,a total of 5 courses.In the false electroacupuncture group,the same acupoints as those in the electroacupuncture group were only needled to the subcutaneous area and connected with electroacupuncture but not electrified.The model group and the control group did not receive any acupuncture treatment,only in the same environment.At the end of the treatment,Morris water maze was used to detect the change of learning and memory ability,immunohistochemistry was used to detect the expression of pfh-1 in hippocampus,Western blotting was used to detect the expression of MAP2,tau-1 and total tau protein in hippocampus,and transmission electron microscopy was used to observe the ultrastructural changes of axons in hippocampus.Results:1.Water maze test showed that: in the navigation experiment,the escape latency of the control group was significantly shorter than that of the model group,the sham electroacupuncture group and the electroacupuncture group;there was no significant difference between the sham electroacupuncture group and the model group on the first day,andthe escape latency of the sham electroacupuncture group was shorter than that of the model group from the second day;the escape latency of the model group was significantly longer than that of the electroacupuncture group;the improvement of the electroacupuncture group was small The learning and memory ability of rats was better than that of the sham electroacupuncture group.In the space exploration experiment: the number of crossing platform in the control group was significantly more than that in the model group,the false electroacupuncture group and the electroacupuncture group;compared with the model group,the number of fictitious platform passing through the target quadrant in the electroacupuncture group and the false electroacupuncture group was significantly increased,but the number of fictitious platform crossing in the electroacupuncture group was significantly more than that in the false electroacupuncture group.2.The ultrastructural changes of the axons in the hippocampus of mice: transmission electron microscopy showed that there was no obvious abnormality in the microtubules and microfilaments of the control group and the electroacupuncture group;the microtubules and microfilaments of the model group and the false electroacupuncture group were arranged in disorder,and even the axons such as the nerve microtubules and microfilaments depolymerization and fracture appeared.3.Immunohistochemistry showed that there were a lot of brownPHF1(ser396 / 404)protein in the cytoplasm of hippocampal neurons in the model group,and the number of PHF1 positive cells in the electroacupuncture group was significantly less than that in the sham electroacupuncture group and the model group;compared with the model group,there was no significant difference in the number of PHF1 positive cells in the sham electroacupuncture group;the number of PHF1 positive cells in the control group was significantly less than that in the electroacupuncture group and the sham electroacupuncture group.The number of PHF1 positive cells in the dentate gyrus of hippocampus in the electroacupuncture group was significantly less than that in the model group and the sham electroacupuncture group.4.The expression of MAP2,tau-1 and total tau protein in hippocampus of mice in each group: the expression of MAP2 protein in hippocampus of mice in the control group was significantly higher than that in the model group,electroacupuncture group and sham electroacupuncture group.Compared with the model group and sham electroacupuncture group,the expression of MAP2 protein in Electroacupuncture group was significantly higher than that in the model group,but there was no significant difference in the expression of MAP2 protein in sham electroacupuncture group.The tau-1 / total tau protein in the hippocampus of the control group was significantly higher than that of the model group,the electroacupuncture group and the shamelectroacupuncture group.There was no significant difference in the relative expression of tau-1 / total tau protein between the model group and the sham electroacupuncture group.Compared with the model group and the sham electroacupuncture group,the relative expression of tau-1 /total tau protein in the hippocampus of the electroacupuncture group was significantly lower.Conclusion:1.Low frequency electroacupuncture can significantly improve the learning and memory ability of AD.2.The improvement of learning and memory ability of AD by low frequency electroacupuncture may be related to the increase of MAP2 protein expression in hippocampus,the decrease of tau protein phosphorylation and the maintenance of axon stability. |
