| Objective:To study the effect of electroacupuncture(EA)on learning and memory ability and mTOR signaling pathway in aged mice with PND after tibial fracture.Methods:According to random number table,A total of 108 male C57 aged mice were selected and divided into three groups: Control group(n = 36),Surgery group(n = 36)and Electroacupuncture group(n = 36).There were 36 mice in each group and 12 mice at every time point: 1,3,and 7 days after surgery.The tibial fracture model was established in the operation group and the electroacupuncture group and intraperitoneal injection of LPS(initial concentration of 10 mg/ml)was administered to each mouse at a dose of 10 mg/kg for 3 consecutive days.In the electroacupuncture group,two acupoints "Baihui" and "Zusanli" were selected,and the density wave(2m A+2/15Hz)was selected for 30 minutes,once a day,for 7 days of continuous electroacupuncture.After cognitive impairment was determined by water maze test at room temperature,the animals were sacrificed by cervical dislocation,and the hippocampi were havested on ice and frozen in a-80 ° C freezer.We measured the contents of IL-1β,TNF-α,and Aβ in the hippocampal tissue by ELISA and the contents of p-mTOR,p-P70S6 K,and p-tau by Western blot.Results:After removing mice with abnormal motor ability,there was no difference in automatic activities among the groups before surgery.After operation,compared with the control group,the walking speed of the model mice in the water maze experiment decreased,but there was no statistical significance(P>0.05).Day after surgery,the number of crossing platforms in the operation group and the electroacupuncture group decreased in the space exploration experiment,and the escape latency in the positioning cruise experiment increased(P<0.05).Both groups were successfully modeled.On the 3rd and 7th days after the operation,the operation group still showed that the number of crossing platforms decreased in the space exploration experiment,and the escape latency increased in the positioning cruise experiment(P<0.05),but there was no significant difference between the two tests(P>0.05)..On the 3rd day after operation,the times of crossing the platform in the electroacupuncture group increased,and the escape latency was shortened,but there was no statistical significance compared with the operation group(P>0.05).Seven days after the operation,the times of crossing the platform in the electroacupuncture group increased significantly,and the escape latency was significantly shortened,which was statistically significant compared with the operation group(P<0.05).On the first day after modeling,compared with the control group,the protein contents of IL-1β,TNF-α,Aβ,p-mTOR,p-Tau and p-P70S6 K in the hippocampus of the operation group and the electroacupuncture group were significantly increased.(P<0.05).3 days after operation,compared with the operation group,the content of related proteins in the electroacupuncture group did not decrease significantly,and there was no statistical significance(P>0.05).Seven days after operation,the protein levels of IL-1β,TNF-α,Aβ,p-mTOR,p-Tau,and p-P70S6 K in the hippocampus of the electroacupuncture group were all decreased compared with those of the operation group,but were still higher than those of the control group(P<0.05).).Conclusion:Electroacupuncture at acupoints of "Baihui" and "Zusanli" can improve the learning and memory ability in aged mice with tibial fractures through inhibiting the mTOR signaling pathway in the brain,thereby reducing the deposition of Aβ protein and the inflammatory response of the central nervous system. |
