Effects Of Electroacupuncture On Hippocampal Ferroptosis And Learning Ability In Aged Mice With Tibial Fracture

Objective:To study how electroacupuncture（EA）can improve the learning and memory ability of aged mice with tibial fracture by regulating the Ferroptosis of hippocampal neurons.Methods:96 male aged C57 mice were randomly divided into 4 groups（n=24）:blank control group,modeling group,electroacupuncture group（electroacupuncture at Baihui and bilateral Zusanli points for 14 consecutive days after surgery）,Liproxstatan-1 group（Lip-1group,intraperitoneal injection of iron death inhibitor for 14 consecutive days after surgery）.On the first day after operation,Morris water maze test was performed to evaluate the cognitive function of mice in each group,and the cognitive dysfunction model mice of tibial fracture were selected.Morris water maze test was carried out to test the learning and memory ability of mice in each group at two time points 1 day and 14 days after operation.After the mice were killed,their heads were cut off and the hippocampus was taken.HE staining was used to observe the morphological structure and damage of hippocampal neurons;The expression levels of GPX4,Fe²⁺,MDA,NADPH and ROS in hippocampus of mice were observed by ELISA;Results:Compared with the control group,the speed of the three treated groups of mice in the water maze experiment decreased but had no statistical significance（P>0.05）.The number of times of crossing the platform in the space exploration experiment and the number of times of escaping the latency crossing the platform in the positioning cruise experiment decreased,and the escape latency increased（P<0.05）.The modeling was successful.On the first day after operation,compared with the control group,the number of neurons in the hippocampus of the other three groups decreased,the histomorphology was damaged（P<0.05）,the content of Fe²⁺,MDA,NADPH and ROS increased,and the expression of GPx4 protein decreased（P<0.05）;In the test 14 days after operation,there was no significant change in cognitive function in the modeling group（P>0.05）.Compared with the modeling group,the times of crossing the platform in the electroacupuncture group and Lip-1 group were significantly increased,and the escape latency was significantly shortened（P<0.05）.The number of neurons in the hippocampus was restored,the tissue morphology was significantly improved（P<0.05）,the content of Fe²⁺,MDA,NADPH,ROS was decreased,but still higher than that in the control group（P<0.05）,and the expression of GPx4 protein was up-regulated（P<0.05）.Conclusion:Electroacupuncture can improve the learning and memory ability of aged mice with tibial fracture by inhibiting the Ferroptosis of hippocampal neurons.