Electroacupuncture Relieves Postoperative Cognitive Dysfunction in Elderly Rats via Regulating AMP-activated Protein Kinase Autophagy Signaling

Postoperative cognitive dysfunction (POCD) is a common complication after surgery in elderly patients. Electroacupuncture (EA) has been reported to relieve POCD in animal models, but the mechanism remains fully elucidated. The objective of this work was to clarify whether EA could alleviate POCD via regulating autophagy. In this study, aged rats were assigned into 4 groups: control, surgery (rats underwent exploratory laparotomy to induce POCD), EA + S (rats received EA pre-stimulation before surgery), and EA + S + Chloroquine (CQ) (rats were intraperitoneally injected with CQ before EA stimulation and then underwent surgery). The cognitive function of rats was assessed by Morris Water Maze (MWM) test after surgery, and autophagy in hippocampal tissues of rats was evaluated by western blotting and transmission electron microscope. Results indicated that the MWM test revealed that rats showed reduced platform crossing and increased total swimming distance after surgery. However, this impaired spatial memory was improved by EA and EA plus CQ pre-treatment. Besides, the surgery caused an increased expression in LC3II, Beclin-1, AMP-activated protein kinase (AMPK), and p-AMPK in hippocampal tissues of rats, while EA and EA plus CQ pre-treatment also reversed this effect. In addition, the surgery-induced increased amount of autophagic vesicles in hippocampal tissues of rats was reduced by EA and EA plus CQ pre-treatment. In conclusion, EA pre-stimulation could effectively attenuate cognitive impairment in aged rats with POCD via inhibiting AMPK signaling-mediated autophagy.