Objective To observe the effects of electroacupuncture pretreatment on postoperative cognitive dysfunction(POCD)

neuronal apoptosis and neuron-inflammation in aged rats. Method Thirty-six male SD rats aged 20 months were randomly divided into sham operation group

model group and electroacupuncture(EA) group

with 12 rats in each group. The POCD rats model was prepared by internal fixation of left tibial fracture. Five days before modeling

EA stimulation(2 Hz/15 Hz

1 mA

30 min) was applied to “Zusanli”(ST36)

“Hegu”(LI4) and “Neiguan”(PC6) on the unaffected side of rats in the EA group

once a day for consecutive 5 d. The learning and memory abilities of rats were evaluated by water maze test 31—35 days after operation. The apoptosis of hippocampal neurons was observed by Tunel/NeuN double staining. The expressions of high mobility group protein B1(HMGB1) and phosphorylated(p)-nuclear factor(NF)-κB in microglia cells in hippocampal dentate gyrus were detected by immunofluorescence staining. The expression levels of interleukin(IL)-6 and IL-1β in the hippocampus were detected by Western blot. Results Compared with the sham operation group

the escape latency was prolonged(P<0.05); the frequency of crossing the original platform

ratio of the swimming distance and the time in the target quadrant of the Morris water maze were significantly decreased(P<0.05); the apoptosis rate of hippocampal neurons was significantly increased(P<0.05); the expressions of HMGB1 and p-NF-κB in microglia cells in the dentate gyrus and the expression levels of IL-6 and IL-1β in hippocampus were increased(P<0.05) in the model group. Compared with the model group

the results of the above indexes were all opposite(P<0.05) in the EA group. Conclusion EA preconditioning can regulate hippocampal inflammatory response

alleviate neuronal apoptosis rate and long-term cognitive dysfunction in aged rats with POCD

the mechanisms may be related to the inhibition of microglia HMGB1/NF-κB pathway in hippocampal dentate gyrus.