The effects of electroacupuncture treatment on the postoperative cognitive function in aged rats with acute myocardial ischemia–reperfusion

• EA improved survival rate and behavior after AMIR.
• EA reduced the excitability of the sympathetic nerve after AMIR.
• EA attenuated neural apoptosis and microglial activation after AMIR.
• EA suppressed oxidative stress and central inflammation after AMIR.

Many literatures have proven that postoperative cognitive dysfunction (POCD) was very common in old patients after the injury of acute myocardial ischemia–reperfusion (AMIR) clinically such as the off-pump coronary artery bypass surgery (OPCAB) without definite mechanism; however, reports on the animal experiments were rarely seen. We hypothesized that AMIR could contribute to cognitive dysfunction, and this severe injury might be impeded by EA via hindering neuroinflammation and oxidative stress response as well as modulating the balance of the autonomic nervous system. The aged male Sprague Dawley rats were randomly assigned into three experimental groups: sham (sham operation), AMIR, and EA (electroacupunture treatment, acupoints GV20 and ST36+AMIR) groups. The survival rate, heart rate variability analysis, examination of pathology within the hippocampal CA1, oxidative stress, systemic inflammation and the behavior testing were evaluated by their corresponding methods. The results showed that the rats subjected to AMIR had lower survival rates, higher malondialdehyde (MDA), decreased superoxide dismutase (SOD) activity, more microglial activation, and presented evidence of severe brain injury and cognitive dysfunction on the 1st, 3rd, 7th days after reperfusion compared to sham-operated controls. Most important of all, the above damages induced by the AMIR were significantly improved by the EA treatment. Our findings indicated that EA treatment could be a neuroprotective therapy for the cognitive dysfunction induced by the AMIR event, which might be attributablefor balancing the autonomic nervous system, inhibiting the neuronic apoptosis, hindering microglial activation, attenuating oxidative stress and restraining the central and peripheral inflammation reactions.