Influence of electroacupuncture preconditioning on cognitive function and adenosine monophosphate-activated protein kinase signaling pathway in depression model rats after electroconvulsive therapy

  Objective  To explore the influence of electroacupuncture preconditioning on cognitive function and adenosine monophosphate-activated protein (AMPK) signaling pathway in depression model rats after electroconvulsive therapy (ECT).

  Methods  Totally 75 male sprague-dawley rats were randomly divided into normal control group (groupⅠ), model group (group Ⅱ), electroconvulsive therapy group (group Ⅲ), electroacupuncture+electroconvulsive therapy group (group Ⅳ), false electroacupuncture+electroconvulsive therapy group (group Ⅴ), with 15 rats in each group. GroupⅡ~Ⅴ were treated by chronic unpredictable mild stress (CUMS) to establish model of depression. After successful modeling, all rats in the four groups were anesthetized with 100 mg/kg by intra-peritoneal injection of propofol. Group Ⅱ was treated by anesthesia without electroconvulsive therapy, the other three groups were treated by electroconvulsive therapy. Group Ⅳ was treated by electric acupuncture at Bai hui (GV20) and Yin tang (GV29) acupoint for 30minutes before ECT. Group Ⅴ was treated by false electric acupuncture at 5 mm next to Bai hui (GV20) and Yin tang (GV29) acupoint for 30 minutes before ECT. The rats were kept adaptively feeding for seven days, then the experiment started (the first day of the experiment). Morris water maze test (positioning navigation experiment and space exploration experiment) was carried out on the 1^st day, the 28^th day and the 40^th day of the experiment respectively. On the 6^th day, the 33^rd day and the 45^th day of the experiment, 5 rats in each group were randomly selected. After the rats were sacrificed, the expressions of AMKP and phosphorylated AMKP (p-AMKP) in the hippocampus were determined by Western blot method.

  Results  Compared with group Ⅰ, the escaping latency and the swimming path extended obviously and the crossing platform number decreased significantly on the 32^nd day in group Ⅱ to Ⅴ and the 44^th day in group Ⅱ, Ⅲ, Ⅴ. Compared with the result on 5^th day, the escaping latency and the swimming path extended obviously and the crossing platform number decreased significantly on the 32^nd day in group Ⅱ to Ⅴ and the 44^th day in group Ⅱ, Ⅲ, Ⅴ. Compared with group Ⅲ, the escaping latency and the swimming path shortened obviously and the crossing platform significantly increased on the 44^th day in group Ⅳ, and there were significant differences (P < 0.05). Compared with group Ⅰ, the expressions of AMPK and p-AMPK in hippocampus significantly reduced on the 32^nd day in group Ⅱ to Ⅴ and the 44^th day in group Ⅱ, Ⅲ, Ⅴ. Compared with the results on 5^th day, the expressions of AMPK and p-AMPK in hippocampus significantly reduced on the 32^nd day in group Ⅱ toⅤ and the 44^th day in group Ⅱ, Ⅲ, Ⅴ. Compared with group Ⅲ, the expressions of AMPK and p-AMPK in hippocampus increased obviously on 44^th day in group Ⅳ, and there were significant differences (P < 0.05).

  Conclusion  Electroacupuncture preconditioning can improve the learningand memory ability of depression model rats after electroconvulsive therapy, and has a good anti-depressant effect. The mechanism may be related to the up-regulation of the expression of AMPK signaling pathway in the hippocampus.