Effects of transcutaneous auricular-vagus nerve stimulation on learning and memory ability and cognitive function in type 2 diabetic rats
Objective It is to investigate the effects of transcutaneous auricular-vagus nerve stimulation(taVNS)on learning ability and cognitive function in rats with type 2 diabetes mellitus(T2DM).Methods Thirty-two SD rats were ran-domly divided into blank group,model group,transcutaneous noninvasive-vagus nerve stimulation(tnVNS)group and taVNS group,with 8 rats in each group.The rats of all groups except for the blank group were were prepared by streptozoto-cin +high fat method to establish T2DM rat models.After successful modeling,the rats of the taVNS group was electrically stimulated at bilateral cavum conchae,and the rats of the tnVNS group was electrically stimulated at bilateral auricular mar-gins,with stimulation strength of 2mA,30 min per time,once daily,continuously treated for 3 weeks.The learning and memory ability of the rats were assessed by Morris water maze test,the morphology of hippocampal tissues was observed by HE staining,the contents of tumor necrosis factor-α(TNF-α)in hippocampal tissues was determined by ELISA,and the expressions of phosphatidylinositol 3-kinase(PI3K)and protein kinase B(Akt)in hippocampal tissues were detected by Western blot method.Results Compared with the blank group,the water maze escape latency of rats in the model group and tnVNS group was significantly increased(P＜0.05),while the times of crossing the platform was significantly de-creased(P＜0.05);compared with the model group and tnVNS group,the water maze escape latency of rats in the taVNS group was significantly shortened(P＜0.05),while the times of crossing the platform was significantly increased(P＜0.05).Compared with the blank group,the content of TNF-αt in hippocampal tissue of rats in the model group was signifi-cantly higher(P＜0.05),and the relative expressions of PI3K and Akt proteins were significantly lower(all P＜0.05);compared with the model group,the content of TNF-α in hippocampal tissue of rats in the taVNS group was significantly lower(P＜0.05),and the relative expressions of PI3K and Akt proteins were significantly higher(all P＜0.05).Con-clusion Transcutaneous auricular-vagus nerve stimulation can improve the learning ability and cognitive function of T2DM rats,its mechanism may be related to inhibiting inflammatory response and activating PI3K/Akt signaling pathway.
type 2 diabetes mellituspercutaneous auricular vagus nerve stimulationcognitive function
NETL
NSTL
万方数据
维普
