Effect of Electroacupuncture on Hippocampal Functional Activity and Molecular Expression Profile in Rats with Vascular Cognitive Impairment

Abstract

<sec><title>Objective</title> To explore the effect of Tongdu Tiaoshen electroacupuncture method on the hippocampal function and the gene expression profile of the hippocampal tissue in rats with vascular cognitive impairment. </sec><sec><title>Methods</title> A total of 24 healthy male SD rats were randomly divided into the sham operation group, the model group and the electroacupuncture group, with 8 rats in each group. Bilateral common carotid artery ligation was used to prepare a rat model of vascular cognitive impairment in the model group and the electroacupuncture group, only bilateral common carotid artery was separated without ligation in the sham operation group. The electroacupuncture group was intervented by stimulating at Baihui (GV20) and Shenting (GV24) acupoints, the frequency of electroacupuncture was 1/20 Hz, 30 min each time, once a day, dilatational wave, continous intervention for 28 days, and the other two groups were grabbed under the same conditions without any other intervention. Barnes maze test was used to evaluate the spatial learning and memory ability of rats; Y maze test was used to evaluate the spatial working memory ability of rats; small animal 7.0 T magnetic resonance resting brain functional imaging was used to analyze the changes of regional homogeneity (ReHo) of hippocampal functional activity; Agilent mRNA expression microarray was used to analyze the differential gene expression of the whole hippocampus genome. </sec><sec><title>Results</title> ① Behavioral analysis results: compared with the sham operation group, the Barnes maze escape latency of the model group increased significantly (<italic>P</italic><0.05), the target quadrant duration percentage decreased significantly (<italic>P</italic><0.05), and the Y maze alternation rate decreased significantly (<italic>P</italic><0.05); compared with the model group, the Barnes maze escape latency of the electroacupuncture group decreased significantly (<italic>P</italic><0.05), the target quadrant duration percentage and the Y maze alternation rate increased significantly (<italic>P</italic><0.05). ② ReHo changes results: compared with the sham operation group, the ReHo of functional activitives of the bilateral prefrontal lobes, hippocampus and other brain regions in the model group decreased significantly (<italic>P</italic><0.005); compared with the model group, the ReHo of functional activities of the bilateral hippocampus, prefrontal lobes and piriform cortex in the model group increased significantly (<italic>P</italic><0.005). ③ Genomics results: a total of 705 genes with 2-fold differential expression of hippocampal mRNA between the model group and the sham operation group (<italic>P</italic><0.05), of which 195 genes (such as Sytl1, Trpv6, Klhl14, Npsr1, Myh3, Galnt3, Nr4a1, Bmp3, Egr2, etc.) were down-regulated, of which 510 genes (such as Insl6, Efcab1, Akr1b1, Tagln, Glrb, Akr1c13, Kcne1L, Ubap1, etc.) were up-regulated. A total of 399 genes with 2-fold differential expression of hippocampal mRNA between the electroacupuncture group and the model group (<italic>P</italic><0.05), of which 166 genes (such as Klhl14, Bmp3, Npsr1, Cacna1e, etc.) were up-regulated, of which 233 genes (such as Insl6, Ube2k, Cdkn1c, Camp, Upk1b,etc.) were down-regulated. </sec><sec><title>Conclusion</title> The Tongdu Tiaoshen electroacupuncture at Baihui and Shenting acupoints can improve the cognitive function of rats with vascular cognitive impairment, and its mechanism may be related to enhance the function of hippocampus, prefrontal lobes and other brain regions, regulate the expression of calcium ions and energy metabolism-related molecules by regulating nerve activity activity. </sec>