The Mechanism Of Zhisanzhen Regulating Hippocampus-Prefrontal Neural Circuit To Improve Cognitive Function Of Vascular Dementia Mice

ObjectiveWe aimed to estimate the mechanism of Zhisan’s regulation of the hippocampal-prefrontal loop in vascular dementia(VaD),VaD model mice were selected as experimental objects,and the Zhisanzhen was used for the main intervention.We observed the effects of the Zhisanzhen group on the cognitive functions of VaD mice,including the behavioral changes,the morphological structure of pyramidal neurons in the hippocampus,variety in the expression of GABA interneurons in the prefrontal lobe and hippocampus,and the density of dendritic spines.MethodsEighty healthy male C57BL6 J mice were randomly divided into a sham operation group(n=15)and an operation group(n=65).The operation group used bilateral common carotid artery occlusion(BCCAO)to establish VaD mice models,and the sham operation group only separated bilateral common carotid arteries.Finally,48 successfully established VaD model mice were randomly divided into three groups according to the computer random number: model group(n=16),non-acupoint group(n=16),and Zhisanzhen group(n=16).After 28 days of acupuncture intervention,the open field test(OF),new object recognition test(NOR),and Y maze behavior test were used to observe the effect of acupuncture on the cognitive function of the VaD mice.Nissl staining was used to evaluate the pathological changes of pyramidal neurons in the hippocampus of CA1,immunofluorescence(IF)staining was employed to observe the expression of GABA interneurons in the prefrontal lobe and hippocampus of CA1.We analyzed the density of dendritic spines by Golgi staining.Results1.Compared with the model group,the OF test showed that the distance in the central area of the Zhisanzhen group decreased,and there was a significant difference between the two groups(P<0.05).Compared with the model group,the NOR test indicated that the Zhisanzhen group showed a higher discrimination coefficient,and there was a statistical difference between the two groups(P<0.05).To contrast with the model group,the Y-maze test revealed that the Alternation percentages of the Zhisanzhen group increased,and there was a statistical difference between the Zhisanzhen group and the model group(P<0.05).2.As compared to the model group,IF test found that the expression level of PV in the prefrontal and hippocampal CA1 area of the Zhisanzhen group significantly increased,and there was a remarkable difference between them(P<0.05).Compared with the non-acupoint group,the expression level of PV in the prefrontal area of Zhisanzhen obviously improved,and there was no significant difference between the two groups(P>0.05).Compared with the model group,there were more SST expression levels in the prefrontal area and hippocampal CA1 area in the Zhisanzhen group and the non-acupoint group,but there was no statistical difference between the groups(P>0.05).Compared with the non-acupoint group,there were more SST expression levels in the prefrontal area and hippocampal of CA1 area in the Zhisanzhen group,but there was no statistical difference between the groups(P>0.05).Compared with the model group,the NPY expression level in the prefrontal lobe and hippocampus CA1 area increased in the Zhisanzhen group,and there was a statistical significance between the two groups(P<0.05).Compared with the non-acupoint group,the number of NPY neurons in the prefrontal area of the Zhisanzhen group significantly growing,and there was a statistical significance between the two groups(P<0.05).3.Compared with the model group,Golgi staining showed that the density of dendritic spines in the prefrontal lobe and hippocampus CA1 area of the Zhisanzhen group increased,and there was a remarkable difference between them(P<0.05).Compared with the non-acupoint group,the density of dendritic spines in the hippocampal CA1 area of the Zhisanzhen group increased,and the comparison between the two groups was statistically significant(P<0.05).Conclusion1.Zhisanzhen group could be able to improve the percentage of alternation and new object discrimination ability of VaD model mice,suggesting that Zhisanzhen help improve the situational memory and working memory of the VaD model mice.2.The Zhisanzhen group significantly boosted the expression of PV and NPY neurons in the prefrontal area and hippocampal CA1 area,revealing that Zhisanzhen could protect PV and NPY interneurons and improve the working memory of VaD mice.3.The Zhisanzhen group increased the dendritic spine density in the prefrontal lobe and hippocampal CA1 area,showing that the Zhisanzhen group could improve synaptic plasticity and ameliorate the cognitive impairment of VaD mice.