The Effect Of Jiawei Yiqi Congming Decoction On Synaptic Plasticity Of Hippocampal Neurons In Rats With Vascular Dementia

Objective: investigating the influence of Jiawei Yiqi Congming Decoction on behavior of VD rats and the role of synaptic structure in hippocampal neurons of rats; Observing the changes of hippocampus neurotransmitter acetylcholine(Ach) and cholinesterase(Ach E) content in rats; surveying the impact on the monoamine neurotransmitters in the cerebral cortexs 5 一 HT,DA,NE. Then to explore the Jiawei Yiqi Congming Decoction in treatment of vascular dementia of the mechanism of action.Methods : 1.grouping methods: Firstly,filter 60 male SD rats which have similar memory ability by the Morris water maze experiment;Secondly,then divide randomly the 60 male SD rats into sham operation group andthe operation group: model group, Nimodipine group(The control group1), Cistanche compound yizhicapsule group(The control group 2), Jia wei Yiqicongming Decoction group(Experimental group). The operation group with an operation has leftand right carotid artery ligation(CCA) for preparing for VD model(CCA). Sham operation group without ligation just Separated and exposed bilateral carotid artery in the process of operation.2. Medication methods: The rats in the control group 1 were given nimodipine in the dose of 6.25mg/kg/d, The rats in the control group 1 were given Cistanche compound yizhi capsule in the dose of 0.375g/Kg/d, The rats in the experimental group were given Jiawei Yiqicongming Decoction in the dose of 14.58g/kg/d, The rats in the sham operation group and model group were given aqua water, All drugs were madeup 2ml/d according to each requirement dosage lasting for 30 days.3. Materials:two rats were randomly selected respectively for the five groups which were insided the heart perfusion paraformaldehyde for fixing the brain tissue after anesthesia for preparing for the biopsy of the electron microscope; the remaining ten rats of each group were beheaded then Stripped of the bilateral hippocampus and cerebral cortex,which were prepared for extracting the hippocampal homogenates and cerebral cortex homogenates after being crushed、liquored and centrifuged, then were stored at 20 degrees below zero in the refrigerator under test; 4.Target detections: Histological changes in rats of each group behavior were mainly detected through the watermaze experi-ment;The content of hippocampus Ach were detected by the means of the ELI-SA method;The determination of hippocampal level of Ach E were detected by the Spectrophotometric method; The determination of cerebral cortex content of 5-HT, DA, NE were detected throgh the fluorescence spectrophoto-metery;Then observing the changes of the componentsof hippocampal neuron synaptic ultrastructure under the electron microscope.Results: 1.behavioristics:(a) Navigation results:To Compare with the sham operation group,the rats in the model group whose escaping latency(EL) were prolonged, and there were statistical meaning(P<0.01),the mice in the control group 1、the control group 2 and the experimental group whose escaping laten -cy(EL) were prolonged slightly, but it was not statistical meaning(P>0.05); To Compare with the model group, the rats in the control group 1、the control gro-up 2 and the experimental group,whose EL were obviously shortened, and the-re were statistical meaning(P<0.05 or P<0.01);There was a little difference on the EL of rats among the control group 1、the experimental group and the control group 2,but it was not statistical meaning(P>0.05).(b) Space exploration experiment:Compared with the sham operation group, the rats in the model group stay on the platform and effective regional time shortened obviously,and the number of striding across the platform and effective area were significantly reduced, there were statistical meaning(P<0.01); To Compare with themodel group,the rats in the control group 1、the control group 2 and the experimental group crossing the number of platform and effective area were increased significantly and the time of staying on the platform and the effective residence were significantly prolon-ged, there were statistical meaning(P<0.05 or P<0.01);There is no great difference on the time of staying on the platform and the number of striding across the platform and effective area along the control group 1、the control group 2 and the experimental group, but it was not statistical meaning(P>0.05).2. ELISA testing results: To compare with the sham operation group, the rats in the model group whose content of Ach in hippocampus were decreased obviously but the content of Ach E in hippocampus were increased obviously,there were statistical meaning(P<0.01); In the meantime,to compare with the sham operation group, the rats in the control group 1、the control group 2 and the ex-perimental group whose content of Ach were decreased significantly but the content of Ach E were increased dramaticlly,there were statistical meaning(P<0.01);To com-pare with the model group,the rats in the control group 1、the control group 2 and the experimentalgroup whose content of Ach were increased markedly but the content of Ach E were decreased markedly in the meantime, there werestatistical meaning(P<0.01); Compared with the control group 1,the content of hippocampus Ach in the control group 2 were decreased but the content of hippocampus Ach E were increased, there were statistical meaning(P<0.05 or P<0.01); To compare with the control group 1,the content of hippocampus Ach in the experimental group were decreased slightly while the content of hippocampus Ach E were increased a little, it was not statistical meaning(P>0.05).Compared with the sham operation group, the content of cortex NE、DA、5-HT in the model group were decreased dramaticlly, there were statistical meaning(P<0.01), Meanwhile, the content of cortex NE、DA、5-HT in the control group 1、the controlgroup 2 and the experimental group were decreased distinctly, there were statistical meaning(P<0.01); Compared with the model group,the content of cortex NE、DA、5-HT in the control group 1、the control group 2 and the experimental group were increased visibly, there were statistical meaning(P<0.01); To compare with the control group 1, the content of cortex NE、DA、5-HT in the control group 2 were decreased, there were statistical meaning(P<0.05 or P<0.01); Meanwhile,the content of cortex NE、DA、5-HT in the experimental group were decreased slightly,but there was no statistical meaning(P>0.05). there was little difference on the content of cortex NE, DA, 5-HT between the control group 2 and the experimental group,and there was no statistical meaning(P>0.05).3 The results of electron microscope: In the sham operation group, hippocampus synaptic concentration were more intensive; The structure was clearly visible; the synaptic structure was distinguished clearly;The coloration of Postsynaptic densezone is further darken. In the model group, the presynaptic membrane became Fuzzy and obviously swelling, the structure of synaptic vesicles、presynapticmembrane、synaptic cleft and postsynaptic membrane becomes blurred and indistinct. The Synaptic population decreased, The coloration of Postsynaptic dense zone becomes more shallower and density were decreased. Compared with the sham operation group, the Synaptic count of hippocampus was decreased significantly, the synaptic cleft became broaden,the thickness of Postsynaptic density material was decreased significantly; Compared with the model group,the Synaptic count of hippocampus in the con trol group 1、the control group 2 and the experimental group were increased significantly,The synaptic gap width was decreased,and the thickness of Postsynaptic density material was increased significantly,The length of presynaptic active zone was lengthen significantly; Compared with the sham operation group, there was little difference on the changes of structure parameters among the control group 1、the control group 2 and the experimental group.Conclusion:1. The means of double blood vessel blocking method(2-VO)can duplicate successfully animal model of vascular dementia,which were related to the dyfunction of learning and memory that caused by the hippocampus ischemia hypoxia.2. It is the Jiawei Yiqi Congming Decoction that can enhance thefunction of learning and memory of VD rats and restore the structure and function of Hippocampal neuron synapses.3. The possible mechanism of Jiawei Yiqi Congming Decoction on VD: it may improve the ischemia and anoxia synaptic structure in hippocampal neurons, then recover the normal synaptic structure and improvesynaptic transmission efficacy; it may increase the content of Ach in thehippocampus and reduce the content of Ach E by the ways of promoting the hippocampus cholinergic neurotransmitter release of Ach and restraining the synthesis of Ach E in hippocampus;it may improve the content of the cerebral cortex NE、DA、5-HT by promoting the release of them from the synaptic vesicle after repairing; At the same time, it canmaintain the integrity of the information transfer function of the hippocampal neurons,and then play a great role in improving the ability of learning andmemory of the VD rats.