Experimental Study On Electroacupuncture In Treating Vascular Dementia (VD)

Objective: To study the mechanism of curative effect of electricacupuncture(EA) therapy in treating Vascular Dementia (VD). Methods: Theanimals were divided into four groups: sham-operated control group, VD group, EA group and Nimotop therapeutic group, modified Pulsinelli's 4-vessel occlusion (4-VO) method was used to establish the models of the global ischemia and reperfusion in Sprague-Dawley (SD) rats. The animals of EA group were stimulated at the point of Baihui and Dazhui that usually be used to treating encephalopathy in clinic by EA. By the methods of neuroethology, neurobiology, histomorphology, stereology and Tunel, the pathogenesis of VD and the protective effect of EA on learning and memory impairment induced by cerebral ischemia injury were studied at cellular and molecular level.Results: EA could significantly improve the learning and memory ability ofVD rats on the Morris water maze test with no significant difference as compared to sham-operated control, and enhance SOD, GSH-Px and NOS activities in brain , inhibited MDA and NO contents. The activities of HO increased more significantly in hippocampus region than those in cerebral cortex during global ischemia-perfusion injury and more CO was engendered, while EA could regulate the increasing HO activities and CO contents. But EA played insignificant role in regulating the contents of cGMP and cAMP. EA could significantly alleviate the injury, improve ultrastructural alteration, inhibit apoptosis and prevent the lose of neurons. Also it could improve the synapticreconstruction and increase the quantity of synapses. Conclusion: EAcould improve learning and memory ability of rats with cerebral ischemia injuried by the following mechanisms: attenuate free radical and NO, antagonize their neurotoxicity.and inhibit degeneration, necroses andmmapoptosis of neurons, thereby protect the morphological structure of synapses ; and regulate the function of neurons and the transmit of communication by accommodating HO activities and CO contents. The results offered conclusive experimental foundation for acupuncture in preventing learning and memory impairment induced by cerebral ischemia. And it was indicated firstly that there were changes of a new neurotransmitter - CO and its synthetase - HO involved in the development of VD. EA also could inhibit the alteration of synaptic plasticity, and even could promote the neurons to come into being new dendrites and synaptic connections, which might be one of the mechanisms of EA in improving learning and memory impairment of VD rats.