The Effect Of Electroacupuncture On Structure Of NNOS-positive Neurons In Ischemic Penumbra Of Cerebral Infarction Rat

Objective:To observe the effect of electroacupuncture on nNOS-positive neurons in the ischemic penumbra of cerebral infarction rat after acute period of ischemia, and to supply experimental evidence for exploring central nervous mechanism of electroacupuncture in ischemic penumbra.Methods:Establishing rat model of cerebral infarction with the cerebral middle artery occlusion (CMAO), the rats were divided into two groups: ischemic group and electroacupuncture-treated group. With immunohistochemical methods, the change of form and number of nNOS-positive neurons were observed in ischemic penumbra of parietal cortex, caudate putamen, hippocampal subfield CA1, CA3 under light microscopic level, and the change of ultrastructure of nNOS-positive neurons in ischemic penumbra of caudate putamen under electronic microscopic level.Results:results gained under light microscopic level:(1) Ischemic group: The staining of the bodies of nNOS-positive neurons was deep, the size decreased at 1st d with ischemia, the processes and the number increased gradually after 7d with ischemia in parietal cortex and caudate putamen. The staining of the bodies of nNOS-positive neurons was deep, the distribution was widespread at 1st d with ischemia, the number decreased obviously at 7th d with ischemia, the number was more at 14th d than at 7th d with ischemia in hippocampus. (2) Electroacupuncture-treated group: the processes and number were more than ischemic group in parietal cortex and caudate putamen. The number was less than ischemic group at 1st d with electroacupuncture, and more than ischemic group after 7d with electroacupuncture in hippocampus.Results gained under electronic microscopic level:(1) Ischemic group: nuclei of nNOS-positive neurons in caudate putamen werelysised. many nNOS-positive DAB particles were deposited in the cytoplasm, there was larger blank region and the mitochondria were vacuolating in the processes of at 1st d with ischemia. Nuclei of nNOS-positive neurons were nearly integrated, and the swelling of mitochondria decreased gradually in the processes of nNOS-positive neurons after 7d with ischemia. (2) Electroacupuncture-treated group: chromatin of nNOS-positive neurons was rarefactive. mitochondria were swelling in the processes of nNOS-positive neurons at 1st d with electroacupuncture. Nuclei of nNOS-positive neurons were more integrated than of ischemic group, the degree of the swelling of mitochondria in the processes was lower than ischemic group after 7d with electroacupuncture.Conclusions:The regulation of electroacupuncture on nNOS-positive neurons has two patterns: it decreased the expression of nNOS-positive neurons at 1 st d with electroacupuncture in hippocampus, decreased the toxicity of NO; it also promoted the restoration of nNOS-positive neurons in parietal cortex, caudate putamen and hippocampus (at 7th, 14th d with electroacupuncture).