| Background The dogma that neuronal replacement is not possible after brain injury has been challenged by recent data[1]. Growing evidence indicates that neurogenesis still occurs in the subgranular zone(SGZ) in hippocampus and the subventricular zone of the lateral ventricle(SVZ). A number of data showed that the two zones retains an ability to generate neurons throughout life that means the two zones contain the adult neural stem cells. It is now expected that neurogensis has a potential to compensate for and recover neural function that were lost by central nervous system disorders. Neurogensis in adult brains increases in such conditions as an exogenous neurotrophic factor supplement,an riched environment, seizure and ischemia[2-6]. It decreases under stress and supplementation of excitatory amino acids or adrenal steroids. Because ischemic stroke often causes loss of the neural functions because of neural cell death neurogensis after ischemia should be important for compensation for and recovery of those functions. Neurogenesis in the mature nervous system is subject to physiologic and pathophysiologic regulation. For example,neural progenitor cells in the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG) can divide and differentiate into neurons after brain injury[6-11].. However,what initiates and promotes this potentially therapeutic response in vivo is still unknown. Among growth factors and neurotrophins that have been implicated, FGF-2 is regarded as one of the most potent. Hippocampal neural progenitor cells in culture proliferate with only FGF-2 supplementation[12]. Scientists have recently demonstrated that FGF-2 is critical for upregulation of neurogenesis in the adult DG after kainate-induced seizures and focal cerebral ischemia[11]. Electroacupuncture is utilized as a clinical treatment for various diseases in Traditional Chinese Medicine. It is known to possess many effects,such as analgesia,promotion of homeostasis and changes in the microcirculatory network as well as improvements in brain circulation[13-15]. The datum indicated that acupuncture may affect cell proliferation in the dentate gyrus of gerbils after ischemia injury[16].Various injury models produce increased neurogenesis in germinal centers,but these regions represent a small portion of the total CNS. What are the prospects for self-repair following injury in other brain structures? Recruitment of endogenous progeny-tors presents a possible method. How to promote proliferation of endogenous neural stem cells? The things that we are interesting in are where the origin of the adult neural stem cells,where they are going and the whole process.Objective (1)In the present study,electroacupuncture was perform-ed consecutively on the rat"He gu"(LI 4) after transient focal ischemia to investigate neurogensis combined Brdu and Nestin and FGF-2 mRNA levels in two main neuroproliferation of the adult rat brain — the SGZ and SVZ and provide a model for investigating one possible mechanisms of this proliferation.(2)To investigate the migration routes of neural stem cells "temporal and spatial"difference of neural stem cells after ischemia/reperfusion. Methods Animals model was made by ligating external carotid artery and inserting a piece of nylon thread into the internal carotid artery among 80 male Wistar rats. Then the rats were randomly devided into two group:I/R group (contain 1,7,14,21,28d five time point,each point n=8)；I/R + EA group (contain 1,7,14,21,28d five time point,each point n=8). Control sham operated(n=4) and normal(n=4) were performed. In addition,Brdu was given at 1,6,13,20,27d. we performed bilateral "He gu"points as stimulation points and stimulated consecutively. Each time is 15 min,once daily. Course of treatment is 7 days.To investigate pathology difference of brain tissue after ischemia/reperfusion by TTC staining and HE staining. The expression difference of Brdu and Nestin in two main neuroproliferation of the adult rat... |
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