| After SCI(spinal cord injury, SCI) the patients themselves not only deeply suffer from the dysfunction, but also bring heavy economic burden to society and families. How to let the paralysis patients stand from the wheelchairs has been the project persuing by clincal doctors and resechers. The finding of NSC(neural stem cells,NSC) will bring splendid prospective and enhance our confidence in overcoming spinal cord injured-diseases.In the past, many people thought that adult neural tissues could not regenerate in mammalian, but the conception changed in these years. In adult rat CNS(central nervous system,CNS), NSC are found in two major areas: subventricular zone and subgranular zone. There exist NSC widely in embryonic CNS. Further research indicates that after injury of neurons in VI layers of cortex , the endogenous NSC of which can differentiate into specific projected neurons to repair the function.Because the number of endogenous neural stem cell is limited to repair serious and wide injury, much attentions were paid to repair CNS with exdogenous NSC. At first, NSC have the ability to self-replicate which can meet the number of transplanted cells. The second, NSC can differentiate into three different lineages: neurons, astrocytes and oligodendrocytes under some conditions which can overcome the shortage of limited function rehabilitation caused by one lineage transplantation and the possibility to forming tumor. The third , different tissue-derived NSC have distinct characteristics in growth and differentiation, for example the differentiated neurons from spinal cord-derived NSC have long neurites which is accordance to the property of neurons in spianl cord,on the contrary the neurons from brain-derived NSC have short neurites. Based on the reasons above mentioned. we isolated , cultured and identified the NSC from embryonic spinal cord of rats and observed the effects of different cytokines on clones forming. In order to identify its ability of multi-differentiation, we studied the differentiation of NSC under different conditions. At the same time, the NSC as donor were transplanted into injuried spinal cord. Regeneration and repairing effects of which were observed by technologies of behavior, neuroelectro-physiology, immunocytochemistry and pathology. We primarilyinvestigated the mechanisms of tranplanted NSC ' repairing effects on injuried spinal cord. The major results are as follows:1. There exists bFGF responsive, self-replicated NSC in embryonic spinal cord of rats, and they can keep the ability of self-replication well.2. During primary culture of neural stem cells, through using three different cultural medium: Neural basal+bFGF ,Neural basal +bFGF+EGF, and Neural basal+EGF, we found Neural basal+bFGF can facilitate the survival and replication of NSC ,which is a more effective and economical method .3. In vitro , neural stem cells can differentiate into three different lineages: neuron ,astrocyte ,oligodencyte and the ratio of three kinds of cells is distinct with the changes of cultural condition. Under serum-free medium the number of neuron is much more than that of the glial. The more serum is, the more the glial cells are.4. Through the detection of pathology and immunochemisty, we found the transplanted NSC can survive for 8 weeks, mend the damaged areas and spread fiber contacting with normal tissues.5. In vivo, the transplanted NSC can differentiate into neurons and glials. The number of glials are overwhelming, but neurons are still existed with much neurites. The morphology of them is clear in injuried spinal cord. 6. With HRP staining , we found the positive neurons in upper region of injuried spinal cord in tranplanted groups are much more than the controlled, which hints the NSC may repair the fiber contact of injuried spinal cord in part.7. After 4,8 weeks of neural stem cells transplantation, by staining with AchE, we observed that the morphology of motor end-plate in transplanted group is nearly normal , which infer that the muscle aquire inne...
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