| Neural stem cells is a kind of cell that can self-renew and give rise to all cell types within the nervous system .It has some chracter below:1 .On the whole vital process,neural stem cells can self-renew and self-maintenance.2.Neural stem cells can self-duplication.3.Neural stem cells can obtain mass offspring by amplificationANeural stem cells has multi-potential,can give rise to all cell types within the nervous system.Because previou neural stem cells mainly come from fetus or embryonic tissue.not only few,but also effected by moral principles,So the application of it suffered restriction.since Reynolds BA extracted neural stem cells from the adult Wistar rats in 1992,the neural stem cells has been paid close attention by more and more scholar.Because the neural stem cells posses multi-potential,can take along ectogenesis therapeutic gene and can obtain immortal cell line by introduce protooncogene,so as a method of thrapy neural regressive disease,neural stem cells has wide prospect.but follow the investigation,people detected that the proliferation and differentiation of neural stem cells are not the same as suppose.In spite of the fate of these stem cells is determined mainly by their initial location within the developing neural tube and their final location post migration from the proliferative zone of the neural tube.,but the proliferation and differentiation are effected by internal and external environment.Melatonin is a kind of indole hormone,secreted mainly by pineal body .The excretion of Melatonin has rhythm that high in night but low in day. As human kind,melatonin has wide physiological function,for example:accelerate sleep reinforce body immunological function repress growth of tumor cells clear free radicak repress the activity of NO synthase prevent lipid peroxidation maintain and activate macrophage/microglia function protect astrocyte from the hurt that pro-hypoxia / suplly oxygen again repress the damage of neuron by NO that provocated by high-kalium andaminoglutaric acid > accelerate adolescent development and prevent senility.Especially within the progress of Alzheimer disease,Melatonin play a very important role.In our study,corpus striatum cells were dissociated from 13-to 16-days-old SD rat's embryo and plated in serum DMEM-F12 and B27 culture medium .divided into four groups,contain nothing/20ng of epidermal growth factor(EGF) per milliliter/2mg of Melatonin per milliliter or 20ng/ml+2mg/ml. Cultured seven days persistently,extracted the floating cell spheres. The floating cell spheres that not dissociated were cultured for a month;The mono-cell suspension that dissociated from the floating cell spheres was divided into four groups.Method is the same as it described before.The result of experiment:1. Cells isolated from corpus striatum were primary cultured in EOF or EGF+MT group,observed in invert microscope the next day,we find cells divided into two layers.in the base layer the plate,we can observed cell clone about ten cell each clone/few nerve cell/astrocyte and fibroblast in 40 X sight;at the same in the floating layer,we can observed cell bud or proliferate .For the last three days,we can observed cell proliferation unceasing in two layers,the numer of the spheres is composed of about 30-40 cells;But in the seven day,the cell clone of base layer is began to differentiate into neural or astrocyte,in the three days,cell is differentiate into neural or astrocyte completely;Yet the floating cell spheres proliferate continue.the number and the size of these two groups is no different.in the vacuity control group and MT group,there is no cell proliferation.2.Extract the floating spheres,make into mono-cellsuspension and subculture,divided into four groups,the next day we can observed cell proliferate,the numer of the sphere is compose of 10-16 cells,in the third day.cell proliferate into 30-40 cells.among the three groups of EGF/EGF+MI7MT,the size and the number of the spheres is no statistical differentia. Subculture as the method described,we can observed the...
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