Comparative Study On Biological Property Of Neural Stem Cells From Embryonic Mouse Cerebral Cortex And Fetal Hippocampus

Neural stem cells (NSCs) are special cells which have some capacity of tropism for tumors, self-renewal, and the potencies to differentiate with multi-direction. There is a broad prospect to use the property of neural stem cells for some diseases treatment in central nervous system, especially, in cell substitute therapy, gene carrier for gene therapy, treatment of CNS trauma, degeneration diseases of CNS and brain tumor, etc. Additionally, the discovery of neural stem cells is a breakthrough for neural regeneration in the central nervous system (CNS). Up to now, some of the properties on neural stem cells are not still clear. Some scholars considered that differentiation of neural stem cells are relevant to the internal environment of cells, neurotrophic factor, differentiating factors and cellular signal transduction. However, the neural stem cells from various resources of species show different reactive capacity to the same differentiating factor. Even so, neural stem cells from the isotype species demonstrate various response to the different factors and different concentration of facilitating differentiating factors. With the exception of above-mentioned, the morphologic structure on biological signal transmission of NSCs, structure of junction-like among neurospheres was not reported in the past papers and webs. To explore the biological property of neural stem cells (NSCs) from embryonic mouse cerebral cortex and fetal hippocampus comparatively and study the molecular mechanism of development of nervous system, we did the study as following.Section oneCultivation, identification of neural stem cells from both embryonic mousecortex and human fetal hippocampus in vitro(1) Cultivation, identification of neural stem cells from human fetal hippocampus in vitro The first step in this part was to dissect and separate hippocampus from the embryo-brain of 10-14weeks. Then, the human stem cells were, isolated from the tissue selected in medium containing HuEGF and bFGF. The cells from fetal hippacampus had an ability of consecutivedifferentiation and forming neurospheres in serum-free medium. Both clusters of cells and naive cells were positive by nestin immunocytochemical staining. Neurofilament-200(NF-200) and glial fibrillary acidic protein (GFAP) antigens were positive in the mature cells, which demonstrated that some of the differentiated cells were neurons and the others were glial cells. These results showed that the primary culture cells were NSCs.(2) Cultivation, identification of neural stem cells from the cerebral cortex of embryo mouse.In this section, the conceived murine belly was cut open under aseptic condition firstly. The next was to isolate the stem cells from the mice cortex in serum-free medium containing EGF from the mouse and bFGF. The primary culture cells had the ability to consecutively proliferate and form neurosphere in the medium. Nestin was positively expressing in these cells which were examined by immunohistochemistry. The cells could differentiate into adult neural cells in medium supplemented with fetal bovine serum. The expression of NF-200 was positive in some of the differentiated cells and some of them were GAFP positive. It demonstrated that some of the differentiated cells were neurons and the others were glial cells. These results showed that the primary culture cells were NSCs.Section twoEffect on regulation of NSCs orientating differentiation by ecdemic signalBy now, there are two kinds of mechanisms on orientating differentiating theory of neural stem cells. One is NSCs autogene regulation and the other is exotic signal regulation. This experiment was designed to explore the morphologic structure on biological signal transmission of neural stem cells (NSCs), morphologic characteristics of NSCs cultured in vitro under the different medium. The results showed as follows. (1) The neural stem cells from mice grew very well in the medium with EGF only. However, most neural stem cells could be induced to differentiate into glial cells and only a few neurons when...