Neural stem cells and its therapeutic application

For a long time, it had been believed that repairing the nervous system was impassible because the mature nerve cells lacked the ability to regenerate. Recently, it was showed that neural stem cells exist not only in the developing mammalian nervous system but also in the adult nervous system of all mammalian organisms, including humans. Neural stern cells have self-renewal capacity and can differentiate into three major component cells of the brain, neurons, astrocytes and oligodendrocytes. Recently, it was also showed that neurons could be efficiently induced from embryonic stem cells, which can differentiate into every cell type and maintain their undiffer entiated status in the presence of LIF. Therefore, neural stem cells and embryonic stem cells are regarded as potential sources for cell transplantation. On the other hand, encapsulated dopamine-secreting cells are also potential donors for a treatment of Parkinson's disease, because encap sulated cells can avoid immunological problems, Nowadays, there is great interest in the possibility of repairing the nervous system by transplanting new cells that can replace those lost through damage or disease, such as Parkinson's disease. In this paper, we are going to review some recent remarkable progress about the regeneration of the nervous system by cell transplantation.