Endogenous neural stem cells in the adult brain.

Despite progress in our understanding molecular mechanisms of neuronal cell death in many central nervous system (CNS) diseases, widely effective treatments remain elusive. Recent studies have shown that neural stem cells (NSCs) are present in the subventricular zone (SVZ) lining the lateral ventricles and the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG) in adult mouse, rat, nonhuman primate, and human brain. Newly generated cells in the SGZ can differentiate into mature, functional neurons and integrate into the DG as granule cells, which are involved in memory formation. In addition, many CNS diseases can stimulate the proliferation of neuronal stem/progenitor cells located in the SVZ and SGZ of the adult rodent brain, and the resulting newborn cells migrate into damaged brain regions, where they express mature neuronal markers. Therefore, it might be possible for damaged cells to be replaced from endogenous neural stem cell pools. However, the capacity of self-repair is obviously not enough. Proliferation, migration, and neuronal differentiation of endogenous NSCs could be manipulated by pharmaceutical tools to reach the adequate benefits for the treatment of CNS diseases.