Review point on neural stem cells and neurogenic areas of the central nervous system

The potential applications of neural stem cells (NSC) in the therapy of degenerative and traumatic diseases of the central nervous system (CNS) have aroused great scientific interest. NSCs can be recovered from specific areas of the CNS from fetuses, embryos and from adult brain as well, and under appropriate culture conditions, may be induced to differentiate into the three major neural cell types, neurons, astrocytes and oligodendrocytes. The main neurogenic areas of mammals are the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus, yet other areas of neurogenic potential have been identified, including frontal and parietal cortices, hippocampus and lateral wall of the lateral ventricle. Neural stem cells and differentiated neural cells are usually identified by expression of specific markers, proteins that are expressed by different cell types and/or at different stages of differentiation. The main cell markers are nestin and Sox-2 for undifferentiated NSCs, beta-III tubulin (B-III tubulin) for neurons, Galactocerebroside (GalC) for oligodendrocytes and Glial fibrillary acid protein (GFAP) for astrocytes. In general, the main neurogenic areas, the neurogenic potential of NSC and the morphological and biological characteristics of differentiated neural cells are strikingly similar among species, yet some differences have been reported. This article presents a brief review of NSCs, neurogenic areas and techniques used for their identification and characterization in humans and experimental animals.