Neural Stem Cells

Recent work has shown that the adult central nervous system (CNS) contains neural progenitors, precursors, and stem cells that are capable of generating new neurons, astrocytes, and oligodendrocytes. These findings challenge previous dogma that no new neurons are born in the adult mammalian CNS and raise the possibility of developing novel neural repair strategies. This article reviews current knowledge about constitutive adult mammalian neurogenesis, highlights the critical differences between neurogenic and nonneurogenic regions in the adult brain, and describes the cardinal features of two well-described neurogenic regions - the subventricular zone/olfactory bulb system and the dentate gyrus of the hippocampus. The possibility of repairing neural circuitry by manipulating neurogenesis is reviewed with a focus on recent efforts to understand the conditions under which neurogenesis can be induced in nonneurogenic regions of the adult CNS. © 2007