Activation of subventricular zone stem cells after neuronal injury.

The mammalian subventricular zone (SVZ) has garnered a tremendous amount of attention as a potential source of replacement cells for neuronal injury. This zone is highly neurogenic, harbours stem cells and supports long-distance migration. The general pattern of activation includes increased proliferation, neurogenesis and emigration towards the injury. Intrinsic transcription factors and environmental signalling molecules are rapidly being discovered that may facilitate the induction of these cells to mount appropriate therapeutic responses. The extent of SVZ neurogenesis in humans is controversial. However, tantalizing new data suggest that humans are capable of generating increased numbers of neurons after a variety of diseases