The multifaceted subventricular zone astrocyte: From a metabolic and pro-neurogenic role to acting as a neural stem cell.

A few decades ago it was discovered that two regions of the adult brain retain the ability to generate new neurons. These regions include the subgranular zone of the hippocampal dentate gyrus and the ventricular-subventricular zone (V-SVZ) located at the border of the lateral ventricle. In the V-SVZ, it was discovered that neural progenitor cells (NPCs) share many features of mature astrocytes and are often referred as V-SVZ astrocytes. We will first describe the markers, the morphology, and the neurophysiological characteristics of the mouse V-SVZ astrocytes. We will then discuss the fact that V-SVZ astrocytes constitute a mixed population with respect to their neurogenic properties, e.g., quiescent versus activated state, neurogenic fate, and transcription factors expression. Finally, we will describe two functions of V-SVZ astrocytes, their metabolic coupling to blood vessels and their neurogenic-supportive role consisting of providing guidance and survival cues to migrating newborn neurons.