Adult Neural Stem Cells from the Subventricular Zone Give Rise to Reactive Astrocytes in the Cortex after Stroke.

Reactive astrocytes (RAs) have been reported to convert to multipotent neural stem cells (NSCs) capable of neurosphere (NS) formation and multilineage differentiation in vitro. Using genetic tagging, we determined that subventricular zone (SVZ) NSCs give rise to NSs derived from the stroke-injured cortex. We demonstrate that these cells can be isolated from the cortex in two different models of stroke and from different stroke-lesioned cortical regions. Interestingly, SVZ NSCs give rise to a subpopulation of RAs in the cortex that contribute to astrogliosis and scar formation. Last, we show that these SVZ derived RAs can be converted to neurons in vivo by forced expression of Ascl1. Identifying the contribution of cells originating from the SVZ to injury repair has implications for neural regeneration strategies.