Neural Stem Cells (NSCs) were isolated from the subventricular zone of postnatal mice under IACUC-approved protocols. The subventricular zone was dissected and enzymatically digested using a solution of papain and DNase I. The resultant cell suspension was filtered through a 70 µm strainer and cultured in a neurosphere-forming medium containing DMEM/F12, epidermal growth factor (EGF), and fibroblast growth factor-2 (FGF-2).