This disclosure describes a novel population of cerebellum-derived neural stem cells that can be isolated from the adult brain, expanded, and differentiated into neurons, astrocytes and oligodendrocytes. This disclosure also describes compositions and methods for producing oligodendrocytes. Oligodendrocytes can be produced in vitro (e.g., in culture) or in vivo (e.g., for therapy or in a non-human transgenic animal) using the compositions and methods described herein.