Astrocytogenesis of embryonic stem-cell-derived neural stem cells: Default differentiation.

Neural stem cells differentiate from embryonic stem cells via formation of neural stem spheres under free-floating conditions in astrocyte-conditioned medium. Subsequent culture of neural stem spheres on an adhesive substrate with fibroblast growth factor-2 promotes the migration of neural stem cells onto the substrate, resulting in an increase in the number of cells. These embryonic stem cell-derived neural stem cells can be differentiated almost exclusively into astrocytes by withdrawing fibroblast growth factor-2 from the medium without any additional instructions.