1. A method of expanding in vitro at least one neural stem cell to an expanded population of neural stem cells, wherein each neural stem cell expansion exceeds thirty cell doublings without differentiating, said method comprising: dissociating neural stem cells from central nervous system tissue; providing at least one extracellular protein to a culture vessel, wherein the extracellular protein includes at least about 10 μg/mL of poly-D-lysine and less than about 1 mg/ml fibronectin; culturing the dissociated neural stem cells in said culture vessel in the absence of serum; adding to the culture vessel at least one growth factor; and passaging the cultured cells prior to confluence.