1. A method of generating neurons, the method comprising: (a) continuous culturing undifferentiated human embryonic stem (ES) cells for 2-3 weeks on a fibroblast feeder layer to generate colonies; (b) selecting from said colonies, small piled, tightly packed, differentiated cells; (c) culturing said differentiated cells in the presence of serum free medium supplemented with growth factors which include epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) to produce neurospheres containing neural progenitor cells, wherein said neurospheres do not express alphafetoprotein; (d) culturing the neural progenitor cells on an adhesive substrate comprising poly-D-lysine in the presence of a serum free media and growth factors; and (e) inducing the neural progenitor cells to differentiate into neurons by withdrawal of the growth factors, thereby generating neurons.