Patent ID: 6913925

Claim:
A method for producing a conditionally-immortalized human mesencephalon neural progenitor cell, comprising: (a) plating human mesencephalon cells on a first surface and in first growth medium that permits proliferation; (b) transfecting said progenitor cells with DNA encoding a selectable marker and an externally regulatable growth-promoting protein; and (c) selecting an adherent monolayer of the transfected cells on a second surface and in a second serum-free growth medium that permits attachment and proliferation, wherein the second serum-free growth medium comprises FGF-2, EGF and PDGF, and therefrom producing a conditionally immortalized human mesencephalon cells in which the growth-promoting protein is regulated by an external factor, such that suppression of the growth promoting protein results in differentiation of the cell into a neuron in the presence of differentiating agents comprising forskolin, GDNF, CNTF, IGF-1 and BDNF.