Abstract: This invention is directed to continuous, non-maligant, neuronal cell lines, the cells of which: a) in the undifferentiated form are essentially free of branched process; b) stain positively for neurofilament protein and neurotransmitters; c) do not stain positively for glial fibrillary acidic protein; and d) in the presence of nerve growth factor differentiate into cells with long branched processes. Derivative cell lines of such cell lines are also contemplated. The cell lines are useful in screening methods for evaluation of chemical and biological compounds as well as for therapeutic uses.