Evaluate certain general properties of neurally derived cells in tissue culture with respect to their interaction with drugs of abuse. The effects of these agents on cellular morphology, growth, macromolecular synthesis, calcium metabolism, cyclic nucleotide activities and neurotransmitter metabolism will be studied. It is the intent of this proposed study to evaluate in vitro biological responses perturbed by various drugs of abuse such that the possible site(s) of action of these compounds can be ascertained and the mechanism(s) of their action determined. In a broader sense these studies may shed some light on how these compounds alter behavioral activity in vivo.