AbstractExplants of substantia nigra and corpus striatum obtained from newborn rats were maintained in tissue culture for up to six days. Explants of substantia nigra exhibited a net increase in the ability to take up H3‐dopamine, a process associated with the dopaminergic neurons; in contrast, the explants of corpus striatum showed a rapid loss in this ability to accumulate H3‐dopamine. After three days in culture, the specific activity of tyrosine hydroxylase and monoamine oxidase had decreased 50% in explants of substantia nigra. A medium including fetal calf serum and chick embryo extracts was necessary for the increase in H3‐dopamine uptake, and nerve growth factor had an inhibitory effect. Histofluorescent examination of nigral explants cultured for three days indicated morphologically normal dopaminergic neurons.