Abstract: | Explants 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. |