The development of the dog nigrostriatal system in organotypic culture.

Portions of the midbrain and the caudate nucleus from newborn dog (1-3 days old) were maintained in explant culture for periods up to 15 weeks. During that time, nerve cells developing in the midbrain explants projected axons into the explants of caudate. Fluorescence microscopic observations indicated that a large number of projective fibers contained catecholamines with many fluorescing terminals visible in caudate explants. Ultrastructural study disclosed synapses in both midbrain and caudate explants. Some axonal profiles in the caudate were compatible with the appearance of catecholaminergic synapses. Neurochemical analysis showed that the nigrostriatal cultures were capable of dopamine uptake and release.