Autoradiographic evidence for dopaminergic innervation in guinea pig spinal cord.

In studies of the localization of the dopaminergic nerve terminals in the cervical cord of guinea pig, autoradiographic analysis of the spinal cord loaded with [3H]dopamine [( 3H]DA) was done under conditions that prevented the nonspecific uptake of [3H]DA. There was specific labeling in the gray matter and a high density of [3H]DA was present in the dorsal horn (DH). Moderate labeling was observed in the neuropil in the vicinity of the central canal. There were grain concentrations in close approximation to the cell bodies of numerous neurons in the DH and to the cell bodies of a few of the motoneurons in the ventral horn (VH). These dopaminergic terminals are possibly linked to sensory transmission and somatic motor function.