Innervation of melanocytes in choroid

The innervation of the choroidal melanocytes of the rabbit was studied by transmission electron microscopy with the aid of 5-hydroxydopamine treatment. Three types of nerve terminals, which were classified as adrenergic, cholinergic, and non-adrenergic/non-cholinergic (NANC), were recognized in relation to melanocytes in the choroid. Morphologically, the contacts between these nerve terminals and melanocytes represent the fashion of synapse. Choroidal melanocytes of the rabbit thus seem to possess NANC as well as adrenergic and cholinergic innervation, although the functional significance of the NANC nerves remains obscure.