Studies on neuromelanin

Abstract

Serial sections from an adult human brainstem demonstrated pigmental neurons in the substantia nigra and its associated nuclei as well as in a column extending the entire length of the brainstem, from the mesencephalon to the nucleus retroambigualis. Histologically, the pigment was characterized as melanin. In the brainstem, there is a striking parallel between the anatomical maps of the neuromelanin neurons described here and the catecholamine cells described by Dahlstrom and Fuxe. Cerebral melanin may be a by-product of norepinephrine and dopamine metabolism and accumulates in aging catecholamine neurons.