Neuromelanin-containing neurons in the substantia nigra degenerate during Parkinsons disease. Motor symptoms of Parkinsons disease are caused by cell death in the substantia nigra, which may be partly due to oxidative stress. This oxidation may be relieved by neuromelanin. Patients with Parkinsons disease had 50% the amount of neuromelanin in the substantia nigra as compared to similar patients of their same age, but without Parkinsons. The death of neuromelanin-containing neurons in the substantia nigra, pars compacta, and locus coeruleus have been linked to Parkinsons disease and also have been visualized in vivo' with neuromelanin imaging.
Neuromelanin has been shown to bind neurotoxic and toxic metals that could promote neurodegeneration.