The substantia nigra (literal translation: “black substance”) is a portion of the midbrain that contains pigmented dopamine-producing neurons. Degeneration of these cells causes relative depigmentation the substantia nigra, representing a finding that is typical of Parkinson Disease, but may also be present in other neurodegenerative disorders such as Alzheimer Disease.
Shown here is the basal surface of a brain belonging to a person with Parkinson Disease. The brainstem and cerebellum have been removed at the level of the midbrain. Note the pallor of the substantia nigra (arrows).