1. A layer of deeply pigmented grey matter in the midbrain; associated with the striate body; is involved in metabolic disturbances associated with Parkinson's disease and with Huntington's disease
   "Degeneration of dopaminergic neurons in the nucleus niger is a hallmark of Parkinson's disease";
   - substantia nigra, locus niger

Type of: neural structure

Part of: mesencephalon, midbrain