黒こく質しつMeanings1nounsubstantia nigraanatomyAnatomical term for a midbrain structure involved in movement and reward. Used in medical and neuroscience contexts.パーキンソン病びょうでは黒こく質しつのドーパミン神しん経けい細さい胞ぼうが減げん少しょうする。In Parkinson's disease, dopamine neurons in the substantia nigra are lost.