• nuclei of the posterior horn (sensory) = substantia gelatinosa of Rolandi + Nucleus proprius + Clark's dorsal nucleus
• nuclei of the anterior horn (motor) = 2 medial + 1 central + 2 lateral groups
• nuclei of the lateral horn (autonomic) = sympathetic (T1-L2/L3) + parasympathetic (S2-S4)

Degeneration of neurons especially in substantia nigra of both sides might cause Parkinson's disease.

substantia nigra

The substantia nigra are located in an area of the brain around the lateral ventricles known as the basal ganglia.

This is an addition to the above-mentioned answer. To be more specific, substantia nigra lies in the midbrain, dorsal to the cerebral peduncles.

Rolando Blackman's birth name is Rolando Antonio Blackman.