CATECHOLAMINES (E.G., DOPAMINE (DA) AND NOREPINEPHRINE (NE)) PLAY VITAL ROLES AS NEUROTRANSMITTERS OR HORMONES AT CENTRAL AND PERIPHERAL LEVELS. DA, WHICH IS DERIVED FROM THE DECARBOXYLATION OF 3, 4-DIHYDROXYPHENYLALANINE (L-DOPA (LD)), IS INVOLVED IN FINE MOTOR ACTIVITY, ...