Tyrosine hydroxylase and dopamine-beta-hydroxylase: distribution in discrete areas of the rat limbic system.

Tyrosine hydroxylase and dopamine-beta-hydroxylase have been measured in 34 discrete areas and nuclei of the limbic system of the rat. Both enzymes showed an uneven distribution in this system. The ratio between tyrosine hydroxylase and dopamine-beta-hydroxylase activities showed a significant correlation when compared with the ratio of dopamine and norepinephrine concentrations for the areas studied. The results strongly suggest that dopaminergic terminals are present in discrete areas of the limbic cortex, and several septal and amygdaloid nuclei, and allow the precise localization of dopaminergic and noradrenergic areas in the limbic system.