Adult male rats were injected with 6-hydroxydopamine, either into the lateral brain ventricle or directly into the dorsal hippocampus. They were adrenalectomized 5-7 days later, and following an additional 24 hours, the specific in vitro 3H-corticosterone binding capacity of dorsal hippocampal slices was determined by estimation of uptake of radioactivity by the nuclear fraction. Specific corticosterone binding was reduced by 40-50% in both experimental groups, as compared to vehicle-treated controls. These results suggest that the maintenance of normal dorsal hippocampal corticosterone binding capacity is dependent upon the integrity of endogenous brain catecholaminergic neural systems.