PROJECTION OF VENTROLATERAL MEDULLARY (A1) CATECHOLAMINE NEURONS TOWARD NUCLEUS TRACTUS SOLITARII

Abstract

The distribution and interconnections of brainstem catecholamine cell groups thought to be important in cardiovascular control were studied using histochemical and ultrastructural techniques in the rabbit. Lesions and microinjections of horseradish peroxidase (HRP) were made in the nucleus tractus solitarii in the dorsomedial medulla, and in the ventrolateral medulla. After lesions of the dorsomedial medulla the fluorescence intensity of the A1-group of catecholamine neurons was increased, and swollen axons could be seen coursing from the ventrolateral medulla toward the lesions on the same side, but not the opposite side. Most of these axons ran in a band about 2 mm in width, centered at th..