Injury to individual nuclei of the anterior and middle parts of the hypothalamus in rabbits by electrocoagulation (anode, 5 mA, 20–25 sec) through previously implanted electrodes was followed by changes in the morphological and functional state of the hypothalamic-pituitary neurosecretory system (HPNS). The closer the focus of injury to the region of the supraoptic nuclei, the higher the functional activity of HPNS. If injury to individual hypothalamic nuclei was combined with administration of an atherogenic diet, marked morphological and functional changes were detected both in HPNS and in the adrenals, but in animals with experimental atherosclerosis, this disease assumed a more severe form under these conditions than in animals simply receiving the atherogenic diet. The results of these experiments point to a close connection between the genesis of atherosclerosis and neurogenic factors.