Epinephrine and norepinephrine secretions were measured before, during, and after electrical stimulation of 66 points in the hypothalamus and adjacent parts of the brain in 19 dogs anesthetized with pentobarbital. The 17-hydroxycorticoid response to stimulation of 21 points in 11 dogs was also measured. Catecholamines increased with I–V stimulation of 18 points in the region of the dorsomedial and posterior nuclei of the hypothalamus and in a band extending laterally, inferiorly, and caudally from them. Blood pressure rose during the stimulation of one of these points, fell during stimulation of six, and was unchanged during stimulation of eight. Catecholamine secretion increased during stimulation of 12 of 19 points stimulated at 3–10 v. Selective increases in norepinephrine secretion were not observed. Output of 17-hydroxycorticoids increased without a change in catecholamine secretion when 4 points in the ventral hypothalamus and orbital frontal lobe were stimulated. Increased adrenal medullary secretion was not associated with increased adrenocortical secretion.
