Effect of Electrical Stimulation of the Limbic System on Pituitary-Thyroidal Function

Abstract

Stimulation of the amygdaloid nuclear complex, the posterior orbital surface and the hippocampal formation was induced in anesthetized dogs previously labeled with J¹³¹ In each of 4 cases in which the posterior orbital surface and the amygdaloid nuclear complex were stimulated, there was no significant increase in the concentration of PBI131 and inorganic I¹³¹ in the thyroid venous blood. In 10 cases in which the hippocampal formation was stimulated, a definite increase was observed with no significant change in the thyroid vein blood flow. Significant increases in the TSH content of the jugular vein blood, assayed in 4 animals by McKenzie’s method, occurred in all cases within 30 min. Hypophysectomy prevented the response of the thyroid to hippocampal stimulation.