Alterations in food and water intake after hypothalamic lesions in the rat

¹ Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania

Electrolytic lesions in the lateral hypothalamus produced aphagia and adipsia. One rat remained adipsic until sacrifice 283 days after operation; 11 rats with lesions continued to drink water while refusing ground laboratory chow. This effect lasted until sacrifice, 8–13 days postlesions, suggesting that areas regulating water and food intake are separable. Lesions designed to induce diabetes insipidus were produced in rats in which variable renal water loss had been eliminated by prior nephrectomy. Rats with lesions drank significantly more than nephrectomized controls during the 2-day observation period. The experiment was repeated, but food was withheld and controls were subjected to sham hypothalamic operation. In this group water intake was greater and weight loss less in rats with lesions than in sham-operated controls, though the difference was less than that in the presence of food. Although the difference in water intake was small, the results suggest that destruction of an inhibitory drinking center may contribute to polydipsia in diabetes insipidus. Water intake may be stimulated by lateral and inhibited by medial areas in the hypothalamus.