Influence of Local Temperature Changes in the Preoptic Area and Rostral Hypothalamus on the Regulation of Food and Water Intake

摘要

Local cooling of the preoptic area and rostral hypothalamus was found to induce eating in the fed goat. When the same animal was dehydrated to the state of aphagia, cooling of this area inhibited the animal's urge to drink and at the same time induced eating. Although in a normal goat feeding practically stops when the rectal temperature exceeds 40C (APPLEMAN and DELOUCHE, 1958), local cooling of the preoptic area and the rostral hypothalamus was found to induce the goat to eat hay with a seemingly good appetite at body temperature above 41C. Warming the same area had the reverse effect. It inhibited eating in the previously hungry animal and at the same time induced the goat to drink large quantities of water. In another goat the preoptic 'heat loss centre' had been permanently inactivated by proton irradiation. This animal became adipsic due to the lesion but was seen to continue to eat hay with a seemingly good appetite at body temperatures above 41C. The anorexic effect of warming the preoptic area thus does not seem to be due to a direct thermal effect on the hypothalamic 'appetite centre'. The results provide direct evidence in favour of BROBECK's (1948) 'thermostatic' theory of the regulation of food intake and justify the further extension of this theory to involve also the regulation of water intake. (Author)