Effects of Chronic Central Cooling on Alimentation and Thermoregulation

Chronic local cooling in the forebrain of 4 un‐anesthetized goats was achieved by perfusion of cold water for 1–7 days through implanted silver thermodes. In 2 goats with thermodes located in the pre‐optic region, chronic central cooling resulted in a marked inhibition of water consumption while causing little alteration of food intake. In a third goat with a thermode in the posterior pre‐optic area and the rostral hypothalamus, central cooling inhibited water intake but also increased food intake slightly. In contrast, in a fourth goat bearing a thermode rostrally in the ventromedial hypothalamus, prolonged chilling resulted in a considerable increase in hay consumption while failing to inhibit drinking. These data provide additional evidence in support of the thermostatic theory of the regulation of food intake (B robeck 1948) and of water intake (A ndersson and L arsson 1961); further, they reveal a differential response in alimentation to cooling of separate areas of the forebrain. On central cooling, all thermode goats rapidly developed sustained hyperthermia without shivering declining over 1–3 days upon cessation of central cooling. The sustained hyperthermia may be the result of peripheral vasoconstriction combined with increased metabolism of non‐shivering origin. To explain the present results, there is no need to postulate the existence of central “cold receptors” or “hypothermia detectors” within the cooled part of the brain.