Regulation of calorie intake in rats with rostral zona incerta lesions: effects of caloric density or palatability of the diet

Following an initial period of hypophagia, the body weights of rats with zona incerta lesions approached asymptotic levels that were significantly lower than those of controls although daily food intake was not reliably depressed. In spite of persisting deficits in feeding efficiency, the ad libitum food intake of the ZI-lesioned rats (relative to body weight) recovered to preoperative levels and was regulated accurately with respect to the caloric density of the diet. However, rats with ZI lesions were finicky eaters and did not maintain stable calorie intake when given unpalatable diets. The water intake of ZI-lesioned rats remained consistently below that of neurologically intact rats but was normal relative to their own food intake and lowered body weight.