Tail pinch-induced arousal and stimulus-bound behavior in rats with lateral hypothalamic lesions. Further evaluation of hypothalamic control of feeding and drinking.

Arousal induced by tail pinching results in stimulus-bound feeding, licking and gnawing in male rats during the aphagic and adipsic phase that follows electrolytic damage to the lateral hypothalamus (LH). Such stimulus-bound behavior is very similar to electrically induced stimulus-bound behavior. Furthermore, brain-damaged animals during tail pinch-induced drinking trials are responsive to the sensory properties of the test liquid. Chocolate milk is consumed but tap water is actively rejected. Tail pinch to sham-operated control rats failed to induce such behavior; instead, it induced rage behavior towards the hand that pinched the tail. The results support the conclusion that rats with LH lesions require an arousing stimulus for feeding but that the same externally applied arousing stimulus enhances active rejection of tap water.