Hypothalamic Cooling Elicits Eating: Differential Effects on Motivation and Pleasure

Abstract

The perceived attractiveness of stimuli to humans has been modulated by changes in cephalic blood temperature. Can similar effects be produced in animals by manipulation of hypothalamic temperature? This study examined the attractiveness and pleasure of food to rats during hypothalamic cooling or hypothalamic heating, by measuring feeding and hedonic and aversive facial reactions to taste. Hypothalamic cooling administered through a permanently implanted thermode elicited feeding. Hypothalamic heating did not. Hedonic and aversive reactions to taste were unaltered by hypothalamic cooling or heating, even for rats that ate during cooling. Hypothalamic cooling may thus potentiate the attractive quality of food without modulating basic taste pleasure.