Abstract
Inbred mouse strains differ in their preferences for sweeteners, due in part to variations in their T1R3 sweet taste receptor. Recent studies of sweet sensitive C57BL/6J (B6) and subsensitive 129P3/J (129) mice indicate that experiential and post-oral effects of sugar substantially modify sweetener preference. In fact, the strain difference in sucrose preference disappeared after the mice were given 23 h/day tests with sucrose at ascending concentrations (0.5-32%). Intragastric infusions of sucrose (16%) also conditioned increased preference for and absolute intake of flavored sweet solutions in B6 and 129 mice. An operant analysis of sweetener appetite revealed, unexpectedly, that sugar-experienced 129 mice respond more vigorously than B6 mice for 16% sucrose rewards. These findings indicate that experiential and nutritional factors can, to some degree, override genetic differences in peripheral taste sensitivity in determining food appetite.