FLAVOR PREFERENCES CONDITIONED BY INTRAGASTRIC INFUSIONS OF DILUTE POLYCOSE SOLUTIONS

Prior studies have obtained strong conditioned preferences (>90%) for flavors paired with intragastric OG) infusions of Polycose (hydrolyzed starch) over different flavors paired with IG water infusions. These experiments used concentrated Polycose solutions (16-32%; 0.6-1.2 kcal /ml) that contributed 50% or more of the animals' daily caloric intake . The present experiment sought to determine if calorically dilute sol utions would also support preference conditioning. Adult female rats w ith gastric cannulas were trained with a cue solution (the CS+) paired with Polycose infusions. On alternate days a different cue solution ( the CS-) was paired with IG water infusions. The CSs were unsweetened or saccharin-sweetened citric acid and sucrose octaacetate solutions t hat were available 22 h/day; chow was freely available. Separate group s were infused with Polycose at concentrations of 0.5%, 1%, 2%, and 4% (0.019-0.152 kcal/ml). The three higher concentrations conditioned fl avor preferences of up to 89%. The infused Polycose represented only 1 -14% of the animals' daily caloric intake and did not reliably reduce chow consumption. These findings demonstrate the sensitivity of the vi scerosensory feedback system mediating flavor conditioning.