Saccharin pre-exposure enhances appetitive flavor learning in pre-weanling rats

In adult rats, data suggest that consumption of sweet tastes that do not deliver anticipated caloric consequences using high-intensity, non-caloric sweeteners, such as saccharin, interferes with learned relations that may contribute to energy balance. The goal of the present study was to assess the development of learning about sweet taste and calories by assessing whether pre-exposure to saccharin solutions reduces cue competition in pre-weanling rats. The results demonstrated that rats pre-exposed to saccharin and then trained with a novel grape flavor paired with a glucose-sweetened solution consumed more of the novel grape flavor presented alone than rats that had been pre-exposed to saccharin and given the grape flavor paired with water alone. No differences in intake of the novel grape flavor were observed in groups given pre-exposure to water or glucose solutions. Thus, by 15 days of age, rats appear to have established an association between sweet tastes and calories, and this association can be weakened by exposure to saccharin.