Reduced acceptance of saccharin solutions by rats previously consuming more highly palatable solutions.

Rats first given 24-h access to 10% sucrose for 4 or 12 days (Stage 1) were then switched to a saccharin solution for a 12-day Stage 2. The initial result of this switch was that these Sucrose groups drank less saccharin than Water groups that had been given only water to drink in Stage 1. This difference was maintained throughout Stage 2 by the females that served in Experiments 1 and 4 and by the males that served in Experiment 3. Experiment 1 also found that access to 10% glucose in Stage 1 produced an essentially identical decrease in subsequent saccharin acceptance as that produced by giving 10% sucrose in Stage 1. The impact on subsequent acceptance of saccharin was also tested in rats given two types of maltodextrin solution. The first type of maltodextrin (Myopure brand) was used with the males in Experiment 2; this failed to find any difference between the Maltodextrin and the Water group. However, when a second type of maltodextrin (SolCarb brand) was given to males in Stage 1 of Experiment 3, the results for this group were similar to those from a group given sucrose in Stage 1. The final experiment confirmed that prior exposure to maltodextrin solutions can reduce saccharin acceptance by female rats. Overall, the results suggest that acceptance of saccharin is sensitive to a contrast effect, in that it is reduced by prior exposure to a solution that is more palatable but not necessarily sweet.