Gender and intrauterine position influence saccharin preference in mice.

Gender differences in saccharin preference in adult Rockland-Swiss mice were examined in Experiment 1. Separate groups of male and female mice received tap water and one of five concentrations of saccharin solution (either 0.10, 0.25, 0.50, 0.75, or 1.00%). A significantly higher preference score was obtained for females vs. males that received the 0.25% solution. Other concentrations did not yield a significant sex difference. The purpose of Experiment 2 was to examine prenatal influences on preference patterns of adult males. Mice were delivered by cesarean section and classified as having resided between two male (2M), two female (0M), or one male and one female (1M) fetuses. Saccharin preference was then examined in separate groups of adult males that received either a 0.25 or a 0.75% solution. A significantly higher preference score was obtained for 0M vs. 2M males that received the 0.25% concentration; no difference was obtained with the 0.75% solution. Differences between 2M and 0M males may be due to the actions of prenatal steroids.