Fig. 7.

Corner visit frequency of IDO1 WT and GKO mice during drinking and non-drinking sessions in R1 and R2. In comparison to the day before drinking sessions were executed (“baseline”), in both R1 (a) and R2 (b) the IDO1 WT and GKO mice maintained the same level of corner visit frequency throughout the drinking sessions. However, they significantly increased their corner visits during non-drinking sessions on the first day, then decreased them on the next day, in R1 (c) and R2 (d), implying that they had become aware that water rewards were not available in some sessions. The visit frequency of test day 1 or 2 was compared to that on the previous day by repeated contrast. The data (mean±SEM) showed no significant genotype effect at each level of repeated contrast. *p<0.05, **p<0.01, ***p<0.001, repeated contrast. Total n=16 mice per WT or GKO group.