Fig. 4.

IDO1 deficiency is associated with minimal change in average number of nosepokes in every visit after 5 h of free adaptation. The average number of nosepokes per diurnal visit was significantly lower in GKO than WT mice in R1 (a) but not in R2 (b). The average number of licks in every diurnal visit was however not significantly different between GKO and WT mice in R1 (c) and R2 (d). In the dark phase, IDO1 deficiency did not alter the average number of nosepokes made by mice in every visit in both R1 (e) and R2 (f). Likewise, there was no significant genotype effect on the average number of licks per visits made by mice during the dark phase of R1 (g) and R2 (h). Percent visits with nosepokes after 5 h of exploration in the light phase during R1 (a) and R2 (b) was not significantly different between WT and GKO mice. A significant genotype effect on percent visits with licks after 5 h of diurnal exploration was observed in R1 (c), but not in R2 (d). Deficiency of TDO2 did not affect percent visits with nosepokes after 5 h of nocturnal exploration in R1 (e) and R2 (f). Data are mean±SEM. ***p<0.001, Mann–Whitney test. Total n=16 WT and n=16 GKO mice.