FIGURE 2.

Baseline anhedonia- and apathy-like behaviors in adult C57BL/6N, DBA/2 and FVB/N mice. (A) In the sucrose preference test, adult DBA/2 mice showed increased baseline anhedonia-like behaviors by having a lower sucrose preference index than C57BL/6N and FVB/N mice. Additionally, FVB/N mice showed a higher sucrose preference index than C57BL/6N mice. (B) The splash test revealed a decreased grooming duration in FVB/N compared to C57BL/6N and DBA/2 mice. (C) C57BL/6N mice exhibited a decreased latency to first grooming in the splash test compared to DBA/2 and FVB/N mice. In panel (A), no sex difference was revealed in the sucrose preference test within any of the aforementioned strains. In panel (B), male FVB/N mice showed a decreased duration of grooming, while male C57BL/6N mice showed an increase in the duration of grooming compared to their female littermates. In panel (C), male FVB/N mice showed an increased latency to first grooming compared to their female littermates. Blue and red dots represent males and females, respectively. Two-way ANOVA was used followed by the Tukey’s post-hoc test for multiple comparisons to determine differences between the three strains C57BL/6N, DBA/2, and FVB/N (**p ≤ 0.01, ***p ≤ 0.001) and Bonferroni correction to check differences between males and females within each strain (in green: #p ≤ 0.05, ##p ≤ 0.01). A green rectangle indicates a significant difference between sexes within a strain. Error bars indicate the standard error of the mean (SEM).