Fig. 6

Mixed B6;129 background enhances sociability and self-grooming in WT, but not in chronically isolated mice. In the reciprocal social interaction test, chronically isolated mice (purple) revealed significant differences compared to WT controls (gray) only in the B6 background, while chronic isolation increased variance in both backgrounds. Social interaction was significantly increased in both WT control and isolated mice from the B6;129 compared to B6 background (A). In the sociability phase of the three-chambered test, sociability preference was observed for both chronically isolated mice and WT control, while this preference was significantly higher in B6;129 background with a higher variance (B). In the motor stereotypy test, there was no difference in the time spent digging or self-grooming between WT and chronically isolated mice, while both WT and isolated mice in B6 background showed increased time spent digging and number of head shakes, while increase in time spent self-grooming was observed in B6;129 WT mice compared to B6 conspecifics (C). Data are presented as individual data, mean ± sd (statistics, n and sex ratio in Table S3). Groups were compared by Kruskal-Wallis tests followed by Dunn post hoc tests, with stars indicating background effect, hash housing effect, and dollar chamber effect (P = adjusted p-value), while the inter-individual variability was compared by Levene’s variance test. *, # or $ p < 0.05; **, ## or $$ p < 0.01; ***, ### or $$$ p < 0.001; ****, #### or $$$$ p < 0.0001.