Fig. 6.

Social preference is reduced by DLaN. Performance on the 3-chamber social test was assessed in mice of each genotype (Cntnap2 KO, WT) under each lighting condition (LD, DLaN) and the resulting data analyzed with 2-way ANOVA. During the social preference stage of the three chamber test, mice freely explored the arena with a novel object (O) in one chamber, and an age- and sex-matched WT stranger mouse (S1) in the other chamber while dwell time is measured. (A) Cntnap2 KO mice do not show a preference for the mouse over an object (t₍₈₎ = 0.533, P = 0.601). Under DLaN, the mutants actually prefer the object and avoid the mouse (t₍₈₎ = 3.791, P = 0.002). (B) WT mice prefer to spend time with the stranger mouse over the object (t₍₉₎ = 4.391, P < 0.001). This preference is lost under DLaN conditions (t₍₈₎ = 0.751, P = 0.464). (C) Normalizing the difference between chamber dwell times by time spent in both chambers produced the social preference index. This index shows significant effects of genotype (F_(1,36) = 11.757, P = 0.002) and treatment (F_{(1, 36)} = 13.892, P < 0.001). Significant (P < 0.05) differences because of treatment are indicated with an asterisk (*) over the treated values while the number sign (#) indicates a genotypic difference. DLaN reduced social performance in both genotypes with the mutant mice appearing to avoid the test mouse.