Fig. 1: Chronic social isolation enhances social interaction in WT and Shank3 KO mice.

In the reciprocal social interaction test, WT isol (burgundy; n = 26, 13 males and 13 females) and KO isol (purple; n = 18, 8 males and 10 females) spent more time in nose contacts (A) with a sex-, housing- and genotype-matched conspecific compared to WT group (gray; n = 62, 32 males and 30 females) and KO group (turquoise; n = 16, 8 males and 8 females). KO isol spent significantly more time huddling (B) than the other conditions. In the three-chambered test, KO isol spent more time in nose contacts with the mouse in the sociability phase (C) and with the novel mouse in the social novelty phase (D) compared to WT group and WT isol. All conditions, except KO group, preferred the novel mouse over the familiar one. Data are presented as mean ± sd (Table S2, sex effect in Fig. S1). Statistical analysis was performed using a linear model followed by pairwise comparisons using the estimated marginal means, with asterisks indicating housing effects and hash symbols indicating preference effects (p = P adjusted in all 10-min tests). * or #: p < 0.05, ** or ##: p < 0.01, *** or ###: p < 0.001. KO group, Shank3 KO raised in groups; KO isol, Shank3 KO exposed to 4-week chronic social isolation; WT group, WT raised in groups; WT isol, WT exposed to 4-week chronic social isolation.