Fig. 2

The NHE9 cKO exhibits behavioral features characteristic of ASD. a Postnatal day 21 (P21) mice were videotaped for 30 min and the amount of time soliciting play, in affiliative and investigative behavior, were scored. ****p < 0.0001 by one-way ANOVA with Bonferroni multiple comparison. *p = 0.016 by two-tailed Student’s t test comparing WT and cKO animals. WT, n = 12; HET, n = 10; cKO, n = 11. b Adult NHE9 cKO mice show selective defects in social interaction. Left panel, the three chamber test shows no difference between cKO and WT mice in the intrinsic interest of a novel mouse or novel object; all genotypes spend more time investigating a novel mouse. WT, n = 10; HET, n = 10; cKO, n = 12. Middle panel, NHE9 HET and cKO mice display deficits in social recognition. Total time spent investigating (sniffing, close following) a novel mouse (at t-0′) was compared with the time spent investigating the same mouse 1 h later (t-60′, middle panel) or a novel mouse 2 h later (t-120′, right panel). *p < 0.05 by two-way ANOVA with Bonferroni comparison. WT, n = 10; HET, n = 10; cKO, n = 10. c cKO mice exhibit repetitive digging behavior in the marble burying test. The number of marbles buried by each genotype was counted at the end of 30 min. **p < 0.01 by one-way ANOVA with Bonferroni comparison. WT, n = 14; HET, n = 14; cKO, n = 21. d NHE9 cKO mice do not distinguish between social, non-social, or aversive odorant cues. **p < 0.01, ***p < 0.001 by one-way ANOVA with Bonferroni comparison. WT, n = 10–17; HET, n = 10–21; cKO, n = 10–28. All bars indicate mean ± s.e.m.