Fig. 2
Behavioural assessment of mild Chd8 hypomorphic mice. a–k Behavioural assessments of a cohort of adult Chd8neo/neo (neo/neo, n = 24; 14 males, 10 females, a, b, d, e, g, i or n = 15; 10 males, 5 females, f, k or n = 11; 6 males, 5 females, j) and Chd8+/+ (+/+, n = 41; 26 males, 15 females, a, b, d, e, g, i or n = 31, 21 males, 10 females, f, k or n = 12; 6 males, 6 females, j) and pup Chd8neo/neo (neo/neo, n = 10; 4 males, 6 females, c) and Chd8+/+ (+/+, n = 12; 6 males, 6 females, c) mice. Chd8+/+ animals are illustrated using filled circles, dotted lines with grey bars and Chd8neo/neo animals with open triangles, solid lines and open bars. Apart from USVs (c), all other tests were conducted on young adults 6–14 weeks of age. a Duration, in seconds, spent in each chamber of the three-chamber sociability test. All mice spent a significantly higher proportion of time in the chamber with the age- and sex- matched stranger con-specific mouse compared to the other chambers. Mean ± SEM; *** < 0.001 (between-subjects ANOVA with student’s t test as post-hoc analysis). b Duration, in seconds, of social investigation over a three-minute period. Social investigation was defined as the combined total duration of head, body and anogenital sniffing of a conspecific mouse. Mean ± SEM (between-subjects ANOVA). c The mean number of ultrasonic vocalisations per minute on indicated postnatal days. Mean ± SEM (repeated-measures ANOVA). d Graph demonstrating the performance in the olfactory habituation/dishabituation test. Mean ± SEM (repeated-measures ANOVA). e The duration, in seconds, mice spent self-grooming during the 10-min self-grooming test. Mean ± SEM (between-subjects ANOVA). f The average number of marbles buried, out of a maximum of 12, within a 30-min period period. Mean ± SEM; * < 0.05, ** < 0.01 (repeated-measures ANOVA with student’s t test as post-hoc analysis). g Representative ethovision tracks of a Chd8neo/neo (neo/neo) and Chd8+/+ (+ / +) animal plotting their movements during the 10-min open field task. h The percentage of time spent in the centre of the open field arena during the 10-min test. Mean ± SEM; **p < 0.01 (between-subjects ANOVA). i The total distance travelled in the outer part of the open field arena over a 10-min time-period. Mean ± SEM; *** < 0.001 (between-subjects ANOVA). j The total activity counts per 12 h period on running wheels in the homecage during 7 days of dark-phase recording. Mean ± SEM; *p < 0.05 (repeated-measures ANOVA). k The mean latency of mice to fall from the rotarod. Mean ± SEM (repeated-measures ANOVA)