Atypical Social Development in Vasopressin-Deficient Brattleboro Rats

Social play is decreased in Hom Brattleboro juveniles. A, B, Number of pins (A) and play attacks (B) of male and female Hom, Het, and WT rats during a 20 min test at P34 or P44. C, D, The temporal profile of play is illustrated in C (for P34) and D (for P44) as the number of total play behaviors binned every 5 min. Sample sizes are indicated within each bar in A and B. Data from each age were obtained from separate cohorts of animals. Genotypes with differing letters differ significantly from each other (p < 0.05, Fisher’s PLSD); where differences approach significance, the p value is included in parentheses next to the letter representing the appropriate comparison. In C and D, significant differences between Hom and WT or Het rats within each bin are indicated by * and #, respectively (p < 0.005, Fisher’s PLSD). See Results for ANOVA details.

Social behavior is altered in Hom Brattleboro juveniles. A–D, Number of total social behaviors (A), total play behaviors (B), social investigation & allogrooming behaviors (C), and huddling episodes (D) of Hom, Het, and WT rats during a 20 min test at P34 or P44. Sample sizes are indicated within each bar. Data from each age were obtained from separate cohorts of animals. Genotypes with differing letters differ significantly from each other (p < 0.05, Fisher’s PLSD). See Results for ANOVA details.

Hom Brattleboro juveniles emit fewer 50 kHz USVs. A–C, Number of all (A), 50 kHz (B), and 22 kHz (C) USVs of male and female Hom, Het, and WT rats during the first 10 min of a 20 min test at P34 or P44. Sample sizes are indicated within each bar. Data from each age were obtained from separate cohorts of animals. Genotypes with differing letters differ significantly from each other (p < 0.05, Fisher’s PLSD); where differences approach significance, the p value is included in parentheses next to the letter representing the appropriate comparison. See Results for ANOVA details.

Ultrasonic vocalization call types emitted during social behavior testing. A, Percentage of USV call types, as defined by Wright et al. (2010), emitted by male and female Hom, Het, and WT juveniles (P34 or P44) during the first 10 min of a 20 min test; data are combined across sex, genotype, and age. B–G, Representative spectrograms of the most common 50 kHz calls [complex (B), upward-ramp (C), flat (D), step-up (E), and trill (F)] as well as the 22 kHz call (G).