Fig. 4.
Effect of oxytocin (OXY, 0.1 mg/kg; s.c.) and vehicle (VEH, 0.154 M saline 1 ml/kg) on social interaction between two male Lister-hooded rats from different litters paired by similar weight and the same previous drug treatment, recorded over 10 min. a individual behaviors (s), b total time in social interaction (s), c body temperature change from basal (immediately prior to injection), before (45 min post injection) and after the interaction trial (55 min post injection as indicated; °C) and d the number of pro-social 50 kHz ultrasonic vocalizations (USVs) emitted by both rats in each pair. All data are presented as mean ± SEM. e Representative spectrographs showing pro-social 50 kHz USVs emitted from rat pairs defined into three subtypes; flat, step and trill, following Fast Fourier transformation and pattern analysis. a *P = 0.05; Student’s unpaired t-test. c *P < 0.05 from OXY. d Following log10 transformation, *P < 0.05 ***P < 0.001 VEH vs. OXY; Sidak post hoc; VEH = saline vehicle, OXY = 0.1 mg/kg oxytocin; n = 8 pairs/group. NB. A different time scale is used to show ano-genital and body sniffing from other, less frequent, behaviors