The effects of prenatal LPS (100 μg/kg at gestational day 9.5) and postnatal pioglitazone (0.25 and 1.0 mg/kg/day between postnatal days 21 and 29) exposures on 50-kHz ultrasonic vocalizations in juvenile male rat offspring. SAL+DMSO, prenatal saline injection and postnatal daily DMSO injection; LPS+DMSO, prenatal LPS injection and postnatal daily DMSO injection; LPS+PI0.25, prenatal LPS injection and postnatal pioglitazone 0.25 mg/kg/day; LPS+PI1.0, prenatal LPS injection and postnatal pioglitazone 1.0 mg/kg/day (n = 8 rats/group). *p < 0.05, **p < 0.01, and ***p < 0.0001 (one-way ANOVA followed by the Newman-Keuls test). The data are expressed as the mean ± the SEM.