Testosterone enhancement during pregnancy influences social coping and gene expression of oxytocin and vasopressin in the brain of adult rats

Abstract

Steroid hormones are important mediators of prenatal maternal effects and play an important role in fetal programming. The aim of our study was to investigate how testosterone enhancement during pregnancy influences neurobehavioral aspects of social coping of rat offspring in adulthood. Pregnant rat dams were exposed to depot form of testosterone during the last third of pregnancy (i.e., beginning on the 14th day of pregnancy). Their adult offspring were later tested in a social interaction test and expression of oxytocin and arginine-vasopressin mRNA in the hypothalamic nuclei was evaluated. Our research showed that prenatal exposure to higher levels of testosterone activated socio‑cohesive and socio‑aversive interactions, but only in males. The testosterone‑exposed group also showed decreased oxytocin mRNA expression in the supraoptic and paraventricular nuclei of the hypothalamus, and increased arginine-vasopressin mRNA expression in the supraoptic and suprachiasmatic nuclei as compared to controls. However, we did not observe any sex differences in the expression of oxytocin and arginine‑vasopressin mRNA in these regions. Our findings show that testosterone enhancement in pregnancy could have long‑lasting effects on oxytocin and arginine-vasopressin levels in the brain of adult animals, but lead to changes in behavioral aspects of coping strategies only in males.