The effects of gestational exposure to endocrine-disrupting chemicals on the adult social behavior in male and female rats

Endocrine disrupting chemicals (EDC) exposures during critical periods of development influence neuronal development and the manifestation of sexually dimorphic behaviors that emerge in adulthood. Among these behaviors, social information processing is sexually dimorphic and regulated by sex steroids. Oxytocin and vasopressin serve as primary neurotransmitters mediating these behaviors; these neuroendocrine circuits are hormone sensitive and potential targets of prenatal EDC exposures. In dissertation, I assess the effects of gestational exposure to EDCs on the social behavior of male and females later in adulthood. A weakly estrogenic PCB mixture, Aroclor 1221, was administered to pregnant Sprague-Dawley rat dams during the time when the hypothalamus undergoes sexual differentiation. The brains of these animals were also used to quantify the presence of oxytocin or vasopressin in the two main regions of production: the paraventricular nucleus (PVN) and the supraoptic nucleus (SON). Another experiment extended this treatment paradigm to encompass a longer period of gestational development, added another EDC treatment group (Vinclozolin), and looked at similar behavioral outcomes. Lastly, I provide a novel way of modeling complex social behaviors in a laboratory setting. Through all of this work, we show that the sexes are differentially susceptible to endocrine disruption by PCBs or vinclozolin. Additionally, we provide evidence that the traditional choice models of social behavior in the rodent may not be reflective of how an animal behaves in a more complex, naturalistic, environment.