Low-dose effects of bisphenol A on sexually dimorphic behavior

Abstract

Bisphenol A (BPA) is an environmental endocrine disrupter that is used in polycarbonate plastics, dental prostheses and dental sealants. Most studies on BPA have dealt with its effect on reproductive systems. A reference dose of 50μg/kg/day has been established based on data of reproductive toxicity. Our study focused on the central nervous system and sexually dimorphic behavior of rats. Both of these factors are sensitive to environmental chemical substances. BPA at 0.1ppm in drinking water was applied to dams during prenatal and postnatal periods. The offspring were examined in the open-field test, elevated plus maze test and passive avoidance test. Both pre- and postnatal exposure to BPA mainly affected male rats and abolished sex differences in exploratory behavior in the open-field test. However, the BPA impact on this sexual dimorphism was not particularly significant when the exposure was postnatal. Avoidance learning and results of the elevated plus maze test were not affected. These results suggest that sexually dimorphic open-field behaviors are highly sensitive to environmental endocrine disrupters.