Perinatal exposure to the estrogenic pollutant Bisphenol A affects behavior in male and female rats

Bisphenol A (BPA) is an environmental estrogen with potentially aversive ef fects on public health. In rats, we studied the effects of perinatal exposu re to BPA on nonsocial behaviors partly influenced by gonadal hormones. BPA was administered orally to one group of mother rats at a concentration wit hin the range of human exposure from 10 days before mating until the weanin g of the pups. In a second group, BPA was given at a higher dosage during a critical period for brain organization, i.e., from day 14 of gestation unt il day 6 after birth. The offspring of the treated mothers were tested in t he holeboard and the elevated plus-maze at 85 days of age. Various aspects of nonsocial behavior were affected by BPA, differently in males and female s, confirming that exposure to a weak environmental estrogen in the period of sexual differentiation of the brain can influence adult behavior. Howeve r, contrary to our expectation, a clear masculinization of females was not observed. In general, the factor analysis indicated that in treated males b oth the motivation to explore and anxiety are reduced, while in females, mo tor activity and motivation to explore are depressed. Because there were no substantial differences between the two modalities of BPA administration, we suggest that the prolonged treatment with the low dosage compensates for the higher dosage given during a shorter steroid-sensitive period. This ma y be a cause of concern for public health, given the greater incidence of p rolonged exposure of humans to low concentrations released into the environ ment. (C) 1999 Elsevier Science Inc.