Behavioral changes in rodents exposed to a single dose of BPA.
Viberg, H, A Fredriksson, S Buratovic and P Eriksson. 2011. Dose-dependent behavioral disturbances after a single neonatal Bisphenol A dose. Toxicology. http://dx.doi.org/10.1016/j.tox.2011.09.006.
A single dose of bisphenol A (BPA) given to mice during infancy had lasting effects on their behavior as adults, report Swedish scientists in the journal Toxicology.
The mice were less active when first placed in new surroundings. This differed from the unexposed rodents and runs counter to what mice normally do in unfamiliar settings.
The results fall in line with some prior studies, which have reported similar behavior changes in mice after prenatal and newborn exposure to BPA.
BPA is used in many consumer products including polycarbonate plastics, resin linings of food containers and thermal paper receipts. Virtually everyone in the United States is exposed to BPA, predominately through diet.
The investigators in this study fed the infant mice a single dose of BPA when they were 10 days old. The time corresponds to the first trimester of pregnancy in humans. Three different low level doses were tested. The male mice were then subjected to several tests of behavior and learning at two and five months of age.
The investigators found that animals exposed to the two highest concentrations of BPA showed changes in their behavior when responding to a novel environment. Typically mice acclimate to a new environment and become less active after being in a new place. The BPA exposed animals did the opposite. They were less active at first, but became more active as time passed in the new environment.
The behavior changes suggest that just one exposure can change the rodent's nervous system and lead to behaviors in the mice that may affect their well-being.
The investigators did not find that a single dose of BPA changed the animal's learning or anxiety.
While this study found that a single dose of BPA can change mouse behaviors, the exposures used in this study cannot be generalized to most infants. The fetus and infant is continuously exposed to BPA at much lower doses than those used in this study. However, some infants may receive very high doses of BPA for a short period of time – like those who receive neonatal intensive care.
Recent studies in humans and rodents suggest that in utero BPA exposure may impact offspring behavior. Future studies will need to determine if single or chronic exposures have lasting impacts on child behavior in humans.
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