Exposure to bisphenol A (BPA) during gestation led to mixed effects on the development of the brain linked to social behaviour patterns in mice spanning four generations, according to a study.
The study, accepted for publication in the journal Endocrinology, found low doses of BPA, which is a endocrine-disrupting chemical (EDC), had immediate and long-lasting trans-generational effects on the brain and social behaviours of 250 mice over a period of two years.
The changes in genes were most dramatic in the first generation (the offspring of the mice that were exposed to BPA in utero), but some of these gene changes persisted into the fourth generation.
Prenatal exposure to BPA in mice is associated with increased anxiety, aggression and cognitive impairments.
The researchers found BPA-exposed mice spent more time sitting next to each other than control diet mice did but while sitting side by side, control mice interacted with each other more than BPA-exposed mice.
Impact on social behaviour and neural expression
The study said: “…we have demonstrated for the first time to our knowledge that a common and widespread EDC has transgenerational actions on social behaviour and neural expression of at least the genes for vasopressin and oxytocin.
“Because exposure to BPA changes social interactions at a dose within the reported human levels, it is possible that this compound has transgenerational actions on human behaviour.”
Female mice received chow with or without BPA before mating and throughout gestation. Plasma levels of BPA in supplemented female mice were in a range similar to those measured in humans.
Juveniles in the first generation exposed to BPA in utero displayed fewer social interactions as compared with control mice at a dose commonly found within the human population and the effect in later generations was to increase these social interactions.
The study shows BPA produces transgenerational alterations in genes and behaviour “perhaps as a consequence of its actions as a steroid hormone agonist/antagonist and/or an epigenetic modifier.”
Emilie Rissman, PhD, of the University of Virginia School of Medicine and lead author of the study, told FoodProductionDaily.com previous literature had hinted at generational exposition.
“It will be interesting to find out what effect, if any, it has in other animals and whether it is a generalised effect.
“It was a social behaviour test to expose just the first generation and monitor effects over the next generations.”
When asked about a possible BPA replacement, Rissman said: “With any test substitute there would have to be a long time dedicated to discovering what the new substance can and cannot do if a substitute is to be found.”
EFSA is working on evaluating the relevance of the low-dose effect of the packaging chemical observed in rodents and significance to human health.
The FDA is considering banning BPA in infant formula packaging following a petition from a US congressman because manufacturers have abandoned the use of the substance in their products.
Published online ahead of print, doi: 10.1210/en.2012-1195
“Gestational Exposure to Bisphenol A Produces Transgenerational Changes in Behaviors and Gene Expression”
Authors: Jennifer T. Wolstenholme, Michelle Edwards, Savera R. J. Shetty, Jessica D. Gatewood, Julia A. Taylor, Emilie F. Rissman and Jessica J. Connelly