Bisphenol A found to disrupt brain function in primates

New research links exposure to bisphenol A, found in polycarbonate and other plastics, to neurological problems including Alzheimer’s disease, learning disabilities, and depression. Researchers from the Yale School of Medicine and Ontario Veterinary College have demonstrated for the first time that bisphenol A can affect brain function in primates, with implications for learning, mood, and degenerative diseases. The researchers exposed twelve monkeys to estrogen alone and in combination with bisphenol A. They then looked at the brains of both sets of monkeys for the expected effects of estrogen on the formation of connections between nerves, known as synapses.

The result: bisphenol A completely blocked the effects of estrogen on synapse formation. Researchers found striking differences in four regions of the brain, including those involved with mood and memory, with the bisphenol A-treated monkeys showing three times fewer synapses.

While the research team had previously found similar effects in rodents, this study is the first to find effects on synapse formation in primates. Patterns in synapse formation play a critical role in important disorders including mental retardation and developmental disabilities, Alzheimer’s disease, schizophrenia, and mood disorders. Previous studies of the effects of bisphenol A in rodents have produced effects related to some of these disorders, including impaired learning and indications of depression.

This research was published in Proceedings of the National Academy of Sciences magazine on Sept. 16, 2008.

Erika Schreder is a staff scientist at Washington Toxics Coalition, where she leads the Coalition’s research on toxic chemicals in children’s products. In 2005 and 2006, she led the research for the Toxic-Free Legacy Coalition’s Pollution in People study. She has a Masters in Resource Ecology and Management from the University of Michigan and a B.S. in molecular biology from MIT.