Summary: New mouse research indicates that exposure to the common chemical bisphenol A (BPA) during pregnancy—even at doses below regulated “safe” human exposure levels—can change the timing of neuron birth and lead to altered brain development and behavior later in life.

Exposure to Low Levels of BPA During Pregnancy Alters Brain Development in Mice

Source: Endocrine Society.

New experimental research in mice offers a mechanistic explanation for how gestational exposure to bisphenol A (BPA), a widely used industrial compound, may disrupt brain development and produce lasting behavioral changes in offspring. The findings, presented at ENDO 2018—the 100th annual meeting of the Endocrine Society—show that even environmentally relevant, low doses of BPA given to pregnant mice changed the timing of neuron formation and produced behavioral effects in their young.

What is BPA and why it matters

BPA is an industrial chemical used in many consumer products such as water bottles, thermal paper receipts, metal can linings, and certain food storage containers. It is classified as an endocrine-disrupting chemical, meaning it can interfere with hormone signaling in the body. Concerns about BPA focus especially on prenatal exposure, because developing brains are highly sensitive to hormonal signals and can be affected by substances that mimic or block natural hormones.

Decades of animal studies and epidemiological work in humans have raised concerns about links between prenatal BPA exposure and adverse health outcomes, particularly in neural and behavioral development. However, regulatory agencies in several countries have evaluated available evidence and concluded BPA exposure within certain limits is safe. The new mouse study addresses a key unresolved question: can low, environmentally relevant exposures to BPA during pregnancy produce subtle but permanent changes in brain development?

Study design and approach

Researchers led by Deborah Kurrasch, Ph.D., Associate Professor at the University of Calgary, examined three groups of pregnant mice that received either BPA-free food, food containing a high dose of BPA, or food containing a low dose of BPA consistent with environmentally relevant exposures. The team tracked neural development in the offspring by measuring the timing and quantity of neurons born during early brain development and then assessed behavioral outcomes in sibling mice as they matured.

Key findings

The study found that both high- and low-dose BPA exposure during gestation increased the number of neurons produced early in development compared with mice whose mothers did not receive BPA. Timing of neuronal birth is tightly regulated: specific classes of neurons are normally generated at precise developmental windows. When neurons are born earlier than expected, they can migrate to incorrect locations and form inappropriate connections, potentially altering the architecture and function of neural circuits.

Behavioral testing of sibling mice revealed that offspring exposed to BPA in utero showed behavioral differences consistent with findings from human epidemiological studies that link prenatal BPA exposure to developmental and behavioral issues in children. Although the exact behaviors assessed are not detailed here, the overall conclusion from the animal experiments is that gestational BPA exposure can produce lasting, possibly permanent, changes in brain development and subsequent behavior.

Implications and context

These results provide a plausible biological mechanism—altered timing of neuron birth—by which prenatal exposure to BPA could result in long-term changes in brain function. The work helps bridge findings from epidemiological studies with laboratory evidence, supporting concerns that even low levels of BPA during pregnancy may carry neurodevelopmental risk.

Lead researcher Dr. Kurrasch emphasized that while translating rodent findings directly to human pregnancy requires careful additional research, the study offers practical information for expectant mothers and public health decision-makers. By identifying how BPA affects neural development, this research contributes to ongoing discussions about chemical safety, regulatory standards, and steps pregnant people can take to reduce exposure.

Source: Jenni Gingery, Endocrine Society
Publisher: Organized by NeuroscienceNews.com
Image source: Public domain image provided by NeuroscienceNews.com
Original presentation: The research was presented at ENDO 2018, the 100th annual meeting of the Endocrine Society, March 19, 2018, in Chicago, Illinois.

Endocrine Society. “Exposure to Low Levels of BPA During Pregnancy Can Lead to Altered Brain Development.” NeuroscienceNews, 18 March 2018.

This study adds to a growing body of evidence suggesting prenatal exposure to endocrine-disrupting chemicals like BPA can alter neural development. Expectant parents and health professionals may consider these findings when evaluating exposure-reduction strategies during pregnancy.