Achieving CLARITY on bisphenol A, brain and behaviour

Area of Science:

• Neuroendocrinology
• Toxicology
• Developmental Biology

Background:

• Bisphenol A (BPA) is a widely used chemical linked to adverse health outcomes, including neurodevelopmental and behavioral effects.
• Traditional toxicity studies often lack neural endpoints, hindering comprehensive risk assessment of BPA.
• The Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY-BPA) was established to address BPA safety controversies.

Purpose of the Study:

• To review findings from the grantee studies within the CLARITY-BPA project focusing on the effects of BPA on brain and behavior.
• To evaluate the impact of developmental BPA exposure on neuroendocrine development and sexual differentiation of the brain and behavior.

Main Methods:

• The CLARITY-BPA project integrated a regulatory-style toxicology study (Core study) with academic-led grantee studies.
• Grantee studies focused on behavioral, molecular, and cellular endpoints using the same animals and tissues as the Core study.
• This review specifically summarizes results from grantee studies investigating brain and behavior.

Main Results:

• Developmental BPA exposure altered neuroendocrine development, including age- and sex-specific expression of estrogen receptors (ERα and ERβ).
• Evidence indicates the abrogation of brain and behavioral sexual dimorphisms following developmental BPA exposure.
• These effects were observed at doses below those considered safe by regulatory agencies.

Conclusions:

• Developmental exposure to BPA contributes to changes in brain and behavior.
• The observed effects are consistent and reproducible across studies, strengthening the evidence.
• Findings suggest that current regulatory safety thresholds for BPA may not fully protect against neurodevelopmental harm.