July 10, 2024

BPA exposure during development alters brain function and behavior in female mice

Chemical influences how males and females experience stress responses and social behaviours

Recent research published in Proceedings of the National Academy of Sciences has provided significant insights into the impact of bisphenol A (BPA), a common industrial chemical, on brain development and behaviour, in mice. This study highlights how gestational exposure to BPA can lead to lasting changes in the hypothalamus, a crucial brain region that controls various essential functions such as hunger, thirst, sleep, and emotions.

The research team studied vasopressin neurons, known as AVP neurons, which control a range of social behaviours including aggression, anxiety, parenting, and bonding. They found that males display more vasopressin neurons than females. They also show that prenatal exposure to bisphenol A (BPA), causes female brains to acquire male-like patterns of vasopressin neurons, suggesting that BPA exposure can disrupt sex differentiation of the fetal brain. Males typically have a higher number of AVP-using neurons compared to females, which influences how males and females experience stress responses and social behaviours.

The study reveals a critical window of sex differentiation in the fetal brain where the AVP neurons undergo significant changes. These neurons in females begin to resemble those typically found in males in several ways. Specifically, the number of AVP-using neurons increases, their connections to other parts of the brain change, and how they generate and transmit electrical signals, is altered. These findings have implications for understanding sex-biased neurodevelopmental disorders such as autism, which often show different prevalence and characteristics between males and females. Understanding the mechanisms behind these differences could lead to more effective and tailored treatments.

“These findings raise important questions about the broader implications of BPA exposure in humans,” says Dr. Jing Zheng, PhD, “It demonstrates the need for further research to understand the changes associated with this chemical.”

The study opens new avenues of research into how genetic and environmental influences might disrupt neurodevelopment. Further, it highlights the need for tighter regulations and greater public awareness about the potential risks of BPA exposure during pregnancy. 

Dr Jing Zheng, PhD is a postdoctoral fellow in the lab of Dr. Deborah Kurrasch, PhD. Dr. Kurrasch is a full member of the Hotchkiss Brain Institute, and the Alberta Children's Hospital Research Institute at the Cumming School of Medicine (CSM).