Study Shows How PFAS Exposure Affects Brain Development in Zebrafish

Per- and polyfluoroalkyl substances (PFAS) are widely used in everyday products due to their special properties, but their accumulation in the environment poses health risks. A recent study conducted by researchers at the Helmholtz Centre for Environmental Research (UFZ) investigates how PFAS exposure impacts brain development, using zebrafish as a model organism.

According to UFZ toxicologist Prof Dr. Tamara Tal, PFAS enter the human body through air, drinking water, and food, making it challenging to avoid these chemicals. The study, published in the journal Environmental Health Perspectives, aims to understand the neurological effects of PFAS exposure.

Using zebrafish, which share genetic similarities with humans, the researchers exposed the fish to PFAS compounds and analyzed the gene activity in their brains. They found that the peroxisome proliferator-activated receptor (ppar) gene group, known to be affected by PFAS exposure in the liver, also showed increased activity in the brain.

Further experiments involved using the CRISPR/Cas9 gene editing technique to investigate the role of ppar genes in mediating behavioral changes in zebrafish exposed to PFAS. The results indicated that PFAS exposure led to hyperactive swimming behavior in the fish, which subsided when the chemicals were removed.

Behavioral Endpoints and Genetic Mechanisms

The study assessed two behavioral endpoints in zebrafish exposed to PFAS, focusing on swimming activity during dark phases and startle responses to stimuli. Fish exposed to PFAS exhibited hyperactive swimming behavior, particularly when exposed continuously during brain development. Genetic knockdown experiments revealed specific ppar genes associated with these behavioral changes.

Dr. Sebastian Gutsfeld, lead author of the study, highlights the relevance of these findings for understanding the neurotoxic effects of PFAS in humans. By identifying the genetic mechanisms underlying PFAS-induced behaviors in zebrafish, the researchers aim to develop better risk assessment methods for environmental chemicals.