Functional Parts of the Polar Bear Brain (image) Aarhus University Caption Different functional parts of the Greenland polar bear brain were investigated for transfer of contaminants over the blood-brain barrier. The inner regions of the brain closer to incoming blood flow (pons/medulla, thalamus, and hypothalamus) contained consistently higher concentrations of perfluorooctane sulfonate (PFOS) and several perfluorinated carboxylates (PFCAs) compared to outer brain regions (cerebellum, striatum, and frontal, occipital, and temporal cortices). Credit Photo: Rune Dietz, Aarhus University. Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.