Meeting Abstract
Each year, new chemicals are introduced to the market, including flame retardants. Techniques for assessing these chemicals for risk assessment have generally not considered their potential impacts on the brain. Some flame retardants accumulate in the brain, and the brain is known to be sensitive to physiological perturbations including contamination. We used an established technique, neuroanatomy, in a novel context, ecotoxicology. We exposed American kestrels (Falco sparverius), key top predators of terrestrial ecosystems, in ovo to one of two commonly used brominated flame retardants (BFRs): 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), or bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH). We measured the volumes of the hippocampus and the telencephalon in the left and right hemispheres to determine whether hippocampus volume relative to the telencephalon and symmetry between hemispheres were affected by BFR exposure. The hippocampus, a region in the telencephalon, plays a crucial role in spatial memory and navigation in birds. BFRs are especially likely to impact the hippocampus because of their known effects on thyroid hormones that influence hippocampus development and neurogenesis, and on sex steroids for which the avian hippocampus expresses androgen and estrogen receptors. Changes in neuroanatomy could have an impact on behaviour at the individual level, and ultimately, affect populations.
