Per- and polyfluoroalkyl substances (PFAS) are widely used in many industrial and domestic applications. The wide range use of PFAS has resulted in unintentional human exposures and bioaccumulation in blood and other organs. Perfluorooctanesulfonate (PFOS) is among the most prevalent PFAS in the environment and has been postulated to affect brain functions in exposed organisms. However, the impacts of PFOS on early neural development have not been well-described. Here, we used zebrafish larvae to assess the effects of PFOS on two fundamental complex behaviors, prey capture and learning. Zebrafish exposed to PFOS concentrations ranging from 2 – 20 µM for differing 48-hour periods were viable through early larval stages. In addition, PFOS uptake was unaffected by the presence of a chorion. We employed two different experimental paradigms; we first assessed the impacts of increasing organismal PFOS bioaccumulation on prey capture and learning, and second, we probed stage-specific sensitivity to PFOS by exposing zebrafish at different developmental stages (0-2 vs 3-5 days post fertilization). Following both assays we measured the amount of PFOS present in each larva. PFOS levels varied in larvae from different groups within each experimental paradigm. Significant negative correlations were observed between larval PFOS accumulation and the percentage of captured prey, while non-significant negative correlations were observed between PFOS accumulation and experienced-induced prey capture learning. These findings suggest that PFOS accumulation negatively affects larval zebrafish's ability to perform complicated multisensory behaviors and highlight potential risks of PFOS exposure to animals in the wild, with implications for human health.

Zebrafish embryos and larvae were exposed to PFOS in multiple different treatment and feeding groups. Subsequent behavior testing was done blinded to both the treatment and feeding group. Following behavior testing, samples were collected for LC-MS/MS analysis, which was also done blind to treatment and feeding group. After the collection of the LC-MS/MS data, the PFOS measurements and behavior analysis were linked to their respective feeding and treatment groups (By the combination of their Group # and Sample #). Analysis of the aggregate data (Tukey HSD and multiple linear regressions) were then performed on each dataset.