Autism spectrum disorder-like behaviors in developing zebrafish exposed to particulate matter.

Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders that can impact communication and social behaviors. Evidence suggests that the causes of ASD are likely a combination of genetic and environmental factors, such as air pollution. Particulate matter (PM) is the solid and liquid portion of air pollution that can vary in size and has been associated with many health impacts, including cardiorespiratory impacts, and has more recently been found to be associated with the prevalence of ASD. However, little is known about the phenotypic presentations of this association between PM and ASD, therefore, the zebrafish (Danio rerio) model was employed to study behaviors often associated with ASD as a result of PM exposure. Zebrafish larvae were exposed for a total of 5 days to PM standard reference material (SRM1649b) and a commonly used home remedy, melatonin, beginning at 6 h post-fertilization and various behavioral assays were performed on subsequent days for a total of 13 days. Observed and quantified behaviors were compared to a positive control, valproic acid (VPA). Generally, PM exposure did not elicit behavior resembling that of VPA exposure and the interactions between PM and VPA did not induce additive or synergistic behavioral patterns, as expected. Melatonin supplementation did not ameliorate most of the observed behavioral impacts of PM or VPA exposure. These results have prompted additional questions about the phenotypic presentations of ASD as a result of PM exposure and contribute to growing knowledge about disease-environment interactions.