LAUSR

Neurotoxic pesticides are used worldwide to protect crops from insects, they are recognized to impact nontarget organisms that live in areas surrounded by treated crops. Many biochemical and cell-based solutions have been developed for testing insecticide neurotoxicity. Nevertheless, such solutions provide a partial assessment of the impact of neurotoxicity, neglecting important phenotypic components such as behavior. Behavior is the apical endpoint altered by neurotoxicity, and scientists are increasingly recommending including behavioral endpoints in available tests or developing new methods for assessing contaminant-induced behavioral changes. In the present work, we extended an existing protocol (the Amphibian Short Term Assay) with a behavioral test. On this purpose we developed a homemade device along with an open-source computing solution for tracking trajectories of X. laevis tadpoles exposed to two organophosphates (OPIs), the insecticides diazinon (DZN) and chlorpyrifos (CPF). The data resulting from the tracking were then analyzed, and the impact of exposure to DZN and CPF was tested on speed- and direction-related components. Our results demonstrate weak impacts of DZN on the behavioral components, while CPF demonstrated strong effects, notably on speed-related components. Our results also suggest a time-dependent alteration of behavior by CPF, with the highest impacts at day 6 and the absence of impact at day 8. Although only two OPIs were tested, we argue that our solution coupled with biochemical biomarkers is promising for testing the neurotoxicity of this pesticide group on amphibians.