Roundup® and Glyphosate Exposure Elicits Proconvulsant Behavior in C. elegans

Abstract

While debate continues over the carcinogenic effects of glyphosate, there is little understood about the neurological impact of glyphosate. With glyphosate use projected to increase 200-fold in the US and dramatic increases globally, it is essential to improve our understanding of the concerns that pesticide use may have on neurological health and physiology. Another critical concern is the one-dimensionality of the majority of studies which examine glyphosate by itself, while farmers and the general public use commercial products which contain a myriad of chemicals in addition to glyphosate. Here we compare how glyphosate and Roundup® affect convulsant behavior in C. elegans. Glyphosate and Roundup® both increase seizure-like behavior, but treatment with an antiepileptic drug rescued the prolonged convulsions. Notably, these effects were found at concentrations that are 1000-fold dilutions of previous findings of neurotoxicity. These physiological findings raise concerns over how pesticide exposure may affect those with epilepsy and seizure disorder, and the unique electroshock assay used in this study can be translated to higher-order rodent models to expand on these findings. Finding neurological effects at very dilute concentrations may also support the concern that herbicide exposure affects mental health symptoms in humans. While high concentrations may be necessary to induce toxicity, lower concentrations may confer behavioral effects such as depressive symptoms in humans. Our findings provide valuable insight into the proconvulsant effects of glyphosate and Roundup®, and these data can be translated to mammalian models to further contextualize the impact that pesticide exposure has on neuronal function and behavior.