Summary: A new study reveals pesticide chlorpyrifos have clear impact on brain development in Northern Leopard frogs.
New research published in Environmental Toxicology & Chemistry reveals that low doses of a commonly used pesticide potentially harm the Northern Leopard frog by inhibiting their brain development.
The pesticide chlorpyifos, which has been used since 1965 in both agricultural and non-agricultural areas, had clear effects on Northern Leopard tadpoles’ neurodevelopment, even in situations where the pesticide did not cause a decline in the amphibians’ food source.
“Organophosphorous pesticides contaminate surface waters throughout the U.S. exposing both animals and humans to these chemicals, often at very low, presumably innocuous levels. However, this study demonstrates that exposure to these contaminants, even at these low concentrations, impacts vertebrate neurodevelopment,” said lead author Sara McClelland, of Duquesne University, in Pittsburgh.
Source: Penny Smith – Wiley
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is credited to Dr. McClelland.
Original Research: Abstract for “Insecticide‐induced changes in amphibian brains: How sublethal concentrations of chlorpyrifos directly affect neurodevelopment” by Sara J. McClelland, Randall J. Bendis, Rick A. Relyea, and Sarah K. Woodley in Environmental Toxicology & Chemistry. Published September 5 2018.
Insecticide‐induced changes in amphibian brains: How sublethal concentrations of chlorpyrifos directly affect neurodevelopment
Widespread use of pesticides often contaminates natural habitats, exposing nontarget organisms to pesticides that were designed to control pest populations. Even low levels of pesticides can affect aquatic communities both directly and indirectly. Previous work has shown that trace amounts of the pesticide chlorpyrifos altered tadpole morphology and neurodevelopment in artificial ponds (mesocosms). To determine whether effects resulted from direct chlorpyrifos exposure or from disruption of the food web due to a pesticide‐induced decline in zooplankton, we examined the impacts of chlorpyrifos on amphibian development in the presence of chlorpyrifos‐resistant zooplankton, a key component of the aquatic trophic community. Northern leopard frog (Lithobates pipiens) tadpoles were reared through metamorphosis in mesocosms containing either 0 or 1 µg/L chlorpyrifos and either chlorpyrifos‐resistant or chlorpyrifos‐sensitive Daphnia pulex zooplankton. Developmental exposure to chlorpyrifos resulted in metamorphs with a relatively wider optic tectum, medulla, and diencephalon compared with controls, and this result was found regardless of the zooplankton population within the mesocosm. Thus, chlorpyrifos directly impacted brain development, independent of the effects on the trophic community. With respect to body shape, chlorpyrifos had no effect on body shape of metamorphs reared in mesocosms with chlorpyrifos‐sensitive zooplankton, but body shape was sensitive to zooplankton population in the absence of chlorpyrifos. To conclude, low, ecologically relevant doses of organophosphorous pesticides can directly impact neurodevelopment in a vertebrate model.