By Eva Greengrove, Summer Intern in Dr. Edward Levin’s lab
This summer, I worked with the Levin lab at the Duke University Superfund Research Center to investigate the behavioral effects of the organophosphate insecticide called diazinon. Although some animal studies have shown demonstrated health effects, neurodevelopment and behavior impacts in humans are relatively unknown, making further research on the health impacts of these pesticides especially important. The research conducted at the Levin lab is crucial for understanding developmental and behavioral health effects of pesticide exposure, an ongoing public health concern.
The lab uses rats to assess exposure effects. We observed these rats perform a series of behavioral tasks. The elevated “plus” maze (so called because it’s shaped like a plus sign) and novel environment suppressed feeding exercise measure anxiety and fear. The “figure eight” maze is used to evaluate locomotion or ease of movement. Novel object recognition, the radial arm maze, and attention tasks test the rat’s working memory.
I observed and collected data for the radial arm maze task, which is performed once a day for twelve days by rats exposed to diazinon. The maze has sixteen “arms” coming out of a circular middle with twelve arms arbitrarily baited with a piece of “Froot Loops” cereal and four arms unbaited (see photo). Each rat is allotted ten minutes to finish the maze. To complete the maze, the rat must “enter” all twelve of the baited arms and retrieve the food. We record the total time (measured in seconds), working memory errors (entering a baited arm more than once) and reference memory errors (entering an unbaited arm) to evaluate their performance.
During the rest of my internship, I observed the remainder of the behavior tasks. I hope to gain a better understanding of how pesticides like diazinon may affect behavior in rats by the end of the program.
If pesticides can alter behavior in rats, shouldn’t we work to reduce human exposure and prevent use of these hazardous chemicals as much as possible? My experience at Duke has shown me the answer to that question is “yes.”
