Vinclozolin is a fungicide commonly used by farmers to treat fruits and vegetables.
To test the effects of stress on rats, the researchers confined some of them to soft, warm cylinders for six hours a day for three weeks. This was done during adolescence, a developmentally sensitive time of life for rats, just as for humans. Months later, the researchers tested the brain chemistry, brain function, gene expression and behavior of the rats as adults.
They discovered that for female rats, ancestral exposure to vinclozolin alone or stress during the animal’s adolescence alone had negligible effects on the rats' hormonal balance and behavior. However, the combination of ancestral exposure and stress caused the female rats to have dramatically higher levels of corticosterone (a stress hormone similar to cortisol in humans), higher expression of genes associated with anxiety and more anxious behaviors.