Behavioral consequences of prenatal exposure to the organophosphate insecticide sumithion.

Prenatal administration of Sumithion 50 EC, an organophosphate insecticide, to CFY rats at 5, 10 and 15 mg/kg from days 7 to 15 of gestation, resulted in dose related decreases in open field activity and motor coordination in the offspring treated with the two higher doses. Long lasting alterations in the acquisition and extinction of a conditioned escape response, as well as increased social interactions were observed in the adult offspring. The results indicate a no effect level at 5 mg/kg under the experimental conditions in the present study.