Prenatal exposure to diazinon induced developmental impairments in rat offspring: Behavioral and biochemical aspects

Abstract

Prenatal acute and chronic exposure to organophosphorus pesticides may evoke physical and behavioral impairments in offspring development. In this report, pregnant Wistar rats were intraperitoneally treated with diazinon (DZN) (10 mg/kg b.w) from G7 to G14 of pregnancy. The animals (males and females) were randomly chosen from the litters. They were observed afterwards for physical (body weight change, incisor eruption and eye opening), neuromotor and behavioral development (surface righting reflex, palmar grasp reflex, negative geotaxis, forelimb support test, open field test and Morris water maze) and brain acetylcholinesterase activity was measured. The Results showed differences in physical and neuromotor parameters and brain acetylcholinesterase activity between treated and control groups. At the adolescence period, the open field test showed hyperactivity, as well as an enhancement of an exploratory state associated with anxiolytic­like effect. The Morris water maze showed an enhancement of spatial memory. We conclude that DZN at high doses was able to disrupt physical and neuromotor development in pups during lactation and also modify behavioral and cognitive state at adolescence period. This may have been linked with organophosphorus mediated inhibition of central nervous system acetylcholinesterase activity.