Investigating the effect of exposure to monosodium glutamate during pregnancy on development of autism in male rat offspring.

In present study, we investigated the relationship between the pregnancy exposure to monosodium glutamate (MSG) and autism development in male offspring of rats. Pregnant Wistar rats were allocated into five groups. The first group was control group that pregnant animals received normal saline orally from day 1-18 of pregnancy. Group 2, 3 and 4 pregnant rats received different doses (1.5, 5 and 10 g/kg) of MSG by the same way respectively. Group 5 received 500 mg/kg of Valproic acid (VPA) on the 12.5th day of pregnancy. Different behavioral tests including marble burying, self-grooming, and Barnes maze test were performed on offspring. The levels of glutamate and GSH markers were also measured. The results showed that MSG similar to VPA led to induction of autistic anxiety and repetitive behaviors. It could also deteriorate the spatial memory. Besides we found that behavioral symptoms potentiated with increasing the MSG dosage. Similarly, we had an increase in glutamate and a reduction in GSH levels in offspring. Findings indicated that MSG was able to induce autism in offspring of rats in a dose-dependent way. This effect could be through increasing of glutamate and reduction of GSH. Consequently, MSG should be avoided during pregnancy.