Effects of prenatal exposure to xylene on postnatal development and behavior in rats.

The effects of prenatal exposure to the organic solvent xylene (dimethylbenzene, CAS-no 1330-20-7) on postnatal development and behavior in rats were studied. Pregnant rats (Mol:WIST) were exposed to 500 ppm technical xylene 6 h per day on gestation days 7-20. The dose level was selected so as not to induce maternal toxicity or decrease the viability of offspring. In the exposed offspring, a delay in the ontogeny of the air righting reflex, a lower absolute brain weight, and impaired performance in behavioral tests for neuromotor abilities (Rotarod) and for learning and memory (Morris water maze) were found. Generally, the effects were most marked in the female offspring.