Effect of prenatal isotretinoin exposure on neuronal population of prefrontal cortex in rats

The isotretinoin, a 13-cis-retinoic acid is used in the most severe acne. In humans, isotretinoin treatment is known to cause psychiatric side effects like depression. It is also known to be teratogenic resulting in reduced IQ scores in children who have exposed to isotretinoin during prenatal development. In animal model studies it is known to cause craniofacial deformities including cleft palate. Isotretinoin is known to affect the adult neurogenesis, but there are no studies indicating the teratogenic effect of isotretinoin on intra-uterine neurogenesis. Hence in the present study we investigate teratogenic effect on neuronal population of prefrontal cortex.Pregnant Wistar rats were exposed to either 8 or 16mg/kg dose of body weight of isotretinoin during early or mid-gestationalperiod of pregnancy. Pups were sacrificed at postnatal day 7 or 21; brains were removed and processed for histological studies using cresyl violet staining. Neuronal population of the prefrontal cortex was quantified. Isotretinoin treatment resulted in 10% mortality at birth in day 6 to 10 treatment schedule. The results of neuronal assay clearly demonstrate that teratogenic effect of isotretinoin is more when administered during early gestational period in rats& the neurotoxic effects were not dependent on the dose of isotretinoin.