Effect of maternal vitamin a excess on S‐100 in neonatal rat cerebellum: A preliminary study

Pregnant rats were administered a teratogenic dose of vitamin A excess on Days 17 and 18 of gestation and intubation controls received the vehicle alone. Pups were sacrificed at birth or on postnatal Days 5 or 10; the cerebellum was removed, frozen, and fixed in preparation for immunohistochemical localization of the brain specific protein, S-100. Vitamin A produced a transient delay in the appearance of S-100 in the external granular layer which was no longer evident on Days 5 and 10. These findings corroborate autoradiographic evidence that vitamin A temporarily interferes with neurogenesis. However, the early damage results in permanent behavioral deficits in adulthood despite apparent cytochemical repair.