Abstract
We studied the effects of prenatal treatment with phenytoin (PHT) on the functional development of the rat brain. Pregnant rats were injected with varying doses (10, 50, 100 or 200 mg/kg) of PHT on days 1-21, 1-10, 14-21 or day 15 of pregnancy. There was no significant difference in the sleeping effect of pentobarbital, ataxic effect of diazepam, or seizure effect of pentetrazol between control-F, and PHT-F1 rats. Prenatal treatment with PHT on days 1-21 of pregnancy induced a marked increase in the duration of haloperidol-induced catalepsy in the male and female F1 rats when tested once a week, beginning on the 9th week and until the 13th week after birth. Hypersensitivity to haloperidol was induced to a greater extent in females. On the other hand, prenatal treatment with PHT on days 14-21 or on day 15 of pregnancy induced a decline in the duration of haloperidol-induced catalepsy in both male and female F1 rats. There was no significant alteration in the growth of the PHT-F1 rats. However, their eye opening was accelerated. The present results suggest that prenatal exposure to phenytoin induces long-lasting alterations in the dopaminergic and/or other neurons related to the manifestation of cataleptic behavior in the rat brain.
