Absence of behavioral effects of intrauterine phenobarbital exposure in rats.
Phenobarbital (Ph) exposure in experimental animals has been associated with impaired brain growth and maturation. In order to look for behavioral correlates of these structural changes, rat pups were tested after intrauterine exposure to Ph. Five Sprague-Dawley rat dams were fed powdered chow containing Ph (0.75 mg/g of chow) from day 8 through the remainder of pregnancy, resulting in serum Ph levels of 19 to 36 micrograms/ml. Control (C) dams were fed plain chow. All pups were cross-fostered to control dams at birth. During their first 3 weeks of age, the acquisition of signs of physical maturation and neurologic development (such as incisor eruption, free-fall righting, rope climbing and descending, etc.) and the development of exploratory behavior in an open chamber were assessed. On days 39 to 48, 24 pups were tested in a water-T maze. Litter size and pup size were smaller in Ph-exposed dams than in controls, but acquisition of all signs of development except eye opening, activity in the exploratory chamber, and time and error scores on water-T maze testing did not differ between the two groups. The reasons that behavioral effects were not found in this study compared with previous studies may include the young age of the animals tested, the differences among behavioral parameters examined, the fact that controls were matched by weight with the experimental animals in this study, and different susceptibility to teratogenic effects among different species.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D005106:Exploratory Behavior / Q000187:drug effects; D005260:Female; D009420:Nervous System / Q000254:growth & development; D010634:Phenobarbital / Q000009:adverse effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats / Q000254:growth & development; D011919:Rats, Inbred Strains; D012018:Reflex / Q000187:drug effects
D010634:Phenobarbital