Effect of prenatal undernutrition and phenobarbitone administration on discrimination learning and passive avoidance behaviour in rats.

ABSTRACT

Effects of prenatal undernutrition and phenobarbitone administration, individually and conjointly, was assessed on learning acquisition and subsequent retention of a black/white discrimination task and passive avoidance behaviour in rats. Undernutrition of the dams was induced by restricting food intake to half, throughout the period of gestation, whereas phenobarbitone sodium (2.5 mg/kg, ip) treatment was given from day 13 to 20 of gestation, this being the critical period for neural development in rats. The pups were subjected to brightness discrimination learning, retention of the learning acquisition in a single unit black/white T-maze and passive avoidance behaviour test at 8-9 weeks of age. The results indicate that prenatal undernutrition induces significant discrimination learning and retention deficits in the offsprings. Prenatal phenobarbitone treatment also caused significant learning acquisition and retention deficits in the discrimination test. Phenobarbitone augmented the learning and retention deficits induced by undernutrition. However, both prenatal undernutrition and phenobarbitone treatments did not affect the retention of the learned passive avoidance. The results indicate that the prenatal interference in the form of undernourishment and anticonvulsant barbiturates, may induce functional deficits resulting in perturbed cognition in the offsprings.