The Effect of Glucocorticoid (Dexamethasone) Administration on the Postnatal Development of the Hippocampus and Growth of the Wistar Rat

Abstract

Synthetic Glucocorticoids are commonly administered to early low birth weight infants to prevent the onset of chronic lung disease. During this period, the brain is undergoing significant structural and functional changes and is vulnerable to external influences. This study observed the effect of early administration of glucocorticoids on the developing hippocampus. Wistar rat pups were grouped into ten groups of six pups each. Five of the groups made up the control, the remaining five were the treatment groups. 0.5mg/kg of dexamethasone was administered to four day old pups for a period of three days. The first group of rat pups was sacrificed immediately after the last administration and the remaining groups were sacrificed at intervals of seven days. Results showed degenerative changes in the neurons of the hippocampus of the first group of rats. Less cell damage was observed in the groups that were sacrificed at later stages. The times of eye opening was advanced and abnormalities of posture and gait were observed in the initial stages of treatment and immediately after withdrawal of the drug. These abnormalities reduced as the animals aged. This suggests that the pathways of neural development may have reached normality by the third week of life.