Effect of Group Housing and Oral Corticosterone Administration on Weight Gain and Locomotor Development in Neonatal Rats
To study the influence of maternal stress on neonatal locomotor development, rat pups of mothers housed singly and in groups were treated orally with corticosterone from 2 to 15 days of age. Control animals received almond oil vehicle only. The rat pups were subjected to swim-tests
from 8 to 20 days of age to evaluate locomotor development. Swim-test performance demonstrated a retardation of locomotor development in pups treated with corticosterone (P < 0.05). Retardation was most marked in the pups from group-housed mothers and between 13 and 15 days of age.
Comparing pups not treated with hormones, the pups born to group-housed mothers showed significantly (P < 0.05) better performance on swim-testing. The weight gain ofpups from group-housed mothers was significantly (P < 0.05) higher than that of pups from individually caged
mothers. Corticosteroid treatment had no effect on weight gain.