Postnatal alcohol exposure in the rat: Its effects on avoidance conditioning, Hebb-Williams maze performance, maternal behavior, and pup development

Abstract

In Experiment 1, lactating Wistar rats consumed a liquid diet containing ethanol during Days 0–17 of the nursing period. Control dams were pair-fed an identical liquid diet containing isocaloric sucrose or received chow and water ad lib. At 75 days of age, offspring were tested on a two-way shock avoidance task and, at 150 days of age, were tested on a Hebb-Williams maze. The offspring of ethanol-fed dams were found to be impaired on the shock-avoidance task when compared with both control groups but did not differ from controls on the Hebb-Williams maze task. Experiment 2 employed repeated time-lapse photographic observations to examine the behavioral development of pups of ethanol-fed mothers and pair-fed control mothers. The behavioral changes observed were restricted to Day 17, during the period immediately following the withdrawal of the ethanol diet. Specifically, dams previously exposed to the ethanol diet spent less time in the nest area with their pups and more time lying outside the nest area and engaged in locomotor activity. Pups whose mothers consumed the ethanol diet displayed increased litter fragmentation and spent more time rearing. Given the transient nature of the observed behavioral changes, it was concluded that the learning deficit observed in Experiment 1 was not mediated via alterations in maternal behavior and was probably due to a direct effect of ethanol on the central nervous system of the developing rat pup.