Prenatal Alcohol Exposure and Dysfunction of Hippocampal Formation in Cognition

Background: Fetal alcohol syndrome is associated with numerous problems in the development and function of the brain. Learning and memory deficits are among well known effects of prenatal exposure to alcohol.
Objective: This study aimed to examine the spatial working memory of 60-day old rats who were exposed to alcohol during their fetal life and to find the relation between the possible alcoholimpaired spatial memory and gestational period of exposure to alcohol.
Materials and Methods: Pregnant rats in different stages of gestation period were administered with ethanol. Using a radial arm maze, the offspring were subjected to spatial working memory training at 60 days of postnatal age.
Results: The rats exposed to ethanol during the first 10 days of fetal life indicated lower performances compared to the controls. Those receiving alcohol during the second half of pregnancy period had no problem in maze navigation. Behavior of the animals exposed to alcohol during the first and the second quarter of the gestation period demonstrated that only the latter were weak in solving maze tasks. The groups related to the third and the forth quarter of gestation period had a similar behavior with the control group. Comparison of the animals' performances in all groups revealed that only the second quarter group was the most disadvantaged.
Conclusion: Our data indicates that the second quarter of the gestation period is more sensitive to harmful effects of alcohol on the areas of brain involved in learning and memory. Since the hippocampus is central in cognitive functions and this part of brain is highly vulnerable to alcohol effects it can be concluded that the hippocampus is mostly affected in the second quarter of prenatal life.

Keywords
Fetal alcohol syndrome, Hippocampus, Learning and memory, Radial arm maze