PRENATAL ETHANOL EXPOSURE DIFFERENTIALLY ALTERS BEHAVIOR IN MALES ANDFEMALES ON THE ELEVATED PLUS-MAZE

Rodents prenatally exposed to ethanol demonstrate hypothalamic-pituita ry-adrenal and behavioral hyperactivity to a variety of stressful situ ations. The present study examined both behavioral and corticosterone (CORT) responses to the elevated plus maze (+-maze), an anxiety-or fea r-provoking task. Sprague-Dawley male and female offspring from fetal ethanol-exposed (E), pair-fed (PF), and ad libitum-fed control (C) gro ups were tested at 60 to 90 days of age. In experiment 1, behavior was measured in animals exposed to the +-maze for 5 min on two consecutiv e days; 2 weeks later, both behavioral and CORT responses were measure d in animals confined to the open and closed arms of the maze for 20 m in. in experiment 2, animals were placed in an open field (OF) for 5 m in before a single B-min exposure to the +-maze. Factor analysis of th e scored behaviors from the two experiments indicated two main factors , designated ''exploration'' and ''fear.'' E males and females both ex hibited higher levels of exploratory behaviors when placed directly on the +-maze from their homecages without prior exposure to the OF, com pared with C males and females. In addition, when confined to the clos ed arms of the C-maze, E males and females demonstrated higher levels of activity, compared with C males and females. After OF exposure, how ever, both E males and females demonstrated lower levels of explorator y behaviors than C males and females, and E females also had increased CORT levels, compared with PF and C females. Interestingly, E females , but not E males, showed an increase in fear-related behaviors on the +-maze, compared with controls, regardless of prior OF exposure. Thes e data demonstrate that prenatal ethanol exposure may differentially a ffect both behavioral and hormonal responses of males and females in a n aversive behavioral task and suggest that there may be a sex differe nce in the sensitivity of the mechanism(s) underlying these responses.