Critical periods for the effects of alcohol exposure on learning in rats

Critical periods for alcohol-induced deficits in spatial navigation and pas sive avoidance learning were investigated with a rat model of fetal alcohol syndrome. Rats were exposed to alcohol prenatally (Gestational Days 1-10 o r 11-22) or postnatally (Postnatal Days 2-10) or throughout all 3 periods. Offspring were tested in either a spatial navigation or an avoidance task a s juveniles or adults. As juveniles, the combined exposure group took longe r to learn the spatial navigation task compared with all other groups. This effect was not seen in adults. Passive avoidance performance was not affec ted. These results suggest that long-term exposure to alcohol during develo pment has adverse effects on spatial learning. The lack of differences in t he short-term exposure groups implies that there may not be 1 critical peri od of alcohol exposure. but that the adverse effects of alcohol during deve lopment may be cumulative on some behaviors.