Embryonic ethanol exposure impairs detour learning in chicks.

Six groups of 30 fertile eggs each were injected with 200 microliters of either sterile water or a 37.5% (v/v) ethanol solution immediately before incubation or on days 7 or 14 of incubation. Regardless of day of injection, the ethanol groups had a lower proportion of chicks who completed pipping and hatching. Of the chicks surviving to pip and hatch, the group injected with ethanol immediately before incubation was delayed significantly in pipping compared to the other ethanol-injected groups and to the group injected with water immediately before incubation (p less than 0.05 in all cases). Also, compared to the chicks injected with water, the chicks in all ethanol groups required more trials to attain criterion on a detour learning task when tested 7-10 days after hatching (p less than 0.05).