Prenatal alcohol exposure and offspring hyperactivity: effects of scopolamine and methylscopolamine.

Rats were fed a liquid diet containing alcohol from days 6-19 of gestation. Controls were pair-fed the same diet with sucrose substituted for ethanol, or received ad lib chow and water. The activity of the offspring was observed at 10, 16, 22 or 28 days of age. Offspring exposed to alcohol prenatally were hyperactive compared to controls at 16 and 22 days, but not at 10 or 28 days. Administration of scopolamine had no effect on activity in any group at 10 days. At 16 days it reduced activity in the alcohol treated offspring but had no effect on the controls. At 22 days it led to a dose-related increase in activity in controls but had no effect on the already high levels of activity in the alcohol treated pups. At 28 days, scopolamine increased activity in all three groups. Administration of the quaternary derivative, methylscopolamine, indicated that the effects of scopolamine at 22 and 28 days were probably central in origin. These data indicate that a putative cholinergic/inhibitory system becomes functional in control pups before 22 days, but in pups exposed to alcohol prenatally development is delayed by a number of days.