CHRONIC ETHANOL ALTERS CNS CHOLINERGIC AND CEREBELLAR DEVELOPMENT IN CHICK-EMBRYOS

Chick embryos were given daily injections of ethanol (approximately 30 mg/day) either chronically from embryonic days 4 to 15 (E4-E15) or E1 8, or acutely from E15 to E18. Untreated and saline-injected embryos s erved as controls. Although morphological indicators of developmental age were not different among groups, chronic ethanol reduced weights o f several brain regions. Similar to rodent models of prenatal ethanol exposure, chronic ethanol treatment reduced cerebellar Purkinje cell n umbers compared to controls. Chronic but not acute ethanol exposure re sulted in a significant reduction in choline acetyltransferase activit y in the optic tectum (OT) and forebrain (FB) compared with controls. This study demonstrates that the chick embryo is a viable model to inv estigate the effects of ethanol exposure on CNS development. Unlike th e mammalian fetus, the avian embryo is isolated from maternal interact ions and may prove more useful in investigating the mechanisms by whic h ethanol directly influences brain development.