This project examines the effect of alcohol on sphingolipid metabolism in mouse brain. Intragastric administration of a single teratogenic dose (6g/kg) of alcohol in pregnant C57BL/6J mice at gestational day 15 alters brain sphingolipids in progeny. Maternal alcohol consumption produces dysmorphic abnormalities in offspring; however, the molecular and biochemical mechanisms leading to these abnormalities are unknown. Glycosphingolipids (Gsls) are expressed specifically during brain development and myelinogenesis. Ethanol exposure during pregnancy reduces the three major myelin Gsls - cerebroside, FMCs (fast migrating cerebrosides), and GM1 - in offspring. This deficiency, including ceramide accumulation, has been anticipated. Brain ceramide levels are elevated (50-175%) by ethanol-exposure at critical stages of development. Sphingoids (sphingosine, dihydrosphingosine, and psychosine), ceramide- sphingomyelin pathway ceramide metabolites, may also accumulate. All are messengers in cell apoptosis and could lead to oligodendroglial/neuronal cell degeneration leading to CNS disorders. The project is approached with these specific aims: 1. Examination of ceramide and sphingoid accumulation in ethanol-exposed developing brain. 2. Evaluation of biochemical pathways for ceramide accumulation after ethanol exposure. Sensitive methodologies to assay sphingolipids and sphingoids from a sample of brain tissue (as little as 100 microgram) were recently developed. Ceramide and sphingolipids, purified by column chromatography, will be assayed by thin-layer, gas, and high performance liquid chromatography. Metabolic enzymes will be assayed using suitable substrate and reaction conditions. This project's long-term goal is to study the role of ceramide in myelinogenesis in alcohol-exposed developing brain.