Ethanol exposure affects trophic factor activity and responsiveness in chick embryo.

Chick embryos were chronically exposed to either ethanol (approximately 30 mg/d) or saline, from E4-E13. Homogenate extract was prepared from forebrain tissue from E16 experimental and control embryos and was applied to cultured dorsal root ganglia (DRG). Neurotrophic activity in the forebrain extract (FBX) was significantly reduced in the ethanol-treated embryos compared to saline controls, both in terms of influences on neuronal survival and process elaboration. In addition, E8-9 DRGs from embryos exposed to ethanol from E4 were less viable in the presence of NGF than were those from controls. DRG survival in the presence of E16 FBX (from untreated embryos) was not different following ethanol treatment, but neurite production was significantly reduced. These results suggest that neurotrophic factor content and responsiveness may be appreciably altered following chronic prenatal ethanol exposure. Such alteration could underlie certain CNS anomalies seen in the fetal alcohol syndrome.