Cell culture
Prenatal alcohol exposure (PAE) is among the most common causes of developmental defects. Depending on the extent of the exposure and the severity of the resulting abnormalities, patients are diagnosed within a continuum of disorders broadly labeled Fetal Alcohol Spectrum Disorder (FASD). Severe FASD can impair neural crest migration, as evidenced by characteristic craniofacial abnormalities including short palpebral fissures, an elongated upper lip, and a smoothened philtrum. However, due to the promiscuous nature of ethanol binding, the mechanisms by which these abnormalities arise is still unclear. Cell culture explants of neural crest cells as well as in vivo developing zebrafish embryos exposed to ethanol show a decreased number of migratory cells and decreased distances travelled by migrating neural crest cells. The mechanisms behind these changes are not well understood, but evidence suggests PAE can increase apoptosis due to increased cytosolic calcium levels caused by IP3-mediated release of calcium from intracellular stores. It has also been proposed that the decreased viability of ethanol-exposed neural crest cells is caused by increased oxidative stress. Despite these, and other advances much remains to be discovered about how ethanol affects neural crest development. For example, it appears that ethanol differentially affects certain neural crest cells over others; that is, while craniofacial abnormalities are common in PAE, neural crest-derived pigment cells appear to be minimally affected.