February 10, 2011

Understanding Fetal Alcohol Syndrome

(Ivanhoe Newswire) -- Mothers who drink alcohol during pregnancy put their babies at risk for fetal alcohol syndrome (FAS) a disorder that damages the developing baby's brain. Despite the severe consequences of drinking while pregnant, mothers-to-be continue their damaging habits- up to 3 in every 1000 babies are born with FAS. FAS causes behavioral problems, growth defects, intellectual disabilities, and abnormal facial features. Previously, it was unsure how alcohol causes these effects, but after researchers studied fruit flies, they established a new system for studying how alcohol causes harmful effects during development.

Ulrike Heberlein and colleagues from the University of California San Francisco exposed fruit flies to alcohol during development, they found that the flies grew more slowly, had smaller brains, abnormal behavior, and were more sensitive to the effects of alcohol as adults. They also confirmed previous findings that the problems were caused in part because alcohol interferes with the function of insulin "“ a molecule essential for normal fetal development "“ in the developing brain. "It was pretty surprising that so many features of FAS were recapitulated in this model, including some of the molecular mechanisms," Heberlein was quoted as saying

The issues of how much alcohol and during what trimester pregnant women can safely drink, if any at all, has been debated again and again. As expected, Heberlein and colleagues found that greater amounts of alcohol had more severe effects on fly development and behavior. More surprisingly, they found that exposure to alcohol later during a fly's development was more harmful than at early stages. Fruit flies are only distantly related to humans, so it is not yet possible to draw direct parallels between this study and the effects of alcohol on human pregnancy.

"We can't truly draw analogies before we know exactly which biological processes are being affected at these different stages of development," Heberlein said, "But it's very clear that exposure to alcohol early, during a rapid phase of growth, has different effects than later, when the brain is getting put together."

An important aspect of this new model system is that fruit flies provide a research advantage that is not available in humans "“ they can be used to very rapidly find the genes that might increase FAS risk. Heberlein and colleagues are undertaking this task now: their hope is that by studying FAS at the genetic level using fruit flies, they can generate results that will guide FAS research in humans and facilitate a more targeted approach to developing new therapies.

SOURCE: Disease Models & Mechanisms, published online February 8, 2011