The University of California,San Francisco,has become a watering hole of sortsfor fruit flies. There,in the lab of Ulrike Heberlein,an addiction researcher,fruit flies are choosing to consume alcohol. They are drinking (or rather,eating alcohol-spiked food) until they are intoxicated,even if they dont like the taste. They are also falling off the wagon. Dr. Heberlein,the author,with Anita V. Devineni,of a paper describing the findings in Current Biology,said the research represented an advance in their work trying to understand the genetic basis of human addictions to substances like alcohol and nicotine through the fruit fly,Drosophila melanogaster. For years,weve been studying simple responses such as intoxication and tolerance development, Dr. Heberlein said. The fruit flys well-known,easily studied genetics make it a model organism for such work. Now,instead of passively giving the flies the alcohol,we are letting them choose to drink. And drink they do,like humans. At first they become hyperactive and disinhibited,and if they keep drinking,become increasingly uncoordinated. Eventually they pass out. The flies internal alcohol concentrations at each stage are very similar to those of human drinkers,she said. The researchers also found that if a fly was deprived of alcohol for a day or two,it would resume drinking when given an opportunity. In some ways the finding is not surprising. After all,fruit flies tend to be found on rotting fruit,where the sugars are fermenting to alcohol. But by quantifying it in the laboratory,researchers will be able to study the genetics behind the behaviour. In effect,Dr. Heberlein said,they have developed an assay for features of addiction researchers will be able to take many strains of Drosophila,each with a known mutation,to see which alter the patterns of alcohol consumption.
