Most scientists believe that alcoholism is a genetic disease linked to differences in the way the genes in different people's brain cells regulate the chemical pathways affected by alcohol. But they've had little success determining exactly which pathways and genes are critical, partly because alcohol affects so many brain functions.

Now, with the help of advanced DNA microarray technology, studies of alcohol-preferring lab mice are narrowing down the possibilities. In a study led by Susan Bergeson, a neurobiologist at the University of Texas at Austin, researchers compared gene expression in the brains of two groups of mice, one averse to alcohol and the other preferring a 10 percent ethanol solution in their water bottles. Using high-throughput microarrays, which can measure the expression levels of thousands of genes at once, Bergeson's team found 3,800 genes that seemed to be associated with how much the mice liked alcohol; 36 in that group were labeled high priority, as similar genes are found in stretches of the human genome that have been implicated in alcoholism.