"All of our cells have exactly the same deoxyribonucleic acid (DNA), which means they all have the same genes," explained William J. McBride, symposium organizer and professor of neurobiology at the Indiana University School of Medicine. "The reason that different cells can appear and work so differently with the same genes giving us, for example, unique eyes, skin, or hair is that only some genes are used or 'turned on' in each cell. This is called gene expression."
McBride said that researchers now know that alcohol can change gene expression in the brain, and that these changes are likely responsible for many of the 'symptoms' of addiction, such as tolerance, physical dependence, and craving, as well as the 'consequences' of alcoholism, such as brain damage.
"The challenge has been to find out which genes out of more than 50,000 are turned on or off in the brains of alcoholics," he said. "Microarray studies the examination of a small glass microscope slide that has thousands of different DNA samples attached to it that are applied to brain function are just beginning in the field of alcoholism. Several years ago, it was impossible to analyze more than a handful of these genes, however, microarray technology has changed that."
Symposium speakers at the June 2004 Research Society on Alcoholism meeting in Vancouver, B.C. presented the following findings from recent studies that used genetic animal models: