Positron emission tomography--a tool for identifying the effects of alcohol dependence on the brain.

To study alcohol's effects on the structure and function of the brain in living human beings, researchers can use various imaging techniques. Positron emission tomography (PET) is a functional imaging approach used to study the metabolism and physiology of the brain. PET studies have found that both acute and chronic alcohol ingestion alter blood flow and metabolism in various brain regions, including the frontal lobes and cerebellum. Other analyses focusing on alcohol's effects on brain chemical (i.e., neurotransmitter) systems have found that both acute and chronic alcohol consumption alter the activities of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) and the excitatory neurotransmitters glutamate, dopamine, and serotonin. These alterations may contribute to the reinforcing and rewarding effects of alcohol as well as to symptoms of alcohol withdrawal. Imaging studies also have demonstrated that some of alcohol's adverse effects on brain function can be reversed by abstinence or alcoholism treatment interventions. In addition, imaging studies may help in the development of new medications for alcoholism treatment.