A study reported in the December issue of Nature Neuroscience (Volume 2, Number 12, pages 1084-1090) identifies a new cell membrane channel where ethanol, the alcohol found in intoxicating beverages, may act. Neurobiologists from the Waggoner Center for Alcohol and Addiction Research and Section on Neurobiology, and the Department of Pharmacology and Toxicology, College of Pharmacy, University of Texas (UT) at Austin discovered actions of alcohol while studying a subtype of potassium channels, a diverse family of ion channels that perform many central nervous system functions. Identification of the alcohol-sensitive channel has significant implications because of its key role in brain function.

"Molecular analysis of this cell memberane channel ultimately will increase our knowledge of how alcohol affects the brain and, thereby, the way a person functions," said Enoch Gordis, M.D., Director, National Institute on Alcohol Abuse and Alcoholism (NIAAA), a component of the National Institutes of Health.

Joanne M. Lewohl, Ph.D., and her associates identified the effect of ethanol on the G-protein-coupled inwardly rectifying potassium channel (GIRK). GIRKs are widely distributed in the brain and play a major role in regulating inhibitory responses in the central nervous system. They act by regulating neuron-to-neuron communication and the rate of this information transfer.

Whereas most potassium channels are either unaffected or inhibited by ethanol and other alcohols, GIRK channels were shown to be sensitive to ethanol at a concentration below the legal level for intoxication (10mM), the researchers found. This high sensitivity to relatively minor changes may influence substantially the capability of neurons to communicate. The researchers conclude that ethanol enhances or exaggerates the effect of normal neurotransmitter action, producing profound physiological effects in the central nervous system.

"The cellular effects of alcohols on the central nervous system have significant implications for understanding alcohol addiction," said R. Adron Harris, Ph.D., study coauthor and Director of the Waggoner Center at the University of Texas. "We have begun genetic manipulation of the new membrane channel to determine how it influences alcohol consumption and dependence."

For interviews with Drs. Lewohl and Harris, telephone 512/232-2514. To interview Dr. Gordis, telephone NIAAA Press, 301/443-3860. For additional alcohol research information, visit http://www.niaaa.nih.gov.