Alcohol's electric effects - research on how alcohol affects brain function - Brief Article

Science News, Jan 11, 1997 by Janet Raloff

Many New Year's revelers enjoyed their libations a little too much again this year, some staggering to bed in a drunken stupor. Though people have long recognized that too much alcohol impairs brain functioning, no one has quite understood how intoxication occurs.

Indeed, observes biochemist Richard W. Gross of Washington University School of Medicine in St. Louis, many test-tube studies have shown that ethanol does not appear to affect brain cells until its concentration becomes so high that it would kill a person. Gross suggests that the flaw in such studies was their use of ethanol-plain alcohol.

When an individual drinks ethanol, the body immediately begins breaking it down. Working with cells grown in the lab, Gross and Rose A. Gubitosi-Klug, also of Washington University School of Medicine, provide evidence that certain ethanol breakdown products, known as fatty acid ethyl esters, are likely to be the direct agents of intoxication.

In the Dec. 20, 1996 Journal of Biological Chemistry, the pair showed that these ethyl esters speed up the movement of potassium ions, which are positively charged, from brain cells through channels in their outer membranes. This flow of ions increases the negative electric potential inside the cells, impairing the action of the voltage-dependent calcium channels.

The cells rely on calcium for responding to messages from other cells. When ethyl esters depress calcium concentrations, Gross says, communications between these cells can become uncoordinated. "And when their timing is off, you're going to have slurred speech" and other symptoms of drunkenness, including a breakdown in the inhibitory pathways that would normally curb inappropriate speech and behavior, he says.

"Our report is the first to show . . . these profound changes in the electrical functions of a [brain cell] at concentrations of alcohol which are present after people drink," Gross told Science News. "If you could prevent those changes from occurring," he says, "then presumably you could interrupt or even prevent the phenomenon of dependence" in alcoholics. "That," he reflects, "is our dream."