The brainteasing chemical cocktail that gets us drunk
By Roger Highfield , Science Editor
SCIENTISTS think they have answered a question that has bothered humans for as long as they have been drinking beer and wine: why does alcohol make us drunk?
The team that made the discovery is already studying the implications of the find, ranging from why some people have a relatively high tolerance to whether it will be possible to develop a sober-up pill.
Researchers at Washington University School of Medicine in St Louis, Missouri, have found that a compound produced by alcohol-soaked brain cells - a fatty acid ethyl ester - can inhibit the release of messenger chemicals, which is what happens in the brain after a few beers.
In this way, the chatter between nerve cells is damped down by alcohol.
Prof Richard Gross, one of the research team, said: "I'm hopeful that we can now figure out a thousand-year mystery. Despite the structural simplicity of alcohol, nobody understands the biochemical mechanisms that are responsible for its neurological effects."
In a study published in the latest issue of the Journal of Biological Chemistry, Prof Gross and Dr Rose Gubitosi-Klug link potentially intoxicating changes in brain chemistry to fatty acid ethyl esters, a group of compounds that are made when alcohol combines with fatty acids.
"Basically, we came up with the concept that it was a chemical in the process, not the ethanol itself, that was the active agent," said Prof Gross.
The compounds apparently speed up the release of charged potassium atoms from brain cells. In the brain, an increased flow of potassium would inhibit the release of messenger chemicals called neurotransmitters, said Dr Gubitosi-Klug.
A slow-down in neurotransmitter release could lead to slurred speech, clumsiness, slow reflexes and a loss of inhibitions in intoxicated people, she added.
The team studied the effects of alcohol on genetically engineered insect cells and cells taken from a part of the brain called the hippocampus. They found that an increased flow of potassium would interfere with communication between brain cells by making it difficult for cells to absorb enough calcium to trigger the release of neurotransmitters, leading to short-term memory loss, a common complication of drunkenness.
The scientists do not know why fatty acid ethyl esters stimulate the flow of potassium in their studies of the hippocampus, nor have they investigated this effect in other parts of the brain.
Understanding all the biochemical pathways of intoxication may eventually lead to new treatments for alcohol addiction, said Dr Gubitosi-Klug.
And a drug that can prevent this reaction between alcohol and fatty acids could be useful to sober up an individual enough to drive home after a night out, said Prof Gross.
