Study Reveals How Alcohol Works
A study has revealed what alcohol does to the brain to give us the intoxicating and pleasant effect. The findings of the study can be used to formulate new treatments to fight alcohol abuse.
Alcohol is being consumed by people all around the world since ancient times. Although the form of alcohol may be different in each part of the world, the effect of alcohol is the same – a pleasant feeling with a simultaneous loss of control.
Despite efforts of researchers around the world to understand the exact working of alcohol, only limited knowledge could be acquired till now.
About a decade ago, a study funded by National Institute of Health’s National Institute of Alcohol Abuse and Alcoholism (NIAAA) uncovered some basic concepts on how alcohol influenced the brain.
The study had identified a membrane channel in brain cells that is activated when any alcoholic beverage is consumed. This channel is called G-protein coupled inwardly rectifying potassium channel (GIRK). It is found on cells in all parts of the brain and is an important contributor to the functioning of the brain.
Later studies confirmed that the effect of alcohol on living beings was through GIRK, at least partly. But scientists could not find out the exact mechanism of alcohol’s influence on GIRK.
The recent study was conducted by Dr. Paul A. Slesinger and his colleagues at the Salk Institute. It was funded by NIAAA and National Institute of General Medical Sciences (NIGMS). The study appeared in the online edition of Nature Neuroscience journal on June 28, 2009.
The study team solved the structure of a molecule related to GIRK. They observed that both the molecule and a protein that enables fruit flies to sense alcohol have alcohol-binding sites similar to an area on GIRK.
The researchers systematically substituted different amino acids in the protein sequence of GIRK in the area they thought was the alcohol binding part. They reported that amino acids with bulkier side chains reduced or eliminated ethanol’s ability to activate GIRK. In contrast, those with smaller side chains didn’t block the alcohol’s effect on GIRK.
The experiments, along with structural analysis, persuaded the scientists to propose a model for how alcohol activates GIRK channels. At rest, the channels open and close, but alcohol binding keeps them open. This leads to alcohol-activated currents in brain cells. The study team believes that alcohol hijacks the intrinsic activation mechanism of GIRK channels and stabilizes the opening of the channel.
Consequences of the study
Identifying the actual site that alcohol uses to exert its effect is an important step in developing new approaches to treat alcohol addiction and abuse. For instance, it might allow scientists to develop a drug that blocks alcohol from entering GIRK’s binding pocket.
For more details on the subject visit National Institutes of Health website.