- Mice in the control group refused to drink alcohol
- When a certain gene was deactivated, they started preferring alcohol over water
- Researchers stress that human alcoholism depends much more on environmental and personal factors
Researchers have discovered a gene that regulates alcohol consumption; when this genes becomes faulty, it makes humans more prone to excessive drinking. They have also identified the mechanism underlying this phenomenon. However, it should be kept in mind that this is only a small cog in the great system of biological and psychological machinery that determines the extent to which a person will use, abuse, or become addicted to alcohol.
Normal mice don’t really like alcohol; when given a choice between a bottle of water and a bottle of diluted alcohol, they rarely chose any alcohol at all. The same goes for pretty much all mammals. However, mice with a mutation in a gene called Gabrb1 overwhelmingly preferred drinking alcohol over water – choosing to consume about 85% of their daily fluids with alcohol (about as strong as wine).
Furthermore, researchers showed mice carrying this mutation were willing to work to obtain the alcohol-containing drink by pushing a lever and, unlike normal mice, did this relentlessly over large periods of time. They would then drink until they got intoxicated and could barely coordinate their movements.
The gene has a significant impact in humans as well:
“We know from previous human studies that the GABA system is involved in controlling alcohol intake. Our studies in mice show that a particular subunit of GABAA receptor has a significant effect and most importantly the existence of these mice has allowed our collaborative group to investigate the mechanism involved. This is important when we come to try to modify this process first in mice and then in man.”
However, the team of researchers from five UK universities – Newcastle University, Imperial College London, Sussex University, University College London and University of Dundee – and the MRC Mammalian Genetics Unit at Harwell published their results in Nature Communications, and they stress that human alcoholism depends much more on environmental and personal factors than on genes.
“It’s amazing to think that a small change in the code for just one gene can have such profound effects on complex behaviours like alcohol consumption. We are continuing our work to establish whether the gene has a similar influence in humans, though we know that in people alcoholism is much more complicated as environmental factors come into play. But there is the real potential for this to guide development of better treatments for alcoholism in the future.”
Anstee, Q. M. et al. Mutations in the Gabrb1 gene promote alcohol consumption through increased tonic inhibition. Nat. Commun. 4:2816 doi: 10.1038/ncomms3816 (2013).