Alcohol Sensitivity Japanese scientists have discovered in mice a gene that may regulate sensitivity to alcohol, a finding that could help explain why some people are more susceptible to alcohol addiction than others. The study, reported in the Oct. 24 issue of Science , may lead to better ways to identify those vulnerable to the disease at an early age. They found that mice without the kinase gene stay drunk longer than normal mice, apparently because the enzyme normally counteracts alcohol's depressive effects on neurons, causing acute tolerance. And because too little Fyn kinase increases alcohol sensitivity, it is possible that too much of the enzyme may lead to lowered sensitivity. If that's the case, Harris said, the Fyn kinase gene may be a target for researchers searching for genes that might predispose people to alcoholism.
Any gene encoding a protein that influences alcohol action becomes a candidate gene for alcoholism.
To judge the animals' sensitivity to alcohol, the researchers, led by Hiroaki Niki, injected ethanol into mice and place them on their backs in V-shaped troughs. Normal mice that had not been injected could stand up almost immediately, while normal injected mice took anywhere from 3 to 40 minutes. However, for each blood level of alcohol tested, mice lacking the Fyn kinase gene took about twice as long to get up as mice with the functioning gene. In their report, the researchers said it is likely the gene is also playing a role in human sensitivity to alcohol. The same gene is found in animals ranging from fish to humans.