Steven McIntire, a neurologist at the University of California at San Francisco, may have found the master switch of drunkenness. After bombarding hundreds of Caenorhabditis elegans worms with DNA-altering chemicals and screening the results, he found that the deletion of just one gene rendered the worms almost completely resistant to alcohol. The drunkenness gene, present in many living things, including humans, regulates a molecular switch that causes neurons to drop into a less active state when triggered. Alcohol modulates the switch, technically known as an ion channel, causing it to open more frequently. As a result, alcohol-exposed worms stop wriggling—the C. elegans version of the sluggish, uncoordinated behavior characteristic of inebriated humans.
Deleting the drunkenness gene eliminated the associated ion channel as well. Mutant worms were unaffected by quantities of alcohol that would leave a normal nematode essentially comatose. McIntire argues that the genetic mechanism probably works much the same in people. “Worms, mice, humans, and even fruit flies show similar effects of intoxication at similar alcohol concentrations,” he says, and human neurons contain a switch similar to that in C. elegans. McIntire is exploring how the discovery of the drunkenness gene could aid in the treatment of alcoholism. “Studies suggest that people with an innate resistance to alcohol have a higher probability of becoming alcoholics,” he says. “It’s possible this could be caused by a defect or natural variation in the ion channel’s functioning.” Further ahead, he envisions developing a drug that could block the channel, thereby triggering instant sobriety or preventing a person from getting drunk.