Alcohol is the most commonly used addictive substance in the United States: 17.6 million people or one in every 12 adults are diagnosed with an alcohol abuse disorder and millions of more individuals engage in risky behaviors such as binge drinking that can potentially lead to alcohol abuse disorder. Alcohol can affect every organ in the body including the brain, liver, heart, pancreas, and stomach resulting in severe medical complications that can lead to death. Only a minority of American adults with high-risk alcohol use receives treatment. Three medications are approved by the U.S. Food and Drug Administration to treat alcohol use disorder: acamprosate, disulfiram, and naltrexone. Acamprosate and naltrexone reduce alcohol consumption and increase abstinence rates, although the effects appear to be modest. Disulfiram causes unpleasant symptoms after drinking alcohol and therefore is used to deter individuals from relapsing. Illicit substances such as opioids as well as legal substances such as alcohol are known to produce euphoric effects creating rewarding memories in individuals due to a specific pathway in the brain. New research has been conducted that examines the biochemical processes involved with alcohol addiction, and researchers have been successful in identifying this specific biochemical pathway. The hope is that by understanding how alcohol addiction occurs there can be an improved treatment plan for alcohol-related disorders and preventing alcohol abuse.

This recent study, from Brown University (U.S.), has been conducted on the brains of fruit flies (which serve as the model for studying many processes in all organisms, including humans). The fruit fly has, at 60 percent, of a group of readily identified genes that are found in a diverse set of human diseases. With the specific research, the brains of fruit flies have similar avoidance and reward memories generated by molecular signals that are analogous to those found in humans. The researchers were able to deactivate specific genes in the fruit flies as they were being taught where to locate alcohol. By disabling the genes and observing the responses, the researchers were able to identify the specific proteins that are essential for rewarding memories.

Looking at the study

With the study, the researchers were able to deactivate specific genes in the fruit flies as they were being taught where to locate alcohol. By observing the response of the flies, this enabled the researchers to identify the proteins that were essential for generating rewarding memories. This led to the discovery that the Notch protein, which controls the signaling of the dopamine-2-like receptor protein, was vital for installing a liking for alcohol. Dopamine is a neurotransmitter in the brain that is responsible for pleasurable effects so it would make sense that this gene is responsible for encoding whether the memory is pleasing or aversive. In humans, researchers believe that one glass of wine is enough to activate this reward pathway, but individuals will return to normal after an hour, however after three glasses of wine, with an hour break in between, the reward pathway does not return to normal until 24 hours later indicating that this pathway can be changed over time with a higher alcohol consumption; potentially resulting in alcoholism.

Why is this important? It is hoped this finding can assist with future addiction treatment. For example, discovering a drug that could block the signals and receptors in this pathway so pleasurable feelings will not be increased with higher alcohol consumption.

Petruccelli et all. Alcohol Activates Scabrous Notch to Influence Associated Memories. Neuron. Article 1. Vol. 5 P1209-1223.