How Alcohol "Hijacks" Dopamine Pathways

By Beth Leipholtz 11/02/18

Researchers explored how alcohol affects memories in a recent study.

man drinking beer

While it’s long been known that alcohol affects the brain’s reward pathways, a new study has shed light on exactly how this happens and how it affects memories made while under the influence. 

According to Inverse, Brown University researchers have proven that alcohol “affects a specific cell signaling pathway in the brains of fruit flies.”

The specific pathway is called "Notch," Inverse reports, and is found in humans and most other multicellular organisms. 

Karla Kaun, assistant professor of neuroscience at Brown University and the study’s corresponding author, tells Newsweek that the way alcohol affects signaling on the Notch pathway can affect associative memory, which can “drive addiction.”

“While you are drinking, you are forming memories for cues in your environment, like the feel of the glass or the bouquet of your wine, that become associated with the feeling of being intoxicated,” she said. “Our study provides genetic and biochemical evidence that fairly low doses of alcohol can activate a highly conserved cell-signaling pathway in the brain, leading to changes in expression of genes important for learning and memory.”

According to Inverse, the signaling of the Notch pathway plays a vital role in developing brains for embryos. But, until now, researchers say the impact of the Notch pathway in adults has been underestimated because the pathway could have to do with how alcohol affects dopamine, the neurotransmitter often connected with positive feelings and substance use disorder. 

During the study, a group of fruit flies was trained to seek out alcohol. In that group, the activation of the Notch pathway affected the flies by changing a certain gene. While alcohol did not decrease, increase or activate the dopamine receptors, it did alter the “gene expression of the dopamine receptors that cells produced,” Inverse reports.

According to study authors, this change indicates that alcohol is “hijacking” how the dopamine pathways in the brain respond to “pleasure and reward.”

“If this works the same way in humans, one glass of wine is enough to activate the pathway, but it returns to normal within an hour,” Kaun told the Independent

However, the more drinks consumed, the longer it takes to revert to normal. 

“After three glasses, with an hour break in between, the pathway doesn’t return to normal after 24 hours,” Kaun added. “We think this persistence is likely what is changing the gene expression in memory circuits.”

Though not involved with the study, Peter Giese, a professor of neuroscience at King’s College London, tells the Independent that studies like this assist in developing a greater understanding of the brains in those battling substance use disorder, and, in turn, a greater chance of helping them.

“[This study] suggests that drug addiction persists because memory mechanisms were hijacked by drug exposure,” Giese told the Independent. “The study not only provides a model for understanding the persistence of drug addiction, it also identifies potential pharmacological targets for treating addiction.”

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Beth is a Minnesota girl who got sober at age 20. By day she is a website designer, and in her spare time she enjoys writing about recovery at, doing graphic design and spending time with her boyfriend and three dogs. Find Beth on LinkedInInstagram and Twitter.