Alcohol changes how the brain creates memories, researchers say

A new study from Brown University suggests that alcohol changes how the brain processes memories, potentially influencing how we become addicted to it. While the study was carried out on fruit flies, it could eventually lead to new ways to help people who struggle with alcohol.

How to make a fruit fly a bar fly

Fruit flies are commonly used in experiments as they provide many advantages over more complex animals. In this case, they have small brains, only 100,000 cells, which can be more easily monitored than a larger animal and a genome that is well known and can be manipulated with few hidden variables.

The flies were taught how to locate alcohol and then turned loose to enjoy the stuff after some of their genes had been turned on and off. By controlling what genes were working, the scientists could isolate what systems were required to activate the reward response. They then examined the flies’ brains to see how the alcohol affected the active systems in their brains.

It was found that the Notch protein was affected by the alcohol. The activation of the Notch protein is the first step in several brain processes, including one that causes the brain to recognize the release of dopamine, the “feel-good” neurotransmitter.

In one particular process the neurotransmitter dopamine-2-like, which helps file memories as good or bad, is activated. When the flies started drinking, however, this neurotransmitter was very subtly altered. One “letter” of a single amino acid was changed.

While the team doesn’t know for sure what that one change does, it could prove very important for understanding why people keep drinking even after the adverse effects start piling up. Dr. Karla Kaun, one of the authors of the study and an assistant professor of neuroscience at Brown, explained the findings to Newsweek:

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. 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.

What does this mean for larger animals, humans for example?

While, with few exceptions, the brain of a fly is very different than that of a human being, the findings may be applicable for other animals. Dr. Kaun explains how this information might relate to human memory and addictions:

We think these results are highly likely to translate to other forms of addiction, but nobody has investigated that. 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. After three glasses, with an hour break in between, the pathway doesn’t return to normal after 24 hours. We think this persistence is likely what is changing the gene expression in memory circuits.

If our brains work like fly brains do, then alcohol affects how we process memories of drinking it. Perhaps the change in a single amino acid makes most memories of drinking good ones, leading to cravings even when you know you shouldn’t drink. Perhaps the duration of the effect prevents us from recalling just how bad that last hangover really was. More research is needed to know if and how this effect relates to addictions. Someday, it could prove the basis for a new pharmacological approach to treating addiction.

The authors acknowledge that this isn’t the end all study, and hope their work leads to further investigations on animals closer to us on the evolutionary tree. Dr. Kaun said that “We hope our work inspires other scientists to translate these findings to mammals in order to understand if the same mechanisms occur in our brains.”

Despite the nasty side effects that alcohol can cause the morning after we have a bit too much, many of us keep reaching for the bottle anyway. If this study is on the right track, it’s because we tend to view our experiences with drugs through rose-colored glasses. Perhaps someday the findings of this study will lead to a way to help us all see drugs with dry eyes. Until then, drink responsibly.