Campus Connection

Getting ready to celebrate at the bar after that big test? Better think twice, as drinking too much may very well affect your performance on the next one. Recent research on young adults and young adult laboratory animals suggests that a bout of heavy drinking can have lasting effects on one’s memory. A recent study of 18-25 year olds, who reported a history of drinking a six-pack or its equivalent on weekend nights, showed a decline in performance when executing memory tasks, as compared to their nondrinking counterparts.

One reason for the observed results may be the fact that the brain of an individual under the age of 25 is still maturing, especially in the frontal lobe and hippocampal regions.  Both of these areas are vital to the formation of new memories and also represent the parts of the brain most affected by alcohol use, effects that are particularly notable in women. 

So how does this happen?

Functional MRI studies of young adults, ages 18-25, showed less brain activity in the frontal lobes of alcohol users than in the controls, after both groups undertook equivalent working memory tasks. Additionally, the hippocampal volumes of young adults with alcohol use disorders were observed to be significantly smaller than those of the nondrinking controls. 

Learning and storing new information involves complex molecular processes and once that information has been learned, it is processed in the frontal lobes and the hippocampus, and then stored in the long-term storage area of the brain.

Alcohol interferes with this process in several different ways. In the hippocampus, it exerts its effects directly, by acting on the hippocampal cells, as well as indirectly, by interfering with the interactions between the hippocampus and other brain regions. The impact of alcohol on the frontal lobes is less well understood. However, there is already much evidence that chronic use of the substance damages the frontal lobes and leads to impaired performance on tasks that rely on the region’s function.

Studies done in rats have proved to be even more revealing. When alcohol was administered to a group of rats at a level equivalent to 2 drinks for a human, suppression of the activity of specific chemical receptors in the hippocampus was observed. At the level of 10 drinks, those same receptors were shown to shut down almost entirely.

Normally, the activation of these receptors initiates a cascade of changes that strengthens synapses and helps create repeated connections between cells. These processes lead to the efficient formation of new memories and are disrupted by the excessive consumption of alcohol.

Other rat studies have shown that consuming large volumes of alcohol affected memory even after the subjects stopped drinking. In a group of former “binge-drinker” rats, changes in the neurons of the hippocampus were observed long after they became sober.   These cellular changes translate into a decreased capacity to revise previously learned information, and a tendency to perseverate on earlier learning, effects that resulted in the inability of the rats to relearn a water maze.

So graduate students, beware! You are trying to absorb an enormous amount of information in a few short years and large volumes of alcohol can really interfere with all that effort.

And why handicap yourself through excess, when you can ensure your success with moderation?      

References and further reading:

Butler, Katy, “The Grim Neurology of Teenage Drinking”, New York Times, July 4, 2006.

Steinberg, Paul, “The Hangover that Lasts” New York Times, Dec. 29, 2007

White, Aaron M., “Topics in Alcohol Research” http://www.duke.edu/~amwhite/      

Dr. Letitia Pierce is a consulting psychiatrist at the University of Maryland, Baltimore Counseling Center.