Why drinking alcohol interferes with concentration

In a new study from UT Health San Antonio, experts have pinpointed why drinking alcohol interferes with our ability to concentrate. The researchers have found that alcohol blocks the release of norepinephrine, which is needed to help us pay attention.

“When we want to focus on something, or when we stand up from a chair and become active, a brain stem nucleus releases a chemical called norepinephrine. Acute exposure to alcohol inhibits this signal in the brain,” said study senior author Dr. Martin Paukert.

When a particular task requires our attention,  norepinephrine is secreted by a brain structure called the locus coeruleus. Dr. Paukert and his colleagues have described, for the first time, what happens next. They discovered that the norepinephrine normally attaches to receptors on cells called Bergmann glia, which elevates calcium levels within these cells. 

Bergmann glia are supporting cells in the cerebellum, a region near the brain stem. “To our knowledge, this paper is the first description that norepinephrine in mammals directly binds to receptors on the Bergmann glia and activates them through calcium elevation,” said Dr. Paukert.

Even though the researchers focused primarily on the Bergmann glia, they also demonstrated that the same type of inhibition takes place in cortical astrocytes. “Most likely vigilance-dependent astrocyte calcium activation is inhibited throughout the brain by acute alcohol intoxication.”

People tend to lose their balance when they are drinking alcohol. The researchers expected to find that the inhibition of calcium rise in Bergmann glia would explain this as well, but it did not. 

“The calcium elevation in Bergmann glia is not critical for motor coordination, which is somewhat surprising because the cerebellum is classically known for its role in motor control,” said Dr. Paukert. “However, our findings are in line with current suggestions that the cerebellum also plays critical roles in non-motor functions, and that astrocytes are not only supporting basic brain maintenance, but they may actively participate in cognitive function.”

Study co-author Dr. Manzoor Bhat suggested that the significance of this groundbreaking research is that it was conducted “in real time in living and breathing animals using state-of-the-art technologies.” 

“The findings will open up new avenues of defining the brain circuits that ultimately determine the state of alertness, and how chemicals that interfere with those circuits essentially dampen this inherent vigilance system of the brain,” said Dr. Bhat. 

The work was funded by the Robert J. Kleberg, Jr. and Helen C. Kleberg Foundation, the National Institute on Alcohol Abuse and Alcoholism, and the National Institute of Mental Health. 

The study is published in the journal Nature Communications.

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By Chrissy Sexton, Earth.com Staff Writer