Scientists from Denmark and the United States have discovered that norepinephrine plays a key role in brain cleansing: during sleep, the brainstem releases the molecule every 50 seconds, causing blood vessels to constrict and creating conditions for the removal of cellular debris, writes Science Daily.
The authors compare this process to a dishwasher running at night: when you open it in the morning, the dishes will already be clean. This discovery led the scientists to wonder when exactly the glymphatic system operates at "maximum speed." To answer this question, they conducted an experiment with mouse models, half of which were given a sedative.
It turned out that while taking the drug, norepinephrine activity was 50% lower than during natural sleep. Although the rodents in the sedative group fell asleep faster, their cerebrospinal fluid flow decreased by 30%. Scientists know that similar waves of norepinephrine activity are observed in humans, so the results may very accurately reflect the processes occurring in the human body.
"Many people take sleeping pills today, so they need to be aware of all the consequences to make informed decisions," said study co-author Natalie Hauglund.
Scientists now better understand why shallow sleep increases the risk of developing neurodegenerative diseases. In future studies, they plan to find a way to prevent these diseases at an early stage.
In another study, scientists previously found that certain areas of the brain become "silent" during sleep, providing a kind of memory reboot.
