Scientists from the University of Oslo have found that pulsating blood vessels clear waste from the brains of mice during sleep. Research published Nature Communication.
Scientists explained that the brain constantly produces waste, and if it accumulates too much, it increases the risk of Alzheimer’s and other neurodegenerative diseases.
They found that the blood vessels, particularly the arteries, in the brains of the mice expanded and contracted in a certain way while the animals were sleeping. No such movement was observed in awake mice. The brain’s waste products are removed through special vessels around the brain’s blood vessels. Therefore, the movement of blood vessels can affect this process.
Until now, it was believed that clearing of the brain occurs only during the deep sleep phase. The new study showed that vessels vibrate in patterns specific to each stage, including brief awakenings. During deep sleep, arteries slowly expand and contract. During REM sleep, the arteries remained enlarged and then contracted rapidly until, at the end of the sleep cycle, they quickly returned to the size they were before falling asleep.
The scientists’ discoveries could help find new ways to treat and even prevent Alzheimer’s and other neurodegenerative diseases, as well as help develop strategies to deliver drugs to the brain more efficiently.