Cleansing the brain prevents dementia 

When mice and humans fall asleep, their brain cells shrink in size. This process makes room for the cleaning fluid that rinses out the debris that has accumulated in the brain cells after a long and active day. 

This has been proven by research into the brain’s support cells, otherwise known as glial cells. Professor Majken Nedergaard from the faculty is responsible for the study that was published in the internationally respected medical journal, Science. It was also acclaimed as the most important research article in 2015.

"The glial cells have a kind of housekeeper function. They make sure our brains are kept nice and clean, so that we can perform optimally. But the housekeeper can only work when we are asleep. It’s one of the reasons why, on a purely biological level, we need sleep", says Professor Maiken Nedergaard from the Centre for Neuroscience.

There are over 1,000 billion glial cells, also called support cells, in our central nervous system. Their real function has only been identified recently through MRI scanning and sleep research. 

20,000 Danes suffer from dementia

Research also shows that glial cells have a major influence on the development of diseases such as dementia, schizophrenia and ADHD.  

"If you study the brain of a person with Alzheimer's,  it is possible to see that the glial cells do not shrink at night. This means that the fluid cannot pass through, and therefore waste substances are not rinsed away. This causes inflammation in the brain", says Majken Nedergaard.

The study has paved the way for researchers to develop a diagnostic test which can predict a person’s risk of developing dementia. In the long term, it should make it possible to detect and prevent the disease early in patients’ lives. 

The next step is to develop a number of techniques that can affect the function of the glial cells.