Why do we sleep? Why we feel frustrated and annoyed whenever we don’t have a good sleep? Scientists have discovered the answers for these questions. They say we sleep as it replenishes a type of brain cell.

While sleeping, there are genes in the brain that are actually turned on. Scientists say these genes are vital for the repair and growth of brain cells.

According to the US researchers, adequate sleep boosts the production of specific brain cells, called oligodendrocytes, that produce the protective layer around the organ.

Oligodendrocytes make myelin (the protective layer) in the healthy brain and in response to injury. Myelin allows electrical impulses to move rapidly from one cell to the next just like the insulation around an electrical wire.

Scientists have known for years that many genes are turned on during sleep and off during periods of wakefulness. These findings could one day lead scientists to new insights about the role sleep plays in brain repair and growth.

Study

In the current study, Chiara Cirelli, MD, PhD, and colleagues at the University of Wisconsin, Madison, measured gene activity in oligodendrocytes from mice that slept or were forced to stay awake.

Dr Chiara Cirelli and colleagues found that the production rate of the myelin making cells, immature oligodendrocytes, doubled as mice slept. In contrast, the genes implicated in cell death and cellular stress response was turned on when the animals stayed awake.

“These findings hint at how sleep or lack of sleep might repair or damage the brain,” said Mehdi Tafti, PhD, who studies sleep at the University of Lausanne in Switzerland. Tafti, however, was not involved in the study reported in the Sep 4 issue of the Journal of Neuroscience.

Why we need to sleep has baffled scientists for centuries. So far we have given a simple reason for the necessity of sleep and i.e. we need to sleep to feel rested and for our mind to function well. However, the biological processes that go on as we slumber have only started to be uncovered relatively with this study.

The study is published in the Journal of Neuroscience.