Scientists have found sleep increases the reproduction of cells that form the insulating material known as myelin, which is essential for the brain to function properly. The findings could one day lead scientists to new insights about sleep’s role in brain repair and growth and a new understanding about multiple sclerosis, a disease that damages myelin. Researchers have known for years that many genes are turned on during sleep and off during periods of wakefulness. However, it was unclear how sleep affects specific cells types, such as oligodendrocytes, which make myelin in the healthy brain and in response to injury. Much like the insulation around an electrical wire, myelin allows electrical impulses to move rapidly from one cell to the next.
