In a major endorsement for taking care of our bodies with proper rest, a scientific study says that sleep allows the body to produce a brain cell that is vital in normal function.

The study in the Journal of Neuroscience says that sleep ramps up the production of cells that make the insulating material myelin that protects brain circuitry. The discovery in mice could lead to insights about sleep’s role in brain repair and possibly provide information to help in the battle against Multiple Sclerosis.

The University of Wisconsin team that conducted the study said mice brains produced twice the amount of myelin making cells when sleeping. Production reached highest points during R.E.M. sleep, the time period of sleeping most associated with dreaming.

“For a long time, sleep researchers focused on how the activity of nerve cells differs when aminals are awake versus when they are asleep,” study member Dr. Chiara Cirelli told the BBC. “Now it is clear that the way other supporting cells in the nervous system operate also changes significantly depending on whether the animal is asleep or awake.”

Cirelli said her team is interested in exploring whether lack of sleep in teen years has an adverse impact on brain development.

The study shows potential impact on the battle with MS because with that disease the immune system destroys myelin in the brain and spinal cord.