Sleep increases the reproduction of cells that are involved in the formation of myelin , the insulating material in nerve cell projections in the brain and spinal cord, according to a study published in the Journal of Neuroscience .
Scientists have known for years that many genes turn on during sleep and turn off during waking periods. However, it was not clear how sleep affects specific cells such as oligodendrocytes, which produce myelin in the healthy brain and respond to injury . Similar to the insulation that surrounds an electrical wire, myelin allows electrical impulses to move rapidly from one cell to the next.
In the new study, Chiara Cirelli and her colleagues at the University of Wisconsin in the United States measured gene activity in oligodendrocytes from mice that slept or were forced to stay awake. The team identified that genes that promote myelin formation are activated during sleep, while those involved in cell death and the response to cellular stress are turned on when the animals wake up . As if that were not enough, an additional analysis revealed that the reproduction of oligodendrocyte precursor cells is doubled during sleep, especially during rapid eye movement , that is, in the so-called REM sleep phase.
In light of the results, Cirelli suspects that extreme and / or chronic loss of sleep could aggravate some of the symptoms of multiple sclerosis (MS), a disease that damages myelin.
