There is nothing like a good night's sleep to help you feel your best the next day. Now scientists are finding that good sleep habits may do more than restore cognitive function on a nightly basis—they may also fortify the brain over the long term, according to a new study in the Journal of Neuroscience.
Researchers at the University of Wisconsin–Madison found that during sleep, activity ramps up in genes that are involved in producing oligodendrocytes—brain cells responsible for coating neurons with myelin. Myelin is the brain's insulating material. The fatty substance surrounds the signal-transmitting tail that extends from every neuron, enabling electrical communications to travel quickly and efficiently to other neurons. Myelin deficiency is at the root of the neurodegenerative disease multiple sclerosis and can contribute to symptoms such as fatigue, vision and hearing impairment, and a loss of coordination.
In this study, sleeping mice had heightened activity in the genes responsible for creating oligodendrocytes, but awake or sleep-deprived rodents showed greater activity in genes involved in cellular stress and death. Chiara Cirelli, a neuroscientist and author on the paper, suggests that sleep helps cells regenerate and repair themselves, by enabling the body to produce new myelin after it has deteriorated. Cellular repair probably takes weeks or even months, however, so pulling an occasional all-nighter is unlikely to disrupt the process.