Sleep may help restore brain function by enabling the brain to remove certain molecules linked with the development of neurodegeneration, suggests a study on mice funded by the National Institute of Neurological Disorders and Stroke (NINDS).
The fact that sleep is a consistent behavior across species suggests it serves an important function that has been preserved through evolution. But the purpose of sleep and why it helps improve brain function remain a bit of a mystery. Moreover, how sleep deprivation inhibits learning, slows reaction time, and possibly triggers seizures is unclear. The study, by Lulu Xie, PhD, of University of Rochester Medical Center, and colleagues, suggests that removal of some harmful molecules from the brain may be one role of sleep (Xie L et al. Science. doi:10.1126/science.1241224 [published online October 18, 2013]).
Kuehn BM. Sleep May Help Remove Harmful Molecules From the Brain. JAMA. 2013;310(20):2140. doi:10.1001/jama.2013.283499