What is the function of sleep?

Although the precise function of sleep remains unknown, there is little question that sleep is required for maintaining optimal performance in a large and diverse number of biological systems. Indeed, cognitive impairments associated with aging and neurodegenerative disorders are frequently accompanied by deficits in sleep physiology and architecture. Thus, understanding how sleep can benefit the brain has the potential of not only improving the daily lives of healthy individuals but may also provide new insights into how sleep might be used to slow or reverse cognitive decline associated with degenerative disease, psychiatric disorders and maybe even restore normal functioning to children with developmental disorders.

Figure: Sleep Deprivation activates ERK and alters neural structure A-B) Immunohistochemistry of ppERK in brains from flies that experienced either a full night of sleep (A) or 12 hours of sleep deprivation (B).