During sleep, the natural cleaning system of the brain goes into action, removing debris and toxic particles. Poor sleep is now associated with a buildup of amyloid and extended poor sleep causes the buildup of tau, another hallmark of the disease.
It turns out that, during wake cycles, amyloid accumulates in the brain. During sleep, cerebrospinal fluid rushes through the brain to clear out unwanted protein particles and debris. One study also pointed to orexin, a neurotransmitter that
regulates the sleep cycle, as likely being involved in the production of increased levels of amyloid. This research helped both to identify orexin as a potential drug target, and to demonstrate the critical importance of adequate sleep in lowering risk for Alzheimer’s disease.
David Holtzman, M.D., Washington University School of Medicine