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A sleep spindle is a burst of oscillatory brain activity visible on an electroencephalography==Function== Sleep spindles (sometimes referred to as "sigma bands" or "sigma waves") may represent periods where the brain is inhibiting processing to keep the sleeper in a tranquil state. Along with K-complexes they are defining characteristics of, and indicate the onset of, stage 2 sleep. They are often tapered at both ends and frequently seen over the frontal and central head regions. They may or may not be synchronous, but they should be symmetrical and bilateral. During sleep these spindles are seen in the brain as a burst of activity immediately following muscle twitching. Researchers think the brain, particularly in the young, is learning about what nerves control what specific muscles when asleep.〔("To sleep, perchance to twitch" )〕〔("Wiring your brain at college – a new perspective on sleep" )〕 Spindles generated in the thalamus have been shown to aid sleeping in the presence of disruptive external sounds. A correlation has been found between the amount of brainwave activity in the thalamus and a sleeper's ability to maintain tranquility.〔Thien Thanh Dang-Vu, Scott M. McKinney, Orfeu M. Buxton, Jo M. Solet, Jeffrey M. Ellenbogen. Spontaneous brain rhythms predict sleep stability in the face of noise. Current Biology - 10 August 2010 (Vol. 20, Issue 15, pp. R626-R627)〕 Sleep spindles result from interactions between cells in the thalamus and the cortex. Sleep spindle activity has furthermore been found to be associated with the integration of new information into existing knowledge〔Tamminen, J.; Payne, J.D.; Stickgold, R.; Wamsley, E.J.; Gareth Gaskell, M. (2010). Sleep spindle activity is associated with the integration of new memories and existing knowledge. ''The Journal of Neuroscience'', 30(43), 14356–60〕 as well as directed remembering and forgetting (fast sleep spindles).〔Saletin, J.M.; Goldstein, A.N.; Walker, M.P (2011). The Role of Sleep in Directed Forgetting and Remembering of Human memories. ''Cerebral Cortex'', 21, 2534–2541〕 During NREM sleep, the brain waves produced by people with schizophrenia lack the normal pattern of slow and fast spindles.〔Ferrarelli, F.; Huber, R.; Peterson, M.J.; Massimini, M.; Murphy, M.; Riedner, B.A.; Watson, A.; Bria, P.; Tononi, G. (2007). Reduced Sleep Spindle Activity in Schizophrenia Patients. ''The American Journal of Psychiatry'', 164, A62〕 Loss of sleep spindles are also a feature of familial fatal insomnia, a prion disease.〔Niedermeyer E, Ribiero M. Considerations of nonconvulsive status epilepticus. Clin Electroencephalogr 2000; 31: 192-195.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「sleep spindle」の詳細全文を読む スポンサード リンク
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