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Book

Physiology, Sleep Stages

Aakash K. Patel  1 , Vamsi Reddy  2 , Karlie R. Shumway  3 , John F. Araujo  4
In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan.
.
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Book

Physiology, Sleep Stages

Aakash K. Patel et al.
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Excerpt

The human body cycles through 2 phases of sleep, (1) rapid eye movement (REM) and (2) nonrapid eye movement (NREM) sleep, which is further divided into 3 stages—N1 to N3. Each phase and stage of sleep includes variations in muscle tone, brain wave patterns, and eye movements. The body cycles through all stages approximately 4 to 6 times each night, averaging 90 minutes for each cycle.

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Conflict of interest statement

Disclosure: Aakash Patel declares no relevant financial relationships with ineligible companies.

Disclosure: Vamsi Reddy declares no relevant financial relationships with ineligible companies.

Disclosure: Karlie Shumway declares no relevant financial relationships with ineligible companies.

Disclosure: John Araujo declares no relevant financial relationships with ineligible companies.

References

    1. Memar P, Faradji F. A Novel Multi-Class EEG-Based Sleep Stage Classification System. IEEE Trans Neural Syst Rehabil Eng. 2018 Jan;26(1):84-95. - PubMed
    1. Gottesmann C. GABA mechanisms and sleep. Neuroscience. 2002;111(2):231-9. - PubMed
    1. Murillo-Rodríguez E, Arias-Carrión O, Sanguino-Rodríguez K, González-Arias M, Haro R. Mechanisms of sleep-wake cycle modulation. CNS Neurol Disord Drug Targets. 2009 Aug;8(4):245-53. - PubMed
    1. Watson CJ, Baghdoyan HA, Lydic R. Neuropharmacology of Sleep and Wakefulness. Sleep Med Clin. 2010 Dec;5(4):513-528. - PMC - PubMed
    1. Vazquez J, Baghdoyan HA. Basal forebrain acetylcholine release during REM sleep is significantly greater than during waking. Am J Physiol Regul Integr Comp Physiol. 2001 Feb;280(2):R598-601. - PubMed

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