title: Mechanisms of REM sleep in health and disease.
abstract: OBJECTIVE
  Our understanding of rapid eye movement (REM) sleep and how it is generated remains a topic of debate. Understanding REM sleep mechanisms is important because several sleep disorders result from disturbances in the neural circuits that control REM sleep and its characteristics. This review highlights recent work concerning how the central nervous system regulates REM sleep, and how the make up and breakdown of these REM sleep-generating circuits contribute to narcolepsy, REM sleep behaviour disorder and sleep apnea.
  
  
  RESULTS
  A complex interaction between brainstem REM sleep core circuits and forebrain and hypothalamic structures is necessary to generate REM sleep. Cholinergic activation and GABAergic inhibition trigger the activation of subcoeruleus neurons, which form the core of the REM sleep circuit.
  
  
  CONCLUSIONS
  Untimely activation of REM sleep circuits leads to cataplexy - involuntary muscle weakness or paralysis - a major symptom of narcolepsy. Degeneration of the REM circuit is associated with excessive muscle activation in REM sleep behaviour disorder. Inappropriate arousal from sleep during obstructive sleep apnea repeatedly disturbs the activity of sleep circuits, particularly the REM sleep circuit.
authors.affiliation: aDepartments of Cell and Systems Biology bPhysiology cMedicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Jimmy J
authors.initials: JJ
authors.lastname: Fraigne
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Grace
authors.forename: Richard L
authors.initials: RL
authors.lastname: Horner
authors.forename: John
authors.initials: J
authors.lastname: Peever
mesh_terms: D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D059329:Cholinergic Neurons / Q000187:drug effects; D059330:GABAergic Neurons / Q000187:drug effects; D006801:Humans; D007031:Hypothalamus / Q000503:physiopathology*; D009290:Narcolepsy / Q000209:etiology / Q000503:physiopathology*; D009434:Neural Pathways / Q000187:drug effects; D020187:REM Sleep Behavior Disorder / Q000150:complications / Q000503:physiopathology*; D012891:Sleep Apnea Syndromes / Q000209:etiology / Q000503:physiopathology*; D012895:Sleep, REM; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D000697:Central Nervous System Stimulants