title: Sleep deprivation before stroke is neuroprotective: a pre-ischemic conditioning related to sleep rebound.
abstract: OBJECTIVE
  We have previously shown in a rat model of focal cerebral ischemia that sleep deprivation after stroke onset aggravates brain damage. Others reported that sleep deprivation prior to stroke is neuroprotective. The main aim of this study was to test the hypothesis that the neuroprotection may be related to an increase in sleep (sleep rebound) during the acute phase of stroke.
  
  
  METHODS
  Male Sprague Dawley rats (n=36) were subjected to continuous polygraphic recordings for baseline, total sleep deprivation (TSD), and 24h after ischemia. TSD for 6h was performed by gentle handling and immediately followed by ischemia. Focal cerebral ischemia was induced by permanent occlusion of distal branches of the middle cerebral artery. Control experiments included ischemia without SD (nSD) and sham surgery with TSD (n=6/group).
  
  
  RESULTS
  Shortly after stroke, the amount of slow wave sleep (SWS) and paradoxical sleep (PS) increased significantly (p<0.05) in the TSD/ischemia, resulting in an increase in the total sleep time by 30% compared to baseline, or by 20% compared with the nSD/ischemia group. The infarct volume decreased significantly by 50% in the TSD/ischemia compared to nSD group (p<0.02). Removal of sleep rebound by allowing TSD-rats sleep for 24h before ischemia eliminated the reduction in the infarct size.
  Sleep deprivation results in sleep rebound and reduces brain damage. Sleep rebound may be causally related to the neuroprotection.
authors.affiliation: Department of Neurology, University Hospital Bern, CH3010 Bern, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Cam
authors.forename: B
authors.initials: B
authors.lastname: Gao
authors.forename: L
authors.initials: L
authors.lastname: Imbach
authors.forename: A
authors.initials: A
authors.lastname: Hodor
authors.forename: C L
authors.initials: CL
authors.lastname: Bassetti
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D020520:Brain Infarction / Q000209:etiology / Q000517:prevention & control; D002452:Cell Count; D004195:Disease Models, Animal; D004569:Electroencephalography; D004576:Electromyography; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation; D020521:Stroke / Q000150:complications / Q000517:prevention & control*; D013997:Time Factors
chemical_list: D010751:Phosphopyruvate Hydratase
keywords: Ischemic preconditioning; Neuroprotection; Sleep; Sleep deprivation; Sleep rebound; Stroke