title: Vagus nerve stimulation reduces infarct size in rat focal cerebral ischemia.
abstract: OBJECTIVE
  We sought to determine the effect of vagus nerve stimulation (VNS) on infarct size after transient focal cerebral ischemia in rats.
  
  
  METHODS
  Ischemia was produced by transient filament occlusion of the right middle cerebral artery. Stimulating electrodes were implanted on the cervical part of the right vagus nerve. Electrical stimulation was initiated 30 min after the induction of ischemia, and delivered for 30s at every 30 min for 3h in experimental group 1 and at every 5 min for 1h in experimental group 2. All the procedures were duplicated but no stimulus was delivered in the control group. Functional deficit was evaluated and animals were killed to determine the infarct size 24h after ischemia.
  
  
  RESULTS
  Ischemic lesion volume was smaller in VNS-treated animals as compared with control animals; the relative percentage of contralateral hemispheric volume that underwent infarction was 16.2+/-3.2% in the VNS and 33.0+/-5.0% in the control arms in experimental group 1 (p<0.05). The respective values for experimental group 2 were 19.8+/-0.5% and 37.9+/-2.6% (p<0.05). VNS-treated animals were significantly more likely to have better functional scores at 24h as compared with control animals. The functional score improved by 50% in experimental group 1 and 44% in experimental group 2 (p<0.05 for both groups).
  
  
  CONCLUSIONS
  VNS appears to offer protection against acute ischemic brain injury.
authors.affiliation: MGH/MIT/HMS A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital-East, 149 13th Street, Charlestown, MA O2129, USA. iay@partners.org
authors.forename: Ilknur
authors.initials: I
authors.lastname: Ay
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
authors.forename: Hakan
authors.initials: H
authors.lastname: Ay
authors.forename: A
authors.initials: A
authors.lastname: Gregory Sorensen
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure; D001921:Brain / Q000473:pathology*; D004567:Electrodes, Implanted; D006339:Heart Rate; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology* / Q000628:therapy*; D002546:Ischemic Attack, Transient / Q000473:pathology* / Q000628:therapy*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function; D015427:Reperfusion Injury / Q000473:pathology / Q000628:therapy; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D055536:Vagus Nerve Stimulation / Q000379:methods