title: Amount but not pattern of protective sensory stimulation alters recovery after permanent middle cerebral artery occlusion.
abstract: OBJECTIVE
  Using a rodent model of ischemia (permanent middle cerebral artery occlusion), our laboratory previously demonstrated that 4.27 minutes of patterned single-whisker stimulation delivered over 120 minutes can fully protect from impending damage when initiated within 2 hours of permanent middle cerebral artery occlusion ("early"). When initiated 3 hours postpermanent middle cerebral artery occlusion ("late"), stimulation resulted in irreversible damage. Here we investigate the effect of altering pattern, distribution, or amount of stimulation in this model.
  
  
  METHODS
  We assessed the cortex using functional imaging and histological analysis with altered stimulation treatment protocols. In 2 groups of animals we administered the same number of whisker deflections but in a random rather than patterned fashion distributed either over 120 minutes or condensed into 10 minutes postpermanent middle cerebral artery occlusion. We also tested increased (full-whisker array versus single-whisker) stimulation.
  
  
  RESULTS
  Early random whisker stimulation (condensed or dispersed) resulted in protection equivalent to early patterned stimulation. Early full-whisker array patterned stimulation also resulted in complete protection but promoted faster recovery. Late full-whisker array patterned stimulation, however, resulted in loss of evoked function and infarct volumes larger than those sustained by single-whisker counterparts.
  
  
  CONCLUSIONS
  When induced early on after ischemic insult, stimulus-evoked cortical activity, irrespective of the parameters of peripheral stimulation that induced it, seems to be the important variable for neuroprotection.
authors.affiliation: University of California-Irvine, 2205 McGaugh Hall, Ring Road, Department of Neurobiology & Behavior, UCI, Irvine CA 92697, USA.
authors.forename: Melissa F
authors.initials: MF
authors.lastname: Davis
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Lay
authors.forename: Cynthia H
authors.initials: CH
authors.lastname: Chen-Bee
authors.forename: Ron D
authors.initials: RD
authors.lastname: Frostig
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D020244:Infarction, Middle Cerebral Artery / Q000503:physiopathology* / Q000517:prevention & control*; D008297:Male; D010812:Physical Stimulation / Q000379:methods; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D013997:Time Factors; D014110:Touch / Q000502:physiology*; D014738:Vibrissae / Q000502:physiology*