title: Posthypoxic moderate hypothermia improves electrophysiological recovery in the rat hippocampal slice.
abstract: BACKGROUND
  Animal studies have shown that prehypoxic or intrahypoxic hypothermia is protective against hypoxic neuronal injury, whereas posthypoxic hypothermia produced divergent findings. This study examined the protective effects of posthypoxic hypothermia on the electrophysiological recovery in the rat hippocampal slice.
  
  
  METHODS
  Eighty-three male Sprague-Dawley rats were used after approval of the Institutional Animal Care and Use Committee. Hippocampal slices were obtained and electrophysiological recordings from the CA1 pyramidal cell layer were used as an indicator of cell function. Moderate hypothermia (30°C) was used for only 30 minutes after hypoxia in the study group, whereas normothermia was maintained throughout the experiment in the control group. Three different periods of hypoxia were used (3, 3.5, and 4 min). Recovery was measured as the ratio of the amplitude of the population spike at the end of 2 hours of recovery to that of the baseline that was obtained immediately before hypoxia.
  
  
  RESULTS
  Posthypoxic hypothermia improved electrophysiological recovery in slices exposed to 3 minutes of hypoxia but not in those exposed to 3.5 or 4 minutes of hypoxia.
  
  
  CONCLUSIONS
  Moderate hypothermia (30°C) applied after hypoxia is protective against short periods (3 min) of hypoxia but not after slightly longer periods (3.5 or 4 min) of hypoxia.
authors.affiliation: Department of Anesthesiology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA. jcharchaflieh@downstate.edu
authors.forename: Jean G
authors.initials: JG
authors.lastname: Charchaflieh
authors.forename: Hector
authors.initials: H
authors.lastname: Torres
authors.forename: James E
authors.initials: JE
authors.lastname: Cottrell
authors.forename: Ira S
authors.initials: IS
authors.lastname: Kass
mesh_terms: D000818:Animals; D001831:Body Temperature; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000187:drug effects; D055724:Electrophysiological Phenomena; D006624:Hippocampus / Q000503:physiopathology*; D007036:Hypothermia, Induced; D002534:Hypoxia, Brain / Q000503:physiopathology* / Q000628:therapy*; D066298:In Vitro Techniques; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D017966:Pyramidal Cells / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function