Reoxygenation with 100% oxygen versus room air: late neuroanatomical and neurofunctional outcome in neonatal mice with hypoxic-ischemic brain injury

Pediatr Res. 2006 Jul;60(1):55-9. doi: 10.1203/01.pdr.0000223766.98760.88. Epub 2006 May 11.


Study investigated neuroutcome in mice subjected at 7-8 d of life to hypoxic-ischemic brain injury (HI) followed by 30 min of reoxygenation with 100% O(2) (Re-O(2)) or room air (Re-Air). At 24 h of recovery, mouse reflexes were tested. At 7 wks after HI spatial orientation and memory were assessed in the same mice. Mortality rate was recorded at 24 h and at 7 wks of recovery. In separate cohort of mice, changes in cerebral blood flow (CBF) during HI-insult and reoxygenation were recorded. Re-O(2)versus Re-Air mice exhibited significantly delayed geotaxis reflex. Adult Re-O(2)versus Re-Air mice exhibited significantly better spatial learning and orientation with strong tendency toward better preserved memory. Histopathology revealed significantly less hippocampal atrophy in Re-O(2)versus Re-Air mice. Following a hypoxia-induced hypoperfusion, Re-O(2) re-established CBF in the ipsilateral side to the prehypoxic level significantly faster than Re-Air. The mortality was higher among Re-O2 versus Re-Air mice, although, it did not reach statistical significance. Re-O(2)versus Re-Air restores CBF significantly faster and results in better late neuroutcome. However, greater early motor deficit and higher mortality rate among Re-O(2)versus Re-Air mice suggest that Re-O(2) may be deleterious at the early stage of recovery.

Publication types

  • Comparative Study

MeSH terms

  • Air*
  • Animals
  • Animals, Newborn / physiology*
  • Atrophy / pathology
  • Atrophy / physiopathology
  • Behavior, Animal / drug effects
  • Behavior, Animal / physiology
  • Female
  • Hippocampus / blood supply
  • Hippocampus / drug effects
  • Hippocampus / pathology*
  • Hippocampus / physiopathology*
  • Hypoxia-Ischemia, Brain / drug therapy*
  • Hypoxia-Ischemia, Brain / pathology
  • Hypoxia-Ischemia, Brain / physiopathology
  • Male
  • Memory / drug effects
  • Memory / physiology
  • Mice
  • Mice, Inbred C57BL
  • Oxygen / pharmacology
  • Oxygen / therapeutic use*
  • Reflex / drug effects
  • Reflex / physiology
  • Regional Blood Flow / drug effects
  • Regional Blood Flow / physiology
  • Space Perception / drug effects
  • Space Perception / physiology
  • Time Factors
  • Treatment Outcome


  • Oxygen