Hyperbaric oxygen therapy improves spatial learning and memory in a rat model of chronic traumatic brain injury

Brain Res. 2007 Oct 12;1174:120-9. doi: 10.1016/j.brainres.2007.06.105. Epub 2007 Aug 16.


In the present experiment we use a rat model of traumatic brain injury to evaluate the ability of low-pressure hyperbaric oxygen therapy (HBOT) to improve behavioral and neurobiological outcomes. The study employed an adaptation of the focal cortical contusion model. 64 Male Long-Evans rats received unilateral cortical contusion and were tested in the Morris Water Task (MWT) 31-33 days post injury. Rats were divided into three groups: an untreated control group (N=22), an HBOT treatment group (N=19) and a sham-treated normobaric air group (N=23). The HBOT group received 80 bid, 7 days/week 1.5 ATA/90-min HBOTs and the sham-treated normobaric air group the identical schedule of air treatments using a sham hyperbaric pressurization. All rats were subsequently retested in the MWT. After testing all rats were euthanized. Blood vessel density was measured bilaterally in hippocampus using a diaminobenzadine stain and was correlated with MWT performance. HBOT caused an increase in vascular density in the injured hippocampus (p<0.001) and an associated improvement in spatial learning (p<0.001) compared to the control groups. The increased vascular density and improved MWT in the HBOT group were highly correlated (p<0.001). In conclusion, a 40-day series of 80 low-pressure HBOTs caused an increase in contused hippocampus vascular density and an associated improvement in cognitive function. These findings reaffirm the clinical experience of HBOT-treated patients with chronic traumatic brain injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal
  • Brain Injuries / pathology
  • Brain Injuries / physiopathology
  • Brain Injuries / therapy*
  • Cerebrovascular Circulation
  • Chronic Disease
  • Conditioning, Psychological / physiology*
  • Disease Models, Animal
  • Hyperbaric Oxygenation*
  • Male
  • Memory / physiology*
  • Rats
  • Rats, Long-Evans
  • Recovery of Function
  • Space Perception / physiology*