title: Hyperbaric oxygen therapy improves spatial learning and memory in a rat model of chronic traumatic brain injury.
abstract: 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.
authors.affiliation: Department of Medicine, LSU Health Sciences Center in New Orleans, Harvey, Louisiana 70058, USA. paulharchmd@aol.com
authors.forename: Paul G
authors.initials: PG
authors.lastname: Harch
authors.forename: Christopher
authors.initials: C
authors.lastname: Kriedt
authors.forename: Keith W
authors.initials: KW
authors.lastname: Van Meter
authors.forename: Robert James
authors.initials: RJ
authors.lastname: Sutherland
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001930:Brain Injuries / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D002560:Cerebrovascular Circulation; D002908:Chronic Disease; D003213:Conditioning, Psychological / Q000502:physiology*; D004195:Disease Models, Animal; D006931:Hyperbaric Oxygenation; D008297:Male; D008568:Memory / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D020127:Recovery of Function; D013028:Space Perception / Q000502:physiology*