Effects of hyperbaric oxygen therapy on the expression level of brain-derived neurotrophic factor after traumatic brain injury in rats

Objective To observe the effect of hyperbaric oxygen(HBO) treatment on the expression of brain-derived neurotrophic factor(BDNF) in cerebral cortex and hippocampus of adult rats with lateral fluid percussion attack.Methods Thirty-two male Wistar rats were divided into brain-injured group and control group with 16 rats in each group.Lateral brain injury model was established in the brain-injured group by fluid percussion attack machine and those rats were divided into two subgroups to be exposed in HBO and nonpressurized air respectively with eight rats in each subgroup.Heads were cut and brains were taken after five days.The morphological changes in cerebral cortex and hippocampus of the brain specimens were observed with electron microscope and the expressions of BDNF were detected with immunohistochemistry.Results There was no significant difference in the number of BDNF positive cells among each normal control groups(P 0.05).But there were more BDNF positive cells in HBO exposed injury group than that in nonpressurized air exposed group(P 0.01),and BDNF positive cells in nonpressurized air exposed group were more than that in normal control group(P 0.01).Conclusion The expression of BDNF in the cortex and hippocampus can be up-regulated by brain injury,which may be further up-regulated by HBO.