Effects of hyperbaric oxygen on brain derived neurotrophic factor and the structure of neurons after the cerebral ischemia-reperfusion in mice

Objective To explore the effects of hyperbaric oxygen(HBO) on brain derived neurotrophic factor(BDNF) and the changes of neuron structure after cerebral ischemia-reperfusion(CIR) in mice. Methods Twenty-seven mice were randomly and evenly divided into three groups : a HBO group, a control group and a sham-operation group (SO group). CIR models were established by clamping both carotid arteries in mice for 30 min,and then, untying clamps. 0.20 MPa HBO was applied once a day for 10 days after establishment of models in HBO group,but not in the control and SO groups. Following sacrifice after treatment and acquirement of cortex and hippocamal tissues, HE stain and immunohistochemistry technique were used to observe the changes of neuron structure and expression of BDNF. Results The neural degeneration and necrosis in cortex and hippocampus (issues) were observed under light microscope after CIR, and the amount of abnormal cells in the control group was more than that in HBO group (P0.05). It is shown by the results of immunohistochemistry that the expression of BDNF in cortex and hippocampus tissues was observed in 3 groups,and compared with that in the SO group,the amount of positive cells in the HBO and control groups was increased obviously (P0.05), so was that in the HBO group with comparison with that in the control group (P0.05). Conclusion HBO could alleviate brain injury after CIR and improve the expression of BDNF significantly. The relationship between HBO and BDNF and its mechanism should be further studied.