Abstract:

BACKGROUND: Ischemic, hypoxic, hypoxia and other stimuli can lead to endogenous neural stem cell proliferation and differentiation, which play a role in brain repair, but it is still not clear whether hypoxic preconditioning can affect the proliferation of endogenous neural stem cells.
OBJECTIVE: To explore the proliferation of endogenous neural stem cells in hippocampus of hypoxic preconditioning mice.
METHODS: Balb/c clean mice were randomly divided into three groups. Mice in the hypoxia control group were placed in a wide-mouthed bottle, blocked by rubber stopper. Animals with the first asthmoid respiration marked tolerance limit of hypoxia, and once hypoxia exposure was completed. Above-mentioned procedures were repeated four times in the hypoxic preconditioning group. Mice in the normal control group were not exposed to hypoxia. The number and fluorescence intensity of BrdU-labeled cells were counted and observed by immunofluorescence and confocal laser scanning microscope.
RESULTS AND CONCLUSION: Compared with hypoxia control group, the tolerance time was significantly longer in the hypoxic preconditioning group (P < 0.01). Fluorescence intensity of BrdU-labeled endogenous neural stem cells was faint, and a few BrdU-positive cells were visible in the hippocampus in the normal control group. The fluorescence intensity and BrdU-positive cell number were significantly increased in the hypoxia control and hypoxic preconditioning groups (P < 0.01). The increased range was greater in the hypoxic preconditioning group compared with the hypoxia control group (P < 0.01). Results suggest that proliferation of endogenous neural stem cells is seen obviously in hippocampus of hypoxic preconditioning mice, which is perhaps involved in cerebral protective mechanism of hypoxic preconditioning.