Morphological study of rat brain neuronal cell after +Gx exposure in simulated spaceship emergency return

    XU Zhiª²Peng1£¬SUN Xiª²Qing1£¬ LIU Tingª²Song1£¬WU Bin2£¬ZHANG Shu1£¬KAN Guangª²Han2

    1Department of Aerospace Biodynamics£¬School of Aerospace Medicine,Fourth Military Medical University£¬Xi¬ðan 710033,China,2Institute of Space Medicoª²Engineering£¬Beijing 100094£¬China

    ¡¾Abstract¡¿ AIM: To investigate the morphological changes of rat brain neuronal cell after +Gx exposure in simulated spaceship emergency return.METHODS: Forty male SD rats were randomly divided into 4 groups with 10 in each: control group,7 d simulated weightlessness group,+15Gx group and +15Gx exposure after 7 d simulating weightlessness group.After undergoing +Gx stress,the rats were anatomized and morphological changes in the cerebral cortex and hippocampi were observed by microscope and electron microscope.RESULTS: There were no obvious changes in the neuronal morphology immediately after +15Gx exposure.On the first day after +15Gx exposure,there were slight changes of brain neuronal morphology,and changes became evident on the third day.The number of ischemic neurons increased on the third day after exposure.Neuron injury and ultrastructure changes were observed immediately and on the first day after simulating weightlessness for 7 d.The injuries reduced on the third day after simulating weightlessness.A number of degenerated neurons and ultrastructure change were observed in +15Gx exposure after simulating weightlessness group immediately and on the first day after stress.The injuries were aggravated and the numbers of degenerated neurons increased obviously on the third day after exposure.CONCLUSION: +15Gx/180 s exposure may induce neuron injury in rat brain, which may be aggravated after simulating weightlessness for 7 days. ......