快速老化与正常老化小鼠脑内神经干细胞增殖的差异**★

背景：在老化过程中，脑内环境改变可引起脑内神经干细胞增殖能力改变。脑内神经干细胞与衰老和退行性神经病变疾病密切相关，增殖能力与年龄存在负相关，但以快速老化小鼠为衰老模型的相关研究未见报道。 目的：比较快速老化与正常老化小鼠嗅球、海马、皮质神经干细胞增殖的差异。 方法：分别取6只快速老化小鼠(SAMP8)和6只正常老化小鼠(SAMR1)的嗅球、海马、皮质组织，在固定、冰冻切片后，运用Ki-67/Nestin免疫荧光双标检测3个脑区的神经干细胞增殖情况。免疫荧光双标在荧光显微镜下通过Leica Qwin v3采图，在40倍物镜和10倍目镜下采图，每一张切片随机选取5 个相邻视野，通过Image-pro-Plus软件完成图像分析。 结果与结论：正常老化小鼠和快速老化小鼠均有神经干细胞增殖现象，但二者存在差异，其差异主要表现在海马和嗅球两个脑区(P < 0.05)。提示快速老化可能会导致海马、嗅球神经干细胞增殖能力降低。

Differences in neural stem cells proliferation between normal senescence and senescence-accelerated mice

BACKGROUND: In the aging process, the changes of environment in the brain can cause changes in proliferation ability of brain neural stem cells. The neural stem cells are closely associated with senescence and neurodegenerative diseases. Proliferation ability is negatively correlated with age. However, no reports have addressed that senescence-accelerated mice served as senescence models. OBJECTIVE: To investigate the differences of neural stem cells proliferation between normal senescence and senescence-accelerated mouse in hippocampus, olfactory bulb and cortex. METHODS: The hippocampus, olfactory bulb and cortex were obtained from 6 senescence-accelerated mice (senescence-accelerated mouse prone 8) and 6 normal senescence mice (senescence-accelerated mouse/resistance 1). Following frozen section, Ki-67/Nestin immunofluorescence double labeling methods were used to detect the proliferation of neural stem cells in hippocampus, olfactory bulb and cortex. Pictures of immunofluorescence double labeling were taken through Leica Qwin v3 under a fluorescence microscope. Using 40× object lens and 10× eyelens, five consecutive visual fields were selected from each section, and image analysis was conducted using Image-pro-Plus software. RESULTS AND CONCLUSION: The proliferation of neural stem cells could be found both in normal senescence and senescence-accelerated mice, but there were differences, mainly in the hippocampus and olfactory bulb (P < 0.05). Results indicated that senescence-accelerated might result in low ability of neural stem cells proliferation in hippocampus and olfactory bulb.