Ehninger Dan, Kempermann Gerd
Max Delbrück Center for Molecular Medicine (MDC), Berlin-Buch, Robert-Rössle-Strasse 10, 13125 Berlin.
Cereb Cortex. 2003 Aug;13(8):845-51. doi: 10.1093/cercor/13.8.845.
We here report that voluntary wheel running led to a regional increase in the number of newly generated cortical microglia. We asked how adult cortical cell genesis would respond to environmental enrichment and physical activity, both stimuli that robustly induce adult hippocampal neurogenesis. After labeling proliferating cells with bromodeoxyuridine (BrdU) and immunohistochemical detection of BrdU, we found that both experimental paradigms did not result in general effects on cell proliferation and cell genesis in the neocortex. However, there were regionally and layer specific changes in the number of BrdU marked cells, both 1 day and 4 weeks after BrdU. Environmental enrichment led to a significant increase in the number of new astrocytes in layer 1 of the motor cortex. Voluntary wheel running, in contrast, caused an induction in the proliferation of microglia in superficial cortical layers of several brain regions. Under no condition was the number of new oligodendrocytes measurably enhanced. In contrast to the hippocampus, we did not find any new neurons in the cortex. The physiological 'activation' of microglia adds a new aspect to the question of microglial function in the healthy brain and of how adult brain cells can plastically react to physiological stimuli.
我们在此报告，自愿性轮转运动导致新生成的皮质小胶质细胞数量在区域上增加。我们探究了成年皮质细胞生成如何对环境丰富化和体育活动作出反应，这两种刺激都能有力地诱导成年海马体神经发生。在用溴脱氧尿苷（BrdU）标记增殖细胞并对BrdU进行免疫组织化学检测后，我们发现这两种实验范式均未对新皮质中的细胞增殖和细胞生成产生总体影响。然而，在BrdU处理后的1天和4周，BrdU标记细胞的数量存在区域和层特异性变化。环境丰富化导致运动皮质第1层新星形胶质细胞数量显著增加。相比之下，自愿性轮转运动导致几个脑区皮质浅层小胶质细胞增殖增加。在任何情况下，新少突胶质细胞的数量均未显著增加。与海马体不同，我们在皮质中未发现任何新的神经元。小胶质细胞的生理性“激活”为健康大脑中小胶质细胞功能问题以及成年脑细胞如何对生理刺激产生可塑性反应增添了新的内容。
