Li Yi, Zhao Lun, Xing Xuan, Lou Shu-jie, He Cheng, Lu Chang-lin
The Second Military Medical University, Shanghai, China.
Space Med Med Eng (Beijing). 2002 Oct;15(5):374-6.
Objective. To examine the effect of electromagnetic fields (EMF) (20 Hz, 8 mT; 5 Hz, 8 mT) on the neuron-orientated differentiation of neural stem cells (NSCs) from midbrains of new-bom rats. Method. Differentiated NSCs were exposed to EMF for 2 x 15 min per day lasting for I d, 5 d, or 10 d. The sham-exposure controls were correspondingly established. Cells were fixed and processed for immunofluorescent staining using the antibody against neuron-specific marker MAP2, then the percentage of MAP2+ cells was calculated. Result. The two EMFs promoted the differentiation of a neuronal fate in different ways. Both of them came into effect even after 1 d exposure. When cells exposed to the 20 Hz EMF, the percentage of neuron-orientated cells gradually increased with longer-term exposure and the most significant effect appeared in 10 d group while that happened in 5 d group under the condition of 5 Hz EMF. The effect contrasted horizontally, significant differences between the two EMFs were observed only at 10 d groups, 20 Hz EMF having more favorable effect than 5 Hz EMF. Conclusion. 20 Hz and 5 Hz EMF could promote the differentiation of midbrain NSCs to a neuronal phenotype in different ways, suggesting that the physical induction might be another strategy to manipulate the differentiation of NSCs.
目的。研究电磁场（EMF）（20赫兹，8毫特斯拉；5赫兹，8毫特斯拉）对新生大鼠中脑来源神经干细胞（NSCs）向神经元方向分化的影响。方法。将分化的NSCs每天暴露于EMF下2×15分钟，持续1天、5天或10天。相应地设立假暴露对照组。细胞固定后，使用抗神经元特异性标志物MAP2的抗体进行免疫荧光染色处理，然后计算MAP2+细胞的百分比。结果。两种EMF以不同方式促进神经元命运的分化。即使在暴露1天后它们也都开始起作用。当细胞暴露于20赫兹EMF时，随着暴露时间延长，向神经元方向分化的细胞百分比逐渐增加，在10天组中效果最为显著，而在5赫兹EMF条件下，这种情况出现在5天组。横向对比效果，仅在10天组观察到两种EMF之间存在显著差异，20赫兹EMF的效果优于5赫兹EMF。结论。20赫兹和5赫兹EMF可以以不同方式促进中脑NSCs向神经元表型分化，表明物理诱导可能是调控NSCs分化的另一种策略。
