模拟动作电位微电场效应能直接始动髓鞘化

Weak electric field effect by modeling action potential can directly initiate myelination

目的:探讨模拟动作电位微电场效应能否直接始动中枢神经轴突髓鞘化。方法:选取2根直径5μm碳纤维(中科院上海生命科学研究院神经科学研究所提供)。将正负极分别与2根碳纤维的导引铜丝相连,刺激频率1Hz,电压40mV,电流10μA,分波宽1×10-2s,1×10-3s,1×10-4s,1×10-5s4组。将碳纤维铺于神经元与胶质细胞共培养的培养皿底部,模拟神经轴索。通入1Hz,40mV,10μA的单相方波电流,30min/次,1次/d。连续10d,动态观察胶质细胞生长及包裹碳纤维情况。结果:①相差显微镜观察:波宽1×10-3s组,培养第7天,可见细胞团粘附于负极碳纤维,细胞团中生长出细胞膜样物质包绕碳纤维并沿纤维向两端延伸。波宽1×10-4s组,培养第12天始,可见小而圆的细胞靠近负极碳纤维。②SP免疫组化染色:波宽1×10-4s,1×10-3s组,有少突胶质细胞或其前体包裹碳纤维负极。结论:动作电位传导过程中造成的局部负电场能直接始动并参与中枢神经轴突髓鞘化。

AIM： To investigate if the effects of weak electric fields by modeling action potential can directly initiate myelination on axon in the central nerve system （CNS）. METHODS： Two 5 μm diameter carbon fibers were selected （provided by Department of Neurology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences）. The positive and negative poles were connected with copper wire of two carbon fibers that electrified in the way （1 Hz, 40 mV, 10μA）. There were 1×10^-2 s,1×10^-3 s, 1×10^-4 s, 1×10^-5 s wave width groups. For simulating axon, arbon fibers were equipped in the bottom of neuron-glial coculture utensil. 1 Hz, 40 mV, 10μA single phase square wave current was electrified, 30 minutes each time, once a day, for 10 days. Growth of glial cells and state of packing carbon fibers were observed dynamically. RESULTS： ①Observation under contrast phase microscope： In the 1×10^-3 s wave width group, cell masses were adhered to negative pole of carbon fiber at day 7. Cell membrane shape substance that wrapped carbon fiber and extended towards the two edges along fibers appeared in cell masses. In the 1×10^-4 s wave width group, small round cells closed to negative pole of carbon fiber at day 12. ②SP immunohistochemical staining： In 1×10^-4 s and 1×10^-3 s wave width groups, the negative carbon fiber could be wrapped by oligodendrocyte or its progenitor cells. CONCLUSION： The local negative electric field that is brought about by action potential can directly initiate and participate in myelination in the CNS.