Schwann cells and oligodendrocytes read distinct signals in establishing myelin sheath thickness
Schwann cells and oligodendrocytes read distinct signals in establishing myelin sheath thickness
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DOI：
10.1002/jnr.1179
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发表时间：
2001-09-15
影响因子：
4.2
通讯作者：
Lazzarini, RA
中科院分区：
文献类型：
--
作者：
Elder, GA;Friedrich, VL;Lazzarini, RA
雪旺细胞和少突胶质细胞产生大小差别很大的髓鞘。这些细胞如何决定特定轴突髓鞘的大小还不完全清楚。轴突直径一直被怀疑是这一过程中的一个信号。我们分析了一系列小鼠突变体的L5腰椎根髓鞘厚度和脊髓白质，这些突变体由于神经丝（NFs）缺乏而导致轴突直径减少。在PNS中，NF突变体的平均轴突直径减少了20-37%。值得注意的是，髓鞘的平均厚度与对照组相比没有变化，回归分析显示，对于给定大小的轴突，髓鞘异常厚。这些数据表明，基因诱导的轴突直径减少不会导致PNS中髓鞘厚度的减少，并表明雪旺细胞在轴突上读取一些可以与轴突直径分离的内在信号。有趣的是，这些动物脊髓中的髓鞘并没有异常厚，这表明轴突直径可能直接参与中枢神经系统髓鞘形成的调节，并且少突胶质细胞和雪旺细胞使用不同的线索来设定髓鞘厚度。j . >。参考文献65:493-499,2001。(C) 2001 Wiley-Liss, Inc。
Schwann cells and oligodendrocytes produce myelin sheaths of widely varying sizes. How these cells determine the size of myelin sheath for a particular axon is incompletely understood. Axonal diameter has long been suspected to be a signal in this process. We have analyzed myelin sheath thickness in L5 lumbar root and spinal cord white matter of a series of mouse mutants with diminished axonal calibers resulting from a deficiency of neurofilaments (NFs). In the PNS, average axonal diameters were reduced by 20-37% in the NF mutants. Remarkably, the average myelin sheath thickness remained unchanged from control values, and regression analysis showed sheaths abnormally thick for a given size of axon. These data show that a genetically induced reduction in axonal caliber does not cause a reduction in myelin sheath thickness in PNS and indicate that Schwann cells read some intrinsic signal on axons that can be uncoupled from axonal diameter. Interestingly, myelin sheaths in the spinal cord of these animals were not abnormally thick, arguing that axonal diameter may contribute directly to the regulation of myelination in the CNS and that oligodendrocytes and Schwann cells use different cues to set myelin sheath thickness. J. Neurosci. Res. 65:493-499, 2001. (C) 2001 Wiley-Liss, Inc.