Waxman S G, Foster R E
Proc R Soc Lond B Biol Sci. 1980 Sep 26;209(1176):441-6. doi: 10.1098/rspb.1980.0105.
Previous studies by a number of workers have shown that the axon membrane in normal mature myelinated fibres is highly differentiated, with the nodal axolemma exhibiting characteristics different to those of the internodal axolemma. However, the development of this axolemmal heterogeneity has not been previously explored. In the present study we used cytochemical methods to examine the development of nodal axolemma during the differentiation of myelinated fibres in rat spinal roots. The staining properties characteristic of normal nodal membrane appear in the axon, at gaps between Schwann cells, before the development of mature compact myelin or well defined paranodal axon--Schwann cell specializations close to the region of nodal axolemmal differentiation. These results are consistent with the hypothesis that the axon membrane differentiates into nodal and internodal regions before, or early in the process of, myelination, and suggest that the differentiation of the axon membrane may provide a signal demarcating the region to be covered by the myelin-forming cell.
此前许多研究人员的研究表明，正常成熟有髓纤维中的轴突膜高度分化，结区轴膜表现出与节间轴膜不同的特征。然而，这种轴膜异质性的发育此前尚未被探究。在本研究中，我们使用细胞化学方法来检查大鼠脊神经根有髓纤维分化过程中结区轴膜的发育情况。在成熟紧密髓鞘形成或靠近结区轴膜分化区域的明确的结旁轴突 - 施万细胞特化形成之前，正常结膜特有的染色特性就出现在轴突中施万细胞之间的间隙处。这些结果与以下假设一致，即轴突膜在髓鞘形成之前或过程早期就分化为结区和节间区，并表明轴突膜的分化可能提供一个信号，划定将被形成髓鞘的细胞覆盖的区域。
