Martini R
Swiss Federal Institute of Technology Zürich.
Glia. 1994 Apr;10(4):311-4. doi: 10.1002/glia.440100409.
The expression of the adhesion molecules N-CAM (neural cell adhesion molecule), L1, myelin-associated glycoprotein (MAG), and P0 has been investigated by postembedding-immunoelectron microscopy in spiral ganglia of adult mice in which both axons and neuronal cell bodies are myelinated. L1 was absent from both axonal and perikaryal myelin of spiral ganglion neurons but was expressed on unmyelinated nerve fibers. P0 was expressed in compacted parts of both types of myelin but was absent from non-compacted myelin. MAG was not detectable in perikaryal myelin but was strongly expressed in axonal myelin both periaxonally and in non-compacted regions. Conversely, N-CAM was detectable at the interface between myelin and neuronal perikarya and in non-compacted regions of perikaryal myelin, whereas it was hardly detectable in axonal myelin. This inverse expression of MAG and N-CAM in perikaryal and axonal myelin points to the possibility that N-CAM may functionally replace MAG in perikaryal myelin of spiral ganglion neurons.
通过包埋后免疫电子显微镜技术，对成年小鼠螺旋神经节中轴突和神经元细胞体均有髓鞘形成的粘附分子N-CAM（神经细胞粘附分子）、L1、髓鞘相关糖蛋白（MAG）和P0的表达进行了研究。螺旋神经节神经元的轴突髓鞘和胞周髓鞘中均未检测到L1，但在无髓神经纤维上有表达。P0在两种类型髓鞘的致密部分均有表达，但在非致密髓鞘中未检测到。在胞周髓鞘中未检测到MAG，但在轴突髓鞘的轴周和非致密区域均有强烈表达。相反，在髓鞘与神经元胞周的界面以及胞周髓鞘的非致密区域可检测到N-CAM，而在轴突髓鞘中几乎检测不到。MAG和N-CAM在胞周髓鞘和轴突髓鞘中的这种反向表达表明，N-CAM可能在功能上替代螺旋神经节神经元胞周髓鞘中的MAG。
