GLIAL INFLUENCES ON AXONAL GROWTH IN THE PRIMARY OLFACTORY SYSTEM
GLIAL INFLUENCES ON AXONAL GROWTH IN THE PRIMARY OLFACTORY SYSTEM
复制标题
DOI：
10.1002/glia.440030602
复制
发表时间：
1990-01-01
期刊：
影响因子：
6.2
通讯作者：
DOUCETTE, R
中科院分区：
文献类型：
--
作者：
DOUCETTE, R
哺乳动物嗅觉上皮的神经发生贯穿其整个生命周期，在第一颅神经损伤后，这些新形成的嗅觉受体神经元的轴突生长到目标组织中，而不是成熟细胞的再生轴突。这些轴突能够进入并在成年动物的中枢神经系统内生长，而不像受伤的背根再生的轴突，它们中的大多数不能深入脊髓。嗅觉轴突如此成功地进入中枢神经系统的一个原因可能是，至少部分是由于它们被一种胶质细胞（鞘细胞）包裹着，这种胶质细胞表达了星形胶质细胞和雪旺细胞的表型特征。鞘细胞和未成熟嗅觉受体神经元的质膜中同时存在L1/Ng - CAM和N - CAM，使得嗅觉轴突能够利用胶质细胞表面作为生长的基质。鞘细胞也可能合成和分泌层粘连蛋白，从而为嗅觉轴突提供额外的粘附底物，以及胶质细胞衍生的连接蛋白和神经生长因子，这两者都是神经促进剂。
Neurogenesis in the olfactory epithelium continues throughout the entire life of mammals, and it is the axons of these newly formed olfactory receptor neurons that grow into the target tissue after the first cranial nerve is injured, not the regenerating axons of mature cells. These axons are able to enter and grow within the CNS of adult animals, unlike regenerating axons in injured dorsal roots, the majority of which are prevented from penetrating very far into the spinal cord. One reason why the olfactory axons are so successful in entering the CNS may be due, at least partially, to the fact that they are ensheathed by a type of glial cell (the ensheathing cell) that expresses phenotypic features of both astrocyte and Schwann cells. The presence of both L1/Ng‐CAM and N‐CAM in the plasma membranes of both ensheathing cells and immature olfactory receptor neurons would enable the olfactory axons to use the glial cell surfaces as a substratum on which to grow. It is probably also true that ensheathing cells synthesize and secrete laminin, thus providing an additional adhesive substrate for the olfactory axons, as well as glia‐derived nexin and nerve growth factor, both of which are neuritepromoting agents.