Landmesser L, Dahm L, Tang J C, Rutishauser U
Department of Physiology and Neurobiology, University of Connecticut, Storrs 06269.
Neuron. 1990 May;4(5):655-67. doi: 10.1016/0896-6273(90)90193-j.
The role of polysialic acid (PSA) during initial innervation of chick muscle was examined. Previously, the adhesion molecules L1 and N-CAM were shown to be important in balancing axon-axon and axon-muscle adhesion during this process. Here we demonstrate developmental changes in the pattern of innervation that are not correlated with levels of L1 or N-CAM expression, but rather with the amount of PSA at the axon surface. Removal of PSA by a specific endoneuraminidase (Endo-N) increased axon fasciculation and reduced nerve branching. In contrast, the nerve trunk defasciculation and increased branching produced by neuromuscular activity blockade were associated with an increase in axonal PSA levels. Furthermore, Endo-N prevented these inactivity-induced effects on branching. Together these results illustrate the potential of PSA as a regulator of cell-cell interactions and provide a direct example of a molecular link between the morphogenic effects of adhesion-mediated and synaptic activity-dependent processes.
研究了多唾液酸（PSA）在鸡肌肉初始神经支配过程中的作用。此前已表明，粘附分子L1和N-CAM在此过程中对平衡轴突-轴突和轴突-肌肉粘附起着重要作用。在此我们证明，神经支配模式的发育变化与L1或N-CAM的表达水平无关，而是与轴突表面PSA的量有关。用特异性神经氨酸酶（Endo-N）去除PSA会增加轴突束集并减少神经分支。相反，神经肌肉活动阻断所产生的神经干解束集和分支增加与轴突PSA水平的升高有关。此外，Endo-N可阻止这些由无活性诱导的对分支的影响。这些结果共同说明了PSA作为细胞间相互作用调节剂的潜力，并提供了一个粘附介导的形态发生效应与突触活动依赖性过程之间分子联系的直接实例。
