Synaptic dynamics at the neuromuscular junction: mechanisms and models.
Synaptic dynamics at the neuromuscular junction: mechanisms and models.
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神经肌肉接头处的突触动力学：机制和模型。
DOI：
10.1002/neu.480210115
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Fraser,SE
中科院分区：
文献类型：
--
作者：
VanEssen,DC;Gordon,H;Soha,JM;Fraser,SE
在发育过程中，神经肌肉接头经历一个广泛的多神经支配阶段，然后是一个大规模突触消除的阶段。在这份报告中，我们讨论了可能调解这些重要发展事件的许多关键方面的机制和相互作用。我们的重点是(1)建立一个总体的概念框架，在这个框架内可以评估许多不同的细胞相互作用和分子因素的作用，以及(2)生成计算机模拟，系统地测试不同模型在解释广泛的生物学数据方面的充分性。我们的分析表明，几种相对简单的机制都能够解释各种实验观察。另一方面，没有一种机制可以解释实验结果的全部光谱。因此，重要的是考虑基于多个机制之间的相互作用的模型。一种潜在的强大组合是基于(1)基底膜或突触后膜中的支架，它由神经末梢诱导，并通过正反馈机制起到稳定终末的作用；(2)发芽因子，其由肌肉纤维释放受到活动和其他因素的下调；(3)运动神经元的内在倾向，即在允许其他连接生长的同时退出一些连接。
During development, the neuromuscular junction passes through a stage of extensive polyinnervation followed by a period of wholesale synapse elimination. In this report we discuss mechanisms and interactions that could mediate many of the key aspects of these important developmental events. Our emphasis is on (1) establishing an overall conceptual framework within which the role of many distinct cellular interactions and molecular factors can be evaluated, and (2) generating computer simulations that systematically test the adequacy of different models in accounting for a wide range of biological data. Our analysis indicates that several relatively simple mechanisms are each capable of explaining a variety of experimental observations. On the other hand, no one mechanism can account for the full spectrum of experimental results. Thus, it is important to consider models that are based on interactions among multiple mechanisms. A potentially powerful combination is one based on (1) a scaffold within the basal lamina or in the postsynaptic membrane which is induced by nerve terminals and which serves to stabilize terminals by a positive feedback mechanism; (2) a sprouting factor whose release by muscle fibers is down‐regulated by activity and perhaps other factors; and (3) an intrinsic tendency of motor neurons to withdraw some connections while allowing others to grow.