Glutamatergic synapses of Drosophila neuromuscular junctions: a high-resolution model for the analysis of experience-dependent potentiation
Glutamatergic synapses of Drosophila neuromuscular junctions: a high-resolution model for the analysis of experience-dependent potentiation
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DOI：
10.1007/s00441-006-0290-5
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发表时间：
2006-08
影响因子：
3.6
通讯作者：
C. Schuster
中科院分区：
文献类型：
--
作者：
C. Schuster
果蝇幼虫发育中的神经肌肉接头（NMJ）的谷氨酸能突触易于接近、形态简单且生理学特征明确。因此，它们作为发现目标识别、突触发生、NMJ 发育和突触可塑性的遗传和分子机制的模型系统，有着悠久且非常成功的传统。然而，由于 NMJ 的发育和活动依赖性完善是同时发生的过程，因此它们不能轻易地通过广泛应用的基因操作分开，而这些基因操作大多具有慢性影响。因此，最近的研究开始系统地将幼虫觅食行为纳入 NMJ 功能的生理和遗传分析中，以分析谷氨酸传递的潜在经验依赖性变化。这些研究表明，最近的爬行经验是 NMJ 谷氨酸能传递的有效调节剂，因为在经验依赖性突触增强的几个后续阶段的初始滞后期之后会产生高爬行活动。根据发生的时间窗口，定义了经验依赖性增强的四个不同阶段。这些增强阶段可以从最初的诱导（第一阶段）一直到先前建立的功能变化（第二阶段）的形态巩固（第三/第四阶段）。因此，这首次建立了涉及谷氨酸突触使用依赖性修饰的机制的时间层次结构。
The glutamatergic synapses of developing neuromuscular junctions (NMJ) ofDrosophilalarvae are readily accessible, morphologically simple, and physiologically well-characterized. They therefore have a long and highly successful tradition as a model system for the discovery of genetic and molecular mechanisms of target recognition, synaptogenesis, NMJ development, and synaptic plasticity. However, since the development and the activity-dependent refinement of NMJs are concurrent processes, they cannot easily be separated by the widely applied genetic manipulations that mostly have chronic effects. Recent studies have therefore begun systematically to incorporate larval foraging behavior into the physiological and genetic analysis of NMJ function in order to analyze potential experience-dependent changes of glutamatergic transmission. These studies have revealed that recent crawling experience is a potent modulator of glutamatergic transmission at NMJs, because high crawling activities result after an initial lag-phase in several subsequent phases of experience-dependent synaptic potentiation. Depending on the time window of occurrence, four distinct phases of experience-dependent potentiation have been defined. These phases of potentiation can be followed from their initial induction (phase-I) up to the morphological consolidation (phase-III/IV) of previously established functional changes (phase-II). This therefore establishes, for the first time, a temporal hierarchy of mechanisms involved in the use-dependent modification of glutamatergic synapses.