Neuromuscular junction in abdominal muscles of Drosophila melanogaster during adulthood and aging
Neuromuscular junction in abdominal muscles of Drosophila melanogaster during adulthood and aging
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DOI：
10.1002/cne.21253
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发表时间：
2007-04-01
影响因子：
2.5
通讯作者：
Cantera, Rafael
中科院分区：
文献类型：
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作者：
Beramendi, Ana;Peron, Samantha;Cantera, Rafael
果蝇的神经肌肉接头（NMJ）是研究胚胎和幼虫突触发生、突触可塑性、囊泡再循环等突触功能的有效模型。它也有潜力的长期可塑性研究在成年生活和与衰老相关的退行性过程。在这里，我们提供了一个详细的描述的形态和超微结构的NMJ的腹背纵肌在整个成年生活从羽化到衰老。在幼虫的情况下，在这些肌肉中的主要类型的终端在成年苍蝇由只有两个或三个分支紧密包装的突触终扣。我们观察到定性和定量的变化，平均终扣大小逐渐增加，在成年期，最大的终扣存在于老飞。在成年期的大部分时间里，神经分支的长度先增加后逐渐减少。分支直径也进行性减小，但分支数目无变化。突触下网状结构逐渐变薄，在老年果蝇中发现了“裸露”的终扣。超微结构特征表明自噬、较大的突触囊泡和受损的内吞作用与年龄相关。我们建议，NMJ老化的苍蝇与受损的内吞作用和膜动力学。这一观点发现了一个功能相关的果蝇携带一个温度敏感性突变shibire可逆块内吞作用;年龄显着减少完全瘫痪所需的时间，并增加恢复的时间，从而确认囊泡动力学的年龄依赖性改变。
The neuromuscular junction (NMJ) of Drosophila melanogaster has been established as a productive model for the study of synaptogenesis, synaptic plasticity, vesicle recycling, and other synaptic functions in embryos and larvae. It also has potential for the study of long-term plasticity during adult life and degenerative processes associated with aging. Here we provide a detailed description of the morphology and ultrastructure of the NMJ on abdominal dorsal longitudinal muscles throughout adult life from eclosion to senescence. In contrast to the case in the larva, the predominant type of terminals in these muscles in the adult fly consists of only two or three branches with tightly packed synaptic boutons. We observed qualitative and quantitative changes as mean bouton size increased gradually during adulthood, and the largest boutons were present in the old fly. The length of nerve branches first increased and thereafter decreased gradually during most of adult life. Branch diameter also decreased progressively, but branch number did not change. The subsynaptic reticulum became progressively thinner, and "naked" boutons were found in old flies. Ultrastructural traits gave indications of an age-associated increment in autophagy, larger synaptic vesicles, and impaired endocytosis. We propose that NMJ aging in the fly correlates with impaired endocytosis and membrane dynamics. This view finds a functional correlate in flies carrying a temperature-sensitive mutation in shibire that reversible blocks endocytosis; age significantly reduces the time required for complete paralysis and increases the time of recovery, thus confirming the age-dependent alteration in vesicle dynamics.