How do deficits in neuronal growth, aging or synaptic function affect the final, mechanical output of a single muscle twitch? We address this in vivo (indeed in situ) with a novel ergometer that records the output of a large specialised muscle, the Drosophila jump muscle. Here, we describe in detail the ergometer, its construction and use. We evaluated the ergometer by showing that adult fly jump muscle output varies little between 3 h and 7 days; but newly eclosed flies produce only 65%. In a mutant with little octopamine (Tbetah), jump muscle performance is reduced by 28%. The initial responses of synaptic growth mutants (highwire and spinster) do not differ from wild type, as expected on the homeostatic hypothesis. However, responses in highwire mutations gradually decline following repeated stimuli, suggesting physiological as well as anatomical abnormalities. We conclude that the assay is robust, sensitive and reliable with a good throughput.

中文翻译：

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用测力计测量野生型和突变果蝇中单个抽搐肌肉的神经肌肉控制。

神经元生长、衰老或突触功能的缺陷如何影响单次肌肉抽搐的最终机械输出？我们使用一种新型测力计在体内（实际上是在原位）解决了这个问题，该测力计记录了大型专门肌肉（果蝇跳跃肌肉）的输出。在这里，我们详细描述了测力计、它的构造和使用。我们通过显示成年苍蝇跳跃肌肉输出在 3 小时到 7 天之间几乎没有变化来评估测力计；但新封闭的苍蝇只产生 65%。在含有少量章鱼胺 (Tbetah) 的突变体中，跳跃肌肉性能降低了 28%。正如稳态假设所预期的那样，突触生长突变体（高线和老处女）的初始反应与野生型没有区别。然而，高线突变的反应在反复刺激后逐渐下降，提示生理和解剖异常。我们得出的结论是，该测定是稳健、灵敏且可靠的，具有良好的吞吐量。