Fast calcium signals in Drosophila motor neuron terminals
Fast calcium signals in Drosophila motor neuron terminals
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DOI：
10.1152/jn.00515.2002
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发表时间：
2002-11-01
影响因子：
2.5
通讯作者：
Atwood, HL
中科院分区：
文献类型：
--
作者：
Macleod, GT;Hegström-Wojtowicz, M;Atwood, HL
果蝇是神经科学家的强大模型，但生理技术还没有跟上分子遗传学的进步。我们介绍了一种可靠的测定果蝇幼虫运动神经元末梢的细胞内钙动力学，和一种新的生理解决方案，提高了幼虫制备的寿命。通过将钙指示剂通过切断的轴突加载到运动神经元终末中，我们用共聚焦显微镜获得了高信噪比，以及钙依赖性荧光变化的良好时间分辨率。我们提供了一个估计的静息细胞内钙离子浓度，第一次描述的钙动力学为一个单一的动作电位（AP），并提高分辨率的钙动力学在AP列车。在单个AP之后钙信号的非常快速的衰减（τ类似于60 ms）表明果蝇运动神经元末梢中的先前未报道的快速钙挤出机制非常适合于在驱动运动活动的高速率脉冲活动期间维持生理过程。
Drosophila is a powerful model for neuroscientists, but physiological techniques have not kept pace with advances in molecular genetics. We introduce a reliable assay for intracellular calcium dynamics in Drosophila larval motor neuron terminals, and a new physiological solution that improves the longevity of the larval preparation. By loading calcium indicators into motor neuron terminals through cut axons, we obtained a high signal-to-noise ratio with confocal microscopy, and good temporal resolution of calcium-dependent fluorescence changes. We provide an estimate for the resting intracellular calcium concentration, the first description of calcium kinetics for a single action potential (AP), and improved resolution of calcium kinetics during AP trains. The very rapid decay of the calcium signal following a single AP (tau similar to 60 ms) indicates a previously unreported fast calcium extrusion mechanism in Drosophila motor neuron terminals well suited for sustaining physiological processes during the high rates of impulse activity which drive locomotor activity.