Macleod Gregory T
Cold Spring Harb Protoc. 2012 Jul 1;2012(7):797-801. doi: 10.1101/pdb.prot070102.
Calcium imaging is a technique in which Ca(2+)-binding molecules are loaded into live cells and as they bind Ca(2+) they "indicate" the concentration of free calcium through a change in either the intensity or the wavelength of light emitted (fluorescence or bioluminescence). There are several possible methods for loading synthetic Ca(2+) indicators into subcellular compartments, including topical application of membrane-permeant Ca(2+) indicators, forward-filling of dextran conjugates, and direct injection. Calcium imaging is a highly informative technique in neurobiology because Ca(2+) is involved in many neuronal signaling pathways and serves as the trigger for neurotransmitter release. This article describes the direct injection of Ca(2+) indicators at the Drosophila larval neuromuscular junction (NMJ). This technique allows rapid loading of most Ca(2+) indicators, but there are drawbacks in that it is a difficult technique to master and requires additional electrophysiological equipment. Also, Ca(2+) indicators that are easily injected are usually susceptible to compartmentalization.
钙成像技术是一种将钙离子结合分子导入活细胞的技术，当这些分子与钙离子结合时，它们会通过发射光（荧光或生物发光）的强度或波长变化来“指示”游离钙的浓度。将合成钙离子指示剂导入亚细胞区室有几种可能的方法，包括局部应用膜通透性钙离子指示剂、葡聚糖缀合物正向填充和直接注射。钙成像在神经生物学中是一种信息丰富的技术，因为钙离子参与许多神经元信号通路，并作为神经递质释放的触发因素。本文描述了在果蝇幼虫神经肌肉接头（NMJ）处直接注射钙离子指示剂的方法。该技术能快速加载大多数钙离子指示剂，但缺点是它是一项难以掌握的技术，并且需要额外的电生理设备。此外，易于注射的钙离子指示剂通常容易出现区室化现象。
