Detection of extracellular calcium gradients with a calcium-specific vibrating electrode.
Detection of extracellular calcium gradients with a calcium-specific vibrating electrode.
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DOI：
10.1083/jcb.110.5.1565
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发表时间：
1990-05
期刊：
影响因子：
--
通讯作者：
Jaffe LF
中科院分区：
文献类型：
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作者：
Kühtreiber WM;Jaffe LF
我们已经开发了一种振动钙特异性电极来测量微小的细胞外钙梯度，从而推断出穿过各种细胞和组织表面的钙电流模式。低电阻钙电极（通常约500 M Ω）通过正交堆叠的压电推动器振动，由阻尼方波以0.5 Hz的最佳频率驱动。电极信号的相敏检测用模拟或数字电子器件来执行。所得到的数据叠加在正在测量的制剂的视频图像上。根据背景钙浓度，这种新的设备可以容易地和可靠地测量稳定的细胞外钙浓度的差异，小到0.01%，空间和时间分辨率分别为几微米和几秒。数字版本可以达到小于1 microV的噪声水平。在探索性研究中，我们已经使用该设备来绘制和测量钙电流的模式，这些钙电流穿过生长中的岩藻卵和烟草花粉的表面，移动的阿米巴和网骨藻蛞蝓，最近受精的海鞘卵，以及肉蝇属卵泡的滋养细胞。这种方法应该很容易扩展到其他特定的离子电流。
We have developed a vibrating calcium-specific electrode to measure minute extracellular calcium gradients and thus infer the patterns of calcium currents that cross the surface of various cells and tissues. Low-resistance calcium electrodes (routinely approximately 500 M omega) are vibrated by means of orthogonally stacked piezoelectrical pushers, driven by a damped square wave at an optimal frequency of 0.5 Hz. Phase- sensitive detection of the electrode signal is performed with either analogue or digital electronics. The resulting data are superimposed on a video image of the preparation that is being measured. Depending on the background calcium concentration, this new device can readily and reliably measure steady extracellular differences of calcium concentration which are as small as 0.01% with spatial and temporal resolutions of a few microns and a few seconds, respectively. The digital version can attain a noise level of less than 1 microV. In exploratory studies, we have used this device to map and measure the patterns of calcium currents that cross the surface of growing fucoid eggs and tobacco pollen, moving amebae and Dictyostelium slugs, recently fertilized ascidian eggs, as well as nurse cells of Sarcophaga follicles. This approach should be easily extendable to other specific ion currents.