1 Ion Channel Biology Lab, Department of Biotechnology, Indian Institute of Technology Hyderabad , Kandi, India .
2 Molecular Engineering and Imaging Lab, School of Biological Sciences, Dr. Harisingh Gour Central University , Sagar, India .
Zebrafish. 2018 Jun;15(3):254-262. doi: 10.1089/zeb.2017.1545. Epub 2018 Mar 13.
For the assessment of cardiac function, heartbeat represents one key parameter. Current methods of heartbeat measurements in the zebrafish larvae usually require larval immobilization, fluorescent transgenic strains and a confocal microscope, costly commercial software for analysis, or strong programming skills if the software is open-source. Here, we present a simple yet powerful method of heartbeat analysis using untethered, unlabeled zebrafish larva using ImageJ (open-source software), which does not require programming skills. We named it as ZebraPace for Zebrafish Precise Algorithm for Cardiac-rhythm Estimation. ZebraPace works directly with AVI videos and requires no image processing steps. ZebraPace uses pixel intensity change in a grayscale video to count the number of beats. We have validated the ZebraPace method by pharmacological alterations of the heartbeat in zebrafish larvae of 48 and 72 hpf stages. We have also determined beat-to-beat interval, which relates to rhythmicity of heartbeat. The results obtained by using ZebraPace corroborates well with the heartbeat values previously reported for similarly aged larvae as determined by using specialized software. We believe that the ZebraPace method is simple, cost-effective, and easy to grasp as it involves fewer steps. It not only reduces the manual workload but also eliminates sample preparation time and researcher subjectivity.
对于心脏功能的评估，心跳是一个关键参数。目前测量斑马鱼幼体心跳的方法通常需要幼体固定、荧光转基因品系和共聚焦显微镜、昂贵的商业分析软件，或者如果软件是开源的，则需要较强的编程技能。在这里，我们使用 ImageJ（开源软件）展示了一种使用未系绳、未标记的斑马鱼幼体进行简单而强大的心跳分析方法，该方法不需要编程技能。我们将其命名为 ZebraPace，用于斑马鱼精确心脏节律估计算法。ZebraPace 可直接处理 AVI 视频，并且不需要图像处理步骤。ZebraPace 使用灰度视频中的像素强度变化来计算心跳次数。我们通过药理学改变 48 和 72 hpf 阶段斑马鱼幼体的心跳来验证 ZebraPace 方法。我们还确定了心跳间隔，它与心跳的节律性有关。使用 ZebraPace 获得的结果与使用专门软件确定的类似年龄幼体的心跳值非常吻合。我们认为 ZebraPace 方法简单、经济高效，易于掌握，因为它涉及的步骤较少。它不仅减少了手动工作量，而且消除了样品制备时间和研究人员的主观性。
