Kilohertz 3D Optical Mapping of Atrial Fibrillation in Beating Zebrafish Hearts

项目概述：心房颤动（AF）是最常见的心律失常，是心脏病的主要危险因素。 缺血性中风，并引起发病率和死亡率沿着显著的经济负担。虽然AF 在各种动物的研究中，胚胎斑马鱼一直是遗传上易于控制的， 透明模型，以研究心脏发育过程中的机电耦合。就像人类一样， 动作电位和随之而来的心肌收缩也是心脏功能的关键指标， 斑马鱼由于其透明性，光学测绘已成为研究其相互作用的主要手段 探讨心房颤动的发生机制。 电和机械耦合的失调是发病机制的重要因素， 在斑马鱼机电解耦的光学映射是不平凡的，因为它需要 同时记录快速传播的电压波和心肌收缩。尤其是在殴打的时候 心脏，快速的心肌收缩很容易使图像模糊-运动伪影掩盖了波 这可能会影响光学地图中出现的图案，并可能阻止对成像数据的进一步分析。药理 解耦已被广泛用于抑制心脏运动。然而，这使得研究机电 耦合不可能。可替代地，采集后同步方法记录电影的z堆栈，每个 覆盖至少一个心动周期。记录完成后，可以重建一个3D心动周期 通过同步电影的时间。然而，这种方法不适用于非周期性运动， 因此，存在开发创新的光学技术以 快速和不规则跳动的AF心脏中机电耦合的高速3D标测。 为了解决这一问题，我们提出了一种光片光场层析成像技术 进行AF的斑马鱼心脏机电耦合的千赫3D成像。我们的方法只有 最近由于两种新兴技术，光场层析成像（LIFT）和光片成像， 显微镜，我们在这两方面都拥有丰富的经验。我们将把LIFT与光片显微镜结合起来 并以前所未有的体积帧速率实现高分辨率3D成像。所产生的系统，光- 片LIFT，将提供足够的时空分辨率，以充分描绘电压波之间的相互作用， 心肌收缩和心内血流。我们期望我们 该方法将促进从单个心房肌电活动的基本机制的理解， 细胞水平。

Project Summary: Atrial fibrillation (AF) is the most frequent cardiac arrhythmia, and it is a major risk factor for ischemic stroke and provokes morbidity and mortality along with a significant economic burden. Although AF has been studied in various animals, the embryonic zebrafish has been the genetically tractable and optically transparent model to investigate electromechanical coupling during cardiac development. Like in humans, the action potential and the consequent myocardial contraction are also key indicators of cardiac function in the zebrafish. By virtual of its transparency, optical mapping has been a primary means to investigate the interplay between cardiac action potential and myocardial contraction to study the mechanisms of AF. Dysregulation of electrical and mechanical coupling is a significant factor underlying the pathogenesis and perpetuation of AF. Optical mapping of electromechanical decoupling in zebrafish is nontrivial because it requires simultaneous recording of fast propagating voltage waves and myocardial contraction. Particularly in a beating heart, the rapid myocardial contraction can easily blur the image—the motion artifacts superimpose the wave patterns appearing in the optical maps and can prohibit further analysis of the imaging data. Pharmacological uncoupling has been widely used to suppress heart motion. However, this makes studying electromechanical coupling impossible. Alternatively, post-acquisition synchronization approach records a z-stack of movies, each covering at least one cardiac cycle. After the recording is completed, one 3D cardiac cycle can be reconstructed by synchronizing the movies in time. Nonetheless, this method is inapplicable to nonperiodic movements, such as irregular heartbeats with AF. Therefore, there is an unmet need to develop innovative optical techniques for high-speed 3D mapping of electromechanical coupling in a rapidly and irregularly beating AF heart. To solve this problem, we propose to develop a light-sheet light-field tomography (light-sheet LIFT) technique for kilohertz 3D imaging of electromechanical coupling in zebrafish hearts undergoing AF. Our method has only recently become possible due to two emerging technologies, light-field tomography (LIFT) and light-sheet microscopy, both of which we have extensive experience with. We will integrate LIFT with light-sheet microscopy and enable high-resolution 3D imaging with an unprecedented volumetric frame rate. The resultant system, light- sheet LIFT, will provide enough spatiotemporal resolution to fully depict the interplay between voltage waves, myocardial contraction, and intracardiac blood flow in a pitx2c zebrafish arrhythmia model. We expect our method will advance the understanding of AF's fundamental mechanism from the electrical activities at a single- cell level.