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

项目简介：房颤(房颤)是最常见的心律失常，也是 缺血性中风会导致发病率和死亡率，并造成重大经济负担。尽管AF有 在各种动物身上进行了研究，胚胎斑马鱼在基因上是易驯服的，在光学上是 研究心脏发育过程中机电耦合的透明模型。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，光学映射已成为研究其相互作用的主要手段 心脏动作电位与心肌收缩之间的关系，研究房颤的发生机制。 电和机械耦合的失调是导致发病和 房颤的永久存在。斑马鱼机电解耦的光学映射不是微不足道的，因为它需要 同时记录快速传播的电压波和心肌收缩。尤其是在一次殴打中 心脏，快速的心肌收缩很容易模糊图像-运动伪影叠加波 在光学地图中出现的图案，并且可能阻止对成像数据的进一步分析。药理作用 解偶联已被广泛用于抑制心脏运动。然而，这使得学习机电 联结不可能。或者，采集后同步方法记录电影的z堆栈，每个 覆盖至少一个心跳周期。记录完成后，可以重建一个3D心跳周期 通过及时同步电影。然而，这种方法不适用于非周期运动，如 房颤时心跳不规律。因此，有一个尚未得到满足的需求，开发创新的光学技术 快速不规则跳动的房颤心脏机电耦合的高速三维标测。 为了解决这个问题，我们建议开发一种光片光场层析成像(光片提升)技术 用于对经历房颤的斑马鱼心脏进行机电耦合的千赫兹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--的出现而成为可能 显微镜，我们在这两个方面都有丰富的经验。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。由此产生的系统，光- 薄片升降，将提供足够的时空分辨率来完全描述电压波之间的相互作用， Pitx2c斑马鱼心律失常模型中的心肌收缩和心内血流量。我们期待我们的 该方法将促进对房颤基本机制的认识，从单个的电活动。 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.