High‐Speed and Long‐Term Imaging of Cell Dynamics in the Developing Heart

Abstract

We developed in vivo image acquisition strategies and digital post‐processing algorithms to follow tissue growth and track individual cells in the developing embryonic zebrafish heart. Cardiac imaging at high spatial resolution is notoriously difficult because the heart is beating while it develops and cell velocities can be as high as 0.5 mm/s. This dynamic environment is an important epigenetic factor for the proper formation of many of the heart's features (e.g. heart tube looping, valve formation). It is therefore essential to capture both the rapid dynamics of the heartbeat and the much slower dynamics of morphogenesis. Although state of the art microscopes provide high framerate capabilities, they still suffer from the inherent limitations of three‐dimensional imaging (images must be acquired successively at multiple depths) and the increased noise level as the number of photons per pixel decreases. We address the problems of imaging at multiple time scales, in three‐dimensions, and at low signal‐to‐noise levels via a general image acquisition and processing procedure that takes advantage of the pseudo‐cyclic motion of the heart and allows us to follow cells and tissue in their native environment as they grow while the heart beats.