Weber, MichaelScherf, NicoMeyer, Alexander MPanáková, DanielaKohl, PeterHuisken, Jan2018-02-262017Weber, Michael, Nico Scherf, Alexander M Meyer, Daniela Panáková, Peter Kohl, and Jan Huisken. 2017. “Cell-accurate optical mapping across the entire developing heart.” eLife 6 (1): e28307. doi:10.7554/eLife.28307. http://dx.doi.org/10.7554/eLife.28307.http://nrs.harvard.edu/urn-3:HUL.InstRepos:34868784Organogenesis depends on orchestrated interactions between individual cells and morphogenetically relevant cues at the tissue level. This is true for the heart, whose function critically relies on well-ordered communication between neighboring cells, which is established and fine-tuned during embryonic development. For an integrated understanding of the development of structure and function, we need to move from isolated snap-shot observations of either microscopic or macroscopic parameters to simultaneous and, ideally continuous, cell-to-organ scale imaging. We introduce cell-accurate three-dimensional Ca2+-mapping of all cells in the entire electro-mechanically uncoupled heart during the looping stage of live embryonic zebrafish, using high-speed light sheet microscopy and tailored image processing and analysis. We show how myocardial region-specific heterogeneity in cell function emerges during early development and how structural patterning goes hand-in-hand with functional maturation of the entire heart. Our method opens the way to systematic, scale-bridging, in vivo studies of vertebrate organogenesis by cell-accurate structure-function mapping across entire organs.en-USCardiac conductionCardiologyLight sheet microscopyOrganogenesisOptical mappingimage analysisZebrafishJournal Article2018-02-2610.7554/eLife.28307