Dynamic Imaging of Mouse Embryos and Cardiodynamics in Static Culture.

The heart is a dynamic organ that undergoes rapid morphological and mechanical changes during early embryonic development. Characterizing these early moments is important for our understanding of proper embryonic development and the treatment of heart disease. Traditionally, tomographic imaging modalities and fluorescence-based microscopy are excellent approaches for visualizing structural features and gene expression patterns, respectively, and connecting aberrant gene programs to pathological phenotypes. However, these approaches typically require static samples or fluorescent markers, which can limit the amount of information we can derive from the dynamic and mechanical changes that regulate heart development. Optical coherence tomography (OCT) is unique in this context because it enables the acquisition of three-dimensional structural images and four-dimensional (3D + time) functional imaging of living mouse embryos without the need for fixation or contrast agents. In this chapter, we focus on how OCT can visualize heart morphology at different stages of development and provide cardiodynamic information to reveal the mechanical properties of the developing heart.