Imaging subcellular dynamics with fast and lightefficient volumetrically parallelized microscopy

In fluorescence microscopy, the serial acquisition of two-dimensional images to form a three-dimensional (3D) volume limits the maximum imaging speed. This is particularly evident when imaging adherent cells in a light-sheet fluorescence microscopy format, as their elongated morphologies require ~200 image planes per image volume. Here, by illuminating the specimen with three light sheets, each independently detected, we present a light-efficient, crosstalk- free, and volumetrically parallelized 3D microscopy technique that is optimized for high-speed (up to 14 Hz) subcellular (300 nm lateral, 600 nm axial resolution) imaging of adherent cells. We demonstrate 3D imaging of intracellular processes, including cytoskeletal dynamics in single-cell migration and collective wound healing for 1500 and 1000 time points, respectively. Furthermore, we capture rapid biological processes, including the trafficking of early endosomes with velocities exceeding 10 µm/s and calcium signaling in primary neurons.