Flexible simultaneous mesoscale two-photon imaging of neural activity at high speeds.

Understanding brain function requires monitoring local and global brain dynamics. Two-photon imaging of the brain across mesoscopic scales has presented trade-offs between imaging area and acquisition speed. We describe a flexible cellular resolution two-photon microscope capable of simultaneous video rate acquisition of four independently targetable brain regions spanning an approximate five-millimeter field of view. With this system, we demonstrate the ability to measure calcium activity across mouse sensorimotor cortex at behaviorally relevant timescales. Functional brain imaging with two-photon microscopy is limited by a tradeoff between imaging area and acquisition speed. Here, the authors present Quadroscope, a flexible microscope which allows for simultaneous video rate acquisition of four independently targetable brain regions across 5 mm.