Voltage imaging with periodic structured illumination.

We utilize periodic structured illumination with pseudo-HiLo (pHiLo) image reconstruction for in vivo voltage imaging. We demonstrate reduced signal from out-of-focus cells, which contaminates voltage activity for in-focus cells of interest, with pHiLo compared to traditional widefield recordings taken with uniform illumination and pseudo-widefield (pWF) reconstructions. We compare spike peak-to-noise ratio (PNR) and cell-background correlation for time courses extracted using pHiLo and soma-targeted widefield illumination (TI). We discuss tradeoffs between out-of-focus light reduction, signal-to-noise ratio, and temporal resolution for pHiLo in the context of high-speed voltage imaging in awake mice.