High-speed, cortex-wide volumetric recording of neuroactivity at cellular resolution using light beads microscopy

Two-photon microscopy has enabled high-resolution imaging of neuroactivity at depth within scattering brain tissue. However, its various realizations have not overcome the tradeoffs between speed and spatiotemporal sampling that would be necessary to enable mesoscale volumetric recording of neuroactivity at cellular resolution and speed compatible with resolving calcium transients. Here, we introduce light beads microscopy (LBM), a scalable and spatiotemporally optimal acquisition approach limited only by fluorescence lifetime, where a set of axially separated and temporally distinct foci record the entire axial imaging range near-simultaneously, enabling volumetric recording at 1.41 x 10(8) voxels per second. Using LBM, we demonstrate mesoscopic and volumetric imaging at multiple scales in the mouse cortex, including cellular-resolution recordings within similar to 3 x 5 x 0.5 mm volumes containing >200,000 neurons at similar to 5 Hz and recordings of populations of similar to 1 million neurons within similar to 5.4 x 6 x 0.5 mm volumes at similar to 2 Hz, as well as higher speed (9.6 Hz) subcellular-resolution volumetric recordings. LBM provides an opportunity for discovering the neurocomputations underlying cortex-wide encoding and processing of information in the mammalian brain.

Automated summary

Two-photon microscopy has enabled high-resolution imaging of neuroactivity within scattering brain tissue, but there are still tradeoffs between speed and spatiotemporal sampling. Light beads microscopy (LBM) introduces a scalable and spatiotemporally optimal acquisition approach for recording neuroactivity at different scales, offering opportunities for discovering neurocomputations in the mammalian brain.