Bringing laser focus to voltage imaging: Enhanced indicators and advanced scanning methods for two-photon recording of dense networks in vivo
Recording the electrical impulses of neurons with optical methods in the brain will be enormously beneficial for understanding how the healthy brain functions, as well as how diseases of the brain impact its normal function. In this project, we will develop methods to record electrical activity from many individual neurons in the brain at once and from several subcellular compartments in individual neurons. Our approach combines engineering of proteins that can report electrical impulses by emitting light and development of advanced microscopy that can capture the fast optical signals from these reporters within the brain.
Understanding precisely how neuronal circuitry processes and relays information, genetically encoded voltage indicators (GEVIs) are essential. GEVI imaging in mammalian brains with 2P (two-photon) excitation has so far been performed at frame rates too slow to track single action potentials. Thus, single-cell single-trial detection of action potentials in multiple neurons in brains by 2P imaging has not yet been achieved. Our collaborative effort aims to break these barriers in the framework of a comprehensive multi-institutional research effort to closely integrate GEVI improvement with optimization of fast 2P excitation methods, enabling fast tracking of electrical activity in dense networks of neurons with high spatial and temporal resolution.
Katalin Toth , University of Ottawa
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