Photoactivated voltage imaging in tissue with an archaerhodopsin-derived reporter
Miao Ping Chien (Erasmus MC, Harvard University, TU Delft - Applied Sciences, Oncode Institute)
Daan Brinks (TU Delft - ImPhys/Microscopy Instrumentation & Techniques, Harvard University, Erasmus MC)
Guilherme Testa-Silva (Howard Hughes Medical Institute, Cambridge, Harvard University)
He Tian (Harvard University)
F. Phil Brooks (Harvard University)
Yoav Adam (Harvard University)
William Bloxham (Harvard University)
Benjamin Gmeiner (Harvard University)
Simon Kheifets (Harvard University)
A.E. Cohen (Harvard University, Howard Hughes Medical Institute, Cambridge)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Photoactivated genetically encoded voltage indicators (GEVIs) have the potential to enable optically sectioned voltage imaging at the intersection of a photoactivation beam and an imaging beam. We developed a pooled high-throughput screen to identify archaerhodopsin mutants with enhanced photoactivation. After screening ~105 cells, we identified a novel GEVI, NovArch, whose one-photon near-infrared fluorescence is reversibly enhanced by weak one-photon blue or two-photon near-infrared excitation. Because the photoactivation leads to fluorescent signals catalytically rather than stoichiometrically, high fluorescence signals, optical sectioning, and high time resolution are achieved simultaneously at modest blue or two-photon laser power. We demonstrate applications of the combined molecular and optical tools to optical mapping of membrane voltage in distal dendrites in acute mouse brain slices and in spontaneously active neurons in vivo.