2017/10/27 by Miao‐Ping Chien, Chien, Miao-Ping, Daan Brinks +9
Biochemistry, Genetics and Molecular Biology · Neuroscience · #Advanced Fluorescence Microscopy Techniques #Biological Physics (physics.bio-ph) #FOS: Biological sciences #FOS: Physical sciences #Neuroscience and Neural Engineering #Photoreceptor and optogenetics research #Quantitative Methods (q-bio.QM)
paper · pdf · doi:10.48550/arxiv.1710.10080
openalex publication_date 2017/10/27 · openalex created_date 2022/10/01 · openalex updated_date 2026/07/28
Robust voltage imaging in tissue remains a technical challenge. Existing\ncombinations of genetically encoded voltage indicators (GEVIs) and microscopy\ntechniques cannot simultaneously achieve sufficiently high voltage sensitivity,\nbackground rejection, and time resolution for high-resolution mapping of\nsub-cellular voltage dynamics in intact brain tissue. We developed a pooled\nhigh-throughput screening approach to identify Archaerhodopsin mutants with\nunusual photophysical properties. After screening ~105 cells, we identified a\nnovel GEVI, NovArch, whose 1-photon near infrared fluorescence is reversibly\nenhanced by weak 2-photon excitation. Because the 2-photon excitation acts\ncatalytically rather than stoichiometrically, high fluorescence signals,\noptical sectioning, and high time resolution are achieved simultaneously, at\nmodest 2- photon laser power. We developed a microscopy system optimized for\nNovArch imaging in tissue. The combination of protein and optical engineering\nenhanced signal contrast sufficiently to enable optical mapping of\nback-propagating action potentials in dendrites in acute mouse brain slice.\n