title: Bright and fast multicoloured voltage reporters via electrochromic FRET.
abstract: Genetically encoded fluorescent reporters of membrane potential promise to reveal aspects of neural function not detectable by other means. We present a palette of multicoloured brightly fluorescent genetically encoded voltage indicators with sensitivities from 8-13% ΔF/F per 100 mV, and half-maximal response times from 4-7 ms. A fluorescent protein is fused to an archaerhodopsin-derived voltage sensor. Voltage-induced shifts in the absorption spectrum of the rhodopsin lead to voltage-dependent nonradiative quenching of the appended fluorescent protein. Through a library screen, we identify linkers and fluorescent protein combinations that report neuronal action potentials in cultured rat hippocampal neurons with a single-trial signal-to-noise ratio from 7 to 9 in a 1 kHz imaging bandwidth at modest illumination intensity. The freedom to choose a voltage indicator from an array of colours facilitates multicolour voltage imaging, as well as combination with other optical reporters and optogenetic actuators.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.
authors.forename: Peng
authors.initials: P
authors.lastname: Zou
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2G2.
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Douglass
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Hochbaum
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.
authors.forename: Daan
authors.initials: D
authors.lastname: Brinks
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Werley
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2G2.
authors.forename: D Jed
authors.initials: DJ
authors.lastname: Harrison
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2G2.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Campbell
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138.|Howard Hughes Medical Institute.
authors.forename: Adam E
authors.initials: AE
authors.lastname: Cohen
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D003116:Color; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D057809:HEK293 Cells; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000502:physiology; D008164:Luminescent Proteins / Q000032:analysis / Q000737:chemistry / Q000502:physiology*; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D051381:Rats; D012243:Rhodopsin
chemical_list: D008164:Luminescent Proteins; D012243:Rhodopsin