title: Improved PeT molecules for optically sensing voltage in neurons.
abstract: VoltageFluor (VF) dyes have the potential to measure voltage optically in excitable membranes with a combination of high spatial and temporal resolution essential to better characterize the voltage dynamics of large groups of excitable cells. VF dyes sense voltage with high speed and sensitivity using photoinduced electron transfer (PeT) through a conjugated molecular wire. We show that tuning the driving force for PeT (ΔGPeT + w) through systematic chemical substitution modulates voltage sensitivity, estimate (ΔGPeT + w) values from experimentally measured redox potentials, and validate the voltage sensitivities in patch-clamped HEK cells for 10 new VF dyes. VF2.1(OMe).H, with a 48% ΔF/F per 100 mV, shows approximately 2-fold improvement over previous dyes in HEK cells, dissociated rat cortical neurons, and medicinal leech ganglia. Additionally, VF2.1(OMe).H faithfully reports pharmacological effects and circuit activity in mouse olfactory bulb slices, thus opening a wide range of previously inaccessible applications for voltage-sensitive dyes.
authors.affiliation: Departments of Chemistry and Biochemistry, ‡Pharmacology, §Neurosciences Graduate Group, ∥Division of Biological Sciences, ⊥Biomedical Sciences, and #Howard Hughes Medical Institute, University of California, San Diego , La Jolla, California 92093, United States.
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Woodford
authors.forename: E Paxon
authors.initials: EP
authors.lastname: Frady
authors.forename: Richard S
authors.initials: RS
authors.lastname: Smith
authors.forename: Benjamin
authors.initials: B
authors.lastname: Morey
authors.forename: Gabriele
authors.initials: G
authors.lastname: Canzi
authors.forename: Sakina F
authors.initials: SF
authors.lastname: Palida
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Araneda
authors.forename: William B
authors.initials: WB
authors.lastname: Kristan
authors.forename: Clifford P
authors.initials: CP
authors.lastname: Kubiak
authors.forename: Evan W
authors.initials: EW
authors.lastname: Miller
authors.forename: Roger Y
authors.initials: RY
authors.lastname: Tsien
mesh_terms: D000818:Animals; D015195:Drug Design; D004579:Electron Transport; D055724:Electrophysiological Phenomena; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D057809:HEK293 Cells; D006801:Humans; D008027:Light; D008564:Membrane Potentials; D051379:Mice; D009474:Neurons / Q000737:chemistry / Q000166:cytology*; D009830:Olfactory Bulb / Q000166:cytology; D061848:Optical Imaging; D055620:Optical Phenomena; D051381:Rats
chemical_list: D005456:Fluorescent Dyes