Bright and fast multicoloured voltage reporters via electrochromic FRET

Nat Commun. 2014 Aug 13;5:4625. doi: 10.1038/ncomms5625.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Action Potentials / physiology*
  • Amino Acid Sequence
  • Animals
  • Cells, Cultured
  • Color*
  • Fluorescence Resonance Energy Transfer / methods*
  • HEK293 Cells
  • Hippocampus / cytology
  • Humans
  • Kidney / cytology
  • Kidney / physiology
  • Luminescent Proteins / analysis
  • Luminescent Proteins / chemistry
  • Luminescent Proteins / physiology*
  • Molecular Sequence Data
  • Neurons / cytology
  • Neurons / physiology*
  • Rats
  • Rhodopsin

Substances

  • Luminescent Proteins
  • Rhodopsin