Abstract

Genetically encoded calcium indicators (GECIs) allow measurement of activity in large populations of neurons and in small neuronal compartments, over times of milliseconds to months. Although GFP-based GECIs are widely used for in vivo neurophysiology, GECIs with red-shifted excitation and emission spectra have advantages for in vivo imaging because of reduced scattering and absorption in tissue, and a consequent reduction in phototoxicity. However, current red GECIs are inferior to the state-of-the-art GFP-based GCaMP6 indicators for detecting and quantifying neural activity. Here we present improved red GECIs based on mRuby (jRCaMP1a, b) and mApple (jRGECO1a), with sensitivity comparable to GCaMP6. We characterized the performance of the new red GECIs in cultured neurons and in mouse, Drosophila, zebrafish and C. elegans in vivo. Red GECIs facilitate deep-tissue imaging, dual-color imaging together with GFP-based reporters, and the use of optogenetics in combination with calcium imaging.

Article and author information

Author details

  1. Hod Dana

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  2. Boaz Mohar

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  3. Yi Sun

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  4. Sujatha Narayan

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  5. Andrew Gordus

    Howard Hughes Medical Institute, The Rockefeller University, New York, United States
    Competing interests
    No competing interests declared.
  6. Jeremy P Hasseman

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  7. Getahun Tsegaye

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  8. Graham T Holt

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  9. Amy Hu

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  10. Deepika Walpita

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  11. Ronak Patel

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  12. John J Macklin

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  13. Cornelia I Bargmann

    Howard Hughes Medical Institute, The Rockefeller University, New York, United States
    Competing interests
    No competing interests declared.
  14. Misha B Ahrens

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  15. Eric R Schreiter

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  16. Vivek Jayaraman

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  17. Loren L Looger

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  18. Karel Svoboda

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
  19. Douglas S Kim

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    For correspondence
    kimd@janelia.hhmi.org
    Competing interests
    Douglas S Kim, The authors have applied for a patent on materials and methods related to the red GECI variants (application number US 14/974,483).

Ethics

Animal experimentation: All experimental protocols were conducted according to NationalInstitutes of Health guidelines for animal research and were approved bythe Institutional Animal Care and Use Committee at Janelia ResearchCampus (protocol 13-95).

Reviewing Editor

  1. Michael Häusser, University College London, United Kingdom

Version history

  1. Received: November 1, 2015
  2. Accepted: March 24, 2016
  3. Accepted Manuscript published: March 24, 2016 (version 1)
  4. Version of Record published: April 26, 2016 (version 2)

Copyright

© 2016, Dana et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Hod Dana
  2. Boaz Mohar
  3. Yi Sun
  4. Sujatha Narayan
  5. Andrew Gordus
  6. Jeremy P Hasseman
  7. Getahun Tsegaye
  8. Graham T Holt
  9. Amy Hu
  10. Deepika Walpita
  11. Ronak Patel
  12. John J Macklin
  13. Cornelia I Bargmann
  14. Misha B Ahrens
  15. Eric R Schreiter
  16. Vivek Jayaraman
  17. Loren L Looger
  18. Karel Svoboda
  19. Douglas S Kim
(2016)
Sensitive red protein calcium indicators for imaging neural activity
eLife 5:e12727.
https://doi.org/10.7554/eLife.12727

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