PT  - JOURNAL ARTICLE
AU  - Hod Dana
AU  - Boaz Mohar
AU  - Yi Sun
AU  - Sujatha Narayan
AU  - Andrew Gordus
AU  - Jeremy P. Hasseman
AU  - Getahun Tsegaye
AU  - Graham T. Holt
AU  - Amy Hu
AU  - Deepika Walpita
AU  - Ronak Patel
AU  - John J Macklin
AU  - Cornelia I. Bargmann
AU  - Misha B. Ahrens
AU  - Eric R. Schreiter
AU  - Vivek Jayaraman
AU  - Loren L. Looger
AU  - Karel Svoboda
AU  - Douglas S. Kim
TI  - Sensitive red protein calcium indicators for imaging neural activity
AID  - 10.1101/041780
DP  - 2016 Jan 01
TA  - bioRxiv
PG  - 041780
4099  - http://biorxiv.org/content/early/2016/02/29/041780.short
4100  - http://biorxiv.org/content/early/2016/02/29/041780.full
AB  - 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.