Improved genetically encoded near-infrared fluorescent calcium ion indicators for in vivo imaging

Yong Qian, Danielle M. Orozco Cosio, Kiryl D. Piatkevich, Sarah Aufmkolk, Wan-Chi Su, Orhan T. Celiker, Anne Schohl, Mitchell H. Murdock, Abhi Aggarwal, Yu-Fen Chang, Paul W. Wiseman, Edward S. Ruthazer (+3 others)
2020 PLoS Biology  
Near-infrared (NIR) genetically encoded calcium ion (Ca2+) indicators (GECIs) can provide advantages over visible wavelength fluorescent GECIs in terms of reduced phototoxicity, minimal spectral cross talk with visible light excitable optogenetic tools and fluorescent probes, and decreased scattering and absorption in mammalian tissues. Our previously reported NIR GECI, NIR-GECO1, has these advantages but also has several disadvantages including lower brightness and limited fluorescence
more » ... luorescence response compared to state-of-the-art visible wavelength GECIs, when used for imaging of neuronal activity. Here, we report 2 improved NIR GECI variants, designated NIR-GECO2 and NIR-GECO2G, derived from NIR-GECO1. We characterized the performance of the new NIR GECIs in cultured cells, acute mouse brain slices, and Caenorhabditis elegans and Xenopus laevis in vivo. Our results demonstrate that NIR-GECO2 and NIR-GECO2G provide substantial improvements over NIR-GECO1 for imaging of neuronal Ca2+ dynamics.
doi:10.1371/journal.pbio.3000965 pmid:33232322 fatcat:xehrwqfmcvawzkdpvhy4kroa7i