Open AccessA near-infrared genetically encoded calcium indicator for in vivo imaging
Author(s) -
Anton A. Shemetov,
Mikhail Monakhov,
Qinrong Zhang,
Jose Ernesto Canton-Josh,
Manish Kumar,
Maomao Chen,
Mikhail E. Matlashov,
Xuan Li,
Wei Yang,
Liming Nie,
Daria M. Shcherbakova,
Yevgenia Kozorovitskiy,
Junjie Yao,
Na Ji,
Vladislav V. Verkhusha
Publication year - 2020
Publication title -
nature biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 15.358
H-Index - 445
eISSN - 1546-1696
pISSN - 1087-0156
DOI - 10.1038/s41587-020-0710-1
Subject(s) - optogenetics , calcium imaging , fluorescence , premovement neuronal activity , förster resonance energy transfer , biophysics , fluorescence lifetime imaging microscopy , two photon excitation microscopy , preclinical imaging , calcium , chemistry , in vivo , biology , neuroscience , optics , physics , microbiology and biotechnology , organic chemistry
While calcium imaging has become a mainstay of modern neuroscience, the spectral properties of current fluorescent calcium indicators limit deep-tissue imaging as well as simultaneous use with other probes. Using two monomeric near-infrared (NIR) fluorescent proteins (FPs), we engineered an NIR Förster resonance energy transfer (FRET)-based genetically encoded calcium indicator (iGECI). iGECI exhibits high levels of brightness and photostability and an increase up to 600% in the fluorescence response to calcium. In dissociated neurons, iGECI detects spontaneous neuronal activity and electrically and optogenetically induced firing. We validated the performance of iGECI up to a depth of almost 400 µm in acute brain slices using one-photon light-sheet imaging. Applying hybrid photoacoustic and fluorescence microscopy, we simultaneously monitored neuronal and hemodynamic activities in the mouse brain through an intact skull, with resolutions of ~3 μm (lateral) and ~25-50 μm (axial). Using two-photon imaging, we detected evoked and spontaneous neuronal activity in the mouse visual cortex, with fluorescence changes of up to 25%. iGECI allows biosensors and optogenetic actuators to be multiplexed without spectral crosstalk.