| First Author | Farrants H | Year | 2024 |
| Journal | Nat Methods | Volume | 21 |
| Issue | 10 | Pages | 1916-1925 |
| PubMed ID | 39304767 | Mgi Jnum | J:379309 |
| Mgi Id | MGI:8279177 | Doi | 10.1038/s41592-024-02411-6 |
| Citation | Farrants H, et al. (2024) A modular chemigenetic calcium indicator for multiplexed in vivo functional imaging. Nat Methods 21(10):1916-1925 |
| abstractText | Genetically encoded fluorescent calcium indicators allow cellular-resolution recording of physiology. However, bright, genetically targetable indicators that can be multiplexed with existing tools in vivo are needed for simultaneous imaging of multiple signals. Here we describe WHaloCaMP, a modular chemigenetic calcium indicator built from bright dye-ligands and protein sensor domains. Fluorescence change in WHaloCaMP results from reversible quenching of the bound dye via a strategically placed tryptophan. WHaloCaMP is compatible with rhodamine dye-ligands that fluoresce from green to near-infrared, including several that efficiently label the brain in animals. When bound to a near-infrared dye-ligand, WHaloCaMP shows a 7x increase in fluorescence intensity and a 2.1-ns increase in fluorescence lifetime upon calcium binding. We use WHaloCaMP1a to image Ca(2+) responses in vivo in flies and mice, to perform three-color multiplexed functional imaging of hundreds of neurons and astrocytes in zebrafish larvae and to quantify Ca(2+) concentration using fluorescence lifetime imaging microscopy (FLIM). |
