Nature Neuroscience, Published online: 16 June 2026; doi:10.1038/s41593-026-02325-w
The authors develop red fluorescent GRAB acetylcholine (ACh) sensors and highlight rACh1h as a robust tool for multiplex recording together with various green sensors. Using fiber photometry, mesoscopic imaging and two-photon imaging, rACh1h is shown to reliably report ACh dynamics in vivo.