Vertebrate Cone Opsins Enable Sustained and Highly Sensitive Rapid Control of Gi/o Signaling in Anxiety Circuitry

G protein-coupled receptors (GPCRs) coupling to G(i/o) signaling pathways are involved in the control of important physiological functions, which are difficult to investigate because of the limitation of tools to control the signaling pathway with precise kinetics and specificity. We established two vertebrate cone opsins, short-and long-wavelength opsin, for long-lasting and repetitive activation of G(i/o) signaling pathways in vitro and in vivo. We demonstrate for both opsins the repetitive fast, membrane-delimited, ultra light-sensitive, and wavelength-dependent activation of the G(i/o) pathway in HEK cells. We also show repetitive control of G(i/o) pathway activation in 5-HT1A receptor domains in the dorsal raphe nucleus (DRN) in brain slices and in vivo, which is sufficient to modulate anxiety behavior in mice. Thus, vertebrate cone opsins represent a class of tools for understanding the role of G(i/o)-coupled GPCRs in health and disease.