During the last decade, optogenetics has emerged as a paradigm-shifting technique to
monitor and steer the behavior of specific cell types in excitable tissues, including the heart.
Activation of cation-conducting channelrhodopsins (ChR) leads to membrane
depolarization, allowing one to effectively trigger action potentials (AP) in cardiomyocytes. In
contrast, the quest for optogenetic tools for hyperpolarization-induced inhibition of AP
generation has remained challenging. The green-light activated ChR from Guillardia theta …