Natural light-gated anion channels: A family of microbial rhodopsins for advanced optogenetics

TLDR

Optogenetic control of neurons relies on rhodopsin light‑sensitive ion channels from green algae, where cation channels depolarize neurons to trigger brief action potentials. The authors aim to introduce algal anion channels that hyperpolarize or silence neurons, offering a complementary strategy to the widely used cation‑channel approach. These channels are engineered to conduct only anions, thereby hyperpolarizing the membrane upon illumination. They exhibit higher light sensitivity, rapid activation, and selective anion conductance compared to existing hyperpolarizing optogenetic tools. Govorunova et al., *Science*, this issue p.

Abstract

Silencing neurons using optogenetics Rhodopsin light-sensitive ion channels from green algae provide a powerful tool to control neuronal circuits. Rhodopsin cation channels effectively depolarize neurons and cause the firing of short-lived electrical membrane potentials. Govorunova et al. describe algal channels that do the opposite; that is, they hyperpolarize or silence particular neurons (see the Perspective by Berndt and Deisseroth). These cation channels provide greater light sensitivity than that of existing hyperpolarizing light-activated channels, operate rapidly, and selectively conduct only anions. This approach is an ideal complement to the widely used technique of creating light-sensitive neurons through the expression of rhodopsin cation channels. Science , this issue p. 647 ; see also p. 590