Abstract
Chemogenetic techniques allow selective manipulation of neurons by activating engineered actuator proteins with otherwise inert effector molecules. A recent study (Magnus et al. Science 2019;364:eaav5282) describes the coevolution of highly potent actuator-effector pairs based on a clinically approved antismoking drug. These tools allow selective excitation or inhibition of neurons in the living brain with high specificity and no detectable side-effects.