Nearly a decade ago, the era of optogenetics was ushered in with the development of channelrhodopsins, light-activated ion channels that can, with the flick of a switch, instantaneously turn on neurons in which they are genetically expressed. What has lagged behind, however, is the ability to use light to inactivate neurons with an equal level of reliability and efficiency. Now, scientists have used an analysis of channelrhodopsin's molecular structure to guide a series of genetic mutations to the ion channel that grant the power to silence neurons with an unprecedented level of control.

Source: Scientists build new 'off switch' to shut down neural activity