You can think of channelrhodopsin as a sort of light-sensitive switch that can be artificially installed in brain cells so that now we can use that switch to activate or inactivate the brain cell simply by clicking it, and in this case we click it on with pulses of light.
你们可以将光敏感通道看作一种光敏开关， 它可以被人工安置于脑细胞中， 因此现在我们就可以使用这一开关 只要简单点击一下开关 我们就能激活或减退脑细胞的活动， 并且我们用的是光波来点击开关。