Abstract
Optogenetics is an emerging technique that enables precise and specific control of biological activities in defined space and time. This technique employs naturally occurring or engineered light-responsive proteins to manipulate the physiological processes of the target cells. To better elucidate the molecular bases of neural functions, substantial efforts have been made to confer light sensitivity onto ion channels and neurotransmitter receptors that mediate signaling events within and between neurons. The chemical strategies for engineering light-switchable channels/receptors and the neuronal implementation of these tools are discussed.