Light-driven channels and ion pumps as tools for neuroscience

Remote control of neural cells by light by means of the light-gated cation channel Channelrhodopsin2 (ChR2) and of the light-driven Cl^- pump Halorhodopsin (NphR) fulfils a long lasting desire of neurobiologists. With this method neurons in culture as well as in the brain of living animals can be activated or inactivated at different wavelengths of the exciting light in a non invasive, electrode free manner with high temporal and even more important with an up to now unknown spatial resolution. This new technique has set the basis for the fast developing field of optogenetics.