Microbial Rhodopsins: Light-gated ion channels and pumps as optogenetic tools in neuro- and cell biology

Microbial Rhodopsins are widely used in these days as optogenetic tools in neuro and cell biology. We were able to show that rhodopsins from the unicellar alga Chlamydomonas reinhardtii with the 7 transmembrane helix motif act as light-gated ion channels, which we named channelrhodopsins(ChR1,2). Together with the light driven Cl^- pump Halorhodopsin ChR2 is used for the non-invasive manipulation of excitable cells and living animals by light with high temporal resolution and more important with extremely high spatial resolution The functional and structural description of this new class of ion channels is given (electrophysiology, noise analysis, flash photolysis and 2D crystallography). New tools with increased spatial resolution and extremely enhanced light sensitivity in neurons are presented. A perspective for basic neurobiology and for medical applications is given.