Peter Hegemann is a Hertie professor for neuroscience and head of Experimental Biophysics at Humboldt-Universitaet zu Berlin. Hegemanns research focused almost entirely on the characterization of natural sensory photoreceptors. Hegemann has characterized behavioral and photoelectric responses of the unicellular alga Chlamydomonas, a work that cumulated in the claim that the photoreceptors for these responses a rhodopsins that unify the sensor and ion channel in one protein. He has finally proven this concept by identifying the light gated channel channelrhodopsin, and its functionality in animal cells.
His group characterized this protein in molecular detail by a wide range of biophysical techniques; in close collaboration with Karl Deisseroth this lead to the deciphering of the ion channel mechanism, including gating and ion selection. This work was the basis for the discovery of Optogenetics, a technology where light activated proteins – first of all channelrhodopsin - allow to control selected cells of large networks as the animal brain with unprecedented precision in space and time just by application of light. The Hegemann group also works on light-activated enzymes which further expand the optogenetic applications to important biochemical pathways.