Channelrhodopsin Protein (IMAGE) Max-Planck-Gesellschaft Caption The light-sensitive channelrhodopsin protein consists of two single molecules (light and dark grey). It forms an ion channel that can be closed in three places. When closed (left), three 'gates' (black bars) prevent ions from flowing through the channel pore (green tube). In the open state (right), a conformational change causes the opening of the channel pore. Channelrhodopsin also pumps positive hydrogen ions (protons) into the molecule's interior (orange arrow) -- a property that is important for the opening of the channel pore. [less] Credit Volkov et al., <i>Science</i> 2017 Usage Restrictions Use of images is limited to editorial coverage of scientific topics relating to the activities of the Max Planck Society. Any kind of commercial use (including, in particular, the exploitation of images by means of sale or incorporation in image databases or image catalogues) as well as any promotional use/use for merchandise purposes, disclosure to third parties or granting of related rights to third parties is expressly not permitted. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.