Scientists Discover Key Mechanism of Vision

Researchers from Case Western Reserve University, University of Basel, and the University of Berne, have answered a long known mystery of how our eyes see. Though it has been known that a chemical process converts light into electrical signals that are sent to the brain, the actual mechanism has only now been identified.
From a statement by the Federation of American Societies for Experimental Biology:

At the center of the discovery is the signaling of rhodopsin to transducin. Rhodopsin is a pigment in the eye that helps detect light. Transducin is a protein (sometimes called “GPCR”) which ultimately signals the brain that light is present. The researchers were able to “freeze frame” the chemical communication between rhodopsin and transducin to study how this takes place and what goes wrong at the molecular level in certain disorders.
According to Krzysztof Palczewski, a senior scientist involved in the research, “The results may have important implications for discovery and development of more specific medicines to treat GPCR-linked dysfunction and disease.” Examples of health problems involving GPCR dysfunction include blindness, diabetes, allergies, depression, cardiovascular defects and some forms of cancer.
To make their discovery, scientists isolated rhodopsin/transducin directly from bovine retinas. These membranes were suspended in solution and exposed to light to start the chemical signaling process. After light exposure, any contaminating proteins were removed, and the remaining rhodopsin and transducin “locked” in their chemical communication were removed using a centrifuge. In addition to helping scientists understand how vision begins, this research may also impact disorders affecting heart beat, blood pressure, memory, pain sensation, and infection response because it is believed that they are regulated by similar chemical communications involving similar proteins.

Press release: Scientists see the light: how vision sends its message to the brain
Abstract in The FASEB Journal…
Image credit: Richard Masoner