From Photon to Receptor Potential: the Biochemistry of Vision

HR Saibil


The perception of light incident on the retina begins with the photoisomerization of the vitamin A-derived chromophore of the visual pigment protein, rhodopsin. We now have a remarkably clear picture of the sequence of events in the photoreceptor cell, in which rhodopsin activates an enzyme cascade that alters the membrane potential. This generates the visual signal that is transmitted through the retinal nerve cells to the brain.