Resumen:
n recent decades, a number of novel non-visual opsin photopigments belonging to the family of G protein- coupled receptors,likely involved in a number of non-image-forming processes, have been identiied and characterized in cells of theinner retina of vertebrates. It is now known that the vertebrate retina is composed of visual photoreceptor cones and rodsresponsible for diurnal/color and nocturnal/black and white vision, and cells like the intrinsically photosensitive retinalganglion cells (ipRGCs) and photosensitive horizontal cells in the inner retina, both detecting blue light and expressing thephotopigment melanopsin (Opn4). Remarkably, these non-visual photopigments can continue to operate even in the absenceof vision under retinal degeneration. Moreover, inner retinal neurons and Müller glial cells have been shown to express otherphotopigments such as the photoisomerase retinal G protein-coupled receptor (RGR), encephalopsin (Opn3), and neuropsin(Opn5), all able to detect blue/