DISCO! Dissociation of cone opsins: the fast and noisy life of cones explained.
Vertebrate retinas contain two types of photoreceptors. Rods are for vision in dim light, while cones provide high-speed color vision in bright light. In this issue of Neuron, Kefalov et al. present data to explain the reduced sensitivity and faster response kinetics of cones. They show that the chromophore dissociates from cone but not rod visual pigment, yielding apo-opsin. This apo-opsin activates the signaling cascade to desensitize cones and speed the photoresponse.
Travis
Gabriel H
GH
Department of Ophthalmology, UCLA School of Medicine, Los Angeles, CA 90095, USA.
D000557:Ambystoma; D000818:Animals; D008954:Models, Biological; D010775:Photic Stimulation / Q000379:methods; D017949:Retinal Cone Photoreceptor Cells / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D012168:Retinal Pigments / Q000378:metabolism*; D017299:Rod Opsins / Q000378:metabolism* / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology*
D012168:Retinal Pigments; D017299:Rod Opsins