title: Recoverin improves rod-mediated vision by enhancing signal transmission in the mouse retina.
abstract: Vision in dim light requires that photons absorbed by rod photoreceptors evoke signals that reliably propagate through the retina. We investigated how a perturbation in rod physiology affects propagation of those signals in the retina and ultimately visual sensitivity. Recoverin is a protein in rods that prolongs phototransduction and enhances visual sensitivity. It is not present in neurons postsynaptic to rods, yet we found that light-evoked responses of rod bipolar and ganglion cells were shortened when measured in recoverin-deficient retinas. Unexpectedly, the effect of recoverin on postsynaptic signals could not be explained by its effect on phototransduction. Instead, it is an effect of recoverin downstream of phototransduction in rods that prolongs signal transmission and enhances visual sensitivity. An important implication of our findings is that the recovery phase of the rod photoresponse does not contribute significantly to visual sensitivity near absolute threshold.
authors.affiliation: Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Alapakkam P
authors.initials: AP
authors.lastname: Sampath
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Strissel
authors.forename: Rajesh
authors.initials: R
authors.lastname: Elias
authors.forename: Vadim Y
authors.initials: VY
authors.lastname: Arshavsky
authors.forename: James F
authors.initials: JF
authors.lastname: McGinnis
authors.forename: Jeannie
authors.initials: J
authors.lastname: Chen
authors.forename: Satoru
authors.initials: S
authors.lastname: Kawamura
authors.forename: Fred
authors.initials: F
authors.lastname: Rieke
authors.forename: James B
authors.initials: JB
authors.lastname: Hurley
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D015151:Immunoblotting; D008074:Lipoproteins / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D051603:Recoverin; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism*; D014785:Vision, Ocular / Q000502:physiology*
chemical_list: D002135:Calcium-Binding Proteins; D005136:Eye Proteins; D008074:Lipoproteins; C496732:Rcvrn protein, mouse; D051603:Recoverin