title: The frequency-response electroretinogram distinguishes cone and abnormal rod function in rd12 mice.
abstract: Early studies on Rpe65 knockout mice reported that remaining visual function was attributable to cone function. However, this finding has been challenged more and more as time has passed. Electroretinograms (ERGs) showed that rd12 mice, a spontaneous animal model of RPE65 Leber's congenital amaurosis, had sizeable photopic responses. Unfortunately, the recorded ERG waveform was difficult to interpret because of a remarkably delayed peak-time, which resembles a rod response more than a cone response. Here, we compare flicker ERGs in animals with normal rod and cone function (C57BL/6J mice), pure rod function (cpfl5 mice), and pure cone function (Rho(-/-) mice) under different adaptation levels and stimulus intensities. These responses were then compared with those obtained from rd12 mice. Our results showed that normal rods respond to low frequency flicker (5 and 15 Hz) and that normal cones respond to both low and high frequency flicker (5-35 Hz). As was seen in cpfl5 mice, rd12 mice had recordable responses to low frequency flicker (5 and 15Hz), but not to high frequency flicker (25 and 35 Hz). We hypothesize that abnormal rods may be the source of residual vision in rd12 mice, which is proved correct here with double mutant rd12mice. In this study, we show, for the first time, that frequency-response ERGs can effectively distinguish cone- and rod-driven responses in the rd12 mouse. It is another simple and valid method for evaluating the respective contributions of retinal rods and cones.
authors.affiliation: Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China; Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Xufeng
authors.initials: X
authors.lastname: Dai
authors.affiliation: Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: He
authors.affiliation: Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Qi
authors.affiliation: The Jackson Laboratory, Bar Harbor, Maine, United States of America.
authors.forename: Bo
authors.initials: B
authors.lastname: Chang
authors.affiliation: Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China; Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Ji-jing
authors.initials: JJ
authors.lastname: Pang
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004596:Electroretinography; D057130:Leber Congenital Amaurosis / Q000503:physiopathology*; D051379:Mice; D018345:Mice, Knockout; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012162:Retinal Degeneration / Q000503:physiopathology*; D019745:cis-trans-Isomerases / Q000235:genetics; D020741:rho GTP-Binding Proteins / Q000235:genetics; D000099178:Retinoid Isomerohydrolase
chemical_list: D019745:cis-trans-Isomerases; D020741:rho GTP-Binding Proteins; D000099178:Retinoid Isomerohydrolase