Papers by Frank Naarendorp
Visual thresholds of mice for the detection of small, brief targets were measured with a novel be... more Visual thresholds of mice for the detection of small, brief targets were measured with a novel behavioral methodology in the dark and in the presence of adapting lights spanning 8 log 10 units of intensity. To help dissect the contributions of rod and cone pathways, both wild-type mice and mice lacking rod (Gnat1 /) or cone (Gnat2 cpfl3) function were studied. Overall, the visual sensitivity of mice was found to be remarkably similar to that of the human peripheral retina. Rod absolute threshold corresponded to 12–15 isomerized pigment molecules (R*) in image fields of 800 to 3000 rods. Rod " dark light " (intrinsic retinal noise in darkness) corresponded to that estimated previously from single-cell recordings, 0.012R*s 1 rod 1 ,indicatingthatspontaneousthermalisomerizationsareresponsible.Psychophysicalrodsaturationwasmeasuredforthefirsttime inanonhumanspeciesandfoundtobeverysimilartothatofthehumanrodmonochromat.Conethresholdcorrespondedto5R*cone 1 inanimage fieldof280cones.Conedarklightwasequivalentto5000R*s 1 cone 1 ,consistentwithprimatesingle-celldatabut100-foldhigherthanpredictedby recentmeasurementsoftherateofthermalisomerizationofmouseconeopsins,indicatingthatnonopsinsourcesofnoisedetermineconethreshold.The new, fully automated behavioral method is based on the ability of mice to learn to interrupt spontaneous wheel running on the presentation of a visual cue and provides an efficient and highly reliable means of examining visual function in naturally behaving normal and mutant mice.
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Papers by Frank Naarendorp