ARVO 2013 Annual Meeting Abstracts 320 Color Vision ...

ARVO 2013 Annual Meeting AbstractsPresentation Time: 8:30 AM - 10:15 AMHigh Throughput Behavioral Estimates of Visual Thresholds inMice in a Watermaze with Cued Escape PlatformArkady Lyubarsky, Muhammad Sheheryar Khan, Meera Sivalingam,Jean Bennett. F.M. Kirby Center for Molecular Ophthalmology,School of Medicine, University of Pennsylvania, Philadelphia, PA.Purpose: To develop a quantitative, sensitive, cost-effective, noninvasivebehavioral technique for evaluation of vision in mice withemphasis on its suitability for the end point characterization in genetherapy of retinal diseases.Methods: The apparatus was a round (1.2 m diameter and 0.7 mhigh) tub made of a dark blue plastic, and filled with water to a 20 cmdepth with a single submerged escape platform (8 cm diameter). Aplastic 20 cm high pole covered with a disposable aluminum foilsleeve and standing at the platform center served as a visual cueassisting animals in finding the platform. Four infrared sourcesprovided a uniform, invisible for mice, illumination of the tub, and avideo camera with an infrared filter was recording animal’s moves.Four regulated visible light sources provided uniform illuminationinside the apparatus in a 1E-5 to 1E+2 scot cd m -2 range. Wild-type(WT) and neural retina leucine zipper (NRL) knock-out (KO) micelacking rod photoreceptors were trained to escape to the platform atthe brightest level of illumination, and then were tested at 0.5 - 0.8log-unit decrements of the illumination intensity. To determine thethreshold, we first evaluated the probability of reaching the platformby chance per second of swimming time; to do this we measured thefrequency of platform encounter by mice swimming in dark with onlyIR illumination on. In test runs an animal was considered as “seeing”the pole if it reached the platform in 3 out of 3 consecutive trials, andthe probability of achieving this result by way of 3 random hits was