Measuring Behavior 2005: Brown

The importance of visual ability in behavioral testing of mice

R.E. Brown

Department of Psychology, Dalhousie University, Halifax, Nova Scotia, Canada

We used a computer-based, two-alternative swim task to evaluate visual discrimination, pattern discrimination and visual acuity in 13 strains of mice (129SI/Sv, A/J, AKR, BALB/cByJ, C3H/HeJ, C57BL/6J, CAST/Ei, DBA/2J, FVB/NJ, MOLF/Ei, SJL/J, SM/J and SPRET/Ei). As predicted by the physiology of their visual system, mice with no known visual defects (129SI/Sv, C57BL/6J and DBA/NJ) performed well on all three visual tasks, mice with poor vision due to photoreceptor damage (AKR/J, BALB/CbyJ) showed moderate improvement and mice with retinal degeneration and other visual defects (A/J, C3H/HeJ, CAST/Ei, FVB/NJ, MOLF/Ei, SJL/J, SM/J and SPRET/Ei) performed at chance levels. These and other mice of the same strains were tested in a behavioral test battery that evaluated anxiety-related behavior, motor performance and learning and memory. Strain differences in visual acuity accounted for a significant proportion of the variance in tasks dependent on visual cues. Some measures of anxiety (centre frequency in the open field) were significantly correlated with visual ability, but others (proportion of time spent in the light zone in the light/dark transition test) were not. Measures of learning in the Morris water maze (latency to find the platform and swim path length) were significantly correlated with visual ability but motor learning performance (latency to fall in the rotarod) was not. Olfactory discrimination learning performance (percentage of time digging for CS+) was enhanced in mice with visual defects. These results indicate that visual ability must be accounted for when testing for strain differences in mice because differences in performance in many tasks may be due to visual deficits rather than differences in higher order cognitive functions. These results have significant implications for the search for the neural and genetic bases of learning and memory in mice. Supported by JAX Phenome project and NSERC of Canada

Paper presented at Measuring Behavior 2005 , 5^th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.