Spatial delayed nonmatching-to-sample performances in long-living Ames dwarf mice

Abstract

Ames dwarf mice have an extended lifespan by comparison with normal mice. Behavioral testing has revealed that sometimes Ames dwarf mice also evince superior performances relative to normal mice, but in other cases they do not. In this experiment, Ames dwarf and normal mice were compared on a T-maze test and on a delayed nonmatching-to-sample variant of a T-maze test. On the simple T-maze, Ames dwarf and normal mice committed comparable numbers of errors. On the nonmatching-to-sample task, normal mice mastered the discrimination by the end of the experiment while Ames dwarf mice did not. The apparatus, distances traveled and session duration were equivalent between the two tasks. The poorer performances of Ames dwarf mice on the nonmatching-to-sample task suggests that Ames dwarf mice may not be as capable of learning relatively cognitively complex tasks as normal mice.

Keywords: Aging; Ames dwarf mouse; Learning; Longevity; Reinforcement.

Fig. 1.

Mean trial duration and mean errors per trial during T-maze training sessions. Vertical lines within the figure show the standard error of the mean.

Fig. 2.

Mean trial duration and mean errors per trial on the nonmatching-to-sample variant of the T-maze task. The 12 days of observation are identified as D1–D12. The lines above each bar show the standard error of the mean.