Development of Spatial Task Performance in the Radial Arm Maze in Weaning Rats

Abstract

The experiment assessed the development of working memory and the use of spatial stimuli. Four groups of weaning rats, 20, 21, 23, 25 days old at the beginning of the experiment (n=12 for each group), were trained in an 8-arm radial maze, 4 trials a day, for 5 days. Both intramaze cues and extramaze spatial stimuli were available. Rewards were placed on the subject-specific cued-arms. On the sixth day, the spatial test in which intramaze cues were eliminated and the cue test in which the use of extramaze stimuli was limited were given to assess the strategies employed to achieve the task. The results indicate that (1) developmental differences were recognized between Groups 21 and 23, and these differences were not compensated after receiving the same number of training, (2) at the age of the experiment, working memory and the use of spatial stimuli were not yet sufficiently developed, and (3) the subjects mainly used the cue strategy when both place and cue strategies could be available.