Spatial learning in preweanling rats trained in a Morris water maze

In three experiments, spatial learning in preweanling rats was examined, using the Morris water maze (MWM). Contrary to previous findings, Experiment 1 revealed that rat pups younger than 20 days of age showed good spatial learning. Experiment 2 revealed that spatial learning in preweanlings was influenced by the nature of the training procedure; a spaced distribution of trials resulted in good spatial learning, but a massed distribution of trials did not. Despite evidence that preweanlings have the capacity for spatial learning, Experiment 3 indicated that they are not as proficient as adults. These results are discussed in terms of procedural variables that may influence MWM performance in immature rats.