USE OF PROXIMAL AND DISTAL CUES IN-PLACE NAVIGATION BY MICE CHANGES DURING ONTOGENY

The ontogeny of the ability of C57BL/6 mice to use different cues for spatial learning was examined in several Morris water maze tasks. In t he first two studies, three learning procedures were used, in which on ly distal cues (place learning), only proximal cues (cue learning), or both proximal and distal cues (cue + place learning) were pertinent t o localize the platform. The results indicated that whatever the proce dure, 22-day-old mice showed the same capabilities as adults. Moreover , in the cue + place-learning procedure, although the distal cues were not necessary to solve the task, both young and adult mice demonstrat ed the integration of distal information by exhibiting a strong spatia l bias during a probe test. However, in the third experiment, it was s hown that nonpertinent proximal cues perturbed 22-day-old mice in a pl ace-learning procedure. Taken together, these results suggest that whi le even the youngest mice show striking spatial navigation abilities, young mice give greater importance to proximal cues for orientation wh ereas adults preferentially use distal information. (C) 1996 John Wile y & Sons, Inc.