Spatial memory deficit in senescent rats

Investigated the spatial memory of senescent (29 mo) and middle-aged (14 mo) Long-Evans rats using 3 tasks. In the 1st, Ss were required to move from the brightly lit surface of a circular platform into a dark tunnel under 1 of 18 holes lining its circumference. The 2nd task dissociated the strategy of preference (i.e., cue, response place) of these Ss in a 2-choice (T-maze) discrimination problem. The 3rd task involved memory for specific places in the environment, with the use of water reward to induce running on a radial 8-arm maze. The senescent Ss exhibited poorer memory for rewarded places; this may be a result of using less efficient performance strategies because of a deficit in spatial memory. (French abstract) (16 ref)