[Gerontological pilot study on learning ability and memory in the stressed rat (author's transl)].

The influence of noise and overcrowding on the learning ability and memory was investigated during a long term cohort study in 120 male Sprague Dawley rats covering an age range from 8 to 14 months. The investigations were performed by means of a semi-automatical multiple-T-maze with 7 choice points. The results showed that noise and overcrowding enhanced the learning ability and memory in rats up to an age of 10 to 12 months. However, the learning ability and memory were declining faster with age in the stressed animals than in the unstressed ones. The stressor "overcrowding" proved to be more effective than the stressor "noise" applied by the authors.