Effect of life-long hypocaloric diet on age-related changes in motor and cognitive behavior in a rat population.

Aged (24 months), adult (12 months), and young (4 months) rats kept on standard or hypocaloric diets from the age of three weeks old were tested in a range of behavioral tests to determine the effects of aging on sensory-motor and cognitive behavior and to assess whether such effects were prevented by life-long calorie restriction. An age-related deterioration of sensory-motor functions, motility and exploratory activity was observed in all the senescent animals independent of diet. Swimming ability did not deteriorate with age. Spatial memory, evaluated by the Morris water maze test, showed some deterioration in normally fed adult rats as indicated by the deceleration in the learning curve. In aged rats, not only was learning slowed down, but memory utilization was also impaired. These cognitive deficiencies were absent in rats fed the hypocaloric diet.