| The impact of food restriction and refeeding on wheel running was examined in 3 groups of rats: 55 day old male rats in Experiment 1; 140 day old male rats in Experiment 2; and 180 day old female rats in Experiment 3. After a baseline period of 24 or 40 days wheel experience with ad lib food access half of the animals were food restricted for 16 days by being given a limited amount of food daily to reduce (and maintain) their body weight at 85% of their baseline weight. After food restriction the rats were returned to ad lib food access and running was observed for another 16 days. Running performed by the food-restricted rats was compared to the running performed by continuously ad lib fed control rats. Results indicate that food restriction induced changes in wheel running are not influenced by age (or some covariate of age, such as body weight) in male rats, but are affected by gender, by baseline levels of running, and are controlled by a separate mechanism than that which causes the individual differences in baseline wheel running. (Abstract shortened by UMI.)... |
