The effects of coffee and its main components (caffeine and chlorogenic acid) on the spontane- ous locomotor activity and the circadian rhythm were assessed in old rats. The intraperitoneal ad- ministration of a high dose of coffee (equivalent to 10 cups/day in a person) stimulated locomotor activity, especially in the dark cycle, and altered its circadian rhythm, while a low dose of coffee (equivalent to 1 cup/day) failed to stimulate it. The effects of caffeine were very similar to those of coffee itself, suggesting that the effects of coffee shown in the present study were probably due t...
