Energy balance and play in juvenile rats.

These experiments systematically analyzed the relationship between energy balance and play in the juvenile rat. As expected, depriving pups of food for 24 hours or more resulted in a reliable reduction in levels of play, with a single meal being sufficient to return play to baseline levels. Consumption of saccharin did not reverse deprivation-induced reductions of play. It is proposed that the food-induced restoration of play in food-deprived pups is perhaps reflective of normal satiety and may be useful in screening putative "satiety agents." Naloxone, cholecystokinin and bombesin, all putative satiety agents, were tested for their ability to reverse deprivation-induced reduction of play. Only bombesin was marginally effective in increasing play of food deprived rats.