Diminution of schedule-induced polydipsia after a long rest period.

Schedule-induced polydipsia was established in four food-deprived rats given daily hourly sessions in which a food pellet was presented once each min. Sessions were then discontinued for approximately six months. After this rest period, the daily sessions were resumed. Relative to the water intake during the last five sessions prior to the rest period, water intake during the first five sessions after the rest period exhibited a 55.5%, 10.3%, 32.0% and 29.6% decrement for the four rats, respectively. These results are discussed in terms of a sensitization view of schedule-induced polydipsia.