The effect of limited water availability on schedule-induced polydipsia

Rats bar-pressing on a 1-min fixed-interval schedule for 100, 45-mg food pellets per session became polydipsic when water was always concurrently available on a fixed-ratio 1 basis via a second response lever. When 15-sec periods of water unavailability were successively inserted in the first, second, third, and fourth quarters of the 1-min fixed-interval food schedule, all rats remained polydipsic although water intakes were slightly lower than those in the control conditions of continuous water availability.