TEST OF THE GENERALITY OF SCHEDULE-INDUCED-POLYDIPSIA TO WILD-CAUGHT NORWAY RATS

Four of 5 food-deprived wild-caught Norway rats failed to develop schedule-induced polydipsia when placed on a fixed-time 1-min food schedule of 45 mg pellets for 30 1-hr sessions. The one wild-caught rat that displayed schedule-induced polydipsia was retarded in the development and only reached session intake level approximately one half that of a control group of domestic laboratory-reared Norway rats. All 5 domestic rats readily acquired schedule-induced polydipsia. The wild-caught and domestic Norway rats differed in their probability of initiating a bout of drinking but not in their lick pattern, bout size or lick efficiency. These data appear to challenge the generality of schedule-induced polydipsia. © 1979.