Schedule-Induced Polydipsia: Species Limitations

Abstract

5 male hamsters were reduced to 80% ad lib. weight and were run in a 3-hr. session with a VI-60 sec. schedule for 20-mg. pellets for 14 consecutive days. Water was freely available at all times. As hamsters did not exhibit the excessive drinking characteristic of other animals under similar paradigms, there appears to be a species limitation to schedule-induced polydipsia.The finding of Falk (1961) that rats bar pressing on a VI-60 sec. schedule of food reinforcement would consume almost half of their body weight in water during an approximate 3-hr. session has lead to the investigation of schedule-induced polydipsia in numerous other studies. Among the species in which this phenomenon has been demonstrated are mice (Palfia, et al., A point worthy of note is that rwo animals known to demonstrate scheduleinduced polydipsia have also been shown to decrease their water consumption when food deprived. Verlplank and Hayes (1953) demonscrated that the rat reduced water intake when food deprived. Similarly, Schuster and Woods (1966) reported a reduction of water intake in the rhesus monkey when food deprived. Noc all animals show a reduction in water intake as a function of food deprivation; the hamster (Kutscher, et al., 1968a) and the gerbil (Kutscher, et al., 1968b; VanderWeele BE TeLlish, 1971; Kutscher, 1973) being notable exceptions. Both of these animals often show dramatic increases in water intake when food deprived. Further, both of these animals are primarily desert creatures whereas none of the animals demonstrating schedule-induced polydipsia are.In view of the diversity of animals for which the phenomenon has been demonstrated, the phenomenor, appears rather universal; however, we need to explore whether this phenomenon can be shown for animals which show fooddeprivation polydipsia. The purpose of this study then was to investigate schedule-induced polydipsia in one such animal (Kutscher, et al., 1968a). METHOD Sic6 jectsSs were five male golden hamsters (Masocricefw ui~ratz~s), whose average weight was 127 gm. at the beginning of the experiment. During the experiment Ss were individually housed and maintained on Wayne Lab-Blox rodent chow.'Now at the University of Louisville. Requests for reprints should be sent to W.

Failure to find schedule-induced polydipsia in the pigeon

“…Wilson and Spencer (1975) recently failed to find schedule-induced polydipsia in the golden hamster. Symons and Sprott (1976) found schedule-induced polydipsia in some but not other strains of mice.…”

Adjunctive drinking during variable and random-interval food reinforcement schedules

“…One of these processes is simply the strong tendency in some species, rats inciuded, to drink after eating (Kissileff, 1969). When this process is absent 01' weak, as it is in hamsters and gerbils, we should not expect food schedule-induced drinking, and indeed none occurs (Wilson & Spencer, 1975). The tendency of rats and some other animals to drink after eating combines, under some reinforcement schedules, with another process: the tendency of locally low probabilities of reinforcement to induce a ciassically conditioned state (Staddon, 1977).…”

Comportamento adjunto: controvérsias e contribuições teóricas

“…Sendo o comportamento organizado em torno de eventos biológicos relevantes, espera-se que a ocorrência do comportamento adjunto sofra restrições quanto à espécie envolvida e à natureza do estímulo consumatório. Alguns estudos mostraram restrições quanto à natureza do estímulo consumatório (Haydu, 1988;Haydu, Luzia, Marinho, Maciel & Silva, 1991;Wetherington & Brownstein, 1977;Wetherington & Riley, 1985); outros têm mostrado restrições relativas à espécie, isto é, o comportamento adjunto observado em uma determinada espécie não é observado em outra (Anderson & Shettleworth, 1977;Shearon & Allen, 1989;Wilson & Spencer, 1975). Esses estudos mostram, é certo, que a organização temporal do comportamento diferencia-se de espécie para espécie e depende da natureza do estímulo consumatório.…”