Role of the pituitary-adrenal hormones in the acquisition of schedule-induced polydipsia.

Abstract

Adrenalectomized female rats failed to develop schedule-induced polydipsia (SIP). Dexamethasone (DEX) injections failed to reinstate SIP in adrenalectomized rats. They did not prevent intact rats from acquiring SIP but interfered with subsequent expression of this behavior. In contrast, corticosterone, the rats' normally occurring glucocorticoid, fully restored the acquisition and subsequent expression of SIP in adrenalectomized rats. This strongly suggests that corticosterone plays an essential role in the normal acquisition and development of this behavior. Data are interpreted in the context of current information concerning adrenal hormone receptors. It is hypothesized SIP acquisition is at least partly regulated by the Type I (mineralocorticoid) receptor.

Schedule-induced polydipsia as a model of compulsive behavior: neuropharmacological and neuroendocrine bases

“…Furthermore, the decrease in corticosterone levels is conditioned to the presence of the bottle of water in the operant chamber; corticosterone levels are increased in polydipsic animals when the water bottle was removed from the experimental situation (Tazi et al 1986). The animals that engaged in excessive drinking in SIP displayed decreased plasma levels of corticosterone and increased levels of prolactin during the course of a SIP session compared with animals not developing this adjunctive behavior (Dantzer et al 1988a,b;Levine and Levine 1989). Adrenalectomy or blockade of corticosterone synthesis decreased SIP acquisition whereas corticosterone administration affected SIP depending on the level of drinking behavior and increased DA efflux in the nucleus accumbens (Mittleman et al 1992).…”

The Physiologic, Neurologic, and Behavioral Effects of Caloric Restriction Related to Aging, Disease, and Environmental Factors

“…The pronounced SIP behavior of rats in this experiment suggests that CR feeding may induce fundamental alterations in neurotransmitters such as dopamine. Pituitary adrenal hormones have also been shown to play an important role in the acquisition of SIP (Levine and Levine, 1989). The glucocorticoids have been hypothesized to be reliable indicators of arousal and aggression (Hennessy and Levine, 1979).…”

Stereotypies: a critical review

“…Further investigation of the association between adjunctive polydipsia and lowered corticosteroids, for example, has revealed the hormones to influence the behaviour, rather than the other way around Levine & Levine 1989). Furthermore, in cases of anxiety-reduction, the effect must be shown to be specific to the stereotypy itself, rather than a general result of increased exercise (see Morgan & Goldston 1987).…”