Pituitary-adrenal and dopaminergic modulation of schedule-induced polydipsia: behavioral and neurochemical evidence.
Five experiments investigated in rats the effects of increasing or decreasing plasma corticosterone levels on schedule-induced polydipsia and dopamine efflux in the nucleus accumbens. The results indicate that the acquisition of schedule-induced polydipsia could be decreased by adrenalectomy, blockade of corticosterone synthesis, or administration of corticosterone. Performance of established schedule-induced polydipsia was also decreased by adrenalectomy. The effects of corticosterone administration on established schedule-induced polydipsia depended on the level of performance. High levels of drinking were enhanced by a high dose of corticosterone, whereas low rates of drinking were increased by a low dose. Similar injections of corticosterone also significantly increased dopamine efflux. The relative involvement of pituitary-adrenal activity and dopamine neurotransmission in the nucleus accumbens in the acquisition and performance of SIP is discussed and related to contemporary hypotheses of schedule-induced behavior.
Mittleman
G
G
University of British Columbia Vancouver, Canada.
Blaha
C D
CD
Phillips
A G
AG
D000818:Animals; D001143:Arousal / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology; D003345:Corticosterone / Q000502:physiology; D004298:Dopamine / Q000502:physiology*; D004327:Drinking Behavior / Q000502:physiology*; D008297:Male; D009714:Nucleus Accumbens / Q000502:physiology*; D010913:Pituitary-Adrenal System / Q000502:physiology*; D051381:Rats; D011954:Receptors, Dopamine / Q000502:physiology*; D012055:Reinforcement Schedule; D013239:Stereotyped Behavior / Q000502:physiology
D011954:Receptors, Dopamine; D004298:Dopamine; D003345:Corticosterone