Sodium homeostasis in chronic decerebrate rats.
Physiological and behavioral concomitants of sodium need were studied in supracollicularly transected and pair-fed intact rats. Chronic decerebrate rats, like intact rats, reduced their urine sodium output when placed on a sodium-deficient diet. Similarly, 24 hr after sodium loading, decerebrate and intact rats excreted comparable levels of the excess sodium. In the 2 hr immediately following the loading, decerebrate rats excreted less sodium. In contrast, behavioral aspects of sodium homeostasis were completely absent in chronic decerebrate rats. In separate experiments, intraoral intake, and taste-reactivity responses, elicited by intraoral infusions of NaCl were measured during sodium-replete and sodium-deficient conditions. In response to oral infusions of NaCl, intact rats consumed significantly more and produced greater numbers of ingestive taste-reactivity responses when they were sodium deficient than when they were sodium replete. The same sodium-depletion treatments in chronic decerebrate rats, however, altered neither the intraoral intake of NaCl nor the frequency of NaCl-elicited ingestive taste-reactivity responses. These results suggest that the behavioral compensatory responses that follow changes in the internal sodium state are dependent upon forebrain mechanisms.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001066:Appetite / Q000502:physiology*; D001933:Brain Stem / Q000502:physiology*; D003391:Cranial Nerves / Q000502:physiology; D003655:Decerebrate State; D006706:Homeostasis; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000652:urine*; D013649:Taste / Q000502:physiology*; D014882:Water-Electrolyte Balance
D012964:Sodium