title: Suprachiasmatic nuclei lesions eliminate light/dark variations in short-term feeding responses to deprivation or insulin treatment in rats.
abstract: Short-term (1-h, 4-h and 12-h) and long-term (24-h) feeding responses to 24-h food deprivation (FD) or insulin treatment (IT) (8 mU/kg IP) were studied in male rats under a 12/12-h light/dark (L/D) cycle. The 24-h FD or the IT began either at onset (Dawn) or offset (Dusk) of the lights. In sham-operated rats (Shams) both protocols elicited greater short-term feeding responses at Dusk (p less than 0.05 or less). In suprachiasmatic nuclei (SCN)-lesioned rats the L/D variations in short-term responses were absent. In both SCN and Shams the 24-h feeding responses did not depend on stimuli time-schedule. We conclude that the regulation of short-term (circadian), but not long-term, feeding responses to metabolic stimuli is dependent on SCN integrity in the rat.
authors.affiliation: Department of Physiology, Medico-Biological Institute, Medical Academy, Sofia, Bulgaria.
authors.forename: A G
authors.initials: AG
authors.lastname: Stoynev
authors.forename: O C
authors.initials: OC
authors.lastname: Ikonomov
authors.forename: I A
authors.initials: IA
authors.lastname: Damova
authors.forename: P D
authors.initials: PD
authors.lastname: Penev
authors.forename: K G
authors.initials: KG
authors.lastname: Usunoff
authors.forename: A M
authors.initials: AM
authors.lastname: Paloff
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002940:Circadian Rhythm / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D006815:Hunger / Q000502:physiology*; D007328:Insulin / Q000502:physiology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013493:Suprachiasmatic Nucleus / Q000502:physiology*
chemical_list: D007328:Insulin