title: Setting the main circadian clock of a diurnal mammal by hypocaloric feeding.
abstract: Caloric restriction attenuates the onset of a number of pathologies related to ageing. In mammals, circadian rhythms, controlled by the hypothalamic suprachiasmatic (SCN) clock, are altered with ageing. Although light is the main synchronizer for the clock, a daily hypocaloric feeding (HF) may also modulate the SCN activity in nocturnal rodents. Here we report that a HF also affects behavioural, physiological and molecular circadian rhythms of the diurnal rodent Arvicanthis ansorgei. Under constant darkness HF, but not normocaloric feeding (NF), entrains circadian behaviour. Under a light–dark cycle, HF at midnight led to phase delays of the rhythms of locomotor activity and plasma corticosterone. Furthermore, Per2 and vasopressin gene oscillations in the SCN were phase delayed in HF Arvicanthis compared with animals fed ad libitum. Moreover, light-induced expression of Per genes in the SCN was modified in HF Arvicanthis, despite a non-significant effect on light-induced behavioural phase delays. Together, our data show that HF affects the circadian system of the diurnal rodent Arvicanthis ansorgei differentially from nocturnal rodents. The Arvicanthis model has relevance for the potential use of HF to manipulate circadian rhythms in diurnal species including humans.
authors.affiliation: Département de Neurobiologie des Rythmes, Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR-3212, 5 rue Blaise Pascal, 67084 Strasbourg, France. jmendoza@inci-cnrs.unistra.fr
authors.forename: Jorge
authors.initials: J
authors.lastname: Mendoza
authors.forename: Sylviane
authors.initials: S
authors.lastname: Gourmelen
authors.forename: Stephanie
authors.initials: S
authors.lastname: Dumont
authors.forename: Dominique
authors.initials: D
authors.lastname: Sage-Ciocca
authors.forename: Paul
authors.initials: P
authors.lastname: Pévet
authors.forename: Etienne
authors.initials: E
authors.lastname: Challet
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001786:Blood Glucose / Q000032:analysis; D031204:Caloric Restriction; D057906:Circadian Clocks / Q000502:physiology*; D015870:Gene Expression; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1 / Q000235:genetics; D056950:Period Circadian Proteins / Q000235:genetics; D012377:Rodentia; D012420:Running; D013493:Suprachiasmatic Nucleus / Q000502:physiology*; D014667:Vasopressins / Q000235:genetics
chemical_list: D001786:Blood Glucose; D009419:Nerve Tissue Proteins; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D056950:Period Circadian Proteins; D014667:Vasopressins