Forebrain oscillators ticking with different clock hands.
Clock proteins like PER1 and PER2 are expressed in the brain, but little is known about their functionality outside the main suprachiasmatic clock. Here we show that PER1 and PER2 were neither uniformly present nor identically phased in forebrain structures of mice fed ad libitum. Altered expression of the clock gene Cry1 was observed in respective Per1 or Per2 mutants. In response to hypocaloric feeding, PERs timing was not markedly affected in few forebrain structures (hippocampus). In most other forebrain oscillators, including those expressing only PER1 (e.g., dorsomedial hypothalamus), PER2 (e.g., paraventricular hypothalamus) or both (e.g., paraventricular thalamus), PER1 was up-regulated and PER2 largely phase-advanced. Cry1 expression was selectively modified in the forebrain of Per mutants challenged with hypocaloric feeding. Our results suggest that there is not one single cerebral clock, but a system of multiple brain oscillators ticking with different clock hands and differentially sensitive to nutritional cues.
Feillet
Céline A
CA
Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, IFR37, University Louis Pasteur,67084 Strasbourg, France.
Mendoza
Jorge
J
Albrecht
Urs
U
Pévet
Paul
P
Challet
Etienne
E
D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D031204:Caloric Restriction; D018797:Cell Cycle Proteins / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics*; D056931:Cryptochromes; D005420:Flavoproteins / Q000235:genetics; D005508:Food Deprivation / Q000502:physiology*; D005786:Gene Expression Regulation / Q000235:genetics; D006624:Hippocampus / Q000378:metabolism; D007031:Hypothalamus / Q000033:anatomy & histology / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics*; D056950:Period Circadian Proteins; D016548:Prosencephalon / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics
D018797:Cell Cycle Proteins; C538964:Cry1 protein, mouse; D056931:Cryptochromes; D005420:Flavoproteins; D009687:Nuclear Proteins; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D014157:Transcription Factors