Université de Fribourg

Behavioural food-anticipation in clock genes deficient mice: confirming old phenotypes, describing new phenotypes

Mendoza, Jorge ; Albrecht, Urs ; Challet, Etienne

In: Genes, Brain and Behavior, 2010, vol. 9, p. -

Animals fed daily at the same time exhibit circadian food-anticipatory activity (FAA), which has been suggested to be driven by one or several food-entrainable oscillators (FEOs). FAA is altered in mice lacking some circadian genes essential for timekeeping in the main suprachiasmatic clock (SCN). Here we confirmed that single mutations of clock genes Per1−/− and...

Université de Fribourg

“Feeding time” for the brain: A matter of clocks

Feillet, Céline A. ; Albrecht, Urs ; Challet, Etienne

In: Journal of Physiology-Paris, 2006, vol. 100, no. 5-6, p. 252-260

Circadian clocks are autonomous time-keeping mechanisms that allow living organisms to predict and adapt to environmental rhythms of light, temperature and food availability. At the molecular level, circadian clocks use clock and clock-controlled genes to generate rhythmicity and distribute temporal signals. In mammals, synchronization of the master circadian clock located in the suprachiasmatic...

Université de Fribourg

Forebrain oscillators ticking with different clock hands

Feillet, Céline A. ; Mendoza, Jorge ; Albrecht, Urs ; Pévet, Paul ; Challet, Etienne

In: Molecular and Cellular Neuroscience, 2008, vol. 37, no. 2, p. 209-221

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...

Université de Fribourg

Lack of Food Anticipation in Per2 Mutant Mice

Feillet, Céline A. ; Ripperger, Jürgen A. ; Magnone, Maria Chiara ; Dulloo, Abdul G. ; Albrecht, Urs ; Challet, Etienne

In: Current Biology, 2006, vol. 16, no. 20, p. 2016-2022

Predicting time of food availability is key for survival in most animals. Under restricted feeding conditions, this prediction is manifested in anticipatory bouts of locomotor activity and body temperature. This process seems to be driven by a food-entrainable oscillator independent of the main, light-entrainable clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus 1 and 2....