Faculté des sciences

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... Plus

Ajouter à la liste personnelle
    Summary
    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 Per2Brdm1 alter FAA expression in constant darkness (DD) or under a light-dark cycle (LD). Furthermore, we found that Per1−/−;Per2Brdm1 and Per2Brdm1;Cry1−/− double mutant animals did not display a stable and significant FAA either in DD or LD. Interestingly, rescued behavioural rhythms in Per2Brdm1;Cry2−/− mice in DD were totally entrained to feeding time and re-synchronized after phase-shifts of mealtime, indicating a higher SCN sensitivity to feeding cues. However, under an LD cycle and restricted feeding at midday, FAA in double Per2Brdm1;Cry2−/− mutant mice was absent. These results indicate that shutting down one or two clock genes results in altered circadian meal anticipation. Moreover, we demonstrate that in a genetically rescued SCN clock (Per2Brdm1;Cry2−/−), food is a powerful zeitgeber to entrain behavioural rhythms, leading the SCN to be more sensitive to feeding cues than in wild-type littermates.