User:Yuwei.zhao/draft

=Ueli Schibler 2nd reference= Schibler and his colleagues have also studied the effect of de-synchronization of peripheral clocks with the central pacemaker. In 2000, he conducted experiments on the effects of restricted feeding time on mice, and observed the uncoupling of circadian oscillators in the peripheral tissues from the central pacemaker in the Suprachiasmatic nucleus (SCN). . Mice are nocturnal mammals and will normally feed during the night. By feeding laboratory mice exclusively during the day, for 9 consecutive days, researchers induced a phase change in the peripheral cells of the heart, liver and pancreas by up to 12 hours, while leaving the phase of cyclic gene expression in the SCN unaffected.[1] Phase change was measured by mRNA expression of putative clock genes PER1, PER2, PER3, CRY1, and clock-controlled genes DBP, Rev-erbα, and CYP2A5. Phases in mRNA changed gradually in the liver with restricted feeding schedule, similar to the light-mediated shifts in the SCN. The phase shift in peripheral tissues and lack of shift in the SCN were observed both in light-dark conditions as in dark-dark conditions. These results show that feeding time functions as a potent Zeitgeber for peripheral cells, but not for the SCN. Schibler and colleagues posited that the food Zeitgeber functions by counteracting the synchronization of peripheral tissues to the central pacemaker in the SCN.