Figure 3.

Rhythmicity of expression of key transcriptional regulators of metabolism is dependent on Mc3r during RF. A) Rhythmicity of expression of Pcg1a, Pgc1β, Foxo1, and Hnf4α is phase-shifted and amplified during RF (compare left panels with right panels) in WT mice. In contrast, Mc3r^−/− mice subjected to RF exhibit a marked loss of rhythmicity of expression during peak activity levels in WT controls. B) Amplification of rhythms of expression of Pcg1a, Pgc1β, Foxo1, and Hnf4α by RF is attenuated by the central infusion of AgRP^82–131 (0.05 nmol/d). Mice receiving AgRP^82–131 or acsf exhibited comparable rhythmicity of gene expression when food was presented at the onset of dark period. However, the phase shift in expression associated with RF observed in controls was attenuated by centrally administered AgRP^82–131. *P < 0.05 vs. corresponding acsf.