The phase of peak PER2::LUC expression is altered in the ME/PT of food deprived mice. (A) Rayleigh vector plots showing the phase of peak PER2::LUC expression in vitro, calculated as the time of peak bioluminescence after cull of animal, in the ME/PT of food deprived and control animals. In control animals the phase was significantly correlated with time of cull, peaking on average 31.3 ± 0.9 h after cull (n = 12) versus 42.4 ± 2.3 h in food deprived animals (n = 5, p < 0.001). (B) Lower panels highlight the differences in phase of PER2::LUC expression in neuronal tissue of the MBH in representative control and food deprived mice. Time of peak PER2::LUC is indicated by colored arrowheads; Arc (red), DMH (blue) and the ME/PT (purple). Note the altered peak phase of the ME/PT in the food deprived mouse.