Figure 4.

Locomotor activity rhythms in chow and high-fat diet-fed mice. Male wild-type mice were single-housed in 12L: 12D with locked (A–D) or freely rotating (E–H) running wheels at 7 weeks old. Chow was provided ad libitum for 1 week (Days 1–7) and then chow was replaced with high-fat diet (HFD) for 1 week (Days 8–15). Representative circular histograms (A–H; plotted in 10-min bins; scale: inner circle, 0; middle circle, 5.5, outer circle, 11; units: activity counts per 10-min bin) show the distribution of general activity (A,B,E,F; measured with a passive infrared sensor) and wheel activity (G,H; no wheel revs in C,D because wheel was locked) for a mouse during chow (Day 7; left panels) and HFD (Day 9; right panels) consumption relative to the time of day (where 0 is lights on and 12 is lights off). Grand mean vectors of general activity (I; n = 5 mice/group) and wheel-running activity (J; n = 5 mice/group) during chow (black and green arrows) or HFD (blue and red arrows) feeding in mice with locked (black and blue arrows) or freely-rotating wheels are plotted on the circular histogram (plotted in 10-min bins; scale: inner circle, 0.35; outer circle, 0.7). The size and length of the arrow represents the uniformity of the distribution of activity where small, short arrows indicate that activity is more evenly distributed across the cycle.