Figure 1.
Limits of entrainment of FAA in wild-type mice.
Representative actograms of locomotor activity plotted at a day length corresponding to each feeding schedule for easier visual assessment of the FAA in intact (A) and SCN-ablated (B) C57BL/6 wild-type mice. Time is plotted left-to-right in 10-min bins. Mice were maintained in constant darkness as indicated by closed bars at the top of the actograms. Feeding time is indicated by gray shaded boxes. (C and D) Mean profiles of locomotor activity are plotted along each RF schedule (C: SCN intact, n = 4; D: SCN ablated, n = 7). Mean profile was calculated using individual mean 7-day profiles. Each data point represents counts per minute averaged across a 20-min bin. Integrated periodogram of SCN-intact wild-type mice in baseline ad libitum feeding (E, top) and 20-h RF schedule (E, bottom) conditions (n = 4). Integrated periodogram of SCN-ablated wild-type mice in the baseline ad libitum feeding condition (F, n = 7). Significance level (dotted line) is P = 0.05 for individuals. (G) FAA ratios of the SCN-ablated mice on serial feeding schedules. Significant differences are indicated by asterisks (n = 7, vs. ad libitum, ANOVA post-hoc Dunnett test). *P<0.05.
Figure 2.
Limits of entrainment of FAA in Cry1- or Cry2-deficient mice.
Representative actograms of locomotor activity plotted at a day length corresponding to each feeding schedule in Cry1−/− (A) and Cry2−/− (B) mice with SCN ablation. Time is plotted left-to-right in 10-min bins. Mice were maintained in constant darkness as indicated by closed bars at the top of the actograms. Feeding time is indicated by gray shaded boxes. (C and D) Mean profiles of locomotor activities are plotted along each RF schedule (C: Cry1−/−, n = 8; D: Cry2−/−, n = 7). Mean profile was calculated using individual mean 7-day profiles. Each data point represents counts per minute averaged across a 20-min bin. (E and F) FAA ratios of Cry1−/− (E) and Cry2−/− (F) mice on serial feeding schedules. Significant differences are indicated by asterisks (E: Cry1−/−, n = 8; F: Cry2−/−, n = 7, vs. ad libitum, ANOVA post-hoc Dunnett test). *P<0.05. (G and H) Mean serial plots of locomotor activity for 82 h represented in a 60-min bin. The last feeding time is set to zero. Cry-deficient mice were food-deprived for 44 h during the 24-h RF schedule (G_T24 and H_T24), then returned to a 24-h RF schedule and food-deprived for 48 h after 21-h (G_T21 and H_T21) and 22-h (G_T22 and H_T22) RF schedules, then returned to ad libitum feeding. Serial-plotted portions are indicated by a thick vertical line in (A) and (B).
Figure 3.
Persistence of FAA rhythms during food deprivation in the case of entrainment.
(A) Representative actogram of locomotor activity in SCN-ablated C57BL/6 wild-type mice under 24 h RF schedule. Time is plotted left-to-right in 10-min bins. Mice were maintained in constant darkness as indicated by closed bars at the top of the actograms. Feeding time is indicated by gray shaded boxes. (B) Periodogram during the baseline before RF from the mouse represented in (A). (C) Group profiles of locomotor activity are plotted for 48 h in a 60-min bin (n = 6). Serial-plotted portions are indicated by a thick vertical line in (A). Previous feeding time is indicated by transparent dotted boxes. (D) Representative actogram of locomotor activity in Bmal1−/− mice under 24 h RF schedule. (E) Circular analysis of inter-day deviation of the pre-feeding activity phase in individual Bmal1−/− mice. The start of feeding time is set to zero. The mean pre-feeding activity phase to 24-h RF schedule is indicated by a thick arrow (n = 5). (F) Mean profiles of locomotor activity are plotted for 48 h in a 60-min bin (n = 6). Serial-plotted portions are indicated by a thick vertical line in (D).
Figure 4.
Broader range of pre-feeding activity rhythms in Bmal1-deficient mice.
(A) Representative actograms of locomotor activity plotted at a day length corresponding to each feeding schedule in Bmal1−/− mice. Time is plotted left-to-right in 10-min bins. Feeding time is indicated by gray shaded boxes. (B) Mean profiles of locomotor activity are plotted along each RF schedule (n = 5). Mean profile was calculated using individual mean 7-day profiles. Representative actograms of locomotor activity plotted at a day length corresponding to 18-h (C) and 15-h (E) RF schedules in Bmal1−/− mice. Mean profiles of locomotor activities are plotted along 18-h (D, n = 7) and 15-h (F, n = 7) RF schedules in a 20-min bin. (G) Pre-feeding activity phases (circular analysis for individuals) to T-cycle schedules. Error bar indicates mean inter-day deviation of pre-feeding activity phases. (H) Food intake per hour during ad libitum and RF conditions.