Figure 2.

Records of locomotor wheel-running activity. (a,b) Activity was measured from wild-type (a) and Kcnma1^−/− (b) mice on an F2 (FVB/NJ) × (C57BL/6J/129) strain background for 8 d in the light-dark condition and for 14 d in constant darkness (shaded area). Actograms are double-plotted on a 48-h axis; dark bars at top indicate lights out in the light-dark condition. (c,d)χ² periodograms for wild-type (c) and Kcnma1^−/− (d) mice, generated from activity data in a and b. There was a dominant circadian peak for both genotypes (23.33 h and 23.83 h, respectively). The line denotes the 0.001 confidence interval. Group averages for all circadian statistics are presented in Table 1. (e,f) Fourier analysis for wild-type (e) and Kcnma1^−/− (f) mice, obtained from activity data in a and b. Arrows at 0.04 cycles per h correspond to the dominant 24-h rhythm. The amplitude of the circadian component was 0.168 for wild-type mice and 0.054 for Kcnma1^−/− mice. (g) Averaged summed total wheel-running activity per day ± s.e.m. for wild-type and Kcnma1^−/− mice in light-dark and constant darkness conditions. *P < 0.05.