FIGURE 3.

Ultradian behavior under constant darkness (DD). (A) Average activity of mice (measured as the fraction of active bins) during the day and during the night under DD and LD cycles. In DD, day and night refer to subjective day and subjective night, respectively. The LD group consists of data from the three T-cycles. Each animal contributed two points, one each to the day and the night groups – pairing is denoted by gray lines. Fold-change in the average activity between night and day is presented as a boxplot. (B,C) The model-based estimates of the mean rest (B) and mean activity (C) bout lengths in the (subjective) night and (subjective) day in DD and LD. Data points from the same mice are connected by gray lines. The bout length averaged over all individuals is marked with black bars. Boxplots show the fold-change in bout lengths from night to day. (D) The relative lengths of the mean rest and mean activity bouts in the (subjective) day and (subjective) night in DD and LD [a different representation of data in panels (B) and (C)].