Fig. 1

Rhythm amplitude (A) and rhythm period (B) of two different LD-cycle rats measured by Clock Lab. Twenty-four-hour sleep duration (C) and the average sleep duration at 16:00 (D) of rats with two rhythms measured by HomeCage. *p < 0.05, **p < 0.01, ***p < 0.001 (two-sample t-test). E The 24-h activity track of the two groups of rats over 12 consecutive days. The green mark represents the number of times the rat pushed the wheel at this time point, and the red dot represents the onset of the rat’s activity. IP prolonged the rhythm period of rats and gradually delayed the onset of activity. F The 24-h sleep duration trajectory of the two groups of rats. The CA group was measured for 2 days (48 h), and the photoperiod was LD. The CM group was continuously measured for 3 days (72 h), and the photoperiods were DL, DD, and LD. The black shading denotes that the rat was in the dark phase. The white area indicates that the rat was in the light phase. The area shaded in pink represents the sleep time of rats from 15:00 to 17:00, and the average sleep time of rat at 16:00. Abbreviations: CA, circadian alignment; CM, circadian misalignment; DD, dark/dark; DL, dark/light; IP, inverted photoperiod; LD, light/dark