No influence of ECS on the circadian clock.
Double-plotted activity records of representative mice receiving one ECS (red triangles) at different times of the day: circadian time (CT) 0, 4, 8, 12, 16, and 20. CT0–12 is the subjective light phase, and CT12–24 is the subjective dark phase. The light and dark periods are indicated by white and gray backgrounds, respectively. Onset of activity shown by green lines was used as the reference phase for the determination of phase shift.