Figure 2.
Delayed phase angle of entrainment. Phase angles of entrainment was recorded over 5 one-week periods selected at 3-5 week intervals throughout the experiment, and the mean (± S.E.M.) was used to compare between two groups. In the final week (134-141 days) of the experiment, the npy-/- mice showed a significantly delayed onset of activity compared to WT mice (the difference of phase angle of entrainment between start point and end point of the treatment WT -15.4 min vs. npy-/- mice -42.9 min; t(17) = -2.11, P < 0.05). Groups did not significantly differ before this time point.