Fig. 4: Impairment in light-induced phase advance in L-PGDS−/− mice.

Phase shift induced by light stimulation at CT 21 (a, b) and CT 15 (c, d) in L-PGDS−/− and wild-type mice. a, c Representative double-plotted actograms. Yellow arrowheads indicate light stimulation (20 lx, 30 min). Paired red lines represent the onset of activity. Quantification of the phase shift induced by light stimulation. The values are expressed as the mean ± SEM (n = 4–5 (b), n = 3–9 (d) per group). *p < 0.05; **p < 0.01. Statistically significant differences were assessed using two-way ANOVA followed by Tukey–Kramer tests. Resynchronization of circadian rhythms to time shifts, 8 h advance (e, f) and 8 h delay (g, h). e, g Representative patterns of wheel running activity. f, h Quantification of the phase shift. The values are expressed as the mean ± SEM (n = 6–8 per group). **p < 0.01. Statistically significant differences were assessed using two-way repeated measures ANOVA.