Fig. 2

Effect of genotype (WT vs. Per2−/−) and restraint stress on CORT levels. Mice were restrained for 20 min (0–20 min; striped bar on x axis). In WT mice (solid black line), CORT peaked at 20 min, immediately at the conclusion of restraint and returned to baseline by 120 min. Similarly, CORT levels in the Per2−/− mice (dotted gray line) were elevated at 20 min (end of restraint stress), but unlike WT mice, CORT levels remained elevated throughout the 120 min time point. *p < 0.05 WT vs. respective Per2−/− time point. (n = 7–11 animals per group)