Fig. 2.

Time-of-day-dependent variations of scratching behavior in NC/Tnd mice. Scratching frequency (a) and duration (b) of 36 NC/Tnd mice (male, n=16; female, n=20) with moderate to severe dermatitis between 12 and 24 weeks of age were recorded for 24 hr. The white and black bars above the graphs indicate the light and dark periods, respectively. Data represent the mean of 36 mice ± SEM. Friedman test detected significant difference of data among the different times in scratching frequency and duration (P<0.05).