Figure 2. Instant heart rate responses to handling and novel environment exposures.

(A) Illustration of the handling method: cup handling [38] (left) and two examples of instant HR response to handling (right). The red bars indicate the duration of handling (49 seconds and 37 seconds, respectively). (B) Instant HR responses of an individual mouse during repeated exposures to a novel environment (left panels) and illustration of a novel environment (right). The blue vertical line indicates the start of stage-I; the red vertical line indicates the end of stage-I; the green vertical line indicates the end of the novel environment exposure. (C) The duration of stage-I during repeated novel environment exposures. Error bars, s.e.m.; n = 7; *P<0.05, **P<0.01, one-way repeated measures ANOVA and Tukey post hoc test.