Figure 4. Effect of chronic social defeat and clomipramine on urinary cortisol and self-grooming behavior.

(A) In the Naïve group, the concentration of urinary cortisol remained constant throughout the entire experiment. In the Sub+Sal group, stress induced a sustained elevation in urinary cortisol. Similarly, urinary free cortisol was elevated throughout the whole stress period in the Sub+Clo group. (B) On Week 7, urinary cortisol rhythm was measured in all groups. Clomipramine reduced urinary cortisol at 16:00–17:00, the time of peak activity for tree shrews. (C) Self-grooming behavior of both Sub+Sal and Sub+Clo groups were increased after 1 week social defeat. From 2 to 6 weeks, the number of autogrooming behavior in Sub+Sal group animals showed fluctuated relative to Sub+Clo group.