Figure 1.

Experimental design and effects of repeated episodes of social defeat on the behaviors of male adolescent mice. (a) Thirty-day-old mice were socially defeated for a period of up to 5 min of physical interaction followed by 30 min of cohabitation with the aggressor (threat period) daily during the afternoon for 21 days. The animals were submitted to the open field (OF), elevated plus-maze (EPM), and forced swimming (FS) tests during the morning and to the sucrose preference (SP) overnight. (b) OF: travelling time (s) in the total area (TA), peripheral area (PA) and central area (CA) over 5 min. (c) EPM: % time spent in the open arms during 5 min. (d) FS: time spent immobile (s) in the final 4 min. (e) SP: %=sucrose intake (ml)/total fluid intake (ml) × 100. Means±s.e.m.; *P<0.05; n=15–18 each for OF, FST, SP; n=6 each for EPM.