Fig. 4

Antidepressant-like effects of ketamine in letrozole pre-treated male and female rats. A Acute (30 min post-treatment) and B repeated (1-day post-treatment) effects exerted by ketamine exposure in male and female rats pre-treated with vehicle or letrozole in the forced-swim test (FST). Data represent mean ± SEM of the time spent (s) immobile, climbing, or swimming. C Repeated effects (3-days post-treatment) exerted by ketamine exposure in male and female rats pre-treated with vehicle or letrozole in the novelty-suppressed feeding test (NSF). Data represent mean ± SEM of the feeding time (s), or distance traveled (cm). D Repeated effects (6–7 days post-treatment) exerted by ketamine exposure in male and female rats pre-treated with vehicle or letrozole in the sucrose preference test (SP). Data represent mean ± SEM of the sucrose intake (g/kg) or preference (%). A–C Individual values for each rat or D cage values (groups of 2–4 rats) are shown (symbols). Three-way ANOVAs (independent variables: Sex, pre-treatment and treatment) or two-way ANOVAs (independent variables: pre-treatment and treatment) were performed and results are shown in Additional file 1: Table S2. ^###p < 0.001 and ^##p < 0.01 when comparing female vs. male rats (effect of Sex). **p < 0.01 and *p < 0.05 for LTZ-Ket vs. LTZ-Sal and ^$p < 0.05 for LTZ-Ket vs. Veh-Ket. Sal saline, Ket ketamine, Veh vehicle, LTZ letrozole