Mus, as GABAA receptor agonist were microinjected to BLA immediately after social aggression. Interestingly, on day 3 after microinjection with Mus or saline, the freezing time of the mice in the Mus-group was lower than that of the mice in the saline-group (Fig. 5c, p < 0.01). Also, the mice in the Mus-group spent more time on the interaction zone than the mice in the saline-group (Fig. 5b, d, p < 0.05). To identify whether social defeat accompanied depression or anxiety, sucrose preference and marble burying test were performed before test of social interaction. The results showed Mus injection increased sucrose preference (Fig. 5e, p < 0.05), but no significant effects on marble burying (Fig. 5f, p > 0.05), which suggested social defeat induced by acute social aggression accompanied depression-like behavior, but not anxiety.Fig. 5Effects of Mus microinjection to the BLA on social defeat stress. a Diagram of experimental flow. b Representative images of the moving track during social interaction. c Freezing time of intruder mice during a 5-min open-field test at day 3 after treatment. d Time spent in the social interaction zone at day 3 after treatment, compared with saline injection. e Sucrose reference at day 3 after treatment. f Marble burying test at day 3 after treatment. Independent student t test was used, *p < 0.05, **p < 0.01 compared with the saline-group, n = 8