Increasing or decreasing astrocytic Rac1 activity in the BLA impairs fear memory acquisition. A Diagram of the experiment timeline. The AAV was injected 3 weeks before the behavioral tests. The laser stimulation (473 nm) was delivered 5 min before and during the 5 trials of CS-US pairing conditioning, then contextual and cued memory retention were tested 1 and 2 days later. B Compared to the Rac1-C450A group, laser activation of Rac1-PA and Rac1-DN/PA both attenuate the fear memory acquisition (Rac1-C450A: n = 20, Rac1-PA: n = 20, Rac1-DN/PA: n = 20; *P < 0.05, **P < 0.01, ***P < 0.001, C450A vs PA, #P < 0.05, ##P < 0.01, ###P < 0.001, C450A vs DN/PA, ANOVA with repeated measures and Bonferroni’s post hoc test). C Similarly, compared to the Rac1-C450A group, laser activation of Rac1-PA and Rac1-DN/PA both impaired contextual and cued fear memory (Rac1-C450A: n = 11, Rac1-PA: n = 13, Rac1-DN/PA: n = 12; *P < 0.05, C450A vs PA, C450A vs DN/PA, one-way ANOVA).