Fig. 4.

Optical stimulation of BLA astrocytic Rac1 decreases the neuronal activation induced by fear conditioning. A Diagram of the experiment timeline. Mice were put into the behavioral chamber, underwent footshock or not, and were perfused 90 min later. B Representative immunofluorescence images of BLA c-Fos⁺ neurons in mice with and without footshock (scale bars, 100 μm). C Quantitative analysis showing that footshock significantly increases c-Fos expression in the BLA (Control: n = 5, Footshock: n = 6; ***P < 0.001, Control vs Footshock, t-test). D Diagram of the experiment timeline. Three weeks after virus injection, the mice underwent 5 trials of CS-US paired conditioning with laser stimulation (473 nm) and were perfused 90 min later. E Representative immunofluorescence images showing c-Fos⁺ neurons in the BLA of mice in the Rac1-C450A, Rac1-PA, and Rac1-DN/PA groups (scale bars, 100 μm). F Quantitative analysis showing that laser stimulation of Rac1-PA and Rac1-DN/PA both significantly decrease c-Fos expression in the BLA (n = 5 in each group; ***P < 0.001, C450A vs PA, C450A vs DN/PA, one-way ANOVA).