(a) Schematic timeline of the experimental procedure. While on a Dox diet (+Dox), AAV-RAM-NLS-mKate2 and AAV-Ef1α-EGFP vectors were injected into the lateral amygdala (LA, b), basal nucleus (BA, d), or central amygdala (CeA, g). After at least 7 days, Dox was removed (-Dox) for 48 hr, the animals were exposed to tone-fear conditioning (TFC; consisting of Tone and Shock, T+S), Tone only, or Shock only and sacrificed 24 hr later. A control cohort of similarly injected and treated animals was left undisturbed in their home cages (HC) for the entire period before being sacrificed. (b) Schematic drawing of the amygdala with the injection and the quantification site (LA) highlighted in blue. (c) Percentage of RAM+ cells among total EGFP+ cells in LA for HC, T+S, Tone, and Shock animals. n = 3–6 animals per condition, one-way ANOVA, Tukey’s post-hoc test. (d) As panel b, but for the BA region. (e) Percentage of RAM+ cells among total EGFP+ cells in BA for HC, T+S, Tone and Shock animals. n = 3–4 animals per condition, one-way ANOVA, Tukey’s post-hoc test. (f) Representative images of neurons labeled in LA and BA for HC, T+S, Tone and Shock conditions. Neurons labeled by AAV-RAM-mKate2 are red and cells labeled by AAV-Ef1α-EGFP are green. The merged left image is enlarged in the two right images. Red arrows indicate RAM and EGFP double-labeled cells. The scale bar is 300 μm and 50 μm for left and right images, respectively. (g) As panel b, but for the CeA region. (h) Percentage of RAM+ cells among total EGFP+ cells in CeA for HC and T+S animals. n = 3 animals per condition, Student’s t-test. (i) Representative images of neurons labeled in CeA region. The scale bar is 150 μm for all images. All data in c, e and h are mean ± SEM. *p<0.05, **p<0.01, ***p<0.001.