Contextual fear conditioning activates a larger CeA fos ensemble than context conditioning. (A–C) Stereotaxic plate drawings of CeA rostro–caudal subregions (left; gray), along with representative examples of TRAPed neurons and corresponding summary distribution plots from context-TRAPed (middle) and fear-TRAPed (right) mice (n = 5/group) in the rostral (A), middle (B), and caudal (C) CeA subregions. Scale bars (context images: middle, left), 200 µm. (D) Average density of tdTomato+ counts in each CeA rostro–caudal subregion. (##) P = 0.0027, (###) P = 0.0003, (####) P < 0.0001 in context-TRAPed (squares) versus fear-TRAPed (circles) mice; (*) P = 0.0484 context group between subregions; (**) P = 0.0070, (***) P = 0.0002 fear group between subregions. Two-way ANOVA with Sidak's posttest. Data are mean ± SEM. (E) Average tdTomato+ count density in the rostral, middle, and caudal subregions of the CeAC and CeAML in context-TRAPed (pink) and fear-TRAPed (red) mice. (#) P = 0.0137, (####) P < 0.0001 between groups; (****) P < 0.0001 fear group between subdivision; (ϕϕϕϕ) P < 0.0001 fear group between rostro–caudal subregions. Three-way ANOVA with Tukey's posttest. Data are mean ± SEM. (F) Correlation between the amount of time spent freezing during memory recall and tdTomato+ counts in context (squares) and fear (circles) groups in the entire CeA (left), CeAC (middle), and CeAML (right). Least squares regression lines are shown along with corresponding Pearson's coefficients (r). Fisher's z-transformation was applied to compute r′ values and thereby compare the strength of correlations between groups for the entire CeA and its CeAC and CeAML subdivisions (see Supplemental Table S2).
