Figure 7

Effects of specific activation of the elPB-CeC pathway on the auditory-conditioned fear. A, A schematic of the experimental approach. B, Representative images showing bright YFP expression at the injection site (right panel) and the corresponding level of atlas [15] (left panel) in the slices prepared after completion of the behavioral experiments (6 weeks after AAV microinjection). C, Representative images showing bright YFP expression in the axonal terminals in the CeC region. Scale bar in the right panel, 100 μm. D, Pseudo-color plots showing the instantaneous freezing ratio of an individual mouse during the retrieval tests in the CS-LED paired group (n = 22, top), the immediate shock (IS) group (n = 7, middle), and the GFP control group (n = 6, bottom). The green horizontal bar indicates the period in which the auditory cue was delivered. E, Summary of freezing ratios during the first 30 s after the animal was placed in the retrieval chamber (baseline) and during the first 30 s after the onset of CS presentation. The mean ± SEM values for the three groups are shown with open circles representing the values for each mouse. In the retrieval test, the freezing ratio in the CS-LED paired group is significantly higher than that in both the IS group and GFP control group (CS-LED paired group vs. control, p < 0.05; CS-LED paired group vs. IS group, p < 0.05; Welch’s t-test followed by correction with Bonferroni-Holm method). The crossed circle in the CS-LED paired group represents an individual showing a higher freezing ratio than the others during the baseline period, yet not during CS presentation, suggesting that higher freezing ratio is not necessarily attributable to this individual. No significant differences in freezing ratio between the IS group and control group. * P < 0.05.