(A) Strategy for targeting of vCA1 PV-INs for photoexcitation with channelrhodopsin-2 (ChR2) or opsin-negative control vectors (eYFP only) in PV-Cre mice.
(B) Representative image of viral expression and optic fiber placement (dashed white line). A solid white box indicates the area of magnification (right).
(C) Design for CFC, extinction, reminder shock-induced relapse, and alternate context exposure, with photoexcitation tests at the indicated time points.
(D) No effect of ChR2-mediated photoexcitation during fear retrieval, extinction retrieval, relapse, and alternate context tests as analyzed by two-way repeated-measures ANOVA across all light-on and light-off epochs.
(E) Change in freezing between the pre-reminder shock BL period and first light-on epoch of the relapse test was not modulated by opsin expression. eYFP: n = 6; ChR2: n = 6. **p < 0.01, ***p < 0.001 by Šídák’s post hoc test. Error bars indicate standard error of mean.