Extended Data Fig. 9. The effect of the optogenetic inhibition and excitation of dopaminergic terminals disappears with additional fear conditioning training.
Freezing response to the CS+ and pre-exposed CS+ did not differ in the eYFP or ChR2 groups on the second session of fear conditioning (Multiple comparison ps >0.05). Freezing to the CS+ was still greater than the freezing response to the pre-exposed CS+ at the end of the session 2 (2-way ANOVA cue × group interaction F(2,36)=4.31, p = 0.02; Multiple comparisons: NpHR pre-exposed CS+ vs. CS+ p=0.04). This suggest that the freezing response to all cues (pre-exposed and non-pre-exposed) reached the asymptotic level with additional training but the enhancing effect of dopamine inhibition during pre-exposure on latent inhibition persisted beyond the initial fear conditioning session. Data represented as mean ± S.E.M., * p<0.05, ns = not significant.