Fig. 2: Experiment 2: chemogenetic inhibition of BLA-projecting IL neurons did not affect safety expression. | Neuropsychopharmacology

Fig. 2: Experiment 2: chemogenetic inhibition of BLA-projecting IL neurons did not affect safety expression.

From: Suppressing fear in the presence of a safety cue requires infralimbic cortical signaling to central amygdala

Fig. 2

A Schematic showing intersectional viral strategy for expressing hM4Di-mCherry in BLA-projecting IL neurons. Bi mCherry expression for one rat in the IL with little to no spillover into prelimbic cortex. White x’s indicate the recording location from (C). Bii GFP expression for one rat in the BLA marking the infusion site, showing little to now spillover into the CeA. C Virus-free (n = 3) and hM4Di-mCherry expressing (n = 2) rats were taken for anesthetized IL recordings under CNO conditions. CNO injection resulted in significant inhibition of spikes per bin in hM4 rats at 40 and 60 min post-CNO injection (**p < 0.01 compared to time 0), and a significant excitation in virus-free rats at 60–120 min (*p < 0.05, **p < 0.01, ****p < 0.0001 compared to time 0). Spikes per bin was significantly lower in hM4 rats at 40–120 min compared to virus-free rats (###p < 0.001, ####p < 0.0001). D, left All rats received vehicle prior to DC1-3. During DC2-3, percent time spent freezing was higher to the fear cue compared to the fear+safety cue (**p < 0.01, ***p < 0.001 compared to fear cue). D, right Using a within-subjects design, rats received CNO before either DC4 or DC5, and vehicle before the other session. Under both vehicle and CNO conditions, percent time freezing was significantly higher to the fear cue compared to the fear + safety cue (***p < 0.001 compared to fear cue). E, left All rats received vehicle prior to DC1-3. For all sessions, percent time at port was higher to the reward cue compared to all other cues (*p < 0.05, **p < 0.01 compared to reward cue). E, right Using a within-subjects design, rats received CNO before either DC4 or DC5, and vehicle before the other session. Under both vehicle and CNO conditions, percent time at port was significantly higher to the reward cue compared to all other cues (****p < 0.0001 compared to reward cue). Data points in red from right panels of (D) and (E) are from the rat that was taken to contribute to recordings shown in (C).

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