Fig. 6
From: A disinhibitory microcircuit in the temporal association cortex for fear retrieval to pure tones
Inhibition of VIP neurons in TeA effectively impaired pure tone auditory fear retrieval. (A) Left, injection of AAV2/9-hEF1a-DIO-eYFP in unilateral TeA of VIP-Cre mice. Right: example images of a VIP neuron’s axon (green) and SST neuron’s body (red) within immunofluorescence staining. (B) Left, schematic of VIP-Cre mice injected with AAV2/1-hEF1a-DIO-eGFP and AAV2/9-SST-mCherry virus in TeA. Right, an SST neuron(yellow) receiving projections from an upstream VIP neuron. (C) Left, injection of AAV2/9-hSyn-DIO-hM4D(Gi)-mCherry or AAV2/9-hSyn-DIO-mCherry in bilateral TeA. Right, hM4D(Gi) (red) expression in TeA. (D) Freezing% during fear conditioning (left) and retrieval test (right) in mice of (C). CS: hM4D- vs. hM4D+, t(18) = 4.71, p = 1.74 × 10−5, t test. (E) Top, injection of AAV2/9-hSyn-DIO-jGCaMP7s in unilateral TeA of VIP-Cre mice. Bottom, jGCaMP7s (green) expression at the injection site. (F) Heat maps (top) and mean Ca2+ traces ± s.e.m. (shaded area) (bottom) of calcium signaling from VIP neurons during preconditioning and retrieval test. (G-H) ΔF/F%(G) and CS-evoked freezing% (H) during the retrieval test for animals during preconditioning (gray) and retrieval (red) in (E). ΔF/F%: preconditioning vs. retrieval, t(7)=−4.19, p = 0.0041, two-sided paired t test; Freezing%: preconditioning vs. retrieval, t(7)=−15.534, p = 0.1 × 10−5, two-sided paired t test.
