Fig. 6: Inhibition of LC-NE projections to the CB impairs auditory fear conditioning.

a Arch3-YFP was bilaterally injected into the LC of TH-Cre mice and optic fibers were bilaterally implanted in the CB vermis. b Stereotaxic and histology location of the optical fibers. On the left is a picture from the mouse brain atlas (Franklin and Paxinos; 2007). On the right is an image of a cerebellar slice showing the fiber placement in the cerebellum. Scale bar, 500 μm. The image is representative of at least four replicates per experimental conditions. c, d Arch3-YFP and TH expression in LC neurons and their axon terminals in the CB. PCL Purkinje cell layer, GL granular layer, and ML molecular layer. Scale bar, 100 μm. Each image is representative of at least four replicates per experimental conditions. e Optogenetic inhibition of LC axons in the CB during CS–US presentation suppressed the freezing response to recall tone (one-way ANOVA F(2, 10) = 16.87, p = 0,0006; Tukey’s post hoc test: Arch3-laser on versus YFP-laser on, p = 0.0013; Arch3-laser on versus Arch3-laser off, p = 0.002; Arch3-laser off versus YFP-laser on, p = 0.62; n = 5 mice treated with Arch3-laser on, n = 5 mice treated with Arch3-laser off, n = 3 mice treated with YFP-laser on). Data are presented as mean values ± SEM. Source data are provided as Source Data file.