Fig. 2

The CeA sends projections to the PnC. a Left, Sagittal representation of the mouse brain illustrating the Fluoro-Gold injection site in the PnC (yellow circle) and the retrograde labeling site in the CeA (red circle, dotted line). Right, Schematic of the hypothesis being tested. b Representative coronal PnC slice showing the extent of the Fluoro-Gold injection. The outer dotted circle indicates the fluorescent Fluoro-Gold injection halo. The inner dotted circle represents the center of the gliotic lesion, medial to the 7th cranial nerve and within the cytoarchitectural boundaries of the PnC. Inset: Representative image of the injection site in a coronal PnC slice, shown at lower magnification. c Representative Nissl-stained PnC section. The darker region surrounded by a dotted circular area indicates the gliotic lesion made by the Fluoro-Gold injection. d Representative image showing the Fluoro-Gold injection site in the PnC mapped to the Paxinos and Franklin Mouse Brain Atlas [52]. e Representative coronal section showing CeA neurons retrogradely labeled with Fluoro-Gold (cyan). f Higher magnification of the CeA neurons shown in e and retrogradely labeled with Fluoro-Gold. Representative of N = 4 mice. Scale bars: b–d 200 μm, e 500 μm, f 100 μm