Fig. 4.

FFN270 is accumulated in NE axons of the barrel cortex. Representative images FFN270 (b) and FFN102 (c) loaded into layer 1 of the barrel cortex (a Bregma: −1.0 mm, Allen Institute)⁵¹ of acute murine brain slices (10 µM, 30 min, 20 µm Z-projections, 2-photon microscopy images). Noradrenergic axons appeared as long strings with punctate release sites, while blood vessels appeared as wider tube structures. FFN270 axonal labeling in Layer 1 of the barrel cortex was inhibited by nomifensine (d 2 µM, Nom.) or reboxetine (e 500 nM, Rebox.). f The average number of puncta per region of interest was significantly higher in control conditions (68.5 ± 22) than with Nom. (7.7 ± 0.7, P < 0.001) and Rebox. (17.5 ± 3.5, P < 0.01, one-way ANOVA; Dunnett’s test, n = 3, average of 2 slices per condition from 3 different animals). Blood vessel labeling was not inhibited. g–i FFN270 (g) labeling also highly colocalized (88.9%, 154/176 axons, 4 animals) with TH-GFP signal (h). All data listed as mean ± SEM. Scale bar: 10 µm