Figure 7.

Mapping the lung innervation by vagal Tac1+ nerves. A, Approach for labeling all Tac1+ afferents with tdTomato and vagal Tac1+ afferents with GFP. B, Lung slice stained for E-cadherin (red) and DAPI (blue) showing GFP-expressing (green) nerves innervating conducting airways (white arrows). C, Lung slice stained for DAPI (blue) showing a large conducting airway trench innervated by GFP-expressing (green) nerves (white arrow) and tdTomato-expressing (red) nerves (gray arrow). D, Lung slice stained for DAPI (blue) showing a conducting airway innervated by fibers expressing both GFP (green) and tdTomato (red). E, Higher magnification of white box in D, with identified tdTomato+ nerve terminal (white arrow). F, Lung slice stained for DAPI (blue) showing a large blood vessel (slightly folded) innervated by GFP-expressing (green) nerves and tdTomato-expressing (red) nerves. G, Individual z-planes (1–3) of the white box in F, at higher magnification, showing fibers expressing only tdTomato innervating the inner muscle layers (gray arrows), whereas GFP-expressing fibers (white arrow) innervate only the outer muscle layer. In some images, lumens are denoted by “L.” Scale bars denote 100 μm (B, C, D, F), 50 μm (G), or 20 μm (E).