Figure 20.

nTS terminations of lung-specific TRPV1⁺ and Tac1⁺ afferents labeled with rAAV-flex-tdT. tdTomato expression enhanced by enhanced by α-DsRed immunoreactivity. A, B, Instillation of Cre-sensitive AAV into lungs of TRPV1-Cre. A, AAV-mediated tdTomato expression (red) identifying lung-specific TRPV1⁺ afferents in vagal ganglia (top) and merged with α-TRPV1 immunoreactivity (green; bottom). B, AAV-mediated tdTomato expression (red) in coronal sections of the medulla (labeling for the position relative to obex), counterstained with native autofluorescence (gray). C–E, instillation of Cre-sensitive AAV into lungs of Tac1-Cre. C, Composite image of serial coronal sections of the nTS (from −520 to −640 μm relative to obex), with tdTomato expression in lung-specific Tac1⁺ afferents labeled in pseudorainbow encoded by rostral–caudal position. D, E, High-magnification images of lung-specific Tac1⁺ afferents (red) in SolC at −520 μm, counterstained by neurotrace (green). D, Branching of afferent denoted by arrows. E, A single afferent makes putative synapses with two distinct intrinsic neurons, denoted by arrowheads. Contact SolC, SolM, and AP from C. F, High-magnification image of SolV, SolVL, and TS from C. The following structures are identified: area postrema (AP), dorsal motor nucleus of the vagus (10N), gracile fasciculus (g), 12N, SolC (C), SolCe (Ce), SolDL (DL), SolG (G), SolM (M), SolV (V), SolVL (VL), and TS. Scale bars: A, 50 μm; B, C, 100 μm; D, E, 10 μm.