Fig. 1.

Spinal cord and NTS injection sites and PVN labelling. (A) Micrograph of a longitudinal section of spinal cord, which shows site of pressure injection of FG (arrowhead) into the IML of the T2 segment that resulted in labelling of neurons in the PVN. (B) Coronal section of the PVN (Bregma −1.6 mm) showing neurons labelled with FG (blue, arrowhead) from the spinal cord and BDA fibres (green, arrows) from the NTS. (C) Micrograph of coronal section of NTS (Bregma −13.8 mm) showing an injection site (arrowhead) of BDA into the interstitial region of the NTS. (D) Coronal map of injection sites into NTS that resulted in axonal labelling in the PVN. Each filled circle represents a deposit of BDA into the NTS that resulted in axonal projections in and around the PVN. Abbreviations used in the figures: 3V, 3rd ventricle; 4V, 4th ventricle; Amb, ambiguus nucleus; AP, area postrema; CAA, central autonomic area; CC, central canal; chp, choroid plexus; CVRG, caudo-ventrolateral respiratory group; dp, dorsal parvocellular; DVN, dorsal vagal nucleus; GLU, glutamate; ICN, intercalated nucleus; IML, intermediolateral cell column; LF, lateral funiculus; M, magnocellular; mp, medial parvocellular; NTS, nucleus tractus solitarius; pp, periventricular parvocellular; Py, pyramidal tracts; RVRG, rostral ventral respiratory group; Sol, nucleus of solitary tract; SolC, nucleus of solitary tract, commissural; SolDM, nucleus of solitary tract, dorsomedial; SolI, nucleus of solitary tract interstitial; SolIM, nucleus of solitary tract, intermediate; SolM, nucleus of solitary tract, medial; SolVL, nucleus of solitary tract, ventrolateral; vp, ventral parvocellular. Scale bars A, C = 200 μm; B = 75 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)