Fig. 1. Micrographs demonstrating the termination of the vagal projections into the medulla marked by the axonal transport of the tracer Fast Blue from an injection site in the nodose ganglion. (A) Transverse section (TS) taken 0.6 mm rostral to obex, showing the vagal sensory (Xs) and motor (Xm) areas, dorso-lateral to the fourth ventricle (4V). (B) TS taken 0.12 mm caudal to obex, showing commissural sensory fibres. (C) TS taken 0.08 mm caudal to obex, showing commissural fibres beneath the central canal (CC) of motor origin. (D) TS taken 0.3 mm rostral of obex to show the nucleus ambiguus (NA), situated ventro-laterally to the Xm. (E) Nissl-stained section from the same animal as in A, 580 µm rostral to obex. White scale bars represent 50 µm and the black scale bar represents 1 mm. Note that the Xs and Xm areas are clearly separate.