Figure 2 - Subnuclear divisions of rat nucleus tractus solitarii (boxed insert) and distribution of central terminals of afferents coursing in the superior laryngeal nerve (SLN).

Besides various afferents unrelated to deglutitive function, the SLN contains the majority of swallowing reflex afferents. The intrasolitarial distribution of anterogradely labeled terminals illustrated in this set of transverse sections overlaps with that revealed after tracer injections into the pharynx, larynx or upper esophagus. Location of NTS subnucleus centralis (core portion) is marked by dotted outline. Numbers indicate anterior-posterior distance (micrometers, m) from rostral edge of area postrema. Fascicles of the solitary tract are shown in color. AP, area postrema; DMV, dorsal motor nucleus of the vagus nerve; D, NTS, nucleus tractus solitarii; cen, central; dl, dorsolateral; gel, gelatinous; int, intermediate; is, interstitial; v, ventral, vl, ventrolateral subnucleus; D, dorsal; L, lateral; TS, tractus solitarius; IV, fourth ventricle; XII, hypoglossal motor nucleus. (Source: Adapted from Altschuler et al.,³⁰ with permission of J. Wiley & Sons).