ABSTRACT
Dating from the 1960s, the basic neuroanatomy of the gustatory relay nucleus in the medulla was established, and all further research relied on this foundation. Specifically, afferent fibers innervating taste buds in the oral cavity, pharynx, and larynx synapse with second-order neurons in the nucleus of the solitary tract (NST). These afferent fibers travel in the facial (VII), glossopharyngeal (IX), and vagus (X) nerves. Their termination in the NST is topographical, the anterior oral cavity terminating in the rostral extent of the NST, the posterior oral cavity terminating more caudally, and the pharyngeal and laryngeal receptive field even more caudally (Figure 1.1). All current studies of the NST assume this basic arrangement of the brainstem taste relay. However, much research was required before these pathways and termination patterns were firmly established. As recently as 1950, Patton stated in a review that “the location of the secondary neurons of the taste pathway is undetermined,”1 yet 10 years later students in Carl Pfaffmann’s laboratory were recording from taste responsive neurons in the NST (see Section 1.5).
