Lab 6 - Auditory, Vestibular, Gustatory and Olfaction Systems

The Central Gustatory System


The Central Gustatory SystemThe central processes of the 1° gustatory afferents enter the solitary tract and ascend (vagus and glossopharyngeal afferents) or descend (facial afferents) the brain stem to terminate in the rostral or gustatory part of the solitary nucleus. Axons of the solitary nucleus (the 2° afferents) ascend the brain stem uncrossed in the central tegmental tract and terminate in the most medial part of the ventral posteromedial (VPM) nucleus of the thalamus.

The axons of these 3° afferents travel in the posterior limb of the internal capsule to terminate in the rostral parietal operculum (the area of the postcentral gyrus lining the lateral fissure) and in the insula. Affective reactions to taste stimuli (e.g., pleasant or unpleasant flavors) appear to involve a different pathway that includes the solitary nucleus, a pontine taste area, and the limbic system and hypothalamus.