Taste (gustatory) sensations from the tongue initiate at taste buds located within specialized papillae. The circumvallate papillae, situated at the back of the tongue, contribute significantly to this pathway. From these papillae, taste signals are primarily carried by the glossopharyngeal nerve (CN IX). The anterior two-thirds of the tongue transmit taste via the chorda tympani branch of the facial nerve (CN VII), while the epiglottis and pharynx use the vagus nerve (CN X).

The first-order neurons, whose cell bodies are in the geniculate, petrosal, and nodose ganglia for CN VII, IX, and X respectively, project centrally. Their axons enter the brainstem and synapse in the nucleus of the solitary tract (NTS), specifically its gustatory portion, located in the medulla. This is the first relay station in the brainstem for all taste afferents.

From the NTS, second-order neurons ascend to the ventral posteromedial (VPM) nucleus of the thalamus. This nucleus acts as a crucial sensory relay station for taste, filtering and processing information before it reaches higher cortical areas.

Finally, third-order neurons originate in the VPM nucleus of the thalamus and project to the primary gustatory cortex, which is predominantly located in the anterior insula and frontal operculum of the cerebral cortex. This cortical region is responsible for conscious perception and discrimination of different taste qualities (sweet, sour, salty, bitter, umami). The integration of taste with smell, texture, and temperature occurs in association cortices, contributing to the complex perception of flavor.