Flavor: taste is often thought to be synonymous with flavor. However, taste refers strictly to the five qualities encoded in the gustatory system. Flavor, with its rich and varied qualities, actually stems from a combination of inputs from the gustatory, olfactory, and somatosensory systems. (Kandel3, 727) Much of what we think of as the flavor of foods derives from information provided by the olfactory system. Molecules released from foods or beverages in the mouth are pumped into the back of the nasal cavity by tongue, cheek, and throat movements that accompany chewing and swallowing. Although the olfactory epithelium of the nose clearly makes a major contribution to sensations of flavor, such sensations are localized in the mouth rather than in the nose. Sensations of flavor also frequently have a somatosensory component that includes the texture of food as well as sensations evoked by spicy and salty foods and by carbonation. (Kandel3, 733)

Gustation Processes: the gustatory system controls the sense of taste. In the gustatory system sensory signals generated in the mouth are relayed through the “brain stem” and “thalamus” to the the ‘gustatory cortex.’ “Tastants” are detected by “taste cells’ that are clustered in “taste buds.” (Kandel3, 726-727)

Gustation Pathways: in the gustatory system, sensory signals generated in the mouth are relayed through the “brain stem” and “thalamus” to the “gustatory cortex.” (Kandel3, 727) The taste area of the thalamus also transmits information both directly and indirectly to the “hypothalamus,” a structure that controls feeding behavior and autonomic responses. (Kandel3, 732)

Gustation Structures: the perception of blends of tastants may evolve the “gustatory cortex,” where some neurons can respond to more than one class of tasting. (Kandel3, 734)

Gustatory Cortex: a region of the cerebral cortex located along the border between the anterior “insula” and the ‘frontal operculum.’ Believed to mediate the conscious perception and discrimination of taste stimuli. (Kandel3, 732)

Taste Buds: a garlic-shaped structure embedded in the epithelium. Although the majority of taste buds in humans are located on the tongue, some can also be found on the palate, pharynx, epiglottis, and upper third of the “esophagus.” Each taste bud contains approximately 100 “taste cells.” The taste bud also contains other… cells that are thought to serve a supporting function, as well as a small number of round cells at the base, which are thought to serve as “stem cells.” (Kandel3, 727-728)

Taste Cells: elongated cells that stretch from the “taste pore” to the “basal” area of the the taste bud. Each taste cell extends ‘microvilli’ into the ‘taste pore,’ allowing the cell to contact chemicals dissolved in saliva at the the epithelial surface. At its end, the taste cell contacts the fibers of gustatory sensory neurons. Taste cells also resemble neurons in that they are electrically excitable. They have “voltage-gated channels” and are capable of generating “action potentials.” Taste cells are short-lived cells and appear to be continually replaced from the stem cell population. (Kandel3, 728)

Taste Pore: a small opening at the epithelial surface (of the taste bud). The point of contact with “tastants.” (Kandel3, 728)

Papillae: structures on the tongue containing taste buds. ‘Fungiform papillae’ are located on the anterior two-thirds of the tongue. They are peg-like structures that are topped with taste buds. Each contains one to five taste buds. ‘Foliate papillae’ and ‘cumvallate papillae’ are structures surrounded by groves lined with tasted buds. Each contains hundreds (of taste buds) (Kandel3, 727)

Tastants: taste chemicals. (Kandel3, 726)