gustative

Gustative, often written gustatory, refers to the sense of taste (gustation). It describes the receptors, neural pathways, and perceptual processes by which chemical stimuli on the tongue and other oral surfaces are identified as distinct taste qualities. The term comes from Latin gustatus, meaning "tasted."

Taste receptors are organized into taste buds, clustered on the tongue's papillae—fungiform on the anterior tongue, circumvallate at the back, and foliate along the sides—as well as in the soft palate and pharynx. Each taste bud contains taste receptor cells that detect chemical compounds and relay signals to gustatory nerve fibers. Sweet, umami, and bitter tastes are largely mediated by G protein–coupled receptors, while salty and sour are primarily detected by ion channels.

Afferent signals travel via cranial nerves VII (facial) for the anterior two-thirds of the tongue, IX (glossopharyngeal) for the posterior third, and X (vagus) for the epiglottis and palate. They converge on the nucleus of the solitary tract in the brainstem, project to the ventral posteromedial nucleus of the thalamus, and reach the gustatory cortex in the insula and frontal operculum.

Gustation contributes to the perception of flavor, which combines taste, smell, texture, temperature, and other cues. While taste refers to basic modalities, flavor is a multisensory experience. Individual differences in taste sensitivity affect food preferences and dietary choices.

Disorders affecting gustation include ageusia (loss of taste), hypogeusia (reduced taste), and dysgeusia (distorted taste). Causes include infections, medications, nutritional deficiencies, and nerve injury. Genetic variation can influence sensitivity to certain tastes, such as bitterness.