Chemical stimulation of single human fungiform taste papillae: sensitivity profiles and locus of stimulation.

Psychophysical responses to chemical stimulation of single human fungiform taste papillae were obtained from 40 papillae in four subjects. Effects of solution concentration and locus of stimulation were examined for nine test compounds. Sensitivity profiles constructed for individual papillae showed that single fungiform papillae mediate more than a single taste quality. In addition, the chemical sensitivities of individual papillae were reflected in their thresholds for all compounds, and correlation coefficients between recognition thresholds were no greater for similar than for dissimilar tasting compounds. No differences in mediation of quality were found as a function of locus of stimulation on the papilla, although sensitivity was found to be greater on the dorsal surface than on the sides. The data were discussed within the context of previous studies of response characteristics of single papilla.