Relationship of papillae number to bitter intensity of quinine and PROP within and between individuals

Subjects were asked to assess the bitterness of one 6-n-propyl-2-thiouracil (PROP) and two quinine HCl (QHCI) concentrations presented via filter pape rs of varying sizes. The number of taste papillae stimulated by these filte r papers was counted in each individual. Whole mouth sensitivity to PROP wa s determined in a separate session. In support of other demonstrations of s patial summation, these data indicated that perceived bitterness intensity increased as a function of area of stimulation within subjects. Between sub jects, there was a significant trend for the perceived bitterness of PROP t o increase with the lingual density of fungiform papillae, although this tr end was highly variable and was only demonstrable among those who showed at least moderate sensitivity to PROP. On the other hand, the number of stimu lated fungiform papillae failed to account for individual differences in pe rceived bitterness of QHCl. (C) 2001 Elsevier Science Inc. All rights reser ved.