First objective evaluation of taste sensitivity to 6-n-propylthiouracil (PROP), a paradigm gustatory stimulus in humans

Abstract

Practical and reliable methods for the objective measure of taste function are critically important for studying eating behavior and taste function impairment. Here, we present direct measures of human gustatory response to a prototypical bitter compound, 6-n-propyltiouracil (PROP), obtained by electrophysiological recordings from the tongue of subjects who were classified for taster status and genotyped for the specific receptor gene (TAS2R38), and in which taste papilla density was determined. PROP stimulation evoked negative slow potentials that represent the summated depolarization of taste cells. Depolarization amplitude and rate were correlated with papilla density and perceived bitterness, and associated with taster status and TAS2R38. Our study provides a robust and generalizable research tool for the quantitative measure of peripheral taste function, which can greatly help to resolve controversial outcomes on the PROP phenotype role in taste perception and food preferences, and be potentially useful for evaluating nutritional status and health.

Taste sensitivity and divergence in host plant acceptance between adult females and larvae ofPapilio hospiton

“…Data were checked for the assumptions of homogeneity of variance and normality. Post hoc comparisons were conducted with the Tukey's test, unless the assumption of homogeneity of variance was violated, in which case Duncan's test was used (Sollai et al, 2017b). Statistical analyses were performed using STA-TISTICA for WINDOWS (version 7.0; StatSoft Inc, Tulsa, OK, USA).…”

“…This time frame was selected as representative of the phasic/phasic‐tonic portions of the GRN response (Dethier & Crnjar, ; Inoue et al ., ). Spike sorting and counting were obtained by means of the Clampfit 10.0 software, on the basis on earlier work (Dolzer et al ., ; Sollai et al ., , ,c; Biolchini et al ., ).…”

Taste Perception of Sweet, Sour, Salty, Bitter, and Umami and Changes Due to l-Arginine Supplementation, as a Function of Genetic Ability to Taste 6-n-Propylthiouracil

“…Both approaches are highly reliable as they strongly correlate with the degree of activation of peripheral taste function [74]. In both tests, the taste-intensity rating for PROP and sodium chloride (NaCl) was collected from each subject, by using the Labeled Magnitude Scale (LMS) [75].…”

6‐n‐propylthiouracil taste disruption and TAS2R38 nontasting form in Parkinson's disease

“…Our results showed an impairment of PROP taste function in PD patients when compared with HCs, determined as a decrease of perceived taste intensity and reduction in the ability to recognize bitter‐taste quality. It is tempting to consider that this objective has been achieved by using a technique of current use, which combines methodological simplicity and noninvasiveness with scientific rigor, as it strongly correlates with the degree of activation of peripheral taste function . These conditions enable the use of a procedure of taste evaluation that is highly reliable without causing discomfort or requiring excessive time, which may produce measurement errors, particularly when elderly patients are tested.…”

“…It is tempting to consider that this objective has been achieved by using a technique of current use, 26,59,62,63,68 which combines methodological simplicity and noninvasiveness with scientific rigor, as it strongly correlates with the degree of activation of peripheral taste function. 69,70 These conditions enable the use of a procedure of taste evaluation that is highly reliable without causing discomfort or requiring excessive time, which may produce measurement errors, particularly when elderly patients are tested. Specifically, the results showed a higher number of PD patients classified as PROP nontasters (54.13%) and a lower number classified as PROP super-tasters (8.25%) when compared with HCs who were classified as PROP nontasters (34.35%) and PROP super-tasters (17.56%).…”