Electrophysiological Responses from the Human Tongue to the Six Taste Qualities and Their Relationships with PROP Taster Status

Abstract

<jats:p>Taste buds containing receptor cells that primarily detect one taste quality provide the basis for discrimination across taste qualities. The molecular receptor multiplicity and the interactions occurring between bud cells encode information about the chemical identity, nutritional value, and potential toxicity of stimuli before transmitting signals to the hindbrain. PROP (6-n-propylthiouracil) tasting is widely considered a marker for individual variations of taste perception, dietary preferences, and health. However, controversial data have been reported. We present measures of the peripheral gustatory system activation in response to taste qualities by electrophysiological recordings from the tongue of 39 subjects classified for PROP taster status. The waveform of the potential variation evoked depended on the taste quality of the stimulus. Direct relationships between PROP sensitivity and electrophysiological responses to taste qualities were found. The largest and fastest responses were recorded in PROP super-tasters, who had the highest papilla density, whilst smaller and slower responses were found in medium tasters and non-tasters with lower papilla densities. The intensities perceived by subjects of the three taster groups correspond to their electrophysiological responses for all stimuli except NaCl. Our results show that each taste quality can generate its own electrophysiological fingerprint on the tongue and provide direct evidence of the relationship between general taste perception and PROP phenotype.</jats:p>

Automated Classification of 6-n-Propylthiouracil Taster Status with Machine Learning

“…According to findings showing associations between perceptions for the five taste qualities [19][20][21]23,25,26,[48][49][50]88] and for PROP, our results showed that the scores that the subjects gave to tastes (that are not mediated by specific receptors) were significant features in facilitating the learning of the model to differentiate categories of PROP tasters.…”

“…The three-solution test, [5] and the impregnated paper screening test [7], which were used to collect PROP and NaCl intensity ratings, allowed us to classify subjects based on their PROP bitter taste status. These two methods have been used in numerous studies [33,34,40,81], and are strongly correlated with the degree of activation of peripheral taste function [86][87][88].…”

Biohybrid Tongue for Evaluation of Taste Interaction between Sweetness and Sourness

“…Citric acid permeates through the membrane, acidifies the cytoplasm and intracellular H + by blocking a proton-sensitive K + channel, and directly depolarizes the taste cell membrane . On the other hand, the transduction of sucrose is mediated by GPCRs, causing activation and diffusion of second messengers, which needs more time to depolarize the cell . For a single concentration, such as 0.625% citric acid, the spiking signal presents a good periodicity, and the amplitude decreases with time.…”

“…31 On the other hand, the transduction of sucrose is mediated by GPCRs, causing activation and diffusion of second messengers, which needs more time to depolarize the cell. 32 For a single concentration, such as 0.625% citric acid, the spiking signal presents a good periodicity, and the amplitude decreases with time. However, due to the high concentration of 1.25% citric acid, the signal pattern changes significantly.…”

Glucagon-Like Peptide 1 and Taste Perception: From Molecular Mechanisms to Potential Clinical Implications

“…Taken together, the basic tastes may be discriminated with the receptor or electrophysiological responses by distinct TBCs subpopulations dedicated to the perceptual taste qualities [ 59 , 60 , 61 ]. The exclusive distribution of the TAS1R and TAS2R families on TBCs at the most primary stage of stimulus processing create specific coding channels regarding information about ligands that are calorically nutritive (sweet and umami), ligands that are potentially toxic (bitter) and salty or sour.…”