Clinical Significance of Umami Taste and Umami-Related Gene Expression Analysis for the Objective Assessment of Umami Taste Loss.

PubMed

Shoji, Noriaki; Satoh-Ku Riwada, Shizuko; Sasano, Takashi

2016-01-01

Loss of umami taste sensation affects quality of life and causes weight loss and health problems, particularly in the elderly. We recently expanded the use of the filter paper disc method to include assessment of umami taste sensitivity, using monosodium glutamate as the test solution. This test showed high diagnostic performance for discriminating between normal taste function and disorders in sensation of the umami taste, according to established cut-off values. The test also revealed: (1) some elderly patients suffered from specific loss of umami taste sensation with preservation of the other four taste sensations (sweet, salty, sour, and bitter); (2) umami taste disorder caused a loss of appetite and decline in weight, resulting in poor health; (3) appetite, weight and overall health improved after appropriate treatment for umami taste disorder. Because of the subjective nature of the test, however, it may not be useful for patients who cannot express which taste sensation is induced by a tastant, such as those with dementia. Most recently, using tissue samples collected from the tongue by scraping the foliate papillae, we showed that evaluation of umami taste receptor gene expression may be clinically useful for the objective genetic diagnosis of umami taste disorders.

Differences in the Density of Fungiform Papillae and Composition of Saliva in Patients With Taste Disorders Compared to Healthy Controls.

PubMed

Walliczek-Dworschak, Ute; Schöps, Franz; Feron, Gilles; Brignot, Helene; Hähner, Antje; Hummel, Thomas

2017-10-01

This study investigated the relation of the fungiform taste papillae density and saliva composition with the taste perception of patients suffering from diagnosed taste disorders. For this purpose, 81 patients and 40 healthy subjects were included. Taste was measured by means of regional and whole mouth chemosensory tests, and electrogustometry. Olfaction was assessed using the Sniffin Sticks. Fungiform papillae were quantified using the "Denver Papillae Protocol for Objective Analysis of Fungiform Papillae". In addition, salivary parameters [flow rate, total proteins, catalase, total anti-oxidative capacity (TAC), carbonic anhydrase VI (caVI), and pH] were determined and the Beck Depression Inventory was administered. Patients showed less taste papillae compared to healthy subjects. The number of papillae correlated with total taste strip score and salivary flow rate. Regarding salivary parameters, the flow rate, protein concentration, and TAC of patients were higher compared to controls. In addition, salivary flow rate, protease, caVI, and catalase values correlated with the summed taste strip score. Regarding various taste disorders, salty-dysgeusia patients showed the lowest taste test scores compared to those with bitter or metal-dysgeusia. Olfactory function of patients was significantly worse compared to healthy controls. This difference was most pronounced for ageusia patients. Compared to controls, patients also exhibited higher depressive symptoms. The density of fungiform papillae seemed to be positively associated with taste perception. Furthermore, patients exhibited changes in saliva composition (higher salivary flow rate, increased protein concentration, proteolysis, and TAC) compared to controls indicating that assessment of saliva may be critical for the diagnostic procedure in taste disorders. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Perceptual and neural responses to sweet taste in humans and rodents.

PubMed

Lemon, Christian H

2015-08-01

This mini-review discusses some of the parallels between rodent neurophysiological and human psychophysical data concerning temperature effects on sweet taste. "Sweet" is an innately rewarding taste sensation that is associated in part with foods that contain calories in the form of sugars. Humans and other mammals can show unconditioned preference for select sweet stimuli. Such preference is poised to influence diet selection and, in turn, nutritional status, which underscores the importance of delineating the physiological mechanisms for sweet taste with respect to their influence on human health. Advances in our knowledge of the biology of sweet taste in humans have arisen in part through studies on mechanisms of gustatory processing in rodent models. Along this line, recent work has revealed there are operational parallels in neural systems for sweet taste between mice and humans, as indexed by similarities in the effects of temperature on central neurophysiological and psychophysical responses to sucrose in these species. Such association strengthens the postulate that rodents can serve as effective models of particular mechanisms of appetitive taste processing. Data supporting this link are discussed here, as are rodent and human data that shed light on relationships between mechanisms for sweet taste and ingestive disorders, such as alcohol abuse. Rodent models have utility for understanding mechanisms of taste processing that may pertain to human flavor perception. Importantly, there are limitations to generalizing data from rodents, albeit parallels across species do exist.

Modulation of taste sensitivity by GLP-1 signaling in taste buds.

PubMed

Martin, Bronwen; Dotson, Cedrick D; Shin, Yu-Kyong; Ji, Sunggoan; Drucker, Daniel J; Maudsley, Stuart; Munger, Steven D

2009-07-01

Modulation of sensory function can help animals adjust to a changing external and internal environment. Even so, mechanisms for modulating taste sensitivity are poorly understood. Using immunohistochemical, biochemical, and behavioral approaches, we found that the peptide hormone glucagon-like peptide-1 (GLP-1) and its receptor (GLP-1R) are expressed in mammalian taste buds. Furthermore, we found that GLP-1 signaling plays an important role in the modulation of taste sensitivity: GLP-1R knockout mice exhibit a dramatic reduction in sweet taste sensitivity as well as an enhanced sensitivity to umami-tasting stimuli. Together, these findings suggest a novel paracrine mechanism for the hormonal modulation of taste function in mammals.

Sweet taste preference in binge-eating disorder: A preliminary investigation.

PubMed

Goodman, Erica L; Breithaupt, Lauren; Watson, Hunna J; Peat, Christine M; Baker, Jessica H; Bulik, Cynthia M; Brownley, Kimberly A

2018-01-01

Research suggests that individuals with high liking for sweets are at increased risk for binge eating, which has been minimally investigated in individuals with binge-eating disorder (BED). Forty-one adults (85% female, 83% white) with binge eating concerns completed a sweet taste test and measures of eating disorder behaviors and food cravings. A subset of participants with BED completed an oral glucose tolerance test (OGTT; N=21) and a 24-hour dietary recall (N=26). Regression models were used to compare highest sweet preferers (HSP [N=18]) to other sweet preferers (OSP [N=23]) and were used to assess associations between sweet taste preference and outcome variables. Effect sizes (ηp 2 ) for differences between HSP and OSP ranged from small (≤0.01) to large (≥0.24); group differences were statistically nonsignificant except for 24-hour caloric intake (ηp 2 =0.16, p=0.04), protein intake (ηp 2 =0.16, p=0.04), and insulin sensitivity index (ηp 2 =0.24, p=0.04), which were higher in HSP, and postprandial insulin, which was smaller in HSP (ηp 2 =0.27, p=0.03). Continuous analyses replicated postprandial insulin response. Compared with OSP, HSP reported numerically higher binge-eating frequency (ηp 2 =0.04), over-eating frequency (ηp 2 =0.06), and carbohydrate intake (ηp 2 =0.14), and they exhibited numerically smaller postprandial glucose AUC (ηp 2 =0.16). Sweet taste preference may have implications for glucose regulation, binge-eating frequency, and nutrient intake in BED. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetics of Taste Receptors

PubMed Central

Bachmanov, Alexander A.; Bosak, Natalia P.; Lin, Cailu; Matsumoto, Ichiro; Ohmoto, Makoto; Reed, Danielle R.; Nelson, Theodore M.

2016-01-01

Taste receptors function as one of the interfaces between internal and external milieus. Taste receptors for sweet and umami (T1R [taste receptor, type 1]), bitter (T2R [taste receptor, type 2]), and salty (ENaC [epithelial sodium channel]) have been discovered in the recent years, but transduction mechanisms of sour taste and ENaC-independent salt taste are still poorly understood. In addition to these five main taste qualities, the taste system detects such noncanonical “tastes” as water, fat, and complex carbohydrates, but their reception mechanisms require further research. Variations in taste receptor genes between and within vertebrate species contribute to individual and species differences in taste-related behaviors. These variations are shaped by evolutionary forces and reflect species adaptations to their chemical environments and feeding ecology. Principles of drug discovery can be applied to taste receptors as targets in order to develop novel taste compounds to satisfy demand in better artificial sweeteners, enhancers of sugar and sodium taste, and blockers of bitterness of food ingredients and oral medications. PMID:23886383

Hydrogen-bonding and the sweet taste mechanism

NASA Astrophysics Data System (ADS)

Mathlouthi, M.; Portmann, M. O.

1990-09-01

The tripartite glucophores (AH-B,γ) of some natural (sugars) and artificial (Aspartame, Acesulfame, Saccharin, NHDHC and Trichlorogalactosucrose) sweeteners are proposed. These propositions are based on the molecular structure and infrared spectra of the studied molecules. The role of water in the sweet taste mechanism of small carbohydrates and artificial sweeteners was derived from the Raman spectra of their aqueous solutions. Comparison of the intensities and frequencies of the calculated components of the experimental Raman band of water on the one hand and of aqueous solutions of sweeteners on the other permitted interpretation of the role of water in the sweetness mechanism.

Behavioral genetics and taste

PubMed Central

Boughter, John D; Bachmanov, Alexander A

2007-01-01

This review focuses on behavioral genetic studies of sweet, umami, bitter and salt taste responses in mammals. Studies involving mouse inbred strain comparisons and genetic analyses, and their impact on elucidation of taste receptors and transduction mechanisms are discussed. Finally, the effect of genetic variation in taste responsiveness on complex traits such as drug intake is considered. Recent advances in development of genomic resources make behavioral genetics a powerful approach for understanding mechanisms of taste. PMID:17903279

Genetics of sweet taste preferences†

PubMed Central

Bachmanov, Alexander A; Bosak, Natalia P; Floriano, Wely B; Inoue, Masashi; Li, Xia; Lin, Cailu; Murovets, Vladimir O; Reed, Danielle R; Zolotarev, Vasily A; Beauchamp, Gary K

2011-01-01

Sweet taste is a powerful factor influencing food acceptance. There is considerable variation in sweet taste perception and preferences within and among species. Although learning and homeostatic mechanisms contribute to this variation in sweet taste, much of it is genetically determined. Recent studies have shown that variation in the T1R genes contributes to within- and between-species differences in sweet taste. In addition, our ongoing studies using the mouse model demonstrate that a significant portion of variation in sweetener preferences depends on genes that are not involved in peripheral taste processing. These genes are likely involved in central mechanisms of sweet taste processing, reward and/or motivation. Genetic variation in sweet taste not only influences food choice and intake, but is also associated with proclivity to drink alcohol. Both peripheral and central mechanisms of sweet taste underlie correlation between sweet-liking and alcohol consumption in animal models and humans. All these data illustrate complex genetics of sweet taste preferences and its impact on human nutrition and health. Identification of genes responsible for within- and between-species variation in sweet taste can provide tools to better control food acceptance in humans and other animals. PMID:21743773

Oxaliplatin Alters Expression of T1R2 Receptor and Sensitivity to Sweet Taste in Rats.

PubMed

Ohishi, Akihiro; Nishida, Kentaro; Yamanaka, Yuri; Miyata, Ai; Ikukawa, Akiko; Yabu, Miharu; Miyamoto, Karin; Bansho, Saho; Nagasawa, Kazuki

2016-01-01

As one of the adverse effects of oxaliplatin, a key agent in colon cancer chemotherapy, a taste disorder is a severe issue in a clinical situation because it decreases the quality of life of patients. However, there is little information on the mechanism underlying the oxaliplatin-induced taste disorder. Here, we examined the molecular and behavioral characteristics of the oxaliplatin-induced taste disorder in rats. Oxaliplatin (4-16 mg/kg) was administered to Sprague-Dawley (SD) rats intraperitoneally for 2 d. Expression levels of mRNA and protein of taste receptors in circumvallate papillae (CP) were measured by real-time quantitative polymerase chain reaction (PCR) and immunohistochemistry, respectively. Taste sensitivity was assessed by their behavioral change using a brief-access test. Morphological change of the taste buds in CP was evaluated by hematoxyline-eosin (HE) staining, and the number of taste cells in taste buds was counted by immunohistochemical analysis. Among taste receptors, the expression levels of mRNA and protein of T1R2, a sweet taste receptor subunit, were increased transiently in CP of oxaliplatin-administered rats on day 7. In a brief-access test, the lick ratio was decreased in oxaliplatin-administered rats on day 7 and the alteration was recovered to the control level on day 14. There was no detectable alteration in the morphology of taste buds, number of taste cells or plasma zinc level in oxaliplatin-administered rats. These results suggest that decreased sensitivity to sweet taste in oxaliplatin-administered rats is due, at least in part, to increased expression of T1R2, while these alterations are reversible.

Interventions for the management of taste disturbances.

PubMed

Nagraj, Sumanth Kumbargere; Naresh, Shetty; Srinivas, Kandula; Renjith George, P; Shrestha, Ashish; Levenson, David; Ferraiolo, Debra M

2014-11-26

The sense of taste is very much essential to the overall health of the individual. It is a necessary component to enjoying one's food, which in turn provides nutrition to an individual. Any disturbance in taste perception can hamper the quality of life in such patients by influencing their appetite, body weight and psychological well-being. Taste disorders have been treated using different modalities of treatment and there is no consensus for the best intervention. Hence this Cochrane systematic review was undertaken. To assess the effects of interventions for the management of patients with taste disturbances. We searched the Cochrane Oral Health Group Trials Register (to 5 March 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2014), MEDLINE via OVID (1948 to 5 March 2014), EMBASE via OVID (1980 to 5 March 2014), CINAHL via EBSCO (1980 to 5 March 2014) and AMED via OVID (1985 to 5 March 2014). We also searched the relevant clinical trial registries and conference proceedings from the International Association of Dental Research/American Association of Dental Research (to 5 March 2014), Association for Research in Otolaryngology (to 5 March 2014), the US National Institutes of Health Trials Register (to 5 March 2014), metaRegister of Controlled Trials (mRCT) (to 5 March 2014), World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) (to 5 March 2014) and International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) Clinical Trials Portal (to 5 March 2014). We included all randomised controlled trials (RCTs) comparing any pharmacological agent with a control intervention or any non-pharmacological agent with a control intervention. We also included cross-over trials in the review. Two authors independently, and in duplicate, assessed the quality of trials and extracted data. Wherever possible, we contacted study authors for additional information. We collected

[Molecular receptors of taste agents].

PubMed

Giliarov, D A; Sakharova, T A; Buzdin, A A

2009-01-01

All representatives of higher eukaryotes can probably differentially perceive nutrients and poisonous substances. Molecular mechanisms of transduction of taste information have been best studied for mammals and for the fruit fly Drosophila. Here, we consider receptor mechanisms and conjugated primary signal processes of stimulation of taste receptor cells by stimuli of various taste modalities.

Lipopolysaccharide-induced inflammation attenuates taste progenitor cell proliferation and shortens the life span of taste bud cells.

PubMed

Cohn, Zachary J; Kim, Agnes; Huang, Liquan; Brand, Joseph; Wang, Hong

2010-06-10

The mammalian taste bud, a complex collection of taste sensory cells, supporting cells, and immature basal cells, is the structural unit for detecting taste stimuli in the oral cavity. Even though the cells of the taste bud undergo constant turnover, the structural homeostasis of the bud is maintained by balancing cell proliferation and cell death. Compared with nongustatory lingual epithelial cells, taste cells express higher levels of several inflammatory receptors and signalling proteins. Whether inflammation, an underlying condition in some diseases associated with taste disorders, interferes with taste cell renewal and turnover is unknown. Here we report the effects of lipopolysaccharide (LPS)-induced inflammation on taste progenitor cell proliferation and taste bud cell turnover in mouse taste tissues. Intraperitoneal injection of LPS rapidly induced expression of several inflammatory cytokines, including tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and interleukin (IL)-6, in mouse circumvallate and foliate papillae. TNF-alpha and IFN-gamma immunoreactivities were preferentially localized to subsets of cells in taste buds. LPS-induced inflammation significantly reduced the number of 5-bromo-2'-deoxyuridine (BrdU)-labeled newborn taste bud cells 1-3 days after LPS injection, suggesting an inhibition of taste bud cell renewal. BrdU pulse-chase experiments showed that BrdU-labeled taste cells had a shorter average life span in LPS-treated mice than in controls. To investigate whether LPS inhibits taste cell renewal by suppressing taste progenitor cell proliferation, we studied the expression of Ki67, a cell proliferation marker. Quantitative real-time RT-PCR revealed that LPS markedly reduced Ki67 mRNA levels in circumvallate and foliate epithelia. Immunofluorescent staining using anti-Ki67 antibodies showed that LPS decreased the number of Ki67-positive cells in the basal regions surrounding circumvallate taste buds, the niche for taste progenitor

Calcium Signaling in Taste Cells

PubMed Central

Medler, Kathryn F.

2014-01-01

The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. PMID:25450977

Taste Receptor Genes

PubMed Central

Bachmanov, Alexander A.; Beauchamp, Gary K.

2009-01-01

In the past several years, tremendous progress has been achieved with the discovery and characterization of vertebrate taste receptors from the T1R and T2R families, which are involved in recognition of bitter, sweet, and umami taste stimuli. Individual differences in taste, at least in some cases, can be attributed to allelic variants of the T1R and T2R genes. Progress with understanding how T1R and T2R receptors interact with taste stimuli and with identifying their patterns of expression in taste cells sheds light on coding of taste information by the nervous system. Candidate mechanisms for detection of salts, acids, fat, complex carbohydrates, and water have also been proposed, but further studies are needed to prove their identity. PMID:17444812

Peripheral coding of taste

PubMed Central

Liman, Emily R.; Zhang, Yali V.; Montell, Craig

2014-01-01

Five canonical tastes, bitter, sweet, umami (amino acid), salty and sour (acid) are detected by animals as diverse as fruit flies and humans, consistent with a near universal drive to consume fundamental nutrients and to avoid toxins or other harmful compounds. Surprisingly, despite this strong conservation of basic taste qualities between vertebrates and invertebrates, the receptors and signaling mechanisms that mediate taste in each are highly divergent. The identification over the last two decades of receptors and other molecules that mediate taste has led to stunning advances in our understanding of the basic mechanisms of transduction and coding of information by the gustatory systems of vertebrates and invertebrates. In this review, we discuss recent advances in taste research, mainly from the fly and mammalian systems, and we highlight principles that are common across species, despite stark differences in receptor types. PMID:24607224

Molecular Mechanisms of Taste Recognition: Considerations about the Role of Saliva

PubMed Central

Fábián, Tibor Károly; Beck, Anita; Fejérdy, Pál; Hermann, Péter; Fábián, Gábor

2015-01-01

The gustatory system plays a critical role in determining food preferences and food intake, in addition to nutritive, energy and electrolyte balance. Fine tuning of the gustatory system is also crucial in this respect. The exact mechanisms that fine tune taste sensitivity are as of yet poorly defined, but it is clear that various effects of saliva on taste recognition are also involved. Specifically those metabolic polypeptides present in the saliva that were classically considered to be gut and appetite hormones (i.e., leptin, ghrelin, insulin, neuropeptide Y, peptide YY) were considered to play a pivotal role. Besides these, data clearly indicate the major role of several other salivary proteins, such as salivary carbonic anhydrase (gustin), proline-rich proteins, cystatins, alpha-amylases, histatins, salivary albumin and mucins. Other proteins like glucagon-like peptide-1, salivary immunoglobulin-A, zinc-α-2-glycoprotein, salivary lactoperoxidase, salivary prolactin-inducible protein and salivary molecular chaperone HSP70/HSPAs were also expected to play an important role. Furthermore, factors including salivary flow rate, buffer capacity and ionic composition of saliva should also be considered. In this paper, the current state of research related to the above and the overall emerging field of taste-related salivary research alongside basic principles of taste perception is reviewed. PMID:25782158

Taste buds: cells, signals and synapses.

PubMed

Roper, Stephen D; Chaudhari, Nirupa

2017-08-01

The past decade has witnessed a consolidation and refinement of the extraordinary progress made in taste research. This Review describes recent advances in our understanding of taste receptors, taste buds, and the connections between taste buds and sensory afferent fibres. The article discusses new findings regarding the cellular mechanisms for detecting tastes, new data on the transmitters involved in taste processing and new studies that address longstanding arguments about taste coding.

Genetics of Amino Acid Taste and Appetite.

PubMed

Bachmanov, Alexander A; Bosak, Natalia P; Glendinning, John I; Inoue, Masashi; Li, Xia; Manita, Satoshi; McCaughey, Stuart A; Murata, Yuko; Reed, Danielle R; Tordoff, Michael G; Beauchamp, Gary K

2016-07-01

The consumption of amino acids by animals is controlled by both oral and postoral mechanisms. We used a genetic approach to investigate these mechanisms. Our studies have shown that inbred mouse strains differ in voluntary amino acid consumption, and these differences depend on sensory and nutritive properties of amino acids. Like humans, mice perceive some amino acids as having a sweet (sucrose-like) taste and others as having an umami (glutamate-like) taste. Mouse strain differences in the consumption of some sweet-tasting amino acids (d-phenylalanine, d-tryptophan, and l-proline) are associated with polymorphisms of a taste receptor, type 1, member 3 gene (Tas1r3), and involve differential peripheral taste responsiveness. Strain differences in the consumption of some other sweet-tasting amino acids (glycine, l-alanine, l-glutamine, and l-threonine) do not depend on Tas1r3 polymorphisms and so must be due to allelic variation in other, as yet unknown, genes involved in sweet taste. Strain differences in the consumption of l-glutamate may depend on postingestive rather than taste mechanisms. Thus, genes and physiologic mechanisms responsible for strain differences in the consumption of each amino acid depend on the nature of its taste and postingestive properties. Overall, mouse strain differences in amino acid taste and appetite have a complex genetic architecture. In addition to the Tas1r3 gene, these differences depend on other genes likely involved in determining the taste and postingestive effects of amino acids. The identification of these genes may lead to the discovery of novel mechanisms that regulate amino acid taste and appetite. © 2016 American Society for Nutrition.

Taste buds: cells, signals and synapses

PubMed Central

Roper, Stephen D.; Chaudhari, Nirupa

2018-01-01

The past decade has witnessed a consolidation and refinement of the extraordinary progress made in taste research. This Review describes recent advances in our understanding of taste receptors, taste buds, and the connections between taste buds and sensory afferent fibres. The article discusses new findings regarding the cellular mechanisms for detecting tastes, new data on the transmitters involved in taste processing and new studies that address longstanding arguments about taste coding. PMID:28655883

A sweet taste receptor‐dependent mechanism of glucosensing in hypothalamic tanycytes

PubMed Central

Benford, Heather; Bolborea, Matei; Pollatzek, Eric; Lossow, Kristina; Hermans‐Borgmeyer, Irm; Liu, Beihui; Meyerhof, Wolfgang; Kasparov, Sergey

2017-01-01

Abstract Hypothalamic tanycytes are glial‐like glucosensitive cells that contact the cerebrospinal fluid of the third ventricle, and send processes into the hypothalamic nuclei that control food intake and body weight. The mechanism of tanycyte glucosensing remains undetermined. While tanycytes express the components associated with the glucosensing of the pancreatic β cell, they respond to nonmetabolisable glucose analogues via an ATP receptor‐dependent mechanism. Here, we show that tanycytes in rodents respond to non‐nutritive sweeteners known to be ligands of the sweet taste (Tas1r2/Tas1r3) receptor. The initial sweet tastant‐evoked response, which requires the presence of extracellular Ca2+, leads to release of ATP and a larger propagating Ca2+ response mediated by P2Y1 receptors. In Tas1r2 null mice the proportion of glucose nonresponsive tanycytes was greatly increased in these mice, but a subset of tanycytes retained an undiminished sensitivity to glucose. Our data demonstrate that the sweet taste receptor mediates glucosensing in about 60% of glucosensitive tanycytes while the remaining 40% of glucosensitive tanycytes use some other, as yet unknown mechanism. PMID:28205335

Excitation of lateral habenula neurons as a neural mechanism underlying ethanol-induced conditioned taste aversion.

PubMed

Tandon, Shashank; Keefe, Kristen A; Taha, Sharif A

2017-02-15

The lateral habenula (LHb) has been implicated in regulation of drug-seeking behaviours through aversion-mediated learning. In this study, we recorded neuronal activity in the LHb of rats during an operant task before and after ethanol-induced conditioned taste aversion (CTA) to saccharin. Ethanol-induced CTA caused significantly higher baseline firing rates in LHb neurons, as well as elevated firing rates in response to cue presentation, lever press and saccharin taste. In a separate cohort of rats, we found that bilateral LHb lesions blocked ethanol-induced CTA. Our results strongly suggest that excitation of LHb neurons is required for ethanol-induced CTA, and point towards a mechanism through which LHb firing may regulate voluntary ethanol consumption. Ethanol, like other drugs of abuse, has both rewarding and aversive properties. Previous work suggests that sensitivity to ethanol's aversive effects negatively modulates voluntary alcohol intake and thus may be important in vulnerability to developing alcohol use disorders. We previously found that rats with lesions of the lateral habenula (LHb), which is implicated in aversion-mediated learning, show accelerated escalation of voluntary ethanol consumption. To understand neural encoding in the LHb contributing to ethanol-induced aversion, we recorded neural firing in the LHb of freely behaving, water-deprived rats before and after an ethanol-induced (1.5 g kg -1 20% ethanol, i.p.) conditioned taste aversion (CTA) to saccharin taste. Ethanol-induced CTA strongly decreased motivation for saccharin in an operant task to obtain the tastant. Comparison of LHb neural firing before and after CTA induction revealed four main differences in firing properties. First, baseline firing after CTA induction was significantly higher. Second, firing evoked by cues signalling saccharin availability shifted from a pattern of primarily inhibition before CTA to primarily excitation after CTA induction. Third, CTA induction reduced

Excitation of lateral habenula neurons as a neural mechanism underlying ethanol‐induced conditioned taste aversion

PubMed Central

Keefe, Kristen A.; Taha, Sharif A.

2016-01-01

Key points The lateral habenula (LHb) has been implicated in regulation of drug‐seeking behaviours through aversion‐mediated learning.In this study, we recorded neuronal activity in the LHb of rats during an operant task before and after ethanol‐induced conditioned taste aversion (CTA) to saccharin.Ethanol‐induced CTA caused significantly higher baseline firing rates in LHb neurons, as well as elevated firing rates in response to cue presentation, lever press and saccharin taste.In a separate cohort of rats, we found that bilateral LHb lesions blocked ethanol‐induced CTA.Our results strongly suggest that excitation of LHb neurons is required for ethanol‐induced CTA, and point towards a mechanism through which LHb firing may regulate voluntary ethanol consumption. Abstract Ethanol, like other drugs of abuse, has both rewarding and aversive properties. Previous work suggests that sensitivity to ethanol's aversive effects negatively modulates voluntary alcohol intake and thus may be important in vulnerability to developing alcohol use disorders. We previously found that rats with lesions of the lateral habenula (LHb), which is implicated in aversion‐mediated learning, show accelerated escalation of voluntary ethanol consumption. To understand neural encoding in the LHb contributing to ethanol‐induced aversion, we recorded neural firing in the LHb of freely behaving, water‐deprived rats before and after an ethanol‐induced (1.5 g kg−1 20% ethanol, i.p.) conditioned taste aversion (CTA) to saccharin taste. Ethanol‐induced CTA strongly decreased motivation for saccharin in an operant task to obtain the tastant. Comparison of LHb neural firing before and after CTA induction revealed four main differences in firing properties. First, baseline firing after CTA induction was significantly higher. Second, firing evoked by cues signalling saccharin availability shifted from a pattern of primarily inhibition before CTA to primarily excitation after CTA

Taste disturbance following tonsillectomy--a prospective study.

PubMed

Heiser, Clemens; Landis, Basile N; Giger, Roland; Cao Van, Helene; Guinand, Nils; Hörmann, Karl; Stuck, Boris A

2010-10-01

Persistent taste disturbance is a rare complication after tonsillectomy and mainly documented by case reports or a few retrospective and prospective trials with a limited number of patients. None could clarify frequency, time course, or prognosis of long-lasting dysgeusia after tonsillectomy. The aim of the study was to provide a symptom-based follow-up after tonsillectomy to assess postoperative taste disorders. Prospective clinical trial. From December 2007 to June 2009 adult patients undergoing tonsillectomy were asked to take part in the trial. Two hundred twenty-three patients (119 female, 104 male; mean age, 33 ± 13 years) were included. The day prior to surgery, and 2 weeks and 6 months after tonsillectomy a standardized questionnaire was completed by patients. The questionnaire focused on taste function, taste disorders, pain, foreign body sensation, and bleeding episodes after tonsillectomy. One hundred eighty-eight (2 weeks) and 181 (6 months) patients returned the questionnaires. Thirty-two percent (n = 60) of patients reported taste disorders after tonsillectomy 2 weeks postoperatively and 15 patients (8%) at 6-month follow-up. Metallic and bitter parageusia were most frequently reported. The mean ratings of gustatory function were significantly lower 2 weeks after surgery (P < .001) and reached preoperative values 6 months after surgery. Almost 30% of patients reported postoperative bleeding, 10% long-lasting postoperative pain, and 20% foreign body sensation. Long-lasting taste disturbance (metallic and bitter parageusia) after tonsillectomy is more frequent than previously reported. Long-lasting pain and foreign body sensation seem to be common symptoms. With regard to these results, a thorough preoperative explanation is mandatory.

Genetics of Amino Acid Taste and Appetite123

PubMed Central

Bosak, Natalia P; Glendinning, John I; Inoue, Masashi; Li, Xia; Manita, Satoshi; McCaughey, Stuart A; Murata, Yuko; Beauchamp, Gary K

2016-01-01

The consumption of amino acids by animals is controlled by both oral and postoral mechanisms. We used a genetic approach to investigate these mechanisms. Our studies have shown that inbred mouse strains differ in voluntary amino acid consumption, and these differences depend on sensory and nutritive properties of amino acids. Like humans, mice perceive some amino acids as having a sweet (sucrose-like) taste and others as having an umami (glutamate-like) taste. Mouse strain differences in the consumption of some sweet-tasting amino acids (d-phenylalanine, d-tryptophan, and l-proline) are associated with polymorphisms of a taste receptor, type 1, member 3 gene (Tas1r3), and involve differential peripheral taste responsiveness. Strain differences in the consumption of some other sweet-tasting amino acids (glycine, l-alanine, l-glutamine, and l-threonine) do not depend on Tas1r3 polymorphisms and so must be due to allelic variation in other, as yet unknown, genes involved in sweet taste. Strain differences in the consumption of l-glutamate may depend on postingestive rather than taste mechanisms. Thus, genes and physiologic mechanisms responsible for strain differences in the consumption of each amino acid depend on the nature of its taste and postingestive properties. Overall, mouse strain differences in amino acid taste and appetite have a complex genetic architecture. In addition to the Tas1r3 gene, these differences depend on other genes likely involved in determining the taste and postingestive effects of amino acids. The identification of these genes may lead to the discovery of novel mechanisms that regulate amino acid taste and appetite. PMID:27422518

Taste of Fat: A Sixth Taste Modality?

PubMed

Besnard, Philippe; Passilly-Degrace, Patricia; Khan, Naim A

2016-01-01

An attraction for palatable foods rich in lipids is shared by rodents and humans. Over the last decade, the mechanisms responsible for this specific eating behavior have been actively studied, and compelling evidence implicates a taste component in the orosensory detection of dietary lipids [i.e., long-chain fatty acids (LCFA)], in addition to textural, olfactory, and postingestive cues. The interactions between LCFA and specific receptors in taste bud cells (TBC) elicit physiological changes that affect both food intake and digestive functions. After a short overview of the gustatory pathway, this review brings together the key findings consistent with the existence of a sixth taste modality devoted to the perception of lipids. The main steps leading to this new paradigm (i.e., chemoreception of LCFA in TBC, cell signaling cascade, transfer of lipid signals throughout the gustatory nervous pathway, and their physiological consequences) will be critically analyzed. The limitations to this concept will also be discussed in the light of our current knowledge of the sense of taste. Finally, we will analyze the recent literature on obesity-related dysfunctions in the orosensory detection of lipids ("fatty" taste?), in relation to the overconsumption of fat-rich foods and the associated health risks. Copyright © 2016 the American Physiological Society.

Expression of the synaptic exocytosis-regulating molecule complexin 2 in taste buds and its participation in peripheral taste transduction.

PubMed

Kurokawa, Azusa; Narukawa, Masataka; Ohmoto, Makoto; Yoshimoto, Joto; Abe, Keiko; Misaka, Takumi

2015-06-01

Taste information from type III taste cells to gustatory neurons is thought to be transmitted via synapses. However, the molecular mechanisms underlying taste transduction through this pathway have not been fully elucidated. In this study, to identify molecules that participate in synaptic taste transduction, we investigated whether complexins (Cplxs), which play roles in regulating membrane fusion in synaptic vesicle exocytosis, were expressed in taste bud cells. Among four Cplx isoforms, strong expression of Cplx2 mRNA was detected in type III taste cells. To investigate the function of CPLX2 in taste transduction, we observed taste responses in CPLX2-knockout mice. When assessed with electrophysiological and behavioral assays, taste responses to some sour stimuli in CPLX2-knockout mice were significantly lower than those in wild-type mice. These results suggested that CPLX2 participated in synaptic taste transduction from type III taste cells to gustatory neurons. A part of taste information is thought to be transmitted via synapses. However, the molecular mechanisms have not been fully elucidated. To identify molecules that participate in synaptic taste transduction, we investigated complexins (Cplxs) expression in taste bud cells. Strong expression of Cplx2 mRNA was detected in taste bud cells. Furthermore, taste responses to some sour stimuli in CPLX2- knockout mice were significantly lower than those in wild-type mice. These suggested that CPLX2 participated in synaptic taste transduction. © 2015 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of The International Society for Neurochemistry.

Human biology of taste.

PubMed

Gravina, Stephen A; Yep, Gregory L; Khan, Mehmood

2013-01-01

Taste or gustation is one of the 5 traditional senses including hearing, sight, touch, and smell. The sense of taste has classically been limited to the 5 basic taste qualities: sweet, salty, sour, bitter, and umami or savory. Advances from the Human Genome Project and others have allowed the identification and determination of many of the genes and molecular mechanisms involved in taste biology. The ubiquitous G protein-coupled receptors (GPCRs) make up the sweet, umami, and bitter receptors. Although less clear in humans, transient receptor potential ion channels are thought to mediate salty and sour taste; however, other targets have been identified. Furthermore, taste receptors have been located throughout the body and appear to be involved in many regulatory processes. An emerging interplay is revealed between chemical sensing in the periphery, cortical processing, performance, and physiology and likely the pathophysiology of diseases such as diabetes.

Taste Bud Homeostasis in Health, Disease, and Aging

PubMed Central

2014-01-01

The mammalian taste bud is an onion-shaped epithelial structure with 50–100 tightly packed cells, including taste receptor cells, supporting cells, and basal cells. Taste receptor cells detect nutrients and toxins in the oral cavity and transmit the sensory information to gustatory nerve endings in the buds. Supporting cells may play a role in the clearance of excess neurotransmitters after their release from taste receptor cells. Basal cells are precursor cells that differentiate into mature taste cells. Similar to other epithelial cells, taste cells turn over continuously, with an average life span of about 8–12 days. To maintain structural homeostasis in taste buds, new cells are generated to replace dying cells. Several recent studies using genetic lineage tracing methods have identified populations of progenitor/stem cells for taste buds, although contributions of these progenitor/stem cell populations to taste bud homeostasis have yet to be fully determined. Some regulatory factors of taste cell differentiation and degeneration have been identified, but our understanding of these aspects of taste bud homoeostasis remains limited. Many patients with various diseases develop taste disorders, including taste loss and taste distortion. Decline in taste function also occurs during aging. Recent studies suggest that disruption or alteration of taste bud homeostasis may contribute to taste dysfunction associated with disease and aging. PMID:24287552

Taste bud homeostasis in health, disease, and aging.

PubMed

Feng, Pu; Huang, Liquan; Wang, Hong

2014-01-01

The mammalian taste bud is an onion-shaped epithelial structure with 50-100 tightly packed cells, including taste receptor cells, supporting cells, and basal cells. Taste receptor cells detect nutrients and toxins in the oral cavity and transmit the sensory information to gustatory nerve endings in the buds. Supporting cells may play a role in the clearance of excess neurotransmitters after their release from taste receptor cells. Basal cells are precursor cells that differentiate into mature taste cells. Similar to other epithelial cells, taste cells turn over continuously, with an average life span of about 8-12 days. To maintain structural homeostasis in taste buds, new cells are generated to replace dying cells. Several recent studies using genetic lineage tracing methods have identified populations of progenitor/stem cells for taste buds, although contributions of these progenitor/stem cell populations to taste bud homeostasis have yet to be fully determined. Some regulatory factors of taste cell differentiation and degeneration have been identified, but our understanding of these aspects of taste bud homoeostasis remains limited. Many patients with various diseases develop taste disorders, including taste loss and taste distortion. Decline in taste function also occurs during aging. Recent studies suggest that disruption or alteration of taste bud homeostasis may contribute to taste dysfunction associated with disease and aging.

Reduced brain response to a sweet taste in Hispanic young adults.

PubMed

Szajer, Jacquelyn; Jacobson, Aaron; Green, Erin; Murphy, Claire

2017-11-01

Hispanics have an increased risk for metabolic disorders, which evidence suggests may be due to interactions between lifespan biological, genetic, and lifestyle factors. Studies show the diet of many U.S. Hispanic groups have high sugar consumption, which has been shown to influence future preference for and consumption of high-sugar foods, and is associated with increased risk for insulin-related disorders and obesity. Taste is a primary determinant of food preference and selection. Differences in neural response to taste have been associated with obesity. Understanding brain response to sweet taste stimuli in healthy Hispanic adults is an important first step in characterizing the potential neural mechanisms for this behavior. We used fMRI to examine brain activation during the hedonic evaluation of sucrose as a function of ethnicity in Hispanic and non-Hispanic young adults. Taste stimuli were administered orally while subjects were scanned at 3T. Data were analyzed with AFNI via 3dROIstats and 3dMEMA, a mixed effects multi-level analysis of whole brain activation. The Hispanic group had significantly lower ROI activation in the left amygdala and significantly lower whole brain activation in regions critical for reward processing, and hedonic evaluation (e.g. frontal, orbitofrontal, and anterior cingulate cortices) than the non-Hispanic group. Differences in processing of sweet tastes have important clinical and public health implications, especially considering increased risk of metabolic syndrome and cognitive decline in Hispanic populations. Future research to better understanding relationships between health risk and brain function in Hispanic populations is warranted to better conceptualize and develop interventions for these populations. Copyright © 2017. Published by Elsevier B.V.

Taste identification in adults with autism spectrum conditions.

PubMed

Tavassoli, T; Baron-Cohen, S

2012-07-01

Sensory issues are widely reported in Autism Spectrum Conditions (ASC). Since taste perception is one of the least studied senses in ASC we explored taste identification in adults with ASC (12 males, 11 females) compared to control participants (14 males, 12 females). 'Taste strips' were used to measure taste identification overall, as well as bitter, sour, sweet and salty tastes. Results revealed lower taste scores overall in the ASC group, as well as for bitter, sour and sweet tastes. Salty taste scores did not differ between the groups. Examining error types showed that adults with ASC more often misidentified a taste as salty or as no taste. Future studies should investigate underlying mechanisms of taste identification difficulties in ASC.

Mechanism of fat taste perception: Association with diet and obesity.

PubMed

Liu, Dongli; Archer, Nicholas; Duesing, Konsta; Hannan, Garry; Keast, Russell

2016-07-01

Energy homeostasis plays a significant role in food consumption and body weight regulation with fat intake being an area of particular interest due to its palatability and high energy density. Increasing evidence from humans and animal studies indicate the existence of a taste modality responsive to fat via its breakdown product fatty acids. These studies implicate multiple candidate receptors and ion channels for fatty acid taste detection, indicating a complex peripheral physiology that is currently not well understood. Additionally, a limited number of studies suggest a reduced ability to detect fatty acids is associated with obesity and a diet high in fat reduces an individual's ability to detect fatty acids. To support this, genetic variants within candidate fatty acid receptors are also associated with obesity reduced ability to detect fatty acids. Understanding oral peripheral fatty acid transduction mechanisms and the association with fat consumption may provide the basis of novel approaches to control development of obesity. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Alteration of sweet taste in high-fat diet induced obese rats after 4 weeks treatment with exenatide.

PubMed

Zhang, Xiao-juan; Wang, Yu-qing; Long, Yang; Wang, Lei; Li, Yun; Gao, Fa-bao; Tian, Hao-ming

2013-09-01

Exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, is effective in inducing weight loss. The exact mechanisms are not fully understood. Reduced appetite and food intake may play important roles. Sweet taste contributes to food palatability, which promotes appetite. Interestingly, GLP-1 and its receptor are expressed in the taste buds of rodents and their interaction has an effect on mediating sweet taste sensitivity. Our aim was to investigate whether sweet taste will be changed after long term treatment with exenatide. The results showed that high-fat diet induced obese rats (HF-C) presented metabolic disorders in food intake, body weight, blood glucose and lipid metabolism compared with long term exenatide treated obese rats (EX) and normal chow fed control rats (NC). Meanwhile, greater preference for sweet taste was observed in HF-C rats but not in EX rats. Compared with NC rats, brain activities induced by sweet taste stimulation were stronger in HF-C rats, however these stronger activities were not found in EX rats. We further found reduced sweet taste receptor T1R3 in circumvallte taste buds of HF-C rats, while GLP-1 was increased. Besides, serum leptin was evaluated in HF-C rats with decreased leptin receptor expressed in taste buds. These changes were not observed in EX rats, which suggest them to be the underlying hormone and molecular mechanisms responsible for alterations in sweet taste of HF-C rats and EX rats. In summary, our results suggest that long term treatment with exenatide could benefit dietary obese rats partially by reversing sweet taste changes. Copyright © 2013 Elsevier Inc. All rights reserved.

Mechanical microencapsulation: The best technique in taste masking for the manufacturing scale - Effect of polymer encapsulation on drug targeting.

PubMed

Al-Kasmi, Basheer; Alsirawan, Mhd Bashir; Bashimam, Mais; El-Zein, Hind

2017-08-28

Drug taste masking is a crucial process for the preparation of pediatric and geriatric formulations as well as fast dissolving tablets. Taste masking techniques aim to prevent drug release in saliva and at the same time to obtain the desired release profile in gastrointestinal tract. Several taste masking methods are reported, however this review has focused on a group of promising methods; complexation, encapsulation, and hot melting. The effects of each method on the physicochemical properties of the drug are described in details. Furthermore, a scoring system was established to evaluate each process using recent published data of selected factors. These include, input, process, and output factors that are related to each taste masking method. Input factors include the attributes of the materials used for taste masking. Process factors include equipment type and process parameters. Finally, output factors, include taste masking quality and yield. As a result, Mechanical microencapsulation obtained the highest score (5/8) along with complexation with cyclodextrin suggesting that these methods are the most preferable for drug taste masking. Copyright © 2017 Elsevier B.V. All rights reserved.

DEVELOPING A SENSE OF TASTE

PubMed Central

Kapsimali, Marika; Barlow, Linda A.

2012-01-01

Taste buds are found in a distributed array on the tongue surface, and are innervated by cranial nerves that convey taste information to the brain. For nearly a century, taste buds were thought to be induced by nerves late in embryonic development. However, this view has shifted dramatically. A host of studies now indicate that taste bud development is initiated and proceeds via processes that are nerve-independent, occur long before birth, and governed by cellular and molecular mechanisms intrinsic to the developing tongue. Here we review the state of our understanding of the molecular and cellular regulation of taste bud development, incorporating important new data obtained through the use of two powerful genetic systems, mouse and zebrafish. PMID:23182899

Vismodegib, an antagonist of hedgehog signaling, directly alters taste molecular signaling in taste buds

PubMed Central

Yang, Hyekyung; Cong, Wei-na; Yoon, Jeong Seon; Egan, Josephine M

2015-01-01

Vismodegib, a highly selective inhibitor of hedgehog (Hh) pathway, is an approved treatment for basal-cell carcinoma. Patients on treatment with vismodegib often report profound alterations in taste sensation. The cellular mechanisms underlying the alterations have not been studied. Sonic Hh (Shh) signaling is required for cell growth and differentiation. In taste buds, Shh is exclusively expressed in type IV taste cells, which are undifferentiated basal cells and the precursors of the three types of taste sensing cells. Thus, we investigated if vismodegib has an inhibitory effect on taste cell turnover because of its known effects on Hh signaling. We gavaged C57BL/6J male mice daily with either vehicle or 30 mg/kg vismodegib for 15 weeks. The gustatory behavior and immunohistochemical profile of taste cells were examined. Vismodegib-treated mice showed decreased growth rate and behavioral responsivity to sweet and bitter stimuli, compared to vehicle-treated mice. We found that vismodegib-treated mice had significant reductions in taste bud size and numbers of taste cells per taste bud. Additionally, vismodegib treatment resulted in decreased numbers of Ki67- and Shh-expressing cells in taste buds. The numbers of phospholipase Cβ2- and α-gustducin-expressing cells, which contain biochemical machinery for sweet and bitter sensing, were reduced in vismodegib-treated mice. Furthermore, vismodegib treatment resulted in reduction in numbers of T1R3, glucagon-like peptide-1, and glucagon-expressing cells, which are known to modulate sweet taste sensitivity. These results suggest that inhibition of Shh signaling by vismodegib treatment directly results in alteration of taste due to local effects in taste buds. PMID:25354792

The role of taste in alcohol preference, consumption and risk behavior.

PubMed

Thibodeau, Margaret; Pickering, Gary J

2017-10-05

Alcohol consumption is widespread, and high levels of use are associated with increased risk of developing an alcohol use disorder. Thus, understanding the factors that influence alcohol intake is important for disease prevention and management. Additionally, elucidating the factors that associate with alcohol preference and intake in non-clinical populations allows for product development and optimisation opportunities for the alcoholic beverage industry. The literature on how taste (orosensation) influences alcohol behavior is critically appraised in this review. Ethanol, the compound common to all alcoholic beverages, is generally aversive as it primarily elicits bitterness and irritation when ingested. Individuals who experience orosensations (both taste and chemesthetic) more intensely tend to report lower liking and consumption of alcoholic beverages. Additionally, a preference for sweetness is likely associated with a paternal history of alcohol use disorders. However, conflicting findings in the literature are common and may be partially attributable to differences in the methods used to access orosensory responsiveness and taste phenotypes. We conclude that while taste is a key driver in alcohol preference, intake and use disorder, no single taste-related factor can adequately predict alcohol behaviour. Areas for further research and suggestions for improved methodological and analytical approaches are highlighted.

Facilitation of Taste Memory Acquisition by Experiencing Previous Novel Taste Is Protein-Synthesis Dependent

ERIC Educational Resources Information Center

Merhav, Maayan; Rosenblum, Kobi

2008-01-01

Very little is known about the biological and molecular mechanisms that determine the effect of previous experience on implicit learning tasks. In the present study, we first defined weak and strong taste inputs according to measurements in the behavioral paradigm known as latent inhibition of conditioned taste aversion. We then demonstrated that…

Vismodegib, an antagonist of hedgehog signaling, directly alters taste molecular signaling in taste buds.

PubMed

Yang, Hyekyung; Cong, Wei-Na; Yoon, Jeong Seon; Egan, Josephine M

2015-02-01

Vismodegib, a highly selective inhibitor of hedgehog (Hh) pathway, is an approved treatment for basal-cell carcinoma. Patients on treatment with vismodegib often report profound alterations in taste sensation. The cellular mechanisms underlying the alterations have not been studied. Sonic Hh (Shh) signaling is required for cell growth and differentiation. In taste buds, Shh is exclusively expressed in type IV taste cells, which are undifferentiated basal cells and the precursors of the three types of taste sensing cells. Thus, we investigated if vismodegib has an inhibitory effect on taste cell turnover because of its known effects on Hh signaling. We gavaged C57BL/6J male mice daily with either vehicle or 30 mg/kg vismodegib for 15 weeks. The gustatory behavior and immunohistochemical profile of taste cells were examined. Vismodegib-treated mice showed decreased growth rate and behavioral responsivity to sweet and bitter stimuli, compared to vehicle-treated mice. We found that vismodegib-treated mice had significant reductions in taste bud size and numbers of taste cells per taste bud. Additionally, vismodegib treatment resulted in decreased numbers of Ki67- and Shh-expressing cells in taste buds. The numbers of phospholipase Cβ2- and α-gustducin-expressing cells, which contain biochemical machinery for sweet and bitter sensing, were reduced in vismodegib-treated mice. Furthermore, vismodegib treatment resulted in reduction in numbers of T1R3, glucagon-like peptide-1, and glucagon-expressing cells, which are known to modulate sweet taste sensitivity. These results suggest that inhibition of Shh signaling by vismodegib treatment directly results in alteration of taste due to local effects in taste buds. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

"What's Your Taste in Music?" A Comparison of the Effectiveness of Various Soundscapes in Evoking Specific Tastes.

PubMed

Wang, Qian Janice; Woods, Andy T; Spence, Charles

2015-12-01

We report on the results of two online experiments designed to compare different soundtracks that had been composed (by various researchers and sound designers) in order to evoke/match different basic tastes. In Experiment 1, 100 participants listened to samples from 24 soundtracks and chose the taste (sweet, sour, salty, or bitter) that best matched each sample. Overall, the sweet soundtracks most effectively evoked the taste intended by the composer (participants chose sweet 56.9% of the time for the sweet soundtracks), whereas the bitter soundtracks were the least effective (participants chose bitter 31.4% of the time for the bitter soundtracks), compared with chance (choosing any specific taste 25% of the time). In Experiment 2, 50 participants rated their emotional responses (in terms of pleasantness and arousal) to the same 24 soundtrack samples and also to imaginary sweet/sour/salty/bitter-tasting foods. Associations between soundtracks and tastes were partly mediated by pleasantness for the sweet and bitter tastes and partly by arousal for the sour tastes. These results demonstrate how emotion mediation may be an additional mechanism behind sound-taste correspondences.

The chemistry and physiology of sour taste--a review.

PubMed

Ramos Da Conceicao Neta, Edith Ramos; Johanningsmeier, Suzanne D; McFeeters, Roger F

2007-03-01

Sour taste is the key element in the flavor profile of food acidulants. Understanding the chemistry and physiology of sour taste is critical for efficient control of flavor in the formulation of acid and acidified foods. After a brief introduction to the main applications of food acidulants, several chemical parameters associated with sour taste are discussed. Special emphasis is given to hydrogen ions, protonated (undissociated) acid species, titratable acidity, anions, molar concentration, and physical and chemical properties of organic acids. This article also presents an overview of the physiology of sour taste and proposed theories for the transduction mechanisms for sour taste. The physiology of sour taste perception remains controversial and significant diversity exists among species with regard to cellular schemes used for detection of stimuli. The variety of mechanisms proposed, even within individual species, highlights the complexity of elucidating sour taste transduction. However, recent evidence suggests that at least one specific sour taste receptor protein has been identified.

The Insula and Taste Learning

PubMed Central

Yiannakas, Adonis; Rosenblum, Kobi

2017-01-01

The sense of taste is a key component of the sensory machinery, enabling the evaluation of both the safety as well as forming associations regarding the nutritional value of ingestible substances. Indicative of the salience of the modality, taste conditioning can be achieved in rodents upon a single pairing of a tastant with a chemical stimulus inducing malaise. This robust associative learning paradigm has been heavily linked with activity within the insular cortex (IC), among other regions, such as the amygdala and medial prefrontal cortex. A number of studies have demonstrated taste memory formation to be dependent on protein synthesis at the IC and to correlate with the induction of signaling cascades involved in synaptic plasticity. Taste learning has been shown to require the differential involvement of dopaminergic GABAergic, glutamatergic, muscarinic neurotransmission across an extended taste learning circuit. The subsequent activation of downstream protein kinases (ERK, CaMKII), transcription factors (CREB, Elk-1) and immediate early genes (c-fos, Arc), has been implicated in the regulation of the different phases of taste learning. This review discusses the relevant neurotransmission, molecular signaling pathways and genetic markers involved in novel and aversive taste learning, with a particular focus on the IC. Imaging and other studies in humans have implicated the IC in the pathophysiology of a number of cognitive disorders. We conclude that the IC participates in circuit-wide computations that modulate the interception and encoding of sensory information, as well as the formation of subjective internal representations that control the expression of motivated behaviors. PMID:29163022

Taste quality decoding parallels taste sensations.

PubMed

Crouzet, Sébastien M; Busch, Niko A; Ohla, Kathrin

2015-03-30

In most species, the sense of taste is key in the distinction of potentially nutritious and harmful food constituents and thereby in the acceptance (or rejection) of food. Taste quality is encoded by specialized receptors on the tongue, which detect chemicals corresponding to each of the basic tastes (sweet, salty, sour, bitter, and savory [1]), before taste quality information is transmitted via segregated neuronal fibers [2], distributed coding across neuronal fibers [3], or dynamic firing patterns [4] to the gustatory cortex in the insula. In rodents, both hardwired coding by labeled lines [2] and flexible, learning-dependent representations [5] and broadly tuned neurons [6] seem to coexist. It is currently unknown how, when, and where taste quality representations are established in the cortex and whether these representations are used for perceptual decisions. Here, we show that neuronal response patterns allow to decode which of four tastants (salty, sweet, sour, and bitter) participants tasted in a given trial by using time-resolved multivariate pattern analyses of large-scale electrophysiological brain responses. The onset of this prediction coincided with the earliest taste-evoked responses originating from the insula and opercular cortices, indicating that quality is among the first attributes of a taste represented in the central gustatory system. These response patterns correlated with perceptual decisions of taste quality: tastes that participants discriminated less accurately also evoked less discriminated brain response patterns. The results therefore provide the first evidence for a link between taste-related decision-making and the predictive value of these brain response patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tasting

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... about 10,000 taste buds. The taste buds are linked to the brain by nerve fibers. Food particles are detected by the taste buds, which send nerve ... to the brain. Certain areas of the tongue are more sensitive to certain tastes, like bitter, sour, ...

The taste cell-related diffuse chemosensory system.

PubMed

Sbarbati, A; Osculati, F

2005-03-01

Elements expressing the molecular mechanisms of gustatory transduction have been described in several organs in the digestive and respiratory apparatuses. These taste cell-related elements are isolated cells, which are not grouped in buds, and they have been interpreted as chemoreceptors. Their presence in epithelia of endodermal origin suggests the existence of a diffuse chemosensory system (DCS) sharing common signaling mechanisms with the "classic" taste organs. The elements of this taste cell-related DCS display a site-related morphologic polymorphism, and in the past they have been indicated with various names (e.g., brush, tuft, caveolated, fibrillo-vesicular or solitary chemosensory cells). It may be that the taste cell-related DCS is like an iceberg: the taste buds are probably only the most visible portion, with most of the iceberg more caudally located in the form of solitary chemosensory cells or chemosensory clusters. Comparative anatomical studies in lower vertebrates suggest that this 'submerged' portion may represent the most phylogenetically ancient component of the system, which is probably involved in defensive or digestive mechanisms. In the taste buds, the presence of several cell subtypes and of a wide range of molecular mechanisms permits precise food analysis. The larger, 'submerged' portion of the iceberg is composed of a polymorphic population of isolated elements or cell clusters in which the molecular cascade of cell signaling needs to be explored in detail. The little data we have strongly suggests a close relationship with taste cells. Morphological and biochemical considerations suggest that the DCS is a potential new drug target. Modulation of the respiratory and digestive apparatuses through substances, which act on the molecular receptors of this chemoreceptive system, could be a new frontier in drug discovery.

Acetylcholine is released from taste cells, enhancing taste signalling

PubMed Central

Dando, Robin; Roper, Stephen D

2012-01-01

Acetylcholine (ACh), a candidate neurotransmitter that has been implicated in taste buds, elicits calcium mobilization in Receptor (Type II) taste cells. Using RT-PCR analysis and pharmacological interventions, we demonstrate that the muscarinic acetylcholine receptor M3 mediates these actions. Applying ACh enhanced both taste-evoked Ca2+ responses and taste-evoked afferent neurotransmitter (ATP) secretion from taste Receptor cells. Blocking muscarinic receptors depressed taste-evoked responses in Receptor cells, suggesting that ACh is normally released from taste cells during taste stimulation. ACh biosensors confirmed that, indeed, taste Receptor cells secrete acetylcholine during gustatory stimulation. Genetic deletion of muscarinic receptors resulted in significantly diminished ATP secretion from taste buds. The data demonstrate a new role for acetylcholine as a taste bud transmitter. Our results imply specifically that ACh is an autocrine transmitter secreted by taste Receptor cells during gustatory stimulation, enhancing taste-evoked responses and afferent transmitter secretion. PMID:22570381

Temperature Affects Human Sweet Taste via At Least Two Mechanisms

PubMed Central

Nachtigal, Danielle

2015-01-01

The reported effects of temperature on sweet taste in humans have generally been small and inconsistent. Here, we describe 3 experiments that follow up a recent finding that cooling from 37 to 21 °C does not reduce the initial sweetness of sucrose but increases sweet taste adaptation. In experiment 1, subjects rated the sweetness of sucrose, glucose, and fructose solutions at 5–41 °C by dipping the tongue tip into the solutions after 0-, 3-, or 10-s pre-exposures to the same solutions or to H2O; experiment 2 compared the effects of temperature on the sweetness of 3 artificial sweeteners (sucralose, aspartame, and saccharin); and experiment 3 employed a flow-controlled gustometer to rule out the possibility the effects of temperature in the preceding experiments were unique to dipping the tongue into a still taste solution. The results (i) confirmed that mild cooling does not attenuate sweetness but can increase sweet taste adaptation; (ii) demonstrated that cooling to 5–12 °C can directly reduce sweetness intensity; and (iii) showed that both effects vary across stimuli. These findings have implications for the TRPM5 hypothesis of thermal effects on sweet taste and raise the possibility that temperature also affects an earlier step in the T1R2–T1R3 transduction cascade. PMID:25963040

Discrimination of taste qualities among mouse fungiform taste bud cells.

PubMed

Yoshida, Ryusuke; Miyauchi, Aya; Yasuo, Toshiaki; Jyotaki, Masafumi; Murata, Yoshihiro; Yasumatsu, Keiko; Shigemura, Noriatsu; Yanagawa, Yuchio; Obata, Kunihiko; Ueno, Hiroshi; Margolskee, Robert F; Ninomiya, Yuzo

2009-09-15

Multiple lines of evidence from molecular studies indicate that individual taste qualities are encoded by distinct taste receptor cells. In contrast, many physiological studies have found that a significant proportion of taste cells respond to multiple taste qualities. To reconcile this apparent discrepancy and to identify taste cells that underlie each taste quality, we investigated taste responses of individual mouse fungiform taste cells that express gustducin or GAD67, markers for specific types of taste cells. Type II taste cells respond to sweet, bitter or umami tastants, express taste receptors, gustducin and other transduction components. Type III cells possess putative sour taste receptors, and have well elaborated conventional synapses. Consistent with these findings we found that gustducin-expressing Type II taste cells responded best to sweet (25/49), bitter (20/49) or umami (4/49) stimuli, while all GAD67 (Type III) taste cells examined (44/44) responded to sour stimuli and a portion of them showed multiple taste sensitivities, suggesting discrimination of each taste quality among taste bud cells. These results were largely consistent with those previously reported with circumvallate papillae taste cells. Bitter-best taste cells responded to multiple bitter compounds such as quinine, denatonium and cyclohexamide. Three sour compounds, HCl, acetic acid and citric acid, elicited responses in sour-best taste cells. These results suggest that taste cells may be capable of recognizing multiple taste compounds that elicit similar taste sensation. We did not find any NaCl-best cells among the gustducin and GAD67 taste cells, raising the possibility that salt sensitive taste cells comprise a different population.

Choice Behavior Guided by Learned, But Not Innate, Taste Aversion Recruits the Orbitofrontal Cortex.

PubMed

Ramírez-Lugo, Leticia; Peñas-Rincón, Ana; Ángeles-Durán, Sandybel; Sotres-Bayon, Francisco

2016-10-12

-guided tasks, our study provides evidence for the key role of orbitofrontal cortex activity in choice behavior and shows that this is dissociable from the adjacent insular cortex-dependent taste aversion memory. Understanding the brain mechanisms that underlie the impact that emotional associations have on survival choice behaviors may lead to better treatments for mental disorders characterized by emotional decision-making deficits. Copyright © 2016 the authors 0270-6474/16/3610574-10$15.00/0.

Glucagon signaling modulates sweet taste responsiveness.

PubMed

Elson, Amanda E T; Dotson, Cedrick D; Egan, Josephine M; Munger, Steven D

2010-10-01

The gustatory system provides critical information about the quality and nutritional value of food before it is ingested. Thus, physiological mechanisms that modulate taste function in the context of nutritional needs or metabolic status could optimize ingestive decisions. We report that glucagon, which plays important roles in the maintenance of glucose homeostasis, enhances sweet taste responsiveness through local actions in the mouse gustatory epithelium. Using immunohistochemistry and confocal microscopy, we found that glucagon and its receptor (GlucR) are coexpressed in a subset of mouse taste receptor cells. Most of these cells also express the T1R3 taste receptor implicated in sweet and/or umami taste. Genetic or pharmacological disruption of glucagon signaling in behaving mice indicated a critical role for glucagon in the modulation of taste responsiveness. Scg5(-/-) mice, which lack mature glucagon, had significantly reduced responsiveness to sucrose as compared to wild-type littermates in brief-access taste tests. No significant differences were seen in responses to prototypical salty, sour, or bitter stimuli. Taste responsiveness to sucrose was similarly reduced upon acute and local disruption of glucagon signaling by the GlucR antagonist L-168,049. Together, these data indicate a role for local glucagon signaling in the peripheral modulation of sweet taste responsiveness.

Processing umami and other tastes in mammalian taste buds.

PubMed

Roper, Stephen D; Chaudhari, Nirupa

2009-07-01

Neuroscientists are now coming to appreciate that a significant degree of information processing occurs in the peripheral sensory organs of taste prior to signals propagating to the brain. Gustatory stimulation causes taste bud cells to secrete neurotransmitters that act on adjacent taste bud cells (paracrine transmitters) as well as on primary sensory afferent fibers (neurocrine transmitters). Paracrine transmission, representing cell-cell communication within the taste bud, has the potential to shape the final signal output that taste buds transmit to the brain. The following paragraphs summarize current thinking about how taste signals generally, and umami taste in particular, are processed in taste buds.

The neural processing of taste

PubMed Central

Lemon, Christian H; Katz, Donald B

2007-01-01

Although there have been many recent advances in the field of gustatory neurobiology, our knowledge of how the nervous system is organized to process information about taste is still far from complete. Many studies on this topic have focused on understanding how gustatory neural circuits are spatially organized to represent information about taste quality (e.g., "sweet", "salty", "bitter", etc.). Arguments pertaining to this issue have largely centered on whether taste is carried by dedicated neural channels or a pattern of activity across a neural population. But there is now mounting evidence that the timing of neural events may also importantly contribute to the representation of taste. In this review, we attempt to summarize recent findings in the field that pertain to these issues. Both space and time are variables likely related to the mechanism of the gustatory neural code: information about taste appears to reside in spatial and temporal patterns of activation in gustatory neurons. What is more, the organization of the taste network in the brain would suggest that the parameters of space and time extend to the neural processing of gustatory information on a much grander scale. PMID:17903281

Taste Receptor Signaling-- From Tongues to Lungs

PubMed Central

Kinnamon, Sue C.

2013-01-01

Taste buds are the transducing endorgans of gustation. Each taste bud comprises 50–100 elongated cells, which extend from the basal lamina to the surface of the tongue, where their apical microvilli encounter taste stimuli in the oral cavity. Salts and acids utilize apically located ion channels for transduction, while bitter, sweet and umami (glutamate) stimuli utilize G protein coupled receptors (GPCRs) and second messenger signaling mechanisms. This review will focus on GPCR signaling mechanisms. Two classes of taste GPCRs have been identified, the T1Rs for sweet and umami (glutamate) stimuli, and the T2Rs for bitter stimuli. These low affinity GPCRs all couple to the same downstream signaling effectors that include Gβγ activation of PLCβ2, IP3-mediated release of Ca2+ from intracellular stores, and Ca2+-dependent activation of the monovalent selective cation channel, TrpM5. These events lead to membrane depolarization, action potentials, and release of ATP as a transmitter to activate gustatory afferents. The Gα subunit, α-gustducin, activates a phosphodiesterase to decrease intracellular cAMP levels, although the precise targets of cAMP have not been identified. With the molecular identification of the taste GPCRs, it has become clear that taste signaling is not limited to taste buds, but occurs in many cell types of the airways. These include solitary chemosensory cells, ciliated epithelial cells, and smooth muscle cells. Bitter receptors are most abundantly expressed in the airways, where they respond to irritating chemicals and promote protective airway reflexes, utilizing the same downstream signaling effectors as taste cells. PMID:21481196

Calcium signaling in taste cells: regulation required.

PubMed

Medler, Kathryn F

2010-11-01

Peripheral taste receptor cells depend on distinct calcium signals to generate appropriate cellular responses that relay taste information to the central nervous system. Some taste cells have conventional chemical synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release from stores to formulate an output signal through a hemichannel. Despite the importance of calcium signaling in taste cells, little is known about how these signals are regulated. This review summarizes recent studies that have identified 2 calcium clearance mechanisms expressed in taste cells, including mitochondrial calcium uptake and sodium/calcium exchangers (NCXs). These studies identified a unique constitutive calcium influx that contributes to maintaining appropriate calcium homeostasis in taste cells and the role of the mitochondria and exchangers in this process. The additional role of NCXs in the regulation of evoked calcium responses is also discussed. Clearly, calcium signaling is a dynamic process in taste cells and appears to be more complex than has previously been appreciated.

The Bad Taste of Medicines: Overview of Basic Research on Bitter Taste

PubMed Central

Mennella, Julie A.; Spector, Alan C.; Reed, Danielle R.; Coldwell, Susan E.

2013-01-01

consume some medicines, they often are not effective in suppressing bitter tastes. Further development of psychophysical tools for children will help us better understand their sensory worlds. Multiple testing strategies will help us refine methods to assess acceptance and compliance/adherence by various pediatric populations. Research involving animal models, in which the gustatory system can be more invasively manipulated, can elucidate mechanisms, ultimately providing potential targets. These approaches, combined with new technologies and guided by findings from clinical studies, will potentially lead to effective ways to enhance drug acceptance and compliance in pediatric populations. PMID:23886820

Cross-modal Associations between Real Tastes and Colors.

PubMed

Saluja, Supreet; Stevenson, Richard J

2018-06-02

People make reliable and consistent matches between taste and color. However, in contrast to other cross-modal correspondences, all of the research to date has used only taste words (and often color words too), potentially limiting our understanding of how taste-color matches arise. Here, participants sampled the five basic tastes, at three concentration steps, and selected their best matching color from a color-wheel. This test was repeated, and in addition, participants evaluated the valence of the taste and their color choice, as well as the qualities/intensities of the taste stimuli. Participants were then presented with taste names and asked to generate the best matching color name, as well as reporting how they made their earlier choices. Color selections were reliable and consistent, and closely followed those based on taste word matches obtained in this and prior studies. Most participants reported basing their color choices on their associated taste-object (often foods). There was marked similarity in valence between taste and color choices, and the saturation of color choices was related to tastant concentration. We discuss what drives color-taste pairings, with learning suggested as one possible mechanism.

Zizyphin modulates calcium signalling in human taste bud cells and fat taste perception in the mouse.

PubMed

Murtaza, Babar; Berrichi, Meryem; Bennamar, Chahid; Tordjmann, Thierry; Djeziri, Fatima Z; Hichami, Aziz; Leemput, Julia; Belarbi, Meriem; Ozdener, Hakan; Khan, Naim A

2017-10-01

Zizyphin, isolated from Zizyphus sps. leaf extracts, has been shown to modulate sugar taste perception, and the palatability of a sweet solution is increased by the addition of fatty acids. We, therefore, studied whether zizyphin also modulates fat taste perception. Zizyphin was purified from edible fruit of Zizyphus lotus L. Zizyphin-induced increases in [Ca 2+ ]i in human taste bud cells (hTBC). Zizyphin shared the endoplasmic reticulum Ca 2+ pool and also recruited, in part, Ca 2+ from extracellular environment via the opening of store-operated Ca 2+ channels. Zizyphin exerted additive actions on linoleic acid (LA)-induced increases in [Ca 2+ ]i in these cells, indicating that zizyphin does not exert its action via fatty acid receptors. However, zizyphin seemed to exert, at least in part, its action via bile acid receptor Takeda-G-protein-receptor-5 in hTBC. In behavioural tests, mice exhibited preference for both LA and zizyphin. Interestingly, zizyphin increased the preference for a solution containing-LA. This study is the first evidence of the modulation of fat taste perception by zizyphin at the cellular level in hTBC. Our study might be helpful for considering the synthesis of zizyphin analogues as 'taste modifiers' with a potential in the management of obesity and lipid-mediated disorders. © 2017 Société Française de Pharmacologie et de Thérapeutique.

Taste-dependent sociophobia: when food and company do not mix.

PubMed

Guitton, Matthieu J; Klin, Yael; Dudai, Yadin

2008-08-22

Using a combination of the paradigm of conditioned taste aversion (CTA) and of the paradigm of social interactions, we report here that in the rat, eating while anxious may result in long-term alterations in social behavior. In the conventional CTA, the subject learns to associate a tastant (the conditioned stimulus, CS) with delayed toxicosis (an unconditioned stimulus, UCS) to yield taste aversion (the conditioned response, CR). However, the association of taste with delayed negative internal states that could generate CRs that are different from taste aversion should not be neglected. Such associations may contribute to the ontogenesis, reinforcement and symptoms of some types of taste- and food-related disorders. We have recently reported that a delayed anxiety-like state, induced by the anxiogenic drug meta-chlorophenylpiperazine (mCPP), can specifically associate with taste to produce CTA. We now show that a similar protocol results in a marked lingering impairment in social interactions in response to the conditioned taste. This is hence a learned situation in which food and company do not mix well.

“What’s Your Taste in Music?” A Comparison of the Effectiveness of Various Soundscapes in Evoking Specific Tastes

PubMed Central

Woods, Andy T.; Spence, Charles

2015-01-01

We report on the results of two online experiments designed to compare different soundtracks that had been composed (by various researchers and sound designers) in order to evoke/match different basic tastes. In Experiment 1, 100 participants listened to samples from 24 soundtracks and chose the taste (sweet, sour, salty, or bitter) that best matched each sample. Overall, the sweet soundtracks most effectively evoked the taste intended by the composer (participants chose sweet 56.9% of the time for the sweet soundtracks), whereas the bitter soundtracks were the least effective (participants chose bitter 31.4% of the time for the bitter soundtracks), compared with chance (choosing any specific taste 25% of the time). In Experiment 2, 50 participants rated their emotional responses (in terms of pleasantness and arousal) to the same 24 soundtrack samples and also to imaginary sweet/sour/salty/bitter-tasting foods. Associations between soundtracks and tastes were partly mediated by pleasantness for the sweet and bitter tastes and partly by arousal for the sour tastes. These results demonstrate how emotion mediation may be an additional mechanism behind sound-taste correspondences. PMID:27551365

Vasoactive intestinal peptide-null mice demonstrate enhanced sweet taste preference, dysglycemia, and reduced taste bud leptin receptor expression.

PubMed

Martin, Bronwen; Shin, Yu-Kyong; White, Caitlin M; Ji, Sunggoan; Kim, Wook; Carlson, Olga D; Napora, Joshua K; Chadwick, Wayne; Chapter, Megan; Waschek, James A; Mattson, Mark P; Maudsley, Stuart; Egan, Josephine M

2010-05-01

It is becoming apparent that there is a strong link between taste perception and energy homeostasis. Recent evidence implicates gut-related hormones in taste perception, including glucagon-like peptide 1 and vasoactive intestinal peptide (VIP). We used VIP knockout mice to investigate VIP's specific role in taste perception and connection to energy regulation. Body weight, food intake, and plasma levels of multiple energy-regulating hormones were measured and pancreatic morphology was determined. In addition, the immunocytochemical profile of taste cells and gustatory behavior were examined in wild-type and VIP knockout mice. VIP knockout mice demonstrate elevated plasma glucose, insulin, and leptin levels, with no islet beta-cell number/topography alteration. VIP and its receptors (VPAC1, VPAC2) were identified in type II taste cells of the taste bud, and VIP knockout mice exhibit enhanced taste preference to sweet tastants. VIP knockout mouse taste cells show a significant decrease in leptin receptor expression and elevated expression of glucagon-like peptide 1, which may explain sweet taste preference of VIP knockout mice. This study suggests that the tongue can play a direct role in modulating energy intake to correct peripheral glycemic imbalances. In this way, we could view the tongue as a sensory mechanism that is bidirectionally regulated and thus forms a bridge between available foodstuffs and the intricate hormonal balance in the animal itself.

Does the taste matter? Taste and medicinal perceptions associated with five selected herbal drugs among three ethnic groups in West Yorkshire, Northern England

PubMed Central

Pieroni, Andrea; Torry, Bren

2007-01-01

In recent years, diverse scholars have addressed the issue of the chemosensory perceptions associated with traditional medicines, nevertheless there is still a distinct lack of studies grounded in the social sciences and conducted from a cross-cultural, comparative perspective. In this urban ethnobotanical field study, 254 informants belonging to the Gujarati, Kashmiri and English ethnic groups and living in Western Yorkshire in Northern England were interviewed about the relationship between taste and medicinal perceptions of five herbal drugs, which were selected during a preliminary study. The herbal drugs included cinnamon (the dried bark of Cinnamomum verum, Lauraceae), mint (the leaves of Mentha spp., Lamiaceae), garlic (the bulbs of Allium sativum, Alliaceae), ginger (the rhizome of Zingiber officinale, Zingiberaceae), and cloves (the dried flower buds of Syzygium aromaticum, Myrtaceae). The main cross-cultural differences in taste perceptions regarded the perception the perception of the spicy taste of ginger, garlic, and cinnamon, of the bitter taste of ginger, the sweet taste of mint, and of the sour taste of garlic. The part of the study of how the five selected herbal drugs are perceived medicinally showed that TK (Traditional Knowledge) is widespread among Kashmiris, but not so prevalent among the Gujarati and especially the English samples. Among Kashmiris, ginger was frequently considered to be helpful for healing infections and muscular-skeletal and digestive disorders, mint was chosen for healing digestive and respiratory troubles, garlic for blood system disorders, and cinnamon was perceived to be efficacious for infectious diseases. Among the Gujarati and Kashmiri groups there was evidence of a strong link between the bitter and spicy tastes of ginger, garlic, cloves, and cinnamon and their perceived medicinal properties, whereas there was a far less obvious link between the sweet taste of mint and cinnamon and their perceived medicinal

A taste for ATP: neurotransmission in taste buds

PubMed Central

Kinnamon, Sue C.; Finger, Thomas E.

2013-01-01

Not only is ATP a ubiquitous source of energy but it is also used widely as an intercellular signal. For example, keratinocytes release ATP in response to numerous external stimuli including pressure, heat, and chemical insult. The released ATP activates purinergic receptors on nerve fibers to generate nociceptive signals. The importance of an ATP signal in epithelial-to-neuronal signaling is nowhere more evident than in the taste system. The receptor cells of taste buds release ATP in response to appropriate stimulation by tastants and the released ATP then activates P2X2 and P2X3 receptors on the taste nerves. Genetic ablation of the relevant P2X receptors leaves an animal without the ability to taste any primary taste quality. Of interest is that release of ATP by taste receptor cells occurs in a non-vesicular fashion, apparently via gated membrane channels. Further, in keeping with the crucial role of ATP as a neurotransmitter in this system, a subset of taste cells expresses a specific ectoATPase, NTPDase2, necessary to clear extracellular ATP which otherwise will desensitize the P2X receptors on the taste nerves. The unique utilization of ATP as a key neurotransmitter in the taste system may reflect the epithelial rather than neuronal origins of the receptor cells. PMID:24385952

Accuracy of self-report in detecting taste dysfunction.

PubMed

Soter, Ana; Kim, John; Jackman, Alexis; Tourbier, Isabelle; Kaul, Arti; Doty, Richard L

2008-04-01

To determine the sensitivity, specificity, and positive and negative predictive value of responses to the following questionnaire statements in detecting taste loss: "I can detect salt in chips, pretzels, or salted nuts," "I can detect sourness in vinegar, pickles, or lemon," "I can detect sweetness in soda, cookies, or ice cream," and "I can detect bitterness, in coffee, beer, or tonic water." Responses to an additional item, "I can detect chocolate in cocoa, cake or candy," was examined to determine whether patients clearly differentiate between taste loss and flavor loss secondary to olfactory dysfunction. A total of 469 patients (207 men, mean age = 54 years, standard deviation = 15 years; and 262 women, mean age = 54 years, standard deviation = 14 years) were administered a questionnaire containing these questions with the response categories of "easily," "somewhat," and "not at all," followed by a comprehensive taste and smell test battery. The questionnaire items poorly detected bona fide taste problems. However, they were sensitive in detecting persons without such problems (i.e., they exhibited low positive but high negative predictive value). Dysfunction categories of the University of Pennsylvania Smell Identification Test (UPSIT) were not meaningfully related to subjects' responses to the questionnaire statements. Both sex and age influenced performance on most of the taste tests, with older persons performing more poorly than younger ones and women typically outperforming men. Although it is commonly assumed that straight-forward questions concerning taste may be useful in detecting taste disorders, this study suggests this is not the case. However, patients who specifically report having no problems with taste perception usually do not exhibit taste dysfunction. The difficulty in detecting true taste problems by focused questionnaire items likely reflects a combination of factors. These include the relatively low prevalence of taste deficits in the

The sweet taste of true synergy: positive allosteric modulation of the human sweet taste receptor.

PubMed

Servant, Guy; Tachdjian, Catherine; Li, Xiaodong; Karanewsky, Donald S

2011-11-01

A diet low in carbohydrates helps to reduce the amount of ingested calories and to maintain a healthy weight. With this in mind, food and beverage companies have reformulated a large number of their products, replacing sugar or high fructose corn syrup with several different types of zero-calorie sweeteners to decrease or even totally eliminate their caloric content. A challenge remains, however, with the level of acceptance of some of these products in the market-place. Many consumers believe that zero-calorie sweeteners simply do not taste like sugar. A recent breakthrough reveals that positive allosteric modulators of the human sweet taste receptor, small molecules that enhance the receptor activity and sweetness perception, could be more effective than other reported taste enhancers at reducing calories in consumer products without compromising on the true taste of sugar. A unique mechanism of action at the receptor level could explain the robust synergy achieved with these new modulators. Copyright © 2011 Elsevier Ltd. All rights reserved.

Expression of aquaporin water channels in rat taste buds.

PubMed

Watson, Kristina J; Kim, Insook; Baquero, Arian F; Burks, Catherine A; Liu, Lidong; Gilbertson, Timothy A

2007-06-01

In order to gain insight into the molecular mechanisms that allow taste cells to respond to changes in their osmotic environment, we have used primarily immunocytochemical and molecular approaches to look for evidence of the presence of aquaporin-like water channels in taste cells. Labeling of isolated taste buds from the fungiform, foliate, and vallate papillae in rat tongue with antibodies against several of the aquaporins (AQPs) revealed the presence of AQP1, AQP2, and AQP5 in taste cells from these areas. AQP3 antibodies failed to label isolated taste buds from any of the papillae. There was an apparent difference in the regional localization of AQP labeling within the taste bud. Antibodies against AQP1 and AQP2 labeled predominantly the basolateral membrane, whereas the AQP5 label was clearly evident on both the apical and basolateral membranes of cells within the taste bud. Double labeling revealed that AQP1 and AQP2 labeled many, but not all, of the same taste cells. Similar double-labeling experiments with anti-AQP2 and anti-AQP5 clearly showed that AQP5 was expressed on or near the apical membranes whereas AQP2 was absent from this area. The presence of these 3 types of AQPs in taste buds but not in non-taste bud-containing epithelia was confirmed using reverse transcription-polymerase chain reaction. Experiments using patch clamp recording showed that the AQP inhibitor, tetraethylammonium, significantly reduced hypoosmotic-induced currents in rat taste cells. We hypothesize that the AQPs may play roles both in the water movement underlying compensatory mechanisms for changes in extracellular osmolarity and, in the case of AQP5 in particular, in the gustatory response to water.

Double blind study of the effects of zinc sulfate on taste and smell dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henkin, R.I.; Schecter, P.J.; Friedewald, W.T.

1976-01-01

A randomized, double blind crossover study of the effects of zinc sulfate and placebo was carried out in 106 patients with taste and smell dysfunction secondary to a variety of etiological factors. In the patient group prior to treatment, mean serum zinc concentration and leukocyte alkaline phosphatase activity were significantly lower than normal. Results indicate that zinc sulfate was effectively equivalent to placebo in the treatment of these disorders. Although these results demonstrate abnormalities of zinc metabolism in some patients with taste and smell dysfunction they fail to provide evidence for a single, therapeutic approach to the many disorders whichmore » are associated with abnormalities of taste and smell. However, the methods and procedures developed in this study demonstrate that taste and smell dysfunction can be studied in a quantitative, systematic manner.« less

Radiation effects on bovine taste bud membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shatzman, A.R.; Mossman, K.L.

1982-11-01

In order to investigate the mechanisms of radiation-induced taste loss, the effects of radiation on preparations of enriched bovine taste bud membranes were studied. Taste buds containing circumvallate papilae, and surrounding control epithelial tissues devoid of taste buds, were obtained from steers and given radiation doses of 0-7000 cGy (rad). Tissue fractions were isolated into membrane-enriched and heterogeneous components using differential and sucrose gradient centrifugation of tissue homogenates. The yield of membranes, as measured by protein content in the buoyant membrane-enriched fractions, was reduced in quantity with increasing radiation dose. The relation between radiation dose and membrane quantity in membrane-enrichedmore » fractions could be fit by a simple exponential model with taste bud-derived membranes twice as radiosensitive as membranes from control epithelial tissue. Binding of sucrose, sodium, and acetate and fluoride stimulation of adenylate cyclase were nearly identical in both irradiated and nonirradiated intact membranes. Radiation had no effect on fractions of heterogeneous components. While it is not clear what changes are occurring in enriched taste cell membranes, damage to membranes may play an important role in the taste loss observed in patients following radiotherapy.« less

Regulation of bitter taste responses by tumor necrosis factor

PubMed Central

Feng, Pu; Jyotaki, Masafumi; Kim, Agnes; Chai, Jinghua; Simon, Nirvine; Zhou, Minliang; Bachmanov, Alexander A.; Huang, Liquan; Wang, Hong

2015-01-01

Inflammatory cytokines are important regulators of metabolism and food intake. Over production of inflammatory cytokines during bacterial and viral infections leads to anorexia and reduced food intake. However, it remains unclear whether any inflammatory cytokines are involved in the regulation of taste reception, the sensory mechanism governing food intake. Previously, we showed that tumor necrosis factor (TNF), a potent proinflammatory cytokine, is preferentially expressed in a subset of taste bud cells. The level of TNF in taste cells can be further induced by inflammatory stimuli. To investigate whether TNF plays a role in regulating taste responses, in this study, we performed taste behavioral tests and gustatory nerve recordings in TNF knockout mice. Behavioral tests showed that TNF-deficient mice are significantly less sensitive to the bitter compound quinine than wild-type mice, while their responses to sweet, umami, salty, and sour compounds are comparable to those of wild-type controls. Furthermore, nerve recording experiments showed that the chorda tympani nerve in TNF knockout mice is much less responsive to bitter compounds than that in wild-type mice. Chorda tympani nerve responses to sweet, umami, salty, and sour compounds are similar between TNF knockout and wild-type mice, consistent with the results from behavioral tests. We further showed that taste bud cells express the two known TNF receptors TNFR1 and TNFR2 and, therefore, are potential targets of TNF. Together, our results suggest that TNF signaling preferentially modulates bitter taste responses. This mechanism may contribute to taste dysfunction, particularly taste distortion, associated with infections and some chronic inflammatory diseases. PMID:25911043

Sensing of Taste

NASA Astrophysics Data System (ADS)

Toko, Kiyoshi

A taste sensor with global selectivity, i. e., electronic tongue, is composed of several kinds of lipid/polymer membranes for transforming information of taste substances into electric signal. The sensor output shows different patterns for chemical substances which have different taste qualities such as saltiness and sourness. Taste interactions such as suppression effect, which occurs between bitterness and sweetness, can be detected and quantified using the taste sensor. Amino acids can be classified into several groups according to their own tastes from sensor outputs. The taste of foodstuffs such as beer, coffee, mineral water and milk can be discussed quantitatively. The taste sensor provides the objective scale for the human sensory expression. We are now standing at the beginning of a new age of communication using digitized taste.

Taste information derived from T1R-expressing taste cells in mice.

PubMed

Yoshida, Ryusuke; Ninomiya, Yuzo

2016-03-01

The taste system of animals is used to detect valuable nutrients and harmful compounds in foods. In humans and mice, sweet, bitter, salty, sour and umami tastes are considered the five basic taste qualities. Sweet and umami tastes are mediated by G-protein-coupled receptors, belonging to the T1R (taste receptor type 1) family. This family consists of three members (T1R1, T1R2 and T1R3). They function as sweet or umami taste receptors by forming heterodimeric complexes, T1R1+T1R3 (umami) or T1R2+T1R3 (sweet). Receptors for each of the basic tastes are thought to be expressed exclusively in taste bud cells. Sweet (T1R2+T1R3-expressing) taste cells were thought to be segregated from umami (T1R1+T1R3-expressing) taste cells in taste buds. However, recent studies have revealed that a significant portion of taste cells in mice expressed all T1R subunits and responded to both sweet and umami compounds. This suggests that sweet and umami taste cells may not be segregated. Mice are able to discriminate between sweet and umami tastes, and both tastes contribute to behavioural preferences for sweet or umami compounds. There is growing evidence that T1R3 is also involved in behavioural avoidance of calcium tastes in mice, which implies that there may be a further population of T1R-expressing taste cells that mediate aversion to calcium taste. Therefore the simple view of detection and segregation of sweet and umami tastes by T1R-expressing taste cells, in mice, is now open to re-examination. © 2016 Authors; published by Portland Press Limited.

Role of Endocannabinoids on Sweet Taste Perception, Food Preference, and Obesity-related Disorders.

PubMed

Tarragon, Ernesto; Moreno, Juan José

2017-12-25

The prevalence of obesity and obesity-related disorders such as type 2 diabetes (T2D) and metabolic syndrome has increased significantly in the past decades, reaching epidemic levels and therefore becoming a major health issue worldwide. Chronic overeating of highly palatable foods is one of the main responsible aspects behind overweight. Food choice is driven by food preference, which is influenced by environmental and internal factors, from availability to rewarding properties of food. Consequently, the acquisition of a dietary habit that may lead to metabolic alterations is the result of a learning process in which many variables take place. From genetics to socioeconomic status, the response to food and how this food affects energy metabolism is heavily influenced, even before birth. In this work, we review how food preference is acquired and established, particularly as regards sweet taste; towards which flavors and tastes we are positively predisposed by our genetic background, our early experience, further lifestyle, and our surroundings; and, especially, the role that the endocannabinoid system (ECS) plays in all of this. Ultimately, we try to summarize why this system is relevant for health purposes and how this is linked to important aspects of eating behavior, as its function as a modulator of energy homeostasis affects, and is affected by, physiological responses directly associated with obesity. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of streptozotocin-induced diabetes on taste buds in rat vallate papillae.

PubMed

Pai, Man-Hui; Ko, Tsui-Ling; Chou, Hsiu-Chu

2007-01-01

Some studies have documented taste changes in patients with diabetes mellitus (DM). In order to understand the relationships between taste disorders caused by DM and the innervation and morphologic changes in the taste buds, we studied the vallate papillae and their taste buds in rats with DM. DM was induced in these rats with streptozotocin (STZ), which causes the death of beta cells of the pancreas. The rats were sacrificed and the vallate papillae were dissected for morphometric and quantitative immunohistochemical analyses. The innervations of the vallate papillae and taste buds in diabetic and control rats were detected using immunohistochemistry employing antibodies directed against protein gene product 9.5 (PGP 9.5) and calcitonin gene-related peptide (CGRP). The results showed that PGP 9.5- and CGRP-immunoreactive nerve fibers in the trench wall of diabetic vallate papillae, as well as taste cells in the taste buds, gradually decreased both intragemmally and intergemmally. The morphometry revealed no significant difference in papilla size between the control and diabetic groups, but there were fewer taste buds per papilla (per animal). The quantification of innervation in taste buds of the diabetic rats supported the visual assessment of immunohistochemical labeling, that the innervation of taste cells was significantly reduced in diabetic animals. These findings suggest that taste impairment in diabetic subjects may be caused by neuropathy defects and/or morphological changes in the taste buds.

Neurochemical markers of human fungiform papillae and taste buds.

PubMed

Astbäck, J; Arvidson, K; Johansson, O

1995-11-10

The presence of distribution of several neurochemical markers in human fungiform papillae and taste buds were investigated by the immunohistochemical technique. The gustatory cells of the taste buds are in synaptic contact with sensory nerve endings, and considering the taste buds strictly as specialized sensory organs, the amounts and distribution of some of the neurochemical markers were different to what we expected. For example, few structures showed immunoreactivity to the tachykinins substance P (SP), calcitonin gene-related peptide (CGRP), and neurokinin A (NKA) also for the peptides vasoactive intestinal polypeptide (VIP), neuropeptide tyrosine (NPY) and galanin, low amounts of immunoreactivity occurred. On the other hand, using antibodies to protein gene product 9.5 (PGP 9.5), protein S-100, and glutamate, numerous nerve fibres and/or immunoreactive cells were found in the fungiform papillae, in the epithelium, in the connective tissue and around blood vessels, as well as in or near taste buds. Incubation with the antibodies against somatostatin, enkephalin, bombesin, peptide histidine isoleucine amide (PHI), cholecystokinin (CCK)/gastrin and dopamine-beta-hydroxylase (DBH) was negative for the fungiform papillae. In conclusion, the present study has shown several immunoreactive structures using antibodies against certain neurochemical markers. Further investigations will hopefully correlate these morphological findings with functional taste perception data. Future studies of patients with taste disorders or other pathological changes correlated with taste and tongue will also be of utmost importance.

Regulation of bitter taste responses by tumor necrosis factor.

PubMed

Feng, Pu; Jyotaki, Masafumi; Kim, Agnes; Chai, Jinghua; Simon, Nirvine; Zhou, Minliang; Bachmanov, Alexander A; Huang, Liquan; Wang, Hong

2015-10-01

Inflammatory cytokines are important regulators of metabolism and food intake. Over production of inflammatory cytokines during bacterial and viral infections leads to anorexia and reduced food intake. However, it remains unclear whether any inflammatory cytokines are involved in the regulation of taste reception, the sensory mechanism governing food intake. Previously, we showed that tumor necrosis factor (TNF), a potent proinflammatory cytokine, is preferentially expressed in a subset of taste bud cells. The level of TNF in taste cells can be further induced by inflammatory stimuli. To investigate whether TNF plays a role in regulating taste responses, in this study, we performed taste behavioral tests and gustatory nerve recordings in TNF knockout mice. Behavioral tests showed that TNF-deficient mice are significantly less sensitive to the bitter compound quinine than wild-type mice, while their responses to sweet, umami, salty, and sour compounds are comparable to those of wild-type controls. Furthermore, nerve recording experiments showed that the chorda tympani nerve in TNF knockout mice is much less responsive to bitter compounds than that in wild-type mice. Chorda tympani nerve responses to sweet, umami, salty, and sour compounds are similar between TNF knockout and wild-type mice, consistent with the results from behavioral tests. We further showed that taste bud cells express the two known TNF receptors TNFR1 and TNFR2 and, therefore, are potential targets of TNF. Together, our results suggest that TNF signaling preferentially modulates bitter taste responses. This mechanism may contribute to taste dysfunction, particularly taste distortion, associated with infections and some chronic inflammatory diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Metallic taste from electrical and chemical stimulation.

PubMed

Lawless, Harry T; Stevens, David A; Chapman, Kathryn W; Kurtz, Anne

2005-03-01

A series of three experiments investigated the nature of metallic taste reports after stimulation with solutions of metal salts and after stimulation with metals and electric currents. To stimulate with electricity, a device was fabricated consisting of a small battery affixed to a plastic handle with the anode side exposed for placement on the tongue or oral tissues. Intensity of taste from metals and batteries was dependent upon the voltage and was more robust in areas dense in fungiform papillae. Metallic taste was reported from stimulation with ferrous sulfate solutions, from metals and from electric stimuli. However, reports of metallic taste were more frequent when the word 'metallic' was presented embedded in a list of choices, as opposed to simple free-choice labeling. Intensity decreased for ferrous sulfate when the nose was occluded, consistent with a decrease in retronasal smell, as previously reported. Intensity of taste evoked by copper metal, bimetallic stimuli (zinc/copper) or small batteries (1.5-3 V) was not affected by nasal occlusion. This difference suggests two distinct mechanisms for evocation of metallic taste reports, one dependent upon retronasal smell and a second mediated by oral chemoreceptors.

Participation of the peripheral taste system in aging-dependent changes in taste sensitivity.

PubMed

Narukawa, Masataka; Kurokawa, Azusa; Kohta, Rie; Misaka, Takumi

2017-09-01

Previous studies have shown that aging modifies taste sensitivity. However, the factors affecting the changes in taste sensitivity remain unclear. To investigate the cause of the age-related changes in taste sensitivity, we compared the peripheral taste detection systems in young and old mice. First, we examined whether taste sensitivity varied according to age using behavioral assays. We confirmed that the taste sensitivities to salty and bitter tastes decreased with aging. In other assays, the gustatory nerve responses to salty and sweet tastes increased significantly with aging, while those to bitter taste did not change. Thus, the profile of the gustatory nerve responses was inconsistent with the profile of the behavioral responses. Next, we evaluated the expressions of taste-related molecules in the taste buds. Although no apparent differences in the expressions of representative taste receptors were observed between the two age groups, the mRNA expressions of signaling effectors were slightly, but significantly, decreased in old mice. No significant differences in the turnover rates of taste bud cells were observed between the two age groups. Thus, we did not observe any large decreases in the expressions of taste-related molecules and turnover rates of taste bud cells with aging. Based on these findings, we conclude that changes in taste sensitivity with aging were not caused by aging-related degradation of peripheral taste organs. Meanwhile, the concentrations of several serum components that modify taste responses changed with age. Thus, taste signal-modifying factors such as serum components may have a contributing role in aging-related changes in taste sensitivity. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Interactions between radiation and amphetamine in taste-aversion learning and the role of the area postrema in amphetamine-induced conditioned taste aversions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rabin, B.M.; Hunt, W.A.; Lee, J.

1987-01-01

Three experiments were run to assess the role of the area postrema in taste-aversion learning resulting from combined treatment with subthreshold unconditioned stimuli and in the acquisition of an amphetamine-induced taste aversion. In the first experiment, it was shown that combined treatment with subthreshold radiation (15 rad) and subthreshold amphetamine (0.5 mg/kg, IP) resulted in the acquisition of a taste aversion. The second experiment showed that lesions of the area postrema blocked taste aversion learning produced by two subthreshold doses of amphetamine. In the third experiment, which looked at the dose-response curve for amphetamine-induced taste aversion learning to intact ratsmore » and rats with area postrema lesions, it was shown that both groups of rats acquired taste aversions following injection of amphetamine, although the rats with lesions showed a less-severe aversion than the intact rats. The results are interpreted as indicating that amphetamine-induced taste-aversion learning may involve area post-remamediated mechanisms, particularly at the lower doses, but an intact area postrema is not a necessary condition of the acquisition of an amphetamine-induced taste aversion.« less

Interactions between radiation and amphetamine in taste aversion learning and the role of the area postrema in amphetamine-induced conditioned taste aversions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rabin, B.M.; Hunt, W.A.; Lee, J.

1987-08-01

Three experiments were run to assess the role of the area postrema in taste aversion learning resulting from combined treatment with subthreshold unconditioned stimuli and in the acquisition of an amphetamine-induced taste aversion. In the first experiment, it was shown that combined treatment with subthreshold radiation (15 rad) and subthreshold amphetamine (0.5 mg/kg, IP) resulted in the acquisition of a taste aversion. The second experiment showed that lesions of the area postrema blocked taste aversion learning produced by two subthreshold doses of amphetamine. In the third experiment, which looked at the dose-response curve for amphetamine-induced taste aversion learning in intactmore » rats and rats with area postrema lesions, it was shown that both groups of rats acquired taste aversions following injection of amphetamine, although the rats with lesions showed a less severe aversion than the intact rats. The results are interpreted as indicating that amphetamine-induced taste aversion learning may involve area postrema-mediated mechanisms, particularly at the lower doses, but that an intact area postrema is not a necessary condition for the acquisition of an amphetamine-induced taste aversion.« less

Liposomal treatment of xerostomia, odor, and taste abnormalities in patients with head and neck cancer.

PubMed

Heiser, Clemens; Hofauer, Benedikt; Scherer, Elias; Schukraft, Johannes; Knopf, Andreas

2016-04-01

Smell and taste disorders, sicca symptoms, can be detected in patients with head and neck cancer. The purpose of this study was to assess the utility of local liposomal application in the treatment of patients with head and neck cancers. Ninety-eight patients with head and neck cancer were included in this study. The groups were defined as: group 1 = only surgery; group 2 = surgery + adjuvant radiochemotherapy; and group 3 = primarily radiochemotherapy. All patients had finished cancer treatment and received liposomal sprays for the nose and mouth for 2 months (LipoNasal, LipoSaliva; Optima Pharmaceutical GmbH, Germany) and suffered from taste and smell disorders. We performed tests with "Sniffin' Sticks," "Taste Strips," and a xerostomia questionnaire before and after treatment. After application of liposomes, patients demonstrated a statistically significant increase in smell and taste, and reduced xerostomia. Our results demonstrate that using nonpharmaceutical liposomal sprays improve smell, taste, and symptoms of xerostomia in patients with head and neck cancer. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1232-E1237, 2016. © 2015 Wiley Periodicals, Inc.

Sarco/Endoplasmic Reticulum Ca2+-ATPases (SERCA) Contribute to GPCR-Mediated Taste Perception

PubMed Central

Iguchi, Naoko; Ohkuri, Tadahiro; Slack, Jay P.; Zhong, Ping; Huang, Liquan

2011-01-01

The sense of taste is important for providing animals with valuable information about the qualities of food, such as nutritional or harmful nature. Mammals, including humans, can recognize at least five primary taste qualities: sweet, umami (savory), bitter, sour, and salty. Recent studies have identified molecules and mechanisms underlying the initial steps of tastant-triggered molecular events in taste bud cells, particularly the requirement of increased cytosolic free Ca2+ concentration ([Ca2+]c) for normal taste signal transduction and transmission. Little, however, is known about the mechanisms controlling the removal of elevated [Ca2+]c from the cytosol of taste receptor cells (TRCs) and how the disruption of these mechanisms affects taste perception. To investigate the molecular mechanism of Ca2+ clearance in TRCs, we sought the molecules involved in [Ca2+]c regulation using a single-taste-cell transcriptome approach. We found that Serca3, a member of the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) family that sequesters cytosolic Ca2+ into endoplasmic reticulum, is exclusively expressed in sweet/umami/bitter TRCs, which rely on intracellular Ca2+ release for signaling. Serca3-knockout (KO) mice displayed significantly increased aversive behavioral responses and greater gustatory nerve responses to bitter taste substances but not to sweet or umami taste substances. Further studies showed that Serca2 was mainly expressed in the T1R3-expressing sweet and umami TRCs, suggesting that the loss of function of Serca3 was possibly compensated by Serca2 in these TRCs in the mutant mice. Our data demonstrate that the SERCA family members play an important role in the Ca2+ clearance in TRCs and that mutation of these proteins may alter bitter and perhaps sweet and umami taste perception. PMID:21829714

A comparison of English and Japanese taste languages: taste descriptive methodology, codability and the umami taste.

PubMed

O'Mahony, M; Ishii, R

1986-05-01

Everyday taste descriptions for a range of stimuli were obtained from selected groups of American and Japanese subjects, using a variety of stimuli, stimulus presentation procedures and response conditions. In English there was a tendency to use a quadrapartite classification system: 'sweet', 'sour', 'salty' and 'bitter'. The Japanese had a different strategy, adding a fifth label: 'Ajinomoto', referring to the taste of monosodium glutamate. This label was generally replaced by umami--the scientific term--by Japanese who were workers or trained tasters involved with glutamate manufacture. Cultural differences in taste language have consequences for taste psychophysicists who impose a quadrapartite restriction on allowable taste descriptions. Stimulus presentation by filter-paper or aqueous solution elicited the same response trends. Language codability was only an indicator of degree of taste mixedness/singularity if used statistically with samples of sufficient size; it had little value as an indicator for individual subjects.

Enhancement of Retronasal Odors by Taste

PubMed Central

Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

2012-01-01

Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste (“sweet,” “sour,” “salty,” and “bitter”) and odor (“other”) intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste–odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of “cherry” and “vanilla” flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods. PMID:21798851

Is fat taste ready for primetime?

PubMed Central

DiPatrizio, Nicholas V.

2014-01-01

Mounting evidence suggests that gustation is important for the orosensory detection of dietary fats, and might contribute to preferences that humans, rodents, and possibly other mammals exhibit for fat-rich foods. In contrast to sweet, sour, salty, bitter, and umami, fat is not widely recognized as a primary taste quality. Recent investigations, however, provide a wealth of information that is helping to elucidate the specific molecular, cellular, and neural mechanisms required for fat detection in mammals. The latest evidence supporting a fat taste will be explored in this review, with a particular focus on recent studies that suggest a surprising role for gut-brain endocannabinoid signaling in controlling intake and preference for fats based on their proposed taste properties. PMID:24631296

Drosophila Bitter Taste(s)

PubMed Central

French, Alice; Ali Agha, Moutaz; Mitra, Aniruddha; Yanagawa, Aya; Sellier, Marie-Jeanne; Marion-Poll, Frédéric

2015-01-01

Most animals possess taste receptors neurons detecting potentially noxious compounds. In humans, the ligands which activate these neurons define a sensory space called “bitter”. By extension, this term has been used in animals and insects to define molecules which induce aversive responses. In this review, based on our observations carried out in Drosophila, we examine how bitter compounds are detected and if bitter-sensitive neurons respond only to molecules bitter to humans. Like most animals, flies detect bitter chemicals through a specific population of taste neurons, distinct from those responding to sugars or to other modalities. Activating bitter-sensitive taste neurons induces aversive reactions and inhibits feeding. Bitter molecules also contribute to the suppression of sugar-neuron responses and can lead to a complete inhibition of the responses to sugar at the periphery. Since some bitter molecules activate bitter-sensitive neurons and some inhibit sugar detection, bitter molecules are represented by two sensory spaces which are only partially congruent. In addition to molecules which impact feeding, we recently discovered that the activation of bitter-sensitive neurons also induces grooming. Bitter-sensitive neurons of the wings and of the legs can sense chemicals from the gram negative bacteria, Escherichia coli, thus adding another biological function to these receptors. Bitter-sensitive neurons of the proboscis also respond to the inhibitory pheromone, 7-tricosene. Activating these neurons by bitter molecules in the context of sexual encounter inhibits courting and sexual reproduction, while activating these neurons with 7-tricosene in a feeding context will inhibit feeding. The picture that emerges from these observations is that the taste system is composed of detectors which monitor different “categories” of ligands, which facilitate or inhibit behaviors depending on the context (feeding, sexual reproduction, hygienic behavior), thus

Age-Related Changes in Mouse Taste Bud Morphology, Hormone Expression, and Taste Responsivity

PubMed Central

Shin, Yu-Kyong; Cong, Wei-na; Cai, Huan; Kim, Wook; Maudsley, Stuart; Martin, Bronwen

2012-01-01

Normal aging is a complex process that affects every organ system in the body, including the taste system. Thus, we investigated the effects of the normal aging process on taste bud morphology, function, and taste responsivity in male mice at 2, 10, and 18 months of age. The 18-month-old animals demonstrated a significant reduction in taste bud size and number of taste cells per bud compared with the 2- and 10-month-old animals. The 18-month-old animals exhibited a significant reduction of protein gene product 9.5 and sonic hedgehog immunoreactivity (taste cell markers). The number of taste cells expressing the sweet taste receptor subunit, T1R3, and the sweet taste modulating hormone, glucagon-like peptide-1, were reduced in the 18-month-old mice. Concordant with taste cell alterations, the 18-month-old animals demonstrated reduced sweet taste responsivity compared with the younger animals and the other major taste modalities (salty, sour, and bitter) remained intact. PMID:22056740

Age-related changes in mouse taste bud morphology, hormone expression, and taste responsivity.

PubMed

Shin, Yu-Kyong; Cong, Wei-na; Cai, Huan; Kim, Wook; Maudsley, Stuart; Egan, Josephine M; Martin, Bronwen

2012-04-01

Normal aging is a complex process that affects every organ system in the body, including the taste system. Thus, we investigated the effects of the normal aging process on taste bud morphology, function, and taste responsivity in male mice at 2, 10, and 18 months of age. The 18-month-old animals demonstrated a significant reduction in taste bud size and number of taste cells per bud compared with the 2- and 10-month-old animals. The 18-month-old animals exhibited a significant reduction of protein gene product 9.5 and sonic hedgehog immunoreactivity (taste cell markers). The number of taste cells expressing the sweet taste receptor subunit, T1R3, and the sweet taste modulating hormone, glucagon-like peptide-1, were reduced in the 18-month-old mice. Concordant with taste cell alterations, the 18-month-old animals demonstrated reduced sweet taste responsivity compared with the younger animals and the other major taste modalities (salty, sour, and bitter) remained intact.

Progress and renewal in gustation: new insights into taste bud development

PubMed Central

Barlow, Linda A.

2015-01-01

The sense of taste, or gustation, is mediated by taste buds, which are housed in specialized taste papillae found in a stereotyped pattern on the surface of the tongue. Each bud, regardless of its location, is a collection of ∼100 cells that belong to at least five different functional classes, which transduce sweet, bitter, salt, sour and umami (the taste of glutamate) signals. Taste receptor cells harbor functional similarities to neurons but, like epithelial cells, are rapidly and continuously renewed throughout adult life. Here, I review recent advances in our understanding of how the pattern of taste buds is established in embryos and discuss the cellular and molecular mechanisms governing taste cell turnover. I also highlight how these findings aid our understanding of how and why many cancer therapies result in taste dysfunction. PMID:26534983

Progress and renewal in gustation: new insights into taste bud development.

PubMed

Barlow, Linda A

2015-11-01

The sense of taste, or gustation, is mediated by taste buds, which are housed in specialized taste papillae found in a stereotyped pattern on the surface of the tongue. Each bud, regardless of its location, is a collection of ∼100 cells that belong to at least five different functional classes, which transduce sweet, bitter, salt, sour and umami (the taste of glutamate) signals. Taste receptor cells harbor functional similarities to neurons but, like epithelial cells, are rapidly and continuously renewed throughout adult life. Here, I review recent advances in our understanding of how the pattern of taste buds is established in embryos and discuss the cellular and molecular mechanisms governing taste cell turnover. I also highlight how these findings aid our understanding of how and why many cancer therapies result in taste dysfunction. © 2015. Published by The Company of Biologists Ltd.

The Role of Sweet Taste in Satiation and Satiety

PubMed Central

Low, Yu Qing; Lacy, Kathleen; Keast, Russell

2014-01-01

Increased energy consumption, especially increased consumption of sweet energy-dense food, is thought to be one of the main contributors to the escalating rates in overweight individuals and obesity globally. The individual’s ability to detect or sense sweetness in the oral cavity is thought to be one of many factors influencing food acceptance, and therefore, taste may play an essential role in modulating food acceptance and/or energy intake. Emerging evidence now suggests that the sweet taste signaling mechanisms identified in the oral cavity also operate in the gastrointestinal system and may influence the development of satiety. Understanding the individual differences in detecting sweetness in both the oral and gastrointestinal system towards both caloric sugar and high intensity sweetener and the functional role of the sweet taste system may be important in understanding the reasons for excess energy intake. This review will summarize evidence of possible associations between the sweet taste mechanisms within the oral cavity, gastrointestinal tract and the brain systems towards both caloric sugar and high intensity sweetener and sweet taste function, which may influence satiation, satiety and, perhaps, predisposition to being overweight and obesity. PMID:25184369

A2BR adenosine receptor modulates sweet taste in circumvallate taste buds.

PubMed

Kataoka, Shinji; Baquero, Arian; Yang, Dan; Shultz, Nicole; Vandenbeuch, Aurelie; Ravid, Katya; Kinnamon, Sue C; Finger, Thomas E

2012-01-01

In response to taste stimulation, taste buds release ATP, which activates ionotropic ATP receptors (P2X2/P2X3) on taste nerves as well as metabotropic (P2Y) purinergic receptors on taste bud cells. The action of the extracellular ATP is terminated by ectonucleotidases, ultimately generating adenosine, which itself can activate one or more G-protein coupled adenosine receptors: A1, A2A, A2B, and A3. Here we investigated the expression of adenosine receptors in mouse taste buds at both the nucleotide and protein expression levels. Of the adenosine receptors, only A2B receptor (A2BR) is expressed specifically in taste epithelia. Further, A2BR is expressed abundantly only in a subset of taste bud cells of posterior (circumvallate, foliate), but not anterior (fungiform, palate) taste fields in mice. Analysis of double-labeled tissue indicates that A2BR occurs on Type II taste bud cells that also express Gα14, which is present only in sweet-sensitive taste cells of the foliate and circumvallate papillae. Glossopharyngeal nerve recordings from A2BR knockout mice show significantly reduced responses to both sucrose and synthetic sweeteners, but normal responses to tastants representing other qualities. Thus, our study identified a novel regulator of sweet taste, the A2BR, which functions to potentiate sweet responses in posterior lingual taste fields.

A2BR Adenosine Receptor Modulates Sweet Taste in Circumvallate Taste Buds

PubMed Central

Yang, Dan; Shultz, Nicole; Vandenbeuch, Aurelie; Ravid, Katya; Kinnamon, Sue C.; Finger, Thomas E.

2012-01-01

In response to taste stimulation, taste buds release ATP, which activates ionotropic ATP receptors (P2X2/P2X3) on taste nerves as well as metabotropic (P2Y) purinergic receptors on taste bud cells. The action of the extracellular ATP is terminated by ectonucleotidases, ultimately generating adenosine, which itself can activate one or more G-protein coupled adenosine receptors: A1, A2A, A2B, and A3. Here we investigated the expression of adenosine receptors in mouse taste buds at both the nucleotide and protein expression levels. Of the adenosine receptors, only A2B receptor (A2BR) is expressed specifically in taste epithelia. Further, A2BR is expressed abundantly only in a subset of taste bud cells of posterior (circumvallate, foliate), but not anterior (fungiform, palate) taste fields in mice. Analysis of double-labeled tissue indicates that A2BR occurs on Type II taste bud cells that also express Gα14, which is present only in sweet-sensitive taste cells of the foliate and circumvallate papillae. Glossopharyngeal nerve recordings from A2BR knockout mice show significantly reduced responses to both sucrose and synthetic sweeteners, but normal responses to tastants representing other qualities. Thus, our study identified a novel regulator of sweet taste, the A2BR, which functions to potentiate sweet responses in posterior lingual taste fields. PMID:22253866

Burning mouth syndrome (BMS): evaluation of thyroid and taste.

PubMed

Femiano, F; Gombos, F; Esposito, V; Nunziata, M; Scully, Crispian

2006-01-01

Burning mouth syndrome (BMS) is a chronic, intraoral burning sensation seen mainly in middle-aged and post-menopausal females, without identifiable oral lesions or abnormal laboratory findings, but often associated with psychogenic disorders such as depression. The latter can have a range of causes, including hormonal. Since there may be connections between BMS, psychogenic changes, hormonal changes and taste abnormalities, we have examined aspects of taste and thyroid function. We selected 50 patients with BMS (study group) and 50 healthy subjects (control group) and analysed their ability to taste bitter, acid and spicy substances and analysed their thyroid function and Undertook thyroid echography. Taste sensation was normal in all controls. However, 30 of the patients with BMS reported ageusia for bitter taste and 2 had ageusia for acid. The use of pepper sauce (Tabasco) (spicy substance) produced a strong burning to the tongue in 28 patients of the BMS group but only in 10 controls. No control patients showed abnormality of thyroid function or echograpic abnormality. Five patients in the BMS group had biochemical evidence of hypothyroidism, 4 patients had raised levels of thyroid auto-antibodies and, of the 41 remaining BMS patients, most (34) had thyroid echographic changes indicative of nodularity. Hypothyroidism may be responsible for a negative influence on taste and consequent increase in trigeminal sensorial sensation (tactile, thermal and painful sensation).

Molecular and Cellular Designs of Insect Taste Receptor System

PubMed Central

Isono, Kunio; Morita, Hiromi

2010-01-01

The insect gustatory receptors (GRs) are members of a large G-protein coupled receptor family distantly related to the insect olfactory receptors. They are phylogenetically different from taste receptors of most other animals. GRs are often coexpressed with other GRs in single receptor neurons. Taste receptors other than GRs are also expressed in some neurons. Recent molecular studies in the fruitfly Drosophila revealed that the insect taste receptor system not only covers a wide ligand spectrum of sugars, bitter substances or salts that are common to mammals but also includes reception of pheromone and somatosensory stimulants. However, the central mechanism to perceive and discriminate taste information is not yet elucidated. Analysis of the primary projection of taste neurons to the brain shows that the projection profiles depend basically on the peripheral locations of the neurons as well as the GRs that they express. These results suggest that both peripheral and central design principles of insect taste perception are different from those of olfactory perception. PMID:20617187

Taste Responses to Linoleic Acid: A Crowdsourced Population Study.

PubMed

Garneau, Nicole L; Nuessle, Tiffany M; Tucker, Robin M; Yao, Mengjie; Santorico, Stephanie A; Mattes, Richard D

2017-10-31

Dietary fats serve multiple essential roles in human health but may also contribute to acute and chronic health complications. Thus, understanding mechanisms that influence fat ingestion are critical. All sensory systems may contribute relevant cues to fat detection, with the most recent evidence supporting a role for the sense of taste. Taste detection thresholds for fat vary markedly between individuals and responses are not normally distributed. Genetics may contribute to these observations. Using crowdsourced data obtained from families visiting the Denver Museum of Nature & Science, our objective was to estimate the heritability of fat taste (oleogustus). A pedigree analysis was conducted with 106 families (643 individuals) who rated the fat taste intensity of graded concentrations of linoleic acid (LA) embedded in taste strips. The findings estimate that 19% (P = 0.043) of the variability of taste response to LA relative to baseline is heritable at the highest concentration tested. © The Author 2017. Published by Oxford University Press.

Taste Responses to Linoleic Acid: A Crowdsourced Population Study

PubMed Central

Nuessle, Tiffany M; Tucker, Robin M; Yao, Mengjie; Santorico, Stephanie A; Mattes, Richard D

2017-01-01

Abstract Dietary fats serve multiple essential roles in human health but may also contribute to acute and chronic health complications. Thus, understanding mechanisms that influence fat ingestion are critical. All sensory systems may contribute relevant cues to fat detection, with the most recent evidence supporting a role for the sense of taste. Taste detection thresholds for fat vary markedly between individuals and responses are not normally distributed. Genetics may contribute to these observations. Using crowdsourced data obtained from families visiting the Denver Museum of Nature & Science, our objective was to estimate the heritability of fat taste (oleogustus). A pedigree analysis was conducted with 106 families (643 individuals) who rated the fat taste intensity of graded concentrations of linoleic acid (LA) embedded in taste strips. The findings estimate that 19% (P = 0.043) of the variability of taste response to LA relative to baseline is heritable at the highest concentration tested. PMID:28968903

Molecular architecture of smell and taste in Drosophila.

PubMed

Vosshall, Leslie B; Stocker, Reinhard F

2007-01-01

The chemical senses-smell and taste-allow animals to evaluate and distinguish valuable food resources from dangerous substances in the environment. The central mechanisms by which the brain recognizes and discriminates attractive and repulsive odorants and tastants, and makes behavioral decisions accordingly, are not well understood in any organism. Recent molecular and neuroanatomical advances in Drosophila have produced a nearly complete picture of the peripheral neuroanatomy and function of smell and taste in this insect. Neurophysiological experiments have begun to provide insight into the mechanisms by which these animals process chemosensory cues. Given the considerable anatomical and functional homology in smell and taste pathways in all higher animals, experimental approaches in Drosophila will likely provide broad insights into the problem of sensory coding. Here we provide a critical review of the recent literature in this field and comment on likely future directions.

Interleukin-10 is produced by a specific subset of taste receptor cells and critical for maintaining structural integrity of mouse taste buds.

PubMed

Feng, Pu; Chai, Jinghua; Zhou, Minliang; Simon, Nirvine; Huang, Liquan; Wang, Hong

2014-02-12

Although inflammatory responses are a critical component in defense against pathogens, too much inflammation is harmful. Mechanisms have evolved to regulate inflammation, including modulation by the anti-inflammatory cytokine interleukin-10 (IL-10). Previously we have shown that taste buds express various molecules involved in innate immune responses, including the proinflammatory cytokine tumor necrosis factor (TNF). Here, using a reporter mouse strain, we show that taste cells also express the anti-inflammatory cytokine IL-10. Remarkably, IL-10 is produced by only a specific subset of taste cells, which are different from the TNF-producing cells in mouse circumvallate and foliate taste buds: IL-10 expression was found exclusively in the G-protein gustducin-expressing bitter receptor cells, while TNF was found in sweet and umami receptor cells as reported previously. In contrast, IL-10R1, the ligand-binding subunit of the IL-10 receptor, is predominantly expressed by TNF-producing cells, suggesting a novel cellular hierarchy for regulating TNF production and effects in taste buds. In response to inflammatory challenges, taste cells can increase IL-10 expression both in vivo and in vitro. These findings suggest that taste buds use separate populations of taste receptor cells that coincide with sweet/umami and bitter taste reception to modulate local inflammatory responses, a phenomenon that has not been previously reported. Furthermore, IL-10 deficiency in mice leads to significant reductions in the number and size of taste buds, as well as in the number of taste receptor cells per taste bud, suggesting that IL-10 plays critical roles in maintaining structural integrity of the peripheral gustatory system.

Interleukin-10 Is Produced by a Specific Subset of Taste Receptor Cells and Critical for Maintaining Structural Integrity of Mouse Taste Buds

PubMed Central

Chai, Jinghua; Zhou, Minliang; Simon, Nirvine; Huang, Liquan

2014-01-01

Although inflammatory responses are a critical component in defense against pathogens, too much inflammation is harmful. Mechanisms have evolved to regulate inflammation, including modulation by the anti-inflammatory cytokine interleukin-10 (IL-10). Previously we have shown that taste buds express various molecules involved in innate immune responses, including the proinflammatory cytokine tumor necrosis factor (TNF). Here, using a reporter mouse strain, we show that taste cells also express the anti-inflammatory cytokine IL-10. Remarkably, IL-10 is produced by only a specific subset of taste cells, which are different from the TNF-producing cells in mouse circumvallate and foliate taste buds: IL-10 expression was found exclusively in the G-protein gustducin-expressing bitter receptor cells, while TNF was found in sweet and umami receptor cells as reported previously. In contrast, IL-10R1, the ligand-binding subunit of the IL-10 receptor, is predominantly expressed by TNF-producing cells, suggesting a novel cellular hierarchy for regulating TNF production and effects in taste buds. In response to inflammatory challenges, taste cells can increase IL-10 expression both in vivo and in vitro. These findings suggest that taste buds use separate populations of taste receptor cells that coincide with sweet/umami and bitter taste reception to modulate local inflammatory responses, a phenomenon that has not been previously reported. Furthermore, IL-10 deficiency in mice leads to significant reductions in the number and size of taste buds, as well as in the number of taste receptor cells per taste bud, suggesting that IL-10 plays critical roles in maintaining structural integrity of the peripheral gustatory system. PMID:24523558

Toll-like receptor 4 mediates fat, sugar, and umami taste preference and food intake and body weight regulation.

PubMed

Camandola, Simonetta; Mattson, Mark P

2017-07-01

Immune and inflammatory pathways play important roles in the pathogenesis of metabolic disorders. This study investigated the role of toll-like receptor 4 (TLR4) in orosensory detection of dietary lipids and sugars. Taste preferences of TLR4 knockout (KO) and wild-type (WT) male mice under a standard and a high-fat, high-sugar diet were assessed with two-bottle tests. Gene expression of taste signaling molecules was analyzed in the tongue epithelium. The role of TLR4 in food intake and weight gain was investigated in TLR4 KO and WT mice fed a high-fat and high-sugar diet for 12 weeks. Compared to WT mice, TLR4 KO mice showed reduced preference for lipids, sugars, and umami in a two-bottle preference test. The altered taste perception was associated with decreased levels of key taste regulatory molecules in the tongue epithelium. TLR4 KO mice on a high-fat and high-sugar diet consumed less food and drink, resulting in diminished weight gain. TLR4 signaling promotes ingestion of sugar and fat by a mechanism involving increased preference for such obesogenic foods. © 2017 The Obesity Society.

Toll-like Receptor 4 Mediates Fat, Sugar and Umami Taste Preference, and Food Intake and Body Weight Regulation

PubMed Central

Camandola, Simonetta; Mattson, Mark P.

2017-01-01

Objective Immune and inflammatory pathways play important roles in the pathogenesis of metabolic disorders. In the present study we investigate the role of TLR4 in orosensory detection of dietary lipids and sugars. Methods Taste preferences of TLR4 knockout (KO) and wild type (WT) male mice under standard, and high fat and high sugar diets were assessed with 2-bottle tests. Gene expression of taste signaling molecules was analyzed in the tongue epithelium The role of TLR4 in food intake, and weigh gain was investigated in TLR4 KO and WT mice fed a high fat and high sugar diet for 12 weeks. Results Compared to WT mice TLR4 KO mice showed reduced preference for lipids, sugars, and umami in 2-bottle preference test. The altered taste perception was associated with decreased levels of key taste regulatory molecules in the tongue epithelium. TLR4 KO mice on a high fat and high sugar diet consumed less food and drink, resulting in diminished weight gain. Conclusions TLR4 signaling promotes ingestion of sugar and fat by a mechanism involving increased preference for such obesogenic foods. PMID:28500692

Does Conspecific Fighting Yield Conditioned Taste Aversion in Rats?

ERIC Educational Resources Information Center

Nakajima, Sadahiko; Kumazawa, Gaku; Ieki, Hayato; Hashimoto, Aya

2012-01-01

Running in an activity wheel yields conditioned aversion to a taste solution consumed before the running, but its underlying physiological mechanism is unknown. According to the claim that energy expenditure or general stress caused by physical exercise is a critical factor for this taste-aversion learning, not only running but also other…

The Taste of Caffeine

PubMed Central

Tordoff, Michael G.

2017-01-01

Many people avidly consume foods and drinks containing caffeine, despite its bitter taste. Here, we review what is known about caffeine as a bitter taste stimulus. Topics include caffeine's action on the canonical bitter taste receptor pathway and caffeine's action on noncanonical receptor-dependent and -independent pathways in taste cells. Two conclusions are that (1) caffeine is a poor prototypical bitter taste stimulus because it acts on bitter taste receptor-independent pathways, and (2) caffeinated products most likely stimulate “taste” receptors in nongustatory cells. This review is relevant for taste researchers, manufacturers of caffeinated products, and caffeine consumers. PMID:28660093

Adenosine enhances sweet taste through A2B receptors in the taste bud

PubMed Central

Dando, Robin; Dvoryanchikov, Gennady; Pereira, Elizabeth; Chaudhari, Nirupa; Roper, Stephen D.

2012-01-01

Mammalian taste buds use ATP as a neurotransmitter. Taste Receptor (Type II) cells secrete ATP via gap junction hemichannels into the narrow extracellular spaces within a taste bud. This ATP excites primary sensory afferent fibers and also stimulates neighboring taste bud cells. Here we show that extracellular ATP is enzymatically degraded to adenosine within mouse vallate taste buds and that this nucleoside acts as an autocrine neuromodulator to selectively enhance sweet taste. In Receptor cells in a lingual slice preparation, Ca2+ mobilization evoked by focally applied artificial sweeteners was significantly enhanced by adenosine (50 µM). Adenosine had no effect on bitter or umami taste responses, and the nucleoside did not affect Presynaptic (Type III) taste cells. We also used biosensor cells to measure transmitter release from isolated taste buds. Adenosine (5 µM) enhanced ATP release evoked by sweet but not bitter taste stimuli. Using single-cell RT-PCR on isolated vallate taste cells, we show that many Receptor cells express adenosine receptors, Adora2b, while Presynaptic (Type III) and Glial-like (Type I) cells seldom do. Furthermore, Adora2b receptors are significantly associated with expression of the sweet taste receptor subunit, Tas1r2. Adenosine is generated during taste stimulation mainly by the action of the ecto-5′-nucleotidase, NT5E, and to a lesser extent, prostatic acid phosphatase (ACPP). Both these ecto-nucleotidases are expressed by Presynaptic cells, as shown by single-cell RT-PCR, enzyme histochemistry and immunofluorescence. Our findings suggest that ATP released during taste reception is degraded to adenosine to exert positive modulation particularly on sweet taste. PMID:22219293

Adenosine enhances sweet taste through A2B receptors in the taste bud.

PubMed

Dando, Robin; Dvoryanchikov, Gennady; Pereira, Elizabeth; Chaudhari, Nirupa; Roper, Stephen D

2012-01-04

Mammalian taste buds use ATP as a neurotransmitter. Taste Receptor (type II) cells secrete ATP via gap junction hemichannels into the narrow extracellular spaces within a taste bud. This ATP excites primary sensory afferent fibers and also stimulates neighboring taste bud cells. Here we show that extracellular ATP is enzymatically degraded to adenosine within mouse vallate taste buds and that this nucleoside acts as an autocrine neuromodulator to selectively enhance sweet taste. In Receptor cells in a lingual slice preparation, Ca(2+) mobilization evoked by focally applied artificial sweeteners was significantly enhanced by adenosine (50 μM). Adenosine had no effect on bitter or umami taste responses, and the nucleoside did not affect Presynaptic (type III) taste cells. We also used biosensor cells to measure transmitter release from isolated taste buds. Adenosine (5 μM) enhanced ATP release evoked by sweet but not bitter taste stimuli. Using single-cell reverse transcriptase (RT)-PCR on isolated vallate taste cells, we show that many Receptor cells express the adenosine receptor, Adora2b, while Presynaptic (type III) and Glial-like (type I) cells seldom do. Furthermore, Adora2b receptors are significantly associated with expression of the sweet taste receptor subunit, Tas1r2. Adenosine is generated during taste stimulation mainly by the action of the ecto-5'-nucleotidase, NT5E, and to a lesser extent, prostatic acid phosphatase. Both these ecto-nucleotidases are expressed by Presynaptic cells, as shown by single-cell RT-PCR, enzyme histochemistry, and immunofluorescence. Our findings suggest that ATP released during taste reception is degraded to adenosine to exert positive modulation particularly on sweet taste.

Targeted taste cell-specific overexpression of brain-derived neurotrophic factor in adult taste buds elevates phosphorylated TrkB protein levels in taste cells, increases taste bud size, and promotes gustatory innervation.

PubMed

Nosrat, Irina V; Margolskee, Robert F; Nosrat, Christopher A

2012-05-11

Brain-derived neurotrophic factor (BDNF) is the most potent neurotrophic factor in the peripheral taste system during embryonic development. It is also expressed in adult taste buds. There is a lack of understanding of the role of BDNF in the adult taste system. To address this, we generated novel transgenic mice in which transgene expression was driven by an α-gustducin promoter coupling BDNF expression to the postnatal expression of gustducin in taste cells. Immunohistochemistry revealed significantly stronger BDNF labeling in taste cells of high BDNF-expressing mouse lines compared with controls. We show that taste buds in these mice are significantly larger and have a larger number of taste cells compared with controls. To examine whether innervation was affected in Gust-BDNF mice, we used antibodies to neural cell adhesion molecule (NCAM) and ATP receptor P2X3. The total density of general innervation and specifically the gustatory innervation was markedly increased in high BDNF-expressing mice compared with controls. TrkB and NCAM gene expression in laser capture microdissected taste epithelia were significantly up-regulated in these mice. Up-regulation of TrkB transcripts in taste buds and elevated taste cell-specific TrkB phosphorylation in response to increased BDNF levels indicate that BDNF controls the expression and activation of its high affinity receptor in taste cells. This demonstrates a direct taste cell function for BDNF. BDNF also orchestrates and maintains taste bud innervation. We propose that the Gust-BDNF transgenic mouse models can be employed to further dissect the specific roles of BDNF in the adult taste system.

Taste and Hypertension in Humans: Targeting Cardiovascular Disease.

PubMed

Roura, Eugeni; Foster, Simon; Winklebach, Anja; Navarro, Marta; Thomas, Walter; Campbell, Katrina; Stowasser, Michael

2016-01-01

The association between salty taste and NaCl intake with hypertension is well-established, although it is far from completely understood. Other taste types such as sweet, umami or bitter have also been related to alterations in blood pressure. Here, we review the mutual relationship between taste and hypertension to identify potential avenues to better control blood pressure. This review focuses on published data involving humans, with the exception of a section on molecular mechanisms. There is compelling evidence to suggest that changes in salty taste sensitivity can be used to predict the onset of hypertension. This goes hand in hand with the medical concept of sodium sensitivity, which also increases with age, particularly in hypertensive patients. The association of hypertension with the loss of taste acuity less definitive with some data/conclusions masked by the use of anti-hypertensive drugs. In fact, this group of therapeutic agents can reduce food taste perception resulting in mild to severe hypogeusia and dysgeusia. In the elderly, antihypertensive drugs may lead to a loss of appetite, thus, selecting treatments with low or no impact on taste perception should be advised. Pharmacological approaches to mitigate cardiovascular disease (CVD) could well take a different spin in the future following the discovery of taste receptors (TAS1R and TAS2R) in the cardiovascular system. Finally, long-term dietary strategies to minimize the risk of development of hypertension and CVD are discussed identifying several nutrients and public health policies with relevant potential.

Presynaptic (Type III) cells in mouse taste buds sense sour (acid) taste.

PubMed

Huang, Yijen A; Maruyama, Yutaka; Stimac, Robert; Roper, Stephen D

2008-06-15

Taste buds contain two types of cells that directly participate in taste transduction - receptor (Type II) cells and presynaptic (Type III) cells. Receptor cells respond to sweet, bitter and umami taste stimulation but until recently the identity of cells that respond directly to sour (acid) tastants has only been inferred from recordings in situ, from behavioural studies, and from immunostaining for putative sour transduction molecules. Using calcium imaging on single isolated taste cells and with biosensor cells to identify neurotransmitter release, we show that presynaptic (Type III) cells specifically respond to acid taste stimulation and release serotonin. By recording responses in cells isolated from taste buds and in taste cells in lingual slices to acetic acid titrated to different acid levels (pH), we also show that the active stimulus for acid taste is the membrane-permeant, uncharged acetic acid moiety (CH(3)COOH), not free protons (H(+)). That observation is consistent with the proximate stimulus for acid taste being intracellular acidification, not extracellular protons per se. These findings may also have implications for other sensory receptors that respond to acids, such as nociceptors.

Whole transcriptome profiling of taste bud cells.

PubMed

Sukumaran, Sunil K; Lewandowski, Brian C; Qin, Yumei; Kotha, Ramana; Bachmanov, Alexander A; Margolskee, Robert F

2017-08-08

Analysis of single-cell RNA-Seq data can provide insights into the specific functions of individual cell types that compose complex tissues. Here, we examined gene expression in two distinct subpopulations of mouse taste cells: Tas1r3-expressing type II cells and physiologically identified type III cells. Our RNA-Seq libraries met high quality control standards and accurately captured differential expression of marker genes for type II (e.g. the Tas1r genes, Plcb2, Trpm5) and type III (e.g. Pkd2l1, Ncam, Snap25) taste cells. Bioinformatics analysis showed that genes regulating responses to stimuli were up-regulated in type II cells, while pathways related to neuronal function were up-regulated in type III cells. We also identified highly expressed genes and pathways associated with chemotaxis and axon guidance, providing new insights into the mechanisms underlying integration of new taste cells into the taste bud. We validated our results by immunohistochemically confirming expression of selected genes encoding synaptic (Cplx2 and Pclo) and semaphorin signalling pathway (Crmp2, PlexinB1, Fes and Sema4a) components. The approach described here could provide a comprehensive map of gene expression for all taste cell subpopulations and will be particularly relevant for cell types in taste buds and other tissues that can be identified only by physiological methods.

Targeted Taste Cell-specific Overexpression of Brain-derived Neurotrophic Factor in Adult Taste Buds Elevates Phosphorylated TrkB Protein Levels in Taste Cells, Increases Taste Bud Size, and Promotes Gustatory Innervation*

PubMed Central

Nosrat, Irina V.; Margolskee, Robert F.; Nosrat, Christopher A.

2012-01-01

Brain-derived neurotrophic factor (BDNF) is the most potent neurotrophic factor in the peripheral taste system during embryonic development. It is also expressed in adult taste buds. There is a lack of understanding of the role of BDNF in the adult taste system. To address this, we generated novel transgenic mice in which transgene expression was driven by an α-gustducin promoter coupling BDNF expression to the postnatal expression of gustducin in taste cells. Immunohistochemistry revealed significantly stronger BDNF labeling in taste cells of high BDNF-expressing mouse lines compared with controls. We show that taste buds in these mice are significantly larger and have a larger number of taste cells compared with controls. To examine whether innervation was affected in Gust-BDNF mice, we used antibodies to neural cell adhesion molecule (NCAM) and ATP receptor P2X3. The total density of general innervation and specifically the gustatory innervation was markedly increased in high BDNF-expressing mice compared with controls. TrkB and NCAM gene expression in laser capture microdissected taste epithelia were significantly up-regulated in these mice. Up-regulation of TrkB transcripts in taste buds and elevated taste cell-specific TrkB phosphorylation in response to increased BDNF levels indicate that BDNF controls the expression and activation of its high affinity receptor in taste cells. This demonstrates a direct taste cell function for BDNF. BDNF also orchestrates and maintains taste bud innervation. We propose that the Gust-BDNF transgenic mouse models can be employed to further dissect the specific roles of BDNF in the adult taste system. PMID:22442142

Tachykinins Stimulate a Subset of Mouse Taste Cells

PubMed Central

Grant, Jeff

2012-01-01

The tachykinins substance P (SP) and neurokinin A (NKA) are present in nociceptive sensory fibers expressing transient receptor potential cation channel, subfamily V, member 1 (TRPV1). These fibers are found extensively in and around the taste buds of several species. Tachykinins are released from nociceptive fibers by irritants such as capsaicin, the active compound found in chili peppers commonly associated with the sensation of spiciness. Using real-time Ca2+-imaging on isolated taste cells, it was observed that SP induces Ca2+ -responses in a subset of taste cells at concentrations in the low nanomolar range. These responses were reversibly inhibited by blocking the SP receptor NK-1R. NKA also induced Ca2+-responses in a subset of taste cells, but only at concentrations in the high nanomolar range. These responses were only partially inhibited by blocking the NKA receptor NK-2R, and were also inhibited by blocking NK-1R indicating that NKA is only active in taste cells at concentrations that activate both receptors. In addition, it was determined that tachykinin signaling in taste cells requires Ca2+-release from endoplasmic reticulum stores. RT-PCR analysis further confirmed that mouse taste buds express NK-1R and NK-2R. Using Ca2+-imaging and single cell RT-PCR, it was determined that the majority of tachykinin-responsive taste cells were Type I (Glial-like) and umami-responsive Type II (Receptor) cells. Importantly, stimulating NK-1R had an additive effect on Ca2+ responses evoked by umami stimuli in Type II (Receptor) cells. This data indicates that tachykinin release from nociceptive sensory fibers in and around taste buds may enhance umami and other taste modalities, providing a possible mechanism for the increased palatability of spicy foods. PMID:22363709

Short-term perception of and conditioned taste aversion to umami taste, and oral expression patterns of umami taste receptors in chickens.

PubMed

Yoshida, Yuta; Kawabata, Fuminori; Kawabata, Yuko; Nishimura, Shotaro; Tabata, Shoji

2018-07-01

Umami taste is one of the five basic tastes (sweet, umami, bitter, sour, and salty), and is elicited by l-glutamate salts and 5'-ribonucleotides. In chickens, the elucidation of the umami taste sense is an important step in the production of new feedstuff for the animal industry. Although previous studies found that chickens show a preference for umami compounds in long-term behavioral tests, there are limitations to our understanding of the role of the umami taste sense in chicken oral tissues because the long-term tests partly reflected post-ingestive effects. Here, we performed a short-term test and observed agonists of chicken umami taste receptor, l-alanine and l-serine, affected the solution intakes of chickens. Using this method, we found that chickens could respond to umami solutions containing monosodium l-glutamate (MSG) + inosine 5'-monophosphate (IMP) within 5 min. We also demonstrated that chickens were successfully conditioned to avoid umami solution by the conditioned taste aversion test. It is noted that conditioning to umami solution was generalized to salty and sweet solutions. Thus, chickens may perceive umami taste as a salty- and sweet-like taste. In addition, we found that umami taste receptor candidates were differentially expressed in different regions of the chicken oral tissues. Taken together, the present results strongly suggest that chickens have a sense of umami taste and have umami taste receptors in their oral tissue. Copyright © 2018 Elsevier Inc. All rights reserved.

Preexposure to salty and sour taste enhances conditioned taste aversion to novel sucrose

PubMed Central

Flores, Veronica L.; Moran, Anan; Bernstein, Max

2016-01-01

Conditioned taste aversion (CTA) is an intensively studied single-trial learning paradigm whereby animals are trained to avoid a taste that has been paired with malaise. Many factors influence the strength of aversion learning; prominently studied among these is taste novelty—the fact that preexposure to the taste conditioned stimulus (CS) reduces its associability. The effect of exposure to tastes other than the CS has, in contrast, received little investigation. Here, we exposed rats to sodium chloride (N) and citric acid (C), either before or within a conditioning session involving novel sucrose (S). Presentation of this taste array within the conditioning session weakened the resultant S aversion, as expected. The opposite effect, however, was observed when exposure to the taste array was provided in sessions that preceded conditioning: such experience enhanced the eventual S aversion—a result that was robust to differences in CS delivery method and number of tastes presented in conditioning sessions. This “non-CS preexposure effect” scaled with the number of tastes in the exposure array (experience with more stimuli was more effective than experience with fewer) and with the amount of exposure sessions (three preexposure sessions were more effective than two). Together, our results provide evidence that exposure and experience with the realm of tastes changes an animal's future handling of even novel tastes. PMID:27084929

Characterization of stem/progenitor cell cycle using murine circumvallate papilla taste bud organoid.

PubMed

Aihara, Eitaro; Mahe, Maxime M; Schumacher, Michael A; Matthis, Andrea L; Feng, Rui; Ren, Wenwen; Noah, Taeko K; Matsu-ura, Toru; Moore, Sean R; Hong, Christian I; Zavros, Yana; Herness, Scott; Shroyer, Noah F; Iwatsuki, Ken; Jiang, Peihua; Helmrath, Michael A; Montrose, Marshall H

2015-11-24

Leucine-rich repeat-containing G-protein coupled receptor 5-expressing (Lgr5(+)) cells have been identified as stem/progenitor cells in the circumvallate papillae, and single cultured Lgr5(+) cells give rise to taste cells. Here we use circumvallate papilla tissue to establish a three-dimensional culture system (taste bud organoids) that develops phenotypic characteristics similar to native tissue, including a multilayered epithelium containing stem/progenitor in the outer layers and taste cells in the inner layers. Furthermore, characterization of the cell cycle of the taste bud progenitor niche reveals striking dynamics of taste bud development and regeneration. Using this taste bud organoid culture system and FUCCI2 transgenic mice, we identify the stem/progenitor cells have at least 5 distinct cell cycle populations by tracking within 24-hour synchronized oscillations of proliferation. Additionally, we demonstrate that stem/progenitor cells have motility to form taste bud organoids. Taste bud organoids provides a system for elucidating mechanisms of taste signaling, disease modeling, and taste tissue regeneration.

Characterization of stem/progenitor cell cycle using murine circumvallate papilla taste bud organoid

PubMed Central

Aihara, Eitaro; Mahe, Maxime M.; Schumacher, Michael A.; Matthis, Andrea L.; Feng, Rui; Ren, Wenwen; Noah, Taeko K.; Matsu-ura, Toru; Moore, Sean R.; Hong, Christian I.; Zavros, Yana; Herness, Scott; Shroyer, Noah F.; Iwatsuki, Ken; Jiang, Peihua; Helmrath, Michael A.; Montrose, Marshall H.

2015-01-01

Leucine-rich repeat-containing G-protein coupled receptor 5-expressing (Lgr5+) cells have been identified as stem/progenitor cells in the circumvallate papillae, and single cultured Lgr5+ cells give rise to taste cells. Here we use circumvallate papilla tissue to establish a three-dimensional culture system (taste bud organoids) that develops phenotypic characteristics similar to native tissue, including a multilayered epithelium containing stem/progenitor in the outer layers and taste cells in the inner layers. Furthermore, characterization of the cell cycle of the taste bud progenitor niche reveals striking dynamics of taste bud development and regeneration. Using this taste bud organoid culture system and FUCCI2 transgenic mice, we identify the stem/progenitor cells have at least 5 distinct cell cycle populations by tracking within 24-hour synchronized oscillations of proliferation. Additionally, we demonstrate that stem/progenitor cells have motility to form taste bud organoids. Taste bud organoids provides a system for elucidating mechanisms of taste signaling, disease modeling, and taste tissue regeneration. PMID:26597788

Calcitonin Gene-Related Peptide Reduces Taste-Evoked ATP Secretion from Mouse Taste Buds.

PubMed

Huang, Anthony Y; Wu, Sandy Y

2015-09-16

Immunoelectron microscopy revealed that peripheral afferent nerve fibers innervating taste buds contain calcitonin gene-related peptide (CGRP), which may be as an efferent transmitter released from peripheral axon terminals. In this report, we determined the targets of CGRP within taste buds and studied what effect CGRP exerts on taste bud function. We isolated mouse taste buds and taste cells, conducted functional imaging using Fura-2, and used cellular biosensors to monitor taste-evoked transmitter release. The findings showed that a subset of Presynaptic (Type III) taste cells (53%) responded to 0.1 μm CGRP with an increase in intracellular Ca(2+). In contrast, Receptor (Type II) taste cells rarely (4%) responded to 0.1 μm CGRP. Using pharmacological tools, the actions of CGRP were probed and elucidated by the CGRP receptor antagonist CGRP(8-37). We demonstrated that this effect of CGRP was dependent on phospholipase C activation and was prevented by the inhibitor U73122. Moreover, applying CGRP caused taste buds to secrete serotonin (5-HT), a Presynaptic (Type III) cell transmitter, but not ATP, a Receptor (Type II) cell transmitter. Further, our previous studies showed that 5-HT released from Presynaptic (Type III) cells provides negative paracrine feedback onto Receptor (Type II) cells by activating 5-HT1A receptors, and reducing ATP secretion. Our data showed that CGRP-evoked 5-HT release reduced taste-evoked ATP secretion. The findings are consistent with a role for CGRP as an inhibitory transmitter that shapes peripheral taste signals via serotonergic signaling during processing gustatory information in taste buds. The taste sensation is initiated with a highly complex set of interactions between a variety of cells located within the taste buds before signal propagation to the brain. Afferent signals from the oral cavity are carried to the brain in chemosensory fibers that contribute to chemesthesis, the general chemical sensitivity of the mucus

Expression of sulfonylurea receptors in rat taste buds.

PubMed

Liu, Dian-Xin; Liu, Xiao-Min; Zhou, Li-Hong; Feng, Xiao-Hong; Zhang, Xiao-Juan

2011-07-01

To test the possibility that a fast-onset promoting agent repaglinide may initiate prandial insulin secretion through the mechanism of cephalic-phase insulin release, we explored the expression and distribution character of sulfonylurea receptors in rat taste buds. Twenty male Wistar rats aged 10 weeks old were killed after general anesthesia. The circumvallate papillae, fungiform papillae and pancreas tissues were separately collected. Immunohistochemical staining was used to detect the expression and distribution of sulfonylurea receptor 1 (SUR1) or sulfonylurea receptor 2 (SUR2) in rat taste buds. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to analyze the expression of SUR1 or SUR2 mRNA. The pancreatic tissues from the same rat were used as positive control. This is the first study to report that SUR1 is uniquely expressed in the taste buds of fungiform papillae of each rat tongue, while the expression of SUR1 or SUR2 was not detected in the taste buds of circumvallate papillae. SUR1 is selectively expressed in rat taste buds, and its distribution pattern may be functionally relevant, suggesting that the rapid insulin secretion-promoting effect of repaglinide may be exerted through the cephalic-phase secretion pathway mediated by taste buds. Copyright © 2010 Elsevier GmbH. All rights reserved.

What Are Taste Buds?

MedlinePlus

... on your tongue and allow you to experience tastes that are sweet, salty, sour, and bitter. How exactly do your taste ... send messages to the brain about how something tastes, so you know if it's sweet, sour, bitter, or salty. The average person has about 10,000 taste ...

Microstructural investigation using synchrotron radiation X-ray microtomography reveals taste-masking mechanism of acetaminophen microspheres.

PubMed

Guo, Zhen; Yin, Xianzhen; Liu, Congbiao; Wu, Li; Zhu, Weifeng; Shao, Qun; York, Peter; Patterson, Laurence; Zhang, Jiwen

2016-02-29

The structure of solid drug delivery systems has considerable influence on drug release behaviors from particles and granules and also impacts other properties relevant to release characteristics such as taste. In this study, lipid-based microspheres of acetaminophen were prepared to mask the undesirable taste of drug and therefore to identify the optimal formulation for drug release. Synchrotron radiation X-ray computed microtomography (SR-μCT) was used to investigate the fine structural architectures of microspheres non-destructively at different sampling times during drug release test, which were simultaneously determined to quantitatively correlate the structural data with drug release behaviors. The results demonstrated that the polymeric formulation component, namely, cationic polymethacrylate (Eudragit E100), was the key factor to mask the bitter taste of acetaminophen by inhibiting immediate drug release thereby reducing the interaction intensity of the bitter material with the oral cavity taste buds. The structure and morphology of the microspheres were found to be influenced by the shape and particle size of the drug, which was also an important factor for taste-masking performance. The quantitative analysis generated detailed structural information which was correlated well with drug release behaviors. Thus, SR-μCT has been proved as a powerful tool to investigate the fine microstructure of particles and provides a new approach in the design of particles for taste masking. Copyright © 2015 Elsevier B.V. All rights reserved.

What is the role of metabolic hormones in taste buds of the tongue.

PubMed

Cai, Huan; Maudsley, Stuart; Martin, Bronwen

2014-01-01

Gustation is one of the important chemical senses that guides the organism to identify nutrition while avoiding toxic chemicals. An increasing number of metabolic hormones and/or hormone receptors have been identified in the taste buds of the tongue and are involved in modulating taste perception. The gustatory system constitutes an additional endocrine regulatory locus that affects food intake, and in turn whole-body energy homeostasis. Here we provide an overview of the main metabolic hormones known to be present in the taste buds of the tongue; discuss their potential functional roles in taste perception and energy homeostasis and how their functional integrity is altered in the metabolic imbalance status (obesity and diabetes) and aging process. Better understanding of the functional roles of metabolic hormones in flavor perception as well as the link between taste perception and peripheral metabolism may be vital for developing strategies to promote healthier eating and prevent obesity or lifestyle-related disorders. © 2014 S. Karger AG, Basel.

Chemosensory Dysfunction in Alcohol-Related Disorders: A Joint Exploration of Olfaction and Taste.

PubMed

Brion, Mélanie; de Timary, Philippe; Vander Stappen, Caroline; Guettat, Lamia; Lecomte, Benoît; Rombaux, Philippe; Maurage, Pierre

2015-11-01

Chemosensory (olfaction-taste) dysfunctions are considered as reliable biomarkers in many neurological and psychiatric states. However, experimental measures of chemosensory abilities are lacking in alcohol-dependence (AD) and Korsakoff Syndrome (KS, a neurological complication of AD), despite the role played by alcohol-related odors and taste in the emergence and maintenance of AD. This study thus investigated chemosensory impairments in AD and KS. Olfactory-gustatory measures were taken among 20 KS, 20 AD, and 20 control participants. Olfaction (odor detection-discrimination-identification) was assessed using the "Sniffin Sticks" battery and taste was measured using the "Taste Strips" task. Impairments were found for high-level olfaction in AD (odor discrimination) and KS (odor discrimination-identification), even after controlling for psychopathological comorbidities. Gustatory deficits were also observed in both groups, indexing a global deficit for chemosensory perception. Finally, the gradient of impairment between the successive disease stages for odor identification suggests that the hypothesis of a continuum between AD and KS regarding cognitive deficits can be generalized to chemosensory perception. AD and KS are thus characterized by deficits in chemosensory abilities, which could constitute a marker of the AD-KS transition. In view of its deleterious influence on everyday life, chemosensory dysfunction should also be taken into account in clinical settings. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Discrete innervation of murine taste buds by peripheral taste neurons.

PubMed

Zaidi, Faisal N; Whitehead, Mark C

2006-08-09

The peripheral taste system likely maintains a specific relationship between ganglion cells that signal a particular taste quality and taste bud cells responsive to that quality. We have explored a measure of the receptoneural relationship in the mouse. By injecting single fungiform taste buds with lipophilic retrograde neuroanatomical markers, the number of labeled geniculate ganglion cells innervating single buds on the tongue were identified. We found that three to five ganglion cells innervate a single bud. Injecting neighboring buds with different color markers showed that the buds are primarily innervated by separate populations of geniculate cells (i.e., multiply labeled ganglion cells are rare). In other words, each taste bud is innervated by a population of neurons that only connects with that bud. Palate bud injections revealed a similar, relatively exclusive receptoneural relationship. Injecting buds in different regions of the tongue did not reveal a topographic representation of buds in the geniculate ganglion, despite a stereotyped patterned arrangement of fungiform buds as rows and columns on the tongue. However, ganglion cells innervating the tongue and palate were differentially concentrated in lateral and rostral regions of the ganglion, respectively. The principal finding that small groups of ganglion cells send sensory fibers that converge selectively on a single bud is a new-found measure of specific matching between the two principal cellular elements of the mouse peripheral taste system. Repetition of the experiments in the hamster showed a more divergent innervation of buds in this species. The results indicate that whatever taste quality is signaled by a murine geniculate ganglion neuron, that signal reflects the activity of cells in a single taste bud.

Galvanic Tongue Stimulation Inhibits Five Basic Tastes Induced by Aqueous Electrolyte Solutions.

PubMed

Aoyama, Kazuma; Sakurai, Kenta; Sakurai, Satoru; Mizukami, Makoto; Maeda, Taro; Ando, Hideyuki

2017-01-01

Galvanic tongue stimulation (GTS) modulates taste sensation. However, the effect of GTS is contingent on the electrode polarity in the proximity of the tongue. If an anodal electrode is attached in the proximity of the tongue, an electrical or metallic taste is elicited. On the other hand, if only cathodal electrode is attached in the proximity of the tongue, the salty taste, which is induced by electrolyte materials, is inhibited. The mechanism of this taste inhibition is not adequately understood. In this study, we aim to demonstrate that the inhibition is cause by ions, which elicit taste and which migrate from the taste sensors on the tongue by GTS. We verified the inhibitory effect of GTS on all five basic tastes induced by electrolyte materials. This technology is effective for virtual reality systems and interfaces to support dietary restrictions. Our findings demonstrate that cathodal-GTS inhibits all the five basic tastes. The results also support our hypothesis that the effects of cathodal-GTS are caused by migrating tasting ions in the mouth.

REVIEW ARTICLE: A taste sensor

NASA Astrophysics Data System (ADS)

Toko, Kiyoshi

1998-12-01

A multichannel taste sensor, namely an electronic tongue, with global selectivity is composed of several kinds of lipid/polymer membranes for transforming information about substances producing taste into electrical signals, which are input to a computer. The sensor output exhibits different patterns for chemical substances which have different taste qualities such as saltiness, sourness and bitterness, whereas it exhibits similar patterns for chemical substances with similar tastes. The sensor responds to the taste itself, as can be understood from the fact that taste interactions such as the suppression effect, which appears for mixtures of sweet and bitter substances, can be reproduced well. The suppression of the bitterness of quinine and a drug substance by sucrose can be quantified. Amino acids can be classified into several groups according to their own tastes on the basis of sensor outputs. The tastes of foodstuffs such as beer, coffee, mineral water, milk, sake, rice, soybean paste and vegetables can be discussed quantitatively using the taste sensor, which provides the objective scale for the human sensory expression. The flavour of a wine is also discriminated using the taste-odour sensory fusion conducted by combining the taste sensor and an odour-sensor array using conducting polymer elements. The taste sensor can also be applied to measurements of water pollution. Miniaturization of the taste sensor using FET produces the same characteristics as those of the above taste sensor by measuring the gate-source voltage. Use of the taste sensor will lead to a new era of food and environmental sciences.

Angiotensin II modulates salty and sweet taste sensitivities.

PubMed

Shigemura, Noriatsu; Iwata, Shusuke; Yasumatsu, Keiko; Ohkuri, Tadahiro; Horio, Nao; Sanematsu, Keisuke; Yoshida, Ryusuke; Margolskee, Robert F; Ninomiya, Yuzo

2013-04-10

Understanding the mechanisms underlying gustatory detection of dietary sodium is important for the prevention and treatment of hypertension. Here, we show that Angiotensin II (AngII), a major mediator of body fluid and sodium homeostasis, modulates salty and sweet taste sensitivities, and that this modulation critically influences ingestive behaviors in mice. Gustatory nerve recording demonstrated that AngII suppressed amiloride-sensitive taste responses to NaCl. Surprisingly, AngII also enhanced nerve responses to sweeteners, but had no effect on responses to KCl, sour, bitter, or umami tastants. These effects of AngII on nerve responses were blocked by the angiotensin II type 1 receptor (AT1) antagonist CV11974. In behavioral tests, CV11974 treatment reduced the stimulated high licking rate to NaCl and sweeteners in water-restricted mice with elevated plasma AngII levels. In taste cells AT1 proteins were coexpressed with αENaC (epithelial sodium channel α-subunit, an amiloride-sensitive salt taste receptor) or T1r3 (a sweet taste receptor component). These results suggest that the taste organ is a peripheral target of AngII. The specific reduction of amiloride-sensitive salt taste sensitivity by AngII may contribute to increased sodium intake. Furthermore, AngII may contribute to increased energy intake by enhancing sweet responses. The linkage between salty and sweet preferences via AngII signaling may optimize sodium and calorie intakes.

Pragmatically on the sense of taste - a short treatise based on culinary art.

PubMed

Waluga, Marek; Jonderko, Krzysztof; Buschhaus, Magdalena

2013-01-01

The sense of taste is essential for proper functioning of the organism. The authors describe, in an accessible way, the complex mechanisms of taste perception. The structure of particular taste receptors, variants of their activation, as well as physical and chemical factors modifying the sensation of taste, are presented. Exquisite culinary examples are given in order to facilitate the reader with the understanding of why, at the level of the cerebral cortex, a virtually infinite number of combinations of taste sensations can be perceived. The discourse is spiced up by reflections of the eminent philosopher of taste, J.A. Brillat-Savarin, who convinces us that food intake should be not only a physiological act, but also a refined pleasure.

Hedgehog pathway blockade with the cancer drug LDE225 disrupts taste organs and taste sensation.

PubMed

Kumari, Archana; Ermilov, Alexandre N; Allen, Benjamin L; Bradley, Robert M; Dlugosz, Andrzej A; Mistretta, Charlotte M

2015-02-01

Taste sensation on the anterior tongue requires chorda tympani nerve function and connections with continuously renewing taste receptor cells. However, it is unclear which signaling pathways regulate the receptor cells to maintain chorda tympani sensation. Hedgehog (HH) signaling controls cell proliferation and differentiation in numerous tissues and is active in taste papillae and taste buds. In contrast, uncontrolled HH signaling drives tumorigenesis, including the common skin cancer, basal cell carcinoma. Systemic HH pathway inhibitors (HPIs) lead to basal cell carcinoma regression, but these drugs cause severe taste disturbances. We tested the hypothesis that taste disruption by HPIs reflects a direct requirement for HH signaling in maintaining taste organs and gustatory sensation. In mice treated with the HPI LDE225 up to 28 days, HH-responding cells were lost in fungiform papilla epithelium, and papillae acquired a conical apex. Taste buds were either absent or severely reduced in size in more than 90% of aberrant papillae. Taste bud remnants expressed the taste cell marker keratin 8, and papillae retained expression of nerve markers, neurofilament and P2X3. Chorda tympani nerve responses to taste stimuli were markedly reduced or absent in LDE225-treated mice. Responses to touch were retained, however, whereas cold responses were retained after 16 days of treatment but lost after 28 days. These data identify a critical, modality-specific requirement for HH signaling in maintaining taste papillae, taste buds and neurophysiological taste function, supporting the proposition that taste disturbances in HPI-treated patients are an on-target response to HH pathway blockade in taste organs. Copyright © 2015 the American Physiological Society.

AP1 transcription factors are required to maintain the peripheral taste system.

PubMed

Shandilya, Jayasha; Gao, Yankun; Nayak, Tapan K; Roberts, Stefan G E; Medler, Kathryn F

2016-10-27

The sense of taste is used by organisms to achieve the optimal nutritional requirement and avoid potentially toxic compounds. In the oral cavity, taste receptor cells are grouped together in taste buds that are present in specialized taste papillae in the tongue. Taste receptor cells are the cells that detect chemicals in potential food items and transmit that information to gustatory nerves that convey the taste information to the brain. As taste cells are in contact with the external environment, they can be damaged and are routinely replaced throughout an organism's lifetime to maintain functionality. However, this taste cell turnover loses efficiency over time resulting in a reduction in taste ability. Currently, very little is known about the mechanisms that regulate the renewal and maintenance of taste cells. We therefore performed RNA-sequencing analysis on isolated taste cells from 2 and 6-month-old mice to determine how alterations in the taste cell-transcriptome regulate taste cell maintenance and function in adults. We found that the activator protein-1 (AP1) transcription factors (c-Fos, Fosb and c-Jun) and genes associated with this pathway were significantly downregulated in taste cells by 6 months and further declined at 12 months. We generated conditional c-Fos-knockout mice to target K14-expressing cells, including differentiating taste cells. c-Fos deletion caused a severe perturbation in taste bud structure and resulted in a significant reduction in the taste bud size. c-Fos deletion also affected taste cell turnover as evident by a decrease in proliferative marker, and upregulation of the apoptotic marker cleaved-PARP. Thus, AP1 factors are important regulators of adult taste cell renewal and their downregulation negatively impacts taste maintenance.

AP1 transcription factors are required to maintain the peripheral taste system

PubMed Central

Shandilya, Jayasha; Gao, Yankun; Nayak, Tapan K; Roberts, Stefan G E; Medler, Kathryn F

2016-01-01

The sense of taste is used by organisms to achieve the optimal nutritional requirement and avoid potentially toxic compounds. In the oral cavity, taste receptor cells are grouped together in taste buds that are present in specialized taste papillae in the tongue. Taste receptor cells are the cells that detect chemicals in potential food items and transmit that information to gustatory nerves that convey the taste information to the brain. As taste cells are in contact with the external environment, they can be damaged and are routinely replaced throughout an organism's lifetime to maintain functionality. However, this taste cell turnover loses efficiency over time resulting in a reduction in taste ability. Currently, very little is known about the mechanisms that regulate the renewal and maintenance of taste cells. We therefore performed RNA-sequencing analysis on isolated taste cells from 2 and 6-month-old mice to determine how alterations in the taste cell-transcriptome regulate taste cell maintenance and function in adults. We found that the activator protein-1 (AP1) transcription factors (c-Fos, Fosb and c-Jun) and genes associated with this pathway were significantly downregulated in taste cells by 6 months and further declined at 12 months. We generated conditional c-Fos-knockout mice to target K14-expressing cells, including differentiating taste cells. c-Fos deletion caused a severe perturbation in taste bud structure and resulted in a significant reduction in the taste bud size. c-Fos deletion also affected taste cell turnover as evident by a decrease in proliferative marker, and upregulation of the apoptotic marker cleaved-PARP. Thus, AP1 factors are important regulators of adult taste cell renewal and their downregulation negatively impacts taste maintenance. PMID:27787515

Preexposure to Salty and Sour Taste Enhances Conditioned Taste Aversion to Novel Sucrose

ERIC Educational Resources Information Center

Flores, Veronica L.; Moran, Anan; Bernstein, Max; Katz, Donald B.

2016-01-01

Conditioned taste aversion (CTA) is an intensively studied single-trial learning paradigm whereby animals are trained to avoid a taste that has been paired with malaise. Many factors influence the strength of aversion learning; prominently studied among these is taste novelty--the fact that preexposure to the taste conditioned stimulus (CS)…

Postnatal reduction of BDNF regulates the developmental remodeling of taste bud innervation

PubMed Central

Huang, Tao; Ma, Liqun; Krimm, Robin F

2015-01-01

The refinement of innervation is a common developmental mechanism that serves to increase the specificity of connections following initial innervation. In the peripheral gustatory system, the extent to which innervation is refined and how refinement might be regulated is unclear. The initial innervation of taste buds is controlled by brain-derived neurotrophic factor (BDNF). Following initial innervation, taste receptor cells are added and become newly innervated. The connections between the taste receptor cells and nerve fibers are likely to be specific in order to retain peripheral coding mechanisms. Here, we explored the possibility that the down-regulation of BDNF regulates the refinement of taste bud innervation during postnatal development. An analysis of BDNF expression in BdnflacZ/+ mice and real-time reverse transcription polymerase chain reaction (RT-PCR) revealed that BDNF was down-regulated between postnatal day (P) 5 and P10. This reduction in BDNF expression was due to a loss of precursor/progenitor cells that express BDNF, while the expression of BDNF in the subpopulations of taste receptor cells did not change. Gustatory innervation, which was identified by P2X3 immunohistochemistry, was lost around the perimeter where most progenitor/precursor cells are located. In addition, the density of innervation in the taste bud was reduced between P5 and P10, because taste buds increase in size without increasing innervation. This reduction of innervation density was blocked by the overexpression of BDNF in the precursor/progenitor population of taste bud cells. Together these findings indicate that the process of BDNF restriction to a subpopulation of taste receptor cells between P5 and P10, results in a refinement of gustatory innervation. We speculate that this refinement results in an increased specificity of connections between neurons and taste receptor cells during development. PMID:26164656

Postnatal reduction of BDNF regulates the developmental remodeling of taste bud innervation.

PubMed

Huang, Tao; Ma, Liqun; Krimm, Robin F

2015-09-15

The refinement of innervation is a common developmental mechanism that serves to increase the specificity of connections following initial innervation. In the peripheral gustatory system, the extent to which innervation is refined and how refinement might be regulated is unclear. The initial innervation of taste buds is controlled by brain-derived neurotrophic factor (BDNF). Following initial innervation, taste receptor cells are added and become newly innervated. The connections between the taste receptor cells and nerve fibers are likely to be specific in order to retain peripheral coding mechanisms. Here, we explored the possibility that the down-regulation of BDNF regulates the refinement of taste bud innervation during postnatal development. An analysis of BDNF expression in Bdnf(lacZ/+) mice and real-time reverse transcription polymerase chain reaction (RT-PCR) revealed that BDNF was down-regulated between postnatal day (P) 5 and P10. This reduction in BDNF expression was due to a loss of precursor/progenitor cells that express BDNF, while the expression of BDNF in the subpopulations of taste receptor cells did not change. Gustatory innervation, which was identified by P2X3 immunohistochemistry, was lost around the perimeter where most progenitor/precursor cells are located. In addition, the density of innervation in the taste bud was reduced between P5 and P10, because taste buds increase in size without increasing innervation. This reduction of innervation density was blocked by the overexpression of BDNF in the precursor/progenitor population of taste bud cells. Together these findings indicate that the process of BDNF restriction to a subpopulation of taste receptor cells between P5 and P10, results in a refinement of gustatory innervation. We speculate that this refinement results in an increased specificity of connections between neurons and taste receptor cells during development. Copyright © 2015 Elsevier Inc. All rights reserved.

Glucose transporters and ATP-gated K+ (KATP) metabolic sensors are present in type 1 taste receptor 3 (T1r3)-expressing taste cells.

PubMed

Yee, Karen K; Sukumaran, Sunil K; Kotha, Ramana; Gilbertson, Timothy A; Margolskee, Robert F

2011-03-29

Although the heteromeric combination of type 1 taste receptors 2 and 3 (T1r2 + T1r3) is well established as the major receptor for sugars and noncaloric sweeteners, there is also evidence of T1r-independent sweet taste in mice, particularly so for sugars. Before the molecular cloning of the T1rs, it had been proposed that sweet taste detection depended on (a) activation of sugar-gated cation channels and/or (b) sugar binding to G protein-coupled receptors to initiate second-messenger cascades. By either mechanism, sugars would elicit depolarization of sweet-responsive taste cells, which would transmit their signal to gustatory afferents. We examined the nature of T1r-independent sweet taste; our starting point was to determine if taste cells express glucose transporters (GLUTs) and metabolic sensors that serve as sugar sensors in other tissues. Using RT-PCR, quantitative PCR, in situ hybridization, and immunohistochemistry, we determined that several GLUTs (GLUT2, GLUT4, GLUT8, and GLUT9), a sodium-glucose cotransporter (SGLT1), and two components of the ATP-gated K(+) (K(ATP)) metabolic sensor [sulfonylurea receptor (SUR) 1 and potassium inwardly rectifying channel (Kir) 6.1] were expressed selectively in taste cells. Consistent with a role in sweet taste, GLUT4, SGLT1, and SUR1 were expressed preferentially in T1r3-positive taste cells. Electrophysiological recording determined that nearly 20% of the total outward current of mouse fungiform taste cells was composed of K(ATP) channels. Because the overwhelming majority of T1r3-expressing taste cells also express SUR1, and vice versa, it is likely that K(ATP) channels constitute a major portion of K(+) channels in the T1r3 subset of taste cells. Taste cell-expressed glucose sensors and K(ATP) may serve as mediators of the T1r-independent sweet taste of sugars.

The Anion Paradox in Sodium Taste Reception: Resolution by Voltage-Clamp Studies

NASA Astrophysics Data System (ADS)

Ye, Qing; Heck, Gerard L.; Desimone, John A.

1991-11-01

Sodium salts are potent taste stimuli, but their effectiveness is markedly dependent on the anion, with chloride yielding the greatest response. The cellular mechanisms that mediate this phenomenon are not known. This "anion paradox" has been resolved by considering the field potential that is generated by restricted electrodiffusion of the anion through paracellular shunts between taste-bud cells. Neural responses to sodium chloride, sodium acetate, and sodium gluconate were studied while the field potential was voltage-clamped. Clamping at electronegative values eliminated the anion effect, whereas clamping at electropositive potentials exaggerated it. Thus, field potentials across the lingual epithelium modulate taste reception, indicating that the functional unit of taste reception includes the taste cell and its paracellular microenvironment.

Quantitative analysis of taste bud cell numbers in fungiform and soft palate taste buds of mice.

PubMed

Ohtubo, Yoshitaka; Yoshii, Kiyonori

2011-01-07

Mammalian taste bud cells (TBCs) consist of several cell types equipped with different taste receptor molecules, and hence the ratio of cell types in a taste bud constitutes the taste responses of the taste bud. Here we show that the population of immunohistochemically identified cell types per taste bud is proportional to the number of total TBCs in the taste bud or the area of the taste bud in fungiform papillae, and that the proportions differ among cell types. This result is applicable to soft palate taste buds. However, the density of almost all cell types, the population of cell types divided by the area of the respective taste buds, is significantly higher in soft palates. These results suggest that the turnover of TBCs is regulated to keep the ratio of each cell type constant, and that taste responsiveness is different between fungiform and soft palate taste buds. Copyright © 2010 Elsevier B.V. All rights reserved.

Cholinergic dependence of taste memory formation: evidence of two distinct processes.

PubMed

Gutiérrez, Ranier; Rodriguez-Ortiz, Carlos J; De La Cruz, Vanesa; Núñez-Jaramillo, Luis; Bermudez-Rattoni, Federico

2003-11-01

Learning the aversive or positive consequences associated with novel taste solutions has a strong significance for an animal's survival. A lack of recognition of a taste's consequences could prevent ingestion of potential edibles or encounter death. We used conditioned taste aversion (CTA) and attenuation of neophobia (AN) to study aversive and safe taste memory formation. To determine if muscarinic receptors in the insular cortex participate differentially in both tasks, we infused the muscarinic antagonists scopolamine at distinct times before or after the presentation of a strong concentration of saccharin, followed by either an i.p. injection of a malaise-inducing agent or no injection. Our results showed that blockade of muscarinic receptors before taste presentation disrupts both learning tasks. However, the same treatment after the taste prevents AN but not CTA. These results clearly demonstrate that cortical cholinergic activity participates in the acquisition of both safe and aversive memory formation, and that cortical muscarinic receptors seem to be necessary for safe but not for aversive taste memory consolidation. These results suggest that the taste memory trace is processed in the insular cortex simultaneously by at least two independent mechanisms, and that their interaction would determine the degree of aversion or preference learned to a novel taste.

Gastric bypass surgery alters behavioral and neural taste functions for sweet taste in obese rats.

PubMed

Hajnal, Andras; Kovacs, Peter; Ahmed, Tamer; Meirelles, Katia; Lynch, Christopher J; Cooney, Robert N

2010-10-01

Roux-en-Y gastric bypass surgery (GBS) is the most effective treatment for morbid obesity. GBS is a restrictive malabsorptive procedure, but many patients also report altered taste preferences. This study investigated the effects of GBS or a sham operation (SH) on body weight, glucose tolerance, and behavioral and neuronal taste functions in the obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats lacking CCK-1 receptors and lean controls (LETO). OLETF-GBS rats lost body weight (-26%) and demonstrated improved glucose tolerance. They also expressed a reduction in 24-h two-bottle preference for sucrose (0.3 and 1.0 M) and decreased 10-s lick responses for sucrose (0.3 through 1.5 M) compared with OLETF-SH or LETO-GBS. A similar effect was noted for other sweet compounds but not for salty, sour, or bitter tastants. In lean rats, GBS did not alter responses to any stimulus tested. Extracellular recordings from 170 taste-responsive neurons of the pontine parabrachial nucleus revealed a rightward shift in concentration responses to oral sucrose in obese compared with lean rats (OLETF-SH vs. LETO-SH): overall increased response magnitudes (above 0.9 M), and maximum responses occurring at higher concentrations (+0.46 M). These effects were reversed by GBS, and neural responses in OLETF-GBS were statistically not different from those in any LETO groups. These findings confirm obesity-related alterations in taste functions and demonstrate the ability of GBS to alleviate these impairments. Furthermore, the beneficial effects of GBS appear to be independent of CCK-1 receptor signaling. An understanding of the underlying mechanisms for reduced preferences for sweet taste could help in developing less invasive treatments for obesity.

Taste Reward Circuitry Related Brain Structures Characterize Ill and Recovered Anorexia Nervosa and Bulimia Nervosa

PubMed Central

Frank, Guido K.; Shott, Megan E.; Hagman, Jennifer O.; Mittal, Vijay A.

2013-01-01

Objective The pathophysiology of the eating disorder anorexia nervosa remains obscure, but structural brain alterations could be functionally important biomarkers. Here we assessed taste pleasantness and reward sensitivity in relation to brain structure, which might be related to food avoidance commonly seen in eating disorders. Method We used structural magnetic resonance brain imaging to study gray and white matter volumes in individuals with restricting type currently ill (n = 19) or recovered-anorexia nervosa (n = 24), bulimia nervosa (n= 19) and healthy control women (n=24). Results All eating disorder groups showed increased gray matter volume of the medial orbitofrontal cortex (gyrus rectus). Manually tracing confirmed larger gyrus rectus volume, and predicted taste pleasantness across all groups. The analyses also indicated other morphological differences between diagnostic categories: Ill and recovered-anorexia nervosa had increased right, while bulimia nervosa had increased left antero-ventral insula gray matter volumes compared to controls. Furthermore, dorsal striatum volumes were reduced in recovered-anorexia and bulimia nervosa, and predicted sensitivity to reward in the eating disorder groups. The eating disorder groups also showed reduced white matter in right temporal and parietal areas when compared to healthy controls. Notably, the results held when controlling for a range of covariates (e.g., age, depression, anxiety, medications). Conclusion Brain structure in medial orbitofrontal cortex, insula and striatum is altered in eating disorders and suggests altered brain circuitry that has been associated with taste pleasantness and reward value. PMID:23680873

Capacitance measurements of regulated exocytosis in mouse taste cells.

PubMed

Vandenbeuch, Aurelie; Zorec, Robert; Kinnamon, Sue C

2010-11-03

Exocytosis, consisting of the merger of vesicle and plasma membrane, is a common mechanism used by different types of nucleated cells to release their vesicular contents. Taste cells possess vesicles containing various neurotransmitters to communicate with adjacent taste cells and afferent nerve fibers. However, whether these vesicles engage in exocytosis on a stimulus is not known. Since vesicle membrane merger with the plasma membrane is reflected in plasma membrane area fluctuations, we measured membrane capacitance (C(m)), a parameter linearly related to membrane surface area. To investigate whether taste cells undergo regulated exocytosis, we used the compensated tight-seal whole-cell recording technique to monitor depolarization-induced changes in C(m) in the different types of taste cells. To identify taste cell types, mice expressing green fluorescent protein from the TRPM5 promoter or from the GAD67 promoter were used to discriminate type II and type III taste cells, respectively. Moreover, the cell types were also identified by monitoring their voltage-current properties. The results demonstrate that only type III taste cells show significant depolarization-induced increases in C(m), which were correlated to the voltage-activated calcium currents. The results suggest that type III, but neither type II nor type I cells exhibit depolarization-induced regulated exocytosis to release transmitter and activate gustatory afferent nerve fibers.

"Turn Up the Taste": Assessing the Role of Taste Intensity and Emotion in Mediating Crossmodal Correspondences between Basic Tastes and Pitch.

PubMed

Wang, Qian Janice; Wang, Sheila; Spence, Charles

2016-05-01

People intuitively match basic tastes to sounds of different pitches, and the matches that they make tend to be consistent across individuals. It is, though, not altogether clear what governs such crossmodal mappings between taste and auditory pitch. Here, we assess whether variations in taste intensity influence the matching of taste to pitch as well as the role of emotion in mediating such crossmodal correspondences. Participants were presented with 5 basic tastants at 3 concentrations. In Experiment 1, the participants rated the tastants in terms of their emotional arousal and valence/pleasantness, and selected a musical note (from 19 possible pitches ranging from C2 to C8) and loudness that best matched each tastant. In Experiment 2, the participants made emotion ratings and note matches in separate blocks of trials, then made emotion ratings for all 19 notes. Overall, the results of the 2 experiments revealed that both taste quality and concentration exerted a significant effect on participants' loudness selection, taste intensity rating, and valence and arousal ratings. Taste quality, not concentration levels, had a significant effect on participants' choice of pitch, but a significant positive correlation was observed between individual perceived taste intensity and pitch choice. A significant and strong correlation was also demonstrated between participants' valence assessments of tastants and their valence assessments of the best-matching musical notes. These results therefore provide evidence that: 1) pitch-taste correspondences are primarily influenced by taste quality, and to a lesser extent, by perceived intensity; and 2) such correspondences may be mediated by valence/pleasantness. © The Author 2016. Published by Oxford University Press.

Modulation of taste responsiveness by the satiation hormone peptide YY

PubMed Central

La Sala, Michael S.; Hurtado, Maria D.; Brown, Alicia R.; Bohórquez, Diego V.; Liddle, Rodger A.; Herzog, Herbert; Zolotukhin, Sergei; Dotson, Cedrick D.

2013-01-01

It has been hypothesized that the peripheral taste system may be modulated in the context of an animal's metabolic state. One purported mechanism for this phenomenon is that circulating gastrointestinal peptides modulate the functioning of the peripheral gustatory system. Recent evidence suggests endocrine signaling in the oral cavity can influence food intake (FI) and satiety. We hypothesized that these hormones may be affecting FI by influencing taste perception. We used immunohistochemistry along with genetic knockout models and the specific reconstitution of peptide YY (PYY) in saliva using gene therapy protocols to identify a role for PYY signaling in taste. We show that PYY is expressed in subsets of taste cells in murine taste buds. We also show, using brief-access testing with PYY knockouts, that PYY signaling modulates responsiveness to bitter-tasting stimuli, as well as to lipid emulsions. We show that salivary PYY augmentation, via viral vector therapy, rescues behavioral responsiveness to a lipid emulsion but not to bitter stimuli and that this response is likely mediated via activation of Y2 receptors localized apically in taste cells. Our findings suggest distinct functions for PYY produced locally in taste cells vs. that circulating systemically.—La Sala, M. S., Hurtado, M. D., Brown, A. R., Bohórquez, D. V., Liddle, R. A., Herzog, H., Zolotukhin, S., Dotson, C. D. Modulation of taste responsiveness by the satiation hormone peptide YY. PMID:24043261

β-catenin is required for taste bud cell renewal and behavioral taste perception in adult mice.

PubMed

Gaillard, Dany; Bowles, Spencer G; Salcedo, Ernesto; Xu, Mingang; Millar, Sarah E; Barlow, Linda A

2017-08-01

Taste stimuli are transduced by taste buds and transmitted to the brain via afferent gustatory fibers. Renewal of taste receptor cells from actively dividing progenitors is finely tuned to maintain taste sensitivity throughout life. We show that conditional β-catenin deletion in mouse taste progenitors leads to rapid depletion of progenitors and Shh+ precursors, which in turn causes taste bud loss, followed by loss of gustatory nerve fibers. In addition, our data suggest LEF1, TCF7 and Wnt3 are involved in a Wnt pathway regulatory feedback loop that controls taste cell renewal in the circumvallate papilla epithelium. Unexpectedly, taste bud decline is greater in the anterior tongue and palate than in the posterior tongue. Mutant mice with this regional pattern of taste bud loss were unable to discern sweet at any concentration, but could distinguish bitter stimuli, albeit with reduced sensitivity. Our findings are consistent with published reports wherein anterior taste buds have higher sweet sensitivity while posterior taste buds are better tuned to bitter, and suggest β-catenin plays a greater role in renewal of anterior versus posterior taste buds.

Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds.

PubMed

Meng, Lingbin; Ohman-Gault, Lisa; Ma, Liqun; Krimm, Robin F

2015-01-01

Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood.

Duplex Bioelectronic Tongue for Sensing Umami and Sweet Tastes Based on Human Taste Receptor Nanovesicles.

PubMed

Ahn, Sae Ryun; An, Ji Hyun; Song, Hyun Seok; Park, Jin Wook; Lee, Sang Hun; Kim, Jae Hyun; Jang, Jyongsik; Park, Tai Hyun

2016-08-23

For several decades, significant efforts have been made in developing artificial taste sensors to recognize the five basic tastes. So far, the well-established taste sensor is an E-tongue, which is constructed with polymer and lipid membranes. However, the previous artificial taste sensors have limitations in various food, beverage, and cosmetic industries because of their failure to mimic human taste reception. There are many interactions between tastants. Therefore, detecting the interactions in a multiplexing system is required. Herein, we developed a duplex bioelectronic tongue (DBT) based on graphene field-effect transistors that were functionalized with heterodimeric human umami taste and sweet taste receptor nanovesicles. Two types of nanovesicles, which have human T1R1/T1R3 for the umami taste and human T1R2/T1R3 for the sweet taste on their membranes, immobilized on micropatterned graphene surfaces were used for the simultaneous detection of the umami and sweet tastants. The DBT platform led to highly sensitive and selective recognition of target tastants at low concentrations (ca. 100 nM). Moreover, our DBT was able to detect the enhancing effect of taste enhancers as in a human taste sensory system. This technique can be a useful tool for the detection of tastes instead of sensory evaluation and development of new artificial tastants in the food and beverage industry.

Changes in taste bud volume during taste disturbance.

PubMed

Srur, Ehab; Pau, Hans Wilhelm; Just, Tino

2011-08-01

On-line mapping and serial volume measurements of taste buds with confocal laser scanning microscopy provide information on the peripheral gustatory organ over time. We report the volumetric measurements of four selected fungiform papillae over 8 weeks in a 62-year-old man with taste disturbance, which was more apparent on the right than on the left side. In the two papillae on the right side, no taste buds were detected within the fungiform papillae in the sixth and eighth week. During sixth and eighth week, there was no response to the highest presented stimuli in electrogustometry (1 mA) on the right-sided tongue tip nor at the tongue edge. The morphology (shape, diameter) of the fungiform papillae on both sides remained unchanged. Comparison of the time course of the volume changes revealed differences corresponding to gustatory sensitivity. These findings suggest that the time course of volume changes indicated taste disturbance in our patient, rather than morphological changes in the fungiform papillae. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Sweet Taste Receptor Signaling Network: Possible Implication for Cognitive Functioning

PubMed Central

Welcome, Menizibeya O.; Mastorakis, Nikos E.; Pereverzev, Vladimir A.

2015-01-01

Sweet taste receptors are transmembrane protein network specialized in the transmission of information from special “sweet” molecules into the intracellular domain. These receptors can sense the taste of a range of molecules and transmit the information downstream to several acceptors, modulate cell specific functions and metabolism, and mediate cell-to-cell coupling through paracrine mechanism. Recent reports indicate that sweet taste receptors are widely distributed in the body and serves specific function relative to their localization. Due to their pleiotropic signaling properties and multisubstrate ligand affinity, sweet taste receptors are able to cooperatively bind multiple substances and mediate signaling by other receptors. Based on increasing evidence about the role of these receptors in the initiation and control of absorption and metabolism, and the pivotal role of metabolic (glucose) regulation in the central nervous system functioning, we propose a possible implication of sweet taste receptor signaling in modulating cognitive functioning. PMID:25653876

Impacts of in utero and early infant taste experiences on later taste acceptance: a systematic review.

PubMed

Nehring, Ina; Kostka, Tanja; von Kries, Rüdiger; Rehfuess, Eva A

2015-06-01

Dietary behavior exerts a critical influence on health and is the outcome of a broad range of interacting factors, including food and taste acceptance. These may be programmed in utero and during early infancy. We examined the hypothesis that fetuses and infants exposed to sweet, salty, sour, bitter, umami, or specific tastes show greater acceptance of that same taste later in life. We conducted a systematic review of the literature, using comprehensive searches and following established procedures for screening, data extraction, and quality appraisal. We used harvest plots to synthesize the evidence graphically. Twenty studies comprising 38 subgroups that differed by taste, age, medium, and duration of exposure were included. Exposure to bitter and specific tastes increased the acceptance of these tastes. Studies on sweet and salty tastes showed equivocal results. Studies on sour tastes were sparse. Our systematic review clearly shows programming of the acceptance of bitter and specific tastes. For other tastes the results were either equivocal or confined to a few number of studies that precluded us from drawing conclusions. Further research should examine the association of salty and sour taste exposures on later preferences of these tastes. Long-term studies and randomized clinical trials on each type of taste are needed. © 2015 American Society for Nutrition.

β-catenin is required for taste bud cell renewal and behavioral taste perception in adult mice

PubMed Central

Gaillard, Dany; Xu, Mingang; Millar, Sarah E.

2017-01-01

Taste stimuli are transduced by taste buds and transmitted to the brain via afferent gustatory fibers. Renewal of taste receptor cells from actively dividing progenitors is finely tuned to maintain taste sensitivity throughout life. We show that conditional β-catenin deletion in mouse taste progenitors leads to rapid depletion of progenitors and Shh+ precursors, which in turn causes taste bud loss, followed by loss of gustatory nerve fibers. In addition, our data suggest LEF1, TCF7 and Wnt3 are involved in a Wnt pathway regulatory feedback loop that controls taste cell renewal in the circumvallate papilla epithelium. Unexpectedly, taste bud decline is greater in the anterior tongue and palate than in the posterior tongue. Mutant mice with this regional pattern of taste bud loss were unable to discern sweet at any concentration, but could distinguish bitter stimuli, albeit with reduced sensitivity. Our findings are consistent with published reports wherein anterior taste buds have higher sweet sensitivity while posterior taste buds are better tuned to bitter, and suggest β-catenin plays a greater role in renewal of anterior versus posterior taste buds. PMID:28846687

Mechanisms of Radiation-Induced Conditioned Taste Aversion Learning

DTIC Science & Technology

1986-01-01

to Walter A. Hunt. 86 4 21 144 . J Jr -.W U *’ = 7 . 7 .: M: W. ,WLW;i , .-, -’ .’P. %k T .- - ’ .: ’W ; .a --,.-" -. t .:-. , 56 RABIN AND HUNT can...8217. 7m. U RADIATION-INDUCED TASTE AVERSIONS 57 induced CTA 11021. Alternatively, when the antihistamine is [ 21 . A radiation-induced CTA can be...in rats. Pharmmad psychioactive drugs. J (omp Phvsiod Pvchld .;’: 21 -26. 1972. Biochem Behav 17: 305-311. 1982. 4. Berger. B. D.. C. D. Wise and L

TRPs in Taste and Chemesthesis

PubMed Central

2015-01-01

TRP channels are expressed in taste buds, nerve fibers, and keratinocytes in the oronasal cavity. These channels play integral roles in transducing chemical stimuli, giving rise to sensations of taste, irritation, warmth, coolness, and pungency. Specifically, TRPM5 acts downstream of taste receptors in the taste transduction pathway. TRPM5 channels convert taste-evoked intracellular Ca2+ release into membrane depolarization to trigger taste transmitter secretion. PKD2L1 is expressed in acid-sensitive (sour) taste bud cells but is unlikely to be the transducer for sour taste. TRPV1 is a receptor for pungent chemical stimuli such as capsaicin and for several irritants (chemesthesis). It is controversial whether TRPV1 is present in the taste buds and plays a direct role in taste. Instead, TRPV1 is expressed in non-gustatory sensory afferent fibers and in keratinocytes of the oronasal cavity. In many sensory fibers and epithelial cells lining the oronasal cavity, TRPA1 is also co-expressed with TRPV1. As with TRPV1, TRPA1 transduces a wide variety of irritants and, in combination with TRPV1, assures that there is a broad response to noxious chemical stimuli. Other TRP channels, including TRPM8, TRPV3, and TRPV4, play less prominent roles in chemesthesis and no known role in taste, per se. The pungency of foods and beverages is likely highly influenced by the temperature at which they are consumed, their acidity, and, for beverages, their carbonation. All these factors modulate the activity of TRP channels in taste buds and in the oronasal mucosa. PMID:24961971

TRPs in taste and chemesthesis.

PubMed

Roper, Stephen D

2014-01-01

TRP channels are expressed in taste buds, nerve fibers, and keratinocytes in the oronasal cavity. These channels play integral roles in transducing chemical stimuli, giving rise to sensations of taste, irritation, warmth, coolness, and pungency. Specifically, TRPM5 acts downstream of taste receptors in the taste transduction pathway. TRPM5 channels convert taste-evoked intracellular Ca(2+) release into membrane depolarization to trigger taste transmitter secretion. PKD2L1 is expressed in acid-sensitive (sour) taste bud cells but is unlikely to be the transducer for sour taste. TRPV1 is a receptor for pungent chemical stimuli such as capsaicin and for several irritants (chemesthesis). It is controversial whether TRPV1 is present in the taste buds and plays a direct role in taste. Instead, TRPV1 is expressed in non-gustatory sensory afferent fibers and in keratinocytes of the oronasal cavity. In many sensory fibers and epithelial cells lining the oronasal cavity, TRPA1 is also co-expressed with TRPV1. As with TRPV1, TRPA1 transduces a wide variety of irritants and, in combination with TRPV1, assures that there is a broad response to noxious chemical stimuli. Other TRP channels, including TRPM8, TRPV3, and TRPV4, play less prominent roles in chemesthesis and no known role in taste, per se. The pungency of foods and beverages is likely highly influenced by the temperature at which they are consumed, their acidity, and, for beverages, their carbonation. All these factors modulate the activity of TRP channels in taste buds and in the oronasal mucosa.

The taste of music.

PubMed

Mesz, Bruno; Trevisan, Marcos A; Sigman, Mariano

2011-01-01

Zarlino, one of the most important music theorists of the XVI century, described the minor consonances as 'sweet' (dolci) and 'soft' (soavi) (Zarlino 1558/1983, in On the Modes New Haven, CT: Yale University Press, 1983). Hector Berlioz, in his Treatise on Modern Instrumentation and Orchestration (London: Novello, 1855), speaks about the 'small acid-sweet voice' of the oboe. In line with this tradition of describing musical concepts in terms of taste words, recent empirical studies have found reliable associations between taste perception and low-level sound and musical parameters, like pitch and phonetic features. Here we investigated whether taste words elicited consistent musical representations by asking trained musicians to improvise on the basis of the four canonical taste words: sweet, sour, bitter, and salty. Our results showed that, even in free improvisation, taste words elicited very reliable and consistent musical patterns:'bitter' improvisations are low-pitched and legato (without interruption between notes), 'salty' improvisations are staccato (notes sharply detached from each other), 'sour' improvisations are high-pitched and dissonant, and 'sweet' improvisations are consonant, slow, and soft. Interestingly, projections of the improvisations of taste words to musical space (a vector space defined by relevant musical parameters) revealed that, in musical space, improvisations based on different taste words were nearly orthogonal or opposite. Decoding methods could classify binary choices of improvisations (i.e., identify the improvisation word from the melody) at performance of around 80%--well above chance. In a second experiment we investigated the mapping from perception of music to taste words. Fifty-seven non-musical experts listened to a fraction of the improvisations. We found that listeners classified with high performance the taste word which had elicited the improvisation. Our results, furthermore, show that associations of taste and music

The effect of imiquimod on taste bud calcium transients and transmitter secretion.

PubMed

Huang, Anthony Y; Wu, Sandy Y

2016-11-01

Imiquimod is an immunomodulator approved for the treatment of basal cell carcinoma and has adverse side effects, including taste disturbances. Paracrine transmission, representing cell-cell communication within taste buds, has the potential to shape the final signals that taste buds transmit to the brain. Here, we tested the underlying assumption that imiquimod modifies taste transmitter secretion in taste buds of mice. Taste buds were isolated from C57BL/6J mice. The effects of imiquimod on transmitter release in taste buds were measured using calcium imaging with cellular biosensors, and examining the net effect of imiquimod on taste-evoked ATP secretion from mouse taste buds. Up to 72% of presynaptic (Type III) taste cells responded to 100 μM imiquimod with an increase in intracellular Ca 2+ concentrations. These Ca 2 + responses were inhibited by thapsigargin, an inhibitor of the sarco/endoplasmic reticulum Ca 2 + -ATPase, and by U73122, a PLC inhibitor, suggesting that the Ca 2 + mobilization elicited by imiquimod was dependent on release from internal Ca 2 + stores. Moreover, combining studies of Ca 2 + imaging with cellular biosensors showed that imiquimod evoked secretion of 5-HT, which then provided negative feedback onto receptor (Type II) cells to reduce taste-evoked ATP secretion. Our results provide evidence that there is a subset of taste cells equipped with a range of intracellular mechanisms that respond to imiquimod. The findings are also consistent with a role of imiquimod as an immune response modifier, which shapes peripheral taste responses via 5-HT signalling. © 2016 The British Pharmacological Society.

Mash1-expressing cells could differentiate to type III cells in adult mouse taste buds.

PubMed

Takagi, Hiroki; Seta, Yuji; Kataoka, Shinji; Nakatomi, Mitsushiro; Toyono, Takashi; Kawamoto, Tatsuo

2018-03-10

The gustatory cells in taste buds have been identified as paraneuronal; they possess characteristics of both neuronal and epithelial cells. Like neurons, they form synapses, store and release transmitters, and are capable of generating an action potential. Like epithelial cells, taste cells have a limited life span and are regularly replaced throughout life. However, little is known about the molecular mechanisms that regulate taste cell genesis and differentiation. In the present study, to begin to understand these mechanisms, we investigated the role of Mash1-positive cells in regulating adult taste bud cell differentiation through the loss of Mash1-positive cells using the Cre-loxP system. We found that the cells expressing type III cell markers-aromatic L-amino acid decarboxylase (AADC), carbonic anhydrase 4 (CA4), glutamate decarboxylase 67 (GAD67), neural cell adhesion molecule (NCAM), and synaptosomal-associated protein 25 (SNAP25)-were significantly reduced in the circumvallate taste buds after the administration of tamoxifen. However, gustducin and phospholipase C beta2 (PLC beta2)-markers of type II taste bud cells-were not significantly changed in the circumvallate taste buds after the administration of tamoxifen. These results suggest that Mash1-positive cells could be differentiated to type III cells, not type II cells in the taste buds.

Failure of Serial Taste-Taste Compound Presentations to Produce Overshadowing of Extinction of Conditioned Taste Aversion

ERIC Educational Resources Information Center

Pineno, Oskar

2010-01-01

Two experiments were conducted to study overshadowing of extinction in a conditioned taste aversion preparation. In both experiments, aversive conditioning with sucrose was followed by extinction treatment with either sucrose alone or in compound with another taste, citric acid. Experiment 1 employed a simultaneous compound extinction treatment…

The number of taste buds is related to bitter taste sensitivity in layer and broiler chickens.

PubMed

Kudo, Ken-ichi; Shiraishi, Jun-ichi; Nishimura, Shotaro; Bungo, Takashi; Tabata, Shoji

2010-04-01

The relationship between taste sensitivity and the number of taste buds using a bitter tastant, quinine hydrochloride, was investigated in White Leghorn, Rhode Island Red, and broiler chickens. The White Leghorn and Rhode Island Red strains were able to perceive 2.0 mmol/L quinine hydrochloride, but the taste sensitivity of Rhode Island Red chickens was higher than that of White Leghorn chickens. Broiler chickens perceived 0.5 mmol/L quinine hydrochloride. The number of taste buds in the White Leghorn strain was the lowest, then the Rhode Island Red strain, with the number of taste buds highest in the broiler chickens. The number of taste buds was well correlated with bitter taste sensitivity. Therefore, we suggest that the number of taste buds is a vital factor in the perception of bitter taste and may be useful in selecting appropriate feeds for chickens.

Neural crest contribution to lingual mesenchyme, epithelium and developing taste papillae and taste buds.

PubMed

Liu, Hong-Xiang; Komatsu, Yoshihiro; Mishina, Yuji; Mistretta, Charlotte M

2012-08-15

The epithelium of mammalian tongue hosts most of the taste buds that transduce gustatory stimuli into neural signals. In the field of taste biology, taste bud cells have been described as arising from "local epithelium", in distinction from many other receptor organs that are derived from neurogenic ectoderm including neural crest (NC). In fact, contribution of NC to both epithelium and mesenchyme in the developing tongue is not fully understood. In the present study we used two independent, well-characterized mouse lines, Wnt1-Cre and P0-Cre that express Cre recombinase in a NC-specific manner, in combination with two Cre reporter mouse lines, R26R and ZEG, and demonstrate a contribution of NC-derived cells to both tongue mesenchyme and epithelium including taste papillae and taste buds. In tongue mesenchyme, distribution of NC-derived cells is in close association with taste papillae. In tongue epithelium, labeled cells are observed in an initial scattered distribution and progress to a clustered pattern between papillae, and within papillae and early taste buds. This provides evidence for a contribution of NC to lingual epithelium. Together with previous reports for the origin of taste bud cells from local epithelium in postnatal mouse, we propose that NC cells migrate into and reside in the epithelium of the tongue primordium at an early embryonic stage, acquire epithelial cell phenotypes, and undergo cell proliferation and differentiation that is involved in the development of taste papillae and taste buds. Our findings lead to a new concept about derivation of taste bud cells that include a NC origin. Copyright © 2012 Elsevier Inc. All rights reserved.

Neural crest contribution to lingual mesenchyme, epithelium and developing taste papillae and taste buds

PubMed Central

Liu, Hong-Xiang; Komatsu, Yoshihiro; Mishina, Yuji; Mistretta, Charlotte M.

2012-01-01

The epithelium of mammalian tongue hosts most of the taste buds that transduce gustatory stimuli into neural signals. In the field of taste biology, taste bud cells have been described as arising from “local epithelium”, in distinction from many other receptor organs that are derived from neurogenic ectoderm including neural crest (NC). In fact, contribution of NC to both epithelium and mesenchyme in the developing tongue is not fully understood. In the present study we used two independent, well-characterized mouse lines, Wnt1-Cre and P0-Cre that express Cre recombinase in a NC-specific manner, in combination with two Cre reporter mouse lines, R26R and ZEG, and demonstrate a contribution of NC-derived cells to both tongue mesenchyme and epithelium including taste papillae and taste buds. In tongue mesenchyme, distribution of NC-derived cells is in close association with taste papillae. In tongue epithelium, labeled cells are observed in an initial scattered distribution and progress to a clustered pattern between papillae, and within papillae and early taste buds. This provides evidence for a contribution of NC to lingual epithelium. Together with previous reports for the origin of taste bud cells from local epithelium in postnatal mouse, we propose that NC cells migrate into and reside in the epithelium of the tongue primordium at an early embryonic stage, acquire epithelial cell phenotypes, and undergo cell proliferation and differentiation that is involved in the development of taste papillae and taste buds. Our findings lead to a new concept about derivation of taste bud cells that include a NC origin. PMID:22659543

Taste preference and psychopathology.

PubMed

Aguayo, G A; Vaillant, M T; Arendt, C; Bachim, S; Pull, C B

2012-01-01

Excessive food intake has been linked to many factors including taste preference and the presence of psychopathology. The purpose of this study was to investigate the association between sweet and salty taste preference and psychopathology in patients with severe obesity. A consecutive series of patients applying for bariatric surgery was recruited for the study. Taste preference was self-reported. Psychopathology was assessed using the revised version of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). 190 patients were included in the study. In comparison with patients who had salty taste preference, patients with sweet taste preference had significantly higher elevations on the depression (OD: 4.090, p = 0.010) and the hysteria (OD: 2.951, p = 0.026) clinical scales of the MMPI-2. The results suggest the presence of an association between taste preference and psychopathology. The findings may be of interest for clinicians who are involved in the treatment of obesity. In particular, they may wish to pay increased attention to patients with sweet taste preference or who have a strong attraction for both sweet and salty foods, in order to detect psychopathology and to adapt the treatment.

(+)-(S)-alapyridaine--a general taste enhancer?

PubMed

Soldo, Tomislav; Blank, Imre; Hofmann, Thomas

2003-06-01

N-(1-Carboxyethyl)-6-hydroxymethyl-pyridinium-3-ol inner salt (alapyridaine), recently identified in heated sugar/amino acid mixtures as well as in beef bouillon, has been shown to exhibit general taste-enhancing activities, although tasteless on its own. Differing from other taste enhancers reported so far, racemic (R/S)-alapyridaine and, to an even greater extent (+)-(S)-alapyridaine, the physiologically active enantiomer, are able to enhance more than one basic taste quality. The threshold concentrations for the sweet taste of glucose and sucrose, for the umami taste of monosodium L-glutamate (MSG) and guanosine-5'-monophosphate (GMP), as well as the salty taste of NaCl, were significantly decreased when alapyridaine was present. In contrast, perception of the bitter tastes of caffeine and L-phenylalanine, as well as of sour-tasting citric acid, was unaffected. Furthermore, alapyridaine was shown to intensify known taste synergies such as, for example, the enhancing effect of L-arginine on the salty taste of NaCl, as well as that of GMP on the umami taste of MSG. The activity of (+)-(S)-alapyridaine could be observed not only in solutions of single taste compounds, but also in more complex tastant mixtures; for example, the umami, sweet and salty taste of a solution containing MSG, sucrose, NaCl and caffeine was significantly modulated, thus indicating that alapyridaine is a general taste enhancer.

Effects of caffeine deprivation on taste and mood.

PubMed

Brauer, L.H.; Buican, B.; de Wit, H.

1994-04-01

Despite its ubiquitous consumption in the natural environment, caffeine has not been a reliable reinforcer in laboratory settings. The reinforcing effects of caffeine are greater in caffeine-dependent subjects relative to non-dependent subjects, but the mechanism underlying this difference remains unclear. We hypothesized that deprivation from caffeine would produce alterations in subjective ratings of stimuli commonly associated with caffeine consumption. Specifically, we hypothesized that hedonic ratings of the coffee taste would be selectively enhanced following caffeine deprivation. Twelve regular caffeine users received acute doses of caffeine (300mg) or placebo after 33h of caffeine deprivation or non-deprivation. They rated the taste of coffee and sucrose, saccharin, and quinine solutions on intensity, bitterness, sweetness, pleasantness, and unpleasantness. Contrary to our hypothesis, subjects' ratings of the pleasantness of the coffee taste were not significantly altered by caffeine deprivation. However, subjects' ratings of the bitterness and sweetness of the coffee taste and ratings of the sucrose solution were altered by caffeine. Implications of these data for caffeine self-administration are discussed.

Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds123

PubMed Central

Meng, Lingbin; Ohman-Gault, Lisa; Ma, Liqun

2015-01-01

Abstract Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood. PMID:26730405

Subtype-dependent postnatal development of taste receptor cells in mouse fungiform taste buds.

PubMed

Ohtubo, Yoshitaka; Iwamoto, Masafumi; Yoshii, Kiyonori

2012-06-01

Taste buds contain two types of taste receptor cells, inositol 1,4,5-triphosphate receptor type 3-immunoreactive cells (type II cells) and synaptosomal-associating protein-25-immunoreactive cells (type III cells). We investigated their postnatal development in mouse fungiform taste buds immunohistochemically and electrophysiologically. The cell density, i.e. the number of cells per taste bud divided by the maximal area of the horizontal cross-section of the taste bud, of type II cells increased by postnatal day (PD)49, where as that of type III cells was unchanged throughout the postnatal observation period and was equal to that of the adult cells at PD1. The immunoreactivity of taste bud cell subtypes was the same as that of their respective subtypes in adult mice throughout the postnatal observation period. Almost all type II cells were immunoreactive to gustducin at PD1, and then the ratio of gustducin-immunoreactive type II cells to all type II cells decreased to a saturation level, ∼60% of all type II cells, by PD15. Type II and III cells generated voltage-gated currents similar to their respective adult cells even at PD3. These results show that infant taste receptor cells are as excitable as those of adults and propagate in a subtype-dependent manner. The relationship between the ratio of each taste receptor cell subtype to all cells and taste nerve responses are discussed. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Pragmatically on the sense of taste – a short treatise based on culinary art

PubMed Central

Jonderko, Krzysztof; Buschhaus, Magdalena

2013-01-01

The sense of taste is essential for proper functioning of the organism. The authors describe, in an accessible way, the complex mechanisms of taste perception. The structure of particular taste receptors, variants of their activation, as well as physical and chemical factors modifying the sensation of taste, are presented. Exquisite culinary examples are given in order to facilitate the reader with the understanding of why, at the level of the cerebral cortex, a virtually infinite number of combinations of taste sensations can be perceived. The discourse is spiced up by reflections of the eminent philosopher of taste, J.A. Brillat-Savarin, who convinces us that food intake should be not only a physiological act, but also a refined pleasure. PMID:24868281

Musical Taste Cultures and Tase Publics

ERIC Educational Resources Information Center

Fox, William A.; Wince, Michael H.

1975-01-01

An analysis of the material tastes of college students support Gan's concepts of taste culture and taste public. While Gan's contention that class has a major effect upon involvement with taste culture, this requires qualification where musical tastes of college students are concerned. (Author/AM)

Is There Any Effect on Smell and Taste Functions with Levothyroxine Treatment in Subclinical Hypothyroidism?

PubMed

Baskoy, Kamil; Ay, Seyid Ahmet; Altundag, Aytug; Kurt, Onuralp; Salihoglu, Murat; Deniz, Ferhat; Tekeli, Hakan; Yonem, Arif; Hummel, Thomas

2016-01-01

Subclinical hypothyroidism has been accused for coronary heart disease, lipid metabolism disorders, neuropsychiatric disorders, infertility or pregnancy related problems with various strength of evidence. Currently there is insufficient knowledge about olfaction and taste functions in subclinical hypothyroidism. Aim of the present study is to investigate the degree of smell and taste dysfunction in patients with subclinical hypothyroidism. 28 subclinical hypothyroid patients, and 31 controls enrolled in the prospective study in Istanbul, Turkey. Subclinical hypothyroid patients were treated with L-thyroxine for 3 months. Psychophysiological olfactory testing was performed using odor dispensers similar to felt-tip pens ("Sniffin' Sticks", Burghart, Wedel, Germany). Taste function tests were made using "Taste Strips" (Burghart, Wedel, Germany) which are basically tastant adsorbed filter paper strip. Patients scored lower on psychophysical olfactory tests than controls (odor thresholds:8.1±1.0 vs 8.9±1.1, p = 0.007; odor discrimination:12.4±1.3 vs 13.1±0.9, p = 0.016; odor identification:13.1±0.9 vs 14.0±1.1, p = 0.001; TDI score: 33.8±2.4 vs 36.9±2.1, p = 0.001). In contrast, results from psychophysical gustatory tests showed only a decreased score for "bitter" in patients, but not for other tastes (5.9±1.8 vs 6.6±1.0, p = 0.045). Three month after onset of treatment olfactory test scores already indicated improvement (odor thresholds:8.1±1.0 vs 8.6±0.6, p<0.001; odor discrimination:12.4±1.31 vs 12.9±0.8, p = 0.011; odor identification:13.1±0.9 vs 13.9±0.8, p<0.001; TDI scores:33.8±2.4 vs 35.5±1.7, p<0.001) respectively. Taste functions did not differ between groups for sweet, salty and, sour tastes but bitter taste was improved after 3 months of thyroxin substitution (patients:5.9±1.8 vs 6.6±1.2, p = 0.045). Correlation of changes in smell and taste, with thyroid function test were also evaluated. TSH, fT4 were found have no correlation with

Allelic variation of the Tas1r3 taste receptor gene selectively affects taste responses to sweeteners: evidence from 129.B6-Tas1r3 congenic mice

PubMed Central

Inoue, Masashi; Glendinning, John I.; Theodorides, Maria L.; Harkness, Sarah; Li, Xia; Bosak, Natalia; Beauchamp, Gary K.; Bachmanov, Alexander A.

2008-01-01

The Tas1r3 gene encodes the T1R3 receptor protein, which is involved in sweet taste transduction. To characterize ligand specificity of the T1R3 receptor and the genetic architecture of sweet taste responsiveness, we analyzed taste responses of 129.B6-Tas1r3 congenic mice to a variety of chemically diverse sweeteners and glucose polymers with three different measures: consumption in 48-h two-bottle preference tests, initial licking responses, and responses of the chorda tympani nerve. The results were generally consistent across the three measures. Allelic variation of the Tas1r3 gene influenced taste responsiveness to nonnutritive sweeteners (saccharin, acesulfame-K, sucralose, SC-45647), sugars (sucrose, maltose, glucose, fructose), sugar alcohols (erythritol, sorbitol), and some amino acids (d-tryptophan, d-phenylalanine, l-proline). Tas1r3 genotype did not affect taste responses to several sweet-tasting amino acids (l-glutamine, l-threonine, l-alanine, glycine), glucose polymers (Polycose, maltooligosaccharide), and nonsweet NaCl, HCl, quinine, monosodium glutamate, and inosine 5′-monophosphate. Thus Tas1r3 polymorphisms affect taste responses to many nutritive and nonnutritive sweeteners (all of which must interact with a taste receptor involving T1R3), but not to all carbohydrates and amino acids. In addition, we found that the genetic architecture of sweet taste responsiveness changes depending on the measure of taste response and the intensity of the sweet taste stimulus. Variation in the T1R3 receptor influenced peripheral taste responsiveness over a wide range of sweetener concentrations, but behavioral responses to higher concentrations of some sweeteners increasingly depended on mechanisms that could override input from the peripheral taste system. PMID:17911381

Oxytocin signaling in mouse taste buds.

PubMed

Sinclair, Michael S; Perea-Martinez, Isabel; Dvoryanchikov, Gennady; Yoshida, Masahide; Nishimori, Katsuhiko; Roper, Stephen D; Chaudhari, Nirupa

2010-08-05

The neuropeptide, oxytocin (OXT), acts on brain circuits to inhibit food intake. Mutant mice lacking OXT (OXT knockout) overconsume salty and sweet (i.e. sucrose, saccharin) solutions. We asked if OXT might also act on taste buds via its receptor, OXTR. Using RT-PCR, we detected the expression of OXTR in taste buds throughout the oral cavity, but not in adjacent non-taste lingual epithelium. By immunostaining tissues from OXTR-YFP knock-in mice, we found that OXTR is expressed in a subset of Glial-like (Type I) taste cells, and also in cells on the periphery of taste buds. Single-cell RT-PCR confirmed this cell-type assignment. Using Ca2+ imaging, we observed that physiologically appropriate concentrations of OXT evoked [Ca2+]i mobilization in a subset of taste cells (EC50 approximately 33 nM). OXT-evoked responses were significantly inhibited by the OXTR antagonist, L-371,257. Isolated OXT-responsive taste cells were neither Receptor (Type II) nor Presynaptic (Type III) cells, consistent with our immunofluorescence observations. We also investigated the source of OXT peptide that may act on taste cells. Both RT-PCR and immunostaining suggest that the OXT peptide is not produced in taste buds or in their associated nerves. Finally, we also examined the morphology of taste buds from mice that lack OXTR. Taste buds and their constituent cell types appeared very similar in mice with two, one or no copies of the OXTR gene. We conclude that OXT elicits Ca2+ signals via OXTR in murine taste buds. OXT-responsive cells are most likely a subset of Glial-like (Type I) taste cells. OXT itself is not produced locally in taste tissue and is likely delivered through the circulation. Loss of OXTR does not grossly alter the morphology of any of the cell types contained in taste buds. Instead, we speculate that OXT-responsive Glial-like (Type I) taste bud cells modulate taste signaling and afferent sensory output. Such modulation would complement central pathways of appetite

Contribution of different taste cells and signaling pathways to the discrimination of "bitter" taste stimuli by an insect.

PubMed

Glendinning, John I; Davis, Adrienne; Ramaswamy, Sudha

2002-08-15

Animals can discriminate among many different types of foods. This discrimination process involves multiple sensory systems, but the sense of taste is known to play a central role. We asked how the taste system contributes to the discrimination of different "bitter" taste stimuli in Manduca sexta caterpillars. This insect has approximately eight bilateral pairs of taste cells that respond selectively to bitter taste stimuli. Each bilateral pair of bitter-sensitive taste cells has a different molecular receptive range (MRR); some of these taste cells also contain two signaling pathways with distinctive MRRs and temporal patterns of spiking. To test for discrimination, we habituated the caterpillar's taste-mediated aversive response to one bitter taste stimulus (salicin) and then asked whether this habituation phenomenon generalized to four other bitter taste stimuli (caffeine, aristolochic acid, Grindelia extract, and Canna extract). We inferred that the two compounds were discriminable if the habituation phenomenon failed to generalize (e.g., from salicin to aristolochic acid). We found that M. sexta could discriminate between salicin and those bitter taste stimuli that activate (1) different populations of bitter-sensitive taste cells (Grindelia extract and Canna extract) or (2) different signaling pathways within the same bitter-sensitive taste cell (aristolochic acid). M. sexta could not discriminate between salicin and a bitter taste stimulus that activates the same signaling pathway within the same bitter-sensitive taste cell (caffeine). We propose that the heterogeneous population of bitter-sensitive taste cells and signaling pathways within this insect facilitates the discrimination of bitter taste stimuli.

Endocannabinoids selectively enhance sweet taste.

PubMed

Yoshida, Ryusuke; Ohkuri, Tadahiro; Jyotaki, Masafumi; Yasuo, Toshiaki; Horio, Nao; Yasumatsu, Keiko; Sanematsu, Keisuke; Shigemura, Noriatsu; Yamamoto, Tsuneyuki; Margolskee, Robert F; Ninomiya, Yuzo

2010-01-12

Endocannabinoids such as anandamide [N-arachidonoylethanolamine (AEA)] and 2-arachidonoyl glycerol (2-AG) are known orexigenic mediators that act via CB(1) receptors in hypothalamus and limbic forebrain to induce appetite and stimulate food intake. Circulating endocannabinoid levels inversely correlate with plasma levels of leptin, an anorexigenic mediator that reduces food intake by acting on hypothalamic receptors. Recently, taste has been found to be a peripheral target of leptin. Leptin selectively suppresses sweet taste responses in wild-type mice but not in leptin receptor-deficient db/db mice. Here, we show that endocannabinoids oppose the action of leptin to act as enhancers of sweet taste. We found that administration of AEA or 2-AG increases gustatory nerve responses to sweeteners in a concentration-dependent manner without affecting responses to salty, sour, bitter, and umami compounds. The cannabinoids increase behavioral responses to sweet-bitter mixtures and electrophysiological responses of taste receptor cells to sweet compounds. Mice genetically lacking CB(1) receptors show no enhancement by endocannnabinoids of sweet taste responses at cellular, nerve, or behavioral levels. In addition, the effects of endocannabinoids on sweet taste responses of taste cells are diminished by AM251, a CB(1) receptor antagonist, but not by AM630, a CB(2) receptor antagonist. Immunohistochemistry shows that CB(1) receptors are expressed in type II taste cells that also express the T1r3 sweet taste receptor component. Taken together, these observations suggest that the taste organ is a peripheral target of endocannabinoids. Reciprocal regulation of peripheral sweet taste reception by endocannabinoids and leptin may contribute to their opposing actions on food intake and play an important role in regulating energy homeostasis.

Shrinkage of ipsilateral taste buds and hyperplasia of contralateral taste buds following chorda tympani nerve transection.

PubMed

Li, Yi-Ke; Yang, Juan-Mei; Huang, Yi-Bo; Ren, Dong-Dong; Chi, Fang-Lu

2015-06-01

The morphological changes that occur in the taste buds after denervation are not well understood in rats, especially in the contralateral tongue epithelium. In this study, we investigated the time course of morphological changes in the taste buds following unilateral nerve transection. The role of the trigeminal component of the lingual nerve in maintaining the structural integrity of the taste buds was also examined. Twenty-four Sprague-Dawley rats were randomly divided into three groups: control, unilateral chorda tympani nerve transection and unilateral chorda tympani nerve transection + lingual nerve transection. Rats were allowed up to 42 days of recovery before being euthanized. The taste buds were visualized using a cytokeratin 8 antibody. Taste bud counts, volumes and taste receptor cell numbers were quantified and compared among groups. No significant difference was detected between the chorda tympani nerve transection and chorda tympani nerve transection + lingual nerve transection groups. Taste bud counts, volumes and taste receptor cell numbers on the ipsilateral side all decreased significantly compared with control. On the contralateral side, the number of taste buds remained unchanged over time, but they were larger, and taste receptor cells were more numerous postoperatively. There was no evidence for a role of the trigeminal branch of the lingual nerve in maintaining the structural integrity of the anterior taste buds.

Longitudinal analysis of calorie restriction on rat taste bud morphology and expression of sweet taste modulators.

PubMed

Cai, Huan; Daimon, Caitlin M; Cong, Wei-Na; Wang, Rui; Chirdon, Patrick; de Cabo, Rafael; Sévigny, Jean; Maudsley, Stuart; Martin, Bronwen

2014-05-01

Calorie restriction (CR) is a lifestyle intervention employed to reduce body weight and improve metabolic functions primarily via reduction of ingested carbohydrates and fats. Taste perception is highly related to functional metabolic status and body adiposity. We have previously shown that sweet taste perception diminishes with age; however, relatively little is known about the effects of various lengths of CR upon taste cell morphology and function. We investigated the effects of CR on taste bud morphology and expression of sweet taste-related modulators in 5-, 17-, and 30-month-old rats. In ad libitum (AL) and CR rats, we consistently found the following parameters altered significantly with advancing age: reduction of taste bud size and taste cell numbers per taste bud and reduced expression of sonic hedgehog, type 1 taste receptor 3 (T1r3), α-gustducin, and glucagon-like peptide-1 (GLP-1). In the oldest rats, CR affected a significant reduction of tongue T1r3, GLP-1, and α-gustducin expression compared with age-matched AL rats. Leptin receptor immunopositive cells were elevated in 17- and 30-month-old CR rats compared with age-matched AL rats. These alterations of sweet taste-related modulators, specifically during advanced aging, suggest that sweet taste perception may be altered in response to different lengths of CR.

Effects of viscosity, taste, and bolus volume on swallowing apnea duration of normal adults.

PubMed

Butler, Susan G; Postma, Gregory N; Fischer, Eileen

2004-12-01

The effects of viscosity, taste, and nectar-thick liquid bolus volume on swallowing apnea duration (SAD) were examined. Twenty-two adults, comprised of 10 males and 12 females, participated. SAD was assessed via nasal airflow during swallow conditions of viscosity (thin liquid, thick liquid, and puree), taste (water, apple juice, lemon concentrate), and nectar-thick liquid bolus volumes (5, 10, 15, and 20 mL) across three trials. A significant main effect of nectar-thick liquid bolus volume was found (P < 0.05). Viscosity and taste were not significant. SAD increased with increases in bolus volume; however, neither changes in bolus viscosity nor changes in taste affected SAD. These findings indicate that since viscosity was not significant, the normative data previously published (by this PI) with 60 healthy adults stratified by age and gender can be utilized for comparison to disordered swallowing without regard to the bolus viscosity being used. D.

Postnatal development of bitter taste avoidance behavior in mice is associated with ACTIN-dependent localization of bitter taste receptors to the microvilli of taste cells.

PubMed

Yamashita, Atsuko; Kondo, Kaori; Kunishima, Yoshimi; Iseki, Sachiko; Kondo, Takashi; Ota, Masato S

2018-01-22

Bitter taste avoidance behavior (BAB) plays a fundamental role in the avoidance of toxic substances with a bitter taste. However, the molecular basis underlying the development of BAB is unknown. To study critical developmental events by which taste buds turn into functional organs with BAB, we investigated the early phase development of BAB in postnatal mice in response to bitter-tasting compounds, such as quinine and thiamine. Postnatal mice started to exhibit BAB for thiamine and quinine at postnatal day 5 (PD5) and PD7, respectively. Histological analyses of taste buds revealed the formation of microvilli in the taste pores starting at PD5 and the localization of type 2 taste receptor 119 (TAS2R119) at the microvilli at PD6. Treatment of the tongue epithelium with cytochalasin D (CytD), which disturbs ACTIN polymerization in the microvilli, resulted in the loss of TAS2R119 localization at the microvilli and the loss of BAB for quinine and thiamine. The release of ATP from the circumvallate papillae tissue due to taste stimuli was also declined following CytD treatment. These results suggest that the localization of TAS2R119 at the microvilli of taste pores is critical for the initiation of BAB. Copyright © 2017 Elsevier Inc. All rights reserved.

Using sound-taste correspondences to enhance the subjective value of tasting experiences

PubMed Central

Reinoso Carvalho, Felipe; Van Ee, Raymond; Rychtarikova, Monika; Touhafi, Abdellah; Steenhaut, Kris; Persoone, Dominique; Spence, Charles

2015-01-01

The soundscapes of those places where we eat and drink can influence our perception of taste. Here, we investigated whether contextual sound would enhance the subjective value of a tasting experience. The customers in a chocolate shop were invited to take part in an experiment in which they had to evaluate a chocolate’s taste while listening to an auditory stimulus. Four different conditions were presented in a between-participants design. Envisioning a more ecological approach, a pre-recorded piece of popular music and the shop’s own soundscape were used as the sonic stimuli. The results revealed that not only did the customers report having a significantly better tasting experience when the sounds were presented as part of the food’s identity, but they were also willing to pay significantly more for the experience. The method outlined here paves a new approach to dealing with the design of multisensory tasting experiences, and gastronomic situations. PMID:26388813

Using sound-taste correspondences to enhance the subjective value of tasting experiences.

PubMed

Reinoso Carvalho, Felipe; Van Ee, Raymond; Rychtarikova, Monika; Touhafi, Abdellah; Steenhaut, Kris; Persoone, Dominique; Spence, Charles

2015-01-01

The soundscapes of those places where we eat and drink can influence our perception of taste. Here, we investigated whether contextual sound would enhance the subjective value of a tasting experience. The customers in a chocolate shop were invited to take part in an experiment in which they had to evaluate a chocolate's taste while listening to an auditory stimulus. Four different conditions were presented in a between-participants design. Envisioning a more ecological approach, a pre-recorded piece of popular music and the shop's own soundscape were used as the sonic stimuli. The results revealed that not only did the customers report having a significantly better tasting experience when the sounds were presented as part of the food's identity, but they were also willing to pay significantly more for the experience. The method outlined here paves a new approach to dealing with the design of multisensory tasting experiences, and gastronomic situations.

Changes in taste receptor cell [Ca2+]i modulate chorda tympani responses to salty and sour taste stimuli

PubMed Central

DeSimone, John A.; Ren, ZuoJun; Phan, Tam-Hao T.; Heck, Gerard L.; Mummalaneni, Shobha

2012-01-01

The relationship between taste receptor cell (TRC) Ca2+ concentration ([Ca2+]i) and rat chorda tympani (CT) nerve responses to salty [NaCl and NaCl+benzamil (Bz)] and sour (HCl, CO2, and acetic acid) taste stimuli was investigated before and after lingual application of ionomycin+Ca2+, 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA-AM), U73122 (phospholipase C blocker), and thapsigargin (Ca2+-ATPase inhibitor) under open-circuit or lingual voltage-clamp conditions. An increase in TRC [Ca2+]i attenuated the tonic Bz-sensitive NaCl CT response and the apical membrane Na+ conductance. A decrease in TRC [Ca2+]i enhanced the tonic Bz-sensitive and Bz-insensitive NaCl CT responses and apical membrane Na+ conductance but did not affect CT responses to KCl or NH4Cl. An increase in TRC [Ca2+]i did not alter the phasic response but attenuated the tonic CT response to acidic stimuli. A decrease in [Ca2+]i did not alter the phasic response but attenuated the tonic CT response to acidic stimuli. In a subset of TRCs, a positive relationship between [H+]i and [Ca2+]i was obtained using in vitro imaging techniques. U73122 inhibited the tonic CT responses to NaCl, and thapsigargin inhibited the tonic CT responses to salty and sour stimuli. The results suggest that salty and sour taste qualities are transduced by [Ca2+]i-dependent and [Ca2+]i-independent mechanisms. Changes in TRC [Ca2+]i in a BAPTA-sensitive cytosolic compartment regulate ion channels and cotransporters involved in the salty and sour taste transduction mechanisms and in neural adaptation. Changes in TRC [Ca2+]i in a separate subcompartment, sensitive to inositol trisphosphate and thapsigargin but inaccessible to BAPTA, are associated with neurotransmitter release. PMID:22956787

Age differences in the brain mechanisms of good taste.

PubMed

Rolls, Edmund T; Kellerhals, Michele B; Nichols, Thomas E

2015-06-01

There is strong evidence demonstrating age-related differences in the acceptability of foods and beverages. To examine the neural foundations underlying these age-related differences in the acceptability of different flavors and foods, we performed an fMRI study to investigate brain and hedonic responses to orange juice, orange soda, and vegetable juice in three different age groups: Young (22), Middle (40) and Elderly (60 years). Orange juice and orange soda were found to be liked by all age groups, while vegetable juice was disliked by the Young, but liked by the Elderly. In the insular primary taste cortex, the activations to these stimuli were similar in the 3 age groups, indicating that the differences in liking for these stimuli between the 3 groups were not represented in this first stage of cortical taste processing. In the agranular insula (anterior to the insular primary taste cortex) where flavor is represented, the activations to the stimuli were similar in the Elderly, but in the Young the activations were larger to the vegetable juice than to the orange drinks; and the activations here were correlated with the unpleasantness of the stimuli. In the anterior midcingulate cortex, investigated as a site where the activations were correlated with the unpleasantness of the stimuli, there was again a greater activation to the vegetable than to the orange stimuli in the Young but not in the Elderly. In the amygdala (and orbitofrontal cortex), investigated as sites where the activations were correlated with the pleasantness of the stimuli, there was a smaller activation to the vegetable than to the orange stimuli in the Young but not in the Elderly. The Middle group was intermediate with respect to the separation of their activations to the stimuli in the brain areas that represent the pleasantness or unpleasantness of flavors. Thus age differences in the activations to different flavors can in some brain areas be related to, and probably cause, the

Functional diversification of taste cells in vertebrates

PubMed Central

Matsumoto, Ichiro; Ohmoto, Makoto; Abe, Keiko

2012-01-01

Tastes are senses resulting from the activation of taste cells distributed in oral epithelia. Sweet, umami, bitter, sour, and salty tastes are called the five “basic” tastes, but why five, and why these five? In this review, we dissect the peripheral gustatory system in vertebrates from molecular and cellular perspectives. Recent behavioral and molecular genetic studies have revealed the nature of functional taste receptors and cells and show that different taste qualities are accounted for by the activation of different subsets of taste cells. Based on this concept, the diversity of basic tastes should be defined by the diversity of taste cells in taste buds, which varies among species. PMID:23085625

Functional dissociation in sweet taste receptor neurons between and within taste organs of Drosophila

PubMed Central

Thoma, Vladimiros; Knapek, Stephan; Arai, Shogo; Hartl, Marion; Kohsaka, Hiroshi; Sirigrivatanawong, Pudith; Abe, Ayako; Hashimoto, Koichi; Tanimoto, Hiromu

2016-01-01

Finding food sources is essential for survival. Insects detect nutrients with external taste receptor neurons. Drosophila possesses multiple taste organs that are distributed throughout its body. However, the role of different taste organs in feeding remains poorly understood. By blocking subsets of sweet taste receptor neurons, we show that receptor neurons in the legs are required for immediate sugar choice. Furthermore, we identify two anatomically distinct classes of sweet taste receptor neurons in the leg. The axonal projections of one class terminate in the thoracic ganglia, whereas the other projects directly to the brain. These two classes are functionally distinct: the brain-projecting neurons are involved in feeding initiation, whereas the thoracic ganglia-projecting neurons play a role in sugar-dependent suppression of locomotion. Distinct receptor neurons for the same taste quality may coordinate early appetitive responses, taking advantage of the legs as the first appendages to contact food. PMID:26893070

[Conversion disorder : functional neuroimaging and neurobiological mechanisms].

PubMed

Lejeune, J; Piette, C; Salmon, E; Scantamburlo, G

2017-04-01

Conversion disorder is a psychiatric disorder often encountered in neurology services. This condition without organic lesions was and still is sometimes referred as an imaginary illness or feigning. However, the absence of organic lesions does not exclude the possibility of cerebral dysfunction. The etiologic mechanisms underlying this disorder remain uncertain even today.The advent of cognitive and functional imaging opens up a field of exploration for psychiatry in understanding the neurobiological mechanisms underlying mental disorders and especially the conversion disorder. This article reports several neuroimaging studies of conversion disorder and attempts to generate hypotheses about neurobiological mechanisms.

The chemistry of sour taste and the strategy to reduce the sour taste of beer.

PubMed

Li, Hong; Liu, Fang

2015-10-15

The contributions of free hydrogen ions, undissociated hydrogen ions in protonated acid species, and anionic acid species to sour taste were studied through sensory experiments. According to tasting results, it can be inferred that the basic substance producing a sour taste is the hydrogen ion, including free hydrogen ions and undissociated hydrogen ions. The intensity of a sour taste is determined by the total concentration of free hydrogen ions and undissociated hydrogen ions. The anionic acid species (without hydrogen ions) does not produce a sour taste but can intensify or weaken the intensity of a sour taste. It seems that hydroxyl or conjugated groups in anionic acid species can intensify the sour taste produced by hydrogen ions. The following strategy to reduce the sensory sourness is advanced: not only reduce free hydrogen ions, namely elevate pH value, but also reduce the undissociated hydrogen ions contained in protonated acid species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single Lgr5- or Lgr6-expressing taste stem/progenitor cells generate taste bud cells ex vivo

PubMed Central

Ren, Wenwen; Lewandowski, Brian C.; Watson, Jaime; Aihara, Eitaro; Iwatsuki, Ken; Bachmanov, Alexander A.; Margolskee, Robert F.; Jiang, Peihua

2014-01-01

Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) and its homologs (e.g., Lgr6) mark adult stem cells in multiple tissues. Recently, we and others have shown that Lgr5 marks adult taste stem/progenitor cells in posterior tongue. However, the regenerative potential of Lgr5-expressing (Lgr5+) cells and the identity of adult taste stem/progenitor cells that regenerate taste tissue in anterior tongue remain elusive. In the present work, we describe a culture system in which single isolated Lgr5+ or Lgr6+ cells from taste tissue can generate continuously expanding 3D structures (“organoids”). Many cells within these taste organoids were cycling and positive for proliferative cell markers, cytokeratin K5 and Sox2, and incorporated 5-bromo-2’-deoxyuridine. Importantly, mature taste receptor cells that express gustducin, carbonic anhydrase 4, taste receptor type 1 member 3, nucleoside triphosphate diphosphohydrolase-2, or cytokeratin K8 were present in the taste organoids. Using calcium imaging assays, we found that cells grown out from taste organoids derived from isolated Lgr5+ cells were functional and responded to tastants in a dose-dependent manner. Genetic lineage tracing showed that Lgr6+ cells gave rise to taste bud cells in taste papillae in both anterior and posterior tongue. RT-PCR data demonstrated that Lgr5 and Lgr6 may mark the same subset of taste stem/progenitor cells both anteriorly and posteriorly. Together, our data demonstrate that functional taste cells can be generated ex vivo from single Lgr5+ or Lgr6+ cells, validating the use of this model for the study of taste cell generation. PMID:25368147

Single Lgr5- or Lgr6-expressing taste stem/progenitor cells generate taste bud cells ex vivo.

PubMed

Ren, Wenwen; Lewandowski, Brian C; Watson, Jaime; Aihara, Eitaro; Iwatsuki, Ken; Bachmanov, Alexander A; Margolskee, Robert F; Jiang, Peihua

2014-11-18

Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) and its homologs (e.g., Lgr6) mark adult stem cells in multiple tissues. Recently, we and others have shown that Lgr5 marks adult taste stem/progenitor cells in posterior tongue. However, the regenerative potential of Lgr5-expressing (Lgr5(+)) cells and the identity of adult taste stem/progenitor cells that regenerate taste tissue in anterior tongue remain elusive. In the present work, we describe a culture system in which single isolated Lgr5(+) or Lgr6(+) cells from taste tissue can generate continuously expanding 3D structures ("organoids"). Many cells within these taste organoids were cycling and positive for proliferative cell markers, cytokeratin K5 and Sox2, and incorporated 5-bromo-2'-deoxyuridine. Importantly, mature taste receptor cells that express gustducin, carbonic anhydrase 4, taste receptor type 1 member 3, nucleoside triphosphate diphosphohydrolase-2, or cytokeratin K8 were present in the taste organoids. Using calcium imaging assays, we found that cells grown out from taste organoids derived from isolated Lgr5(+) cells were functional and responded to tastants in a dose-dependent manner. Genetic lineage tracing showed that Lgr6(+) cells gave rise to taste bud cells in taste papillae in both anterior and posterior tongue. RT-PCR data demonstrated that Lgr5 and Lgr6 may mark the same subset of taste stem/progenitor cells both anteriorly and posteriorly. Together, our data demonstrate that functional taste cells can be generated ex vivo from single Lgr5(+) or Lgr6(+) cells, validating the use of this model for the study of taste cell generation.

Effects of smoking on taste: assessment with contact endoscopy and taste strips.

PubMed

Konstantinidis, Iordanis; Chatziavramidis, Angelos; Printza, Athanasia; Metaxas, Spyros; Constantinidis, Jannis

2010-10-01

This study aims to compare the taste function between smokers and nonsmokers with clinical testing, subjective ratings, and contact endoscopy of the tongue. Cross-sectional survey. Data were collected from 38 smokers (mean age 37 years; 25 female, 23 male) and 34 nonsmokers (mean age 33.5 years; 18 female, 16 male). The parameters assessed were the number of fungiform papillae per square centimeter in a noncontact way and their morphology (surface, capillary vessels) by contact endoscopy. The morphology of the filiform papillae has also been assessed. In addition, clinical testing of gustatory function was performed by means of taste strips and subjective intensity ratings of natural taste stimuli. No significant difference was found in clinical testing and intensity ratings between the two study groups. A trend toward significance was found in taste strip results for decreased bitter taste in heavy smokers (P = .06). The number and the size of fungiform papillae did not significantly differ between the study groups. No sex-related differences were observed. Smokers exhibited significantly more keratin structures on the fungiform papillae surface, less tortuous capillary vessels, and a significant distortion of their filiform papillae. Taste function presents significant resistance to smoking, although changes in morphology of fungiform and filiform papillae have been observed especially in heavy smokers. Laryngoscope, 2010.

Kokumi Substances, Enhancers of Basic Tastes, Induce Responses in Calcium-Sensing Receptor Expressing Taste Cells

PubMed Central

Maruyama, Yutaka; Yasuda, Reiko; Kuroda, Motonaka; Eto, Yuzuru

2012-01-01

Recently, we reported that calcium-sensing receptor (CaSR) is a receptor for kokumi substances, which enhance the intensities of salty, sweet and umami tastes. Furthermore, we found that several γ-glutamyl peptides, which are CaSR agonists, are kokumi substances. In this study, we elucidated the receptor cells for kokumi substances, and their physiological properties. For this purpose, we used Calcium Green-1 loaded mouse taste cells in lingual tissue slices and confocal microscopy. Kokumi substances, applied focally around taste pores, induced an increase in the intracellular Ca2+ concentration ([Ca2+]i) in a subset of taste cells. These responses were inhibited by pretreatment with the CaSR inhibitor, NPS2143. However, the kokumi substance-induced responses did not require extracellular Ca2+. CaSR-expressing taste cells are a different subset of cells from the T1R3-expressing umami or sweet taste receptor cells. These observations indicate that CaSR-expressing taste cells are the primary detectors of kokumi substances, and that they are an independent population from the influenced basic taste receptor cells, at least in the case of sweet and umami. PMID:22511946

Neural correlates of taste and pleasantness evaluation in the metabolic syndrome

PubMed Central

Green, Erin; Jacobson, Aaron; Haase, Lori; Murphy, Claire

2015-01-01

Metabolic syndrome (MetS) is a constellation of cardiometabolic abnormalities that commonly occur together and increase risk for cardiovascular disease and type II diabetes. Having MetS, especially during middle-age, increases the risk for dementia in later life. Abdominal obesity is a central feature of MetS; therefore, increased efforts to prevent obesity and identify predictors of weight gain are of extreme importance. Altered processing of food reward in the brain of obese individuals has been suggested to be a possible mechanism related to overeating. We scanned fifteen healthy middle-aged controls (aged 44–54) and sixteen middle-aged adults with MetS after a fast (hungry) and after a preload (sated), while they rated the pleasantness of sucrose (sweet) and caffeine (bitter) solutions. Data were analyzed using voxelwise linear mixed-effects modeling, and a region of interest analysis to examine associations between hypothalamic activation to sweet taste and BMI during hunger and satiety. The results indicate that middle-aged individuals with MetS respond with significantly less brain activation than controls without MetS during pleasantness evaluation of sweet and bitter tastes in regions involved in sensory and higher-level taste processing. Participants with higher BMI had greater hypothalamic response during pleasantness evaluation of sucrose in the sated condition. Importantly, this study is the first to document differential brain circuitry in middle-aged adults with MetS, a population at risk for poor physical and cognitive outcomes. Future research aimed at better understanding relationships among MetS, obesity, and brain function is warranted to better conceptualize and develop interventions for overeating in these disorders. PMID:25842372

Neural correlates of taste and pleasantness evaluation in the metabolic syndrome.

PubMed

Green, Erin; Jacobson, Aaron; Haase, Lori; Murphy, Claire

2015-09-16

Metabolic syndrome (MetS) is a constellation of cardiometabolic abnormalities that commonly occur together and increase risk for cardiovascular disease and type II diabetes. Having MetS, especially during middle-age, increases the risk for dementia in later life. Abdominal obesity is a central feature of MetS; therefore, increased efforts to prevent obesity and identify predictors of weight gain are of extreme importance. Altered processing of food reward in the brain of obese individuals has been suggested to be a possible mechanism related to overeating. We scanned fifteen healthy middle-aged controls (aged 44-54) and sixteen middle-aged adults with MetS after a fast (hungry) and after a preload (sated), while they rated the pleasantness of sucrose (sweet) and caffeine (bitter) solutions. Data were analyzed using voxelwise linear mixed-effects modeling, and a region of interest analysis to examine associations between hypothalamic activation to sweet taste and BMI during hunger and satiety. The results indicate that middle-aged individuals with MetS respond with significantly less brain activation than controls without MetS during pleasantness evaluation of sweet and bitter tastes in regions involved in sensory and higher-level taste processing. Participants with higher BMI had greater hypothalamic response during pleasantness evaluation of sucrose in the sated condition. Importantly, this study is the first to document differential brain circuitry in middle-aged adults with MetS, a population at risk for poor physical and cognitive outcomes. Future research aimed at better understanding relationships among MetS, obesity, and brain function is warranted to better conceptualize and develop interventions for overeating in these disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Intensity of regionally applied tastes in relation to administration method: an investigation based on the "taste strips" test.

PubMed

Manzi, Brian; Hummel, Thomas

2014-02-01

To compare various methods to apply regional taste stimuli to the tongue. "Taste strips" are a clinical tool to determine gustatory function. How a patient perceives the chemical environment in the mouth is a result of many factors such as taste bud distribution and interactions between the cranial nerves. To date, there have been few studies describing the different approaches to administer taste strips to maximize taste identification accuracy and intensity. This is a normative value acquisition pilot and single-center study. The investigation involved 30 participants reporting a normal sense of smell and taste (18 women, 12 men, mean age 33 years). The taste test was based on spoon-shaped filter paper strips impregnated with four taste qualities (sweet, sour, salty, and bitter) at concentrations shown to be easily detectable by young healthy subjects. The strips were administered in three methods (held stationary on the tip of the tongue, applied across the tongue, held in the mouth), resulting in a total of 12 trials per participant. Subjects identified the taste from a list of four descriptors, (sweet, sour, salty, bitter) and ranked the intensity on a scale from 0 to 10. Statistical analyses were performed on the accuracy of taste identification and rated intensities. The participants perceived in order of most to least intense: salt, sour, bitter, sweet. Of the four tastes, sour consistently was least accurately identified. Presenting the taste strip inside the closed mouth of the participants produced the least accurate taste identification, whereas moving the taste strip across the tongue led to a significant increase in intensity for the sweet taste. In this study of 30 subjects at the second concentration, optimized accuracy and intensity of taste identification was observed through administration of taste strips laterally across the anterior third of the extended tongue. Further studies are required on more subjects and the additional concentrations

Biomimetic chemical sensors using bioengineered olfactory and taste cells.

PubMed

Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

2014-01-01

Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well.

Effect of environmental pollutants on taste and smell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schiffman, S.S.; Nagle, H.T.

1992-06-01

Various man-made and naturally occurring chemicals and substances can modify the chemosensory systems of animals and man. This article provides an overview of research studies that investigate the impact of pollution on taste and smell perception. Acute and chronic alterations in taste and olfaction are discussed for solvents, herbicides, fungicides, pesticides, disinfectants, germicides, soil fumigants, dyes, pharmaceuticals, textile wastes, smog, tobacco smoke, perfumes, flavors, plastics, synthetic rubber, and other industrial substances. The mechanisms by which pollutants may cause physiologic and biologic changes are highlighted. Natural detoxification systems are discussed, as well as treatments for chemosensory deficits.89 references.

Taste responses in mice lacking taste receptor subunit T1R1

PubMed Central

Kusuhara, Yoko; Yoshida, Ryusuke; Ohkuri, Tadahiro; Yasumatsu, Keiko; Voigt, Anja; Hübner, Sandra; Maeda, Katsumasa; Boehm, Ulrich; Meyerhof, Wolfgang; Ninomiya, Yuzo

2013-01-01

The T1R1 receptor subunit acts as an umami taste receptor in combination with its partner, T1R3. In addition, metabotropic glutamate receptors (brain and taste variants of mGluR1 and mGluR4) are thought to function as umami taste receptors. To elucidate the function of T1R1 and the contribution of mGluRs to umami taste detection in vivo, we used newly developed knock-out (T1R1−/−) mice, which lack the entire coding region of the Tas1r1 gene and express mCherry in T1R1-expressing cells. Gustatory nerve recordings demonstrated that T1R1−/− mice exhibited a serious deficit in inosine monophosphate-elicited synergy but substantial residual responses to glutamate alone in both chorda tympani and glossopharyngeal nerves. Interestingly, chorda tympani nerve responses to sweeteners were smaller in T1R1−/− mice. Taste cell recordings demonstrated that many mCherry-expressing taste cells in T1R1+/− mice responded to sweet and umami compounds, whereas those in T1R1−/− mice responded to sweet stimuli. The proportion of sweet-responsive cells was smaller in T1R1−/− than in T1R1+/− mice. Single-cell RT-PCR demonstrated that some single mCherry-expressing cells expressed all three T1R subunits. Chorda tympani and glossopharyngeal nerve responses to glutamate were significantly inhibited by addition of mGluR antagonists in both T1R1−/− and T1R1+/− mice. Conditioned taste aversion tests demonstrated that both T1R1−/− and T1R1+/− mice were equally capable of discriminating glutamate from other basic taste stimuli. Avoidance conditioned to glutamate was significantly reduced by addition of mGluR antagonists. These results suggest that T1R1-expressing cells mainly contribute to umami taste synergism and partly to sweet sensitivity and that mGluRs are involved in the detection of umami compounds. PMID:23339178

The effect of imiquimod on taste bud calcium transients and transmitter secretion

PubMed Central

Wu, Sandy Y

2016-01-01

Background and Purpose Imiquimod is an immunomodulator approved for the treatment of basal cell carcinoma and has adverse side effects, including taste disturbances. Paracrine transmission, representing cell–cell communication within taste buds, has the potential to shape the final signals that taste buds transmit to the brain. Here, we tested the underlying assumption that imiquimod modifies taste transmitter secretion in taste buds of mice. Experimental Approach Taste buds were isolated from C57BL/6J mice. The effects of imiquimod on transmitter release in taste buds were measured using calcium imaging with cellular biosensors, and examining the net effect of imiquimod on taste‐evoked ATP secretion from mouse taste buds. Key Results Up to 72% of presynaptic (Type III) taste cells responded to 100 μM imiquimod with an increase in intracellular Ca2+ concentrations. These Ca2 + responses were inhibited by thapsigargin, an inhibitor of the sarco/endoplasmic reticulum Ca2 +‐ATPase, and by U73122, a PLC inhibitor, suggesting that the Ca2 + mobilization elicited by imiquimod was dependent on release from internal Ca2 + stores. Moreover, combining studies of Ca2 + imaging with cellular biosensors showed that imiquimod evoked secretion of 5‐HT, which then provided negative feedback onto receptor (Type II) cells to reduce taste‐evoked ATP secretion. Conclusion and Implications Our results provide evidence that there is a subset of taste cells equipped with a range of intracellular mechanisms that respond to imiquimod. The findings are also consistent with a role of imiquimod as an immune response modifier, which shapes peripheral taste responses via 5‐HT signalling. PMID:27464850

Interacting Mechanisms of Impulsivity in Bipolar Disorder and Antisocial Personality Disorder

PubMed Central

Swann, Alan C.; Lijffijt, Marijn; Lane, Scott D.; Steinberg, Joel L.; Moeller, F. Gerard

2011-01-01

Background Bipolar disorder and antisocial personality disorder (ASPD) overlap in clinical characteristics and behavioral consequences. Impulsivity is prominent in both, but there is little information on how specific mechanisms of impulsivity differentiate, bridge, or underlie the disorders. Methods Subjects, all males, were controls (n=46), bipolar disorder without cluster B personality disorder (n=21), ASPD without bipolar disorder (n=50), and bipolar disorder with ASPD (n=16). Impulsivity measures were the Immediate Memory Task (IMT), a continuous performance test of response inhibition measuring ability to evaluate a stimulus before responding, and the Two Choice Impulsivity Paradigm (TCIP), a choice between smaller-sooner and larger-later reward. Data were analyzed using general linear models analysis. Results Subjects with bipolar disorder had fewer IMT correct detections and slower reaction times than controls. Reaction times were faster with combined diagnoses than in bipolar disorder alone. TCIP responding in either diagnosis alone resembled controls, but was more impulsive in combined disorders. These differences persisted after correction for age and education, which had significant independent effects. In combined ASPD and bipolar disorder, increased reaction speed, impulsive response bias, and reward-delay impulsivity occurred independent of substance-use disorder history. Conclusions Impulsivity was increased in the combined disorders over either disorder alone. Results were consistent with at least partially distinct mechanisms of impulsivity in ASPD and bipolar disorder. Compensatory mechanisms for impulsivity in uncomplicated ASPD or bipolar disorder appear to be compromised or lost when the disorders are combined. PMID:21719028

Peptide regulators of peripheral taste function.

PubMed

Dotson, Cedrick D; Geraedts, Maartje C P; Munger, Steven D

2013-03-01

The peripheral sensory organ of the gustatory system, the taste bud, contains a heterogeneous collection of sensory cells. These taste cells can differ in the stimuli to which they respond and the receptors and other signaling molecules they employ to transduce and encode those stimuli. This molecular diversity extends to the expression of a varied repertoire of bioactive peptides that appear to play important functional roles in signaling taste information between the taste cells and afferent sensory nerves and/or in processing sensory signals within the taste bud itself. Here, we review studies that examine the expression of bioactive peptides in the taste bud and the impact of those peptides on taste functions. Many of these peptides produced in taste buds are known to affect appetite, satiety or metabolism through their actions in the brain, pancreas and other organs, suggesting a functional link between the gustatory system and the neural and endocrine systems that regulate feeding and nutrient utilization. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sweets and fats tasting in patients with anorexia nervosa: the role of the thought-shape fusion cognitive distortion.

PubMed

Monje Moreno, José Manuel; Alvarez Amor, Leticia; Ruiz-Prieto, Inmaculada; Bolaños-Ríos, Patricia; Jáuregui-Lobera, Ignacio

2014-05-01

It has been found that the olfactorygustatory function is altered in patients with eating disorders, with an impairment affecting the perception of olfactory and gustatory stimuli. The aim was to explore the subjective reactivity after the exposure and tasting of foods with different gradient of sweetness and different fats textures. In addition, changes in the thought-shape fusion (TSF) cognitive distortion were assessed after tasting those different presentations as well as the correlations between the initial scores on TSF-Questionnaire (TSF-Q) and the different responses after that tasting. A total of 15 healthy controls and 23 outpatients with anorexia nervosa underwent two sessions of tasting (sweets with different gradient of sweetness and fats with different textures) and they filled several questionnaires (pre- and post-tasting) to measure their responses after tasting. Participants showed less "self-control" after tasting sweets. The score on TSF-Q increased significantly after the sweets tasting in the patients group. Patients had the worst response after tasting presentations with more quantity of glucose (less gradient of sweetness) than after tasting those with more amount of sucrose (much more sweetness). With respect to the fats, patients showed the worst reaction after tasting the most unfamiliar texture. Pre fats tasting TSF-Q scores correlated significantly with all responses in the patients group. Both psychological and biological (e.g. genetic) factors could be involved in the reactions of patients with anorexia nervosa after tasting sweets and fats. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Effectiveness of Taste Lessons with and without additional experiential learning activities on children's willingness to taste vegetables.

PubMed

Battjes-Fries, Marieke C E; Haveman-Nies, Annemien; Zeinstra, Gertrude G; van Dongen, Ellen J I; Meester, Hante J; van den Top-Pullen, Rinelle; Van't Veer, Pieter; de Graaf, Kees

2017-02-01

This study assessed the effectiveness of the Dutch school programme Taste Lessons with and without additional experiential learning activities on children's willingness to taste unfamiliar vegetables. Thirty-three primary schools (877 children in grades 6-7 with a mean age of 10.3 years) participated in Taste Lessons Vegetable Menu (TLVM, lessons and extra activities), Taste Lessons (TL, lessons), or a control group. A baseline and follow-up measurement was used to assess for each child: number of four familiar and four unfamiliar vegetables tasted, quantity tasted, choice of vegetable of which to eat more, and number of vegetables willing to taste again later. Furthermore, children filled out a questionnaire on daily vegetable intake and food neophobia. Multilevel and Cox regression analyses were conducted to compare changes in the outcome measures between the three study groups. No significant intervention effects were found on willingness to taste unfamiliar vegetables. Neither were effects found on familiar vegetables, except for number of familiar vegetables tasted (p < 0.05). Furthermore, no significant intervention effects were found on daily vegetable consumption and food neophobia. These results indicate that more intensive school-based nutrition education activities are needed to increase children's willingness to taste unfamiliar vegetables and increase their vegetable intake. Copyright © 2016. Published by Elsevier Ltd.

E-tongue: a tool for taste evaluation.

PubMed

Gupta, Himanshu; Sharma, Aarti; Kumar, Suresh; Roy, Saroj K

2010-01-01

Taste has an important role in the development of oral pharmaceuticals. With respect to patient acceptability and compliance, taste is one of the prime factors determining the market penetration and commercial success of oral formulations, especially in pediatric medicine. Taste assessment is one important quality-control parameter for evaluating taste-masked formulations. Hence, pharmaceutical industries invest time, money and resources into developing palatable and pleasant-tasting products. The primary method for the taste measurement of a drug substance or a formulation is by human sensory evaluation, in which tasting a sample is relayed to inspectors. However, this method is impractical for early stage drug development because the test in humans is expensive and the taste of a drug candidate may not be important to the final product. Therefore, taste-sensing analytical devices, which can detect tastes, have been replacing the taste panelists. In the present review we are presenting different aspect of electronic tongue. The review article also discussed some useful patents and instrument with respect to E-tongue.

What Does Diabetes "Taste" Like?

PubMed

Neiers, Fabrice; Canivenc-Lavier, Marie-Chantal; Briand, Loïc

2016-06-01

The T1R2 (taste type 1 receptor, member 2)/T1R3 (taste type 1 receptor, member 3) sweet taste receptor is expressed in taste buds on the tongue, where it allows the detection of energy-rich carbohydrates of food. This single receptor responds to all compounds perceived as sweet by humans, including natural sugars and natural and artificial sweeteners. Importantly, the T1R2/T1R3 sweet taste receptor is also expressed in extra-oral tissues, including the stomach, pancreas, gut, liver, and brain. Although its physiological role remains to be established in numerous organs, T1R2/T1R3 is suspected to be involved in the regulation of metabolic processes, such as sugar sensing, glucose homeostasis, and satiety hormone release. In this review, the physiological role of the sweet taste receptor in taste perception and metabolic regulation is discussed by focusing on dysfunctions leading to diabetes. Current knowledge of T1R2/T1R3 inhibitors making this receptor a promising therapeutic target for the treatment of type 2 diabetes is also summarized and discussed.

Mice Lacking Pannexin 1 Release ATP and Respond Normally to All Taste Qualities.

PubMed

Vandenbeuch, Aurelie; Anderson, Catherine B; Kinnamon, Sue C

2015-09-01

Adenosine triphosphate (ATP) is required for the transmission of all taste qualities from taste cells to afferent nerve fibers. ATP is released from Type II taste cells by a nonvesicular mechanism and activates purinergic receptors containing P2X2 and P2X3 on nerve fibers. Several ATP release channels are expressed in taste cells including CALHM1, Pannexin 1, Connexin 30, and Connexin 43, but whether all are involved in ATP release is not clear. We have used a global Pannexin 1 knock out (Panx1 KO) mouse in a series of in vitro and in vivo experiments. Our results confirm that Panx1 channels are absent in taste buds of the knockout mice and that other known ATP release channels are not upregulated. Using a luciferin/luciferase assay, we show that circumvallate taste buds from Panx1 KO mice normally release ATP upon taste stimulation compared with wild type (WT) mice. Gustatory nerve recordings in response to various tastants applied to the tongue and brief-access behavioral testing with SC45647 also show no difference between Panx1 KO and WT. These results confirm that Panx1 is not required for the taste evoked release of ATP or for neural and behavioral responses to taste stimuli. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nutritional status alters saccharin intake and sweet receptor mRNA expression in rat taste buds.

PubMed

Chen, Ke; Yan, Jianqun; Suo, Yi; Li, Jinrong; Wang, Qian; Lv, Bo

2010-04-14

Sweet taste usually signifies the presence of caloric food. It is commonly accepted that a close association exists among sweet taste perception, preference, and nutritional status. However, the mechanisms involved remain unknown. To investigate whether nutritional status affects the preference for palatable solutions and alters sweet taste receptor gene expression in rats, we measured saccharin intake and preference using a two-bottle preference test, and changes in body weight, plasma leptin levels, and gene expression for the sweet taste receptor in taste buds in high-fat diet-induced obese rats and chronically diet-restricted rats. We found that the consumption and preference ratios for 0.01 and 0.04 M saccharin were significantly lower in the high-fat diet-induced obese rats than in the normal diet rats, while the serum leptin levels were markedly increased in obese rats. Consistent with the changes in saccharin intake, the gene expression level of the sweet taste receptor T1R3 was significantly decreased in the high-fat diet-induced obese rats compared with the control rats. By contrast, the chronically diet-restricted rats showed remarkably enhanced consumption and preference for 0.04 M saccharin. The serum leptin concentration was decreased, and the gene expression of the leptin receptor was markedly increased in the taste buds. In conclusion, our results suggest that nutritional status alters saccharin preference and the expression of T1R3 in taste buds. These processes may be involved in the mechanisms underlying the modulation of peripheral sweet taste sensitivity, in which leptin plays a role. Copyright 2010 Elsevier B.V. All rights reserved.

Acid sensing by sweet and bitter taste neurons in Drosophila melanogaster.

PubMed

Charlu, Sandhya; Wisotsky, Zev; Medina, Adriana; Dahanukar, Anupama

2013-01-01

Drosophila melanogaster can taste various compounds and separate them into few basic categories such as sweet, bitter and salt taste. Here we investigate mechanisms underlying acid detection in Drosophila and report that the fly displays strong taste aversion to common carboxylic acids. We find that acid tastants act by the activation of a subset of bitter neurons and inhibition of sweet neurons. Bitter neurons begin to respond at pH 5 and show an increase in spike frequency as the extracellular pH drops, which does not rely on previously identified chemoreceptors. Notably, sweet neuron activity depends on the balance of sugar and acid tastant concentrations. This is independent of bitter neuron firing, and allows the fly to avoid acid-laced food sources even in the absence of functional bitter neurons. The two mechanisms may allow the fly to better evaluate the risk of ingesting acidic foods and modulate its feeding decisions accordingly.

Salt taste inhibition by cathodal current.

PubMed

Hettinger, Thomas P; Frank, Marion E

2009-09-28

Effects of cathodal current, which draws cations away from the tongue and drives anions toward the tongue, depend on the ionic content of electrolytes through which the current is passed. To address the role of cations and anions in human salt tastes, cathodal currents of -40 microA to -80 microA were applied to human subjects' tongues through supra-threshold salt solutions. The salts were sodium chloride, sodium bromide, potassium chloride, ammonium chloride, calcium chloride, sodium nitrate, sodium sulfate, sodium saccharin, sodium acetate and sodium benzoate, which taken together encompass salty, bitter, sour and sweet taste qualities. The taste of NaCl, the salty and bitter tastes of the other chloride salts and the taste of NaNO(3) was inhibited, suggesting the current displaced stimulatory cations from salty and bitter receptors. However, bitter tastes of non-halide sodium salts were not inhibited, likely because other bitter receptors respond to anions. A discharge current at cathode-off ubiquitously evoked a metallic taste reminiscent of anodal taste used in clinical electrogustometry. Analogous effects on ambient NaCl responses were recorded from the hamster chorda tympani nerve. Increases in tastes of the saccharin and benzoate anions were not evoked during current flow, suggesting that cathodal current does not carry stimulatory anions to sweet receptors. Cathodal current may selectively inhibit salty and bitter-salty tastes for which proximal stimuli are cations.

Understanding taste dysfunction in patients with cancer.

PubMed

McLaughlin, Laura; Mahon, Suzanne M

2012-04-01

Taste dysfunction is a significant but underestimated issue for patients with cancer. Impaired taste results in changes in diet and appetite, early satiety, and impaired social interactions. Nurses can play a key role in educating patients and families on the pathophysiology of taste dysfunction by suggesting interventions to treat the consequences of taste dysfunction, when available, and offering psychosocial support as patients cope with this often devastating consequence of treatment. Taste recognition helps humans identify the nutritional quality of food and signals the digestive tract to begin secreting enzymes. Spoiled or tainted foods typically are recognized by their bad taste. Along with the other sensory systems, taste is crucial for helping patients treated for cancer feel normal. This article will review the anatomy and physiology of taste; define the different types of taste dysfunction, including the underlying pathophysiologic basis related to cancer treatment; and discuss potential nursing interventions to manage the consequences of taste dysfunction.

Longitudinal Analysis of Calorie Restriction on Rat Taste Bud Morphology and Expression of Sweet Taste Modulators

PubMed Central

Cai, Huan; Daimon, Caitlin M.; Cong, Wei-na; Wang, Rui; Chirdon, Patrick; de Cabo, Rafael; Sévigny, Jean; Maudsley, Stuart; Martin, Bronwen

2014-01-01

Calorie restriction (CR) is a lifestyle intervention employed to reduce body weight and improve metabolic functions primarily via reduction of ingested carbohydrates and fats. Taste perception is highly related to functional metabolic status and body adiposity. We have previously shown that sweet taste perception diminishes with age; however, relatively little is known about the effects of various lengths of CR upon taste cell morphology and function. We investigated the effects of CR on taste bud morphology and expression of sweet taste–related modulators in 5-, 17-, and 30-month-old rats. In ad libitum (AL) and CR rats, we consistently found the following parameters altered significantly with advancing age: reduction of taste bud size and taste cell numbers per taste bud and reduced expression of sonic hedgehog, type 1 taste receptor 3 (T1r3), α-gustducin, and glucagon-like peptide-1 (GLP-1). In the oldest rats, CR affected a significant reduction of tongue T1r3, GLP-1, and α-gustducin expression compared with age-matched AL rats. Leptin receptor immunopositive cells were elevated in 17- and 30-month-old CR rats compared with age-matched AL rats. These alterations of sweet taste–related modulators, specifically during advanced aging, suggest that sweet taste perception may be altered in response to different lengths of CR. PMID:24077597

Taste buds as peripheral chemosensory processors

PubMed Central

Roper, Stephen D.

2012-01-01

Taste buds are peripheral chemosensory organs situated in the oral cavity. Each taste bud consists of a community of 50–100 cells that interact synaptically during gustatory stimulation. At least three distinct cell types are found in mammalian taste buds – Type I cells, Receptor (Type II) cells, and Presynaptic (Type III) cells. Type I cells appear to be glial-like cells. Receptor cells express G protein-coupled taste receptors for sweet, bitter, or umami compounds. Presynaptic cells transduce acid stimuli (sour taste). Cells that sense salt (NaCl) taste have not yet been confidently identified in terms of these cell types. During gustatory stimulation, taste bud cells secrete synaptic, autocrine, and paracrine transmitters. These transmitters include ATP, acetylcholine (ACh), serotonin (5-HT), norepinephrine (NE), and GABA. Glutamate is an efferent transmitter that stimulates Presynaptic cells to release 5-HT. This chapter discusses these transmitters, which cells release them, the postsynaptic targets for the transmitters, and how cell–cell communication shapes taste bud signaling via these transmitters. PMID:23261954

Taste buds as peripheral chemosensory processors.

PubMed

Roper, Stephen D

2013-01-01

Taste buds are peripheral chemosensory organs situated in the oral cavity. Each taste bud consists of a community of 50-100 cells that interact synaptically during gustatory stimulation. At least three distinct cell types are found in mammalian taste buds - Type I cells, Receptor (Type II) cells, and Presynaptic (Type III) cells. Type I cells appear to be glial-like cells. Receptor cells express G protein-coupled taste receptors for sweet, bitter, or umami compounds. Presynaptic cells transduce acid stimuli (sour taste). Cells that sense salt (NaCl) taste have not yet been confidently identified in terms of these cell types. During gustatory stimulation, taste bud cells secrete synaptic, autocrine, and paracrine transmitters. These transmitters include ATP, acetylcholine (ACh), serotonin (5-HT), norepinephrine (NE), and GABA. Glutamate is an efferent transmitter that stimulates Presynaptic cells to release 5-HT. This chapter discusses these transmitters, which cells release them, the postsynaptic targets for the transmitters, and how cell-cell communication shapes taste bud signaling via these transmitters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Taste acuity of the human palate. III. Studies with taste solutions on subjects in different age groups.

PubMed

Nilsson, B

1979-01-01

The taste acuity at the midline of the hard and soft palate near their junction and, for comparison, on representative areas of the tongue was determined in 80 subjects aged 11-79 years by applying test solutions of the four basic tastes. Twenty-one subjects (26%) could identify at least one taste on the hard palate but none could recognize all four tastes. Seventy subjects (87%) could identify at least one taste on the soft palate and 37 subjects (46%) could recognize all four tastes. Taste thresholds were much higher on the hard palate than on the tongue and were in most cases higher on the soft palate than on the tongue. The ability to recognize all four tastes was less frequent in older than in younger subjects and the difference was greatest on the soft palate and least at the foliate papillae. The differences were greatest for citric acid and least for sucrose. There was a tendency to lower thresholds for women compared to men for all four tastes on all areas examined which was most pronounced on the soft palate. No differences in taste thresholds were found between denture wearers and subjects with natural dentition. Smokers had higher thresholds than non-smokers only for salt on the soft palate and the base of the tongue.

NaCl responsive taste cells in the mouse fungiform taste buds.

PubMed

Yoshida, R; Horio, N; Murata, Y; Yasumatsu, K; Shigemura, N; Ninomiya, Y

2009-03-17

Previous studies have demonstrated that rodents' chorda tympani (CT) nerve fibers responding to NaCl can be classified according to their sensitivities to the epithelial sodium channel (ENaC) blocker amiloride into two groups: amiloride-sensitive (AS) and -insensitive (AI). The AS fibers were shown to respond specifically to NaCl, whereas AI fibers broadly respond to various electrolytes, including NaCl. These data suggest that salt taste transduction in taste cells may be composed of at least two different systems; AS and AI ones. To further address this issue, we investigated the responses to NaCl, KCl and HCl and the amiloride sensitivity of mouse fungiform papilla taste bud cells which are innervated by the CT nerve. Comparable with the CT data, the results indicated that 56 NaCl-responsive cells tested were classified into two groups; 25 cells ( approximately 44%) narrowly responded to NaCl and their NaCl response were inhibited by amiloride (AS cells), whereas the remaining 31 cells ( approximately 56%) responded not only to NaCl, but to KCl and/or HCl and showed no amiloride inhibition of NaCl responses (AI cells). Amiloride applied to the basolateral side of taste cells had no effect on NaCl responses in the AS and AI cells. Single cell reverse transcription-polymerase chain reaction (RT-PCR) experiments indicated that ENaC subunit mRNA was expressed in a subset of AS cells. These findings suggest that the mouse fungiform taste bud is composed of AS and AI cells that can transmit taste information differently to their corresponding types of CT fibers, and apical ENaCs may be involved in the NaCl responses of AS cells.

A question of taste.

PubMed

Mitchison, T J

2013-11-01

A career in science is shaped by many factors, one of the most important being our tastes in research. These typically form early and are shaped by subsequent successes and failures. My tastes run to microscopes, chemistry, and spatial organization of cytoplasm. I will try to identify where they came from, how they shaped my career, and how they continue to evolve. My hope is to inspire young scientists to identify and celebrate their own unique tastes.

A question of taste

PubMed Central

Mitchison, T. J.

2013-01-01

A career in science is shaped by many factors, one of the most important being our tastes in research. These typically form early and are shaped by subsequent successes and failures. My tastes run to microscopes, chemistry, and spatial organization of cytoplasm. I will try to identify where they came from, how they shaped my career, and how they continue to evolve. My hope is to inspire young scientists to identify and celebrate their own unique tastes. PMID:24174461

Attitudes toward health and taste of food among women with bulimia nervosa and women of a non-clinical sample.

PubMed

Koritar, Priscila; Philippi, Sonia Tucunduva; Alvarenga, Marle Dos Santos

2017-06-01

Taste preferences and health concerns play important roles in determining eating attitudes, thus influencing food choices. Disordered eating attitudes are common among women, and can lead to the development and maintenance of eating disorders (ED). Attitudes toward health and taste of food among ED patients and its comparison with non-clinical women are not well known, and this knowledge could improve eating interventions. In this study, we compared taste preferences and health concerns in 27 women with diagnosis of bulimia nervosa (BN) and 216 women of a non-clinical sample. All participants completed the Health and Taste Attitude Scale (HTAS). Using analysis of covariance we compared the HTAS scores of the BN patients with those of the college students. Risk behaviors for ED (assessed by the Eating Attitudes Test) were identified in 54 (25%) of the non-clinical sample, all of whom were therefore excluded in comparison of BN patients. Non-clinical sample, compared to patients, scored higher on the HTAS Taste domain (p < 0.001) and its pleasure subscale (p < 0.001), whereas patients scored higher on the HTAS Health domain (p < 0.05) and its light product interest subscale (p < 0.05). Based on our data, eating attitudes of women of non-clinical sample are related to taste and pleasure, whereas women with BN are concerned with adopting a diet regarded as healthy, thus increasing their interest in "light" products. Therefore, the taste and health concerns must be considered in nutrition interventions for women in general, and prevention and treatment of ED as determinants of food choice. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Impact of Pregnancy on Taste Function.

PubMed

Choo, Ezen; Dando, Robin

2017-05-01

It is common for women to report a change in taste (for instance an increased bitter or decreased sweet response) during pregnancy, however specifics of any variation in taste with pregnancy remain elusive. Here we review studies of taste in pregnancy, and discuss how physiological changes occurring during pregnancy may influence taste signaling. We aim to consolidate studies of human pregnancy and "taste function" (studies of taste thresholds, discrimination, and intensity perception, rather than hedonic response or self-report), discussing differences in methodology and findings. Generally, the majority of studies report either no change, or an increase in threshold/decrease in perceived taste intensity, particularly in the early stages of pregnancy, suggesting a possible decrease in taste acuity when pregnant. We further discuss several non-human studies of taste and pregnancy that may extend our understanding. Findings demonstrate that taste buds express receptors for many of the same hormones and circulating factors that vary with pregnancy. Circulating gonadal hormones or other contributions from the endocrine system, as well as physiological changes in weight and immune response could all bear some responsibility for such a modulation of taste during pregnancy. Given our growing understanding of taste, we propose that a change in taste function during pregnancy may not be solely driven by hormonal fluctuations of progesterone and estrogen, as many have suggested. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Rewiring the taste system.

PubMed

Lee, Hojoon; Macpherson, Lindsey J; Parada, Camilo A; Zuker, Charles S; Ryba, Nicholas J P

2017-08-17

In mammals, taste buds typically contain 50-100 tightly packed taste-receptor cells (TRCs), representing all five basic qualities: sweet, sour, bitter, salty and umami. Notably, mature taste cells have life spans of only 5-20 days and, consequently, are constantly replenished by differentiation of taste stem cells. Given the importance of establishing and maintaining appropriate connectivity between TRCs and their partner ganglion neurons (that is, ensuring that a labelled line from sweet TRCs connects to sweet neurons, bitter TRCs to bitter neurons, sour to sour, and so on), we examined how new connections are specified to retain fidelity of signal transmission. Here we show that bitter and sweet TRCs provide instructive signals to bitter and sweet target neurons via different guidance molecules (SEMA3A and SEMA7A). We demonstrate that targeted expression of SEMA3A or SEMA7A in different classes of TRCs produces peripheral taste systems with miswired sweet or bitter cells. Indeed, we engineered mice with bitter neurons that now responded to sweet tastants, sweet neurons that responded to bitter or sweet neurons responding to sour stimuli. Together, these results uncover the basic logic of the wiring of the taste system at the periphery, and illustrate how a labelled-line sensory circuit preserves signalling integrity despite rapid and stochastic turnover of receptor cells.

Rewiring the Taste System

PubMed Central

Lee, Hojoon; Macpherson, Lindsey J.; Parada, Camilo A.; Zuker, Charles S.; Ryba, Nicholas J.P.

2018-01-01

In mammals, taste buds typically contain 50-100 tightly packed taste receptor cells (TRCs) representing all five basic qualities: sweet, sour, bitter, salty and umami1,2. Notably, mature taste cells have life spans of only 5-20 days, and consequently, are constantly replenished by differentiation of taste stem cells3. Given the importance of establishing and maintaining appropriate connectivity between TRCs and their partner ganglion neurons (i.e. ensuring that a labeled line from sweet TRCs connects to sweet neurons, bitter TRCs to bitter neurons, sour to sour, etc.), we examined how new connections are specified to retain fidelity of signal transmission. Our results show that bitter and sweet TRCs provide instructive signals to bitter and sweet target neurons via different guidance molecules (Sema3A and Sema7A)4-6. Here, we demonstrate that targeted expression of Sema3A or Sema7A in different classes of TRCs produce peripheral taste systems with miswired sweet or bitter cells. Indeed, we engineered animals whereby bitter neurons now respond to sweet tastants, sweet neurons respond to bitter, or with sweet neurons responding to sour stimuli. Together, these results uncover the basic logic of the wiring of the taste system at the periphery, and illustrate how a labeled-line sensory circuit preserves signaling integrity despite rapid and stochastic turnover of receptor cells. PMID:28792937

Random-field-induced disordering mechanism in a disordered ferromagnet: Between the Imry-Ma and the standard disordering mechanism

NASA Astrophysics Data System (ADS)

Andresen, Juan Carlos; Katzgraber, Helmut G.; Schechter, Moshe

2017-12-01

Random fields disorder Ising ferromagnets by aligning single spins in the direction of the random field in three space dimensions, or by flipping large ferromagnetic domains at dimensions two and below. While the former requires random fields of typical magnitude similar to the interaction strength, the latter Imry-Ma mechanism only requires infinitesimal random fields. Recently, it has been shown that for dilute anisotropic dipolar systems a third mechanism exists, where the ferromagnetic phase is disordered by finite-size glassy domains at a random field of finite magnitude that is considerably smaller than the typical interaction strength. Using large-scale Monte Carlo simulations and zero-temperature numerical approaches, we show that this mechanism applies to disordered ferromagnets with competing short-range ferromagnetic and antiferromagnetic interactions, suggesting its generality in ferromagnetic systems with competing interactions and an underlying spin-glass phase. A finite-size-scaling analysis of the magnetization distribution suggests that the transition might be first order.

Developing and regenerating a sense of taste.

PubMed

Barlow, Linda A; Klein, Ophir D

2015-01-01

Taste is one of the fundamental senses, and it is essential for our ability to ingest nutritious substances and to detect and avoid potentially toxic ones. Taste buds, which are clusters of neuroepithelial receptor cells, are housed in highly organized structures called taste papillae in the oral cavity. Whereas the overall structure of the taste periphery is conserved in almost all vertebrates examined to date, the anatomical, histological, and cell biological, as well as potentially the molecular details of taste buds in the oral cavity are diverse across species and even among individuals. In mammals, several types of gustatory papillae reside on the tongue in highly ordered arrangements, and the patterning and distribution of the mature papillae depend on coordinated molecular events in embryogenesis. In this review, we highlight new findings in the field of taste development, including how taste buds are patterned and how taste cell fate is regulated. We discuss whether a specialized taste bud stem cell population exists and how extrinsic signals can define which cell lineages are generated. We also address the question of whether molecular regulation of taste cell renewal is analogous to that of taste bud development. Finally, we conclude with suggestions for future directions, including the potential influence of the maternal diet and maternal health on the sense of taste in utero. © 2015 Elsevier Inc. All rights reserved.

Developing and regenerating a sense of taste

PubMed Central

Barlow, Linda A.; Klein, Ophir D.

2015-01-01

Taste is one of the fundamental senses, and it is essential for our ability to ingest nutritious substances and to detect and avoid potentially toxic ones. Taste buds, which are clusters of neuroepithelial receptor cells, are housed in highly organized structures called taste papillae in the oral cavity. Whereas the overall structure of the taste periphery is conserved in almost all vertebrates examined to date, the anatomical, histological, and cell biological, as well as potentially the molecular details of taste buds in the oral cavity are diverse across species and even among individuals. In mammals, several types of gustatory papillae reside on the tongue in highly ordered arrangements, and the patterning and distribution of the mature papillae depends on coordinated molecular events in embryogenesis. In this review, we highlight new findings in the field of taste development, including how taste buds are patterned and how taste cell fate is regulated. We discuss whether a specialized taste bud stem cell population exists and how extrinsic signals can define which cell lineages are generated. We also address the question of whether molecular regulation of taste cell renewal is analogous to that of taste bud development. Finally, we conclude with suggestions for future directions, including the potential influence of the maternal diet and maternal health on the sense of taste in utero. PMID:25662267

Insulin-Like Growth Factors Are Expressed in the Taste System, but Do Not Maintain Adult Taste Buds.

PubMed

Biggs, Bradley T; Tang, Tao; Krimm, Robin F

2016-01-01

Growth factors regulate cell growth and differentiation in many tissues. In the taste system, as yet unknown growth factors are produced by neurons to maintain taste buds. A number of growth factor receptors are expressed at greater levels in taste buds than in the surrounding epithelium and may be receptors for candidate factors involved in taste bud maintenance. We determined that the ligands of eight of these receptors were expressed in the E14.5 geniculate ganglion and that four of these ligands were expressed in the adult geniculate ganglion. Of these, the insulin-like growth factors (IGF1, IGF2) were expressed in the ganglion and their receptor, insulin-like growth factor receptor 1 (IGF1R), were expressed at the highest levels in taste buds. To determine whether IGF1R regulates taste bud number or structure, we conditionally eliminated IGF1R from the lingual epithelium of mice using the keratin 14 (K14) promoter (K14-Cre::Igf1rlox/lox). While K14-Cre::Igf1rlox/lox mice had significantly fewer taste buds at P30 compared with control mice (Igf1rlox/lox), this difference was not observed by P80. IGF1R removal did not affect taste bud size or cell number, and the number of phospholipase C β2- (PLCβ2) and carbonic anhydrase 4- (Car4) positive taste receptor cells did not differ between genotypes. Taste buds at the back of the tongue fungiform taste field were larger and contained more cells than those at the tongue tip, and these differences were diminished in K14-Cre::Igf1rlox/lox mice. The epithelium was thicker at the back versus the tip of the tongue, and this difference was also attenuated in K14-Cre::Igf1rlox/lox mice. We conclude that, although IGFs are expressed at high levels in the taste system, they likely play little or no role in maintaining adult taste bud structure. IGFs have a potential role in establishing the initial number of taste buds, and there may be limits on epithelial thickness in the absence of IGF1R signaling.

Insulin-Like Growth Factors Are Expressed in the Taste System, but Do Not Maintain Adult Taste Buds

PubMed Central

Biggs, Bradley T.; Tang, Tao; Krimm, Robin F.

2016-01-01

Growth factors regulate cell growth and differentiation in many tissues. In the taste system, as yet unknown growth factors are produced by neurons to maintain taste buds. A number of growth factor receptors are expressed at greater levels in taste buds than in the surrounding epithelium and may be receptors for candidate factors involved in taste bud maintenance. We determined that the ligands of eight of these receptors were expressed in the E14.5 geniculate ganglion and that four of these ligands were expressed in the adult geniculate ganglion. Of these, the insulin-like growth factors (IGF1, IGF2) were expressed in the ganglion and their receptor, insulin-like growth factor receptor 1 (IGF1R), were expressed at the highest levels in taste buds. To determine whether IGF1R regulates taste bud number or structure, we conditionally eliminated IGF1R from the lingual epithelium of mice using the keratin 14 (K14) promoter (K14-Cre::Igf1rlox/lox). While K14-Cre::Igf1rlox/lox mice had significantly fewer taste buds at P30 compared with control mice (Igf1rlox/lox), this difference was not observed by P80. IGF1R removal did not affect taste bud size or cell number, and the number of phospholipase C β2- (PLCβ2) and carbonic anhydrase 4- (Car4) positive taste receptor cells did not differ between genotypes. Taste buds at the back of the tongue fungiform taste field were larger and contained more cells than those at the tongue tip, and these differences were diminished in K14-Cre::Igf1rlox/lox mice. The epithelium was thicker at the back versus the tip of the tongue, and this difference was also attenuated in K14-Cre::Igf1rlox/lox mice. We conclude that, although IGFs are expressed at high levels in the taste system, they likely play little or no role in maintaining adult taste bud structure. IGFs have a potential role in establishing the initial number of taste buds, and there may be limits on epithelial thickness in the absence of IGF1R signaling. PMID:26901525

A National Test of Taste and Smell

MedlinePlus

... Javascript on. Feature: Taste, Smell, Hearing, Language, Voice, Balance At Last: A National Test of Taste and ... smell. Read More "Taste, Smell, Hearing, Language, Voice, Balance" Articles At Last: A National Test of Taste ...

Taste of Clindamycin and Acetaminophen.

PubMed

Hashiba, Kimberlee A; Wo, Shane R; Yamamoto, Loren G

2017-02-01

This study evaluated the taste palatability of liquid clindamycin and acetaminophen products on the market. Subjects rated the palatability of 3 clindamycin suspensions, 1 amoxicillin suspension (tasted twice), an acetaminophen elixir, and an acetaminophen suspension in a randomized blinded fashion on a 0 to 5 scale. Forty-six adults aged 20 to 82 years volunteered for this study. Means (and 95% confidence intervals) were as follows: amoxicillin-first taste 3.6 (3.3-3.9), amoxicillin-second taste 3.5 (3.2-3.7). Clindamycin Rising, Perrigo, Greenstone; 2.0 (1.6-2.5), 3.0 (2.7-3.3), and 2.2 (1.8-2.6), respectively. Acetaminophen elixir 0.6 (0.4-0.8) and acetaminophen suspension 3.4 (3.1-3.6). One clindamycin tasted significantly better than the others. Additionally, although 2 acetaminophen formulations are currently available over-the-counter, the suspension is more palatable and less costly. Medicaid drug programs that perpetuate the use of elixir should change their coverage to save money and provide patients access to better tasting acetaminophen.

Oleogustus: The Unique Taste of Fat.

PubMed

Running, Cordelia A; Craig, Bruce A; Mattes, Richard D

2015-09-01

Considerable mechanistic data indicate there may be a sixth basic taste: fat. However, evidence demonstrating that the sensation of nonesterified fatty acids (NEFA, the proposed stimuli for "fat taste") differs qualitatively from other tastes is lacking. Using perceptual mapping, we demonstrate that medium and long-chain NEFA have a taste sensation that is distinct from other basic tastes (sweet, sour, salty, and bitter). Although some overlap was observed between these NEFA and umami taste, this overlap is likely due to unfamiliarity with umami sensations rather than true similarity. Shorter chain fatty acids stimulate a sensation similar to sour, but as chain length increases this sensation changes. Fat taste oral signaling, and the different signals caused by different alkyl chain lengths, may hold implications for food product development, clinical practice, and public health policy. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Stimulus-Dependent Effects of Temperature on Bitter Taste in Humans

PubMed Central

Andrew, Kendra

2017-01-01

This study investigated the effects of temperature on bitter taste in humans. The experiments were conducted within the context of current understanding of the neurobiology of bitter taste and recent evidence of stimulus-dependent effects of temperature on sweet taste. In the first experiment, the bitterness of caffeine and quinine sampled with the tongue tip was assessed at 4 different temperatures (10°, 21°, 30°, and 37 °C) following pre-exposure to the same solution or to water for 0, 3, or 10 s. The results showed that initial bitterness (0-s pre-exposure) followed an inverted U-shaped function of temperature for both stimuli, but the differences across temperature were statistically significant only for quinine. Conversely, temperature significantly affected adaptation to the bitterness of quinine but not caffeine. A second experiment used the same procedure to test 2 additional stimuli, naringin and denatonium benzoate. Temperature significantly affected the initial bitterness of both stimuli but had no effect on adaptation to either stimulus. These results confirm that like sweet taste, temperature affects bitter taste sensitivity and adaptation in stimulus-dependent ways. However, the thermal effect on quinine adaptation, which increased with warming, was opposite to what had been found previously for adaptation to sweetness. The implications of these results are discussed in relation to findings from prior studies of temperature and bitter taste in humans and the possible neurobiological mechanisms of gustatory thermal sensitivity. PMID:28119357

Salt taste adaptation: the psychophysical effects of adapting solutions and residual stimuli from prior tastings on the taste of sodium chloride.

PubMed

O'Mahony, M

1979-01-01

The paper reviews how adaptation to sodium chloride, changing in concentration as a result of various experimental procedures, affects measurements of the sensitivity, intensity, and quality of the salt taste. The development of and evidence for the current model that the salt taste depends on an adaptation level (taste zero) determined by the sodium cation concentration is examined and found to be generally supported, despite great methodological complications. It would seem that lower adaptation levels elicit lower thresholds, higher intensity estimates, and altered quality descriptions with predictable effects on psychophysical measures.

β-Catenin Signaling Biases Multipotent Lingual Epithelial Progenitors to Differentiate and Acquire Specific Taste Cell Fates

PubMed Central

Gaillard, Dany; Xu, Mingang; Liu, Fei; Millar, Sarah E.; Barlow, Linda A.

2015-01-01

Continuous taste bud cell renewal is essential to maintain taste function in adults; however, the molecular mechanisms that regulate taste cell turnover are unknown. Using inducible Cre-lox technology, we show that activation of β-catenin signaling in multipotent lingual epithelial progenitors outside of taste buds diverts daughter cells from a general epithelial to a taste bud fate. Moreover, while taste buds comprise 3 morphological types, β-catenin activation drives overproduction of primarily glial-like Type I taste cells in both anterior fungiform (FF) and posterior circumvallate (CV) taste buds, with a small increase in Type II receptor cells for sweet, bitter and umami, but does not alter Type III sour detector cells. Beta-catenin activation in post-mitotic taste bud precursors likewise regulates cell differentiation; forced activation of β-catenin in these Shh+ cells promotes Type I cell fate in both FF and CV taste buds, but likely does so non-cell autonomously. Our data are consistent with a model where β-catenin signaling levels within lingual epithelial progenitors dictate cell fate prior to or during entry of new cells into taste buds; high signaling induces Type I cells, intermediate levels drive Type II cell differentiation, while low levels may drive differentiation of Type III cells. PMID:26020789

β-Catenin Signaling Biases Multipotent Lingual Epithelial Progenitors to Differentiate and Acquire Specific Taste Cell Fates.

PubMed

Gaillard, Dany; Xu, Mingang; Liu, Fei; Millar, Sarah E; Barlow, Linda A

2015-05-01

Continuous taste bud cell renewal is essential to maintain taste function in adults; however, the molecular mechanisms that regulate taste cell turnover are unknown. Using inducible Cre-lox technology, we show that activation of β-catenin signaling in multipotent lingual epithelial progenitors outside of taste buds diverts daughter cells from a general epithelial to a taste bud fate. Moreover, while taste buds comprise 3 morphological types, β-catenin activation drives overproduction of primarily glial-like Type I taste cells in both anterior fungiform (FF) and posterior circumvallate (CV) taste buds, with a small increase in Type II receptor cells for sweet, bitter and umami, but does not alter Type III sour detector cells. Beta-catenin activation in post-mitotic taste bud precursors likewise regulates cell differentiation; forced activation of β-catenin in these Shh+ cells promotes Type I cell fate in both FF and CV taste buds, but likely does so non-cell autonomously. Our data are consistent with a model where β-catenin signaling levels within lingual epithelial progenitors dictate cell fate prior to or during entry of new cells into taste buds; high signaling induces Type I cells, intermediate levels drive Type II cell differentiation, while low levels may drive differentiation of Type III cells.

TGF-beta3 is expressed in taste buds and inhibits proliferation of primary cultured taste epithelial cells.

PubMed

Nakamura, Shin-ichi; Kawai, Takayuki; Kamakura, Takashi; Ookura, Tetsuya

2010-01-01

Transforming growth factor-betas (TGF-betas), expressed in various tissues, play important roles in embryonic development and adult tissue homeostasis through their effects on cell proliferation, cell differentiation, cell death, and cell motility. However, expression of TGF-beta signaling components and their biological effect on taste epithelia has not been elucidated. We performed expression analysis of TGF-beta signaling components in taste epithelia and found that the TGF-beta3 mRNA was specifically expressed in taste buds. Type II TGF-betas receptor (TbetaR-II) mRNA was specifically expressed in the tongue epithelia including the taste epithelia. To elucidate the biological function of TGF-beta3 in taste epithelia, we performed proliferation assay with primary cultured taste epithelial cells. In the presence of TGF-beta3, percentage of BrdU-labeled cells decreased significantly, suggesting that the TGF-beta3 inhibited the proliferation of cultured taste epithelial cells through inhibiting cell-cycle entry into S phase. By quantitative reverse transcription-polymerase chain reaction assay, we found that the TGF-beta3 resulted in an increased level of expression of p15Ink4b and p21Cip1, suggesting that the TGF-beta3 inhibited the taste epithelial cell proliferation through inhibiting G1cyclin-Cdk complexes. Taken together, these results suggested that the TGF-beta3 may regulate taste epithelial cell homeostasis through controlling cell proliferation.

Gut-expressed gustducin and taste receptors regulate secretion of glucagon-like peptide-1

PubMed Central

Jang, Hyeung-Jin; Kokrashvili, Zaza; Theodorakis, Michael J.; Carlson, Olga D.; Kim, Byung-Joon; Zhou, Jie; Kim, Hyeon Ho; Xu, Xiangru; Chan, Sic L.; Juhaszova, Magdalena; Bernier, Michel; Mosinger, Bedrich; Margolskee, Robert F.; Egan, Josephine M.

2007-01-01

Glucagon-like peptide-1 (GLP-1), released from gut endocrine L cells in response to glucose, regulates appetite, insulin secretion, and gut motility. How glucose given orally, but not systemically, induces GLP-1 secretion is unknown. We show that human duodenal L cells express sweet taste receptors, the taste G protein gustducin, and several other taste transduction elements. Mouse intestinal L cells also express α-gustducin. Ingestion of glucose by α-gustducin null mice revealed deficiencies in secretion of GLP-1 and the regulation of plasma insulin and glucose. Isolated small bowel and intestinal villi from α-gustducin null mice showed markedly defective GLP-1 secretion in response to glucose. The human L cell line NCI-H716 expresses α-gustducin, taste receptors, and several other taste signaling elements. GLP-1 release from NCI-H716 cells was promoted by sugars and the noncaloric sweetener sucralose, and blocked by the sweet receptor antagonist lactisole or siRNA for α-gustducin. We conclude that L cells of the gut “taste” glucose through the same mechanisms used by taste cells of the tongue. Modulating GLP-1 secretion in gut “taste cells” may provide an important treatment for obesity, diabetes and abnormal gut motility. PMID:17724330

A Molecular and Cellular Context-Dependent Role for Ir76b in Detection of Amino Acid Taste.

PubMed

Ganguly, Anindya; Pang, Lisa; Duong, Vi-Khoi; Lee, Angelina; Schoniger, Hanni; Varady, Erika; Dahanukar, Anupama

2017-01-17

Amino acid taste is expected to be a universal property among animals. Although sweet, bitter, salt, and water tastes have been well characterized in insects, the mechanisms underlying amino acid taste remain elusive. From a Drosophila RNAi screen, we identify an ionotropic receptor, Ir76b, as necessary for yeast preference. Using calcium imaging, we identify Ir76b + amino acid taste neurons in legs, overlapping partially with sweet neurons but not those that sense other tastants. Ir76b mutants have reduced responses to amino acids, which are rescued by transgenic expression of Ir76b and a mosquito ortholog AgIr76b. Co-expression of Ir20a with Ir76b is sufficient for conferring amino acid responses in sweet-taste neurons. Notably, Ir20a also serves to block salt response of Ir76b. Our study establishes the role of a highly conserved receptor in amino acid taste and suggests a mechanism for mutually exclusive roles of Ir76b in salt- and amino-acid-sensing neurons. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Radiation-induced taste aversion: effects of radiation exposure level and the exposure-taste interval

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spector, A.C.; Smith, J.C.; Hollander, G.R.

1986-05-01

Radiation-induced taste aversion has been suggested to possibly play a role in the dietary difficulties observed in some radiotherapy patients. In rats, these aversions can still be formed even when the radiation exposure precedes the taste experience by several hours. This study was conducted to examine whether increasing the radiation exposure level could extend the range of the exposure-taste interval that would still support the formation of a taste aversion. Separate groups of rats received either a 100 or 300 R gamma-ray exposure followed 1, 3, 6, or 24 h later by a 10-min saccharin (0.1% w/v) presentation. A controlmore » group received a sham exposure followed 1 h later by a 10-min saccharin presentation. Twenty-four hours following the saccharin presentation all rats received a series of twelve 23-h two-bottle preference tests between saccharin and water. The results indicated that the duration of the exposure-taste interval plays an increasingly more important role in determining the initial extent of the aversion as the dose decreases. The course of recovery from taste aversion seems more affected by dose than by the temporal parameters of the conditioning trial.« less

Expression of synaptogyrin-1 in T1R2-expressing type II taste cells and type III taste cells of rat circumvallate taste buds.

PubMed

Kotani, Takeshi; Toyono, Takashi; Seta, Yuji; Kitou, Ayae; Kataoka, Shinji; Toyoshima, Kuniaki

2013-09-01

Synaptogyrins are conserved components of the exocytic apparatus and function as regulators of Ca(2+)-dependent exocytosis. The synaptogyrin family comprises three isoforms: two neuronal (synaptogyrin-1 and -3) and one ubiquitous (synaptogyrin-2) form. Although the expression patterns of the exocytic proteins synaptotagmin-1, SNAP-25, synaptobrevin-2 and synaptophysin have been elucidated in taste buds, the function and expression pattern of synaptogyrin-1 in rat gustatory tissues have not been determined. Therefore, we examined the expression patterns of synaptogyrin-1 and several cell-specific markers of type II and III cells in rat gustatory tissues. Reverse transcription/polymerase chain reaction assays and immunoblot analysis revealed the expression of synaptogyrin-1 mRNA and its protein in circumvallate papillae. In fungiform, foliate and circumvallate papillae, the antibody against synaptogyrin-1 immunolabeled a subset of taste bud cells and intra- and subgemmal nerve processes. Double-labeling experiments revealed the expression of synaptogyrin-1 in most taste cells immunoreactive for aromatic L-amino acid decarboxylase and the neural cell adhesion molecule. A subset of synaptogyrin-1-immunoreactive taste cells also expressed phospholipase Cβ2, gustducin, or sweet taste receptor (T1R2). In addition, most synaptogyrin-1-immunoreactive taste cells expressed synaptobrevin-2. These results suggest that synaptogyrin-1 plays a regulatory role in transmission at the synapses of type III cells and is involved in exocytic function with synaptobrevin-2 in a subset of type II cells in rat taste buds.

Defense Mechanisms in "Pure" Anxiety and "Pure" Depressive Disorders.

PubMed

Colovic, Olga; Lecic Tosevski, Dusica; Perunicic Mladenovic, Ivana; Milosavljevic, Maja; Munjiza, Ana

2016-10-01

Our study was intended to test whether there are any differences in the way defense mechanisms are used by patients suffering from pure anxiety and those with pure depressive disorders. The sample size was as follows: depressive disorders without psychotic symptoms 30, anxiety disorders 30, and the healthy control group 30. The assessment of defense mechanisms was made using the DSQ-40 questionnaire. Our findings show that "pure" anxiety disorders differ from "pure" depressive disorders only in the use of immature defense mechanisms. The group with depressive disorders was significantly more prone to use immature defense mechanisms than the group with anxiety disorders (p = 0.005), primarily projection (p = 0.001) and devaluation (p = 0.003). These defense mechanisms may therefore be used both to differentiate between anxiety and depressive disorders and also to determine which symptoms (anxiety or depressive disorders) are dominant at any given stage of treatment.

Type III Cells in Anterior Taste Fields Are More Immunohistochemically Diverse Than Those of Posterior Taste Fields in Mice.

PubMed

Wilson, Courtney E; Finger, Thomas E; Kinnamon, Sue C

2017-10-31

Activation of Type III cells in mammalian taste buds is implicated in the transduction of acids (sour) and salty stimuli. Several lines of evidence suggest that function of Type III cells in the anterior taste fields may differ from that of Type III cells in posterior taste fields. Underlying anatomy to support this observation is, however, scant. Most existing immunohistochemical data characterizing this cell type focus on circumvallate taste buds in the posterior tongue. Equivalent data from anterior taste fields-fungiform papillae and soft palate-are lacking. Here, we compare Type III cells in four taste fields: fungiform, soft palate, circumvallate, and foliate in terms of reactivity to four canonical markers of Type III cells: polycystic kidney disease 2-like 1 (PKD2L1), synaptosomal associated protein 25 (SNAP25), serotonin (5-HT), and glutamate decarboxylase 67 (GAD67). Our findings indicate that while PKD2L1, 5-HT, and SNAP25 are highly coincident in posterior taste fields, they diverge in anterior taste fields. In particular, a subset of taste cells expresses PKD2L1 without the synaptic markers, and a subset of SNAP25 cells lacks expression of PKD2L1. In posterior taste fields, GAD67-positive cells are a subset of PKD2L1 expressing taste cells, but anterior taste fields also contain a significant population of GAD67-only expressing cells. These differences in expression patterns may underlie the observed functional differences between anterior and posterior taste fields. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The good taste of peptides.

PubMed

Temussi, Piero A

2012-02-01

The taste of peptides is seldom one of the most relevant issues when one considers the many important biological functions of this class of molecules. However, peptides generally do have a taste, covering essentially the entire range of established taste modalities: sweet, bitter, umami, sour and salty. The last two modalities cannot be attributed to peptides as such because they are due to the presence of charged terminals and/or charged side chains, thus reflecting only the zwitterionic nature of these compounds and/or the nature of some side chains but not the electronic and/or conformational features of a specific peptide. The other three tastes, that is, sweet, umami and bitter, are represented by different families of peptides. This review describes the main peptides with a sweet, umami or bitter taste and their relationship with food acceptance or rejection. Particular emphasis will be given to the sweet taste modality, owing to the practical and scientific relevance of aspartame, the well-known sweetener, and to the theoretical importance of sweet proteins, the most potent peptide sweet molecules. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.

Oral lipase activities and fat-taste receptors for fat-taste sensing in chickens.

PubMed

Kawabata, Yuko; Kawabata, Fuminori; Nishimura, Shotaro; Tabata, Shoji

2018-01-01

It has been reported that a functional fat-taste receptor, GPR120, is present in chicken oral tissues, and that chickens can detect fat taste in a behavioral test. However, although triglycerides need to be digested to free fatty acids to be recognized by fat-taste receptors such as GPR120, it remains unknown whether lipase activities exist in chicken oral tissues. To examine this question, we first cloned another fat-taste receptor candidate gene, CD36, from the chicken palate. Then, using RT-PCR, we determined that GPR120 and CD36 were broadly expressed in chicken oral and gastrointestinal tissues. Also by RT-PCR, we confirmed that several lipase genes were expressed in both oral and gastrointestinal tissues. Finally, we analyzed the lipase activities of oral tissues by using a fluorogenic triglyceride analog as a lipase substrate. We found there are functional lipases in oral tissues as well as in the stomach and pancreas. These results suggested that chickens have a basic fat-taste reception system that incorporates a triglycerides/oral-lipases/free fatty acids/GPR120 axis and CD36 axis. Copyright © 2017 Elsevier Inc. All rights reserved.

Umami the Fifth Basic Taste: History of Studies on Receptor Mechanisms and Role as a Food Flavor

PubMed Central

Kurihara, Kenzo

2015-01-01

Three umami substances (glutamate, 5′-inosinate, and 5′-guanylate) were found by Japanese scientists, but umami has not been recognized in Europe and America for a long time. In the late 1900s, umami was internationally recognized as the fifth basic taste based on psychophysical, electrophysiological, and biochemical studies. Three umami receptors (T1R1 + T1R3, mGluR4, and mGluR1) were identified. There is a synergism between glutamate and the 5′-nucleotides. Among the above receptors, only T1R1 + T1R3 receptor exhibits the synergism. In rats, the response to a mixture of glutamate and 5′-inosinate is about 1.7 times larger than that to glutamate alone. In human, the response to the mixture is about 8 times larger than that to glutamate alone. Since glutamate and 5′-inosinate are contained in various foods, we taste umami induced by the synergism in daily eating. Hence umami taste induced by the synergism is a main umami taste in human. PMID:26247011

Cross-cultural differences in crossmodal correspondences between basic tastes and visual features

PubMed Central

Wan, Xiaoang; Woods, Andy T.; van den Bosch, Jasper J. F.; McKenzie, Kirsten J.; Velasco, Carlos; Spence, Charles

2014-01-01

We report a cross-cultural study designed to investigate crossmodal correspondences between a variety of visual features (11 colors, 15 shapes, and 2 textures) and the five basic taste terms (bitter, salty, sour, sweet, and umami). A total of 452 participants from China, India, Malaysia, and the USA viewed color patches, shapes, and textures online and had to choose the taste term that best matched the image and then rate their confidence in their choice. Across the four groups of participants, the results revealed a number of crossmodal correspondences between certain colors/shapes and bitter, sour, and sweet tastes. Crossmodal correspondences were also documented between the color white and smooth/rough textures on the one hand and the salt taste on the other. Cross-cultural differences were observed in the correspondences between certain colors, shapes, and one of the textures and the taste terms. The taste-patterns shown by the participants from the four countries tested in the present study are quite different from one another, and these differences cannot easily be attributed merely to whether a country is Eastern or Western. These findings therefore highlight the impact of cultural background on crossmodal correspondences. As such, they raise a number of interesting questions regarding the neural mechanisms underlying crossmodal correspondences. PMID:25538643

Cross-cultural differences in crossmodal correspondences between basic tastes and visual features.

PubMed

Wan, Xiaoang; Woods, Andy T; van den Bosch, Jasper J F; McKenzie, Kirsten J; Velasco, Carlos; Spence, Charles

2014-01-01

We report a cross-cultural study designed to investigate crossmodal correspondences between a variety of visual features (11 colors, 15 shapes, and 2 textures) and the five basic taste terms (bitter, salty, sour, sweet, and umami). A total of 452 participants from China, India, Malaysia, and the USA viewed color patches, shapes, and textures online and had to choose the taste term that best matched the image and then rate their confidence in their choice. Across the four groups of participants, the results revealed a number of crossmodal correspondences between certain colors/shapes and bitter, sour, and sweet tastes. Crossmodal correspondences were also documented between the color white and smooth/rough textures on the one hand and the salt taste on the other. Cross-cultural differences were observed in the correspondences between certain colors, shapes, and one of the textures and the taste terms. The taste-patterns shown by the participants from the four countries tested in the present study are quite different from one another, and these differences cannot easily be attributed merely to whether a country is Eastern or Western. These findings therefore highlight the impact of cultural background on crossmodal correspondences. As such, they raise a number of interesting questions regarding the neural mechanisms underlying crossmodal correspondences.

Crystal structure of the sweet-tasting protein thaumatin II at 1.27 A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masuda, Tetsuya, E-mail: t2masuda@kais.kyoto-u.ac.jp; Department Natural Resources, Graduate School of Global Environmental Studies, Kyoto University, Uji, Kyoto 611-0011; Ohta, Keisuke

2011-07-08

Highlights: {yields} X-ray crystallographic structure of sweet-tasting protein, thaumatin II, was determined at a resolution of 1.27 A. {yields} The overall structure of thaumatin II is similar to that of thaumatin I, but a slight shift of the C{alpha} atom of G96 in thaumatin II was observed. {yields} The side chain of two critical residues, 67 and 82, for sweetness was modeled in two alternative conformations. {yields} The flexibility and fluctuation of side chains at 67 and 82 seems to be suitable for interaction of thaumatin molecules with sweet receptors. -- Abstract: Thaumatin, an intensely sweet-tasting protein, elicits a sweetmore » taste sensation at 50 nM. Here the X-ray crystallographic structure of one of its variants, thaumatin II, was determined at a resolution of 1.27 A. Overall structure of thaumatin II is similar to thaumatin I, but a slight shift of the C{alpha} atom of G96 in thaumatin II was observed. Furthermore, the side chain of residue 67 in thaumatin II is highly disordered. Since residue 67 is one of two residues critical to the sweetness of thaumatin, the present results suggested that the critical positive charges at positions 67 and 82 are disordered and the flexibility and fluctuation of these side chains would be suitable for interaction of thaumatin molecules with sweet receptors.« less

The candidate sour taste receptor, PKD2L1, is expressed by type III taste cells in the mouse.

PubMed

Kataoka, Shinji; Yang, Ruibiao; Ishimaru, Yoshiro; Matsunami, Hiroaki; Sévigny, Jean; Kinnamon, John C; Finger, Thomas E

2008-03-01

The transient receptor potential channel, PKD2L1, is reported to be a candidate receptor for sour taste based on molecular biological and functional studies. Here, we investigated the expression pattern of PKD2L1-immunoreactivity (IR) in taste buds of the mouse. PKD2L1-IR is present in a few elongate cells in each taste bud as reported previously. The PKD2L1-expressing cells are different from those expressing PLCbeta2, a marker of Type II cells. Likewise PKD2L1-immunoreactive taste cells do not express ecto-ATPase which marks Type I cells. The PKD2L1-positive cells are immunoreactive for neural cell adhesion molecule, serotonin, PGP-9.5 (ubiquitin carboxy-terminal transferase), and chromogranin A, all of which are present in Type III taste cells. At the ultrastructural level, PKD2L1-immunoreactive cells form synapses onto afferent nerve fibers, another feature of Type III taste cells. These results are consistent with the idea that different taste cells in each taste bud perform distinct functions. We suggest that Type III cells are necessary for transduction and/or transmission of information about "sour", but have little or no role in transmission of taste information of other taste qualities.

The candidate sour taste receptor, PKD2L1, is expressed by type III taste cells in the mouse

PubMed Central

Kataoka, Shinji; Yang, Ruibiao; Ishimaru, Yoshiro; Matsunami, Hiroaki; Kinnamon, John C.; Finger, Thomas E.

2008-01-01

The transient receptor potential (TRP) channel, PKD2L1, is reported to be a candidate receptor for sour taste based on molecular biological and functional studies. Here, we investigated the expression pattern of PKD2L1-immunoreactivity (IR) in taste buds of the mouse. PKD2L1-IR is present in a few elongate cells in each taste bud as reported previously. The PKD2L1-expressing cells are different from those expressing PLCβ2, a marker of Type II cells. Likewise PKD2L1-immunoreactive taste cells do not express ecto-ATPase which marks Type I cells. The PKD2L1 positive cells are immunoreactive for NCAM, serotonin, PGP-9.5 (ubiquitin carboxy terminal transferase) and chromogranin A, all of which are present in Type III taste cells. At the ultrastructural level, PKD2L1-immunoreactive cells form synapses onto afferent nerve fibers, another feature of Type III taste cells. These results are consistent with the idea that different taste cells in each taste bud perform distinct functions. We suggest that Type III cells are necessary for transduction and/or transmission of information about “sour”, but have little or no role in transmission of taste information of other taste qualities. PMID:18156604

Food reward in the absence of taste receptor signaling.

PubMed

de Araujo, Ivan E; Oliveira-Maia, Albino J; Sotnikova, Tatyana D; Gainetdinov, Raul R; Caron, Marc G; Nicolelis, Miguel A L; Simon, Sidney A

2008-03-27

Food palatability and hedonic value play central roles in nutrient intake. However, postingestive effects can influence food preferences independently of palatability, although the neurobiological bases of such mechanisms remain poorly understood. Of central interest is whether the same brain reward circuitry that is responsive to palatable rewards also encodes metabolic value independently of taste signaling. Here we show that trpm5-/- mice, which lack the cellular machinery required for sweet taste transduction, can develop a robust preference for sucrose solutions based solely on caloric content. Sucrose intake induced dopamine release in the ventral striatum of these sweet-blind mice, a pattern usually associated with receipt of palatable rewards. Furthermore, single neurons in this same ventral striatal region showed increased sensitivity to caloric intake even in the absence of gustatory inputs. Our findings suggest that calorie-rich nutrients can directly influence brain reward circuits that control food intake independently of palatability or functional taste transduction.

Fabrication of taste sensor for education

NASA Astrophysics Data System (ADS)

Wu, Xiao; Tahara, Yusuke; Toko, Kiyoshi; Kuriyaki, Hisao

2017-03-01

In order to solve the unconcern to usefulness of learning science among high school students in Japan, we developed a simple fabricated taste sensor with sensitivity and selectivity to each taste quality, which can be applied in science class. A commercialized Teflon membrane was used as the polymer membrane holding lipids. In addition, a non-adhesive method is considered to combine the membrane and the sensor electrode using a plastic cap which is easily accessible. The taste sensor for education fabricated in this way showed a good selectivity and sensitivity. By adjusting the composition of trioctylmethylammonium chloride (TOMA) and phosphoric acid di(2-ethylhexyl) ester (PAEE) included in lipid solution, we improved the selectivity of this simple taste sensor to saltiness and sourness. To verify this taste sensor as a useful science teaching material for science class, we applied this taste sensor into a science class for university students. By comparing the results between the sensory test and the sensor response, humans taste showed the same tendency just as the sensor response, which proved the sensor as a useful teaching material for science class.

Expression and localization of taste receptor genes in the vallate papillae of rats: effect of zinc deficiency.

PubMed

Ikeda, Atsuo; Sekine, Hiroki; Takao, Kyoichi; Ikeda, Minoru

2013-09-01

We found a difference in expression sites between TAS2Rs and ENaC (epithelial sodium channels). The number of TAS2R-positive cells and ENaC-positive cells were decreased in zinc-deficient diet rats. These findings suggest that decreased expression of taste receptor genes may play an important role in the onset of zinc deficiency-associated taste disorder. The present study was aimed at histologically investigating the expression and localization of TAS2Rs and ENaC in the vallate taste buds of rats. Changes in expression of the taste receptor genes in zinc-deficient rats were also investigated. The vallate papillae of five rats fed a normal diet and five rats fed a zinc-deficient diet were used. In situ hybridization was performed to investigate the expression and localization of TAS2Rs and ENaC. TAS2R-positive cells per taste bud were counted, and differences in number between the normal and zinc-deficient diet rats were investigated. In the normal rats, expression of TAS2Rs was observed specifically in the taste bud cells. In contrast, ENaC-positive cells were observed in a part of the taste bud cells and a large number of epithelial cells. Fewer cells were positive for TAS2Rs and ENaC in the zinc-deficient diet rats.

Intravital Microscopic Interrogation of Peripheral Taste Sensation

NASA Astrophysics Data System (ADS)

Choi, Myunghwan; Lee, Woei Ming; Yun, Seok Hyun

2015-03-01

Intravital microscopy is a powerful tool in neuroscience but has not been adapted to the taste sensory organ due to anatomical constraint. Here we developed an imaging window to facilitate microscopic access to the murine tongue in vivo. Real-time two-photon microscopy allowed the visualization of three-dimensional microanatomy of the intact tongue mucosa and functional activity of taste cells in response to topically administered tastants in live mice. Video microscopy also showed the calcium activity of taste cells elicited by small-sized tastants in the blood circulation. Molecular kinetic analysis suggested that intravascular taste sensation takes place at the microvilli on the apical side of taste cells after diffusion of the molecules through the pericellular capillaries and tight junctions in the taste bud. Our results demonstrate the capabilities and utilities of the new tool for taste research in vivo.

Intravital microscopic interrogation of peripheral taste sensation.

PubMed

Choi, Myunghwan; Lee, Woei Ming; Yun, Seok Hyun

2015-03-02

Intravital microscopy is a powerful tool in neuroscience but has not been adapted to the taste sensory organ due to anatomical constraint. Here we developed an imaging window to facilitate microscopic access to the murine tongue in vivo. Real-time two-photon microscopy allowed the visualization of three-dimensional microanatomy of the intact tongue mucosa and functional activity of taste cells in response to topically administered tastants in live mice. Video microscopy also showed the calcium activity of taste cells elicited by small-sized tastants in the blood circulation. Molecular kinetic analysis suggested that intravascular taste sensation takes place at the microvilli on the apical side of taste cells after diffusion of the molecules through the pericellular capillaries and tight junctions in the taste bud. Our results demonstrate the capabilities and utilities of the new tool for taste research in vivo.

Localization of phosphatidylinositol signaling components in rat taste cells: Role in bitter taste transduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, P.M.; Verma, A.; Bredt, D.S.

1990-10-01

To assess the role of phosphatidylinositol turnover in taste transduction we have visualized, in rat tongue, ATP-dependent endoplasmic reticular accumulation of {sup 45}Ca{sup 2+}, inositol 1,4,5-trisphosphate receptor binding sites, and phosphatidylinositol turnover monitored by autoradiography of ({sup 3}H)cytidine diphosphate diacylglycerol formed from ({sup 3}H)cytidine. Accumulated {sup 45}Ca{sup 2+}, inositol 1,4,5-trisphosphate receptors, and phosphatidylinositol turnover are selectively localized to apical areas of the taste buds of circumvallate papillae, which are associated with bitter taste. Further evidence for a role of phosphatidylinositol turnover in bitter taste is our observation of a rapid, selective increase in mass levels of inositol 1,4,5-trisphosphate elicited bymore » low concentrations of denatonium, a potently bitter tastant.« less

Acid-sensing ion channels and transient-receptor potential ion channels in zebrafish taste buds.

PubMed

Levanti, M; Randazzo, B; Viña, E; Montalbano, G; Garcia-Suarez, O; Germanà, A; Vega, J A; Abbate, F

2016-09-01

Sensory information from the environment is required for life and survival, and it is detected by specialized cells which together make up the sensory system. The fish sensory system includes specialized organs that are able to detect mechanical and chemical stimuli. In particular, taste buds are small organs located on the tongue in terrestrial vertebrates that function in the perception of taste. In fish, taste buds occur on the lips, the flanks, and the caudal (tail) fins of some species and on the barbels of others. In fish taste receptor cells, different classes of ion channels have been detected which, like in mammals, presumably participate in the detection and/or transduction of chemical gustatory signals. However, since some of these ion channels are involved in the detection of additional sensory modalities, it can be hypothesized that taste cells sense stimuli other than those specific for taste. This mini-review summarizes current knowledge on the presence of transient-receptor potential (TRP) and acid-sensing (ASIC) ion channels in the taste buds of teleosts, especially adult zebrafish. Up to now ASIC4, TRPC2, TRPA1, TRPV1 and TRPV4 ion channels have been found in the sensory cells, while ASIC2 was detected in the nerves supplying the taste buds. Copyright © 2016 Elsevier GmbH. All rights reserved.

Light and electron microscopic observation of regenerated fungiform taste buds in patients with recovered taste function after severing chorda tympani nerve.

PubMed

Saito, Takehisa; Ito, Tetsufumi; Narita, Norihiko; Yamada, Takechiyo; Manabe, Yasuhiro

2011-11-01

The aim of this study was to evaluate the mean number of regenerated fungiform taste buds per papilla and perform light and electron microscopic observation of taste buds in patients with recovered taste function after severing the chorda tympani nerve during middle ear surgery. We performed a biopsy on the fungiform papillae (FP) in the midlateral region of the dorsal surface of the tongue from 5 control volunteers (33 total FP) and from 7 and 5 patients with and without taste recovery (34 and 29 FP, respectively) 3 years 6 months to 18 years after surgery. The specimens were observed by light and transmission electron microscopy. The taste function was evaluated by electrogustometry. The mean number of taste buds in the FP of patients with completely recovered taste function was significantly smaller (1.9 +/- 1.4 per papilla; p < 0.01) than that of the control subjects (3.8 +/- 2.2 per papilla). By transmission electron microscopy, 4 distinct types of cell (type I, II, III, and basal cells) were identified in the regenerated taste buds. Nerve fibers and nerve terminals were also found in the taste buds. It was clarified that taste buds containing taste cells and nerve endings do regenerate in the FP of patients with recovered taste function.

Taste receptors of the gut: emerging roles in health and disease.

PubMed

Depoortere, Inge

2014-01-01

Recent progress in unravelling the nutrient-sensing mechanisms in the taste buds of the tongue has triggered studies on the existence and role of chemosensory cells in the gut. Indeed, the gastrointestinal tract is the key interface between food and the human body and can sense basic tastes in much the same way as the tongue, through the use of similar G-protein-coupled taste receptors. These receptors 'taste' the luminal content and transmit signals that regulate nutrient transporter expression and nutrient uptake, and also the release of gut hormones and neurotransmitters involved in the regulation of energy and glucose homeostasis. Hence, they play a prominent role in the communication between the lumen, epithelium, smooth muscle cells, afferent nerve fibres and the brain to trigger adaptive responses that affect gastrointestinal function, food intake and glucose metabolism. This review summarises how sensing of nutrients by taste receptors along the gut plays a key role in the process of digestion, and how disturbances or adaptations of these chemosensory signalling pathways may contribute to the induction or resolution of a number of pathological conditions related to diabetes, obesity, or diet-induced symptom generation in irritable bowel syndrome. Targeting these receptors may represent a promising novel route for the treatment of a number of these diseases.

Eating Disorders as Coping Mechanisms

ERIC Educational Resources Information Center

Wagener, Amy M.; Much, Kari

2010-01-01

This article focuses on the complex nature of eating disorders, specifically highlighting their use as coping mechanisms for underlying emotional and psychological concerns. Case examples of college counseling center clients are discussed in order to illustrate common ways in which eating disorders are utilized by clients with varying…

Coevolutionary patterning of teeth and taste buds.

PubMed

Bloomquist, Ryan F; Parnell, Nicholas F; Phillips, Kristine A; Fowler, Teresa E; Yu, Tian Y; Sharpe, Paul T; Streelman, J Todd

2015-11-03

Teeth and taste buds are iteratively patterned structures that line the oro-pharynx of vertebrates. Biologists do not fully understand how teeth and taste buds develop from undifferentiated epithelium or how variation in organ density is regulated. These organs are typically studied independently because of their separate anatomical location in mammals: teeth on the jaw margin and taste buds on the tongue. However, in many aquatic animals like bony fishes, teeth and taste buds are colocalized one next to the other. Using genetic mapping in cichlid fishes, we identified shared loci controlling a positive correlation between tooth and taste bud densities. Genome intervals contained candidate genes expressed in tooth and taste bud fields. sfrp5 and bmper, notable for roles in Wingless (Wnt) and bone morphogenetic protein (BMP) signaling, were differentially expressed across cichlid species with divergent tooth and taste bud density, and were expressed in the development of both organs in mice. Synexpression analysis and chemical manipulation of Wnt, BMP, and Hedgehog (Hh) pathways suggest that a common cichlid oral lamina is competent to form teeth or taste buds. Wnt signaling couples tooth and taste bud density and BMP and Hh mediate distinct organ identity. Synthesizing data from fish and mouse, we suggest that the Wnt-BMP-Hh regulatory hierarchy that configures teeth and taste buds on mammalian jaws and tongues may be an evolutionary remnant inherited from ancestors wherein these organs were copatterned from common epithelium.

Coevolutionary patterning of teeth and taste buds

PubMed Central

Bloomquist, Ryan F.; Parnell, Nicholas F.; Phillips, Kristine A.; Fowler, Teresa E.; Yu, Tian Y.; Sharpe, Paul T.; Streelman, J. Todd

2015-01-01

Teeth and taste buds are iteratively patterned structures that line the oro-pharynx of vertebrates. Biologists do not fully understand how teeth and taste buds develop from undifferentiated epithelium or how variation in organ density is regulated. These organs are typically studied independently because of their separate anatomical location in mammals: teeth on the jaw margin and taste buds on the tongue. However, in many aquatic animals like bony fishes, teeth and taste buds are colocalized one next to the other. Using genetic mapping in cichlid fishes, we identified shared loci controlling a positive correlation between tooth and taste bud densities. Genome intervals contained candidate genes expressed in tooth and taste bud fields. sfrp5 and bmper, notable for roles in Wingless (Wnt) and bone morphogenetic protein (BMP) signaling, were differentially expressed across cichlid species with divergent tooth and taste bud density, and were expressed in the development of both organs in mice. Synexpression analysis and chemical manipulation of Wnt, BMP, and Hedgehog (Hh) pathways suggest that a common cichlid oral lamina is competent to form teeth or taste buds. Wnt signaling couples tooth and taste bud density and BMP and Hh mediate distinct organ identity. Synthesizing data from fish and mouse, we suggest that the Wnt-BMP-Hh regulatory hierarchy that configures teeth and taste buds on mammalian jaws and tongues may be an evolutionary remnant inherited from ancestors wherein these organs were copatterned from common epithelium. PMID:26483492

Exposure to the taste of alcohol elicits activation of the mesocorticolimbic neurocircuitry.

PubMed

Filbey, Francesca M; Claus, Eric; Audette, Amy R; Niculescu, Michelle; Banich, Marie T; Tanabe, Jody; Du, Yiping P; Hutchison, Kent E

2008-05-01

A growing number of imaging studies suggest that alcohol cues, mainly visual, elicit activation in mesocorticolimbic structures. Such findings are consistent with the growing recognition that these structures play an important role in the attribution of incentive salience and the pathophysiology of addiction. The present study investigated whether the presentation of alcohol taste cues can activate brain regions putatively involved in the acquisition and expression of incentive salience. Using functional magnetic resonance imaging, we recorded BOLD activity while delivering alcoholic tastes to 37 heavy drinking but otherwise healthy volunteers. The results yielded a pattern of BOLD activity in mesocorticolimbic structures (ie prefrontal cortex, striatum, ventral tegmental area/substantia nigra) relative to an appetitive control. Further analyses suggested strong connectivity between these structures during cue-elicited urge and demonstrated significant positive correlations with a measure of alcohol use problems (ie the Alcohol Use Disorders Identification Test). Thus, repeated exposure to the taste alcohol in the scanner elicits activation in mesocorticolimbic structures, and this activation is related to measures of urge and severity of alcohol problems.

Exposure to the Taste of Alcohol Elicits Activation of the Mesocorticolimbic Neurocircuitry

PubMed Central

Filbey, Francesca M; Claus, Eric; Audette, Amy R; Niculescu, Michelle; Banich, Marie T; Tanabe, Jody; Du, Yiping P; Hutchison, Kent E

2010-01-01

A growing number of imaging studies suggest that alcohol cues, mainly visual, elicit activation in mesocorticolimbic structures. Such findings are consistent with the growing recognition that these structures play an important role in the attribution of incentive salience and the pathophysiology of addiction. The present study investigated whether the presentation of alcohol taste cues can activate brain regions putatively involved in the acquisition and expression of incentive salience. Using functional magnetic resonance imaging, we recorded BOLD activity while delivering alcoholic tastes to 37 heavy drinking but otherwise healthy volunteers. The results yielded a pattern of BOLD activity in mesocorticolimbic structures (ie prefrontal cortex, striatum, ventral tegmental area/substantia nigra) relative to an appetitive control. Further analyses suggested strong connectivity between these structures during cue-elicited urge and demonstrated significant positive correlations with a measure of alcohol use problems (ie the Alcohol Use Disorders Identification Test). Thus, repeated exposure to the taste alcohol in the scanner elicits activation in mesocorticolimbic structures, and this activation is related to measures of urge and severity of alcohol problems. PMID:17653109

Molecular neurobiology of Drosophila taste

PubMed Central

Freeman, Erica Gene; Dahanukar, Anupama

2015-01-01

Drosophila is a powerful model in which to study the molecular and cellular basis of taste coding. Flies sense tastants via populations of taste neurons that are activated by compounds of distinct categories. The past few years have borne witness to studies that define the properties of taste neurons, identifying functionally distinct classes of sweet and bitter taste neurons that express unique subsets of gustatory receptor (Gr) genes, as well as water, salt, and pheromone sensing neurons that express members of the pickpocket (ppk) or ionotropic receptor (Ir) families. There has also been significant progress in terms of understanding how tastant information is processed and conveyed to higher brain centers, and modulated by prior dietary experience or starvation. PMID:26102453

Diversity in cell motility reveals the dynamic nature of the formation of zebrafish taste sensory organs.

PubMed

Soulika, Marina; Kaushik, Anna-Lila; Mathieu, Benjamin; Lourenço, Raquel; Komisarczuk, Anna Z; Romano, Sebastian Alejo; Jouary, Adrien; Lardennois, Alicia; Tissot, Nicolas; Okada, Shinji; Abe, Keiko; Becker, Thomas S; Kapsimali, Marika

2016-06-01

Taste buds are sensory organs in jawed vertebrates, composed of distinct cell types that detect and transduce specific taste qualities. Taste bud cells differentiate from oropharyngeal epithelial progenitors, which are localized mainly in proximity to the forming organs. Despite recent progress in elucidating the molecular interactions required for taste bud cell development and function, the cell behavior underlying the organ assembly is poorly defined. Here, we used time-lapse imaging to observe the formation of taste buds in live zebrafish larvae. We found that tg(fgf8a.dr17)-expressing cells form taste buds and get rearranged within the forming organs. In addition, differentiating cells move from the epithelium to the forming organs and can be displaced between developing organs. During organ formation, tg(fgf8a.dr17) and type II taste bud cells are displaced in random, directed or confined mode relative to the taste bud they join or by which they are maintained. Finally, ascl1a activity in the 5-HT/type III cell is required to direct and maintain tg(fgf8a.dr17)-expressing cells into the taste bud. We propose that diversity in displacement modes of differentiating cells acts as a key mechanism for the highly dynamic process of taste bud assembly. © 2016. Published by The Company of Biologists Ltd.

Expression and secretion of TNF-α in mouse taste buds: a novel function of a specific subset of type II taste cells.

PubMed

Feng, Pu; Zhao, Hang; Chai, Jinghua; Huang, Liquan; Wang, Hong

2012-01-01

Taste buds are chemosensory structures widely distributed on the surface of the oral cavity and larynx. Taste cells, exposed to the oral environment, face great challenges in defense against potential pathogens. While immune cells, such as T-cells and macrophages, are rarely found in taste buds, high levels of expression of some immune-response-associated molecules are observed in taste buds. Yet, the cellular origins of these immune molecules such as cytokines in taste buds remain to be determined. Here, we show that a specific subset of taste cells selectively expresses high levels of the inflammatory cytokine tumor necrosis factor-α (TNF-α). Based on immuno-colocalization experiments using taste-cell-type markers, the TNF-α-producing cells are predominantly type II taste cells expressing the taste receptor T1R3. These cells can rapidly increase TNF-α production and secretion upon inflammatory challenges, both in vivo and in vitro. The lipopolysaccharide (LPS)-induced TNF-α expression in taste cells was completely eliminated in TLR2(-/-)/TLR4(-/-) double-gene-knockout mice, which confirms that the induction of TNF-α in taste buds by LPS is mediated through TLR signaling pathways. The taste-cell-produced TNF-α may contribute to local immune surveillance, as well as regulate taste sensation under normal and pathological conditions.

Insights on consciousness from taste memory research.

PubMed

Gallo, Milagros

2016-01-01

Taste research in rodents supports the relevance of memory in order to determine the content of consciousness by modifying both taste perception and later action. Associated with this issue is the fact that taste and visual modalities share anatomical circuits traditionally related to conscious memory. This challenges the view of taste memory as a type of non-declarative unconscious memory.

Study of Odours and taste for Space Food

NASA Astrophysics Data System (ADS)

Katayama, Naomi; Space Agriculture Task Force; Nakata, Seiichi; Teranishi, Masaaki; Sone, Michihiko; Nakashima, Tsutomu; Hamajima, Nobuyuki; Ito, Yoshihiro

2012-07-01

The sense of taste and smell come under some kind of influences in the space environment. In the space, the astronaut was changed their food habits from light taste and smell food to like strong taste and smells food. When an astronaut live in the space comes to have weak bone like osteoporosis. It may become the physiologic condition like the old man on the earth. Therefore this study performed fact-finding of the smell and the taste in the old man on the earth as test bed of astronaut in space. Based on this finding, it was intended to predict the taste and the olfactory change of the astronaut in the space. The study included 179 males and 251 females aged 30-90 years in Yakumo Town, Hokkaido, Japan. Odours were tested using a ``standard odours by odour stick identification''method of organoleptic testing. Taste were tested using a ``standard taste by taste disc identification'' method of chemical testing. Correct answers for identification odours consisted of average 6.0±3.0 in male subjects and average 6.9±2.8 in female subjects. Correct answers for identification of sweet taste consisted of 81% males and 87% females, salty taste consisted of 86% males and 91%, sour taste consisted of 75% males and 78% females, bitter taste consisted of 76% males and 88% females. It became clear that overall approximately 20% were in some kind of abnormality in sense of smell and taste. I want to perform the investigation that continued more in future.

The endocrinology of taste receptors

PubMed Central

Santa-Cruz Calvo, Sara; Egan, Josephine M.

2016-01-01

Levels of obesity have reached epidemic proportions on a global scale, which has led to considerable increases in health problems and increased risk of several diseases, including cardiovascular and pulmonary diseases, cancer and diabetes mellitus. People with obesity consume more food than is needed to maintain an ideal body weight, despite the discrimination that accompanies being overweight and the wealth of available information that overconsumption is detrimental to health. The relationship between energy expenditure and energy intake throughout an individual’s lifetime is far more complicated than previously thought. An improved comprehension of the relationships between taste, palatability, taste receptors and hedonic responses to food might lead to increased understanding of the biological underpinnings of energy acquisition, as well as why humans sometimes eat more than is needed and more than we know is healthy. This Review discusses the role of taste receptors in the tongue, gut, pancreas and brain and their hormonal involvement in taste perception, as well as the relationship between taste perception, overeating and the development of obesity. PMID:25707779

The endocrinology of taste receptors.

PubMed

Calvo, Sara Santa-Cruz; Egan, Josephine M

2015-04-01

Levels of obesity have reached epidemic proportions on a global scale, which has led to considerable increases in health problems and increased risk of several diseases, including cardiovascular and pulmonary diseases, cancer and diabetes mellitus. People with obesity consume more food than is needed to maintain an ideal body weight, despite the discrimination that accompanies being overweight and the wealth of available information that overconsumption is detrimental to health. The relationship between energy expenditure and energy intake throughout an individual's lifetime is far more complicated than previously thought. An improved comprehension of the relationships between taste, palatability, taste receptors and hedonic responses to food might lead to increased understanding of the biological underpinnings of energy acquisition, as well as why humans sometimes eat more than is needed and more than we know is healthy. This Review discusses the role of taste receptors in the tongue, gut, pancreas and brain and their hormonal involvement in taste perception, as well as the relationship between taste perception, overeating and the development of obesity.

The science and complexity of bitter taste.

PubMed

Drewnowski, A

2001-06-01

Food choices and eating habits are largely influenced by how foods taste. Without being the dominant taste sensation, bitter taste contributes to the complexity and enjoyment of beverages and foods. Compounds that are perceived as bitter do not share a similar chemical structure. In addition to peptides and salts, bitter compounds in foods may include plant-derived phenols and polyphenols, flavonoids, catechins, and caffeine. Recent studies have shown that humans possess a multitude of bitter taste receptors and that the transduction of bitter taste may differ between one compound and another. Studies of mixture interactions suggest further that bitter compounds suppress or enhance sweet and sour tastes and interact with volatile flavor molecules. Caffeine, a natural ingredient of tea, coffee, and chocolate, has a unique flavor profile. Used as a flavoring agent, it enhances the sensory appeal of beverages. Research developments on the genetics and perception of bitter taste add to our understanding of the role of bitterness in relation to food preference.

Exploring taste hyposensitivity in Japanese senior high school students.

PubMed

Ohnuki, Mari; Shinada, Kayoko; Ueno, Masayuki; Zaitsu, Takashi; Wright, Fredrick Allan Clive; Kawaguchi, Yoko

2012-02-01

The main objective of this study was to investigate the prevalence of taste hyposensitivity and the relationships between sex, oral health status, and eating habits with taste hyposensitivity in Japanese senior high school students. Oral examinations, sweet and salt whole-mouth taste tests, and a questionnaire about eating habits were conducted on 234 senior high school students. Factors affecting taste hyposensitivity were investigated using a multivariate analysis. Sweet-taste hyposensitivity was observed in 7.3% of the students, and salt-taste hyposensitivity in 22.2%. Approximately 3% of the students had both sweet- and salt-taste hyposensitivity, and 22.6% had either sweet- or salt-taste hyposensitivity. In total, 26% had a taste hyposensitivity. There were significant relationships between the intake of instant noodles with sweet-taste hyposensitivity, and the intake of vegetables or isotonic drinks with salt-taste hyposensitivity. There was a significant association between eating habits and taste hyposensitivity in Japanese senior high school students. Taste tests would be a helpful adjunct for students to recognize variations in taste sensitivity, and a questionnaire about their eating habits might provide an effective self-review of their eating habits, and therefore, provide motivation to change. © 2011 Blackwell Publishing Asia Pty Ltd.

The ad-libitum alcohol 'taste test': secondary analyses of potential confounds and construct validity.

PubMed

Jones, Andrew; Button, Emily; Rose, Abigail K; Robinson, Eric; Christiansen, Paul; Di Lemma, Lisa; Field, Matt

2016-03-01

Motivation to drink alcohol can be measured in the laboratory using an ad-libitum 'taste test', in which participants rate the taste of alcoholic drinks whilst their intake is covertly monitored. Little is known about the construct validity of this paradigm. The objective of this study was to investigate variables that may compromise the validity of this paradigm and its construct validity. We re-analysed data from 12 studies from our laboratory that incorporated an ad-libitum taste test. We considered time of day and participants' awareness of the purpose of the taste test as potential confounding variables. We examined whether gender, typical alcohol consumption, subjective craving, scores on the Alcohol Use Disorders Identification Test and perceived pleasantness of the drinks predicted ad-libitum consumption (construct validity). We included 762 participants (462 female). Participant awareness and time of day were not related to ad-libitum alcohol consumption. Males drank significantly more alcohol than females (p < 0.001), and individual differences in typical alcohol consumption (p = 0.04), craving (p < 0.001) and perceived pleasantness of the drinks (p = 0.04) were all significant predictors of ad-libitum consumption. We found little evidence that time of day or participant awareness influenced alcohol consumption. The construct validity of the taste test was supported by relationships between ad-libitum consumption and typical alcohol consumption, craving and pleasantness ratings of the drinks. The ad-libitum taste test is a valid method for the assessment of alcohol intake in the laboratory.

Sugar-activated ion transport in canine lingual epithelium. Implications for sugar taste transduction

PubMed Central

1988-01-01

There is good evidence indicating that ion-transport pathways in the apical regions of lingual epithelial cells, including taste bud cells, may play a role in salt taste reception. In this article, we present evidence that, in the case of the dog, there also exists a sugar- activated ion-transport pathway that is linked to sugar taste transduction. Evidence was drawn from two parallel lines of experiments: (a) ion-transport studies on the isolated canine lingual epithelium, and (b) recordings from the canine chorda tympani. The results in vitro showed that both mono- and disaccharides in the mucosal bath stimulate a dose-dependent increase in the short-circuit current over the concentration range coincident with mammalian sugar taste responses. Transepithelial current evoked by glucose, fructose, or sucrose in either 30 mM NaCl or in Krebs-Henseleit buffer (K-H) was partially blocked by amiloride. Among current carriers activated by saccharides, the current response was greater with Na than with K. Ion flux measurements in K-H during stimulation with 3-O-methylglucose showed that the sugar-evoked current was due to an increase in the Na influx. Ouabain or amiloride reduced the sugar-evoked Na influx without effect on sugar transport as measured with tritiated 3-O-methylglucose. Amiloride inhibited the canine chorda tympani response to 0.5 M NaCl by 70-80% and the response to 0.5 M KCl by approximately 40%. This agreed with the percent inhibition by amiloride of the short-circuit current supported in vitro by NaCl and KCl. Amiloride also partially inhibited the chorda tympani responses to sucrose and to fructose. The results indicate that in the dog: (a) the ion transporter subserving Na taste also subserves part of the response to K, and (b) a sugar-activated, Na- preferring ion-transport system is one mechanism mediating sugar taste transduction. Results in the literature indicate a similar sweet taste mechanism for humans. PMID:3171536

Taste bud cells of adult mice are responsive to Wnt/β-catenin signaling: implications for the renewal of mature taste cells

PubMed Central

Gaillard, Dany; Barlow, Linda A.

2012-01-01

Wnt/β-catenin signaling initiates taste papilla development in mouse embryos, however, its involvement in taste cell turnover in adult mice has not been explored. Here we used the BATGAL reporter mouse model, which carries an engineered allele in which the LacZ gene is expressed in the presence of activated β-catenin, to determine the responsiveness of adult taste bud cells to canonical Wnt signaling. Double immunostaining with markers of differentiated taste cells revealed that a subset of type I, II and III taste cells express β-galactosidase. Using in situ hybridization, we showed that β-catenin activates the transcription of the LacZ gene mainly in intragemmal basal cells that are immature taste cells, identified by their expression of Sonic Hedgehog (Shh). Finally, we showed that β-catenin activity is significantly reduced in taste buds of 25 week-old mice compared to 10 week-old animals. Our data suggest that Wnt/β-catenin signaling may influence taste cell turnover by regulating cell differentiation. Reduced canonical Wnt signaling in older mice could explain in part the loss of taste sensitivity with aging, implicating a possible deficiency in the rate of taste cell renewal. More investigations are now necessary to understand if and how Wnt signaling regulates adult taste cell turnover. PMID:21328519

The Effect of Temperature on Umami Taste

PubMed Central

Alvarado, Cynthia; Andrew, Kendra; Nachtigal, Danielle

2016-01-01

The effect of temperature on umami taste has not been previously studied in humans. Reported here are 3 experiments in which umami taste was measured for monopotassium glutamate (MPG) and monosodium glutamate (MSG) at solution temperatures between 10 and 37 °C. Experiment 1 showed that for subjects sensitive to MPG on the tongue tip, 1) cooling reduced umami intensity whether sampled with the tongue tip or in the whole mouth, but 2) had no effect on the rate of umami adaptation on the tongue tip. Experiment 2 showed that temperature had similar effects on the umami taste of MSG and MPG on the tongue tip but not in the whole mouth, and that contrary to umami taste, cooling to 10 °C increased rather than decreased the salty taste of both stimuli. Experiment 3 was designed to investigate the contribution of the hT1R1–hT1R3 glutamate receptor to the cooling effect on umami taste by using the T1R3 inhibitor lactisole. However, lactisole failed to block the umami taste of MPG at any temperature, which supports prior evidence that lactisole does not block umami taste for all ligands of the hT1R1–hT1R3 receptor. We conclude that temperature can affect sensitivity to the umami and salty tastes of glutamates, but in opposite directions, and that the magnitude of these effects can vary across stimuli and modes of tasting (i.e., whole mouth vs. tongue tip exposures). PMID:27102813

Extinction, Spontaneous Recovery and Renewal of Flavor Preferences Based on Taste-Taste Learning

ERIC Educational Resources Information Center

Diaz, Estrella; De la Casa, L. G.

2011-01-01

This paper presents evidence of extinction, spontaneous recovery and renewal in a conditioned preferences paradigm based on taste-taste associations. More specifically, in three experiments rats exposed to a simultaneous compound of citric acid-saccharin solution showed a preference for the citric solution when the preference was measured with a…

The formation of endoderm-derived taste sensory organs requires a Pax9-dependent expansion of embryonic taste bud progenitor cells.

PubMed

Kist, Ralf; Watson, Michelle; Crosier, Moira; Robinson, Max; Fuchs, Jennifer; Reichelt, Julia; Peters, Heiko

2014-10-01

In mammals, taste buds develop in different regions of the oral cavity. Small epithelial protrusions form fungiform papillae on the ectoderm-derived dorsum of the tongue and contain one or few taste buds, while taste buds in the soft palate develop without distinct papilla structures. In contrast, the endoderm-derived circumvallate and foliate papillae located at the back of the tongue contain a large number of taste buds. These taste buds cluster in deep epithelial trenches, which are generated by intercalating a period of epithelial growth between initial placode formation and conversion of epithelial cells into sensory cells. How epithelial trench formation is genetically regulated during development is largely unknown. Here we show that Pax9 acts upstream of Pax1 and Sox9 in the expanding taste progenitor field of the mouse circumvallate papilla. While a reduced number of taste buds develop in a growth-retarded circumvallate papilla of Pax1 mutant mice, its development arrests completely in Pax9-deficient mice. In addition, the Pax9 mutant circumvallate papilla trenches lack expression of K8 and Prox1 in the taste bud progenitor cells, and gradually differentiate into an epidermal-like epithelium. We also demonstrate that taste placodes of the soft palate develop through a Pax9-dependent induction. Unexpectedly, Pax9 is dispensable for patterning, morphogenesis and maintenance of taste buds that develop in ectoderm-derived fungiform papillae. Collectively, our data reveal an endoderm-specific developmental program for the formation of taste buds and their associated papilla structures. In this pathway, Pax9 is essential to generate a pool of taste bud progenitors and to maintain their competence towards prosensory cell fate induction.

Intracellular acidification is required for full activation of the sweet taste receptor by miraculin

PubMed Central

Sanematsu, Keisuke; Kitagawa, Masayuki; Yoshida, Ryusuke; Nirasawa, Satoru; Shigemura, Noriatsu; Ninomiya, Yuzo

2016-01-01

Acidification of the glycoprotein, miraculin (MCL), induces sweet taste in humans, but not in mice. The sweet taste induced by MCL is more intense when acidification occurs with weak acids as opposed to strong acids. MCL interacts with the human sweet receptor subunit hTAS1R2, but the mechanisms by which the acidification of MCL activates the sweet taste receptor remain largely unexplored. The work reported here speaks directly to this activation by utilizing a sweet receptor TAS1R2 + TAS1R3 assay. In accordance with previous data, MCL-applied cells displayed a pH dependence with citric acid (weak acid) being right shifted to that with hydrochloric acid (strong acid). When histidine residues in both the intracellular and extracellular region of hTAS1R2 were exchanged for alanine, taste-modifying effect of MCL was reduced or abolished. Stronger intracellular acidification of HEK293 cells was induced by citric acid than by HCl and taste-modifying effect of MCL was proportional to intracellular pH regardless of types of acids. These results suggest that intracellular acidity is required for full activation of the sweet taste receptor by MCL. PMID:26960429

Expression and Secretion of TNF-α in Mouse Taste Buds: A Novel Function of a Specific Subset of Type II Taste Cells

PubMed Central

Feng, Pu; Zhao, Hang; Chai, Jinghua; Huang, Liquan; Wang, Hong

2012-01-01

Taste buds are chemosensory structures widely distributed on the surface of the oral cavity and larynx. Taste cells, exposed to the oral environment, face great challenges in defense against potential pathogens. While immune cells, such as T-cells and macrophages, are rarely found in taste buds, high levels of expression of some immune-response-associated molecules are observed in taste buds. Yet, the cellular origins of these immune molecules such as cytokines in taste buds remain to be determined. Here, we show that a specific subset of taste cells selectively expresses high levels of the inflammatory cytokine tumor necrosis factor-α (TNF-α). Based on immuno-colocalization experiments using taste-cell-type markers, the TNF-α-producing cells are predominantly type II taste cells expressing the taste receptor T1R3. These cells can rapidly increase TNF-α production and secretion upon inflammatory challenges, both in vivo and in vitro. The lipopolysaccharide (LPS)-induced TNF-α expression in taste cells was completely eliminated in TLR2−/−/TLR4−/− double-gene-knockout mice, which confirms that the induction of TNF-α in taste buds by LPS is mediated through TLR signaling pathways. The taste-cell-produced TNF-α may contribute to local immune surveillance, as well as regulate taste sensation under normal and pathological conditions. PMID:22905218

An investigation into the mechanisms of drug release from taste-masking fatty acid microspheres.

PubMed

Qi, Sheng; Deutsch, David; Craig, Duncan Q M

2008-09-01

Fatty acid microspheres based on stearic and palmitic acids are known to form effective taste masking systems, although the mechanisms by which the drug is preferentially released in the lower gastrointestinal tract are not known. The objective of the present study was to identify the mechanisms involved, with a particular view to clarify the role of acid soap formation in the dissolution process. Microspheres were prepared by a spray chilling process. Using benzoic acid as a model drug and an alkaline dissolution medium, a faster drug release was observed in the mixed fatty acid formulation (50:50 stearic:palmitic acid (w/w)) compared to the single fatty acid component systems. Thermal and powder X-ray diffraction studies indicated a greater degree of acid soap formation for the mixed formulation in alkaline media compared to the single fatty acid systems. Particle size and porosity studies indicated a modest reduction in size for the mixed systems and an increase in porosity on immersion in the dissolution medium. It is proposed that the mixed fatty acid system form a mixed crystal system which in turn facilitates interaction with the dissolution medium, thereby leading to a greater propensity for acid soap formation which in turn forms a permeable liquid crystalline phase through which the drug may diffuse. The role of dissolution of palmitic acid into the dissolution medium is also discussed as a secondary mechanism.

Finite-temperature mechanical instability in disordered lattices.

PubMed

Zhang, Leyou; Mao, Xiaoming

2016-02-01

Mechanical instability takes different forms in various ordered and disordered systems and little is known about how thermal fluctuations affect different classes of mechanical instabilities. We develop an analytic theory involving renormalization of rigidity and coherent potential approximation that can be used to understand finite-temperature mechanical stabilities in various disordered systems. We use this theory to study two disordered lattices: a randomly diluted triangular lattice and a randomly braced square lattice. These two lattices belong to two different universality classes as they approach mechanical instability at T=0. We show that thermal fluctuations stabilize both lattices. In particular, the triangular lattice displays a critical regime in which the shear modulus scales as G∼T(1/2), whereas the square lattice shows G∼T(2/3). We discuss generic scaling laws for finite-T mechanical instabilities and relate them to experimental systems.

Human sweet taste receptor mediates acid-induced sweetness of miraculin

PubMed Central

Koizumi, Ayako; Tsuchiya, Asami; Nakajima, Ken-ichiro; Ito, Keisuke; Terada, Tohru; Shimizu-Ibuka, Akiko; Briand, Loïc; Asakura, Tomiko; Misaka, Takumi; Abe, Keiko

2011-01-01

Miraculin (MCL) is a homodimeric protein isolated from the red berries of Richadella dulcifica. MCL, although flat in taste at neutral pH, has taste-modifying activity to convert sour stimuli to sweetness. Once MCL is held on the tongue, strong sweetness is sensed over 1 h each time we taste a sour solution. Nevertheless, no molecular mechanism underlying the taste-modifying activity has been clarified. In this study, we succeeded in quantitatively evaluating the acid-induced sweetness of MCL using a cell-based assay system and found that MCL activated hT1R2-hT1R3 pH-dependently as the pH decreased from 6.5 to 4.8, and that the receptor activation occurred every time an acid solution was applied. Although MCL per se is sensory-inactive at pH 6.7 or higher, it suppressed the response of hT1R2-hT1R3 to other sweeteners at neutral pH and enhanced the response at weakly acidic pH. Using human/mouse chimeric receptors and molecular modeling, we revealed that the amino-terminal domain of hT1R2 is required for the response to MCL. Our data suggest that MCL binds hT1R2-hT1R3 as an antagonist at neutral pH and functionally changes into an agonist at acidic pH, and we conclude this may cause its taste-modifying activity. PMID:21949380

Taste Receptor Cells That Discriminate Between Bitter Stimuli

PubMed Central

Caicedo, Alejandro; Roper, Stephen D.

2013-01-01

Recent studies showing that single taste bud cells express multiple bitter taste receptors have reignited a long-standing controversy over whether single gustatory receptor cells respond selectively or broadly to tastants. We examined calcium responses of rat taste receptor cells in situ to a panel of bitter compounds to determine whether individual cells distinguish between bitter stimuli. Most bitter-responsive taste cells were activated by only one out of five compounds tested. In taste cells that responded to multiple stimuli, there were no significant associations between any two stimuli. Bitter sensation does not appear to occur through the activation of a homogeneous population of broadly tuned bitter-sensitive taste cells. Instead, different bitter stimuli may activate different subpopulations of bitter-sensitive taste cells. PMID:11222863

Taste bud cells of adult mice are responsive to Wnt/β-catenin signaling: implications for the renewal of mature taste cells.

PubMed

Gaillard, Dany; Barlow, Linda A

2011-04-01

Wnt/β-catenin signaling initiates taste papilla development in mouse embryos, however, its involvement in taste cell turnover in adult mice has not been explored. Here we used the BATGAL reporter mouse model, which carries an engineered allele in which the LacZ gene is expressed in the presence of activated β-catenin, to determine the responsiveness of adult taste bud cells to canonical Wnt signaling. Double immunostaining with markers of differentiated taste cells revealed that a subset of Type I, II, and III taste cells express β-galactosidase. Using in situ hybridization, we showed that β-catenin activates the transcription of the LacZ gene mainly in intragemmal basal cells that are immature taste cells, identified by their expression of Sonic Hedgehog (Shh). Finally, we showed that β-catenin activity is significantly reduced in taste buds of 25-week-old mice compared with 10-week-old animals. Our data suggest that Wnt/β-catenin signaling may influence taste cell turnover by regulating cell differentiation. Reduced canonical Wnt signaling in older mice could explain in part the loss of taste sensitivity with aging, implicating a possible deficiency in the rate of taste cell renewal. More investigations are now necessary to understand if and how Wnt signaling regulates adult taste cell turnover. Copyright © 2011 Wiley-Liss, Inc.

Taste changing in staggered quarks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quentin Mason et al.

2004-01-05

The authors present results from a systematic perturbative investigation of taste-changing in improved staggered quarks. They show one-loop taste-changing interactions can be removed perturbatively by an effective four-quark term and calculate the necessary coefficients.

Differences in taste between two polyethylene glycol preparations.

PubMed

Szojda, Maria M; Mulder, Chris J J; Felt-Bersma, Richelle J F

2007-12-01

Polyethylene glycol preparations (PEG) are increasingly used for chronic constipation in both adults and children. There are some suggestions that PEG 4000 with orange flavour (Forlax) tastes better than PEG 3350 which contains salt (Movicolon). Poor taste is an important factor for non-compliance and is one of the leading causes of therapy failure. The aim of the study was to compare the taste of two commonly used PEG preparations, PEG 4000 and PEG 3350. A double-blind, cross over randomised trial. A hundred people were recruited by advertisement. All tasted both preparations without swallowing and after tasting each of the preparations, they rinsed their mouths. Then a score, on a 5-point scale, was given for both preparations. 100 volunteers were included (27 males and 73 females, mean age 36). The taste score for PEG 4000 (mean 3.9, SD 0.7) was significantly better than for PEG 3350 (mean 2.7, SD 0.7) (p<0.0001, Wilcoxon matched pairs test). No difference in gender or age was observed. The volunteers which tasted PEG 3350 liked it more, when they tasted it first rather than when they tasted it after PEG 4000 (p<0.0001). The order in which volunteers tested PEG 4000 had no influence on the taste results. PEG 4000 tastes better than PEG 3350. This may have implications for patient compliance and effectiveness of treatment in patients with chronic constipation.

Voltage-gated sodium channels in taste bud cells.

PubMed

Gao, Na; Lu, Min; Echeverri, Fernando; Laita, Bianca; Kalabat, Dalia; Williams, Mark E; Hevezi, Peter; Zlotnik, Albert; Moyer, Bryan D

2009-03-12

Taste bud cells transmit information regarding the contents of food from taste receptors embedded in apical microvilli to gustatory nerve fibers innervating basolateral membranes. In particular, taste cells depolarize, activate voltage-gated sodium channels, and fire action potentials in response to tastants. Initial cell depolarization is attributable to sodium influx through TRPM5 in sweet, bitter, and umami cells and an undetermined cation influx through an ion channel in sour cells expressing PKD2L1, a candidate sour taste receptor. The molecular identity of the voltage-gated sodium channels that sense depolarizing signals and subsequently initiate action potentials coding taste information to gustatory nerve fibers is unknown. We describe the molecular and histological expression profiles of cation channels involved in electrical signal transmission from apical to basolateral membrane domains. TRPM5 was positioned immediately beneath tight junctions to receive calcium signals originating from sweet, bitter, and umami receptor activation, while PKD2L1 was positioned at the taste pore. Using mouse taste bud and lingual epithelial cells collected by laser capture microdissection, SCN2A, SCN3A, and SCN9A voltage-gated sodium channel transcripts were expressed in taste tissue. SCN2A, SCN3A, and SCN9A were expressed beneath tight junctions in subsets of taste cells. SCN3A and SCN9A were expressed in TRPM5 cells, while SCN2A was expressed in TRPM5 and PKD2L1 cells. HCN4, a gene previously implicated in sour taste, was expressed in PKD2L1 cells and localized to cell processes beneath the taste pore. SCN2A, SCN3A and SCN9A voltage-gated sodium channels are positioned to sense initial depolarizing signals stemming from taste receptor activation and initiate taste cell action potentials. SCN2A, SCN3A and SCN9A gene products likely account for the tetrodotoxin-sensitive sodium currents in taste receptor cells.

Decreased expression of CD36 in circumvallate taste buds of high-fat diet induced obese rats.

PubMed

Zhang, Xiao-Juan; Zhou, Li-Hong; Ban, Xiang; Liu, Dian-Xin; Jiang, Wei; Liu, Xiao-Min

2011-10-01

Mammals spontaneously prefer lipid rich foods. Overconsumption of high-fat diet leads to obesity and related diseases. Recent findings indicate that taste may participate in the orosensory perception of dietary lipids and the fatty taste may contribute to a preference for and excessive consumption of dietary fat. CD36, a trans-membrane glycoprotein, which is located in the taste buds of circumvallate papillae of rodents, appears to be a plausible receptor for this fatty taste. Obese subjects present a stronger preference for fatty foods, though the mechanisms involved are complex and are not fully investigated. Our data from immunofluorescence and real-time RT-PCR showed that the expression levels of CD36 in circumvallate taste buds were significantly lower in high-fat diet induced obese rats as compared with that of control rats fed a normal diet. These results suggest that decreased expression of CD36 in circumvallate taste buds of high-fat diet induced obese rats may be associated with diminished fatty taste sensitivity and in order to compensate the preference for dietary fat, rats consume more fatty foods. Therapeutic strategies designed to alter or manipulate CD36 expression or function in taste buds may have important implications in treating obesity and related diseases. Copyright © 2010 Elsevier GmbH. All rights reserved.

Taste cell-expressed α-glucosidase enzymes contribute to gustatory responses to disaccharides

PubMed Central

Sukumaran, Sunil K.; Yee, Karen K.; Iwata, Shusuke; Kotha, Ramana; Quezada-Calvillo, Roberto; Nichols, Buford L.; Mohan, Sankar; Pinto, B. Mario; Shigemura, Noriatsu; Ninomiya, Yuzo; Margolskee, Robert F.

2016-01-01

The primary sweet sensor in mammalian taste cells for sugars and noncaloric sweeteners is the heteromeric combination of type 1 taste receptors 2 and 3 (T1R2+T1R3, encoded by Tas1r2 and Tas1r3 genes). However, in the absence of T1R2+T1R3 (e.g., in Tas1r3 KO mice), animals still respond to sugars, arguing for the presence of T1R-independent detection mechanism(s). Our previous findings that several glucose transporters (GLUTs), sodium glucose cotransporter 1 (SGLT1), and the ATP-gated K+ (KATP) metabolic sensor are preferentially expressed in the same taste cells with T1R3 provides a potential explanation for the T1R-independent detection of sugars: sweet-responsive taste cells that respond to sugars and sweeteners may contain a T1R-dependent (T1R2+T1R3) sweet-sensing pathway for detecting sugars and noncaloric sweeteners, as well as a T1R-independent (GLUTs, SGLT1, KATP) pathway for detecting monosaccharides. However, the T1R-independent pathway would not explain responses to disaccharide and oligomeric sugars, such as sucrose, maltose, and maltotriose, which are not substrates for GLUTs or SGLT1. Using RT-PCR, quantitative PCR, in situ hybridization, and immunohistochemistry, we found that taste cells express multiple α-glycosidases (e.g., amylase and neutral α glucosidase C) and so-called intestinal “brush border” disaccharide-hydrolyzing enzymes (e.g., maltase-glucoamylase and sucrase-isomaltase). Treating the tongue with inhibitors of disaccharidases specifically decreased gustatory nerve responses to disaccharides, but not to monosaccharides or noncaloric sweeteners, indicating that lingual disaccharidases are functional. These taste cell-expressed enzymes may locally break down dietary disaccharides and starch hydrolysis products into monosaccharides that could serve as substrates for the T1R-independent sugar sensing pathways. PMID:27162343

Relation between acute and late irradiation impairment of four basic tastes and irradiated tongue volume in patients with head-and-neck cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamashita, Hideomi; Nakagawa, Keiichi; Nakamura, Naoki

2006-12-01

Purpose: Taste loss is a major cause of morbidity in patients undergoing head-and-neck irradiation. The relationship between the time course and the degree of taste disorder was studied in both acute and late phases. Methods and Materials: Taste ability was measured by the taste threshold for the four basic tastes using a filter paper disc method in patients before, during, and after radiotherapy. The subjects were divided into two groups. In Group A, Radiation fields included most of the tongue (n = 100), and in Group B Radiation fields did not include the tip of the tongue (n = 18).more » Results: In Group A, there was a significant impairment of the threshold of all four basic tastes at 3 weeks after starting radiotherapy (RT), and this impairment remained at 8 weeks (p < 0.05). This was not seen in Group B. In Group A, there was no significant difference in the patterns of taste sensitivity change between the high-dose (>20 Gy) and low-dose ({<=}20 Gy) groups. In the late phase, recovery of taste loss was seen in both groups since 4 months after completing RT. Conclusions: Unless the anterior part of the tongue was irradiated, taste loss was not observed during RT. When the anterior part of the tongue was irradiated, a difference by radiation dose was not observed in the taste loss pattern. Additionally, radiation-induced taste dysfunction appears to be a temporal effect.« less

Role of the area postrema in radiation-induced taste aversion learning and emesis in cats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rabin, B.M.; Hunt, W.A.; Chedester, A.L.

1986-01-01

The role of the area postrema in radiation-induced emesis and taste aversion learning and the relationship between these behaviors were studied in cats. The potential involvement of neural factors which might be independent of the area postrema was minimized by using low levels of ionizing radiation (100 rads at a dose rate of 40 rads/min) to elicit a taste aversion, and by using body-only exposures (4500 and 6000 rads at 450 rads/min) to produce emesis. Lesions of the area postrema disrupted both taste aversion learning and emesis following irradiation. These results, which indicate that the area postrema is involved inmore » the mediation of both radiation-induced emesis and taste aversion learning in cats under these experimental conditions, are interpreted as being consistent with the hypotheses that similar mechanisms mediate both responses to exposure to ionizing radiation, and that the taste aversion learning paradigm can therefore serve as a model system for studying radiation-induced emesis.« less

Relationship between umami taste acuity with sweet or bitter taste acuity and food selection in Japanese women university students.

PubMed

Kubota, Masaru; Toda, Chikako; Nagai-Moriyama, Ayako

2018-01-01

Although there are many studies on the umami receptor and its signaling pathway, literature on the effect of umami taste acuity on dietary choices in healthy subjects is limited. The current study aims to clarify the relationship between umami taste acuity with sweet or bitter taste acuity, food preference and intake. Forty-two healthy Japanese female university students were enrolled. The acuity for umami, sweet, and bitter tastes was evaluated using the filter-paper disc method. The study population was divided into 32 umami normal tasters and 10 hypo-tasters based on the taste acuity at the posterior part of the tongue using monosodium glutamate. Umami hypo-tasters exhibited a significantly lower sensitivity to sweet tastes than normal tasters. However, the sensitivity to bitter taste was comparable between the two groups. Food preference was examined by the food preference checklist consisted of 81 food items. Among them, umami tasters preferred shellfish, tomato, carrot, milk, low fat milk, cheese, dried shiitake, and kombu significantly more than umami hypo-tasters did. A self-reported food frequency questionnaire revealed no significant differences in the intake of calories and three macronutrients between the two groups; however, umami tasters were found to eat more seaweeds and less sugar than umami hypo-tasters. These data together may indicate the possibility that umami taste acuity has an effect on a dietary life. Therefore, training umami taste acuity from early childhood is important for a healthy diet later in life.

[Influence of a high-carbohydrate meal on taste perception].

PubMed

Suchecka, Wanda; Klimacka-Nawrot, Ewa; Gałazka, Andrzej; Hartman, Magdalena; Błońska-Fajfrowska, Barbara

2011-01-01

Taste sensitivity varies greatly in individuals and depends on many external and metabolic conditions. The studied group consisted of healthy, non-smoking 41 women and 40 men, aged 19-29. The volunteers were examined in fasting state and after a high-carbohydrate meal. Taste sensitivity to sweet, salty and sour as well as hedonic response to taste were examined by means of gustometry examination recommended by Polski Komitet Normalizacyjny (Polish Committee for Standardization). It has been shown that in women the meal did not influence the intensity of sweet taste perception of saccharose solutions or the hedonic response to taste, whereas in men it caused a statistically significant decrease in the intensity of taste perception and in the hedonic response to the sweet taste of suprathreshold saccharose solutions. The meal did not influence the salty taste perception in a statistically significant way, neither in men nor in women. After the meal, the women perceived the sour taste with more intensity than in fasting state, whereas in men such influence was not observed. 1. The consumption of a high-carbohydrate meal influences the sweet and sour taste perception and the effect is sex-dependent: - in men, both the taste sensitivity to saccharose and the hedonic response to sweet taste were decreased, whereas in women such influence was not observed; - in women, the taste sensitivity to citric acid increased and the hedonic response to sour taste decreased, whereas in men such influence was not observed. 2. There is negative correlation between the intensity of taste perception and the hedonic response to the sweet taste both in men and in women after a high-carbohydrate meal, whereas in fasting state such correlation was not observed.

Bacterial D-Amino Acids Suppress Sinonasal Innate Immunity Through Sweet Taste Receptors in Solitary Chemosensory Cells

PubMed Central

Lee, Robert J.; Hariri, Benjamin M.; McMahon, Derek B.; Chen, Bei; Doghramjii, Laurel; Adappa, Nithin D.; Palmer, James N.; Kennedy, David W.; Jiang, Peihua; Margolskee, Robert F.; Cohen, Noam A.

2017-01-01

In the upper respiratory epithelium, bitter and sweet taste receptors present in solitary chemosensory cells influence antimicrobial innate immune defense responses. Whereas activation of the bitter taste receptor (T2R) stimulates surrounding epithelial cells to release antimicrobial peptides, activation of the sweet taste receptor (T1R) in the same cells inhibits this response. It is thought that this mechanism exists to control the magnitude of antimicrobial peptide release based upon the sugar content of airway surface liquid. We hypothesized that D-amino acids, which are produced by various bacteria and activate T1R in taste receptor cells in the mouth, may also activate T1R in the airway. Here, we show that both the T1R2 and T1R3 subunits of the sweet taste receptor (T1R2/3) are present in the same chemosensory cells of primary human sinonasal epithelial cultures. Respiratory isolates of Staphylococcus species, but not Pseudomonas aeruginosa, produced at least two D-amino acids that activate the sweet taste receptor. In addition to inhibiting P. aeruginosa biofilm formation, D-amino acids derived from Staphylococcus inhibited T2R-mediated signaling and defensin secretion in sinonasal cells by activating T1R2/3. D-amino acid–mediated activation of T1R2/3 also enhanced epithelial cell death during challenge with Staphylococcus aureus in the presence of the bitter-receptor–activating compound denatonium benzoate. These data establish a potential mechanism for interkingdom signaling in the airway mediated by bacterial D-amino acids and the mammalian sweet taste receptor in airway chemosensory cells. PMID:28874606

Biomimetic Sensors for the Senses: Towards Better Understanding of Taste and Odor Sensation.

PubMed

Wu, Chunsheng; Du, Ya-Wen; Huang, Liquan; Ben-Shoshan Galeczki, Yaron; Dagan-Wiener, Ayana; Naim, Michael; Niv, Masha Y; Wang, Ping

2017-12-11

Taste and smell are very important chemical senses that provide indispensable information on food quality, potential mates and potential danger. In recent decades, much progress has been achieved regarding the underlying molecular and cellular mechanisms of taste and odor senses. Recently, biosensors have been developed for detecting odorants and tastants as well as for studying ligand-receptor interactions. This review summarizes the currently available biosensing approaches, which can be classified into two main categories: in vitro and in vivo approaches. The former is based on utilizing biological components such as taste and olfactory tissues, cells and receptors, as sensitive elements. The latter is dependent on signals recorded from animals' signaling pathways using implanted microelectrodes into living animals. Advantages and disadvantages of these two approaches, as well as differences in terms of sensing principles and applications are highlighted. The main current challenges, future trends and prospects of research in biomimetic taste and odor sensors are discussed.

Biomimetic Sensors for the Senses: Towards Better Understanding of Taste and Odor Sensation

PubMed Central

Wu, Chunsheng; Du, Ya-Wen; Huang, Liquan; Ben-Shoshan Galeczki, Yaron; Dagan-Wiener, Ayana; Naim, Michael; Wang, Ping

2017-01-01

Taste and smell are very important chemical senses that provide indispensable information on food quality, potential mates and potential danger. In recent decades, much progress has been achieved regarding the underlying molecular and cellular mechanisms of taste and odor senses. Recently, biosensors have been developed for detecting odorants and tastants as well as for studying ligand-receptor interactions. This review summarizes the currently available biosensing approaches, which can be classified into two main categories: in vitro and in vivo approaches. The former is based on utilizing biological components such as taste and olfactory tissues, cells and receptors, as sensitive elements. The latter is dependent on signals recorded from animals’ signaling pathways using implanted microelectrodes into living animals. Advantages and disadvantages of these two approaches, as well as differences in terms of sensing principles and applications are highlighted. The main current challenges, future trends and prospects of research in biomimetic taste and odor sensors are discussed. PMID:29232897

Leptin suppresses sweet taste responses of enteroendocrine STC-1 cells.

PubMed

Jyotaki, Masafumi; Sanematsu, Keisuke; Shigemura, Noriatsu; Yoshida, Ryusuke; Ninomiya, Yuzo

2016-09-22

Leptin is an important hormone that regulates food intake and energy homeostasis by acting on central and peripheral targets. In the gustatory system, leptin is known to selectively suppress sweet responses by inhibiting the activation of sweet sensitive taste cells. Sweet taste receptor (T1R2+T1R3) is also expressed in gut enteroendocrine cells and contributes to nutrient sensing, hormone release and glucose absorption. Because of the similarities in expression patterns between enteroendocrine and taste receptor cells, we hypothesized that they may also share similar mechanisms used to modify/regulate the sweet responsiveness of these cells by leptin. Here, we used mouse enteroendocrine cell line STC-1 and examined potential effect of leptin on Ca(2+) responses of STC-1 cells to various taste compounds. Ca(2+) responses to sweet compounds in STC-1 cells were suppressed by a rodent T1R3 inhibitor gurmarin, suggesting the involvement of T1R3-dependent receptors in detection of sweet compounds. Responses to sweet substances were suppressed by ⩾1ng/ml leptin without affecting responses to bitter, umami and salty compounds. This effect was inhibited by a leptin antagonist (mutant L39A/D40A/F41A) and by ATP gated K(+) (KATP) channel closer glibenclamide, suggesting that leptin affects sweet taste responses of enteroendocrine cells via activation of leptin receptor and KATP channel expressed in these cells. Moreover, leptin selectively inhibited sweet-induced but not bitter-induced glucagon-like peptide-1 (GLP-1) secretion from STC-1 cells. These results suggest that leptin modulates sweet taste responses of enteroendocrine cells to regulate nutrient sensing, hormone release and glucose absorption in the gut. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Taste Changes in Vitamin A Deficiency

PubMed Central

Bernard, Rudy A.; Halpern, Bruce P.

1968-01-01

Taste preferences were studied in two groups of rats depleted of vitamin A by dietary restriction. One group received sufficient vitamin A acid supplement to maintain normal growth. The other group was repleted with vitamin A alcohol after the classical deficiency symptoms had appeared; this group gradually lost normal preferences for NaCl and aversion to quinine solutions during depletion. Vitamin A alcohol repletion tended to restore taste preferences to normal. In contrast, the group receiving vitamin A acid showed normal taste preferences throughout the depletion period. When the vitamin A acid supplement was removed taste preferences became abnormal and returned to normal when vitamin A acid was restored. Peripheral gustatory neural activity of depleted rats without any form of vitamin A was less than normal both at rest and when the tongue was stimulated with NaCl solutions. Histological examination showed keratin infiltrating the pores of the taste buds. Accessory glandular tissues were atrophied and debris filled the trenches of the papillae. It is concluded that vitamin A acid can provide the vitamin A required for normal taste, as contrasted with its inability to maintain visual function. It is suggested that the effect of vitamin A is exerted at the receptor level, as a result of its role in the biosynthesis of mucopolysaccharides, which have been recently identified in the pore area of taste buds, as well as being present in the various secretions of the oral cavity. PMID:4299794

Sugars, Sweet Taste Receptors, and Brain Responses

PubMed Central

Lee, Allen A.; Owyang, Chung

2017-01-01

Sweet taste receptors are composed of a heterodimer of taste 1 receptor member 2 (T1R2) and taste 1 receptor member 3 (T1R3). Accumulating evidence shows that sweet taste receptors are ubiquitous throughout the body, including in the gastrointestinal tract as well as the hypothalamus. These sweet taste receptors are heavily involved in nutrient sensing, monitoring changes in energy stores, and triggering metabolic and behavioral responses to maintain energy balance. Not surprisingly, these pathways are heavily regulated by external and internal factors. Dysfunction in one or more of these pathways may be important in the pathogenesis of common diseases, such as obesity and type 2 diabetes mellitus. PMID:28672790

Sugars, Sweet Taste Receptors, and Brain Responses.

PubMed

Lee, Allen A; Owyang, Chung

2017-06-24

Sweet taste receptors are composed of a heterodimer of taste 1 receptor member 2 (T1R2) and taste 1 receptor member 3 (T1R3). Accumulating evidence shows that sweet taste receptors are ubiquitous throughout the body, including in the gastrointestinal tract as well as the hypothalamus. These sweet taste receptors are heavily involved in nutrient sensing, monitoring changes in energy stores, and triggering metabolic and behavioral responses to maintain energy balance. Not surprisingly, these pathways are heavily regulated by external and internal factors. Dysfunction in one or more of these pathways may be important in the pathogenesis of common diseases, such as obesity and type 2 diabetes mellitus.

Changes in Gustatory Function and Taste Preference Following Weight Loss.

PubMed

Sauer, Helene; Ohla, Kathrin; Dammann, Dirk; Teufel, Martin; Zipfel, Stephan; Enck, Paul; Mack, Isabelle

2017-03-01

To investigate taste changes of obese children during an inpatient weight reduction treatment in comparison with normal weight children. Obese (n = 60) and normal weight (n = 27) children aged 9-17 years were assessed for gustatory functions using taste strips (taste identification test for the taste qualities sour, salty, sweet, and bitter), taste preferences, and experienced taste sensitivity. Obese children were examined upon admission (T1) and before discharge (T2). Normal weight children served as the control group. Irrespective of taste quality, obese children exhibited a lower ability to identify taste (total taste score) than normal weight children (P < .01); this overall score remained stable during inpatient treatment in obese children. Group and treatment effects were seen when evaluating individual taste qualities. In comparison with normal weight children, obese children exhibited poorer sour taste identification performance (P < .01). Obese children showed improvement in sour taste identification (P < .001) and deterioration in sweet taste identification (P < .001) following treatment. Subjective reports revealed a lower preference for sour taste in obese children compared with normal weight children (P < .05). The sweet and bitter taste ability at T1 predicted the body mass index z score at T2 (R 2  = .23, P < .01). We identified differences in the ability to discriminate tastes and in subjective taste perception between groups. Our findings of increased sour and reduced sweet taste discrimination after the intervention in obese children are indicative of an exposure-related effect on taste performance, possibly mediated by increased acid and reduced sugar consumption during the intervention. Because the sweet and bitter taste ability at T1 predicted weight loss, addressing gustatory function could be relevant in individualized obesity treatment approaches. Germanctr.de: DRKS00005122. Copyright © 2016 Elsevier Inc

Immunohistochemical Analysis of Human Vallate Taste Buds

PubMed Central

Tizzano, Marco; Grigereit, Laura; Shultz, Nicole; Clary, Matthew S.

2015-01-01

The morphology of the vallate papillae from postmortem human samples was investigated with immunohistochemistry. Microscopically, taste buds were present along the inner wall of the papilla, and in some cases in the outer wall as well. The typical taste cell markers PLCβ2, GNAT3 (gustducin) and the T1R3 receptor stain elongated cells in human taste buds consistent with the Type II cells in rodents. In the human tissue, taste bud cells that stain with Type II cell markers, PLCβ2 and GNAT3, also stain with villin antibody. Two typical immunochemical markers for Type III taste cells in rodents, PGP9.5 and SNAP25, fail to stain any taste bud cells in the human postmortem tissue, although these antibodies do stain numerous nerve fibers throughout the specimen. Car4, another Type III cell marker, reacted with only a few taste cells in our samples. Finally, human vallate papillae have a general network of innervation similar to rodents and antibodies directed against SNAP25, PGP9.5, acetylated tubulin and P2X3 all stain free perigemmal nerve endings as well as intragemmal taste fibers. We conclude that with the exception of certain molecular features of Type III cells, human vallate papillae share the structural, morphological, and molecular features observed in rodents. PMID:26400924

Positive allosteric modulators of the human sweet taste receptor enhance sweet taste

PubMed Central

Servant, Guy; Tachdjian, Catherine; Tang, Xiao-Qing; Werner, Sara; Zhang, Feng; Li, Xiaodong; Kamdar, Poonit; Petrovic, Goran; Ditschun, Tanya; Java, Antoniette; Brust, Paul; Brune, Nicole; DuBois, Grant E.; Zoller, Mark; Karanewsky, Donald S.

2010-01-01

To identify molecules that could enhance sweetness perception, we undertook the screening of a compound library using a cell-based assay for the human sweet taste receptor and a panel of selected sweeteners. In one of these screens we found a hit, SE-1, which significantly enhanced the activity of sucralose in the assay. At 50 μM, SE-1 increased the sucralose potency by >20-fold. On the other hand, SE-1 exhibited little or no agonist activity on its own. SE-1 effects were strikingly selective for sucralose. Other popular sweeteners such as aspartame, cyclamate, and saccharin were not enhanced by SE-1 whereas sucrose and neotame potency were increased only by 1.3- to 2.5-fold at 50 μM. Further assay-guided chemical optimization of the initial hit SE-1 led to the discovery of SE-2 and SE-3, selective enhancers of sucralose and sucrose, respectively. SE-2 (50 μM) and SE-3 (200 μM) increased sucralose and sucrose potencies in the assay by 24- and 4.7-fold, respectively. In human taste tests, 100 μM of SE-1 and SE-2 allowed for a reduction of 50% to >80% in the concentration of sucralose, respectively, while maintaining the sweetness intensity, and 100 μM SE-3 allowed for a reduction of 33% in the concentration of sucrose while maintaining the sweetness intensity. These enhancers did not exhibit any sweetness when tasted on their own. Positive allosteric modulators of the human sweet taste receptor could help reduce the caloric content in food and beverages while maintaining the desired taste. PMID:20173092

Taste Identification in Adults with Autism Spectrum Conditions

ERIC Educational Resources Information Center

Tavassoli, T.; Baron-Cohen, S.

2012-01-01

Sensory issues are widely reported in Autism Spectrum Conditions (ASC). Since taste perception is one of the least studied senses in ASC we explored taste identification in adults with ASC (12 males, 11 females) compared to control participants (14 males, 12 females). "Taste strips" were used to measure taste identification overall, as well as…

Matters of Taste: Bridging Molecular Physiology and the Humanities

ERIC Educational Resources Information Center

Rangachari, P. K.; Rangachari, Usha

2015-01-01

Taste perception was the focus of an undergraduate course in the health sciences that bridged the sciences and humanities. A problem-based learning approach was used to study the biological issues, whereas the cultural transmutations of these molecular mechanisms were explored using a variety of resources (novels, cookbooks, and films). Multiple…

PTC/PROP tasting: anatomy, psychophysics, and sex effects.

PubMed

Bartoshuk, L M; Duffy, V B; Miller, I J

1994-12-01

Taste worlds of humans vary because of taste blindness to phenylthiocarbamide (PTC) and its chemical relative, 6-n-propylthiouracil (PROP). We review early PTC studies and apply modern statistical analyses to show that a higher frequency of women tasted PTC crystals, and were tasters (threshold classification). In our laboratory, scaling of PROP bitterness led to the identification of a subset of tasters (supertasters) who rate PROP as intensely bitter. Supertasters also perceive stronger tastes from a variety of bitter and sweet substances, and perceive more burn from oral irritants (alcohol and capsaicin). The density of taste receptors on the anterior tongue (fungiform papillae, taste buds) correlate significantly with perceived bitterness of PROP and support the supertaster concept. Psychophysical data from studies in our laboratory also show a sex effect; women are supertasters more frequently. The anatomical data also support the sex difference; women have more fungiform papillae and more taste buds. Future investigations of PTC/PROP tasting and food behaviors should include scaling to identify supertasters and separate sex effects.

Genomic evidence of bitter taste in snakes and phylogenetic analysis of bitter taste receptor genes in reptiles

PubMed Central

Zhong, Huaming; Shang, Shuai; Wu, Xiaoyang; Chen, Jun; Zhu, Wanchao; Yan, Jiakuo; Li, Haotian

2017-01-01

As nontraditional model organisms with extreme physiological and morphological phenotypes, snakes are believed to possess an inferior taste system. However, the bitter taste sensation is essential to distinguish the nutritious and poisonous food resources and the genomic evidence of bitter taste in snakes is largely scarce. To explore the genetic basis of the bitter taste of snakes and characterize the evolution of bitter taste receptor genes (Tas2rs) in reptiles, we identified Tas2r genes in 19 genomes (species) corresponding to three orders of non-avian reptiles. Our results indicated contractions of Tas2r gene repertoires in snakes, however dramatic gene expansions have occurred in lizards. Phylogenetic analysis of the Tas2rs with NJ and BI methods revealed that Tas2r genes of snake species formed two clades, whereas in lizards the Tas2r genes clustered into two monophyletic clades and four large clades. Evolutionary changes (birth and death) of intact Tas2r genes in reptiles were determined by reconciliation analysis. Additionally, the taste signaling pathway calcium homeostasis modulator 1 (Calhm1) gene of snakes was putatively functional, suggesting that snakes still possess bitter taste sensation. Furthermore, Phylogenetically Independent Contrasts (PIC) analyses reviewed a significant correlation between the number of Tas2r genes and the amount of potential toxins in reptilian diets, suggesting that insectivores such as some lizards may require more Tas2rs genes than omnivorous and carnivorous reptiles. PMID:28828281

Glutamate: Tastant and Neuromodulator in Taste Buds.

PubMed

Vandenbeuch, Aurelie; Kinnamon, Sue C

2016-07-01

In taste buds, glutamate plays a double role as a gustatory stimulus and neuromodulator. The detection of glutamate as a tastant involves several G protein-coupled receptors, including the heterodimer taste receptor type 1, member 1 and 3 as well as metabotropic glutamate receptors (mGluR1 and mGluR4). Both receptor types participate in the detection of glutamate as shown with knockout animals and selective antagonists. At the basal part of taste buds, ionotropic glutamate receptors [N-methyl-d-aspartate (NMDA) and non-NMDA] are expressed and participate in the modulation of the taste signal before its transmission to the brain. Evidence suggests that glutamate has an efferent function on taste cells and modulates the release of other neurotransmitters such as serotonin and ATP. This short article reviews the recent developments in the field with regard to glutamate receptors involved in both functions as well as the influence of glutamate on the taste signal. © 2016 American Society for Nutrition.

Evaluation of taste solutions by sensor fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kojima, Yohichiro; Sato, Eriko; Atobe, Masahiko

In our previous studies, properties of taste solutions were discriminated based on sound velocity and amplitude of ultrasonic waves propagating through the solutions. However, to make this method applicable to beverages which contain many taste substances, further studies are required. In this study, the waveform of an ultrasonic wave with frequency of approximately 5 MHz propagating through a solution was measured and subjected to frequency analysis. Further, taste sensors require various techniques of sensor fusion to effectively obtain chemical and physical parameter of taste solutions. A sensor fusion method of ultrasonic wave sensor and various sensors, such as the surfacemore » plasmon resonance (SPR) sensor, to estimate tastes were proposed and examined in this report. As a result, differences among pure water and two basic taste solutions were clearly observed as differences in their properties. Furthermore, a self-organizing neural network was applied to obtained data which were used to clarify the differences among solutions.« less

Modulation of sweet responses of taste receptor cells.

PubMed

Yoshida, Ryusuke; Niki, Mayu; Jyotaki, Masafumi; Sanematsu, Keisuke; Shigemura, Noriatsu; Ninomiya, Yuzo

2013-03-01

Taste receptor cells play a major role in detection of chemical compounds in the oral cavity. Information derived from taste receptor cells, such as sweet, bitter, salty, sour and umami is important for evaluating the quality of food components. Among five basic taste qualities, sweet taste is very attractive for animals and influences food intake. Recent studies have demonstrated that sweet taste sensitivity in taste receptor cells would be affected by leptin and endocannabinoids. Leptin is an anorexigenic mediator that reduces food intake by acting on leptin receptor Ob-Rb in the hypothalamus. Endocannabinoids such as anandamide [N-arachidonoylethanolamine (AEA)] and 2-arachidonoyl glycerol (2-AG) are known as orexigenic mediators that act via cannabinoid receptor 1 (CB1) in the hypothalamus and limbic forebrain to induce appetite and stimulate food intake. At the peripheral gustatory organs, leptin selectively suppresses and endocannabinoids selectively enhance sweet taste sensitivity via Ob-Rb and CB1 expressed in sweet sensitive taste cells. Thus leptin and endocannabinoids not only regulate food intake via central nervous systems but also modulate palatability of foods by altering peripheral sweet taste responses. Such reciprocal modulation of leptin and endocannabinoids on peripheral sweet sensitivity may play an important role in regulating energy homeostasis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Music Influences Hedonic and Taste Ratings in Beer

PubMed Central

Reinoso Carvalho, Felipe; Velasco, Carlos; van Ee, Raymond; Leboeuf, Yves; Spence, Charles

2016-01-01

The research presented here focuses on the influence of background music on the beer-tasting experience. An experiment is reported in which different groups of customers tasted a beer under three different conditions (N = 231). The control group was presented with an unlabeled beer, the second group with a labeled beer, and the third group with a labeled beer together with a customized sonic cue (a short clip from an existing song). In general, the beer-tasting experience was rated as more enjoyable with music than when the tasting was conducted in silence. In particular, those who were familiar with the band that had composed the song, liked the beer more after having tasted it while listening to the song, than those who knew the band, but only saw the label while tasting. These results support the idea that customized sound-tasting experiences can complement the process of developing novel beverage (and presumably also food) events. We suggest that involving musicians and researchers alongside brewers in the process of beer development, offers an interesting model for future development. Finally, we discuss the role of attention in sound-tasting experiences, and the importance that a positive hedonic reaction toward a song can have for the ensuing tasting experience. PMID:27199862

Norepinephrine is coreleased with serotonin in mouse taste buds.

PubMed

Huang, Yijen A; Maruyama, Yutaka; Roper, Stephen D

2008-12-03

ATP and serotonin (5-HT) are neurotransmitters secreted from taste bud receptor (type II) and presynaptic (type III) cells, respectively. Norepinephrine (NE) has also been proposed to be a neurotransmitter or paracrine hormone in taste buds. Yet, to date, the specific stimulus for NE release in taste buds is not well understood, and the identity of the taste cells that secrete NE is not known. Chinese hamster ovary cells were transfected with alpha(1A) adrenoceptors and loaded with fura-2 ("biosensors") to detect NE secreted from isolated mouse taste buds and taste cells. Biosensors responded to low concentrations of NE (>or=10 nm) with a reliable fura-2 signal. NE biosensors did not respond to stimulation with KCl or taste compounds. However, we recorded robust responses from NE biosensors when they were positioned against mouse circumvallate taste buds and the taste buds were stimulated with KCl (50 mm) or a mixture of taste compounds (cycloheximide, 10 microm; saccharin, 2 mm; denatonium, 1 mm; SC45647, 100 microm). NE biosensor responses evoked by stimulating taste buds were reversibly blocked by prazosin, an alpha(1A) receptor antagonist. Together, these findings indicate that taste bud cells secrete NE when they are stimulated. We isolated individual taste bud cells to identify the origin of NE release. NE was secreted only from presynaptic (type III) taste cells and not receptor (type II) cells. Stimulus-evoked NE release depended on Ca(2+) in the bathing medium. Using dual biosensors (sensitive to 5-HT and NE), we found all presynaptic cells secrete 5-HT and 33% corelease NE with 5-HT.

Perceptual variation in umami taste and polymorphisms in TAS1R taste receptor genes1234

PubMed Central

Chen, Qing-Ying; Alarcon, Suzanne; Tharp, Anilet; Ahmed, Osama M; Estrella, Nelsa L; Greene, Tiffani A; Rucker, Joseph; Breslin, Paul AS

2009-01-01

Background: The TAS1R1 and TAS1R3 G protein–coupled receptors are believed to function in combination as a heteromeric glutamate taste receptor in humans. Objective: We hypothesized that variations in the umami perception of glutamate would correlate with variations in the sequence of these 2 genes, if they contribute directly to umami taste. Design: In this study, we first characterized the general sensitivity to glutamate in a sample population of 242 subjects. We performed these experiments by sequencing the coding regions of the genomic TAS1R1 and TAS1R3 genes in a separate set of 87 individuals who were tested repeatedly with monopotassium glutamate (MPG) solutions. Last, we tested the role of the candidate umami taste receptor hTAS1R1-hTAS1R3 in a functional expression assay. Results: A subset of subjects displays extremes of sensitivity, and a battery of different psychophysical tests validated this observation. Statistical analysis showed that the rare T allele of single nucleotide polymorphism (SNP) R757C in TAS1R3 led to a doubling of umami ratings of 25 mmol MPG/L. Other suggestive SNPs of TAS1R3 include the A allele of A5T and the A allele of R247H, which both resulted in an approximate doubling of umami ratings of 200 mmol MPG/L. We confirmed the potential role of the human TAS1R1-TAS1R3 heteromer receptor in umami taste by recording responses, specifically to l-glutamate and inosine 5′-monophosphate (IMP) mixtures in a heterologous expression assay in HEK (human embryonic kidney) T cells. Conclusions: There is a reliable and valid variation in human umami taste of l-glutamate. Variations in perception of umami taste correlated with variations in the human TAS1R3 gene. The putative human taste receptor TAS1R1-TAS1R3 responds specifically to l-glutamate mixed with the ribonucleotide IMP. Thus, this receptor likely contributes to human umami taste perception. PMID:19587085

The Addition of Saccharin to Taste Cues Affects Taste Preference Conditioning in Thirsty Rats

ERIC Educational Resources Information Center

Forestell, Catherine A.; LoLordo, Vincent M.

2004-01-01

Previous failures to condition preferences for the unacceptable taste cues sucrose octaacetate (SOA) and citric acid (CA) using a reverse-order, differential conditioning procedure (Forestell & LoLordo, 2000) may have been the result of low consumption of the taste cues in training or of their relatively low acceptability to rats that are thirsty…

The heterodimeric sweet taste receptor has multiple potential ligand binding sites.

PubMed

Cui, Meng; Jiang, Peihua; Maillet, Emeline; Max, Marianna; Margolskee, Robert F; Osman, Roman

2006-01-01

The sweet taste receptor is a heterodimer of two G protein coupled receptors, T1R2 and T1R3. This discovery has increased our understanding at the molecular level of the mechanisms underlying sweet taste. Previous experimental studies using sweet receptor chimeras and mutants show that there are at least three potential binding sites in this heterodimeric receptor. Receptor activity toward the artificial sweeteners aspartame and neotame depends on residues in the amino terminal domain of human T1R2. In contrast, receptor activity toward the sweetener cyclamate and the sweet taste inhibitor lactisole depends on residues within the transmembrane domain of human T1R3. Furthermore, receptor activity toward the sweet protein brazzein depends on the cysteine rich domain of human T1R3. Although crystal structures are not available for the sweet taste receptor, useful homology models can be developed based on appropriate templates. The amino terminal domain, cysteine rich domain and transmembrane helix domain of T1R2 and T1R3 have been modeled based on the crystal structures of metabotropic glutamate receptor type 1, tumor necrosis factor receptor, and bovine rhodopsin, respectively. We have used homology models of the sweet taste receptors, molecular docking of sweet ligands to the receptors, and site-directed mutagenesis of the receptors to identify potential ligand binding sites of the sweet taste receptor. These studies have led to a better understanding of the structure and function of this heterodimeric receptor, and can act as a guide for rational structure-based design of novel non-caloric sweeteners, which can be used in the fighting against obesity and diabetes.

Modulation of sweet taste by umami compounds via sweet taste receptor subunit hT1R2.

PubMed

Shim, Jaewon; Son, Hee Jin; Kim, Yiseul; Kim, Ki Hwa; Kim, Jung Tae; Moon, Hana; Kim, Min Jung; Misaka, Takumi; Rhyu, Mee-Ra

2015-01-01

Although the five basic taste qualities-sweet, sour, bitter, salty and umami-can be recognized by the respective gustatory system, interactions between these taste qualities are often experienced when food is consumed. Specifically, the umami taste has been investigated in terms of whether it enhances or reduces the other taste modalities. These studies, however, are based on individual perception and not on a molecular level. In this study we investigated umami-sweet taste interactions using umami compounds including monosodium glutamate (MSG), 5'-mononucleotides and glutamyl-dipeptides, glutamate-glutamate (Glu-Glu) and glutamate-aspartic acid (Glu-Asp), in human sweet taste receptor hT1R2/hT1R3-expressing cells. The sensitivity of sucrose to hT1R2/hT1R3 was significantly attenuated by MSG and umami active peptides but not by umami active nucleotides. Inhibition of sweet receptor activation by MSG and glutamyl peptides is obvious when sweet receptors are activated by sweeteners that target the extracellular domain (ECD) of T1R2, such as sucrose and acesulfame K, but not by cyclamate, which interact with the T1R3 transmembrane domain (TMD). Application of umami compounds with lactisole, inhibitory drugs that target T1R3, exerted a more severe inhibitory effect. The inhibition was also observed with F778A sweet receptor mutant, which have the defect in function of T1R3 TMD. These results suggest that umami peptides affect sweet taste receptors and this interaction prevents sweet receptor agonists from binding to the T1R2 ECD in an allosteric manner, not to the T1R3. This is the first report to define the interaction between umami and sweet taste receptors.

Leptin Suppresses Mouse Taste Cell Responses to Sweet Compounds

PubMed Central

Noguchi, Kenshi; Shigemura, Noriatsu; Jyotaki, Masafumi; Takahashi, Ichiro; Margolskee, Robert F.

2015-01-01

Leptin is known to selectively suppress neural and behavioral responses to sweet-tasting compounds. However, the molecular basis for the effect of leptin on sweet taste is not known. Here, we report that leptin suppresses sweet taste via leptin receptors (Ob-Rb) and KATP channels expressed selectively in sweet-sensitive taste cells. Ob-Rb was more often expressed in taste cells that expressed T1R3 (a sweet receptor component) than in those that expressed glutamate-aspartate transporter (a marker for Type I taste cells) or GAD67 (a marker for Type III taste cells). Systemically administered leptin suppressed taste cell responses to sweet but not to bitter or sour compounds. This effect was blocked by a leptin antagonist and was absent in leptin receptor–deficient db/db mice and mice with diet-induced obesity. Blocking the KATP channel subunit sulfonylurea receptor 1, which was frequently coexpressed with Ob-Rb in T1R3-expressing taste cells, eliminated the effect of leptin on sweet taste. In contrast, activating the KATP channel with diazoxide mimicked the sweet-suppressing effect of leptin. These results indicate that leptin acts via Ob-Rb and KATP channels that are present in T1R3-expressing taste cells to selectively suppress their responses to sweet compounds. PMID:26116698

Influence of the perceived taste intensity of chemesthetic stimuli on swallowing parameters given age and genetic taste differences in healthy adult women.

PubMed

Pelletier, Cathy A; Steele, Catriona M

2014-02-01

This study examined whether the perceived taste intensity of liquids with chemesthetic properties influenced lingua-palatal pressures and submental surface electromyography (sEMG) in swallowing, compared with water. Swallowing was studied in 80 healthy women, stratified by age group and genetic taste status. General Labeled Magnitude Scale ratings of taste intensity were collected for deionized water; carbonated water; 2.7% w/v citric acid; and diluted ethanol. These stimuli were swallowed, with measurement of tongue-palate pressures and submental sEMG. Path analysis differentiated stimulus, genetic taste status, age, and perceived taste intensity effects on swallowing. Signal amplitude during effortful saliva swallowing served as a covariate representing participant strength. Significant differences (p < .05) in taste intensity were seen across liquids: citric acid > ethanol > carbonated water > water. Supertasters perceived greater taste intensity than did nontasters. Lingua-palatal pressure and sEMG amplitudes were correlated with the strength covariate. Anterior palate pressures and sEMG amplitudes were significantly higher for the citric acid stimulus. Perceived taste intensity was a significant mediator of stimulus differences. These data provide confirmatory evidence that high-intensity sour stimuli do influence swallowing behaviors. In addition, taste genetics influence the perception of taste intensity for stimuli with chemesthetic properties, which modulates behavioral responses.

Immunohistochemical Analysis of Human Vallate Taste Buds.

PubMed

Tizzano, Marco; Grigereit, Laura; Shultz, Nicole; Clary, Matthew S; Finger, Thomas E

2015-11-01

The morphology of the vallate papillae from postmortem human samples was investigated with immunohistochemistry. Microscopically, taste buds were present along the inner wall of the papilla, and in some cases in the outer wall as well. The typical taste cell markers PLCβ2, GNAT3 (gustducin) and the T1R3 receptor stain elongated cells in human taste buds consistent with the Type II cells in rodents. In the human tissue, taste bud cells that stain with Type II cell markers, PLCβ2 and GNAT3, also stain with villin antibody. Two typical immunochemical markers for Type III taste cells in rodents, PGP9.5 and SNAP25, fail to stain any taste bud cells in the human postmortem tissue, although these antibodies do stain numerous nerve fibers throughout the specimen. Car4, another Type III cell marker, reacted with only a few taste cells in our samples. Finally, human vallate papillae have a general network of innervation similar to rodents and antibodies directed against SNAP25, PGP9.5, acetylated tubulin and P2X3 all stain free perigemmal nerve endings as well as intragemmal taste fibers. We conclude that with the exception of certain molecular features of Type III cells, human vallate papillae share the structural, morphological, and molecular features observed in rodents. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The K+ channel KIR2.1 functions in tandem with proton influx to mediate sour taste transduction

PubMed Central

Ye, Wenlei; Chang, Rui B.; Bushman, Jeremy D.; Tu, Yu-Hsiang; Mulhall, Eric M.; Wilson, Courtney E.; Cooper, Alexander J.; Chick, Wallace S.; Hill-Eubanks, David C.; Nelson, Mark T.; Kinnamon, Sue C.; Liman, Emily R.

2016-01-01

Sour taste is detected by a subset of taste cells on the tongue and palate epithelium that respond to acids with trains of action potentials. Entry of protons through a Zn2+-sensitive proton conductance that is specific to sour taste cells has been shown to be the initial event in sour taste transduction. Whether this conductance acts in concert with other channels sensitive to changes in intracellular pH, however, is not known. Here, we show that intracellular acidification generates excitatory responses in sour taste cells, which can be attributed to block of a resting K+ current. We identify KIR2.1 as the acid-sensitive K+ channel in sour taste cells using pharmacological and RNA expression profiling and confirm its contribution to sour taste with tissue-specific knockout of the Kcnj2 gene. Surprisingly, acid sensitivity is not conferred on sour taste cells by the specific expression of Kir2.1, but by the relatively small magnitude of the current, which makes the cells exquisitely sensitive to changes in intracellular pH. Consistent with a role of the K+ current in amplifying the sensory response, entry of protons through the Zn2+-sensitive conductance produces a transient block of the KIR2.1 current. The identification in sour taste cells of an acid-sensitive K+ channel suggests a mechanism for amplification of sour taste and may explain why weak acids that produce intracellular acidification, such as acetic acid, taste more sour than strong acids. PMID:26627720

The Role of Cholecystokinin in Peripheral Taste Signaling in Mice

PubMed Central

Yoshida, Ryusuke; Shin, Misa; Yasumatsu, Keiko; Takai, Shingo; Inoue, Mayuko; Shigemura, Noriatsu; Takiguchi, Soichi; Nakamura, Seiji; Ninomiya, Yuzo

2017-01-01

Cholecystokinin (CCK) is a gut hormone released from enteroendocrine cells. CCK functions as an anorexigenic factor by acting on CCK receptors expressed on the vagal afferent nerve and hypothalamus with a synergistic interaction between leptin. In the gut, tastants such as amino acids and bitter compounds stimulate CCK release from enteroendocrine cells via activation of taste transduction pathways. CCK is also expressed in taste buds, suggesting potential roles of CCK in taste signaling in the peripheral taste organ. In the present study, we focused on the function of CCK in the initial responses to taste stimulation. CCK was coexpressed with type II taste cell markers such as Gα-gustducin, phospholipase Cβ2, and transient receptor potential channel M5. Furthermore, a small subset (~30%) of CCK-expressing taste cells expressed a sweet/umami taste receptor component, taste receptor type 1 member 3, in taste buds. Because type II taste cells are sweet, umami or bitter taste cells, the majority of CCK-expressing taste cells may be bitter taste cells. CCK-A and -B receptors were expressed in both taste cells and gustatory neurons. CCK receptor knockout mice showed reduced neural responses to bitter compounds compared with wild-type mice. Consistently, intravenous injection of CCK-Ar antagonist lorglumide selectively suppressed gustatory nerve responses to bitter compounds. Intravenous injection of CCK-8 transiently increased gustatory nerve activities in a dose-dependent manner whereas administration of CCK-8 did not affect activities of bitter-sensitive taste cells. Collectively, CCK may be a functionally important neurotransmitter or neuromodulator to activate bitter nerve fibers in peripheral taste tissues. PMID:29163209

Innervation of single fungiform taste buds during development in rat.

PubMed

Krimm, R F; Hill, D L

1998-08-17

To determine whether the innervation of taste buds changes during postnatal development, the number of geniculate ganglion cells that innervated single fungiform taste buds were quantified in the tip- and midregions of the tongue of adult and developing rats. There was substantial variation in both the size of individual taste buds and number of geniculate ganglion cells that innervated them. Importantly, taste bud morphology and innervation were highly related. Namely, the number of labeled geniculate ganglion cells that innervated a taste bud was highly correlated with the size of the taste bud (r = 0.91, P < .0003): The larger the taste bud, the more geniculate ganglion cells that innervated it. The relationship between ganglion cell number and taste bud volume emerged during the first 40 days postnatal. Whereas there was no difference in the average number of ganglion cells that innervated individual taste buds in rats aged 10 days postnatal through adulthood, taste bud volumes increased progressively between 10 and 40 days postnatal, at which age taste bud volumes were similar to adults. The maturation of taste bud size was accompanied by the emergence of the relationship between taste bud volume and number of innervating neurons. Specifically, there was no correlation between taste bud size and number of innervating geniculate ganglion cells in 10-, 20-, or 30-day-old rats, whereas taste bud size and the number of innervating ganglion cells in 40-day-old rats were positively correlated (r = .80, P < .002). Therefore, the relationship between taste bud size and number of innervating ganglion cells develops over a prolonged postnatal period and is established when taste buds grow to their adult size.

An in-vitro-in-vivo taste assessment of bitter drug: comparative electronic tongues study.

PubMed

Maniruzzaman, Mohammed; Douroumis, Dennis

2015-01-01

The efficiency of the Astree e-tongue and Taste Sensing system TS5000Z for the evaluation of the taste masking effect of hot melt extruded formulations was investigated in this study. Hot melt extrusion (HME) processing was optimized using Randcastle single screw extruder (USA) to manufacture extrudates with desirable characteristics. Cationic model drug propranolol HCl (PRP) was processed with the anionic polymers - Eudragit L100 (L100) and Eudragit L100-55 (Acryl-EZE). Solid state of the drug in polymer matrices was evaluated by scanning electron microscopy (SEM), differential scanning calorimetry, particle size analysis, Fourier transform infrared (FTIR) and Nuclear magnetic resonance (NMR) analysis. In-vitro taste masking efficiency of the two polymers was performed by using two different e-tongues (Astree e-tongue and TS5000Z). The results obtained from both e-tongues were further compared and contrast to find out the sensor outputs in all formulations. Solid state analysis of the extruded formulations revealed the presence of amorphous PRP. Both e-tongues were able to detect the taste masking variations of the extrudates and were in good agreement with the in-vivo results obtained from a panel of six healthy human volunteers (R(2)  > 0.84). However, each e-tongue sensor demonstrated different sensitivity, suggesting a careful consideration of the experimental findings during melt extrusion, is necessary for the development of taste-masked formulations. Furthermore, FTIR spectroscopy and NMR studies revealed possible drug polymer intermolecular interactions as the mechanism of successful taste masking. HME can effectively be used to manufacture taste-masked extruded formulations, while both e-tongues demonstrated satisfactory taste analysis for the development of taste-masked formulations. © 2014 Royal Pharmaceutical Society.

Visual-gustatory interaction: orbitofrontal and insular cortices mediate the effect of high-calorie visual food cues on taste pleasantness.

PubMed

Ohla, Kathrin; Toepel, Ulrike; le Coutre, Johannes; Hudry, Julie

2012-01-01

Vision provides a primary sensory input for food perception. It raises expectations on taste and nutritional value and drives acceptance or rejection. So far, the impact of visual food cues varying in energy content on subsequent taste integration remains unexplored. Using electrical neuroimaging, we assessed whether high- and low-calorie food cues differentially influence the brain processing and perception of a subsequent neutral electric taste. When viewing high-calorie food images, participants reported the subsequent taste to be more pleasant than when low-calorie food images preceded the identical taste. Moreover, the taste-evoked neural activity was stronger in the bilateral insula and the adjacent frontal operculum (FOP) within 100 ms after taste onset when preceded by high- versus low-calorie cues. A similar pattern evolved in the anterior cingulate (ACC) and medial orbitofrontal cortex (OFC) around 180 ms, as well as, in the right insula, around 360 ms. The activation differences in the OFC correlated positively with changes in taste pleasantness, a finding that is an accord with the role of the OFC in the hedonic evaluation of taste. Later activation differences in the right insula likely indicate revaluation of interoceptive taste awareness. Our findings reveal previously unknown mechanisms of cross-modal, visual-gustatory, sensory interactions underlying food evaluation.

Visual-Gustatory Interaction: Orbitofrontal and Insular Cortices Mediate the Effect of High-Calorie Visual Food Cues on Taste Pleasantness

PubMed Central

Ohla, Kathrin; Toepel, Ulrike; le Coutre, Johannes; Hudry, Julie

2012-01-01

Vision provides a primary sensory input for food perception. It raises expectations on taste and nutritional value and drives acceptance or rejection. So far, the impact of visual food cues varying in energy content on subsequent taste integration remains unexplored. Using electrical neuroimaging, we assessed whether high- and low-calorie food cues differentially influence the brain processing and perception of a subsequent neutral electric taste. When viewing high-calorie food images, participants reported the subsequent taste to be more pleasant than when low-calorie food images preceded the identical taste. Moreover, the taste-evoked neural activity was stronger in the bilateral insula and the adjacent frontal operculum (FOP) within 100 ms after taste onset when preceded by high- versus low-calorie cues. A similar pattern evolved in the anterior cingulate (ACC) and medial orbitofrontal cortex (OFC) around 180 ms, as well as, in the right insula, around 360 ms. The activation differences in the OFC correlated positively with changes in taste pleasantness, a finding that is an accord with the role of the OFC in the hedonic evaluation of taste. Later activation differences in the right insula likely indicate revaluation of interoceptive taste awareness. Our findings reveal previously unknown mechanisms of cross-modal, visual-gustatory, sensory interactions underlying food evaluation. PMID:22431974

Changes in taste receptor cell [Ca2+]i modulate chorda tympani responses to bitter, sweet, and umami taste stimuli

PubMed Central

DeSimone, John A.; Phan, Tam-Hao T.; Ren, ZuoJun; Mummalaneni, Shobha

2012-01-01

The relationship between taste receptor cell (TRC) intracellular Ca2+ ([Ca2+]i) and rat chorda tympani (CT) nerve responses to bitter (quinine and denatonium), sweet (sucrose, glycine, and erythritol), and umami [monosodium glutamate (MSG) and MSG + inosine 5′-monophosphate (IMP)] taste stimuli was investigated before and after lingual application of ionomycin (Ca2+ ionophore) + Ca2+, 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA-AM; Ca2+ chelator), U73122 (phospholipase C blocker), thapsigargin (Ca2+-ATPase blocker), and diC8-PIP2 (synthetic phosphatidylinositol 4,5-bisphosphate). The phasic CT response to quinine was indifferent to changes in [Ca2+]i. However, a decrease in [Ca2+]i inhibited the tonic part of the CT response to quinine. The CT responses to sweet and umami stimuli were indifferent to changes in TRC [Ca2+]i. However, a decrease in [Ca2+]i attenuated the synergistic effects of ethanol on the CT response to sweet stimuli and of IMP on the glutamate CT response. U73122 and thapsigargin inhibited the phasic and tonic CT responses to bitter, sweet, and umami stimuli. Although diC8-PIP2 increased the CT response to bitter and sweet stimuli, it did not alter the CT response to glutamate but did inhibit the synergistic effect of IMP on the glutamate response. The results suggest that bitter, sweet, and umami taste qualities are transduced by [Ca2+]i-dependent and [Ca2+]i-independent mechanisms. Changes in TRC [Ca2+]i in the BAPTA-sensitive cytosolic compartment regulate quality-specific taste receptors and ion channels that are involved in the neural adaptation and mixture interactions. Changes in TRC [Ca2+]i in a separate subcompartment, sensitive to inositol trisphosphate and thapsigargin but inaccessible to BAPTA and ionomycin + Ca2+, are associated with neurotransmitter release. PMID:22993258

Purification and complete amino acid sequence of a new type of sweet protein taste-modifying activity, curculin.

PubMed

Yamashita, H; Theerasilp, S; Aiuchi, T; Nakaya, K; Nakamura, Y; Kurihara, Y

1990-09-15

A new taste-modifying protein named curculin was extracted with 0.5 M NaCl from the fruits of Curculigo latifolia and purified by ammonium sulfate fractionation, CM-Sepharose ion-exchange chromatography, and gel filtration. Purified curculin thus obtained gave a single band having a Mr of 12,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of 8 M urea. The molecular weight determined by low-angle laser light scattering was 27,800. These results suggest that native curculin is a dimer of a 12,000-Da polypeptide. The complete amino acid sequence of curculin was determined by automatic Edman degradation. Curculin consists of 114 residues. Curculin itself elicits a sweet taste. After curculin, water elicits a sweet taste, and sour substances induce a stronger sense of sweetness. No protein with both sweet-tasting and taste-modifying activities has ever been found. There are five sets of tripeptides common to miraculin (a taste-modifying protein), six sets of tripeptides common to thaumatin (a sweet protein), and two sets of tripeptides common to monellin (a sweet protein). Anti-miraculin serum was not immunologically reactive with curculin. The mechanism of the taste-modifying action of curculin is discussed.

Volumetry of human taste buds using laser scanning microscopy.

PubMed

Just, T; Srur, E; Stachs, O; Pau, H W

2009-10-01

In vivo laser scanning confocal microscopy is a relatively new, non-invasive method for assessment of oral cavity epithelia. The penetration depth of approximately 200-400 microm allows visualisation of fungiform papillae and their taste buds. This paper describes the technique of in vivo volumetry of human taste buds. Confocal laser scanning microscopy used a diode laser at 670 nm for illumination. Digital laser scanning confocal microscopy equipment consisted of the Heidelberg Retina Tomograph HRTII and the Rostock Cornea Module. Volume scans of fungiform papillae were used for three-dimensional reconstruction of the taste bud. This technique supplied information on taste bud structure and enabled measurement and calculation of taste bud volume. Volumetric data from a 23-year-old man over a nine-day period showed only a small deviation in values. After three to four weeks, phenomenological changes in taste bud structures were found (i.e. a significant increase in volume, followed by disappearance of the taste bud and appearance of a new taste bud). The data obtained indicate the potential application of this non-invasive imaging modality: to evaluate variation of taste bud volume in human fungiform papillae with ageing; to study the effects of chorda tympani nerve transection on taste bud volume; and to demonstrate recovery of taste buds in patients with a severed chorda tympani nerve who show recovery of gustatory sensibility after surgery.

A Subset of Mouse Colonic Goblet Cells Expresses the Bitter Taste Receptor Tas2r131

PubMed Central

Prandi, Simone; Bromke, Marta; Hübner, Sandra; Voigt, Anja; Boehm, Ulrich; Meyerhof, Wolfgang; Behrens, Maik

2013-01-01

The concept that gut nutrient sensing involves taste receptors has been fueled by recent reports associating the expression of taste receptors and taste-associated signaling molecules in the gut and in gut-derived cell lines with physiological responses induced by known taste stimuli. However, for bitter taste receptors (Tas2rs), direct evidence for their functional role in gut physiology is scarce and their cellular expression pattern remained unknown. We therefore investigated Tas2r expression in mice. RT-PCR experiments assessed the presence of mRNA for Tas2rs and taste signaling molecules in the gut. A gene-targeted mouse strain was established to visualize and identify cell types expressing the bitter receptor Tas2r131. Messenger RNA for various Tas2rs and taste signaling molecules were detected by RT-PCR in the gut. Using our knock-in mouse strain we demonstrate that a subset of colonic goblet cells express Tas2r131. Cells that express this receptor are absent in the upper gut and do not correspond to enteroendocrine and brush cells. Expression in colonic goblet cells is consistent with a role of Tas2rs in defense mechanisms against potentially harmful xenobiotics. PMID:24367558

Hypoxanthine enhances the cured meat taste

PubMed Central

Nakamura, Yukinobu; Yoshida, Yuka; Hattori, Akihito

2016-01-01

Abstract We evaluated the enhancement of cured meat taste during maturation by sensory analysis. We focused on the heat‐stable sarcoplasmic fraction (HSSF) to identify the factors related to cured meat taste. Because the dry matter of HSSF contained more than 30% nitrogen, nitrogen compounds such as free amino acids, small peptides and adenosine triphosphate‐related compounds seemed to be the important components of HSSF. The samples cured with HSSF for 2 h exhibited the same taste profile as ones cured without HSSF for 168 h. Therefore, the changes in the amount and fractions of nitrogen compounds were examined in HSSF during incubation from 0 to 168 h. The concentration of hypoxanthine (Hx) gradually increased, while inosine‐5′‐monophosphate decreased during the incubation. The samples cured with pickles containing various concentrations of Hx were subjected to sensory analysis. The addition of Hx, in a dose‐dependent fashion, enhanced cured meat taste by maturation for 2 h. It was concluded that Hx is essential for the enhancement of cured meat taste. PMID:27169902

[Smell and taste thresholds in older people].

PubMed

Thumfart, W; Plattig, K H; Schlicht, N

1980-01-01

The smell and taste ability of 105 persons at an age of 65 to 93 years was examined by adequate qualitative and semiquantitative chemical and electrogustometric methods. The basic levels of seniors were found above the levels of younger people. For the sense of smelling a significant connection of age and smell sensitivity could be measured. There was no difference between men and women using chemical test methods. With electrogustometry, however, women had a better taste sensitivity than men. At the age of 65 the taste levels are at a fix point. No higher levels could be realized in older persons. A significant reduction of smell ability was recognized in persons with reduction of cerebral blood flow and in smokers. The taste ability was disturbed in cases of diabetes, in persons using dental prostheses and selectively for "salty" in cases of hypertonia and "bitter" in smokers. Loss of taste was recognized in two women who used NaF-drugs, but also some other drugs were able to induce smell and taste alteration.

A Preference Test for Sweet Taste That Uses Edible Strips

PubMed Central

Smutzer, Gregory; Patel, Janki Y.; Stull, Judith C.; Abarintos, Ray A.; Khan, Neiladri K.; Park, Kevin C.

2014-01-01

A novel delivery method is described for the rapid determination of taste preferences for sweet taste in humans. This forced-choice paired comparison approach incorporates the non-caloric sweetener sucralose into a set of one-inch square edible strips for the rapid determination of sweet taste preferences. When compared to aqueous sucrose solutions, significantly lower amounts of sucralose were required to identify the preference for sweet taste. The validity of this approach was determined by comparing sweet taste preferences obtained with five different sucralose-containing edible strips to a set of five intensity-matched sucrose solutions. When compared to the solution test, edible strips required approximately the same number of steps to identify the preferred amount of sweet taste stimulus. Both approaches yielded similar distribution patterns for the preferred amount of sweet taste stimulus. In addition, taste intensity values for the preferred amount of sucralose in strips were similar to that of sucrose in solution. The hedonic values for the preferred amount of sucralose were lower than for sucrose, but the taste quality of the preferred sucralose strip was described as sweet. When taste intensity values between sucralose strips and sucralose solutions containing identical amounts of taste stimulus were compared, sucralose strips produced a greater taste intensity and more positive hedonic response. A preference test that uses edible strips for stimulus delivery should be useful for identifying preferences for sweet taste in young children, and in clinical populations. This test should also be useful for identifying sweet taste preferences outside of the lab or clinic. Finally, edible strips should be useful for developing preference tests for other primary taste stimuli and for taste mixtures. PMID:24225255

Investigation of the effects of color on judgments of sweetness using a taste adaptation method.

PubMed

Hidaka, Souta; Shimoda, Kazumasa

2014-01-01

It has been reported that color can affect the judgment of taste. For example, a dark red color enhances the subjective intensity of sweetness. However, the underlying mechanisms of the effect of color on taste have not been fully investigated; in particular, it remains unclear whether the effect is based on cognitive/decisional or perceptual processes. Here, we investigated the effect of color on sweetness judgments using a taste adaptation method. A sweet solution whose color was subjectively congruent with sweetness was judged as sweeter than an uncolored sweet solution both before and after adaptation to an uncolored sweet solution. In contrast, subjective judgment of sweetness for uncolored sweet solutions did not differ between the conditions following adaptation to a colored sweet solution and following adaptation to an uncolored one. Color affected sweetness judgment when the target solution was colored, but the colored sweet solution did not modulate the magnitude of taste adaptation. Therefore, it is concluded that the effect of color on the judgment of taste would occur mainly in cognitive/decisional domains.

Extraversion and taste sensitivity.

PubMed

Zverev, Yuriy; Mipando, Mwapatsa

2008-03-01

The rationale for investigating the gustatory reactivity as influenced by personality dimensions was suggested by some prior findings of an association between extraversion and acuity in other sensory systems. Detection thresholds for sweet, salty, and bitter qualities of taste were measured in 60 young healthy male and female volunteers using a two-alternative forced-choice technique. Personality of the responders was assessed using the Eysenck Personality Inventory. Multivariate analysis of variance failed to demonstrate a statistically significant interaction between an extraversion-introversion score, neuroticism score, smoking, gender and age. The only reliable negative association was found between the body mass index (BMI) and taste sensitivity (Roy's largest root = 0.05, F(7436.5) = 8.34, P = 0.003). Possible reasons for lack of differences between introverts and extraverts in the values of taste detection thresholds were discussed.

An ATP sensitive light addressable biosensor for extracellular monitoring of single taste receptor cell.

PubMed

Wu, Chunsheng; Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping

2012-12-01

Adenosine triphosphate (ATP) is considered as the key neurotransmitter in taste buds for taste signal transmission and processing. Measurements of ATP secreted from single taste receptor cell (TRC) with high sensitivity and specificity are essential for investigating mechanisms underlying taste cell-to-cell communications. In this study, we presented an aptamer-based biosensor for the detection of ATP locally secreted from single TRC. ATP sensitive DNA aptamer was used as recognition element and its DNA competitor was served as signal transduction element that was covalently immobilized on the surface of light addressable potentiometric sensor (LAPS). Due to the light addressable capability of LAPS, local ATP secretion from single TRC can be detected by monitoring the working potential shifts of LAPS. The results show this biosensor can detect ATP with high sensitivity and specificity. It is demonstrated this biosensor can effectively detect the local ATP secretion from single TRC responding to tastant mixture. This biosensor could provide a promising new tool for the research of taste cell-to-cell communications as well as for the detection of local ATP secretion from other types of ATP secreting individual cells.

GWAS of human bitter taste perception identifies new loci and reveals additional complexity of bitter taste genetics.

PubMed

Ledda, Mirko; Kutalik, Zoltán; Souza Destito, Maria C; Souza, Milena M; Cirillo, Cintia A; Zamboni, Amabilene; Martin, Nathalie; Morya, Edgard; Sameshima, Koichi; Beckmann, Jacques S; le Coutre, Johannes; Bergmann, Sven; Genick, Ulrich K

2014-01-01

Human perception of bitterness displays pronounced interindividual variation. This phenotypic variation is mirrored by equally pronounced genetic variation in the family of bitter taste receptor genes. To better understand the effects of common genetic variations on human bitter taste perception, we conducted a genome-wide association study on a discovery panel of 504 subjects and a validation panel of 104 subjects from the general population of São Paulo in Brazil. Correction for general taste-sensitivity allowed us to identify a SNP in the cluster of bitter taste receptors on chr12 (10.88- 11.24 Mb, build 36.1) significantly associated (best SNP: rs2708377, P = 5.31 × 10(-13), r(2) = 8.9%, β = -0.12, s.e. = 0.016) with the perceived bitterness of caffeine. This association overlaps with-but is statistically distinct from-the previously identified SNP rs10772420 influencing the perception of quinine bitterness that falls in the same bitter taste cluster. We replicated this association to quinine perception (P = 4.97 × 10(-37), r(2) = 23.2%, β = 0.25, s.e. = 0.020) and additionally found the effect of this genetic locus to be concentration specific with a strong impact on the perception of low, but no impact on the perception of high concentrations of quinine. Our study, thus, furthers our understanding of the complex genetic architecture of bitter taste perception.

A preference test for sweet taste that uses edible strips.

PubMed

Smutzer, Gregory; Patel, Janki Y; Stull, Judith C; Abarintos, Ray A; Khan, Neiladri K; Park, Kevin C

2014-02-01

A novel delivery method is described for the rapid determination of taste preferences for sweet taste in humans. This forced-choice paired comparison approach incorporates the non-caloric sweetener sucralose into a set of one-inch square edible strips for the rapid determination of sweet taste preferences. When compared to aqueous sucrose solutions, significantly lower amounts of sucralose were required to identify the preference for sweet taste. The validity of this approach was determined by comparing sweet taste preferences obtained with five different sucralose-containing edible strips to a set of five intensity-matched sucrose solutions. When compared to the solution test, edible strips required approximately the same number of steps to identify the preferred amount of sweet taste stimulus. Both approaches yielded similar distribution patterns for the preferred amount of sweet taste stimulus. In addition, taste intensity values for the preferred amount of sucralose in strips were similar to that of sucrose in solution. The hedonic values for the preferred amount of sucralose were lower than for sucrose, but the taste quality of the preferred sucralose strip was described as sweet. When taste intensity values between sucralose strips and sucralose solutions containing identical amounts of taste stimulus were compared, sucralose strips produced a greater taste intensity and more positive hedonic response. A preference test that uses edible strips for stimulus delivery should be useful for identifying preferences for sweet taste in young children, and in clinical populations. This test should also be useful for identifying sweet taste preferences outside of the lab or clinic. Finally, edible strips should be useful for developing preference tests for other primary taste stimuli and for taste mixtures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Functional cell types in taste buds have distinct longevities.

PubMed

Perea-Martinez, Isabel; Nagai, Takatoshi; Chaudhari, Nirupa

2013-01-01

Taste buds are clusters of polarized sensory cells embedded in stratified oral epithelium. In adult mammals, taste buds turn over continuously and are replenished through the birth of new cells in the basal layer of the surrounding non-sensory epithelium. The half-life of cells in mammalian taste buds has been estimated as 8-12 days on average. Yet, earlier studies did not address whether the now well-defined functional taste bud cell types all exhibit the same lifetime. We employed a recently developed thymidine analog, 5-ethynil-2'-deoxyuridine (EdU) to re-evaluate the incorporation of newly born cells into circumvallate taste buds of adult mice. By combining EdU-labeling with immunostaining for selected markers, we tracked the differentiation and lifespan of the constituent cell types of taste buds. EdU was primarily incorporated into basal extragemmal cells, the principal source for replenishing taste bud cells. Undifferentiated EdU-labeled cells began migrating into circumvallate taste buds within 1 day of their birth. Type II (Receptor) taste cells began to differentiate from EdU-labeled precursors beginning 2 days after birth and then were eliminated with a half-life of 8 days. Type III (Presynaptic) taste cells began differentiating after a delay of 3 days after EdU-labeling, and they survived much longer, with a half-life of 22 days. We also scored taste bud cells that belong to neither Type II nor Type III, a heterogeneous group that includes mostly Type I cells, and also undifferentiated or immature cells. A non-linear decay fit described these cells as two sub-populations with half-lives of 8 and 24 days respectively. Our data suggest that many post-mitotic cells may remain quiescent within taste buds before differentiating into mature taste cells. A small number of slow-cycling cells may also exist within the perimeter of the taste bud. Based on their incidence, we hypothesize that these may be progenitors for Type III cells.

Functional Cell Types in Taste Buds Have Distinct Longevities

PubMed Central

Perea-Martinez, Isabel; Nagai, Takatoshi; Chaudhari, Nirupa

2013-01-01

Taste buds are clusters of polarized sensory cells embedded in stratified oral epithelium. In adult mammals, taste buds turn over continuously and are replenished through the birth of new cells in the basal layer of the surrounding non-sensory epithelium. The half-life of cells in mammalian taste buds has been estimated as 8–12 days on average. Yet, earlier studies did not address whether the now well-defined functional taste bud cell types all exhibit the same lifetime. We employed a recently developed thymidine analog, 5-ethynil-2′-deoxyuridine (EdU) to re-evaluate the incorporation of newly born cells into circumvallate taste buds of adult mice. By combining EdU-labeling with immunostaining for selected markers, we tracked the differentiation and lifespan of the constituent cell types of taste buds. EdU was primarily incorporated into basal extragemmal cells, the principal source for replenishing taste bud cells. Undifferentiated EdU-labeled cells began migrating into circumvallate taste buds within 1 day of their birth. Type II (Receptor) taste cells began to differentiate from EdU-labeled precursors beginning 2 days after birth and then were eliminated with a half-life of 8 days. Type III (Presynaptic) taste cells began differentiating after a delay of 3 days after EdU-labeling, and they survived much longer, with a half-life of 22 days. We also scored taste bud cells that belong to neither Type II nor Type III, a heterogeneous group that includes mostly Type I cells, and also undifferentiated or immature cells. A non-linear decay fit described these cells as two sub-populations with half-lives of 8 and 24 days respectively. Our data suggest that many post-mitotic cells may remain quiescent within taste buds before differentiating into mature taste cells. A small number of slow-cycling cells may also exist within the perimeter of the taste bud. Based on their incidence, we hypothesize that these may be progenitors for Type III cells. PMID:23320081

Taste - impaired

MedlinePlus

... last slightly longer. Causes of impaired taste include: Bell's palsy Common cold Flu and other viral infections Nasal ... any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should ...

Tasting Wine: A Learning Experience

ERIC Educational Resources Information Center

King, Tanya J.; Donaldson, Jilleen A.; Harry, Emma

2012-01-01

This paper describes a field trip by senior undergraduate anthropology students to a local winery, where they participated in a wine-tasting class with winery staff. In response to explicit hints from a wine-tasting facilitator, and more subtle cues from the cultural capital embedded in their surroundings and the winery staff, the students…

Bioelectronic tongue using heterodimeric human taste receptor for the discrimination of sweeteners with human-like performance.

PubMed

Song, Hyun Seok; Jin, Hye Jun; Ahn, Sae Ryun; Kim, Daesan; Lee, Sang Hun; Kim, Un-Kyung; Simons, Christopher T; Hong, Seunghun; Park, Tai Hyun

2014-10-28

The sense of taste helps humans to obtain information and form a picture of the world by recognizing chemicals in their environments. Over the past decade, large advances have been made in understanding the mechanisms of taste detection and mimicking its capability using artificial sensor devices. However, the detection capability of previous artificial taste sensors has been far inferior to that of animal tongues, in terms of its sensitivity and selectivity. Herein, we developed a bioelectronic tongue using heterodimeric human sweet taste receptors for the detection and discrimination of sweeteners with human-like performance, where single-walled carbon nanotube field-effect transistors were functionalized with nanovesicles containing human sweet taste receptors and used to detect the binding of sweeteners to the taste receptors. The receptors are heterodimeric G-protein-coupled receptors (GPCRs) composed of human taste receptor type 1 member 2 (hTAS1R2) and human taste receptor type 1 member 3 (hTAS1R3), which have multiple binding sites and allow a human tongue-like broad selectivity for the detection of sweeteners. This nanovesicle-based bioelectronic tongue can be a powerful tool for the detection of sweeteners as an alternative to labor-intensive and time-consuming cell-based assays and the sensory evaluation panels used in the food and beverage industry. Furthermore, this study also allows the artificial sensor to exam the functional activity of dimeric GPCRs.

Multiple Shh signaling centers participate in fungiform papilla and taste bud formation and maintenance

PubMed Central

Liu, H-X; Ermilov, A; Grachtchouk, M; Li, L; Gumucio, DL; Dlugosz, AA; Mistretta, CM

2014-01-01

organs, the fungiform papilla and taste bud, and surrounding lingual cells. Shh signaling has roles in forming and maintaining fungiform papillae and taste buds, most likely via stage-specific autocrine and/or paracrine mechanisms, and by engaging epithelial/mesenchymal interactions. PMID:23916850

Multiple Shh signaling centers participate in fungiform papilla and taste bud formation and maintenance.

PubMed

Liu, Hong Xiang; Ermilov, Alexandre; Grachtchouk, Marina; Li, Libo; Gumucio, Deborah L; Dlugosz, Andrzej A; Mistretta, Charalotte M

2013-10-01

organs, the fungiform papilla and taste bud, and surrounding lingual cells. Shh signaling has roles in forming and maintaining fungiform papillae and taste buds, most likely via stage-specific autocrine and/or paracrine mechanisms, and by engaging epithelial/mesenchymal interactions. © 2013 Elsevier Inc. All rights reserved.

Advanced Taste Sensors Based on Artificial Lipids with Global Selectivity to Basic Taste Qualities and High Correlation to Sensory Scores

PubMed Central

Kobayashi, Yoshikazu; Habara, Masaaki; Ikezazki, Hidekazu; Chen, Ronggang; Naito, Yoshinobu; Toko, Kiyoshi

2010-01-01

Effective R&D and strict quality control of a broad range of foods, beverages, and pharmaceutical products require objective taste evaluation. Advanced taste sensors using artificial-lipid membranes have been developed based on concepts of global selectivity and high correlation with human sensory score. These sensors respond similarly to similar basic tastes, which they quantify with high correlations to sensory score. Using these unique properties, these sensors can quantify the basic tastes of saltiness, sourness, bitterness, umami, astringency and richness without multivariate analysis or artificial neural networks. This review describes all aspects of these taste sensors based on artificial lipid, ranging from the response principle and optimal design methods to applications in the food, beverage, and pharmaceutical markets. PMID:22319306

Taste bud cell dynamics during normal and sodium-restricted development.

PubMed

Hendricks, Susan J; Brunjes, Peter C; Hill, David L

2004-04-26

Taste bud volume increases over the postnatal period to match the number of neurons providing innervation. To clarify age-related changes in fungiform taste bud volume, the current study investigated developmental changes in taste bud cell number, proliferation rate, and life span. Taste bud growth can largely be accounted for by addition of cytokeratin-19-positive taste bud cells. Examination of taste bud cell kinetics with 3H-thymidine autoradiography revealed that cell life span and turnover periods were not altered during normal development but that cells were produced more rapidly in young rats, a prominent modification that could lead to increased taste bud size. By comparison, dietary sodium restriction instituted during pre- and postnatal development results in small taste buds at adulthood as a result of fewer cytokeratin-19-positive cells. The dietary manipulation also had profound influences on taste bud growth kinetics, including an increased latency for cells to enter the taste bud and longer life span and turnover periods. These studies provide fundamental, new information about taste bud development under normal conditions and after environmental manipulations that impact nerve/target matching. Copyright 2004 Wiley-Liss, Inc.

Change of the human taste bud volume over time.

PubMed

Srur, Ehab; Stachs, Oliver; Guthoff, Rudolf; Witt, Martin; Pau, Hans Wilhelm; Just, Tino

2010-08-01

The specific aim of this study is to measure the taste volume in healthy human subjects over a 2.5-month period and to demonstrate morphological changes of the peripheral taste organs. Eighteen human taste buds in four fungiform papillae (fPap) were examined over a 10-week period. The fungiform papillae investigated were selected based on the form of the papillae or the arrangement of surface taste pores. Measurements were performed over 10 consecutive weeks, with five scans in a day once a week. The following parameters were measured: height and diameter of the taste bud, diameter of the fungiform papilla and diameter of the taste pore. The findings of this exploratory study indicated that (1) taste bud volumes changed over a 10-week period, (2) the interval between two volume maxima within the 10-week period was 3-5 weeks, and (3) the diameter of the fPap did not correlate with the volume of a single taste bud or with the volume of all taste buds in the fPap within the 10-week period. This exploratory in vivo study revealed changes in taste bud volumes in healthy humans with age-related gustatory sensitivity. These findings need to be considered when studying the effect of denervation of fungiform papillae in vivo using confocal microscopy. Crown Copyright 2009. Published by Elsevier Ireland Ltd. All rights reserved.

Different Neural Processing of Umami and Salty Taste Determined by Umami Identification Ability Independent of Repeated Umami Exposure.

PubMed

Han, Pengfei; Mohebbi, Mohebbat; Unrath, Manja; Hummel, Cornelia; Hummel, Thomas

2018-07-15

There is a large inter-individual variation for umami taste perception. However the neural mechanism for this variability is not well understood. This study investigated brain responses to umami and salty taste among individuals with different umami identification abilities and the effect of repeated oral umami exposure on umami identification and neural processing of taste perceptions. Fifteen participants with high umami identification ability ("High Tasters, HT) and fifteen with low umami identification ability ("Low Tasters", LT) underwent three weeks of controlled exposure to umami taste (umami training). Prior to and after the training, participants underwent fMRI scans during which the umami taste solution and a control taste (salty) solution were delivered to their mouth using a gustometer. Taste intensity and pleasantness were rated after each scan. Umami taste identification was assessed before and after the umami training using "Taste Strips" test. Neuroimaging results showed different central processing of umami and salty taste based on umami identification ability, in which the umami LT had stronger activation in the thalamus and hippocampus while the umami HT showed stronger activation in the primary gustatory cortex. In addition, umami identification was significantly improved after umami training for LT. However, it was not reflected in changes in neural activation. The current study shows that attention and association/memory related brain structures play a significant role in the perception of umami taste; and with reference to the results of repeated umami exposure, the presence of very subtle changes regarding the neural processing. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

To Go or Not to Go: A Proof of Concept Study Testing Food-Specific Inhibition Training for Women with Eating and Weight Disorders.

PubMed

Turton, Robert; Nazar, Bruno P; Burgess, Emilee E; Lawrence, Natalia S; Cardi, Valentina; Treasure, Janet; Hirsch, Colette R

2018-01-01

Inefficient food-specific inhibitory control is a potential mechanism that underlies binge eating in bulimia nervosa and binge eating disorder. Go/no-go training tools have been developed to increase inhibitory control over eating impulses. Using a within-subjects design, this study examined whether one session of food-specific go/no-go training, versus general inhibitory control training, modifies eating behaviour. The primary outcome measure was food consumption on a taste test following each training session. Women with bulimia nervosa and binge eating disorder had small non-significant reductions in high-calorie food consumption on the taste test following the food-specific compared with the general training. There were no effects on eating disorder symptomatic behaviour (i.e. binge eating/purging) in the 24 h post-training. The training task was found to be acceptable by the clinical groups. More research is needed with larger sample sizes to determine the effectiveness of this training approach for clinical populations. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Common sense about taste: from mammals to insects.

PubMed

Yarmolinsky, David A; Zuker, Charles S; Ryba, Nicholas J P

2009-10-16

The sense of taste is a specialized chemosensory system dedicated to the evaluation of food and drink. Despite the fact that vertebrates and insects have independently evolved distinct anatomic and molecular pathways for taste sensation, there are clear parallels in the organization and coding logic between the two systems. There is now persuasive evidence that tastant quality is mediated by labeled lines, whereby distinct and strictly segregated populations of taste receptor cells encode each of the taste qualities.

Shared and unique mechanisms underlying binge eating disorder and addictive disorders

PubMed Central

Schulte, Erica M.; Grilo, Carlos M.; Gearhardt, Ashley N.

2018-01-01

Scientific interest in “food addiction” is growing, but the topic remains controversial. One critique of “food addiction” is its high degree of phenotypic overlap with binge eating disorder (BED). In order to examine associations between problematic eating behaviors, such as binge eating and “food addiction,” we propose the need to move past examining similarities and differences in symptomology. Instead, focusing on relevant mechanisms may more effectively determine whether “food addiction” contributes to disordered eating behavior for some individuals. This paper reviews the evidence for mechanisms that are shared (i.e., reward dysfunction, impulsivity) and unique for addiction (i.e., withdrawal, tolerance) and eating disorder (i.e., dietary restraint, shape/weight concern) frameworks. This review will provide a guiding framework to outline future areas of research needed to evaluate the validity of the “food addiction” model and to understand its potential contribution to disordered eating. PMID:26879210

Distinct Contributions of T1R2 and T1R3 Taste Receptor Subunits to the Detection of Sweet Stimuli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie,Y.; Vigues, S.; Hobbs, J.

2005-01-01

The molecular mechanisms by which G protein-coupled receptor (GPCR)-type chemosensory receptors of animals selectively interact with their cognate ligands remain poorly understood. There is growing evidence that many chemosensory receptors exist in multimeric complexes, though little is known about the relative contributions of individual subunits to receptor functions. This study showed that each of the two subunits in the mammalian heteromeric T1R2:T1R3 sweet taste receptor binds sweet stimuli, though with distinct affinities and conformational changes. Furthermore, ligand affinities for T1R3 are drastically reduced by the introduction of a single amino acid change associated with decreased sweet taste sensitivity in mice.more » Thus, individual T1R subunits increase the receptive range of the sweet taste receptor, offering a functional mechanism for phenotypic variations in sweet taste.« less

[Molecular logic of alcohol and taste].

PubMed

Matsumoto, Ichiro; Abe, Keiko; Arai, Soichi

2006-10-01

Ethanol, a main constituent of every alcohol beverage, has long been calling our attention to its gustatory effect. Recent molecular dynamics studies have suggested that ethanol as well as other tastants in foods, when taken in the oral cavity, gives rise to a taste signal which is expressed via reception at taste cells in the taste bud, intracellular signal transduction in collaboration with G proteins and effecters, and signal transmission to synapsed taste neurons, and/or simultaneous reception at and signal transduction in somatosensory neurons. The taste of ethanol and its acceptability are then recognized and judged at the higher center, with generation of various physiological phenomena in the body. We have tried to make an all-inclusive DNA microarray analysis, demonstrating that when a rat tongue is stimulated with a drop of aqueous ethanol in vivo, several particular genes are specifically up- or down-regulated in trigeminal ganglions. These initial gene expression changes at peripheral neurocytes might in whole or in part trigger some of the ethanol-associated gustatory and bodily response. The importance of defining a related molecular logic is emphasized to understand academic and industrial significances of this unique food constituent, ethanol.

Hypoxanthine enhances the cured meat taste.

PubMed

Ichimura, Sayaka; Nakamura, Yukinobu; Yoshida, Yuka; Hattori, Akihito

2017-02-01

We evaluated the enhancement of cured meat taste during maturation by sensory analysis. We focused on the heat-stable sarcoplasmic fraction (HSSF) to identify the factors related to cured meat taste. Because the dry matter of HSSF contained more than 30% nitrogen, nitrogen compounds such as free amino acids, small peptides and adenosine triphosphate-related compounds seemed to be the important components of HSSF. The samples cured with HSSF for 2 h exhibited the same taste profile as ones cured without HSSF for 168 h. Therefore, the changes in the amount and fractions of nitrogen compounds were examined in HSSF during incubation from 0 to 168 h. The concentration of hypoxanthine (Hx) gradually increased, while inosine-5'-monophosphate decreased during the incubation. The samples cured with pickles containing various concentrations of Hx were subjected to sensory analysis. The addition of Hx, in a dose-dependent fashion, enhanced cured meat taste by maturation for 2 h. It was concluded that Hx is essential for the enhancement of cured meat taste. © 2016 The Authors. Animal Science Journal published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Animal Science.

Taste avoidance induced by wheel running: effects of backward pairings and robustness of conditioned taste aversion.

PubMed

Salvy, Sarah-Jeanne; Pierce, W David; Heth, Donald C; Russell, James C

2004-09-15

Rats repeatedly exposed to a distinctive novel solution (conditioned stimulus, CS) followed by the opportunity to run in a wheel subsequently drink less of this solution. Investigations on this phenomenon indicate that wheel running is an effective unconditioned stimulus (US) for establishing conditioned taste aversion (CTA) when using a forward conditioning procedure (i.e., the US-wheel running follows the CS-taste). However, other studies show that wheel running produces reliable preference for a distinctive place when pairings are backward (i.e., the CS-location follows the US-wheel running). One possibility to account for these results is that rewarding aftereffects of wheel running conditioned preference to the CS. The main objective of the present study was to assess the effects of backward conditioning using wheel running as the US and a distinctive taste as the CS. In a between-groups design, two experimental groups [i.e., forward (FC) and backward conditioning (BC)] and two control groups [CS-taste alone (TA) and CS-US unpaired (UNP)] were compared. Results from this experiment indicated that there is less suppression of drinking when a CS-taste followed a bout of wheel running. In fact, rats in the BC group drank more of the paired solution than all the other groups.

Metallic taste in cancer patients treated with chemotherapy.

PubMed

IJpma, I; Renken, R J; Ter Horst, G J; Reyners, A K L

2015-02-01

Metallic taste is a taste alteration frequently reported by cancer patients treated with chemotherapy. Attention to this side effect of chemotherapy is limited. This review addresses the definition, assessment methods, prevalence, duration, etiology, and management strategies of metallic taste in chemotherapy treated cancer patients. Literature search for metallic taste and chemotherapy was performed in PubMed up to September 2014, resulting in 184 articles of which 13 articles fulfilled the inclusion criteria: English publications addressing metallic taste in cancer patients treated with FDA-approved chemotherapy. An additional search in Google Scholar, in related articles of both search engines, and subsequent in the reference lists, resulted in 13 additional articles included in this review. Cancer patient forums were visited to explore management strategies. Prevalence of metallic taste ranged from 9.7% to 78% among patients with various cancers, chemotherapy treatments, and treatment phases. No studies have been performed to investigate the influence of metallic taste on dietary intake, body weight, and quality of life. Several management strategies can be recommended for cancer patients: using plastic utensils, eating cold or frozen foods, adding strong herbs, spices, sweetener or acid to foods, eating sweet and sour foods, using 'miracle fruit' supplements, and rinsing with chelating agents. Although metallic taste is a frequent side effect of chemotherapy and a much discussed topic on cancer patient forums, literature regarding metallic taste among chemotherapy treated cancer patients is scarce. More awareness for this side effect can improve the support for these patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

Conditioned taste aversion, drugs of abuse and palatability

PubMed Central

Lin, Jian-You; Arthurs, Joe; Reilly, Steve

2014-01-01

LIN, J.-Y., J. Arthurs and S. Reilly. Conditioned taste aversion: Palatability and drugs of abuse. NEUROSCI BIOBEHAV REV XX(x) XXX-XXX, 2014. – We consider conditioned taste aversion to involve a learned reduction in the palatability of a taste (and hence in amount consumed) based on the association that develops when a taste experience is followed by gastrointestinal malaise. The present article evaluates the well-established finding that drugs of abuse, at doses that are otherwise considered rewarding and self-administered, cause intake suppression. Our recent work using lick pattern analysis shows that drugs of abuse also cause a palatability downshift and, therefore, support conditioned taste aversion learning. PMID:24813806

Evolution: a study in bad taste?

PubMed

Wooding, Stephen

2005-10-11

Bitter tastes are among the most salient of life's experiences--who can forget one's first encounter with dandelion milk or a stout beer? Studies of the genes underlying these tastes are providing new perspectives on human origins and health.

Males and females show differential brain activation to taste when hungry and sated in gustatory and reward areas

PubMed Central

Haase, Lori; Green, Erin; Murphy, Claire

2011-01-01

Although males and females differ in eating behavior and prevalence rates for eating disorders and obesity, little is known about gender differences in cortical activation to pleasant and unpleasant pure tastes during the physiological states of hunger and satiety. Twenty-one healthy young adults (12 females and 9 males) underwent two functional magnetic resonance imaging scans. Using four pure tastants of differing qualities (i.e., salty, sour, bitter, sweet), the present study examined gender differences in fMRI activation during two motivational states (hunger and satiety). There was greater change in fMRI activation from hunger to satiety in males than females in response to all tastes within the middle frontal gyrus (BA 10), insula, and cerebellum. Males also had greater change in activation from hunger to satiety, relative to females, in limbic regions including dorsal striatum, amygdala, parahippocampal gyrus, and posterior and anterior cingulate; however, activation was stimulus dependent, despite equivalent ratings in perceived pleasantness and intensity. Interestingly, males and females showed significant change from hunger to satiety in response to citric acid, suggesting that in addition to gender and physiological condition, stimulus quality is an important factor in taste fMRI activation. These gender differences may have implications for the pathophysiology of eating disorders and obesity. PMID:21718731

“Turn Up the Taste”: Assessing the Role of Taste Intensity and Emotion in Mediating Crossmodal Correspondences between Basic Tastes and Pitch

PubMed Central

Wang, Sheila; Spence, Charles

2016-01-01

People intuitively match basic tastes to sounds of different pitches, and the matches that they make tend to be consistent across individuals. It is, though, not altogether clear what governs such crossmodal mappings between taste and auditory pitch. Here, we assess whether variations in taste intensity influence the matching of taste to pitch as well as the role of emotion in mediating such crossmodal correspondences. Participants were presented with 5 basic tastants at 3 concentrations. In Experiment 1, the participants rated the tastants in terms of their emotional arousal and valence/pleasantness, and selected a musical note (from 19 possible pitches ranging from C2 to C8) and loudness that best matched each tastant. In Experiment 2, the participants made emotion ratings and note matches in separate blocks of trials, then made emotion ratings for all 19 notes. Overall, the results of the 2 experiments revealed that both taste quality and concentration exerted a significant effect on participants’ loudness selection, taste intensity rating, and valence and arousal ratings. Taste quality, not concentration levels, had a significant effect on participants’ choice of pitch, but a significant positive correlation was observed between individual perceived taste intensity and pitch choice. A significant and strong correlation was also demonstrated between participants’ valence assessments of tastants and their valence assessments of the best-matching musical notes. These results therefore provide evidence that: 1) pitch–taste correspondences are primarily influenced by taste quality, and to a lesser extent, by perceived intensity; and 2) such correspondences may be mediated by valence/pleasantness. PMID:26873934