WorldWideScience

Sample records for salt taste receptor

  1. Bioelectronic tongue of taste buds on microelectrode array for salt sensing.

    Science.gov (United States)

    Liu, Qingjun; Zhang, Fenni; Zhang, Diming; Hu, Ning; Wang, Hua; Hsia, K Jimmy; Wang, Ping

    2013-02-15

    Taste has received great attention for its potential applications. In this work, we combine the biological tissue with micro-chips to establish a novel bioelectronic tongue system for salt taste detection. Before experiment, we established a computational model of action potential in salt taste receptor cell, simulating the responsive results to natural salt stimuli of NaCl solution with various concentrations. Then 36-channel microelectrode arrays (MEA) with the diameter of 30 μm were fabricated on the glass substrate, and taste epithelium was stripped from rat and fixed on MEA. When stimulated by the salt stimuli, electrophysiological activities of taste receptor cells in taste buds were measured through a multi-channel recording system. Both simulation and experiment results showed a dose-dependent increase in NaCl-induced potentials of taste receptor cells, which indicated good applications in salt measurements. The multi-channel analysis demonstrated that different groups of MEA channels were activated during stimulations, indicating non-overlapping populations of receptor cells in taste buds involved in salt taste perception. The study provides an effective and reliable biosensor platform to help recognize and distinguish salt taste components. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Taste Receptor Signaling-- From Tongues to Lungs

    Science.gov (United States)

    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

  3. Evaluation of Taste Properties of Commercially Available Salts

    OpenAIRE

    ISHIKAWA, Kyoko; SUGIMOTO, Maho; KUMAGAI, Masanori; MATSUNAGA, Ryuji

    2006-01-01

    This study examined commercially available salts'taste properties. The salts were used in preparation of four dishes: asazuke of cucumber, asazuke of Chinese cabbage, clear soup, and green soybean rice. The respective tastes of the salts in those prepared foods differed from those of the salts alone. We evaluated the parameters: saltiness, mildness, unpleasantness, and palatability. Differences of the salt samples affected the perception of saltiness. Results of taste sensor analyses showed t...

  4. Relationship Between Salt Intake, Salt-Taste Threshold and Blood ...

    African Journals Online (AJOL)

    Conclusion: Sodium intake measured as 24-hour urinary sodium is increased in subjects with hypertension attesting to sodium intake as a risk factor for the development of high blood pressure. Subjects with high salt taste threshold also have increased urinary sodium excretion which may predispose them to deveploment ...

  5. Expression of GABAergic receptors in mouse taste receptor cells.

    Directory of Open Access Journals (Sweden)

    Margaret R Starostik

    Full Text Available BACKGROUND: Multiple excitatory neurotransmitters have been identified in the mammalian taste transduction, with few studies focused on inhibitory neurotransmitters. Since the synthetic enzyme glutamate decarboxylase (GAD for gamma-aminobutyric acid (GABA is expressed in a subset of mouse taste cells, we hypothesized that other components of the GABA signaling pathway are likely expressed in this system. GABA signaling is initiated by the activation of either ionotropic receptors (GABA(A and GABA(C or metabotropic receptors (GABA(B while it is terminated by the re-uptake of GABA through transporters (GATs. METHODOLOGY/PRINCIPAL FINDINGS: Using reverse transcriptase-PCR (RT-PCR analysis, we investigated the expression of different GABA signaling molecules in the mouse taste system. Taste receptor cells (TRCs in the circumvallate papillae express multiple subunits of the GABA(A and GABA(B receptors as well as multiple GATs. Immunocytochemical analyses examined the distribution of the GABA machinery in the circumvallate papillae. Both GABA(A-and GABA(B- immunoreactivity were detected in the peripheral taste receptor cells. We also used transgenic mice that express green fluorescent protein (GFP in either the Type II taste cells, which can respond to bitter, sweet or umami taste stimuli, or in the Type III GAD67 expressing taste cells. Thus, we were able to identify that GABAergic receptors are expressed in some Type II and Type III taste cells. Mouse GAT4 labeling was concentrated in the cells surrounding the taste buds with a few positively labeled TRCs at the margins of the taste buds. CONCLUSIONS/SIGNIFICANCE: The presence of GABAergic receptors localized on Type II and Type III taste cells suggests that GABA is likely modulating evoked taste responses in the mouse taste bud.

  6. A2BR Adenosine Receptor Modulates Sweet Taste in Circumvallate Taste Buds

    Science.gov (United States)

    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

  7. A2BR adenosine receptor modulates sweet taste in circumvallate taste buds.

    Directory of Open Access Journals (Sweden)

    Shinji Kataoka

    Full Text Available 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.

  8. A2BR adenosine receptor modulates sweet taste in circumvallate taste buds.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  10. Perirhinal Cortex Muscarinic Receptor Blockade Impairs Taste Recognition Memory Formation

    Science.gov (United States)

    Gutierrez, Ranier; De la Cruz, Vanesa; Rodriguez-Ortiz, Carlos J.; Bermudez-Rattoni, Federico

    2004-01-01

    The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition…

  11. Sweet Taste Receptor Signaling Network: Possible Implication for Cognitive Functioning

    Directory of Open Access Journals (Sweden)

    Menizibeya O. Welcome

    2015-01-01

    Full Text Available 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.

  12. Perirhinal Cortex Muscarinic Receptor Blockade Impairs Taste Recognition Memory Formation

    OpenAIRE

    Gutiérrez, Ranier; De la Cruz, Vanesa; Rodriguez-Ortiz, Carlos J.; Bermudez-Rattoni, Federico

    2004-01-01

    The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition memory using attenuation of neophobia as an index. In addition, learned taste aversion in both short- and long-term memory tests was exclusively impa...

  13. GABA, its receptors, and GABAergic inhibition in mouse taste buds.

    Science.gov (United States)

    Dvoryanchikov, Gennady; Huang, Yijen A; Barro-Soria, Rene; Chaudhari, Nirupa; Roper, Stephen D

    2011-04-13

    Taste buds consist of at least three principal cell types that have different functions in processing gustatory signals: glial-like (type I) cells, receptor (type II) cells, and presynaptic (type III) cells. Using a combination of Ca2+ imaging, single-cell reverse transcriptase-PCR and immunostaining, we show that GABA is an inhibitory transmitter in mouse taste buds, acting on GABA(A) and GABA(B) receptors to suppress transmitter (ATP) secretion from receptor cells during taste stimulation. Specifically, receptor cells express GABA(A) receptor subunits β2, δ, and π, as well as GABA(B) receptors. In contrast, presynaptic cells express the GABA(A) β3 subunit and only occasionally GABA(B) receptors. In keeping with the distinct expression pattern of GABA receptors in presynaptic cells, we detected no GABAergic suppression of transmitter release from presynaptic cells. We suggest that GABA may serve function(s) in taste buds in addition to synaptic inhibition. Finally, we also defined the source of GABA in taste buds: GABA is synthesized by GAD65 in type I taste cells as well as by GAD67 in presynaptic (type III) taste cells and is stored in both those two cell types. We conclude that GABA is an inhibitory transmitter released during taste stimulation and possibly also during growth and differentiation of taste buds.

  14. Research progress of the bitter taste receptor genes in primates.

    Science.gov (United States)

    Feng, Ping; Luo, Rui-Jian

    2018-02-20

    Among the five basic tastes (umami, sweet, bitter, salty and sour), the perception of bitterness is believed to protect animals from digesting toxic and harmful substances, thus it is vital for animal survival. The taste of bitterness is triggered by the interaction between bitter substances and bitter taste receptors, which are encoded by Tas2rs. The gene numbers vary largely across species to meet different demands. So far, several ligands of bitter receptors have been identified in primates. They also discovered that the selective pressure of certain bitter taste receptor genes vary across taxa, genes or even different functional regions of the gene. In this review, we summarize the research progress of bitter taste receptor genes in primates by introducing the functional diversity of bitter receptors, the specific interaction between bitter taste receptors and ligands, the relationship between the evolutionary pattern of bitter taste receptors and diets, and the adaptive evolution of bitter taste receptor genes. We aim to provide a reference for further research on bitter receptor genes in primates.

  15. [Functional properties of taste bud cells. Mechanisms of afferent neurotransmission in Type II taste receptor cells].

    Science.gov (United States)

    Romanov, R A

    2013-01-01

    Taste Bud cells are heterogeneous in their morphology and functionality. These cells are responsible for sensing a wide variety of substances and for associating detected compounds with a different taste: bitter, sweet, salty, sour and umami. Today we know that each of the five basic tastes corresponds to distinct cell populations organized into three basic morpho-functional cell types. In addition, some receptor cells of the taste bud demonstrate glia-related functions. In this article we expand on some properties of these three morphological receptor cell types. Main focus is devoted to the Type II cells and unusual mechanism for afferent neurotransmission in these cells. Taste cells of the Type II consist of three populations detecting bitter, sweet and umami tastes, and, thus, evoke a serious scientific interest.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Salivary Proteome Patterns Affecting Human Salt Taste Sensitivity.

    Science.gov (United States)

    Stolle, Theresa; Grondinger, Freya; Dunkel, Andreas; Meng, Chen; Médard, Guillaume; Kuster, Bernhard; Hofmann, Thomas

    2017-10-25

    To investigate the role of perireceptor events in inter-individual variability in salt taste sensitivity, 31 volunteers were monitored in their detection functions for sodium chloride (NaCl) and classified into sensitive (0.6-1.7 mmol/L), medium-sensitive (1.8-6.9 mmol/L), and nonsensitive (7.0-11.2 mmol/L) subjects. Chemosensory intervention of NaCl-sensitive (S + ) and nonsensitive (S - ) panellists with potassium chloride, ammonium chloride, and sodium gluconate showed the salt taste sensitivity to be specific for NaCl. As no significant differences were found between S + and S - subjects in salivary sodium and protein content, salivary proteome differences and their stimulus-induced dynamic changes were analyzed by tryptic digestion, iTRAQ labeling, and liquid chromatography-tandem mass spectrometry analysis. Differences in the salivary proteome between S + and S - subjects were found primarily in resting saliva and were largely independent of the dynamic alterations observed upon salt stimulation. Gene ontology enrichment analysis of key proteins, i.e., immunoglobulin heavy constant y1, myeloblastin, cathepsin G, and kallikrein, revealed significantly increased serine-type endopeptidase activity for the S + group, while the S - group exhibited augmented cysteine-type endopeptidase inhibitor activity by increased abundances in lipocalin-1 and cystatin-D, -S, and -SN, respectively. As proteases have been suggested to facilitate transepithelial sodium transport by cleaving the y-subunit of the epithelial sodium channel (ENaC) and protease inhibitors have been shown to reduce ENaC-mediated sodium transport, the differentially modulated proteolytic activity patterns observed in vivo for S + and S - subjects show evidence of them playing a crucial role in affecting human NaCl sensitivity.

  20. Liking, salt taste perception and use of table salt when consuming reduced-salt chicken stews in light of South Africa's new salt regulations.

    Science.gov (United States)

    De Kock, H L; Zandstra, E H; Sayed, N; Wentzel-Viljoen, E

    2016-01-01

    This study investigated the impact of salt reduction on liking, salt taste perception, and use of table salt when consuming chicken stew in light of South Africa's new salt recommendations. In total, 432 South-African consumers (aged 35.2 ± 12.3 years) consumed a full portion of a chicken stew meal once at a central location. Four stock cube powders varying in salt content were used to prepare chicken stews: 1) no reduction - 2013 Na level; regular salt level as currently available on the South African market (24473 mg Na/100 g), 2) salt reduction smaller than 2016 level, i.e. 10%-reduced (22025 mg Na/100 g), 3) 2016 salt level, as per regulatory prescriptions (18000 mg Na/100 g), 4) 2019 salt level, as per regulatory prescriptions (13000 mg Na/100 g). Consumers were randomly allocated to consume one of the four meals. Liking, salt taste perception, and use of table salt and pepper were measured. Chicken stews prepared with reduced-salt stock powders were equally well-liked as chicken stews with the current salt level. Moreover, a gradual reduction of the salt in the chicken stews resulted in a reduced salt intake, up to an average of 19% for the total group compared to the benchmark 2013 Na level stew. However, 19% of consumers compensated by adding salt back to full compensation in some cases. More salt was added with increased reductions of salt in the meals, even to the point of full compensation. Further investigation into the impacts of nutrition communication and education about salt reduction on salt taste perception and use is needed. This research provides new consumer insights on salt use and emphasises the need for consumer-focused behaviour change approaches, in addition to reformulation of products. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  2. The Role of the Sweet Taste Receptor in Enteroendocrine Cells and Pancreatic β-Cells

    Directory of Open Access Journals (Sweden)

    Itaru Kojima

    2011-10-01

    Full Text Available The sweet taste receptor is expressed in taste cells located in taste buds of the tongue. This receptor senses sweet substances in the oral cavity, activates taste cells, and transmits the taste signals to adjacent neurons. The sweet taste receptor is a heterodimer of two G protein-coupled receptors, T1R2 and T1R3. Recent studies have shown that this receptor is also expressed in the extragustatory system, including the gastrointestinal tract, pancreatic β-cells, and glucose-responsive neurons in the brain. In the intestine, the sweet taste receptor regulates secretion of incretin hormones and glucose uptake from the lumen. In β-cells, activation of the sweet taste receptor leads to stimulation of insulin secretion. Collectively, the sweet taste receptor plays an important role in recognition and metabolism of energy sources in the body.

  3. Expression of sulfonylurea receptors in rat taste buds.

    Science.gov (United States)

    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.

  4. Genetic diversity of bitter taste receptor gene family in Sichuan

    Indian Academy of Sciences (India)

    Genetic diversity of bitter taste receptor gene family in Sichuan domestic and Tibetan chicken populations. YUAN SU DIYAN LI UMA GAUR YAN WANG NAN WU BINLONG CHEN HONGXIAN XU HUADONG YIN YAODONG HU QING ZHU. RESEARCH ARTICLE Volume 95 Issue 3 September 2016 pp 675-681 ...

  5. Genetic diversity of bitter taste receptor gene family in Sichuan ...

    Indian Academy of Sciences (India)

    Previous research had revealed that chicken has only three bitter taste receptor genes (Tas2r1, ... Journal of Genetics, DOI 10.1007/s12041-016-0684-4, Vol. ..... between red-winged blackbirds and European starlings. ... Academic Press,.

  6. Discrimination of taste qualities among mouse fungiform taste bud cells.

    Science.gov (United States)

    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.

  7. Molecular Features Underlying Selectivity in Chicken Bitter Taste Receptors

    Directory of Open Access Journals (Sweden)

    Antonella Di Pizio

    2018-01-01

    Full Text Available Chickens sense the bitter taste of structurally different molecules with merely three bitter taste receptors (Gallus gallus taste 2 receptors, ggTas2rs, representing a minimal case of bitter perception. Some bitter compounds like quinine, diphenidol and chlorpheniramine, activate all three ggTas2rs, while others selectively activate one or two of the receptors. We focus on bitter compounds with different selectivity profiles toward the three receptors, to shed light on the molecular recognition complexity in bitter taste. Using homology modeling and induced-fit docking simulations, we investigated the binding modes of ggTas2r agonists. Interestingly, promiscuous compounds are predicted to establish polar interactions with position 6.51 and hydrophobic interactions with positions 3.32 and 5.42 in all ggTas2rs; whereas certain residues are responsible for receptor selectivity. Lys3.29 and Asn3.36 are suggested as ggTas2r1-specificity-conferring residues; Gln6.55 as ggTas2r2-specificity-conferring residue; Ser5.38 and Gln7.42 as ggTas2r7-specificity conferring residues. The selectivity profile of quinine analogs, quinidine, epiquinidine and ethylhydrocupreine, was then characterized by combining calcium-imaging experiments and in silico approaches. ggTas2r models were used to virtually screen BitterDB compounds. ~50% of compounds known to be bitter to human are likely to be bitter to chicken, with 25, 20, 37% predicted to be ggTas2r1, ggTas2r2, ggTas2r7 agonists, respectively. Predicted ggTas2rs agonists can be tested with in vitro and in vivo experiments, contributing to our understanding of bitter taste in chicken and, consequently, to the improvement of chicken feed.

  8. T1r3 taste receptor involvement in gustatory neural responses to ethanol and oral ethanol preference.

    Science.gov (United States)

    Brasser, Susan M; Norman, Meghan B; Lemon, Christian H

    2010-05-01

    Elevated alcohol consumption is associated with enhanced preference for sweet substances across species and may be mediated by oral alcohol-induced activation of neurobiological substrates for sweet taste. Here, we directly examined the contribution of the T1r3 receptor protein, important for sweet taste detection in mammals, to ethanol intake and preference and the neural processing of ethanol taste by measuring behavioral and central neurophysiological responses to oral alcohol in T1r3 receptor-deficient mice and their C57BL/6J background strain. T1r3 knockout and wild-type mice were tested in behavioral preference assays for long-term voluntary intake of a broad concentration range of ethanol, sucrose, and quinine. For neurophysiological experiments, separate groups of mice of each genotype were anesthetized, and taste responses to ethanol and stimuli of different taste qualities were electrophysiologically recorded from gustatory neurons in the nucleus of the solitary tract. Mice lacking the T1r3 receptor were behaviorally indifferent to alcohol (i.e., ∼50% preference values) at concentrations typically preferred by wild-type mice (5-15%). Central neural taste responses to ethanol in T1r3-deficient mice were significantly lower compared with C57BL/6J controls, a strain for which oral ethanol stimulation produced a concentration-dependent activation of sweet-responsive NTS gustatory neurons. An attenuated difference in ethanol preference between knockouts and controls at concentrations >15% indicated that other sensory and/or postingestive effects of ethanol compete with sweet taste input at high concentrations. As expected, T1r3 knockouts exhibited strongly suppressed behavioral and neural taste responses to sweeteners but did not differ from wild-type mice in responses to prototypic salt, acid, or bitter stimuli. These data implicate the T1r3 receptor in the sensory detection and transduction of ethanol taste.

  9. A kinetic study of bitter taste receptor sensing using immobilized porcine taste bud tissues.

    Science.gov (United States)

    Wei, Lihui; Qiao, Lixin; Pang, Guangchang; Xie, Junbo

    2017-06-15

    At present, developing an efficient assay method for truly reflecting the real feelings of gustatory tissues is of great importance. In this study, a novel biosensor was fabricated to investigate the kinetic characteristics of the receptors in taste bud tissues sensing bitter substances for the first time. Porcine taste bud tissues were used as the sensing elements, and the sandwich-type sensing membrane was fixed onto a glassy carbon electrode for assembling the biosensor. With the developed sensor, the response currents induced by sucrose octaacetate, denatonium benzoate, and quercetin stimulating corresponding receptors were determined. The results demonstrated that the interaction between the analyst with their receptors were fitting to hyperbola (R 2 =0.9776, 0.9980 and 0.9601), and the activation constants were 8.748×10 -15 mol/L, 1.429×10 -12 mol/L, 6.613×10 -14 mol/L, respectively. The average number of receptors per cell was calculated as 1.75, 28.58, and 13.23, while the signal amplification factors were 1.08×10 4 , 2.89×10 3 and 9.76×10 4 . These suggest that the sensor can be used to quantitatively describe the interaction characteristics of cells or tissue receptors with their ligands, the role of cellular signaling cascade, the number of receptors, and the signal transmission pathways. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Caffeine May Reduce Perceived Sweet Taste in Humans, Supporting Evidence That Adenosine Receptors Modulate Taste.

    Science.gov (United States)

    Choo, Ezen; Picket, Benjamin; Dando, Robin

    2017-09-01

    Multiple recent reports have detailed the presence of adenosine receptors in sweet sensitive taste cells of mice. These receptors are activated by endogenous adenosine in the plasma to enhance sweet signals within the taste bud, before reporting to the primary afferent. As we commonly consume caffeine, a powerful antagonist for such receptors, in our daily lives, an intriguing question we sought to answer was whether the caffeine we habitually consume in coffee can inhibit the perception of sweet taste in humans. 107 panelists were randomly assigned to 2 groups, sampling decaffeinated coffee supplemented with either 200 mg of caffeine, about the level found in a strong cup of coffee, or an equally bitter concentration of quinine. Participants subsequently performed sensory testing, with the session repeated in the alternative condition in a second session on a separate day. Panelists rated both the sweetened coffee itself and subsequent sucrose solutions as less sweet in the caffeine condition, despite the treatment having no effect on bitter, sour, salty, or umami perception. Panelists were also unable to discern whether they had consumed the caffeinated or noncaffeinated coffee, with ratings of alertness increased equally, but no significant improvement in reaction times, highlighting coffee's powerful placebo effect. This work validates earlier observations in rodents in a human population. © 2017 Institute of Food Technologists®.

  11. Sweet taste receptor gene variation and aspartame taste in primates and other species.

    Science.gov (United States)

    Li, Xia; Bachmanov, Alexander A; Maehashi, Kenji; Li, Weihua; Lim, Raymond; Brand, Joseph G; Beauchamp, Gary K; Reed, Danielle R; Thai, Chloe; Floriano, Wely B

    2011-06-01

    Aspartame is a sweetener added to foods and beverages as a low-calorie sugar replacement. Unlike sugars, which are apparently perceived as sweet and desirable by a range of mammals, the ability to taste aspartame varies, with humans, apes, and Old World monkeys perceiving aspartame as sweet but not other primate species. To investigate whether the ability to perceive the sweetness of aspartame correlates with variations in the DNA sequence of the genes encoding sweet taste receptor proteins, T1R2 and T1R3, we sequenced these genes in 9 aspartame taster and nontaster primate species. We then compared these sequences with sequences of their orthologs in 4 other nontasters species. We identified 9 variant sites in the gene encoding T1R2 and 32 variant sites in the gene encoding T1R3 that distinguish aspartame tasters and nontasters. Molecular docking of aspartame to computer-generated models of the T1R2 + T1R3 receptor dimer suggests that species variation at a secondary, allosteric binding site in the T1R2 protein is the most likely origin of differences in perception of the sweetness of aspartame. These results identified a previously unknown site of aspartame interaction with the sweet receptor and suggest that the ability to taste aspartame might have developed during evolution to exploit a specialized food niche.

  12. Altered lipid and salt taste responsivity in ghrelin and GOAT null mice.

    Directory of Open Access Journals (Sweden)

    Huan Cai

    Full Text Available Taste perception plays an important role in regulating food preference, eating behavior and energy homeostasis. Taste perception is modulated by a variety of factors, including gastric hormones such as ghrelin. Ghrelin can regulate growth hormone release, food intake, adiposity, and energy metabolism. Octanoylation of ghrelin by ghrelin O-acyltransferase (GOAT is a specific post-translational modification which is essential for many biological activities of ghrelin. Ghrelin and GOAT are both widely expressed in many organs including the gustatory system. In the current study, overall metabolic profiles were assessed in wild-type (WT, ghrelin knockout (ghrelin(-/-, and GOAT knockout (GOAT(-/- mice. Ghrelin(-/- mice exhibited decreased food intake, increased plasma triglycerides and increased ketone bodies compared to WT mice while demonstrating WT-like body weight, fat composition and glucose control. In contrast GOAT(-/- mice exhibited reduced body weight, adiposity, resting glucose and insulin levels compared to WT mice. Brief access taste behavioral tests were performed to determine taste responsivity in WT, ghrelin(-/- and GOAT(-/- mice. Ghrelin and GOAT null mice possessed reduced lipid taste responsivity. Furthermore, we found that salty taste responsivity was attenuated in ghrelin(-/- mice, yet potentiated in GOAT(-/- mice compared to WT mice. Expression of the potential lipid taste regulators Cd36 and Gpr120 were reduced in the taste buds of ghrelin and GOAT null mice, while the salt-sensitive ENaC subunit was increased in GOAT(-/- mice compared with WT mice. The altered expression of Cd36, Gpr120 and ENaC may be responsible for the altered lipid and salt taste perception in ghrelin(-/- and GOAT(-/- mice. The data presented in the current study potentially implicates ghrelin signaling activity in the modulation of both lipid and salt taste modalities.

  13. Rewiring the gustatory system: specificity between nerve and taste bud field is critical for normal salt discrimination.

    Science.gov (United States)

    Spector, Alan C; Blonde, Ginger; Garcea, Mircea; Jiang, Enshe

    2010-01-15

    Forty years have passed since it was demonstrated that a cross-regenerated gustatory nerve in the rat tongue adopts the stimulus-response properties of the taste receptor field it cross-reinnervates. Nevertheless, the functional consequences of channeling peripheral taste signals through inappropriate central circuits remain relatively unexplored. Here we tested whether histologically confirmed cross-regeneration of the chorda tympani nerve (CT) into the posterior tongue in the absence of the glossopharyngeal nerve (GL) (CT-PostTongue) or cross-regeneration of the GL into the anterior tongue in the absence of the CT (GL-AntTongue) would maintain presurgically trained performance in an operant NaCl vs. KCl taste discrimination task in rats. Before surgery all groups were averaging over 90% accuracy. Oral amiloride treatment dropped performance to virtually chance levels. During the first week after surgery, sham-operated rats, GL-transected rats, and rats with regenerated CTs displayed highly competent discrimination performance. In contrast, CT-transected rats were severely impaired (59% accuracy). Both the CT-PostTongue and the GL-AntTongue groups were impaired to a similar degree as CT-transected rats. These initially impaired groups improved their performance over the weeks of postsurgical testing, suggesting that the rats were capable of relearning the task with discriminable signals in the remaining taste nerves. This relearned performance was dependent on input from amiloride-sensitive receptors likely in the palate. Overall, these results suggest that normal competence in a salt discrimination task is dependent on the taste receptor field origin of the input as well as the specific nerve transmitting the signals to its associated circuits in the brain. Copyright 2009 Elsevier B.V. All rights reserved.

  14. Behavioral analysis of Drosophila transformants expressing human taste receptor genes in the gustatory receptor neurons.

    Science.gov (United States)

    Adachi, Ryota; Sasaki, Yuko; Morita, Hiromi; Komai, Michio; Shirakawa, Hitoshi; Goto, Tomoko; Furuyama, Akira; Isono, Kunio

    2012-06-01

    Transgenic Drosophila expressing human T2R4 and T2R38 bitter-taste receptors or PKD2L1 sour-taste receptor in the fly gustatory receptor neurons and other tissues were prepared using conventional Gal4/UAS binary system. Molecular analysis showed that the transgene mRNAs are expressed according to the tissue specificity of the Gal4 drivers. Transformants expressing the transgene taste receptors in the fly taste neurons were then studied by a behavioral assay to analyze whether transgene chemoreceptors are functional and coupled to the cell response. Since wild-type flies show strong aversion against the T2R ligands as in mammals, the authors analyzed the transformants where the transgenes are expressed in the fly sugar receptor neurons so that they promote feeding ligand-dependently if they are functional and activate the neurons. Although the feeding preference varied considerably among different strains and individuals, statistical analysis using large numbers of transformants indicated that transformants expressing T2R4 showed a small but significant increase in the preference for denatonium and quinine, the T2R4 ligands, as compared to the control flies, whereas transformants expressing T2R38 did not. Similarly, transformants expressing T2R38 and PKD2L1 also showed a similar preference increase for T2R38-specific ligand phenylthiocarbamide (PTC) and a sour-taste ligand, citric acid, respectively. Taken together, the transformants expressing mammalian taste receptors showed a small but significant increase in the feeding preference that is taste receptor and also ligand dependent. Although future improvements are required to attain performance comparable to the endogenous robust response, Drosophila taste neurons may serve as a potential in vivo heterologous expression system for analyzing chemoreceptor function.

  15. Effect of Chorda Tympani Nerve Transection on Salt Taste Perception in Mice

    Science.gov (United States)

    Ishiwatari, Yutaka; Theodorides, Maria L.; Bachmanov, Alexander A.

    2011-01-01

    Effects of gustatory nerve transection on salt taste have been studied extensively in rats and hamsters but have not been well explored in the mouse. We examined the effects of chorda tympani (CT) nerve transection on NaCl taste preferences and thresholds in outbred CD-1 mice using a high-throughput phenotyping method developed in our laboratory. To measure taste thresholds, mice were conditioned by oral self-administration of LiCl or NaCl and then presented with NaCl concentration series in 2-bottle preference tests. LiCl-conditioned and control NaCl-exposed mice were given bilateral transections of the CT nerve (LiCl-CTX, NaCl-CTX) or were left intact as controls (LiCl-CNT, NaCl-CNT). After recovery from surgery, mice received a concentration series of NaCl (0–300 mM) in 48-h 2-bottle tests. CT transection increased NaCl taste thresholds in LiCl-conditioned mice and eliminated avoidance of concentrated NaCl in control NaCl-exposed mice. This demonstrates that in mice, the CT nerve is important for detection and recognition of NaCl taste and is necessary for the normal avoidance of high concentrations of NaCl. The results of this experiment also show that the method of high-throughput phenotyping of salt taste thresholds is suitable for detecting changes in the taste periphery in mouse genetic studies. PMID:21743094

  16. 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.

    Science.gov (United States)

    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.

  17. Independent Evolution of Strychnine Recognition by Bitter Taste Receptor Subtypes

    Directory of Open Access Journals (Sweden)

    Ava Yuan Xue

    2018-03-01

    Full Text Available The 25 human bitter taste receptors (hT2Rs recognize thousands of structurally and chemically diverse bitter substances. The binding modes of human bitter taste receptors hT2R10 and hT2R46, which are responsible for strychnine recognition, were previously established using site-directed mutagenesis, functional assays, and molecular modeling. Here we construct a phylogenetic tree and reconstruct ancestral sequences of the T2R10 and T2R46 clades. We next analyze the binding sites in view of experimental data to predict their ability to recognize strychnine. This analysis suggests that the common ancestor of hT2R10 and hT2R46 is unlikely to bind strychnine in the same mode as either of its two descendants. Estimation of relative divergence times shows that hT2R10 evolved earlier than hT2R46. Strychnine recognition was likely acquired first by the earliest common ancestor of the T2R10 clade before the separation of primates from other mammals, and was highly conserved within the clade. It was probably independently acquired by the common ancestor of T2R43-47 before the homo-ape speciation, lost in most T2Rs within this clade, but enhanced in the hT2R46 after humans diverged from the rest of primates. Our findings suggest hypothetical strychnine T2R receptors in several species, and serve as an experimental guide for further study. Improved understanding of how bitter taste receptors acquire the ability to be activated by particular ligands is valuable for the development of sensors for bitterness and for potential toxicity.

  18. Independent Evolution of Strychnine Recognition by Bitter Taste Receptor Subtypes

    Science.gov (United States)

    Xue, Ava Yuan; Di Pizio, Antonella; Levit, Anat; Yarnitzky, Tali; Penn, Osnat; Pupko, Tal; Niv, Masha Y.

    2018-01-01

    The 25 human bitter taste receptors (hT2Rs) recognize thousands of structurally and chemically diverse bitter substances. The binding modes of human bitter taste receptors hT2R10 and hT2R46, which are responsible for strychnine recognition, were previously established using site-directed mutagenesis, functional assays, and molecular modeling. Here we construct a phylogenetic tree and reconstruct ancestral sequences of the T2R10 and T2R46 clades. We next analyze the binding sites in view of experimental data to predict their ability to recognize strychnine. This analysis suggests that the common ancestor of hT2R10 and hT2R46 is unlikely to bind strychnine in the same mode as either of its two descendants. Estimation of relative divergence times shows that hT2R10 evolved earlier than hT2R46. Strychnine recognition was likely acquired first by the earliest common ancestor of the T2R10 clade before the separation of primates from other mammals, and was highly conserved within the clade. It was probably independently acquired by the common ancestor of T2R43-47 before the homo-ape speciation, lost in most T2Rs within this clade, but enhanced in the hT2R46 after humans diverged from the rest of primates. Our findings suggest hypothetical strychnine T2R receptors in several species, and serve as an experimental guide for further study. Improved understanding of how bitter taste receptors acquire the ability to be activated by particular ligands is valuable for the development of sensors for bitterness and for potential toxicity. PMID:29552563

  19. Effect of umami taste on pleasantness of low-salt soups during repeated testing.

    Science.gov (United States)

    Roininen, K; Lähteenmäki, L; Tuorila, H

    1996-09-01

    In the present study the effects of the umami substances, monosodium glutamate (0.2%) and 5'-ribonucleotides (0.05%), on the acceptance of low-salt soups in two groups of subjects, one with low-salt (n = 21) and the other with high-salt (n = 23) preferences were assessed. The groups were presented with soups containing 0.3% sodium chloride (low-salt group) and 0.5% sodium chloride (high-salt group). The subjects three times consumed leek-potato or minestrone soup with umami and three times the other soup without umami during six sessions over 5 weeks (sessions 2-7). In addition they tasted these and two other soups (lentil and mushroom soup) during sessions 1 and 8, during which they evaluated the pleasantness, taste intensity, and ideal saltiness of the soups with and without added umami. These ratings were higher when soups contained umami in both the low- and high-salt groups, and they remained higher regardless of which of the soups served for lunch contained umami. The low- and high-salt groups did not differ in pleasantness ratings, although the former rated the taste intensity of their soups higher and ideal saltiness closer to the ideal than did the latter. The pleasantness ratings of soups without umami were significantly lower at the end of the study than at the beginning, whereas those of soups with umami remained unchanged. These data suggest that the pleasantness of reduced-salt foods could be increased by addition of appropriate flavors.

  20. Intrinsic nitric oxide regulates the taste response of the sugar receptor cell in the blowfly, Phormia regina.

    Science.gov (United States)

    Murata, Yoshihiro; Mashiko, Masashi; Ozaki, Mamiko; Amakawa, Taisaku; Nakamura, Tadashi

    2004-01-01

    The taste organ in insects is a hair-shaped taste sensory unit having four functionally differentiated contact chemoreceptor cells. In the blowfly, Phormia regina, cGMP has been suggested to be a second messenger for the sugar receptor cell. Generally, cGMP is produced by membranous or soluble guanylyl cyclase (sGC), which can be activated by nitric oxide (NO). In the present paper, we electrophysiologically showed that an NO scavenger, 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO), an NO donor, 1-hydroxy-2-oxo-3-(N-methyl-3-aminopropyl)-3-methyl-1-triazene (NOC 7) or an NO synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) specifically affected the response in the sugar receptor cell, but not in other receptor cells. PTIO, when introduced into the receptor cells in a sensillum aided by sodium deoxycholate (DOC, pH 7.2), depressed the response of sugar receptor cells to sucrose but did not affect those of the salt or water receptor cells. NOC 7, given extracellularly, latently induced the response of sugar receptor cells; and L-NAME, when introduced into the receptor cells, depressed the response of sugar receptor cells. The results clearly suggest that NO, which may be produced by intrinsic NOS in sugar receptor cells, participates in the transduction cascade of these cells in blowfly.

  1. Glucose transporters are expressed in taste receptor cells.

    Science.gov (United States)

    Merigo, Flavia; Benati, Donatella; Cristofoletti, Mirko; Osculati, Francesco; Sbarbati, Andrea

    2011-08-01

    In the intestine, changes of sugar concentration generated in the lumen during digestion induce adaptive responses of glucose transporters in the epithelium. A close matching between the intestinal expression of glucose transporters and the composition and amount of the diet has been provided by several experiments. Functional evidence has demonstrated that the regulation of glucose transporters into enterocytes is induced by the sensing of sugar of the enteroendocrine cells through activation of sweet taste receptors (T1R2 and T1R3) and their associated elements of G-protein-linked signaling pathways (e.g. α-gustducin, phospholipase C β type 2 and transient receptor potential channel M5), which are signaling molecules also involved in the perception of sweet substances in the taste receptor cells (TRCs) of the tongue. Considering this phenotypical similarity between the intestinal cells and TRCs, we evaluated whether the TRCs themselves possess proteins of the glucose transport mechanism. Therefore, we investigated the expression of the typical intestinal glucose transporters (i.e. GLUT2, GLUT5 and SGLT1) in rat circumvallate papillae, using immunohistochemistry, double-labeling immunofluorescence, immunoelectron microscopy and reverse transcriptase-polymerase chain reaction analysis. The results showed that GLUT2, GLUT5 and SGLT1 are expressed in TRCs; their immunoreactivity was also observed in cells that displayed staining for α-gustducin and T1R3 receptor. The immunoelectron microscopic results confirmed that GLUT2, GLUT5 and SGLT1 were predominantly expressed in cells with ultrastructural characteristics of chemoreceptor cells. The presence of glucose transporters in TRCs adds a further link between chemosensory information and cellular responses to sweet stimuli that may have important roles in glucose homeostasis, contributing to a better understanding of the pathways implicated in glucose metabolism. © 2011 The Authors. Journal of Anatomy © 2011

  2. Amino acid sensing in hypothalamic tanycytes via umami taste receptors.

    Science.gov (United States)

    Lazutkaite, Greta; Soldà, Alice; Lossow, Kristina; Meyerhof, Wolfgang; Dale, Nicholas

    2017-11-01

    Hypothalamic tanycytes are glial cells that line the wall of the third ventricle and contact the cerebrospinal fluid (CSF). While they are known to detect glucose in the CSF we now show that tanycytes also detect amino acids, important nutrients that signal satiety. Ca 2+ imaging and ATP biosensing were used to detect tanycyte responses to l-amino acids. The downstream pathway of the responses was determined using ATP receptor antagonists and channel blockers. The receptors were characterized using mice lacking the Tas1r1 gene, as well as an mGluR4 receptor antagonist. Amino acids such as Arg, Lys, and Ala evoke Ca 2+ signals in tanycytes and evoke the release of ATP via pannexin 1 and CalHM1, which amplifies the signal via a P2 receptor dependent mechanism. Tanycytes from mice lacking the Tas1r1 gene had diminished responses to lysine and arginine but not alanine. Antagonists of mGluR4 greatly reduced the responses to alanine and lysine. Two receptors previously implicated in taste cells, the Tas1r1/Tas1r3 heterodimer and mGluR4, contribute to the detection of a range of amino acids by tanycytes in CSF. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Huaming Zhong

    2017-08-01

    Full Text Available 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.

  4. Ric-8A, a Gα protein guanine nucleotide exchange factor potentiates taste receptor signaling

    Directory of Open Access Journals (Sweden)

    Claire J Fenech

    2009-10-01

    Full Text Available Taste receptors for sweet, bitter and umami tastants are G-protein coupled receptors (GPCRs. While much effort has been devoted to understanding G-protein-receptor interactions and identifying the components of the signalling cascade downstream of these receptors, at the level of the G-protein the modulation of receptor signal transduction remains relatively unexplored. In this regard a taste-specific regulator of G-protein signaling (RGS, RGS21, has recently been identified. To study whether guanine nucleotide exchange factors (GEFs are involved in the transduction of the signal downstream of the taste GPCRs we investigated the expression of Ric-8A and Ric-8B in mouse taste cells and their interaction with G-protein subunits found in taste buds. Mammalian Ric-8 proteins were initially identified as potent GEFs for a range of Gα subunits and Ric-8B has recently been shown to amplify olfactory signal transduction. We find that both Ric-8A and Ric-8B are expressed in a large portion of taste bud cells and that most of these cells contain IP3R-3 a marker for sweet, umami and bitter taste receptor cells. Ric-8A interacts with Gα-gustducin and Gαi2 through which it amplifies the signal transduction of hTas2R16, a receptor for bitter compounds. Overall, these findings are consistent with a role for Ric-8 in mammalian taste signal transduction.

  5. Dynamic evolution of bitter taste receptor genes in vertebrates

    Directory of Open Access Journals (Sweden)

    Jones Gareth

    2009-01-01

    Full Text Available Abstract Background Sensing bitter tastes is crucial for many animals because it can prevent them from ingesting harmful foods. This process is mainly mediated by the bitter taste receptors (T2R, which are largely expressed in the taste buds. Previous studies have identified some T2R gene repertoires, and marked variation in repertoire size has been noted among species. However, the mechanisms underlying the evolution of vertebrate T2R genes remain poorly understood. Results To better understand the evolutionary pattern of these genes, we identified 16 T2R gene repertoires based on the high coverage genome sequences of vertebrates and studied the evolutionary changes in the number of T2R genes during birth-and-death evolution using the reconciled-tree method. We found that the number of T2R genes and the fraction of pseudogenes vary extensively among species. Based on the results of phylogenetic analysis, we showed that T2R gene families in teleost fishes are more diverse than those in tetrapods. In addition to the independent gene expansions in teleost fishes, frogs and mammals, lineage-specific gene duplications were also detected in lizards. Furthermore, extensive gains and losses of T2R genes were detected in each lineage during their evolution, resulting in widely differing T2R gene repertoires. Conclusion These results further support the hypotheses that T2R gene repertoires are closely related to the dietary habits of different species and that birth-and-death evolution is associated with adaptations to dietary changes.

  6. The Role of 5-HT3 Receptors in Signaling from Taste Buds to Nerves.

    Science.gov (United States)

    Larson, Eric D; Vandenbeuch, Aurelie; Voigt, Anja; Meyerhof, Wolfgang; Kinnamon, Sue C; Finger, Thomas E

    2015-12-02

    Activation of taste buds triggers the release of several neurotransmitters, including ATP and serotonin (5-hydroxytryptamine; 5-HT). Type III taste cells release 5-HT directly in response to acidic (sour) stimuli and indirectly in response to bitter and sweet tasting stimuli. Although ATP is necessary for activation of nerve fibers for all taste stimuli, the role of 5-HT is unclear. We investigated whether gustatory afferents express functional 5-HT3 receptors and, if so, whether these receptors play a role in transmission of taste information from taste buds to nerves. In mice expressing GFP under the control of the 5-HT(3A) promoter, a subset of cells in the geniculate ganglion and nerve fibers in taste buds are GFP-positive. RT-PCR and in situ hybridization confirmed the presence of 5-HT(3A) mRNA in the geniculate ganglion. Functional studies show that only those geniculate ganglion cells expressing 5-HT3A-driven GFP respond to 10 μM 5-HT and this response is blocked by 1 μM ondansetron, a 5-HT3 antagonist, and mimicked by application of 10 μM m-chlorophenylbiguanide, a 5-HT3 agonist. Pharmacological blockade of 5-HT3 receptors in vivo or genetic deletion of the 5-HT3 receptors reduces taste nerve responses to acids and other taste stimuli compared with controls, but only when urethane was used as the anesthetic. We find that anesthetic levels of pentobarbital reduce taste nerve responses apparently by blocking the 5-HT3 receptors. Our results suggest that 5-HT released from type III cells activates gustatory nerve fibers via 5-HT3 receptors, accounting for a significant proportion of the neural taste response. Copyright © 2015 the authors 0270-6474/15/3515984-12$15.00/0.

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

    Science.gov (United States)

    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.

  8. Knocking out P2X receptors reduces transmitter secretion in taste buds

    Science.gov (United States)

    Huang, Yijen A.; Stone, Leslie M.; Pereira, Elizabeth; Yang, Ruibiao; Kinnamon, John C.; Dvoryanchikov, Gennady; Chaudhari, Nirupa; Finger, Thomas E.; Kinnamon, Sue C.; Roper, Stephen D.

    2011-01-01

    In response to gustatory stimulation, taste bud cells release a transmitter, ATP, that activates P2X2 and P2X3 receptors on gustatory afferent fibers. Taste behavior and gustatory neural responses are largely abolished in mice lacking P2X2 and P2X3 receptors (P2X2 and P2X3 double knockout, or “DKO” mice). The assumption has been that eliminating P2X2 and P2X3 receptors only removes postsynaptic targets but that transmitter secretion in mice is normal. Using functional imaging, ATP biosensor cells, and a cell-free assay for ATP, we tested this assumption. Surprisingly, although gustatory stimulation mobilizes Ca2+ in taste Receptor (Type II) cells from DKO mice, as from wild type (WT) mice, taste cells from DKO mice fail to release ATP when stimulated with tastants. ATP release could be elicited by depolarizing DKO Receptor cells with KCl, suggesting that ATP-release machinery remains functional in DKO taste buds. To explore the difference in ATP release across genotypes, we employed reverse transcriptase (RT)-PCR, immunostaining, and histochemistry for key proteins underlying ATP secretion and degradation: Pannexin1, TRPM5, and NTPDase2 (ecto-ATPase) are indistinguishable between WT and DKO mice. The ultrastructure of contacts between taste cells and nerve fibers is also normal in the DKO mice. Finally, quantitative RT-PCR show that P2X4 and P2X7, potential modulators of ATP secretion, are similarly expressed in taste buds in WT and DKO taste buds. Importantly, we find that P2X2 is expressed in WT taste buds and appears to function as an autocrine, positive feedback signal to amplify taste-evoked ATP secretion. PMID:21940456

  9. Knocking out P2X receptors reduces transmitter secretion in taste buds.

    Science.gov (United States)

    Huang, Yijen A; Stone, Leslie M; Pereira, Elizabeth; Yang, Ruibiao; Kinnamon, John C; Dvoryanchikov, Gennady; Chaudhari, Nirupa; Finger, Thomas E; Kinnamon, Sue C; Roper, Stephen D

    2011-09-21

    In response to gustatory stimulation, taste bud cells release a transmitter, ATP, that activates P2X2 and P2X3 receptors on gustatory afferent fibers. Taste behavior and gustatory neural responses are largely abolished in mice lacking P2X2 and P2X3 receptors [P2X2 and P2X3 double knock-out (DKO) mice]. The assumption has been that eliminating P2X2 and P2X3 receptors only removes postsynaptic targets but that transmitter secretion in mice is normal. Using functional imaging, ATP biosensor cells, and a cell-free assay for ATP, we tested this assumption. Surprisingly, although gustatory stimulation mobilizes Ca(2+) in taste Receptor (Type II) cells from DKO mice, as from wild-type (WT) mice, taste cells from DKO mice fail to release ATP when stimulated with tastants. ATP release could be elicited by depolarizing DKO Receptor cells with KCl, suggesting that ATP-release machinery remains functional in DKO taste buds. To explore the difference in ATP release across genotypes, we used reverse transcriptase (RT)-PCR, immunostaining, and histochemistry for key proteins underlying ATP secretion and degradation: Pannexin1, TRPM5, and NTPDase2 (ecto-ATPase) are indistinguishable between WT and DKO mice. The ultrastructure of contacts between taste cells and nerve fibers is also normal in the DKO mice. Finally, quantitative RT-PCR show that P2X4 and P2X7, potential modulators of ATP secretion, are similarly expressed in taste buds in WT and DKO taste buds. Importantly, we find that P2X2 is expressed in WT taste buds and appears to function as an autocrine, positive feedback signal to amplify taste-evoked ATP secretion.

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

    Science.gov (United States)

    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.

  11. Lower expressions of the human bitter taste receptor TAS2R in smokers: reverse transcriptase-polymerase chain reaction analysis

    OpenAIRE

    Aoki, Mieko; Takao, Tetsuya; Takao, Kyoichi; Koike, Fumihiko; Suganuma, Narufumi

    2014-01-01

    Background Despite the fact that smokers have deficit in detecting taste, particularly bitter taste, no study has investigated its biological correlate. Methods In this context, we compared the expression of the bitter taste receptor gene, taste 2 receptor (TAS2R) in the tongues of smokers and non-smokers. Tissue samples were collected from the lateral portion of the tongues of 22 smokers and 22 age- and gender-matched healthy volunteers (19 males and three females) with no history of smoking...

  12. Vampire bats exhibit evolutionary reduction of bitter taste receptor genes common to other bats

    Science.gov (United States)

    Hong, Wei; Zhao, Huabin

    2014-01-01

    The bitter taste serves as an important natural defence against the ingestion of poisonous foods and is thus believed to be indispensable in animals. However, vampire bats are obligate blood feeders that show a reduced behavioural response towards bitter-tasting compounds. To test whether bitter taste receptor genes (T2Rs) have been relaxed from selective constraint in vampire bats, we sampled all three vampire bat species and 11 non-vampire bats, and sequenced nine one-to-one orthologous T2Rs that are assumed to be functionally conserved in all bats. We generated 85 T2R sequences and found that vampire bats have a significantly greater percentage of pseudogenes than other bats. These results strongly suggest a relaxation of selective constraint and a reduction of bitter taste function in vampire bats. We also found that vampire bats retain many intact T2Rs, and that the taste signalling pathway gene Calhm1 remains complete and intact with strong functional constraint. These results suggest the presence of some bitter taste function in vampire bats, although it is not likely to play a major role in food selection. Together, our study suggests that the evolutionary reduction of bitter taste function in animals is more pervasive than previously believed, and highlights the importance of extra-oral functions of taste receptor genes. PMID:24966321

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

    Science.gov (United States)

    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.

  14. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor

    Science.gov (United States)

    Baldwin, Maude W.; Toda, Yasuka; Nakagita, Tomoya; O'Connell, Mary J.; Klasing, Kirk C.; Misaka, Takumi; Edwards, Scott V.; Liberles, Stephen D.

    2015-01-01

    Sensory systems define an animal's capacity for perception and can evolve to promote survival in new environmental niches. We have uncovered a noncanonical mechanism for sweet taste perception that evolved in hummingbirds since their divergence from insectivorous swifts, their closest relatives. We observed the widespread absence in birds of an essential subunit (T1R2) of the only known vertebrate sweet receptor, raising questions about how specialized nectar feeders such as hummingbirds sense sugars. Receptor expression studies revealed that the ancestral umami receptor (the T1R1-T1R3 heterodimer) was repurposed in hummingbirds to function as a carbohydrate receptor. Furthermore, the molecular recognition properties of T1R1-T1R3 guided taste behavior in captive and wild hummingbirds. We propose that changing taste receptor function enabled hummingbirds to perceive and use nectar, facilitating the massive radiation of hummingbird species. PMID:25146290

  15. Sensory biology. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor.

    Science.gov (United States)

    Baldwin, Maude W; Toda, Yasuka; Nakagita, Tomoya; O'Connell, Mary J; Klasing, Kirk C; Misaka, Takumi; Edwards, Scott V; Liberles, Stephen D

    2014-08-22

    Sensory systems define an animal's capacity for perception and can evolve to promote survival in new environmental niches. We have uncovered a noncanonical mechanism for sweet taste perception that evolved in hummingbirds since their divergence from insectivorous swifts, their closest relatives. We observed the widespread absence in birds of an essential subunit (T1R2) of the only known vertebrate sweet receptor, raising questions about how specialized nectar feeders such as hummingbirds sense sugars. Receptor expression studies revealed that the ancestral umami receptor (the T1R1-T1R3 heterodimer) was repurposed in hummingbirds to function as a carbohydrate receptor. Furthermore, the molecular recognition properties of T1R1-T1R3 guided taste behavior in captive and wild hummingbirds. We propose that changing taste receptor function enabled hummingbirds to perceive and use nectar, facilitating the massive radiation of hummingbird species. Copyright © 2014, American Association for the Advancement of Science.

  16. Ghrelin is produced in taste cells and ghrelin receptor null mice show reduced taste responsivity to salty (NaCl and sour (citric acid tastants.

    Directory of Open Access Journals (Sweden)

    Yu-Kyong Shin

    2010-09-01

    Full Text Available The gustatory system plays a critical role in determining food preferences, food intake and energy balance. The exact mechanisms that fine tune taste sensitivity are currently poorly defined, but it is clear that numerous factors such as efferent input and specific signal transduction cascades are involved.Using immunohistochemical analyses, we show that ghrelin, a hormone classically considered to be an appetite-regulating hormone, is present within the taste buds of the tongue. Prepro-ghrelin, prohormone convertase 1/3 (PC 1/3, ghrelin, its cognate receptor (GHSR, and ghrelin-O-acyltransferase (GOAT , the enzyme that activates ghrelin are expressed in Type I, II, III and IV taste cells of mouse taste buds. In addition, ghrelin and GHSR co-localize in the same taste cells, suggesting that ghrelin works in an autocrine manner in taste cells. To determine a role for ghrelin in modifying taste perception, we performed taste behavioral tests using GHSR null mice. GHSR null mice exhibited significantly reduced taste responsivity to sour (citric acid and salty (sodium chloride tastants.These findings suggest that ghrelin plays a local modulatory role in determining taste bud signaling and function and could be a novel mechanism for the modulation of salty and sour taste responsivity.

  17. The repertoire of bitter taste receptor genes in canids.

    Science.gov (United States)

    Shang, Shuai; Wu, Xiaoyang; Chen, Jun; Zhang, Huanxin; Zhong, Huaming; Wei, Qinguo; Yan, Jiakuo; Li, Haotian; Liu, Guangshuai; Sha, Weilai; Zhang, Honghai

    2017-07-01

    Bitter taste receptors (Tas2rs) play important roles in mammalian defense mechanisms by helping animals detect and avoid toxins in food. Although Tas2r genes have been widely studied in several mammals, minimal research has been performed in canids. To analyze the genetic basis of Tas2r genes in canids, we first identified Tas2r genes in the wolf, maned wolf, red fox, corsac fox, Tibetan fox, fennec fox, dhole and African hunting dog. A total of 183 Tas2r genes, consisting of 118 intact genes, 6 partial genes and 59 pseudogenes, were detected. Differences in the pseudogenes were observed among nine canid species. For example, Tas2r4 was a pseudogene in the dog but might play a functional role in other canid species. The Tas2r42 and Tas2r10 genes were pseudogenes in the maned wolf and dhole, respectively, and the Tas2r5 and Tas2r34 genes were pseudogenes in the African hunting dog; however, these genes were intact genes in other canid species. The differences in Tas2r pseudogenes among canids might suggest that the loss of intact Tas2r genes in canid species is species-dependent. We further compared the 183 Tas2r genes identified in this study with Tas2r genes from ten additional carnivorous species to evaluate the potential influence of diet on the evolution of the Tas2r gene repertoire. Phylogenetic analysis revealed that most of the Tas2r genes from the 18 species intermingled across the tree, suggesting that Tas2r genes are conserved among carnivores. Within canids, we found that some Tas2r genes corresponded to the traditional taxonomic groupings, while some did not. PIC analysis showed that the number of Tas2r genes in carnivores exhibited no positive correlation with diet composition, which might be due to the limited number of carnivores included in our study.

  18. Bone marrow stromal and vascular smooth muscle cells have chemosensory capacity via bitter taste receptor expression.

    Directory of Open Access Journals (Sweden)

    Troy C Lund

    Full Text Available The ability of cells to detect changes in the microenvironment is important in cell signaling and responsiveness to environmental fluctuations. Our interest is in understanding how human bone marrow stromal-derived cells (MSC and their relatives, vascular smooth muscle cells (VSMC, interact with their environment through novel receptors. We found, through a proteomics screen, that MSC express the bitter taste receptor, TAS2R46, a protein more typically localized to the taste bud. Expression was also confirmed in VSMCs. A prototypical bitter compound that binds to the bitter taste receptor class, denatonium, increased intracellular calcium release and decreased cAMP levels as well as increased the extracellular release of ATP in human MSC. Denatonium also bound and activated rodent VSMC with a change in morphology upon compound exposure. Finally, rodents given denatonium in vivo had a significant drop in blood pressure indicating a vasodilator response. This is the first description of chemosensory detection by MSC and VSMCs via a taste receptor. These data open a new avenue of research into discovering novel compounds that operate through taste receptors expressed by cells in the marrow and vascular microenvironments.

  19. Differential involvement of cortical muscarinic and NMDA receptors in short- and long-term taste aversion memory.

    Science.gov (United States)

    Ferreira, G; Gutiérrez, R; De La Cruz, V; Bermúdez-Rattoni, F

    2002-09-01

    In conditioned taste aversion, an animal avoids a taste previously associated with toxic effects, and this aversive memory formation requires an intact insular cortex. In this paper, we investigated the possible differential involvement of cholinergic and glutamatergic receptors in the insular cortex in short-term memory (STM) and long-term memory (LTM) of taste aversion in rats. Taste aversion was induced by intraperitoneal administration of lithium chloride (a malaise-inducing drug) 15 min after experience with an unfamiliar taste. In order to test STM and LTM of taste aversion, taste stimulus was again presented 4 h and 72 h after lithium injection, respectively. During the acquisition, microinjection of the muscarinic antagonist, scopolamine, in the insular cortex before, but not after, the presentation of the new taste, abolished STM as well as LTM. Blockade of the NMDA receptor, in the insular cortex, by AP5 before, but not after, the presentation of the taste stimulus, impaired LTM but left STM intact. Moreover, when injected 1 h after malaise induction (i.e., during taste-illness association), AP5 disrupted both STM and LTM. These results suggest that activation of muscarinic receptors in the insular cortex is involved in the acquisition of taste memory, whereas NMDA receptors participate in taste memory consolidation. These data demonstrate that different neurochemical mechanisms subserve different memory phases. NMDA receptors are also probably involved in processing the visceral input, thus allowing subsequent taste-illness association. This indicates that in the same cortical area the same neurotransmitter system can be involved in distinct processes: taste memory consolidation vs. taste-illness association.

  20. Expression of taste receptors in Solitary Chemosensory Cells of rodent airways

    Directory of Open Access Journals (Sweden)

    Sbarbati Andrea

    2011-01-01

    Full Text Available Abstract Background Chemical irritation of airway mucosa elicits a variety of reflex responses such as coughing, apnea, and laryngeal closure. Inhaled irritants can activate either chemosensitive free nerve endings, laryngeal taste buds or solitary chemosensory cells (SCCs. The SCC population lies in the nasal respiratory epithelium, vomeronasal organ, and larynx, as well as deeper in the airway. The objective of this study is to map the distribution of SCCs within the airways and to determine the elements of the chemosensory transduction cascade expressed in these SCCs. Methods We utilized a combination of immunohistochemistry and molecular techniques (rtPCR and in situ hybridization on rats and transgenic mice where the Tas1R3 or TRPM5 promoter drives expression of green fluorescent protein (GFP. Results Epithelial SCCs specialized for chemoreception are distributed throughout much of the respiratory tree of rodents. These cells express elements of the taste transduction cascade, including Tas1R and Tas2R receptor molecules, α-gustducin, PLCβ2 and TrpM5. The Tas2R bitter taste receptors are present throughout the entire respiratory tract. In contrast, the Tas1R sweet/umami taste receptors are expressed by numerous SCCs in the nasal cavity, but decrease in prevalence in the trachea, and are absent in the lower airways. Conclusions Elements of the taste transduction cascade including taste receptors are expressed by SCCs distributed throughout the airways. In the nasal cavity, SCCs, expressing Tas1R and Tas2R taste receptors, mediate detection of irritants and foreign substances which trigger trigeminally-mediated protective airway reflexes. Lower in the respiratory tract, similar chemosensory cells are not related to the trigeminal nerve but may still trigger local epithelial responses to irritants. In total, SCCs should be considered chemoreceptor cells that help in preventing damage to the respiratory tract caused by inhaled irritants and

  1. Expression of taste receptors in solitary chemosensory cells of rodent airways.

    Science.gov (United States)

    Tizzano, Marco; Cristofoletti, Mirko; Sbarbati, Andrea; Finger, Thomas E

    2011-01-13

    Chemical irritation of airway mucosa elicits a variety of reflex responses such as coughing, apnea, and laryngeal closure. Inhaled irritants can activate either chemosensitive free nerve endings, laryngeal taste buds or solitary chemosensory cells (SCCs). The SCC population lies in the nasal respiratory epithelium, vomeronasal organ, and larynx, as well as deeper in the airway. The objective of this study is to map the distribution of SCCs within the airways and to determine the elements of the chemosensory transduction cascade expressed in these SCCs. We utilized a combination of immunohistochemistry and molecular techniques (rtPCR and in situ hybridization) on rats and transgenic mice where the Tas1R3 or TRPM5 promoter drives expression of green fluorescent protein (GFP). Epithelial SCCs specialized for chemoreception are distributed throughout much of the respiratory tree of rodents. These cells express elements of the taste transduction cascade, including Tas1R and Tas2R receptor molecules, α-gustducin, PLCβ2 and TrpM5. The Tas2R bitter taste receptors are present throughout the entire respiratory tract. In contrast, the Tas1R sweet/umami taste receptors are expressed by numerous SCCs in the nasal cavity, but decrease in prevalence in the trachea, and are absent in the lower airways. Elements of the taste transduction cascade including taste receptors are expressed by SCCs distributed throughout the airways. In the nasal cavity, SCCs, expressing Tas1R and Tas2R taste receptors, mediate detection of irritants and foreign substances which trigger trigeminally-mediated protective airway reflexes. Lower in the respiratory tract, similar chemosensory cells are not related to the trigeminal nerve but may still trigger local epithelial responses to irritants. In total, SCCs should be considered chemoreceptor cells that help in preventing damage to the respiratory tract caused by inhaled irritants and pathogens.

  2. Humans Can Taste Glucose Oligomers Independent of the hT1R2/hT1R3 Sweet Taste Receptor.

    Science.gov (United States)

    Lapis, Trina J; Penner, Michael H; Lim, Juyun

    2016-08-23

    It is widely accepted that humans can taste mono- and disaccharides as sweet substances, but they cannot taste longer chain oligo- and polysaccharides. From the evolutionary standpoint, the ability to taste starch or its oligomeric hydrolysis products would be highly adaptive, given their nutritional value. Here, we report that humans can taste glucose oligomer preparations (average degree of polymerization 7 and 14) without any other sensorial cues. The same human subjects could not taste the corresponding glucose polymer preparation (average degree of polymerization 44). When the sweet taste receptor was blocked by lactisole, a known sweet inhibitor, subjects could not detect sweet substances (glucose, maltose, and sucralose), but they could still detect the glucose oligomers. This suggests that glucose oligomer detection is independent of the hT1R2/hT1R3 sweet taste receptor. Human subjects described the taste of glucose oligomers as "starchy," while they describe sugars as "sweet." The dose-response function of glucose oligomer was also found to be indistinguishable from that of glucose on a molar basis. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Immunocytochemical evidence for co-expression of Type III IP3 receptor with signaling components of bitter taste transduction

    Directory of Open Access Journals (Sweden)

    Kinnamon Sue C

    2001-04-01

    Full Text Available Abstract Background Taste receptor cells are responsible for transducing chemical stimuli into electrical signals that lead to the sense of taste. An important second messenger in taste transduction is IP3, which is involved in both bitter and sweet transduction pathways. Several components of the bitter transduction pathway have been identified, including the T2R/TRB taste receptors, phospholipase C β2, and the G protein subunits α-gustducin, β3, and γ13. However, the identity of the IP3 receptor subtype in this pathway is not known. In the present study we used immunocytochemistry on rodent taste tissue to identify the IP3 receptors expressed in taste cells and to examine taste bud expression patterns for IP3R3. Results Antibodies against Type I, II, and III IP3 receptors were tested on sections of rat and mouse circumvallate papillae. Robust cytoplasmic labeling for the Type III IP3 receptor (IP3R3 was found in a large subset of taste cells in both species. In contrast, little or no immunoreactivity was seen with antibodies against the Type I or Type II IP3 receptors. To investigate the potential role of IP3R3 in bitter taste transduction, we used double-label immunocytochemistry to determine whether IP3R3 is expressed in the same subset of cells expressing other bitter signaling components. IP3R3 immunoreactive taste cells were also immunoreactive for PLCβ2 and γ13. Alpha-gustducin immunoreactivity was present in a subset of IP3R3, PLCβ2, and γ13 positive cells. Conclusions IP3R3 is the dominant form of the IP3 receptor expressed in taste cells and our data suggest it plays an important role in bitter taste transduction.

  4. Delta receptor antagonism, ethanol taste reactivity, and ethanol consumption in outbred male rats.

    Science.gov (United States)

    Higley, Amanda E; Kiefer, Stephen W

    2006-11-01

    Naltrexone, a nonspecific opioid antagonist, produces significant changes in ethanol responsivity in rats by rendering the taste of ethanol aversive as well as producing a decrease in voluntary ethanol consumption. The present study investigated the effect of naltrindole, a specific antagonist of delta opioid receptors, on ethanol taste reactivity and ethanol consumption in outbred rats. In the first experiment, rats received acute treatment of naltrexone, naltrindole, or saline followed by the measurement of ethanol consumption in a short-term access period. The second experiment involved the same treatments and investigated ethanol palatability (using the taste-reactivity test) as well as ethanol consumption. Results indicated that treatment with 3 mg/kg naltrexone significantly affected palatability (rendered ethanol more aversive, Experiment 2) and decreased voluntary ethanol consumption (Experiments 1 and 2). The effects of naltrindole were inconsistent. In Experiment 1, 8 mg/kg naltrindole significantly decreased voluntary ethanol consumption but this was not replicated in Experiment 2. The 8 mg/kg dose produced a significant increase in aversive responding (Experiment 2) but did not affect ingestive responding. Lower doses of naltrindole (2 and 4 mg/kg) were ineffective in altering rats' taste-reactivity response to and consumption of ethanol. While these data suggest that delta receptors are involved in rats' taste-reactivity response to ethanol and rats' ethanol consumption, it is likely that multiple opioid receptors mediate both behavioral responses.

  5. Expression and Purification of Functional Ligand-binding Domains of T1R3 Taste Receptors

    Energy Technology Data Exchange (ETDEWEB)

    Nie,Y.; Hobbs, J.; Vigues, S.; Olson, W.; Conn, G.; Munger, S.

    2006-01-01

    Chemosensory receptors, including odor, taste, and vomeronasal receptors, comprise the largest group of G protein-coupled receptors (GPCRs) in the mammalian genome. However, little is known about the molecular determinants that are critical for the detection and discrimination of ligands by most of these receptors. This dearth of understanding is due in part to difficulties in preparing functional receptors suitable for biochemical and biophysical analyses. Here we describe in detail two strategies for the expression and purification of the ligand-binding domain of T1R taste receptors, which are constituents of the sweet and umami taste receptors. These class C GPCRs contain a large extracellular N-terminal domain (NTD) that is the site of interaction with most ligands and that is amenable to expression as a separate polypeptide in heterologous cells. The NTD of mouse T1R3 was expressed as two distinct fusion proteins in Escherichia coli and purified by column chromatography. Spectroscopic analysis of the purified NTD proteins shows them to be properly folded and capable of binding ligands. This methodology should not only facilitate the characterization of T1R ligand interactions but may also be useful for dissecting the function of other class C GPCRs such as the large family of orphan V2R vomeronasal receptors.

  6. Functional expression of ionotropic purinergic receptors on mouse taste bud cells.

    Science.gov (United States)

    Hayato, Ryotaro; Ohtubo, Yoshitaka; Yoshii, Kiyonori

    2007-10-15

    Neurotransmitter receptors on taste bud cells (TBCs) and taste nerve fibres are likely to contribute to taste transduction by mediating the interaction among TBCs and that between TBCs and taste nerve fibres. We investigated the functional expression of P2 receptor subtypes on TBCs of mouse fungiform papillae. Electrophysiological studies showed that 100 microm ATP applied to their basolateral membranes either depolarized or hyperpolarized a few cells per taste bud. Ca(2+) imaging showed that similarly applied 1 mum ATP, 30 microm BzATP (a P2X(7) agonist), or 1 microm 2MeSATP (a P2Y(1) and P2Y(11) agonist) increased intracellular Ca(2+) concentration, but 100 microm UTP (a P2Y(2) and P2Y(4) agonist) and alpha,beta-meATP (a P2X agonist except for P2X(2), P2X(4) and P2X(7)) did not. RT-PCR suggested the expression of P2X(2), P2X(4), P2X(7), P2Y(1), P2Y(13) and P2Y(14) among the seven P2X subtypes and seven P2Y subtypes examined. Immunohistostaining confirmed the expression of P2X(2). The exposure of the basolateral membranes to 3 mm ATP for 30 min caused the uptake of Lucifer Yellow CH in a few TBCs per taste bud. This was antagonized by 100 microm PPADS (a non-selective P2 blocker) and 1 microm KN-62 (a P2X(7) blocker). These results showed for the first time the functional expression of P2X(2) and P2X(7) on TBCs. The roles of P2 receptor subtypes in the taste transduction, and the renewal of TBCs, are discussed.

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

    Science.gov (United States)

    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.

  8. Selective Deletion of Sodium Salt Taste during Development Leads to Expanded Terminal Fields of Gustatory Nerves in the Adult Mouse Nucleus of the Solitary Tract.

    Science.gov (United States)

    Sun, Chengsan; Hummler, Edith; Hill, David L

    2017-01-18

    Neuronal activity plays a key role in the development of sensory circuits in the mammalian brain. In the gustatory system, experimental manipulations now exist, through genetic manipulations of specific taste transduction processes, to examine how specific taste qualities (i.e., basic tastes) impact the functional and structural development of gustatory circuits. Here, we used a mouse knock-out model in which the transduction component used to discriminate sodium salts from other taste stimuli was deleted in taste bud cells throughout development. We used this model to test the hypothesis that the lack of activity elicited by sodium salt taste impacts the terminal field organization of nerves that carry taste information from taste buds to the nucleus of the solitary tract (NST) in the medulla. The glossopharyngeal, chorda tympani, and greater superficial petrosal nerves were labeled to examine their terminal fields in adult control mice and in adult mice in which the α-subunit of the epithelial sodium channel was conditionally deleted in taste buds (αENaC knockout). The terminal fields of all three nerves in the NST were up to 2.7 times greater in αENaC knock-out mice compared with the respective field volumes in control mice. The shapes of the fields were similar between the two groups; however, the density and spread of labels were greater in αENaC knock-out mice. Overall, our results show that disruption of the afferent taste signal to sodium salts disrupts the normal age-dependent "pruning" of all terminal fields, which could lead to alterations in sensory coding and taste-related behaviors. Neural activity plays a major role in the development of sensory circuits in the mammalian brain. To date, there has been no direct test of whether taste-elicited neural activity has a role in shaping central gustatory circuits. However, recently developed genetic tools now allow an assessment of how specific taste stimuli, in this case sodium salt taste, play a role

  9. Postsynaptic P2X3-containing receptors in gustatory nerve fibres mediate responses to all taste qualities in mice.

    Science.gov (United States)

    Vandenbeuch, Aurelie; Larson, Eric D; Anderson, Catherine B; Smith, Steven A; Ford, Anthony P; Finger, Thomas E; Kinnamon, Sue C

    2015-03-01

    Taste buds release ATP to activate ionotropic purinoceptors composed of P2X2 and P2X3 subunits, present on the taste nerves. Mice with genetic deletion of P2X2 and P2X3 receptors (double knockout mice) lack responses to all taste stimuli presumably due to the absence of ATP-gated receptors on the afferent nerves. Recent experiments on the double knockout mice showed, however, that their taste buds fail to release ATP, suggesting the possibility of pleiotropic deficits in these global knockouts. To test further the role of postsynaptic P2X receptors in afferent signalling, we used AF-353, a selective antagonist of P2X3-containing receptors to inhibit the receptors acutely during taste nerve recording and behaviour. The specificity of AF-353 for P2X3-containing receptors was tested by recording Ca(2+) transients to exogenously applied ATP in fura-2 loaded isolated geniculate ganglion neurons from wild-type and P2X3 knockout mice. ATP responses were completely inhibited by 10 μm or 100 μm AF-353, but neither concentration blocked responses in P2X3 single knockout mice wherein the ganglion cells express only P2X2-containing receptors. Furthermore, AF-353 had no effect on taste-evoked ATP release from taste buds. In wild-type mice, i.p. injection of AF-353 or simple application of the drug directly to the tongue, inhibited taste nerve responses to all taste qualities in a dose-dependent fashion. A brief access behavioural assay confirmed the electrophysiological results and showed that preference for a synthetic sweetener, SC-45647, was abolished following i.p. injection of AF-353. These data indicate that activation of P2X3-containing receptors is required for transmission of all taste qualities. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  10. A large increase of sour taste receptor cells in Skn-1-deficient mice does not alter the number of their sour taste signal-transmitting gustatory neurons.

    Science.gov (United States)

    Maeda, Naohiro; Narukawa, Masataka; Ishimaru, Yoshiro; Yamamoto, Kurumi; Misaka, Takumi; Abe, Keiko

    2017-05-01

    The connections between taste receptor cells (TRCs) and innervating gustatory neurons are formed in a mutually dependent manner during development. To investigate whether a change in the ratio of cell types that compose taste buds influences the number of innervating gustatory neurons, we analyzed the proportion of gustatory neurons that transmit sour taste signals in adult Skn-1a -/- mice in which the number of sour TRCs is greatly increased. We generated polycystic kidney disease 1 like 3-wheat germ agglutinin (pkd1l3-WGA)/Skn-1a +/+ and pkd1l3-WGA/Skn-1a -/- mice by crossing Skn-1a -/- mice and pkd1l3-WGA transgenic mice, in which neural pathways of sour taste signals can be visualized. The number of WGA-positive cells in the circumvallate papillae is 3-fold higher in taste buds of pkd1l3-WGA/Skn-1a -/- mice relative to pkd1l3-WGA/Skn-1a +/+ mice. Intriguingly, the ratio of WGA-positive neurons to P2X 2 -expressing gustatory neurons in nodose/petrosal ganglia was similar between pkd1l3-WGA/Skn-1a +/+ and pkd1l3-WGA/Skn-1a -/- mice. In conclusion, an alteration in the ratio of cell types that compose taste buds does not influence the number of gustatory neurons that transmit sour taste signals. Copyright © 2017. Published by Elsevier B.V.

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

    Science.gov (United States)

    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.

  12. Type II and III Taste Bud Cells Preferentially Expressed Kainate Glutamate Receptors in Rats.

    Science.gov (United States)

    Lee, Sang-Bok; Lee, Cil-Han; Kim, Se-Nyun; Chung, Ki-Myung; Cho, Young-Kyung; Kim, Kyung-Nyun

    2009-12-01

    Glutamate-induced cobalt uptake reveals that non-NMDA glutamate receptors (GluRs) are present in rat taste bud cells. Previous studies involving glutamate induced cobalt staining suggest this uptake mainly occurs via kainate type GluRs. It is not known which of the 4 types of taste bud cells express subunits of kainate GluR. Circumvallate and foliate papillae of Sprague-Dawley rats (45~60 days old) were used to search for the mRNAs of subunits of non-NMDA GluRs using RT-PCR with specific primers for GluR1-7, KA1 and KA2. We also performed RT-PCR for GluR5, KA1, PLCbeta2, and NCAM/SNAP 25 in isolated single cells from taste buds. Taste epithelium, including circumvallate or foliate papilla, express mRNAs of GluR5 and KA1. However, non-taste tongue epithelium expresses no subunits of non-NMDA GluRs. Isolated single cell RT-PCR reveals that the mRNAs of GluR5 and KA1 are preferentially expressed in Type II and Type III cells over Type I cells.

  13. The binding site for neohesperidin dihydrochalcone at the human sweet taste receptor

    Directory of Open Access Journals (Sweden)

    Kratochwil Nicole A

    2007-10-01

    Full Text Available Abstract Background Differences in sweet taste perception among species depend on structural variations of the sweet taste receptor. The commercially used isovanillyl sweetener neohesperidin dihydrochalcone activates the human but not the rat sweet receptor TAS1R2+TAS1R3. Analysis of interspecies combinations and chimeras of rat and human TAS1R2+TAS1R3 suggested that the heptahelical domain of human TAS1R3 is crucial for the activation of the sweet receptor by neohesperidin dihydrochalcone. Results By mutational analysis combined with functional studies and molecular modeling we identified a set of different amino acid residues within the heptahelical domain of human TAS1R3 that forms the neohesperidin dihydrochalcone binding pocket. Sixteen amino acid residues in the transmembrane domains 2 to 7 and one in the extracellular loop 2 of hTAS1R3 influenced the receptor's response to neohesperidin dihydrochalcone. Some of these seventeen residues are also part of the binding sites for the sweetener cyclamate or the sweet taste inhibitor lactisole. In line with this observation, lactisole inhibited activation of the sweet receptor by neohesperidin dihydrochalcone and cyclamate competitively, whereas receptor activation by aspartame, a sweetener known to bind to the N-terminal domain of TAS1R2, was allosterically inhibited. Seven of the amino acid positions crucial for activation of hTAS1R2+hTAS1R3 by neohesperidin dihydrochalcone are thought to play a role in the binding of allosteric modulators of other class C GPCRs, further supporting our model of the neohesperidin dihydrochalcone pharmacophore. Conclusion From our data we conclude that we identified the neohesperidin dihydrochalcone binding site at the human sweet taste receptor, which overlaps with those for the sweetener cyclamate and the sweet taste inhibitor lactisole. This readily delivers a molecular explanation of our finding that lactisole is a competitive inhibitor of the receptor

  14. Characterization of the Binding Site of Aspartame in the Human Sweet Taste Receptor.

    Science.gov (United States)

    Maillet, Emeline L; Cui, Meng; Jiang, Peihua; Mezei, Mihaly; Hecht, Elizabeth; Quijada, Jeniffer; Margolskee, Robert F; Osman, Roman; Max, Marianna

    2015-10-01

    The sweet taste receptor, a heterodimeric G protein-coupled receptor comprised of T1R2 and T1R3, binds sugars, small molecule sweeteners, and sweet proteins to multiple binding sites. The dipeptide sweetener, aspartame binds in the Venus Flytrap Module (VFTM) of T1R2. We developed homology models of the open and closed forms of human T1R2 and human T1R3 VFTMs and their dimers and then docked aspartame into the closed form of T1R2's VFTM. To test and refine the predictions of our model, we mutated various T1R2 VFTM residues, assayed activity of the mutants and identified 11 critical residues (S40, Y103, D142, S144, S165, S168, Y215, D278, E302, D307, and R383) in and proximal to the binding pocket of the sweet taste receptor that are important for ligand recognition and activity of aspartame. Furthermore, we propose that binding is dependent on 2 water molecules situated in the ligand pocket that bridge 2 carbonyl groups of aspartame to residues D142 and L279. These results shed light on the activation mechanism and how signal transmission arising from the extracellular domain of the T1R2 monomer of the sweet receptor leads to the perception of sweet taste. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Breadth of Tuning and Taste Coding in Mammalian Taste Buds

    OpenAIRE

    Tomchik, Seth M.; Berg, Stephanie; Kim, Joung Woul; Chaudhari, Nirupa; Roper, Stephen D.

    2007-01-01

    A longstanding question in taste research concerns taste coding and, in particular, how broadly are individual taste bud cells tuned to taste qualities (sweet, bitter, umami, salty, and sour). Taste bud cells express G-protein-coupled receptors for sweet, bitter, or umami tastes but not in combination. However, responses to multiple taste qualities have been recorded in individual taste cells. We and others have shown previously there are two classes of taste bud cells directly involved in gu...

  16. Sonic hedgehog-expressing basal cells are general post-mitotic precursors of functional taste receptor cells

    Science.gov (United States)

    Miura, Hirohito; Scott, Jennifer K.; Harada, Shuitsu; Barlow, Linda A.

    2014-01-01

    Background Taste buds contain ~60 elongate cells and several basal cells. Elongate cells comprise three functional taste cell types: I - glial cells, II - bitter/sweet/umami receptor cells, and III - sour detectors. Although taste cells are continuously renewed, lineage relationships among cell types are ill-defined. Basal cells have been proposed as taste bud stem cells, a subset of which express Sonic hedgehog (Shh). However, Shh+ basal cells turnover rapidly suggesting that Shh+ cells are precursors of some or all taste cell types. Results To fate map Shh-expressing cells, mice carrying ShhCreERT2 and a high (CAG-CAT-EGFP) or low (R26RLacZ) efficiency reporter allele were given tamoxifen to activate Cre in Shh+ cells. Using R26RLacZ, lineage-labeled cells occur singly within buds, supporting a post-mitotic state for Shh+ cells. Using either reporter, we show that Shh+ cells differentiate into all three taste cell types, in proportions reflecting cell type ratios in taste buds (I > II > III). Conclusions Shh+ cells are not stem cells, but are post-mitotic, immediate precursors of taste cells. Shh+ cells differentiate into each of the three taste cell types, and the choice of a specific taste cell fate is regulated to maintain the proper ratio within buds. PMID:24590958

  17. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor

    OpenAIRE

    Baldwin, Maude Wheeler; Toda, Y.; Nakagita, T.; O'Connell, Mary J.; Klasing, Kirk C.; Misaka, T.; Edwards, Scott V.; Liberles, Stephen D

    2014-01-01

    Sensory systems define an animal's capacity for perception and can evolve to promote survival in new environmental niches. We have uncovered a noncanonical mechanism for sweet taste perception that evolved in hummingbirds since their divergence from insectivorous swifts, their closest relatives. We observed the widespread absence in birds of an essential subunit (T1R2) of the only known vertebrate sweet receptor, raising questions about how specialized nectar feeders such as hummingbirds sens...

  18. Selective expression of muscarinic acetylcholine receptor subtype M3 by mouse type III taste bud cells.

    Science.gov (United States)

    Mori, Yusuke; Eguchi, Kohgaku; Yoshii, Kiyonori; Ohtubo, Yoshitaka

    2016-11-01

    Each taste bud cell (TBC) type responds to a different taste. Previously, we showed that an unidentified cell type(s) functionally expresses a muscarinic acetylcholine (ACh) receptor subtype, M3, and we suggested the ACh-dependent modification of its taste responsiveness. In this study, we found that M3 is expressed by type III TBCs, which is the only cell type that possesses synaptic contacts with taste nerve fibers in taste buds. The application of ACh to the basolateral membrane of mouse fungiform TBCs in situ increased the intracellular Ca 2+ concentration in 2.4 ± 1.4 cells per taste bud (mean ± SD, n = 14). After Ca 2+ imaging, we supravitally labeled type II cells (phospholipase C β2 [PLCβ2]-immunoreactive cells) with Lucifer yellow CH (LY), a fluorescent dye and investigated the positional relationship between ACh-responding cells and LY-labeled cells. After fixation, the TBCs were immunohistostained to investigate the positional relationships between immunohistochemically classified cells and LY-labeled cells. The overlay of the two positional relationships obtained by superimposing the LY-labeled cells showed that all of the ACh-responding cells were type III cells (synaptosomal-associated protein 25 [SNAP-25]-immunoreactive cells). The ACh responses required no added Ca 2+ in the bathing solution. The addition of 1 μM U73122, a phospholipase C inhibitor, decreased the magnitude of the ACh response, whereas that of 1 μM U73343, a negative control, had no effect. These results suggest that type III cells respond to ACh and release Ca 2+ from intracellular stores. We also discuss the underlying mechanism of the Ca 2+ response and the role of M3 in type III cells.

  19. Differential effects of beta-adrenergic receptor blockade in the medial prefrontal cortex during aversive and incidental taste memory formation.

    Science.gov (United States)

    Reyes-López, J; Nuñez-Jaramillo, L; Morán-Guel, E; Miranda, M I

    2010-08-11

    The medial prefrontal cortex (mPFC) is a brain area crucial for memory, attention, and decision making. Specifically, the noradrenergic system in this cortex is involved in aversive learning, as well as in the retrieval of these memories. Some evidence suggests that this area has an important role during taste memory, particularly during conditioned taste aversion (CTA), a model of aversive memory. Despite some previous evidence, there is scarce information about the role of adrenergic receptors in the mPFC during formation of aversive taste memory and appetitive/incidental taste memory. The goal of this research was to evaluate the role of mPFC beta-adrenergic receptors during CTA acquisition/consolidation or CTA retrieval, as well as during incidental taste memory formation using the model of latent inhibition of CTA. The results showed that infusions in the mPFC of the beta-adrenergic antagonist propranolol before CTA acquisition impaired both short- and long-term aversive taste memory formation, and also that propranolol infusions before the memory test impaired CTA retrieval. However, propranolol infusions before pre-exposure to the taste during the latent inhibition procedure had no effect on incidental taste memory acquisition or consolidation. These data indicate that beta-adrenergic receptors in the mPFC have different functions during taste memory formation: they have an important role during aversive taste association as well as during aversive retrieval but not during incidental taste memory formation. Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. The bitter pill: clinical drugs that activate the human bitter taste receptor TAS2R14.

    Science.gov (United States)

    Levit, Anat; Nowak, Stefanie; Peters, Maximilian; Wiener, Ayana; Meyerhof, Wolfgang; Behrens, Maik; Niv, Masha Y

    2014-03-01

    Bitter taste receptors (TAS2Rs) mediate aversive response to toxic food, which is often bitter. These G-protein-coupled receptors are also expressed in extraoral tissues, and emerge as novel targets for therapeutic indications such as asthma and infection. Our goal was to identify ligands of the broadly tuned TAS2R14 among clinical drugs. Molecular properties of known human bitter taste receptor TAS2R14 agonists were incorporated into pharmacophore- and shape-based models and used to computationally predict additional ligands. Predictions were tested by calcium imaging of TAS2R14-transfected HEK293 cells. In vitro testing of the virtual screening predictions resulted in 30-80% success rates, and 15 clinical drugs were found to activate the TAS2R14. hERG potassium channel, which is predominantly expressed in the heart, emerged as a common off-target of bitter drugs. Despite immense chemical diversity of known TAS2R14 ligands, novel ligands and previously unknown polypharmacology of drugs were unraveled by in vitro screening of computational predictions. This enables rational repurposing of traditional and standard drugs for bitter taste signaling modulation for therapeutic indications.

  1. L-Amino Acids Elicit Diverse Response Patterns in Taste Sensory Cells: A Role for Multiple Receptors

    Science.gov (United States)

    Pal Choudhuri, Shreoshi; Delay, Rona J.; Delay, Eugene R.

    2015-01-01

    Umami, the fifth basic taste, is elicited by the L-amino acid, glutamate. A unique characteristic of umami taste is the response potentiation by 5’ ribonucleotide monophosphates, which are also capable of eliciting an umami taste. Initial reports using human embryonic kidney (HEK) cells suggested that there is one broadly tuned receptor heterodimer, T1r1+T1r3, which detects L-glutamate and all other L-amino acids. However, there is growing evidence that multiple receptors detect glutamate in the oral cavity. While much is understood about glutamate transduction, the mechanisms for detecting the tastes of other L-amino acids are less well understood. We used calcium imaging of isolated taste sensory cells and taste cell clusters from the circumvallate and foliate papillae of C57BL/6J and T1r3 knockout mice to determine if other receptors might also be involved in detection of L-amino acids. Ratiometric imaging with Fura-2 was used to study calcium responses to monopotassium L-glutamate, L-serine, L-arginine, and L-glutamine, with and without inosine 5’ monophosphate (IMP). The results of these experiments showed that the response patterns elicited by L-amino acids varied significantly across taste sensory cells. L-amino acids other than glutamate also elicited synergistic responses in a subset of taste sensory cells. Along with its role in synergism, IMP alone elicited a response in a large number of taste sensory cells. Our data indicate that synergistic and non-synergistic responses to L-amino acids and IMP are mediated by multiple receptors or possibly a receptor complex. PMID:26110622

  2. Functional Analyses of Bitter Taste Receptors in Domestic Cats (Felis catus.

    Directory of Open Access Journals (Sweden)

    Weiwei Lei

    Full Text Available Cats are obligate carnivores and under most circumstances eat only animal products. Owing to the pseudogenization of one of two subunits of the sweet receptor gene, they are indifferent to sweeteners, presumably having no need to detect plant-based sugars in their diet. Following this reasoning and a recent report of a positive correlation between the proportion of dietary plants and the number of Tas2r (bitter receptor genes in vertebrate species, we tested the hypothesis that if bitter perception exists primarily to protect animals from poisonous plant compounds, the genome of the domestic cat (Felis catus should have lost functional bitter receptors and they should also have reduced bitter receptor function. To test functionality of cat bitter receptors, we expressed cat Tas2R receptors in cell-based assays. We found that they have at least 7 functional receptors with distinct receptive ranges, showing many similarities, along with some differences, with human bitter receptors. To provide a comparative perspective, we compared the cat repertoire of intact receptors with those of a restricted number of members of the order Carnivora, with a range of dietary habits as reported in the literature. The numbers of functional bitter receptors in the terrestrial Carnivora we examined, including omnivorous and herbivorous species, were roughly comparable to that of cats thereby providing no strong support for the hypothesis that a strict meat diet influences bitter receptor number or function. Maintenance of bitter receptor function in terrestrial obligate carnivores may be due to the presence of bitter compounds in vertebrate and invertebrate prey, to the necessary role these receptors play in non-oral perception, or to other unknown factors. We also found that the two aquatic Carnivora species examined had fewer intact bitter receptors. Further comparative studies of factors driving numbers and functions of bitter taste receptors will aid in

  3. Functional Analyses of Bitter Taste Receptors in Domestic Cats (Felis catus).

    Science.gov (United States)

    Lei, Weiwei; Ravoninjohary, Aurore; Li, Xia; Margolskee, Robert F; Reed, Danielle R; Beauchamp, Gary K; Jiang, Peihua

    2015-01-01

    Cats are obligate carnivores and under most circumstances eat only animal products. Owing to the pseudogenization of one of two subunits of the sweet receptor gene, they are indifferent to sweeteners, presumably having no need to detect plant-based sugars in their diet. Following this reasoning and a recent report of a positive correlation between the proportion of dietary plants and the number of Tas2r (bitter receptor) genes in vertebrate species, we tested the hypothesis that if bitter perception exists primarily to protect animals from poisonous plant compounds, the genome of the domestic cat (Felis catus) should have lost functional bitter receptors and they should also have reduced bitter receptor function. To test functionality of cat bitter receptors, we expressed cat Tas2R receptors in cell-based assays. We found that they have at least 7 functional receptors with distinct receptive ranges, showing many similarities, along with some differences, with human bitter receptors. To provide a comparative perspective, we compared the cat repertoire of intact receptors with those of a restricted number of members of the order Carnivora, with a range of dietary habits as reported in the literature. The numbers of functional bitter receptors in the terrestrial Carnivora we examined, including omnivorous and herbivorous species, were roughly comparable to that of cats thereby providing no strong support for the hypothesis that a strict meat diet influences bitter receptor number or function. Maintenance of bitter receptor function in terrestrial obligate carnivores may be due to the presence of bitter compounds in vertebrate and invertebrate prey, to the necessary role these receptors play in non-oral perception, or to other unknown factors. We also found that the two aquatic Carnivora species examined had fewer intact bitter receptors. Further comparative studies of factors driving numbers and functions of bitter taste receptors will aid in understanding the forces

  4. Genetic diversity of bitter taste receptor gene family in Sichuan domestic and Tibetan chicken populations.

    Science.gov (United States)

    Su, Yuan; Li, Diyan; Gaur, Uma; Wang, Yan; Wu, Nan; Chen, Binlong; Xu, Zhongxian; Yin, Huadong; Hu, Yaodong; Zhu, Qing

    2016-09-01

    The sense of bitter taste plays a critical role in animals as it can help them to avoid intake of toxic and harmful substances. Previous research had revealed that chicken has only three bitter taste receptor genes (Tas2r1, Tas2r2 and Tas2r7). To better understand the genetic polymorphisms and importance of bitter taste receptor genes (Tas2rs) in chicken, here, we sequenced Tas2rs of 30 Sichuan domestic chickens and 30 Tibetan chickens. Thirteen single-nucleotide polymorphisms (SNPs) including three nonsynonymous mutations (m.359G>C, m.503C>A and m.583A>G) were detected in Tas2r1 (m. is the abbreviation for mutation); three SNPs were detected in Tas2r2, but none of them were missense mutation; eight SNPs were detected in Tas2r7 including six nonsynonymous substitutions (m.178G>A, m.421A>C, m.787C>T, m.832G>T, m.907A>T and m.943G>A). Tajima's D neutral test indicates that there is no population expansion in both populations, and the size of the population is relatively stable. All the three networks indicate that red jungle fowls share haplotypes with domestic chickens. In addition, we found that haplotypes H1 and HE1 were positively associated with high-altitude adaptation, whereas haplotypes H4 and HE4 showed a negative correlation with high-altitude adaptation in Tas2rs. Although, chicken has only three Tas2rs, our results showed that both Sichuan domestic chickens and Tibetan chickens have abundant haplotypes in Tas2rs, especially in Tas2r7, which might help chickens to recognize a wide variety of bitter-tasting compounds.

  5. Ligand binding modes from low resolution GPCR models and mutagenesis: chicken bitter taste receptor as a test-case.

    Science.gov (United States)

    Di Pizio, Antonella; Kruetzfeldt, Louisa-Marie; Cheled-Shoval, Shira; Meyerhof, Wolfgang; Behrens, Maik; Niv, Masha Y

    2017-08-15

    Bitter taste is one of the basic taste modalities, warning against consuming potential poisons. Bitter compounds activate members of the bitter taste receptor (Tas2r) subfamily of G protein-coupled receptors (GPCRs). The number of functional Tas2rs is species-dependent. Chickens represent an intriguing minimalistic model, because they detect the bitter taste of structurally different molecules with merely three bitter taste receptor subtypes. We investigated the binding modes of several known agonists of a representative chicken bitter taste receptor, ggTas2r1. Because of low sequence similarity between ggTas2r1 and crystallized GPCRs (~10% identity, ~30% similarity at most), the combination of computational approaches with site-directed mutagenesis was used to characterize the agonist-bound conformation of ggTas2r1 binding site between TMs 3, 5, 6 and 7. We found that the ligand interactions with N93 in TM3 and/or N247 in TM5, combined with hydrophobic contacts, are typically involved in agonist recognition. Next, the ggTas2r1 structural model was successfully used to identify three quinine analogues (epiquinidine, ethylhydrocupreine, quinidine) as new ggTas2r1 agonists. The integrated approach validated here may be applicable to additional cases where the sequence identity of the GPCR of interest and the existing experimental structures is low.

  6. Impaired Glucose Metabolism in Mice Lacking the Tas1r3 Taste Receptor Gene.

    Science.gov (United States)

    Murovets, Vladimir O; Bachmanov, Alexander A; Zolotarev, Vasiliy A

    2015-01-01

    The G-protein-coupled sweet taste receptor dimer T1R2/T1R3 is expressed in taste bud cells in the oral cavity. In recent years, its involvement in membrane glucose sensing was discovered in endocrine cells regulating glucose homeostasis. We investigated importance of extraorally expressed T1R3 taste receptor protein in age-dependent control of blood glucose homeostasis in vivo, using nonfasted mice with a targeted mutation of the Tas1r3 gene that encodes the T1R3 protein. Glucose and insulin tolerance tests, as well as behavioral tests measuring taste responses to sucrose solutions, were performed with C57BL/6ByJ (Tas1r3+/+) inbred mice bearing the wild-type allele and C57BL/6J-Tas1r3tm1Rfm mice lacking the entire Tas1r3 coding region and devoid of the T1R3 protein (Tas1r3-/-). Compared with Tas1r3+/+ mice, Tas1r3-/- mice lacked attraction to sucrose in brief-access licking tests, had diminished taste preferences for sucrose solutions in the two-bottle tests, and had reduced insulin sensitivity and tolerance to glucose administered intraperitoneally or intragastrically, which suggests that these effects are due to absence of T1R3. Impairment of glucose clearance in Tas1r3-/- mice was exacerbated with age after intraperitoneal but not intragastric administration of glucose, pointing to a compensatory role of extraoral T1R3-dependent mechanisms in offsetting age-dependent decline in regulation of glucose homeostasis. Incretin effects were similar in Tas1r3+/+ and Tas1r3-/- mice, which suggests that control of blood glucose clearance is associated with effects of extraoral T1R3 in tissues other than the gastrointestinal tract. Collectively, the obtained data demonstrate that the T1R3 receptor protein plays an important role in control of glucose homeostasis not only by regulating sugar intake but also via its extraoral function, probably in the pancreas and brain.

  7. Impaired Glucose Metabolism in Mice Lacking the Tas1r3 Taste Receptor Gene.

    Directory of Open Access Journals (Sweden)

    Vladimir O Murovets

    Full Text Available The G-protein-coupled sweet taste receptor dimer T1R2/T1R3 is expressed in taste bud cells in the oral cavity. In recent years, its involvement in membrane glucose sensing was discovered in endocrine cells regulating glucose homeostasis. We investigated importance of extraorally expressed T1R3 taste receptor protein in age-dependent control of blood glucose homeostasis in vivo, using nonfasted mice with a targeted mutation of the Tas1r3 gene that encodes the T1R3 protein. Glucose and insulin tolerance tests, as well as behavioral tests measuring taste responses to sucrose solutions, were performed with C57BL/6ByJ (Tas1r3+/+ inbred mice bearing the wild-type allele and C57BL/6J-Tas1r3tm1Rfm mice lacking the entire Tas1r3 coding region and devoid of the T1R3 protein (Tas1r3-/-. Compared with Tas1r3+/+ mice, Tas1r3-/- mice lacked attraction to sucrose in brief-access licking tests, had diminished taste preferences for sucrose solutions in the two-bottle tests, and had reduced insulin sensitivity and tolerance to glucose administered intraperitoneally or intragastrically, which suggests that these effects are due to absence of T1R3. Impairment of glucose clearance in Tas1r3-/- mice was exacerbated with age after intraperitoneal but not intragastric administration of glucose, pointing to a compensatory role of extraoral T1R3-dependent mechanisms in offsetting age-dependent decline in regulation of glucose homeostasis. Incretin effects were similar in Tas1r3+/+ and Tas1r3-/- mice, which suggests that control of blood glucose clearance is associated with effects of extraoral T1R3 in tissues other than the gastrointestinal tract. Collectively, the obtained data demonstrate that the T1R3 receptor protein plays an important role in control of glucose homeostasis not only by regulating sugar intake but also via its extraoral function, probably in the pancreas and brain.

  8. Overcoming chemoresistance in pancreatic cancer cells: role of the bitter taste receptor T2R10.

    Science.gov (United States)

    Stern, Louisa; Giese, Nathalia; Hackert, Thilo; Strobel, Oliver; Schirmacher, Peter; Felix, Klaus; Gaida, Matthias M

    2018-01-01

    Bitter taste receptors (T2Rs) are G-protein coupled transmembrane proteins initially identified in the gustatory system as sensors for the taste of bitter. Recent evidence on expression of these receptors outside gustatory tissues suggested alternative functions, and there is growing interest of their potential role in cancer biology. In this study, we report for the first time, expression and functionality of the bitter receptor family member T2R10 in both human pancreatic ductal adenocarcinoma (PDAC) tissue and PDAC derived cell lines. Caffeine, a known ligand for T2R10, rendered the tumor cells more susceptible to two standard chemotherapeutics, Gemcitabine and 5-Fluoruracil. Knocking down T2R10 in the cell line BxPC-3 reduced the caffeine-induced effect. As possible underlying mechanism, we found that caffeine via triggering T2R10 inhibited Akt phosphorylation and subsequently downregulated expression of ABCG2, the so-called multi-drug resistance protein that participates in rendering cells resistant to a variety of chemotherapeutics. In conclusion, T2R10 is expressed in pancreatic cancer and it downmodulates the chemoresistance of the tumor cells.

  9. Effects of haemodialysis on taste for salt in relation to changes in blood constituents.

    Science.gov (United States)

    Farleigh, C A; Shepherd, R; Jevons, S; Pryor, J S

    1987-11-01

    Taste sensitivity and preference for sodium chloride in bread and pea soup were assessed before and after haemodialysis in 12 female chronic renal failure patients. Blood samples were also taken pre- and post-dialysis and analysed for zinc, sodium and renin. The patients demonstrated an increased sensitivity to, and decreased preference for, sodium chloride in both bread and pea soup following dialysis. These taste changes were found to correlate with pre- to post-dialysis changes in the zinc levels in the blood. Patients receiving a more severely sodium-restricted diet showed a greater sensitivity to the taste of sodium chloride in the foods tested. Renin levels dropped in all patients following dialysis, the size of the change correlating with the size of the change in body weight.

  10. Taste buds as peripheral chemosensory processors.

    Science.gov (United States)

    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.

  11. Genetic Variation in the TAS2R38 Bitter Taste Receptor and Smoking Behaviors.

    Directory of Open Access Journals (Sweden)

    Davide S Risso

    Full Text Available Common TAS2R38 taste receptor gene variants specify the ability to taste phenylthiocarbamide (PTC, 6-n-propylthiouracil (PROP and structurally related compounds. Tobacco smoke contains a complex mixture of chemical substances of varying structure and functionality, some of which activate different taste receptors. Accordingly, it has been suggested that non-taster individuals may be more likely to smoke because of their inability to taste bitter compounds present in tobacco smoke, but results to date have been conflicting. We studied three cohorts: 237 European-Americans from the state of Georgia, 1,353 European-Americans and 2,363 African-Americans from the Dallas Heart Study (DHS, and 4,973 African-Americans from the Dallas Biobank. Tobacco use data was collected and TAS2R38 polymorphisms were genotyped for all participants, and PTC taste sensitivity was assessed in the Georgia population. In the Georgia group, PTC tasters were less common among those who smoke: 71.5% of smokers were PTC tasters while 82.5% of non-smokers were PTC tasters (P = 0.03. The frequency of the TAS2R38 PAV taster haplotype showed a trend toward being lower in smokers (38.4% than in non-smokers (43.1%, although this was not statistically significant (P = 0.31. In the DHS European-Americans, the taster haplotype was less common in smokers (37.0% vs. 44.0% in non-smokers, P = 0.003, and conversely the frequency of the non-taster haplotype was more common in smokers (58.7% vs. 51.5% in non-smokers, P = 0.002. No difference in the frequency of these haplotypes was observed in African Americans in either the Dallas Heart Study or the Dallas Biobank. We conclude that TAS2R38 haplotypes are associated with smoking status in European-Americans but not in African-American populations. PTC taster status may play a role in protecting individuals from cigarette smoking in specific populations.

  12. Lower expressions of the human bitter taste receptor TAS2R in smokers: reverse transcriptase-polymerase chain reaction analysis.

    Science.gov (United States)

    Aoki, Mieko; Takao, Tetsuya; Takao, Kyoichi; Koike, Fumihiko; Suganuma, Narufumi

    2014-01-01

    Despite the fact that smokers have deficit in detecting taste, particularly bitter taste, no study has investigated its biological correlate. In this context, we compared the expression of the bitter taste receptor gene, taste 2 receptor (TAS2R) in the tongues of smokers and non-smokers. Tissue samples were collected from the lateral portion of the tongues of 22 smokers and 22 age- and gender-matched healthy volunteers (19 males and three females) with no history of smoking. Reverse transcriptase-polymerase chain reaction was used to examine the expression of TAS2R in the two groups, and the effect of aging on TAS2R expression was also assessed. TAS2R expression was significantly lower among smokers than non-smokers (t = 6.525, P vs. 2.09 ± 2.8, mean ± SD, non-smokers vs. smokers). Further, a positive correlation between age and expression of TAS2R was observed in non-smokers (r = .642, P = .001), but not smokers (r = .124, P = .584). This correlation difference was significant (Z = 1.96, P = .0496). Smokers showed a significantly lower expression of the bitter taste receptor gene than non-smokers, which is potentially caused by their inability to acquire such receptors with age because of cigarette smoking, in contrast to non-smokers.

  13. Bitter taste receptors in the wrong place: novel airway smooth muscle targets for treating asthma.

    Science.gov (United States)

    Liggett, Stephen B

    2014-01-01

    There is a need to expand the classes of drugs used to treat obstructive lung diseases to achieve better outcomes. With only one class of direct bronchodilators (β-agonists), we sought to find receptors on human airway smooth muscle (ASM) that act via a unique mechanism to relax the muscle, have a diverse agonist binding profile to enhance the probability of finding new therapeutics, and relax ASM with equal or greater efficacy than β-agonists. We have found that human and mouse ASM express six bitter taste receptor (TAS2R) subtypes, previously thought only to exist in taste buds of the tongue. Agonists acting at TAS2Rs evoke profound bronchodilation via a Ca(2+)-dependent mechanism. TAS2R function is not altered in asthma models, undergoes minimal tachyphylaxis upon repetitive dosing, and relaxes even under extreme desensitization of relaxation by β-agonists. Taken together, TAS2Rs on ASM represent a novel pathway to consider for development of agonists in the treatment of asthma and chronic obstructive lung disease.

  14. Genetic variation in the hTAS2R38 taste receptor and brassica vegetable intake

    DEFF Research Database (Denmark)

    Gorovic, Nela; Afzal, Shoaib; Tjonneland, Anne

    2011-01-01

    The human TAS2R38 receptor is believed to be partly responsible for the ability to taste phenylthiocarbamide (PTC), a bitter compound very similar to the bitter glucosinolates found in brassica vegetables. These vegetables and their active compounds have chemo-protective properties. This study...... investigated the relationship between genetic variation in the hTAS2R38 receptor and the actual consumption of brassica vegetables with the hypothesis that taster status was associated with intake of these vegetables. Furthermore, secondary intake information on alcohol, chocolate, coffee, smoking, BMI...... on their brassica vegetables intake from the upper quartile (>= a parts per thousand yen23 g/day) and the lower quartile (brassicas from a randomly selected sub-cohort of DCH. DNA was analysed for three functional SNPs in the hTAS2R38 gene. The hTAS2R38...

  15. Taste, Salt Consumption, and Local Explanations around Hypertension in a Rural Population in Northern Peru

    OpenAIRE

    Pesantes, M. Amalia; Diez-Canseco, Francisco; Bernab?-Ortiz, Antonio; Ponce-Lucero, Vilarmina; Miranda, J. Jaime

    2017-01-01

    Interventions to promote behaviors to reduce sodium intake require messages tailored to local understandings of the relationship between what we eat and our health. We studied local explanations about hypertension, the relationship between local diet, salt intake, and health status, and participants? opinions about changing food habits. This study provided inputs for a social marketing campaign in Peru promoting the use of a salt substitute containing less sodium than regular salt. Qualitativ...

  16. TRPM5, a taste-signaling transient receptor potential ion-channel, is a ubiquitous signaling component in chemosensory cells

    Directory of Open Access Journals (Sweden)

    Hofmann Thomas

    2007-07-01

    Full Text Available Abstract Background A growing number of TRP channels have been identified as key players in the sensation of smell, temperature, mechanical forces and taste. TRPM5 is known to be abundantly expressed in taste receptor cells where it participates in sweet, amino acid and bitter perception. A role of TRPM5 in other sensory systems, however, has not been studied so far. Results Here, we systematically investigated the expression of TRPM5 in rat and mouse tissues. Apart from taste buds, where we found TRPM5 to be predominantly localized on the basolateral surface of taste receptor cells, TRPM5 immunoreactivity was seen in other chemosensory organs – the main olfactory epithelium and the vomeronasal organ. Most strikingly, we found solitary TRPM5-enriched epithelial cells in all parts of the respiratory and gastrointestinal tract. Based on their tissue distribution, the low cell density, morphological features and co-immunostaining with different epithelial markers, we identified these cells as brush cells (also known as tuft, fibrillovesicular, multivesicular or caveolated cells. In terms of morphological characteristics, brush cells resemble taste receptor cells, while their origin and biological role are still under intensive debate. Conclusion We consider TRPM5 to be an intrinsic signaling component of mammalian chemosensory organs, and provide evidence for brush cells being an important cellular correlate in the periphery.

  17. Biochemical enrichment and biophysical characterization of a taste receptor for L-arginine from the catfish, Ictalurus puntatus

    Directory of Open Access Journals (Sweden)

    Spielman Andrew I

    2004-07-01

    Full Text Available Abstract Background The channel catfish, Ictalurus punctatus, is invested with a high density of cutaneous taste receptors, particularly on the barbel appendages. Many of these receptors are sensitive to selected amino acids, one of these being a receptor for L-arginine (L-Arg. Previous neurophysiological and biophysical studies suggested that this taste receptor is coupled directly to a cation channel and behaves as a ligand-gated ion channel receptor (LGICR. Earlier studies demonstrated that two lectins, Ricinus communis agglutinin I (RCA-I and Phaseolus vulgaris Erythroagglutinin (PHA-E, inhibited the binding of L-Arg to its presumed receptor sites, and that PHA-E inhibited the L-Arg-stimulated ion conductance of barbel membranes reconstituted into lipid bilayers. Results Both PHA-E and RCA-I almost exclusively labeled an 82–84 kDa protein band of an SDS-PAGE of solubilized barbel taste epithelial membranes. Further, both rhodamine-conjugated RCA-I and polyclonal antibodies raised to the 82–84 kDa electroeluted peptides labeled the apical region of catfish taste buds. Because of the specificity shown by RCA-I, lectin affinity was chosen as the first of a three-step procedure designed to enrich the presumed LGICR for L-Arg. Purified and CHAPS-solubilized taste epithelial membrane proteins were subjected successively to (1, lectin (RCA-I affinity; (2, gel filtration (Sephacryl S-300HR; and (3, ion exchange chromatography. All fractions from each chromatography step were evaluated for L-Arg-induced ion channel activity by reconstituting each fraction into a lipid bilayer. Active fractions demonstrated L-Arg-induced channel activity that was inhibited by D-arginine (D-Arg with kinetics nearly identical to those reported earlier for L-Arg-stimulated ion channels of native barbel membranes reconstituted into lipid bilayers. After the final enrichment step, SDS-PAGE of the active ion channel protein fraction revealed a single band at 82–84 k

  18. Ancient protostome origin of chemosensory ionotropic glutamate receptors and the evolution of insect taste and olfaction.

    Directory of Open Access Journals (Sweden)

    Vincent Croset

    2010-08-01

    Full Text Available Ionotropic glutamate receptors (iGluRs are a highly conserved family of ligand-gated ion channels present in animals, plants, and bacteria, which are best characterized for their roles in synaptic communication in vertebrate nervous systems. A variant subfamily of iGluRs, the Ionotropic Receptors (IRs, was recently identified as a new class of olfactory receptors in the fruit fly, Drosophila melanogaster, hinting at a broader function of this ion channel family in detection of environmental, as well as intercellular, chemical signals. Here, we investigate the origin and evolution of IRs by comprehensive evolutionary genomics and in situ expression analysis. In marked contrast to the insect-specific Odorant Receptor family, we show that IRs are expressed in olfactory organs across Protostomia--a major branch of the animal kingdom that encompasses arthropods, nematodes, and molluscs--indicating that they represent an ancestral protostome chemosensory receptor family. Two subfamilies of IRs are distinguished: conserved "antennal IRs," which likely define the first olfactory receptor family of insects, and species-specific "divergent IRs," which are expressed in peripheral and internal gustatory neurons, implicating this family in taste and food assessment. Comparative analysis of drosophilid IRs reveals the selective forces that have shaped the repertoires in flies with distinct chemosensory preferences. Examination of IR gene structure and genomic distribution suggests both non-allelic homologous recombination and retroposition contributed to the expansion of this multigene family. Together, these findings lay a foundation for functional analysis of these receptors in both neurobiological and evolutionary studies. Furthermore, this work identifies novel targets for manipulating chemosensory-driven behaviours of agricultural pests and disease vectors.

  19. Bitter taste receptors as targets for tocolytics in preterm labor therapy.

    Science.gov (United States)

    Zheng, Kaizhi; Lu, Ping; Delpapa, Ellen; Bellve, Karl; Deng, Ruitang; Condon, Jennifer C; Fogarty, Kevin; Lifshitz, Lawrence M; Simas, Tiffany A Moore; Shi, Fangxiong; ZhuGe, Ronghua

    2017-09-01

    Preterm birth (PTB) is the leading cause of neonatal mortality and morbidity, with few prevention and treatment options. Uterine contraction is a central feature of PTB, so gaining new insights into the mechanisms of this contraction and consequently identifying novel targets for tocolytics are essential for more successful management of PTB. Here we report that myometrial cells from human and mouse express bitter taste receptors (TAS2Rs) and their canonical signaling components ( i.e., G-protein gustducin and phospholipase C β2). Bitter tastants can completely relax myometrium precontracted by different uterotonics. In isolated single mouse myometrial cells, a phenotypical bitter tastant (chloroquine, ChQ) reverses the rise in intracellular Ca 2+ concentration ([Ca 2+ ] i ) and cell shortening induced by uterotonics, and this reversal effect is inhibited by pertussis toxin and by genetic deletion of α-gustducin. In human myometrial cells, knockdown of TAS2R14 but not TAS2R10 inhibits ChQ's reversal effect on an oxytocin-induced rise in [Ca 2+ ] i Finally, ChQ prevents mouse PTBs induced by bacterial endotoxin LPS or progesterone receptor antagonist mifepristone more often than current commonly used tocolytics, and this prevention is largely lost in α-gustducin-knockout mice. Collectively, our results reveal that activation of the canonical TAS2R signaling system in myometrial cells produces profound relaxation of myometrium precontracted by a broad spectrum of contractile agonists, and that targeting TAS2Rs is an attractive approach to developing effective tocolytics for PTB management.-Zheng, K., Lu, P., Delpapa, E., Bellve, K., Deng, R., Condon, J. C., Fogarty, K., Lifshitz, L. M., Simas, T. A. M., Shi, F., ZhuGe, R. Bitter taste receptors as targets for tocolytics in preterm labor therapy. © FASEB.

  20. Taste, Salt Consumption, and Local Explanations around Hypertension in a Rural Population in Northern Peru.

    Science.gov (United States)

    Pesantes, M Amalia; Diez-Canseco, Francisco; Bernabé-Ortiz, Antonio; Ponce-Lucero, Vilarmina; Miranda, J Jaime

    2017-07-05

    Interventions to promote behaviors to reduce sodium intake require messages tailored to local understandings of the relationship between what we eat and our health. We studied local explanations about hypertension, the relationship between local diet, salt intake, and health status, and participants' opinions about changing food habits. This study provided inputs for a social marketing campaign in Peru promoting the use of a salt substitute containing less sodium than regular salt. Qualitative methods (focus groups and in-depth interviews) were utilized with local populations, people with hypertension, and health personnel in six rural villages. Participants were 18-65 years old, 41% men. Participants established a direct relationship between emotions and hypertension, regardless of age, gender, and hypertension status. Those without hypertension established a connection between eating too much/eating fried food and health status but not between salt consumption and hypertension. Participants rejected dietary changes. Economic barriers and high appreciation of local culinary traditions were the main reasons for this. It is the conclusion of this paper that introducing and promoting salt substitutes require creative strategies that need to acknowledge local explanatory disease models such as the strong association between emotional wellbeing and hypertension, give a positive spin to changing food habits, and resist the "common sense" strategy of information provision around the causal connection between salt consumption and hypertension.

  1. Association between taste receptor (TAS) genes and the perception of wine characteristics.

    Science.gov (United States)

    Carrai, Maura; Campa, Daniele; Vodicka, Pavel; Flamini, Riccardo; Martelli, Irene; Slyskova, Jana; Jiraskova, Katerina; Rejhova, Alexandra; Vodenkova, Sona; Canzian, Federico; Bertelli, Alberto; Dalla Vedova, Antonio; Bavaresco, Luigi; Vodickova, Ludmila; Barale, Roberto

    2017-08-23

    Several studies have suggested a possible relationship between polymorphic variants of the taste receptors genes and the acceptance, liking and intake of food and beverages. In the last decade investigators have attempted to link the individual ability to taste 6-n-propylthiouracil (PROP) and the sensations, such as astringency and bitterness, elicited by wine or its components, but with contradictory results. We have used the genotype instead of the phenotype (responsiveness to PROP or other tastants), to test the possible relation between genetic variability and the perception of wine characteristic in 528 subjects from Italy and the Czech Republic. We observed several interesting associations, among which the association between several TAS2R38 gene single nucleotide polymorphisms (P = 0.002) and the TAS2R16-rs6466849 polymorphism with wine sourness P = 0.0003). These associations were consistent in both populations, even though the country of origin was an important factor in the two models, thus indicating therefore that genetics alongside cultural factors also play a significant role in the individual liking of wine.

  2. Sweet Taste Receptor Activation in the Gut Is of Limited Importance for Glucose-Stimulated GLP-1 and GIP Secretion

    DEFF Research Database (Denmark)

    Saltiel, Monika Yosifova; Kuhre, Rune Ehrenreich; Christiansen, Charlotte Bayer

    2017-01-01

    Glucose stimulates the secretion of the incretin hormones: glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). It is debated whether the sweet taste receptor (STR) triggers this secretion. We investigated the role of STR activation for glucose-stimulated incretin...

  3. Impact of obesity on taste receptor expression in extra-oral tissues : emphasis on hypothalamus and brainstem

    NARCIS (Netherlands)

    Herrera, Moro Chao D.; Argmann, C.; Eijk, van M.; Boot, R.G.; Ottenhoff, R.; Roomen, van C.; Foppen, E.; Siljee, J.E.; Unmehopa, U.A.; Kalsbeek, A.; Aerts, J.M.F.G.

    2016-01-01

    Sweet perception promotes food intake, whereas that of bitterness is inhibitory. Surprisingly, the expression of sweet G protein-coupled taste receptor (GPCTR) subunits (T1R2 and T1R3) and bitter GPCTRs (T2R116, T2R118, T2R138 and T2R104), as well as the α-subunits of the associated signalling

  4. Impact of obesity on taste receptor expression in extra-oral tissues: emphasis on hypothalamus and brainstem

    NARCIS (Netherlands)

    Herrera Moro Chao, D.; Argmann, C.; van Eijk, M.; Boot, R. G.; Ottenhoff, R.; van Roomen, C.; Foppen, E.; Siljee, J. E.; Unmehopa, U. A.; Kalsbeek, A.; Aerts, J. M. F. G.

    2016-01-01

    Sweet perception promotes food intake, whereas that of bitterness is inhibitory. Surprisingly, the expression of sweet G protein-coupled taste receptor (GPCTR) subunits (T1R2 and T1R3) and bitter GPCTRs (T2R116, T2R118, T2R138 and T2R104), as well as the alpha-subunits of the associated signalling

  5. Identification of a bitter-taste receptor gene repertoire in different Lagomorphs species

    Directory of Open Access Journals (Sweden)

    Ana M. Ferreira

    2016-04-01

    Full Text Available The repertoires of bitter taste receptor (T2R gene have been described for several animal species, but these data are still scarce for Lagomorphs. The aim of the present work is to identify potential repertoires of T2R in several Lagomorph species, covering a wide geographical distribution. We studied these genes in Lepus timidus, Lepus europaeus, Oryctolagus cuniculus algirus, Romerolagus diazi and Sylvilagus floridanus, using Oryctolagus cuniculus cuniculus as control species for PCR and DNA sequencing. We studied the identities of the DNA sequences and built the corresponding phylogenetic tree. Sequencing was successful for both subspecies of Oryctolagus cuniculus for all T2R genes studied, for five genes in Lepus, and for three genes in Romerolagus diazi and Sylvilagus floridanus. We describe for the first time the partial repertoires of T2R genes for Lagomorphs species, other than the common rabbit. Our phylogenetic analyses indicate that sequence proximity levels follow the established taxonomic classification.

  6. Fluorescence-based optimization of human bitter taste receptor expression in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Sugawara, Taishi; Ito, Keisuke; Shiroishi, Mitsunori; Tokuda, Natsuko; Asada, Hidetsugu; Yurugi-Kobayashi, Takami; Shimamura, Tatsuro; Misaka, Takumi; Nomura, Norimichi; Murata, Takeshi; Abe, Keiko; Iwata, So

    2009-01-01

    Human TAS2 receptors (hTAS2Rs) perceive bitter tastants, but few studies have explored the structure-function relationships of these receptors. In this paper, we report our trials on the large-scale preparations of hTAS2Rs for structural analysis. Twenty-five hTAS2Rs were expressed using a GFP-fusion yeast system in which the constructs and the culture conditions (e.g., the signal sequence, incubation time and temperature after induction) were optimized by measuring GFP fluorescence. After optimization, five hTAS2Rs (hTAS2R7, hTAS2R8, hTAS2R16, hTAS2R41, and hTAS2R48) were expressed at levels greater than 1 mg protein/L of culture, which is a preferable level for purification and crystallization. Among these five bitter taste receptors, hTAS2R41 exhibited the highest detergent solubilization efficiency of 87.1% in n-dodecyl-β-D-maltopyranoside (DDM)/cholesteryl hemisuccinate (CHS). Fluorescence size-exclusion chromatography showed that hTAS2R41 exhibited monodispersity in DDM/CHS without aggregates, suggesting that hTAS2R41 is a good target for future crystallization trials.

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

    Science.gov (United States)

    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.

  8. Taste neurons consist of both a large TrkB-receptor-dependent and a small TrkB-receptor-independent subpopulation.

    Directory of Open Access Journals (Sweden)

    Da Fei

    Full Text Available Brain-derived neurotrophic factor (BDNF and neurotrophin-4 (NT-4 are two neurotrophins that play distinct roles in geniculate (taste neuron survival, target innervation, and taste bud formation. These two neurotrophins both activate the tropomyosin-related kinase B (TrkB receptor and the pan-neurotrophin receptor p75. Although the roles of these neurotrophins have been well studied, the degree to which BDNF and NT-4 act via TrkB to regulate taste development in vivo remains unclear. In this study, we compared taste development in TrkB(-/- and Bdnf(-/-/Ntf4(-/- mice to determine if these deficits were similar. If so, this would indicate that the functions of both BDNF and NT-4 can be accounted for by TrkB-signaling. We found that TrkB(-/- and Bdnf(-/-/Ntf4(-/- mice lose a similar number of geniculate neurons by E13.5, which indicates that both BDNF and NT-4 act primarily via TrkB to regulate geniculate neuron survival. Surprisingly, the few geniculate neurons that remain in TrkB(-/- mice are more successful at innervating the tongue and taste buds compared with those neurons that remain in Bdnf(-/-/Ntf4(-/- mice. The remaining neurons in TrkB(-/- mice support a significant number of taste buds. In addition, these remaining neurons do not express the TrkB receptor, which indicates that either BDNF or NT-4 must act via additional receptors to influence tongue innervation and/or targeting.

  9. Requirement of NMDA receptor reactivation for consolidation and storage of nondeclarative taste memory revealed by inducible NR1 knockout.

    Science.gov (United States)

    Cui, Zhenzhong; Lindl, Kathryn A; Mei, Bing; Zhang, Shuqing; Tsien, Joe Z

    2005-08-01

    We employed an inducible, reversible and region-specific gene knockout technique to investigate the requirements for cortical NMDA receptors (NMDAR) during the various stages (acquisition, consolidation and storage, and retrieval) of nondeclarative, hippocampal-independent memory in mice using a conditioned taste aversion memory paradigm. Here we show that temporary knockout of the cortical NMDAR during either the learning or postlearning consolidation stage, but not during the retrieval stage, causes severe performance deficits in the 1-month taste memory retention tests. More importantly, we found that the consolidation and storage of the long-term nondeclarative taste memories requires cortical NMDAR reactivation. Thus, the dynamic engagement of the NMDAR during the postlearning stage leads us to postulate that NMDAR reactivation-mediated synaptic re-entry reinforcement is crucial for overcoming the destabilizing effects intrinsic to synaptic protein turnover and for achieving consolidation and storage of nondeclarative memories in the brain.

  10. Taste isn't just for taste buds anymore

    OpenAIRE

    Finger, Thomas E.; Kinnamon, Sue C.

    2011-01-01

    Taste is a discriminative sense involving specialized receptor cells of the oral cavity (taste buds) and at least two distinct families of G protein-coupled receptor molecules that detect nutritionally important substances or potential toxins. Yet the receptor mechanisms that drive taste also are utilized by numerous systems throughout the body. How and why these so-called taste receptors are used to regulate digestion and respiration is now a matter of intense study. In this article we provi...

  11. Mice lacking the p75 receptor fail to acquire a normal complement of taste buds and geniculate ganglion neurons by adulthood

    OpenAIRE

    Krimm, Robin F.

    2006-01-01

    Brain derived neurotrophic factor and neurotrophin-4 are required for normal taste bud development. Although these neurotrophins normally function via the tyrosine kinase receptor, trkB, they also bind to the pan-neurotrophin receptor, p75. The goal of the present study was to determine whether the p75 receptor is required for the development or maintenance of a full complement of adult taste buds. Mice with p75 null mutations lose 34% of their circumvallate taste buds, 36% of their fungiform...

  12. The different effects of over-expressing murine NMDA receptor 2B subunit in the forebrain on conditioned taste aversion.

    Science.gov (United States)

    Li, Shijia; Gu, Yiran; Meng, Bo; Mei, Bing; Li, Fei

    2010-09-10

    The glutamate transmission system and the N-methyl-D-aspartate receptor (NMDA-R), in particular its 2B subunit (NR2B), have been reported to be possibly related to taste memory as a result of treatment with NMDA antagonists and agonists. In order to further study the role of the NR2B subunit in gustation memory, we applied four different taste aversive tasks to observe the behavior of a transgenic mice model in which the NR2B subunit was specifically over-expressed in the forebrain. We found that in both short- and long-term conditioned taste aversion (CTA) experiments, mice with forebrain expression of the NR2B transgene (Tg) showed significantly enhanced CTA 2 days after training. However, both the Tg and the wild-type (Wt) mice shared the same level of aversive memory on the 30th day after training. In both fast and slow extinction experiments, Tg mice maintained a higher CTA memory than that of control mice in most extinction trials. The third experiment, which involved testing the memory for familiar taste, demonstrated that NR2B augmentation had no benefit on the latent inhibition (LI) of CTA. In addition, the last experiment (two-taste LI) showed a suppression of enhanced CTA in Tg mice when the mice were exposed to both novel and familiar tastes. These data suggested that forebrain NR2B over-expression had different effects on gustatory learning and memory. The transgenic animals were only sensitive to novel but not familiar tastes, and up-regulation of NR2B resulted in enhanced CTA function for only a short period of time. 2010 Elsevier B.V. All rights reserved.

  13. Association of a bitter taste receptor mutation with Balkan Endemic Nephropathy (BEN

    Directory of Open Access Journals (Sweden)

    Wooding Stephen P

    2012-10-01

    Full Text Available Abstract Background Balkan Endemic Nephropathy (BEN is late-onset kidney disease thought to arise from chronic exposure to aristolochic acid, a phytotoxin that contaminates wheat supplies in rural areas of Eastern Europe. It has recently been demonstrated that humans are capable of perceiving aristolochic acid at concentrations below 40 nM as the result of high-affinity interactions with the TAS2R43 bitter taste receptor. Further, TAS2R43 harbors high-frequency loss-of-function mutations resulting in 50-fold variability in perception. This suggests that genetic variation in TAS2R43 might affect susceptibility to BEN, with individuals carrying functional forms of the receptor being protected by an ability to detect tainted foods. Methods To determine whether genetic variation in TAS2R43 predicts BEN susceptibility, we examined genotype-phenotype associations in a case–control study. A cohort of 88 affected and 99 control subjects from western Bulgaria were genotyped with respect to two key missense variants and a polymorphic whole-gene deletion of TAS2R43 (W35S, H212R, and wt/Δ, which are known to affect taste sensitivity to aristolochic acid. Tests for association between haplotypes and BEN status were then performed. Results Three major TAS2R43 haplotypes observed in previous studies (TAS2R43-W35/H212, -S35/R212 and –Δ were present at high frequencies (0.17, 0.36, and 0.47 respectively in our sample, and a significant association between genotype and BEN status was present (P = 0.020; odds ratio 1.18. However, contrary to expectation, BEN was positively associated with TAS2R43-W35/H212, a highly responsive allele previously shown to confer elevated bitter sensitivity to aristolochic acid, which should drive aversion but might also affect absorption, altering toxin activation. Conclusions Our findings are at strong odds with the prediction that carriers of functional alleles of TAS2R43 are protected from BEN by an ability to detect and

  14. The Role of Quinine-Responsive Taste Receptor Family 2 in Airway Immune Defense and Chronic Rhinosinusitis

    Directory of Open Access Journals (Sweden)

    Alan D. Workman

    2018-03-01

    Full Text Available BackgroundBitter (T2R and sweet (T1R taste receptors in the airway are important in innate immune defense, and variations in taste receptor functionality in one T2R (T2R38 correlate with disease status and disease severity in chronic rhinosinusitis (CRS. Quinine is a bitter compound that is an agonist for several T2Rs also expressed on sinonasal cells, but not for T2R38. Because of this property, quinine may stimulate innate immune defense mechanisms in the airway, and functional differences in quinine perception may be reflective of disease status in CRS.MethodsDemographic and taste intensity data were collected prospectively from CRS patients and non-CRS control subjects. Sinonasal tissue from patients undergoing rhinologic surgery was also collected and grown at an air–liquid interface (ALI. Nitric oxide (NO production and dynamic regulation of ciliary beat frequency in response to quinine stimulation were assessed in vitro.ResultsQuinine reliably increased ciliary beat frequency and NO production in ALI cultures in a manner consistent with T2R activation (p < 0.01. Quinine taste intensity rating was performed in 328 CRS patients and 287 control subjects demonstrating that CRS with nasal polyps (CRSwNP patients rated quinine as significantly less intense than did control subjects.ConclusionQuinine stimulates airway innate immune defenses by increasing ciliary beat frequency and stimulating NO production in a manner fitting with T2R activation. Patient variability in quinine sensitivity is observed in taste intensity ratings, and gustatory quinine “insensitivity” is associated with CRSwNP status. Thus, taste tests for quinine may be a biomarker for CRSwNP, and topical quinine has therapeutic potential as a stimulant of innate defenses.

  15. Differential bitterness in capsaicin, piperine, and ethanol associates with polymorphisms in multiple bitter taste receptor genes.

    Science.gov (United States)

    Nolden, Alissa A; McGeary, John E; Hayes, John E

    2016-03-15

    To date, the majority of research exploring associations with genetic variability in bitter taste receptors has understandably focused on compounds and foods that are predominantly or solely perceived as bitter. However, other chemosensory stimuli are also known to elicit bitterness as a secondary sensation. Here we investigated whether TAS2R variation explains individual differences in bitterness elicited by chemesthetic stimuli, including capsaicin, piperine and ethanol. We confirmed that capsaicin, piperine and ethanol elicit bitterness in addition to burning/stinging sensations. Variability in perceived bitterness of capsaicin and ethanol were significantly associated with TAS2R38 and TAS2R3/4/5 diplotypes. For TAS2R38, PAV homozygotes perceived greater bitterness from capsaicin and ethanol presented on circumvallate papillae, compared to heterozygotes and AVI homozygotes. For TAS2R3/4/5, CCCAGT homozygotes rated the greatest bitterness, compared to heterozygotes and TTGGAG homozygotes, for both ethanol and capsaicin when presented on circumvallate papillae. Additional work is needed to determine how these and other chemesthetic stimuli differ in bitterness perception across concentrations and presentation methods. Furthermore, it would be beneficial to determine which TAS2R receptors are activated in vitro by chemesthetic compounds. Copyright © 2016. Published by Elsevier Inc.

  16. Sixth taste – starch taste?

    Directory of Open Access Journals (Sweden)

    Zygmunt Zdrojewicz

    2017-06-01

    Full Text Available Scientists from Oregon State University, USA, came up with the newest theory of the sixth taste – starch taste that might soon join the basic five tastes. This argument is supported by studies done on both animals and humans, the results of which seem to indicate the existence of separate receptors for starch taste, others than for sweet taste. Starch is a glucose homopolymer that forms an α-glucoside chain called glucosan or glucan. This polysaccharide constitutes the most important source of carbohydrates in food. It can be found in groats, potatoes, legumes, grains, manioc and corn. Apart from its presence in food, starch is also used in textile, pharmaceutical, cosmetic and stationery industries as well as in glue production. This polysaccharide is made of an unbranched helical structure – amylose (15–20%, and a structure that forms branched chains – amylopectin (80–85%. The starch structure, degree of its crystallisation or hydration as well as its availability determine the speed of food-contained starch hydrolysis by amylase. So far, starch has been considered tasteless, but the newest report shows that for people of different origins it is associated with various aliments specific for each culture. Apart from a number of scientific experiments using sweet taste inhibitors, the existence of the sixth taste is also confirmed by molecular studies. However, in order to officially include starch taste to the basic human tastes, it must fulfil certain criteria. The aim of the study is to present contemporary views on starch.

  17. Characterization of the Sweet Taste Receptor Tas1r2 from an Old World Monkey Species Rhesus Monkey and Species-Dependent Activation of the Monomeric Receptor by an Intense Sweetener Perillartine.

    Directory of Open Access Journals (Sweden)

    Chenggu Cai

    Full Text Available Sweet state is a basic physiological sensation of humans and other mammals which is mediated by the broadly acting sweet taste receptor-the heterodimer of Tas1r2 (taste receptor type 1 member 2 and Tas1r3 (taste receptor type 1 member 3. Various sweeteners interact with either Tas1r2 or Tas1r3 and then activate the receptor. In this study, we cloned, expressed and functionally characterized the taste receptor Tas1r2 from a species of Old World monkeys, the rhesus monkey. Paired with the human TAS1R3, it was shown that the rhesus monkey Tas1r2 could respond to natural sugars, amino acids and their derivates. Furthermore, similar to human TAS1R2, rhesus monkey Tas1r2 could respond to artificial sweeteners and sweet-tasting proteins. However, the responses induced by rhesus monkey Tas1r2 could not be inhibited by the sweet inhibitor amiloride. Moreover, we found a species-dependent activation of the Tas1r2 monomeric receptors of human, rhesus monkey and squirrel monkey but not mouse by an intense sweetener perillartine. Molecular modeling and sequence analysis indicate that the receptor has the conserved domains and ligand-specific interactive residues, which have been identified in the characterized sweet taste receptors up to now. This is the first report of the functional characterization of sweet taste receptors from an Old World monkey species.

  18. Characterization of the Sweet Taste Receptor Tas1r2 from an Old World Monkey Species Rhesus Monkey and Species-Dependent Activation of the Monomeric Receptor by an Intense Sweetener Perillartine.

    Science.gov (United States)

    Cai, Chenggu; Jiang, Hua; Li, Lei; Liu, Tianming; Song, Xuejie; Liu, Bo

    2016-01-01

    Sweet state is a basic physiological sensation of humans and other mammals which is mediated by the broadly acting sweet taste receptor-the heterodimer of Tas1r2 (taste receptor type 1 member 2) and Tas1r3 (taste receptor type 1 member 3). Various sweeteners interact with either Tas1r2 or Tas1r3 and then activate the receptor. In this study, we cloned, expressed and functionally characterized the taste receptor Tas1r2 from a species of Old World monkeys, the rhesus monkey. Paired with the human TAS1R3, it was shown that the rhesus monkey Tas1r2 could respond to natural sugars, amino acids and their derivates. Furthermore, similar to human TAS1R2, rhesus monkey Tas1r2 could respond to artificial sweeteners and sweet-tasting proteins. However, the responses induced by rhesus monkey Tas1r2 could not be inhibited by the sweet inhibitor amiloride. Moreover, we found a species-dependent activation of the Tas1r2 monomeric receptors of human, rhesus monkey and squirrel monkey but not mouse by an intense sweetener perillartine. Molecular modeling and sequence analysis indicate that the receptor has the conserved domains and ligand-specific interactive residues, which have been identified in the characterized sweet taste receptors up to now. This is the first report of the functional characterization of sweet taste receptors from an Old World monkey species.

  19. Phytochemicals from Ruta graveolens Activate TAS2R Bitter Taste Receptors and TRP Channels Involved in Gustation and Nociception

    Directory of Open Access Journals (Sweden)

    Giuseppe Mancuso

    2015-10-01

    Full Text Available Ruta graveolens (rue is a spontaneous plant in the Mediterranean area with a strong aroma and a very intense bitter taste, used in gastronomy and in folk medicine. From the leaves, stems and fruits of rue, we isolated rutin, rutamarin, three furanocoumarins, two quinolinic alkaloids, a dicoumarin and two long chain ketones. Bitter taste and chemesthetic properties have been evaluated by in vitro assays with twenty receptors of the TAS2R family and four TRP ion channels involved in gustation and nociception. Among the alkaloids, skimmianine was active as a specific agonist of T2R14, whereas kokusaginin did not activate any of the tested receptors. The furanocoumarins activates TAS2R10, 14, and 49 with different degrees of selectivity, as well as the TRPA1 somatosensory ion channel. Rutamarin is an agonist of TRPM5 and TRPV1 and a strong antagonist of TRPM8 ion channels.

  20. Phytochemicals from Ruta graveolens Activate TAS2R Bitter Taste Receptors and TRP Channels Involved in Gustation and Nociception.

    Science.gov (United States)

    Mancuso, Giuseppe; Borgonovo, Gigliola; Scaglioni, Leonardo; Bassoli, Angela

    2015-10-16

    Ruta graveolens (rue) is a spontaneous plant in the Mediterranean area with a strong aroma and a very intense bitter taste, used in gastronomy and in folk medicine. From the leaves, stems and fruits of rue, we isolated rutin, rutamarin, three furanocoumarins, two quinolinic alkaloids, a dicoumarin and two long chain ketones. Bitter taste and chemesthetic properties have been evaluated by in vitro assays with twenty receptors of the TAS2R family and four TRP ion channels involved in gustation and nociception. Among the alkaloids, skimmianine was active as a specific agonist of T2R14, whereas kokusaginin did not activate any of the tested receptors. The furanocoumarins activates TAS2R10, 14, and 49 with different degrees of selectivity, as well as the TRPA1 somatosensory ion channel. Rutamarin is an agonist of TRPM5 and TRPV1 and a strong antagonist of TRPM8 ion channels.

  1. Dextromethorphan mediated bitter taste receptor activation in the pulmonary circuit causes vasoconstriction.

    Science.gov (United States)

    Upadhyaya, Jasbir D; Singh, Nisha; Sikarwar, Anurag S; Chakraborty, Raja; Pydi, Sai P; Bhullar, Rajinder P; Dakshinamurti, Shyamala; Chelikani, Prashen

    2014-01-01

    Activation of bitter taste receptors (T2Rs) in human airway smooth muscle cells leads to muscle relaxation and bronchodilation. This finding led to our hypothesis that T2Rs are expressed in human pulmonary artery smooth muscle cells and might be involved in regulating the vascular tone. RT-PCR was performed to reveal the expression of T2Rs in human pulmonary artery smooth muscle cells. Of the 25 T2Rs, 21 were expressed in these cells. Functional characterization was done by calcium imaging after stimulating the cells with different bitter agonists. Increased calcium responses were observed with most of the agonists, the largest increase seen for dextromethorphan. Previously in site-directed mutational studies, we have characterized the response of T2R1 to dextromethorphan, therefore, T2R1 was selected for further analysis in this study. Knockdown with T2R1 specific shRNA decreased mRNA levels, protein levels and dextromethorphan-induced calcium responses in pulmonary artery smooth muscle cells by up to 50%. To analyze if T2Rs are involved in regulating the pulmonary vascular tone, ex vivo studies using pulmonary arterial and airway rings were pursued. Myographic studies using porcine pulmonary arterial and airway rings showed that stimulation with dextromethorphan led to contraction of the pulmonary arterial and relaxation of the airway rings. This study shows that dextromethorphan, acting through T2R1, causes vasoconstrictor responses in the pulmonary circuit and relaxation in the airways.

  2. Dextromethorphan mediated bitter taste receptor activation in the pulmonary circuit causes vasoconstriction.

    Directory of Open Access Journals (Sweden)

    Jasbir D Upadhyaya

    Full Text Available Activation of bitter taste receptors (T2Rs in human airway smooth muscle cells leads to muscle relaxation and bronchodilation. This finding led to our hypothesis that T2Rs are expressed in human pulmonary artery smooth muscle cells and might be involved in regulating the vascular tone. RT-PCR was performed to reveal the expression of T2Rs in human pulmonary artery smooth muscle cells. Of the 25 T2Rs, 21 were expressed in these cells. Functional characterization was done by calcium imaging after stimulating the cells with different bitter agonists. Increased calcium responses were observed with most of the agonists, the largest increase seen for dextromethorphan. Previously in site-directed mutational studies, we have characterized the response of T2R1 to dextromethorphan, therefore, T2R1 was selected for further analysis in this study. Knockdown with T2R1 specific shRNA decreased mRNA levels, protein levels and dextromethorphan-induced calcium responses in pulmonary artery smooth muscle cells by up to 50%. To analyze if T2Rs are involved in regulating the pulmonary vascular tone, ex vivo studies using pulmonary arterial and airway rings were pursued. Myographic studies using porcine pulmonary arterial and airway rings showed that stimulation with dextromethorphan led to contraction of the pulmonary arterial and relaxation of the airway rings. This study shows that dextromethorphan, acting through T2R1, causes vasoconstrictor responses in the pulmonary circuit and relaxation in the airways.

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

    Science.gov (United States)

    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.

  4. A novel regulatory function of sweet taste-sensing receptor in adipogenic differentiation of 3T3-L1 cells.

    Directory of Open Access Journals (Sweden)

    Yosuke Masubuchi

    Full Text Available BACKGROUND: Sweet taste receptor is expressed not only in taste buds but also in nongustatory organs such as enteroendocrine cells and pancreatic beta-cells, and may play more extensive physiological roles in energy metabolism. Here we examined the expression and function of the sweet taste receptor in 3T3-L1 cells. METHODOLOGY/PRINCIPAL FINDINGS: In undifferentiated preadipocytes, both T1R2 and T1R3 were expressed very weakly, whereas the expression of T1R3 but not T1R2 was markedly up-regulated upon induction of differentiation (by 83.0 and 3.8-fold, respectively at Day 6. The α subunits of Gs (Gαs and G14 (Gα14 but not gustducin were expressed throughout the differentiation process. The addition of sucralose or saccharin during the first 48 hours of differentiation considerably reduced the expression of peroxisome proliferator activated receptor γ (PPARγ and CCAAT/enhancer-binding protein α (C/EBPα at Day 2, the expression of aP2 at Day 4 and triglyceride accumulation at Day 6. These anti-adipogenic effects were attenuated by short hairpin RNA-mediated gene-silencing of T1R3. In addition, overexpression of the dominant-negative mutant of Gαs but not YM-254890, an inhibitor of Gα14, impeded the effects of sweeteners, suggesting a possible coupling of Gs with the putative sweet taste-sensing receptor. In agreement, sucralose and saccharin increased the cyclic AMP concentration in differentiating 3T3-L1 cells and also in HEK293 cells heterologously expressing T1R3. Furthermore, the anti-adipogenic effects of sweeteners were mimicked by Gs activation with cholera toxin but not by adenylate cyclase activation with forskolin, whereas small interfering RNA-mediated knockdown of Gαs had the opposite effects. CONCLUSIONS: 3T3-L1 cells express a functional sweet taste-sensing receptor presumably as a T1R3 homomer, which mediates the anti-adipogenic signal by a Gs-dependent but cAMP-independent mechanism.

  5. Differences in food intake and genetic variability in taste receptors between Czech pregnant women with and without gestational diabetes mellitus.

    Science.gov (United States)

    Bartáková, Vendula; Kuricová, Katarína; Zlámal, Filip; Bělobrádková, Jana; Kaňková, Katetřina

    2018-03-01

    Gestational diabetes mellitus (GDM) represents the most frequent metabolic disorder in pregnancy. Since dietary intake plays an important role in obesity and type 2 diabetes development, it is likely to be for the susceptibility to GDM too. Food preferences, driving partly the diet composition, are changing during pregnancy. Taste and genetic variability in taste receptors is an important factor in determining food preferences. Aims of our study were (1) to characterize dietary habits of pregnant women and to find possible differences in food preferences between healthy pregnant women and those with GDM and (2) to ascertain possible association of several single nucleotide polymorphisms (SNPs) in taste receptor (TR) genes with GDM. A total of 363 pregnant women (293 with GDM and 70 with physiologic pregnancy) were included in the study. Dietary pattern spanning the period of approx. 6 months preceding the time of GDM screening was assessed using a semi-quantitative food frequency questionnaire. A total of five SNPs in TR genes were selected for genotyping based on their functionality or previous associations. Women with GDM exhibited significantly more frequent meat consumption (esp. poultry, pork and smoked meat), dairy products and sweet beverages consumption. The legumes consumption was found to be inversely correlated with fasting glycaemia (P = 0.007, Spearman). CC genotype in TAS2R9 gene (SNP rs3741845) was significantly associated with GDM (P = 0.0087, Chi-square test). Our study showed differences in dietary intake of selected food items between healthy pregnant women and those with GDM and genetic association of bitter taste receptor allele with GDM.

  6. Sweet taste receptor serves to activate glucose- and leptin-responsive neurons in the hypothalamic arcuate nucleus and participates in glucose responsiveness.

    Directory of Open Access Journals (Sweden)

    Daisuke Kohno

    2016-11-01

    Full Text Available The hypothalamic feeding center plays an important role in energy homeostasis. In the feeding center, whole-body energy signals including hormones and nutrients are sensed, processed, and integrated. As a result, food intake and energy expenditure are regulated. Two types of glucose-sensing neurons exist in the hypothalamic arcuate nucleus (ARC: glucose-excited neurons and glucose-inhibited neurons. While some molecules are known to be related to glucose sensing in the hypothalamus, the mechanism underlying glucose sensing in the hypothalamus are not fully understood. The sweet taste receptor is a heterodimer of taste type 1 receptor 2 (T1R2 and taste type 1 receptor 3 (T1R3 and senses sweet tastes. T1R2 and T1R3 receptors are distributed in multiple organs including the tongue, pancreas, adipose tissue, and hypothalamus. However, the role of sweet taste receptors in the ARC remains to be clarified. To examine the role of sweet taste receptors in the ARC, cytosolic Ca2+ concentration ([Ca2+]i in isolated single ARC neurons were measured using Fura-2 fluorescent imaging. An artificial sweetener, sucralose at 10-5 M-10-2 M dose dependently increased [Ca2+]i in 12-16% of ARC neurons. The sucralose-induced [Ca2+]i increase was suppressed by a sweet taste receptor inhibitor, gurmarin. The sucralose-induced [Ca2+]i increase was inhibited under an extracellular Ca2+-free condition and in the presence of an L-type Ca2+ channel blocker, nitrendipine. Sucralose-responding neurons were activated by high-concentration of glucose. This response to glucose was markedly suppressed by gurmarin. More than half of sucralose-responding neurons were activated by leptin but not ghrelin. Percentage of proopiomelanocortin (POMC neurons among sucralose-responding neurons and sweet taste receptor expressing neurons were low, suggesting that majority of sucralose-responding neurons are non-POMC neurons. These data suggest that sweet taste receptor-mediated cellular

  7. Potential arms race in the coevolution of primates and angiosperms: brazzein sweet proteins and gorilla taste receptors.

    Science.gov (United States)

    Guevara, Elaine E; Veilleux, Carrie C; Saltonstall, Kristin; Caccone, Adalgisa; Mundy, Nicholas I; Bradley, Brenda J

    2016-09-01

    We explored whether variation in the sweet taste receptor protein T1R3 in primates could contribute to differences in sweet taste repertoire among species, potentially reflecting coevolution with local plants. Specifically, we examined which primates are likely to be sweet "tasters" of brazzein, a protein found in the fruit of the African plant Pentadiplandra brazzeana that tastes intensely sweet to humans, but provides little energy. Sweet proteins like brazzein are thought to mimic the taste of sugars to entice seed dispersers. We examined the evolution of T1R3 and assessed whether primates are likely "deceived" by such biochemical mimicry. Using published and new sequence data for TAS1R3, we characterized 57 primates and other mammals at the two amino acid sites necessary to taste brazzein to determine which species are tasters. We further used dN/dS-based methods to look for statistical evidence of accelerated evolution in this protein across primate lineages. The taster genotype is shared across most catarrhines, suggesting that most African primates can be "tricked" into eating and dispersing P. brazzeana's seeds for little caloric gain. Western gorillas (Gorilla gorilla), however, exhibit derived mutations at the two brazzein-critical positions, and although fruit is a substantial portion of the western gorilla diet, they have not been observed to eat P. brazzeana. Our analyses of protein evolution found no signature of positive selection on TAS1R3 along the gorilla lineage. We propose that the gorilla-specific mutations at the TAS1R3 locus encoding T1R3 could be a counter-adaptation to the false sweet signal of brazzein. © 2016 Wiley Periodicals, Inc.

  8. Sweet Taste Receptor Serves to Activate Glucose- and Leptin-Responsive Neurons in the Hypothalamic Arcuate Nucleus and Participates in Glucose Responsiveness.

    Science.gov (United States)

    Kohno, Daisuke; Koike, Miho; Ninomiya, Yuzo; Kojima, Itaru; Kitamura, Tadahiro; Yada, Toshihiko

    2016-01-01

    The hypothalamic feeding center plays an important role in energy homeostasis. In the feeding center, whole-body energy signals including hormones and nutrients are sensed, processed, and integrated. As a result, food intake and energy expenditure are regulated. Two types of glucose-sensing neurons exist in the hypothalamic arcuate nucleus (ARC): glucose-excited neurons and glucose-inhibited neurons. While some molecules are known to be related to glucose sensing in the hypothalamus, the mechanisms underlying glucose sensing in the hypothalamus are not fully understood. The sweet taste receptor is a heterodimer of taste type 1 receptor 2 (T1R2) and taste type 1 receptor 3 (T1R3) and senses sweet tastes. T1R2 and T1R3 are distributed in multiple organs including the tongue, pancreas, adipose tissue, and hypothalamus. However, the role of sweet taste receptors in the ARC remains to be clarified. To examine the role of sweet taste receptors in the ARC, cytosolic Ca 2+ concentration ([Ca 2+ ] i ) in isolated single ARC neurons were measured using Fura-2 fluorescent imaging. An artificial sweetener, sucralose at 10 -5 -10 -2 M dose dependently increased [Ca 2+ ] i in 12-16% of ARC neurons. The sucralose-induced [Ca 2+ ] i increase was suppressed by a sweet taste receptor inhibitor, gurmarin. The sucralose-induced [Ca 2+ ] i increase was inhibited under an extracellular Ca 2+ -free condition and in the presence of an L-type Ca 2+ channel blocker, nitrendipine. Sucralose-responding neurons were activated by high-concentration of glucose. This response to glucose was markedly suppressed by gurmarin. More than half of sucralose-responding neurons were activated by leptin but not ghrelin. Percentages of proopiomelanocortin (POMC) neurons among sucralose-responding neurons and sweet taste receptor expressing neurons were low, suggesting that majority of sucralose-responding neurons are non-POMC neurons. These data suggest that sweet taste receptor-mediated cellular activation

  9. Distinct human and mouse membrane trafficking systems for sweet taste receptors T1r2 and T1r3.

    Science.gov (United States)

    Shimizu, Madoka; Goto, Masao; Kawai, Takayuki; Yamashita, Atsuko; Kusakabe, Yuko

    2014-01-01

    The sweet taste receptors T1r2 and T1r3 are included in the T1r taste receptor family that belongs to class C of the G protein-coupled receptors. Heterodimerization of T1r2 and T1r3 is required for the perception of sweet substances, but little is known about the mechanisms underlying this heterodimerization, including membrane trafficking. We developed tagged mouse T1r2 and T1r3, and human T1R2 and T1R3 and evaluated membrane trafficking in human embryonic kidney 293 (HEK293) cells. We found that human T1R3 surface expression was only observed when human T1R3 was coexpressed with human T1R2, whereas mouse T1r3 was expressed without mouse T1r2 expression. A domain-swapped chimera and truncated human T1R3 mutant showed that the Venus flytrap module and cysteine-rich domain (CRD) of human T1R3 contain a region related to the inhibition of human T1R3 membrane trafficking and coordinated regulation of human T1R3 membrane trafficking. We also found that the Venus flytrap module of both human T1R2 and T1R3 are needed for membrane trafficking, suggesting that the coexpression of human T1R2 and T1R3 is required for this event. These results suggest that the Venus flytrap module and CRD receive taste substances and play roles in membrane trafficking of human T1R2 and T1R3. These features are different from those of mouse receptors, indicating that human T1R2 and T1R3 are likely to have a novel membrane trafficking system.

  10. On the Emerging Role of the Taste Receptor Type 1 (T1R Family of Nutrient-Sensors in the Musculoskeletal System

    Directory of Open Access Journals (Sweden)

    Shoichiro Kokabu

    2017-03-01

    Full Text Available The special sense of taste guides and guards food intake and is essential for body maintenance. Salty and sour tastes are sensed via ion channels or gated ion channels while G protein-coupled receptors (GPCRs of the taste receptor type 1 (T1R family sense sweet and umami tastes and GPCRs of the taste receptor type 2 (T2R family sense bitter tastes. T1R and T2R receptors share similar downstream signaling pathways that result in the stimulation of phospholipase-C-β2. The T1R family includes three members that form heterodimeric complexes to recognize either amino acids or sweet molecules such as glucose. Although these functions were originally described in gustatory tissue, T1R family members are expressed in numerous non-gustatory tissues and are now viewed as nutrient sensors that play important roles in monitoring global glucose and amino acid status. Here, we highlight emerging evidence detailing the function of T1R family members in the musculoskeletal system and review these findings in the context of the musculoskeletal diseases sarcopenia and osteoporosis, which are major public health problems among the elderly that affect locomotion, activities of daily living, and quality of life. These studies raise the possibility that T1R family member function may be modulated for therapeutic benefit.

  11. Taste buds: cells, signals and synapses.

    Science.gov (United States)

    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.

  12. Conditioned taste aversion: modulation by 5-HT receptor activity and corticosterone

    DEFF Research Database (Denmark)

    Boris, Gorzalka; Hanson, Laura; Harrington, J

    2003-01-01

    Two experiments were designed to elucidate the involvement of the hypothalamic-pituitary-adrenal axis and the 5-hydroxytryptamine (5-HT) system in the acquisition of lithium chloride-conditioned taste aversion. In Experiment 1, rats were administered either vehicle or 50 mg/kg nefazodone daily fo......, corticosterone-treated animals required more trials to reach extinction. These results suggest the involvement of both the 5-HT system and the hypothalamic-pituitary-adrenal axis in lithium chloride-conditioned taste aversion....

  13. A non-multimacrocyclic heteroditopic receptor that cooperatively binds and effectively extracts KAcO salt.

    Science.gov (United States)

    Zakrzewski, Maciej; Kwietniewska, Natalia; Walczak, Wojciech; Piątek, Piotr

    2018-06-06

    Prepared in only three synthetic steps, a non-multimacrocyclic heteroditopic receptor binds potassium salts of halides and carboxylates with unusually high cooperativity, suggesting salt binding as associated ion-pairs. Unprecedented extraction of highly hydrophilic KAcO salt from water to organic solution is also demonstrated.

  14. Regulation of Rac1 GTPase activity by quinine through G-protein and bitter taste receptor T2R4.

    Science.gov (United States)

    Sidhu, Crystal; Jaggupilli, Appalaraju; Chelikani, Prashen; Bhullar, Rajinder P

    2017-02-01

    Rac1 belongs to the Rho family of small GTPases and regulates actin cytoskeleton reorganization. T2R4 is a bitter taste receptor belonging to the G protein-coupled receptor family of proteins. In addition to mediating bitter taste perception from the tongue, T2R4s are found in extra-oral tissues, e.g., nasal epithelium, airways, brain, testis suggesting a much broader physiological function for these receptors. Anti-malarial drug and a bitter tasting compound, quinine, is a known agonist for T2R4, whereas BCML (Nα,Nα-Bis(carboxymethyl)-L-lysine) acts as an inverse agonist. Using western blot and Ca ++ mobilization assays, the effects of quinine on Rac1 activity in HEK293T cells stably expressing T2R4/Gα 16/44 , T2R4, or Gα 16/44 and transiently transfected with HA-Rac1 were investigated. Quinine treatment caused a significant reduction in the amount of active Rac1, whereas in the presence of BCML, quinine failed to cause any significant change in active Rac1. No significant change in Rac1 activity was observed in BAPTA-AM plus quinine-treated Gα 16/44 cells, suggesting possibility of a pathway in addition to the canonical Ca ++ -dependent pathway. A noticeable role for Gα 16/44 independent of T2R4 is observed in quinine-mediated Rac1 inactivation. Further, a significant difference in quinine-induced Ca ++ response in T2R4/Gα 16/44 or T2R4 cells was observed validating the partial role of calcium and importance of Gα 16/44 . This study is the first to show an inhibitory downstream action of a T2R4 agonist on Rac1 function. Further investigation will help in better understanding the downstream signal transduction network of T2R4 and its extra-oral physiological roles.

  15. Altered learning, memory, and social behavior in type 1 taste receptor subunit 3 knock-out mice are associated with neuronal dysfunction.

    Science.gov (United States)

    Martin, Bronwen; Wang, Rui; Cong, Wei-Na; Daimon, Caitlin M; Wu, Wells W; Ni, Bin; Becker, Kevin G; Lehrmann, Elin; Wood, William H; Zhang, Yongqing; Etienne, Harmonie; van Gastel, Jaana; Azmi, Abdelkrim; Janssens, Jonathan; Maudsley, Stuart

    2017-07-07

    The type 1 taste receptor member 3 (T1R3) is a G protein-coupled receptor involved in sweet-taste perception. Besides the tongue, the T1R3 receptor is highly expressed in brain areas implicated in cognition, including the hippocampus and cortex. As cognitive decline is often preceded by significant metabolic or endocrinological dysfunctions regulated by the sweet-taste perception system, we hypothesized that a disruption of the sweet-taste perception in the brain could have a key role in the development of cognitive dysfunction. To assess the importance of the sweet-taste receptors in the brain, we conducted transcriptomic and proteomic analyses of cortical and hippocampal tissues isolated from T1R3 knock-out (T1R3KO) mice. The effect of an impaired sweet-taste perception system on cognition functions were examined by analyzing synaptic integrity and performing animal behavior on T1R3KO mice. Although T1R3KO mice did not present a metabolically disrupted phenotype, bioinformatic interpretation of the high-dimensionality data indicated a strong neurodegenerative signature associated with significant alterations in pathways involved in neuritogenesis, dendritic growth, and synaptogenesis. Furthermore, a significantly reduced dendritic spine density was observed in T1R3KO mice together with alterations in learning and memory functions as well as sociability deficits. Taken together our data suggest that the sweet-taste receptor system plays an important neurotrophic role in the extralingual central nervous tissue that underpins synaptic function, memory acquisition, and social behavior. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Genotype-Specific Regulation of Oral Innate Immunity by T2R38 Taste Receptor

    Science.gov (United States)

    Gil, Sucheol; Coldwell, Susan; Drury, Jeanie L.; Arroyo, Fabiola; Phi, Tran; Saadat, Sanaz; Kwong, Danny; Chung, Whasun Oh

    2015-01-01

    The bitter taste receptor T2R38 has been shown to regulate mucosal innate immune responses in the upper airway epithelium. Furthermore, SNPs in T2R38 influence the sensitivity to 6-n-propylthiouracil (PROP) and are associated with caries risk/protection. However, no study has been reported on the role of T2R38 in the innate immune responses to oral bacteria. We hypothesize that T2R38 regulates oral innate immunity and that this regulation is genotype-specific. Primary gingival epithelial cells carrying three common genotypes, PAV/PAV (PROP super-taster), AVI/PAV (intermediate) and AVI/AVI (non-taster) were stimulated with cariogenic bacteria Streptococcus mutans, periodontal pathogen Porphyromonas gingivalis or non-pathogen Fusobacterium nucleatum. QRT-PCR analyzed T2R38 mRNA, and T2R38-specific siRNA and ELISA were utilized to evaluate induction of hBD-2 (antimicrobial peptide), IL-1α and IL-8 in various donor-lines. Experiments were set up in duplicate and repeated three times. T2R38 mRNA induction in response to S. mutans was highest in PAV/PAV (4.3-fold above the unstimulated controls; p<0.05), while lowest in AVI/AVI (1.2-fold). In PAV/PAV, hBD-2 secretion in response to S. mutans was decreased by 77% when T2R38 was silenced. IL-1α secretion was higher in PAV/PAV compared to AVI/PAV or AVI/AVI with S. mutans stimulation, but it was reduced by half when T2R38 was silenced (p<0.05). In response to P. gingivalis, AVI/AVI showed 4.4-fold increase (p<0.05) in T2R38 expression, whereas the levels in PAV/PAV and AVI/PAV remained close to that of the controls. Secretion levels of IL-1α and IL-8 decreased in AVI/AVI in response to P. gingivalis when T2R38 was silenced (p<0.05), while the changes were not significant in PAV/PAV. Our data suggest that the regulation of gingival innate immunity by T2R38 is genotype-dependent and that the ability to induce a high level of hBD-2 by PAV/PAV carriers may be a reason for protection against caries in this group. PMID

  17. Recent Advances in Molecular Mechanisms of Taste Signaling and Modifying.

    Science.gov (United States)

    Shigemura, Noriatsu; Ninomiya, Yuzo

    2016-01-01

    The sense of taste conveys crucial information about the quality and nutritional value of foods before it is ingested. Taste signaling begins with taste cells via taste receptors in oral cavity. Activation of these receptors drives the transduction systems in taste receptor cells. Then particular transmitters are released from the taste cells and activate corresponding afferent gustatory nerve fibers. Recent studies have revealed that taste sensitivities are defined by distinct taste receptors and modulated by endogenous humoral factors in a specific group of taste cells. Such peripheral taste generations and modifications would directly influence intake of nutritive substances. This review will highlight current understanding of molecular mechanisms for taste reception, signal transduction in taste bud cells, transmission between taste cells and nerves, regeneration from taste stem cells, and modification by humoral factors at peripheral taste organs. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Sweet taste receptor expressed in pancreatic beta-cells activates the calcium and cyclic AMP signaling systems and stimulates insulin secretion.

    Directory of Open Access Journals (Sweden)

    Yuko Nakagawa

    Full Text Available BACKGROUND: Sweet taste receptor is expressed in the taste buds and enteroendocrine cells acting as a sugar sensor. We investigated the expression and function of the sweet taste receptor in MIN6 cells and mouse islets. METHODOLOGY/PRINCIPAL FINDINGS: The expression of the sweet taste receptor was determined by RT-PCR and immunohistochemistry. Changes in cytoplasmic Ca(2+ ([Ca(2+](c and cAMP ([cAMP](c were monitored in MIN6 cells using fura-2 and Epac1-camps. Activation of protein kinase C was monitored by measuring translocation of MARCKS-GFP. Insulin was measured by radioimmunoassay. mRNA for T1R2, T1R3, and gustducin was expressed in MIN6 cells. In these cells, artificial sweeteners such as sucralose, succharin, and acesulfame-K increased insulin secretion and augmented secretion induced by glucose. Sucralose increased biphasic increase in [Ca(2+](c. The second sustained phase was blocked by removal of extracellular calcium and addition of nifedipine. An inhibitor of inositol(1, 4, 5-trisphophate receptor, 2-aminoethoxydiphenyl borate, blocked both phases of [Ca(2+](c response. The effect of sucralose on [Ca(2+](c was inhibited by gurmarin, an inhibitor of the sweet taste receptor, but not affected by a G(q inhibitor. Sucralose also induced sustained elevation of [cAMP](c, which was only partially inhibited by removal of extracellular calcium and nifedipine. Finally, mouse islets expressed T1R2 and T1R3, and artificial sweeteners stimulated insulin secretion. CONCLUSIONS: Sweet taste receptor is expressed in beta-cells, and activation of this receptor induces insulin secretion by Ca(2+ and cAMP-dependent mechanisms.

  19. Genetic tracing of the gustatory and trigeminal neural pathways originating from T1R3-expressing taste receptor cells and solitary chemoreceptor cells.

    Science.gov (United States)

    Ohmoto, Makoto; Matsumoto, Ichiro; Yasuoka, Akihito; Yoshihara, Yoshihiro; Abe, Keiko

    2008-08-01

    We established transgenic mouse lines expressing a transneuronal tracer, wheat germ agglutinin (WGA), under the control of mouse T1R3 gene promoter/enhancer. In the taste buds, WGA transgene was faithfully expressed in T1R3-positive sweet/umami taste receptor cells. WGA protein was transferred not laterally to the synapse-bearing, sour-responsive type III cells in the taste buds but directly to a subset of neurons in the geniculate and nodose/petrosal ganglia, and further conveyed to a rostro-central region of the nucleus of solitary tract. In addition, WGA was expressed in solitary chemoreceptor cells in the nasal epithelium and transferred along the trigeminal sensory pathway to the brainstem neurons. The solitary chemoreceptor cells endogenously expressed T1R3 together with bitter taste receptors T2Rs. This result shows an exceptional signature of receptor expression. Thus, the t1r3-WGA transgenic mice revealed the sweet/umami gustatory pathways from taste receptor cells and the trigeminal neural pathway from solitary chemoreceptor cells.

  20. Taste sensor; Mikaku sensor

    Energy Technology Data Exchange (ETDEWEB)

    Toko, K. [Kyushu University, Fukuoka (Japan)

    1998-03-05

    This paper introduces a taste sensor having a lipid/polymer membrane to work as a receptor of taste substances. The paper describes the following matters: this sensor uses a hollow polyvinyl chloride rod filled with KCl aqueous solution, and placed with silver and silver chloride wires, whose cross section is affixed with a lipid/polymer membrane as a lipid membrane electrode to identify taste from seven or eight kinds of response patterns of electric potential output from the lipid/polymer membrane; measurements of different substances presenting acidic taste, salty taste, bitter taste, sweet taste and flavor by using this sensor identified clearly each taste (similar response is shown to a similar taste even if the substances are different); different responses are indicated on different brands of beers; from the result of measuring a great variety of mineral waters, a possibility was suggested that this taste sensor could be used for water quality monitoring sensors; and application of this taste sensor may be expected as a maturation control sensor for Japanese sake (wine) and miso (bean paste) manufacturing. 2 figs., 1 tab.

  1. Qing-Hua Granule induces GLP-1 secretion via bitter taste receptor in db/db mice.

    Science.gov (United States)

    Li, Junyan; Xu, Jie; Hou, Ruifang; Jin, Xin; Wang, Jingyi; Yang, Na; Yang, Li; Liu, Li; Tao, Feng; Lu, Hao

    2017-05-01

    Qing-Hua Granule (QHG), the modified formulation of a classical Chinese prescription named Gegen Qinlian Decoction, was clinically employed to treat type 2 diabetes mellitus (T2DM) through regulation of glucagon-like peptide-1 (GLP-1). However, the potential mechanism is unknown. We investigate whether QHG induces GLP-1 secretion via activation of bitter taste receptor (TAS2R) pathway in the gastrointestinal tract of db/db mice. The db/db mice were intragastrically (i.g.) administered QHG (low/medium/high dose) once daily for 8 weeks. GLP-1 secretion was evaluated. The bitter receptor signaling pathway, which regulates GLP-1 secretion, including TAS2R5 (a subtype of TAS2R), α-gustducin (Gαgust), 1-phosphatidylinositol-4, 5-bisphosphate phosphodiesterase beta-2 (PLCβ2), transient receptor potential cation channel subfamily M member 5 (TRPM5), was assessed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot and immunohistochemistry (IHC). The biochemical observations of ileum and pancreas tissue were detected histopathologically. Acquity Ultra Performance LCTM - Micromass ZQ 2000 (UPLC-MS) was used for the phytochemical analysis. QHG exhibited significant and dose-dependent effect on GLP-1 secretion in db/db mice, along with significant up-regulation of TAS2R5 mRNA level and activation of TAS2R pathway (p<0.05). In addition, QHG improved the histopathological structure of ileum and pancreatic tissue. Seventeen compounds were identified in QHG. In conclusion, QHG induces GLP-1 secretion in db/db mice, most likely through the bitter taste receptor pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. The role of dopamine D2 receptors in the nucleus accumbens during taste-aversive learning and memory extinction after long-term sugar consumption.

    Science.gov (United States)

    Miranda, María Isabel; Rangel-Hernández, José Alejandro; Vera-Rivera, Gabriela; García-Medina, Nadia Edith; Soto-Alonso, Gerardo; Rodríguez-García, Gabriela; Núñez-Jaramillo, Luis

    2017-09-17

    The nucleus accumbens (NAcc) is a forebrain region that may significantly contribute to the integration of taste and visceral signals during food consumption. Changes in dopamine release in the NAcc have been observed during consumption of a sweet taste and during compulsive consumption of dietary sugars, suggesting that NAcc dopaminergic transmission is strongly correlated with taste familiarity and the hedonic value content. NAcc core and shell nuclei are differentially involved during and after sugar exposure and, particularly, previous evidence suggests that dopamine D2 receptors could be related with the strength of the latent inhibition (LI) of conditioned taste aversion (CTA), which depends on the length of the taste stimulus pre-exposure. Thus, the objective of this work was to evaluate, after long-term exposure to sugar, the function of dopaminergic D2 receptors in the NAcc core during taste memory retrieval preference test, and during CTA. Adult rats were exposed during 14days to 10% sugar solution as a single liquid ad libitum. NAcc core bilateral injections of D2 dopamine receptor antagonist, haloperidol (1μg/μL), were made before third preference test and CTA acquisition. We found that sugar was similarly preferred after 3 acute presentations or 14days of continued sugar consumption and that haloperidol did not disrupt this appetitive memory retrieval. Nevertheless, D2 receptors antagonism differentially affects aversive memory formation after acute or long-term sugar consumption. These results demonstrate that NAcc dopamine D2 receptors have a differential function during CTA depending on the degree of sugar familiarity. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. Association between taste receptor (TAS) genes and the perception of wine characteristics

    Czech Academy of Sciences Publication Activity Database

    Carrai, M.; Campa, D.; Vodička, Pavel; Flamini, R.; Martelli, I.; Slyšková, Jana; Jirásková, Kateřina; Rejhová, Alexandra; Vodenková, Soňa; Canzian, F.; Bertelli, A.; Dalla Vedova, A.; Bavaresco, L.; Vodičková, Ludmila; Barale, R.

    2017-01-01

    Roč. 7, aug (2017), s. 9239 ISSN 2045-2322 R&D Projects: GA MZd(CZ) NV15-27580A; GA MŠk(CZ) LD14050 Institutional support: RVO:68378041 Keywords : single-nucleotide polymorphisms * bitter-taste * alcohol-consumption Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.259, year: 2016

  4. Expression of taste receptors in Solitary Chemosensory Cells of rodent airways

    OpenAIRE

    Tizzano, Marco; Cristofoletti, Mirko; Sbarbati, Andrea; Finger, Thomas E

    2011-01-01

    Abstract Background Chemical irritation of airway mucosa elicits a variety of reflex responses such as coughing, apnea, and laryngeal closure. Inhaled irritants can activate either chemosensitive free nerve endings, laryngeal taste buds or solitary chemosensory cells (SCCs). The SCC population lies in the nasal respiratory epithelium, vomeronasal organ, and larynx, as well as deeper in the airway. The objective of this study is to map the distribution of SCCs within the airways and to determi...

  5. Anatomy, physiology and diagnostic considerations of taste and smell disorders

    NARCIS (Netherlands)

    A. Visser; R. van Weissenbruch; A. Vissink; A. van Nieuw Amerongen; F.K.L. Spijkervet; Dr. Harriët Jager-Wittenaar

    2013-01-01

    Taste and smell perception are closely related. The taste perception is performed by taste buds which can distinguish salt, sour, sweet, bitter, and umami. Moreover, 2,000-4,000 smells can be recognized. Many taste disorders are in fact smell disorders. Saliva affects taste perception because it

  6. Explaining and predicting individually experienced liking of berry fractions by the hTAS2R38 taste receptor genotype.

    Science.gov (United States)

    Laaksonen, Oskar; Ahola, Johanna; Sandell, Mari

    2013-02-01

    The roles of taste and astringent properties, food choice motives and health concerns in liking of bilberry and crowberry samples were studied using a sensory panel prescreened for the hTAS2R38 taste receptor genotype. The subjects rated the intensity of sourness, bitterness and two astringent properties (soft, velvety and rough, puckering) of all berry samples. They also scored the liking of juice fractions and completed a food choice motive and health concern questionnaire. Regression models were used to combine different data sets and to predict liking of the extracts. Sourness contributed positively to the liking of berry fractions, and bitterness and rough astringency were negative factors. The hTAS2R38 genotype affected the liking of polyphenol-rich extracts, which were significantly bitter and astringent. Based on the genotype grouping of subjects, PAV homozygotes gave lower ratings to the attributes than AVI homozygotes. In contrast, PAV homozygotes were predicted to dislike the extracts notably more than AVI homozygotes. Health concern and food choice motives related to health and weight control had significant roles in individual liking of juice fractions. Our results indicate that mood was more important to the PAV homozygotes than to the AVI homozygotes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. PENGARUH PEMBERIAN GULA MERAH DAN LAMA PENYIMPANAN TERHADAP KADAR GIZI DAN RASA TELUR ITIK ASIN [The Effect of Palm Sugar and Storage on Nutrient Content and Taste of Salted Ducks Egg

    Directory of Open Access Journals (Sweden)

    Yenni Yusriani

    2004-12-01

    Full Text Available This research used 150 duck eggs age one as subject day. There were two factors analyzed here. The first was the amount of palm sugar which consisted of 25 grams, 50 grams, and 75 grams. The second factor were the storage duration which consisted of 3, 4, and 5 weeks. The nutrient content parameters measured were rates protein, fat and ash content. Sensory quality parameters measured were color and taste. The analysis showed that in processing/making salted duck egg, palm sugar addition influenced protein content significantly (Fc = 7,0 > Ftab = 4,5 fat content ( Fc 67,3 > Ftab= 8,7 and ash content (Fc = 64,6 > F tab = 8,7 very significantly. However, organoleptic test showed that palm sugar addition did not influenced color and taste of salted duck egg significantly. Storage duration influenced protein content significantly (Fc= 6,9 F tab = 8,7 but did not significantly influenced ash content (Fc = 3,5 < Ftab = 4,46. Storage duration also influenced taste of salted duck egg, but did not for its color. The interaction of treatment between palm sugar addition and storage duration just influenced fat content of salted duck egg significantly. The salted duck egg made by addition 75 grams palm sugar and stored 5 weeks (A3B3 the highest content of fat. The salted ducks eeg made by addition of 25 grams palm sugar and stored duration produced the salted ducks egg with high content of fat and ash. Organoleptic test indicated that the panelis preferred the salted taste duck egg made by addition of palm sugar 25 grams and storaged for 3 weeks having reddish yellow color.

  8. A taste for ATP: neurotransmission in taste buds

    Science.gov (United States)

    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

  9. A taste for ATP: neurotransmission in taste buds

    Directory of Open Access Journals (Sweden)

    Thomas E. Finger

    2013-12-01

    Full Text Available 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.

  10. Single Nucleotide Polymorphisms in Taste Receptor Genes Are Associated with Snacking Patterns of Preschool-Aged Children in the Guelph Family Health Study: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Elie Chamoun

    2018-01-01

    Full Text Available Snacking is an integral component of eating habits in young children that is often overlooked in nutrition research. While snacking is a substantial source of calories in preschoolers’ diets, there is limited knowledge about the factors that drive snacking patterns. The genetics of taste may help to better understand the snacking patterns of children. The rs1761667 single nucleotide polymorphism (SNP in the CD36 gene has been linked to fat taste sensitivity, the rs35874116 SNP in the TAS1R2 gene has been related to sweet taste preference, and the rs713598 SNP in the TAS2R38 gene has been associated with aversion to bitter, green leafy vegetables. This study seeks to determine the cross-sectional associations between three taste receptor SNPs and snacking patterns among preschoolers in the Guelph Family Health Study. Preschoolers’ snack quality, quantity, and frequency were assessed using three-day food records and saliva was collected for SNP genotyping (n = 47. Children with the TT genotype in TAS1R2 consumed snacks with significantly more calories from sugar, and these snacks were consumed mostly in the evening. Total energy density of snacks was highest in the CC and CG genotypes compared to the GG genotype in TAS2R38, and also greater in the AA genotype in CD36 compared to G allele carriers, however this difference was not individually attributable to energy from fat, carbohydrates, sugar, or protein. Genetic variation in taste receptors may influence snacking patterns of preschoolers.

  11. The human taste receptor hTAS2R14 responds to a variety of different bitter compounds

    International Nuclear Information System (INIS)

    Behrens, Maik; Brockhoff, Anne; Kuhn, Christina; Bufe, Bernd; Winnig, Marcel; Meyerhof, Wolfgang

    2004-01-01

    The recent advances in the functional expression of TAS2Rs in heterologous systems resulted in the identification of bitter tastants that specifically activate receptors of this family. All bitter taste receptors reported to date exhibit a pronounced selectivity for single substances or structurally related bitter compounds. In the present study we demonstrate the expression of the hTAS2R14 gene by RT-PCR analyses and in situ hybridisation in human circumvallate papillae. By functional expression in HEK-293T cells we show that hTAS2R14 displays a, so far, unique broad tuning towards a variety of structurally diverse bitter compounds, including the potent neurotoxins, (-)-α-thujone, the pharmacologically active component of absinthe, and picrotoxinin, a poisonous substance of fishberries. The observed activation of heterologously expressed hTAS2R14 by low concentrations of (-)-α-thujone and picrotoxinin suggests that the receptor is sufficiently sensitive to caution us against the ingestion of toxic amounts of these substances

  12. Activation of the sweet taste receptor, T1R3, by the artificial sweetener sucralose regulates the pulmonary endothelium.

    Science.gov (United States)

    Harrington, Elizabeth O; Vang, Alexander; Braza, Julie; Shil, Aparna; Chichger, Havovi

    2018-01-01

    A hallmark of acute respiratory distress syndrome (ARDS) is pulmonary vascular permeability. In these settings, loss of barrier integrity is mediated by cell-contact disassembly and actin remodeling. Studies into molecular mechanisms responsible for improving microvascular barrier function are therefore vital in the development of therapeutic targets for reducing vascular permeability in ARDS. The sweet taste receptor T1R3 is a G protein-coupled receptor, activated following exposure to sweet molecules, to trigger a gustducin-dependent signal cascade. In recent years, extraoral locations for T1R3 have been identified; however, no studies have focused on T1R3 within the vasculature. We hypothesize that activation of T1R3, in the pulmonary vasculature, plays a role in regulating endothelial barrier function in settings of ARDS. Our study demonstrated expression of T1R3 within the pulmonary vasculature, with a drop in expression levels following exposure to barrier-disruptive agents. Exposure of lung microvascular endothelial cells to the intensely sweet molecule sucralose attenuated LPS- and thrombin-induced endothelial barrier dysfunction. Likewise, sucralose exposure attenuated bacteria-induced lung edema formation in vivo. Inhibition of sweet taste signaling, through zinc sulfate, T1R3, or G-protein siRNA, blunted the protective effects of sucralose on the endothelium. Sucralose significantly reduced LPS-induced increased expression or phosphorylation of the key signaling molecules Src, p21-activated kinase (PAK), myosin light chain-2 (MLC2), heat shock protein 27 (HSP27), and p110α phosphatidylinositol 3-kinase (p110αPI3K). Activation of T1R3 by sucralose protects the pulmonary endothelium from edemagenic agent-induced barrier disruption, potentially through abrogation of Src/PAK/p110αPI3K-mediated cell-contact disassembly and Src/MLC2/HSP27-mediated actin remodeling. Identification of sweet taste sensing in the pulmonary vasculature may represent a novel

  13. Selective solid-liquid extraction of lithium halide salts using a ditopic macrobicyclic receptor.

    Science.gov (United States)

    Mahoney, Joseph M; Beatty, Alicia M; Smith, Bradley D

    2004-11-29

    A ditopic salt receptor that is known to bind and extract solid NaCl, KCl, NaBr, and KBr into organic solution as their contact ion pairs is now shown by NMR and X-ray crystallography to bind and extract solid LiCl and LiBr as water-separated ion pairs. The receptor can transport these salts from an aqueous phase through a liquid organic membrane with a cation selectivity of K+ > Na+ > Li+. However, the selectivity order is strongly reversed when the receptor extracts solid alkali metal chlorides and bromides into organic solution. For a three-component mixture of solid LiCl, NaCl, and KCl, the ratio of salts extracted and complexed to the receptor in CDCl3 was 94:4:2, respectively. The same strong lithium selectivity was also observed in the case of a three-component mixture of solid LiBr, NaBr, and KBr where the ratio of extracted salts was 92:5:3. This observation is attributed to the unusually high solubility of lithium salts in organic solvents. The study suggests that ditopic receptors with an ability to extract solid salts as associated ion pairs may have application in separation processes.

  14. Differential regulation of renal prostaglandin receptor mRNAs by dietary salt intake in the rat

    DEFF Research Database (Denmark)

    Jensen, B L; Mann, Birgitte; Skøtt, O

    1999-01-01

    and cells by ribonuclease protection assay and reverse transcription-polymerase chain reaction analysis. Functional correlates were studied by measurement of PGE2-induced cAMP formation and renin secretion in juxtaglomerular (JG) cells isolated from animals on various salt intakes. RESULTS: EP1 and EP3......BACKGROUND: In this study, we tested the hypothesis that prostaglandin (PG) receptor expression in the rat kidney is subject to physiological regulation by dietary salt intake. METHODS: Rats were fed diets with 0.02 or 4% NaCl for two weeks. PG receptor expression was assayed in kidney regions...... did not affect the expression of EP1 or IP receptors, whereas EP4 transcripts in glomeruli were increased twofold by salt deprivation. Consistent with this, we found that PGE2-evoked cAMP production and renin secretion by JG cells from salt-deprived animals were significantly higher compared...

  15. Polycose Taste Pre-Exposure Fails to Influence Behavioral and Neural Indices of Taste Novelty

    OpenAIRE

    Barot, Sabiha K.; Bernstein, Ilene L.

    2005-01-01

    Taste novelty can strongly modulate the speed and efficacy of taste aversion learning. Novel sweet tastes enhance c-Fos-like immunoreactivity (FLI) in the central amygdala and insular cortex. The present studies examined whether this neural correlate of novelty extends to different taste types by measuring FLI signals after exposure to novel and familiar polysaccharide (Polycose®) and salt (NaCl) tastes. Novel Polycose not only failed to elevate FLI expression in central amygdala and insular ...

  16. Sea Salt vs. Table Salt: What's the Difference?

    Science.gov (United States)

    ... and healthy eating What's the difference between sea salt and table salt? Answers from Katherine Zeratsky, R.D., L.D. The main differences between sea salt and table salt are in their taste, texture ...

  17. Taste bud cells and nerves

    OpenAIRE

    武田,正子/内田,暢彦/鈴木,裕子; タケダ,マサコ/ウチダ,ノブヒコ/スズキ,ユウコ; TAKEDA,Masako/UCHIDA,Nobuhiko/SUZUKI,Yuko

    2002-01-01

    Sectioning of glossopharyngeal nerves which innervate the taste buds in the circumvallate papillae caused apoptosis of taste buds, the numbers decreasing and the taste buds disappearing after 11 days. This indicates that gustatory nerves may release a trophic substance that induces and maintains taste buds. Taste bud cells contain neurotrophins, NCAM, NSE, PGP9.5, and NeuroD which are specific markers of neurons. The BDNF and GDNF of neurotrophins, and Trk B and GFRαl of their receptors were ...

  18. Anti-cancer stemness and anti-invasive activity of bitter taste receptors, TAS2R8 and TAS2R10, in human neuroblastoma cells.

    Directory of Open Access Journals (Sweden)

    Yoona Seo

    Full Text Available Neuroblastoma (NB originates from immature neuronal cells and currently has a poor clinical outcome. NB cells possess cancer stem cells (CSCs characteristics that facilitate the initiation of a tumor, as well as its metastasis. Human bitter taste receptors, referred to as TAS2Rs, are one of five types of basic taste receptors and they belong to a family of G-protein coupled receptors. The recent finding that taste receptors are expressed in non-gustatory tissues suggest that they mediate additional functions distinct from taste perception. While it is generally admitted that the recognition of bitter tastes may be associated with a self-defense system to prevent the ingestion of poisonous food compounds, this recognition may also serve as a disease-related function in the human body. In particular, the anti-cancer stemness and invasion effects of TAS2Rs on NB cells remain poorly understood. In the present study, endogenous expression of TAS2R8 and TAS2R10 in SK-N-BE(2C and SH-SY5Y cells was examined. In addition, higher levels of TAS2R8 and TAS2R10 expression were investigated in more differentiated SY5Y cells. Both TAS2Rs were up-regulated following the induction of neuronal cell differentiation by retinoic acid. In addition, ectopic transfection of the two TAS2Rs induced neurite elongation in the BE(2C cells, and down-regulated CSCs markers (including DLK1, CD133, Notch1, and Sox2, and suppressed self-renewal characteristics. In particular, TAS2RS inhibited tumorigenicity. Furthermore, when TAS2Rs was over-expressed, cell migration, cell invasion, and matrix metalloproteinases activity were inhibited. Expression levels of hypoxia-inducible factor-1α, a well-known regulator of tumor metastasis, as well as its downstream targets, vascular endothelial growth factor and glucose transporter-1, were also suppressed by TAS2Rs. Taken together, these novel findings suggest that TAS2Rs targets CSCs by suppressing cancer stemness characteristics and NB

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

    Science.gov (United States)

    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.

  20. Effects of dietary salt on adrenomedullin and its receptor mRNAs in rat kidney

    DEFF Research Database (Denmark)

    Jensen, B L; Gambaryan, S; Schmaus, E

    1998-01-01

    There is accumulating evidence that adrenomedullin (ADM) is involved in the control of salt and water homeostasis. ADM is considered to act primarily in a paracrine fashion, and since the kidneys are target organs for ADM, we investigated the localization and regulation of ADM and ADM receptor (ADM...... and a preferential action of ADM in the papilla. Ten days of feeding a low-salt (0.02%) or a high-salt diet (4%) did not change ADM mRNA or ADM-R mRNA in any kidney zone....

  1. The Gustatory Signaling Pathway and Bitter Taste Receptors Affect the Development of Obesity and Adipocyte Metabolism in Mice.

    Directory of Open Access Journals (Sweden)

    Bert Avau

    Full Text Available Intestinal chemosensory signaling pathways involving the gustatory G-protein, gustducin, and bitter taste receptors (TAS2R have been implicated in gut hormone release. Alterations in gut hormone profiles may contribute to the success of bariatric surgery. This study investigated the involvement of the gustatory signaling pathway in the development of diet-induced obesity and the therapeutic potential of targeting TAS2Rs to induce body weight loss. α-gustducin-deficient (α-gust-/- mice became less obese than wild type (WT mice when fed a high-fat diet (HFD. White adipose tissue (WAT mass was lower in α-gust-/- mice due to increased heat production as a result of increases in brown adipose tissue (BAT thermogenic activity, involving increased protein expression of uncoupling protein 1. Intra-gastric treatment of obese WT and α-gust-/- mice with the bitter agonists denatonium benzoate (DB or quinine (Q during 4 weeks resulted in an α-gustducin-dependent decrease in body weight gain associated with a decrease in food intake (DB, but not involving major changes in gut peptide release. Both WAT and 3T3-F442A pre-adipocytes express TAS2Rs. Treatment of pre-adipocytes with DB or Q decreased differentiation into mature adipocytes. In conclusion, interfering with the gustatory signaling pathway protects against the development of HFD-induced obesity presumably through promoting BAT activity. Intra-gastric bitter treatment inhibits weight gain, possibly by directly affecting adipocyte metabolism.

  2. Amiloride-sensitive channels in type I fungiform taste cells in mouse

    Directory of Open Access Journals (Sweden)

    Clapp Tod R

    2008-01-01

    Full Text Available Abstract Background Taste buds are the sensory organs of taste perception. Three types of taste cells have been described. Type I cells have voltage-gated outward currents, but lack voltage-gated inward currents. These cells have been presumed to play only a support role in the taste bud. Type II cells have voltage-gated Na+ and K+ current, and the receptors and transduction machinery for bitter, sweet, and umami taste stimuli. Type III cells have voltage-gated Na+, K+, and Ca2+ currents, and make prominent synapses with afferent nerve fibers. Na+ salt transduction in part involves amiloride-sensitive epithelial sodium channels (ENaCs. In rodents, these channels are located in taste cells of fungiform papillae on the anterior part of the tongue innervated by the chorda tympani nerve. However, the taste cell type that expresses ENaCs is not known. This study used whole cell recordings of single fungiform taste cells of transgenic mice expressing GFP in Type II taste cells to identify the taste cells responding to amiloride. We also used immunocytochemistry to further define and compare cell types in fungiform and circumvallate taste buds of these mice. Results Taste cell types were identified by their response to depolarizing voltage steps and their presence or absence of GFP fluorescence. TRPM5-GFP taste cells expressed large voltage-gated Na+ and K+ currents, but lacked voltage-gated Ca2+ currents, as expected from previous studies. Approximately half of the unlabeled cells had similar membrane properties, suggesting they comprise a separate population of Type II cells. The other half expressed voltage-gated outward currents only, typical of Type I cells. A single taste cell had voltage-gated Ca2+ current characteristic of Type III cells. Responses to amiloride occurred only in cells that lacked voltage-gated inward currents. Immunocytochemistry showed that fungiform taste buds have significantly fewer Type II cells expressing PLC signalling

  3. Variation in the Sweet Taste Receptor Gene and Dietary Intake in a Swedish Middle-Aged Population

    Directory of Open Access Journals (Sweden)

    Caroline Habberstad

    2017-12-01

    Full Text Available BackgroundThe preference for sweet taste is partially genetically determined. The major allele of the single nucleotide polymorphism rs12033832 in the sweet taste receptor (TAS1R2 has previously been associated with lower sugar sensitivity and higher sugar intake among overweight individuals. The aim of the present study was to examine the association between dietary intake and the TAS1R2 genotype in lean and overweight individuals in the population-based Malmö Diet and Cancer (MDC cohort using dietary intake data with a high validity.MethodsIn total, 3,602 participants (46–68 years old from the MDC cohort who underwent baseline examinations between 1991 and 1994, who were non-smokers without diabetes, and for whom information regarding TAS1R2 rs7534618 (a proxy for rs12033832 was available were included in this study. After excluding individuals with potentially misreported and unstable food habits, 2,204 individuals were retained. A modified dietary history method, including a 7-day food diary of prepared meals, which was specifically designed for the MDC study was used.ResultsOnly modest associations were observed between dietary intake and the TAS1R2 genotype. We observed slightly stronger associations after excluding individuals with potentially misreported and unstable food habits. Among the participants with a BMI ≥25, the major (T allele carriers consumed more carbohydrates [TT = 45.2 percentage of energy intake (E%; TG = 45.2E%; GG = 43.7E%; p = 0.01] and less fat (p = 0.03, but these participants did not consume more sucrose than the G-allele carriers. No association was observed between the genotype and dietary intake among the participants with a BMI <25.ConclusionAlthough the higher carbohydrate intake among the major allele carriers was consistent with that reported in a previous study, the magnitudes of the associations were substantially smaller. Because we observed no association with sucrose, this

  4. Systemic modulation of serotonergic synapses via reuptake blockade or 5HT1A receptor antagonism does not alter perithreshold taste sensitivity in rats.

    Science.gov (United States)

    Mathes, Clare M; Spector, Alan C

    2014-09-01

    Systemic blockade of serotonin (5HT) reuptake with paroxetine has been shown to increase sensitivity to sucrose and quinine in humans. Here, using a 2-response operant taste detection task, we measured the effect of paroxetine and the 5HT1A receptor antagonist WAY100635 on the ability of rats to discriminate sucrose, NaCl, and citric acid from water. After establishing individual psychometric functions, 5 concentrations of each taste stimulus were chosen to represent the dynamic portion of the concentration-response curve, and the performance of the rats to these stimuli was assessed after vehicle, paroxetine (7mg/kg intraperitoneally), and WAY100635 (0.3mg/kg subcutaneously; 1mg/kg intravenously) administration. Although, at times, overall performance across concentrations dropped, at most, 5% from vehicle to drug conditions, no differences relative to vehicle were seen on the parameters of the psychometric function (asymptote, slope, or EC50) after drug administration. In contrast to findings in humans, our results suggest that modulation of 5HT activity has little impact on sucrose detectability at perithreshold concentrations in rats, at least at the doses used in this task. In the rat model, the purported paracrine/neurocrine action of serotonin in the taste bud may work in a manner that does not impact overt taste detection behavior. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Bitter Taste Receptors in The Wrong Place: Novel Airway Smooth Muscle Targets For Treating Asthma

    OpenAIRE

    Liggett, Stephen B.

    2014-01-01

    There is a need to expand the classes of drugs used to treat obstructive lung diseases to achieve better outcomes. With only one class of direct bronchodilators (β-agonists), we sought to find receptors on human airway smooth muscle (ASM) that act via a unique mechanism to relax the muscle, have a diverse agonist binding profile to enhance the probability of finding new therapeutics, and relax ASM with equal or greater efficacy than β-agonists. We have found that human and mouse ASM express s...

  6. Rewiring the taste system.

    Science.gov (United States)

    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.

  7. The human bitter taste receptor T2R38 is broadly tuned for bacterial compounds.

    Directory of Open Access Journals (Sweden)

    Christophe Verbeurgt

    Full Text Available T2R38 has been shown to be a specific bacterial detector implicated in innate immune defense mechanism of human upper airway. Several clinical studies have demonstrated that this receptor is associated with the development of chronic rhinosinusitis (CRS. T2R38 was previously reported to bind to homoserine lactones (HSL, quorum sensing molecules specific of Pseudomonas Aeruginosa and other gram negative species. Nevertheless, these bacteria are not the major pathogens found in CRS. Here we report on the identification of bacterial metabolites acting as new agonists of T2R38 based on a single cell calcium imaging study. Two quorum sensing molecules (Agr D1 thiolactone from Staphylococcus Aureus and CSP-1 from Streptococcus Pneumoniae and a list of 32 bacterial metabolites from pathogens frequently implicated in CRS were tested. First, we observed that HSL failed to activate T2R38 in our experimental system, but that the dimethylsulfoxide (DMSO, used as a solvent for these lactones may, by itself, account for the agonistic effect previously described. Secondly, we showed that both Agr D1 thiolactone and CSP-1 are inactive but that at least 7 bacterial metabolites (acetone, 2-butanone, 2-pentanone, 2-methylpropanal, dimethyl disulfide, methylmercaptan, γ-butyrolactone are able to specifically trigger this receptor. T2R38 is thus much more broadly tuned for bacterial compounds than previously thought.

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

    Directory of Open Access Journals (Sweden)

    Anindya Ganguly

    2017-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  10. Taste of Fat: A Sixth Taste Modality?

    Science.gov (United States)

    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.

  11. Liver Receptor Homolog-1 Is Critical for Adequate Up-regulation of Cyp7a1 Gene Transcription and Bile Salt Synthesis During Bile Salt Sequestration

    NARCIS (Netherlands)

    Out, Carolien; Hageman, Jurre; Bloks, Vincent W.; Gerrits, Han; Gelpke, Maarten D. Sollewijn; Bos, Trijnie; Havinga, Rick; Smit, Martin J.; Kuipers, Folkert; Groen, Albert K.

    Liver receptor homolog-1 (LRH-1) is a nuclear receptor that controls a variety of metabolic pathways. In cultured cells, LRH-1 induces the expression of CYP7A1 and CYP8B1, key enzymes in bile salt synthesis. However, hepatic Cyp7a1 mRNA levels were not reduced upon hepatocyte-specific Lrh-1 deletion

  12. Exploring taste hyposensitivity in Japanese senior high school students.

    Science.gov (United States)

    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.

  13. Linking GABA(A) receptor subunits to alcohol-induced conditioned taste aversion and recovery from acute alcohol intoxication.

    Science.gov (United States)

    Blednov, Y A; Benavidez, J M; Black, M; Chandra, D; Homanics, G E; Rudolph, U; Harris, R A

    2013-04-01

    GABA type A receptors (GABA(A)-R) are important for ethanol actions and it is of interest to link individual subunits with specific ethanol behaviors. We studied null mutant mice for six different GABA(A)-R subunits (α1, α2, α3, α4, α5 and δ). Only mice lacking the α2 subunit showed reduction of conditioned taste aversion (CTA) to ethanol. These results are in agreement with data from knock-in mice with mutation of the ethanol-sensitive site in the α2-subunit (Blednov et al., 2011). All together, they indicate that aversive property of ethanol is dependent on ethanol action on α2-containing GABA(A)-R. Deletion of the α2-subunit led to faster recovery whereas absence of the α3-subunit slowed recovery from ethanol-induced incoordination (rotarod). Deletion of the other four subunits did not affect this behavior. Similar changes in this behavior for the α2 and α3 null mutants were found for flurazepam motor incoordination. However, no differences in recovery were found in motor-incoordinating effects of an α1-selective modulator (zolpidem) or an α4-selective agonist (gaboxadol). Therefore, recovery of rotarod incoordination is under control of two GABA(A)-R subunits: α2 and α3. For motor activity, α3 null mice demonstrated higher activation by ethanol (1 g/kg) whereas both α2 (-/-) and α3 (-/Y) knockout mice were less sensitive to ethanol-induced reduction of motor activity (1.5 g/kg). These studies demonstrate that the effects of ethanol at GABAergic synapses containing α2 subunit are important for specific behavioral effects of ethanol which may be relevant to the genetic linkage of the α2 subunit with human alcoholism. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. LINKING GABAA RECEPTOR SUBUNITS TO ALCOHOL-INDUCED CONDITIONED TASTE AVERSION AND RECOVERY FROM ACUTE ALCOHOL INTOXICATION

    Science.gov (United States)

    Blednov, Y.A.; Benavidez, J.M.; Black, M.; Chandra, D.; Homanics, G.E.; Rudolph, U.; Harris, R.A.

    2012-01-01

    GABA type A receptors (GABAA-R) are important for ethanol actions and it is of interest to link individual subunits with specific ethanol behaviors. We studied null mutant mice for six different GABAA-R subunits (α1, α2, α3, α4, α5 and δ). Only mice lacking the α2 subunit showed reduction of conditioned taste aversion (CTA) to ethanol. These results are in agreement with data from knock-in mice with mutation of the ethanol-sensitive site in the α2-subunit (Blednov et al., 2011) and indicate this aversive property of ethanol is dependent on ethanol action on α2-containing GABAA-R. Deletion of the α2-subunit led to faster recovery whereas absence of the α3-subunit slowed recovery from ethanol-induced incoordination (rotarod). Deletion of the other four subunits did not affect this behavior. Similar changes in this behavior for the α2 and α3 null mutants were found for flurazepam motor-incoordination. However, no differences in recovery were found in motor-incoordinating effects of an α1-selective modulator (zolpidem) or an α4-selective agonist (gaboxadol). Therefore, recovery of rotarod incoordination is under control of two GABAA-R subunits: α2 and α3. For motor activity, α3 null mice demonstrated higher activation by ethanol (1 g/kg) whereas both α2 and α3 (-/-) knockout mice were less sensitive to ethanol-induced reduction of motor activity (1.5 g/kg). These studies demonstrate that the effects of ethanol at GABAergic synapses containing α2 subunit are important for specific behavioral effects of ethanol which may be relevant to the genetic linkage of the α2 subunit with human alcoholism. PMID:23147414

  15. Electrophysiological studies of salty taste modification by organic acids in the labellar taste cell of the blowfly.

    Science.gov (United States)

    Murata, Yoshihiro; Kataoka-Shirasugi, Naoko; Amakawa, Taisaku

    2002-01-01

    Using the labellar salt receptor cells of the blowfly, Phormia regina, we electrophysiologically showed that the response to NaCl and KCl aqueous solutions was enhanced and depressed by acetic, succinic and citric acids. The organic acid concentrations at which the most enhanced salt response (MESR) was obtained were found to be different: 0.05-1 mM citric acid, 0.5-2 mM succinic acid and 5-50 mM acetic acid. Moreover, the degree of the salt response was not always dependent on the pH values of the stimulating solutions. The salt response was also enhanced by HCl (pH 3.5-3.0) only when the NaCl concentration was greater than the threshold, indicating that the salty taste would be enhanced by the comparatively lower concentrations of hydrogen ions. Another explanation for the enhancement is that the salty taste may also be enhanced by undissociated molecules of the organic acids, because the MESRs were obtained at the pH values lower than the pKa(1) or pKa(2) values of these organic acids. On the other hand, the salty taste could be depressed by both the lower pH range (pH 2.5-2.0) and the dissociated organic anions from organic acid molecules with at least two carboxyl groups.

  16. TRPs in Taste and Chemesthesis

    Science.gov (United States)

    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

  17. Change of Taste Sensitivity of Clove Cigarette Smokers in Medan

    Directory of Open Access Journals (Sweden)

    Marlina Simamora

    2013-07-01

    Full Text Available Tongue has taste buds that contain taste receptor which affected by many factors, including smoking habit. Objective: To analyze the differences of sweet and bitter taste sensitivity in the pedicab driver clove cigarette smokers compared to non-smokers in Medan Padang Bulan. Methods: This study was conducted by placing the sweet taste strips and bitter taste strips on four taste receptors of the tongue, with increasing solution concentration in 74 subjects. This was a cross sectional study on pedicab driver population in Medan Padang Bulan. Results: There were differences between clove cigarette smokers and non-smokers on sweet taste examination (p<0.005. There was a difference between clove cigarette smokers and non-smokers on examination bitter taste receptors (p<0.005. On the clove cigarette smokers, there was no significant difference between sweet taste and bitter taste on the receptors itself. Conclusion: Non-smokers are more sensitive to sweet taste than the clove cigarette smokers. Bitter taste sensitivity is greater in cigarettes smokers than in non-smokers. Taste receptors on all location of the tongue could taste sweet and bitter substances, but a certain location of taste receptors were more sensitive compared to others.

  18. Habitual Tastes and Embedded Taste

    DEFF Research Database (Denmark)

    Hedegaard, Liselotte

    2016-01-01

    The interest of this paper is to position taste within the framework of time. This might seem peculiar given that taste, in its physical sense, is referred to as an ephemeral experience taking place in the mouth. Taste, however, is more than that. It is the transient experience that infiltrates...... may be bridged by story-telling or other ways of handing over historically embedded practices, but this leaves a more fundamental question unanswered. Namely, that given that all remembrance has individual recollection as the point of departure, then how does individual recollection of tastes...

  19. T1R3 homomeric sweet taste receptor regulates adipogenesis through Gαs-mediated microtubules disassembly and Rho activation in 3T3-L1 cells.

    Directory of Open Access Journals (Sweden)

    Yosuke Masubuchi

    Full Text Available We previously reported that 3T3-L1 cells express a functional sweet taste receptor possibly as a T1R3 homomer that is coupled to Gs and negatively regulates adipogenesis by a Gαs-mediated but cAMP-independent mechanism. Here, we show that stimulation of this receptor with sucralose or saccharin induced disassembly of the microtubules in 3T3-L1 preadipocytes, which was attenuated by overexpression of the dominant-negative mutant of Gαs (Gαs-G226A. In contrast, overexpression of the constitutively active mutant of Gαs (Gαs-Q227L as well as treatment with cholera toxin or isoproterenol but not with forskolin caused disassembly of the microtubules. Sweetener-induced microtubule disassembly was accompanied by activation of RhoA and Rho-associated kinase (ROCK. This was attenuated with by knockdown of GEF-H1, a microtubule-localized guanine nucleotide exchange factor for Rho GTPase. Furthermore, overexpression of the dominant-negative mutant of RhoA (RhoA-T19N blocked sweetener-induced dephosphorylation of Akt and repression of PPARγ and C/EBPα in the early phase of adipogenic differentiation. These results suggest that the T1R3 homomeric sweet taste receptor negatively regulates adipogenesis through Gαs-mediated microtubule disassembly and consequent activation of the Rho/ROCK pathway.

  20. Genomic regression of claw keratin, taste receptor and light-associated genes provides insights into biology and evolutionary origins of snakes.

    Science.gov (United States)

    Emerling, Christopher A

    2017-10-01

    Regressive evolution of anatomical traits often corresponds with the regression of genomic loci underlying such characters. As such, studying patterns of gene loss can be instrumental in addressing questions of gene function, resolving conflicting results from anatomical studies, and understanding the evolutionary history of clades. The evolutionary origins of snakes involved the regression of a number of anatomical traits, including limbs, taste buds and the visual system, and by analyzing serpent genomes, I was able to test three hypotheses associated with the regression of these features. The first concerns two keratins that are putatively specific to claws. Both genes that encode these keratins are pseudogenized/deleted in snake genomes, providing additional evidence of claw-specificity. The second hypothesis is that snakes lack taste buds, an issue complicated by conflicting results in the literature. I found evidence that different snakes have lost one or more taste receptors, but all snakes examined retained at least one gustatory channel. The final hypothesis addressed is that the earliest snakes were adapted to a dim light niche. I found evidence of deleted and pseudogenized genes with light-associated functions in snakes, demonstrating a pattern of gene loss similar to other dim light-adapted clades. Molecular dating estimates suggest that dim light adaptation preceded the loss of limbs, providing some bearing on interpretations of the ecological origins of snakes. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Taste bud homeostasis in health, disease, and aging.

    Science.gov (United States)

    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.

  2. Taste Bud Homeostasis in Health, Disease, and Aging

    Science.gov (United States)

    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

  3. Taste Bud Homeostasis in Health, Disease, and Aging

    OpenAIRE

    Feng, Pu; Huang, Liquan; Wang, Hong

    2013-01-01

    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...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  6. Coarse-grained/molecular mechanics of the TAS2R38 bitter taste receptor: experimentally-validated detailed structural prediction of agonist binding.

    Directory of Open Access Journals (Sweden)

    Alessandro Marchiori

    Full Text Available Bitter molecules in humans are detected by ∼25 G protein-coupled receptors (GPCRs. The lack of atomic resolution structure for any of them is complicating an in depth understanding of the molecular mechanisms underlying bitter taste perception. Here, we investigate the molecular determinants of the interaction of the TAS2R38 bitter taste receptor with its agonists phenylthiocarbamide (PTC and propylthiouracil (PROP. We use the recently developed hybrid Molecular Mechanics/Coarse Grained (MM/CG method tailored specifically for GPCRs. The method, through an extensive exploration of the conformational space in the binding pocket, allows the identification of several residues important for agonist binding that would have been very difficult to capture from the standard bioinformatics/docking approach. Our calculations suggest that both agonists bind to Asn103, Phe197, Phe264 and Trp201, whilst they do not interact with the so-called extra cellular loop 2, involved in cis-retinal binding in the GPCR rhodopsin. These predictions are consistent with data sets based on more than 20 site-directed mutagenesis and functional calcium imaging experiments of TAS2R38. The method could be readily used for other GPCRs for which experimental information is currently lacking.

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

    Science.gov (United States)

    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.

  8. Bile salt receptor complex activates a pathogenic type III secretion system

    Science.gov (United States)

    Li, Peng; Rivera-Cancel, Giomar; Kinch, Lisa N; Salomon, Dor; Tomchick, Diana R; Grishin, Nick V; Orth, Kim

    2016-01-01

    Bile is an important component of the human gastrointestinal tract with an essential role in food absorption and antimicrobial activities. Enteric bacterial pathogens have developed strategies to sense bile as an environmental cue to regulate virulence genes during infection. We discovered that Vibrio parahaemolyticus VtrC, along with VtrA and VtrB, are required for activating the virulence type III secretion system 2 in response to bile salts. The VtrA/VtrC complex activates VtrB in the presence of bile salts. The crystal structure of the periplasmic domains of the VtrA/VtrC heterodimer reveals a β-barrel with a hydrophobic inner chamber. A co-crystal structure of VtrA/VtrC with bile salt, along with biophysical and mutational analysis, demonstrates that the hydrophobic chamber binds bile salts and activates the virulence network. As part of a family of conserved signaling receptors, VtrA/VtrC provides structural and functional insights into the evolutionarily conserved mechanism used by bacteria to sense their environment. DOI: http://dx.doi.org/10.7554/eLife.15718.001 PMID:27377244

  9. Bile salt receptor complex activates a pathogenic type III secretion system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peng; Rivera-Cancel, Giomar; Kinch, Lisa N.; Salomon, Dor; Tomchick, Diana R.; Grishin, Nick V.; Orth, Kim

    2016-07-05

    Bile is an important component of the human gastrointestinal tract with an essential role in food absorption and antimicrobial activities. Enteric bacterial pathogens have developed strategies to sense bile as an environmental cue to regulate virulence genes during infection. We discovered thatVibrio parahaemolyticusVtrC, along with VtrA and VtrB, are required for activating the virulence type III secretion system 2 in response to bile salts. The VtrA/VtrC complex activates VtrB in the presence of bile salts. The crystal structure of the periplasmic domains of the VtrA/VtrC heterodimer reveals a β-barrel with a hydrophobic inner chamber. A co-crystal structure of VtrA/VtrC with bile salt, along with biophysical and mutational analysis, demonstrates that the hydrophobic chamber binds bile salts and activates the virulence network. As part of a family of conserved signaling receptors, VtrA/VtrC provides structural and functional insights into the evolutionarily conserved mechanism used by bacteria to sense their environment.

  10. Calcium Homeostasis Modulator 1-Like Currents in Rat Fungiform Taste Cells Expressing Amiloride-Sensitive Sodium Currents.

    Science.gov (United States)

    Bigiani, Albertino

    2017-05-01

    Salt reception by taste cells is still the less understood transduction process occurring in taste buds, the peripheral sensory organs for the detection of food chemicals. Although there is evidence suggesting that the epithelial sodium channel (ENaC) works as sodium receptor, yet it is not clear how salt-detecting cells signal the relevant information to nerve endings. Taste cells responding to sweet, bitter, and umami substances release ATP as neurotransmitter through a nonvesicular mechanism. Three different channel proteins have been proposed as conduit for ATP secretion: pannexin channels, connexin hemichannels, and calcium homeostasis modulator 1 (CALHM1) channels. In heterologous expression systems, these channels mediate outwardly rectifying membrane currents with distinct biophysical and pharmacological properties. I therefore tested whether also salt-detecting taste cells were endowed with these currents. To this aim, I applied the patch-clamp techniques to single cells in isolated taste buds from rat fungiform papillae. Salt-detecting cells were functionally identified by exploiting the effect of amiloride, which induces a current response by shutting down ENaCs. I looked for the presence of outwardly rectifying currents by using appropriate voltage-clamp protocols and specific pharmacological tools. I found that indeed salt-detecting cells possessed these currents with properties consistent with the presence, at least in part, of CALHM1 channels. Unexpectedly, CALHM1-like currents in taste cells were potentiated by known blockers of pannexin, suggesting a possible inhibitory action of this protein on CALMH1. These findings indicate that communication between salt-detecting cells and nerve endings might involve ATP release by CALMH1 channels. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. New method for recognition of sterol signalling molecules: Methinium salts as receptors for sulphated steroids

    Czech Academy of Sciences Publication Activity Database

    Kejík, Z.; Bříza, T.; Králová, Jarmila; Mikula, I.; Poučková, P.; Martásek, P.; Král, V.

    2015-01-01

    Roč. 94, February 2015 (2015), s. 15-20 ISSN 1878-5867 R&D Projects: GA TA ČR(CZ) TE01020028; GA ČR(CZ) GAP303/11/1291; GA MŠk(CZ) LH14008; GA MŠk(CZ) CZ.1.07/2.300/30.0060; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : Polymethinium salts * Sulphated sterols * Molecular recognition * Synthetic receptors Subject RIV: EB - Genetics ; Molecular Biology

  12. Acid stimulation (sour taste elicits GABA and serotonin release from mouse taste cells.

    Directory of Open Access Journals (Sweden)

    Yijen A Huang

    Full Text Available Several transmitter candidates including serotonin (5-HT, ATP, and norepinephrine (NE have been identified in taste buds. Recently, γ-aminobutyric acid (GABA as well as the associated synthetic enzymes and receptors have also been identified in taste cells. GABA reduces taste-evoked ATP secretion from Receptor cells and is considered to be an inhibitory transmitter in taste buds. However, to date, the identity of GABAergic taste cells and the specific stimulus for GABA release are not well understood. In the present study, we used genetically-engineered Chinese hamster ovary (CHO cells stably co-expressing GABA(B receptors and Gαqo5 proteins to measure GABA release from isolated taste buds. We recorded robust responses from GABA biosensors when they were positioned against taste buds isolated from mouse circumvallate papillae and the buds were depolarized with KCl or a stimulated with an acid (sour taste. In contrast, a mixture of sweet and bitter taste stimuli did not trigger GABA release. KCl- or acid-evoked GABA secretion from taste buds was Ca(2+-dependent; removing Ca(2+ from the bathing medium eliminated GABA secretion. Finally, we isolated individual taste cells to identify the origin of GABA secretion. GABA was released only from Presynaptic (Type III cells and not from Receptor (Type II cells. Previously, we reported that 5-HT released from Presynaptic cells inhibits taste-evoked ATP secretion. Combined with the recent findings that GABA depresses taste-evoked ATP secretion, the present results indicate that GABA and 5-HT are inhibitory transmitters in mouse taste buds and both likely play an important role in modulating taste responses.

  13. Smell and Taste

    Science.gov (United States)

    ... Gustatory (taste nerve) cells are clustered in the taste buds of the mouth and throat. They react to ... that can be seen on the tongue contain taste buds. These surface cells send taste information to nearby ...

  14. Developing and regenerating a sense of taste.

    Science.gov (United States)

    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.

  15. Intrauterine growth restriction modifies the hedonic response to sweet taste in newborn pups - Role of the accumbal μ-opioid receptors.

    Science.gov (United States)

    Laureano, D P; Dalle Molle, R; Alves, M B; Luft, C; Desai, M; Ross, M G; Silveira, P P

    2016-05-13

    Intrauterine growth restriction (IUGR) is associated with increased preference for palatable foods. The hedonic response to sweet taste, modulated by the nucleus accumbens μ-opioid-receptors, may be involved. We investigated hedonic responses and receptor levels in IUGR and Control animals. From pregnancy day 10, Sprague-Dawley dams received either an ad libitum (Control), or a 50% food restricted (FR) diet. At birth, pups were cross-fostered, and nursed by Adlib fed dams. The hedonic response was evaluated at 1 day after birth and at 90 days of life, by giving sucrose solution or water and analyzing the hedonic facial responses (within 60s). Control pups exposed either to water or sucrose resolved their hedonic responses after 16 and 18s, respectively, while FR hedonic responses to sucrose persisted over 20s. FR pups had deceased phospho-μ-opioid-receptor (p=0.009) and reduced phosphor:total mu opioid receptor ratio compared to controls pups (p=0.003). In adults, there was an interaction between group and solution at the end of the evaluation (p=0.044): Control decreased the response after sucrose solution, FR did not change over time. There were no differences in phosphorylation of μ-opioid-receptor in adults. These results demonstrate IUGR newborn rats exhibit alterations in hedonic response accompanied by a decrease in μ-opioid-receptor phosphorylation, though these alterations do not persist at 3 months of age. Opioid system alterations in early life may contribute to the development of preference for highly palatable foods and contribute to rapid weight gain and obesity in IUGR offspring. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. A targeted genotyping approach enhances identification of variants in taste receptor and appetite/reward genes of potential functional importance for obesity-related porcine traits

    DEFF Research Database (Denmark)

    Cirera, S.; Clop, A.; Jacobsen, M. J.

    2018-01-01

    Taste receptors (TASRs) and appetite and reward (AR) mechanisms influence eating behaviour, which in turn affects food intake and risk of obesity. In a previous study, we used next generation sequencing to identify potentially functional mutations in TASR and AR genes and found indications...... for genetic associations between identified variants and growth and fat deposition in a subgroup of animals (n = 38) from the UNIK resource pig population. This population was created for studying obesity and obesity-related diseases. In the present study we validated results from our previous study...... by investigating genetic associations between 24 selected single nucleotide variants in TASR and AR gene variants and 35 phenotypes describing obesity and metabolism in the entire UNIK population (n = 564). Fifteen variants showed significant association with specific obesity-related phenotypes after Bonferroni...

  17. The Role of Cholecystokinin in Peripheral Taste Signaling in Mice

    Directory of Open Access Journals (Sweden)

    Ryusuke Yoshida

    2017-10-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Yi-ke Li

    2015-01-01

    Full Text Available 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.

  20. Loss of ethanol conditioned taste aversion and motor stimulation in knockin mice with ethanol-insensitive α2-containing GABA(A) receptors.

    Science.gov (United States)

    Blednov, Y A; Borghese, C M; McCracken, M L; Benavidez, J M; Geil, C R; Osterndorff-Kahanek, E; Werner, D F; Iyer, S; Swihart, A; Harrison, N L; Homanics, G E; Harris, R A

    2011-01-01

    GABA type A receptors (GABA(A)-Rs) are potential targets of ethanol. However, there are multiple subtypes of this receptor, and, thus far, individual subunits have not been definitively linked with specific ethanol behavioral actions. Interestingly, though, a chromosomal cluster of four GABA(A)-R subunit genes, including α2 (Gabra2), was associated with human alcoholism (Am J Hum Genet 74:705-714, 2004; Pharmacol Biochem Behav 90:95-104, 2008; J Psychiatr Res 42:184-191, 2008). The goal of our study was to determine the role of receptors containing this subunit in alcohol action. We designed an α2 subunit with serine 270 to histidine and leucine 277 to alanine mutations that was insensitive to potentiation by ethanol yet retained normal GABA sensitivity in a recombinant expression system. Knockin mice containing this mutant subunit were tested in a range of ethanol behavioral tests. These mutant mice did not develop the typical conditioned taste aversion in response to ethanol and showed complete loss of the motor stimulant effects of ethanol. Conversely, they also demonstrated changes in ethanol intake and preference in multiple tests. The knockin mice showed increased ethanol-induced hypnosis but no difference in anxiolytic effects or recovery from acute ethanol-induced motor incoordination. Overall, these studies demonstrate that the effects of ethanol at GABAergic synapses containing the α2 subunit are important for specific behavioral effects of ethanol that may be relevant to the genetic linkage of this subunit with human alcoholism.

  1. Loss of Ethanol Conditioned Taste Aversion and Motor Stimulation in Knockin Mice with Ethanol-Insensitive α2-Containing GABAA Receptors

    Science.gov (United States)

    Borghese, C. M.; McCracken, M. L.; Benavidez, J. M.; Geil, C. R.; Osterndorff-Kahanek, E.; Werner, D. F.; Iyer, S.; Swihart, A.; Harrison, N. L.; Homanics, G. E.; Harris, R. A.

    2011-01-01

    GABA type A receptors (GABAA-Rs) are potential targets of ethanol. However, there are multiple subtypes of this receptor, and, thus far, individual subunits have not been definitively linked with specific ethanol behavioral actions. Interestingly, though, a chromosomal cluster of four GABAA-R subunit genes, including α2 (Gabra2), was associated with human alcoholism (Am J Hum Genet 74:705–714, 2004; Pharmacol Biochem Behav 90:95–104, 2008; J Psychiatr Res 42:184–191, 2008). The goal of our study was to determine the role of receptors containing this subunit in alcohol action. We designed an α2 subunit with serine 270 to histidine and leucine 277 to alanine mutations that was insensitive to potentiation by ethanol yet retained normal GABA sensitivity in a recombinant expression system. Knockin mice containing this mutant subunit were tested in a range of ethanol behavioral tests. These mutant mice did not develop the typical conditioned taste aversion in response to ethanol and showed complete loss of the motor stimulant effects of ethanol. Conversely, they also demonstrated changes in ethanol intake and preference in multiple tests. The knockin mice showed increased ethanol-induced hypnosis but no difference in anxiolytic effects or recovery from acute ethanol-induced motor incoordination. Overall, these studies demonstrate that the effects of ethanol at GABAergic synapses containing the α2 subunit are important for specific behavioral effects of ethanol that may be relevant to the genetic linkage of this subunit with human alcoholism. PMID:20876231

  2. Polycose taste pre-exposure fails to influence behavioral and neural indices of taste novelty.

    Science.gov (United States)

    Barot, Sabiha K; Bernstein, Ilene L

    2005-12-01

    Taste novelty can strongly modulate the speed and efficacy of taste aversion learning. Novel sweet tastes enhance c-Fos-like immunoreactivity (FLI) in the central amygdala and insular cortex. The present studies examined whether this neural correlate of novelty extends to different taste types by measuring FLI signals after exposure to novel and familiar polysaccharide (Polycose) and salt (NaCl) tastes. Novel Polycose not only failed to elevate FLI expression in central amygdala and insular cortex, but also failed to induce stronger taste aversion learning than familiar Polycose. Novel NaCl, on the other hand, showed patterns of FLI activation and aversion learning similar to that of novel sweet tastes. Possible reasons for the resistance of Polycose to typical pre-exposure effects are discussed. Copyright (c) 2006 APA, all rights reserved.

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

    Science.gov (United States)

    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.

  4. Members of Bitter Taste Receptor Cluster Tas2r143/Tas2r135/Tas2r126 Are Expressed in the Epithelium of Murine Airways and Other Non-gustatory Tissues

    Directory of Open Access Journals (Sweden)

    Shuya Liu

    2017-10-01

    Full Text Available The mouse bitter taste receptors Tas2r143, Tas2r135, and Tas2r126 are encoded by genes that cluster on chromosome 6 and have been suggested to be expressed under common regulatory elements. Previous studies indicated that the Tas2r143/Tas2r135/Tas2r126 cluster is expressed in the heart, but other organs had not been systematically analyzed. In order to investigate the expression of this bitter taste receptor gene cluster in non-gustatory tissues, we generated a BAC (bacterial artificial chromosome based transgenic mouse line, expressing CreERT2 under the control of the Tas2r143 promoter. After crossing this line with a mouse line expressing EGFP after Cre-mediated recombination, we were able to validate the Tas2r143-CreERT2 transgenic mouse line and monitor the expression of Tas2r143. EGFP-positive cells, indicating expression of members of the cluster, were found in about 47% of taste buds, and could also be found in several other organs. A population of EGFP-positive cells was identified in thymic epithelial cells, in the lamina propria of the intestine and in vascular smooth muscle cells of cardiac blood vessels. EGFP-positive cells were also identified in the epithelium of organs readily exposed to pathogens including lower airways, the gastrointestinal tract, urethra, vagina, and cervix. With respect to the function of cells expressing this bitter taste receptor cluster, RNA-seq analysis in EGFP-positive cells isolated from the epithelium of trachea and stomach showed expression of genes related to innate immunity. These data further support the concept that bitter taste receptors serve functions outside the gustatory system.

  5. Identification of protein-damaging mutations in 10 swine taste receptors and 191 appetite-reward genes

    DEFF Research Database (Denmark)

    Clop, Alex; Sharaf, Abdoallah; Castelló, Anna

    2016-01-01

    . In the intestine, they regulate nutrient absorption and gut motility. Upon ligand binding, TASRs activate the appetite-reward circuitry to signal the nervous system and keep body homeostasis. With the aim to identify genetic variation in the swine TASRs and in the genes from the appetite and the reward pathways......, we have sequenced the exons of 201 TASRs and appetite-reward genes from 304 pigs belonging to ten breeds, wild boars and to two phenotypically extreme groups from a F2 resource with data on growth and fat deposition. RESULTS: We identified 2,766 coding variants 395 of which were predicted to have...... in the appetite and the reward mechanisms. Some of these genes have been already associated to taste preferences, appetite or behaviour in humans and mouse. We have also detected indications of a potential relationship of some of these genes with growth and fat deposition, which could have been caused by changes...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Taste: The Bedrock of Flavor

    Directory of Open Access Journals (Sweden)

    Gary K Beauchamp

    2014-07-01

    There are two general approaches to reducing dietary sodium. First, there is considerable interest in developing salt substitutes and salt enhancers. Potassium chloride is widely used (usually in combination with NaCl as a substitute but it is not ideal since many find it has an unpleasant off-taste. There is considerable academic and industry research to identify new substitutes but to date there are none for salty as there are for sweet taste. A second approach to lowering sodium intake on a population-wide level in the United States, where more than 80% of the average person’s salt intake comes from food purchased and not from being added during cooking or at the table, is for food manufacturers and restaurants to gradually reduce the amount of salt in prepared foods. Experimental studies have demonstrated that if one reduces salt intake preferences for salt are similarly reduced. Based on this, the Institute of Medicine (IOM recommended that the Food and Drug Administration require gradual reduction by food manufacturers and large restaurant chains (IOM. The FDA has not acted on this recommendation. Conclusion. As illustrated by the difficulties in reducing salt in spite of the health benefits (a similar set of arguments for reducing excess consumption of carbohydrate sugars could be made, the sense of taste is a powerful driver of food intake. A deeper understanding of this important but neglected sensory system is required if we are to adequately address critical health problems in modern society that are often driven by excess consumption of tasty nutrients.

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

    Science.gov (United States)

    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

  10. Inflammation Activates the Interferon Signaling Pathways in Taste Bud Cells

    OpenAIRE

    Wang, Hong; Zhou, Minliang; Brand, Joseph; Huang, Liquan

    2007-01-01

    Patients with viral and bacterial infections or other inflammatory illnesses often experience taste dysfunctions. The agents responsible for these taste disorders are thought to be related to infection-induced inflammation, but the mechanisms are not known. As a first step in characterizing the possible role of inflammation in taste disorders, we report here evidence for the presence of interferon (IFN)-mediated signaling pathways in taste bud cells. IFN receptors, particularly the IFN-γ rece...

  11. 5-HT1A receptor antagonists reduce food intake and body weight by reducing total meals with no conditioned taste aversion.

    Science.gov (United States)

    Dill, M Joelle; Shaw, Janice; Cramer, Jeff; Sindelar, Dana K

    2013-11-01

    Serotonin acts through receptors controlling several physiological functions, including energy homeostasis regulation and food intake. Recent experiments demonstrated that 5-HT1A receptor antagonists reduce food intake. We sought to examine the microstructure of feeding with 5-HT1A receptor antagonists using a food intake monitoring system. We also examined the relationship between food intake, inhibition of binding and pharmacokinetic (PK) profiles of the antagonists. Ex vivo binding revealed that, at doses used in this study to reduce food intake, inhibition of binding of a 5-HT1A agonist by ~40% was reached in diet-induced obese (DIO) mice with a trend for higher binding in DIO vs. lean animals. Additionally, PK analysis detected levels from 2 to 24h post-compound administration. Male DIO mice were administered 5-HT1A receptor antagonists LY439934 (10 or 30 mg/kg, p.o.), WAY100635 (3 or 10mg/kg, s.c.), SRA-333 (10 or 30 mg/kg, p.o.), or NAD-299 (3 or 10mg/kg, s.c.) for 3 days and meal patterns were measured. Analyses revealed that for each antagonist, 24-h food intake was reduced through a specific decrease in the total number of meals. Compared to controls, meal number was decreased 14-35% in the high dose. Average meal size was not changed by any of the compounds. The reduction in food intake reduced body weight 1-4% compared to Vehicle controls. Subsequently, a conditioned taste aversion (CTA) assay was used to determine whether the feeding decrease might be an indicator of aversion, nausea, or visceral illness caused by the antagonists. Using a two bottle preference test, it was found that none of the compounds produced a CTA. The decrease in food intake does not appear to be a response to nausea or malaise. These results indicate that 5-HT1A receptor antagonist suppresses feeding, specifically by decreasing the number of meals, and induce weight loss without an aversive side effect. © 2013 Elsevier Inc. All rights reserved.

  12. Oxytocin signaling in mouse taste buds.

    Directory of Open Access Journals (Sweden)

    Michael S Sinclair

    2010-08-01

    Full Text Available 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

  13. Oxytocin signaling in mouse taste buds.

    Science.gov (United States)

    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

  14. Glutamate: Tastant and Neuromodulator in Taste Buds.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. A targeted genotyping approach enhances identification of variants in taste receptor and appetite/reward genes of potential functional importance for obesity-related porcine traits.

    Science.gov (United States)

    Cirera, S; Clop, A; Jacobsen, M J; Guerin, M; Lesnik, P; Jørgensen, C B; Fredholm, M; Karlskov-Mortensen, P

    2018-04-01

    Taste receptors (TASRs) and appetite and reward (AR) mechanisms influence eating behaviour, which in turn affects food intake and risk of obesity. In a previous study, we used next generation sequencing to identify potentially functional mutations in TASR and AR genes and found indications for genetic associations between identified variants and growth and fat deposition in a subgroup of animals (n = 38) from the UNIK resource pig population. This population was created for studying obesity and obesity-related diseases. In the present study we validated results from our previous study by investigating genetic associations between 24 selected single nucleotide variants in TASR and AR gene variants and 35 phenotypes describing obesity and metabolism in the entire UNIK population (n = 564). Fifteen variants showed significant association with specific obesity-related phenotypes after Bonferroni correction. Six of the 15 genes, namely SIM1, FOS, TAS2R4, TAS2R9, MCHR2 and LEPR, showed good correlation between known biological function and associated phenotype. We verified a genetic association between potentially functional variants in TASR/AR genes and growth/obesity and conclude that the combination of identification of potentially functional variants by next generation sequencing followed by targeted genotyping and association studies is a powerful and cost-effective approach for increasing the power of genetic association studies. © 2018 Stichting International Foundation for Animal Genetics.

  17. Inflammation activates the interferon signaling pathways in taste bud cells.

    Science.gov (United States)

    Wang, Hong; Zhou, Minliang; Brand, Joseph; Huang, Liquan

    2007-10-03

    Patients with viral and bacterial infections or other inflammatory illnesses often experience taste dysfunctions. The agents responsible for these taste disorders are thought to be related to infection-induced inflammation, but the mechanisms are not known. As a first step in characterizing the possible role of inflammation in taste disorders, we report here evidence for the presence of interferon (IFN)-mediated signaling pathways in taste bud cells. IFN receptors, particularly the IFN-gamma receptor IFNGR1, are coexpressed with the taste cell-type markers neuronal cell adhesion molecule and alpha-gustducin, suggesting that both the taste receptor cells and synapse-forming cells in the taste bud can be stimulated by IFN. Incubation of taste bud-containing lingual epithelia with recombinant IFN-alpha and IFN-gamma triggered the IFN-mediated signaling cascades, resulting in the phosphorylation of the downstream STAT1 (signal transducer and activator of transcription protein 1) transcription factor. Intraperitoneal injection of lipopolysaccharide or polyinosinic:polycytidylic acid into mice, mimicking bacterial and viral infections, respectively, altered gene expression patterns in taste bud cells. Furthermore, the systemic administration of either IFN-alpha or IFN-gamma significantly increased the number of taste bud cells undergoing programmed cell death. These findings suggest that bacterial and viral infection-induced IFNs can act directly on taste bud cells, affecting their cellular function in taste transduction, and that IFN-induced apoptosis in taste buds may cause abnormal cell turnover and skew the representation of different taste bud cell types, leading to the development of taste disorders. To our knowledge, this is the first study providing direct evidence that inflammation can affect taste buds through cytokine signaling pathways.

  18. The FERONIA Receptor Kinase Maintains Cell-Wall Integrity during Salt Stress through Ca2+ Signaling.

    Science.gov (United States)

    Feng, Wei; Kita, Daniel; Peaucelle, Alexis; Cartwright, Heather N; Doan, Vinh; Duan, Qiaohong; Liu, Ming-Che; Maman, Jacob; Steinhorst, Leonie; Schmitz-Thom, Ina; Yvon, Robert; Kudla, Jörg; Wu, Hen-Ming; Cheung, Alice Y; Dinneny, José R

    2018-03-05

    Cells maintain integrity despite changes in their mechanical properties elicited during growth and environmental stress. How cells sense their physical state and compensate for cell-wall damage is poorly understood, particularly in plants. Here we report that FERONIA (FER), a plasma-membrane-localized receptor kinase from Arabidopsis, is necessary for the recovery of root growth after exposure to high salinity, a widespread soil stress. The extracellular domain of FER displays tandem regions of homology with malectin, an animal protein known to bind di-glucose in vitro and important for protein quality control in the endoplasmic reticulum. The presence of malectin-like domains in FER and related receptor kinases has led to widespread speculation that they interact with cell-wall polysaccharides and can potentially serve a wall-sensing function. Results reported here show that salinity causes softening of the cell wall and that FER is necessary to sense these defects. When this function is disrupted in the fer mutant, root cells explode dramatically during growth recovery. Similar defects are observed in the mur1 mutant, which disrupts pectin cross-linking. Furthermore, fer cell-wall integrity defects can be rescued by treatment with calcium and borate, which also facilitate pectin cross-linking. Sensing of these salinity-induced wall defects might therefore be a direct consequence of physical interaction between the extracellular domain of FER and pectin. FER-dependent signaling elicits cell-specific calcium transients that maintain cell-wall integrity during salt stress. These results reveal a novel extracellular toxicity of salinity, and identify FER as a sensor of damage to the pectin-associated wall. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Genetic and molecular basis of individual differences in human umami taste perception.

    Directory of Open Access Journals (Sweden)

    Noriatsu Shigemura

    Full Text Available Umami taste (corresponds to savory in English is elicited by L-glutamate, typically as its Na salt (monosodium glutamate: MSG, and is one of five basic taste qualities that plays a key role in intake of amino acids. A particular property of umami is the synergistic potentiation of glutamate by purine nucleotide monophosphates (IMP, GMP. A heterodimer of a G protein coupled receptor, TAS1R1 and TAS1R3, is proposed to function as its receptor. However, little is known about genetic variation of TAS1R1 and TAS1R3 and its potential links with individual differences in umami sensitivity. Here we investigated the association between recognition thresholds for umami substances and genetic variations in human TAS1R1 and TAS1R3, and the functions of TAS1R1/TAS1R3 variants using a heterologous expression system. Our study demonstrated that the TAS1R1-372T creates a more sensitive umami receptor than -372A, while TAS1R3-757C creates a less sensitive one than -757R for MSG and MSG plus IMP, and showed a strong correlation between the recognition thresholds and in vitro dose-response relationships. These results in human studies support the propositions that a TAS1R1/TAS1R3 heterodimer acts as an umami receptor, and that genetic variation in this heterodimer directly affects umami taste sensitivity.

  20. Caffeine taste signaling in Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi A Apostolopoulou

    2016-08-01

    Full Text Available The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal and ventral organ. However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative coreceptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s. This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviours.

  1. Voltage-gated sodium channels in taste bud cells.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. Suplementação com zinco pode recuperar apetite para refeições de sal Zinc supplementation may recover taste for salt meals

    Directory of Open Access Journals (Sweden)

    Dioclécio Campos Jr

    2004-02-01

    Full Text Available OBJETIVO: Avaliar o efeito do zinco em crianças de 8 meses a 5 anos de idade com falta de apetite para refeições de sal. POPULAÇÃO E MÉTODOS: Estudo duplo-cego com placebo. Dois grupos de crianças apresentando recusa a alimentos de sal foram acompanhados durante 6 meses. As crianças do primeiro grupo receberam 1 mg/kg/dia de zinco sob forma de quelato, durante três meses, enquanto as do segundo grupo receberam uma solução placebo durante o mesmo período. Os dois grupos eram semelhantes quanto a idade, sexo, peso, duração do aleitamento materno, idade de desmame e exames hetamatológicos e bioquímicos. A resposta das crianças ao tratamento foi informada em questionário preenchido regularmente pelas mães. RESULTADOS: 17/20 (85% das crianças que receberam zinco e 10/20 (50% das que receberam placebo recuperaram o apetite para refeições de sal. A diferença foi estatisticamente significativa para p OBJECTIVE: To evaluate the effect of zinc on the appetite for salt foods in children aged 8 months to 5 years. METHOD: Double-blind, placebo-controlled study. Two groups of 20 children refusing to eat salt foods were followed during six months. The children in the first group received zinc chelate 1 mg/kg daily for three months. The second group received a placebo solution. The two groups were similar in terms of age, sex, weight, duration of breastfeeding, age at weaning, biochemical and hematological data. The response of children to treatment was informed by their mothers. RESULTS: 17/20 (85% of the children receiving zinc chelate and 10/20 (50% of the children receiving placebo improved their appetite for salt foods. The difference was statistically significant (p < 0.05, chi-square test. CONCLUSION: Zinc supplementation may improve the acceptance of salt foods by children.

  4. Dual Nicotinic Acetylcholine Receptor α4β2 Antagonists/α7 Agonists: Synthesis, Docking Studies, and Pharmacological Evaluation of Tetrahydroisoquinolines and Tetrahydroisoquinolinium Salts

    DEFF Research Database (Denmark)

    Crestey, François; Jensen, Anders A; Soerensen, Christian

    2018-01-01

    We describe the synthesis of tetrahydroisoquinolines and tetrahydroisoquinolinium salts together with their pharmacological properties at various nicotinic acetylcholine receptors. In general, the compounds were α4β2 nAChR antagonists, with the tetrahydroisoquinolinium salts being more potent than...

  5. Sweet Taste Receptor TAS1R2 Polymorphism (Val191Val Is Associated with a Higher Carbohydrate Intake and Hypertriglyceridemia among the Population of West Mexico

    Directory of Open Access Journals (Sweden)

    Omar Ramos-Lopez

    2016-02-01

    Full Text Available Some high-carbohydrate diets may lead to obesity and multiple metabolic disorders, including hypertriglyceridemia (HTG. This lipid abnormality is considered an important risk factor for cardiovascular disease and type 2 diabetes. The sweet taste receptor TAS1R2 polymorphism (Ile191Val has been reported to be associated with carbohydrate intake. The aim of this study was to analyze the association of the TAS1R2 gene polymorphism with carbohydrate intake and HTG among the population of West Mexico. In a cross-sectional study, 441 unrelated subjects were analyzed for TAS1R2 genotypes (Ile/Ile, Ile/Val and Val/Val by an allelic discrimination assay. Biochemical tests and a three-day food record were assessed. The Val/Val genotype carriers had a higher intake of total carbohydrates, fiber and servings of cereals and vegetables than the other genotype carriers. The Val/Val genotype conferred a higher risk for HTG than the Ile/Val and Ile/Ile genotypes (OR = 3.26, 95%CI 1.35–7.86, p = 0.006 and OR = 2.61, 95%CI 1.12–6.07, p = 0.02, respectively. Furthermore, the Val/Val genotype was associated with approximately 30% higher triglycerides compared with Ile/Val and Ile/Ile genotypes (β = 44.09, 95%CI 9.94–78.25, p = 0.01 and β = 45.7, 95%CI 10.85–80.54, p = 0.01, respectively. In conclusion, the Val/Val genotype of TAS1R2 was associated with a higher carbohydrate intake and HTG.

  6. Intracerebroventricular infusion of the (Pro)renin receptor antagonist PRO20 attenuates deoxycorticosterone acetate-salt-induced hypertension.

    Science.gov (United States)

    Li, Wencheng; Sullivan, Michelle N; Zhang, Sheng; Worker, Caleb J; Xiong, Zhenggang; Speth, Robert C; Feng, Yumei

    2015-02-01

    We previously reported that binding of prorenin to the (pro)renin receptor (PRR) plays a major role in brain angiotensin II formation and the development of deoxycorticosterone acetate (DOCA)-salt hypertension. Here, we designed and developed an antagonistic peptide, PRO20, to block prorenin binding to the PRR. Fluorescently labeled PRO20 bound to both mouse and human brain tissues with dissociation constants of 4.4 and 1.8 nmol/L, respectively. This binding was blocked by coincubation with prorenin and was diminished in brains of neuron-specific PRR-knockout mice, indicating specificity of PRO20 for PRR. In cultured human neuroblastoma cells, PRO20 blocked prorenin-induced calcium influx in a concentration- and AT(1) receptor-dependent manner. Intracerebroventricular infusion of PRO20 dose-dependently inhibited prorenin-induced hypertension in C57Bl6/J mice. Furthermore, acute intracerebroventricular infusion of PRO20 reduced blood pressure in both DOCA-salt and genetically hypertensive mice. Chronic intracerebroventricular infusion of PRO20 attenuated the development of hypertension and the increase in brain hypothalamic angiotensin II levels induced by DOCA-salt. In addition, chronic intracerebroventricular infusion of PRO20 improved autonomic function and spontaneous baroreflex sensitivity in mice treated with DOCA-salt. In summary, PRO20 binds to both mouse and human PRRs and decreases angiotensin II formation and hypertension induced by either prorenin or DOCA-salt. Our findings highlight the value of the novel PRR antagonist, PRO20, as a lead compound for a novel class of antihypertensive agents and as a research tool to establish the validity of brain PRR antagonism as a strategy for treating hypertension. © 2014 American Heart Association, Inc.

  7. Glutamate may be an efferent transmitter that elicits inhibition in mouse taste buds.

    Directory of Open Access Journals (Sweden)

    Yijen A Huang

    Full Text Available Recent studies suggest that l-glutamate may be an efferent transmitter released from axons innervating taste buds. In this report, we determined the types of ionotropic synaptic glutamate receptors present on taste cells and that underlie this postulated efferent transmission. We also studied what effect glutamate 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 show that a large fraction of Presynaptic (Type III taste bud cells (∼50% respond to 100 µM glutamate, NMDA, or kainic acid (KA with an increase in intracellular Ca(2+. In contrast, Receptor (Type II taste cells rarely (4% responded to 100 µM glutamate. At this concentration and with these compounds, these agonists activate glutamatergic synaptic receptors, not glutamate taste (umami receptors. Moreover, applying glutamate, NMDA, or KA caused taste buds to secrete 5-HT, a Presynaptic taste cell transmitter, but not ATP, a Receptor cell transmitter. Indeed, glutamate-evoked 5-HT release inhibited taste-evoked ATP secretion. The findings are consistent with a role for glutamate in taste buds as an inhibitory efferent transmitter that acts via ionotropic synaptic glutamate receptors.

  8. Glutamate may be an efferent transmitter that elicits inhibition in mouse taste buds.

    Science.gov (United States)

    Huang, Yijen A; Grant, Jeff; Roper, Stephen

    2012-01-01

    Recent studies suggest that l-glutamate may be an efferent transmitter released from axons innervating taste buds. In this report, we determined the types of ionotropic synaptic glutamate receptors present on taste cells and that underlie this postulated efferent transmission. We also studied what effect glutamate 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 show that a large fraction of Presynaptic (Type III) taste bud cells (∼50%) respond to 100 µM glutamate, NMDA, or kainic acid (KA) with an increase in intracellular Ca(2+). In contrast, Receptor (Type II) taste cells rarely (4%) responded to 100 µM glutamate. At this concentration and with these compounds, these agonists activate glutamatergic synaptic receptors, not glutamate taste (umami) receptors. Moreover, applying glutamate, NMDA, or KA caused taste buds to secrete 5-HT, a Presynaptic taste cell transmitter, but not ATP, a Receptor cell transmitter. Indeed, glutamate-evoked 5-HT release inhibited taste-evoked ATP secretion. The findings are consistent with a role for glutamate in taste buds as an inhibitory efferent transmitter that acts via ionotropic synaptic glutamate receptors.

  9. Peptide regulators of peripheral taste function.

    Science.gov (United States)

    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.

  10. Immunohistochemical Analysis of Human Vallate Taste Buds.

    Science.gov (United States)

    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.

  11. De Gustibus: time scale of loss and recovery of tastes caused by radiotherapy

    International Nuclear Information System (INIS)

    Maes, Annelies; Huygh, Ingrid; Weltens, Caroline; Vandevelde, Guy; Delaere, Pierre; Evers, Georges; Bogaert, Walter van den

    2002-01-01

    Purpose: To quantify the prevalence and distress of taste loss at different intervals after radiotherapy (RT) for head and neck cancer. Materials and methods: In four different groups of head and neck cancer patients (73 patients in total), taste loss and distress due to taste loss were evaluated by taste acuity tests and taste questionnaires. Group 1 (n=17) was analyzed prior to RT. Groups 2 (n=17), 3 (n=17) and 4 (n=22) were at 2, 6 and 12-24 months after treatment, respectively. A cross-sectional analysis was performed between these four groups. Results: Prior to initiation of RT (group 1), partial taste loss was observed in 35, 18 and 6% of patients for bitter, salt and sweet, respectively. At 2 months after RT (group 2), taste loss (partial or total) was seen in 88, 82, 76 and 53% for bitter, salt, sweet and sour, respectively. At 6 months (group 3), partial taste loss was seen in 71, 65, 41 and 41% (bitter, salt, sweet, sour) and after 1-2 years (group 4) in 41, 50, 27 and 27% (bitter, salt, sweet, sour). Distress caused by taste loss was most frequent in group 2 (82%). Conclusions: In this study, loss of taste after RT was found to be most pronounced after 2 months. Bitter and salt qualities were most impaired. Gradual recovery was seen during the first year after treatment. Partial taste loss still persisted 1-2 years after treatment and was responsible for slight to moderate discomfort

  12. Sensibilidade gustativa ao sal, natriúria e pressão arterial em indivíduos normotensos Salt taste threshold, 24 hour natriuresis and blood pressure variation in normotensive individuals

    Directory of Open Access Journals (Sweden)

    Vicente Sperb Antonello

    2007-04-01

    Full Text Available OBJETIVO: O estudo avalia sensibilidade gustativa ao sal, excreção urinária de sódio e pressão arterial (PA em normotensos. A hipótese foi de que limiar de sensibilidade gustativa ao sal (LSGS aumentado se associasse a maior natriúria em 24 horas e níveis aumentados de PA. MÉTODOS: Foram avaliados 24 voluntários sem diagnóstico de HA. Para avaliar LSGS, usou-se soluções de cloreto de sódio (NaCl em diferentes concentrações. Os voluntários foram submetidos à monitorização ambulatorial da pressão arterial (MAPA de 24 horas e coleta de urina de 24 horas para dosagem de sódio (NaU. Para análise, foram agrupados de acordo com o LSGS, aumentado ou normal. RESULTADOS: Os grupos não diferiram para idade, índice de massa corporal (IMC, variáveis demográficas, uso de álcool, fumo e PA. NaU foi significativamente maior no grupo com LSGS aumentado. Utilizando-se o coeficiente de correlação de Pearson, com significância determinada pelo teste t, houve correlação de forte intensidade entre médias de PA sistólica e diastólica com IMC, de regular intensidade entre LSGS e NaU, assim como para PA sistólica e NaU. CONCLUSÃO: Natriúria de 24 horas foi maior em indivíduos com LSGS aumentado, sugerindo que esta maior avidez ao sal determine maior ingestão de sódio. Houve forte associação entre PA e IMC. Não foi evidenciada associação entre LSGS e PA, diferente do já documentado em pacientes com PA aumentada. Aumentando-se o número de pessoas, faixa etária e pacientes com níveis pressóricos aumentados, talvez se respondam outras perguntas a respeito da relação entre LSGS, natriúria e PA.OBJECTIVE: The study evaluates salt taste sensibility, urinary sodium excretion and blood pressure (BP in normotensive persons. The hypothesis was that a higher salt taste threshold (STT can be associated to a higher 24 hour natriuresis and increased BP levels. METHODS: Twenty four not hypertensive volunteers were selected. To

  13. Norepinephrine is coreleased with serotonin in mouse taste buds.

    Science.gov (United States)

    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.

  14. Hepatic farnesoid X-receptor isoforms α2 and α4 differentially modulate bile salt and lipoprotein metabolism in mice.

    Directory of Open Access Journals (Sweden)

    Marije Boesjes

    Full Text Available The nuclear receptor FXR acts as an intracellular bile salt sensor that regulates synthesis and transport of bile salts within their enterohepatic circulation. In addition, FXR is involved in control of a variety of crucial metabolic pathways. Four FXR splice variants are known, i.e. FXRα1-4. Although these isoforms show differences in spatial and temporal expression patterns as well as in transcriptional activity, the physiological relevance hereof has remained elusive. We have evaluated specific roles of hepatic FXRα2 and FXRα4 by stably expressing these isoforms using liver-specific self-complementary adeno-associated viral vectors in total body FXR knock-out mice. The hepatic gene expression profile of the FXR knock-out mice was largely normalized by both isoforms. Yet, differential effects were also apparent; FXRα2 was more effective in reducing elevated HDL levels and transrepressed hepatic expression of Cyp8b1, the regulator of cholate synthesis. The latter coincided with a switch in hydrophobicity of the bile salt pool. Furthermore, FXRα2-transduction caused an increased neutral sterol excretion compared to FXRα4 without affecting intestinal cholesterol absorption. Our data show, for the first time, that hepatic FXRα2 and FXRα4 differentially modulate bile salt and lipoprotein metabolism in mice.

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

    Science.gov (United States)

    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.

  16. Induction of ectopic taste buds by SHH reveals the competency and plasticity of adult lingual epithelium

    Science.gov (United States)

    Castillo, David; Seidel, Kerstin; Salcedo, Ernesto; Ahn, Christina; de Sauvage, Frederic J.; Klein, Ophir D.; Barlow, Linda A.

    2014-01-01

    Taste buds are assemblies of elongated epithelial cells, which are innervated by gustatory nerves that transmit taste information to the brain stem. Taste cells are continuously renewed throughout life via proliferation of epithelial progenitors, but the molecular regulation of this process remains unknown. During embryogenesis, sonic hedgehog (SHH) negatively regulates taste bud patterning, such that inhibition of SHH causes the formation of more and larger taste bud primordia, including in regions of the tongue normally devoid of taste buds. Here, using a Cre-lox system to drive constitutive expression of SHH, we identify the effects of SHH on the lingual epithelium of adult mice. We show that misexpression of SHH transforms lingual epithelial cell fate, such that daughter cells of lingual epithelial progenitors form cell type-replete, onion-shaped taste buds, rather than non-taste, pseudostratified epithelium. These SHH-induced ectopic taste buds are found in regions of the adult tongue previously thought incapable of generating taste organs. The ectopic buds are composed of all taste cell types, including support cells and detectors of sweet, bitter, umami, salt and sour, and recapitulate the molecular differentiation process of endogenous taste buds. In contrast to the well-established nerve dependence of endogenous taste buds, however, ectopic taste buds form independently of both gustatory and somatosensory innervation. As innervation is required for SHH expression by endogenous taste buds, our data suggest that SHH can replace the need for innervation to drive the entire program of taste bud differentiation. PMID:24993944

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

    Directory of Open Access Journals (Sweden)

    Dany Gaillard

    2017-08-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  20. The Importance of G Protein-Coupled Receptor Kinase 4 (GRK4 in Pathogenesis of Salt Sensitivity, Salt Sensitive Hypertension and Response to Antihypertensive Treatment

    Directory of Open Access Journals (Sweden)

    Brian Rayner

    2015-03-01

    Full Text Available Salt sensitivity is probably caused by either a hereditary or acquired defect of salt excretion by the kidney, and it is reasonable to consider that this is the basis for differences in hypertension between black and white people. Dopamine acts in an autocrine/paracrine fashion to promote natriuresis in the proximal tubule and thick ascending loop of Henle. G-protein receptor kinases (or GRKs are serine and threonine kinases that phosphorylate G protein-coupled receptors in response to agonist stimulation and uncouple the dopamine receptor from its G protein. This results in a desensitisation process that protects the cell from repeated agonist exposure. GRK4 activity is increased in spontaneously hypertensive rats, and infusion of GRK4 antisense oligonucleotides attenuates the increase in blood pressure (BP. This functional defect is replicated in the proximal tubule by expression of GRK4 variants namely p.Arg65Leu, p.Ala142Val and p.Val486Ala, in cell lines, with the p.Ala142Val showing the most activity. In humans, GRK4 polymorphisms were shown to be associated with essential hypertension in Australia, BP regulation in young adults, low renin hypertension in Japan and impaired stress-induced Na excretion in normotensive black men. In South Africa, GRK4 polymorphisms are more common in people of African descent, associated with impaired Na excretion in normotensive African people, and predict blood pressure response to Na restriction in African patients with mild to moderate essential hypertension. The therapeutic importance of the GRK4 single nucleotide polymorphisms (SNPs was emphasised in the African American Study of Kidney Disease (AASK where African-Americans with hypertensive nephrosclerosis were randomised to receive amlodipine, ramipril or metoprolol. Men with the p.Ala142Val genotype were less likely to respond to metoprolol, especially if they also had the p.Arg65Leu variant. Furthermore, in the analysis of response to treatment in

  1. Radiation-induced changes in taste acuity in cancer patients

    International Nuclear Information System (INIS)

    Mossman, K.L.; Henkin, R.I.

    1978-01-01

    Changes in taste acuity were measured in 27 patients with various forms of cancer who received radiation to the head and neck region. In 9 of these patients (group I), measurements of taste acuity were made more than 1 year after completion of radiation therapy. In the other 18 patients (group II), taste measurements were made before, during, and approximately 1 month after radiation therapy. Taste acuity was measured for four taste qualities (salt, sweet, sour, and bitter) by a forced choice-three stimulus drop technique which measured detection and recognition thresholds and by a forced scaling technique which measured taste intensity responsiveness. In group II patients, impaired acuity, as indicated by elevated detection and recognition thresholds, was observed approximately 3 weeks after initiation of radiotherapy. The bitter and salt qualities showed the earliest and greatest impairment and the sweet quality the least. Taste intensity responsiveness also was impaired in group II patients. As for thresholds, scaling impairment was most severe for bitter and salt taste qualities. Scaling impairment occurred before changes in either detection or recognition thresholds. Detection and recognition thresholds determined in group I patients also showed salt and bitter qualities were affected more severely than either sweet or sour qualities. Zinc administration to group I patients in an uncontrolled study suggested that zinc therapy may be useful in ameliorating taste impairment in some patients. These results suggest that taste loss may be a factor in the anorexia and weight loss that is observed commonly in patients who have undergone radiation treatment. Correction of this abnormality may be useful in aiding the nutritional status of these patients

  2. 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.

    Science.gov (United States)

    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.

  3. 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*

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Brand Joseph

    2010-06-01

    Full Text Available Abstract Background 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. Results Intraperitoneal injection of LPS rapidly induced expression of several inflammatory cytokines, including tumor necrosis factor (TNF-α, interferon (IFN-γ, and interleukin (IL-6, in mouse circumvallate and foliate papillae. TNF-α and IFN-γ 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

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

    Science.gov (United States)

    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

  6. Accuracy of self-report in detecting taste dysfunction.

    Science.gov (United States)

    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

  7. Taste disorders: A review

    Directory of Open Access Journals (Sweden)

    Vijay Kumar Ambaldhage

    2014-01-01

    Full Text Available For maintenance of the health of an individual, taste sensation is very important. It is an important sensation that serves to assess the nutritious content of food, support oral intake, and prevent ingestion of potentially toxic substances. Disturbances in the perception of taste can lead to loss of appetite, causing malnutrition and thus distressing both the physical and psychological well-being of the patient. Oral physicians are often the first clinicians who hear complaints about alteration in taste from the patients. In spite of the effect of taste changes on health, literature on the diagnosis, pathogenesis, and precise treatment of taste disorders are less. Taste changes may lead patients to seek inappropriate dental treatments. Proper diagnosis of the etiology is the foremost step in the treatment of taste disorders. Thus, it is important that dental clinicians to be familiar with the various causes and proper management of taste changes. In this article, we have reviewed related articles focusing on taste disorders and their management, to provide a quick sketch for the clinicians. A detailed search was performed to identify the systematic reviews and research articles on taste disorders, using PUBMED and Cochrane. All the authors independently extracted data for analysis and review. Ultimately, 26 articles underwent a full text review. In conclusion, the research to date certainly offers us valid management strategies for taste disorders. Meanwhile, practical strategies with the highest success are needed for further intervention.

  8. Taste sensing FET (TSFET)

    Energy Technology Data Exchange (ETDEWEB)

    Toko, K.; Yasuda, R.; Ezaki, S. [Kyushu University, Fukuoka (Japan); Fujiyoshi, T. [Kumamoto University, Kumamoto (Japan). Faculty of Engineering

    1997-12-20

    Taste can be quantified using a multichannel taste sensor with lipid/polymer membranes. Its sensitivity and stability are superior to those of humans. A present study is concerned with the first step of miniaturization and integration of the taste sensor with lipid/polymer membranes using FET. As a result, it was found that gate-source voltage of the taste sensing FET showed the same behaviors as the conventional taste sensor utilizing the membrane-potential change due to five kinds of taste substances. Discrimination of foodstuffs was very easy. A thin lipid membrane formed using LB technique was also tried. These results will open doors to fabrication of a miniaturized, integrated taste sensing system. 12 refs., 6 figs.

  9. Differences in taste between two polyethylene glycol preparations.

    Science.gov (United States)

    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) (pPEG 3350 liked it more, when they tasted it first rather than when they tasted it after PEG 4000 (pPEG 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.

  10. Metallic taste from electrical and chemical stimulation.

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    1990-01-01

    To assess the role of phosphatidylinositol turnover in taste transduction we have visualized, in rat tongue, ATP-dependent endoplasmic reticular accumulation of 45 Ca 2+ , inositol 1,4,5-trisphosphate receptor binding sites, and phosphatidylinositol turnover monitored by autoradiography of [ 3 H]cytidine diphosphate diacylglycerol formed from [ 3 H]cytidine. Accumulated 45 Ca 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 by low concentrations of denatonium, a potently bitter tastant

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. Tachykinins stimulate a subset of mouse taste cells.

    Directory of Open Access Journals (Sweden)

    Jeff Grant

    Full Text Available 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 Ca(2+-imaging on isolated taste cells, it was observed that SP induces Ca(2+ -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 Ca(2+-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 Ca(2+-release from endoplasmic reticulum stores. RT-PCR analysis further confirmed that mouse taste buds express NK-1R and NK-2R. Using Ca(2+-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 Ca(2+ 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.

  15. Role of the ectonucleotidase NTPDase2 in taste bud function.

    Science.gov (United States)

    Vandenbeuch, Aurelie; Anderson, Catherine B; Parnes, Jason; Enjyoji, Keiichi; Robson, Simon C; Finger, Thomas E; Kinnamon, Sue C

    2013-09-03

    Taste buds are unusual in requiring ATP as a transmitter to activate sensory nerve fibers. In response to taste stimuli, taste cells release ATP, activating purinergic receptors containing the P2X2 and P2X3 subunits on taste nerves. In turn, the released ATP is hydrolyzed to ADP by a plasma membrane nucleoside triphosphate previously identified as nucleoside triphosphate diphosphohydrolase-2 (NTPDase2). In this paper we investigate the role of this ectonucleotidase in the function of taste buds by examining gene-targeted Entpd2-null mice globally lacking NTPDase2. RT-PCR confirmed the absence of NTPDase2, and ATPase enzyme histochemistry reveals no reaction product in taste buds of knockout mice, suggesting that NTPDase2 is the dominant form in taste buds. RT-PCR and immunocytochemistry demonstrated that in knockout mice all cell types are present in taste buds, even those cells normally expressing NTPDase2. In addition, the overall number and size of taste buds are normal in Entpd2-null mice. Luciferin/luciferase assays of circumvallate tissue of knockout mice detected elevated levels of extracellular ATP. Electrophysiological recordings from two taste nerves, the chorda tympani and glossopharyngeal, revealed depressed responses to all taste stimuli in Entpd2-null mice. Responses were more depressed in the glossopharyngeal nerve than in the chorda tympani nerve and involved all taste qualities; responses in the chorda tympani were more depressed to sweet and umami stimuli than to other qualities. We suggest that the excessive levels of extracellular ATP in the Entpd2-knockout animals desensitize the P2X receptors associated with nerve fibers, thereby depressing taste responses.

  16. Tasting with Eyes

    Directory of Open Access Journals (Sweden)

    Nobuyuki Sakai

    2011-10-01

    Full Text Available Whenever we eat and drink something, we experience the sense of taste. We attribute the sense of taste to gustation without doubt, but it is not true. The olfaction is the most important component of the flavor. On the other hand, the gustation (basic tastes is affected strongly by the olfaction; when participants tasted solutions containing odors without any tastants, they reported there were some tastes. Odors of the foods and beverages show interaction with (potentiate and/or inhibit basic tastes, and determined the flavor of them. Here, some experiments exploring about the role of the vision in the sense of taste are shown: The color of sushi distorted (enhanced or eliminated the perception of fishy, the color of the packages of chocolate distorted the perception of taste, the color of syrup determined the participants' ability of identification of the flavor, and so on. These results show the vision is an important component of the sense of taste. These visual effects on taste are supposed to be mediated by the olfaction. It is because there are many studies showing the vision affects the olfaction, but studies showing the vision affects gustation are very little and inconsistent with each other.

  17. Texture-taste interactions: Enhancement of taste intensity by structural modifications of the food matrix

    NARCIS (Netherlands)

    Stieger, M.A.

    2011-01-01

    The reduction of salt and sugar in food products remains a challenge due to the importance of those ingredients in providing a highly desired taste quality, enhancing flavor, determining the behavior of structuring ingredients, and ensuring microbiological safety. Several technologies have been used

  18. Leptin Suppresses Mouse Taste Cell Responses to Sweet Compounds.

    Science.gov (United States)

    Yoshida, Ryusuke; Noguchi, Kenshi; Shigemura, Noriatsu; Jyotaki, Masafumi; Takahashi, Ichiro; Margolskee, Robert F; Ninomiya, Yuzo

    2015-11-01

    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. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  19. Optical sensing of sulfate by polymethinium salt receptors: colorimetric sensor for heparin

    Czech Academy of Sciences Publication Activity Database

    Bříza, T.; Kejík, Z.; Císařová, I.; Králová, Jarmila; Martásek, P.; Král, V.

    2008-01-01

    Roč. 16, - (2008), s. 1901-1903 ISSN 1359-7345 R&D Projects: GA AV ČR KAN200200651; GA ČR(CZ) GA203/06/1038 Institutional research plan: CEZ:AV0Z50520514 Keywords : colorimetric sensor * heparin * polymethinium salt Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.340, year: 2008

  20. Physiological responses to taste signals of functional food components.

    Science.gov (United States)

    Narukawa, Masataka

    2018-02-01

    The functions of food have three categories: nutrition, palatability, and bioregulation. As the onset of lifestyle-related diseases has increased, many people have shown interest in functional foods that are beneficial to bioregulation. We believe that functional foods should be highly palatable for increased acceptance from consumers. In order to design functional foods with a high palatability, we have investigated about the palatability, especially in relation to the taste of food. In this review, we discuss (1) the identification of taste receptors that respond to functional food components; (2) an analysis of the peripheral taste transduction system; and (3) the investigation of the relationship between physiological functions and taste signals.

  1. Taste in holon paradigm

    Directory of Open Access Journals (Sweden)

    Klimova G. P.

    2016-07-01

    Full Text Available in this research the authors tried to investigate and generalize theoretic and applied studies of aesthetic taste, as well as, opportunities of its productivity distribution in terms of socio-cultural, person-professional and psychological levels. The article deals with traditional outlooks upon the origin of taste and its relationship with art and its current situation of taste functioning in terms of increasing globalization, virtualization and informatization of modern society.

  2. Video: Taste - no waste

    DEFF Research Database (Denmark)

    Kamuk, Anette; Mortensen, Birthe Kofoed; Mithril, Charlotte Elisabeth

    2017-01-01

    of different foods. In addition, the aim was to create experiences which could show how taste and taste courage are influenced by social interactions and relations. A final aim was to bring awareness of how you can reduce waste with the example of how to use all parts of fruits and vegetables. In total......, approximately 120 children aged 10-12 years participated. In one workshop, children experimented with making juice to explore the basic tastes and worked with the pulp as an example of how to reduce food waste. In another workshop, the children prepared and tasted roasted insects as an example of a future novel...

  3. Abstract: Taste - no waste

    DEFF Research Database (Denmark)

    Mithril, Charlotte Elisabeth; Kamuk, Anette; Hoffmeyer, Agnete

    of different foods. In addition, the aim was to create experiences which could show how taste and taste courage are influenced by social interactions and relations. A final aim was to bring awareness of how you can reduce waste with the example of how to use all parts of fruits and vegetables. In total......, approximately 120 children aged 10-12 years participated. In one workshop, children experimented with making juice to explore the basic tastes and worked with the pulp as an example of how to reduce food waste. In another workshop, the children prepared and tasted roasted insects as an example of a future novel...

  4. Lgr5 Identifies Progenitor Cells Capable of Taste Bud Regeneration after Injury.

    Directory of Open Access Journals (Sweden)

    Norifumi Takeda

    Full Text Available Taste buds are composed of a variety of taste receptor cell types that develop from tongue epithelium and are regularly replenished under normal homeostatic conditions as well as after injury. The characteristics of cells that give rise to regenerating taste buds are poorly understood. Recent studies have suggested that Lgr5 (leucine-rich repeat-containing G-protein coupled receptor 5 identifies taste bud stem cells that contribute to homeostatic regeneration in adult circumvallate and foliate taste papillae, which are located in the posterior region of the tongue. Taste papillae in the adult anterior region of the tongue do not express Lgr5. Here, we confirm and extend these studies by demonstrating that Lgr5 cells give rise to both anterior and posterior taste buds during development, and are capable of regenerating posterior taste buds after injury induced by glossopharyngeal nerve transection.

  5. Lgr5 Identifies Progenitor Cells Capable of Taste Bud Regeneration after Injury.

    Science.gov (United States)

    Takeda, Norifumi; Jain, Rajan; Li, Deqiang; Li, Li; Lu, Min Min; Epstein, Jonathan A

    2013-01-01

    Taste buds are composed of a variety of taste receptor cell types that develop from tongue epithelium and are regularly replenished under normal homeostatic conditions as well as after injury. The characteristics of cells that give rise to regenerating taste buds are poorly understood. Recent studies have suggested that Lgr5 (leucine-rich repeat-containing G-protein coupled receptor 5) identifies taste bud stem cells that contribute to homeostatic regeneration in adult circumvallate and foliate taste papillae, which are located in the posterior region of the tongue. Taste papillae in the adult anterior region of the tongue do not express Lgr5. Here, we confirm and extend these studies by demonstrating that Lgr5 cells give rise to both anterior and posterior taste buds during development, and are capable of regenerating posterior taste buds after injury induced by glossopharyngeal nerve transection.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Bradley T Biggs

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  9. Processing umami and other tastes in mammalian taste buds.

    Science.gov (United States)

    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.

  10. Caenorhabditis elegans response to salt

    NARCIS (Netherlands)

    O.O. Umuerri (Oluwatoroti Omowayewa)

    2012-01-01

    textabstractThis thesis describes my work, where I used genetic methods to identify new genes involved in salt taste in C. elegans. In addition, I used calcium imaging to characterize the cellular response of C. elegans to salt. The thesis is divided into five sections and each section is summarized

  11. Calcium channel blockers, more than diuretics, enhance vascular protective effects of angiotensin receptor blockers in salt-loaded hypertensive rats.

    Directory of Open Access Journals (Sweden)

    Eiichiro Yamamoto

    Full Text Available The combination therapy of an angiotensin receptor blocker (ARB with a calcium channel blocker (CCB or with a diuretic is favorably recommended for the treatment of hypertension. However, the difference between these two combination therapies is unclear. The present work was undertaken to examine the possible difference between the two combination therapies in vascular protection. Salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP were divided into 6 groups, and they were orally administered (1 vehicle, (2 olmesartan, an ARB, (3 azelnidipine, a CCB, (4 hydrochlorothiazide, a diuretic, (5 olmesartan combined with azelnidipine, or (6 olmesartan combined with hydrochlorothiazide. Olmesartan combined with either azelnidipine or hydrochlorothiazide ameliorated vascular endothelial dysfunction and remodeling in SHRSP more than did monotherapy with either agent. However, despite a comparable blood pressure lowering effect between the two treatments, azelnidipine enhanced the amelioration of vascular endothelial dysfunction and remodeling by olmesartan to a greater extent than did hydrochlorothiazide in salt-loaded SHRSP. The increased enhancement by azelnidipine of olmesartan-induced vascular protection than by hydrochlorothiazide was associated with a greater amelioration of vascular nicotinamide adenine dinucleotide phosphate (NADPH oxidase activation, superoxide, mitogen-activated protein kinase activation, and with a greater activation of the Akt/endothelial nitric oxide synthase (eNOS pathway. These results provided the first evidence that a CCB potentiates the vascular protective effects of an ARB in salt-sensitive hypertension, compared with a diuretic, and provided a novel rationale explaining the benefit of the combination therapy with an ARB and a CCB.

  12. An Examination of the Role of L-Glutamate and Inosine 5'-Monophosphate in Hedonic Taste-Guided Behavior by Mice Lacking the T1R1 + T1R3 Receptor.

    Science.gov (United States)

    Blonde, Ginger D; Spector, Alan C

    2017-06-01

    The heterodimeric T1R1 + T1R3 receptor is considered critical for normal signaling of L-glutamate and 5'-ribonucleotides in the oral cavity. However, some taste-guided responsiveness remains in mice lacking one subunit of the receptor, suggesting that other receptors are sufficient to support some behaviors. Here, mice lacking both receptor subunits (KO) and wild-type (WT, both n = 13) mice were tested in a battery of behavioral tests. Mice were trained and tested in gustometers with a concentration series of Maltrin-580, a maltodextrin, in a brief-access test (10-s trials) as a positive control. Similar tests followed with monosodium glutamate (MSG) with and without the ribonucleotide inosine 5'-monophosphate (IMP), but always in the presence of the epithelial sodium channel blocker amiloride (A). Brief-access tests were repeated following short-term (30-min) and long-term (48-h) exposures to MSG + A + IMP and were also conducted with sodium gluconate replacing MSG. Finally, progressive ratio tests were conducted with Maltrin-580 or MSG + A + IMP, to assess appetitive behavior while minimizing satiation. Overall, MSG generated little concentration-dependent responding in either food-restricted WT or KO mice, even in combination with IMP. However, KO mice licked less to the amino acid stimuli, a measure of consummatory behavior in the brief-access tests. In contrast, both groups initiated a similar number of trials and had a similar breakpoint in the progressive ratio task, both measures of appetitive (approach) behavior. Collectively, these results suggest that while the T1R1 + T1R3 receptor is necessary for consummatory responding to MSG (+IMP), other receptors are sufficient to maintain appetitive responding to this "umami" stimulus complex in food-restricted mice. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Voltage-gated sodium channels in taste bud cells

    Directory of Open Access Journals (Sweden)

    Williams Mark E

    2009-03-01

    Full Text Available Abstract Background 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. Results 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. Conclusion 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.

  14. Genome-wide analysis of gene expression in primate taste buds reveals links to diverse processes.

    Directory of Open Access Journals (Sweden)

    Peter Hevezi

    Full Text Available Efforts to unravel the mechanisms underlying taste sensation (gustation have largely focused on rodents. Here we present the first comprehensive characterization of gene expression in primate taste buds. Our findings reveal unique new insights into the biology of taste buds. We generated a taste bud gene expression database using laser capture microdissection (LCM procured fungiform (FG and circumvallate (CV taste buds from primates. We also used LCM to collect the top and bottom portions of CV taste buds. Affymetrix genome wide arrays were used to analyze gene expression in all samples. Known taste receptors are preferentially expressed in the top portion of taste buds. Genes associated with the cell cycle and stem cells are preferentially expressed in the bottom portion of taste buds, suggesting that precursor cells are located there. Several chemokines including CXCL14 and CXCL8 are among the highest expressed genes in taste buds, indicating that immune system related processes are active in taste buds. Several genes expressed specifically in endocrine glands including growth hormone releasing hormone and its receptor are also strongly expressed in taste buds, suggesting a link between metabolism and taste. Cell type-specific expression of transcription factors and signaling molecules involved in cell fate, including KIT, reveals the taste bud as an active site of cell regeneration, differentiation, and development. IKBKAP, a gene mutated in familial dysautonomia, a disease that results in loss of taste buds, is expressed in taste cells that communicate with afferent nerve fibers via synaptic transmission. This database highlights the power of LCM coupled with transcriptional profiling to dissect the molecular composition of normal tissues, represents the most comprehensive molecular analysis of primate taste buds to date, and provides a foundation for further studies in diverse aspects of taste biology.

  15. The PGE(2)-EP4 receptor is necessary for stimulation of the renin-angiotensin-aldosterone system in response to low dietary salt intake in vivo

    DEFF Research Database (Denmark)

    Pöschke, Antje; Kern, Niklas; Maruyama, Takayuki

    2012-01-01

    , creatinine clearance, and plasma antidiuretic hormone (ADH) concentration. Following salt restriction, plasma renin and aldosterone concentrations and kidney renin mRNA level rose significantly in EP4(+/+) but not in EP4(-/-) and in wild-type mice treated with EP4 antagonist ONO-AE3-208. In the latter two...... groups, the low-salt diet caused a significantly greater rise in PGE(2) excretion. Furthermore, mRNA expression for COX-2 and PGE(2) synthetic activity was significantly greater in EP4(-/-) than in EP4(+/+) mice. We conclude that low dietary salt intake induces expression of COX-2 followed by enhanced...... renal PGE(2) synthesis, which stimulates the renin-angiotensin-aldosterone system by activation of EP4 receptor. Most likely, defects at the step of EP4 receptor block negative feedback mechanisms on the renal COX system, leading to persistently high PGE(2) levels, diuresis, and K(+) loss....

  16. Olfaction, taste, and cognition

    National Research Council Canada - National Science Library

    Rouby, Catherine

    2002-01-01

    .... The book is conveniently divided into sections, including linguistic representations, emotion, memory, neural bases, and individual variation. Leading experts have written chapters on many facets of taste and smell, including odor memory, cortical representations, psychophysics and functional imaging studies, genetic variation in taste, and ...

  17. What Are Taste Buds?

    Science.gov (United States)

    ... Sexual Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español What Are Taste Buds? KidsHealth / For Kids / What Are Taste Buds? ...

  18. Flavylium salts as in vitro precursors of potent ligands to brain GABA-A receptors

    DEFF Research Database (Denmark)

    Kueny-Stotz, Marie; Chassaing, Stefan; Brouillard, Raymond

    2008-01-01

    The synthesis of a series of derivatized flavylium cations was undertaken and the affinity to the benzodiazepine binding site of the GABA-A receptor evaluated. The observed high affinity for some derivatives (sub-muM range) was explained by an in vitro transformation of the flavylium cations into...

  19. NMDA receptor activation and PKC but not PKA lead to the modification of the long-term potentiation in the insular cortex induced by conditioned taste aversion: differential role of kinases in metaplasticity.

    Science.gov (United States)

    Rodríguez-Durán, Luis F; Escobar, Martha L

    2014-06-01

    It has been reported that training in behavioral tasks modifies the ability to induce long-term potentiation (LTP) in an N-methyl-D-aspartate receptor (NMDAR)-dependent manner. This receptor leads to calcium entry into neuronal cells, promoting the activation of protein kinases as protein kinase A (PKA) and protein kinase C (PKC), which contribute significantly to the formation of different types of memories and play a pivotal role in the expression of LTP. Our previous studies involving the insular cortex (IC) have demonstrated that induction of LTP in the basolateral amygdaloid nucleus (BLA)-IC projection prior to conditioned taste aversion (CTA) training enhances the retention of this task. Recently, we showed that CTA training triggers a persistent impairment in the ability to induce subsequent synaptic plasticity on the BLA-IC pathway in a protein synthesis-dependent manner, but the underlying molecular mechanisms remain unclear. In the present study we investigated whether the blockade of NMDAR, as well as the inhibition of PKC and PKA affects the CTA-dependent impairment of the IC-LTP. Thus, CTA-trained rats received high frequency stimulation in the Bla-IC projection in order to induce LTP 48 h after the aversion test. The NMDAR antagonist CPP and the specific inhibitors for PKC (chelerythrine) and PKA (KT-5720) were intracortically administered during the acquisition session. Our results show that the blockade of NMDAR and the inhibition of PKC activity prevent the CTA memory-formation as well as the IC-LTP impairment. Nevertheless, PKA inhibition prevents the memory formation of taste aversion but produces no interference with the CTA-dependent impairment of the IC-LTP. These findings reveal the differential roles of protein kinases on CTA-dependent modification of IC-LTP enhancing our understanding of the effects of memory-related changes on synaptic function. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.

  1. A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis.

    Science.gov (United States)

    Lu, Pu; Magwanga, Richard Odongo; Lu, Hejun; Kirungu, Joy Nyangasi; Wei, Yangyang; Dong, Qi; Wang, Xingxing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Kunbo; Liu, Fang

    2018-04-12

    Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs) are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 ( TOM1 ), a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum , 9 in Gossypium arboreum , and 11 in Gossypium raimondii . The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY) values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM) was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H₂O₂. The low malondialdehyde (MDA) level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM) can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress-tolerant cotton

  2. A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis

    Directory of Open Access Journals (Sweden)

    Pu Lu

    2018-04-01

    Full Text Available Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 (TOM1, a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum, 9 in Gossypium arboreum, and 11 in Gossypium raimondii. The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H2O2. The low malondialdehyde (MDA level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress

  3. LCZ696, Angiotensin II Receptor-Neprilysin Inhibitor, Ameliorates High-Salt-Induced Hypertension and Cardiovascular Injury More Than Valsartan Alone.

    Science.gov (United States)

    Kusaka, Hiroaki; Sueta, Daisuke; Koibuchi, Nobutaka; Hasegawa, Yu; Nakagawa, Takashi; Lin, BoWen; Ogawa, Hisao; Kim-Mitsuyama, Shokei

    2015-12-01

    LCZ696, an angiotensin receptor-neprilysin inhibitor, has recently been demonstrated to exert more beneficial effects on hypertensive or heart failure patients than conventional renin-angiotensin system blockers. However, the mechanism underlying the benefit of LCZ696 remains to be understood. The present study was undertaken to examine the effect of LCZ696 compared with valsartan on hypertension and cardiovascular injury. (i) Using telemetry, we compared the hypotensive effect of LCZ696 and valsartan in spontaneously hypertensive rats (SHR) that were fed a high-salt diet followed by a low-salt diet. (ii) We also examined the comparative effect of LCZ696 and valsartan on salt loaded SHRcp, a model of metabolic syndrome. (i) LCZ696 exerted a greater blood pressure (BP) lowering effect than valsartan in SHR regardless of high-salt or low-salt intake. Additive BP reduction by LCZ696 was associated with a significant increase in urinary sodium excretion and sympathetic activity suppression. (ii) LCZ696 significantly ameliorated cardiac hypertrophy and inflammation, coronary arterial remodeling, and vascular endothelial dysfunction in high-salt loaded SHRcp compared with valsartan. LCZ696 caused greater BP reduction than valsartan in SHR regardless of the degree of salt intake, which was associated with a significant enhancement in urinary sodium excretion and sympathetic activity suppression. Furthermore, an additive BP lowering effect of LCZ696 led to greater cardiovascular protection in hypertensive rats. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Late taste disorders in bone marrow transplantation: clinical evaluation with taste solutions in autologous and allogeneic bone marrow recipients.

    Science.gov (United States)

    Marinone, M G; Rizzoni, D; Ferremi, P; Rossi, G; Izzi, T; Brusotti, C

    1991-01-01

    The aim of this work was to determine the type and the significance of taste disorders in allogeneic bone marrow transplanted patients. In a retrospective study the taste threshold of a cohort of 15 allogeneic bone marrow transplanted patients, 4-51 months after transplantation (mean: 30.6 +/- 15.8), was compared to the taste threshold of 8 autologous bone marrow recipients, 4-48 months after transplantation (mean: 24.12 +/- 12.18), and to the taste threshold of a group of 20 consecutive normal subjects. Allogeneic bone marrow transplanted patients showed a significant hypogeusia for salt (Pearson's chi square p = 0.0002; Yates' correction p = 0.0007) and sour (Pearson's chi square p = 0.001; Yates' correction p = 0.008). No significant variations were observed for sweet and bitter. Autologous bone marrow recipients did not show any significant variation of taste acuity for sweet, salt or sour; a constant reduction of the taste threshold for bitter was observed, but the values were not significantly different from normal (Pearson's chi square p = 0.47; Yates' correction p = 0.83). So, late and selective taste disorders are observed in allogeneic bone marrow transplanted patients. Since the severity of the disorders is not strictly related to the severity of chronic oral G.V.H.D., taste analysis could discover the slightest, clinically undetectable cases of chronic oral G.V.H.D. The mechanism of immune aggression on the sensorial taste cells is poorly understood. Further trials are needed to define variations of taste acuity not only after allogeneic bone marrow transplantation, but also in systemic immune diseases.

  5. Evaluation of changes in the taste of cooked meat products during curing using an artificial taste sensor.

    Science.gov (United States)

    Nodake, Kazumasa; Numata, Masahiro; Kosai, Kiichi; Kim, Yun-Jung; Nishiumi, Tadayuki

    2013-08-01

    The purpose of this study was to assess an evaluation method using an artificial taste sensor, in comparison with chemical analysis and sensory evaluation of the taste of meat during curing. Samples of Canadian pork were treated with salt, nitrite and phosphate. Curing time ranged from 0 to 168 h. In the sensory evaluation, there were no significant differences in the all characteristic items at 72-h cured sample compared to the 0-h sample. Some of the characteristic items for the 168-h sample (umami, overall taste, richness and overall palatability) showed significant difference (P meat products. © 2013 Japanese Society of Animal Science.

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

    Science.gov (United States)

    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.

  7. Substance P as a putative efferent transmitter mediates GABAergic inhibition in mouse taste buds.

    Science.gov (United States)

    Huang, Anthony Y; Wu, Sandy Y

    2018-04-01

    Capsaicin-mediated modulation of taste nerve responses is thought to be produced indirectly by the actions of neuropeptides, for example, CGRP and substance P (SP), on taste cells implying they play a role in taste sensitivity. During the processing of gustatory information in taste buds, CGRP shapes peripheral taste signals via serotonergic signalling. The underlying assumption has been that SP exerts its effects on taste transmitter secretion in taste buds of mice. To test this assumption, we investigated the net effect of SP on taste-evoked ATP secretion from mouse taste buds, using functional calcium imaging with CHO cells expressing high-affinity transmitter receptors as cellular biosensors. Our results showed that SP elicited PLC activation-dependent intracellular Ca 2+ transients in taste cells via neurokinin 1 receptors, most likely on glutamate-aspartate transporter-expressing Type I cells. Furthermore, SP caused Type I cells to secrete GABA. Combined with the recent findings that GABA depresses taste-evoked ATP secretion, the current results indicate that SP elicited secretion of GABA, which provided negative feedback onto Type II (receptor) cells to reduce taste-evoked ATP secretion. These findings are consistent with a role for SP as an inhibitory transmitter that shapes the peripheral taste signals, via GABAergic signalling, during the processing of gustatory information in taste buds. Notably, the results suggest that SP is intimately associated with GABA in mammalian taste signal processing and demonstrate an unanticipated route for sensory information flow within the taste bud. © 2018 The British Pharmacological Society.

  8. Gli3 is a negative regulator of Tas1r3-expressing taste cells

    Science.gov (United States)

    Jyotaki, Masafumi; Redding, Kevin; Jiang, Peihua

    2018-01-01

    Mouse taste receptor cells survive from 3–24 days, necessitating their regeneration throughout adulthood. In anterior tongue, sonic hedgehog (SHH), released by a subpopulation of basal taste cells, regulates transcription factors Gli2 and Gli3 in stem cells to control taste cell regeneration. Using single-cell RNA-Seq we found that Gli3 is highly expressed in Tas1r3-expressing taste receptor cells and Lgr5+ taste stem cells in posterior tongue. By PCR and immunohistochemistry we found that Gli3 was expressed in taste buds in all taste fields. Conditional knockout mice lacking Gli3 in the posterior tongue (Gli3CKO) had larger taste buds containing more taste cells than did control wild-type (Gli3WT) mice. In comparison to wild-type mice, Gli3CKO mice had more Lgr5+ and Tas1r3+ cells, but fewer type III cells. Similar changes were observed ex vivo in Gli3CKO taste organoids cultured from Lgr5+ taste stem cells. Further, the expression of several taste marker and Gli3 target genes was altered in Gli3CKO mice and/or organoids. Mirroring these changes, Gli3CKO mice had increased lick responses to sweet and umami stimuli, decreased lick responses to bitter and sour taste stimuli, and increased glossopharyngeal taste nerve responses to sweet and bitter compounds. Our results indicate that Gli3 is a suppressor of stem cell proliferation that affects the number and function of mature taste cells, especially Tas1r3+ cells, in adult posterior tongue. Our findings shed light on the role of the Shh pathway in adult taste cell regeneration and may help devise strategies for treating taste distortions from chemotherapy and aging. PMID:29415007

  9. Drugs and taste aversion

    International Nuclear Information System (INIS)

    Rondeau, D.B.; Jolicoeur, F.B.; Merkel, A.D.; Wayner, M.J.

    1981-01-01

    The literature on the effects of drugs on the acquisition and the magnitude of taste aversion is reviewed and discussed. Then, the results of a series of experiments on the effects of phenobarbital and related drugs on taste aversion are reported. A standard taste aversion model was used in all experiments; test drugs were injected prior to drinking in a one bottle situation on the first test day following the taste aversion treatment. Phenobarbital in doses ranging from 20 to 80 mg/kg significantly attenuated taste aversion induced by lithium chloride (LiCl) and x-radiation, the maximal effect occurred with the 60 mg/kg dose. The attenuating effect was found to be dependent upon the magnitude of the aversion to the sapid solution. Phenobarbital completely abolished aversion produced by 0.375 mEq LiCl while the attenuation effect decreased linearly with higher doses of LiCl. Results also indicate that phenobarbital's attenuating effect cannot be solely attributed to its dipsogenic characteristic or to its state dependent learning effect. Attenuation of LiCl aversion to a saccharin solution was also observed following single doses of amobarbital, 30 mg/kg, pentobarbital, 15 mg/kg, and chloropromazine, 0.75 mg/kg. Taste aversion was not affected by other doses of those drugs or by hexobarbital, barbital, and chlordiazepoxide. Phenobarbital's attenuating effect on taste aversion is discussed in relation to other known behavioral and neurophysiological effects of the drug

  10. Modulation of taste responsiveness by the satiation hormone peptide YY

    Science.gov (United States)

    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

  11. What is taste and how do we teach taste?

    DEFF Research Database (Denmark)

    Wistoft, Karen; Qvortrup, Lars

    2017-01-01

    students to learn about taste. This section presents a systematic division of taste into its four main dimensions: The dimension of good taste, the dimension of healthy taste, the dimension of perceived taste, and the dimension of moral taste. The second section comprises taste as an instrument of teaching....... Here, the intention is to use ‘taste’ as a means to teach home economics and food education. This section answers the question of how to teach in a way that enables the students to develop knowledge and skills in relation to the four dimensions of taste. In this section four knowledge types...... and argument forms are presented, each related to one of the four taste dimensions, because they provide a basis for structuring an appropriate curriculum of taste. The final aim is to enable students to make well-reasoned food decisions with ‘taste’ as the compass of judgment....

  12. Taste, terroir, and technology

    Directory of Open Access Journals (Sweden)

    Pinder RM

    2016-03-01

    Full Text Available Roger M PinderInternational Journal of Wine Research, York, UKWine drinkers have long acknowledged the link between taste and terroir, the often unmistakable connection between the flavor of a wine and the particular patch of ground in which the vines were grown. But the science behind the connection, indeed the whole concept of taste and terroir, has long been disputed. New technological developments in both "neuroenology" – how the brain creates the taste of wine1 – and in wine chemistry2 have offered more insight into the science.

  13. Evolution of taste and solitary chemoreceptor cell systems.

    Science.gov (United States)

    Finger, T E

    1997-01-01

    Vertebrates possess four distinct chemosensory systems distinguishable on the basis of structure, innervation and utilization: olfaction, taste, solitary chemoreceptor cells (SCC) and the common chemical sense (free nerve endings). Of these, taste and the SCC sense rely on secondary receptor cells situated in the epidermis and synapsing on sensory nerve fibers innervating them near their base. The SCC sense occurs in anamniote aquatic craniates, including hagfish, and may be used for feeding or predator avoidance. The sense of taste occurs only in vertebrates and is always utilized for feeding. The SCC system achieves a high degree of specialization in two teleosts: sea robins (Prionotus) and rocklings (Ciliata). In sea robins, SCCs are abundant on the three anterior fin rays of the pectoral fin which are free of fin webbing and are used in active exploration of the substrate. Behavioral and physiological studies show that this SCC system responds to feeding cues and drives feeding behavior. It is connected centrally like a somatosensory system. In contrast, the specialized SCC system of rocklings occurs on the anterior dorsal fin which actively samples the surrounding water. This system responds to mucus substances and may serve as a predator detector. The SCC system in rocklings is connected centrally like a gustatory system. Taste buds contain multiple receptor cell types, including a serotonergic Merkel-like cell. Taste receptor cells respond to nutritionally relevant substances. Due to similarities between SCCs and one type of taste receptor cell, the suggestion is made that taste buds may be compound sensory organs that include some cells related to SCCs and others related to cutaneous Merkel cells. The lack of taste buds in hagfish and their presence in all vertebrates may indicate that the phylogenetic development of taste buds coincided with the elaboration of head structures at the craniate-vertebrate transition.

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

    Science.gov (United States)

    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.

  15. Taste bud development and patterning in sighted and blind morphs of Astyanax mexicanus.

    Science.gov (United States)

    Varatharasan, Nirupa; Croll, Roger P; Franz-Odendaal, Tamara

    2009-12-01

    In the blind cave-dwelling morph of A. mexicanus, the eye degenerates while other sensory systems, such as gustation, are expanded compared to their sighted (surface-dwelling) ancestor. This study compares the development of taste buds along the jaws of each morph. To determine whether cavefish have an altered onset or rate of taste bud development, we fluorescently labeled basal and receptor cells within taste buds over a developmental series. Our results show that taste bud number increases during development in both morphs. The rate of development is, however, accelerated in cavefish; a small difference in taste bud number exists at 5 dpf reaching threefold by 22 dpf. The expansion of taste buds in cavefish is, therefore, detectable after the onset of eye degeneration. This study provides important insights into the timing of taste bud expansion in cavefish as well as enhances our understanding of taste bud development in teleosts in general. (c) 2009 Wiley-Liss, Inc.

  16. Tasting Pseudomonas aeruginosa biofilms.Human neutrophils express the bitter receptor T2R38 as sensor for the quorum sensing molecule N-(3-oxododecanoyl-L-homoserine lactone

    Directory of Open Access Journals (Sweden)

    Susanne eMaurer

    2015-07-01

    Full Text Available Bacteria communicate with each other via specialized signalling molecules, known as quorum sensing molecules or autoinducers. The Pseudomonas aeruginosa-derived quorum sensing molecule N-(3-oxododecanoyl-L-homoserine lactone (AHL-12, however, also activates mammalian cells. As shown previously, AHL-12 induced chemotaxis, up-regulated CD11b expression, and enhanced phagocytosis of polymorphonuclear neutrophils (PMN. Circumstantial evidence concurred with a receptor for AHL-12, which so far has been elusive. We investigated the bitter receptor T2R38 as a potential candidate. Although identified as a taste receptor, cells outside the gustatory system express T2R38, for example epithelial cells in the lung. We now detected T2R38 in peripheral blood neutrophils, monocytes and lymphocytes on the cell membrane, but also intracellular. In neutrophils, T2R38 was located in vesicles with characteristics of lipid droplets, and super-resolution microscopy showed a co-localisation with the lipid droplet membrane. Neutrophils take up AHL-12, and it co-localized with T2R38 as seen by laser scan microscopy. Binding of AHL-12 to T2R28 was confirmed by pull-down assays using biotin-coupled AHL-12 as bait. A commercially available antibody to T2R38 inhibited binding of AHL-12 to neutrophils, and this antibody by itself stimulated neutrophils, similarly to AHL-12. In conclusion, our data provide evidence for expression of functional T2R38 on neutrophils, and are compatible with the notion that T2R38 is the receptor for AHL-12 on neutrophils.

  17. Taste didactic reflection theory

    DEFF Research Database (Denmark)

    Wistoft, Karen; Qvortrup, Lars

    and gastrophysicists), and social sciences (anthropologists) as well as educators (preschool, elementary, secondary and vocational schools, colleges and universities) and chefs. Through interdisciplinary research collaboration and communication we attempt to span the perceived chasm separating food-sensory science......, high schools and vocational educations. By integrating research, taste, learning, didactics and communication, our projects focus on three main areas: sensory sciences and didactics; gastrophysics and the integration of scientific disciplines; and innovation and honing of culinary skills. While we...... teach pupils, students and the broader public in educational institutions and festivals about and through taste, we also study their use of taste, taste preferences, and learning processes by gathering empirical data for anthropological, sensory and pedagogical research. At the conference, we wish...

  18. Smelling and Tasting Underwater.

    Science.gov (United States)

    Atema, Jelle

    1980-01-01

    Discusses differences between smell and taste, comparing these senses in organisms in aquatic and terrestrial environments. Describes the chemical environment underwater and in air, differences in chemoreceptors to receive stimuli, and the organs, brain, and behavior involved in chemoreception. (CS)

  19. Taste as feeling

    OpenAIRE

    Highmore, Ben

    2016-01-01

    This article is premised on two presumptions. The first is, I think, uncontroversial, the second less so. The first presumption is that today, serious discussions about taste usually start out by rehearsing Pierre Bourdieu’s contribution to our understanding of how taste preferences operate in society. This, then, is merely to recognize that when Bourdieu first published books such as The Love of Art (1969, written with Alain Darbel) and Distinctions: A Social Critique of the Judgement of Tas...

  20. Taste perception, associated hormonal modulation, and nutrient intake

    Science.gov (United States)

    Loper, Hillary B.; La Sala, Michael; Dotson, Cedrick

    2015-01-01

    It is well known that taste perception influences food intake. After ingestion, gustatory receptors relay sensory signals to the brain, which segregates, evaluates, and distinguishes the stimuli, leading to the experience known as “flavor.” It is well accepted that five taste qualities – sweet, salty, bitter, sour, and umami – can be perceived by animals. In this review, the anatomy and physiology of human taste buds, the hormonal modulation of taste function, the importance of genetic chemosensory variation, and the influence of gustatory functioning on macronutrient selection and eating behavior are discussed. Individual genotypic variation results in specific phenotypes of food preference and nutrient intake. Understanding the role of taste in food selection and ingestive behavior is important for expanding our understanding of the factors involved in body weight maintenance and the risk of chronic diseases including obesity, atherosclerosis, cancer, diabetes, liver disease, and hypertension. PMID:26024495

  1. Neural modulation of salt secretion in teleostopercular epithelium by 2-adrenergic receptors and inositol 1,4,5-trisphosphate

    Science.gov (United States)

    Marshall; Duquesnay; Gillis; Bryson; Liedtke

    1998-05-21

    Opercular epithelia from seawater-adapted killifish (Fundulus heteroclitus) were dissected with the nerve intact, mounted in Ussing-style membrane chambers and bathed in symmetrical saline solutions. Nerve stimulation rapidly inhibited transepithelial current (a measure of Cl- secretion rate) by 27.3+/-3.3 % (N=22), and the effect could be sustained for more than 10 min using intermittent pulse trains at 10 Hz. The effect was blocked in a dose-dependent manner by yohimbine, but not by propranolol, atropine or tubocurarine, indicating mediation by 2-adrenergic receptors. The effect was also present, but significantly diminished, in opercular membranes from animals that had been transferred to sea water for 48 h (18+/-8.6 % inhibition, N=14). The resting current and the effect were absent in membranes from freshwater-adapted animals. The addition of clonidine (1.0 micromol l-1 serosal side) started to inhibit Cl- current after 40-60 s; immediately before this, at 30 s, there was a significant rise (Plevel, but no change at later times, compared with LiCl-treated control membranes and measured by radiolabeled receptor assay. The results indicate that seawater-adapted killifish can decrease their Cl- secretion rate through the action of the sympathetic nervous system, a response appropriate for the entry of estuarine fish to fresh water, and that the effect is mediated by 2-adrenoceptors via InsP3. The results imply that euryhaline fish entering fresh water can undergo an autonomic reflex reduction in salt secretion that does not require a stress response.

  2. Induction of ectopic taste buds by SHH reveals the competency and plasticity of adult lingual epithelium.

    Science.gov (United States)

    Castillo, David; Seidel, Kerstin; Salcedo, Ernesto; Ahn, Christina; de Sauvage, Frederic J; Klein, Ophir D; Barlow, Linda A

    2014-08-01

    Taste buds are assemblies of elongated epithelial cells, which are innervated by gustatory nerves that transmit taste information to the brain stem. Taste cells are continuously renewed throughout life via proliferation of epithelial progenitors, but the molecular regulation of this process remains unknown. During embryogenesis, sonic hedgehog (SHH) negatively regulates taste bud patterning, such that inhibition of SHH causes the formation of more and larger taste bud primordia, including in regions of the tongue normally devoid of taste buds. Here, using a Cre-lox system to drive constitutive expression of SHH, we identify the effects of SHH on the lingual epithelium of adult mice. We show that misexpression of SHH transforms lingual epithelial cell fate, such that daughter cells of lingual epithelial progenitors form cell type-replete, onion-shaped taste buds, rather than non-taste, pseudostratified epithelium. These SHH-induced ectopic taste buds are found in regions of the adult tongue previously thought incapable of generating taste organs. The ectopic buds are composed of all taste cell types, including support cells and detectors of sweet, bitter, umami, salt and sour, and recapitulate the molecular differentiation process of endogenous taste buds. In contrast to the well-established nerve dependence of endogenous taste buds, however, ectopic taste buds form independently of both gustatory and somatosensory innervation. As innervation is required for SHH expression by endogenous taste buds, our data suggest that SHH can replace the need for innervation to drive the entire program of taste bud differentiation. © 2014. Published by The Company of Biologists Ltd.

  3. Leptin's effect on taste bud calcium responses and transmitter secretion.

    Science.gov (United States)

    Meredith, Tricia L; Corcoran, Alan; Roper, Stephen D

    2015-05-01

    Leptin, a peptide hormone released by adipose tissue, acts on the hypothalamus to control cravings and appetite. Leptin also acts to decrease taste responses to sweet substances, though there is little detailed information regarding where leptin acts in the taste transduction cascade. The present study examined the effects of leptin on sweet-evoked responses and neuro transmitter release from isolated taste buds. Our results indicate that leptin moderately decreased sweet-evoked calcium mobilization in isolated mouse taste buds. We also employed Chinese hamster ovary biosensor cells to examine taste transmitter release from isolated taste buds. Leptin reduced ATP and increased serotonin release in response to sweet stimulation. However, leptin has no effect on bitter-evoked transmitter release, further showing that the action of leptin is sweet specific. Our results support those of previous studies, which state that leptin acts on taste tissue via the leptin receptor, most likely on Type II (Receptor) cells, but also possibly on Type III (Presynaptic) cells. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Association between Salivary Leptin Levels and Taste Perception in Children

    Directory of Open Access Journals (Sweden)

    Lénia Rodrigues

    2017-01-01

    Full Text Available The satiety inducing hormone leptin acts not only at central nervous system but also at peripheral level. Leptin receptors are found in several sense related organs, including the mouth. A role of leptin in sweet taste response has been suggested but, until now, studies have been based on in vitro experiments, or in assessing the levels of the hormone in circulation. The present study investigated whether the levels of leptin in saliva are related to taste perception in children and whether Body Mass Index (BMI affects such relationship. Sweet and bitter taste sensitivity was assessed for 121 children aged 9-10 years and unstimulated whole saliva was collected for leptin quantification, using ELISA technique. Children females with lower sweet taste sensitivity presented higher salivary leptin levels, but this is only in the normal weight ones. For bitter taste, association between salivary leptin and caffeine threshold detection was observed only in preobese boys, with higher levels of salivary hormone in low sensitive individuals. This study is the first presenting evidences of a relationship between salivary leptin levels and taste perception, which is sex and BMI dependent. The mode of action of salivary leptin at taste receptor level should be elucidated in future studies.

  5. Lipid-Lowering Pharmaceutical Clofibrate Inhibits Human Sweet Taste

    OpenAIRE

    Kochem, Matthew; Breslin, Paul A.S.

    2016-01-01

    T1R2-T1R3 is a heteromeric receptor that binds sugars, high potency sweeteners, and sweet taste blockers. In rodents, T1R2-T1R3 is largely responsible for transducing sweet taste perception. T1R2-T1R3 is also expressed in non-taste tissues, and a growing body of evidence suggests that it helps regulate glucose and lipid metabolism. It was previously shown that clofibric acid, a blood lipid-lowering drug, binds T1R2-T1R3 and inhibits its activity in vitro. The purpose of this study was to dete...

  6. Glucagon-like peptide-1 is specifically involved in sweet taste transmission.

    Science.gov (United States)

    Takai, Shingo; Yasumatsu, Keiko; Inoue, Mayuko; Iwata, Shusuke; Yoshida, Ryusuke; Shigemura, Noriatsu; Yanagawa, Yuchio; Drucker, Daniel J; Margolskee, Robert F; Ninomiya, Yuzo

    2015-06-01

    Five fundamental taste qualities (sweet, bitter, salty, sour, umami) are sensed by dedicated taste cells (TCs) that relay quality information to gustatory nerve fibers. In peripheral taste signaling pathways, ATP has been identified as a functional neurotransmitter, but it remains to be determined how specificity of different taste qualities is maintained across synapses. Recent studies demonstrated that some gut peptides are released from taste buds by prolonged application of particular taste stimuli, suggesting their potential involvement in taste information coding. In this study, we focused on the function of glucagon-like peptide-1 (GLP-1) in initial responses to taste stimulation. GLP-1 receptor (GLP-1R) null mice had reduced neural and behavioral responses specifically to sweet compounds compared to wild-type (WT) mice. Some sweet responsive TCs expressed GLP-1 and its receptors were expressed in gustatory neurons. GLP-1 was released immediately from taste bud cells in response to sweet compounds but not to other taste stimuli. Intravenous administration of GLP-1 elicited transient responses in a subset of sweet-sensitive gustatory nerve fibers but did not affect other types of fibers, and this response was suppressed by pre-administration of the GLP-1R antagonist Exendin-4(3-39). Thus GLP-1 may be involved in normal sweet taste signal transmission in mice. © FASEB.

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

    Science.gov (United States)

    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.

  8. Processing Umami and Other Tastes in Mammalian Taste Buds

    OpenAIRE

    Roper, Stephen D.; Chaudhari, Nirupa

    2009-01-01

    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 potentia...

  9. Tasting in mundane practices

    DEFF Research Database (Denmark)

    Mann, Anna

    2015-01-01

    This thesis presents an ethnographic investigation into practices of tasting. Based on ethnographic fieldwork in various Western Europe settings in which people sensually engaged with food and drinks, the chapters show how tasting is done by research subjects in sensory science laboratories; guests...... response to a food object, leading on to a multi-sensory experience of its qualities, that do not just emerge from the food but are co-shaped by the context and that give rise to sensorial knowledge. By investigating specificities, articulating alternatives, showing construction processes, and typecasting...... particular practices, the chapters unpack each of these assumptions. What emerges is an alternative, composite understanding of tasting as variously done in varied mundane practices....

  10. Mechanisms of taste bud cell loss after head and neck irradiation.

    Science.gov (United States)

    Nguyen, Ha M; Reyland, Mary E; Barlow, Linda A

    2012-03-07

    Taste loss in human patients following radiotherapy for head and neck cancer is a common and significant problem, but the cellular mechanisms underlying this loss are not understood. Taste stimuli are transduced by receptor cells within taste buds, and like epidermal cells, taste cells are regularly replaced throughout adult life. This renewal relies on progenitor cells adjacent to taste buds, which continually supply new cells to each bud. Here we treated adult mice with a single 8 Gy dose of x-ray irradiation to the head and neck, and analyzed taste epithelium at 1-21 d postirradiation (dpi). We found irradiation targets the taste progenitor cells, which undergo cell cycle arrest (1-3 dpi) and apoptosis (within 1 dpi). Taste progenitors resume proliferation at 5-7 dpi, with the proportion of cells in S and M phase exceeding control levels at 5-6 and 6 dpi, respectively, suggesting that proliferation is accelerated and/or synchronized following radiation damage. Using 5-bromo-2-deoxyuridine birthdating to identify newborn cells, we found that the decreased proliferation following irradiation reduces the influx of cells at 1-2 dpi, while the robust proliferation detected at 6 dpi accelerates entry of new cells into taste buds. In contrast, the number of differentiated taste cells was not significantly reduced until 7 dpi. These data suggest a model where continued natural taste cell death, paired with temporary interruption of cell replacement, underlies taste loss after irradiation.

  11. Mechanisms of taste bud cell loss after head and neck irradiation

    Science.gov (United States)

    Nguyen, Ha M.; Reyland, Mary E.; Barlow, Linda A.

    2012-01-01

    Taste loss in human patients following radiotherapy for head and neck cancer is a common and significant problem, but the cellular mechanisms underlying this loss are not understood. Taste stimuli are transduced by receptor cells within taste buds, and like epidermal cells, taste cells are regularly replaced throughout adult life. This renewal relies on a progenitor cells adjacent to taste buds, which continually supply new cells to each bud. Here we treated adult mice with a single 8 Gy dose of X-ray irradiation to the head and neck, and analyzed taste epithelium at 1–21 days post-irradiation (dpi). We found irradiation targets the taste progenitor cells, which undergo cell cycle arrest (1–3 dpi) and apoptosis (within 1 dpi). Taste progenitors resume proliferation at 5–7 dpi, with the proportion of cells in S and M phase exceeding control levels at 5–6 and 6 dpi, respectively, suggesting that proliferation is accelerated and/or synchronized following radiation damage. Using BrdU birthdating to identify newborn cells, we found that the decreased proliferation following irradiation reduces the influx of cells at 1–2 dpi, while the robust proliferation detected at 6 dpi accelerates entry of new cells into taste buds. By contrast, the number of differentiated taste cells was not significantly reduced until 7 dpi. These data suggest a model where continued natural taste cell death, paired with temporary interruption of cell replacement underlies taste loss after irradiation. PMID:22399770

  12. Mixing methods, tasting fingers

    DEFF Research Database (Denmark)

    Mann, Anna; Mol, Annemarie; Satalkar, Priya

    2011-01-01

    This article reports on an ethnographic experiment. Four finger eating experts and three novices sat down for a hot meal and ate with their hands. Drawing on the technique of playing with the familiar and the strange, our aim was not to explain our responses, but to articulate them. As we seek...... words to do so, we are compelled to stretch the verb "to taste." Tasting, or so our ethnographic experiment suggests, need not be understood as an activity confined to the tongue. Instead, if given a chance, it may viscously spread out to the fingers and come to include appreciative reactions otherwise...

  13. Is wine savory? Umami taste in wine

    OpenAIRE

    Alice, Vilela; António, Inês; Fernanda, Cosme

    2016-01-01

    Umami is an important taste element in natural products like wine. The umami taste has distinctive properties that differentiate it from other tastes, including a taste-enhancing synergism between two umami compounds, L-glutamate and 5’-ribonulceotides, and a prolonged aftertaste. In human taste cells, taste buds transduce the chemicals that elicit the umami tastes into membrane depolarization, which triggers release of transmitter to activate gustatory afferent nerve fibers. Umami taste stim...

  14. Genetics of sweet taste preferences†

    OpenAIRE

    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 sign...

  15. Molecular and cellular organization of taste neurons in adult Drosophila pharynx

    Science.gov (United States)

    Chen, Yu-Chieh (David); Dahanukar, Anupama

    2017-01-01

    SUMMARY The Drosophila pharyngeal taste organs are poorly characterized despite their location at important sites for monitoring food quality. Functional analysis of pharyngeal neurons has been hindered by the paucity of molecular tools to manipulate them, as well as their relative inaccessibility for neurophysiological investigations. Here, we generate receptor-to-neuron maps of all three pharyngeal taste organs by performing a comprehensive chemoreceptor-GAL4/LexA expression analysis. The organization of pharyngeal neurons reveals similarities and distinctions in receptor repertoires and neuronal groupings compared to external taste neurons. We validate the mapping results by pinpointing a single pharyngeal neuron required for feeding avoidance of L-canavanine. Inducible activation of pharyngeal taste neurons reveals functional differences between external and internal taste neurons and functional subdivision within pharyngeal sweet neurons. Our results provide road maps of pharyngeal taste organs in an insect model system for probing the role of these understudied neurons in controlling feeding behaviors. PMID:29212040

  16. NaCl responsive taste cells in the mouse fungiform taste buds.

    Science.gov (United States)

    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.

  17. Functional cell types in taste buds have distinct longevities.

    Directory of Open Access Journals (Sweden)

    Isabel Perea-Martinez

    Full Text Available 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.

  18. Functional cell types in taste buds have distinct longevities.

    Science.gov (United States)

    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.

  19. Sweet taste disorder and vascular complications in patients with abnormal glucose tolerance.

    Science.gov (United States)

    Tsujimoto, Tetsuro; Imai, Kenjiro; Kanda, Sayaka; Kakei, Masafumi; Kajio, Hiroshi; Sugiyama, Takehiro

    2016-10-15

    It remains unknown whether taste disorders can be a risk factor for micro- and macro-vascular diseases in patients with abnormal glucose tolerance. A cross-sectional study in a nationally representative samples of 848 and 849 US adults (aged ≥40years) with diabetes or prediabetes who had sweet and salt taste disorders, respectively, from the National Health and Nutrition Examination Survey 2011-2012. Among the study population, 5.7% had sweet taste disorder and 8.6% had salt taste disorder. These data correspond to approximately 1.5 million and 1.8 million individuals with abnormal glucose tolerance aged 40years or older in the US population, respectively. In the adjusted model, sweet taste disorder was significantly associated with complication of ischemic heart disease (adjusted odds ratio [OR], 2.45; 95% confidence interval [CI], 1.03-5.81; P=0.04). Moreover, sweet taste disorder in patients with diabetes was significantly associated with diabetic retinopathy (adjusted OR, 2.89; 95% CI, 1.09-7.69; P=0.03) and diabetic nephropathy (adjusted OR, 3.17; 95% CI, 1.07-9.36; P=0.03). Meanwhile, salt taste disorder was not significantly associated with diabetic retinopathy, diabetic nephropathy, ischemic heart disease, or stroke. Total sugar intake was significantly higher in patients with sweet taste disorder than in those without it, whereas total daily intake of carbohydrate did not differ significantly. No significant association was observed between salt taste disorder and daily intake of sodium after multivariate analysis. Sweet taste disorder in patients with abnormal glucose tolerance was associated with increased sugar intake and vascular complications. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  20. Molecular and Cellular Organization of Taste Neurons in Adult Drosophila Pharynx

    Directory of Open Access Journals (Sweden)

    Yu-Chieh David Chen

    2017-12-01

    Full Text Available Summary: The Drosophila pharyngeal taste organs are poorly characterized despite their location at important sites for monitoring food quality. Functional analysis of pharyngeal neurons has been hindered by the paucity of molecular tools to manipulate them, as well as their relative inaccessibility for neurophysiological investigations. Here, we generate receptor-to-neuron maps of all three pharyngeal taste organs by performing a comprehensive chemoreceptor-GAL4/LexA expression analysis. The organization of pharyngeal neurons reveals similarities and distinctions in receptor repertoires and neuronal groupings compared to external taste neurons. We validate the mapping results by pinpointing a single pharyngeal neuron required for feeding avoidance of L-canavanine. Inducible activation of pharyngeal taste neurons reveals functional differences between external and internal taste neurons and functional subdivision within pharyngeal sweet neurons. Our results provide roadmaps of pharyngeal taste organs in an insect model system for probing the role of these understudied neurons in controlling feeding behaviors. : Chen and Dahanukar carry out a large-scale, systematic analysis to understand the molecular organization of pharyngeal taste neurons. Taking advantage of the molecular genetic toolkit that arises from this map, they use genetic dissection strategies to probe the functional roles of selected pharyngeal neurons in food choice. Keywords: Drosophila, taste, pharynx, chemosensory receptors, gustatory receptors, ionotropic receptors, feeding

  1. Tasting the World

    DEFF Research Database (Denmark)

    Eriksson, Birgit

    2011-01-01

    Recent research in sociology of art indicates an increasing heterogeneity and openness in cultural taste and consumption. This tendency also appears to be sanctified by developments in the arts and aesthetic theory of the last decades. Compared to former more exclusive and elitist cultures of tas...

  2. The taste looks good

    NARCIS (Netherlands)

    Polder, G.; Young, T.; Schrauwers, A.

    2005-01-01

    For over two decades, fruit and other agricultural products have been sorted using the 'electronic eye'. The eye selects purely by such external properties as colour, and cannot judge taste. Dr Gerrit Polder, an electrical engineer at Wageningen University, carried out his doctorate research at

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

    OpenAIRE

    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

    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 ...

  4. Learning through the taste system

    Directory of Open Access Journals (Sweden)

    Thomas R. Scott

    2011-11-01

    Full Text Available Taste is the final arbiter of which chemicals from the environment will be admitted to the body. The action of swallowing a substance leads to a physiological consequence of which the taste system should be informed. Accordingly, taste neurons in the central nervous system are closely allied with those that receive input from the viscera so as to monitor the impact of a recently ingested substance. There is behavioral, anatomical, electrophysiological, gene expression, and neurochemical evidence that the consequences of ingestion influence subsequent food selection through development of either a conditioned taste aversion (if illness ensues or a conditioned taste preference (if satiety. This ongoing communication between taste and the viscera permits the animal to tailor its taste system to its individual needs over a lifetime.

  5. Oxytocin decreases sweet taste sensitivity in mice.

    Science.gov (United States)

    Sinclair, Michael S; Perea-Martinez, Isabel; Abouyared, Marianne; St John, Steven J; Chaudhari, Nirupa

    2015-03-15

    Oxytocin (OXT) suppresses food intake and lack of OXT leads to overconsumption of sucrose. Taste bud cells were recently discovered to express OXT-receptor. In the present study we tested whether administering OXT to wild-type mice affects their licking behavior for tastants in a paradigm designed to be sensitive to taste perception. We injected C57BL/6J mice intraperitoneally (i.p.) with 10mg/kg OXT and assayed their brief-access lick responses, motivated by water deprivation, to NaCl (300mM), citric acid (20mM), quinine (0.3mM), saccharin (10mM), and a mix of MSG and IMP (100mM and 0.5mM respectively). OXT had no effect on licking for NaCl, citric acid, or quinine. A possible effect of OXT on saccharin and MSG+IMP was difficult to interpret due to unexpectedly low lick rates to water (the vehicle for all taste solutions), likely caused by the use of a high OXT dose that suppressed licking and other behaviors. A subsequent experiment focused on another preferred tastant, sucrose, and employed a much lower OXT dose (0.1mg/kg). This modification, based on our measurements of plasma OXT following i.p. injection, permitted us to elevate plasma [OXT] sufficiently to preferentially activate taste bud cells. OXT at this low dose significantly reduced licking responses to 0.3M sucrose, and overall shifted the sucrose concentration - behavioral response curves rightward (mean EC50saline=0.362M vs. EC50OXT=0.466M). Males did not differ from females under any condition in this study. We propose that circulating oxytocin is another factor that modulates taste-based behavior. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Expression, regulation and putative nutrient-sensing function of taste GPCRs in the heart.

    Directory of Open Access Journals (Sweden)

    Simon R Foster

    Full Text Available G protein-coupled receptors (GPCRs are critical for cardiovascular physiology. Cardiac cells express >100 nonchemosensory GPCRs, indicating that important physiological and potential therapeutic targets remain to be discovered. Moreover, there is a growing appreciation that members of the large, distinct taste and odorant GPCR families have specific functions in tissues beyond the oronasal cavity, including in the brain, gastrointestinal tract and respiratory system. To date, these chemosensory GPCRs have not been systematically studied in the heart. We performed RT-qPCR taste receptor screens in rodent and human heart tissues that revealed discrete subsets of type 2 taste receptors (TAS2/Tas2 as well as Tas1r1 and Tas1r3 (comprising the umami receptor are expressed. These taste GPCRs are present in cultured cardiac myocytes and fibroblasts, and by in situ hybridization can be visualized across the myocardium in isolated cardiac cells. Tas1r1 gene-targeted mice (Tas1r1(Cre/Rosa26(tdRFP strikingly recapitulated these data. In vivo taste receptor expression levels were developmentally regulated in the postnatal period. Intriguingly, several Tas2rs were upregulated in cultured rat myocytes and in mouse heart in vivo following starvation. The discovery of taste GPCRs in the heart opens an exciting new field of cardiac research. We predict that these taste receptors may function as nutrient sensors in the heart.

  7. The importance of α-CT and Salt bridges in the Formation of Insulin and its Receptor Complex by Computational Simulation.

    Science.gov (United States)

    Dehghan-Shasaltaneh, Marzieh; Lanjanian, Hossein; Riazi, Gholam Hossein; Masoudi-Nejad, Ali

    2018-01-01

    Insulin hormone is an important part of the endocrine system. It contains two polypeptide chains and plays a pivotal role in regulating carbohydrate metabolism. Insulin receptors (IR) located on cell surface interacts with insulin to control the intake of glucose. Although several studies have tried to clarify the interaction between insulin and its receptor, the mechanism of this interaction remains elusive because of the receptor's structural complexity and structural changes during the interaction. In this work, we tried to fractionate the interactions. Therefore, sequential docking method utilization of HADDOCK was used to achieve the mentioned goal, so the following processes were done: the first, two pdb files of IR i.e., 3LOH and 3W11 were concatenated using modeller. The second, flexible regions of IR were predicted by HingeProt. Output files resulting from HingeProt were uploaded into HADDOCK. Our results predict new salt bridges in the complex and emphasize on the role of salt bridges to maintain an inverted V structure of IR. Having an inverted V structure leads to activate intracellular signaling pathway. In addition to presence salt bridges to form a convenient structure of IR, the importance of α-chain of carboxyl terminal (α-CT) to interact with insulin was surveyed and also foretokened new insulin/IR contacts, particularly at site 2 (rigid parts 2 and 3). Finally, several conformational changes in residues Asn711-Val715 of α-CT were occurred, we suggest that α-CT is a suitable situation relative to insulin due to these conformational alterations.

  8. Regulation of bitter taste responses by tumor necrosis factor.

    Science.gov (United States)

    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.

  9. Expression of Galpha14 in sweet-transducing taste cells of the posterior tongue

    Directory of Open Access Journals (Sweden)

    Kim Soochong

    2008-11-01

    Full Text Available Abstract Background "Type II"/Receptor cells express G protein-coupled receptors (GPCRs for sweet, umami (T1Rs and mGluRs or bitter (T2Rs, as well as the proteins for downstream signalling cascades. Transduction downstream of T1Rs and T2Rs relies on G-protein and PLCβ2-mediated release of stored Ca2+. Whereas Gαgus (gustducin couples to the T2R (bitter receptors, which Gα-subunit couples to the sweet (T1R2 + T1R3 receptor is presently not known. We utilized RT-PCR, immunocytochemistry and single-cell gene expression profiling to examine the expression of the Gαq family (q, 11, 14 in mouse taste buds. Results By RT-PCR, Gα14 is expressed strongly and in a taste selective manner in posterior (vallate and foliate, but not anterior (fungiform and palate taste fields. Gαq and Gα11, although detectable, are not expressed in a taste-selective fashion. Further, expression of Gα14 mRNA is limited to Type II/Receptor cells in taste buds. Immunocytochemistry on vallate papillae using a broad Gαq family antiserum reveals specific staining only in Type II taste cells (i.e. those expressing TrpM5 and PLCβ2. This staining persists in Gαq knockout mice and immunostaining with a Gα11-specific antiserum shows no immunoreactivity in taste buds. Taken together, these data show that Gα14 is the dominant Gαq family member detected. Immunoreactivity for Gα14 strongly correlates with expression of T1R3, the taste receptor subunit present in taste cells responsive to either umami or sweet. Single cell gene expression profiling confirms a tight correlation between the expression of Gα14 and both T1R2 and T1R3, the receptor combination that forms sweet taste receptors. Conclusion Gα14 is co-expressed with the sweet taste receptor in posterior tongue, although not in anterior tongue. Thus, sweet taste transduction may rely on different downstream transduction elements in posterior and anterior taste fields.

  10. (Re)tasting places

    DEFF Research Database (Denmark)

    Hedegaard, Liselotte

    2015-01-01

    What does geographical origin mean? It is an expression that associates food and wine with a specific place, an association embedded in the concept ‘terroir’ that refers to the complex interaction between a physical environment and local craftsmanship. It is a claim protected through labelling......-schemes and a claim that adds value to the place-related foods. However, viewing the connection between food and place as a question of proving a relationship or as a matter of protecting commercial claims does not seem to provide a satisfactory account for the status of geographically designated foods as being...... particularly attractive Central to the interest of this paper is to approach an understanding of geographical origin as a point of reference for taste. In terms of being sensory experience, taste is subjective. It is difficult to describe verbally and yet at the same time it is a trigger of the memory of past...

  11. Isolation of chicken taste buds for real-time Ca2+ imaging.

    Science.gov (United States)

    Kudo, Ken-ichi; Kawabata, Fuminori; Nomura, Toumi; Aridome, Ayumi; Nishimura, Shotaro; Tabata, Shoji

    2014-10-01

    We isolated chicken taste buds and used a real-time Ca2+ imaging technique to investigate the functions of the taste cells. With RT-PCR, we found that isolated chicken taste bud-like cell subsets express chicken gustducin messenger RNA. Immunocytochemical techniques revealed that the cell subsets were also immunopositive for chicken gustducin. These results provided strong evidence that the isolated cell subsets contain chicken taste buds. The isolated cell subsets were spindle-shaped and approximately 61-75 μm wide and 88-98 μm long, and these characteristics are similar to those of sectional chicken taste buds. Using Ca2+ imaging, we observed the buds' response to 2 mmol/L quinine hydrochloride (a bitter substance) and their response to a mixture of 25 mmol/L L-glutamic acid monopotassium salt monohydrate and 1 mmol/L inosine 5'-monophosphate disodium salt, umami substances. The present study is the first morphological demonstration of isolated chicken taste buds, and our results indicate that the isolated taste buds were intact and functional approaches for examining the taste senses of the chicken using Ca2+ imaging can be informative. © 2014 Japanese Society of Animal Science.

  12. Taste aversion memory reconsolidation is independent of its retrieval.

    Science.gov (United States)

    Rodriguez-Ortiz, Carlos J; Balderas, Israela; Garcia-DeLaTorre, Paola; Bermudez-Rattoni, Federico

    2012-10-01

    Reconsolidation refers to the destabilization/re-stabilization memory process upon its activation. However, the conditions needed to undergo reconsolidation, as well as its functional significance is quite unclear and a matter of intense investigation. Even so, memory retrieval is held as requisite to initiate reconsolidation. Therefore, in the present work we examined whether transient pharmacological disruption of memory retrieval impedes reconsolidation of stored memory in the widely used associative conditioning task, taste aversion. We found that AMPA receptors inhibition in the amygdala impaired retrieval of taste aversion memory. Furthermore, AMPA receptors blockade impeded retrieval regardless of memory strength. However, inhibition of retrieval did not affect anisomycin-mediated disruption of reconsolidation. These results indicate that retrieval is a dispensable condition to undergo reconsolidation and provide evidence of molecular dissociation between retrieval and activation of memory in the non-declarative memory model taste aversion. Copyright © 2012 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  15. Calcium Signaling in Taste Cells

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. New Thermal Taste Actuation Technology for Future Multisensory Virtual Reality and Internet.

    Science.gov (United States)

    Karunanayaka, Kasun; Johari, Nurafiqah; Hariri, Surina; Camelia, Hanis; Bielawski, Kevin Stanley; Cheok, Adrian David

    2018-04-01

    Today's virtual reality (VR) applications such as gaming, multisensory entertainment, remote dining, and online shopping are mainly based on audio, visual, and touch interactions between humans and virtual worlds. Integrating the sense of taste into VR is difficult since humans are dependent on chemical-based taste delivery systems. This paper presents the 'Thermal Taste Machine', a new digital taste actuation technology that can effectively produce and modify thermal taste sensations on the tongue. It modifies the temperature of the surface of the tongue within a short period of time (from 25°C to 40 °C while heating, and from 25°C to 10 °C while cooling). We tested this device on human subjects and described the experience of thermal taste using 20 known (taste and non-taste) sensations. Our results suggested that rapidly heating the tongue produces sweetness, fatty/oiliness, electric taste, warmness, and reduces the sensibility for metallic taste. Similarly, cooling the tongue produced mint taste, pleasantness, and coldness. By conducting another user study on the perceived sweetness of sucrose solutions after the thermal stimulation, we found that heating the tongue significantly enhances the intensity of sweetness for both thermal tasters and non-thermal tasters. Also, we found that faster temperature rises on the tongue produce more intense sweet sensations for thermal tasters. This technology will be useful in two ways: First, it can produce taste sensations without using chemicals for the individuals who are sensitive to thermal taste. Second, the temperature rise of the device can be used as a way to enhance the intensity of sweetness. We believe that this technology can be used to digitally produce and enhance taste sensations in future virtual reality applications. The key novelties of this paper are as follows: 1. Development of a thermal taste actuation technology for stimulating the human taste receptors, 2. Characterization of the thermal taste

  20. Cisplatin-Induced Conditioned Taste Aversion: Attenuation by Dexamethasone but not Zacopride or GR38032F

    Science.gov (United States)

    1992-01-01

    SR2-1 Cisplatin-induced conditioned taste aversion: ateuto by dexamethasone but not zacopride or GR38032F Nm I- Paul C Mele, John R. McDonough, David...to 5-H1’, receptor blockade. 5-HT., receptor antagonists; Zacopridc: GR38032F; Desamethasone: Cisplatin: Taste aversion (conditioned) I. Introductlon...intake) was used as the area known as the chemoreceptor trigger zone (Borri- index of the CTA. son, 1974). Moreover. the findings that rats, ferrets

  1. Salt craving: The psychobiology of pathogenic sodium intake

    OpenAIRE

    Morris, Michael J.; Na, Elisa S.; Johnson, Alan Kim

    2008-01-01

    Ionic sodium, obtained from dietary sources usually in the form of sodium chloride (NaCl, common table salt) is essential to physiological function, and in humans salt is generally regarded as highly palatable. This marriage of pleasant taste and physiological utility might appear fortunate – an appealing taste helps to ensure that such a vital substance is ingested. However, the powerful mechanisms governing sodium retention and sodium balance are unfortunately best adapted for an environmen...

  2. Formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations - A review.

    Science.gov (United States)

    Zhao, Cindy J; Schieber, Andreas; Gänzle, Michael G

    2016-11-01

    Fermented foods are valued for their rich and complex odour and taste. The metabolic activity of food-fermenting microorganisms determines food quality and generates odour and taste compounds. This communication reviews the formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations. Pathways of the generation of taste compounds are presented for soy sauce, cheese, fermented meats, and bread. Proteolysis or autolysis during food fermentations generates taste-active amino acids and peptides; peptides derived from proteolysis particularly impart umami taste (e.g. α-glutamyl peptides) or bitter taste (e.g. hydrophobic peptides containing proline). Taste active peptide derivatives include pyroglutamyl peptides, γ-glutamyl peptides, and succinyl- or lactoyl amino acids. The influence of fermentation microbiota on proteolysis, and peptide hydrolysis, and the metabolism of glutamate and arginine is well understood, however, the understanding of microbial metabolic activities related to the formation of taste-active peptide derivatives is incomplete. Improved knowledge of the interactions between taste-active compounds will enable the development of novel fermentation strategies to develop tastier, less bitter, and low-salt food products, and may provide novel and "clean label" ingredients to improve the taste of other food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  4. Evidence for a role of glutamate as an efferent transmitter in taste buds

    Directory of Open Access Journals (Sweden)

    Anderson Catherine B

    2010-06-01

    Full Text Available Abstract Background Glutamate has been proposed as a transmitter in the peripheral taste system in addition to its well-documented role as an umami taste stimulus. Evidence for a role as a transmitter includes the presence of ionotropic glutamate receptors in nerve fibers and taste cells, as well as the expression of the glutamate transporter GLAST in Type I taste cells. However, the source and targets of glutamate in lingual tissue are unclear. In the present study, we used molecular, physiological and immunohistochemical methods to investigate the origin of glutamate as well as the targeted receptors in taste buds. Results Using molecular and immunohistochemical techniques, we show that the vesicular transporters for glutamate, VGLUT 1 and 2, but not VGLUT3, are expressed in the nerve fibers surrounding taste buds but likely not in taste cells themselves. Further, we show that P2X2, a specific marker for gustatory but not trigeminal fibers, co-localizes with VGLUT2, suggesting the VGLUT-expressing nerve fibers are of gustatory origin. Calcium imaging indicates that GAD67-GFP Type III taste cells, but not T1R3-GFP Type II cells, respond to glutamate at concentrations expected for a glutamate transmitter, and further, that these responses are partially blocked by NBQX, a specific AMPA/Kainate receptor antagonist. RT-PCR and immunohistochemistry confirm the presence of the Kainate receptor GluR7 in Type III taste cells, suggesting it may be a target of glutamate released from gustatory nerve fibers. Conclusions Taken together, the results suggest that glutamate may be released from gustatory nerve fibers using a vesicular mechanism to modulate Type III taste cells via GluR7.

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

    Science.gov (United States)

    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.

  6. The taste of desserts' packages.

    Science.gov (United States)

    Overbeeke, C J; Peters, M E

    1991-10-01

    This article reports an experiment on expressing the behavioural meaning of designed objects. Can a designer express the taste of a desert in the form of its packaging and can consumers match these forms when tasting the desserts? Analysis of responses of 12 adults indicates positive answers to these questions.

  7. Tasting Wine: A Learning Experience

    Science.gov (United States)

    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…

  8. DEVELOPING A SENSE OF TASTE

    Science.gov (United States)

    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

  9. Taste and hypertension in humans

    DEFF Research Database (Denmark)

    Roura, Eugeni; Foster, Simon; Winklebach, Anja

    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...

  10. Limited taste discrimination in Drosophila.

    Science.gov (United States)

    Masek, Pavel; Scott, Kristin

    2010-08-17

    In the gustatory systems of mammals and flies, different populations of sensory cells recognize different taste modalities, such that there are cells that respond selectively to sugars and others to bitter compounds. This organization readily allows animals to distinguish compounds of different modalities but may limit the ability to distinguish compounds within one taste modality. Here, we developed a behavioral paradigm in Drosophila melanogaster to evaluate directly the tastes that a fly distinguishes. These studies reveal that flies do not discriminate among different sugars, or among different bitter compounds, based on chemical identity. Instead, flies show a limited ability to distinguish compounds within a modality based on intensity or palatability. Taste associative learning, similar to olfactory learning, requires the mushroom bodies, suggesting fundamental similarities in brain mechanisms underlying behavioral plasticity. Overall, these studies provide insight into the discriminative capacity of the Drosophila gustatory system and the modulation of taste behavior.

  11. Clofibrate inhibits the umami-savory taste of glutamate.

    Science.gov (United States)

    Kochem, Matthew; Breslin, Paul A S

    2017-01-01

    In humans, umami taste can increase the palatability of foods rich in the amino acids glutamate and aspartate and the 5'-ribonucleotides IMP and GMP. Umami taste is transduced, in part, by T1R1-T1R3, a heteromeric G-protein coupled receptor. Umami perception is inhibited by sodium lactisole, which binds to the T1R3 subunit in vitro. Lactisole is structurally similar to the fibrate drugs. Clofibric acid, a lipid lowering drug, also binds the T1R3 subunit in vitro. The purpose of this study was to determine whether clofibric acid inhibits the umami taste of glutamate in human subjects. Ten participants rated the umami taste intensity elicited by 20 mM monosodium glutamate (MSG) mixed with varying concentrations of clofibric acid (0 to 16 mM). In addition, fourteen participants rated the effect of 1.4 mM clofibric acid on umami enhancement by 5' ribonucleotides. Participants were instructed to rate perceived intensity using a general Labeled Magnitude Scale (gLMS). Each participant was tested in triplicate. Clofibric acid inhibited umami taste intensity from 20 mM MSG in a dose dependent manner. Whereas MSG neat elicited "moderate" umami taste intensity, the addition of 16 mM clofibric acid elicited only "weak" umami intensity on average, and in some subjects no umami taste was elicited. We further show that 1.4 mM clofibric acid suppressed umami enhancement from GMP, but not from IMP. This study provides in vivo evidence that clofibric acid inhibits glutamate taste perception, presumably via T1R1-T1R3 inhibition, and lends further evidence that the T1R1-T1R3 receptor is the principal umami receptor in humans. T1R receptors are expressed extra-orally throughout the alimentary tract and in regulatory organs and are known to influence glucose and lipid metabolism. Whether clofibric acid as a lipid-lowering drug affects human metabolism, in part, through T1R inhibition warrants further examination.

  12. Clofibrate inhibits the umami-savory taste of glutamate

    OpenAIRE

    Kochem, Matthew; Breslin, Paul A. S.

    2017-01-01

    In humans, umami taste can increase the palatability of foods rich in the amino acids glutamate and aspartate and the 5'-ribonucleotides IMP and GMP. Umami taste is transduced, in part, by T1R1-T1R3, a heteromeric G-protein coupled receptor. Umami perception is inhibited by sodium lactisole, which binds to the T1R3 subunit in vitro. Lactisole is structurally similar to the fibrate drugs. Clofibric acid, a lipid lowering drug, also binds the T1R3 subunit in vitro. The purpose of this study was...

  13. Enteroendocrine cells: a site of 'taste' in gastrointestinal chemosensing.

    Science.gov (United States)

    Sternini, Catia; Anselmi, Laura; Rozengurt, Enrique

    2008-02-01

    This review discusses the role of enteroendocrine cells of the gastrointestinal tract as chemoreceptors that sense lumen contents and induce changes in gastrointestinal function and food intake through the release of signaling substances acting on a variety of targets locally or at a distance. Recent evidence supports the concept that chemosensing in the gut involves G protein-coupled receptors and effectors that are known to mediate gustatory signals in the oral cavity. These include sweet-taste and bitter-taste receptors, and their associated G proteins, which are expressed in the gastrointestinal mucosa, including selected populations of enteroendocrine cells. In addition, taste receptor agonists elicit a secretory response in enteroendocrine cells in vitro and in animals in vivo, and induce neuronal activation. Taste-signaling molecules expressed in the gastrointestinal mucosa might participate in the functional detection of nutrients and harmful substances in the lumen and prepare the gut to absorb them or initiate a protective response. They might also participate in the control of food intake through the activation of gut-brain neural pathways. These findings provide a new dimension to unraveling the regulatory circuits initiated by luminal contents of the gastrointestinal tract.

  14. Defects in the peripheral taste structure and function in the MRL/lpr mouse model of autoimmune disease.

    Directory of Open Access Journals (Sweden)

    Agnes Kim

    Full Text Available While our understanding of the molecular and cellular aspects of taste reception and signaling continues to improve, the aberrations in these processes that lead to taste dysfunction remain largely unexplored. Abnormalities in taste can develop in a variety of diseases, including infections and autoimmune disorders. In this study, we used a mouse model of autoimmune disease to investigate the underlying mechanisms of taste disorders. MRL/MpJ-Fas(lpr/J (MRL/lpr mice develop a systemic autoimmunity with phenotypic similarities to human systemic lupus erythematosus and Sjögren's syndrome. Our results show that the taste tissues of MRL/lpr mice exhibit characteristics of inflammation, including infiltration of T lymphocytes and elevated levels of some inflammatory cytokines. Histological studies reveal that the taste buds of MRL/lpr mice are smaller than those of wild-type congenic control (MRL/+/+ mice. 5-Bromo-2'-deoxyuridine (BrdU pulse-chase experiments show that fewer BrdU-labeled cells enter the taste buds of MRL/lpr mice, suggesting an inhibition of taste cell renewal. Real-time RT-PCR analyses show that mRNA levels of several type II taste cell markers are lower in MRL/lpr mice. Immunohistochemical analyses confirm a significant reduction in the number of gustducin-positive taste receptor cells in the taste buds of MRL/lpr mice. Furthermore, MRL/lpr mice exhibit reduced gustatory nerve responses to the bitter compound quinine and the sweet compound saccharin and reduced behavioral responses to bitter, sweet, and umami taste substances compared with controls. In contrast, their responses to salty and sour compounds are comparable to those of control mice in both nerve recording and behavioral experiments. Together, our results suggest that type II taste receptor cells, which are essential for bitter, sweet, and umami taste reception and signaling, are selectively affected in MRL/lpr mice, a model for autoimmune disease with chronic

  15. A taste of cosmology

    International Nuclear Information System (INIS)

    Verde, L.

    2011-01-01

    This is the summary of two lectures that aim to give an overview of cosmology. I will not try to be toa rigorous in derivations, nor to give a full historical overview. The idea is to provide a 'taste' of cosmology and some of the interesting topics it covers. The standard cosmological model is presented and I highlight the successes of cosmology over the past decade or so. Keys to the development of the standard cosmological model are observations of the cosmic microwave background and of large-scale structure, which are introduced. Inflation and dark energy and the outlook for the future are also discussed. Slides from the lectures are available from the school web site: physicschool.web.cern.ch/PhysicSchool/CLASHEP/CLASHEP2011/. (author)

  16. A Taste of Cosmology

    CERN Document Server

    Verde, L.

    2013-06-27

    This is the summary of two lectures that aim to give an overview of cosmology. I will not try to be too rigorous in derivations, nor to give a full historical overview. The idea is to provide a "taste" of cosmology and some of the interesting topics it covers. The standard cosmological model is presented and I highlight the successes of cosmology over the past decade or so. Keys to the development of the standard cosmological model are observations of the cosmic microwave background and of large-scale structure, which are introduced. Inflation and dark energy and the outlook for the future are also discussed. Slides from the lectures are available from the school website: physicschool.web.cern.ch/PhysicSchool/CLASHEP/CLASHEP2011/.

  17. Chronic Blockade of Brain Endothelin Receptor Type-A (ETA Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Luis R. Cassinotti

    2018-02-01

    Full Text Available Overactivity of the sympathetic nervous system and central endothelins (ETs are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA-salt hypertensive rats. Following brain ET receptor type A (ETA blockade by BQ610 (selective antagonist, transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ETA blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein in the right OB of hypertensive animals. However, ETA blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ETA are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

  18. Chronic Blockade of Brain Endothelin Receptor Type-A (ETA) Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats.

    Science.gov (United States)

    Cassinotti, Luis R; Guil, María J; Schöller, Mercedes I; Navarro, Mónica P; Bianciotti, Liliana G; Vatta, Marcelo S

    2018-02-27

    Overactivity of the sympathetic nervous system and central endothelins (ETs) are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB) also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Following brain ET receptor type A (ET A ) blockade by BQ610 (selective antagonist), transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH) were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ET A blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein) in the right OB of hypertensive animals. However, ET A blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ET A are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

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

    Science.gov (United States)

    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.

  20. Gustatory papillae and taste bud development and maintenance in the absence of TrkB ligands BDNF and NT-4.

    Science.gov (United States)

    Ito, Akira; Nosrat, Christopher A

    2009-09-01

    Taste buds and the peripheral nerves innervating them are two important components of the peripheral gustatory system. They require appropriate connections for the taste system to function. Neurotrophic factors play crucial roles in the innervation of peripheral sensory organs and tissues. Both brain-derived neurotrophic factor (BDNF) null-mutated and neurotrophin-4 (NT-4) null-mutated mice exhibit peripheral gustatory deficits. BDNF and NT-4 bind to a common high affinity tyrosine kinase receptor, TrkB (NTRK-2), and a common p75 neurotrophin receptor (NGFR). We are currently using a transgenic mouse model to study peripheral taste system development and innervation in the absence of both TrkB ligands. We show that taste cell progenitors express taste cell markers during early stages of taste bud development in both BDNF(-/-)xNT-4(-/-) and wild-type mice. At early embryonic stages, taste bud progenitors express Troma-1, Shh, and Sox2 in all mice. At later stages, lack of innervation becomes a prominent feature in BDNF(-/-)xNT-4(-/-) mice leading to a decreasing number of fungiform papillae and morphologically degenerating taste cells. A total loss of vallate taste cells also occurs in postnatal transgenic mice. Our data indicate an initial independence but a later permissive and essential role for innervation in taste bud development and maintenance.

  1. The taste cell-related diffuse chemosensory system.

    Science.gov (United States)

    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.

  2. Insights on consciousness from taste memory research.

    Science.gov (United States)

    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.

  3. Discrete innervation of murine taste buds by peripheral taste neurons.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Dany Gaillard

    2015-05-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  6. Understanding taste dysfunction in patients with cancer.

    Science.gov (United States)

    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.

  7. Conformational coupling between receptor and kinase binding sites through a conserved salt bridge in a signaling complex scaffold protein.

    Directory of Open Access Journals (Sweden)

    Davi R Ortega

    Full Text Available Bacterial chemotaxis is one of the best studied signal transduction pathways. CheW is a scaffold protein that mediates the association of the chemoreceptors and the CheA kinase in a ternary signaling complex. The effects of replacing conserved Arg62 of CheW with other residues suggested that the scaffold protein plays a more complex role than simply binding its partner proteins. Although R62A CheW had essentially the same affinity for chemoreceptors and CheA, cells expressing the mutant protein are impaired in chemotaxis. Using a combination of molecular dynamics simulations (MD, NMR spectroscopy, and circular dichroism (CD, we addressed the role of Arg62. Here we show that Arg62 forms a salt bridge with another highly conserved residue, Glu38. Although this interaction is unimportant for overall protein stability, it is essential to maintain the correct alignment of the chemoreceptor and kinase binding sites of CheW. Computational and experimental data suggest that the role of the salt bridge in maintaining the alignment of the two partner binding sites is fundamental to the function of the signaling complex but not to its assembly. We conclude that a key feature of CheW is to maintain the specific geometry between the two interaction sites required for its function as a scaffold.

  8. Disorders of Smell and Taste

    Science.gov (United States)

    ... RESOURCES Medical Societies Patient Education About this Website Font Size + - Home > CONDITIONS > Disorders of Smell & Taste Adult ... permanent smell loss. Patients who have had this type of loss describe immediate burning sensation when using ...

  9. Acquiring taste in home economics?

    DEFF Research Database (Denmark)

    Stenbak Larsen, Christian

    Objective: To explore how home economics was taught in Denmark before the recent Danish school reform, which also revised the objectives and content of home economics, naming it Food Knowledge (Madkundskab) Methods: Participant observation was done in home economic lessons in two case schools...... appreciated by the group of boys, and others again learned to stick with their idiosyncrasies when pressured by the teacher. Conclusions: Children were acquiring taste in the home economic lessons, but not only the kind of tastes that the teacher had planned for. This leads to reflections on the very complex...... process of taste acquiring and to a call for further research into taste acquiring in complex real life contexts as home economics lessons....

  10. Innervation of taste buds revealed with Brainbow-labeling in mouse.

    Science.gov (United States)

    Zaidi, Faisal N; Cicchini, Vanessa; Kaufman, Daniel; Ko, Elizabeth; Ko, Abraham; Van Tassel, Heather; Whitehead, Mark C

    2016-12-01

    Nerve fibers that surround and innervate the taste bud were visualized with inherent fluorescence using Brainbow transgenic mice that were generated by mating the founder line L with nestin-cre mice. Multicolor fluorescence revealed perigemmal fibers as branched within the non-taste epithelium and ending in clusters of multiple rounded swellings surrounding the taste pore. Brainbow-labeling also revealed the morphology and branching pattern of single intragemmal fibers. These taste bud fibers frequently innervated both the peripheral bud, where immature gemmal cells are located, and the central bud, where mature, differentiated cells are located. The fibers typically bore preterminal and terminal swellings, growth cones with filopodia, swellings, and rounded retraction bulbs. These results establish an anatomical substrate for taste nerve fibers to contact and remodel among receptor cells at all stages of their differentiation, an interpretation that was supported by staining with GAP-43, a marker for growing fibers and growth cones. © 2016 Anatomical Society.

  11. Taste bud-derived BDNF maintains innervation of a subset of TrkB-expressing gustatory nerve fibers.

    Science.gov (United States)

    Tang, Tao; Rios-Pilier, Jennifer; Krimm, Robin

    2017-07-01

    Taste receptor cells transduce different types of taste stimuli and transmit this information to gustatory neurons that carry it to the brain. Taste receptor cells turn over continuously in adulthood, requiring constant new innervation from nerve fibers. Therefore, the maintenance of innervation to taste buds is an active process mediated by many factors, including brain-derived neurotrophic factor (BDNF). Specifically, 40% of taste bud innervation is lost when Bdnf is removed during adulthood. Here we speculated that not all gustatory nerve fibers express the BDNF receptor, TrkB, resulting in subsets of neurons that vary in their response to BDNF. However, it is also possible that the partial loss of innervation occurred because the Bdnf gene was not effectively removed. To test these possibilities, we first determined that not all gustatory nerve fibers express the TrkB receptor in adult mice. We then verified the efficiency of Bdnf removal specifically in taste buds of K14-CreER:Bdnf mice and found that Bdnf expression was reduced to 1%, indicating efficient Bdnf gene recombination. BDNF removal resulted in a 55% loss of TrkB-expressing nerve fibers, which was greater than the loss of P2X3-positive fibers (39%), likely because taste buds were innervated by P2X3+/TrkB- fibers that were unaffected by BDNF removal. We conclude that gustatory innervation consists of both TrkB-positive and TrkB-negative taste fibers and that BDNF is specifically important for maintaining TrkB-positive innervation to taste buds. In addition, although taste bud size was not affected by inducible Bdnf removal, the expression of the γ subunit of the ENaC channel was reduced. So, BDNF may regulate expression of some molecular components of taste transduction pathways. Copyright © 2017. Published by Elsevier Inc.

  12. A Physiologic Role for Serotonergic Transmission in Adult Rat Taste Buds

    Science.gov (United States)

    Jaber, Luc; Zhao, Fang-li; Kolli, Tamara; Herness, Scott

    2014-01-01

    Of the multiple neurotransmitters and neuropeptides expressed in the mammalian taste bud, serotonin remains both the most studied and least understood. Serotonin is expressed in a subset of taste receptor cells that form synapses with afferent nerve fibers (type III cells) and was once thought to be essential to neurotransmission (now understood as purinergic). However, the discovery of the 5-HT1A serotonin receptor in a subset of taste receptor cells paracrine to type III cell suggested a role in cell-to-cell communication during the processing of taste information. Functional data describing this role are lacking. Using anatomical and neurophysiological techniques, this study proposes a modulatory role for serotonin during the processing of taste information. Double labeling immunocytochemical and single cell RT-PCR technique experiments documented that 5-HT1A-expressing cells co-expressed markers for type II cells, cells which express T1R or T2R receptors and release ATP. These cells did not co-express type III cells markers. Neurophysiological recordings from the chorda tympani nerve, which innervates anterior taste buds, were performed prior to and during intravenous injection of a 5-HT1A receptor antagonist. These experiments revealed that serotonin facilitates processing of taste information for tastants representing sweet, sour, salty, and bitter taste qualities. On the other hand, injection of ondansetron, a 5-HT3 receptor antagonist, was without effect. Collectively, these data support the hypothesis that serotonin is a crucial element in a finely-tuned feedback loop involving the 5-HT1A receptor, ATP, and purinoceptors. It is hypothesized that serotonin facilitates gustatory signals by regulating the release of ATP through ATP-release channels possibly through phosphatidylinositol 4,5-bisphosphate resynthesis. By doing so, 5-HT1A activation prevents desensitization of post-synaptic purinergic receptors expressed on afferent nerve fibers and enhances the

  13. A physiologic role for serotonergic transmission in adult rat taste buds.

    Directory of Open Access Journals (Sweden)

    Luc Jaber

    Full Text Available Of the multiple neurotransmitters and neuropeptides expressed in the mammalian taste bud, serotonin remains both the most studied and least understood. Serotonin is expressed in a subset of taste receptor cells that form synapses with afferent nerve fibers (type III cells and was once thought to be essential to neurotransmission (now understood as purinergic. However, the discovery of the 5-HT1A serotonin receptor in a subset of taste receptor cells paracrine to type III cell suggested a role in cell-to-cell communication during the processing of taste information. Functional data describing this role are lacking. Using anatomical and neurophysiological techniques, this study proposes a modulatory role for serotonin during the processing of taste information. Double labeling immunocytochemical and single cell RT-PCR technique experiments documented that 5-HT1A-expressing cells co-expressed markers for type II cells, cells which express T1R or T2R receptors and release ATP. These cells did not co-express type III cells markers. Neurophysiological recordings from the chorda tympani nerve, which innervates anterior taste buds, were performed prior to and during intravenous injection of a 5-HT1A receptor antagonist. These experiments revealed that serotonin facilitates processing of taste information for tastants representing sweet, sour, salty, and bitter taste qualities. On the other hand, injection of ondansetron, a 5-HT3 receptor antagonist, was without effect. Collectively, these data support the hypothesis that serotonin is a crucial element in a finely-tuned feedback loop involving the 5-HT1A receptor, ATP, and purinoceptors. It is hypothesized that serotonin facilitates gustatory signals by regulating the release of ATP through ATP-release channels possibly through phosphatidylinositol 4,5-bisphosphate resynthesis. By doing so, 5-HT1A activation prevents desensitization of post-synaptic purinergic receptors expressed on afferent nerve fibers

  14. A physiologic role for serotonergic transmission in adult rat taste buds.

    Science.gov (United States)

    Jaber, Luc; Zhao, Fang-li; Kolli, Tamara; Herness, Scott

    2014-01-01

    Of the multiple neurotransmitters and neuropeptides expressed in the mammalian taste bud, serotonin remains both the most studied and least understood. Serotonin is expressed in a subset of taste receptor cells that form synapses with afferent nerve fibers (type III cells) and was once thought to be essential to neurotransmission (now understood as purinergic). However, the discovery of the 5-HT1A serotonin receptor in a subset of taste receptor cells paracrine to type III cell suggested a role in cell-to-cell communication during the processing of taste information. Functional data describing this role are lacking. Using anatomical and neurophysiological techniques, this study proposes a modulatory role for serotonin during the processing of taste information. Double labeling immunocytochemical and single cell RT-PCR technique experiments documented that 5-HT1A-expressing cells co-expressed markers for type II cells, cells which express T1R or T2R receptors and release ATP. These cells did not co-express type III cells markers. Neurophysiological recordings from the chorda tympani nerve, which innervates anterior taste buds, were performed prior to and during intravenous injection of a 5-HT1A receptor antagonist. These experiments revealed that serotonin facilitates processing of taste information for tastants representing sweet, sour, salty, and bitter taste qualities. On the other hand, injection of ondansetron, a 5-HT3 receptor antagonist, was without effect. Collectively, these data support the hypothesis that serotonin is a crucial element in a finely-tuned feedback loop involving the 5-HT1A receptor, ATP, and purinoceptors. It is hypothesized that serotonin facilitates gustatory signals by regulating the release of ATP through ATP-release channels possibly through phosphatidylinositol 4,5-bisphosphate resynthesis. By doing so, 5-HT1A activation prevents desensitization of post-synaptic purinergic receptors expressed on afferent nerve fibers and enhances the

  15. Gustatory stimuli representing different perceptual qualities elicit distinct patterns of neuropeptide secretion from taste buds.

    Science.gov (United States)

    Geraedts, Maartje C P; Munger, Steven D

    2013-04-24

    Taste stimuli that evoke different perceptual qualities (e.g., sweet, umami, bitter, sour, salty) are detected by dedicated subpopulations of taste bud cells that use distinct combinations of sensory receptors and transduction molecules. Here, we report that taste stimuli also elicit unique patterns of neuropeptide secretion from taste buds that are correlated with those perceptual qualities. We measured tastant-dependent secretion of glucagon-like peptide-1 (GLP-1), glucagon, and neuropeptide Y (NPY) from circumvallate papillae of Tas1r3(+/+), Tas1r3(+/-) and Tas1r3 (-/-) mice. Isolated tongue epithelia were mounted in modified Ussing chambers, permitting apical stimulation of taste buds; secreted peptides were collected from the basal side and measured by specific ELISAs. Appetitive stimuli (sweet: glucose, sucralose; umami: monosodium glutamate; polysaccharide: Polycose) elicited GLP-1 and NPY secretion and inhibited basal glucagon secretion. Sweet and umami stimuli were ineffective in Tas1r3(-/-) mice, indicating an obligatory role for the T1R3 subunit common to the sweet and umami taste receptors. Polycose responses were unaffected by T1R3 deletion, consistent with the presence of a distinct polysaccharide taste receptor. The effects of sweet stimuli on peptide secretion also required the closing of ATP-sensitive K(+) (KATP) channels, as the KATP channel activator diazoxide inhibited the effects of glucose and sucralose on both GLP-1 and glucagon release. Both sour citric acid and salty NaCl increased NPY secretion but had no effects on GLP-1 or glucagon. Bitter denatonium showed no effects on these peptides. Together, these results suggest that taste stimuli of different perceptual qualities elicit unique patterns of neuropeptide secretion from taste buds.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Chunsheng Wu

    2017-12-01

    Full Text Available 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.

  18. Contribution of Underlying Connective Tissue Cells to Taste Buds in Mouse Tongue and Soft Palate

    Science.gov (United States)

    Mederacke, Ingmar; Komatsu, Yoshihiro; Stice, Steve; Schwabe, Robert F.; Mistretta, Charlotte M.; Mishina, Yuji; Liu, Hong-Xiang

    2016-01-01

    Taste buds, the sensory organs for taste, have been described as arising solely from the surrounding epithelium, which is in distinction from other sensory receptors that are known to originate from neural precursors, i.e., neural ectoderm that includes neural crest (NC). Our previous study suggested a potential contribution of NC derived cells to early immature fungiform taste buds in late embryonic (E18.5) and young postnatal (P1-10) mice. In the present study we demonstrated the contribution of the underlying connective tissue (CT) to mature taste buds in mouse tongue and soft palate. Three independent mouse models were used for fate mapping of NC and NC derived connective tissue cells: (1) P0-Cre/R26-tdTomato (RFP) to label NC, NC derived Schwann cells and derivatives; (2) Dermo1-Cre/RFP to label mesenchymal cells and derivatives; and (3) Vimentin-CreER/mGFP to label Vimentin-expressing CT cells and derivatives upon tamoxifen treatment. Both P0-Cre/RFP and Dermo1-Cre/RFP labeled cells were abundant in mature taste buds in lingual taste papillae and soft palate, but not in the surrounding epithelial cells. Concurrently, labeled cells were extensively distributed in the underlying CT. RFP signals were seen in the majority of taste buds and all three types (I, II, III) of differentiated taste bud cells, with the neuronal-like type III cells labeled at a greater proportion. Further, Vimentin-CreER labeled cells were found in the taste buds of 3-month-old mice whereas Vimentin immunoreactivity was only seen in the CT. Taken together, our data demonstrate a previously unrecognized origin of taste bud cells from the underlying CT, a conceptually new finding in our knowledge of taste bud cell derivation, i.e., from both the surrounding epithelium and the underlying CT that is primarily derived from NC. PMID:26741369

  19. Contribution of Underlying Connective Tissue Cells to Taste Buds in Mouse Tongue and Soft Palate.

    Directory of Open Access Journals (Sweden)

    Kristin Boggs

    Full Text Available Taste buds, the sensory organs for taste, have been described as arising solely from the surrounding epithelium, which is in distinction from other sensory receptors that are known to originate from neural precursors, i.e., neural ectoderm that includes neural crest (NC. Our previous study suggested a potential contribution of NC derived cells to early immature fungiform taste buds in late embryonic (E18.5 and young postnatal (P1-10 mice. In the present study we demonstrated the contribution of the underlying connective tissue (CT to mature taste buds in mouse tongue and soft palate. Three independent mouse models were used for fate mapping of NC and NC derived connective tissue cells: (1 P0-Cre/R26-tdTomato (RFP to label NC, NC derived Schwann cells and derivatives; (2 Dermo1-Cre/RFP to label mesenchymal cells and derivatives; and (3 Vimentin-CreER/mGFP to label Vimentin-expressing CT cells and derivatives upon tamoxifen treatment. Both P0-Cre/RFP and Dermo1-Cre/RFP labeled cells were abundant in mature taste buds in lingual taste papillae and soft palate, but not in the surrounding epithelial cells. Concurrently, labeled cells were extensively distributed in the underlying CT. RFP signals were seen in the majority of taste buds and all three types (I, II, III of differentiated taste bud cells, with the neuronal-like type III cells labeled at a greater proportion. Further, Vimentin-CreER labeled cells were found in the taste buds of 3-month-old mice whereas Vimentin immunoreactivity was only seen in the CT. Taken together, our data demonstrate a previously unrecognized origin of taste bud cells from the underlying CT, a conceptually new finding in our knowledge of taste bud cell derivation, i.e., from both the surrounding epithelium and the underlying CT that is primarily derived from NC.

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

    Science.gov (United States)

    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

  1. Contribution of Underlying Connective Tissue Cells to Taste Buds in Mouse Tongue and Soft Palate.

    Science.gov (United States)

    Boggs, Kristin; Venkatesan, Nandakumar; Mederacke, Ingmar; Komatsu, Yoshihiro; Stice, Steve; Schwabe, Robert F; Mistretta, Charlotte M; Mishina, Yuji; Liu, Hong-Xiang

    2016-01-01

    Taste buds, the sensory organs for taste, have been described as arising solely from the surrounding epithelium, which is in distinction from other sensory receptors that are known to originate from neural precursors, i.e., neural ectoderm that includes neural crest (NC). Our previous study suggested a potential contribution of NC derived cells to early immature fungiform taste buds in late embryonic (E18.5) and young postnatal (P1-10) mice. In the present study we demonstrated the contribution of the underlying connective tissue (CT) to mature taste buds in mouse tongue and soft palate. Three independent mouse models were used for fate mapping of NC and NC derived connective tissue cells: (1) P0-Cre/R26-tdTomato (RFP) to label NC, NC derived Schwann cells and derivatives; (2) Dermo1-Cre/RFP to label mesenchymal cells and derivatives; and (3) Vimentin-CreER/mGFP to label Vimentin-expressing CT cells and derivatives upon tamoxifen treatment. Both P0-Cre/RFP and Dermo1-Cre/RFP labeled cells were abundant in mature taste buds in lingual taste papillae and soft palate, but not in the surrounding epithelial cells. Concurrently, labeled cells were extensively distributed in the underlying CT. RFP signals were seen in the majority of taste buds and all three types (I, II, III) of differentiated taste bud cells, with the neuronal-like type III cells labeled at a greater proportion. Further, Vimentin-CreER labeled cells were found in the taste buds of 3-month-old mice whereas Vimentin immunoreactivity was only seen in the CT. Taken together, our data demonstrate a previously unrecognized origin of taste bud cells from the underlying CT, a conceptually new finding in our knowledge of taste bud cell derivation, i.e., from both the surrounding epithelium and the underlying CT that is primarily derived from NC.

  2. Bortezomib alters sour taste sensitivity in mice

    Directory of Open Access Journals (Sweden)

    Akihiro Ohishi

    Full Text Available Chemotherapy-induced taste disorder is one of the critical issues in cancer therapy. Bortezomib, a proteasome inhibitor, is a key agent in multiple myeloma therapy, but it induces a taste disorder. In this study, we investigated the characteristics of bortezomib-induced taste disorder and the underlying mechanism in mice. Among the five basic tastes, the sour taste sensitivity of mice was significantly increased by bortezomib administration. In bortezomib-administered mice, protein expression of PKD2L1 was increased. The increased sour taste sensitivity induced by bortezomib returned to the control level on cessation of its administration. These results suggest that an increase in protein expression of PKD2L1 enhances the sour taste sensitivity in bortezomib-administered mice, and this alteration is reversed on cessation of its administration. Keywords: Taste disorder, Bortezomib, Sour taste, Chemotherapy, Adverse effect

  3. The Insula and Taste Learning

    Directory of Open Access Journals (Sweden)

    Adonis Yiannakas

    2017-11-01

    Full Text Available 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.

  4. Expression of genes encoding multi-transmembrane proteins in specific primate taste cell populations.

    Directory of Open Access Journals (Sweden)

    Bryan D Moyer

    Full Text Available BACKGROUND: Using fungiform (FG and circumvallate (CV taste buds isolated by laser capture microdissection and analyzed using gene arrays, we previously constructed a comprehensive database of gene expression in primates, which revealed over 2,300 taste bud-associated genes. Bioinformatics analyses identified hundreds of genes predicted to encode multi-transmembrane domain proteins with no previous association with taste function. A first step in elucidating the roles these gene products play in gustation is to identify the specific taste cell types in which they are expressed. METHODOLOGY/PRINCIPAL FINDINGS: Using double label in situ hybridization analyses, we identified seven new genes expressed in specific taste cell types, including sweet, bitter, and umami cells (TRPM5-positive, sour cells (PKD2L1-positive, as well as other taste cell populations. Transmembrane protein 44 (TMEM44, a protein with seven predicted transmembrane domains with no homology to GPCRs, is expressed in a TRPM5-negative and PKD2L1-negative population that is enriched in the bottom portion of taste buds and may represent developmentally immature taste cells. Calcium homeostasis modulator 1 (CALHM1, a component of a novel calcium channel, along with family members CALHM2 and CALHM3; multiple C2 domains; transmembrane 1 (MCTP1, a calcium-binding transmembrane protein; and anoctamin 7 (ANO7, a member of the recently identified calcium-gated chloride channel family, are all expressed in TRPM5 cells. These proteins may modulate and effect calcium signalling stemming from sweet, bitter, and umami receptor activation. Synaptic vesicle glycoprotein 2B (SV2B, a regulator of synaptic vesicle exocytosis, is expressed in PKD2L1 cells, suggesting that this taste cell population transmits tastant information to gustatory afferent nerve fibers via exocytic neurotransmitter release. CONCLUSIONS/SIGNIFICANCE: Identification of genes encoding multi-transmembrane domain proteins

  5. The Miracle Fruit: An Undergraduate Laboratory Exercise in Taste Sensation and Perception.

    Science.gov (United States)

    Lipatova, Olga; Campolattaro, Matthew M

    2016-01-01

    "Miracle Fruit" is a taste-altering berry that causes sour foods to be perceived as sweet. The present paper describes a laboratory exercise that uses Miracle Fruit to educate students about the sensation and perception of taste. This laboratory exercise reinforces course material pertaining to the function of sweet taste receptors covered in a Sensation and Perception course at Christopher Newport University. Here we provide a step-by-step explanation of the methodology, and an example of data collected and analyzed by one group of students who participated in this laboratory exercise. The origins of the Miracle Fruit, the structure and the physiological function of miraculin (the glycoprotein responsible for the taste-modifying effect found in the pulp of the Miracle Fruit) were discussed before the laboratory exercise. Students then sampled foods known to target different types of tastes (i.e., sweet, sour, bitter and salty) and rated their perception of taste intensity for each food item. Next, students each consumed Miracle Fruit berries, then resampled each original food item and again recorded their perception of taste intensity ratings for these foods. The data confirmed that the sour food items were perceived sweeter after the Miracle Fruit was consumed. The students also completed a written assignment to assess what they learned about the origins, structure, and physiological function of Miracle Fruit. This hands-on laboratory exercise received positive feedback from students. The exercise can be used by other neuroscience educators to teach concepts related to the sensory system of taste.

  6. Lgr5-EGFP marks taste bud stem/progenitor cells in posterior tongue.

    Science.gov (United States)

    Yee, Karen K; Li, Yan; Redding, Kevin M; Iwatsuki, Ken; Margolskee, Robert F; Jiang, Peihua

    2013-05-01

    Until recently, reliable markers for adult stem cells have been lacking for many regenerative mammalian tissues. Lgr5 (leucine-rich repeat-containing G-protein-coupled receptor 5) has been identified as a marker for adult stem cells in intestine, stomach, and hair follicle; Lgr5-expressing cells give rise to all types of cells in these tissues. Taste epithelium also regenerates constantly, yet the identity of adult taste stem cells remains elusive. In this study, we found that Lgr5 is strongly expressed in cells at the bottom of trench areas at the base of circumvallate (CV) and foliate taste papillae and weakly expressed in the basal area of taste buds and that Lgr5-expressing cells in posterior tongue are a subset of K14-positive epithelial cells. Lineage-tracing experiments using an inducible Cre knockin allele in combination with Rosa26-LacZ and Rosa26-tdTomato reporter strains showed that Lgr5-expressing cells gave rise to taste cells, perigemmal cells, along with self-renewing cells at the bottom of trench areas at the base of CV and foliate papillae. Moreover, using subtype-specific taste markers, we found that Lgr5-expressing cell progeny include all three major types of adult taste cells. Our results indicate that Lgr5 may mark adult taste stem or progenitor cells in the posterior portion of the tongue. Copyright © 2013 AlphaMed Press.

  7. Sweet Taste and Nutrient Value Subdivide Rewarding Dopaminergic Neurons in Drosophila

    OpenAIRE

    Huetteroth, Wolf; Perisse, Emmanuel; Lin, Suewei; Klappenbach, Mart?n; Burke, Christopher; Waddell, Scott

    2015-01-01

    Dopaminergic neurons provide reward learning signals in mammals and insects. Recent work in Drosophila has demonstrated that water-reinforcing dopaminergic neurons are different to those for nutritious sugars. Here, we tested whether the sweet taste and nutrient properties of sugar reinforcement further subdivide the fly reward system. We found that dopaminergic neurons expressing the OAMB octopamine receptor specifically convey the short-term reinforcing effects of sweet taste. These dopamin...

  8. Molecular and Cellular Organization of Taste Neurons in Adult Drosophila Pharynx

    OpenAIRE

    Yu-Chieh David Chen; Anupama Dahanukar

    2017-01-01

    Summary: The Drosophila pharyngeal taste organs are poorly characterized despite their location at important sites for monitoring food quality. Functional analysis of pharyngeal neurons has been hindered by the paucity of molecular tools to manipulate them, as well as their relative inaccessibility for neurophysiological investigations. Here, we generate receptor-to-neuron maps of all three pharyngeal taste organs by performing a comprehensive chemoreceptor-GAL4/LexA expression analysis. The ...

  9. Taste acuity, plasma zinc levels, and weight loss during radiotherapy: a study of relationships

    International Nuclear Information System (INIS)

    Bolze, M.S.; Fosmire, G.J.; Stryker, J.A.; Chung, C.K.; Flipse, B.G.

    1982-01-01

    Thirty-five patients who were to undergo radiotherapy and 13 normal subjects were evaluated with taste questionnaires, taste acuity tests, and plasma zinc analyses. The studies were repeated on the patients in the fifth week of radiotherapy. The mean taste thresholds for NaCl (salt), sucrose (sweet), HCl (sour), and urea (bitter) were elevated and the plasma zinc levels were lower (77.2 +/- 11.8 vs. 94.6 +/- 30.1 g/100 ml, p . 0.055) for the patients than for the controls. However, there was not a significant correlation between the taste thresholds and plasma zinc levels at any time. The mean weight loss experienced by the 14 patients who reported subjective taste alteration in the fifth week was 3.1 kg versus 0.1 kg (p . 0.005) for those who did not report taste alteration. The data suggest that alterations in taste acuity, but not plasma zinc levels, are associated with weight loss during radiotherapy

  10. Taste acuity, plasma zinc levels, and weight loss during radiotherapy: a study of relationships

    International Nuclear Information System (INIS)

    Bolze, M.S.; Fosmire, G.J.; Stryker, J.A.; Chung, C.K.; Flipse, B.G.

    1982-01-01

    Thirty-five patients who were to undergo radiotherapy and 13 normal subjects were evaluated with taste questionnaires, taste acuity tests, and plasma zinc analyses. The studies were repeated on the patients in the fifth week of radiotherapy. The mean taste thresholds for NaCl (salt), sucrose (sweet), HCl (sour), and urea (bitter) were elevated and the plasma zinc levels were lower (77.2 +/- 11.8 vs. 94.6 +/- 30.1 g/100 ml, p = 0.055) for the patients than for the controls. However, there was not a significant correlation between the taste thresholds and plasma zinc levels at any time. The mean weight loss experienced by the 14 patients who reported subjective taste alteration in the fifth week was 3.1 kg versus 0.1 kg (p = 0.005) for those who did not report taste alteration. The data suggest that alterations in taste acuity, but not plasma zinc levels, are associated with weight loss during radiotherapy

  11. Texture and savoury taste influences on food intake in a realistic hot lunch time meal

    NARCIS (Netherlands)

    Forde, C.G.; Kuijk, van N.L.; Thaler, T.; Graaf, de C.; Martin, N.

    2013-01-01

    Background: Previous studies with model foods have shown that softer textures lead to higher eating rates and higher ad libitum food intake and higher intensity of salt taste has been shown to result in a lower ad libitum food intake. These observations have yet to be replicated in the context of

  12. Olfactory Receptor Database: a sensory chemoreceptor resource

    OpenAIRE

    Skoufos, Emmanouil; Marenco, Luis; Nadkarni, Prakash M.; Miller, Perry L.; Shepherd, Gordon M.

    2000-01-01

    The Olfactory Receptor Database (ORDB) is a WWW-accessible database that has been expanded from an olfactory receptor resource to a chemoreceptor resource. It stores data on six classes of G-protein-coupled sensory chemoreceptors: (i) olfactory receptor-like proteins, (ii) vomeronasal receptors, (iii) insect olfactory receptors, (iv) worm chemoreceptors, (v) taste papilla receptors and (vi) fungal pheromone receptors. A complementary database of the ligands of these receptors (OdorDB) has bee...

  13. Ongoing ingestive behavior is rapidly suppressed by a preabsorptive, intestinal "bitter taste" cue.

    Science.gov (United States)

    Schier, Lindsey A; Davidson, Terry L; Powley, Terry L

    2011-11-01

    The discovery that cells in the gastrointestinal (GI) tract express the same molecular receptors and intracellular signaling components known to be involved in taste has generated great interest in potential functions of such post-oral "taste" receptors in the control of food intake. To determine whether taste cues in the GI tract are detected and can directly influence behavior, the present study used a microbehavioral analysis of intake, in which rats drank from lickometers that were programmed to simultaneously deliver a brief yoked infusion of a taste stimulus to the intestines. Specifically, in daily 30-min sessions, thirsty rats with indwelling intraduodenal catheters were trained to drink hypotonic (0.12 M) sodium chloride (NaCl) and simultaneously self-infuse a 0.12 M NaCl solution. Once trained, in a subsequent series of intestinal taste probe trials, rats reduced licking during a 6-min infusion period, when a bitter stimulus denatonium benzoate (DB; 10 mM) was added to the NaCl vehicle for infusion, apparently conditioning a mild taste aversion. Presentation of the DB in isomolar lithium chloride (LiCl) for intestinal infusions accelerated the development of the response across trials and strengthened the temporal resolution of the early licking suppression in response to the arrival of the DB in the intestine. In an experiment to evaluate whether CCK is involved as a paracrine signal in transducing the intestinal taste of DB, the CCK-1R antagonist devazepide partially blocked the response to intestinal DB. In contrast to their ability to detect and avoid the bitter taste in the intestine, rats did not modify their licking to saccharin intraduodenal probe infusions. The intestinal taste aversion paradigm developed here provides a sensitive and effective protocol for evaluating which tastants-and concentrations of tastants-in the lumen of the gut can control ingestion.

  14. Changes in taste bud volume during taste disturbance.

    Science.gov (United States)

    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.

  15. Taste bud regeneration and the search for taste progenitor cells.

    Science.gov (United States)

    Miura, H; Barlow, L A

    2010-06-01

    While the taste periphery has been studied for over a century, we are only beginning to understand how this important sensory system is maintained throughout adult life. With the advent of molecular genetics in rodent models, and the upswing in translational approaches that impact human patients, we expect the field will make significant advances in the near future.

  16. Sarco/Endoplasmic reticulum Ca2+-ATPases (SERCA contribute to GPCR-mediated taste perception.

    Directory of Open Access Journals (Sweden)

    Naoko Iguchi

    Full Text Available 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 Ca(2+ concentration ([Ca(2+](c for normal taste signal transduction and transmission. Little, however, is known about the mechanisms controlling the removal of elevated [Ca(2+](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 Ca(2+ clearance in TRCs, we sought the molecules involved in [Ca(2+](c regulation using a single-taste-cell transcriptome approach. We found that Serca3, a member of the sarco/endoplasmic reticulum Ca(2+-ATPase (SERCA family that sequesters cytosolic Ca(2+ into endoplasmic reticulum, is exclusively expressed in sweet/umami/bitter TRCs, which rely on intracellular Ca(2+ 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 Ca(2+ clearance in TRCs and that mutation of these proteins may alter bitter and perhaps sweet and umami taste perception.

  17. A potential sex dimorphism in the relationship between bitter taste and alcohol consumption.

    Science.gov (United States)

    Beckett, Emma Louise; Duesing, Konsta; Boyd, Lyndell; Yates, Zoe; Veysey, Martin; Lucock, Mark

    2017-03-22

    Bitterness is an innate aversive taste important in detecting potentially toxic substances, including alcohol. However, bitter compounds exist in many foods and beverages, and can be desirable, such as in beer. TAS2R38 is a well-studied bitter taste receptor with common polymorphisms. Some have reported relationships between TAS2R38 genotypes, bitter taste phenotype and alcohol intake, however results have been mixed. These mixed results may be explained by the varying taste properties of different alcoholic beverages or a sex dimorphism in responses. Bitter taste phenotype was assessed using PROP taste test and TAS2R38-P49A genotype was assessed by RFLP-PCR. Alcohol intake was assessed by food frequency questionnaire and classified by beverage type (beer, wine, spirits or mixed drinks). The relationships between bitter taste phenotype and carriage of the P allele of the TAS2R38-A49P gene and alcohol intake were assessed adjusted for and stratified by sex, and the interaction between taste and sex was evaluated. The relationship between alcohol intake and bitter taste phenotype varied by beverage type, with significant results for beer, spirits and mixed drinks, but not wine. When stratified, results varied by sex, and were only significant in males. Significant interactions were found for taster phenotype and sex (total alcohol intake and intake of beer and spirits). Results were similar for carriage of the TAS2R38-P49A P allele. Sex-specific interactions between bitter taste phenotype, TAS2R38 genotype and alcohol intake may explain variance in previous studies and may have implications for sex-specific disease risk and public health interventions.

  18. Distribution of sensory taste thresholds for phenylthiocarbamide ...

    African Journals Online (AJOL)

    The ability to taste Phenylthiocarbamide (PTC), a bitter organic compound has been described as a bimodal autosomal trait in both genetic and anthropological studies. This study is based on the ability of a person to taste PTC. The present study reports the threshold distribution of PTC taste sensitivity among some Muslim ...

  19. A novel pungency biosensor prepared with fixing taste-bud tissue of rats.

    Science.gov (United States)

    Qiao, Lixin; Jiao, Lihua; Pang, Guangchang; Xie, Junbo

    2015-06-15

    A novel taste biosensor based on ligand-receptor interaction was developed through fixing taste-bud tissues of SD rats to a glassy carbon electrode. Using the sodium alginate-starch gel as a fixing agent, taste-bud tissues of SD rats were fixed between two nuclear microporous membranes to make a sandwich-type sensing membrane. With the taste biosensor, the response current induced by capsaicin and gingerol stimulating the corresponding receptors was measured. The results showed that the lowest limit of detection of this biosensor to capsaicin was 1×10(-13) mol/L and the change rate of response current was the highest at the concentration of 9×10(-13) mol/L, indicating that the capsaicin receptor was saturated at this point. The lowest limit of detection of this biosensor to gingerol was 1×10(-12) mol/L, and the gingerol receptor was saturated when the concentration of gingerol was 3×10(-11) mol/L. It was demonstrated that the interaction curves of capsaicin and gingerol with their respective receptors exhibited high correlation (R(2): 0.9841 and 0.9904). The binding constant and dissociation constant of gingerol with its receptor were 1.564×10(-11) and 1.815×10(-11) respectively, which were all higher than those of capsaicin with its receptor (1.249×10(-12) and 2.078×10(-12)). This study, for the first time, made it possible to quantitatively determine the interaction of the taste receptor and pungent substances with a new biosensor, thus providing a simple approach for monitoring pungent substances and investigating the mechanism of ligand-receptor interaction. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Sweet taste signaling functions as a hypothalamic glucose sensor

    Directory of Open Access Journals (Sweden)

    Xueying Ren

    2009-06-01

    Full Text Available Brain glucosensing is essential for normal body glucose homeostasis and neuronal function. However, the exact signaling mechanisms involved in the neuronal sensing of extracellular glucose levels remain poorly understood. Of particular interest is the identification of candidate membrane molecular sensors allowing neurons to change firing rates independently of intracellular glucose metabolism. Here we describe for the first time the expression of the taste receptor genes Tas1r1, Tas1r2 and Tas1r3, and their associated G-protein genes, in the mammalian brain. Neuronal expression of taste genes was detected in different nutrient-sensing forebrain regions, including the paraventricular and arcuate nuclei of the hypothalamus, the CA fields and dentate gyrus of the hippocampus, the habenula, and cortex. Expression was also observed in the intra-ventricular epithelial cells of the choroid plexus. These same regions were found to express the corresponding gene products that form the heterodimeric T1R2/T1R3 and T1R1/T1R3 sweet and L-amino acid taste G-protein coupled receptors, respectively. These regions were also found to express the taste G-protein α-Gustducin. Moreover, in vivo studies in mice demonstrate that the hypothalamic expression of taste-related genes is regulated by the nutritional state of the animal, with food deprivation significantly increasing expression levels of Tas1r1 and Tas1r2 in hypothalamus, but not in cortex. Furthermore, exposing mouse hypothalamic cells to a low-glucose medium, while maintaining normal L-amino acid concentrations, specifically resulted in higher expression levels of the sweet-associated gene Tas1r2. This latter effect was reversed by adding the non-metabolizable artificial sweetener sucralose to the low-glucose medium, indicating that taste-like signaling in hypothalamic neurons does not require intracellular glucose oxidation. Our findings suggest that the G-protein coupled sweet receptor T1R2/T1R3 is a

  1. Sensory science research on taste

    DEFF Research Database (Denmark)

    Mann, Anna

    2018-01-01

    Recent ethnographies from the anthropology of food and the senses have shown how moments in which people taste foods are shaped by scientific knowledge, methods and rationales. Building on approaches developed in science and technology studies, this paper offers an ethnography of the field to which...

  2. Context-driven Salt Seeking Test (Rats)

    Science.gov (United States)

    Chang, Stephen E.; Smith, Kyle S.

    2018-01-01

    Changes in reward seeking behavior often occur through incremental learning based on the difference between what is expected and what actually happens. Behavioral flexibility of this sort requires experience with rewards as better or worse than expected. However, there are some instances in which behavior can change through non-incremental learning, which requires no further experience with an outcome. Such an example of non-incremental learning is the salt appetite phenomenon. In this case, animals such as rats will immediately seek out a highly-concentrated salt solution that was previously undesired when they are put in a novel state of sodium deprivation. Importantly, this adaptive salt-seeking behavior occurs despite the fact that the rats never tasted salt in the depleted state, and therefore never tasted it as a highly desirable reward. The following protocol is a method to investigate the neural circuitry mediating adaptive salt seeking using a conditioned place preference (CPP) procedure. The procedure is designed to provide an opportunity to discover possible dissociations between the neural circuitry mediating salt seeking and salt consumption to replenish the bodily deficit after sodium depletion. Additionally, this procedure is amenable to incorporating a number of neurobiological techniques for studying the brain basis of this behavior.

  3. Bitter taste – cheese failure

    Directory of Open Access Journals (Sweden)

    Slavko Kirin

    2001-10-01

    Full Text Available Bitter taste is serous and very often cheese failure in modern cheesemaking process. In this paper the sources and bitter taste development in cheese will be presented. Bitterness in cheese is linked to bitter compounds development during cheese ripening. Most of the bitter compounds come from bitter peptides, the mechanism of theirs development being due to proteasepeptidase system of the cured enzymes and the milk cultures as well as other proteases present in cheese. By the action of curd enzymes, the milk protein - casein - is firstly degraded into high molecular weight compounds possessing no bitter taste. Those compounds are then degraded, by milk protease cultures, to hydrophobic bitter peptides of low molecular weight further degraded, by bacterial endopeptidase during cheese ripening, to bitter peptides and amino acids. In the case when no balance exists, between bitter compounds development and breakdown by lactic acid bacteria peptidase, an accumulation of bitter peptides occurs thus having an influence on cheese bitterness. During cheese ripening naturally occurring milk protease – plasmin, and thermostable proteases of raw milk microflora are also involved in proteolytic process. Fat cheese lipases, initiated by lipase originating from psychrotrophic bacteria in raw milk as well as other cheese lipases, are also associated with bitter taste generation. The other sources of bitterness come from the forages, the medicament residues as well as washing and disinfecting agents. In order to eliminate these failures a special care should be taken in milk quality as well as curd and milk culture selection. At this point technological norms and procedures, aimed to maintain the proteolysis balance during cheese ripening, should be adjusted, thus eliminating the bitter taste of the cheese.

  4. Lipid-Lowering Pharmaceutical Clofibrate Inhibits Human Sweet Taste

    Science.gov (United States)

    Kochem, Matthew

    2017-01-01

    T1R2-T1R3 is a heteromeric receptor that binds sugars, high potency sweeteners, and sweet taste blockers. In rodents, T1R2-T1R3 is largely responsible for transducing sweet taste perception. T1R2-T1R3 is also expressed in non-taste tissues, and a growing body of evidence suggests that it helps regulate glucose and lipid metabolism. It was previously shown that clofibric acid, a blood lipid-lowering drug, binds T1R2-T1R3 and inhibits its activity in vitro. The purpose of this study was to determine whether clofibric acid inhibits sweetness perception in humans and is, therefore, a T1R2-T1R3 antagonist in vivo. Fourteen participants rated the sweetness intensity of 4 sweeteners (sucrose, sucralose, Na cyclamate, acesulfame K) across a broad range of concentrations. Each sweetener was prepared in solution neat and in mixture with either clofibric acid or lactisole. Clofibric acid inhibited sweetness of every sweetener. Consistent with competitive binding, inhibition by clofibric acid was diminished with increasing sweetener concentration. This study provides in vivo evidence that the lipid-lowering drug clofibric acid inhibits sweetness perception and is, therefore, a T1R carbohydrate receptor inhibitor. Our results are consistent with previous in vitro findings. Given that T1R2-T1R3 may in part regulate glucose and lipid metabolism, future studies should investigate the metabolic effects of T1R inhibition. PMID:27742692

  5. The bamboo-eating giant panda (Ailuropoda melanoleuca) has a sweet tooth: behavioral and molecular responses to compounds that taste sweet to humans.

    Science.gov (United States)

    Jiang, Peihua; Josue-Almqvist, Jesusa; Jin, Xuelin; Li, Xia; Brand, Joseph G; Margolskee, Robert F; Reed, Danielle R; Beauchamp, Gary K

    2014-01-01

    A growing body of behavioral and genetic information indicates that taste perception and food sources are highly coordinated across many animal species. For example, sweet taste perception is thought to serve to detect and motivate consumption of simple sugars in plants that provide calories. Supporting this is the observation that most plant-eating mammals examined exhibit functional sweet perception, whereas many obligate carnivores have independently lost function of their sweet taste receptors and exhibit no avidity for simple sugars that humans describe as tasting sweet. As part of a larger effort to compare taste structure/function among species, we examined both the behavioral and the molecular nature of sweet taste in a plant-eating animal that does not consume plants with abundant simple sugars, the giant panda (Ailuropoda melanoleuca). We evaluated two competing hypotheses: as plant-eating mammals, they should have a well-developed sweet taste system; however, as animals that do not normally consume plants with simple sugars, they may have lost sweet taste function, as has occurred in strict carnivores. In behavioral tests, giant pandas avidly consumed most natural sugars and some but not all artificial sweeteners. Cell-based assays revealed similar patterns of sweet receptor responses toward many of the sweeteners. Using mixed pairs of human and giant panda sweet taste receptor units (hT1R2+gpT1R3 and gpT1R2+hT1R3) we identified regions of the sweet receptor that may account for behavioral differences in giant pandas versus humans toward various sugars and artificial sweeteners. Thus, despite the fact that the giant panda's main food, bamboo, is very low in simple sugars, the species has a marked preference for several compounds that taste sweet to humans. We consider possible explanations for retained sweet perception in this species, including the potential extra-oral functions of sweet taste receptors that may be required for animals that consume

  6. Intravital Microscopic Interrogation of Peripheral Taste Sensation

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Xiaoang eWan

    2014-12-01

    Full Text Available We report a cross-cultural study designed to investigate crossmodal correspondences between a variety of visual features (11 colours, 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 colour 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 colours/shapes and bitter, sour, and sweet tastes. Crossmodal correspondences were also documented between the colour 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 colours, shapes, and one of the textures and the taste terms. The taste-patterns shown by the participants from the four countries tested in 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.

  10. ALTERNATIVE METHODS OF TECHNOLOGICAL PROCESSING TO REDUCE SALT IN MEAT PRODUCTS

    Directory of Open Access Journals (Sweden)

    E. K. Tunieva

    2017-01-01

    Full Text Available The world trends in table salt reduction in meat products contemplate the use of different methods for preservation of taste and consistency in finished products as well as shelf life prolongation. There are several approaches to a sodium chloride reduction in meat products. The paper presents a review of the foreign studies that give evidence of the possibility to maintain quality of traditional meat products produced with the reduced salt content. The studies in the field of salty taste perception established that a decrease in a salt crystal size to 20 µm enabled reducing an amount of added table salt due to an increase in the salty taste intensity in food products. Investigation of the compatibility of different taste directions is also interesting as one of the approaches to a sodium chloride reduction in food products. The use of water-in-oil-in-water (w/o/w double emulsions allows controlling a release of encapsulated ingredients (salt, which enables enhancement of salty taste. The other alternative method of technological processing of meat raw material for reducing salt in meat products is the use of high pressure processing. This method has several advantages and allows not only an increase in the salty taste intensity, but also formation of a stable emulsion, an increase in water binding capacity of minced meat and extension of shelf-life.

  11. Immunocytochemical analysis of P2X2 in rat circumvallate taste buds.

    Science.gov (United States)

    Yang, Ruibiao; Montoya, Alana; Bond, Amanda; Walton, Jenna; Kinnamon, John C

    2012-05-23

    Our laboratory has shown that classical synapses and synaptic proteins are associated with Type III cells. Yet it is generally accepted that Type II cells transduce bitter, sweet and umami stimuli. No classical synapses, however, have been found associated with Type II cells. Recent studies indicate that the ionotropic purinergic receptors P2X2/P2X3 are present in rodent taste buds. Taste nerve processes express the ionotropic purinergic receptors (P2X2/P2X3). P2X2/P2X3(Dbl-/-) mice are not responsive to sweet, umami and bitter stimuli, and it has been proposed that ATP acts as a neurotransmitter in taste buds. The goal of the present study is to learn more about the nature of purinergic contacts in rat circumvallate taste buds by examining immunoreactivity to antisera directed against the purinergic receptor P2X2. P2X2-like immunoreactivity is present in intragemmal nerve processes in rat circumvallate taste buds. Intense immunoreactivity can also be seen in the subgemmal nerve plexuses located below the basal lamina. The P2X2 immunoreactive nerve processes also display syntaxin-1-LIR. The immunoreactive nerves are in close contact with the IP(3)R3-LIR Type II cells and syntaxin-1-LIR and/or 5-HT-LIR Type III cells. Taste cell synapses are observed only from Type III taste cells onto P2X2-LIR nerve processes. Unusually large, "atypical" mitochondria in the Type II taste cells are found only at close appositions with P2X2-LIR nerve processes. P2X2 immunogold particles are concentrated at the membranes of nerve processes at close appositions with taste cells. Based on our immunofluorescence and immunoelectron microscopical studies we believe that both perigemmal and most all intragemmal nerve processes display P2X2-LIR. Moreover, colloidal gold immunoelectron microscopy indicates that P2X2-LIR in nerve processes is concentrated at sites of close apposition with Type II cells. This supports the hypothesis that ATP may be a key neurotransmitter in taste transduction

  12. Immunocytochemical analysis of P2X2 in rat circumvallate taste buds

    Directory of Open Access Journals (Sweden)

    Yang Ruibiao

    2012-05-01

    Full Text Available Abstract Background Our laboratory has shown that classical synapses and synaptic proteins are associated with Type III cells. Yet it is generally accepted that Type II cells transduce bitter, sweet and umami stimuli. No classical synapses, however, have been found associated with Type II cells. Recent studies indicate that the ionotropic purinergic receptors P2X2/P2X3 are present in rodent taste buds. Taste nerve processes express the ionotropic purinergic receptors (P2X2/P2X3. P2X2/P2X3Dbl−/− mice are not responsive to sweet, umami and bitter stimuli, and it has been proposed that ATP acts as a neurotransmitter in taste buds. The goal of the present study is to learn more about the nature of purinergic contacts in rat circumvallate taste buds by examining immunoreactivity to antisera directed against the purinergic receptor P2X2. Results P2X2-like immunoreactivity is present in intragemmal nerve processes in rat circumvallate taste buds. Intense immunoreactivity can also be seen in the subgemmal nerve plexuses located below the basal lamina. The P2X2 immunoreactive nerve processes also display syntaxin-1-LIR. The immunoreactive nerves are in close contact with the IP3R3-LIR Type II cells and syntaxin-1-LIR and/or 5-HT-LIR Type III cells. Taste cell synapses are observed only from Type III taste cells onto P2X2-LIR nerve processes. Unusually large, “atypical” mitochondria in the Type II taste cells are found only at close appositions with P2X2-LIR nerve processes. P2X2 immunogold particles are concentrated at the membranes of nerve processes at close appositions with taste cells. Conclusions Based on our immunofluorescence and immunoelectron microscopical studies we believe that both perigemmal and most all intragemmal nerve processes display P2X2-LIR. Moreover, colloidal gold immunoelectron microscopy indicates that P2X2-LIR in nerve processes is concentrated at sites of close apposition with Type II cells. This supports the hypothesis

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

    Science.gov (United States)

    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.

  14. 5-HT3A -driven green fluorescent protein delineates gustatory fibers innervating sour-responsive taste cells: A labeled line for sour taste?

    Science.gov (United States)

    Stratford, J M; Larson, E D; Yang, R; Salcedo, E; Finger, T E

    2017-07-01

    Taste buds contain multiple cell types with each type expressing receptors and transduction components for a subset of taste qualities. The sour sensing cells, Type III cells, release serotonin (5-HT) in response to the presence of sour (acidic) tastants and this released 5-HT activates 5-HT 3 receptors on the gustatory nerves. We show here, using 5-HT 3A GFP mice, that 5-HT 3 -expressing nerve fibers preferentially contact and receive synaptic contact from Type III taste cells. Further, these 5-HT 3 -expressing nerve fibers terminate in a restricted central-lateral portion of the nucleus of the solitary tract (nTS)-the same area that shows increased c-Fos expression upon presentation of a sour tastant (30 mM citric acid). This acid stimulation also evokes c-Fos in the laterally adjacent mediodorsal spinal trigeminal nucleus (DMSp5), but this trigeminal activation is not associated with the presence of 5-HT 3 -expressing nerve fibers as it is in the nTS. Rather, the neuronal activation in the trigeminal complex likely is attributable to direct depolarization of acid-sensitive trigeminal nerve fibers, for example, polymodal nociceptors, rather than through taste buds. Taken together, these findings suggest that transmission of sour taste information involves communication between Type III taste cells and 5-HT 3 -expressing afferent nerve fibers that project to a restricted portion of the nTS consistent with a crude mapping of taste quality information in the primary gustatory nucleus. © 2017 Wiley Periodicals, Inc.

  15. Taste dysfunction in irradiated patients with head and neck cancer

    International Nuclear Information System (INIS)

    Zheng, Wen-Kai; Yamamoto, Tomoya; Komiyama, Sohtaro

    2002-01-01

    Taste disorders caused by radiation therapy for head and neck cancer are common. This prospective study of 40 patients with head and neck cancer assessed changes in taste sensations during radiation therapy. The relationship between the time course and the degree of taste disorder was studied. The taste recognition threshold and supra-threshold taste intensity performance for the four basic tastes were measured using the whole-mouth taste method before, during, and after radiation therapy. Bitter taste was affected most. An increase in threshold for sweet taste depended upon whether the tip of tongue was included within the radiation field. The slope of the taste intensity performance did not change during or after radiotherapy. The pattern of salivary dysfunction was different from that of taste dysfunction. The main cause of taste disorders during radiation support the hypothesis that taste dysfunction is due to damage to the taste buds in the radiation field. (author)

  16. Taste dysfunction in irradiated patients with head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Wen-Kai; Yamamoto, Tomoya; Komiyama, Sohtaro [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine; Inokuchi, Akira [Saga Medical School (Japan)

    2002-04-01

    Taste disorders caused by radiation therapy for head and neck cancer are common. This prospective study of 40 patients with head and neck cancer assessed changes in taste sensations during radiation therapy. The relationship between the time course and the degree of taste disorder was studied. The taste recognition threshold and supra-threshold taste intensity performance for the four basic tastes were measured using the whole-mouth taste method before, during, and after radiation therapy. Bitter taste was affected most. An increase in threshold for sweet taste depended upon whether the tip of tongue was included within the radiation field. The slope of the taste intensity performance did not change during or after radiotherapy. The pattern of salivary dysfunction was different from that of taste dysfunction. The main cause of taste disorders during radiation support the hypothesis that taste dysfunction is due to damage to the taste buds in the radiation field. (author)

  17. A longitudinal study of altered taste and smell perception and change in blood pressure.

    Science.gov (United States)

    Liu, Y-H; Huang, Z; Vaidya, A; Li, J; Curhan, G C; Wu, S; Gao, X

    2018-05-29

    Previous studies suggest that olfactory receptors, which mediate smell chemosensation, are located in the kidney and involved in blood pressure regulation. Mammalian epithelial sodium channels located in taste receptor cells are also found to participate in blood pressure regulation. However, there is currently no human study that has examined the association between taste and smell function and blood pressure. We thus conducted a longitudinal study to examine whether participants with altered taste and smell perception had larger increases in blood pressure compared with those without altered perception in a community-based cohort. The study included 5190 Chinese adults (4058 men and 1132 women) who were normotensive at baseline. Taste and smell perception were assessed via questionnaire in 2012 (baseline). Blood pressure was measured in 2012 and 2014 to determine relative change in blood pressure. Mean differences of 2-year blood pressure change and 95% confidence intervals (CIs) across four categories of taste and smell perception were calculated after adjusting for known risk factors for hypertension. After adjusting for potential confounders, individuals with altered taste and smell perception had larger increases in systolic blood pressure (adjusted mean difference = 5.1 mmHg, 95% CI: 0.1-10.0, p-value: 0.04) and mean arterial pressure (adjusted mean difference = 3.8 mmHg, 95% CI: 0.4-7.1, p-value: 0.03) after two years of follow-up compared with those having neither altered taste nor altered smell perception. No significant association was observed in individuals with altered taste or smell perception only. Our results suggest an association between chemosensory function and blood pressure. Copyright © 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights

  18. Drosophila fatty acid taste signals through the PLC pathway in sugar-sensing neurons.

    Directory of Open Access Journals (Sweden)

    Pavel Masek

    Full Text Available Taste is the primary sensory system for detecting food quality and palatability. Drosophila detects five distinct taste modalities that include sweet, bitter, salt, water, and the taste of carbonation. Of these, sweet-sensing neurons appear to have utility for the detection of nutritionally rich food while bitter-sensing neurons signal toxicity and confer repulsion. Growing evidence in mammals suggests that taste for fatty acids (FAs signals the presence of dietary lipids and promotes feeding. While flies appear to be attracted to fatty acids, the neural basis for fatty acid detection and attraction are unclear. Here, we demonstrate that a range of FAs are detected by the fly gustatory system and elicit a robust feeding response. Flies lacking olfactory organs respond robustly to FAs, confirming that FA attraction is mediated through the gustatory system. Furthermore, flies detect FAs independent of pH, suggesting the molecular basis for FA taste is not due to acidity. We show that low and medium concentrations of FAs serve as an appetitive signal and they are detected exclusively through the same subset of neurons that sense appetitive sweet substances, including most sugars. In mammals, taste perception of sweet and bitter substances is dependent on phospholipase C (PLC signaling in specialized taste buds. We find that flies mutant for norpA, a Drosophila ortholog of PLC, fail to respond to FAs. Intriguingly, norpA mutants respond normally to other tastants, including sucrose and yeast. The defect of norpA mutants can be rescued by selectively restoring norpA expression in sweet-sensing neurons, corroborating that FAs signal through sweet-sensing neurons, and suggesting PLC signaling in the gustatory system is specifically involved in FA taste. Taken together, these findings reveal that PLC function in Drosophila sweet-sensing neurons is a conserved molecular signaling pathway that confers attraction to fatty acids.

  19. Taste as a didactic approach

    DEFF Research Database (Denmark)

    Wistoft, Karen; Christensen, Jacob

    2016-01-01

    of expectations to students’ learning. This article presents the results of a new quantitative study that investigates students’ work with taste in relation to their own expected learning in the subject Food Knowledge, viewed in the light of three didactic elements: motivation, student participation......Teaching does not necessarily condition learning, and specific didactic elements do not necessarily condition the best learning outcome; this also applies to ‘food and meal’ lessons in schools. Teachers’ didactic reflections usually reflect the content and form of the teaching, as well as a number...... and innovation in school. The method is a questionnaire among students (N= 769) who have competed in Food Fight, a competition that forms part of Food Knowledge. The connection between taste and learning is a relatively unexplored field, and the analysis in this article indicates that the experience of working...

  20. Taste is a didactic approach

    DEFF Research Database (Denmark)

    Christensen, Jacob Højgaard

    2015-01-01

    of expectations to students’ learning. This article presents the results of a new quantitative study that investigates students’ work with taste in relation to their own expected learning in the subject Food Knowledge, viewed in the light of three didactic elements: motivation, student participation......Teaching does not necessarily condition learning, and specific didactic elements do not necessarily condition the best learning outcome; this also applies to ‘food and meal’ lessons in schools. Teachers’ didactic reflections usually reflect the content and form of the teaching, as well as a number...... and innovation in school. The method is a questionnaire among students (N= 769) who have competed in Food Fight, a competition that forms part of Food Knowledge. The connection between taste and learning is a relatively unexplored field, and the analysis in this article indicates that the experience of working...

  1. Wine Expertise Predicts Taste Phenotype.

    Science.gov (United States)

    Hayes, John E; Pickering, Gary J

    2012-03-01

    Taste phenotypes have long been studied in relation to alcohol intake, dependence, and family history, with contradictory findings. However, on balance - with appropriate caveats about populations tested, outcomes measured and psychophysical methods used - an association between variation in taste responsiveness and some alcohol behaviors is supported. Recent work suggests super-tasting (operationalized via propylthiouracil (PROP) bitterness) not only associates with heightened response but also with more acute discrimination between stimuli. Here, we explore relationships between food and beverage adventurousness and taste phenotype. A convenience sample of wine drinkers (n=330) were recruited in Ontario and phenotyped for PROP bitterness via filter paper disk. They also filled out a short questionnaire regarding willingness to try new foods, alcoholic beverages and wines as well as level of wine involvement, which was used to classify them as a wine expert (n=110) or wine consumer (n=220). In univariate logisitic models, food adventurousness predicted trying new wines and beverages but not expertise. Likewise, wine expertise predicted willingness to try new wines and beverages but not foods. In separate multivariate logistic models, willingness to try new wines and beverages was predicted by expertise and food adventurousness but not PROP. However, mean PROP bitterness was higher among wine experts than wine consumers, and the conditional distribution functions differed between experts and consumers. In contrast, PROP means and distributions did not differ with food adventurousness. These data suggest individuals may self-select for specific professions based on sensory ability (i.e., an active gene-environment correlation) but phenotype does not explain willingness to try new stimuli.

  2. Taste: The Bedrock of Flavor

    OpenAIRE

    Gary K Beauchamp

    2014-01-01

    The significance of taste for human health:Throughout most of human evolution, the daily decisions of what to put into ones mouth and swallow and what to reject presented challenges fraught with danger. Energy-rich foods were often difficult to find; protein was in short supply; sodium was scarce. Moreover, many plants that did contain nutrients were also equipped with defensive compounds that were poisonous. Now many humans over consume exactly the foods that they evolved to find particu...

  3. Coevolutionary patterning of teeth and taste buds

    Science.gov (United States)

    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

  4. Coevolutionary patterning of teeth and taste buds.

    Science.gov (United States)

    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.

  5. Evaluation of whey, milk, and delactosed permeates as salt substitutes.

    Science.gov (United States)

    Smith, S T; Metzger, L; Drake, M A

    2016-11-01

    Whey and milk permeates are by-products of high-protein dairy powder manufacture. Previous work has shown that these permeates contribute to salty taste without contributing significantly to sodium content. The objective of this study was to explore the sensory characteristics and compositional analysis of permeates from different milk and whey streams and a low-sodium product application made from them. Skim milk, Cheddar, cottage, and Mozzarella cheese whey permeates were manufactured in triplicate, and delactosed whey permeate was obtained in triplicate. Composition (protein, fat, solids, minerals) was conducted on permeates. Organic acid composition was determined using HPLC. Volatile compounds were extracted from permeates by solid phase microextraction with gas chromatography-mass spectrometry. A trained sensory panel documented sensory attributes of permeates and cream of broccoli soups with and without salt or permeates followed by consumer acceptance testing (n=105) on the soups. Cottage cheese whey permeate contained a higher lactic acid content than other permeates, which has been shown to contribute to a higher salty taste. Cottage cheese whey permeate also contained potato or brothy and caramel flavors and sour and salty tastes, whereas delactosed whey permeate had high intensities of cardboard and beefy or brothy flavors and salty taste. Milk, Cheddar, and Mozzarella cheese whey permeates were characterized by sweet taste and cooked milky flavor. Permeates with higher cardboard flavor had higher levels of aldehydes. All permeates contributed to salty taste and to salty taste perception in soups; although the control soup with added salt was perceived as saltier and was preferred by consumers over permeate soups. Soup with permeate from cottage cheese was the least liked of all soups, likely due to its sour taste. All other permeate soups scored at parity for liking. These results demonstrate the potential for milk, whey, and delactosed permeates from

  6. The role of identified neurotransmitter systems in the response of insular cortex to unfamiliar taste: activation of ERK1-2 and formation of a memory trace.

    Science.gov (United States)

    Berman, D E; Hazvi, S; Neduva, V; Dudai, Y

    2000-09-15

    In the behaving rat, the consumption of an unfamiliar taste activates the extracellular signal-regulated kinase 1-2 (ERK1-2) in the insular cortex, which contains the taste cortex. In contrast, consumption of a familiar taste has no effect. Furthermore, activation of ERK1-2, culminating in modulation of gene expression, is obligatory for the encoding of long-term, but not short-term, memory of the new taste (Berman et al., 1998). Which neurotransmitter and neuromodulatory systems are involved in the activation of ERK1-2 by the unfamiliar taste and in the long-term encoding of the new taste information? Here we show, by the use of local microinjections of pharmacological agents to the insular cortex in the behaving rat, that multiple neurotransmitters and neuromodulators are required for encoding of taste memory in cortex. However, these systems vary in the specificity of their role in memory acquisition and in their contribution to the activation of ERK1-2. NMDA receptors, metabotropic glutamate receptors, muscarinic, and beta-adrenergic and dopaminergic receptors, all contribute to the acquisition of the new taste memory but not to its retrieval. Among these, only NMDA and muscarinic receptors specifically mediate taste-dependent activation of ERK1-2, whereas the beta-adrenergic function is independent of ERK1-2, and dopaminergic receptors regulate also the basal level of ERK1-2 activation. The data are discussed in the context of postulated novelty detection circuits in the central taste system.

  7. Analysis of Facial Expression by Taste Stimulation

    Science.gov (United States)

    Tobitani, Kensuke; Kato, Kunihito; Yamamoto, Kazuhiko

    In this study, we focused on the basic taste stimulation for the analysis of real facial expressions. We considered that the expressions caused by taste stimulation were unaffected by individuality or emotion, that is, such expressions were involuntary. We analyzed the movement of facial muscles by taste stimulation and compared real expressions with artificial expressions. From the result, we identified an obvious difference between real and artificial expressions. Thus, our method would be a new approach for facial expression recognition.

  8. Salt Tolerance

    OpenAIRE

    Xiong, Liming; Zhu, Jian-Kang

    2002-01-01

    Studying salt stress is an important means to the understanding of plant ion homeostasis and osmo-balance. Salt stress research also benefits agriculture because soil salinity significantly limits plant productivity on agricultural lands. Decades of physiological and molecular studies have generated a large body of literature regarding potential salt tolerance determinants. Recent advances in applying molecular genetic analysis and genomics tools in the model plant Arabidopsis thaliana are sh...

  9. Sea salt

    OpenAIRE

    Galvis-Sánchez, Andrea C.; Lopes, João Almeida; Delgadillo, Ivone; Rangel, António O. S. S.

    2013-01-01

    The geographical indication (GI) status links a product with the territory and with the biodiversity involved. Besides, the specific knowledge and cultural practices of a human group that permit transforming a resource into a useful good is protected under a GI designation. Traditional sea salt is a hand-harvested product originating exclusively from salt marshes from specific geographical regions. Once salt is harvested, no washing, artificial drying or addition of anti-caking agents are all...

  10. Arecoline Alters Taste Bud Cell Morphology, Reduces Body Weight, and Induces Behavioral Preference Changes in Gustatory Discrimination in C57BL/6 Mice.

    Science.gov (United States)

    Peng, Wei-Hau; Chau, Yat-Pang; Lu, Kuo-Shyan; Kung, Hsiu-Ni

    2016-01-01

    Arecoline, a major alkaloid in areca nuts, is involved in the pathogenesis of oral diseases. Mammalian taste buds are the structural unit for detecting taste stimuli in the oral cavity. The effects of arecoline on taste bud morphology are poorly understood. Arecoline was injected intraperitoneally (IP) into C57BL/6 mice twice daily for 1-4 weeks. After arecoline treatment, the vallate papillae were processed for electron microscopy and immunohistochemistry analysis of taste receptor proteins (T1R2, T1R3, T1R1, and T2R) and taste associated proteins (α-gustducin, PLCβ2, and SNAP25). Body weight, food intake and water consumption were recorded. A 2-bottle preference test was also performed. The results demonstrated that 1) arecoline treatment didn't change the number and size of the taste buds or taste bud cells, 2) electron microscopy revealed the change of organelles and the accumulation of autophagosomes in type II cells, 3) immunohistochemistry demonstrated a decrease of taste receptor T1R2- and T1R3-expressing cells, 4) the body weight and food intake were markedly reduced, and 5) the sweet preference behavior was reduced. We concluded that the long-term injection of arecoline alters the morphology of type II taste bud cells, retards the growth of mice, and affects discrimination competencies for sweet tastants. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Fgf signaling controls pharyngeal taste bud formation through miR-200 and Delta-Notch activity.

    Science.gov (United States)

    Kapsimali, Marika; Kaushik, Anna-Lila; Gibon, Guillaume; Dirian, Lara; Ernest, Sylvain; Rosa, Frederic M

    2011-08-01

    Taste buds, the taste sensory organs, are conserved in vertebrates and composed of distinct cell types, including taste receptor, basal/presynaptic and support cells. Here, we characterize zebrafish taste bud development and show that compromised Fgf signaling in the larva results in taste bud reduction and disorganization. We determine that Fgf activity is required within pharyngeal endoderm for formation of Calb2b(+) cells and reveal miR-200 and Delta-Notch signaling as key factors in this process. miR-200 knock down shows that miR-200 activity is required for taste bud formation and in particular for Calb2b(+) cell formation. Compromised delta activity in mib(-/-) dramatically reduces the number of Calb2b(+) cells and increases the number of 5HT(+) cells. Conversely, larvae with increased Notch activity and ascl1a(-/-) mutants are devoid of 5HT(+) cells, but have maintained and increased Calb2b(+) cells, respectively. These results show that Delta-Notch signaling is required for intact taste bud organ formation. Consistent with this, Notch activity restores Calb2b(+) cell formation in pharyngeal endoderm with compromised Fgf signaling, but fails to restore the formation of these cells after miR-200 knock down. Altogether, this study provides genetic evidence that supports a novel model where Fgf regulates Delta-Notch signaling, and subsequently miR-200 activity, in order to promote taste bud cell type differentiation.

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

    Science.gov (United States)

    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.

  13. Fingerprinting taste buds: intermediate filaments and their implication for taste bud formation.

    OpenAIRE

    Witt, M; Reutter, K; Ganchrow, D; Ganchrow, J R

    2000-01-01

    Intermediate filaments in taste organs of terrestrial (human and chick) as well as aquatic (Xenopus laevis) species were detected using immunohistochemistry and electron microscopy. During development, the potential importance of the interface between the taste bud primordium and non-gustatory adjacent tissues is evidenced by the distinct immunoreactivity of a subpopulation of taste bud cells for cytokeratins and vimentin. In human foetuses, the selective molecular marker for taste bud primor...

  14. Enhancement of Retronasal Odors by Taste

    OpenAIRE

    Green, Barry G.; Nachtigal, Danielle; Hammond, Samuel; Lim, Juyun

    2011-01-01

    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 (“ot...

  15. The neuropeptides CCK and NPY and the changing view of cell-to-cell communication in the taste bud.

    Science.gov (United States)

    Herness, Scott; Zhao, Fang-Li

    2009-07-14

    The evolving view of the taste bud increasingly suggests that it operates as a complex signal processing unit. A number of neurotransmitters and neuropeptides and their corresponding receptors are now known to be expressed in subsets of taste receptor cells in the mammalian bud. These expression patterns set up hard-wired cell-to-cell communication pathways whose exact physiological roles still remain obscure. As occurs in other cellular systems, it is likely that neuropeptides are co-expressed with neurotransmitters and function as neuromodulators. Several neuropeptides have been identified in taste receptor cells including cholecystokinin (CCK), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), and glucagon-like peptide 1 (GLP-1). Of these, CCK and NPY are the best studied. These two peptides are co-expressed in the same presynaptic cells; however, their postsynaptic actions are both divergent and antagonistic. CCK and its receptor, the CCK-1 subtype, are expressed in the same subset of taste receptor cells and the autocrine activation of these cells produces a number of excitatory physiological actions. Further, most of these cells are responsive to bitter stimuli. On the other hand, NPY and its receptor, the NPY-1 subtype, are expressed in different cells. NPY, acting in a paracrine fashion on NPY-1 receptors, results in inhibitory actions on the cell. Preliminary evidence suggests the NPY-1 receptor expressing cell co-expresses T1R3, a member of the T1R family of G-protein coupled receptors thought to be important in detection of sweet and umami stimuli. Thus the neuropeptide expressing cells co-express CCK, NPY, and CCK-1 receptor. Neuropeptides released from these cells during bitter stimulation may work in concert to both modulate the excitation of bitter-sensitive taste receptor cells while concurrently inhibiting sweet-sensitive cells. This modulatory process is similar to the phenomenon of lateral inhibition that occurs in other sensory systems.

  16. Post-learning molecular reactivation underlies taste memory consolidation

    Directory of Open Access Journals (Sweden)

    Kioko eGuzman-Ramos

    2011-09-01

    Full Text Available It is considered that memory consolidation is a progressive process that requires post-trial stabilization of the information. In this regard, it has been speculated that waves of receptors activation, expression of immediate early genes and replenishment of receptor subunit pools occur to induce functional or morphological changes to maintain the information for longer periods. In this paper, we will review data related to neuronal changes in the post-acquisition stage of taste aversion learning that could be involved in further stabilization of the memory trace. In order to achieve such stabilization, evidence suggests that the functional integrity of the insular cortex (IC and the amygdala (AMY is required. Particularly the increase of extracellular levels of glutamate and activation of N-methyl-D-aspartate (NMDA receptors within the IC shows a main role in the consolidation process. Additionally the modulatory actions of the dopaminergic system in the IC appear to be involved in the mechanisms that lead to taste aversion memory consolidation through the activation of pathways related to enhancement of protein synthesis such as the Protein Kinase A pathway. In summary, we suggest that post-acquisition molecular and neuronal changes underlying memory consolidation are dependent on the interactions between the AMY and the IC.

  17. The Importance of Taste for Food Demand and the Experienced Taste Effect of Healthy Labels

    DEFF Research Database (Denmark)

    Thunström, Linda; Nordström, Leif Jonas

    findings imply a large positive effect on demand for potato chips from higher taste scores: when consumers’ experienced taste from potato chips improves by one unit, the average WTP for a 150 gram bag of chips increases by 20 euro cents. The effect from taste on bread demand seems smaller, but may...

  18. Neural response to alcohol taste cues in youth : Effects of the OPRM1 gene

    NARCIS (Netherlands)

    Korucuoglu, Ozlem; Gladwin, Thomas E.; Baas, Frank; Mocking, Roel J. T.; Ruhé, Henricus G.; Groot, Paul F. C.; Wiers, Reinout W.

    2017-01-01

    Genetic variations in the mu-opioid receptor (OPRM1) gene have been related to high sensitivity to rewarding effects of alcohol. The current study focuses on the neural circuitry underlying this phenomenon using an alcohol versus water taste-cue reactivity paradigm in a young sample at relatively

  19. Neural response to alcohol taste cues in youth : effects of the OPRM1 gene

    NARCIS (Netherlands)

    Korucuoglu, O.; Gladwin, T.E.; Baas, F.; Mocking, R.J.T.; Ruhé, H.G.; Groot, P.F.C.; Wiers, R.W.

    2017-01-01

    Genetic variations in the mu-opioid receptor (OPRM1) gene have been related to high sensitivity to rewarding effects of alcohol. The current study focuses on the neural circuitry underlying this phenomenon using an alcohol versus water taste-cue reactivity paradigm in a young sample at relatively

  20. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  1. THE INFLUENCE OF SALT CONTENT AT DIFFERENT CONCENTRATIONS OF TERASI TO THE SENSORY CHARACTERISTICS OF SAMBAL TERASI, THE CHILI SAUCE ADDED WITH TERASI.

    Science.gov (United States)

    Ambarita, N T Damanik; De Meulenaer, B

    2015-01-01

    The type of terasi (the Indonesian seafood fermented paste) and the ingredients used can give sambal terasi (ST), the chili sauce added with terasi, its identity and taste distinction. Inherit from its production, salt content differs the flavor(s) of product added with terasi. This research explored the role of terasi salt content, either from the origin of terasi or by salt adjustment, to the products acceptability and sensory characteristics perceived during subsequent sensorial evaluations. Six types of terasi were characterized based on the proximate and salt content, and prepared as STs with and without salt adjustment at several terasi concentrations. 118 panelists conducted sensory evaluations for overall acceptability at 12.5% terasi; at lower concentration specific tastes (sweet, bitter, salty, sour, umami, fishy and rebon) were characterized by 80 panelists. Results showed that the acceptance of ST is more due to its innate origin salt content and to the suitability saltiness perceived. The specific odor of terasi, combining with other taste(s), when prepared at higher terasi concentration as practiced in restaurant, home and commercial products showed masking effect(s). After saltiness adjusted, different types of terasi showed different taste characteristics. Preferred ST were different between higher and lower concentration. Better tastes characteristics and stronger spices taste were found at lower salt content (and terasi concentration).

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

    Science.gov (United States)

    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…

  3. Taste-independent detection of the caloric content of sugar in Drosophila.

    Science.gov (United States)

    Dus, Monica; Min, SooHong; Keene, Alex C; Lee, Ga Young; Suh, Greg S B

    2011-07-12

    Feeding behavior is influenced primarily by two factors: nutritional needs and food palatability. However, the role of food deprivation and metabolic needs in the selection of appropriate food is poorly understood. Here, we show that the fruit fly, Drosophila melanogaster, selects calorie-rich foods following prolonged food deprivation in the absence of taste-receptor signaling. Flies mutant for the sugar receptors Gr5a and Gr64a cannot detect the taste of sugar, but still consumed sugar over plain agar after 15 h of starvation. Similarly, pox-neuro mutants that are insensitive to the taste of sugar preferentially consumed sugar over plain agar upon starvation. Moreover, when given a choice between metabolizable sugar (sucrose or D-glucose) and nonmetabolizable (zero-calorie) sugar (sucralose or L-glucose), starved Gr5a; Gr64a double mutants preferred metabolizable sugars. These findings suggest the existence of a taste-independent metabolic sensor that functions in food selection. The preference for calorie-rich food correlates with a decrease in the two main hemolymph sugars, trehalose and glucose, and in glycogen stores, indicating that this sensor is triggered when the internal energy sources are depleted. Thus, the need to replenish depleted energy stores during periods of starvation may be met through the activity of a taste-independent metabolic sensing pathway.

  4. Cell lineage mapping of taste bud cells and keratinocytes in the mouse tongue and soft palate.

    Science.gov (United States)

    Okubo, Tadashi; Clark, Cheryl; Hogan, Brigid L M

    2009-02-01

    The epithelium of the mouse tongue and soft palate consists of at least three distinct epithelial cell populations: basal cells, keratinized cells organized into filiform and fungiform papillae, and taste receptor cells present in tight clusters known as taste buds in the fungiform and circumvallate papillae and soft palate. All three cell types develop from the simple epithelium of the embryonic tongue and palate, and are continually replaced in the adult by cell turnover. Previous studies using pulse-chase tritiated thymidine labeling in the adult mouse provided evidence for a high rate of cell turnover in the keratinocytes (5-7 days) and taste buds (10 days). However, little is known about the localization and phenotype of the long-term stem or progenitor cells that give rise to the mature taste bud cells and surrounding keratinocytes in these gustatory tissues. Here, we make use of a tamoxifen-inducible K14-CreER transgene and the ROSA26 LacZ reporter allele to lineage trace the mature keratinocytes and taste bud cells of the early postnatal and adult mouse tongue and soft palate. Our results support the hypothesis that both the pore keratinocytes and receptor cells of the taste bud are derived from a common K14(+)K5(+)Trp63(+)Sox2(+) population of bipotential progenitor cells located outside the taste bud. The results are also compatible with models in which the keratinocytes of the filiform and fungiform papillae are derived from basal progenitor cells localized at the base of these structures.

  5. Bitter and sweet tasting molecules: It's complicated.

    Science.gov (United States)

    Di Pizio, Antonella; Ben Shoshan-Galeczki, Yaron; Hayes, John E; Niv, Masha Y

    2018-04-19

    "Bitter" and "sweet" are frequently framed in opposition, both functionally and metaphorically, in regard to affective responses, emotion, and nutrition. This oppositional relationship is complicated by the fact that some molecules are simultaneously bitter and sweet. In some cases, a small chemical modification, or a chirality switch, flips the taste from sweet to bitter. Molecules humans describe as bitter are recognized by a 25-member subfamily of class A G-protein coupled receptors (GPCRs) known as TAS2Rs. Molecules humans describe as sweet are recognized by a TAS1R2/TAS1R3 heterodimer of class C GPCRs. Here we characterize the chemical space of bitter and sweet molecules: the majority of bitter compounds show higher hydrophobicity compared to sweet compounds, while sweet molecules have a wider range of sizes. Importantly, recent evidence indicates that TAS1Rs and TAS2Rs are not limited to the oral cavity; moreover, some bitterants are pharmacologically promiscuous, with the hERG potassium channel, cytochrome P450 enzymes, and carbonic anhydrases as common off-targets. Further focus on polypharmacology may unravel new physiological roles for tastant molecules. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Salt processed food and gastric cancer in a Chinese population.

    Science.gov (United States)

    Lin, Si-Hao; Li, Yuan-Hang; Leung, Kayee; Huang, Cheng-Yu; Wang, Xiao-Rong

    2014-01-01

    To investigate the association between salt processed food and gastric cancer, a hospital based case-control study was conducted in a high risk area of China. One hundred and seven newly diagnosed cases with histological confirmation of gastric cancer and 209 controls were recruited. Information on dietary intake was collected with a validated food frequency questionnaire. Unconditional logistic regression was applied to estimate the odds ratios with adjustment for other potential confounders. Comparing the high intake group with never consumption of salt processed foods, salted meat, pickled vegetables and preserved vegetables were significantly associated with increased risk of gastric cancer. Meanwhile, salt taste preference in diet showed a dose-response relationship with gastric cancer. Our results suggest that consumption of salted meat, pickled and preserved vegetables, are positively associated with gastric cancer. Reduction of salt and salt processed food in diets might be one practical measure to preventing gastric cancer.

  7. Chemical and physical parameters of dried salted pork meat

    Directory of Open Access Journals (Sweden)

    Petronela Cviková

    2016-07-01

    Full Text Available The aim of the present study was analysed and evaluated chemical and physical parameters of dried salted pork neck and ham. Dried salted meat is one of the main meat products typically produced with a variety of flavors and textures. Neck (14 samples and ham (14 samples was salted by nitrite salt mixture during 1week. The nitrite salt mixture for salting process (dry salting was used. This salt mixture contains: salt, dextrose, maltodextrin, flavourings, stabilizer E316, taste enhancer E621, nitrite mixture. The meat samples were dried at 4 °C and relative humudity 85% after 1 week salting. The weight of each sample was approximately 1 kg. After salting were vacuum-packed and analysed after 1 week. The traditional dry-cured meat such as dry-cured ham and neck obtained after 12 - 24 months of ripening under controlled conditions. The average protein content was significantly (p <0.001 lower in dried pork neck in comparison with dried salted pork ham. The average intramuscular fat was significantly (p <0.001 lower in dried pork ham in comparison with dried salted pork neck. The average moisture was significantly lower (p ≤0.05 in dried salted ham in comparison with dried pork neck. The average pH value was 5.50 in dried salted pork ham and 5.75 in dried salted pork neck. The content of arginine, phenylalanine, isoleucine, leucine and threonine in dried salted ham was significantly lower (p <0.001 in comparison with dried salted pork neck. The proportion of analysed amino acids from total proteins was 56.31% in pork salted dried ham and 56.50% in pork salted dried neck.  Normal 0 21 false false false EN-GB X-NONE X-NONE Normal 0 21 false false false SK X-NONE X-NONE

  8. Measuring taste impairment in epidemiologic studies: the Beaver Dam Offspring Study.

    Science.gov (United States)

    Cruickshanks, K J; Schubert, C R; Snyder, D J; Bartoshuk, L M; Huang, G H; Klein, B E K; Klein, R; Nieto, F J; Pankow, J S; Tweed, T S; Krantz, E M; Moy, G S

    2009-07-01

    Taste or gustatory function may play an important role in determining diet and nutritional status and therefore indirectly impact health. Yet there have been few attempts to study the spectrum of taste function and dysfunction in human populations. Epidemiologic studies are needed to understand the impact of taste function and dysfunction on public health, to identify modifiable risk factors, and to develop and test strategies to prevent clinically significant dysfunction. However, measuring taste function in epidemiologic studies is challenging and requires repeatable, efficient methods that can measure change over time. Insights gained from translating laboratory-based methods to a population-based study, the Beaver Dam Offspring Study (BOSS) will be shared. In this study, a generalized labeled magnitude scale (gLMS) method was used to measure taste intensity of filter paper disks saturated with salt, sucrose, citric acid, quinine, or 6-n-propylthiouracil, and a gLMS measure of taste preferences was administered. In addition, a portable, inexpensive camera system to capture digital images of fungiform papillae and a masked grading system to measure the density of fungiform papillae were developed. Adult children of participants in the population-based Epidemiology of Hearing Loss Study in Beaver Dam, Wisconsin, are eligible for this ongoing study. The parents were residents of Beaver Dam and 43-84 years of age in 1987-1988; offspring ranged in age from 21-84 years in 2005-2008. Methods will be described in detail and preliminary results about the distributions of taste function in the BOSS cohort will be presented.

  9. Effect of ionizing radiation on the taste function of patients submitted to head and neck radiotherapy

    International Nuclear Information System (INIS)

    Silva, Amaro Ilidio Vespasiano; Galante, Celio

    2011-01-01

    Objective: to evaluate the effects of ionizing radiation on the taste function in patients submitted to radiotherapy in the head and neck region. Materials and methods: twenty patients diagnosed with head and neck tumors and undergoing treatment in the Division of Radiotherapy at Santa Casa de Misericordia de Belo Horizonte, MG, Brazil, were selected. For their taste function testing, four solutions were manipulated with salt (NaCl), sugar (sucrose), citric acid (for acidity), and urea (for bitterness), at three different (low, medium and high) concentrations. Weekly tests were performed during the first three weeks of radiotherapy, with random administration of the solutions (three drops each) respecting the order of their concentration levels (low, medium and high). After the application of each solution, the patient reported which flavor he/she tasted. Results: a statistically significant difference was observed in the loss of taste function as the results in the 1st and 4th weeks of treatment were compared, with salty solution at the three concentration levels, with the sweet solution at low and medium concentrations, and with the sour and bitter solutions, only at low concentration. Conclusion: ionizing radiation alters the taste function of patients submitted to head and neck radiotherapy. (author)

  10. Effect of ionizing radiation on the taste function of patients submitted to head and neck radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Amaro Ilidio Vespasiano [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Galante, Celio [Santa Casa de Misericordia de Belo Horizonte, MG (Brazil). Div. de Radioterapia; Manzi, Flavio Ricardo, E-mail: manzi@pucminas.b [Pontificia Universidade Catolica de Minas Gerais (PUC-MG), Belo Horizonte, MG (Brazil)

    2011-09-15

    Objective: to evaluate the effects of ionizing radiation on the taste function in patients submitted to radiotherapy in the head and neck region. Materials and methods: twenty patients diagnosed with head and neck tumors and undergoing treatment in the Division of Radiotherapy at Santa Casa de Misericordia de Belo Horizonte, MG, Brazil, were selected. For their taste function testing, four solutions were manipulated with salt (NaCl), sugar (sucrose), citric acid (for acidity), and urea (for bitterness), at three different (low, medium and high) concentrations. Weekly tests were performed during the first three weeks of radiotherapy, with random administration of the solutions (three drops each) respecting the order of their concentration levels (low, medium and high). After the application of each solution, the patient reported which flavor he/she tasted. Results: a statistically significant difference was observed in the loss of taste function as the results in the 1st and 4th weeks of treatment were compared, with salty solution at the three concentration levels, with the sweet solution at low and medium concentrations, and with the sour and bitter solutions, only at low concentration. Conclusion: ionizing radiation alters the taste function of patients submitted to head and neck radiotherapy. (author)

  11. Sweet and sour taste preferences of children

    NARCIS (Netherlands)

    Liem, D.G.

    2004-01-01

    In the industrialized countries children have many foods to choose from, both healthy and unhealthy products, these choices mainly depend on children's taste preferences. The present thesis focused on preferences for sweet and sour taste of young children (4- to 12-years of age) living in the US and

  12. Learning Consumer Tastes Through Dynamic Assortments

    NARCIS (Netherlands)

    Ulu, C.; Honhon, D.B.L.P.; Alptekinoglu, A.

    2012-01-01

    How should a firm modify its product assortment over time when learning about consumer tastes? In this paper, we study dynamic assortment decisions in a horizontally differentiated product category for which consumers' diverse tastes can be represented as locations on a Hotelling line. We presume

  13. Taste and smell changes in cancer patients

    NARCIS (Netherlands)

    IJpma, Irene

    2017-01-01

    Patients with cancer often experience changes in taste and smell perception during chemotherapy. The aim of this dissertation was to investigate taste