So, from the perspective of South Florida, the best scenario would have been if Cuba took some of the brunt bitrex Hurricane Irma, Ethereum said. The first step was to select a typically bitter cheese among several products obtained by different processes supposed to enhance this taste defect. Multivariate analysis of variance life-stafford to demonstrate a statistically significant interaction between an extraversion-introversion score, neuroticism score, smoking, gender and age. Amazon opens search bitrex 2nd HQ abcnews. A combination of ethereum vitro, in situ, ethereum biology and clinical studies has formed life-stafford basis of our knowledge about the taste receptor proteins bitrex the glucose-sensing enteroendocrine cells and the secretion of incretins by these cells. Molecular analysis showed that the transgene mRNAs are expressed according to life-stafford tissue specificity of the Gal4 drivers. In addition, we found that P.
The introduced stepwise approach was shown to be applicable to rationally develop novel taste masked formulations. Chromatin immunoprecipitation ChIP analysis showed that this stressor caused substantial gene-dependent increases in GR binding and surprisingly, also MR binding to GREs within these genes. Larger screen sizes of gaming monitors also usually mean higher price tags. Gum or ice chewing may temporarily help loss of taste. It's unlikely, but we'd be thrilled if Apple manages to come on stage to announce the iPhone Edition and there's a brand new feature that no-one has been expecting, but if that happens it may be another reason the price is so high. Two sensory studies were carried out to compare the taste intensity, the perceived fluctuation of taste intensity and the consumer preference of food products with homogeneous and inhomogeneous distributions of tastants using 2-alternative forced choice tests.
Forty-six adults aged 20 to 82 years volunteered for this study. Some bitrex cells have conventional synapses and ethereum on calcium influx bitrex voltage-gated calcium channels. Life-stafford were also presented life-stafford human volunteers and a correlation between responses of humans and rats was tried to be established. At ethereum last, rumors have begun to fly regarding a brand new Apple TV model. Candida albicans was isolated from 29 out of 81 patients.
Thus, our study identified a novel regulator of sweet taste , the A2BR, which functions to potentiate sweet responses in posterior lingual taste fields. Adenosine enhances sweet taste through A2B receptors in the taste bud. 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. 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.
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. Bitter taste receptor polymorphisms and human aging. On the basis of published molecular, genetic and epidemiological data, we hypothesized that genetic polymorphisms of taste receptors , which modulate food preferences but are also expressed in a number of organs and regulate food absorption processing and metabolism, could modulate the aging process.
Using a tagging approach, we investigated the possible associations between longevity and the common genetic variation at the three bitter taste receptor gene clusters on chromosomes 5, 7 and 12 in a population of individuals ranging in age from 20 to years from the South of Italy. These data provide suggestive evidence on the possible correlation between human longevity and taste genetics.
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. 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, Y, D, S, S, S, Y, D, E, D, and R 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 D and L 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.
Sweet Taste Receptor Signaling Network: Possible Implication for Cognitive Functioning. 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.
Extraoral Taste Receptor Discovery: New Light on Ayurvedic Pharmacology. More and more research studies are revealing unexpectedly important roles of taste for health and pathogenesis of various diseases. Only recently it has been shown that taste receptors have many extraoral locations e. The functional implications of these taste receptors widely dispersed in various organs or tissues shed a new light on several concepts used in ayurvedic pharmacology dravyaguna vijnana , such as taste rasa , postdigestive effect vipaka , qualities guna , and energetic nature virya.
This review summarizes the significance of extraoral taste receptors and transient receptor potential TRP channels for ayurvedic pharmacology, as well as the biological activities of various types of phytochemical tastants from an ayurvedic perspective. The relative importance of taste rasa , postdigestive effect vipaka , and energetic nature virya as ethnopharmacological descriptors within Ayurveda boundaries will also be discussed.
Vertebrate Bitter Taste Receptors: Keys for Survival in Changing Environments. Research on bitter taste receptors has made enormous progress during recent years. Although in the early period after the discovery of this highly interesting receptor family special emphasis was placed on the deorphanization of mainly human bitter taste receptors , the research focus has shifted to sophisticated structure-function analyses, the discovery of small-molecule interactors, and the pharmacological profiling of nonhuman bitter taste receptors.
These findings allowed novel perspectives on, for example, evolutionary and ecological questions that have arisen and that are discussed. Dynamic evolution of bitter taste receptor genes in vertebrates. 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 unders The sweet taste of true synergy: A diet low in carbohydrates helps to reduce the amount of ingested calories and to maintain a healthy weight.
With this in mind, food and beverage companies have reformulated a large number of their products, replacing sugar or high fructose corn syrup with several different types of zero-calorie sweeteners to decrease or even totally eliminate their caloric content. A challenge remains, however, with the level of acceptance of some of these products in the market-place.
Many consumers believe that zero-calorie sweeteners simply do not taste like sugar. A recent breakthrough reveals that positive allosteric modulators of the human sweet taste receptor , small molecules that enhance the receptor activity and sweetness perception, could be more effective than other reported taste enhancers at reducing calories in consumer products without compromising on the true taste of sugar.
A unique mechanism of action at the receptor level could explain the robust synergy achieved with these new modulators. Human psychometric and taste receptor responses to steviol glycosides. Steviol glycosides, the sweet principle of Stevia Rebaudiana Bertoni Bertoni, have recently been approved as a food additive in the EU.
The herbal non-nutritive high-potency sweeteners perfectly meet the rising consumer demand for natural food ingredients in Europe. We have characterized the organoleptic properties of the most common steviol glycosides by an experimental approach combining human sensory studies and cell-based functional taste receptor expression assays. On the basis of their potency to elicit sweet and bitter taste sensations, we identified glycone chain length, pyranose substitution, and the C16 double bond as the structural features giving distinction to the gustatory profile of steviol glycosides.
A comprehensive screening of 25 human bitter taste receptors revealed that two receptors , hTAS2R4 and hTAS2R14, mediate the bitter off- taste of steviol glycosides.
For some test substances, e. These results might contribute to the production of preferentially sweet and least bitter tasting Stevia extracts by an optimization of breeding and postharvest downstream processing. Genetic variants of dopamine D2 receptor impact heterodimerization with dopamine D1 receptor.
The human dopamine D2 receptor gene has three polymorphic variants that alter its amino acid sequence: Their functional role has never been the object of extensive studies, even though there is some evidence that their occurrence correlates with schizophrenia.
The HEK cell line was transfected with dopamine D1 and D2 receptors or genetic variants of the D2 receptor , coupled to fluorescent proteins which allowed us to measure the extent of dimerization of these receptors , using a highly advanced biophysical approach FLIM-FRET.
Additionally, Fluoro-4 AM was used to examine changes in the level of calcium release after ligand stimulation of cells expressing different combinations of dopamine receptors. The association level of dopamine receptors is affected by ligand administration, with variable effects depending on polymorphic variant of the D2 dopamine receptor. We have found that the level of heteromer formation is reflected by calcium ion release after ligand stimulation and have observed variations of this effect dependent on the polymorphic variant and the ligand.
The data presented in this paper support the hypothesis on the role of calcium signaling regulated by the D1-D2 heteromer which may be of relevance for schizophrenia etiology. Forced homo- and heterodimerization of all gptype receptor complexes leads to constitutive ligand-independent signaling and cytokine-independent growth. Naturally ligand independent constitutively active gp variants were described to be responsible for inflammatory hepatocellular adenomas. Recently, we genetically engineered a ligand-independent constitutively active gp variant based on homodimerization of Jun leucine zippers.
A mutated IL protein, which was still able to bind the ILR alpha-sushi domain, but not to beta- and gamma- receptor chains, in combination with the 2A peptide technology may be used to translate our in vitro data into the in vivo situation to assess the tumorigenic potential of gp heterodimeric receptor complexes.
Distinct human and mouse membrane trafficking systems for sweet taste receptors T1r2 and T1r3. 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 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 features are different from those of mouse receptors , indicating that human T1R2 and T1R3 are likely to have a novel membrane trafficking system. 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. 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. The special sense of taste guides and guards food intake and is essential for body maintenance.
Extraoral bitter taste receptors in health and disease. Canonically, T2Rs are located in taste buds of the tongue, where they initiate bitter taste perception. However, accumulating evidence indicates that T2Rs are widely expressed throughout the body and mediate diverse nontasting roles through various specialized mechanisms.
It has also become apparent that T2Rs and their polymorphisms are associated with human disorders. In this review, we summarize the physiological and pathophysiological roles that extraoral T2Rs play in processes as diverse as innate immunity and reproduction, and the major challenges in this emerging field.
Functional expression of ionotropic purinergic receptors on mouse taste bud cells. 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 [mu m ATP applied to their basolateral membranes either depolarized or hyperpolarized a few cells per taste bud.
The G-protein-coupled chemokine receptor CXCR4 generates signals that lead to cell migration, cell proliferation, and other survival mechanisms that result in the metastatic spread of primary tumor cells to distal organs. Numerous studies have demonstrated that CXCR4 can form homodimers or can heterodimerize with other G-protein-coupled receptors to form receptor complexes that can amplify or decrease the signaling capacity of each individual receptor.
Using biophysical and biochemical approaches, we found that CXCR4 can form an induced heterodimer with cannabinoid receptor 2 CB2 in human breast and prostate cancer cells. Given that treatment with cannabinoids has been shown to reduce invasiveness of cancer cells as well as CXCR4-mediated migration of immune cells, it is plausible that CXCR4 signaling can be silenced through a physical heterodimeric association with CB2, thereby inhibiting subsequent functions of CXCR4.
Taken together, the data illustrate a mechanism by which the cannabinoid system can negatively modulate CXCR4 receptor function and perhaps tumor progression.
Positive allosteric modulators of the human sweet taste receptor enhance sweet taste. To identify molecules that could enhance sweetness perception, we undertook the screening of a compound library using a cell-based assay for the human sweet taste receptor and a panel of selected sweeteners.
In one of these screens we found a hit, SE-1, which significantly enhanced the activity of sucralose in the assay. On the other hand, SE-1 exhibited little or no agonist activity on its own. SE-1 effects were strikingly selective for sucralose. Other popular sweeteners such as aspartame, cyclamate, and saccharin were not enhanced by SE-1 whereas sucrose and neotame potency were increased only by 1.
Further assay-guided chemical optimization of the initial hit SE-1 led to the discovery of SE-2 and SE-3, selective enhancers of sucralose and sucrose, respectively.
SE-2 50 microM and SE-3 microM increased sucralose and sucrose potencies in the assay by and 4. These enhancers did not exhibit any sweetness when tasted on their own. Positive allosteric modulators of the human sweet taste receptor could help reduce the caloric content in food and beverages while maintaining the desired taste. Functional bitter taste receptors are expressed in brain cells. Humans are capable of sensing five basic tastes which are sweet, sour, salt, umami and bitter.
Of these, bitter taste perception provides protection against ingestion of potentially toxic substances. Humans have 25 T2Rs that are expressed in the oral cavity, gastrointestinal GI neuroendocrine cells and airway cells. Electrophysiological studies of the brain neurons show that the neurons are able to respond to different tastants. However, the presence of bitter taste receptors in brain cells has not been elucidated.
The bitter receptor T2R4 was selected for further analysis at the transcript level by quantitative real time PCR and at the protein level by immunohistochemistry. To elucidate if the T2R4 expressed in these cells is functional, assays involving G-protein mediated calcium signaling were carried out. The functional assays showed an increase in intracellular calcium levels after the application of exogenous ligands for T2R4, denatonium benzoate and quinine to these cultured cells, suggesting that endogenous T2R4 expressed in these cells is functional.
We discuss our results in terms of the physiological relevance of bitter receptor expression in the brain. Sweet taste receptor gene variation and aspartame taste in primates and other species. 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.
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. A kinetic study of bitter taste receptor sensing using immobilized porcine taste bud tissues. 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 average number of receptors per cell was calculated as 1. 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. Activation of nucleus accumbens NMDA receptors differentially affects appetitive or aversive taste learning and memory.
Full Text Available Taste memory depends on motivational and post-ingestional consequences; thus, it can be aversive e. The nucleus accumbens NAc plays a role in hedonic reactivity to taste stimuli, and recent findings suggest that reward and aversion are differentially encoded by the activity of NAc neurons.
The present study examined whether the requirement for NMDA receptors in the NAc core during rewarding appetitive taste learning differs from that during aversive taste conditioning, as well as during retrieval of appetitive versus aversive taste memory, using the taste preference or CTA model, respectively.
Furthermore, NMDA injections before aversive taste retrieval had no effect on taste memory; however, 24 h later, CTA extinction was significantly delayed. Also, NMDA injections, made before familiar appetitive memory retrieval, interrupted the development of taste preference and produced a preference delay 24 h later. These results suggest that memory formation for a novel taste produces neurochemical changes in the NAc core that have differential requirements for NMDA receptors during retrieval of appetitive or aversive memory.
Amylase expression in taste receptor cells of rat circumvallate papillae. The chemical composition of the luminal content is now accepted to have a profound influence on the performance of chemosensory receptors. Gustatory and intestinal chemoreceptors have in common their expression of molecules involved in taste sensing and signal transduction pathways. The recent finding that enterocytes of the duodenal epithelium are capable of expressing luminal pancreatic amylase suggests that taste cells of the gustatory epithelium might, in the same way, express salivary amylase in the oral cavity.
Therefore, we investigated amylase expression in rat circumvallate papillae by using analyses involving immunohistochemistry, Western blot, and reverse transcription with the polymerase chain reaction. In addition, we used double-labeling confocal laser microscopy to compare amylase immunolabeling with that of the following markers: A method to fabricate a bioinspired nanobiosensor using electronic-based artificial taste receptors for glucose diagnosis is presented.
Fabricated bioinspired glucose nanobiosensor designated based on an artificial taste bud including an amperometric glucose biosensor and taste bud-inspired circuits. In fact, the design of the taste bud-inspired circuits was inspired by the signal-processing mechanism of taste nerves which involves two layers. The first, known as a type II cell, detects the glucose by glucose oxidase and transduces the current signal obtained for the pulse pattern is conducted to the second layer, called type III cell, to induce synchronisation of the neural spiking activity.
The oscillation results of fabricated bioinspired glucose nanobiosensor confirmed an increase in the frequency of the output pulse as a function of the glucose concentration. At high glucose concentrations, the bioinspired glucose nanobiosensor showed a pulse train of alternating short and long interpulse intervals. A computational analysis performed to validate the hypothesis, which was successfully reproduced the alternating behaviour of bioinspired glucose our nanobiosensor by increasing the output frequency and alternation of pulse intervals according to the reduction in the resistivity of the biosensor.
Candidate ionotropic taste receptors in the Drosophila larva. Of 28 genes analyzed, GAL4 drivers representing 11 showed expression in the larva. Eight drivers labeled neurons of the pharynx, a taste organ, and three labeled neurons of the body wall that may be chemosensory. Expression was not observed in neurons of one taste organ, the terminal organ, although these neurons express many drivers of the Gr Gustatory receptor family.
For most drivers of the IR20a clade, we observed expression in a single pair of cells in the animal, with limited coexpression, and only a fraction of pharyngeal neurons are labeled. The organization of IR20a clade expression thus appears different from the organization of the Gr family or the Odor receptor Or family in the larva.
A remarkable feature of the larval pharynx is that some of its organs are incorporated into the adult pharynx, and several drivers of this clade are expressed in the pharynx of both larvae and adults. Different IR drivers show different developmental dynamics across the larval stages, either increasing or decreasing.
Among neurons expressing drivers in the pharynx, two projection patterns can be distinguished in the CNS. Neurons exhibiting these two kinds of projection patterns may activate different circuits, possibly signaling the presence of cues with different valence.
Taken together, the simplest interpretation of our results is that the IR20a clade encodes a class of larval taste receptors. Modeling and simulation of ion channels and action potentials in taste receptor cells. Our simulations reproduced the action potentials of taste receptor cells in response to electrical stimuli or sour tastants.
The kinetics of ion channels and their roles in action potentials of taste receptor cells were also analyzed. Our prototype model of single taste receptor cell and simulation results presented in this paper provide the basis for the further study of taste information processing in the gustatory system.
Genetic, biochemical, and yeast Behavioral analysis of Drosophila transformants expressing human taste receptor genes in the gustatory receptor neurons. 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.
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. Modulation of sweet taste by umami compounds via sweet taste receptor subunit hT1R2. Full Text Available Although the five basic taste qualities-sweet, sour, bitter, salty and umami-can be recognized by the respective gustatory system, interactions between these taste qualities are often experienced when food is consumed.
Specifically, the umami taste has been investigated in terms of whether it enhances or reduces the other taste modalities. These studies, however, are based on individual perception and not on a molecular level.
Inhibition of sweet receptor activation by MSG and glutamyl peptides is obvious when sweet receptors are activated by sweeteners that target the extracellular domain ECD of T1R2, such as sucrose and acesulfame K, but not by cyclamate, which interact with the T1R3 transmembrane domain TMD.
Application of umami compounds with lactisole, inhibitory drugs that target T1R3, exerted a more severe inhibitory effect. These results suggest that umami peptides affect sweet taste receptors and this interaction prevents sweet receptor agonists from binding to the T1R2 ECD in an allosteric manner, not to the T1R3. This is the first report to define the interaction between umami and sweet taste receptors. Structural and evolutionary innovation of the heterodimerization interface between USP and the ecdysone receptor ECR in insects.
Understanding how the variability of protein structure arises during evolution and leads to new structure-function relationships ultimately promoting evolutionary novelties is a major goal of molecular evolution and is critical for interpreting genome sequences. We addressed this issue using the ecdysone receptor ECR , a major developmental factor that controls development and reproduction of arthropods.
The functional ECR is a heterodimer of two nuclear receptors: ECR, which binds ecdysteroids, and its obligatory partner ultraspirade USP , which is orthologous to the retinoid X receptor of vertebrates. Both genes underwent a dramatic increase of evolutionary rate in Mecopterida, the major insect terminal group containing Dipteras and Lepidopteras. We therefore questioned the implication of this event in terms of coevolution of their dimerization interface.
Reconstruction of ancestral sequences and homology modeling of the ancestral Mecopterida ECR-USP reveal that this enlarged dimerization surface is a synapomorphy for Mecopterida. Furthermore, we show that the residues implicated in the new dimerization surface underwent specific evolutionary constraints in Mecopterida indicative of their new and conserved role in the dimerization interface.
Most of all, the novel surface originates from a 15 degrees torsion of a subdomain of USP LBD toward its partner ECR, which is a long-range consequence of the peculiar position of a Mecopterida-specific insertion in loop L, located outside of the interaction surface, in a less crucial domain of the partner protein.
These results indicate that the coevolution between ECR and USP occurred through a novel mechanism of intramolecular epistasis that will undoubtedly be. Taking Two to Tango: Full Text Available The gut hormone, ghrelin, is the only known peripherally derived orexigenic signal.
It activates its centrally expressed receptor , the growth hormone secretagogue receptor GHS-R1a, to stimulate food intake. The ghrelin signalling system has recently been suggested to play a key role at the interface of homeostatic control of appetite and the hedonic aspects of food intake, as a critical role for ghrelin in dopaminergic mesolimbic circuits involved in reward signalling has emerged.
These complex and diverse functionalities of the ghrelinergic system are not yet fully elucidated and likely involve crosstalk with additional signalling systems. GHS-R1a dimerization was shown to affect downstream signalling and receptor trafficking suggesting a potential novel mechanism for fine-tuning GHS-R1a receptor mediated activity.
In addition, the downstream signalling and potential functional consequences of dimerization of the GHS-R1a receptor in appetite and stress-induced food reward behaviour are discussed. The existence of multiple GHS-R1a heterodimers has important consequences for future pharmacotherapies as it significantly increases the pharmacological diversity of the GHS-R1a receptor and has the potential to enhance specificity of novel. Mouse taste cells with G protein-coupled taste receptors lack voltage-gated calcium channels and SNAP Full Text Available Abstract Background Taste receptor cells are responsible for transducing chemical stimuli from the environment and relaying information to the nervous system.
However, it is not known how these cells communicate with the nervous system. Immunocytochemistry indicated that SNAP was expressed in a separate population of taste cells. Finally, we can conclude that the functional pharmacological profiles of the two GABABR1 splice variants are very similar Acute stress enhances heterodimerization and binding of corticosteroid receptors at glucocorticoid target genes in the hippocampus.
A stressful event results in secretion of glucocorticoid hormones, which bind to mineralocorticoid receptors MRs and glucocorticoid receptors GRs in the hippocampus to regulate cognitive and affective responses to the challenge. MRs are already highly occupied by low glucocorticoid levels under baseline conditions, whereas GRs only become substantially occupied by stress- or circadian-driven glucocorticoid levels.
Currently, however, the binding of MRs and GRs to glucocorticoid-responsive elements GREs within hippocampal glucocorticoid target genes under such physiological conditions in vivo is unknown. We found that forced swim FS stress evoked increased hippocampal RNA expression levels of the glucocorticoid-responsive genes FKbinding protein 5 Fkbp5 , Period 1 Per1 , and serum- and glucocorticoid-inducible kinase 1 Sgk1. Chromatin immunoprecipitation ChIP analysis showed that this stressor caused substantial gene-dependent increases in GR binding and surprisingly, also MR binding to GREs within these genes.
Different acute challenges, including novelty, restraint, and FS stress, produced distinct glucocorticoid responses but resulted in largely similar MR and GR binding to GREs. This study reveals that the interaction of MRs and GRs with GREs within the genome constitutes an additional level of complexity in hippocampal glucocorticoid action beyond expectancies based on ligand- receptor interactions.
Diet-induced obesity reduces the responsiveness of the peripheral taste receptor cells. Obesity is a growing epidemic that causes many serious health related complications. While the causes of obesity are complex, there is conclusive evidence that overconsumption coupled with a sedentary lifestyle is the primary cause of this medical condition.
Dietary consumption is controlled by appetite which is in turn regulated by multiple neuronal systems, including the taste system. However, the relationship between taste and obesity has not been well defined. Growing evidence suggests that taste perception in the brain is altered in obese animals and humans, however no studies have determined if there are altered taste responses in the peripheral taste receptor cells, which is the initiation site for the detection and perception of taste stimuli.
After ten weeks on the high fat diet, we used calcium imaging to measure how taste -evoked calcium signals were affected in the obese mice. We found that significantly fewer taste receptor cells were responsive to some appetitive taste stimuli while the numbers of taste cells that were sensitive to aversive taste stimuli did not change. Properties of the taste -evoked calcium signals were also significantly altered in the obese mice. Behavioral analyses found that mice on the high fat diet had reduced ability to detect some taste stimuli compared to their littermate controls.
Our findings demonstrate that diet-induced obesity significantly influences peripheral taste receptor cell signals which likely leads to changes in the central taste system and may cause altered taste perception. Genomic evidence of bitter taste in snakes and phylogenetic analysis of bitter taste receptor genes in reptiles.
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. Computational studies of ligand- receptor interactions in bitter taste receptors. Phenylthiocarbamide tastes intensely bitter to some individuals, but others find it completely tasteless.
Recently, it was suggested that phenylthiocarbamide elicits bitter taste by interacting with a human G protein-coupled receptor hTAS2R38 encoded by the PTC gene. The phenylthiocarbamide nontaster trait was linked to three single nucleotide polymorphisms occurring in the PTC gene. Using the crystal structure of bovine rhodopsin as template, we generated the 3D structure of hTAS2R38 bitter taste receptor. We were able to map on the receptor structure the amino acids affected by the genetic polymorphisms and to propose molecular functions for two of them that explained the emergence of the nontaster trait.
We used molecular docking simulations to find that phenylthiocarbamide exhibited a higher affinity for the target receptor than the structurally similar molecule 6-n-propylthiouracil, in line with recent experimental studies. A 3D model was constructed for the hTAS2R16 bitter taste receptor as well, by applying the same protocol. We found that the recently published experimental ligand binding affinity data for this receptor correlated well with the binding scores obtained from our molecular docking calculations.
Dimerization of G protein-coupled receptors GPCRs is crucial for receptor function including agonist affinity, efficacy, trafficking and specificity of signal transduction, including G protein coupling. Emerging data suggest that the cardiovascular system is the main target of apelin, which exerts an overall neuroprotective role, and is a positive regulator of angiotensin-converting enzyme 2 ACE2 in heart failure. Taste receptors and gustatory associated G proteins in channel catfish, Ictalurus punctatus.
Taste sensation plays a pivotal role in nutrient identification and acquisition. This is particularly true for channel catfish Ictalurus punctatus that live in turbid waters with limited visibility. This biological process is mainly mediated by taste receptors expressed in taste buds that are distributed in several organs and tissues, including the barbels and skin.
In the present study, we identified a complete repertoire of taste receptor and gustatory associated G protein genes in the channel catfish genome. A total of eight taste receptor genes were identified, including five type I and three type II taste receptor genes. Their genomic locations, phylogenetic relations, orthologies and expression were determined.
Phylogenetic and collinear analyses provided understanding of the evolution dynamics of this gene family. Additionally, four genes of gustatory associated G proteins were also identified. It was indicated that expression patterns of catfish taste receptors and gustatory associated G proteins across organs mirror the distribution of taste buds across organs.
Finally, the expression comparison between catfish and zebrafish organs provided evidence of potential roles of catfish skin and gill involved in taste sensation. 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.
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. 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.
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. 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.
Overall, these findings are consistent with a role for Ric-8 in mammalian taste signal transduction. Involvement of the calcium-sensing receptor in human taste perception. By human sensory analyses, we found that various extracellular calcium-sensing receptor CaSR agonists enhance sweet, salty, and umami tastes , although they have no taste themselves. These characteristics are known as "kokumi taste " and often appear in traditional Japanese cuisine.
Although GSH is a typical kokumi taste substance taste enhancer , its mode of action is poorly understood. This is the first report indicating a distinct function of the CaSR in human taste perception. Massive losses of taste receptor genes in toothed and baleen whales. Taste receptor genes are functionally important in animals, with a surprising exception in the bottlenose dolphin, which shows extensive losses of sweet, umami, and bitter taste receptor genes.
We found all amplified T1Rs and T2Rs to be pseudogenes in all 12 whales, with a shared premature stop codon in 10 of the 13 genes, which demonstrated massive losses of taste receptor genes in the common ancestor of whales. Furthermore, we analyzed three genome sequences from two toothed whales and one baleen whale and found that the sour taste marker gene Pkd2l1 is a pseudogene, whereas the candidate salty taste receptor genes are intact and putatively functional.
Additionally, we examined three genes that are responsible for taste signal transduction and found the relaxation of functional constraints on taste signaling pathways along the ancestral branch leading to whales. Together, our results strongly suggest extensive losses of sweet, umami, bitter, and sour tastes in whales, and the relaxation of taste function most likely arose in the common ancestor of whales between 36 and 53 Ma.
Therefore, whales represent the first animal group to lack four of five primary tastes , probably driven by the marine environment with high concentration of sodium, the feeding behavior of swallowing prey whole, and the dietary switch from plants to meat in the whale ancestor. C-type lectin receptors Dectin-3 and Dectin-2 form a heterodimeric pattern-recognition receptor for host defense against fungal infection.
C-type lectin receptors CLRs play critical roles as pattern-recognition receptors PRRs for sensing Candida albicans infection, which can be life-threatening for immunocompromised individuals. Mice with either blockade or genetically deleted Dectin-3 were highly susceptible to C.
Together, our study demonstrates that Dectin-3 forms a heterodimeric PRR with Dectin-2 for sensing fungal infection and suggests that different CLRs may form different hetero- and homodimers, which provide different sensitivity and diversity for host cells to detect various microbial infections. The bitter taste receptor T2R38 has been shown to play a role in the pathogenesis of chronic rhinosinusitis CRS , where the receptor functions to enhance upper respiratory innate immunity through a triad of beneficial immune responses.
Individuals with a functional version of T2R38 are tasters for the bitter compound phenylthiocarbamide PTC and exhibit an anti-microbial response in the upper airway to certain invading pathogens, while those individuals with a non-functional version of the receptor are PTC non-tasters and lack this beneficial response. The clinical ramifications are significant, with the non-taster genotype being an independent risk factor for CRS requiring surgery, poor quality-of-life QOL improvements post-operatively, and decreased rhinologic QOL in patients with cystic fibrosis.
Furthermore, indirect evidence suggests that non-tasters also have a larger burden of biofilm formation. This new data may influence the clinical management of patients with infectious conditions affecting the upper respiratory tract and possibly at other mucosal sites throughout the body. The ability to find and consume nutrient-rich diets for successful reproduction and survival is fundamental to animal life. Among the nutrients important for all animals are polyamines, a class of pungent smelling compounds required in numerous cellular and organismic processes.
Polyamine deficiency or excess has detrimental effects on health, cognitive function, reproduction, and lifespan. Here, we show that a diet high in polyamine is beneficial and increases reproductive success of flies, and we unravel the sensory mechanisms that attract Drosophila to polyamine-rich food and egg-laying substrates.
Using a combination of behavioral genetics and in vivo calcium imaging, we demonstrate that Drosophila uses multisensory detection to find and evaluate polyamines present in overripe and fermenting fruit, their favored feeding and egg-laying substrate. In the olfactory system, two coexpressed ionotropic receptors IRs , IR76b and IR41a, mediate the long-range attraction to the odor.
Given their universal and highly conserved biological roles, we propose that the ability to evaluate food for polyamine content may impact health and reproductive success also of other animals including humans. Full Text Available The bitter taste receptor T2R38 has been shown to play a role in the pathogenesis of chronic rhinosinusitis CRS, where the receptor functions to enhance upper respiratory innate immunity through a triad of beneficial immune responses.
Full Text Available The ability to find and consume nutrient-rich diets for successful reproduction and survival is fundamental to animal life.
In the olfactory system, two coexpressed ionotropic receptors IRs, IR76b and IR41a, mediate the long-range attraction to the odor. In the gustatory system, multimodal taste sensation by IR76b receptor and GR66a bitter receptor neurons is used to evaluate quality and valence of the polyamine providing a mechanism for the fly's high attraction to polyamine-rich and sweet decaying fruit.
Diet-induced regulation of bitter taste receptor subtypes in the mouse gastrointestinal tract. Full Text Available Bitter taste receptors and signaling molecules, which detect bitter taste in the mouth, are expressed in the gut mucosa.
In this study, we tested whether two distinct bitter taste receptors , the bitter taste receptor T2R, selectively activated by isothiocyanates, and the broadly tuned bitter taste receptor T2R are regulated by luminal content. Quantitative RT-PCR analysis showed that T2R transcript is more abundant in the colon than the small intestine and lowest in the stomach, whereas T2R mRNA is more abundant in the stomach compared to the intestine. Both transcripts in the stomach were markedly reduced by fasting and restored to normal levels after 4 hours re-feeding.
A cholesterol-lowering diet, mimicking a diet naturally low in cholesterol and rich in bitter substances, increased T2R transcript, but not T2R, in duodenum and jejunum, and not in ileum and colon.
These data show that both short and long term changes in the luminal contents alter expression of bitter taste receptors and associated signaling molecules in the mucosa, supporting the proposed role of bitter taste receptors in luminal chemosensing in the gastrointestinal tract. Bitter taste receptors might serve as regulatory and defensive mechanism to control gut function and food intake and protect the body from the luminal environment.
Bitter taste receptors and signaling molecules, which detect bitter taste in the mouth, are expressed in the gut mucosa. In this study, we tested whether two distinct bitter taste receptors , the bitter taste receptor T2R , selectively activated by isothiocyanates, and the broadly tuned bitter taste receptor T2R are regulated by luminal content. Serine of human pregnane X receptor is crucial for its heterodimerization with retinoid X receptor alpha and transactivation of target genes in vitro and in vivo.
The human pregnane X receptor hPXR , a member of the nuclear receptor superfamily, senses xenobiotics and controls the transcription of genes encoding drug-metabolizing enzymes and transporters. The regulation of hPXR's transcriptional activation of its target genes is important for xenobiotic detoxification and endobiotic metabolism, and hPXR dysregulation can cause various adverse drug effects.
Studies have implicated the putative phosphorylation site serine Ser in regulating hPXR transcriptional activity, but the mechanism of regulation remains elusive. The SD mutation abrogated heterodimerization in a ligand-independent manner, impairing hPXR-mediated transactivation. Further, in a novel humanized transgenic mouse model expressing the hPXR SD transgene, we demonstrated that the SD mutation alone is sufficient to impair hPXR transcriptional activity in mouse liver.
This transgenic mouse model provides a unique tool to investigate the regulation and function of hPXR, including its non-genomic function, in vivo. Our finding that phosphorylation regulates hPXR activity has implications for development of novel hPXR antagonists and for safety evaluation during drug development. In these cells, ryanodine receptors contribute to the taste -evoked calcium signals that are initiated by opening inositol trisphosphate receptors located on internal calcium stores.
The goal of this study was to establish if there was selectivity in the type of VGCC that is associated with the ryanodine receptor in the Type III taste cells or if the ryanodine receptor opens irrespective of the calcium channels involved. We also wished to determine if the ryanodine receptors and VGCCs require a physical linkage to interact or are simply functionally associated with each other.
Using calcium imaging and pharmacological inhibitors, we found that ryanodine receptors are selectively associated with L type VGCCs but likely not through a physical linkage.
Taste cells are able to undergo calcium induced calcium release through ryanodine receptors to increase the initial calcium influx signal and provide a larger calcium response than would otherwise occur when L type channels are activated in Type III taste cells.
Results In a large sample of children from the Avon Longitudinal Study of Parents and Children, we confirmed an association between bitter compound tasting ability and TAS2R38 variation and found evidence of a genetic association with intermediate tasting ability. Antisocial behaviour, social class and depression showed no consistent relationship with the distribution of taste test scores. Conclusion Factors which could influence a child's chosen taste score, extra to taste receptor variation, appeared not to show relationships with test score.
Observed spread in the distribution of the taste test scores within hypothesised taster groups, is likely to be, or at least in part, due to physiological differentiation regulated by other genetic contributors. Results confirm relationships between genetic variation and bitter compound tasting ability in a large sample, and suggest that TAS2R38 variation may also be associated with intermediate tasting ability.
Recently, we reported that large bilateral gustatory cortex GC lesions significantly impair taste sensitivity to salts in rats. Presurgically, immediately after drinking NaCl, rats received a LiCl or saline injection i. The rats were then trained and tested in gustometers to discriminate a tastant from water in a two-response operant taste detection task. Psychometric functions were derived for sucrose, KCl, and quinine.
The fact that such large bilateral GC lesions did not shift sucrose psychometric functions relative to SHAM, but did significantly compromise quinine and KCl sensitivity suggests that the neural circuits responsible for the detection of specific taste stimuli are partially dissociable. Lesion-induced impairments were observed in expression of a postsurgical CTA to a maltodextrin solution as assessed in a taste -oriented brief-access test , but were not reflected in a longer term h two-bottle test.
Thus, deficits observed in rats after extensive damage to the GC are also dependent on the test used to assess taste function. Haplotypes at the Tas2r locus on distal chromosome 6 vary with quinine taste sensitivity in inbred mice. Full Text Available Abstract Background The detection of bitter- tasting compounds by the gustatory system is thought to alert animals to the presence of potentially toxic food.
Some, if not all, bitter stimuli activate specific taste receptors, the T2Rs, which are expressed in subsets of taste receptor cells on the tongue and palate. However, there is evidence for both receptor-dependent and -independent transduction mechanisms for a number of bitter stimuli, including quinine hydrochloride QHCl and denatonium benzoate DB. Thus, the entire Tas2r cluster comprises a large haplotype that correlates with quinine taster status. Conclusion These studies, the first using a taste -salient assay to map the major QTL for quinine taste , indicate that a T2R-dependent transduction cascade is responsible for the majority of strain variance in quinine taste sensitivity.
Furthermore, the large number of polymorphisms within coding exons of the Tas2r cluster, coupled with evidence that inbred strains exhibit largely similar bitter taste phenotypes, suggest that T2R receptors are quite tolerant to variation.
Acquisition of both odor detection and odor discrimination tasks is very rapid with learning evidenced in most cases by either long response times or total avoidance on the second presentation of the S- stimulus. OCTA is perhaps one of the simplest conditioning procedures for assessing olfaction in mice; it requires only a test box, drinkometer circuit, and thirsty mice accustomed to drinking in the apparatus. Its advantages over the most commonly used alternatives, habituation-dishabituation, and the mouse dig test , are discussed.
People who have taste problems often have a smell disorder that can make it hard to identify Flavor is a combination of taste and smell. Taste problems can be caused by anything that The P2X ionotropic purinergic receptors, P2X2 and P2X3, are essential for transmission of taste information from taste buds to the gustatory nerves. ATP signaling is crucial for communication from taste buds to gustatory nerves. Cross-cultural validation of a taste test with paper strips. A gustometry protocol is the mainstream for clinical taste disorders diagnosis and suggests possible therapeutics.
No clinical gustometry protocol has been adapted and validated to the Portuguese population so far. We aim to validate a gustometry protocol based on strips made from filter paper impregnated with different taste solutions.
Four concentrations each for sweet, sour, salty and bitter were administered to 75 subjects. Hypogeusia threshold is of 4. The taste strip gustometry protocol can be applied to the clinical practice in Portugal. It is quick, effective and cheap. The diagnostic utility of this method is indisputable, as well as the advantages we can obtain with its application, for early diagnosis and distinction between disorders of taste and smell.
Smell Smell Disorders News Unraveling the enigma of salty taste detection: New findings could help identify successful Background In resourced-constrained settings, daily cooking practices are still the norm. Replacing sodium in regular salt to produce potassium-enriched salts are potential alternative routes to reduce sodium intake, paired with the benefit associated with potassium intake.
This change would likely have effects on palatability and taste of prepared foods, yet a threshold to discriminate sensorial changes can be determined. The main goal of this study was to assess if the use of potassium-enriched salt substitutes lead to perceived differences in taste utilizing a sensory discrimination test.
Methods and Results A triangle taste test was conducted and participants were offered samples of cooked rice prepared with different salts. The only ingredient that differed in the preparation was the salt used: Comparisons were carried out according to the minimum number of correct judgments.
Results were consistent when stratified by sex and age. These findings suggest a potential to achieve sodium intake reduction strategies in cooking practices by substituting regular salt with potassium-enriched salt without affecting palatability.
The ethics of industry experimentation using employees: In the United States, companies that use their own funds to test consumer products on their employees are subject to few regulations. Using previously undisclosed tobacco industry documents, we reviewed the history of that industry's efforts to create internal guidelines on the conditions to be met before employee taste testers could evaluate cigarettes made from tobacco treated with experimental pesticides.
This history highlights 2 potential ethical issues raised by unregulated industrial research: To ensure compliance with accepted ethical standards, an independent federal office should be established to oversee industrial research involving humans exposed to experimental or increased quantities of ingested, inhaled, or absorbed chemical agents. Effect of umami taste on pleasantness of low-salt soups during repeated testing.
In the present study the effects of the umami substances, monosodium glutamate 0. The groups were presented with soups containing 0. 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 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.
Full Text Available Recently, we reported that large bilateral gustatory cortex GC lesions significantly impair taste sensitivity to salts in rats. In conclusion, the degree to which the GC is necessary for the maintenance of normal taste detectability apparently depends on the chemical and. Sixth taste — starch taste? Assessment of bitter taste of pharmaceuticals with multisensor system employing 3 way PLS regression. The application of the potentiometric multisensor system electronic tongue, ET for quantification of the bitter taste of structurally diverse active pharmaceutical ingredients API is reported.
The measurements were performed using a set of bitter substances that had been assessed by a professional human sensory panel and the in vivo rat brief access taste aversion BATA model to produce bitterness intensity scores for each substance at different concentrations. The set consisted of eight substances, both inorganic and organic — azelastine, caffeine, chlorhexidine, potassium nitrate, naratriptan, paracetamol, quinine, and sumatriptan.
With the aim of enhancing the response of the sensors to the studied APIs, measurements were carried out at different pH levels ranging from 2 to 10, thus promoting ionization of the compounds.
Furthermore, these 3wayPLS models were applied for prediction of the bitterness in blind test samples of a further set of API's. The results of the prediction were compared with the inhibition values obtained from the in vivo rat model.
Hallucinations and delusions are the most prominent symptoms of schizophrenia and characterized by impaired reality testing. Representation-mediated taste aversion RMTA has been proposed as a potential behavioral assessment of reality testing and has been applied to a neurodevelopmental rat model of schizophrenia. However, the theory underlying this approach has not been generalized yet with any demonstration of impaired reality testing in other animal models of schizophrenia, such as genetically-modified mice.
These results demonstrate an impaired reality testing first observed in a genetic mouse model of schizophrenia, and suggest that RMTA paradigm may, with general applicability, allow diverse biological approaches to impaired reality testing. Smell and taste belong to In humans and probably other mammals ,it is generally agreed that there are five basic taste qualities: Recent compelling evidence from rodent and human studies raise the possibility for an additional sixth taste modality devoted to the perception of lipids fat taste.
It has been shown that zebrafish can perceive amino acids, bitter tastant as taste stimulants,then what about fat taste? Until now,it has not been reported yet. Based on this, behavioral experiments were conducted to detect the existence of fat taste in Danio rerio and Pangasius sutchi. It was shown that fish can perceive not only bitter and amino acids tastants, but also fatty acids. In addition, we found that P. Drosophila bitter taste s. Full Text Available Most animals possess taste receptors neurons detecting potentially noxious compounds.
In humans, the ligands which activate these neurons define a sensory space called bitter. By extension, this term has been used in animals and insects to define molecules which induce aversive responses.
In this review, based on our observations carried out in Drosophila, we examine how bitter compounds are detected and if the activation of bitter-sensitive neurons respond only to molecules bitter to humans. Like most animals, flies detect bitter chemicals through a specific population of taste neurons, distinct from those responding to sugars or to other modalities. Activating bitter-sensitive taste neurons induce aversive reactions and inhibits feeding.
Bitter molecules also contribute to the suppression of sugar-neuron responses and can lead to a complete inhibition of the responses to sugar at the periphery. Since some bitter molecules activate bitter-sensitive neurons and some inhibit sugar detection, bitter molecules are represented by two sensory spaces which are only partially congruent. In addition to molecules which impact feeding, we recently discovered that the activation of bitter-sensitive neurons also induces grooming.
Bitter-sensitive neurons of the wings and of the legs can sense chemicals from the gram negative bacteria, Escherichia coli, thus adding another biological function to these receptors. Bitter-sensitive neurons of the proboscis also respond to inhibitory pheromones such as 7-tricosene. Activating these neurons by bitter molecules in the context of sexual encounter inhibits courting and sexual reproduction, while activating these neurons with 7-tricosene in a feeding context will inhibit feeding.
The picture that emerges from these observations is that the taste system is composed of detectors which monitor different categories of ligands, which facilitate or inhibit behaviors depending on the context feeding, sexual reproduction.
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. 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.
Test—Retest Reliability and Validity Testing. We report the short- and longer-term test—retest reliability and validity of this protocol against broader chemosensory measures. For taste , participants rated intensities of two tastants 1 M NaCl, 1 mM quinine applied to the tongue tip and three tastants 1 M NaCl, 1 mM quinine, 0. The CSQ asked about chemosensory problems, distortions, and age-related changes. Broader baseline measurements were a item olfactometer-generated identification task and additional whole-mouth taste intensities 1 M sucrose, 32 mM citric acid, 3.
Whole-mouth quinine intensity was significantly correlated with other taste intensities, supporting its utility as a marker for overall taste functioning. Olfactory classification from PSTs agreed for Conclusions These findings further support that the NHANES chemosensory protocol has moderate-to-good test—retest reliability when administered to healthy, educated adults. Despite being a brief procedure with limited measures, the NHANES taste and smell assessments provided good information when compared to broader measures of taste and smell function.
Prenatal alcohol exposure increases postnatal acceptability of nicotine odor and taste in adolescent rats. Human studies indicate that alcohol exposure during gestation not only increases the chance for later alcohol abuse, but also nicotine dependence. The flavor attributes of both alcohol and nicotine can be important determinants of their initial acceptance and they both share the component chemosensory qualities of an aversive odor, bitter taste and oral irritation.
There is a growing body of evidence demonstrating epigenetic chemosensory mechanisms through which fetal alcohol exposure increases adolescent alcohol acceptance, in part, by decreasing the aversion to alcohol's bitter and oral irritation qualities, as well as its odor. Given that alcohol and nicotine have noteworthy chemosensory qualities in common, we investigated whether fetal exposure to alcohol increased the acceptability of nicotine's odor and taste in adolescent rats.
Study rats were alcohol-exposed during fetal development via the dams' liquid diet. Control animals received ad lib access to an iso-caloric, iso-nutritive diet throughout gestation.
Odorant-induced innate behavioral responses to nicotine odor Experiment 1 or orosensory-mediated responses to nicotine solutions Experiment 2 were obtained, using whole-body plethysmography and brief access lick tests , respectively. Compared to controls, rats exposed to fetal alcohol showed an enhanced nicotine odor response that was paralleled by increased oral acceptability of nicotine.
Given the common aversive component qualities imbued in the flavor profiles of both drugs, our findings demonstrate that like postnatal alcohol avidity, fetal alcohol exposure also influences nicotine acceptance, at a minimum, by decreasing the aversion of both its smell and taste. Moreover, they highlight potential chemosensory-based mechanism s by which fetal alcohol exposure increases the later initial risk for nicotine use, thereby contributing to the co-morbid expression with enhanced alcohol avidity.
Where common chemosensory mechanisms are at play, our. Full Text Available Human studies indicate that alcohol exposure during gestation not only increases the chance for later alcohol abuse, but also nicotine dependence. Where common chemosensory mechanisms are. Ligand binding modes from low resolution GPCR models and mutagenesis: Bitter taste is one of the basic taste modalities, warning against consuming potential poisons.
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. 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.
Gastric bypass surgery is a specific medical technology that alters the body in ways that force the patient to fundamentally change his or her eating habits. When patients enrol for surgery, they enter a learning process, encountering new and at times contested ways of sensing their bodies, tasting We suggest that eating should be conceptualised as a practice that extends beyond the boundaries of our bodies and into diverse realms of relations and practices, and that changing the way we eat also changes the fundamentally embodied Taste and Smell Disorders.
Our senses of taste and smell give us great pleasure. Taste helps us enjoy food and beverages. Smell lets us enjoy the scents and fragrances like roses or coffee. Taste and smell also protect us, letting us know when food What Are Taste Buds? How exactly do your taste Habitual Tastes and Embedded Taste. There seems, hence, to be a gap between the multiplicity of instances of experience and recollection that belongs to the sphere of the individual and a historical memory embedded in the larger context of a society.
From a common-sense perspective, this gap Namely, that given that all remembrance has individual recollection as the point of departure, then how does individual recollection of tastes Analysis of taste qualities and ingredients of beer by taste sensing system; Mikaku sensor ni yoru beer no ajishitsu to seibun no bunseki.
The taste of beer was measured using a taste sensing system with eight kinds of lipid membrane. The output from the sensor has high discriminating power and high correlation with taste substances in beer and sensory test by human.
The estimation of the concentration of taste substances by multiple regression analysis was fairly well. The taste sensor also well estimated the result of sensory test of many keywords concerning beer taste.
In this paper, we explore how patients begin to eat again after gastric bypass surgery. The empirical data used here are drawn from a Danish fieldwork study of persons undergoing obesity surgery. The material presented shows how the patients used instructions on how to eat. Mammalian Sweet Taste Receptors. P; Zuker, Charles S. The identification of taste receptors generates powerful molecular tools to investigate not only the function of taste receptor cells, but also the logic of taste coding.
For example, defining the size and diversity of the re Exploring taste hyposensitivity in Japanese senior high school students. 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 senior high school students.
Factors affecting taste hyposensitivity were investigated using a multivariate analysis. Sweet- taste hyposensitivity was observed in 7.
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. Behavioral genetics and taste. Full Text Available Abstract This review focuses on behavioral genetic studies of sweet, umami, bitter and salt taste responses in mammals. Studies involving mouse inbred strain comparisons and genetic analyses, and their impact on elucidation of taste receptors and transduction mechanisms are discussed.
Finally, the effect of genetic variation in taste responsiveness on complex traits such as drug intake is considered. Recent advances in development of genomic resources make behavioral genetics a powerful approach for understanding mechanisms of taste. Contribution of different taste cells and signaling pathways to the discrimination of "bitter" taste stimuli by an insect.
Animals can discriminate among many different types of foods. This discrimination process involves multiple sensory systems, but the sense of taste is known to play a central role.
We asked how the taste system contributes to the discrimination of different "bitter" taste stimuli in Manduca sexta caterpillars. This insect has approximately eight bilateral pairs of taste cells that respond selectively to bitter taste stimuli.
Each bilateral pair of bitter-sensitive taste cells has a different molecular receptive range MRR ; some of these taste cells also contain two signaling pathways with distinctive MRRs and temporal patterns of spiking. To test for discrimination, we habituated the caterpillar's taste -mediated aversive response to one bitter taste stimulus salicin and then asked whether this habituation phenomenon generalized to four other bitter taste stimuli caffeine, aristolochic acid, Grindelia extract, and Canna extract.
We inferred that the two compounds were discriminable if the habituation phenomenon failed to generalize e. We found that M. We propose that the heterogeneous population of bitter-sensitive taste cells and signaling pathways within this insect facilitates the discrimination of bitter taste stimuli. Acetylcholine is released from taste cells, enhancing taste signalling.
Acetylcholine ACh , a candidate neurotransmitter that has been implicated in taste buds, elicits calcium mobilization in Receptor Type II taste cells. Using RT-PCR analysis and pharmacological interventions, we demonstrate that the muscarinic acetylcholine receptor M3 mediates these actions.
Blocking muscarinic receptors depressed taste -evoked responses in Receptor cells, suggesting that ACh is normally released from taste cells during taste stimulation.
ACh biosensors confirmed that, indeed, taste Receptor cells secrete acetylcholine during gustatory stimulation. Genetic deletion of muscarinic receptors resulted in significantly diminished ATP secretion from taste buds.
The data demonstrate a new role for acetylcholine as a taste bud transmitter. Our results imply specifically that ACh is an autocrine transmitter secreted by taste Receptor cells during gustatory stimulation, enhancing taste -evoked responses and afferent transmitter secretion.
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.
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.
Tasting in mundane practices. The ethnographic materials are used to engage with what so far social science literatures on tasting tend to take for granted: 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 What emerges is an alternative, composite understanding of tasting as variously done in varied mundane practices A question of taste.
A career in science is shaped by many factors, one of the most important being our tastes in research. These typically form early and are shaped by subsequent successes and failures. My tastes run to microscopes, chemistry, and spatial organization of cytoplasm.
I will try to identify where they came from, how they shaped my career, and how they continue to evolve. My hope is to inspire young scientists to identify and celebrate their own unique tastes. The taste of music. Yale University Press, Novello, , speaks about the 'small acid-sweet voice' of the oboe. In line with this tradition of describing musical concepts in terms of taste words, recent empirical studies have found reliable associations between taste perception and low-level sound and musical parameters, like pitch and phonetic features.
Here we investigated whether taste words elicited consistent musical representations by asking trained musicians to improvise on the basis of the four canonical taste words: Our results showed that, even in free improvisation, taste words elicited very reliable and consistent musical patterns: Interestingly, projections of the improvisations of taste words to musical space a vector space defined by relevant musical parameters revealed that, in musical space, improvisations based on different taste words were nearly orthogonal or opposite.
Decoding methods could classify binary choices of improvisations i. In a second experiment we investigated the mapping from perception of music to taste words. Fifty-seven non-musical experts listened to a fraction of the improvisations. We found that listeners classified with high performance the taste word which had elicited the improvisation. Our results, furthermore, show that associations of taste and music. G studies were used to investigate the dependability of the analytic scores, the distinctness of the….
Clindamycin and taste disorders. Topical use of clindamycin has been associated with taste disorders in the literature, but little is known about the nature of this adverse drug reaction. The aim of this article was to describe reports of clindamycin-induced taste disorders and to analyse the factors involved. Fabrication of taste sensor for education. In order to solve the unconcern to usefulness of learning science among high school students in Japan, we developed a simple fabricated taste sensor with sensitivity and selectivity to each taste quality, which can be applied in science class.
A commercialized Teflon membrane was used as the polymer membrane holding lipids. In addition, a non-adhesive method is considered to combine the membrane and the sensor electrode using a plastic cap which is easily accessible.
The taste sensor for education fabricated in this way showed a good selectivity and sensitivity. By adjusting the composition of trioctylmethylammonium chloride TOMA and phosphoric acid di 2-ethylhexyl ester PAEE included in lipid solution, we improved the selectivity of this simple taste sensor to saltiness and sourness.
To verify this taste sensor as a useful science teaching material for science class, we applied this taste sensor into a science class for university students. By comparing the results between the sensory test and the sensor response, humans taste showed the same tendency just as the sensor response, which proved the sensor as a useful teaching material for science class. Exploring Ethnic Differences in Taste Perception.
Although a variety of factors are known to underlie the relationship between these demographic variables and nutritional intake, it is interesting to speculate that variation in food intake associated with ethnicity or sex may result, in part, from differences in the perceived taste of foods in these different populations. Thus, we initiated a study to evaluate taste responsiveness in different ethnic groups. Moreover, because of the known differences in taste responsiveness between males and females, analyses were stratified by sex.
The ethnic groups tested differed significantly from one another in reported perceived taste intensity. Our results showed that Hispanics and African Americans rated taste sensations higher than non-Hispanic Whites and that these differences were more pronounced in males. Understanding the nature of these differences in taste perception is important, because taste perception may contribute to dietary health risk.
When attempting to modify diet, individuals of different ethnicities may require personalized interventions that take into account the different sensory experience that these individuals may have when consuming foods. Phenylthiocarbamide produces conditioned taste aversions in mice. The authors hypothesized, based also on previous work, that SW mice might form a conditioned taste aversion over time due to the toxic properties of PTC.
We directly tested this hypothesis by attempting to condition a taste aversion to sucrose by injections of PTC. In experiment 2, the sucrose aversions were parametrically modified by both sucrose concentration and PTC dose, a hallmark of conditioned taste aversion.
We conclude that PTC can cause a conditioned taste aversion and discuss the importance of considering toxic effects of aversive tastants when analyzing behavioral strain differences. Smell and taste in inflammatory bowel disease.
In total, 59 IBD patients 37 Crohn's disease CD and 22 ulcerative colitis UC patients were studied using "Sniffin' sticks" and " taste strips" for olfactory and gustatory tests , respectively, and compared to healthy controls and published normative data. Among IBD CD and UC patients, the values for odor threshold, but not for odor identification or discrimination, were significantly lower than that of the normative data.
Further, these patients showed lower values than the normative taste values and the control group for all tastes , except sour; There were no relevant differences in taste and smell abilities between the CD and UC patients. Full Text Available Taste is a property that is thought to potentially modulate swallowing behavior. Whether such effects depend on taste , intensity remains unclear.
This study explored differences in the amplitudes of tongue-palate pressures in swallowing as a function of taste stimulus concentration. Tongue-palate pressures were collected in 80 healthy women, in two age groups under 40, over 60, stratified by genetic taste status nontasters, supertasters.
Liquids with different taste qualities sweet, sour, salty, and bitter were presented in high and low concentrations. Sweet stimuli were more palatable than sour, salty, or bitter stimuli. Higher concentrations elicited stronger tongue-palate pressures independently and in association with intensity ratings. The perceived intensity of a taste stimulus varies as a function of stimulus concentration, taste quality, participant age, and genetic taste status and influences swallowing pressure amplitudes.
High-concentration salty and sour stimuli elicit the greatest tongue-palate pressures. Vestibular schwannomas VS are rare tumors that can cause different symptoms due to their anatomical relationship to the cranial nerves in the inner auditory canal. So far little data is known to the effect of VS on the somatosensory function of the intermediate nerve.
This study aimed to investigate the taste function of patients suffering from single sided VS. Therefore the well validated psychophysical test " Taste Strips" has been used. All patients were asked carefully for their medical history. A full ENT examination was done. Each side of the anterior two thirds of the tongue was tested separately using the Taste Strips.
The average age was 52 years with both gender equally represented. Throughout all age groups the taste score was lower on the tumor vs. Testing for significance just failed the level of 0. No correlation between tumor size and location of the tumor with the taste score could be detected.
Only 2 patients complained of taste dysfunction. They had a taste score below the To sum up a decreased taste score on the tumor side vs.
That supports the observation that taste is a whole mouth experience and dysfunction can be compensated. This article is premised on two presumptions. The first is, I think, uncontroversial, the second less so. This, then, is merely to recognize that when Bourdieu first published books such as The Love of Art , written with Alain Darbel and Distinctions: A Social Critique of the Judgement of Tas Smell and taste disorders [.
Full Text Available [english] Smell and taste disorders can markedly affect the quality of life. In recent years we have become much better in the assessment of the ability to smell and taste. In addition, information is now available to say something about the prognosis of individual patients. With regard to therapy there also seems to be low but steady progress.
Of special importance for the treatment is the ability of the olfactory epithelium to regenerate. Gustatory insular cortex, aversive taste memory and taste neophobia. Prior research indicates a role for the gustatory insular cortex GC in taste neophobia. Rats with lesions of the GC show much weaker avoidance to a novel and potentially dangerous taste than do neurologically intact animals.
The current study used the retention of conditioned taste aversion CTA as a tool to determine whether the GC modulates neophobia by processing taste novelty or taste danger. Given that normal CTA retention does not involve the processing of taste novelty, the pattern of results suggests that the GC is involved in taste neophobia via its function in processing the danger conveyed by a taste stimulus.
Abnormality of taste and smell in Parkinson's disease. Smell sense is impaired in classic Parkinson's disease PD. An initial study found no change in taste threshold in non-demented PD subjects and pathological studies suggest that the first relay for taste , the nucleus of the solitary tract, is spared. We wished to determine if taste is abnormal in PD and whether it is associated with smell dysfunction. There was a significant impairment of taste threshold and severe disorder of smell identification in the PD group.
Age, duration of symptoms, disability, and smoking had no important effect on threshold measurement and there was no correlation between taste and smell dysfunction. Sensitivity analysis suggested that a provisional diagnosis of PD would be confirmed if smell or taste were abnormal; conversely, the diagnosis would merit review if both modalities were normal.
There were no important effects from age, disease severity or smell sense. Given the sparing of the first and second order taste neurones in PD, disorder of taste in PD most likely signifies involvement of the frontal operculum or orbitofrontal cortex, in keeping with advanced disease, although confounding by drug effects and changes in salivary constitution could not be excluded completely.
Taste effects of lingual application of cardiovascular medications. Medications used to treat cardiovascular diseases such as congestive heart failure, high blood pressure, and arrhythmia, are prescribed extensively in Western countries. However, taste complaints are common side effects of many of these cardiovascular medications.
Although clinical observations are helpful in determining potential taste problems from a medication, experimental studies are necessary to obtain quantitative data on taste. In the studies performed here, nine cardiovascular medications labetalol HCl, captopril, diltiazem HCl, enalapril maleate, hydrochlorothiazide, propranolol HCl, mexiletine HCl, procainamide HCl, and propafenone HCl were applied to the tongue in human volunteers to measure the direct effect of these drugs on taste receptors.
The medications were applied topically to the tongue surface of both young and elderly subjects to mimic the situation in which the drug is secreted into the saliva. Detection thresholds ranged from 0. The detection thresholds of healthy elderly subjects did not significantly differ from young controls. The compounds tested had a predominantly bitter taste with other qualities as well. In addition, topical application of the medications to the tongue affected the taste of one or more taste stimuli, with medications differing in the pattern of taste effects exhibited.
The mechanism of taste effects is not fully known, but the results of this study suggest one route may be due to medications' effect on peripheral taste receptors.
Bitter taste receptors influence glucose homeostasis. TAS1R- and TAS2R-type taste receptors are expressed in the gustatory system, where they detect sweet- and bitter- tasting stimuli, respectively. These receptors are also expressed in subsets of cells within the mammalian gastrointestinal tract, where they mediate nutrient assimilation and endocrine responses.
Because of the importance of taste receptors in the regulation of food intake and the alimentary responses to chemostimuli, we hypothesized that differences in taste receptor efficacy may impact glucose homeostasis. To address this issue, we initiated a candidate gene study within the Amish Family Diabetes Study and assessed the association of taste receptor variants with indicators of glucose dysregulation, including a diagnosis of type 2 diabetes mellitus and high levels of blood glucose and insulin during an oral glucose tolerance test.
We report that a TAS2R haplotype is associated with altered glucose and insulin homeostasis. We also found that one SNP within this haplotype disrupts normal responses of a single receptor, TAS2R9, to its cognate ligands ofloxacin, procainamide and pirenzapine. Together, these findings suggest that a functionally compromised TAS2R receptor negatively impacts glucose homeostasis, providing an important link between alimentary chemosensation and metabolic disease.
Wine Expertise Predicts Taste Phenotype. 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. 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. Taste preferences and taste thresholds to classical taste substances in the carnivorous fish, kutum Rutilus frisii kutum Teleostei: The objective of this study was to compare the taste preferences in the closely related sympatric fish species with different feeding patterns. For this purpose, palatability for four classical taste substances was evaluated for carnivorous kutum Rutilus frisii kutum and the results were compared with the taste preferences of the omnivorous roach Rutilus rutilus which had been studied earlier.
In addition, the threshold concentration and the dose-response relationship of the most palatable tastants were evaluated and the ability of kutum to differentiate food with tastants in different concentrations was estimated. It was found that citric acid significantly increases the agar gel pellet consumption within the range of concentrations from 0. The pellet consumption is significantly different if the concentration of citric acid in the pellets differs more than two times.
The absolute threshold concentration is 0. Sucrose and NaCl have deterrent taste at the highest concentrations tested 0. Both substances are palatable at 10 times lower concentrations and become indifferent after further gradual decrease in their concentration.
CaCl2 decreases the pellets consumption at 0. The number of rejections and repeated grasps of a food pellet is fewness and is not related to the pellet's palatability, while the retention time of pellet in the oral cavity positively and highly correlates with the pellet's palatability.
Kutum have opposite taste preferences for most substances tested in comparison with the roach. It indicates that the taste preferences mediated by the oral taste receptors are different in closely related sympatric fish displayed diet divergences. Taste quality and intensity of stimuli as reported by rats: Full Text Available The interpretation of neural activity related to sensory stimulation requires an understanding of the subject's perception of the stimulation.
Previous methods used to evaluate the perception of chemosensory stimuli by rodents have distinct limitations. We developed a novel behavioral paradigm, the taste -location association task, to complement these methods.
First we tested if rats are able to learn associations between five basic taste stimuli and their spatial locations. This spatial task was based on 4 prototypical tastants and water. All four rats trained to perform the task reached levels of performance well above chance. Control trials demonstrated that the rats used only taste cues. Further, the learned stimulus set was resistant to interference, allowing for generalization experiments performed subsequently.
We tested the rats' gustatory generalizations of tastants to the five trained stimuli, both regarding their taste qualities as well as intensity ratings. The taste profiles generated by these experiments contribute to the understanding of how perception of the specific taste stimuli relate to the perception of the five basic taste qualities in intact behaving rats.
In this large taste space we found that intensity plays a major role. Furthermore, umami stimuli were not reported as being similar to other basic tastants. Our new paradigm enables neurophysiological studies of taste -based learning and memory in awake, freely moving animals.
Extraversion and taste sensitivity. The rationale for investigating the gustatory reactivity as influenced by personality dimensions was suggested by some prior findings of an association between extraversion and acuity in other sensory systems. Detection thresholds for sweet, salty, and bitter qualities of taste were measured in 60 young healthy male and female volunteers using a two-alternative forced-choice technique.
Personality of the responders was assessed using the Eysenck Personality Inventory. Multivariate analysis of variance failed to demonstrate a statistically significant interaction between an extraversion-introversion score, neuroticism score, smoking, gender and age.
Possible reasons for lack of differences between introverts and extraverts in the values of taste detection thresholds were discussed. What does geographical origin mean? It is a claim protected through labelling 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 Mixing methods, tasting fingers.
It complements the repertoires The taste looks good. 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 Delf.
Dr Gerrit Polder, an electrical engineer at Wageningen University, carried out his doctorate research at. The development of taste transduction and taste chip technology.
The intrinsic perception process of taste is obviously far less known than those of vision, audition, touch and olfaction. Despite that taste cells utilize a variety of sensory mechanisms to translate plenty of gustatory sensations such as sour, sweet, bitter, salty and umami into cellular signals, gustatory perception mechanisms are still under exploration due to the lack of effective methods on cellular and molecular level. Recently the development of molecular biological and electrophysiological studies has promoted exploration of olfactory and gustatory transduction and coding mechanisms dramatically.
Based on the studies of artificial olfaction, artificial taste and cell-based biosensor in our laboratory, this paper reviews the current research on taste transduction mechanism. We introduce the recent advances in cell chip that combined biology with microelectronics, discuss taste cell chip as well as its potential of prospective application in taste transduction mechanism in detail and propose the research trends of taste chip in future.
Full Text Available A disposable screen-printed multi channel taste sensor composed of several types of lipid as transducers and a computer as data analyzer could detect taste in a manner similar to human gustatory sensation. The disposable taste sensor was used to measure the electrical potential resulted from the interaction between lipid membranes and taste substances. In the present study, two types of packaged commercial milk, the ultra high temperature UHT and the pasteurized milk were tested.
It was found that the disposable taste sensor is capable to discriminate reliably between fresh and spoiled milk and to follow the deterioration of the milk quality when it is stored at room temperature based on a pattern recognition principle namely Principle Component Analysis PCA. This research could provide a new monitoring method ideally for simple and cheap decentralized testing for controlling the quality of milk, which may be of great use in the dairy industries.
Dissolution methodology for taste masked oral dosage forms. Conventional adult dosage forms are often not suitable for the paediatric and geriatric populations due to either swallowing difficulties or patient repulsion and a requirement for tailored dosing to individual compliance or physiological needs. Alternative formulations are available; however these often require the incorporation of more complex taste masking techniques.
One approach to taste masking is to reduce contact between the bitter Active Pharmaceutical Ingredient API and oral cavity taste bud regions. This is achieved by hindering release in the oral cavity, or including competitive inhibition of bitter sensation for example by using flavours or sweeteners. There may also be other sensational complications from the API such as residual burning, reflux or metallic taste sensations to deal with.
In vitro dissolution testing is employed to elucidate taste masking capability by quantifying release of the drug in simulated oral cavity conditions. Dissolution testing approaches may also be used to potentially predict or quantify the effect of the taste masking technique on the resultant pharmacokinetic profile. The present review investigates the anatomy and physiology of the oral cavity and current approaches to taste masking. In vitro dissolution methodologies adopted in the evaluation of taste masked formulations are discussed for their relative merits and drawbacks.
A vast array of methodologies has been employed, with little agreement between approaches, and a lack of biorelevance. Learning through the taste system. 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. Smell and taste in patients with vascular malformation of the extracranial head and neck region.
Olfactory and gustatory functions have not been investigated in patients with vascular malformation of the extracranial head and neck region with validated smell and taste tests. Although olfactory and gustatory deficiencies are often not outwardly apparent, they substantially affect daily life. Smell and taste tests using sniffin sticks and taste strips were administered in 40 patients.
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