The effect of calcium buffering and calcium sensor type on the sensitivity of an array-based bitter receptor screening assay.
Abstract The genetically encoded calcium sensor protein Cameleon YC3.6 has previously been applied for functional G protein-coupled receptor screening using receptor cell arrays. However, different types of sensors are available, with a wide range in [Ca2+] sensitivity, Hill coefficients, calcium binding domains and fluorophores, that could potentially improve the performance of the assay. Here, we compared the responses of three structurally different calcium sensor proteins (Cameleon YC3.6, Nano140 and Twitch2B) simultaneously, on a single chip, at different cytosolic expression levels and in combination with tw...
Source: Chemical Senses - July 5, 2019 Category: Biochemistry Authors: Roelse M, Wehrens R, Henquet MGL, Witkamp RF, Hall RD, Jongsma MA Tags: Chem Senses Source Type: research

Cerebellar grey matter and olfactory performance.
Abstract The role of the cerebellum in the chemical senses is still poorly understood. This voxel-based morphometry (VBM) study investigated associations between grey matter volume (GMV) in subregions of the cerebellum and olfactory performance. VBM data from 48 men were analyzed. The participants were tested with a standardized olfactory test that measured olfactory threshold, discrimination and identification ability. The investigated sample covered a wide range of olfactory performance including individuals with a reduced sense of smell (anosmia, hyposmia) and normosmia. The computed regression analyses reveale...
Source: Chemical Senses - July 4, 2019 Category: Biochemistry Authors: Wabnegger A, Schienle A Tags: Chem Senses Source Type: research

Metabolism of Odorant Molecules in Human Nasal/Oral Cavity Affects the Odorant Perception.
In this study, we examined the mode of metabolism of food odorant molecules in the human nasal/oral cavity in vitro and in vivo. We selected 4 odorants, 2-furfurylthiol (2-FT), hexanal, benzyl acetate, and methyl raspberry ketone, which are potentially important for designing food flavors. In vitro metabolic assays of odorants with saliva/nasal mucus analyzed by gas chromatography mass spectrometry revealed that human saliva and nasal mucus exhibit the following 3 enzymatic activities: (i) methylation of 2-FT into furfuryl methylsulfide (FMS); (ii) reduction of hexanal into hexanol; and (iii) hydrolysis of benzyl acetate i...
Source: Chemical Senses - June 29, 2019 Category: Biochemistry Authors: Ijichi C, Wakabayashi H, Sugiyama S, Ihara Y, Nogi Y, Nagashima A, Ihara S, Niimura Y, Shimizu Y, Kondo K, Touhara K Tags: Chem Senses Source Type: research

Expression of bitter taste receptors and solitary chemosensory cell markers in the human sinonasal cavity.
Abstract Some bitter taste receptors, (TAS2R gene products) are expressed in the human sinonasal cavity and may function to detect airborne irritants. The expression of all 25 human bitter taste receptors and their location within the upper airway is not yet clear. The aim of this study is to characterize the presence and distribution of TAS2R transcripts and solitary chemosensory cells (SCCs) in different locations of the human sinonasal cavity. Biopsies were obtained from human subjects at up to four different sinonasal anatomic sites. PCR, microarray, and qRT-PCR were used to examine gene transcript expression....
Source: Chemical Senses - June 20, 2019 Category: Biochemistry Authors: Chen J, Larson ED, Anderson CB, Agarwal P, Frank DN, Kinnamon SC, Ramakrishnan VR Tags: Chem Senses Source Type: research

The Chemosensory Pleasure Scale: A New Assessment for Measuring Hedonic Smell and Taste Capacities.
We examined the reliability and validity of the CPS in our study. First, we conducted exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to identify and examine the structure of the CPS. Second, the CPS's validity and test-retest stability were investigated. The CPS was correlated with other measurements of anhedonia and pleasure experience. Furthermore, the empirical validity of CPS was also examined in our study. The results indicated that the CPS is a reliable and valid measure for assessing an individual's hedonic capacity for smell and taste pleasure in nonclinical samples. Further application of...
Source: Chemical Senses - June 14, 2019 Category: Biochemistry Authors: Zhao JB, Wang YL, Ma QW, Zhao JB, Zhang XY, Zou LQ Tags: Chem Senses Source Type: research

Automated canine scent-detection apparatus: Technical description and training outcomes.
Abstract To date, laboratory scent-detection work with dogs has been a manual process whereby some or all aspects of the procedures are mediated by researchers. Automation of this process would eliminate issues associated with cuing, subjectivity in data collection, and reinforcement delivery. Herein, I describe an automated apparatus that can accommodate almost any type of sample that can be brought into the laboratory. The apparatus consists of a 17-segment carousel that rotates behind a panel. Dogs can access a single sample at a time through a port in the panel. Infrared beams are used to detect sample observa...
Source: Chemical Senses - June 12, 2019 Category: Biochemistry Authors: Edwards TL Tags: Chem Senses Source Type: research

Taste perception and cerebral activity in the human gustatory cortex induced by glucose, fructose and sucrose solutions.
Abstract Glucose, fructose and sucrose are important carbohydrates in Western diets with particular sweetness intensity and metabolisms. No study has compared their cerebral detection and their taste perception. Gustatory evoked potentials (GEPs), taste detection thresholds, intensity perception and pleasantness were compared in response to glucose, fructose and sucrose solutions at similar sweetness intensities and at identical molar concentrations. 23 healthy subjects were randomly stimulated with three solutions of similar sweetness intensity (0.75 M of glucose, 0.47 M of fructose and 0.29 M of sucros...
Source: Chemical Senses - June 4, 2019 Category: Biochemistry Authors: Mouillot T, Barthet S, Janin L, Creteau C, Devilliers H, Brindisi MC, Penicaud L, Leloup C, Brondel L, Jacquin-Piques A Tags: Chem Senses Source Type: research

Nasal cavity of green sea turtles contains three independent sensory epithelia.
Abstract The morphological and histological features of the nasal cavity are diverse among animal species, and the nasal cavities of terrestrial and semi-aquatic turtles possess two regions lined with each different types of sensory epithelium. Sea turtles can inhale both of volatile and water-soluble odorants with high sensitivity, but details of the architectural features and the distribution of the sensory epithelia within the sea turtle nasal cavity remain uncertain. The present study analyzed the nasal cavity of green sea turtles using morphological, computed tomographic and histological methods. We found tha...
Source: Chemical Senses - June 1, 2019 Category: Biochemistry Authors: Kondoh D, Kitayama C, Yamaguchi Y, Yanagawa M, Kawai YK, Suzuki C, Itakura R, Fujimoto A, Satow T, Kondo S, Sato T Tags: Chem Senses Source Type: research

Mammalian Taste Cells Express Functional Olfactory Receptors.
Abstract The peripheral taste and olfactory systems in mammals are separate and independent sensory systems. In the current model of chemosensation, gustatory, and olfactory receptors are genetically divergent families expressed in anatomically distinct locations that project to disparate downstream targets. Although information from the 2 sensory systems merges to form the perception of flavor, the first cross talk is thought to occur centrally, in the insular cortex. Recent studies have shown that gustatory and olfactory receptors are expressed throughout the body and serve as chemical sensors in multiple tissue...
Source: Chemical Senses - May 29, 2019 Category: Biochemistry Authors: Malik B, Elkaddi N, Turkistani J, Spielman AI, Ozdener MH Tags: Chem Senses Source Type: research

Taste Receptor Cells in Mice Express Receptors for the Hormone Adiponectin.
Abstract The metabolic hormone adiponectin is secreted into the circulation by adipocytes, and mediates key biological functions including insulin sensitivity, adipocyte development, and fatty acid oxidation. Adiponectin is also abundant in saliva, where its functions are poorly understood. Here we report that murine taste receptor cells express specific adiponectin receptors, and may be a target for salivary adiponectin. This is supported by the presence of all three known adiponectin receptors in transcriptomic data obtained by RNA-seq analysis of purified circumvallate taste buds. As well, immunohistochemical a...
Source: Chemical Senses - May 24, 2019 Category: Biochemistry Authors: Crosson SM, Marques A, Dib P, Dotson CD, Munger SD, Zolotukhin S Tags: Chem Senses Source Type: research

A method for controlled odor delivery in olfactory field-testing.
Abstract A widely recognized limitation in mammalian olfactory research is the lack of current methods for measuring odor availability (i.e. the quantifiable amount of odor presented and thus available for olfaction) of training or testing materials during behavioral or operational testing. This research utilized an existing technology known as Controlled Odor Mimic Permeation Systems (COMPS) to produce a reproducible, field-appropriate odor delivery method that can be analytically validated and quantified, akin to laboratory-based research methods, such as permeation devices that deliver a stable concentration of...
Source: Chemical Senses - May 21, 2019 Category: Biochemistry Authors: Simon AG, DeGreeff LE, Frank K, Peranich K, Holness H, Furton KG Tags: Chem Senses Source Type: research

Behavioral and neural responses to vitamin C solution in vitamin C-deficient Osteogenic Disorder Shionogi/Shi Jcl-od/od rats.
Abstract To investigate the appetite for vitamin C (VC), we conducted behavioral and neural experiments using Osteogenic Disorder Shionogi/Shi Jcl-od/od (od/od) rats, which lack the ability to synthesize VC, and their wild-type controls (+/+). In the behavioral study, rats were deprived of VC for 25 days and then received two-bottle preference tests with a choice between water and 10 mM VC. The preference for 10 mM VC solution of od/od rats was significantly greater than that of +/+ rats. In the neural study, the relative magnitudes of the whole chorda tympani nerve (CTN) responses to 100 - 1000 mM VC, 3 - 10 mM H...
Source: Chemical Senses - May 18, 2019 Category: Biochemistry Authors: Yasuo T, Suwabe T, Sako N Tags: Chem Senses Source Type: research

Clinical usefulness of self-rated olfactory performance - a data science-based assessment of 6000 patients.
l T Abstract In clinical practice, with its time constraints, a frequent conclusion is that asking about the ability to smell may suffice to detect olfactory problems. To address this question systematically, 6,049 subjects were asked about how well they can perceive odors, with five possible responses. Participants presented at a University Department of Otorhinolaryngology where olfactory testing was part of the routine investigation performed in patient receiving surgery at the clinic (for various reasons). According to an odor identification test 1,227 subjects had functional anosmia and 3,113 were labeled wit...
Source: Chemical Senses - May 11, 2019 Category: Biochemistry Authors: Lötsch J, Hummel T Tags: Chem Senses Source Type: research

Quality of life in patients with olfactory loss is better predicted by flavor identification than by orthonasal olfactory function.
l T Abstract To date, most studies on the relationship between chemosensory performance and quality of life have focused on orthonasal measures of olfactory function. In the current investigation, we examined the predictive value of orthonasal and flavor identification indices of olfactory function on a wide spectrum of health and sociopsychological factors, including quality of life, life satisfaction, overall health and depressive symptoms. Participants were 178 ENT patients (Mage=58±1) representing various causes of olfactory loss: idiopathic smell loss (n=51; Mage=63±2), sinunasal disease (n...
Source: Chemical Senses - May 2, 2019 Category: Biochemistry Authors: Oleszkiewicz A, Park D, Resler K, Draf J, Schulze A, Zang Y, Hähner A, Hummel T Tags: Chem Senses Source Type: research

Chemogenic Subqualities of Mouthfeel.
Abstract Mouthfeel refers to the physical or textural sensations in the mouth caused by foods and beverages that are essential to the acceptability of many edible products. The sensory subqualities contributing to mouthfeel are often chemogenic in nature and include heat, burning, cooling, tingling, and numbing. These "chemesthetic" sensations are a result of the chemical activation of receptors that are associated with nerve fibers mediating pain and mechanotransduction. Each of these chemesthetic sensations in the oral cavity are transduced in the nervous system by a combination of different molecular ...
Source: Chemical Senses - April 30, 2019 Category: Biochemistry Authors: Simons CT, Klein AH, Carstens E Tags: Chem Senses Source Type: research

Effects of Tokishakuyakusan on regeneration of murine olfactory neurons in vivo and in vitro.
Abstract Post-upper respiratory tract infection related olfactory dysfunction typically occurs due to neural damage after an upper respiratory tract infection associated with a common cold or influenza. Recently, Tokishakuyakusan, a Japanese traditional Kampo medicine, has been found to be effective for post-viral olfactory dysfunction. However, the pharmacodynamics of Tokishakuyakusan in the treatment of post-viral olfactory dysfunction remain unresolved. We investigated the effects of Tokishakuyakusan on the regeneration of olfactory neurons and expression of nerve growth factor (NGF) in neural systems, using in...
Source: Chemical Senses - April 16, 2019 Category: Biochemistry Authors: Noda T, Shiga H, Yamada K, Harita M, Nakamura Y, Ishikura T, Kumai M, Kawakami Z, Kaneko A, Hatta T, Sakata-Haga H, Shimada H, Miwa T Tags: Chem Senses Source Type: research

Long-Term Taste Impairment after Intensity-Modulated Radiotherapy to Treat Head-and-Neck Cancer: Correlations with Glossectomy and the Mean Radiation Dose to the Oral Cavity.
Abstract We explored the effects of various parameters on taste impairments in head-and-neck cancer patients receiving intensity-modulated radiotherapy. From Jan. 2014 to Sep. 2017, 88 head-and-neck cancer patients subjected to curative or postoperative intensity-modulated radiotherapy were enrolled in this prospective study. All patients underwent at least 1 year of follow-up after intensity-modulated radiotherapy. Quality-of-life assessments in terms of patient-reported gustatory function were measured using the taste-related questions of the EORTC H&N35 questionnaires. At a median follow-up time of 27 month...
Source: Chemical Senses - April 8, 2019 Category: Biochemistry Authors: Chen WC, Tsai MS, Tsai YT, Lai CH, Lee CP, Chen MF Tags: Chem Senses Source Type: research

Odor identification performance in Idiopathic Parkinson's disease is associated with gender and the genetic variability of the olfactory binding-protein (OBPIIa).
In conclusion, our results confirmed a sex effect on the reduced olfactory performance of patients with PD and identified the OBPIIa locus, which may provide a mechanism to determine the risk factor for olfactory deficits in women with PD at the molecular level. PMID: 30944919 [PubMed - as supplied by publisher] (Source: Chemical Senses)
Source: Chemical Senses - April 3, 2019 Category: Biochemistry Authors: Melis M, Sollai G, Masala C, Pisanu C, Cossu G, Melis M, Sarchioto M, Oppo V, Morelli M, Crnjar R, Hummel T, Tomassini Barbarossa I Tags: Chem Senses Source Type: research

Conserved residues control the T1R3-specific allosteric signaling pathway of the mammalian sweet taste receptor.
cci S Abstract Mammalian sensory systems detect sweet taste through the activation of a single heteromeric T1R2/T1R3 receptor belonging to class C G-protein-coupled receptors. Allosteric ligands are known to interact within the transmembrane domain, yet a complete view of receptor activation remains elusive. By combining site-directed mutagenesis with computational modeling, we investigate the structure and dynamics of the allosteric binding pocket of the T1R3 sweet taste receptor in its apo form, and in the presence of an allosteric ligand, cyclamate. A novel positively-charged residue at the extracellular loop 2...
Source: Chemical Senses - March 20, 2019 Category: Biochemistry Authors: Chéron JB, Soohoo A, Wang Y, Golebiowski J, Antonczak S, Jiang P, Fiorucci S Tags: Chem Senses Source Type: research

SmellSpace: An Odor-Based Social Network as a Platform for Collecting Olfactory Perceptual Data.
Abstract A common goal in olfaction research is modeling the link between odorant structure and odor perception. Such modeling efforts require large datasets on olfactory perception, yet only a few of these are publicly and freely available. Given that individual odor perception may be informative on personal makeup and interpersonal relationships, we hypothesized that people would gladly provide olfactory perceptual estimates in the context of an odor-based social network. We developed a web-based infrastructure for such a network we called SmellSpace, and distributed 10,000 scratch-and-sniff registration booklet...
Source: Chemical Senses - March 11, 2019 Category: Biochemistry Authors: Snitz K, Perl O, Honigstein D, Secundo L, Ravia A, Yablonka A, Endevelt-Shapira Y, Sobel N Tags: Chem Senses Source Type: research

Chemical Profiles of Integumentary and Glandular Substrates in Australian Sea Lion Pups (Neophoca cinerea).
Abstract Recognition of individuals or classes of individuals plays an important role in the communication systems of many mammals. The ability of otariid (i.e., fur seal and sea lion) females to locate and identify their offspring in colonies after returning from regular foraging trips is essential to successful pup rearing. It has been shown that olfaction is used to confirm the identity of the pup by the mother when they reunite, yet the processes by which this chemical recognition occurs remain unclear. Using gas chromatography-mass spectrometry, we examined chemical profiles of integumentary and glandular sec...
Source: Chemical Senses - February 25, 2019 Category: Biochemistry Authors: Wierucka K, Barthes N, Pitcher BJ, Schaal B, Charrier I, Harcourt RG Tags: Chem Senses Source Type: research

Recognizing taste: coding patterns along the neural axis in mammals.
Abstract The gustatory system encodes information about chemical identity, nutritional value, and concentration of sensory stimuli before transmitting the signal from taste buds to central neurons that process and transform the signal. Deciphering the coding logic for taste quality requires examining responses at each level along the neural axis - from peripheral sensory organs to gustatory cortex. From the earliest single fiber recordings, it was clear that some afferent neurons respond uniquely, others to stimuli of multiple qualities.  There is frequently a "best stimulus" for a given neuron, lea...
Source: Chemical Senses - February 20, 2019 Category: Biochemistry Authors: Ohla K, Yoshida R, Roper SD, Di Lorenzo PM, Victor JD, Boughter JD, Fletcher M, Katz DB, Chaudhari N Tags: Chem Senses Source Type: research

Scent Chemicals of the Tail Gland of the Red Fox, Vulpes vulpes.
Abstract Like all animals, the red fox uses chemical signals for social communication. The supracaudal or tail gland smells of violets, attributed to the presence of carotenoid degradation products, or apocarotenoids, which commonly occur as aromatics in flowers. We have more fully characterised the scent chemistry of the fox tail gland. Volatile chemicals were analysed by GC-MS and identified from their electron ionisation mass spectra and Kovats retention indices. The three previously reported apocarotenoids were confirmed, and many additional compounds found. These include the apocarotenoids β-cyclocitral,...
Source: Chemical Senses - February 7, 2019 Category: Biochemistry Authors: McLean S, Davies NW, Nichols DS Tags: Chem Senses Source Type: research

Salivary α-Amylase Activity and Starch-Related Sweet Taste.
Salivary α-Amylase Activity and Starch-Related Sweet Taste. Chem Senses. 2019 Feb 07;: Authors: Aji GK, Warren FJ, Roura E Abstract Starch-related sweet taste perception plays an important role as a part of the dietary nutrient sensing mechanisms in the oral cavity. However, the release of sugars from starchy foods eliciting sweetness has been less studied in humans than in laboratory rodents. Thus, twenty-eight respondents were recruited and evaluated for their starch-related sweet taste perception, salivary alpha-amylase (sAA) activity, oral release of reducing sugars, and salivary leptin. The...
Source: Chemical Senses - February 7, 2019 Category: Biochemistry Authors: Aji GK, Warren FJ, Roura E Tags: Chem Senses Source Type: research

Achieving olfactory expertise: Training for transfer in odor identification.
This study compared how odor identification training with either single odors or binary mixtures affected identification performance, as well as transfer effects to untrained tasks and odors. Twenty-seven healthy participants (22 F; 28.0 ± 4.7 years old) completed identification training of 8 odors using a list of 16 veridical names. The study included 8 training sessions, as well as pre-test and post-test evaluations. Results suggest notable effects of learning, as well as transfer to novel tasks and odors. Overall, training with single odors led to slightly better results than the binary mixture condition, suggest...
Source: Chemical Senses - February 3, 2019 Category: Biochemistry Authors: Morquecho-Campos P, Larsson M, Boesveldt S, Olofsson JK Tags: Chem Senses Source Type: research

Development of the Chinese Smell Identification Test.
Abstract Smell identification ability reflects the functional integrity of the human olfactory system. Its deficit is a prodromal marker for Parkinson's disease and is also implicated in Alzheimer's disease and other neurological and psychiatric disorders. Considering the impact of cultural factors on odor identifiability, we have developed a smell identification test specifically for the Chinese population (CSIT), which includes 40 odor items that are familiar to this population, presented in a multiple-choice format. The CSIT has a test-retest reliability of 0.92 and is validated against the University of Pennsy...
Source: Chemical Senses - January 30, 2019 Category: Biochemistry Authors: Feng G, Zhuang Y, Yao F, Ye Y, Wan Q, Zhou W Tags: Chem Senses Source Type: research

A novel olfactometer for efficient and flexible odorant delivery.
Abstract Understanding how sensory space maps to neural activity in the olfactory system requires efficiently and flexibly delivering numerous odorants within single experimental preparations. Such delivery is difficult with current olfactometer designs, which typically include limited numbers of stimulus channels and are subject to inter-trial and inter-channel contamination of odorants. Here, we present a novel olfactometer design that is easily constructed, modular, and capable of delivering an unlimited number of odorants in air with temporal precision and no detectable inter-trial or inter-channel contaminati...
Source: Chemical Senses - January 18, 2019 Category: Biochemistry Authors: Burton SD, Wipfel M, Guo M, Eiting TP, Wachowiak M Tags: Chem Senses Source Type: research

Characterizing Dysgeusia in Hemodialysis Patients.
Abstract Dysgeusia (abnormal taste) is common in those with chronic kidney disease and contributes to poor nutritional intake. Previous sensory work has shown that taste improves after dialysis sessions. The goal of this pilot study was to characterize altered taste perceptions in patients on dialysis compared to healthy adults, and to evaluate relationships between serum parameters with taste perceptions. We hypothesized that patients undergoing dialysis would experience blunted taste intensities compared to controls, and that serum levels of potential tastants would be inversely related to taste perception of co...
Source: Chemical Senses - January 9, 2019 Category: Biochemistry Authors: Fitzgerald C, Wiese G, Moorthi RN, Moe SM, Hill Gallant K, Running CA Tags: Chem Senses Source Type: research

Taste sensitivity and taste preference measures are correlated in healthy young adults.
The objectives of this study were to examine, in healthy adults (age 24.6 ± 0.6 years, n=49), 1) correlations among measures of taste sensitivity, including detection threshold (DT) and suprathreshold sensitivity (ST), and taste preference (PR) within sweet, salt, sour, umami, and fat tastes, 2) the underlying associations among DT, ST and PR measurements using principal component analysis, and 3) associations between measured PR and bitter intensity rating with self-reported food PRs. DTs and STs were negatively correlated within each taste modality. Salt, sweet, and umami DTs and STs were positively and negatively...
Source: Chemical Senses - December 26, 2018 Category: Biochemistry Authors: Chamoun E, Liu AAS, Duizer LM, Darlington G, Duncan AM, Haines J, Ma DWL Tags: Chem Senses Source Type: research

The Value of Homework: Exposure to Odors in the Home Cage Enhances Odor Discrimination Learning In Mice.
Abstract Perceptual learning is an enhancement in discriminability of similar stimuli following experience with those stimuli. Here, we examined the efficacy of adding additional active training following a standard training session, compared to additional stimulus exposure in the absence of associated task performance. Mice were trained daily in an odor-discrimination task, and then, several hours later each day, received one of three different manipulations: 1) a second active-training session, 2) non-task-related odor exposure in the home cage, or 3) no second session. For home-cage exposure, odorants were pres...
Source: Chemical Senses - December 24, 2018 Category: Biochemistry Authors: Fleming G, Wright BA, Wilson DA Tags: Chem Senses Source Type: research

Necessary conditions for social transmission of food preference through feces in the house mouse, Mus musculus domesticus.
uat P Abstract Mice can obtain information about a new food source through olfactory cues of conspecifics and consequently develop an attraction for this diet. The social transmission of food preference (STFP) takes place directly, during an encounter with a conspecific or indirectly, via feces. In indirect STFP, the digestive process can degrade odorant compounds characterizing the food, impairing the matching between feces and food. In a previous study, indirect STFP was efficient when the information support was a composite odorant. We, thus, hypothesized that the acquisition of indirect STFP depends on the mul...
Source: Chemical Senses - December 20, 2018 Category: Biochemistry Authors: Forestier T, Féron C, Leroy C, d'Ettorre P, Gouat P Tags: Chem Senses Source Type: research

Subjective olfactory loss in older adults concurs with long-term odor identification decline.
sson JK Abstract Olfactory impairments may provide early indications of future health outcomes in older adults. Thus, an important question concerns whether these impairments can be self-assessed. Previous findings of cross-sectional studies indicate low correlations between self-reported olfactory function and objective olfactory performance. On the other hand, subjective olfactory impairments predict future dementia and mortality in longitudinal settings. No previous study has assessed the relationship between subjectively and objectively measured decline in olfaction over time. Based on data for 903 older adult...
Source: Chemical Senses - December 13, 2018 Category: Biochemistry Authors: Ekström I, Josefsson M, Larsson M, Rönnlund M, Nordin S, Olofsson JK Tags: Chem Senses Source Type: research

Proceedings from the 2018 Association for Chemoreception Annual Meeting Symposium: Bariatric Surgery and Its Effects on Taste and Food Selection.
This article provides a summary of the topics discussed at the symposium titled Bariatric Surgery and Its Effects on Taste and Food Selection which was held at the Fortieth Annual Meeting of the Association for Chemoreception Sciences. Bariatric surgery such as Roux-en-Y gastric bypass (RYGB) is currently one of the most effective treatments available for weight loss and Type-2 diabetes. For this reason, it is of great interest to clinicians as well as to basic scientists studying the controls of feeding and energy balance. Despite the commonly held view by clinicians that RYGB patients change their food preferences away f...
Source: Chemical Senses - December 4, 2018 Category: Biochemistry Authors: Spector AC, Kapoor N, Price RK, Pepino MY, E Livingstone MB, le Roux CW Tags: Chem Senses Source Type: research

Cannabinoids, Chemical Senses, and Regulation of Feeding Behavior.
Abstract The herb Cannabis sativa has been traditionally used in many cultures and all over the world for thousands of years as medicine and recreation. However, because it was brought to the Western world in the late 19th century, its use has been a source of controversy with respect to its physiological effects as well as the generation of specific behaviors. In this regard, the CB1 receptor represents the most relevant target molecule of cannabinoid components on nervous system and whole-body energy homeostasis. Thus, the promotion of CB1 signaling can increase appetite and stimulate feeding, whereas blockade o...
Source: Chemical Senses - November 27, 2018 Category: Biochemistry Authors: Tarragon E, Moreno JJ Tags: Chem Senses Source Type: research

Interspecific variation of olfactory preferences in flies, mice, and humans.
Abstract Aiming to unravel interspecific differences in olfactory preferences, we performed comparative studies of odor valence in flies, mice, and humans. Our analysis suggests a model where flies and mice share similar olfactory preferences, but neither species share odor preferences with humans. This model contrasts with a previous study by Mandairon and colleagues, which suggested that the olfactory preferences of mice and humans are similar. A probabilistic examination revealed that underpowered studies can result in spurious significant correlations, which can account for the differences between both studies...
Source: Chemical Senses - November 15, 2018 Category: Biochemistry Authors: Manoel D, Makhlouf M, Scialdone A, Saraiva LR Tags: Chem Senses Source Type: research

Brain responses to anticipation and consumption of beer with and without alcohol.
In conclusion, we found no differences in acute brain reward upon consumption of NA-beer with and without alcohol, when presented in a context where regular alcoholic beer is expected. This suggests that in regular consumers beer flavor rather than the presence of alcohol is the main driver of the consumption experience. PMID: 30423017 [PubMed - as supplied by publisher] (Source: Chemical Senses)
Source: Chemical Senses - November 13, 2018 Category: Biochemistry Authors: Smeets PAM, de Graaf C Tags: Chem Senses Source Type: research

Selective effects of temperature on the sensory irritation but not taste of NaCl and citric acid.
This study investigated the effect of temperature on taste and chemesthetic sensations produced by the prototypical salty and sour stimuli NaCl and citric acid. Experiment 1 measured the perceived intensity of irritation (burning, stinging) and taste (saltiness, sourness) produced on the tongue tip by brief (3 sec) exposures to suprathreshold concentrations of NaCl and citric acid at 3 different temperatures (12, 34, 42°C). No significant effects of temperature were found on the taste or sensory irritation of either stimulus. Experiment 2 investigated the potential effects of temperature on sensory irritation at peri-t...
Source: Chemical Senses - November 12, 2018 Category: Biochemistry Authors: Nachtigal D, Andrew K, Green BG Tags: Chem Senses Source Type: research

Experience-Dependent c-Fos Expression in the Mediodorsal Thalamus Varies with Chemosensory Modality.
Abstract The mediodorsal thalamus is a higher-order thalamic nucleus critical for many cognitive behaviors. Defined by its reciprocal connections with the prefrontal cortex, the mediodorsal thalamus receives strong projections from chemosensory cortical areas for taste and smell, gustatory cortex and piriform cortex. Recent studies indicate the mediodorsal thalamus is involved in experience-dependent chemosensory processes, including olfactory attention and discrimination and the hedonic perception of odor-taste mixtures. How novel and familiar chemosensory stimuli are represented within this structure remains unc...
Source: Chemical Senses - November 2, 2018 Category: Biochemistry Authors: Fredericksen KE, McQueen KA, Samuelsen CL Tags: Chem Senses Source Type: research

Machine learning in human olfactory research.
l T Abstract The complexity of the human sense of smell is increasingly reflected in complex and high-dimensional data, which opens opportunities for data driven approaches that complement hypothesis driven research. Contemporary developments in computational and data science, with its currently most popular implementation as machine learning, facilitate complex data driven research approaches. The use of machine-learning in human olfactory research included major approaches comprising (i) the study of the physiology of pattern-based odor detection and recognition processes, (ii) pattern recognition in olfactory p...
Source: Chemical Senses - October 27, 2018 Category: Biochemistry Authors: Lötsch J, Kringel D, Hummel T Tags: Chem Senses Source Type: research

Spilanthol enhances sensitivity to sodium in mouse taste bud cells.
Abstract Overconsumption of NaCl has been linked to increased hypertension related morbidity. Compounds that can enhance NaCl responses in taste cells could help reduce human NaCl consumption without sacrificing perceived saltiness. Spilanthol is an unsaturated alkylamide isolated from the Jambu plant (Acmella oleracea) that can induce tingling, pungency, and numbing in the mouth. Structurally similar fatty acid amides, such as sanshool, elicit numbing and tingling sensations by inhibiting 2-pore domain potassium leak channels on trigeminal sensory neurons. Even when insufficient to induce action potential firing,...
Source: Chemical Senses - October 26, 2018 Category: Biochemistry Authors: Xu J, Lewandowski B, Miyazawa T, Shoji Y, Yee K, Bryant B Tags: Chem Senses Source Type: research

Tissue-dependent expression of bitter receptor TAS2R38 mRNA.
Abstract TAS2R38 is a human bitter receptor gene with a common but inactive allele; people homozygous for the inactive form cannot perceive low concentrations of certain bitter compounds. The frequency of the inactive and active form of this receptor is nearly equal in many human populations, and heterozygotes with one copy of the active form and one copy of the inactive form have the most common diplotype. However, even though they have the same genotype, heterozygotes differ markedly in their perception of bitterness, perhaps in part because of differences in TAS2R38 mRNA expression. Other tissues express this r...
Source: Chemical Senses - October 23, 2018 Category: Biochemistry Authors: Douglas JE, Lin C, Mansfield CJ, Arayata CJ, Cowart BJ, Spielman AI, Adappa ND, Palmer JN, Cohen NA, Reed DR Tags: Chem Senses Source Type: research

Perceived Properties Are Not Free-Floating.
PMID: 30299463 [PubMed - as supplied by publisher] (Source: Chemical Senses)
Source: Chemical Senses - October 9, 2018 Category: Biochemistry Authors: Lindemann B Tags: Chem Senses Source Type: research

Detected Objects, Perceived Properties.
PMID: 30299465 [PubMed - as supplied by publisher] (Source: Chemical Senses)
Source: Chemical Senses - October 9, 2018 Category: Biochemistry Authors: Keller A Tags: Chem Senses Source Type: research

Massive expansion of bitter taste receptors in blind cavefish, Astyanax mexicanus.
We report no adaptation for four mudskipper species, which exhibit 3-4 bitter taste receptor genes, and thus a typical teleost repertoire, shaped by few gene losses and minor gene duplications from an ancestral repertoire of four genes. However, and in sharp contrast to all other teleost fish species analysed, blind cavefish possess over twenty intact bitter taste receptors plus several pseudogenes, rivalling the complexity of the human bitter taste receptor repertoire. The gene duplications giving rise to the current cavefish bitter taste receptor repertoire appear to have occurred well before the loss of vision, consiste...
Source: Chemical Senses - October 5, 2018 Category: Biochemistry Authors: Shiriagin V, Korsching SI Tags: Chem Senses Source Type: research

Can the Identification of Odorants Within a Mixture Be Trained?
This study supports the idea that the number of odors we can recognize within a mixture is limited but suggests training can improve the performance: a short olfactory training is enough to enhance the ability to identify single odorants, whereas expertise refines identification ability of mixtures of up to 4 odorants. PMID: 30260369 [PubMed - as supplied by publisher] (Source: Chemical Senses)
Source: Chemical Senses - September 27, 2018 Category: Biochemistry Authors: Poupon D, Fernandez P, Boisvert SA, Migneault-Bouchard C, Frasnelli J Tags: Chem Senses Source Type: research

Signal detection and coding in the accessory olfactory system.
Abstract In many mammalian species, the accessory olfactory system (AOS) plays a central role in guiding behavioral and physiological responses to social and reproductive interactions. Because of its relatively compact structure and its direct access to amygdalar and hypothalamic nuclei, the accessory olfactory pathway provides an ideal system to study sensory control of complex mammalian behavior. During the last several years, many studies employing molecular, behavioral, and physiological approaches have significantly expanded and enhanced our understanding of this system. The purpose of the current review is t...
Source: Chemical Senses - September 25, 2018 Category: Biochemistry Authors: Mohrhardt J, Nagel M, Fleck D, Ben-Shaul Y, Spehr M Tags: Chem Senses Source Type: research

Impaired Odor Perception in Autism Spectrum Disorder Is Associated with Decreased Activity in Olfactory Cortex.
In conclusion, these findings suggest, that the known alterations in olfaction in ASD are rooted in the primary olfactory cortex. PMID: 30219913 [PubMed - as supplied by publisher] (Source: Chemical Senses)
Source: Chemical Senses - September 14, 2018 Category: Biochemistry Authors: Koehler L, Fournel A, Albertowski K, Roessner V, Gerber J, Hummel C, Hummel T, Bensafi M Tags: Chem Senses Source Type: research

Individual variation in PROP status, fungiform papillae density and responsiveness to taste stimuli in a large population sample.
Abstract Despite considerable research investigating the role of PROP bitterness perception and variation of fungiform papillae density (FPD) in food perception, this relationship remains controversial as well as the association between the two phenotypes. Data from 1119 subjects (38.6% male; 18-60 years) enrolled in the Italian Taste project were analysed. Responsiveness to the bitterness of PROP was assessed on the general Labelled Magnitude Scale. FPD was determined from manual counting on digital images of the tongue. Solutions of tastes, astringent and pungent sensations were prepared to be moderate/strong on...
Source: Chemical Senses - September 10, 2018 Category: Biochemistry Authors: Dinnella C, Monteleone E, Piochi M, Spinelli S, Prescott J, Pierguidi L, Gasperi F, Laureati M, Pagliarini E, Predieri S, Torri L, Barbieri S, Valli E, Bianchi P, Braghieri A, Del Caro A, Di Monaco R, Favotto S, Moneta E Tags: Chem Senses Source Type: research

Postnatal exposure to ethanol increases its oral acceptability to adolescent rats.
Abstract The aversive flavor of ethanol limits intake by many consumers. We asked whether intermittent consumption of ethanol increases its oral acceptability, using rats as a model system. We focused on adolescent rats because they (like their human counterparts) have a higher risk for alcohol overconsumption than do adult rats following experience with the drug. We measured the impact of ethanol exposure on (i) the oral acceptability of ethanol and surrogates for its bitter (quinine) and sweet (sucrose) flavor components in brief-access lick tests; and (ii) responses of the glossopharyngeal (GL) taste nerve to o...
Source: Chemical Senses - August 29, 2018 Category: Biochemistry Authors: Tang J, Youngentob SL, Glendinning JI Tags: Chem Senses Source Type: research

Regional Differences in Taste Responsiveness: Effect of Stimulus and Tasting Mode.
This study was set up to revisit previous work by investigating the effects of tasting mode ('passive' vs. 'active') on regional differences in taste responsiveness to sucrose, monopotassium glutamate (MPG), and quinine, while also investigating potential regional differences in responsiveness to MOS. The stimuli were applied to one of four target areas, the left and right sides of the front and back of the tongue, using cotton-tipped swabs. In the passive tasting condition, the front of the tongue was found to be more responsive to both sucrose and MOS, but no regional differences were seen for quinine and MPG. In contras...
Source: Chemical Senses - August 27, 2018 Category: Biochemistry Authors: Colvin JL, Pullicin AJ, Lim J Tags: Chem Senses Source Type: research