Read by QxMD icon Read

Chemical Senses

Julia Y Q Low, Robert L McBride, Kathleen E Lacy, Russell S J Keast
Sweetness is one of the 5 prototypical tastes and is activated by sugars and non-nutritive sweeteners (NNS). The aim of this study was to investigate measures of sweet taste function [detection threshold (DT), recognition threshold (RT), and suprathreshold intensity ratings] across multiple sweeteners. Sixty participants, 18-52 years of age (mean age in years = 26, SD = ±7.8), were recruited to participate in the study. DT and RT were collected for caloric sweeteners (glucose, fructose, sucrose, erythritol) and NNS (sucralose, rebaudioside A)...
October 20, 2016: Chemical Senses
Matthew Kochem, Paul A S Breslin
T1R2-T1R3 is a heteromeric receptor that binds sugars, high potency sweeteners, and sweet taste blockers. In rodents, T1R2-T1R3 is largely responsible for transducing sweet taste perception. T1R2-T1R3 is also expressed in non-taste tissues, and a growing body of evidence suggests that it helps regulate glucose and lipid metabolism. It was previously shown that clofibric acid, a blood lipid-lowering drug, binds T1R2-T1R3 and inhibits its activity in vitro The purpose of this study was to determine whether clofibric acid inhibits sweetness perception in humans and is, therefore, a T1R2-T1R3 antagonist in vivo Fourteen participants rated the sweetness intensity of 4 sweeteners (sucrose, sucralose, Na cyclamate, acesulfame K) across a broad range of concentrations...
October 14, 2016: Chemical Senses
Zhudong Liu, Yucui Xin, Bingbing Xu, Kenneth F Raffa, Jianghua Sun
For insects that aggregate on host plants, both attraction and antiaggregation among conspecifics can be important mechanisms for overcoming host resistance and avoiding overcrowding, respectively. These mechanisms can involve multiple sensory modalities, such as sound and pheromones. We explored how acoustic and chemical signals are integrated by the bark beetle Dendroctonus valens to limit aggregation in China. In its native North American range, this insect conducts nonlethal attacks on weakened trees at very low densities, but in its introduced zone in China, it uses mixtures of host tree compounds and the pheromone component frontalin to mass attack healthy trees...
October 5, 2016: Chemical Senses
Melanie Yvonne Denzer-Lippmann, Jonathan Beauchamp, Jessica Freiherr, Norbert Thuerauf, Johannes Kornhuber, Andrea Buettner
Olfactory tests are an important tool in human nutritional research for studying food preferences, yet comprehensive tests dedicated solely to food odors are currently lacking. Therefore, within this study, an innovative food-associated olfactory test (FAOT) system was developed. The FAOT comprises 16 odorant pens that contain representative food odors relating to different macronutrient classes. The test underwent a sensory validation based on identification rate, intensity, hedonic value, and food association scores...
September 28, 2016: Chemical Senses
Steven J St John
Three experiments assessed potential changes in the rat's perception of sodium chloride (NaCl) during a state of sodium appetite. In Experiment 1, sodium-sufficient rats licking a range of NaCl concentrations (0.028-0.89M) in 15s trials showed an inverted U-shaped concentration response function peaking at 0.281M. Depleted rats (furosemide) showed an identical function, merely elevated, suggesting altered qualitative or hedonic perception but no change in perceived intensity. In Experiment 2, sodium-depleted rats were tested with NaCl, sodium gluconate, and potassium chloride (KCl; 0...
September 22, 2016: Chemical Senses
Camille Ferdenzi, Pauline Joussain, Bérengère Digard, Lucie Luneau, Jelena Djordjevic, Moustafa Bensafi
Olfactory perception is highly variable from one person to another, as a function of individual and contextual factors. Here, we investigated the influence of 2 important factors of variation: culture and semantic information. More specifically, we tested whether cultural-specific knowledge and presence versus absence of odor names modulate odor perception, by measuring these effects in 2 populations differing in cultural background but not in language. Participants from France and Quebec, Canada, smelled 4 culture-specific and 2 non-specific odorants in 2 conditions: first without label, then with label...
September 21, 2016: Chemical Senses
Bastian Henkel, Willem Bintig, S Sneha Bhat, Marc Spehr, Eva M Neuhaus
In most mammals, the vomeronasal system detects a variety of (semio)chemicals that mediate olfactory-driven social and sexual behaviors. Vomeronasal chemosensation depends on G protein-coupled receptors (V1R, V2R, and FPR-rs) that operate at remarkably low stimulus concentrations, thus, indicating a highly sensitive and efficient signaling pathway. We identified the PDZ domain-containing protein, Na(+)/H(+) exchanger regulatory factor-1 (NHERF1), as putative molecular organizer of signal transduction in vomeronasal neurons...
September 21, 2016: Chemical Senses
Jenne M Westberry, Michael Meredith
Chemosensory stimuli from same species (conspecific) and different species (heterospecific) elicit categorically different immediate-early gene (IEG) response patterns in medial amygdala in male hamsters and mice. All heterospecific stimuli activate anterior medial amygdala (MeA) but only especially salient heterospecific stimuli, such as those from predators activate posterior medial amygdala (MeP). We previously reported that characteristic patterns of response in separate populations of cells in MeA and MeP distinguish between different conspecific stimuli...
September 20, 2016: Chemical Senses
Boriana Atanasova, Fayçal Mehdi Goumeidane, François Kazour, Henri Schmitt, Marion Husson, Philippe Gaillard, Wissam El-Hage, Nicolas Ballon
As the olfactory system is closely connected with the brain areas responsible for the most crucial alterations in psychiatric populations, especially cognitive and emotional impairments, the study of olfactory processing may be a relevant approach to identify specific markers of alcohol dependence. The aim of this study was to propose the probable olfactory markers for alcohol dependence through a study of the olfactory parameters that involve the central olfactory pathway. We recruited the same 41 alcohol-dependent patients in an early (day 8) and late (day 67) stage of abstinence and 41 controls matched for gender, age, and smoking status...
September 14, 2016: Chemical Senses
Yoshihisa Katagawa, Toshiaki Yasuo, Takeshi Suwabe, Tomoki Yamamura, Keika Gen, Noritaka Sako
This behavioral study investigated how rats conditioned to binary mixtures of preferred and aversive taste stimuli, respectively, responded to the individual components in a conditioned taste aversion (CTA) paradigm. The preference of stimuli was determined based on the initial results of 2 bottle preference test. The preferred stimuli included 5mM sodium saccharin (Sacc), 0.03M NaCl (Na), 0.1M Na, 5mM Sacc + 0.03M Na, and 5mM Sacc + 0.2mM quinine hydrochloride (Q), whereas the aversive stimuli tested were 1...
September 13, 2016: Chemical Senses
Andreas Stadlbauer, Martin Kaltenhäuser, Michael Buchfelder, Sebastian Brandner, Winfried L Neuhuber, Bertold Renner
The dynamics of early-stage cortical and subcortical responses in the human brain to odor stimulation are currently unknown. The objective of the present study was to analyze spatiotemporal patterns of human brain activity during odor perception using magnetoencephalography (MEG). In 12 normosmic healthy subjects, we investigated the onset of brain activity in relation to ipsilateral and contralateral stimulation with 2 odorants. Olfactory stimuli (200ms duration) were applied using an olfactometer, and brain activity was recorded with a 248-magnetometer whole-head MEG system...
August 31, 2016: Chemical Senses
Mei Peng, Michael J Hautus, Sara R Jaeger
In psychophysics, the detection of sensory signals can be depicted by a psychometric function (PF)-a sigmoid function determined by the intercept (i.e., threshold) and the slope (i.e., the rate of increase of detection probability). Fitting psychometric functions is, however, unpopular in chemosensory research, particularly in olfaction. Most olfactory studies adopt ad hoc methods involving a fixed-performance criterion, which result only in a threshold estimate rather than a complete detection profile. This study illustrates the method selection process for fitting olfactory PFs, using a unique odorant-β-ionone-as an exemplar...
August 26, 2016: Chemical Senses
Jörn Lötsch, Alfred Ultsch, Thomas Hummel
In the clinical diagnosis of olfactory function, 2 quantitative extremes of either lost or normal olfactory function are in the focus while no particular attention is directed at the interval between the 2 main diagnoses of "anosmia" or "normosmia", respectively. We analyzed the modal distribution of olfactory scores with the intention to describe a complex human olfactory pathology in a unifying model. In a cross-sectional retrospective study, olfactory performance scores acquired from 10714 individuals by means of a clinically established psychophysical test were analyzed with respect to their modal distribution by fitting a Gaussian mixture model (GMM) to the data...
August 26, 2016: Chemical Senses
Trina J Lapis, Michael H Penner, Juyun Lim
It is widely accepted that humans can taste mono- and disaccharides as sweet substances, but they cannot taste longer chain oligo- and polysaccharides. From the evolutionary standpoint, the ability to taste starch or its oligomeric hydrolysis products would be highly adaptive, given their nutritional value. Here, we report that humans can taste glucose oligomer preparations (average degree of polymerization 7 and 14) without any other sensorial cues. The same human subjects could not taste the corresponding glucose polymer preparation (average degree of polymerization 44)...
August 23, 2016: Chemical Senses
Paulo E Jorge, Paulo A M Marques, Belmiro V Pinto, John B Phillips
The role of odors in the long-distance navigation of birds has elicited intense debate for more than half a century. Failure to resolve many of the issues fueling this debate is due at least in part to the absence of controls for a variety of non-specific effects that odors have on the navigational process. The present experiments were carried out to investigate whether the olfactory inputs are involved only in "activation" of neuronal circuitry involved in navigation or are also playing a role in providing directional information...
August 11, 2016: Chemical Senses
Liang-Dar Hwang, Paul A S Breslin, Danielle R Reed, Gu Zhu, Nicholas G Martin, Margaret J Wright
Perceived intensities of sweetness and bitterness are correlated with one another and each is influenced by genetics. The extent to which these correlations share common genetic variation, however, remains unclear. In a mainly adolescent sample (n = 1901, mean age 16.2 years), including 243 monozygotic (MZ) and 452 dizygotic (DZ) twin pairs, we estimated the covariance among the perceived intensities of 4 bitter compounds (6-n-propylthiouracil [PROP], sucrose octa-acetate, quinine, caffeine) and 4 sweeteners (the weighted mean ratings of glucose, fructose, neohesperidine dihydrochalcone, aspartame) with multivariate genetic modeling...
August 9, 2016: Chemical Senses
Bo Lu, Joseph M Breza, Robert J Contreras
Temperature profoundly affects the perceived intensity of taste, yet we know little of the extent of temperature's effect on taste in the peripheral nervous system. Accordingly, we investigated the influence of temperature from 23 °C to 43 °C in 4 °C intervals on the integrated responses of the chorda tympani (CT) nerve to a large series of chemical stimuli representing sweet, salty, sour, bitter, and umami tastes in C57BL/J6 mice. We also measured neural responses to NaCl, Na-gluconate, Na-acetate, Na-sulfate, and MSG with and without 5 µM benzamil, an epithelial sodium channel (ENaC) antagonist, to assess the influence of temperature on ENaC-dependent and ENaC-independent response components...
August 6, 2016: Chemical Senses
Sayaka Yagi-Nakanishi, Satoru Kondo, Misako Kaneda, Fumi Ozaki, Takayoshi Ueno, Mitsuharu Aga, Kazunori Yamada, Mitsuhiro Kawano, Tomokazu Yoshizaki
IgG4-related disease is a newly recognized systemic disease, and its elucidation is progressing. However, little is known about its sinonasal manifestations. The aim of this study was to assess the olfaction of patients with IgG4-related disease. Twenty-five patients with IgG4-related disease underwent T&T olfactometry to measure olfactory function. We analyzed the clinical features, including serum IgG4 and IgE levels, involved organs, and sinonasal computed tomography scores to explore the etiology of olfactory dysfunction...
August 1, 2016: Chemical Senses
(no author information available yet)
No abstract text is available yet for this article.
October 2016: Chemical Senses
(no author information available yet)
No abstract text is available yet for this article.
October 2016: Chemical Senses
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"