Taste of breath: the temporal order of taste and smell synchronized with breathing as a determinant for taste and olfactory integration.
Ontology highlight
ABSTRACT:
SUBMITTER: Kakutani Y
PROVIDER: S-EPMC5566545 | biostudies-other | 2017 Aug
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The pathophysiology of blepharospasm is incompletely understood. Current concepts suggest that blepharospasm is a network disorder, involving basal ganglia, thalamus, cortex, and, possibly, the cerebellum. Tracing, imaging, and clinical studies revealed that these structures are also concerned with olfaction and taste. Because of this anatomical overlap, dysfunction of the chemical senses in blepharospasm is expected. Injections of botulinum toxin into the eyelid muscles are the first-line treatment of blepharospasm. Yet, the effects of botulinum toxin on the chemical senses have not been systematically assessed. To contribute to a better understanding of blepharospasm, olfactory and gustatory abilities were assessed in 17 subjects with blepharospasm and 17 age-/sex-matched healthy controls. Sniffin Sticks were used to assess odor threshold, odor discrimination, and odor identification. Results of these three Sniffin Sticks subtests were added to the composite olfactory score. The Taste Strips were applied to assess taste. In an adjacent study, we assessed the sense of smell and taste in eight subjects with blepharospasm before and 4 weeks after botulinum toxin treatment. Subjects with blepharospasm had significantly lower (= worse) scores for odor threshold and for the composite olfactory score than healthy controls, while odor discrimination, odor identification, and the composite taste score were not different between groups. The adjacent study revealed that botulinum toxin did not impact the chemical senses. In this study, subjects with blepharospasm had a lower (= worse) odor threshold than healthy controls. As olfaction is important in daily life, findings justify further research of olfaction in blepharospasm.
| S-EPMC8237775 | biostudies-literature
Project description:PurposeTwo-thirds of cancer patients report taste disorders during and after chemotherapy. Taste disorders impact on nutritional status which is highly relevant for treatment efficacy and overall prognosis. Improvement of taste disorder is of particular importance for cancer patients' outcomes, thus the TASTE trial was conducted to improve taste disorders with a taste and smell training.MethodsIn this trial, patients undergoing chemotherapy were screened for taste disorders. Subsequently, patients were allocated based on the detection of taste disorders (≤8 taste strips points) to an intervention group with a taste and smell training at baseline and week 3-5 or were only followed up, if no taste disorder was detected (≥9 taste strips points) (non-intervention group). At baseline, all patients received a nutritional counseling. The primary endpoint was the minimal clinically relevant improvement of taste strips score by 2 taste strips points in at least 50% of the patients with taste disorders.ResultsThe trial included 62 patients (48 women [77%], 14 male [23%], age 54.5±11.6 years) who had gastrointestinal (n=29), breast (n=31), or lung cancer (n=2). Taste disorders were more frequent in gastrointestinal than in breast cancer patients. Out of 62 patients screened, 30 patients showed taste disorders. The primary endpoint was met with 92% (n=23 of 25) of the patients completing the intervention. In the intervention group, the patients' taste significantly improved from baseline (median taste strips: 7.0 points) to week 12 (median taste strips: 10.0 points) (P≤0.001). Patients of the non-intervention group who completed the reassessment (n=27 of 32) experienced no change in taste perception in the 3-month follow-up (P=0.897).ConclusionIntensified nutritional counseling with taste and smell training may improve taste perception of patients undergoing chemotherapy. A confirmatory randomized trial is planned.
| S-EPMC6526926 | biostudies-literature
Project description:Smell dysfunction is a common and underdiagnosed medical condition that can have serious consequences. It is also an early biomarker of neurodegenerative diseases, including Alzheimer's disease, where olfactory deficits precede detectable memory loss. Clinical tests that evaluate the sense of smell face two major challenges. First, human sensitivity to individual odorants varies significantly, so test results may be unreliable in people with low sensitivity to a test odorant but an otherwise normal sense of smell. Second, prior familiarity with odor stimuli can bias smell test performance. We have developed nonsemantic tests for olfactory sensitivity (SMELL-S) and olfactory resolution (SMELL-R) that use mixtures of odorants that have unfamiliar smells. The tests can be self-administered by healthy individuals with minimal training and show high test-retest reliability. Because SMELL-S uses odor mixtures rather than a single molecule, odor-specific insensitivity is averaged out, and the test accurately distinguished people with normal and dysfunctional smell. SMELL-R is a discrimination test in which the difference between two stimulus mixtures can be altered stepwise. This is an advance over current discrimination tests, which ask subjects to discriminate monomolecular odorants whose difference in odor cannot be quantified. SMELL-R showed significantly less bias in scores between North American and Taiwanese subjects than conventional semantically based smell tests that need to be adapted to different languages and cultures. Based on these proof-of-principle results in healthy individuals, we predict that SMELL-S and SMELL-R will be broadly effective in diagnosing smell dysfunction.
| S-EPMC5664538 | biostudies-literature
Project description:Given a noisy sensory world, the nervous system integrates perceptual evidence over time to optimize decision-making. Neurophysiological accumulation of sensory information is well-documented in the animal visual system, but how such mechanisms are instantiated in the human brain remains poorly understood. Here we combined psychophysical techniques, drift-diffusion modeling, and functional magnetic resonance imaging (fMRI) to establish that odor evidence integration in the human olfactory system enhances discrimination on a two-alternative forced-choice task. Model-based measures of fMRI brain activity highlighted a ramp-like increase in orbitofrontal cortex (OFC) that peaked at the time of decision, conforming to predictions derived from an integrator model. Combined behavioral and fMRI data further suggest that decision bounds are not fixed but collapse over time, facilitating choice behavior in the presence of low-quality evidence. These data highlight a key role for the orbitofrontal cortex in resolving sensory uncertainty and provide substantiation for accumulator models of human perceptual decision-making.
| S-EPMC3441053 | biostudies-literature
Project description:Objectives To assess the frequency of loss of smell and taste in children during Covid-19 infection and their prevalence along with other symptoms, as well as the recovery of chemosensory function once healed. Methods To evaluate symptoms during infection, we adapted the Scandinavian adaptation of the Multi-Clinic Smell and Taste Questionnaire and the modified Monel-Jefferson questionnaire. For smell analysis we used Odor Identification (OI) and two variants of the Odor Discrimination (OD) test, and we compared the results with those of a control group. Results We enrolled nine patients in our experimental group and nine in our control group. Fever was the most frequent symptom (55% of cases), followed by anosmia and ageusia (44% of cases), muscle pain and asthenia (22% of cases) and diarrhea, abdominal pain, cough, and headache (11% of cases). In 11% of cases, olfactory symptoms were the only manifestation of the disease. There was no statistically significant difference in OI test and OD tests between the two groups (Children healed from Covid-19 and Control Group). Conclusion Loss of smell and taste are the second most common symptoms of pediatric Covid-19, and they should always be tested because they can be the only manifestations of infection. Olfactory function in Covid-19 children decreases with increasing age and improves with the passage of time after illness.
| S-EPMC9768832 | biostudies-literature
Project description:Sudden loss of smell and/or taste has been identified as an early symptom of SARS-CoV-2 2019 (COVID-19) infection, and presents an effective target for prompt self-isolation and reducing community spread. The current study sought to develop and test a novel, rapid, self-administered test to objectively measure smell and taste losses associated with COVID-19, and administered self-report questionnaires to characterise symptoms associated with COVID-19 in Singapore. Participants (N = 99) completed questionnaires to record recent changes in smell and taste ability. This was followed by the 'Singapore Smell and Taste Test' (SSTT), a personal, objective testing kit for daily self-assessment of smell and taste function at their place of residence. Seventy-two recruited participants were confirmed as COVID-19 positive at baseline, of which 58 completed the SSTT at home. Of these, 36.2% had objectively measured smell and/or taste loss. The SSTT measures of smell and taste function were positively associated with participants' self-reported smell and taste acuity, and rated smell intensity of 6 common household items. This study presents the first application of the SSTT as a rapid, cost-effective, objective tool to self-monitor smell and taste function in a residential setting, and ensures comparability across individuals through the use of standardised stimuli. The SSTT has potential for future application in populations with limited access to formal COVID-19 testing as a self-administered objective method to monitor sudden changes in smell and taste, and to prompt early self-isolation, in order to reduce community transmission of COVID-19.
| S-EPMC8612753 | biostudies-literature
Project description:Oropharyngeal sensitivity plays a vital role in the initiation of the swallowing reflex and is thought to decline as part of the aging-process. Taste and smell functions appear to decline with age as well. The aim of our study was to generate data of oral sensitivity in healthy participants for future studies and to analyse age-related changes and their interdependence by measuring oral sensitivity, taste, and smell function. The experiment involved 30 participants younger than and 30 participants older than 60. Sensitivity threshold as a surrogate of oral sensitivity was measured at the anterior faucial pillar by electrical stimulation using commercially available pudendal electrode mounted on a gloved finger. Smell and taste were evaluated using commercially available test kits. Mean sensitivity was lower in young participants compared to older participants (1.9 ± 0.59 mA vs. 2.42 ± 1.03 mA; p = 0.021). Young participants also performed better in smell (Score 11.13 ± 0.86 vs 9.3 ± 1.93; p < 0.001) and taste examinations (Score 11.83 ± 1.86 vs 8.53 ± 3.18; p < 0.001). ANCOVA revealed a statistical association between sensitivity and smell (p = 0.08) that was moderated by age (p = 0.044). Electrical threshold testing at the anterior faucial pillar is a simple, safe, and accurate diagnostic measure of oral sensitivity. We detected a decline of oral sensitivity, taste, and smell in older adults.Trial registration: Clinicaltrials.gov, NCT03240965. Registered 7th August 2017- https://clinicaltrials.gov/ct2/show/NCT03240965 .
| S-EPMC8795375 | biostudies-literature
Project description:The orbitofrontal cortex (OFC) has been implicated in a multiplicity of complex brain functions, including representations of expected outcome properties, post-decision confidence, momentary food-reward values, complex flavors and odors. As breathing rhythm has an influence on odor processing at primary olfactory areas, we tested the hypothesis that it may also influence neuronal activity in the OFC, a prefrontal area involved also in higher order processing of odors. We recorded spike timing of orbitofrontal neurons as well as local field potentials (LFPs) in awake, head-fixed mice, together with the breathing rhythm. We observed that a large majority of orbitofrontal neurons showed robust phase-coupling to breathing during immobility and running. The phase coupling of action potentials to breathing was significantly stronger in orbitofrontal neurons compared to cells in the medial prefrontal cortex. The characteristic synchronization of orbitofrontal neurons with breathing might provide a temporal framework for multi-variable processing of olfactory, gustatory and reward-value relationships.
| S-EPMC5920025 | biostudies-literature
Project description:Survivors of head and neck squamous cell cancers (HNSCC) frequently complain of taste dysfunction long after radiation therapy is completed, which contradicts findings from most sensory evaluation studies that predict dysfunction should resolve few months after treatment. Therefore, it remains unclear whether taste and smell function fully recovers in HNSCC survivors. We evaluated HNSCC survivors (n = 40; age 63 ± 12 years, mean ± standard deviation) who received radiation therapy between 6 months and 10 years before recruitment and compared their responses to those of a healthy control group (n = 20) equivalent in age, sex, race, smoking history, and body mass index. We assessed regional (tongue tip) and whole-mouth taste intensity perception using the general Labeled Magnitude Scale and smell function using the University of Pennsylvania Smell Identification Test (UPSIT). To determine possible differences between groups in retronasal smell perception, we used solutions of sucrose with strawberry extract, citric acid with lemon extract, sodium chloride in vegetable broth, and caffeine in coffee and asked participants to rate perceived smell and taste intensities with and without nose clips. We found groups had similar UPSIT and taste intensity scores when solutions were experienced in the whole mouth. However, HNSCC survivors were less likely to identify low concentrations of bitter, sweet, or salty stimuli in the tongue tip relative to healthy controls. Our findings suggest persistent and subtle localized damage to the chorda tympani or to the taste buds in the fungiform papillae of HNSCC survivors, which could explain their sensory complaints long after completion of radiotherapy.
| S-EPMC8349111 | biostudies-literature
Project description: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. 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. 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.
| S-EPMC4856413 | biostudies-literature