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Animals have evolved innate responses to cues including social, food, and predator odors. In the natural environment, animals are faced with choices that involve balancing risk and reward where innate significance may be at odds with internal need. The ability to update the value of a cue through learning is essential for navigating changing and uncertain environments. However, the mechanisms involved in this modulation are not well defined in mammals. We have established a new olfactory assay that challenges a thirsty mouse to choose an aversive odor over an attractive odor in foraging for water, thus overriding their innate behavioral response to odor. Innately, mice prefer the attractive odor port over the aversive odor port. However, decreasing the probability of water at the attractive port leads mice to prefer the aversive port, reflecting a learned override of the innate response to the odors. The orbitofrontal cortex (OFC) is a fourth-order olfactory brain area, involved in flexible value association, with behaviorally relevant outputs throughout the limbic system. We performed optogenetic and chemogenetic silencing experiments that demonstrate the OFC is necessary for this learned modulation of innate aversion to odor. Further, we characterized odor evoked c-fos expression in learned and control mice and found significant suppression of activity in the bed nucleus of the stria terminalis, lateral septum, and central and medial amygdala. These findings reveal that the OFC is necessary for the learned override of innate behavior and may signal to limbic structures to modulate innate response to odor.

The central nervous system coordinates peripheral cellular stress responses, including the unfolded protein response of the mitochondria (UPRMT); however, the contexts for which this regulatory capability evolved are unknown. UPRMT is up-regulated upon pathogenic infection and in metabolic flux, and the olfactory nervous system has been shown to regulate pathogen resistance and peripheral metabolic activity. Therefore, we asked whether the olfactory nervous system in Caenorhabditis elegans controls the UPRMT cell nonautonomously. We found that silencing a single inhibitory olfactory neuron pair, AWC, led to robust induction of UPRMT and reduction of oxidative phosphorylation dependent on serotonin signaling and parkin-mediated mitophagy. Further, AWC ablation confers resistance to the pathogenic bacteria Pseudomonas aeruginosa partially dependent on the UPRMT transcription factor atfs-1 and fully dependent on mitophagy machinery. These data illustrate a role for the olfactory nervous system in regulating whole-organism mitochondrial dynamics, perhaps in preparation for postprandial metabolic stress or pathogenic infection.

The mammalian brain implements sophisticated sensory processing algorithms along multilayered (deep) neural networks. Strategies that insects use to meet similar computational demands, while relying on smaller nervous systems with shallow architectures, remain elusive. Using Drosophila as a model, we uncover the algorithmic role of odor preprocessing by a shallow network of compartmentalized olfactory receptor neurons. Each compartment operates as a ratiometric unit for specific odor-mixtures. This computation arises from a simple mechanism: electrical coupling between two differently sized neurons. We demonstrate that downstream synaptic connectivity is shaped to optimally leverage amplification of a hedonic value signal in the periphery. Furthermore, peripheral preprocessing is shown to markedly improve novel odor classification in a higher brain center. Together, our work highlights a far-reaching functional role of the sensory periphery for downstream processing. By elucidating the implementation of powerful computations by a shallow network, we provide insights into general principles of efficient sensory processing algorithms.

Working memory, the process through which information is transiently maintained and manipulated over a brief period, is essential for most cognitive functions1-4. However, the mechanisms underlying the generation and evolution of working-memory neuronal representations at the population level over long timescales remain unclear. Here, to identify these mechanisms, we trained head-fixed mice to perform an olfactory delayed-association task in which the mice made decisions depending on the sequential identity of two odours separated by a 5 s delay. Optogenetic inhibition of secondary motor neurons during the late-delay and choice epochs strongly impaired the task performance of the mice. Mesoscopic calcium imaging of large neuronal populations of the secondary motor cortex (M2), retrosplenial cortex (RSA) and primary motor cortex (M1) showed that many late-delay-epoch-selective neurons emerged in M2 as the mice learned the task. Working-memory late-delay decoding accuracy substantially improved in the M2, but not in the M1 or RSA, as the mice became experts. During the early expert phase, working-memory representations during the late-delay epoch drifted across days, while the stimulus and choice representations stabilized. In contrast to single-plane layer 2/3 (L2/3) imaging, simultaneous volumetric calcium imaging of up to 73,307 M2 neurons, which included superficial L5 neurons, also revealed stabilization of late-delay working-memory representations with continued practice. Thus, delay- and choice-related activities that are essential for working-memory performance drift during learning and stabilize only after several days of expert performance.

IntroductionThe Vietnamese Smell Identification Test (VSIT) has been validated in determining olfactory dysfunction in the Vietnamese population; however, its value in diagnosing Parkinson's disease (PD) has not been established.MethodsThis case-control study was conducted at University Medical Center HCMC, Ho Chi Minh City, Vietnam. The study sample included non-demented PD patients and healthy controls (HC) who were gender- and age-matched. All participants were evaluated for odor identification ability using the VSIT and the Brief Smell Identification Test (BSIT).ResultsA total of 218 HCs and 218 PD patients participated in the study. The median VSIT and BSIT scores were significantly different between PD and HC groups (VSIT, 5 (3) vs. 9 (2), P  0.05).ConclusionThe VSIT can be a valuable ancillary tool for supporting the diagnosis of PD in Vietnam. Olfactory dysfunction in PD was unrelated to the disease duration and severity. The VSIT can be applied to improve the accuracy of clinical PD diagnosis.

INTRODUCTION: While localized inflammation has been implicated in the pathophysiology of acute coronavirus disease of 2019 (COVID-19) olfactory dysfunction (OD), persistent COVID-19 OD remains poorly understood with limited therapeutics. Our prospective study evaluated olfactory cleft (OC) biomarkers as predictors of persistent OD in mucus sampling. METHODS: COVID-19 subjects with persistent OD >3 months confirmed by psychophysical olfaction tests were compared to COVID-19 subjects with no OD and those with no prior infection. OC mucus samples were evaluated for 13 anti-viral and inflammatory biomarkers. Cohorts were compared using analysis of variance (ANOVA) and Mann-Whitney tests with multi-comparison adjustment. Viral RNA was assessed through RT-PCR using the COVID-19 N2 primer. RESULTS: Thirty-five samples were collected (20 COVID persistent OD, 8 COVID no OD, and 7 non-COVID no OD). Significant differences in IFN-λ1 (p = 0.007) and IFN-γ (p = 0.006) expression in OC mucus were found across all three groups, with the highest cytokine concentrations corresponding to COVID OD. IFN-α2 levels were elevated in COVID OD versus no OD (p = 0.026). Mean IFN-γ levels were the highest in COVID OD, but there were higher levels found in COVID no OD compared to non-COVID no OD (p = 0.008). No difference was seen in IL6. No N2 gene expression was detected in all cohorts. CONCLUSION: IFN pathway cytokines were found elevated in the olfactory microenvironment of COVID-19 persistent OD compared to those with no OD and no prior history of COVID-19 infection.

This paper is aimed at comprehensively reviewing olfactory and gustatory disorders caused by SARS-CoV-2 in children and adults. An electronic and manual search was done on three data bases: MEDLINE, Embase, and Web of Science. Inclusion criteria included publications written in English, involving humans in the age range of 0 to 99 years that were captured by a controlled vocabulary of thesaurus terms. Olfactory and gustatory disorders rates in COVID-19 ranged from 22% to 71.9% in adults and 16.6% to 25.8% in children. Olfactory and gustatory disorders might appear as the first symptom, and in adults might even be the only symptom (4.8% to 10%). Anosmia is the most common olfactory disorder and hypogeusia is the most common gustatory disorder. In 33% to 89% of cases, olfactory and gustatory disorders resolve spontaneously within a few weeks, coinciding with the resolution of other COVID-19 symptoms, both in adults and children. However, in some patients, olfactory and gustatory disorders persist beyond the resolution of other symptoms. Notably, children generally experience a swifter and more favorable recovery compared to adults. The precise pathogenesis underlying olfactory and gustatory disorders in the context of COVID-19 remains unclear and is likely multifactorial. Presently, no established treatment protocol exists for olfactory and gustatory disorders and current treatments reviewed lack robust evidence and are not readily available for clinical use. Olfactory training represents the only therapy currently recommended by international authorities. Pediatric practitioners and general dental practitioners should be aware of olfactory and gustatory disorders in both pediatric and adult populations, including their biologic mechanisms, treatment options, and recovery rates. [ABSTRACT FROM AUTHOR]

The olfactory system plays crucial roles in perceiving and interacting with their surroundings. Previous studies have deciphered basic odor perceptions, but how information processing in the olfactory system is associated with learning and memory is poorly understood. In this review, we summarize recent studies on the anatomy and functional dynamics of the mouse olfactory learning pathway, focusing on how neuronal circuits in the olfactory bulb (OB) and olfactory cortical areas integrate odor information in learning. We also highlight in vivo evidence for the role of the lateral entorhinal cortex (LEC) in olfactory learning. Altogether, these studies demonstrate that brain regions throughout the olfactory system are critically involved in forming and representing learned knowledge. The role of olfactory areas in learning and memory, and their susceptibility to dysfunction in neurodegenerative diseases, necessitate further research.

BACKGROUND: We examined the relationship between baseline olfactory performance and incident significant depressive symptoms and longitudinal depression trajectories in well-functioning older adults. Inflammation and cognitive status were examined as potential mediators. METHODS: Older adults (n = 2 125, 71-82 years, 51% female, 37% Black) completed an odor identification task at Year 3 (our study baseline) of the Health, Aging, and Body Composition study. Cognitive assessments, depressive symptoms, and inflammatory markers were ascertained across multiple visits over 8 years. Discrete-time complementary log-log models, group-based trajectory models, and multivariable-adjusted multinomial logistic regression were employed to assess the relationship between baseline olfaction and incident depression and longitudinal depression trajectories. Mediation analysis assessed the influence of cognitive status on these relationships. RESULTS: Individuals with lower olfaction had an increased risk of developing significant depressive symptoms at follow-up (hazard ratio = 1.04, 95% confidence interval [CI]: 1.00, 1.08). Of the 3 patterns of longitudinal depression scores identified (stable low, stable moderate, and stable high), poorer olfaction was associated with a 6% higher risk of membership in the stable moderate (relative risk ratio [RRR] = 1.06, 95% CI: 1.02, 1.10)/stable high (RRR = 1.06, 95% CI: 1.00, 1.12) groups, compared to the stable low group. Poor cognitive status, but not inflammation, partially mediated the relationship between olfactory performance and incident depression symptom severity. CONCLUSIONS: Suboptimal olfaction could serve as a prognostic indicator of vulnerability for the development of late-life depression. These findings underscore the need for a greater understanding of olfaction in late-life depression and the demographic, cognitive, and biological factors that influence these relationships over time.

BACKGROUND: Early identification of deficits in our ability to perceive odors is important as many normal (i.e., aging) and pathological (i.e., sinusitis, viral, neurodegeneration) processes can result in diminished olfactory function. To realistically enable population-level measurements of olfaction, validated olfaction tests must be capable of being administered outside the research laboratory and clinical setting. AIM: The purpose of this study was to determine the feasibility of remotely testing olfactory performance using a test that was developed with funding from the National Institutes of Health as part of a ready-to-use, non-proprietary set of measurements useful for epidemiologic studies (NIH Toolbox Odor ID Test). MATERIALS AND METHODS: Eligible participants older than 39 years and active (within 6 months) in the Brain Health Registry (BHR), an online cognitive assessment platform which connects participants with researchers, were recruited for this study. Interested participants were mailed the NIH Toolbox Odor ID Test along with instructions on accessing a website to record their responses. Data obtained from subjects who performed the test at home was compared to the normative data collected when the NIH Toolbox Odor ID Test was administered by a tester in a research setting and validated against the Smell Identification Test. The age-range and composition of the population ensured we had the ability to observe both age-related decline and gender-related deficits in olfactory ability, as shown in the experimental setting. RESULTS: We observed that age-associated olfactory decline and gender-associated performance was comparable to performance on the administered test. Self-administration of this test showed the age-related loss in olfactory acuity, F(4, 1156)=14.564, p

AbstractThe study of olfaction in Drosophila melanogaster has greatly benefited from genetic reagents such as olfactory receptor mutant lines and GAL4 reporter lines. The CRISPR/Cas9 gene-editing system has been increasingly used to create null receptor mutants or replace coding regions with GAL4 reporters. To further expand this toolkit for manipulating fly olfactory receptor neurons (ORNs), we generated null alleles for 11 different olfactory receptors by using CRISPR/Cas9 to knock in LexA drivers, including multiple lines for receptors which have thus far lacked knock-in mutants. The targeted neuronal types represent a broad range of antennal ORNs from all four morphological sensillum classes. Additionally, we confirmed their loss-of-function phenotypes, assessed receptor haploinsufficiency, and evaluated the specificity of the LexA knock-in drivers. These receptor mutant lines have been deposited at the Bloomington Drosophila Stock Center for use by the broader scientific community. [ABSTRACT FROM AUTHOR]

Animals have evolved to rapidly detect and recognize brief and intermittent encounters with odor packages, exhibiting recognition capabilities within milliseconds. Artificial olfaction has faced challenges in achieving comparable results--existing solutions are either slow; or bulky, expensive, and power-intensive--limiting applicability in real-world scenarios for mobile robotics. Here, we introduce a miniaturized high-speed electronic nose, characterized by high-bandwidth sensor readouts, tightly controlled sensing parameters, and powerful algorithms. The system is evaluated on a high-fidelity odor delivery benchmark. We showcase successful classification of tens-of-millisecond odor pulses and demonstrate temporal pattern encoding of stimuli switching with up to 60 hertz. Those timescales are unprecedented in miniaturized low-power settings and demonstrably exceed the performance observed in mice. It is now possible to match the temporal resolution of animal olfaction in robotic systems. This will allow for addressing challenges in environmental and industrial monitoring, security, neuroscience, and beyond. [ABSTRACT FROM AUTHOR]

To better cope with stress in emergencies, emergency personnel undergo virtual reality (VR) stress training. Such training typically includes visual, auditory and sometimes tactile impressions, whereas olfactory stimuli are mostly neglected. This concept paper therefore examines whether odors might be beneficial for further enhancing the experience of presence and immersion into a simulated environment. The aim is to demonstrate the benefits of VR civilian stress training for emergency personnel and to investigate the role of odors as stressors by manipulating the degree of perceived psychophysiological stress via olfactory impressions. Moreover, the current paper presents the development and validation of a convenient and portable fragrance dosing system that allows personalized odor presentation in VR. The presented system can transport reproducible small quantities of an air-fragrance mixture close to the human nose using piezoelectric stainless steel micropumps. The results of the fluidic system validation indicate that the micropump is suitable for releasing odors close to the nose with constant amounts of odor presentation. Furthermore, the theoretical background and the planned experimental design of VR stress training, including odor presentation via olfactory VR technology, are elucidated. [ABSTRACT FROM AUTHOR]

Key points: AI‐based CT sinus analysis may have advantages over visual based systems, for example, Lund–Mackay score.Here, we show multi‐institutional validation of an AI algorithm using novel OMC classification.Significant, robust correlations are seen between algorithm outputs and clinical outcomes. [ABSTRACT FROM AUTHOR]

Purpose: To estimate long-term prognosis of chemosensory dysfunctions among patients recovering from COVID-19 disease. Methods: Between April 2020 and July 2022, we conducted a prospective, observational study enrolling 48 patients who experienced smell and/or taste dysfunction during the acute-phase of COVID-19. Patients were evaluated for chemosensory function up to 24 months after disease onset. Results: During the acute-phase of COVID-19, 80% of patients reported anosmia, 15% hyposmia, 63% ageusia, and 33% hypogeusia. At two years' follow-up, 53% still experienced smell impairment, and 42% suffered from taste impairment. Moreover, 63% of patients who reported parosmia remained with olfactory disturbance. Interestingly, we found a negative correlation between visual analogue scale scores for smell and taste impairments during the acute-phase of COVID-19 and the likelihood of long-term recovery. Conclusion: Our study sheds light on the natural history and long-term follow-up of chemosensory dysfunction in patients recovering from COVID-19 disease. Most patients who initially suffered from smell and/or taste disturbance did not reach full recovery after 2 years follow-up. The severity of impairment may serve as a prognostic indicator for full recovery. [ABSTRACT FROM AUTHOR]

Objective: To investigate the platelet-rich plasma (PRP) effectiveness in patients with a long-lasting postviral olfactory dysfunction (LPOD). Methods: Forty-three consecutive patients with a long-lasting postviral OD were prospectively recruited. The injection of 1 mL of PRP was carried out in both olfactory clefts. The pre- to 6-month post-PRP injection change in olfaction was assessed with the olfactory disorder questionnaire (ODQ) and the threshold, discrimination, and identification (TDI) tests. Results: Forty-three patients received bilateral PRP injections (24 females). The mean age of patients was 58.9 ± 16.8 years. The mean duration of LPOD was 8.7 years. The pre to 6-month post-injection mean TDI significantly improved from 10.3 ± 10.2 to 20.12 ± 12.07 (p = 0.001). The mean ODQ significantly decreased from 29.8 ± 13.0 to 23.4 ± 11.3 (p = 0.013). The average change of the TDI and the ODQ were 9.8 and 6.4, respectively. Age was inversely associated with the 6-month threshold score. Conclusion: PRP appears to be a promising therapeutic strategy for long-lasting postviral OD. Our findings support the conduction of controlled randomized trial in this population of patients. [ABSTRACT FROM AUTHOR]

Describing a particular taste or smell is subjective. Tools such as word clouds, checklists, and regular training can help water utilities gather more reliable data to deal with taste‐and‐odor events. [ABSTRACT FROM AUTHOR]

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To investigate disparities in sensitisation to Staphylococcus aureus enterotoxin A/B (SEA/SEB) and olfactory function in patients with chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), those with CRS without nasal polyps (CRSsNP), and healthy controls who underwent septoplasty only. We retrospectively reviewed the medical records of 388 subjects aged ≥ 8 years, collected between January 2021 and June 2023. We analysed patient demographics, medical history, serum IgE levels against staphylococcal enterotoxins (SEs), and serum total IgE levels against inhalant allergens. We performed olfactory and taste function tests in the participants to evaluate the relationship between olfactory function and SEs. Of 388 patients enrolled, 145 were healthy controls, 111 had CRSsNP, and 133 had CRSwNP. The prevalence of SEA/SEB positivity was significantly higher among the patients with CRSwNP than among those in the CRSsNP and healthy controls. The olfactory test results showed significant differences among the groups; anosmia was observed in 9.7% of healthy controls, 22.7% of patients with CRSsNP, and 45.1% of patients with CRSwNP. Olfactory threshold deterioration was evident in patients with CRS. Distinction and identification were more impaired in patients with CRSwNP than in those of the other groups. Finally, the olfactory function scores decreased as the serum levels of SEs increased. Sinusitis patients seem to suffer from perceiving odours, and patients with CRSwNP have difficulty distinguishing odours. Olfactory function test scores decreased in patients with a history of asthma, and as serum levels of staphylococcus enterotoxin and blood eosinophil percentage increase. Furthermore, our result suggests a potential role for SE sensitisation and eosinophil percentage in deteriorating olfaction, especially in patients with CRSwNP. [ABSTRACT FROM AUTHOR]

The article examines the impact of the IL-4-IL-4Rα axis on olfactory neuroimmune signaling and its role in inducing loss of smell. Through studies on mice and human translational data, the research reveals that IL-4 disrupts olfactory sensory neurons' responsiveness to odors, leading to neuroinflammation and immune responses in the olfactory epithelium. The findings suggest that IL-4-IL-4Rα signaling mediates neuroimmune crosstalk, driving olfactory dysfunction in conditions like chronic rhinosinusitis with nasal polyps. The study, conducted by researchers from Sanofi and Regeneron Pharmaceuticals, provides insights into potential therapeutic strategies for addressing olfactory dysfunction and related conditions. [Extracted from the article]

Neurodegenerative diseases such as Alzheimer's disease and polyglutamine diseases are characterized by abnormal accumulation of misfolded proteins, leading to neuronal dysfunction and subsequent neuron death. However, there is a lack of studies that integratemolecular, morphological, and functional analyses in neurodegenerative models to fully characterize these time-dependent processes. In this study, we used C. elegans models expressing Ab1-42 and polyglutamine to investigate early neuronal pathogenic features in olfactory neurons. Both models demonstrated significant reductions in odor sensitivity in AWB and AWC chemosensory neurons as early as day 1 of adulthood, while AWA chemosensory neurons showed no such decline, suggesting cell-type-specific early neuronal dysfunction. At the molecular level, Ab1-42 or Q40 expression caused age-dependent protein aggregation and morphological changes in neurons. By day 6, both models displayed prominent protein aggregates in neuronal cell bodies and neurites. Notably, AWB neurons in both models showed significantly shortened cilia and increased instances of enlarged cilia as early as day 1 of adulthood. Furthermore, AWC neurons expressing Ab1-42 displayed calcium signaling defects, with significantly reduced responses to odor stimuli on day 1, further supporting early behavioral dysfunction. In contrast, AWA neuron did not exhibit reduced calciumresponses, consistent with the absence of detectable decreases in olfactory sensitivity in these neurons. These findings suggest that decreased calcium signaling and dysfunction in specific sensory neuron subtypes are early indicators of neurodegeneration in C. elegans, occurring prior to the formation of visible protein aggregates. We found that the ER unfolded protein response (UPR) is significantly activated in worms expressing Ab1-42. Activation of the AMPK pathway alleviates olfactory defects and reduces fibrillar Ab in these worms. This study underscores the use of C. elegans olfactory neurons as a model to elucidate mechanisms of proteostasis in neurodegenerative diseases and highlights the importance of integrated approaches. [ABSTRACT FROM AUTHOR]

One of the still-debated topics regarding the olfactory function concerns the presence or absence of sex-related differences in individuals. In this study, we checked for a relationship between the olfactory function of females and males and their ability to perceive single molecules, and researched how this can influence the intensity with which the complex odor formed by a set of single molecules is perceived. First, females and males were classified as normosmic or hyposmic based on the TDI olfactory score obtained using the Sniffin' Sticks test. Subsequently, the headspace of roasted coffee beans, as a complex olfactory stimulus, was broken down into single molecules by means of a chromatographic column; these were simultaneously conveyed to a mass spectrometer (for their subsequent classification) and to the human nose, which acts as a chemical sensor by means of an olfactometer port. The results obtained with this gas chromatography–olfactometry approach show both qualitative and quantitative differences between females and males, with females performing better than males. In addition, the odor intensity reported by females when sniffing pen #10, containing coffee aroma, is significantly higher than that reported by males. In conclusion, these data highlight that the human ability to perceive both single compounds and complex odors is strongly conditioned, not only by the olfactory function of individuals, but also by their sex. [ABSTRACT FROM AUTHOR]

To identify the differences between COVID-19-associated and non-COVID-19-associated olfactory dysfunction (OD), we analyzed demographic and clinical characteristics based on the causative virus (COVID versus non-COVID groups) in patients with post-infectious olfactory dysfunction (PIOD) who underwent the olfactory questionnaire and olfactory function test. Out of 169 patients with PIOD, 99 were diagnosed with COVID-19 (COVID group), while 70 were not (non-COVID group). The COVID group was younger and had a higher percentage of male patients as well as patients with parosmia than the non-COVID group. In the initial olfactory function tests, the TDI, discrimination and identification scores were significantly higher in the COVID group than in the non-COVID group. TDI scores were significantly increased in patients with PIOD after treatment, regardless of the group. The threshold score was significantly increased by 1.38 in the COVID group while the identification score was significantly increased by 2.67 in the non-COVID group. Patients with COVID-19-associated OD were younger in age, tended to be male, had a higher incidence of parosmia, and had better initial olfactory function test results compared to those with non-COVID-19-associated OD. Following treatment, odor detection threshold improved in the COVID group, whereas odor identification improved in the non-COVID group. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Olfactory dysfunction (OD) is a key symptom of chronic rhinosinusitis (CRS). Although extensively studied in CRS with nasal polyps (CRSwNP), OD in CRS without nasal polyps (CRSsNP) remains under‐researched. This study aims to assess the prevalence of OD and its evolution in surgically naïve patients with CRSsNP undergoing endoscopic sinus surgery (ESS).This prospective study included 97 participants with CRSsNP (mean age, 46.5 years; 70.1% men) and 97 healthy controls (mean age, 46.5 years; 70.1% men). Participants underwent psychophysical evaluations of orthonasal (using the Sniffin’ Sticks test) and retronasal olfaction (using powdered aromas) at enrolment and 6 months post‐ESS.Out of 97 patients, 81 (83.5%) completed all assessments. At enrolment, 23 (28.4%) CRSsNP patients had OD based on composite threshold, discrimination, identification scores, compared with 7 (8.6%) controls (absolute % difference, 19.8% [95% CI, 8.2–31.4]). Retronasal olfactory function was also significantly worse in CRSsNP patients. Six months post‐ESS, 30 patients (37.0%) experienced a clinically significant improvement in olfactory, whereas nonsignificant changes were observed in retronasal olfactory score, and 3.7% of patients experienced a deterioration of the olfactory function.In conclusion, although 37% of patients experienced a clinically significant improvement in their sense of smell following ESS, the overall prevalence of OD in this surgically naive population appears relatively low, especially when compared to that observed in patients with CRSwNP. Therefore, ESS may offer some benefits for enhancing orthonasal olfactory function, but the extent of these improvements appears to be limited. [ABSTRACT FROM AUTHOR]

Simple Summary: The sweet potato whitefly is a major global pest in vegetable production. The management of this pest has typically relied heavily on insecticide treatments. Many populations of sweet potato whitefly are now resistant to insecticides. Therefore, alternative means to control this pest are needed. Many predatory insects consume sweet potato whiteflies, so helping lure and attract both predators and the pest to the same location could improve control. This study investigates attractive odors for sweet potato whiteflies and two predator species that could be used to improve sweet potato whitefly pest management. Traditionally, olfaction was thought to play a minor role in the behavioral ecology of the sweet potato whitefly, Bemisia tabaci (Gennadius). However, recent research is uncovering significant potential for whitefly management based on olfaction. Incorporating chemical attractants with standard whitefly management programs could significantly improve control. The integration of attractants with biological control is exceptionally promising. Therefore, the behavioral response of B. tabaci and two generalist predators to the green leaf volatiles (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexenyl acetate, and (Z)-3-hexe-1-ol were investigated in Y-tube olfactometers. Three of the four green leaf volatiles resulted in the attraction of female B. tabaci. Blend optimization indicated a two-chemical blend to be the most attractive blend for female B. tabaci. In addition, this blend was attractive to female Macrolophus praeclarus (Distant) but did not elicit a behavioral response from either male or female Delphastus catalinae (Horn). The two-chemical blend of green leaf volatiles could be further developed as a lure to attract B. tabaci and its predator, M. praeclarus. [ABSTRACT FROM AUTHOR]

Naming common odors is a surprisingly difficult task: Odors are frequently misnamed. Little is known about the linguistic properties of odor misnamings. We test whether odor misnamings of old adults carry information about olfactory perception and its connection to lexical‐semantic processing. We analyze the olfactory–semantic content of odor source naming failures in a large sample of older adults in Sweden (n = 2479; age 58–100 years). We investigate whether linguistic factors and semantic proximity to the target odor name predict how odors are misnamed, and how these factors relate to overall odor identification performance. We also explore the primary semantic dimensions along which misnamings are distributed. We find that odor misnamings consist of surprisingly many vague and unspecific terms, such as category names (e.g., fruit) or abstract or evaluative terms (e.g., sweet). Odor misnamings are often strongly associated with the correct name, capturing properties such as its category or other abstract features. People are also biased toward misnaming odors with high‐frequency terms that are associated with olfaction or gustation. Linguistic properties of odor misnamings and their semantic proximity to the target odor name predict odor identification performance, suggesting that linguistic processing facilitates odor identification. Further, odor misnamings constitute an olfactory–semantic space that is similar to the olfactory vocabulary of English. This space is primarily differentiated along pleasantness, edibility, and concreteness dimensions. Odor naming failures thus contain plenty of information about semantic odor knowledge. [ABSTRACT FROM AUTHOR]

The article in Acta Paediatrica discusses the importance of olfactory stimulation in neonatal clinical care, particularly in hospital settings where natural smells are disrupted. The review highlights the positive effects of olfactory stimulation on term and preterm infants, such as enhancing feeding, reducing pain and stress, and preventing apnoea. Breastmilk and vanilla were the most frequently studied odorants, showing beneficial outcomes. However, there is a need for further research to understand the full impact of olfactory stimulation on neonatal development and to establish standardized protocols for optimal results. [Extracted from the article]

Objectives: A self-administered Computerized Brief Smell Identification Test (cB-SIT) was developed recently to perform the olfactory identification test under computer control. The aim of this study was to evaluate the clinical applicability of the cB-SIT as compared with the traditional Brief Smell Identification Test (B-SIT). Methods: Sixty healthy volunteers with self-reported normal olfactory function, 30 hyposmic patients, and 30 anosmic patients were enrolled from June 2023 to May 2024. All enrolled participants received both B-SIT and cB-SIT in a random order to measure their odor identification ability. Thirty healthy volunteers took the second B-SIT and cB-SIT at least one week later. Results: The score was significantly different in both B-SIT and cB-SIT among healthy volunteers, hyposmic, and anosmic patients. The correct answer rate was significantly different in 10 items of the B-SIT and in 7 items of the cB-SIT among the three groups, but the post hoc test showed significant differences in correct answer rates between healthy volunteers and hyposmic patients in 7 items of both the B-SIT and cB-SIT. Test–retest results showed the score of the second B-SIT test was significantly higher than that of the first test, but the scores of the two tests of the cB-SIT were not significantly different. In the B-SIT, the lemon odorant had a higher correct answer rate in the second test than in the first test, but in the cB-SIT, the correct answer rate was not significantly different between the first and second tests in all 12 items. Conclusions: Our findings demonstrate that the cB-SIT was similar to the B-SIT and can be administered in the diagnosis of patients with olfactory dysfunction. [ABSTRACT FROM AUTHOR]

The sense of smell is still considered a fuzzy sensation. Softly wafting aromas can stimulate the appetite and trigger memories; however, there are many unexplored aspects of its underlying mechanisms, and not all of these have been elucidated. Although the final sense of smell takes place in the brain, it is greatly affected during the preliminary stage, when odorants are converted into electrical signals. After signal conversion through ion channels in olfactory cilia, action potentials are generated through other types of ion channels located in the cell body. Spike trains through axons transmit this information as digital signals to the brain, however, before odorants are converted into digital electric signals, such as an action potential, modification of the transduction signal has already occurred. This review focuses on the early stages of olfactory signaling. Modification of signal transduction mechanisms and their effect on the human sense of smell through three characteristics (signal amplification, olfactory adaptation, and olfactory masking) produced by olfactory cilia, which is the site of signal transduction are being addressed in this review. [ABSTRACT FROM AUTHOR]

Recognizing objects by smell is a crucial ability for many species. To accomplish this, the brain must associate activity patterns of olfactory sensory neurons with the objects that elicited them. Recognition is hard because objects are dynamic entities whose molecular composition varies due to extrinsic and intrinsic factors and because background odors are often present. These factors lead to variability in receptor activation patterns evoked by any given object. Currently, the behavioral ability to overcome these sources of variance and the underlying neuronal mechanisms are poorly understood. We propose that extraction of invariant object representations is a major function of the elaborate olfactory cortical network. Revealing the limits of olfactory capabilities, and the neuronal mechanisms that enable them, calls for integration of natural sources of stimulus variability in experimental paradigms. Many animal species use olfaction to extract information about objects in their environment. Yet, the specific molecular signature that any given object emits varies due to various factors. Here, we detail why such variability makes chemosensory-mediated object recognition such a hard problem, and we propose that a major function of the elaborate chemosensory network is to overcome it. We describe previous work addressing different elements of the problem and outline future research directions that we consider essential for a full understanding of object-oriented olfaction. In particular, we call for extensive representation of olfactory object variability in chemical, behavioral, and electrophysiological analyses. While written with an emphasis on macrosmatic mammalian species, our arguments apply to all organisms that employ chemosensation to navigate complex environments. [ABSTRACT FROM AUTHOR]

Previous research has shown a strong link between our sense of smell and emotion. More recently, the importance we attach to olfaction has been found to relate to our susceptibility to 'catch' the emotions of others. We explore this further by examining the relation between a newly developed measure of olfaction (social odour scale, SOS), which measures awareness of social odours, and emotional contagion susceptibility in female participants. The study therefore aimed to test the strength of this relationship and also help validate the English language version of the SOS. Female (n = 148) participants completed an online study that measured odour awareness [SOS; important of odour questionnaire, IOQ] and emotional contagion (EC). We found that the English version of the SOS yielded high reliability and supported the previous factor structure of the scale; additionally, we demonstrated a strong association between the SOS and IOQ which provides criterion validity for its usage. The study also revealed that whilst both the SOS and IOQ were positively associated with EC, the SOS was the more accurate predictor. These findings provide further validation for the use of the SOS and suggest that our subjective awareness of olfaction, especially concerning 'social odours' is an accurate predictor of emotional contagion. [ABSTRACT FROM AUTHOR]

Balanced energy protein (BEP) supplementation in pregnancy is recommended in the context of undernutrition for the reduction of small‐for‐gestational age neonates and stillbirths. To inform an effectiveness trial, we evaluated the acceptability of a packaged, ready‐to‐eat fortified BEP product among women of reproductive age and their health care providers (HCPs) in rural Bangladesh and explored the feasibility of adhering to daily supplementation. We implemented a formative study using focus groups discussions with women (n = 29) and HCPs (n = 17) to introduce the product and investigate components of acceptability. A "trials of improved practice" activity was conducted in subset of women (n = 16) to evaluate adherence to BEP over a 2‐week period, followed by focus group discussions to identify challenges with adherence and strategies employed. Contributors to BEP acceptability included the product's sensory attributes, such as taste, smell and texture; the attractive packaging and informative labelling; and the perceived benefits of use. Participants also identified household and community level factors influencing the adoption of BEP, such as trust in the provider, cultural beliefs on supplement use in pregnancy, and family member tasting and approval. Over the 2‐week period, women consumed over 80% of the supplements provided to them and identified strategies for adherence, including visual aids and reminders from family members or providers. HCPs recommended targeted communication messages for mothers‐in‐law to foster a supportive home environment. Findings informed changes to the BEP product to improve acceptability and shaped the content of communication messages to optimise adherence in a forthcoming effectiveness trial. Key messages: The balanced energy protein (BEP) product introduced in this formative study was well accepted by women of reproductive age and their health care providers (HCPs), especially with regards to the overall taste, product packaging and labelling, and perceived benefits. Acceptability may be influenced by cultural beliefs around nutritional supplement use during pregnancy, and factors such as family members' approval of the product, and trust in the provider of BEP supplements.Women who consumed the product over 2 weeks had high daily adherence and identified strategies such as reminders from family members and/or providers and visual aids in the home to enhance regular use. HCPs recommended communication messages that encouraged buy in from husbands and mothers‐in‐law.Findings from this study informed changes to the BEP product format to improve acceptability and shaped the content of communication messages to encourage adherence in a forthcoming effectiveness trial. [ABSTRACT FROM AUTHOR]

Chronic stress alters reward sensitivity and contributes to anhedonia. Chemosensation is dominated by a hedonic dimension, but little is known about the association between chronic perceived stress and hedonic chemosensation in non‐clinical populations. In the current study, 325 participants (201 females) completed a questionnaire‐based survey measuring their chronic perceived stress (Perceived Stress Scale; PSS), chemosensory pleasure (Chemosensory Pleasure Scale; CPS), and olfactory metacognitive abilities (odor awareness, affective impact of odor, importance of olfaction). For females, higher PSS scores significantly predicted lower CPS scores, which is mediated by the positive odor awareness. Moreover, negative odor awareness was identified as a moderator underlying the relationship between PSS and CPS scores in females but not in males. For females, higher PSS predicted lower CPS for those with lower, but not for those with higher levels of negative odor awareness. These results show that the link between chronic perceived stress and chemosensory anhedonia is pronounced in females, with olfactory perception playing a key role. The current study provides insights into the understanding of stress‐related anhedonia and into the development of effective treatments. [ABSTRACT FROM AUTHOR]

Introduction: The Sensory Processing Measure 2 (SPM2) and the Sensory Profile 2 (SP2) are two sensory processing scales often used by occupational therapists. The SPM2 and SP2 both claim to assess aspects of children's sensory processing. This cross‐sectional study examined the convergent validity of the SPM2‐Home Form (SPM2‐HF) and Child SP2 for school‐aged neurotypical children. Methods: Thirty parents/caregivers of neurotypical children aged 7 to 12 completed the SPM2‐HF and the Child SP2 about their child. Spearman rho's correlation coefficient with bootstrapping was used to investigate the correlations among the sensory, behavioural, and quadrant scores of the Child SP2 and SPM2‐HF subscale scores. Consumer and Community Involvement: Given the topic, consumers and community members were not involved in the design, execution, or write up of the study results. Results: Several statistically significant correlations were found between the sensory and quadrant subscales of the Child SP2 with the SPM‐HF. Strong to moderate correlations were established between the sensory subscales of the Child SP2 and the SPM2‐HF, ranging from 0.40 to 0.74 (p < 0.05). Additionally, correlations between the quadrant subscales of the Child SP2 and the subscales of the SPM2‐HF ranged from weak (0.38) to strong (0.77) correlations (p < 0.05). Conclusion: These results provide evidence of convergent validity between the SPM2‐HF and Child SP2 for neurotypical school‐aged children. Further research on the psychometric properties of the SPM2‐HF and Child SP2 is recommended. PLAIN LANGUAGE SUMMARY: The Sensory Processing Measure 2 (SPM2) and the Sensory Profile 2 (SP2) are two scales used by occupational therapists to assess aspects of children's sensory processing. This study looked at the relationship between the SPM2‐Home Form (SPM2‐HF) and Child SP2 for healthy school‐aged children. Thirty parents/caregivers of children aged 7–12 years completed the SPM2‐HF and the Child SP2 about their child. Correlations between the Child SP2 and SPM2‐HF subscale scores were examined using statistics. Consumers and community members were not involved in completing the project or writing the project results. Several statistically significant correlations, ranging from 0.38 to 0.77, were found between the Child SP2 and the SPM‐HF subscales. The Child SP2 and the SPM‐HF had several subscales that were significantly correlated with one another. These findings contribute to the knowledge about children's sensory processing assessments and will help occupational therapists when working with children and their families. Study limitations were the small sample size and recruiting volunteer participants which can influence bias. Strengths of the study include the use of standardised data collection tools and following ethical principles when conducting all phases of the study. [ABSTRACT FROM AUTHOR]

Purpose: This pilot study aimed to determine whether the Henkin olfactory test discriminates between the olfactory function of patients with olfactory loss and healthy individuals, and whether the Henkin test is correlated with a validated psychophysical olfactory test. Methods: Participants underwent olfactory testing using the modified Henkin test (including detection [DT] and recognition [RT] thresholds, magnitude estimation [ME], and hedonic ratings [H], for four different odors) and the extended "Sniffin' Sticks" test battery (odor detection, discrimination, identification). Results: Forty-four individuals (28 women, aged 19–81 years, mean: 39 years) were included. Twenty-three were healthy (mean age: 38 years) and 21 had olfactory dysfunction (OD) (mean age: 40 years). OD patients had worse mean DT, lower composite RT, and lower ME ratings. Mean and individual odor H ratings were not significantly different between the groups. Most individuals were classified as hyposmic when using the prescribed classification by Henkin, with only very few satisfying the stringent criteria of anosmia and normosmia. Modified Henkin subtests were all positively correlated with each other and with the "Sniffin' Sticks", except for Unpleasant Mean H which was only correlated with Pleasant Mean H; and Pleasant mean H which was not correlated with mean DT scores. Conclusion: The Henkin test is able to separate between OD patients and controls. However, modifications to the conduct of this test may be required. Studies that used this test should be carefully interpreted. Level of evidence: 3. [ABSTRACT FROM AUTHOR]

Purpose: Evaluating the impact of radioiodine therapy (RIT) on olfactory function in thyroid cancer patients through quantitative and qualitative olfactory tests. Method: In this cohort study, patients with thyroid cancer were included. Demographic, clinical, and laboratory data were collected. To subjectively evaluate the olfactory changes aftter RIT, the Visual Analog Scale (VAS), Self-Reported Mini-Olfactory Questionnaire (self-MOQ), and the University of Washington Quality of Life Questionnaire (UW-QOL) were assessed. Out of UW-QOL questions those related to saliva, taste, and overall health condition were analysed. For objective assessment, patients underwent both the Butanol Threshold Test (BTT) and the a version of Smell Identification Test (SIT). Patients were assessed before, one month, and six months after RIT. Results: Ninety eight patients were included (Male = 17). A statistically significant decrement was observed in olfaction based on the VAS, between the baseline and one (pvalue = 0.015) and six months (pvalue = 0.031) of follow-up. Additionally, saliva (pvalue = 0.001), taste (pvalue = 0.000), and overall health condition (pvalue = 0.010) significantly decreased one-month after RIT. The measures were not different between the baseline and 6-month follow up and the improvement of index of taste was significant from 1-month to 6-months follow ups (pvalue = 0.000). However, none of the objective tests (the BTT and the SIT) indicated a significant decline in olfaction during the follow up. Conclusion: A subjective RIT related decrease in smell function, taste, and saliva production was documented without any objective olfactory dysfunction. [ABSTRACT FROM AUTHOR]

Because of the brief and cryptic nature of predatory behavior, sentinel prey has been widely adopted as an indirect way to identify predators and understand trophic interactions. However, sentinel prey presents only static visual cues, potentially biasing toward visually oriented predators while ignoring those that utilize other sensory cues for foraging. Despite this, the effectiveness of sentinel prey has rarely been tested. In this study, we focused on the weaver ant Oecophylla smaragdina Fabricius (Hymenoptera: Formicidae), a keystone predator widespread in the Asian and Australian tropics. As this species has large eyes and is known to visually navigate in its arboreal habitats, we hypothesized that it relies on visual cues to forage and that its predatory behavior will be captured by caterpillar‐shaped sentinel prey. Ants were collected as colonies, and preference trials on baits were conducted using combinations of olfactory and static visual cues, including the caterpillar shape. Surprisingly, O. smaragdina showed little or no preference for baits in the absence of olfactory cues and did not differentiate the shapes of baits regardless of olfactory cues. Our results indicate that O. smaragdina is likely to make predatory decisions based primarily on olfactory cues, whereas visual cues might be used for other behaviors. Furthermore, O. smaragdina is likely to be left out by the predation studies using sentinel prey models, which is particularly alarming considering the dominant role of this species in the trophic interactions of tropical rainforests. Our study demonstrates that morphological characteristics, arboreal habitats, and visually oriented behavior do not necessarily suggest the use of static visual cues for predatory decisions. We suggest that sentinel prey models should not be used alone when the dominant predators are unlikely to use visual cues to make predatory decisions. [ABSTRACT FROM AUTHOR]

Converging global trends (digitization, globalization, datafication) have influenced all aspects of children's literacies, including children's picturebooks. The recent turn towards embodied, affective and sensory literacies, stimulated our interest in multisensory picturebooks that engage all children's senses, including the sense of smell (olfaction). Olfactory children's picturebooks demand new forms of literary conversations, which capitalise on unique properties of odours and integrate these with stories. Drawing on a systematic search of children's picturebooks about, and with, smell, in paper-based and digital formats, we identified three principal ways in which olfaction is currently embedded in children's picturebooks: 1, as an add-on to depiction of objects (including foods, plants) and places, 2, as a device to introduce humour into a story, and 3, as an engagement tool for children's active participation in the story. We mobilise Sipe's (2008) concept of seven constituting elements in children's picturebooks to describe how current olfactory picturebooks apply the elements in their design and make recommendations for future development of children's olfactory picturebooks. Reflecting on the generative potential of literary theories and olfactory power to stimulate children's non-linguistic embodied interactions with picturebooks, we propose some extensions to the current olfactory picturebook landscape. [ABSTRACT FROM AUTHOR]

This study is a researcher-practitioner action inquiry which was used to explore children's sensory experiences with a focus on the sense of smell (olfaction). We critically considered the early childhood theories that positioned children's sensory learning within equitable, socially just early childhood approaches and connected them to an action inquiry approach. The data comprise a systematic documentation of the odours experienced by children in the classroom, an olfactory log of the kindergarten space as well as children's 'smellmaps' from outdoor 'smellwalks'. We interpret children's olfactory experiences and reflect on the ways in which the multi-sensory approach to literacy might extend the field's understanding of the multi-dimensional ways in which educational researchers and practitioners can cultivate their joint inquiries in early childhood education. We present implications for adopting an olfactory researcher-practitioner collaboration in early childhood and conclude that such an approach exemplifies a sensorially sensitive early childhood curriculum. [ABSTRACT FROM AUTHOR]

Background Prospective studies comparing quality-of-life and olfaction in patients undergoing endoscopic uni-nostril versus bi-nostril trans-sphenoidal pituitary surgery have not been published. Methods We prospectively compared olfaction and quality-of-life at baseline and at 3 to 6 months follow-up using the Anterior Skull Base Nasal Inventory-12 (ASK-12) questionnaire, composite olfaction score, and Lund–Kennedy Endoscopic Score (LKES) in 43 patients who underwent endoscopic excision of pituitary adenoma with either a uni-nostril (24 patients) or a bi-nostril (19 patients) approach. Results Baseline data for both groups were comparable. In the uni-nostril group, ASK-12 and LKES scores were not significantly different at follow-up when compared with the preoperative scores. In the bi-nostril group, there was a significant postoperative worsening of ASK-12 scores (mean: 3.2 vs. 5.3; p = 0.04) and the LKES (mean: 2.9 vs. 6.6; p = 0.01). Composite olfaction score was not significantly affected postoperatively with either approach. Nasal complications were also more in the bi-nostril group (5/18, 27.8% vs. 1/23, 4.3%) but this was not statistically significant (p = 0.07). Conclusion Both approaches preserve olfactory function but the uni-nostril approach is associated with better postoperative quality-of-life and endoscopic scores and subjective olfaction outcomes. At least in short term, the postoperative morbidity is higher in the bi-nostril approach compared with the uni-nostril approach. Although preference for a particular approach is related to a surgeon's preference, preoperative counselling of the patients regarding sinonasal morbidity is important. [ABSTRACT FROM AUTHOR]

Objective: Delta Smelt Hypomesus transpacificus are thought to be close to extinction in the wild, which has spurred multiagency conservation efforts to supplement their population. In conjunction with these recent efforts, monitoring is needed to assess the effectiveness of supplementation. Such monitoring often uses large‐scale tagging of released fish to distinguish between hatchery‐origin and wild‐origin fish that are captured during later surveys. Methods: In this study, we evaluated the use of visible implant elastomer tags in Delta Smelt to determine whether fish survival, fish growth, or tag retention were dependent on (1) tag color (blue, green, orange, red, yellow, and no‐tag control) or (2) tagged body location (posterior‐dorsal, anterior‐dorsal, mid‐lateral line, and no‐tag control). Result: Over 165 days of the first experiment, there was no difference in growth rate (mean = 0.073 mm/d, range = 0.072–0.075 mm/d) or survival (mean = 68%, range = 63–77%) among tag colors. Across all color groups, mean tag retention was 96% (range = 87–100%). Over 120 days of the second experiment, tag location had no influence on fish growth rate (mean = 0.064 mm/d, range = 0.062–0.067 mm/d) or survival (mean = 50%, range = 43–58%). For the surviving fish in experiment 2, the tags that were placed at the mid‐lateral line were retained less (84% on day 120) than those at posterior‐dorsal and anterior‐dorsal locations (99% and 98%, respectively). Conclusion: Our results suggest that visible implant elastomer tagging is a suitable method for marking adult Delta Smelt (>50 mm fork length) for up to 165 days and can be useful for conservation monitoring efforts. Impact StatementSupplementation of Delta Smelt is needed to avert its extinction in the wild. We experimentally evaluated the suitability of visible implant elastomer tags to distinguish hatchery‐ and wild‐origin Delta Smelt captured in monitoring surveys during the spawning season. [ABSTRACT FROM AUTHOR]

Background: Few primary studies have examined the impact of olfactory and gustatory stimulation on premature infants, and variability exists in reported outcomes. Purpose: To explore the effects of olfactory and gustatory stimulation on feeding outcomes in preterm infants. Data Sources: A literature search was conducted in 4 databases (CENTRAL, PubMed, Embase, CINAHL) from the inception of the databases to May 2024. Study Selection: Randomized controlled trials (RCTs) or quasi-RCTs to explore the effects of olfactory and gustatory stimulation on feeding outcomes in preterm infants were included. Data Extraction: Two reviewers independently extracted data from the included studies and completed the form designed for data extraction. Results: Eleven RCTs and quasi-RCTs comprising 1009 preterm infants were included. Meta-analysis found that olfactory and gustatory stimulation significantly shortened the time to reach full oral feeds (days) (mean difference [MD]: -2.52, 95% confidence interval [CI]: -3.88 to -1.16, P = .0003), while they had no significant differences in time to achieve full enteral feeds (days), postmenstrual age (PMA) at the removal of the nasogastric tube (weeks), weight at discharge (grams), weight gain (grams), head circumference at discharge (cm), length at discharge (cm), total duration of parenteral nutrition (days), necrotizing enterocolitis, hospitalization duration (days), PMA at discharge (weeks). Implications for Practice and Research: Large sample, multicenter studies are needed to demonstrate the effectiveness of olfactory and gustatory stimulation on feeding outcomes in preterm infants. [ABSTRACT FROM AUTHOR]

Background: Several medical diagnoses generate unpleasant smells, which cause suffering for patients. There is no culturally accepted language for malodour, and the topic is encircled by silence in nursing. Aim: To facilitate communication with patients on unpleasant smell. Method: A linguistic analysis of verbal expressions from 11 patients suffering from malodour was conducted. Discourse-based metaphor theory guided the analysis. Findings: Metaphors of comparison and orientation were the most common categories of metaphors. The comparisons referred to bodily waste products and rotting processes. Metaphors of orientation illuminated how the unpleasant smell moved around and settled down in the body and in their homes without the patients' control. Swearing was used to convey suffering. Conclusion: The figures of speech provided new insight into how malodour affected the patients existentially by threatening social relations, freedom and integrity. Recognizing the patients verbal expressions may act as a starting point for communication. [ABSTRACT FROM AUTHOR]

Background: Olfactory dysfunction was associated with poorer cognition. However, the association between transient receptor potential cation channel subfamily A member 1 (TRPA1) and cognitive function have not been studied. This study aimed to evaluate the mediation effect of TRPA1 on the association between olfactory and cognitive function among Chinese older adults. Methods: We recruited 121 participants with cognitive impairment (CI) and 135 participants with normal cognition (NC) from a memory clinic and the "Shanghai Aging Study." Olfactory identification of each participant was measured by the Sniffin' Sticks Screening Test 12 (SSST-12). Serum TRPA1 were quantified using the Enzyme-Linked Immunosorbent Assay. The mediation effects of TRPA1 on the association between olfactory function and cognitive function were explored using mediation analysis. Results: The CI group had a significantly higher proportion of the high level of serum TRPA1 (58.7%) than the NC group (42.2%) (p = 0.0086). After adjusted for gender, age, and years of education, mediation analysis verified that TRPA1 partially mediated the association between SSST-12 and Mini Mental State Examination (MMSE). It also verified that TRPA1 partially mediated the association between the identification of peppermint and MMSE. Conclusion: Our study emphasizes the mediation role of TRPA1 in the relationship between olfactory and cognitive function among older adults. Further research is necessary to explore the mechanism of TRPA1 on the relationship between olfactory and cognitive decline. [ABSTRACT FROM AUTHOR]

Since the introduction of vaccines for severe acute respiratory syndrome coronavirus 2 in the United States, there has been significant vaccine hesitancy, in part due to fear of adverse effects. We sought to investigate the rates of smell and taste changes after COVID‐19 vaccination compared to other common vaccines. Our study cohort included individuals identified by Current Procedural Terminology code in the TriNetX database receiving the COVID‐19 first series, COVID‐19 booster, influenza, tetanus, diphtheria, pertussis (TDAP), or pneumococcal vaccines between December 15, 2020, and August 15, 2023. After 1:1 propensity score matching, postvaccination incidence of disturbance of smell and taste was significantly less likely after COVID‐19 first series vaccine compared to influenza (odds ratios, OR: 0.27 [95% confidence interval, CI: 0.20‐0.36]), TDAP (OR: 0.35 [95% CI: 0.26‐0.47]), and pneumococcal vaccines (OR: 0.17 [95% CI: 0.09‐0.32]). Similarly, incidence of disturbance of smell and taste was significantly less likely after COVID‐19 booster vaccine compared to the influenza (OR: 0.60 [95% CI: 0.48‐0.76]), TDAP (OR: 0.63 [95% CI: 0.47‐0.85]), and pneumococcal vaccines (OR: 0.44 [95% CI: 0.28‐0.68]). This study builds upon the literature demonstrating the safety of COVID‐19 vaccination. [ABSTRACT FROM AUTHOR]

AbstractTo enhance the engagement and significance of olfaction as a novel medium in multimedia systems, we aim to integrate different hedonic odorous cues into narratives to augment immersion in virtual experiences. We introduce the ScentClue system, comprising (1) an original and murder-themed experimental film incorporating four distinct hedonic odor cues synchronized with audiovisual elements, (2) a neck-worn scent delivery device capable of dispensing four different odors, and (3) an Unreal Engine-based virtual cinema environment enabling rapid control of video playback and odor dissemination. Experimenting with 18 participants divided into control groups with and without odor stimuli, we validated the system’s usability and effectiveness of odor cue settings. Furthermore, we found that the use of odors with different hedonic qualities could enhance odor recognition, amplify thematic story ambiance, and aid in the rapid differentiation of complex relationships. Finally, we discussed expanded scenarios and interaction modalities for ScentClue, proposing future narrative-driven olfaction-enhanced multimedia designs with considerations for odor cue settings, odor material selection, and scent-releasing setup, particularly unpleasant odors. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Methodology Results Conclusions Fortunately, the majority of COVID‐19 patients recover from olfactory dysfunction (OD) within the first couple of weeks. However, from approximately 5% up to 20% continue to suffer from OD even more than 1 year after the onset. Nonetheless, factors associated with long‐lasting OD are hardly known. The aim of this study was to identify favourable and disadvantageous markers of persisting OD in COVID‐19 patients.Sixty‐six patients (46 female; mean age: 39.9 years) that suffer from OD longer than 6 months due to laboratory‐confirmed SARS‐CoV‐2 infection have participated in this longitudinal study. Participants completed comprehensive psychophysical chemosensory tests (i.e., Sniffin' Sticks = TDI) and questionnaires twice at our department—on average 219 ± 80 (T‐1) and 489 ± 89 (T‐2) days after the onset of symptoms, respectively. Olfactory recovery rates were associated with demographic factors and questionnaires using linear regression analysis.Patients below 40 years of age improved better (TDI: 4.1 ± 4.3 vs. 0.7 ± 5.8; p = 0.008) and achieved statistically significant higher scores (TDI: 31.5 ± 4.0 vs. 27.3 ± 6.7; p = 0.033) regarding psychophysical chemosensory tests. Furthermore, linear regression analysis revealed that parosmia was associated with worse orthonasal smell function (T‐1: β = −0.346, p = 0.004; T‐2: β = −0.384, p = 0.001), especially concerning identification subtest (T‐1: β = −0.395, p = 0.001; T‐2: β = −0.398, p < 0.001). Moreover, increasing parosmia between T‐1and T‐2 led to worse orthonasal olfactory function (β = −0.294, p = 0.016).Older age and parosmia seem to be unfavourable factors of persisting OD in COVID‐19 patients. [ABSTRACT FROM AUTHOR]

Detecting chemical signals is important for identifying food sources and avoiding harmful agents. Like many animals, C. elegans use olfaction to chemotax towards their main food source, bacteria. However, little is known about the bacterial compounds governing C. elegans attraction to bacteria and the physiological importance of these compounds to bacteria. Here, we address these questions by investigating the function of a small RNA, P11, in the pathogen, Pseudomonas aeruginosa, that was previously shown to mediate learned pathogen avoidance. We discovered that this RNA also affects the attraction of untrained C. elegans to P. aeruginosa and does so by controlling production of ammonia, a volatile odorant produced during nitrogen assimilation. We describe the complex regulation of P. aeruginosa nitrogen assimilation, which is mediated by a partner-switching mechanism involving environmental nitrates, sensor proteins, and P11. In addition to mediating C. elegans attraction, we demonstrate that nitrogen assimilation mutants perturb bacterial fitness and pathogenesis during C. elegans infection by P. aeruginosa. These studies define ammonia as a major mediator of trans-kingdom signaling, implicate nitrogen assimilation as important for both bacteria and host organisms, and highlight how a bacterial metabolic pathway can either benefit or harm a host in different contexts. Ammonia production enzymes mediate the initial attraction of C. elegans towards P. aeruginosa. Here, Marogi et al show that the bacterial small RNA, P11, affects worm attraction by modulating nitrogen assimilation. [ABSTRACT FROM AUTHOR]

This study investigates olfaction, a complex and not well-understood sensory modality. The chemical mechanism behind smell can be described by so far proposed two theories: vibrational and docking theories. The vibrational theory has been gaining acceptance lately but needs more extensive validation. To fill this gap for the first time, we, with the help of data-driven classification, clustering, and Explainable AI techniques, systematically analyze a large dataset of vibrational spectra (VS) of 3018 molecules obtained from the atomistic simulation. The study utlizes image representations of VS using Gramian Angular Fields and Markov Transition Fields, allowing computer vision techniques to be applied for better feature extraction and improved odor classification. Furthermore, we fuse the PCA-reduced fingerprint features with image features, which show additional improvement in classification results. We use two clustering methods, agglomerative hierarchical (AHC) and k-means, on dimensionality reduced (UMAP, MDS, t-SNE, and PCA) VS and image features, which shed further insight into the connections between molecular structure, VS, and odor. Additionally, we contrast our method with an earlier work that employed traditional machine learning on fingerprint features for the same dataset, and demonstrate that even with a representative subset of 3018 molecules, our deep learning model outperforms previous results. This comprehensive and systematic analysis highlights the potential of deep learning in furthering the field of olfactory research while confirming the vibrational theory of olfaction. [ABSTRACT FROM AUTHOR]