Olfaction Research Articles

Subjective and objective effects of radioiodine therapy on the sense of smell.

Evaluating the impact of radioiodine therapy (RIT) on olfactory function in thyroid cancer patients through quantitative and qualitative olfactory tests. 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. 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. A subjective RIT related decrease in smell function, taste, and saliva production was documented without any objective olfactory dysfunction.

The Application Of Medication And Strategies For The Implementation Of Hallucinations In Tn. S (Terra Neutral Separated) With A Nursing Diagnosis Of Sensory Perception Disorders (Hallucinations)

Hallucinations are sensory perception disorders that attack the five senses, where a person perceives an object or image and thoughts that do not occur or are not real. Hallucinations include sound, sight, taste, touch, or smell sensations without real stimulus. Treatment for patients with hallucinations is by identifying the type of hallucination, applying medication, and implementing strategies to distract or overcome the hallucinations experienced. The objectives of this study include (1) Describing problems regarding sensory perception disorders and (2) Describing and implementing nursing care in cases of mental disorders with a medical diagnosis of schizophrenia at Soerojo Hospital Magelang. This study uses a qualitative approach with case studies as the primary method, using observation sheets, interviews, and documentation studies. The subject of this study used one patient, Mr S, who had a nursing diagnosis of sensory perception disorders at RSD Soerojo Hospital Magelang. Nursing care for patient Mr S with a diagnosis of sensory perception disorder (hallucinations) in this case showed success as indicated by the signs and symptoms experienced by the patient decreasing. After four days of intervention, the patient was able to overcome hallucinations by scolding, interacting with the surrounding environment, and taking care of himself by bathing and dressing more neatly.

Genome-Wide Association Study Meta-Analysis Uncovers Novel Genetic Variants Associated with Olfactory Dysfunction.

Olfactory dysfunction is among the earliest signs of many age-related neurodegenerative diseases and has been associated with increased mortality in older adults; however, its genetic basis remains largely unknown. To identify the genetic loci associated with olfactory dysfunction in the general population. This genome-wide association study meta-analysis (GWMA) included participants of European ancestry (N = 22,730) enrolled in four different large population-based studies, followed by a multi-ancestry GWMA including participants of African ancestry (N = 1,030). The data analysis was performed from March 2023 through June 2024. Genome-wide single nucleotide polymorphisms. Olfactory dysfunction was the outcome and assessed using a 12-item smell identification test. GWMA revealed a novel genome-wide significant locus (tagged by rs11228623 at 11q12) associated with olfactory dysfunction. Gene-based analysis revealed a high enrichment for olfactory receptor genes in this region. Phenome-wide association studies demonstrated associations between genetic variants related to olfactory dysfunction and blood cell counts, kidney function, skeletal muscle mass, cholesterol levels and cardiovascular disease. Using individual-level data, we also confirmed and quantified the strength of these associations on a phenotypic level. Moreover, employing two-sample Mendelian Randomization analyses, we found evidence for causal associations between olfactory dysfunction and these phenotypes. These findings provide novel insights into the genetic architecture of the sense of smell and highlight its importance for many aspects of human health.

Receptors Involved in COVID-19-Related Anosmia: An Update on the Pathophysiology and the Mechanistic Aspects.

Olfactory perception is an important physiological function for human well-being and health. Loss of olfaction, or anosmia, caused by viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has received considerable attention, especially in persistent cases that take a long time to recover. This review discusses the integration of different components of the olfactory epithelium to serve as a structural and functional unit and explores how they are affected during viral infections, leading to the development of olfactory dysfunction. The review mainly focused on the role of receptors mediating the disruption of olfactory signal transduction pathways such as angiotensin converting enzyme 2 (ACE2), transmembrane protease serine type 2 (TMPRSS2), neuropilin 1 (NRP1), basigin (CD147), olfactory, transient receptor potential vanilloid 1 (TRPV1), purinergic, and interferon gamma receptors. Furthermore, the compromised function of the epithelial sodium channel (ENaC) induced by SARS-CoV-2 infection and its contribution to olfactory dysfunction are also discussed. Collectively, this review provides fundamental information about the many types of receptors that may modulate olfaction and participate in olfactory dysfunction. It will help to understand the underlying pathophysiology of virus-induced anosmia, which may help in finding and designing effective therapies targeting molecules involved in viral invasion and olfaction. To the best of our knowledge, this is the only review that covered all the receptors potentially involved in, or mediating, the disruption of olfactory signal transduction pathways during COVID-19 infection. This wide and complex spectrum of receptors that mediates the pathophysiology of olfactory dysfunction reflects the many ways in which anosmia can be therapeutically managed.

Sensory Changes Related to Swallowing in Motor Neurone Disease.

Dysphagia is common in motor neurone disease (MND) and associated with negative health and psychosocial outcomes. Although largely considered a motor disease, a growing body of evidence suggests that MND can also affect the sensory system. As intact sensation is vital for safe swallowing, and sensory changes can influence the clinical management of dysphagia in people living with MND, this review evaluated and summarised the current evidence for sensory changes related to swallowing in MND. Of 3,481 articles originally identified, 29 met the inclusion criteria. Of these, 20 studies reported sensory changes, which included laryngeal sensation, taste, gag reflex, cough reflex, tongue sensation, smell, palatal and pharyngeal sensation, silent aspiration, and undefined sensation of the swallowing mechanism. Sensory changes were either described as decreased (n = 16) or heightened (n = 4). In the remaining nine studies, sensory function was reported as unaffected. The presence of changes to sensory function related to swallowing in MND remains inconclusive, although an increasing number of studies report sensory changes in some sensory domains. Future research is needed to evaluate the prevalence of sensory changes in MND and how such changes may influence dysphagia and its management.

Multidisciplinary approach to severe intracranial, intraorbital allergic fungal sinusitis

BackgroundAllergic fungal sinusitis (AFS) is a form of paranasal mycosis that often involves bone destruction and can extend into the orbit and anterior skull base. Intracranial and intraorbital involvement are published but not both in each included patient of a series. The purpose of the present study was to review cases of extensive AFS with orbital or/and skull base erosion, including the presenting symptoms, patient socioeconomic background, imaging features, surgical technique, and post-operative outcomes. MethodsThe records of 30 patients with the histological diagnosis of AFS and both intracranial and intraorbital involvement were reviewed. ResultsThe average age of the patients was 25.2 years. 83 % of patients were male. 70 % were African American. 66 % of patients had Medicaid or were uninsured. Presenting symptoms were headaches (80 %), nasal obstruction (33 %), proptosis (40 %), vision change (23 %), facial pressure (10 %), and decreased sense of smell (7 %). 100 % of patients had bone erosion observed on computerized tomography scans with disease extending intracranially through the anterior skull base or posterior wall of the frontal sinus along with disease that eroded through the lamina papyracea. All patients had failed medical management. All patients underwent surgery by Otolaryngology, Ophthalmology, and Neurosurgery with transnasal endoscopic approaches and orbitotomy. 80 % also underwent a bifrontal craniotomy for removal of intracranial extradural disease with cranialization. 53 % of patients had orbital implants remaining after surgery; 23 % had nasal stents. There were no postoperative cerebrospinal fluid leaks. Average hospital stay was 4.8 days. Preoperatively, 13 % of patients underwent allergy testing. 94 % saw an Allergist postoperatively. 21 % required follow up surgery. ConclusionsA team approach of Otolaryngologists, Ophthalmologists, and Neurosurgeons is recommended for this slowly growing but locally destructive disease. Most patients with AFS will present with headaches and nasal obstruction. While most cases of AFS can be successfully managed with transnasal endoscopic techniques, orbitotomy and craniotomy represents an effective treatment for severe AFS cases with extensive intracranial and intraorbital involvement. This disease is found most commonly in young African American males and in the underinsured.

The effect of smell training on COVID-19 induced smell loss.

while smell training appears to be effective for post viral smell loss, its effectiveness in COVID-19 induced smell loss is currently not well known. Therefore, we aim to investigate the potential effect of smell training on patients with COVID-19 induced smell loss. we conducted a case-control study with two comparable cohorts. One of which (n=111) was instructed to perform smell training twice daily for 12 weeks, therapeutical adherence was monitored on a daily schedule, while the other cohort (n=50) did not perform smell training. The Sniffin' Sticks Test (SST) was used to objectify participants' sense of smell at baseline and after 12 weeks, reported as a Threshold, Discrimination, and Identification (TDI) score. We also determined the association between therapeutical adherence and the TDI scores. we found a significant difference in psychophysical smell function between patients with COVID-19 induced smell disorders who performed 12 weeks of smell training and those who did not. Median TDI difference between groups was 2.00 However, there was no association between the therapeutical adherence and olfactory function. we discovered a significant moderate difference in psychophysical smell function between patients with COVID-19-induced smell disorders who performed smell training and those who did not, implying a possible advantage of training. However, no relationship was found between therapeutical adherence of smell training and olfactory function.

Effect of Lavender Essential Oil Topical Treatment on the Autonomic Nervous System in Human Subjects Without Olfactory Influence: A Pilot Study

Objective/background As part of a scientific study into the effects of aromatherapy, we investigated the effects of lavender essential oil (LEO) treatment on the autonomic nervous system in subjects for whom the sense of smell had been eliminated. Methods This study used a single-blinded cross-over design for verification. Heart rate variability was measured and effects on the autonomic nervous system were investigated. Results and discussion Although no significant differences were found, aromatherapy treatment with 1% LEO tended to increase parasympathetic nervous system activity. Further, when differences between values before and during aromatherapy treatment were compared, LEO treatment significantly increased parasympathetic nervous system activity. Given these findings, LEO appears to increase parasympathetic nervous system activity, even in the absence of a psychological effect due to an absence of olfactory stimulation. Conclusion The present results provide a scientific method for verifying the effects of aromatherapy and will aid in further elucidation of aromatherapy.

The Association of Odor Identification With Nutritional Status and Systemic Inflammation in Patients With Advanced Chronic Kidney Disease

BackgroundAnorexia is common in patients with chronic kidney disease (CKD) and could lead to protein energy wasting (PEW). An altered sense of smell, a reflection of olfactory dysfunction, is a potential mechanism that exacerbates the impact of anorexia on PEW. In this study, we examined the extent of the altered sense of smell and its association with PEW in patients with moderate to advanced CKD. MethodsWe studied 139 individuals (34 healthy subjects - controls, 50 patients with stage 3-4 CKD, 55 patients on maintenance hemodialysis - MHD) using the odor identification test (Sniffin’ Sticks odor screening test containing 12 different smells). The odor identification test was scored as either correct or incorrect, and each participant's total odor score was calculated. Malnutrition Inflammation Score (MIS) was used to assess PEW. ResultsPatients with CKD had higher C-reactive protein (CRP) and lower serum albumin concentrations compared to healthy individuals. Total odor scores were different between groups, with controls having the highest scores and MHD patients having the lowest scores. A similar difference was observed in MIS, MHD patients displaying the worst nutritional score (p ≤ 0.001). The number of participants with severe olfactory dysfunction (≤ 6 correct answers) was significantly higher in the CKD and MHD groups compared to the controls (p ≤ 0.01). There was an inverse trend between the total odor score and the MIS score for the study population. However, this relationship was not statistically significant (r = -0.124, p = 0.21). ConclusionThis cross-sectional study suggests that olfactory dysfunction, as assessed by the odor identification test, is altered in patients with advanced CKD, most notably in ones on MHD. Although the diminished sense of smell was observed alongside development of PEW, we explicitly noted that there is no statistically significant correlation.

Olfactory perceptual fingerprints of people with olfactory dysfunction and healthy controls.

An olfactory perceptual fingerprint (OPF) defines one's olfactory perception using perceptual descriptor ratings (such as odor pleasantness, intensity) for a set of odors. OPFs have been shown to distinguish patients with COVID-related olfactory dysfunction (OD) and healthy controls with 86% accuracy. However, all participants rated the same odorants. With the aim to evaluate whether the OPFs are indeed odorant independent, previously published dataset by Lötsch et al. was reanalyzed. Furthermore, this independent dataset was used to check whether the OPFs separate patients with OD due to various causes from controls. The study included 104 controls and 42 patients, who were randomized into four odor sets with 10 odorants each. Odorants were presented using a computer-controlled olfactometer and evaluated on scales from 1 (not at all) to 5 (very) using perceptual descriptors pleasant, intensive, familiar, edible, irritating, cold/warm, and painful. Permutational multivariate analysis of variance showed that the odor set did not have a significant effect on the OPFs, confirming that the OPFs are indeed odorant independent. On the other hand, both diagnosis and age affected the OPFs (p < .001) and explained around 11% and 5% of the variance of the OPFs, respectively. Furthermore, a supervised machine learning method, random forest classifier, showed that OPF can distinguish patients and controls with 80% accuracy. OPFs are odorant independent. Patients perceived odors as less familiar, less intense, and less edible than controls. Other perceptual descriptors were much less important for the separation of patients and controls. 3.

Adherence to olfactory training improves orthonasal and retronasal olfaction in post-COVID-19 olfactory loss.

Olfactory loss (OL) has emerged as one of the most prevalent and debilitating symptoms of SARS-CoV-2 infection and long-COVID-19. The present prospective observational study aimed to evaluate the efficacy of olfactory training (OT) on orthonasal and retronasal olfactory function in a cohort of individuals with persistent post-COVID-19 OL. Participants with post-COVID-19 olfactory impairment underwent 4 months of OT, self-assessing their smell perception and undergoing comprehensive psychophysical evaluation of orthonasal and retronasal olfaction at baseline and after training. Orthonasal olfactory function was assessed using the extended Sniffin' Sticks test battery. Retronasal olfactory function was tested with powdered aromas. Among 114 participants with post-COVID-19 olfactory loss, adherence to OT was 60%. In adherents, the average increase in composite TDI score was 6.0 points compared to 2.6 points in non-adherents. Fifty-seven percent of adherent participants achieved a clinically significant improvement in TDI score (≥5.5 points), compared to 22% of non-adherents. In retronasal olfactory identification, 56% of adherents achieved a clinically significant improvement (≥4 points), compared to 16% of non-adherents. Adherence to a 4-month OT regimen can yield clinically meaningful improvements in both orthonasal and retronasal olfactory function among individuals with persistent post-COVID-19 olfactory dysfunction.

Genome-wide association analysis of hypertension and epigenetic aging reveals shared genetic architecture and identifies novel risk loci

Hypertension is a disease associated with epigenetic aging. However, the pathogenic mechanism underlying this relationship remains unclear. We aimed to characterize the shared genetic architecture of hypertension and epigenetic aging, and identify novel risk loci. Leveraging genome-wide association studies (GWAS) summary statistics of hypertension (129,909 cases and 354,689 controls) and four epigenetic clocks (N = 34,710), we investigated genetic architectures and genetic overlap using bivariate casual mixture model and conditional/conjunctional false discovery rate methods. Functional gene-sets pathway analyses were performed by functional mapping and gene annotation (FUMA) protocol. Hypertension was polygenic with 2.8 K trait-influencing genetic variants. We observed cross-trait genetic enrichment and genetic overlap between hypertension and all four measures of epigenetic aging. Further, we identified 32 distinct genomic loci jointly associated with hypertension and epigenetic aging. Notably, rs1849209 was shared between hypertension and three epigenetic clocks (HannumAge, IEAA, and PhenoAge). The shared loci exhibited a combination of concordant and discordant allelic effects. Functional gene-set analyses revealed significant enrichment in biological pathways related to sensory perception of smell and nervous system processes. We observed genetic overlaps with mixed effect directions between hypertension and all four epigenetic aging measures, and identified 32 shared distinct loci with mixed effect directions, 25 of which were novel for hypertension. Shared genes enriched in biological pathways related to olfaction.

Development of a noninvasive olfactory stimulation fMRI system in marmosets

Olfactory dysfunction is associated with aging and the earliest stages of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases; it is thought to be an early biomarker of cognitive decline. In marmosets, a small non-human primate model used in brain research, olfactory pathway activity during olfactory stimulation has not been well studied because of the difficulty in clearly switching olfactory stimuli inside a narrow MRI. Here, we developed an olfactory-stimulated fMRI system using a small-aperture MRI machine. The olfactory presentation system consisted of two tubes, one for supply and one for suction of olfactory stimulants and a balloon valve. A balloon valve installed in the air supply tube controlled the presentation of the olfactory stimulant, which enabled sharp olfactory stimulation within MRI, such as 30 s of stimulation repeated five times at five-minute intervals. The olfactory stimulation system was validated in vivo and in a simulated system. fMRI analysis showed a rapid increase in signal values within 30 s of olfactory stimulation in eight regions related to the sense of smell. As these regions include those associated with Alzheimer’s and Parkinson’s diseases, olfactory stimulation fMRI may be useful in clarifying the relationship between olfactory dysfunction and dementia in non-human primates.

Identification of nonsense variants in the genomes of 15 Murciano-Granadina bucks and analysis of their segregation in parent-offspring trios

Nonsense variants can inactivate gene function by causing the synthesis of truncated proteins or by inducing nonsense mediated decay of messenger RNAs. The occurrence of such variants in the genomes of livestock species is modulated by multiple demographic and selective factors. Even though nonsense variants can have causal effects on embryo lethality, abortions, and disease, their genomic distribution and segregation in domestic goats have not been characterized in depth yet. In this work, we have sequenced the genomes of 15 Murciano-Granadina bucks with an average coverage of 32.92 × ± 1.45 × . Bioinformatic analysis revealed 947 nonsense variants consistently detected with SnpEff and Ensembl-VEP. These variants were especially abundant in the 3'end of the protein-coding regions. Genes related to olfactory perception, ATPase activity coupled to transmembrane movement of substances, defense to virus, hormonal response, and sensory perception of taste were particularly enriched in nonsense variants. Seventeen nonsense variants expected to have harmful effects on fitness were genotyped in parent-offspring trios. We observed that several nonsense variants predicted to be lethal based on mouse knockout data did not have such effect, a finding that could be explained by the existence of multiple mechanisms counteracting lethality. These findings demonstrate that predicting the effects of putative nonsense variants on fitness is extremely challenging. As a matter of fact, such a goal could only be achieved by generating a high quality telomere-to-telomere goat reference genome combined with carefully curated annotation and functional testing of promising candidate variants.

The validity of clinical guidelines and nasal endoscopy in the diagnosis of chronic rhinosinusitis—a prospective observational study

BackgroundChronic rhinosinusitis is a common disease entity seen by ENT surgeons as well as general practitioners all over the world. This study is aimed to evaluate and validate whether the clinical guideline symptoms (set by AAO-HNS 2015) alone and/or nasal endoscopic findings can predict the diagnosis of CRS, taking CT as the gold standard.MethodsA total of 118 patients with symptoms of chronic rhinosinusitis were taken. They were divided into two groups on the basis of whether they fulfilled the Guideline symptom criteria laid down by AAO-HNS in 2015 for diagnosing chronic rhinosinusitis. Each group underwent diagnostic nasal endoscopy (DNE), and patients with either purulence, edema in the middle meatus or ethmoid, and polyps in the nasal cavity or middle meatus were considered positive for DNE. A Lund-Mackay CT score of > 4 was considered diagnostic of CRS. Each group was analyzed separately. Sensitivity, specificity, and positive predictive value of guideline symptom with and without the addition of nasal endoscopy was recorded taking CT as the gold standard.ResultsNasal obstruction was the most common seen in all cases (100%) followed by headache in 45 (38.1%), facial pain in 32 (27.1%), anterior nasal discharge in 28 (23.7%), decreased sense of smell in 22 (18.6%), and posterior nasal discharge in 19 (16.1%). Two-thirds of patients (78, 66.1%) fulfilled the clinical guideline symptoms criteria, and one-third of patients (40, 33.9%) did not fulfill the clinical guideline symptoms criteria. A positive finding on DNE was found in 59.3% (n = 70) of patients. More than half of patients (62, 52.5%) had mild grade on endoscopic examination, while only 8 (6.8%) had moderate grade, and none had severe grade. Guideline symptoms have a high sensitivity (80%) but a low specificity (50.94%) in the diagnosis of CRS, with a fair level of agreement with CT diagnosis (Kappa = 0.32). DNE has a moderate sensitivity (72.31%) but a low specificity (56.60%) in the diagnosis of CRS, with a fair level of agreement with CT diagnosis (Kappa = 0.29). Sensitivity and specificity were 80.77% and 57.69% respectively when guideline symptoms and DNE findings are taken in series.ConclusionWe conclude that neither Guideline Symptom Criteria nor DNE is independently sufficient enough to have a high diagnostic accuracy for CRS. Comparing the diagnostic efficiency among various modalities, we report that in patients who meet guideline symptom criteria for CRS, the addition of nasal endoscopy turned out to be a cost-effective diagnostic approach and improves the diagnostic accuracy of DNE for CRS reasonably, hence should be emphasized as a diagnostic tool in the evaluation of patients for CRS.

Understanding Olfactory Perception and its Significance in The Exploration of Sensescape Scenarios in Asian Cities

Researchers and designers have begun to devote more time and energy to studying urban escape scenarios because they know how important it is to comprehend the complex ways in which people perceive and interact with the built environment. Olfaction, the sense of scent, is an important part of this multimodal experience since it greatly influences how perceive and engage with the environment. The importance of smell is magnified in Asian urban settings since these places frequently offer a varied and varied sensory landscape, marked by a multitude of environmental, cultural, and gastronomic influences. Architects, urban planners, and legislators may develop more inclusive and responsive natural settings that cater to the multimodal demands of various people by understanding the function of olfactory perception in constructing the sensescape in these cities.

Distinct olfactory mucosal macrophage populations mediate neuronal maintenance and pathogen defense

The olfactory mucosa is important for both the sense of smell and as a mucosal immune barrier to the upper airway and brain. However, little is known about how the immune system mediates the conflicting goals of neuronal maintenance and inflammation in this tissue. A number of immune cell populations reside within the olfactory mucosa and yet we have little understanding of how these resident olfactory immune cells functionally interact with the chemosensory environment. Identifying these interactions will allow therapeutic manipulations that treat disorders such as post-viral olfactory dysfunction. Macrophages are the most prevalent immune cell type in the uninflamed olfactory mucosa and here, we identify two distinct tissue macrophage populations in murine olfactory mucosa. P2ry12hi macrophages are transcriptionally specialized for neuron interactions, closely associated with olfactory neuron cell bodies, long-term tissue residents, and functionally specialized to phagocytose cells and debris, including olfactory neurons. Conversely, MHC Class IIhi macrophages are transcriptionally dedicated to cytokine production and antigen presentation, localized primarily within the olfactory lamina propria, more rapidly replaced by blood monocytes, and rapidly produce chemokines in response to viral infection. We further show that these macrophage signatures are present in human olfactory biopsies, and P2ry12-like olfactory macrophages are reduced in patients with long-term smell loss following COVID-19. Together, these data show that two olfactory macrophage populations regulate neurons and initiate the immune response, contributing to our understanding of both olfactory immunity and tissue-resident macrophage biology.

Identification and characterization of olfactory gene families in Macrobrachium rosenbergii based on full-length transcripts and genome sequences

The olfactory gene families include odorant binding proteins (OBPs), chemosensory proteins (CSPs), olfactory receptors (ORs), ionotropic receptors (IRs) and gustatory receptors (GRs). To investigate the molecular function of olfactory perception in Macrobrachium rosenbergii, we integrated the full-length transcripts and whole-genome sequences to identify the olfactory gene families. In this study, a total of 38,955 full-length transcripts with an N50 length of 3383 bp were obtained through PacBio SMRT sequencing. Through the annotation of full-length transcripts and whole-genome sequences, several olfactory gene families were identified, including 18 MrORs, 16 MrIRs, 151 MrIGluRs (ionotropic glutamate receptors), 2 MrVIGluRs (variant ionotropic glutamate receptors) and 3 MrCRs (chemosensory receptors). Notably, the CRs were first identified in prawns and shrimps. Additionally, the olfactory gene families in M. nipponense were identified, comprising 4 MnORs, 21 MnIRs, 79 MnIGluRs, 5 MnVIGluRs, 1 MnGR and 1 MnOBP, using the available whole-genome sequences. Meanwhile, the external morphology of the chemical sensory organs of M. rosenbergii was explored, and the presence of plumose setae (PS), hard thorn setae (HTS), bamboo shoot setae (BSS), soft thorn setae (STS) and aesthetascs (AE) on the antennules, HTS and BSS on the second antennae, and PS on the pereiopods were observed by scanning electron microscope. This study provides valuable insights for future functional studies into the olfactory perception of crustaceans and establishes a theoretical basis for molecular design breeding in M. rosenbergii.

Predicting multiple taste sensations with a multiobjective machine learning method

Taste perception plays a pivotal role in guiding nutrient intake and aiding in the avoidance of potentially harmful substances through five basic tastes - sweet, bitter, umami, salty, and sour. Taste perception originates from molecular interactions in the oral cavity between taste receptors and chemical tastants. Hence, the recognition of taste receptors and the subsequent perception of taste heavily rely on the physicochemical properties of food ingredients. In recent years, several advances have been made towards the development of machine learning-based algorithms to classify chemical compounds’ tastes using their molecular structures. Despite the great efforts, there remains significant room for improvement in developing multi-class models to predict the entire spectrum of basic tastes. Here, we present a multi-class predictor aimed at distinguishing bitter, sweet, and umami, from other taste sensations. The development of a multi-class taste predictor paves the way for a comprehensive understanding of the chemical attributes associated with each fundamental taste. It also opens the potential for integration into the evolving realm of multi-sensory perception, which encompasses visual, tactile, and olfactory sensations to holistically characterize flavour perception. This concept holds promise for introducing innovative methodologies in the rational design of foods, including pre-determining specific tastes and engineering complementary diets to augment traditional pharmacological treatments.

Reinforced colour preference of parasitoid wasps in the presence of floral scent: a case study of a cross-modal effect

We examined the possibility of a cross-modal effect in naïve Cotesia vestalis, a parasitoid wasp of diamondback moth larvae, by using artificial flower models of four colours (blue, green, yellow, and red) in the absence or presence of floral scent collected from Brassica rapa inflorescences. In a four-choice test, regardless of the floral scent, non-starved female wasps visited green and yellow models significantly more often than blue and red ones, although no significant difference was observed between visits to the green and yellow models. They seldom visited blue and red models. When starved, the wasps became even more particular, visiting yellow significantly more frequently than green models, irrespective of the presence of the floral scent, indicating that they preferred to use yellow visual cues in their food search. Furthermore, a factorial analysis of variance revealed a significant effect of the interaction between model colour and floral scent on the wasps’ visits to flower models. The floral scent induced starved and non-starved wasps to visit yellow and green models about twice as often as without the scent. A cross-modal effect of olfactory perception on the use of chromatic information by wasps may allow them to search efficiently for food sources.