Performance of a cost-effective olfactory test to evaluate hyposmia in Parkinson's disease patients.

BACKGROUND: Parkinson's disease (PD) causes motor and non-motor symptoms such as hyposmia, which is evaluated through olfactory tests in the clinical practice. OBJECTIVE: To assess the feasibility of using the modified Connecticut Chemosensory Clinical Research Center (mCCCRC) olfactory test and to compare its performance with the Sniffin' Sticks-12 (SS-12, Burghart Messtechnik GmbH, Wedel, Germany) test. METHODS: A transversal case-control study in which the patients were divided into the PD group (PDG) and the control group (CG). The cost and difficulty in handling substances to produce the mCCCRC test kits were evaluated. Sociodemographic characteristics, smoking habits, past coronavirus disease 2019 (COVID-19) infections, self-perception of odor sense, and cognition through the Montreal Cognitive Assessment (MoCA) were also evaluated. The PDG was scored by part III of the Unified Parkinson's Disease Rating Scale (UPDRS-III) and the Hoehn and Yahr Scale (H&Y) scale. Correlations were assessed through the Spearman rank correlation coefficient test (ρ, or rho). RESULTS: The mCCCRC test was easily manufactured and handled at a cost ten times lower compared with the SS-12. The groups (PDG: n = 34; CG: n = 38) were similar in terms of age, sex, level of schooling, smoking habits, and history of COVID-19. The tests results showed moderate correlation (rho = 0.65; p < 0.0001). The CG presented better cognitive performance and scored better in both tests (p < 0.0001). There was a tendency for a negative correlation with age, but good correlation with the MoCA (p = 0.0029). The results of the PDG group showed no correlation with olfactory results and motor performance or disease duration. The self-perception of hyposmia was low in both groups. CONCLUSION: The mCCCRC is an easy-to-apply and inexpensive method that demonstrated a similar performance to that of the SS-12 in evaluating olfaction in PD patients and healthy controls.

ANTECEDENTES: A doença de Parkinson (DP) cursa com sintomas motores e não motores como a hiposmia, que é avaliada por diferentes testes olfativos na prática clínica. OBJETIVO: Avaliar a viabilidade do teste olfatório Connecticut Chemosensory Clinical Research Center modificado (mCCCRC) e compará-la à do teste Sniffin' Sticks-12 (SS-12, Burghart Messtechnik GmbH, Wedel, Alemanha). MéTODOS: Estudo transversal de caso-controle em que os pacientes foram divididos no grupo DP (GDP) e no grupo controle (GC). O custo e as dificuldades no manuseio das substâncias necessárias para a produção dos kits do teste mCCCRC foram avaliados. Características sociodemográficas, tabagismo, histórico de infecção por doença do coronavírus 2019 (coronavírus disease 2019, COVID-19, em inglês), autopercepção do olfato e cognição pelo Montreal Cognitive Assessment (MoCA) também foram avaliados. O GDP foi avaliado pela parte III da Unified Parkinson's Disease Rating Scale (UPDRS-III) e pela escala de Hoehn and Yahr (H&Y). As correlações utilizaram o teste do coeficiente de correlação de postos de Spearman (ρ, ou rho). RESULTADOS: O mCCCRC foi facilmente poroduzido e manipulado com custo dez vezes inferior ao do SS-12. Os grupos (GDP: n = 34; GC: n = 38) eram similares em termos de idade, sexo, escolaridade, tabagismo e histórico de COVID-19. Os resultados obtidos em ambos os testes mostraram excelente correlação (rho = 0.65; p < 0.0001). O GC teve um desempenho cognitivo melhor e pontuou melhor nos dois testes (p < 0.0001). Houve uma tendência a uma correlação negativa com a idade, mas boa correlação com a pontuação no MoCA (p = 0.0029). Os resultados olfativos do GDP não mostraram correlação com desempenho motor ou duração da doença. A autopercepção de hiposmia foi baixa em ambos os grupos. CONCLUSãO: O mCCCRC é um teste de fácil aplicação, baixo custo, e apresentou um desempenho semelhante ao do SS-12 na avaliação olfativa de pacientes com DP e controles saudáveis.

Type 2 and Non-type 2 Inflammation in the Upper Airways: Cellular and Molecular Alterations in Olfactory Neuroepithelium Cell Populations.

PURPOSE OF REVIEW: Neurogenesis occurring in the olfactory epithelium is critical to continuously replace olfactory neurons to maintain olfactory function, but is impaired during chronic type 2 and non-type 2 inflammation of the upper airways. In this review, we describe the neurobiology of olfaction and the olfactory alterations in chronic rhinosinusitis with nasal polyps (type 2 inflammation) and post-viral acute rhinosinusitis (non-type 2 inflammation), highlighting the role of immune response attenuating olfactory neurogenesis as a possibly mechanism for the loss of smell in these diseases. RECENT FINDINGS: Several studies have provided relevant insights into the role of basal stem cells as direct participants in the progression of chronic inflammation identifying a functional switch away from a neuro-regenerative phenotype to one contributing to immune defense, a process that induces a deficient replacement of olfactory neurons. The interaction between olfactory stem cells and immune system might critically underlie ongoing loss of smell in type 2 and non-type 2 inflammatory upper airway diseases. In this review, we describe the neurobiology of olfaction and the olfactory alterations in type 2 and non-type 2 inflammatory upper airway diseases, highlighting the role of immune response attenuating olfactory neurogenesis, as a possibly mechanism for the lack of loss of smell recovery.

Effect of preservation versus resection of turbinate on olfactory function in endoscopic trans-nasal trans-sphenoidal pituitary surgery: a systematic review and meta-analysis.

BACKGROUND: Utilizing endoscopes in surgery offers advantages and concerns, including potential nasal function impacts. Hyposmia following Transseptal Transsphenoidal hypophysectomy ranges from 0% to 2.2%. Debates persist about managing the M.T. in endoscopic sinus surgery due to its impact on nasal function. While preservation is recommended for sinonasal health, debates continue, as certain cases require resection. Our meta-analysis aims to compare turbinate resection and preservation effects on olfactory function. METHODS: We searched five electronic databases to collect all relevant studies. Records were screened for eligibility. Data were extracted from the included studies independently. Our continuous outcomes were pooled as standardized mean difference with 95% CI. Statistical analyses was done by RevMan. RESULTS: Our meta-analysis included four studies involving 235 patients (81 males). Evaluating changes in olfaction scores, two one-month studies (82 patients) revealed no significant difference between preservation and resection groups (Std.MD = 0.05[-0.39, 0.50], p = 0.81). For three-month assessments (146 patients), SNOT tests indicated no significant difference (Std.MD = 0.21, 95% CI[-0.11, 0.54], p = 0.20). Two studies used other tests on 70 patients at three months, yielding no significant difference (Std.MD = 0.13, 95% CI [-0.35, 0.62], p = 0.59). Two six-month studies (72 patients) similarly found no significant difference (Std.MD = 0.09, 95% CI [-0.39, 0.56], p = 0.72). CONCLUSION: Our meta-analysis involving 235 patients examined olfaction score changes over various time frames in trans-nasal trans-sphenoidal pituitary surgeries. No significant differences were observed between turbinate preservation and resection groups at one month, three months, or six months post-surgery.

A method for detecting spatiotemporal patterns of cancer biomarkers-evoked activity using radial basis function network extracted time-domain features from calcium imaging data.

BACKGROUND: Two-photon calcium imaging is widely used to study the odor-evoked glomerular activity in the dorsal olfactory bulb of macrosmatic animals. The nonstationary character of activated patterns sets a limit on the use of a traditional image processing approaches. NEW METHOD: The developed method makes it possible to automatically map cancer biomarkers-activated glomeruli in the rat dorsal olfactory bulb. We interpolated fluorescence intensity of calcium dynamics based on the Gaussian RBF network and synthesized the physiological fluorescence model of the receptive glomerular field. RESULTS: The experiments on 5 rats confirmed the correctness of the developed approach. Patterns evoked by the 6-methyl-5-hepten-2-one (stomach cancer biomarker) and benzene (lung cancer biomarker) were correctly identified. COMPARISON WITH EXISTING METHODS: The proposed method was compared with the nonnegative matrix factorization method and with the method based on computer vision algorithms. The developed approach showed better accuracy in experiments and provided the mathematical models of the odor-evoked patterns synthesis. These models can be used to generate synthetic images of odor-evoked glomerular activity and thus to overcome the problem of small experimental data collected in calcium imaging. CONCLUSIONS: The proposed method should be considered part of the toolkit for fully automatic analysis of calcium imaging-based studies. Currently available methodology is not able to use breath biomarkers to reliably discriminate between cancer patients and healthy controls. Nevertheless, the effective identification of the spatial patterns of cancer biomarkers-evoked glomerular activity can serve as the foundation for highly sensitive biohybrid systems for cancer screening.

Does vaping affect the taste and smell perception? An exploratory study with New Zealand young adults.

OBJECTIVE: The study aimed to assess potential effects of vaping on individual taste and smell perception in a sample of young adult New Zealanders. DESIGN: This cross-sectional study measured taste and smell perception using intensity and hedonic ratings to two olfactory (i.e., vanillin, methional) and two gustatory stimuli (i.e., sucrose, monosodium glutamate), representing sweet and savoury flavours. Detection sensitivities to sucrose and vanillin were also assessed using a forced choice detection paradigm aligned with the signal detection framework. MANCOVAs were employed to compare sensory perception between groups based on vaping use frequency. Additional regression analyses were conducted to identify potential predictors of intensity and hedonic sensory ratings. SETTING: Participants were recruited from the University of Otago student population and surrounding neighbourhoods of Dunedin, New Zealand in 2023. PARTICIPANTS: The study included 213 university students (98 vapers and 115 non-vapers) RESULTS: We found a significant difference in hedonic ratings for vanillin, indicating a stronger preference among non-vapers. However, no other differences between the two groups were significant. Notably, the use of tobacco and mint flavours were emerged as significant predictors for hedonic responses to the savoury smell and sweet taste stimulus, respectively. No significant differences were observed between groups in the ability to detect weak stimuli. CONCLUSIONS: Our findings suggest that vape use, particularly with specific flavours, may be associated with alterations in hedonic responses to smells. This finding may have potential implications for how vaping affects on food preferences and dietary choices.

Mepolizumab improves sense of smell in severe chronic rhinosinusitis with nasal polyps: SYNAPSE.

BACKGROUND: Loss of smell is one of the most bothersome and difficult-to-treat symptoms in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). METHODOLOGY: SYNAPSE was a 52-week Phase III study of 4-weekly mepolizumab (100 mg subcutaneously) plus standard of care in adults with severe bilateral CRSwNP. This post hoc analysis assessed changes from baseline to study end in loss of smell visual analogue scale (VAS) symptom score, in patients stratified by several baseline clinical characteristics. SinoNasal Outcomes Test (SNOT)-22 sense of smell/taste item and University of Pennsylvania Smell Identification Test (UPSIT) scores were also assessed. RESULTS: SYNAPSE enrolled 407 patients (mepolizumab=206; placebo=201) with impaired sense of smell at baseline. Improvements from baseline to study end in loss of smell VAS score were greater with mepolizumab versus placebo (treatment difference: -0.37) and most notable in patients with fewer or more recent prior surgeries (treatment difference: 1 vs 2 vs more than 2 prior surgeries,-1.29 vs -0.23 vs -0.07; =3 years since last surgery, -.89 vs 0.22). Approximately 25% of patients had baseline UPSIT scoresavailable; among those scoring =19 by study end. The SNOT-22 sense of smell/taste item score improved with mepolizumab versus placebo. CONCLUSIONS: Mepolizumab treatment improved patients' perceived sense of smell, as measured by loss of smell VAS score and SNOT-22 sense of smell/taste item score in patients with severe refractory CRSwNP.

Olfactory status in neurodegeneration with brain iron accumulation disorders.

BACKGROUND: Olfactory dysfunction has been suggested as a diagnostic and discriminative biomarker in some neurodegenerative disorders. However, there are few studies regarding the olfactory status in rare diseases including neurodegeneration with brain iron accumulation (NBIA) disorders. METHODS: Genetically-confirmed NBIA patients were enrolled. Neurological and cognitive examinations were conducted according to the Pantothenate Kinase-Associated Neurodegeneration-Disease Rating Scale (PKAN-DRS) and the Mini-Mental State Examination (MMSE) questionnaire, respectively. Olfaction was assessed in three domains of odor threshold (OT), odor discrimination (OD), odor identification (OI), and total sum (TDI) score by the Sniffin' Sticks test. The olfactory scores were compared to a control group and a normative data set. RESULTS: Thirty-seven patients, including 22 PKAN, 6 Kufor Rakeb syndrome, 4 Mitochondrial membrane Protein-Associated Neurodegeneration (MPAN), 5 cases of other 4 subtypes, and 37 controls were enrolled. The mean PKAN-DRS score was 51.83±24.93. Sixteen patients (55.2%) had normal cognition based on MMSE. NBIA patients had significantly lower olfactory scores compared to the controls in TDI and all three subtests, and 60% of them were hyposmic according to the normative data. Including only the cognitively-normal patients, still, OI and TDI scores were significantly lower compared to the controls. The phospholipase A2-Associated Neurodegeneration (PLAN) and MPAN patients had a significantly lower OI score compared to the cognitively-matched PKAN patients. CONCLUSION: Olfactory impairment as a common finding in various subtypes of NBIA disorder can potentially be considered a discriminative biomarker. Better OI in PKAN compared to PLAN and MPAN patients may be related to the different underlying pathologies.

Trigeminal function in patients with COVID-associated olfactory loss.

PURPOSE: Olfactory dysfunction (OD) can be a long-term consequence of various viral infections, including COVID-19. Dysfunction includes hyposmia/anosmia and parosmia (odor distortions). Interactions of the virus with the olfactory nerve have been extensively researched, but little is known about the interactions of the intranasal trigeminal nerve system in modulating this sensory loss. METHODS: We investigated intranasal trigeminal function across COVID-19 OD patients with and without parosmia compared to normosmic controls, to determine whether (1) post-viral hyposmia and/or (2) post-viral hyposmia with parosmia is associated with altered trigeminal function. OD patients (n = 27) were tested for olfactory function using the extended Sniffin' Sticks olfactory test and for trigeminal function through three methods-odor lateralization, subjective ratings of nasal patency, and ammonium vapor pain intensity ratings. This group was subsequently compared to controls, normosmic subjects (n = 15). RESULTS: Our findings revealed that post-COVID OD patients without parosmia experienced decreased sensitivity in ammonium vapor pain intensity ratings and odor lateralization scores-but similar nasal patency ratings-compared to normosmic controls. There were no significant differences in trigeminal function between OD patients with and without parosmia. CONCLUSIONS: Based on our results, we conclude that the trigeminal nerve dysfunction may partially explain post-viral OD, but does not seem to be a major factor in the generation of parosmia pathophysiology.

Chronic rhinosinusitis and olfaction after highly effective modulator therapy: The role of individual sinus inflammation.

KEY POINTS: Individual sinus opacification (ISO) is measurable via a convolutional neural network approach. ISO decreased through 2 years after highly effective modulator therapy was initiated. In adults with cystic fibrosis, ISO did not correlate with quality of life or olfaction.

International clinical assessment of smell: An international, cross-sectional survey of current practice in the assessment of olfaction.

OBJECTIVES: Olfactory dysfunction (OD) is common and carries significant personal and societal burden. Accurate assessment is necessary for good clinical and research practice but is highly dependent on the assessment technique used. Current practice with regards to UK/international clinical assessment is unknown. We aimed to capture current clinical practice, with reference to contemporaneously available guidelines. We further aimed to compare UK to international practice. DESIGN: Anonymous online questionnaire with cross-sectional non-probability sampling. Subgroup analysis according to subspeciality training in rhinology ('rhinologists' and 'non-rhinologists') was performed, with geographical comparisons only made according to subgroup. PARTICIPANTS: ENT surgeons who assess olfaction. RESULTS: Responses were received from 465 clinicians (217 from UK and 17 countries total). Country-specific response rate varied, with the lowest rate being obtained from Japan (1.4%) and highest from Greece (72.5%). Most UK clinicians do not perform psychophysical smell testing during any of the presented clinical scenarios-though rhinologists did so more often than non-rhinologists. The most frequent barriers to testing related to service provision (e.g., time/funding limitations). Whilst there was variability in practice, in general, international respondents performed psychophysical testing more frequently than those from the UK. Approximately 3/4 of all respondents said they would like to receive training in psychophysical smell testing. Patient reported outcome measures were infrequently used in the UK/internationally. More UK respondents performed diagnostic MRI scanning than international respondents. CONCLUSIONS: To our knowledge, this is the most comprehensive UK-based, and only international survey of clinical practice in the assessment of OD. We present recommendations to improve practice, including increased education and funding for psychophysical smell testing. We hope this will promote accurate and reliable olfactory assessment, as is the accepted standard in other sensory systems.

Intra Nasal Use of Ethylene Diamine Tetra Acetic Acid for Improving Olfactory Dysfunction Post COVID-19.

BACKGROUND: COVID-19 has been associated with olfactory dysfunction in many infected patients. The rise of calcium levels in the nasal secretions plays an essential role in the olfaction process with a desensitization effect on the olfactory receptor neurons and a negative impact on the olfaction transmission. Ethylene diamine tetra acetic acid (EDTA) is a chelating agent that can bind free calcium in the nasal secretions, thereby reducing the adverse effects of calcium on olfactory function. OBJECTIVES: The objective of this work is to demonstrate the effect of intranasal EDTA on improving olfactory dysfunction following COVID-19. METHODS: Fifty patients with a history of COVID-19 and olfactory dysfunction that persisted for more than 6 months were enrolled in the current prospective randomized clinical trial. Participants were randomized into 2 equal groups. Twenty-five patients were treated with olfactory training only, while the remaining 25 patients received treatment with olfactory training and a topical nasal spray of ethylene diamine tetra acetic acid. The olfactory function was assessed before treatment and 3 months later using the Sniffin' Sticks test. Additionally, the determination of calcium level in the nasal secretions was performed using an ion-selective electrode before treatment and 3 months later. RESULTS: Eighty-eight percent of the patients treated with olfactory training in addition to EDTA exhibited clinical improvement, while 60% showed improvement in patients treated with olfactory training only. Furthermore, a significant decrease in the measured calcium level in the nasal secretions was demonstrated after the use of ethylene diamine tetra compared to patients treated with olfactory training only. CONCLUSION: Ethylene diamine tetra acetic acid may be associated with an improvement of the olfactory function post-COVID-19.

Active Tracking of Temporally Changing Gas-Phase Odor Mixture Using an Array of Cells Expressing Olfactory Receptors.

A cell expressing an olfactory receptor (OR) exhibits excellent odorant detection ability and thus is widely applied in odor biosensors. Most of those biosensors, however, could detect only liquid-phase nonchanging single-component odorants. In this paper, we raised up an odor biosensor for the active tracking of temporally changing gas-phase odor mixture by an array of cells expressing ORs. A thin stable liquid film covered the cell, thus allowing gas-phase odorants to penetrate. The online image processing generated individual cell brightness data which were used to compute the biosensor response. Based on the obtained responses, we adjusted the known odor components to be similar with the unknown odor. The function of our biosensor was validated by tracking the variable single-component odorant or the binary odor mixture. The influence from the sensor drift could be overcome by comparing the adjacent unknown and known odor responses. In the odor mixture quantification, adding the OR label to mixed cells and then quantifying separately (named as the pre-label method) was more efficient, while directly using the cell response pattern (named as the label-free method) was still capable even if the OR odor had cross-sensitivity.

Global olfactory function correlates with global sexual functioning in men and women.

BACKGROUND: Olfaction is intimately involved in reproductive behaviors. However, there is limited evidence about the relationship between olfactory and sexual functioning, and whether this relationship is modulated by gender. This study aimed to investigate the correlates between olfactory and sexual functioning in a cohort of young healthy individuals; secondary outcomes were the possible correlates between disgust and perceived vulnerability to illness, with particular relation to sexual attitudes. METHODS: Between January 2019 and December 2022, we enrolled 125 participants (51 males and 74 females) without known sexual disorders. The mean age was 28.47±8.6, and the mean Body Mass Index (BMI) was 23.86±3.3 without major disease or concomitant drug assumption, except for nutraceutical use. Olfactory sensitivity was tested with the Sniffin' Sticks Test (SST). Body Odor Disgust Scale (BODS) and Perceived Vulnerability to Disease (PVD) questionnaires were administered for the evaluation of perceived susceptibility to illness along with the Sexual Attitude Scale (SAS) for the evaluation of sexual attitudes. Sexual function was evaluated by the Female Sexual Function Index (FSFI) and International Index of Erectile Function (IIEF) questionnaires, respectively. RESULTS: Overall, a close relationship between sexual function and olfaction in both sexes (P<0.05) was found. In the male sample, better olfactive scores were positively correlated to all IIEF sub-domains but negatively with BMI and age, respectively (P<0.05). Moreover, olfaction was negatively correlated with a restrictive attitude towards sexuality (SAS) (P<0.05). The latter was also positively correlated with PVD (P<0.01). In the female sample, all FSFI subscales but sexual desire was positively correlated with olfaction (P<0.05). CONCLUSIONS: We herein confirm that olfactory capacities positively correlate with sexual behavior in both sexes. In males, these findings were mostly dependent upon increasing age and BMI. In females all domains of sexual function but sexual desire correlated with olfactory capacity, thus suggesting independent neural pathway activation for sexual desire. Finally, better olfactory capacities seem to determine sexual attitudes and disease avoidance behaviors irrespective of gender.

Orthonasal and retronasal odor identification in patients with parosmia.

OBJECTIVE: To compare retronasal and orthonasal perception in parosmic COVID-19 patients, in order to determine whether COVID-19 has a differential effect on these functions. METHODS: Using the Sniffin Sticks test battery orthonasal function was examined for odor threshold, discrimination and identification. Retronasal function was assessed using 20 tasteless aromatized powders. Gustatory function was measured using the Taste Strips test. RESULTS: This study included 177 patients (127 women, 50 men; mean age 45 years), of whom 127 (72%) were hyposmic and 50 (28%) normosmic. Compared to patients without parosmia, parosmic patients performed worse in odor identification for both orthonasal (F = 4.94, p = 0.03) and retronasal tests (F = 11.95, p < 0.01). However, an interaction effect between route of odor identification (orthonasal or retronasal) and parosmia status was found (F = 4.67, p = 0.03): patients with parosmia had relatively lower retronasal scores than patients without parosmia. CONCLUSION: Our results suggest that COVID-19 may affect the olfactory mucosa differently along the anterior-posterior axis, thereby possibly contributing to the pathophysiology of parosmia. Patients with parosmia also exhibit a higher degree of impairment when odors are presented through the retronasal route during eating and drinking.

Correlations between gustatory, trigeminal, and olfactory functions and nasal airflow.

PURPOSE: To determine the relationship of chemosensory screening and nasal airflow tests among the same set of participants, and to determine other factors that are related to the outcomes of these tests. METHODS: Participants had no chemosensory complaints. Structured medical history was taken. Participants underwent 5 screening tests: q-sticks (orthonasal olfaction), q-powders (retronasal olfaction), trigeminal lateralization test, taste sprays, and peak nasal inspiratory flow (PNIF). Ratings of smell/taste ability and nasal airflow were obtained using visual analogue scales (VAS). Composite sinusitis symptoms and significance of olfaction questionnaire scores were also determined. RESULTS: Four hundred participants were included in the study, 156 men, 244 women; aged 18-82 years (mean: 46). The q-powders and taste spray scores were weakly positively correlated with all the other chemosensory tests and PNIF. However, chemosensory test scores were not correlated with VAS, composite sinusitis symptoms, and significance of olfaction questionnaire scores. Various tests showed significant decrease starting at specific ages (in years, PNIF and trigeminal lateralization: 40, q-powders: 60, and q-sticks: 70). CONCLUSION: Chemosensory screening tests and self-rated chemosensory function showed no correlation in participants without chemosensory complaints. In addition, gustatory function appeared to be correlated with olfactory and trigeminal function but also with nasal airflow, and nasal airflow was related not only to olfactory but also to trigeminal and taste function. Over all, the results suggest that chemosensory functions (orthonasal olfactory, trigeminal, retronasal olfactory, gustatory) and nasal airflow are correlated with each other, which we propose may be possibly mediated, at least in part, through central nervous system interactions.

The Effects of Chronic Asprosin Administration on Sense of Smell and Sexual Behavior in Female Rats.

INTRODUCTION: Asprosin is an adipokine released from white adipose tissue during fasting and acts through the olfactory receptor. It is known that adipokines play roles in reproductive physiology in mammals. However, there are very few studies conducted on role of asprosin in reproductive functions. There are no studies on its relationship with sexual motivation. It was shown in the literature that administration of asprosin to male mice improves olfaction. It is also known that there is a strong correlation between smell and sexual desire. In view of this, it was hypothesized that chronic administration of asprosin would improve olfactory performance and increase sexual incentive motivation in female rats for male partners. METHODS: This hypothesis was tested by applying the hidden cookie test, sexual incentive test, active research test, and sexual behavior test. The changes in serum hormone levels in female rats that chronically received asprosin were also measured and compared. RESULTS: Chronic asprosin exposure increased olfactory performance, male preference ratio, male investigation preference ratio, activity index, and anogenital investigation behavior. Also, serum oxytocin and estradiol levels increased following chronic administration of asprosin in female rats. CONCLUSION: These data suggest that chronic administration of asprosin can result in increased sexual incentive motivation for opposite sex in female rats over increased olfactory performance and changes in reproductive hormones.

Body odor disgust sensitivity (BODS) is related to extreme odor valence perception.

Odors are important disease cues, and disgust sensitivity to body odors reflects individual differences in disease avoidance. The body odor disgust sensitivity (BODS) scale provides a rapid and valid assessment of individual differences. Nevertheless, little is known about how individual differences in BODS might correlate with overall odor perception or how it is related to other differences in emotional reactivity (e.g., affect intensity). We investigated how BODS relates to perceptual ratings of pleasant and unpleasant odors. We aggregated data from 4 experiments (total N = 190) that were conducted in our laboratory, and where valence and intensity ratings were collected. Unpleasant odors were body-like (e.g., sweat-like valeric acid), which may provide disease cues. The pleasant odors were, in contrast, often found in soap and cleaning products (e.g., lilac, lemon). Across experiments, we show that individuals with higher BODS levels perceived smells as more highly valenced overall: unpleasant smells were rated as more unpleasant, and pleasant smells were rated as more pleasant. These results suggest that body odor disgust sensitivity is associated with a broader pattern of affect intensity which causes stronger emotional responses to both negative and positive odors. In contrast, BODS levels were not associated with odor intensity perception. Furthermore, disgust sensitivity to odors coming from external sources (e.g., someone else's sweat) was the best predictor of odor valence ratings. The effects were modest in size. The results validate the BODS scale as it is explicitly associated with experimental ratings of odor valence.

Surgical Approaches for Possible Positions of an Olfactory Implant to Stimulate the Olfactory Bulb.

INTRODUCTION: Current scientific developments seem to allow for an "olfactory implant" in analogy to cochlear implants. However, the position and surgical approaches for electrical stimulation of the olfactory system are unclear. METHODS: In a human anatomic cadaver study, we investigated different endoscopic approaches to electrically stimulate the olfactory bulb (OB) based on the following considerations: (1) the stimulating electrode should be close to the OB. (2) The surgical procedure should be as non-invasive and safe as possible and (3) as easy as possible for an experienced ENT surgeon. RESULTS: In summary, the endoscopic intracranial positioning of the electrode via a widened ostium of the fila olfactoria or a frontal sinus surgery like a Draf IIb procedure is a good option in terms of patients' risk, degree of difficulty for ENT surgeons, and position to the OB. Endoscopic intranasal positioning appeared to be the best option in terms of patient risk and the degree of difficulty for ENT surgeons. Although a bigger approach to the OB using a drill and the combined intranasal endoscopic and external approach enabled a close placement of the electrode to the OB, they do not seem relevant in practice due to their higher invasiveness. CONCLUSION: The study suggested that an intranasal positioning of a stimulating electrode is possible, with placements beneath the cribriform plate, extra- or intracranially, applying elegant surgical techniques with low or medium risk to the patient and a close placement to OB.

Future therapeutic strategies for olfactory disorders: electrical stimulation, stem cell therapy, and transplantation of olfactory epithelium-an overview.

Olfactory disorders may be temporary or permanent and can have various causes. Currently, many COVID-19 patients report a reduced or complete loss of olfactory function. A wide range of treatment options have been investigated in the past, such as olfactory training, acupuncture, medical therapy, transcranial magnetic stimulation, or surgical excision of olfactory epithelium, e.g., in severe qualitative smell disorders. The development of a bioelectric nose, e.g., in connection with direct electrical stimulation or transplantation of olfactory epithelium or stem cells, represent treatment options of the future. The basis of these developments and the state of knowledge is discussed in the following work.

Relationship between the severity of olfactory dysfunction and serum zinc levels.

PURPOSE: Although the association between zinc deficiency and olfactory dysfunction is inconclusive, zinc deficiency causes apoptosis of the olfactory ensheathing cells which is involved in olfactory nerve turnover and axon regeneration, thereby suggesting a possible relationship. We investigated the relationship between serum zinc levels and olfactory function in patients with olfactory dysfunction. METHODS: Ninety patients who had been diagnosed with post-infectious, posttraumatic, drug-induced, neurological and idiopathic olfactory dysfunction were included. Patients were divided into zinc normal group and zinc deficiency groups according to three reference values for serum zinc levels (60, 65, 70 µg/dL). The results of olfactory tests and patient backgrounds were used to compare the differences between the two groups. RESULTS: There were significantly worse detection and recognition thresholds in the T&T olfactometer and Open Essence (odor identification test) results in the zinc deficiency group (< 60 µg/dL). In addition, significant correlations between olfactory tests (detection/recognition thresholds in the T&T olfactometer and Open Essence results) and serum zinc levels < 65 µg/dL were observed. The zinc deficiency group < 70 µg/dL with idiopathic olfactory dysfunction had significantly worse olfactory tests (detection/recognition thresholds in the T&T olfactometer and Open Essence). In addition, there was a significant correlation between the detection/recognition thresholds in the T&T olfactometer and serum zinc levels in idiopathic olfactory dysfunction. CONCLUSIONS: Our findings suggest that zinc deficiency may exacerbate the severity of olfactory dysfunction. Furthermore, idiopathic olfactory dysfunction may be partly caused by zinc deficiency.