Sensory input from osphradium is involved in fluoride detection that alters feeding and memory phenotype in Lymnaea stagnalis.

Fluoride (F-) exposure in organisms remains a significant concern due to its widespread presence and potential health implications. Investigating its detection and subsequent effects on behaviour in aquatic organisms like Lymnaea stagnalis provides valuable insights. Our study focused on elucidating the sensory pathways involved in F- detection and its impact on feeding and memory formation. We explored two potential detection mechanisms: direct flow across the integument onto neurons; and sensory input to the central nervous system (CNS) via the osphradium-osphradial ganglion-osphradial nerve pathway (snails use this system for olfactory sensation of multiple compounds). Injection of F- into snails did not alter feeding behaviour or central neuronal activity, suggesting that internalization might not be the primary detection mode. In contrast, severing the osphradial nerve abolished F-'s suppressive effects on feeding and memory formation, implicating the osphradial pathway in F- sensing and behavioural changes. This finding supports the idea that osphradial nerve signaling mediates the behavioural effects of F-. Our study underscores the importance of sensory pathways in F- detection and behavioural modulation in L. stagnalis. Understanding these mechanisms could provide critical insights into how organisms respond to and adapt to environmental chemical stressors like F-.

Screening olfaction under dupilumab in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) frequently leads to olfactory dysfunction. This study aimed to assess the impact of dupilumab on CRSwNP patients, focusing on olfactory outcomes and potential correlations with other clinical factors. METHODS: CRSwNP patients eligible for dupilumab therapy received subcutaneous Dupixent® injections every two weeks (300mg/2ml dupilumab). The 12-item Sniffin' Sticks Test (SST-12), fractional exhaled nitric oxide (FeNO) and Nasal Polyp Score (NPS) were assessed at baseline and after one, three, and six months. Patients also completed the Sino-Nasal Outcome Test (SNOT-22) weekly. RESULTS: 26 CRSwNP patients were included. After one month, dupilumab led to substantial reductions in FeNO, SNOT scores, andNPS, whereas SST-12 scores improved significantly only after three months. A shift toward normosmia occurred, with 81% achieving normosmia after six months, and a drop in anosmia prevalence to 9.5%. Significant negative correlations between olfaction (SST-12) and polyp severity (NPS) at baseline and after six months were found, while no significant correlations were observed between SST-12 and FeNO or SNOT scores. Age did not correlate with olfaction. CONCLUSIONS: Dupilumab demonstrated efficacy in restoring olfaction in CRSwNP patients. Reaching normosmia in over 80% ofpatients after six months of treatment underscores the drug's effectiveness in managing this challenging symptom.

Oxytocin induces the formation of distinctive cortical representations and cognitions biased toward familiar mice.

Social recognition is essential for the formation of social structures. Many times, recognition comes with lesser exploration of familiar animals. This lesser exploration has led to the assumption that recognition may be a habituation memory. The underlying memory mechanisms and the thereby acquired cortical representations of familiar mice have remained largely unknown, however. Here, we introduce an approach directly examining the recognition process from volatile body odors among male mice. We show that volatile body odors emitted by mice are sufficient to identify individuals and that more salience is assigned to familiar mice. Familiarity is encoded by reinforced population responses in two olfactory cortex hubs and communicated to other brain regions. The underlying oxytocin-induced plasticity promotes the separation of the cortical representations of familiar from other mice. In summary, neuronal encoding of familiar animals is distinct and utilizes the cortical representational space more broadly, promoting storage of complex social relationships.

Mice learn to identify and discriminate sugar solutions based on odor cues.

This study examined how olfaction impacts ingestive responses of mice to sugar solutions. Experiment 1 asked whether naïve C57BL/6 (B6) mice could identify 1 M glucose, fructose, or sucrose solutions based on odor cues, during a 30-min 2-bottle acceptability test. We tested mice both before and after they were rendered anosmic with ZnSO4 treatment. We used 2 indirect measures of odor-mediated response: number of trials initiated and latency to initiate licking. Before ZnSO4 treatment, the mice learned how to identify 1 M glucose and fructose (but not sucrose) solutions based on odor cues. ZnSO4 treatment eliminated their ability to identify the glucose and fructose solutions. Experiment 2 asked whether 2 d of exposure to a 1 M glucose, fructose, or sucrose solution improved the identification of the same sugar solution. Following exposure, the B6 mice identified all 3 sugar solutions based on odor cues. Experiment 3 asked whether T1R3 knockout mice (i.e. mice lacking the T1R3 subunit of the T1R2 + R3 sweet taste receptor) could learn to discriminate 0.44 M glucose and fructose solutions based on odor cues. All mice were subjected to a 1-h preference test, both before and after exposure to the 0.44 M glucose and fructose solutions. During exposure, the experimental mice received ZnSO4 treatment, whereas the control mice received saline treatment. Before exposure, neither type of mouse preferred the glucose solution. After exposure, the control mice preferred the glucose solution, whereas the experimental mice did not. Our results reveal that mice can learn to use odor cues to identify and discriminate between sugar solutions.

Steroid responsiveness predicts olfactory function recovery in dupilumab treated CRSwNP.

BACKGROUND: There is no known predictor for olfactory function recovery with dupilumab treatment in chronic rhinosinusitis with nasal polyps (CRSwNP). This study assessed whether patient-reported recovery of olfactory function on oral corticosteroids (OCS) is a prognostic factor. METHODS: Retrospective analysis of pre-biological OCS-responsiveness on olfactory functioning (OCS-responsive or OCS-unresponsive; OCS-r and OCR-u, respectively) as predictor for olfactory functioning after 6 months of dupilumab therapy for severe CRSwNP. RESULTS: 212 CRSwNP patients treated with dupilumab were divided between OCS-r (reported improvement of olfactory function with OCS before dupilumab treatment, n = 152), and OCS-u (OCS-unresponsive; no such improvement, n = 60). Olfactory function was tested with Sniffin's Sticks Identification Test (12 pens; SSIT-12). At baseline, both groups had a median SSIT-12 score of 3 / 12 indicating anosmia. Hyposmia and normosmia rates were also comparable (5.9% and 3.3% in OCS-r, respectively; 5.0% and 1.7% in OCS-u, respectively). After 6 months of dupilumab treatment, OCS-r showed higher olfactory scores (median SSIT-12: 8/12; 52.6% hyposmia and 17.8% normosmia) than OCS-u (median SSIT-12: 5/12; 31.7% hyposmia and 3.3% normosmia). The positive predictive value of OCS-responsiveness on scoring <7 (normosmia/hyposmia) on the SSIT-12 after 6 months of dupilumab treatment was 70.4%. Conversely, the negative predictive value of OCS-unresponsiveness on scoring <7 (anosmia) on the SSIT-12 after 6 months of dupilumab treatment was 65.0%. CONCLUSION: Patients who report olfactory function improvement on OCS have a higher chance of recovery of olfactory function during the first six months of treatment with dupilumab than patients who do not.

Effects of water quality on palladium-induced olfactory toxicity and bioaccumulation in rainbow trout (Oncorhynchus mykiss).

Through emission processes, palladium (Pd) particulates from industrial sources are introduced into a range of ecosystems including freshwater environments. Despite this, research on Pd-induced bioaccumulation, uptake, and toxicity is limited for freshwater fishes. Unlike other metals, there are currently no regulations or protective guidelines to limit Pd release into aquatic systems, indicating a global absence of measures addressing its environmental impact. To assess the olfactory toxicity potential of Pd, the present study aimed to explore Pd accumulation in olfactory tissues, olfactory disruption, and oxidative stress in rainbow trout (Oncorhynchus mykiss) following waterborne Pd exposure. Olfactory sensitivity, measured by electro-olfactography, demonstrated that Pd inhibits multiple pathways of the olfactory system following 96 h of Pd exposure. In this study, the concentrations of Pd for inhibition of olfactory function by 20% (2.5 µg/L; IC20) and 50% (19 µg/L; IC50) were established. Rainbow trout were then exposed to IC20 and IC50 Pd concentrations in combination with varying exposure conditions, as changes in water quality alter the toxicity of metals. Independent to Pd, increased water hardness resulted in decreased olfactory perception owing to ion competition at the olfactory epithelium. No other environmental parameter in this study significantly influenced Pd-induced olfactory toxicity. Membrane-associated Pd was measured at the olfactory rosette and gill following exposure; however, this accumulation did not translate to oxidative stress as measured by the production of malondialdehyde. Our data suggest that Pd is toxic to rainbow trout via waterborne contamination near field-measured levels. This study further demonstrated Pd bioavailability and uptake at water-adjacent tissues, adding to our collective understanding of the toxicological profile of Pd. Taken together, our results provide novel insights into the olfactory toxicity in fish following Pd exposure. Integr Environ Assess Manag 2024;20:1407-1419. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

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.

Short term olfactory memory and olfactory function after inhalation anesthetic agents: a randomized clinical trial / Memória olfativa de curta duração e função olfativa após anestésicos inalatórios: estudo clínico randomizado

Abstract Background and objectives: This clinical trial aimed to evaluate the effects of two different inhalation anesthetic agents on postoperative olfactory memory and olfactory function in patients who underwent micro laryngeal surgery. Methods: This randomized prospective controlled study consisted of 102 consecutive patients with a voice disorder. The patients underwent micro laryngeal surgery for voice disorders under general anesthesia. Patients who did not meet inclusion criteria and/or declined to participate (n = 34) were excluded from the study. Patients were divided into two groups. Four patients from Group 1 and four patients from Group 2 were lost to follow-up. Group 1 (n = 30) received sevoflurane, and Group 2 (n = 30) received desflurane during anesthesia. We compared the results by performing the pre-op and post-op Connecticut Chemosensory Clinical Research Center Olfactory test. Results: Thirty-three patients (55%) were male and 27 (45%) were female. The mean age was 48.18 ± 13.88 years (range: 19‒70 years). Preoperative and postoperative olfactory functions did not show a significant difference within the groups postoperatively (p > 0.05). Preoperative and postoperative olfactory memory showed a significant decrease 3 hours after the surgery (p < 0.05). Conclusions: Olfactory functions and memory were not affected by desflurane in the early postoperative period. Although sevoflurane did not affect olfactory functions, it had a temporary negative effect on olfactory memory in the early postoperative period.

Resumo Introdução e objetivos: O estudo avaliou o efeito pós-operatório de dois agentes anestésicos inalatórios distintos na memória olfativa de curta duração e na função olfativa em pacientes submetidos à microcirurgia de laringe. Método: O estudo prospectivo controlado randomizado avaliou, consecutivamente, 102 pacientes com alteração vocal submetidos à microcirurgia de laringe sob anestesia geral. Trinta e quatro pacientes não obedeceram aos critérios de inclusão e/ou não aceitaram participar do estudo e foram excluídos. Os pacientes foram divididos em dois grupos. Quatro pacientes do Grupo 1 e quatro do Grupo 2 foram perdidos durante o seguimento. O Grupo 1 (n = 30) recebeu sevoflurano durante a anestesia e o Grupo 2 (n = 30), desflurano. Comparamos resultados pré e pós-operatórios de memória olfativa e funções olfativas, realizando o Connecticut Chemosensory Clinical Research Center Olfactory test. Resultados: Foram incluídos um total de 33 (55%) homens e 27 (45%) mulheres. A idade média foi 48,18 ± 13,88 anos (variação: 19-70 anos). As funções olfativas pré e pós-operatórias não apresentaram diferença estatisticamente significante dentro dos grupos no pós-operatório (p > 0,05). A memória olfativa pré e pós-operatória não mostrou diminuição estatisticamente significante quando avaliada três horas após a cirurgia (p< 0,05). Conclusões: Memória e funções olfativas não foram alteradas pelo desflurano no pós-operatório imediato. Embora o sevoflurano não tenha alterado as funções olfativas, causou efeito temporário negativo na memória olfativa no pós-operatório imediato.

Effects of isotretinoin on the olfactory function in patients with acne

Abstract: Background: Isotretinoin is a synthetic analog of vitamin A. Recent studies support a role for retinoic acid in the recovery of olfactory function following injury in mice. Objective: This study aimed at determining the effect of isotretinoin on olfactory function in patients who have acne and are otherwise healthy. Methods: Forty-five patients (aged 25-40 years) with acne were included in the study. All patients underwent a rhinological examination. Olfactory function was assessed by the Sniffin' Sticks Test. The test was assessed at baseline and in the third month of isotretinoin treatment. Results: Isotretinoin improved the performance of patients in the olfactory test. The SST score increased from 8.7±1.09 to 9.5±1.19 (p<0.001), prevalence of hyposmia decreased from 40% to 24% and normosmia increased from 60% to 75% (p=0.059). The percentage of patients whose olfactory function was categorized as "good" increased from 6% to 21.3%. This increase was statistically significant (p<0.05). Study limitations: Absence of a control group is one of the limitations of this study. Also, we did not evaluate patients with smell test after stopping isotretinoin treatment. Conclusion: We examined the effect of systemic isotretinoin on olfactory function. It can be concluded from the present investigation that isotretinoin therapy improves the sense of smell.

Fatores que alteram a percepção gustativa / Factors that alter taste perception

A disfunção da percepção gustativa é um problema significativo para muitos indivíduos. Anomalias do gosto podem afetar a saúde não somente pelos efeitos diretos sobre a ingestão de alimentos líquidos e sólidos, mas também devido à perda da moral associada à privação de uma importante fonte de prazer. Inúmeros fatores alteram a percepção gustativa, a saber: lesões na mucosa oral, cigarro, radiação, quimioterapia, enfermidade renal, hepatite, lepra, hormônios, nutrição, prótese total, medicamentos e idade. Muitas idéias simples podem ser sugeridas a pacientes com alterações de gosto. A mastigação de goma ou de gelo pode atuar como uma ajuda temporária na hipogeusia. Os pacientes devem ser encorajados a mastigar seus alimentos muito bem, alterando os lados de sua boca ou então os seus alimentos. Infelizmente, em muitos casos, não há cura para esta alteração, a paciência é freqüentemente o último recurso