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Landry C, Nazar R, Simon M, Genest F, Giguère FL, Lepore F, Frasnelli J. Behavioural evidence for enhanced olfactory and trigeminal perception in congenital hearing loss. Eur J Neurosci 2024; 59:434-445. [PMID: 38185810 DOI: 10.1111/ejn.16216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 11/05/2023] [Accepted: 11/20/2023] [Indexed: 01/09/2024]
Abstract
Sensory deprivation, especially hearing loss (HL), offers a valuable model for studying neuroplasticity in the human brain and adaptive behaviours that support the daily lives of those with limited or absent sensory input. The study of olfactory function is particularly important as it is an understudied aspect of sensory deprivation. This study aimed to compare the effects of congenital HL on olfactory capacity by using psychophysical tasks. Methodological concerns from previous studies regarding the onset of HL and cognitive assessments were addressed. We recruited 11 individuals with severe-to-profound sensorineural HL (SNHL) since birth and 11 age- and sex-matched typical hearing non-signers. We used standardized neuropsychological tests to assess typical cognition among participants with SNHL. We evaluated olfactory functions by assessing olfactory detection threshold, odour discrimination and odour identification. Hearing-impaired participants outperformed their typical hearing counterparts in olfactory tasks. We further evaluated the accuracy and response time in identifying and localizing odours to disentangle olfactory sensitivity from trigeminal system sensitivity. Participants with SNHL demonstrated higher sensitivity to both the identification and localization tasks. These findings suggest that congenital SNHL is associated with enhanced higher-level olfactory processing and increased trigeminal sensitivity.
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Affiliation(s)
- Catherine Landry
- Département de Psychologie, Université de Montréal, Montréal, QC, Canada
| | - Rim Nazar
- Département de Psychologie, Université de Montréal, Montréal, QC, Canada
- Research Institute of the MUHC, Montréal, QC, Canada
| | - Marie Simon
- Département de Psychologie, Université de Montréal, Montréal, QC, Canada
| | - François Genest
- Département de Psychologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Fanny Lécuyer Giguère
- Département de Psychologie, Université de Montréal, Montréal, QC, Canada
- Centre de recherche de l'hôpital Sacré-Coeur de Montréal, Montréal, QC, Canada
| | - Franco Lepore
- Département de Psychologie, Université de Montréal, Montréal, QC, Canada
| | - Johannes Frasnelli
- Département de Psychologie, Université de Montréal, Montréal, QC, Canada
- Centre de recherche de l'hôpital Sacré-Coeur de Montréal, Montréal, QC, Canada
- Département d'anatomie, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
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Genovese F, Xu J, Tizzano M, Reisert J. Quantifying Peripheral Modulation of Olfaction by Trigeminal Agonists. J Neurosci 2023; 43:7958-7966. [PMID: 37813571 PMCID: PMC10669757 DOI: 10.1523/jneurosci.0489-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 08/15/2023] [Accepted: 09/06/2023] [Indexed: 10/17/2023] Open
Abstract
In the mammalian nose, two chemosensory systems, the trigeminal and the olfactory mediate the detection of volatile chemicals. Most odorants are able to activate the trigeminal system, and vice versa, most trigeminal agonists activate the olfactory system as well. Although these two systems constitute two separate sensory modalities, trigeminal activation modulates the neural representation of an odor. The mechanisms behind the modulation of olfactory response by trigeminal activation are still poorly understood. We addressed this question by looking at the olfactory epithelium (OE), where olfactory sensory neurons (OSNs) and trigeminal sensory fibers co-localize and where the olfactory signal is generated. Our study was conducted in a mouse model. Both sexes, males and females, were included. We characterize the trigeminal activation in response to five different odorants by measuring intracellular Ca2+ changes from primary cultures of trigeminal neurons (TGNs). We also measured responses from mice lacking TRPA1 and TRPV1 channels known to mediate some trigeminal responses. Next, we tested how trigeminal activation affects the olfactory response in the olfactory epithelium using electro-olfactogram (EOG) recordings from wild-type (WT) and TRPA1/V1-knock out (KO) mice. The trigeminal modulation of the olfactory response was determined by measuring responses to the odorant, 2-phenylethanol (PEA), an odorant with little trigeminal potency after stimulation with a trigeminal agonist. Trigeminal agonists induced a decrease in the EOG response to PEA, which depended on the level of TRPA1 and TRPV1 activation induced by the trigeminal agonist. This suggests that trigeminal activation can alter odorant responses even at the earliest stage of the olfactory sensory transduction.SIGNIFICANCE STATEMENT Most odorants reaching the olfactory epithelium (OE) can simultaneously activate olfactory and trigeminal systems. Although these two systems constitute two separate sensory modalities, trigeminal activation can alter odor perception. Here, we analyzed the trigeminal activity induced by different odorants proposing an objective quantification of their trigeminal potency independent from human perception. We show that trigeminal activation by odorants reduces the olfactory response in the olfactory epithelium and that such modulation correlates with the trigeminal potency of the trigeminal agonist. These results show that the trigeminal system impacts the olfactory response from its earliest stage.
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Affiliation(s)
| | - Jiang Xu
- Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104
| | - Marco Tizzano
- Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104
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Federica G, Jiang X, Marco T, Johannes R. Quantifying peripheral modulation of olfaction by trigeminal agonists. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.13.532477. [PMID: 36993353 PMCID: PMC10054987 DOI: 10.1101/2023.03.13.532477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
In the mammalian nose, two chemosensory systems, the trigeminal and the olfactory mediate the detection of volatile chemicals. Most odorants in fact are able to activate the trigeminal system, and vice versa, most trigeminal agonists activate the olfactory system as well. Although these two systems constitute two separate sensory modalities, trigeminal activation modulates the neural representation of an odor. The mechanisms behind the modulation of olfactory response by trigeminal activation are still poorly understood. In this study, we addressed this question by looking at the olfactory epithelium, where olfactory sensory neurons and trigeminal sensory fibers co-localize and where the olfactory signal is generated. We characterize the trigeminal activation in response to five different odorants by measuring intracellular Ca2+ changes from primary cultures of trigeminal neurons (TGNs). We also measured responses from mice lacking TRPA1 and TRPV1 channels known to mediate some trigeminal responses. Next, we tested how trigeminal activation affects the olfactory response in the olfactory epithelium using electro-olfactogram (EOG) recordings from WT and TRPA1/V1-KO mice. The trigeminal modulation of the olfactory response was determined by measuring responses to the odorant, 2-phenylethanol (PEA), an odorant with little trigeminal potency after stimulation with a trigeminal agonist. Trigeminal agonists induced a decrease in the EOG response to PEA, which depended on the level of TRPA1 and TRPV1 activation induced by the trigeminal agonist. This suggests that trigeminal activation can alter odorant responses even at the earliest stage of the olfactory sensory transduction.
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Affiliation(s)
| | - Xu Jiang
- Monell Chemical Senses Center, 19104 Philadelphia, PA, USA
| | - Tizzano Marco
- Monell Chemical Senses Center, 19104 Philadelphia, PA, USA
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Changes in smell and taste perception related to COVID-19 infection: a case-control study. Sci Rep 2022; 12:8192. [PMID: 35581235 PMCID: PMC9112641 DOI: 10.1038/s41598-022-11864-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 04/22/2022] [Indexed: 01/05/2023] Open
Abstract
The main aim of the present study was to psychophysically evaluate smell and taste functions in hospitalized COVID-19 patients and to compare those results with a group of healthy subjects. Another aim of the study was to assess the relationship of changes in patients’ smell and taste functions with a number of clinical parameters, symptoms, and other physiological signs as well as with severity of disease. Olfactory and gustatory functions were tested in 61 hospitalized patients positive for SARS-CoV-2 infection and in a control group of 54 healthy individuals. Overall, we found a significant impairment of olfactory and gustatory functions in COVID-19 patients compared with the control group. Indeed, about 45% of patients self-reported complaints about or loss of either olfactory or gustatory functions. These results were confirmed by psychophysical testing, which showed a significantly reduced performance in terms of intensity perception and identification ability for both taste and smell functions in COVID-19 patients. Furthermore, gustatory and olfactory impairments tended to be more evident in male patients suffering from more severe respiratory failure (i.e., pneumonia with need of respiratory support need during hospitalization).
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Puleo S, Braghieri A, Pacelli C, Bendini A, Toschi TG, Torri L, Piochi M, Di Monaco R. Food Neophobia, Odor and Taste Sensitivity, and Overall Flavor Perception in Food. Foods 2021; 10:foods10123122. [PMID: 34945673 PMCID: PMC8702209 DOI: 10.3390/foods10123122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/07/2021] [Accepted: 12/14/2021] [Indexed: 01/25/2023] Open
Abstract
Smell, which allows us to gather information about the hedonic value of an odor, is affected by many factors. This study aimed to assess the relationship among individual factors, odor sensitivity, and enjoyment, and to evaluate how overall flavor perception and liking in actual food samples are affected by odor sensitivity. A total of 749 subjects, from four different Italian regions, participated in the study. The olfactory capabilities test on four odors (anise, banana, mint, and pine), as well as PROP (6-n-prpyl-2-thiouracil) status and food neophobia were assessed. The subjects were clustered into three groups of odor sensitivity, based on the perceived intensity of anise. The liking and intensity of the overall flavor were evaluated for four chocolate puddings with increasing sweetness (C1, C2, C3, and C4). The individual variables significantly affected the perceived intensity and liking of the odors. Even if all of the odor sensitivity groups perceived the more intensely flavored samples as the C1 and C4 chocolate puddings, the high-sensitivity group scored the global flavor of all of the samples as more intense than the low-sensitivity group. The low-sensitive subjects evaluated the liking of the sweeter samples with higher scores than the moderate-sensitive subjects, whereas the high-sensitive subjects gave intermediate scores. In conclusion, odor sensitivity plays a pivotal role in the perception and liking of real food products; this has to be taken into account in the formulation of new products, suitable for particular categories with reduced olfactory abilities.
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Affiliation(s)
- Sharon Puleo
- Department of Agricultural Sciences, Food Science and Technology Division, University of Naples Federico II, 80055 Portici, Italy; (S.P.); (R.D.M.)
| | - Ada Braghieri
- School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, 85100 Potenza, Italy;
- Correspondence: ; Tel.: +39-0971-205101
| | - Corrado Pacelli
- School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, 85100 Potenza, Italy;
| | - Alessandra Bendini
- Department of Agricultural and Food Sciences (DiSTAL), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; (A.B.); (T.G.T.)
| | - Tullia Gallina Toschi
- Department of Agricultural and Food Sciences (DiSTAL), University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; (A.B.); (T.G.T.)
| | - Luisa Torri
- Sensory and Consumer Science, University of Gastronomic Sciences, 12042 Pollenzo, Italy; (L.T.); (M.P.)
| | - Maria Piochi
- Sensory and Consumer Science, University of Gastronomic Sciences, 12042 Pollenzo, Italy; (L.T.); (M.P.)
| | - Rossella Di Monaco
- Department of Agricultural Sciences, Food Science and Technology Division, University of Naples Federico II, 80055 Portici, Italy; (S.P.); (R.D.M.)
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Piochi M, Dinnella C, Spinelli S, Monteleone E, Torri L. Individual differences in responsiveness to oral sensations and odours with chemesthetic activity: Relationships between sensory modalities and impact on the hedonic response. Food Qual Prefer 2021. [DOI: 10.1016/j.foodqual.2020.104112] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Patel D, Taudte RV, Nizio K, Herok G, Cranfield C, Shimmon R. Headspace analysis of E-cigarette fluids using comprehensive two dimensional GC×GC-TOF-MS reveals the presence of volatile and toxic compounds. J Pharm Biomed Anal 2021; 196:113930. [PMID: 33581591 DOI: 10.1016/j.jpba.2021.113930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/18/2021] [Accepted: 01/22/2021] [Indexed: 11/30/2022]
Abstract
The analysis of electronic cigarrete (E-cigarette) fluids by high performance liquid chromatography or gas chromatography (GC) coupled to mass spectrometry (MS), GC hyphenated to flame-ionisation detection, or nuclear magnetic resonance spectroscopy poses many challenges due to the complex matrix and extremely high number of compounds present. In order to overcome these challenges, this study focused on the detection of the multiple complex compounds classes produced by the pyrolysis of E-cigarette liquids using comprehensive two dimensional gas chromatography (GCxGC) coupled to time of flight (TOF)-MS. Gas samples were prepared by heating E-liquids inside aluminium tins for 5 min. The tins were placed in a sand bath, which was temperature controlled at 200 °C. The samples were collected using thermal desorption tubes connected to volatile organic compound (VOC) sampling pump attached and subsequently analysed using GCxGC-TOF-MS. The greater peak resolution obtained when using GCxGC-TOF-MS allowed to distinguish many toxic compounds and VOCs that could not be detected by the other methods mentioned above. As a result, a comprehensive list of volatile compounds emitted from E-cigarette fluids when heated was established, which might allow a better understanding of potential health effects of vaping. Heating E-liquids to moderate temperature results in the emission of over 1000 volatile compounds of which over 150 are toxic. These compounds are either present in the liquid or can be formed during storage or heating leading to a more complex volatile profile of E-cigarette liquids than previously assumed. The application of GCxGC-TOF-MS allows the elucidation of this profile and therefore a better understanding of possible health implications.
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Affiliation(s)
- Darshil Patel
- Centre for Forensic Science, University of Technology Sydney, Sydney, NSW, Australia; Department of Chimie-Biochimie-Physique, University du Quebec a Trois Rivieres, Trois Rivieres, Canada
| | - R Verena Taudte
- Centre for Forensic Science, University of Technology Sydney, Sydney, NSW, Australia; Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University, Erlangen, Nuremberg, Germany.
| | - Katie Nizio
- Centre for Forensic Science, University of Technology Sydney, Sydney, NSW, Australia
| | - George Herok
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Charles Cranfield
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Ronald Shimmon
- Centre for Forensic Science, University of Technology Sydney, Sydney, NSW, Australia
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Hossain MZ, Ando H, Unno S, Kitagawa J. Targeting Chemosensory Ion Channels in Peripheral Swallowing-Related Regions for the Management of Oropharyngeal Dysphagia. Int J Mol Sci 2020; 21:E6214. [PMID: 32867366 PMCID: PMC7503421 DOI: 10.3390/ijms21176214] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/22/2022] Open
Abstract
Oropharyngeal dysphagia, or difficulty in swallowing, is a major health problem that can lead to serious complications, such as pulmonary aspiration, malnutrition, dehydration, and pneumonia. The current clinical management of oropharyngeal dysphagia mainly focuses on compensatory strategies and swallowing exercises/maneuvers; however, studies have suggested their limited effectiveness for recovering swallowing physiology and for promoting neuroplasticity in swallowing-related neuronal networks. Several new and innovative strategies based on neurostimulation in peripheral and cortical swallowing-related regions have been investigated, and appear promising for the management of oropharyngeal dysphagia. The peripheral chemical neurostimulation strategy is one of the innovative strategies, and targets chemosensory ion channels expressed in peripheral swallowing-related regions. A considerable number of animal and human studies, including randomized clinical trials in patients with oropharyngeal dysphagia, have reported improvements in the efficacy, safety, and physiology of swallowing using this strategy. There is also evidence that neuroplasticity is promoted in swallowing-related neuronal networks with this strategy. The targeting of chemosensory ion channels in peripheral swallowing-related regions may therefore be a promising pharmacological treatment strategy for the management of oropharyngeal dysphagia. In this review, we focus on this strategy, including its possible neurophysiological and molecular mechanisms.
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Affiliation(s)
- Mohammad Zakir Hossain
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan;
| | - Hiroshi Ando
- Department of Biology, School of Dentistry, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano 399-0781, Japan;
| | - Shumpei Unno
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan;
| | - Junichi Kitagawa
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan;
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Erythropel HC, Jabba SV, DeWinter TM, Mendizabal M, Anastas PT, Jordt SE, Zimmerman JB. Formation of flavorant-propylene Glycol Adducts With Novel Toxicological Properties in Chemically Unstable E-Cigarette Liquids. Nicotine Tob Res 2020; 21:1248-1258. [PMID: 30335174 DOI: 10.1093/ntr/nty192] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 09/13/2018] [Indexed: 12/12/2022]
Abstract
INTRODUCTION "Vaping" electronic cigarettes (e-cigarettes) is increasingly popular with youth, driven by the wide range of available flavors, often created using flavor aldehydes. The objective of this study was to examine whether flavor aldehydes remain stable in e-cigarette liquids or whether they undergo chemical reactions, forming novel chemical species that may cause harm to the user. METHODS Gas chromatography was used to determine concentrations of flavor aldehydes and reaction products in e-liquids and vapor generated from a commercial e-cigarette. Stability of the detected reaction products in aqueous media was monitored by ultraviolet spectroscopy and nuclear magnetic resonance spectroscopy, and their effects on irritant receptors determined by fluorescent calcium imaging in HEK-293T cells. RESULTS Flavor aldehydes including benzaldehyde, cinnamaldehyde, citral, ethylvanillin, and vanillin rapidly reacted with the e-liquid solvent propylene glycol (PG) after mixing, and upward of 40% of flavor aldehyde content was converted to flavor aldehyde PG acetals, which were also detected in commercial e-liquids. Vaping experiments showed carryover rates of 50%-80% of acetals to e-cigarette vapor. Acetals remained stable in physiological aqueous solution, with half-lives above 36 hours, suggesting they persist when inhaled by the user. Acetals activated aldehyde-sensitive TRPA1 irritant receptors and aldehyde-insensitive TRPV1 irritant receptors. CONCLUSIONS E-liquids are potentially reactive chemical systems in which new compounds can form after mixing of constituents and during storage, as demonstrated here for flavor aldehyde PG acetals, with unexpected toxicological effects. For regulatory purposes, a rigorous process is advised to monitor the potentially changing composition of e-liquids and e-vapors over time, to identify possible health hazards. IMPLICATIONS This study demonstrates that e-cigarette liquids can be chemically unstable, with reactions occurring between flavorant and solvent components immediately after mixing at room temperature. The resulting compounds have toxicological properties that differ from either the flavorants or solvent components. These findings suggest that the reporting of manufacturing ingredients of e-liquids is insufficient for a safety assessment. The establishment of an analytical workflow to detect newly formed compounds in e-liquids and their potential toxicological effects is imperative for regulatory risk analysis.
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Affiliation(s)
- Hanno C Erythropel
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT.,Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT
| | - Sairam V Jabba
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT.,Department of Anesthesiology, Duke University School of Medicine, Durham, NC
| | - Tamara M DeWinter
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT.,Yale School of Forestry and Environmental Studies, Yale University, New Haven, CT
| | - Melissa Mendizabal
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT
| | - Paul T Anastas
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT.,Yale School of Forestry and Environmental Studies, Yale University, New Haven, CT.,Department of Chemistry, Yale University, New Haven, CT.,Yale School of Public Health, Yale University, New Haven, CT
| | - Sven E Jordt
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT.,Department of Anesthesiology, Duke University School of Medicine, Durham, NC
| | - Julie B Zimmerman
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT.,Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT.,Yale School of Forestry and Environmental Studies, Yale University, New Haven, CT
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11
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Schütz M, Oertel BG, Heimann D, Doehring A, Walter C, Dimova V, Geisslinger G, Lötsch J. Consequences of a human TRPA1 genetic variant on the perception of nociceptive and olfactory stimuli. PLoS One 2014; 9:e95592. [PMID: 24752136 PMCID: PMC4005389 DOI: 10.1371/journal.pone.0095592] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 03/28/2014] [Indexed: 01/13/2023] Open
Abstract
Background TRPA1 ion channels are involved in nociception and are also excited by pungent odorous substances. Based on reported associations of TRPA1 genetics with increased sensitivity to thermal pain stimuli, we therefore hypothesized that this association also exists for increased olfactory sensitivity. Methods Olfactory function and nociception was compared between carriers (n = 38) and non-carriers (n = 43) of TRPA1 variant rs11988795 G>A, a variant known to enhance cold pain perception. Olfactory function was quantified by assessing the odor threshold, odor discrimination and odor identification, and by applying 200-ms pulses of H2S intranasal. Nociception was assessed by measuring pain thresholds to experimental nociceptive stimuli (blunt pressure, electrical stimuli, cold and heat stimuli, and 200-ms intranasal pulses of CO2). Results Among the 11 subjects with moderate hyposmia, carriers of the minor A allele (n = 2) were underrepresented (34 carriers among the 70 normosmic subjects; p = 0.049). Moreover, carriers of the A allele discriminated odors significantly better than non-carriers (13.1±1.5 versus 12.3±1.6 correct discriminations) and indicated a higher intensity of the H2S stimuli (29.2±13.2 versus 21±12.8 mm VAS, p = 0.006), which, however, could not be excluded to have involved a trigeminal component during stimulation. Finally, the increased sensitivity to thermal pain could be reproduced. Conclusions The findings are in line with a previous association of a human TRPA1 variant with nociceptive parameters and extend the association to the perception of odorants. However, this addresses mainly those stimulants that involve a trigeminal component whereas a pure olfactory effect may remain disputable. Nevertheless, findings suggest that future TRPA1 modulating drugs may modify the perception of odorants.
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Affiliation(s)
- Michael Schütz
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
| | - Bruno G. Oertel
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
- Fraunhofer Institute of Molecular Biology and Applied Ecology - Project Group Translational Medcine and Pharmacology (IME-TMP), Frankfurt am Main, Germany
| | - Dirk Heimann
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
| | - Alexandra Doehring
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
| | - Carmen Walter
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
| | - Violeta Dimova
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
| | - Gerd Geisslinger
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
- Fraunhofer Institute of Molecular Biology and Applied Ecology - Project Group Translational Medcine and Pharmacology (IME-TMP), Frankfurt am Main, Germany
| | - Jörn Lötsch
- Institute of Clinical Pharmacology, Goethe - University, Frankfurt am Main, Germany
- Fraunhofer Institute of Molecular Biology and Applied Ecology - Project Group Translational Medcine and Pharmacology (IME-TMP), Frankfurt am Main, Germany
- * E-mail:
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Tabanca N, Avonto C, Wang M, Parcher JF, Ali A, Demirci B, Raman V, Khan IA. Comparative investigation of Umbellularia californica and Laurus nobilis leaf essential oils and identification of constituents active against Aedes aegypti. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:12283-12291. [PMID: 24266426 DOI: 10.1021/jf4052682] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Umbellularia californica (California bay laurel) and Laurus nobilis (Mediterranean bay laurel) leaves may be mistaken or used as a substitute on the market due to their morphological similarity. In this study, a comparison of anatomical and chemical features and biological activity of both plants is presented. L. nobilis essential oil biting deterrent and larvicidal activity were negligible. On the other hand, U. californica leaf oil showed biting deterrent activity against Aedes aegypti . The identified active repellents was thymol, along with (-)-umbellulone, 1,8-cineole, and (-)-α-terpineol. U. californica essential oil also demonstrated good larvicidal activity against 1-day-old Ae. aegypti larvae with a LD50 value of 52.6 ppm. Thymol (LD50 = 17.6 ppm), p-cymene, (-)-umbellulone, and methyleugenol were the primary larvicidal in this oil. Umbellulone was found as the principal compound (37%) of U. californica essential oil, but was not present in L. nobilis essential oil. Umbellulone mosquito activity is here reported for the first time.
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Affiliation(s)
- Nurhayat Tabanca
- National Center for Natural Products Research, University of Mississippi , University, Mississippi 38677, United States
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Saunders CJ, Li WY, Patel TD, Muday JA, Silver WL. Dissecting the role of TRPV1 in detecting multiple trigeminal irritants in three behavioral assays for sensory irritation. F1000Res 2013; 2:74. [PMID: 24358880 PMCID: PMC3814916 DOI: 10.12688/f1000research.2-74.v1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/04/2013] [Indexed: 01/11/2023] Open
Abstract
Polymodal neurons of the trigeminal nerve innervate the nasal cavity, nasopharynx, oral cavity and cornea. Trigeminal nociceptive fibers express a diverse collection of receptors and are stimulated by a wide variety of chemicals. However, the mechanism of stimulation is known only for relatively few of these compounds. Capsaicin, for example, activates transient receptor potential vanilloid 1 (TRPV1) channels. In the present study, wildtype (C57Bl/6J) and TRPV1 knockout mice were tested in three behavioral assays for irritation to determine if TRPV1 is necessary to detect trigeminal irritants in addition to capsaicin. In one assay mice were presented with a chemical via a cotton swab and their response scored on a 5 level scale. In another assay, a modified two bottle preference test, which avoids the confound of mixing irritants with the animal’s drinking water, was used to assess aversion. In the final assay, an air dilution olfactometer was used to administer volatile compounds to mice restrained in a double-chambered plethysmograph where respiratory reflexes were monitored. TRPV1 knockouts showed deficiencies in the detection of benzaldehyde, cyclohexanone and eugenol in at least one assay. However, cyclohexanone was the only substance tested that appears to act solely through TRPV1.
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Affiliation(s)
- C J Saunders
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA ; Rocky Mountain Taste and Smell Center, Neuroscience Program, Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Winston Y Li
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA
| | - Tulsi D Patel
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA
| | - Jeffrey A Muday
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA
| | - Wayne L Silver
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA
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Viana F. Chemosensory properties of the trigeminal system. ACS Chem Neurosci 2011; 2:38-50. [PMID: 22778855 PMCID: PMC3369707 DOI: 10.1021/cn100102c] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 12/14/2010] [Indexed: 11/28/2022] Open
Abstract
The capacity of cutaneous, including trigeminal endings, to detect chemicals is known as chemesthesis or cutaneous chemosensation. This sensory function involves the activation of nociceptor and thermoreceptor endings and has a protective or defensive function, as many of these substances are irritants or poisonous. However, humans have also developed a liking for the distinct sharpness or pungency of many foods, beverages, and spices following activation of the same sensory afferents. Our understanding of the cellular and molecular mechanisms of chemosensation in the trigeminal system has experienced enormous progress in the past decade, following the cloning and functional characterization of several ion channels activated by physical and chemical stimuli. This brief review attempts to summarize our current knowledge in this field, including a functional description of various sensory channels, especially TRP channels, involved in trigeminal chemosensitivy. Finally, some of these new findings are discussed in the context of the pathophysiology of trigeminal chemosensation, including pain, pruritus, migraine, cough, airway inflammation, and ophthalmic diseases.
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Affiliation(s)
- Félix Viana
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550, San Juan de Alicante, Spain.
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