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Reisert J, Pifferi S, Guarneri G, Ricci C, Menini A, Dibattista M. The Ca 2+-activated Cl - channel TMEM16B shapes the response time course of olfactory sensory neurons. J Physiol 2024. [PMID: 39167717 DOI: 10.1113/jp286959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 07/24/2024] [Indexed: 08/23/2024] Open
Abstract
Mammalian olfactory sensory neurons (OSNs) generate an odorant-induced response by sequentially activating two ion channels, which are in their ciliary membranes. First, a cationic, Ca2+-permeable cyclic nucleotide-gated channel is opened following odorant stimulation via a G protein-coupled transduction cascade and an ensuing rise in cAMP. Second, the increase in ciliary Ca2+ opens the excitatory Ca2+-activated Cl- channel TMEM16B, which carries most of the odorant-induced receptor current. While the role of TMEM16B in amplifying the response has been well established, it is less understood how this secondary ion channel contributes to response kinetics and action potential generation during single as well as repeated stimulation and, on the other hand, which response properties the cyclic nucleotide-gated (CNG) channel determines. We first demonstrate that basic membrane properties such as input resistance, resting potential and voltage-gated currents remained unchanged in OSNs that lack TMEM16B. The CNG channel predominantly determines the response delay and adaptation during odorant exposure, while the absence of the Cl- channels shortens both the time the response requires to reach its maximum and the time to terminate after odorant stimulation. This faster response termination in Tmem16b knockout OSNs allows them, somewhat counterintuitively despite the large reduction in receptor current, to fire action potentials more reliably when stimulated repeatedly in rapid succession, a phenomenon that occurs both in isolated OSNs and in OSNs within epithelial slices. Thus, while the two olfactory ion channels act in concert to generate the overall response, each one controls specific aspects of the odorant-induced response. KEY POINTS: Mammalian olfactory sensory neurons (OSNs) generate odorant-induced responses by activating two ion channels sequentially in their ciliary membranes: a Na+, Ca2⁺-permeable cyclic nucleotide-gated (CNG) channel and the Ca2⁺-activated Cl⁻ channel TMEM16B. The CNG channel controls response delay and adaptation during odorant exposure, while TMEM16B amplifies the response and influences the time required for the response to reach its peak and terminate. OSNs lacking TMEM16B display faster response termination, allowing them to fire action potentials more reliably during rapid repeated stimulation. The CNG and TMEM16B channels have distinct and complementary roles in shaping the kinetics and reliability of odorant-induced responses in OSNs.
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Affiliation(s)
| | - Simone Pifferi
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
| | - Giorgia Guarneri
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
| | - Chiara Ricci
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
| | - Anna Menini
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
| | - Michele Dibattista
- Department of Translational Biomedicine and Neuroscience, University of Bari Aldo Moro, Bari, Italy
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Ollitrault G, Achebouche R, Dreux A, Murail S, Audouze K, Tromelin A, Taboureau O. Pred-O3, a web server to predict molecules, olfactory receptors and odor relationships. Nucleic Acids Res 2024; 52:W507-W512. [PMID: 38661190 PMCID: PMC11223793 DOI: 10.1093/nar/gkae305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/04/2024] [Accepted: 04/23/2024] [Indexed: 04/26/2024] Open
Abstract
The sense of smell is a biological process involving volatile molecules that interact with proteins called olfactory receptors to transmit a nervous message that allows the recognition of a perceived odor. However, the relationships between odorant molecules, olfactory receptors and odors (O3) are far from being well understood due to the combinatorial olfactory codes and large family of olfactory receptors. This is the reason why, based on 5802 odorant molecules and their annotations to 863 olfactory receptors (human) and 7029 odors and flavors annotations, a web server called Pred-O3 has been designed to provide insights into olfaction. Predictive models based on Artificial Intelligence have been developed allowing to suggest olfactory receptors and odors associated with a new molecule. In addition, based on the encoding of the odorant molecule's structure, physicochemical features related to odors and/or olfactory receptors are proposed. Finally, based on the structural models of the 98 olfactory receptors a systematic docking protocol can be applied and suggest if a molecule can bind or not to an olfactory receptor. Therefore, Pred-O3 is well suited to aid in the design of new odorant molecules and assist in fragrance research and sensory neuroscience. Pred-O3 is accessible at ' https://odor.rpbs.univ-paris-diderot.fr/'.
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Affiliation(s)
| | | | - Antoine Dreux
- Inserm U1133, CNRS UMR 8251, Université Paris Cité, Paris, France
| | - Samuel Murail
- Inserm U1133, CNRS UMR 8251, Université Paris Cité, Paris, France
| | | | - Anne Tromelin
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
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3
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Takayama Y, Tominaga M. Interaction between TRP channels and anoctamins. Cell Calcium 2024; 121:102912. [PMID: 38823351 DOI: 10.1016/j.ceca.2024.102912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/27/2024] [Accepted: 05/27/2024] [Indexed: 06/03/2024]
Abstract
Anoctamin 1 (ANO1) binds to transient receptor potential (TRP) channels (protein-protein interaction) and then is activated by TRP channels (functional interaction). TRP channels are non-selective cation channels that are expressed throughout the body and play roles in multiple physiological functions. Studies on TRP channels increased after the identification of TRP vanilloid 1 (TRPV1) in 1997. Calcium-activated chloride channel anoctamin 1 (ANO1, also called TMEM16A and DOG1) was identified in 2008. ANO1 plays a major role in TRP channel-mediated functions, as first shown in 2014 with the demonstration of a protein-protein interaction between TRPV4 and ANO1. In cells that co-express TRP channels and ANO1, calcium entering cells through activated TRP channels causes ANO1 activation. Therefore, in many tissues, the physiological functions related to TRP channels are modulated through chloride flux associated with ANO1 activation. In this review, we summarize the latest understanding of TRP-ANO1 interactions, particularly interaction of ANO1 with TRPV4, TRP canonical 6 (TRPC6), TRPV3, TRPV1, and TRPC2 in the salivary glands, blood vessels, skin keratinocytes, primary sensory neurons, and vomeronasal organs, respectively.
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Affiliation(s)
- Yasunori Takayama
- Department of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo, Japan.
| | - Makoto Tominaga
- Division of Cell Signaling, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Aza-Higashiyama, Myodaiji, Okazaki, Aichi, Japan; Thermal Biology Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, 5-1 Aza-Higashiyama, Myodaiji, Okazaki, Aichi, Japan; Thermal Biology Research Group, Nagoya Advanced Research and Development Center, Nagoya City University, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, Japan.
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4
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Kawai F. Somatic ion channels and action potentials in olfactory receptor cells and vomeronasal receptor cells. J Neurophysiol 2024; 131:455-471. [PMID: 38264787 DOI: 10.1152/jn.00137.2023] [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: 04/02/2023] [Revised: 01/10/2024] [Accepted: 01/17/2024] [Indexed: 01/25/2024] Open
Abstract
Olfactory receptor cells are primary sensory neurons that catch odor molecules in the olfactory system, and vomeronasal receptor cells catch pheromones in the vomeronasal system. When odor or pheromone molecules bind to receptor proteins expressed on the membrane of the olfactory cilia or vomeronasal microvilli, receptor potentials are generated in their receptor cells. This initial excitation is transmitted to the soma via dendrites, and action potentials are generated in the soma and/or axon and transmitted to the central nervous system. Thus, olfactory and vomeronasal receptor cells play an important role in converting chemical signals into electrical signals. In this review, the electrophysiological characteristics of ion channels in the somatic membrane of olfactory receptor cells and vomeronasal receptor cells in various species are described and the differences between the action potential dynamics of olfactory receptor cells and vomeronasal receptor cells are compared.
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Affiliation(s)
- Fusao Kawai
- Department of Physiology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
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Velez Z, Hubbard PC, Alves A, Costa RA, Guerreiro PM. Environmental salinity modulates olfactory sensitivity in the euryhaline European seabass, Dicentrarchus labrax, acclimated to seawater and brackish water. J Exp Biol 2024; 227:jeb246448. [PMID: 38197261 DOI: 10.1242/jeb.246448] [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: 07/23/2023] [Accepted: 12/29/2023] [Indexed: 01/11/2024]
Abstract
The olfactory epithelium of fish is - of necessity - in intimate contact with the surrounding water. In euryhaline fish, movement from seawater to freshwater (and vice versa) exposes the epithelium to massive changes in salinity and ionic concentrations. How does the olfactory system function in the face of such changes? The current study compared olfactory sensitivity in seawater- (35‰) and brackish water-adapted seabass (5‰) using extracellular multi-unit recording from the olfactory nerve. Seawater-adapted bass had higher olfactory sensitivity to amino acid odorants when delivered in seawater than in freshwater. Conversely, brackish water-adapted bass had largely similar sensitivities to the same odorants when delivered in seawater or freshwater, although sensitivity was still slightly higher in seawater. The olfactory system of seawater-adapted bass was sensitive to decreases in external [Ca2+], whereas brackish water-adapted bass responded to increases in [Ca2+]; both seawater- and brackish water-adapted bass responded to increases in external [Na+] but the sensitivity was markedly higher in brackish water-adapted bass. In seawater-adapted bass, olfactory sensitivity to l-alanine depended on external Ca2+ ions, but not Na+; brackish water-adapted bass did respond to l-alanine in the absence of Ca2+, albeit with lower sensitivity, whereas sensitivity was unaffected by removal of Na+ ions. A possible adaptation of the olfactory epithelium was the higher number of mucous cells in brackish water-adapted bass. The olfactory system of seabass is able to adapt to low salinities, but this is not immediate; further studies are needed to identify the processes involved.
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Affiliation(s)
- Zélia Velez
- Comparative Endocrinology and Integrative Biology Group, Centre for Marine Sciences, University of Algarve, Campus of Gambelas, Building 7, 8005-139 Faro, Portugal
| | - Peter C Hubbard
- Comparative Endocrinology and Integrative Biology Group, Centre for Marine Sciences, University of Algarve, Campus of Gambelas, Building 7, 8005-139 Faro, Portugal
| | - Alexandra Alves
- Comparative Endocrinology and Integrative Biology Group, Centre for Marine Sciences, University of Algarve, Campus of Gambelas, Building 7, 8005-139 Faro, Portugal
| | - Rita A Costa
- Comparative Endocrinology and Integrative Biology Group, Centre for Marine Sciences, University of Algarve, Campus of Gambelas, Building 7, 8005-139 Faro, Portugal
| | - Pedro M Guerreiro
- Comparative Endocrinology and Integrative Biology Group, Centre for Marine Sciences, University of Algarve, Campus of Gambelas, Building 7, 8005-139 Faro, Portugal
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McLaren AMR, Kawaja MD. Olfactory Dysfunction and Alzheimer's Disease: A Review. J Alzheimers Dis 2024; 99:811-827. [PMID: 38728185 DOI: 10.3233/jad-231377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
Alzheimer's disease is the most common cause of dementia, and it is one of the leading causes of death globally. Identification and validation of biomarkers that herald the onset and progression of Alzheimer's disease is of paramount importance for early reliable diagnosis and effective pharmacological therapy commencement. A substantial body of evidence has emerged demonstrating that olfactory dysfunction is a preclinical symptom of neurodegenerative diseases including Alzheimer's disease. While a correlation between olfactory dysfunction and Alzheimer's disease onset and progression in humans exists, the mechanism underlying this relationship remains unknown. The aim of this article is to review the current state of knowledge regarding the range of potential factors that may contribute to the development of Alzheimer's disease-related olfactory dysfunction. This review predominantly focuses on genetic mutations associated with Alzheimer's disease including amyloid-β protein precursor, presenilin 1 and 2, and apolipoprotein E mutations, that may (in varying ways) drive the cellular events that lead to and sustain olfactory dysfunction.
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Affiliation(s)
| | - Michael D Kawaja
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, ON, Canada
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, ON, Canada
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7
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Hernandez-Clavijo A, Sánchez Triviño CA, Guarneri G, Ricci C, Mantilla-Esparza FA, Gonzalez-Velandia KY, Boscolo-Rizzo P, Tofanelli M, Bonini P, Dibattista M, Tirelli G, Menini A. Shedding light on human olfaction: Electrophysiological recordings from sensory neurons in acute slices of olfactory epithelium. iScience 2023; 26:107186. [PMID: 37456832 PMCID: PMC10345129 DOI: 10.1016/j.isci.2023.107186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/19/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023] Open
Abstract
The COVID-19 pandemic brought attention to our limited understanding of human olfactory physiology. While the cellular composition of the human olfactory epithelium is similar to that of other vertebrates, its functional properties are largely unknown. We prepared acute slices of human olfactory epithelium from nasal biopsies and used the whole-cell patch-clamp technique to record electrical properties of cells. We measured voltage-gated currents in human olfactory sensory neurons and supporting cells, and action potentials in neurons. Additionally, neuronal inward current and action potentials responses to a phosphodiesterase inhibitor suggested a transduction cascade involving cAMP as a second messenger. Furthermore, responses to odorant mixtures demonstrated that the transduction cascade was intact in this preparation. This study provides the first electrophysiological characterization of olfactory sensory neurons in acute slices of the human olfactory epithelium, paving the way for future research to expand our knowledge of human olfactory physiology.
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Affiliation(s)
- Andres Hernandez-Clavijo
- Neuroscience Area, SISSA, Scuola Internazionale Superiore di Studi Avanzati, 34136 Trieste, Italy
| | | | - Giorgia Guarneri
- Neuroscience Area, SISSA, Scuola Internazionale Superiore di Studi Avanzati, 34136 Trieste, Italy
| | - Chiara Ricci
- Neuroscience Area, SISSA, Scuola Internazionale Superiore di Studi Avanzati, 34136 Trieste, Italy
| | | | | | - Paolo Boscolo-Rizzo
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy
| | - Margherita Tofanelli
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy
| | - Pierluigi Bonini
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy
| | - Michele Dibattista
- Department of Translational Biomedicine and Neuroscience, University of Bari A. Moro, 70121 Bari, Italy
| | - Giancarlo Tirelli
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy
| | - Anna Menini
- Neuroscience Area, SISSA, Scuola Internazionale Superiore di Studi Avanzati, 34136 Trieste, Italy
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8
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Peng YJ, Nanduri J, Wang N, Kumar GK, Bindokas V, Paul BD, Chen X, Fox AP, Vignane T, Filipovic MR, Prabhakar NR. Hypoxia sensing requires H 2S-dependent persulfidation of olfactory receptor 78. SCIENCE ADVANCES 2023; 9:eadf3026. [PMID: 37406126 PMCID: PMC10321732 DOI: 10.1126/sciadv.adf3026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 05/31/2023] [Indexed: 07/07/2023]
Abstract
Oxygen (O2) sensing by the carotid body is critical for maintaining cardiorespiratory homeostasis during hypoxia. Hydrogen sulfide (H2S) signaling is implicated in carotid body activation by low O2. Here, we show that persulfidation of olfactory receptor 78 (Olfr78) by H2S is an integral component of carotid body activation by hypoxia. Hypoxia and H2S increased persulfidation in carotid body glomus cells and persulfidated cysteine240 in Olfr78 protein in heterologous system. Olfr78 mutants manifest impaired carotid body sensory nerve, glomus cell, and breathing responses to H2S and hypoxia. Glomus cells are positive for GOlf, adenylate cyclase 3 (Adcy3) and cyclic nucleotide-gated channel alpha 2 (Cnga2), key molecules of odorant receptor signaling. Adcy3 or Cnga2 mutants exhibited impaired carotid body and glomus cell responses to H2S and breathing responses to hypoxia. These results suggest that H2S through redox modification of Olfr78 participates in carotid body activation by hypoxia to regulate breathing.
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Affiliation(s)
- Ying-Jie Peng
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, IL, USA
| | - Jayasri Nanduri
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, IL, USA
| | - Ning Wang
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, IL, USA
| | - Ganesh K Kumar
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, IL, USA
| | - Vytautas Bindokas
- Department of Physiology and Pharmacological Sciences, Biological Sciences Division, University of Chicago, Chicago, IL, USA
| | - Bindu D Paul
- Department of Pharmacology, The Johns Hopkins University, Baltimore, MD, USA
| | - Xuanmao Chen
- Department of Molecular, Cellular and Biomedical Sciences, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH USA
| | - Aaron P Fox
- Department of Physiology and Pharmacological Sciences, Biological Sciences Division, University of Chicago, Chicago, IL, USA
| | - Thibaut Vignane
- Leibniz-Institut für Analytische Wissenschaften-ISAS, Bunsen-Kirchhoff-Straße, 1144139 Dortmund, Germany
| | - Milos R Filipovic
- Leibniz-Institut für Analytische Wissenschaften-ISAS, Bunsen-Kirchhoff-Straße, 1144139 Dortmund, Germany
| | - Nanduri R Prabhakar
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, IL, USA
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9
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Crowther GJ, Knight TA. Using Test Question Templates to teach physiology core concepts. ADVANCES IN PHYSIOLOGY EDUCATION 2023; 47:202-214. [PMID: 36701495 PMCID: PMC10026985 DOI: 10.1152/advan.00024.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/21/2022] [Accepted: 01/24/2023] [Indexed: 06/16/2023]
Abstract
The past ∼15 years have seen increasing interest in defining disciplinary core concepts. Within the field of physiology, Michael, McFarland, Modell, and colleagues have published studies that defined physiology core concepts and have elaborated many of these as detailed conceptual frameworks. With such helpful definitions now in place, attention is turning to the related issue of how to maximize student understanding of the core concepts by linking these "big ideas" to concrete student-facing resources for active learning and assessment. Our practitioner-based view begins with the recognition that in many if not most undergraduate physiology courses assessment drives learning. We have therefore linked published conceptual frameworks to Test Question Templates (TQTs), whose structure promotes transparent assessments as well as the active learning needed to prepare for such assessments. We provide examples of conceptual framework-linked TQTs for the physiology core concepts of Homeostasis, Flow Down Gradients, the Cell Membrane, and Cell-Cell Communication. We argue that this deployment of TQTs has at least two distinct benefits for the teaching and learning of core concepts. First, documenting the connections between conceptual frameworks and TQTs may clarify coverage and assessment of the core concepts for both instructors and students. Second, misconceptions about core concepts may be directly targeted and dispelled via thoughtful construction, arrangement, and iteration of TQTs. We propose that the TQT framework or similar approaches may be applied fruitfully to any sufficiently articulated physiology core concept for high school, undergraduate, or graduate students.NEW & NOTEWORTHY Our students often focus on the grades they need to advance through academic programs. How can instructors harness this understandable interest in grades to help students gain a true understanding of core concepts? The new framework of Test Question Templates (TQTs) shows promise in linking student priorities like test scores to instructor priorities like core concepts.
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Affiliation(s)
- Gregory J Crowther
- Life Sciences Department, Everett Community College, Everett, Washington, United States
- Division of Biological Sciences, University of Washington Bothell, Bothell, Washington, United States
| | - Thomas A Knight
- Department of Biology, Whitman College, Walla Walla, Washington, United States
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Takeuchi H, Kurahashi T. Segregation of Ca2+ signaling in olfactory signal transduction. J Gen Physiol 2023; 155:213865. [PMID: 36787110 PMCID: PMC9960254 DOI: 10.1085/jgp.202213165] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 11/04/2022] [Accepted: 01/13/2023] [Indexed: 02/15/2023] Open
Abstract
Olfactory signal transduction is conducted through a cAMP-mediated second messenger cascade. The cytoplasmic Ca2+ concentration increases through the opening of CNG channels, a phenomenon that underlies two major functions, namely, signal boosting and olfactory adaptation. Signal boosting is achieved by an additional opening of the Ca2+-activated Cl- channel whereas adaptation is regulated by Ca2+ feedback to the CNG channel. Thus, the influx of Ca2+ and the resultant increase in cytoplasmic Ca2+ levels play seemingly opposing effects: increasing the current while reducing the current through adaptation. The two functions could be interpreted as compensating for each other. However, in real cells, both functions should be segregated. Ca2+ dynamics in olfactory cilia need to be directly measured, but technical difficulties accompanying the thin structure of olfactory cilia have prevented systematic analyses. In this study, using a combination of electrophysiology, local photolysis of caged cAMP, and Ca2+ imaging, we found that free Ca2+ in the local ciliary cytoplasm decreased along with a reduction in the current containing Ca2+-activated Cl- components returning to the basal level, whereas Ca2+-dependent adaptation persisted for a longer period. The activity of Cl- channels is highly likely to be regulated by the free Ca2+ that is present only immediately after the influx through the CNG channel, and an exclusive interaction between Ca2+ and Ca2+-binding proteins that mediate the adaptation may modulate the adaptation lifetime.
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Affiliation(s)
- Hiroko Takeuchi
- Department of Biophysical Dynamics, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
- Correspondence to Hiroko Takeuchi:
| | - Takashi Kurahashi
- Department of Biophysical Dynamics, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
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11
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Kim H, Kim H, Nguyen LT, Ha T, Lim S, Kim K, Kim SH, Han K, Hyeon SJ, Ryu H, Park YS, Kim SH, Kim IB, Hong GS, Lee SE, Choi Y, Cohen LB, Oh U. Amplification of olfactory signals by Anoctamin 9 is important for mammalian olfaction. Prog Neurobiol 2022; 219:102369. [PMID: 36330924 DOI: 10.1016/j.pneurobio.2022.102369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
Sensing smells of foods, prey, or predators determines animal survival. Olfactory sensory neurons in the olfactory epithelium (OE) detect odorants, where cAMP and Ca2+ play a significant role in transducing odorant inputs to electrical activity. Here we show Anoctamin 9, a cation channel activated by cAMP/PKA pathway, is expressed in the OE and amplifies olfactory signals. Ano9-deficient mice had reduced olfactory behavioral sensitivity, electro-olfactogram signals, and neural activity in the olfactory bulb. In line with the difference in olfaction between birds and other vertebrates, chick ANO9 failed to respond to odorants, whereas chick CNGA2, a major transduction channel, showed greater responses to cAMP. Thus, we concluded that the signal amplification by ANO9 is important for mammalian olfactory transduction.
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Affiliation(s)
- Hyungsup Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Hyesu Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 08826, Republic of Korea
| | - Luan Thien Nguyen
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Taewoong Ha
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Sujin Lim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyungmin Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Soon Ho Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Kyungreem Han
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Seung Jae Hyeon
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Hoon Ryu
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Yong Soo Park
- Department of Anatomy, Catholic Institute for Applied Anatomy, College of Medicine, Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Sang Hyun Kim
- Department of Anatomy, Catholic Institute for Applied Anatomy, College of Medicine, Catholic University of Korea, Seoul 06591, Republic of Korea
| | - In-Beom Kim
- Department of Anatomy, Catholic Institute for Applied Anatomy, College of Medicine, Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Gyu-Sang Hong
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Seung Eun Lee
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Yunsook Choi
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Lawrence B Cohen
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Uhtaek Oh
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 08826, Republic of Korea.
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12
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Brix KV, De Boeck G, Baken S, Fort DJ. Adverse Outcome Pathways for Chronic Copper Toxicity to Fish and Amphibians. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:2911-2927. [PMID: 36148934 PMCID: PMC9828004 DOI: 10.1002/etc.5483] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/22/2022] [Accepted: 09/15/2022] [Indexed: 05/28/2023]
Abstract
In the present review, we synthesize information on the mechanisms of chronic copper (Cu) toxicity using an adverse outcome pathway framework and identify three primary pathways for chronic Cu toxicity: disruption of sodium homeostasis, effects on bioenergetics, and oxidative stress. Unlike acute Cu toxicity, disruption of sodium homeostasis is not a driving mechanism of chronic toxicity, but compensatory responses in this pathway contribute to effects on organism bioenergetics. Effects on bioenergetics clearly contribute to chronic Cu toxicity with impacts at multiple lower levels of biological organization. However, quantitatively translating these impacts into effects on apical endpoints such as growth, amphibian metamorphosis, and reproduction remains elusive and requires further study. Copper-induced oxidative stress occurs in most tissues of aquatic vertebrates and is clearly a significant driver of chronic Cu toxicity. Although antioxidant responses and capacities differ among tissues, there is no clear indication that specific tissues are more sensitive than others to oxidative stress. Oxidative stress leads to increased apoptosis and cellular damage in multiple tissues, including some that contribute to bioenergetic effects. This also includes oxidative damage to tissues involved in neuroendocrine axes and this damage likely alters the normal function of these tissues. Importantly, Cu-induced changes in hormone concentrations and gene expression in endocrine-mediated pathways such as reproductive steroidogenesis and amphibian metamorphosis are likely the result of oxidative stress-induced tissue damage and not endocrine disruption. Overall, we conclude that oxidative stress is likely the primary driver of chronic Cu toxicity in aquatic vertebrates, with bioenergetic effects and compensatory response to disruption of sodium homeostasis contributing to some degree to observed effects on apical endpoints. Environ Toxicol Chem 2022;41:2911-2927. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Kevin V. Brix
- EcoToxMiamiFloridaUSA
- Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Department of Marine Biology and EcologyUniversity of MiamiMiamiFloridaUSA
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13
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Omura M, Takabatake Y, Lempert E, Benjamin-Hong S, D'Hulst C, Feinstein P. A genetic platform for functionally profiling odorant receptors in olfactory cilia ex vivo. Sci Signal 2022; 15:eabm6112. [PMID: 35944068 DOI: 10.1126/scisignal.abm6112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The molecular basis for odor perception in humans remains enigmatic because of the difficulty in studying odorant receptors (ORs) outside their native environment. Efforts toward OR expression and functional profiling have been met with limited success because of the poor efficiency of their cell surface expression in vitro. Structures protruding from the surface of olfactory sensory neurons called cilia contain all of the components of the olfactory signal transduction machinery and can be placed in an ex vivo plate assay to rapidly measure odor-specific responses. Here, we describe an approach using cilia isolated from the olfactory sensory neurons of mice expressing two human ORs, OR1A1 and OR5AN1, that showed 10- to 100-fold more sensitivity to ligands as compared to previous assays. A single mouse can produce enough olfactory cilia for up to 4000 384-well assay wells, and isolated cilia can be stored frozen and thus preserved. This pipeline offers a sensitive and highly scalable ex vivo odor-screening platform that has the potential to decode human olfaction.
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Affiliation(s)
- Masayo Omura
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY 10065, USA.,Yesse Technologies Inc., New York, NY 10016, USA
| | - Yukie Takabatake
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY 10065, USA.,Yesse Technologies Inc., New York, NY 10016, USA
| | - Eugene Lempert
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY 10065, USA
| | | | - Charlotte D'Hulst
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY 10065, USA.,Yesse Technologies Inc., New York, NY 10016, USA
| | - Paul Feinstein
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY 10065, USA.,Yesse Technologies Inc., New York, NY 10016, USA.,Graduate Center Programs in Biochemistry, Biology and CUNY Neuroscience Collaborative, 365 5th Ave., New York, NY 10016, USA
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14
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Expression pattern of Stomatin-domain proteins in the peripheral olfactory system. Sci Rep 2022; 12:11447. [PMID: 35794236 PMCID: PMC9259621 DOI: 10.1038/s41598-022-15572-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/27/2022] [Indexed: 11/29/2022] Open
Abstract
Recent data show that Stomatin-like protein 3 (STOML3), a member of the stomatin-domain family, is expressed in the olfactory sensory neurons (OSNs) where it modulates both spontaneous and evoked action potential firing. The protein family is constituted by other 4 members (besides STOML3): STOM, STOML1, STOML2 and podocin. Interestingly, STOML3 with STOM and STOML1 are expressed in other peripheral sensory neurons: dorsal root ganglia. In here, they functionally interact and modulate the activity of the mechanosensitive Piezo channels and members of the ASIC family. Therefore, we investigated whether STOM and STOML1 are expressed together with STOML3 in the OSNs and whether they could interact. We found that all three are indeed expressed in ONSs, although STOML1 at very low level. STOM and STOML3 share a similar expression pattern and STOML3 is necessary for STOM to properly localize to OSN cilia. In addition, we extended our investigation to podocin and STOML2, and while the former is not expressed in the olfactory system, the latter showed a peculiar expression pattern in multiple cell types. In summary, we provided a first complete description of stomatin-domain protein family in the olfactory system, highlighting the precise compartmentalization, possible interactions and, finally, their functional implications.
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15
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Time-Dependent Odorant Sensitivity Modulation in Insects. INSECTS 2022; 13:insects13040354. [PMID: 35447796 PMCID: PMC9028461 DOI: 10.3390/insects13040354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/18/2023]
Abstract
Simple Summary Insects, including blood-feeding female mosquitoes, can transmit deadly diseases, such as malaria, encephalitis, dengue, and yellow fever. Insects use olfaction to locate food sources, mates, and hosts. The nature of odorant plumes poses a challenge for insects in locating odorant sources in the environment. In order to modulate the system for the detection of fresh stimuli or changes in odorant concentrations, the olfaction system desensitizes to different concentrations and durations of stimuli. Without this ability, the chemotaxis behaviors of insects are defective. Thus, understanding how insects adjust their olfactory response dynamics to parse the chemical language of the external environment is not only a basic biology question but also has far-reaching implications for repellents and pest control. Abstract Insects use olfaction to detect ecologically relevant chemicals in their environment. To maintain useful responses over a variety of stimuli, olfactory receptor neurons are desensitized to prolonged or high concentrations of stimuli. Depending on the timescale, the desensitization is classified as short-term, which typically spans a few seconds; or long-term, which spans from minutes to hours. Compared with the well-studied mechanisms of desensitization in vertebrate olfactory neurons, the mechanisms underlying invertebrate olfactory sensitivity regulation remain poorly understood. Recently, using a large-scale functional screen, a conserved critical receptor phosphorylation site has been identified in the model insect Drosophila melanogaster, providing new insight into the molecular basis of desensitization in insects. Here, we summarize the progress in this area and provide perspectives on future directions to determine the molecular mechanisms that orchestrate the desensitization in insect olfaction.
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16
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The Arrangement of the Peripheral Olfactory System of Pleuragramma antarcticum: A Well-Exploited Small Sensor, an Aided Water Flow, and a Prominent Effort in Primary Signal Elaboration. Animals (Basel) 2022; 12:ani12050663. [PMID: 35268231 PMCID: PMC8909514 DOI: 10.3390/ani12050663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 12/04/2022] Open
Abstract
Simple Summary How animals perceive their surrounding environment is crucial to their reactions and behavior. Olfaction, among others, is one of the more important senses for wide-range communication and in low-light environments. This study aims to give a morphological description of the peripheral olfactory system of the Antarctic silverfish, which is a key species in the coastal Antarctic ecosystem. The head of the Antarctic silverfish is specialized to assure that the olfactory organ keeps in contact with a large volume of water, even when the fish is not actively swimming. The sensory surface area and the number of neurons in the primary olfactory brain region show that this fish invests energy in the detection and elaboration of olfactory signals. In the cold waters of the Southern Ocean, the Antarctic silverfish is therefore likely to rely considerably on olfaction. Abstract The olfactory system is constituted in a consistent way across vertebrates. Nasal structures allow water/air to enter an olfactory cavity, conveying the odorants to a sensory surface. There, the olfactory neurons form, with their axons, a sensory nerve projecting to the telencephalic zone—named the olfactory bulb. This organization comes with many different arrangements, whose meaning is still a matter of debate. A morphological description of the olfactory system of many teleost species is present in the literature; nevertheless, morphological investigations rarely provide a quantitative approach that would help to provide a deeper understanding of the structures where sensory and elaborating events happen. In this study, the peripheral olfactory system of the Antarctic silverfish, which is a keystone species in coastal Antarctica ecosystems, has also been described, employing some quantitative methods. The olfactory chamber of this species is connected to accessory nasal sacs, which probably aid water movements in the chamber; thus, the head of the Antarctic silverfish is specialized to assure that the olfactory organ keeps in contact with a large volume of water—even when the fish is not actively swimming. Each olfactory organ, shaped like an asymmetric rosette, has, in adult fish, a sensory surface area of about 25 mm2, while each olfactory bulb contains about 100,000 neurons. The sensory surface area and the number of neurons in the primary olfactory brain region show that this fish invests energy in the detection and elaboration of olfactory signals and allow comparisons among different species. The mouse, for example—which is considered a macrosmatic vertebrate—has a sensory surface area of the same order of magnitude as that of the Antarctic silverfish, but ten times more neurons in the olfactory bulb. Catsharks, on the other hand, have a sensory surface area that is two orders of magnitude higher than that of the Antarctic silverfish, while the number of neurons has the same order of magnitude. The Antarctic silverfish is therefore likely to rely considerably on olfaction.
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Di Natale C, Gros CP, Paolesse R. Corroles at work: a small macrocycle for great applications. Chem Soc Rev 2022; 51:1277-1335. [PMID: 35037929 DOI: 10.1039/d1cs00662b] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Corrole chemistry has witnessed an impressive boost in studies in the last 20 years, thanks to the possibility of preparing corrole derivatives by simple synthetic procedures. The investigation of a large number of corroles has highlighted some peculiar characteristics of these macrocycles, having features different from those of the parent porphyrins. With this progress in the elucidation of corrole properties, attention has been focused on the potential for the exploitation of corrole derivatives in different important application fields. In some areas, the potential of corroles has been studied in certain detail, for example, the use of corrole metal complexes as electrocatalysts for energy conversion. In some other areas, the field is still in its infancy, such as in the exploitation of corroles in solar cells. Herein, we report an overview of the different applications of corroles, focusing on the studies reported in the last five years.
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Affiliation(s)
- Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Viale del Politecnico, 00133 Rome, Italy.
| | - Claude P Gros
- Université Bourgogne Franche-Comté, ICMUB (UMR CNRS 6302), 9 Avenue Alain Savary, BP 47870, 21078 Dijon, Cedex, France.
| | - Roberto Paolesse
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
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18
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Takei Y. Evolution of the membrane/particulate guanylyl cyclase: From physicochemical sensors to hormone receptors. Gen Comp Endocrinol 2022; 315:113797. [PMID: 33957096 DOI: 10.1016/j.ygcen.2021.113797] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/19/2021] [Accepted: 04/28/2021] [Indexed: 12/26/2022]
Abstract
Guanylyl cyclase (GC) is an enzyme that produces 3',5'-cyclic guanosine monophosphate (cGMP), one of the two canonical cyclic nucleotides used as a second messenger for intracellular signal transduction. The GCs are classified into two groups, particulate/membrane GCs (pGC) and soluble/cytosolic GCs (sGC). In relation to the endocrine system, pGCs include hormone receptors for natriuretic peptides (GC-A and GC-B) and guanylin peptides (GC-C), while sGC is a receptor for nitric oxide and carbon monoxide. Comparing the functions of pGCs in eukaryotes, it is apparent that pGCs perceive various environmental factors such as light, temperature, and various external chemical signals in addition to endocrine hormones, and transmit the information into the cell using the intracellular signaling cascade initiated by cGMP, e.g., cGMP-dependent protein kinases, cGMP-sensitive cyclic nucleotide-gated ion channels and cGMP-regulated phosphodiesterases. Among vertebrate pGCs, GC-E and GC-F are localized on retinal epithelia and are involved in modifying signal transduction from the photoreceptor, rhodopsin. GC-D and GC-G are localized in olfactory epithelia and serve as sensors at the extracellular domain for external chemical signals such as odorants and pheromones. GC-G also responds to guanylin peptides in the urine, which alters sensitivity to other chemicals. In addition, guanylin peptides that are secreted into the intestinal lumen, a pseudo-external environment, act on the GC-C on the apical membrane for regulation of epithelial transport. In this context, GC-C and GC-G appear to be in transition from exocrine pheromone receptor to endocrine hormone receptor. The pGCs also exist in various deuterostome and protostome invertebrates, and act as receptors for environmental, exocrine and endocrine factors including hormones. Tracing the evolutionary history of pGCs, it appears that pGCs first appeared as a sensor for physicochemical signals in the environment, and then evolved to function as hormone receptors. In this review, the author proposes an evolutionary history of pGCs that highlights the emerging role of the GC/cGMP system for signal transduction in hormone action.
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Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Department of Marine Bioscience, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan.
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19
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Adaptive cardiorespiratory changes to chronic continuous and intermittent hypoxia. HANDBOOK OF CLINICAL NEUROLOGY 2022; 188:103-123. [PMID: 35965023 PMCID: PMC9906984 DOI: 10.1016/b978-0-323-91534-2.00009-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This chapter reviews cardiorespiratory adaptations to chronic hypoxia (CH) experienced at high altitude and cardiorespiratory pathologies elicited by chronic intermittent hypoxia (CIH) occurring with obstructive sleep apnea (OSA). Short-term CH increases breathing (ventilatory acclimatization to hypoxia) and blood pressure (BP) through carotid body (CB) chemo reflex. Hyperplasia of glomus cells, alterations in ion channels, and recruitment of additional excitatory molecules are implicated in the heightened CB chemo reflex by CH. Transcriptional activation of hypoxia-inducible factors (HIF-1 and 2) is a major molecular mechanism underlying respiratory adaptations to short-term CH. High-altitude natives experiencing long-term CH exhibit blunted hypoxic ventilatory response (HVR) and reduced BP due to desensitization of CB response to hypoxia and impaired processing of CB sensory information at the central nervous system. Ventilatory changes evoked by long-term CH are not readily reversed after return to sea level. OSA patients and rodents subjected to CIH exhibit heightened CB chemo reflex, increased hypoxic ventilatory response, and hypertension. Increased generation of reactive oxygen species (ROS) is a major cellular mechanism underlying CIH-induced enhanced CB chemo reflex and the ensuing cardiorespiratory pathologies. ROS generation by CIH is mediated by nontranscriptional, disrupted HIF-1 and HIF-2-dependent transcriptions as well as epigenetic mechanisms.
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20
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AlMatrouk A, Lemons K, Ogura T, Lin W. Modification of the Peripheral Olfactory System by Electronic Cigarettes. Compr Physiol 2021; 11:2621-2644. [PMID: 34661289 DOI: 10.1002/cphy.c210007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Electronic cigarettes (e-cigs) are used by millions of adolescents and adults worldwide. Commercial e-liquids typically contain flavorants, propylene glycol, and vegetable glycerin with or without nicotine. These chemical constituents are detected and evaluated by chemosensory systems to guide and modulate vaping behavior and product choices of e-cig users. The flavorants in e-liquids are marketing tools. They evoke sensory percepts of appealing flavors through activation of chemical sensory systems to promote the initiation and sustained use of e-cigs. The vast majority of flavorants in e-liquids are volatile odorants, and as such, the olfactory system plays a dominant role in perceiving these molecules that enter the nasal cavity either orthonasally or retronasally during vaping. In addition to flavorants, e-cig aerosol contains a variety of by-products generated through heating the e-liquids, including odorous irritants, toxicants, and heavy metals. These harmful substances can directly and adversely impact the main olfactory epithelium (MOE). In this article, we first discuss the olfactory contribution to e-cig flavor perception. We then provide information on MOE cell types and their major functions in olfaction and epithelial maintenance. Olfactory detection of flavorants, nicotine, and odorous irritants and toxicants are also discussed. Finally, we discuss the cumulated data on modification of the MOE by flavorant exposure and toxicological impacts of formaldehyde, acrolein, and heavy metals. Together, the information presented in this overview may provide insight into how e-cig exposure may modify the olfactory system and adversely impact human health through the alteration of the chemosensory factor driving e-cig use behavior and product selections. © 2021 American Physiological Society. Compr Physiol 11:2621-2644, 2021.
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Affiliation(s)
- Abdullah AlMatrouk
- General Department of Criminal Evidence, Forensic Laboratories, Ministry of Interior, Farwaniyah, Kuwait.,Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Kayla Lemons
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, USA.,Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Tatsuya Ogura
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Weihong Lin
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, USA
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21
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Sharma A, Saha BK, Kumar R, Varadwaj PK. OlfactionBase: a repository to explore odors, odorants, olfactory receptors and odorant-receptor interactions. Nucleic Acids Res 2021; 50:D678-D686. [PMID: 34469532 PMCID: PMC8728123 DOI: 10.1093/nar/gkab763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/13/2021] [Accepted: 08/28/2021] [Indexed: 12/04/2022] Open
Abstract
Olfaction is a multi-stage process that initiates with the odorants entering the nose and terminates with the brain recognizing the odor associated with the odorant. In a very intricate way, the process incorporates various components functioning together and in synchronization. OlfactionBase is a free, open-access web server that aims to bring together knowledge about many aspects of the olfaction mechanism in one place. OlfactionBase contains detailed information of components like odors, odorants, and odorless compounds with physicochemical and ADMET properties, olfactory receptors (ORs), odorant- and pheromone binding proteins, OR-odorant interactions in Human and Mus musculus. The dynamic, user-friendly interface of the resource facilitates exploration of different entities: finding chemical compounds having desired odor, finding odorants associated with OR, associating chemical features with odor and OR, finding sequence information of ORs and related proteins. Finally, the data in OlfactionBase on odors, odorants, olfactory receptors, human and mouse OR-odorant pairs, and other associated proteins could aid in the inference and improved understanding of odor perception, which might provide new insights into the mechanism underlying olfaction. The OlfactionBase is available at https://bioserver.iiita.ac.in/olfactionbase/.
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Affiliation(s)
- Anju Sharma
- Department of Applied Science, Indian Institute of Information Technology, Allahabad, Uttar Pradesh 211015, India
| | | | - Rajnish Kumar
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Uttar Pradesh 226028, India
| | - Pritish Kumar Varadwaj
- Department of Applied Science, Indian Institute of Information Technology, Allahabad, Uttar Pradesh 211015, India
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22
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Martelli C, Storace DA. Stimulus Driven Functional Transformations in the Early Olfactory System. Front Cell Neurosci 2021; 15:684742. [PMID: 34413724 PMCID: PMC8369031 DOI: 10.3389/fncel.2021.684742] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/06/2021] [Indexed: 11/17/2022] Open
Abstract
Olfactory stimuli are encountered across a wide range of odor concentrations in natural environments. Defining the neural computations that support concentration invariant odor perception, odor discrimination, and odor-background segmentation across a wide range of stimulus intensities remains an open question in the field. In principle, adaptation could allow the olfactory system to adjust sensory representations to the current stimulus conditions, a well-known process in other sensory systems. However, surprisingly little is known about how adaptation changes olfactory representations and affects perception. Here we review the current understanding of how adaptation impacts processing in the first two stages of the vertebrate olfactory system, olfactory receptor neurons (ORNs), and mitral/tufted cells.
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Affiliation(s)
- Carlotta Martelli
- Institute of Developmental Biology and Neurobiology, University of Mainz, Mainz, Germany
| | - Douglas Anthony Storace
- Department of Biological Science, Florida State University, Tallahassee, FL, United States
- Program in Neuroscience, Florida State University, Tallahassee, FL, United States
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23
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Gupta R, Mittal A, Agrawal V, Gupta S, Gupta K, Jain RR, Garg P, Mohanty SK, Sogani R, Chhabra HS, Gautam V, Mishra T, Sengupta D, Ahuja G. OdoriFy: A conglomerate of artificial intelligence-driven prediction engines for olfactory decoding. J Biol Chem 2021; 297:100956. [PMID: 34265305 PMCID: PMC8342790 DOI: 10.1016/j.jbc.2021.100956] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 06/24/2021] [Accepted: 07/09/2021] [Indexed: 12/01/2022] Open
Abstract
The molecular mechanisms of olfaction, or the sense of smell, are relatively underexplored compared with other sensory systems, primarily because of its underlying molecular complexity and the limited availability of dedicated predictive computational tools. Odorant receptors (ORs) allow the detection and discrimination of a myriad of odorant molecules and therefore mediate the first step of the olfactory signaling cascade. To date, odorant (or agonist) information for the majority of these receptors is still unknown, limiting our understanding of their functional relevance in odor-induced behavioral responses. In this study, we introduce OdoriFy, a Web server featuring powerful deep neural network-based prediction engines. OdoriFy enables (1) identification of odorant molecules for wildtype or mutant human ORs (Odor Finder); (2) classification of user-provided chemicals as odorants/nonodorants (Odorant Predictor); (3) identification of responsive ORs for a query odorant (OR Finder); and (4) interaction validation using Odorant-OR Pair Analysis. In addition, OdoriFy provides the rationale behind every prediction it makes by leveraging explainable artificial intelligence. This module highlights the basis of the prediction of odorants/nonodorants at atomic resolution and for the ORs at amino acid levels. A key distinguishing feature of OdoriFy is that it is built on a comprehensive repertoire of manually curated information of human ORs with their known agonists and nonagonists, making it a highly interactive and resource-enriched Web server. Moreover, comparative analysis of OdoriFy predictions with an alternative structure-based ligand interaction method revealed comparable results. OdoriFy is available freely as a web service at https://odorify.ahujalab.iiitd.edu.in/olfy/.
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Affiliation(s)
- Ria Gupta
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Aayushi Mittal
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Vishesh Agrawal
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Sushant Gupta
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Krishan Gupta
- Department of Computer Science and Engineering, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Rishi Raj Jain
- Department of Computer Science and Design, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Prakriti Garg
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Sanjay Kumar Mohanty
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Riya Sogani
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Harshit Singh Chhabra
- Department of Computer Science and Engineering, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Vishakha Gautam
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India
| | - Tripti Mishra
- Pathfinder Research and Training Foundation, Greater Noida, Uttar Pradesh, India
| | - Debarka Sengupta
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India; Department of Computer Science and Engineering, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India; Centre for Artificial Intelligence, Indraprastha Institute of Information Technology, New Delhi, India; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Gaurav Ahuja
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), New Delhi, India.
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24
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A Comparative Perspective on Functionally-Related, Intracellular Calcium Channels: The Insect Ryanodine and Inositol 1,4,5-Trisphosphate Receptors. Biomolecules 2021; 11:biom11071031. [PMID: 34356655 PMCID: PMC8301844 DOI: 10.3390/biom11071031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/08/2021] [Accepted: 07/10/2021] [Indexed: 02/03/2023] Open
Abstract
Calcium (Ca2+) homeostasis is vital for insect development and metabolism, and the endoplasmic reticulum (ER) is a major intracellular reservoir for Ca2+. The inositol 1,4,5- triphosphate receptor (IP3R) and ryanodine receptor (RyR) are large homotetrameric channels associated with the ER and serve as two major actors in ER-derived Ca2+ supply. Most of the knowledge on these receptors derives from mammalian systems that possess three genes for each receptor. These studies have inspired work on synonymous receptors in insects, which encode a single IP3R and RyR. In the current review, we focus on a fundamental, common question: “why do insect cells possess two Ca2+ channel receptors in the ER?”. Through a comparative approach, this review covers the discovery of RyRs and IP3Rs, examines their structures/functions, the pathways that they interact with, and their potential as target sites in pest control. Although insects RyRs and IP3Rs share structural similarities, they are phylogenetically distinct, have their own structural organization, regulatory mechanisms, and expression patterns, which explains their functional distinction. Nevertheless, both have great potential as target sites in pest control, with RyRs currently being targeted by commercial insecticide, the diamides.
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Manzini I, Schild D, Di Natale C. Principles of odor coding in vertebrates and artificial chemosensory systems. Physiol Rev 2021; 102:61-154. [PMID: 34254835 DOI: 10.1152/physrev.00036.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The biological olfactory system is the sensory system responsible for the detection of the chemical composition of the environment. Several attempts to mimic biological olfactory systems have led to various artificial olfactory systems using different technical approaches. Here we provide a parallel description of biological olfactory systems and their technical counterparts. We start with a presentation of the input to the systems, the stimuli, and treat the interface between the external world and the environment where receptor neurons or artificial chemosensors reside. We then delineate the functions of receptor neurons and chemosensors as well as their overall I-O relationships. Up to this point, our account of the systems goes along similar lines. The next processing steps differ considerably: while in biology the processing step following the receptor neurons is the "integration" and "processing" of receptor neuron outputs in the olfactory bulb, this step has various realizations in electronic noses. For a long period of time, the signal processing stages beyond the olfactory bulb, i.e., the higher olfactory centers were little studied. Only recently there has been a marked growth of studies tackling the information processing in these centers. In electronic noses, a third stage of processing has virtually never been considered. In this review, we provide an up-to-date overview of the current knowledge of both fields and, for the first time, attempt to tie them together. We hope it will be a breeding ground for better information, communication, and data exchange between very related but so far little connected fields.
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Affiliation(s)
- Ivan Manzini
- Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University Medical Center, University of Göttingen, Göttingen, Germany
| | - Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy
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26
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Resolving different presynaptic activity patterns within single olfactory glomeruli of Xenopus laevis larvae. Sci Rep 2021; 11:14258. [PMID: 34244587 PMCID: PMC8270923 DOI: 10.1038/s41598-021-93677-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 06/25/2021] [Indexed: 11/18/2022] Open
Abstract
Olfactory sensing is generally organized into groups of similarly sensing olfactory receptor neurons converging into their corresponding glomerulus, which is thought to behave as a uniform functional unit. It is however unclear to which degree axons within a glomerulus show identical activity, how many converge into a glomerulus, and to answer these questions, how it is possible to visually separate them in live imaging. Here we investigate activity of olfactory receptor neurons and their axon terminals throughout olfactory glomeruli using electrophysiological recordings and rapid 4D calcium imaging. While single olfactory receptor neurons responsive to the same odor stimulus show a diversity of responses in terms of sensitivity and spontaneous firing rate on the level of the somata, their pre-synaptic calcium activity in the glomerulus is homogeneous. In addition, we could not observe the correlated spontaneous calcium activity that is found on the post-synaptic side throughout mitral cell dendrites and has been used in activity correlation imaging. However, it is possible to induce spatio-temporal presynaptic response inhomogeneities by applying trains of olfactory stimuli with varying amino acid concentrations. Automated region-of-interest detection and correlation analysis then visually distinguishes at least two axon subgroups per glomerulus that differ in odor sensitivity.
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27
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Salinity-dependent expression of calcium-sensing receptors in Atlantic salmon (Salmo salar) tissues. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2021; 207:505-522. [PMID: 34114081 DOI: 10.1007/s00359-021-01493-3] [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: 12/31/2020] [Revised: 05/23/2021] [Accepted: 05/26/2021] [Indexed: 10/21/2022]
Abstract
Multiple reports suggest that calcium-sensing receptors (CaSRs) are involved in calcium homeostasis, osmoregulation, and/or salinity sensing in fish (Loretz 2008, Herberger and Loretz 2013). We have isolated three unique full-length CaSR cDNAs from Atlantic salmon (Salmo salar) kidney that share many features with other reported CaSRs. Using anti-CaSR antibodies and PCR primers specific for individual salmon CaSR transcripts we show expression in osmoregulatory, neuroendocrine and sensory tissues. Furthermore, CaSRs are expressed in different patterns in salmon tissues where mRNA and protein expression are modified by freshwater or seawater acclimation. For example, in seawater, CaSR mRNA and protein expression is increased significantly in kidney as compared to freshwater. Electrophysiological recordings of olfactory responses produced upon exposure of salmon olfactory epithelium to CaSR agonists suggest a role for CaSRs in chemoreception in this species consistent with other freshwater, anadromous, and marine species where similar olfactory responses to divalent and polyvalent cations have been reported. These data provide further support for a role of CaSR proteins in osmoregulatory and sensory functions in Atlantic salmon, an anadromous species that experiences a broad range of environmental salinities in its life history.
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28
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Shi W, Sun S, Han Y, Tang Y, Zhou W, Du X, Liu G. Microplastics impair olfactory-mediated behaviors of goldfish Carassius auratus. JOURNAL OF HAZARDOUS MATERIALS 2021; 409:125016. [PMID: 33444954 DOI: 10.1016/j.jhazmat.2020.125016] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/15/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Recently, the ubiquitous presence of microplastics (MPs) has drawn worldwide concern over its potential threat to aquatic organisms. However, the effects of MPs on the olfactory ability of fish and the subsequent odorant evoked behaviors remain elusive. In the present study, we analyzed the potential olfactory toxicity of polystyrene (PS) MPs by assessing olfactory-driven behaviors of goldfish in response to odorants. Our results showed that the olfactory-driven behavioral responses of goldfish to L-cysteine and taurocholic acid were significantly hampered by a 28-day MP exposure. Further analysis demonstrated that exposure to MPs may suppress the expression of genes encoding olfactory G protein-coupled receptors, inhibit the enzyme activities of cation transport ATPases crucial for action potential generation, alter the in vivo contents of neurotransmitters as well as metabolites involved in the transduction of electrical signals, and cause olfactory bulb injury and neurotoxicity closely related to the processing of electrical signals. In conclusion, the results obtained in the present study suggest that MPs at environmentally relevant concentrations could impair the olfactory-mediated behavioral responses of goldfish, probably through hampering odorant identification, action potential generation, olfactory neural signal transduction, and olfactory information processing.
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Affiliation(s)
- Wei Shi
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Shuge Sun
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Yu Han
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Yu Tang
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Weishang Zhou
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Xueying Du
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Guangxu Liu
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China.
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29
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Gerkin RC. Parsing Sage and Rosemary in Time: The Machine Learning Race to Crack Olfactory Perception. Chem Senses 2021; 46:6226923. [PMID: 33860304 DOI: 10.1093/chemse/bjab020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Color and pitch perception are largely understandable from characteristics of physical stimuli: the wavelengths of light and sound waves, respectively. By contrast, understanding olfactory percepts from odorous stimuli (volatile molecules) is much more challenging. No intuitive set of molecular features is up to the task. Here in Chemical Senses, the Ray lab reports using a predictive modeling framework-first breaking molecular structure into thousands of features and then using this to train a predictive statistical model on a wide range of perceptual descriptors-to create a tool for predicting the odor character of hundreds of thousands of available but previously uncharacterized molecules (Kowalewski et al. 2021). This will allow future investigators to representatively sample the space of odorous molecules as well as identify previously unknown odorants with a target odor character. Here, I put this work into the context of other modeling efforts and highlight the urgent need for large new datasets and transparent benchmarks for the field to make and evaluate modeling breakthroughs, respectively.
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Affiliation(s)
- Richard C Gerkin
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85287, USA
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30
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Wang B, Peng YJ, Su X, Zhang C, Nagati JS, Garcia JA, Prabhakar NR. Olfactory receptor 78 regulates erythropoietin and cardiorespiratory responses to hypobaric hypoxia. J Appl Physiol (1985) 2021; 130:1122-1132. [PMID: 33539264 DOI: 10.1152/japplphysiol.00817.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Olfactory receptor (Olfr) 78 is expressed in the carotid bodies (CB) and participates in CB responses to acute hypoxia. Olfr78 is also expressed in the kidney, which is a major site of erythropoietin (Epo) production by hypoxia. The present study examined the role of Olfr78 in cardiorespiratory and renal Epo gene responses to hypobaric hypoxia (HH), simulating low O2 condition experienced at high altitude. Studies were performed on adult, male wild-type (WT) and Olfr78 null mice treated with 18 h of HH (0.4 atmospheres). HH-treated WT mice exhibited increased baseline breathing, augmented hypoxic ventilatory response, elevated blood pressure, and plasma norepinephrine (NE) levels. These effects were associated with increased baseline CB sensory nerve activity and augmented CB sensory nerve response to subsequent acute hypoxia. In contrast, HH-treated Olfr78 null mice showed an absence of cardiorespiratory and CB sensory nerve responses, suggesting impaired CB-dependent cardiorespiratory adaptations. WT mice responded to HH with activation of the renal Epo gene expression and elevated plasma Epo levels, and these effects were attenuated or absent in Olfr78 null mice. The attenuated Epo activation by HH was accompanied with markedly reduced hypoxia-inducible factor (HIF)-2α protein and reduced activation of HIF-2 target gene Sod-1 in Olfr78 null mice, suggesting impaired transcriptional activation of HIF-2 contributes to attenuated Epo responses to HH. These results demonstrate a hitherto uncharacterized role for Olfr78 in cardiorespiratory adaptations and renal Epo gene activation by HH such as that experienced at high altitude.NEW & NOTEWORTHY In this study, we delineated a previously uncharacterized role for olfactory receptor 78 (Olfr78), a G-protein-coupled receptor in regulation of erythropoietin and cardiorespiratory responses to hypobaric hypoxia. Our results demonstrate a striking loss of cardiorespiratory adaptations accompanied by an equally striking absence of carotid body sensory nerve responses to hypobaric hypoxia in Olfr78 null mice. We further demonstrate a hitherto uncharacterized role for Olfr78 in erythropoietin activation by hypobaric hypoxia.
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Affiliation(s)
- Benjamin Wang
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Ying-Jie Peng
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Xiaoyu Su
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Chongxu Zhang
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Jason S Nagati
- Department of Medicine, Division of Cardiology, Columbia University, New York, New York
| | - Joseph A Garcia
- Department of Medicine, Division of Cardiology, Columbia University, New York, New York
| | - Nanduri R Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
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31
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Abbas F, Vinberg F. Transduction and Adaptation Mechanisms in the Cilium or Microvilli of Photoreceptors and Olfactory Receptors From Insects to Humans. Front Cell Neurosci 2021; 15:662453. [PMID: 33867944 PMCID: PMC8046925 DOI: 10.3389/fncel.2021.662453] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/02/2021] [Indexed: 12/11/2022] Open
Abstract
Sensing changes in the environment is crucial for survival. Animals from invertebrates to vertebrates use both visual and olfactory stimuli to direct survival behaviors including identification of food sources, finding mates, and predator avoidance. In primary sensory neurons there are signal transduction mechanisms that convert chemical or light signals into an electrical response through ligand binding or photoactivation of a receptor, that can be propagated to the olfactory and visual centers of the brain to create a perception of the odor and visual landscapes surrounding us. The fundamental principles of olfactory and phototransduction pathways within vertebrates are somewhat analogous. Signal transduction in both systems takes place in the ciliary sub-compartments of the sensory cells and relies upon the activation of G protein-coupled receptors (GPCRs) to close cyclic nucleotide-gated (CNG) cation channels in photoreceptors to produce a hyperpolarization of the cell, or in olfactory sensory neurons open CNG channels to produce a depolarization. However, while invertebrate phototransduction also involves GPCRs, invertebrate photoreceptors can be either ciliary and/or microvillar with hyperpolarizing and depolarizing responses to light, respectively. Moreover, olfactory transduction in invertebrates may be a mixture of metabotropic G protein and ionotropic signaling pathways. This review will highlight differences of the visual and olfactory transduction mechanisms between vertebrates and invertebrates, focusing on the implications to the gain of the transduction processes, and how they are modulated to allow detection of small changes in odor concentration and light intensity over a wide range of background stimulus levels.
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Affiliation(s)
- Fatima Abbas
- Vinberg Lab, Department of Ophthalmology and Visual Science, John A. Moran Center, University of Utah, Salt Lake City, UT, United States
| | - Frans Vinberg
- Vinberg Lab, Department of Ophthalmology and Visual Science, John A. Moran Center, University of Utah, Salt Lake City, UT, United States
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32
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A Role for STOML3 in Olfactory Sensory Transduction. eNeuro 2021; 8:ENEURO.0565-20.2021. [PMID: 33637538 PMCID: PMC7986538 DOI: 10.1523/eneuro.0565-20.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/25/2021] [Accepted: 02/08/2021] [Indexed: 11/24/2022] Open
Abstract
Stomatin-like protein-3 (STOML3) is an integral membrane protein expressed in the cilia of olfactory sensory neurons (OSNs), but its functional role in this cell type has never been addressed. STOML3 is also expressed in dorsal root ganglia neurons, where it has been shown to be required for normal touch sensation. Here, we extended previous results indicating that STOML3 is mainly expressed in the knob and proximal cilia of OSNs. We additionally showed that mice lacking STOML3 have a morphologically normal olfactory epithelium. Because of its presence in the cilia, together with known olfactory transduction components, we hypothesized that STOML3 could be involved in modulating odorant responses in OSNs. To investigate the functional role of STOML3, we performed loose patch recordings from wild-type (WT) and Stoml3 knock-out (KO) OSNs. We found that spontaneous mean firing activity was lower with additional shift in interspike intervals (ISIs) distributions in Stoml3 KOs compared with WT neurons. Moreover, the firing activity in response to stimuli was reduced both in spike number and duration in neurons lacking STOML3 compared with WT neurons. Control experiments suggested that the primary deficit in neurons lacking STOML3 was at the level of transduction and not at the level of action potential generation. We conclude that STOML3 has a physiological role in olfaction, being required for normal sensory encoding by OSNs.
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33
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Boccaccio A, Menini A, Pifferi S. The cyclic AMP signaling pathway in the rodent main olfactory system. Cell Tissue Res 2021; 383:429-443. [PMID: 33447881 DOI: 10.1007/s00441-020-03391-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/10/2020] [Indexed: 01/15/2023]
Abstract
Odor perception begins with the detection of odorant molecules by the main olfactory epithelium located in the nasal cavity. Odorant molecules bind to and activate a large family of G-protein-coupled odorant receptors and trigger a cAMP-mediated transduction cascade that converts the chemical stimulus into an electrical signal transmitted to the brain. Morever, odorant receptors and cAMP signaling plays a relevant role in olfactory sensory neuron development and axonal targeting to the olfactory bulb. This review will first explore the physiological response of olfactory sensory neurons to odorants and then analyze the different components of cAMP signaling and their different roles in odorant detection and olfactory sensory neuron development.
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Affiliation(s)
- Anna Boccaccio
- Institute of Biophysics, National Research Council (CNR), Genova, Italy.
| | - Anna Menini
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
| | - Simone Pifferi
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy.,Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
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34
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Weiss L, Manzini I, Hassenklöver T. Olfaction across the water-air interface in anuran amphibians. Cell Tissue Res 2021; 383:301-325. [PMID: 33496878 PMCID: PMC7873119 DOI: 10.1007/s00441-020-03377-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/03/2020] [Indexed: 12/13/2022]
Abstract
Extant anuran amphibians originate from an evolutionary intersection eventually leading to fully terrestrial tetrapods. In many ways, they have to deal with exposure to both terrestrial and aquatic environments: (i) phylogenetically, as derivatives of the first tetrapod group that conquered the terrestrial environment in evolution; (ii) ontogenetically, with a development that includes aquatic and terrestrial stages connected via metamorphic remodeling; and (iii) individually, with common changes in habitat during the life cycle. Our knowledge about the structural organization and function of the amphibian olfactory system and its relevance still lags behind findings on mammals. It is a formidable challenge to reveal underlying general principles of circuity-related, cellular, and molecular properties that are beneficial for an optimized sense of smell in water and air. Recent findings in structural organization coupled with behavioral observations could help to understand the importance of the sense of smell in this evolutionarily important animal group. We describe the structure of the peripheral olfactory organ, the olfactory bulb, and higher olfactory centers on a tissue, cellular, and molecular levels. Differences and similarities between the olfactory systems of anurans and other vertebrates are reviewed. Special emphasis lies on adaptations that are connected to the distinct demands of olfaction in water and air environment. These particular adaptations are discussed in light of evolutionary trends, ontogenetic development, and ecological demands.
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Affiliation(s)
- Lukas Weiss
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Ivan Manzini
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany
| | - Thomas Hassenklöver
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 38, 35392, Giessen, Germany.
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35
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Kalra S, Mittal A, Bajoria M, Mishra T, Maryam S, Sengupta D, Ahuja G. Challenges and possible solutions for decoding extranasal olfactory receptors. FEBS J 2020; 288:4230-4241. [PMID: 33085840 DOI: 10.1111/febs.15606] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/29/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022]
Abstract
Olfactory receptors are primarily known to be expressed in the olfactory epithelium of the nasal cavity and therefore assist in odor perception. With the advent of high-throughput omics technologies such as tissue microarray or RNA sequencing, a large number of olfactory receptors have been reported to be expressed in the nonolfactory tissues. Although these technologies uncovered the expression of these olfactory receptors in the nonchemosensory tissues, unfortunately, they failed to reveal the information about their cell type of origin. Accurate characterization of the cell types should be the first step towards devising cell type-specific assays for their functional evaluation. Single-cell RNA-sequencing technology resolved some of these apparent limitations and opened new means to interrogate the expression of these extranasal olfactory receptors at the single-cell resolution. Moreover, the availability of large-scale, multi-organ/species single-cell expression atlases offer ample resources for the systematic reannotation of these receptors in a cell type-specific manner. In this Viewpoint article, we discuss some of the technical limitations that impede the in-depth understanding of these extranasal olfactory receptors, with a special focus on odorant receptors. Moreover, we also propose a list of single cell-based omics technologies that could further promulgate the opportunity to decipher the regulatory network that drives the odorant receptors expression at atypical locations.
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Affiliation(s)
- Siddhant Kalra
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Aayushi Mittal
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Manisha Bajoria
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Tripti Mishra
- Pathfinder Research and Training Foundation, Greater Noida, India
| | - Sidrah Maryam
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
| | - Debarka Sengupta
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India.,Department of Computer Science and Engineering, Indraprastha Institute of Information Technology, New Delhi, India, India.,Centre for Artificial Intelligence, Indraprastha Institute of Information Technology, New Delhi, India.,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Gaurav Ahuja
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India, India
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36
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The odorant receptor OR2W3 on airway smooth muscle evokes bronchodilation via a cooperative chemosensory tradeoff between TMEM16A and CFTR. Proc Natl Acad Sci U S A 2020; 117:28485-28495. [PMID: 33097666 PMCID: PMC7668088 DOI: 10.1073/pnas.2003111117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Odorant sensing GPCRs are the largest gene family in the human genome. We previously found multiple olfactory receptors and their obligate downstream effectors expressed in the smooth muscle of human bronchi. However, the extent to which odorant-sensing receptors (and the ligands to which they respond) on airway smooth muscle (ASM) are physiologically relevant is not established. Here we show that a monoterpene nerol activates the odorant receptor OR2W3 to relax ASM in both cell and tissue models. Surprisingly, the mechanism of action of OR2W3-mediated ASM relaxation involves paradoxical increases in [Ca2+]i that invoke a cooperative activation of TMEM16A and CFTR to compartmentalize calcium and regulate excitation-contraction coupling in human ASM cells. The recent discovery of sensory (tastant and odorant) G protein-coupled receptors on the smooth muscle of human bronchi suggests unappreciated therapeutic targets in the management of obstructive lung diseases. Here we have characterized the effects of a wide range of volatile odorants on the contractile state of airway smooth muscle (ASM) and uncovered a complex mechanism of odorant-evoked signaling properties that regulate excitation-contraction (E-C) coupling in human ASM cells. Initial studies established multiple odorous molecules capable of increasing intracellular calcium ([Ca2+]i) in ASM cells, some of which were (paradoxically) associated with ASM relaxation. Subsequent studies showed a terpenoid molecule (nerol)-stimulated OR2W3 caused increases in [Ca2+]i and relaxation of ASM cells. Of note, OR2W3-evoked [Ca2+]i mobilization and ASM relaxation required Ca2+ flux through the store-operated calcium entry (SOCE) pathway and accompanied plasma membrane depolarization. This chemosensory odorant receptor response was not mediated by adenylyl cyclase (AC)/cyclic nucleotide-gated (CNG) channels or by protein kinase A (PKA) activity. Instead, ASM olfactory responses to the monoterpene nerol were predominated by the activity of Ca2+-activated chloride channels (TMEM16A), including the cystic fibrosis transmembrane conductance regulator (CFTR) expressed on endo(sarco)plasmic reticulum. These findings demonstrate compartmentalization of Ca2+ signals dictates the odorant receptor OR2W3-induced ASM relaxation and identify a previously unrecognized E-C coupling mechanism that could be exploited in the development of therapeutics to treat obstructive lung diseases.
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Mast TG, Zuk K, Rinke A, Quasem K, Savard B, Brobbey C, Reiss J, Dryden M. Temporary Anosmia in Mice Following Nasal Lavage With Dilute Detergent Solution. Chem Senses 2020; 44:639-648. [PMID: 31363734 DOI: 10.1093/chemse/bjz047] [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] [Indexed: 11/13/2022] Open
Abstract
Olfactory sensory deprivation induces anosmia and reduces tyrosine hydroxylase and dopamine levels in the olfactory bulb. The behavioral consequences specific to the loss of olfactory bulb dopamine are difficult to determine because sensory deprivation protocols are either confounded by side effects or leave the animal anosmic. A new method to both induce sensory deprivation and to measure the behavioral and circuit consequences is needed. We developed a novel, recoverable anosmia protocol using nasal lavage with a dilute detergent solution. Detergent treatment did not damage the olfactory epithelium as measured by scanning electron microscopy, alcian blue histology, and acetylated tubulin immunohistochemistry. One treatment-induced anosmia that lasted 24 to 48 h. Three treatments over 5 days reduced olfactory bulb tyrosine hydroxylase and dopamine levels indicating that anosmia persists between treatments. Importantly, even with multiple treatments, olfactory ability recovered within 48 h. This is the first report of a sensory deprivation protocol that induces recoverable anosmia and can be paired with biochemical, histological, and behavioral investigations of olfaction.
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Affiliation(s)
- Thomas Gerald Mast
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA.,Neuroscience Interdisciplinary Program, Eastern Michigan University, Ypsilanti, MI, USA
| | - Kelsey Zuk
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Andrew Rinke
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Khaleel Quasem
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA.,Neuroscience Interdisciplinary Program, Eastern Michigan University, Ypsilanti, MI, USA
| | - Bradley Savard
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA.,Neuroscience Interdisciplinary Program, Eastern Michigan University, Ypsilanti, MI, USA
| | - Charles Brobbey
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Jacob Reiss
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Michael Dryden
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
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38
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Makeyeva Y, Nicol C, Ledger WL, Ryugo DK. Immunocytochemical Localization of Olfactory-signaling Molecules in Human and Rat Spermatozoa. J Histochem Cytochem 2020; 68:491-513. [PMID: 32603211 DOI: 10.1369/0022155420939833] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Expression of olfactory receptors (ORs) in non-olfactory tissues has been widely reported over the last 20 years. Olfactory marker protein (OMP) is highly expressed in mature olfactory sensory neurons (mOSNs) of the olfactory epithelium. It is involved in the olfactory signal transduction pathway, which is mediated by well-conserved components, including ORs, olfactory G protein (Golf), and adenylyl cyclase 3 (AC3). OMP is widely expressed in non-olfactory tissues with an apparent preference for motile cells. We hypothesized that OMP is expressed in compartment-specific locations and co-localize with an OR, Golf, and AC3 in rat epididymal and human-ejaculated spermatozoa. We used immunocytochemistry to examine the expression patterns of OMP and OR6B2 (human OR, served as positive olfactory control) in experimentally induced modes of activation and determine whether there are any observable differences in proteins expression during the post-ejaculatory stages of spermatozoal functional maturation. We found that OMP was expressed in compartment-specific locations in human and rat spermatozoa. OMP was co-expressed with Golf and AC3 in rat spermatozoa and with OR6B2 in all three modes of activation (control, activated, and hyperactivated), and the mode of activation changed the co-expression pattern in acrosomal-reacted human spermatozoa. These observations suggest that OMP expression is a reliable indicator of OR-mediated chemoreception, may be used to identify ectopically expressed ORs, and could participate in second messenger signaling cascades that mediate fertility.
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Affiliation(s)
- Yuliya Makeyeva
- Garvan Institute of Medical Research, Royal Hospital for Women, Sydney, NSW, Australia.,Westfield Research Laboratories, School of Women's and Children's Health, Royal Hospital for Women, Sydney, NSW, Australia
| | - Christopher Nicol
- UNSW Sydney, Sydney, NSW, Australia, and Andrology Laboratory, NSW Health Pathology, Royal Hospital for Women, Sydney, NSW, Australia
| | - William L Ledger
- Fertility & Research Centre, Royal Hospital for Women, Sydney, NSW, Australia
| | - David K Ryugo
- Garvan Institute of Medical Research, Royal Hospital for Women, Sydney, NSW, Australia.,School of Medical Sciences, UNSW, Royal Hospital for Women, Sydney, NSW, Australia.,Department of Otolaryngology, Head, Neck & Skull Base Surgery, St. Vincent's Hospital, Royal Hospital for Women, Sydney, NSW, Australia
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39
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Peng YJ, Gridina A, Wang B, Nanduri J, Fox AP, Prabhakar NR. Olfactory receptor 78 participates in carotid body response to a wide range of low O 2 levels but not severe hypoxia. J Neurophysiol 2020; 123:1886-1895. [PMID: 32208891 DOI: 10.1152/jn.00075.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The role of olfactory receptor 78 (Olfr78) in carotid body (CB) response to hypoxia was examined. BL6 mice with global deletion of Olfr78 manifested an impaired hypoxic ventilatory response (HVR), a hallmark of the CB chemosensory reflex, CB sensory nerve activity, and reduced intracellular Ca2+ concentration ([Ca2+]i) response of glomus cells to hypoxia (Po2 ~ 40 mmHg). In contrast, severe hypoxia (Po2 ~ 10 mmHg) depressed breathing and produced a very weak CB sensory nerve excitation but robust elevation of [Ca2+]i in Olfr78 null glomus cells. CB sensory nerve excitation evoked by Olfr78 ligands, lactate, propionate, acetate, and butyrate were unaffected in mutant mice and were smaller than that evoked by hypoxia (Po2 ~ 40mmHg). Similar results were obtained in Olfr78 null mice on a JAX genetic background. These results demonstrate a role for Olfr78 in CB responses to a wide range of hypoxia, but not severe hypoxia, and do not require either lactate or any other short-chain fatty acids.NEW & NOTEWORTHY The current study demonstrates that olfactory receptor 78 (Olfr78), a G protein-coupled receptor, is an integral component of the hypoxic sensing mechanism of the carotid body to a wide range of low oxygen levels, but not severe hypoxia, and that Olfr78 participation does not require either lactate or any other short-chain fatty acids, proposed ligands of Olfr78.
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Affiliation(s)
- Ying-Jie Peng
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Anna Gridina
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Benjamin Wang
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Jayasri Nanduri
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Aaron P Fox
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
| | - Nanduri R Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, University of Chicago, Chicago, Illinois
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40
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Abstract
Olfactory and taste receptors are expressed primarily in the nasal olfactory epithelium and gustatory taste bud cells, where they transmit real-time sensory signals to the brain. However, they are also expressed in multiple extra-nasal and extra-oral tissues, being implicated in diverse biological processes including sperm chemotaxis, muscle regeneration, bronchoconstriction and bronchodilatation, inflammation, appetite regulation and energy metabolism. Elucidation of the physiological roles of these ectopic receptors is revealing potential therapeutic and diagnostic applications in conditions including wounds, hair loss, asthma, obesity and cancers. This Review outlines current understanding of the diverse functions of ectopic olfactory and taste receptors and assesses their potential to be therapeutically exploited.
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41
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Malik B, Elkaddi N, Turkistani J, Spielman AI, Ozdener MH. Mammalian Taste Cells Express Functional Olfactory Receptors. Chem Senses 2019; 44:289-301. [PMID: 31140574 PMCID: PMC6538964 DOI: 10.1093/chemse/bjz019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The peripheral taste and olfactory systems in mammals are separate and independent sensory systems. In the current model of chemosensation, gustatory, and olfactory receptors are genetically divergent families expressed in anatomically distinct locations that project to disparate downstream targets. Although information from the 2 sensory systems merges to form the perception of flavor, the first cross talk is thought to occur centrally, in the insular cortex. Recent studies have shown that gustatory and olfactory receptors are expressed throughout the body and serve as chemical sensors in multiple tissues. Olfactory receptor cDNA has been detected in the tongue, yet the presence of physiologically functional olfactory receptors in taste cells has not yet been demonstrated. Here we report that olfactory receptors are functionally expressed in taste papillae. We found expression of olfactory receptors in the taste papillae of green fluorescent protein-expressing transgenic mice and, using immunocytochemistry and real-time quantitative polymerase chain reaction experiments, the presence of olfactory signal transduction molecules and olfactory receptors in cultured human fungiform taste papilla (HBO) cells. Both HBO cells and mouse taste papilla cells responded to odorants. Knockdown of adenylyl cyclase mRNA by specific small inhibitory RNA and pharmacological block of adenylyl cyclase eliminated these responses, leading us to hypothesize that the gustatory system may receive olfactory information in the periphery. These results provide the first direct evidence of the presence of functional olfactory receptors in mammalian taste cells. Our results also demonstrate that the initial integration of gustatory and olfactory information may occur as early as the taste receptor cells.
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Affiliation(s)
- Bilal Malik
- Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Nadia Elkaddi
- Monell Chemical Senses Center, Philadelphia, PA, USA
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42
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Hu J, Wang Y, Le Q, Yu N, Cao X, Kuang S, Zhang M, Gu W, Sun Y, Yang Y, Yan X. Transcriptome sequencing of olfactory-related genes in olfactory transduction of large yellow croaker ( Larimichthy crocea) in response to bile salts. PeerJ 2019; 7:e6627. [PMID: 30918761 PMCID: PMC6431138 DOI: 10.7717/peerj.6627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/15/2019] [Indexed: 11/20/2022] Open
Abstract
Fish produce and release bile salts as chemical signalling substances that act as sensitive olfactory stimuli. To investigate how bile salts affect olfactory signal transduction in large yellow croaker (Larimichthy crocea), deep sequencing of olfactory epithelium was conducted to analyse olfactory-related genes in olfactory transduction. Sodium cholates (SAS) have typical bile salt chemical structures, hence we used four different concentrations of SAS to stimulate L. crocea, and the fish displayed a significant behavioural preference for 0.30% SAS. We then sequenced olfactory epithelium tissues, and identified 9938 unigenes that were significantly differentially expressed between SAS-stimulated and control groups, including 9055 up-regulated and 883 down-regulated unigenes. Subsequent Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses found eight categories linked to the olfactory transduction pathway that was highly enriched with some differentially expressed genes (DEGs), including the olfactory receptor (OR), Adenylate cyclase type 3 (ADCY3) and Calmodulin (CALM). Genes in these categories were analysed by RT-qPCR, which revealed aspects of the pathway transformation between odor detection, and recovery and adaptation. The results provide new insight into the effects of bile salt stimulation in olfactory molecular mechanisms in fishes, and expands our knowledge of olfactory transduction, and signal generation and decline.
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Affiliation(s)
- Jiabao Hu
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Yajun Wang
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Qijun Le
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China.,Ningbo Entry-Exit Inspection and Quarantine Bureau Technical Centre, Ningbo, China
| | - Na Yu
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Xiaohuan Cao
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Siwen Kuang
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Man Zhang
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Weiwei Gu
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Yibo Sun
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Yang Yang
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
| | - Xiaojun Yan
- Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.,Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo, China.,College of Marine Sciences, Ningbo University, Ningbo, China
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43
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Tamari K, Takeuchi H, Kobayashi M, Takeuchi K, Kurahashi T, Yamamoto T. Electrical properties of cells from human olfactory epithelium. Auris Nasus Larynx 2019; 46:734-741. [PMID: 30850172 DOI: 10.1016/j.anl.2019.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/19/2018] [Accepted: 01/14/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The electrical properties of olfactory cells (OCs) are typically examined using animals such as newts, mice, and frogs, with few studies on human OCs. This study investigated the electrical properties of human cells from olfactory epithelium (hCOEs) obtained from subjects of olfactory epithelium showing no clinical symptoms during endoscopic sinus surgery. METHODS hCOEs were isolated by collagenase treatment for whole-cell patch clamp recording. The identity of the cells was confirmed by immunohistochemistry with an antibody against olfactory maker protein. Under the voltage clamp with the whole-cell recording configuration, the voltage-gated currents of isolated hCOEs were recorded when the membrane potential was depolarized from a holding potential of -100 mV in a stepwise manner between -90 mV and + 40 mV. RESULTS Only one of 14 hCOE samples expressed a transient inward current at the depolarizing voltage step that was activated by depolarization beyond -40 mV and reached a peak at -30 mV. Delayed and sustained outward currents (444 ± 106 pA at + 40 mV pulse; n = 20) were suppressed by tetraethyl ammonium (n = 3), which is consistent with the properties of newt OCs. CONCLUSIONS Most hCOEs did not exhibit the transient inward current observed in animal models. These findings provide insight into the physiological basis of the unique aspects of human olfactory signal transduction.
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Affiliation(s)
- Kengo Tamari
- College of Liberal Arts and Sciences, Mie University, Tsu, Mie 514-8507, Japan; Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan.
| | - Hiroko Takeuchi
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Masayoshi Kobayashi
- Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Kazuhiko Takeuchi
- Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Takashi Kurahashi
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Tetsuro Yamamoto
- Department of Neurophysiology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
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44
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Williams CR, Dittman AH, McElhany P, Busch DS, Maher M, Bammler TK, MacDonald JW, Gallagher EP. Elevated CO 2 impairs olfactory-mediated neural and behavioral responses and gene expression in ocean-phase coho salmon (Oncorhynchus kisutch). GLOBAL CHANGE BIOLOGY 2019; 25:963-977. [PMID: 30561876 PMCID: PMC7065673 DOI: 10.1111/gcb.14532] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/06/2018] [Indexed: 05/16/2023]
Abstract
Elevated concentrations of CO2 in seawater can disrupt numerous sensory systems in marine fish. This is of particular concern for Pacific salmon because they rely on olfaction during all aspects of their life including during their homing migrations from the ocean back to their natal streams. We investigated the effects of elevated seawater CO2 on coho salmon (Oncorhynchus kisutch) olfactory-mediated behavior, neural signaling, and gene expression within the peripheral and central olfactory system. Ocean-phase coho salmon were exposed to three levels of CO2 , ranging from those currently found in ambient marine water to projected future levels. Juvenile coho salmon exposed to elevated CO2 levels for 2 weeks no longer avoided a skin extract odor that elicited avoidance responses in coho salmon maintained in ambient CO2 seawater. Exposure to these elevated CO2 levels did not alter odor signaling in the olfactory epithelium, but did induce significant changes in signaling within the olfactory bulb. RNA-Seq analysis of olfactory tissues revealed extensive disruption in expression of genes involved in neuronal signaling within the olfactory bulb of salmon exposed to elevated CO2 , with lesser impacts on gene expression in the olfactory rosettes. The disruption in olfactory bulb gene pathways included genes associated with GABA signaling and maintenance of ion balance within bulbar neurons. Our results indicate that ocean-phase coho salmon exposed to elevated CO2 can experience significant behavioral impairments likely driven by alteration in higher-order neural signal processing within the olfactory bulb. Our study demonstrates that anadromous fish such as salmon may share a sensitivity to rising CO2 levels with obligate marine species suggesting a more wide-scale ecological impact of ocean acidification.
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Affiliation(s)
- Chase R. Williams
- Department of Environmental and Occupational Health Sciences. University of Washington. Seattle, WA 98105
| | - Andrew H. Dittman
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd E Seattle WA 98112, USA
- Corresponding author at NOAA fisheries, Andrew H. Dittman, Ph.D., Tel: 206-860-3392,
| | - Paul McElhany
- Conservation Biology Division, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 802 Front Street, Mukilteo, WA 98275, USA
| | - D. Shallin Busch
- Conservation Biology Division, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 802 Front Street, Mukilteo, WA 98275, USA
- Ocean Acidification Program, Office of Oceanic and Atmospheric Research, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd E, Seattle WA 98112, USA
| | - Michael Maher
- Conservation Biology Division, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 802 Front Street, Mukilteo, WA 98275, USA
| | - Theo K. Bammler
- Department of Environmental and Occupational Health Sciences. University of Washington. Seattle, WA 98105
| | - James W. MacDonald
- Department of Environmental and Occupational Health Sciences. University of Washington. Seattle, WA 98105
| | - Evan P. Gallagher
- Department of Environmental and Occupational Health Sciences. University of Washington. Seattle, WA 98105
- Corresponding author at the University of Washington, Evan P. Gallagher, Ph.D., Tel: 1-206-616-4739,
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45
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Kim J, Ahn M, Choi Y, Ekanayake P, Park CM, Moon C, Jung K, Tanaka A, Matsuda H, Shin T. Gene Expression Profile of Olfactory Transduction Signaling in an Animal Model of Human Multiple Sclerosis. Exp Neurobiol 2019; 28:74-84. [PMID: 30853826 PMCID: PMC6401553 DOI: 10.5607/en.2019.28.1.74] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/26/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022] Open
Abstract
Olfactory dysfunction occurs in multiple sclerosis in humans, as well as in an animal model of experimental autoimmune encephalomyelitis (EAE). The aim of this study was to analyze differentially expressed genes (DEGs) in olfactory bulb of EAE-affected mice by next generation sequencing, with a particular focus on changes in olfaction-related signals. EAE was induced in C57BL/6 mice following immunization with myelin oligodendrocyte glycoprotein and adjuvant. Inflammatory lesions were identified in the olfactory bulbs as well as in the spinal cord of immunized mice. Analysis of DEGs in the olfactory bulb of EAE-affected mice revealed that 44 genes were upregulated (and which were primarily related to inflammatory mediators), while 519 genes were downregulated; among the latter, olfactory marker protein and stomatin-like 3, which have been linked to olfactory signal transduction, were significantly downregulated (log2 [fold change] >1 and p-value <0.05). These findings suggest that inflammation in the olfactory bulb of EAE-affected mice is associated with the downregulation of some olfactory signal transduction genes, particularly olfactory marker protein and stomatin-like 3, which may lead to olfactory dysfunction in an animal model of human multiple sclerosis.
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Affiliation(s)
- Jeongtae Kim
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Korea
| | - Meejung Ahn
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Korea
| | - Yuna Choi
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Korea
| | - Poornima Ekanayake
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Korea
| | - Chul Min Park
- Department of Obstetrics and Gynecology, School of Medicine, Jeju National University, Jeju 63243, Korea
| | - Changjong Moon
- Department of Veterinary Anatomy, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, Korea
| | - Kyungsook Jung
- Immunoregulatory Materials Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Korea
| | - Akane Tanaka
- Laboratory of Comparative Animal Medicine, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Hiroshi Matsuda
- Laboratory of Veterinary Molecular Pathology and Therapeutics, Division of Animal Life Science, Graduate School, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju 63243, Korea
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46
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Kuznetsov AE, Komarova NV, Kuznetsov EV, Andrianova MS, Grudtsov VP, Rybachek EN, Puchnin KV, Ryazantsev DV, Saurov AN. Integration of a field effect transistor-based aptasensor under a hydrophobic membrane for bioelectronic nose applications. Biosens Bioelectron 2019; 129:29-35. [PMID: 30682686 DOI: 10.1016/j.bios.2019.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/02/2019] [Accepted: 01/04/2019] [Indexed: 01/29/2023]
Abstract
A new bioelectronic nose based on a field effect transistor coupled with an aptamer as the sensing element was developed. The gas-to-liquid extraction interface required for appropriate aptamer function was integrated into standard CMOS technology. It was developed with the use of a sacrificial aluminium etching technique combined with surface modifications by silanes for wettability control. As a proof of concept, aptamer Van74 for vanillin was immobilized on the sensitive surface of the ISFET. The developed microsystem can selectively detect vanillin vapor in a concentration range from 2.7 ppt to 0.3 ppm, with a detection limit of 2.7 ppt. The sensor was able to detect vanillin in a gas sample obtained from roasted coffee beans. This outcome provides a foundation for developing a new generation of bioelectronic noses for the detection and discrimination of volatile compounds.
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Affiliation(s)
- Alexander E Kuznetsov
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation.
| | - Natalia V Komarova
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
| | - Evgeniy V Kuznetsov
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
| | - Maria S Andrianova
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
| | - Vitaliy P Grudtsov
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
| | - Elena N Rybachek
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
| | - Kirill V Puchnin
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
| | - Dmitriy V Ryazantsev
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
| | - Alexander N Saurov
- Scientific-Manufacturing Complex Technological Centre, 1-7 Shokin Square, Zelenograd, 124498 Moscow, Russian Federation
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47
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Sharma A, Kumar R, Aier I, Semwal R, Tyagi P, Varadwaj P. Sense of Smell: Structural, Functional, Mechanistic Advancements and Challenges in Human Olfactory Research. Curr Neuropharmacol 2019; 17:891-911. [PMID: 30520376 PMCID: PMC7052838 DOI: 10.2174/1570159x17666181206095626] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 11/08/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023] Open
Abstract
Olfaction, the sense of smell detects and discriminate odors as well as social cues which influence our innate responses. The olfactory system in human beings is found to be weak as compared to other animals; however, it seems to be very precise. It can detect and discriminate millions of chemical moieties (odorants) even in minuscule quantities. The process initiates with the binding of odorants to specialized olfactory receptors, encoded by a large family of Olfactory Receptor (OR) genes belonging to the G-protein-coupled receptor superfamily. Stimulation of ORs converts the chemical information encoded in the odorants, into respective neuronal action-potentials which causes depolarization of olfactory sensory neurons. The olfactory bulb relays this signal to different parts of the brain for processing. Odors are encrypted using a combinatorial approach to detect a variety of chemicals and encode their unique identity. The discovery of functional OR genes and proteins provided an important information to decipher the genomic, structural and functional basis of olfaction. ORs constitute 17 gene families, out of which 4 families were reported to contain more than hundred members each. The olfactory machinery is not limited to GPCRs; a number of non- GPCRs is also employed to detect chemosensory stimuli. The article provides detailed information about such olfaction machinery, structures, transduction mechanism, theories of odor perception, and challenges in the olfaction research. It covers the structural, functional and computational studies carried out in the olfaction research in the recent past.
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Affiliation(s)
| | | | | | | | | | - Pritish Varadwaj
- Address correspondence to this author at the Department of Applied Science, Indian Institute of Information Technology, Allahabad, Uttar Pradesh, India; E-mail:
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48
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Takeuchi H, Kurahashi T. Second messenger molecules have a limited spread in olfactory cilia. J Gen Physiol 2018; 150:1647-1659. [PMID: 30352795 PMCID: PMC6279364 DOI: 10.1085/jgp.201812126] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 08/12/2018] [Accepted: 10/03/2018] [Indexed: 01/12/2023] Open
Abstract
Olfactory responses in the cilia of olfactory receptor cells last for longer than 10 s, which cannot be explained by free diffusion of second messengers. Takeuchi and Kurahashi show that these signaling molecules have a limited spread and remain at the site of generation for a long time. Odorants are detected by olfactory receptors on the sensory cilia of olfactory receptor cells (ORCs). These cylindrical cilia have a diameters of 100–200 nm, within which the components required for signal transduction by the adenylyl cyclase–cAMP system are located. The kinetics of odorant responses are determined by the lifetimes of active proteins as well as the production, diffusion, and extrusion/degradation of second messenger molecules (cAMP and Ca2+). However, there is limited information about the molecular kinetics of ORC responses, mostly because of the technical limitations involved in studying such narrow spaces and fine structures. In this study, using a combination of electrophysiology, photolysis of caged substances, and spot UV laser stimulation, we show that second messenger molecules work only in the vicinity of their site of generation in the olfactory cilia. Such limited spreading clearly explains a unique feature of ORCs, namely, the integer multiple of unitary events that they display in low Ca2+ conditions. Although the small ORC uses cAMP and Ca2+ for various functions in different regions of the cell, these substances seem to operate only in the compartment that has been activated by the appropriate stimulus. We also show that these substances remain in the same vicinity for a long time. This enables the ORC to amplify the odorant signal and extend the lifetime of Ca2+-dependent adaptation. Cytoplasmic buffers and extrusion/degradation systems seem to play a crucial role in limiting molecular spreading. In addition, binding sites on the cytoplasmic surface of the plasma membrane may limit molecular diffusion in such a narrow space because of the high surface/volume ratio. Such efficient energy conversion may also be broadly used in other biological systems that have not yet been subjected to systematic experiments.
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Affiliation(s)
- Hiroko Takeuchi
- Department of Biophysical Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Takashi Kurahashi
- Department of Biophysical Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
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49
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Zak JD, Grimaud J, Li RC, Lin CC, Murthy VN. Calcium-activated chloride channels clamp odor-evoked spike activity in olfactory receptor neurons. Sci Rep 2018; 8:10600. [PMID: 30006552 PMCID: PMC6045664 DOI: 10.1038/s41598-018-28855-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/02/2018] [Indexed: 02/06/2023] Open
Abstract
The calcium-activated chloride channel anoctamin-2 (Ano2) is thought to amplify transduction currents in olfactory receptor neurons (ORNs), a hypothesis supported by previous studies in dissociated neurons from Ano2−/− mice. Paradoxically, despite a reduction in transduction currents in Ano2−/− ORNs, their spike output for odor stimuli may be higher. We examined the role of Ano2 in ORNs in their native environment in freely breathing mice by imaging activity in ORN axons as they arrive in the olfactory bulb glomeruli. Odor-evoked responses in ORN axons of Ano2−/− animals were consistently larger for a variety of odorants and concentrations. In an open arena, Ano2−/− animals took longer to approach a localized odor source than Ano2+/+ animals, revealing clear olfactory behavioral deficits. Our studies provide the first in vivo evidence toward an alternative or additional role for Ano2 in the olfactory transduction cascade, where it may serve as a feedback mechanism to clamp ORN spike output.
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Affiliation(s)
- Joseph D Zak
- Department of Molecular and Cellular Biology & Center for Brain Science, Harvard University, 16 Divinity Ave, Cambridge, MA, 02138, USA
| | - Julien Grimaud
- Department of Molecular and Cellular Biology & Center for Brain Science, Harvard University, 16 Divinity Ave, Cambridge, MA, 02138, USA.,Molecules, Cells & Organisms Program, Harvard University, Cambridge, 02138, MA, USA
| | - Rong-Chang Li
- Johns Hopkins University School of Medicine, Preclinical Teaching Building Room 905A, 725 North Wolfe Street, MD, 21205, Baltimore, USA
| | - Chih-Chun Lin
- Johns Hopkins University School of Medicine, Preclinical Teaching Building Room 905A, 725 North Wolfe Street, MD, 21205, Baltimore, USA
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology & Center for Brain Science, Harvard University, 16 Divinity Ave, Cambridge, MA, 02138, USA.
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Ramaihgari B, Pustovyy OM, Waggoner P, Beyers RJ, Wildey C, Morrison E, Salibi N, Katz JS, Denney TS, Vodyanoy VJ, Deshpande G. Zinc Nanoparticles Enhance Brain Connectivity in the Canine Olfactory Network: Evidence From an fMRI Study in Unrestrained Awake Dogs. Front Vet Sci 2018; 5:127. [PMID: 30013977 PMCID: PMC6036133 DOI: 10.3389/fvets.2018.00127] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 05/23/2018] [Indexed: 01/01/2023] Open
Abstract
Prior functional Magnetic Resonance Imaging (fMRI) studies have indicated increased neural activation when zinc nanoparticles are added to odorants in canines. Here we demonstrate that zinc nanoparticles up-regulate directional brain connectivity in parts of the canine olfactory network. This provides an explanation for previously reported enhancement in the odor detection capability of the dogs in the presence of zinc nanoparticles. In this study, we obtained fMRI data from awake and unrestrained dogs while they were being exposed to odorants with and without zinc nanoparticles, zinc nanoparticles suspended in water vapor, as well as just water vapor alone. We obtained directional connectivity between the brain regions of the olfactory network that were significantly stronger for the condition of odorant + zinc nanoparticles compared to just odorants, water vapor + zinc nanoparticles and water vapor alone. We observed significant strengthening of the paths of the canine olfactory network in the presence of zinc nanoparticles. This result indicates that zinc nanoparticles could potentially be used to increase canine detection capabilities in the environments of very low concentrations of the odorants, which would have otherwise been undetected.
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Affiliation(s)
- Bhavitha Ramaihgari
- Auburn University MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States
| | - Oleg M. Pustovyy
- Department of Anatomy, Physiology and Pharmacology, Auburn University, Auburn, AL, United States
| | - Paul Waggoner
- Canine Detection Research Institute, Auburn UniversityAuburn, AL, United States
| | - Ronald J. Beyers
- Auburn University MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States
| | - Chester Wildey
- MRRA Inc., University of Alabama at Birmingham, Euless, TX, United States
| | - Edward Morrison
- Department of Anatomy, Physiology and Pharmacology, Auburn University, Auburn, AL, United States
| | - Nouha Salibi
- Auburn University MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States
- MR Research and Development, Siemens Healthcare, Malvern, PA, United States
| | - Jeffrey S. Katz
- Auburn University MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States
- Department of Psychology, Auburn University, Auburn, AL, United States
- Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, Birmingham, AL, United States
| | - Thomas S. Denney
- Auburn University MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States
- Department of Psychology, Auburn University, Auburn, AL, United States
- Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, Birmingham, AL, United States
| | - Vitaly J. Vodyanoy
- Department of Anatomy, Physiology and Pharmacology, Auburn University, Auburn, AL, United States
| | - Gopikrishna Deshpande
- Auburn University MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States
- Department of Psychology, Auburn University, Auburn, AL, United States
- Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, Birmingham, AL, United States
- Center for Health Ecology and Equity Research, Auburn University, Auburn, AL, United States
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