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Takase D, Shirai T, Misawa K, Matsunami H, Yoshikawa K. An odorant receptor for a key odor constituent of ambergris. Commun Biol 2025; 8:792. [PMID: 40410270 PMCID: PMC12102163 DOI: 10.1038/s42003-025-08229-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2025] [Accepted: 05/14/2025] [Indexed: 05/25/2025] Open
Abstract
Ambergris, a substance derived from the digestive system of sperm whales, has been valued for centuries for its unique aromatic properties. However, historical accounts indicate that certain human populations, particularly in East Asia, utilized ambergris without regard for its odor quality. These observations suggest that ambergris offers a model for studying how pleasant olfactory perception and its regional variations are constructed. Despite its historical and cultural significance, the molecular basis of ambergris perception has remained unclear. Here, we identified OR7A17 as an odorant receptor tuned to (-)-Ambroxide, a key odorant in ambergris. Analysis of genetic and functional variations in OR7A17 revealed that non-functional alleles of this receptor are prevalent in human populations, especially in East Asia. Individuals lacking functional OR7A17 alleles could still detect (-)-Ambroxide but found its scent less pleasant compared to those with functional alleles. These findings elucidate a molecular mechanism that influences the perceived pleasantness of ambergris and shed light on its enduring legacy in perfumery.
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Affiliation(s)
- Dan Takase
- Sensory Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga, Tochigi, 321-3497, Japan
| | - Tomohiro Shirai
- Sensory Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga, Tochigi, 321-3497, Japan
| | - Kensuke Misawa
- Biological Material Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga, Tochigi, 321-3497, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC, 27710, USA
| | - Keiichi Yoshikawa
- Sensory Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga, Tochigi, 321-3497, Japan.
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2
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Xu L, Dai Q, Yu Y, Yu H. Correlation between olfactory receptor basal activity and odor response: An observational study. Medicine (Baltimore) 2025; 104:e42085. [PMID: 40295251 PMCID: PMC12040046 DOI: 10.1097/md.0000000000042085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2025] [Revised: 03/15/2025] [Accepted: 03/20/2025] [Indexed: 04/30/2025] Open
Abstract
Olfactory receptors (ORs) are the largest group of G-protein-coupled human receptors responsible for detecting and distinguishing odors. However, the fundamental mechanisms underlying OR responses remain poorly understood. This study aims to evaluate the basal activity of mouse and human ORs in the Hana3A cell line and examine the correlation between their basal activity and response characteristics to odor stimuli. Using a luciferase assay on the Hana3A cell line, the results showed that the 10 mouse ORs with the highest basal activity levels were positively correlated with their total response to odor stimuli. However, there was no significant correlation between the basal activity of human-derived ORs and their total response to odor stimuli. These findings indicate that basal activity levels significantly influence OR responses to odors, as evidenced by the positive correlation in the 10 mouse ORs with the highest basal activity levels and their odor response. This supports the notion that the receptor binding cavity is crucial in determining OR responses to odors.
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Affiliation(s)
- Lun Xu
- Department of Otolaryngology, Ear, Nose & Throat Institute, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People’s Republic of China
- Clinical and Research Center for Olfactory Disorders, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Qi Dai
- Department of Otolaryngology, Ear, Nose & Throat Institute, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People’s Republic of China
- Clinical and Research Center for Olfactory Disorders, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Yiqun Yu
- Department of Otolaryngology, Ear, Nose & Throat Institute, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People’s Republic of China
- Clinical and Research Center for Olfactory Disorders, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People’s Republic of China
| | - Hongmeng Yu
- Department of Otolaryngology, Ear, Nose & Throat Institute, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People’s Republic of China
- Research Units of New Technologies of Endoscopic Surgery in Skull Base Tumor (2018RU003), Chinese Academy of Medical Sciences, Shanghai, People’s Republic of China
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3
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Chi H, Wan J, Melin AD, DeCasien AR, Wang S, Zhang Y, Cui Y, Guo X, Zhao L, Williamson J, Zhang T, Li Q, Zhan Y, Li N, Guo J, Xu Z, Hou W, Cao Y, Yuan J, Zheng J, Shao Y, Wang J, Chen W, Song S, Lu X, Qi X, Zhang G, Rossiter SJ, Wu DD, Liu Y, Lu H, Li G. Genomic and phenotypic evidence support visual and olfactory shifts in primate evolution. Nat Ecol Evol 2025; 9:721-733. [PMID: 40021902 DOI: 10.1038/s41559-025-02651-5] [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: 08/27/2023] [Accepted: 01/31/2025] [Indexed: 03/03/2025]
Abstract
Sensory trade-offs between vision and olfaction in the evolution and radiation of primates have long been debated. However, insights have been limited by a lack of sensory gene sequences and accompanying functional predictions. Here we conduct large-scale functional analyses of visual and olfactory receptors and related brain regions across extant primates. Our results reveal a visual shift from ultraviolet to violet colour sensitivity in early haplorrhine primates, followed by acceleration in the rhodopsin retinal release rates at the origin of anthropoids, both of which are expected to greatly enhance visual acuity under brighter light conditions. Additionally, we find that the sensitivity of olfactory receptors shifted from narrowly to broadly tuned early in anthropoid evolution. In contrast, strepsirrhines appear to have retained sensitive dim-light vision and underwent functional enhancement of narrowly tuned olfactory receptors. Our models indicate that this would have enhanced odorant discrimination and facilitated olfaction-mediated physiology and behaviour. These differences in tuning patterns of olfactory receptors between major primate lineages mirror well-established morphological differences in external anatomy and brain structures, revealing new mechanisms of olfactory adaptation and evolutionary plasticity. Our multisystem analyses reveal patterns of co-evolution in genomic, molecular and neuroanatomical traits that are consistent with a sensory 'reallocation' rather than strict trade-offs.
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Affiliation(s)
- Hai Chi
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Jiahui Wan
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Alex R DeCasien
- Computational and Evolutionary Neurogenomics Unit, National Institute on Aging, Bethesda, MD, USA
| | - Sufang Wang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Yudan Zhang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Yimeng Cui
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Xin Guo
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Le Zhao
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
- QinLing-Bashan Mountains Bioresources Comprehensive Development C. I. C., School of Bioscience and Engineering, Shaanxi University of Technology, Hanzhong, China
| | - Joseph Williamson
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, UK
| | - Tianmin Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Qian Li
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Yue Zhan
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Na Li
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Jinqu Guo
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Zhe Xu
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Wenhui Hou
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yumin Cao
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Jiaqing Yuan
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Jiangmin Zheng
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Yong Shao
- State Key Laboratory of Genetic Evolution & Animal Models, Kunming Natural History Museum of Zoology, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Jinhong Wang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Wu Chen
- Guangzhou Zoo & Guangzhou Wildlife Research Center, Guangzhou, China
| | - Shengjing Song
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Xiaoli Lu
- School of Life Sciences, Westlake University, Hangzhou, China
| | - Xiaoguang Qi
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China
| | - Guojie Zhang
- State Key Laboratory of Genetic Evolution & Animal Models, Kunming Natural History Museum of Zoology, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- BGI-Shenzhen, Shenzhen, China
- Villum Center for Biodiversity Genomics, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Stephen J Rossiter
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, UK
| | - Dong-Dong Wu
- State Key Laboratory of Genetic Evolution & Animal Models, Kunming Natural History Museum of Zoology, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
- National Resource Center for Non-Human Primates, Kunming Primate Research Center, and National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China.
| | - Yang Liu
- College of Life Sciences, Shaanxi Normal University, Xi'an, China.
| | - Huimeng Lu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
| | - Gang Li
- College of Life Sciences, Shaanxi Normal University, Xi'an, China.
- QinLing-Bashan Mountains Bioresources Comprehensive Development C. I. C., School of Bioscience and Engineering, Shaanxi University of Technology, Hanzhong, China.
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4
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Ben Khemis I, Aouaini F, Bukhari L, Albadrani GM, Alruwaili A, Knani S, Ben Lamine A. Theoretical assessment of the adsorption mechanism of carvone enantiomers on cow btOR1A1: New microscopic interpretations. Int J Biol Macromol 2025; 293:139332. [PMID: 39743076 DOI: 10.1016/j.ijbiomac.2024.139332] [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: 07/22/2024] [Revised: 12/27/2024] [Accepted: 12/28/2024] [Indexed: 01/04/2025]
Abstract
In this study, the olfactory threshold concentration was introduced in the statistical physics approach to provide fruitful and deep discussions. Indeed, a modified mono-layer mono-energy model established using statistical physics theory was successfully used to theoretically study the adsorption involved in the olfactory response of (R)-(-)-carvone and (S)-(+)-carvone key food odorants (KFOs) on cow (Bos taurus) olfactory receptor btOR1A1 through the analysis of the different model physicochemical parameters. Thus, stereographic results indicated that the two carvone enantiomers were non-parallelly docked on btOR1A1 binding sites during the adsorption process since the different values of n were superior to 1. Molecular docking studies suggest that the high olfactory response of (R)-(-)-carvone was attributed to the specific types of interactions observed. The energetic results showed via the fitted values of the molar adsorption energies, which were positive and lower than 5 kJ/mol, that the studied enantiomers were exothermically physisorbed via conventional hydrogen bond, pi-alkyl, alkyl, pi-sigma, and van der Waals interactions for (R)-(-)-carvone-btOR1A1 complex and via carbon hydrogen bond, alkyl, pi-alkyl, pi-sigma, and van der Waals interactions for (S)-(+)-carvone-btOR1A1 complex. Moreover, the cow olfactory responses were detected only when 0.49 % and 8.63 % of btOR1A1 binding sites are fired or occupied by (R)-(-)-carvone and (S)-(+)-carvone, respectively. These parameters may also be employed to quantitatively characterize the two olfactory systems.
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Affiliation(s)
- Ismahene Ben Khemis
- Laboratory of Quantum and Statistical Physics LR 18 ES 18, Faculty of Sciences of Monastir, Environnement Street, 5019 Monastir, Tunisia.
| | - Fatma Aouaini
- Department of Physics, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Lamies Bukhari
- Department of Physics, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Ghadeer Mohsen Albadrani
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Amani Alruwaili
- Department of Physics, College of Science, Northern Border University, Arar, Saudi Arabia
| | - Salah Knani
- Center for Scientific Research and Entrepreneurship, Northern Border University, 73213 Arar, Saudi Arabia
| | - Abdelmottaleb Ben Lamine
- Laboratory of Quantum and Statistical Physics LR 18 ES 18, Faculty of Sciences of Monastir, Environnement Street, 5019 Monastir, Tunisia
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Takayama I, Araki N, Tewari J, Yohda M, Matsunami H, Fukutani Y. Antagonists Enhance Cell-Surface Expression of Mammalian Odorant Receptors. Int J Mol Sci 2025; 26:1458. [PMID: 40003926 PMCID: PMC11855683 DOI: 10.3390/ijms26041458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2024] [Revised: 01/31/2025] [Accepted: 02/08/2025] [Indexed: 02/27/2025] Open
Abstract
Functional characterization of vertebrate odorant receptors (ORs), members of the G protein-coupled receptor (GPCR) family, is essential for understanding olfaction. However, the functional expression of ORs in heterologous cells is often challenging, at least partly caused by structural instability in non-olfactory cells. Antagonists have been shown to restore membrane expression of some non-olfactory GPCR mutants, likely by transient increase in structural stability upon antagonist binding. Based on this premise, we examined whether antagonists could enhance OR membrane expression in heterologous cells. Using phenyl salicylate (PES) on cells expressing the mouse OR Or11g7, we observed increased cell surface expression exceeding the effects of co-expression with the OR chaperone RTP1S. After removing the antagonist, Or11g7 retained normal agonist responsiveness. Similar enhancements in cell surface expression were observed for a human OR OR2T11 treated with its antagonists. These findings suggest that small-molecule antagonists act as pharmacological chaperones to stabilize OR conformation, enhancing surface expression in a manner similar to molecular chaperones. Our study reveals a novel role for odorant antagonists in OR biogenesis and may inform future research on olfactory training mechanisms.
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Affiliation(s)
- Ikumi Takayama
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei 184-8588, Tokyo, Japan; (I.T.); (N.A.); (M.Y.)
| | - Nako Araki
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei 184-8588, Tokyo, Japan; (I.T.); (N.A.); (M.Y.)
| | - Jeevan Tewari
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei 184-8588, Tokyo, Japan; (I.T.); (N.A.); (M.Y.)
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yosuke Fukutani
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei 184-8588, Tokyo, Japan; (I.T.); (N.A.); (M.Y.)
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Dong X, Lv M, Zeng M, Chen X, Wang J, Liang XF. Genome-Wide Identification, Characterization of the ORA (Olfactory Receptor Class A) Gene Family, and Potential Roles in Bile Acid and Pheromone Recognition in Mandarin Fish ( Siniperca chuatsi). Cells 2025; 14:189. [PMID: 39936981 PMCID: PMC11817882 DOI: 10.3390/cells14030189] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2024] [Revised: 01/17/2025] [Accepted: 01/24/2025] [Indexed: 02/13/2025] Open
Abstract
The ORA (olfactory receptor class A) gene family in teleosts is related to the V1R (vomeronasal 1 receptors) family in mammals and plays a key role in odor detection. Although ORA genes have been identified in several teleosts, their characteristics in mandarin fish (Siniperca chuatsi) have not been explored. In this study, we conducted a comprehensive genomic analysis of the mandarin fish and discovered a complete ORA gene family consisting of five members located on chromosome 2 (ORA1, ORA2, ORA3, ORA4) and chromosome 16 (ORA6). Phylogenetic, synteny, and gene structure analyses revealed typical exon-intron conservation with strong evidence of purifying selection. Tissue expression analysis showed distinct expression profiles for each ORA gene, with some showing sexual dimorphism in specific tissues. The expression of ORA1 and ORA2 in the olfactory epithelium exhibits sexual dimorphism, while ORA3 shows sexual dimorphism in the brain. In situ hybridization confirmed that ORA1, ORA2, ORA3, and ORA6 are expressed in the microvillar sensory neurons of the olfactory epithelium, while ORA4 is expressed in crypt cells. Additionally, molecular docking simulations indicated that the five ORA proteins have a high binding affinity with seven bile acids (LAC, GLAC, CA, TLCA, 3-KLCA, 7-KLCA, and 12-KLCA), with ORAs showing stronger binding affinity with LCA and CA. This study comprehensively characterizes the ORA gene family in mandarin fish, examining its phylogeny, synteny, gene structure, and selection pressure. Furthermore, we found that each ORA displays a distinct expression pattern across multiple tissues, with notable sexual dimorphism, and shows potential binding interactions with specific bile acids and pheromones. Our findings provide valuable insights that enhance the overall understanding of fish ORAs and their potential functions.
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Affiliation(s)
- Xiaoru Dong
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (X.D.); (M.Z.); (X.C.); (J.W.)
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
| | - Maolin Lv
- Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China;
| | - Ming Zeng
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (X.D.); (M.Z.); (X.C.); (J.W.)
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
| | - Xiaochuan Chen
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (X.D.); (M.Z.); (X.C.); (J.W.)
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
| | - Jiale Wang
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (X.D.); (M.Z.); (X.C.); (J.W.)
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
| | - Xu-Fang Liang
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (X.D.); (M.Z.); (X.C.); (J.W.)
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
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Li H, Covington JA, Tian F, Wu Z, Liu Y, Hu L. Development and analysis of an artificial olfactory bulb. Talanta 2024; 279:126551. [PMID: 39018948 DOI: 10.1016/j.talanta.2024.126551] [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: 03/26/2024] [Revised: 06/24/2024] [Accepted: 07/10/2024] [Indexed: 07/19/2024]
Abstract
This article presents the development of an artificial olfactory bulb (OB) using an electronic nose with thermally modulated metal-oxide sensors. Inspired by animal OBs, our approach employs thermal modulation to replicate the spatial encoding patterns of glomeruli clusters and subclusters. This new approach enhances the classification capabilities of traditional electronic noses and offers new insights for biomimetic olfaction. Molecular receptive range (MRR) analysis confirms that our artificial OB effectively mimics the glomerular distribution of animal OBs. Additionally, the incorporation of a short axon cell (SAC) network, inspired by the animal olfactory system, significantly improves lifetime sparseness and qualitative ability of the artificial OB through extensive lateral inhibition, providing a theoretical framework for enhanced olfactory performance.
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Affiliation(s)
- Hantao Li
- School of Microelectronic and Communication Engineering, Chongqing University, 400044, Chongqing, China
| | | | - Fengchun Tian
- School of Microelectronic and Communication Engineering, Chongqing University, 400044, Chongqing, China; Chongqing Key Laboratory of Bio-perception and Intelligent Information Processing, 400044, Chongqing, China.
| | - Zhiyuan Wu
- School of Microelectronic and Communication Engineering, Chongqing University, 400044, Chongqing, China; School of Engineering, University of Warwick, CV47AL, Coventry, UK
| | - Yue Liu
- School of Microelectronic and Communication Engineering, Chongqing University, 400044, Chongqing, China
| | - Li Hu
- School of Microelectronic and Communication Engineering, Chongqing University, 400044, Chongqing, China
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Philbrook A, O’Donnell MP, Grunenkovaite L, Sengupta P. Cilia structure and intraflagellar transport differentially regulate sensory response dynamics within and between C. elegans chemosensory neurons. PLoS Biol 2024; 22:e3002892. [PMID: 39591402 PMCID: PMC11593760 DOI: 10.1371/journal.pbio.3002892] [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: 05/10/2024] [Accepted: 10/10/2024] [Indexed: 11/28/2024] Open
Abstract
Sensory neurons contain morphologically diverse primary cilia that are built by intraflagellar transport (IFT) and house sensory signaling molecules. Since both ciliary structural and signaling proteins are trafficked via IFT, it has been challenging to decouple the contributions of IFT and cilia structure to neuronal responses. By acutely inhibiting IFT without altering cilia structure and vice versa, here we describe the differential roles of ciliary trafficking and sensory ending morphology in shaping chemosensory responses in Caenorhabditis elegans. We show that a minimum cilium length but not continuous IFT is necessary for a subset of responses in the ASH nociceptive neurons. In contrast, neither cilia nor continuous IFT are necessary for odorant responses in the AWA olfactory neurons. Instead, continuous IFT differentially modulates response dynamics in AWA. Upon acute inhibition of IFT, cilia-destined odorant receptors are shunted to ectopic branches emanating from the AWA cilia base. Spatial segregation of receptors in these branches from a cilia-restricted regulatory kinase results in odorant desensitization defects, highlighting the importance of precise organization of signaling molecules at sensory endings in regulating response dynamics. We also find that adaptation of AWA responses upon repeated exposure to an odorant is mediated by IFT-driven removal of its cognate receptor, whereas adaptation to a second odorant is regulated via IFT-independent mechanisms. Our results reveal unexpected complexity in the contribution of IFT and cilia organization to the regulation of responses even within a single chemosensory neuron type and establish a critical role for these processes in the precise modulation of olfactory behaviors.
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Affiliation(s)
- Alison Philbrook
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Michael P. O’Donnell
- Department of Molecular, Cellular, and Developmental Biology, Yale University, Connecticut, United States of America
| | - Laura Grunenkovaite
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
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Howe JR, Chan CL, Lee D, Blanquart M, Lee JH, Romero HK, Zadina AN, Lemieux ME, Mills F, Desplats PA, Tye KM, Root CM. Control of innate olfactory valence by segregated cortical amygdala circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.26.600895. [PMID: 38979308 PMCID: PMC11230396 DOI: 10.1101/2024.06.26.600895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Animals exhibit innate behaviors that are stereotyped responses to specific evolutionarily relevant stimuli in the absence of prior learning or experience. These behaviors can be reduced to an axis of valence, whereby specific odors evoke approach or avoidance responses. The posterolateral cortical amygdala (plCoA) mediates innate attraction and aversion to odor. However, little is known about how this brain area gives rise to behaviors of opposing motivational valence. Here, we sought to define the circuit features of plCoA that give rise to innate attraction and aversion to odor. We characterized the physiology, gene expression, and projections of this structure, identifying a divergent, topographic organization that selectively controls innate attraction and avoidance to odor. First, we examined odor-evoked responses in these areas and found sparse encoding of odor identity, but not valence. We next considered a topographic organization and found that optogenetic stimulation of the anterior and posterior domains of plCoA elicits attraction and avoidance, respectively, suggesting a functional axis for valence. Using single cell and spatial RNA sequencing, we identified the molecular cell types in plCoA, revealing an anteroposterior gradient in cell types, whereby anterior glutamatergic neurons preferentially express VGluT2 and posterior neurons express VGluT1. Activation of these respective cell types recapitulates appetitive and aversive behaviors, and chemogenetic inhibition reveals partial necessity for responses to innate appetitive or aversive odors. Finally, we identified topographically organized circuits defined by projections, whereby anterior neurons preferentially project to medial amygdala, and posterior neurons preferentially project to nucleus accumbens, which are respectively sufficient and necessary for innate attraction and aversion. Together, these data advance our understanding of how the olfactory system generates stereotypic, hardwired attraction and avoidance, and supports a model whereby distinct, topographically distributed plCoA populations direct innate olfactory responses by signaling to divergent valence-specific targets, linking upstream olfactory identity to downstream valence behaviors, through a population code. This suggests a novel amygdala circuit motif in which valence encoding is represented not by the firing properties of individual neurons, but by population level identity encoding that is routed through divergent targets to mediate distinct behaviors of opposing appetitive and aversive responses.
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Affiliation(s)
- James R. Howe
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
- These authors contributed equally
| | - Chung-Lung Chan
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
- These authors contributed equally
| | - Donghyung Lee
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Marlon Blanquart
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - James H. Lee
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Haylie K. Romero
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Abigail N. Zadina
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, 10027, USA
| | | | - Fergil Mills
- Salk Institute for Biological Sciences, La Jolla, CA 92037, USA
| | - Paula A. Desplats
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kay M. Tye
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
- Salk Institute for Biological Sciences, La Jolla, CA 92037, USA
- Howard Hughes Medical Institute, La Jolla, CA 92037, USA
| | - Cory M. Root
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
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10
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Ye Y, Wang Y, Zhuang Y, Tan H, Zuo Z, Yun H, Yuan K, Zhou W. Decomposition of an odorant in olfactory perception and neural representation. Nat Hum Behav 2024; 8:1150-1162. [PMID: 38499771 DOI: 10.1038/s41562-024-01849-0] [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: 01/01/2023] [Accepted: 02/19/2024] [Indexed: 03/20/2024]
Abstract
Molecules-the elementary units of substances-are commonly considered the units of processing in olfactory perception, giving rise to undifferentiated odour objects invariant to environmental variations. By selectively perturbing the processing of chemical substructures with adaptation ('the psychologist's microelectrode') in a series of psychophysical and neuroimaging experiments (458 participants), we show that two perceptually distinct odorants sharing part of their structural features become significantly less discernible following adaptation to a third odorant containing their non-shared structural features, in manners independent of olfactory intensity, valence, quality or general olfactory adaptation. The effect is accompanied by reorganizations of ensemble activity patterns in the posterior piriform cortex that parallel subjective odour quality changes, in addition to substructure-based neural adaptations in the anterior piriform cortex and amygdala. Central representations of odour quality and the perceptual outcome thus embed submolecular structural information and are malleable by recent olfactory encounters.
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Affiliation(s)
- Yuting Ye
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- Institute of Psychology, School of Public Affairs, Xiamen University, Xiamen, China
| | - Yanqing Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- School of Psychology, Northwest Normal University, Lanzhou, China
| | - Yuan Zhuang
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Huibang Tan
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Zhentao Zuo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
- Sino-Dannish College, University of Chinese Academy of Sciences, Beijing, China
| | - Hanqi Yun
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Kaiqi Yuan
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Wen Zhou
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
- Chinese Institute for Brain Research, Beijing, China.
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11
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Philbrook A, O'Donnell MP, Grunenkovaite L, Sengupta P. Differential modulation of sensory response dynamics by cilia structure and intraflagellar transport within and across chemosensory neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594529. [PMID: 38798636 PMCID: PMC11118401 DOI: 10.1101/2024.05.16.594529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Sensory neurons contain morphologically diverse primary cilia that are built by intraflagellar transport (IFT) and house sensory signaling molecules. Since both ciliary structural and signaling proteins are trafficked via IFT, it has been challenging to decouple the contributions of IFT and cilia structure to neuronal responses. By acutely inhibiting IFT without altering cilia structure and vice versa , here we describe the differential roles of ciliary trafficking and sensory ending morphology in shaping chemosensory responses in C. elegans. We show that a minimum cilium length but not continuous IFT is necessary for a subset of responses in the ASH nociceptive neurons. In contrast, neither cilia nor continuous IFT are necessary for odorant responses in the AWA olfactory neurons. Instead, continuous IFT differentially modulates response dynamics in AWA. Upon acute inhibition of IFT, cilia-destined odorant receptors are shunted to ectopic branches emanating from the cilia base. Spatial segregation of receptors in these branches from a cilia-restricted regulatory kinase results in odorant desensitization defects, highlighting the importance of precise organization of signaling molecules at sensory endings in regulating response dynamics. We also find that adaptation of AWA responses upon repeated exposure to an odorant is mediated by IFT-driven removal of its cognate receptor, whereas adaptation to a second odorant is regulated via IFT-independent mechanisms. Our results reveal unexpected complexity in the contribution of IFT and cilia organization to the regulation of responses even within a single chemosensory neuron type, and establish a critical role for these processes in the precise modulation of olfactory behaviors.
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12
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Kanata E, Duffié R, Schulz EG. Establishment and maintenance of random monoallelic expression. Development 2024; 151:dev201741. [PMID: 38813842 PMCID: PMC11166465 DOI: 10.1242/dev.201741] [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] [Indexed: 05/31/2024]
Abstract
This Review elucidates the regulatory principles of random monoallelic expression by focusing on two well-studied examples: the X-chromosome inactivation regulator Xist and the olfactory receptor gene family. Although the choice of a single X chromosome or olfactory receptor occurs in different developmental contexts, common gene regulatory principles guide monoallelic expression in both systems. In both cases, an event breaks the symmetry between genetically and epigenetically identical copies of the gene, leading to the expression of one single random allele, stabilized through negative feedback control. Although many regulatory steps that govern the establishment and maintenance of monoallelic expression have been identified, key pieces of the puzzle are still missing. We provide an overview of the current knowledge and models for the monoallelic expression of Xist and olfactory receptors. We discuss their similarities and differences, and highlight open questions and approaches that could guide the study of other monoallelically expressed genes.
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Affiliation(s)
- Eleni Kanata
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Rachel Duffié
- Department of Biochemistry and Molecular Biophysics, Mortimer B. Zuckerman Mind, Brain, and Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Edda G. Schulz
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
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13
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Mathur A, Mehta V, Obulareddy VT, Kumar P. Narrative review on artificially intelligent olfaction in halitosis. J Oral Maxillofac Pathol 2024; 28:275-283. [PMID: 39157836 PMCID: PMC11329069 DOI: 10.4103/jomfp.jomfp_448_23] [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: 10/16/2023] [Revised: 12/22/2023] [Accepted: 12/30/2023] [Indexed: 08/20/2024] Open
Abstract
Halitosis, commonly known as oral malodor, is a multifactorial health concern that significantly impacts the psychological and social well-being of individuals. It is the third most frequent reason for individuals to seek dental treatment, after dental caries and periodontal diseases. For an in-depth exploration of the topic of halitosis, an extensive literature review was conducted. The review focused on articles published in peer-reviewed journals and only those written in the English language were considered. The search for relevant literature began by employing subject headings such as 'halitosis, oral malodor, volatile sulfur compounds, artificial intelligence, and olfaction' in databases such as PubMed/Medline, Scopus, Google Scholar, Web of Science, and EMBASE. Additionally, a thorough hand search of references was conducted to ensure the comprehensiveness of the review. After amalgamating the search outcomes, a comprehensive analysis revealed the existence of precisely 134 full-text articles that bore relevance to the study. Abstracts and editorial letters were excluded from this study, and almost 50% of the full-text articles were deemed immaterial to dental practice. Out of the remaining articles, precisely 54 full-text articles were employed in this review. As primary healthcare providers, dentists are responsible for diagnosing and treating oral issues that may contribute to the development of halitosis. To effectively manage this condition, dentists must educate their patients about the underlying causes of halitosis, as well as proper oral hygiene practices such as tongue cleaning, flossing, and selecting appropriate mouthwash and toothpaste. This narrative review summarises all possible AI olfaction in halitosis.
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Affiliation(s)
- Ankita Mathur
- Department of Dental Research Cell, Dr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil Vidyapeeth, Pune, Maharashtra, India
| | - Vini Mehta
- Department of Dental Research Cell, Dr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil Vidyapeeth, Pune, Maharashtra, India
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14
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Dias BG. Legacies of salient environmental experiences-insights from chemosensation. Chem Senses 2024; 49:bjae002. [PMID: 38219073 PMCID: PMC10825851 DOI: 10.1093/chemse/bjae002] [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: 06/23/2023] [Indexed: 01/15/2024] Open
Abstract
Evidence for parental environments profoundly influencing the physiology, biology, and neurobiology of future generations has been accumulating in the literature. Recent efforts to understand this phenomenon and its underlying mechanisms have sought to use species like rodents and insects to model multi-generational legacies of parental experiences like stress and nutritional exposures. From these studies, we have come to appreciate that parental exposure to salient environmental experiences impacts the cadence of brain development, hormonal responses to stress, and the expression of genes that govern cellular responses to stress in offspring. Recent studies using chemosensory exposure have emerged as a powerful tool to shed new light on how future generations come to be influenced by environments to which parents are exposed. With a specific focus on studies that have leveraged such use of salient chemosensory experiences, this review synthesizes our current understanding of the concept, causes, and consequences of the inheritance of chemosensory legacies by future generations and how this field of inquiry informs the larger picture of how parental experiences can influence offspring biology.
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Affiliation(s)
- Brian G Dias
- Developmental Neuroscience and Neurogenetics Program, The Saban Research Institute, Los Angeles, CA, United States
- Division of Endocrinology, Diabetes and Metabolism, Children’s Hospital Los Angeles, Los Angeles, CA, United States
- Department of Pediatrics, Keck School of Medicine of USC, Los Angeles, CA, United States
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15
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Lalis M, Hladiš M, Abi Khalil S, Deroo C, Marin C, Bensafi M, Baldovini N, Briand L, Fiorucci S, Topin J. A status report on human odorant receptors and their allocated agonists. Chem Senses 2024; 49:bjae037. [PMID: 39400708 DOI: 10.1093/chemse/bjae037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Indexed: 10/15/2024] Open
Abstract
Olfactory perception begins when odorous substances interact with specialized receptors located on the surface of dedicated sensory neurons. The recognition of smells depends on a complex mechanism involving a combination of interactions between an odorant and a set of odorant receptors (ORs), where molecules are recognized according to a combinatorial activation code of ORs. Although these interactions have been studied for decades, the rules governing this ligand recognition remain poorly understood, and the complete combinatorial code is only known for a handful of odorants. We have carefully analyzed experimental results regarding the interactions between ORs and molecules to provide a status report on the deorphanization of ORs, i.e. the identification of the first agonist for a given sequence. This meticulous analysis highlights the influence of experimental methodology (cell line or readout) on molecule-receptor association results and shows that 83% of the results are conserved regardless of experimental conditions. The distribution of another key parameter, EC50, indicates that most OR ligand activities are in the micromolar range and that impurities could lead to erroneous conclusions. Focusing on the human ORs, our study shows that 88% of the documented sequences still need to be deorphanized. Finally, we also estimate the size of the ORs' recognition range, or broadness, as the number of odorants activating a given OR. By analogously estimating molecular broadness and combining the two estimates we propose a basic framework that can serve as a comparison point for future machine learning algorithms predicting OR-molecule activity.
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Affiliation(s)
- Maxence Lalis
- Institut de Chimie de Nice, UMR 7272, Université Côte d'Azur, Nice, France
| | - Matej Hladiš
- Institut de Chimie de Nice, UMR 7272, Université Côte d'Azur, Nice, France
| | - Samar Abi Khalil
- Institut de Chimie de Nice, UMR 7272, Université Côte d'Azur, Nice, France
| | - Christophe Deroo
- Expressions Parfumées, 136 chemin de St Marc, 06130, Grasse, France
| | - Christophe Marin
- Expressions Parfumées, 136 chemin de St Marc, 06130, Grasse, France
| | - Moustafa Bensafi
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028, University Claude Bernard Lyon, Bron, France
| | - Nicolas Baldovini
- Institut de Chimie de Nice, UMR 7272, Université Côte d'Azur, Nice, France
| | - Loïc Briand
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, F-21000, Dijon, France
| | - Sébastien Fiorucci
- Institut de Chimie de Nice, UMR 7272, Université Côte d'Azur, Nice, France
| | - Jérémie Topin
- Institut de Chimie de Nice, UMR 7272, Université Côte d'Azur, Nice, France
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16
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Shaffer C, Barrett LF, Quigley KS. Signal processing in the vagus nerve: Hypotheses based on new genetic and anatomical evidence. Biol Psychol 2023; 182:108626. [PMID: 37419401 PMCID: PMC10563766 DOI: 10.1016/j.biopsycho.2023.108626] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 06/25/2023] [Accepted: 07/03/2023] [Indexed: 07/09/2023]
Abstract
Each organism must regulate its internal state in a metabolically efficient way as it interacts in space and time with an ever-changing and only partly predictable world. Success in this endeavor is largely determined by the ongoing communication between brain and body, and the vagus nerve is a crucial structure in that dialogue. In this review, we introduce the novel hypothesis that the afferent vagus nerve is engaged in signal processing rather than just signal relay. New genetic and structural evidence of vagal afferent fiber anatomy motivates two hypotheses: (1) that sensory signals informing on the physiological state of the body compute both spatial and temporal viscerosensory features as they ascend the vagus nerve, following patterns found in other sensory architectures, such as the visual and olfactory systems; and (2) that ascending and descending signals modulate one another, calling into question the strict segregation of sensory and motor signals, respectively. Finally, we discuss several implications of our two hypotheses for understanding the role of viscerosensory signal processing in predictive energy regulation (i.e., allostasis) as well as the role of metabolic signals in memory and in disorders of prediction (e.g., mood disorders).
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Affiliation(s)
- Clare Shaffer
- Department of Psychology, College of Science, Northeastern University, Boston, MA, USA.
| | - Lisa Feldman Barrett
- Department of Psychology, College of Science, Northeastern University, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Karen S Quigley
- Department of Psychology, College of Science, Northeastern University, Boston, MA, USA.
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17
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Fukutani Y, Abe M, Saito H, Eguchi R, Tazawa T, de March CA, Yohda M, Matsunami H. Antagonistic interactions between odorants alter human odor perception. Curr Biol 2023; 33:2235-2245.e4. [PMID: 37220745 PMCID: PMC10394640 DOI: 10.1016/j.cub.2023.04.072] [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: 09/04/2022] [Revised: 03/19/2023] [Accepted: 04/27/2023] [Indexed: 05/25/2023]
Abstract
The olfactory system uses hundreds of odorant receptors (ORs), the largest group of the G-protein-coupled receptor (GPCR) superfamily, to detect a vast array of odorants. Each OR is activated by specific odorous ligands, and like other GPCRs, antagonism can block activation of ORs. Recent studies suggest that odorant antagonisms in mixtures influence olfactory neuron activities, but it is unclear how this affects perception of odor mixtures. In this study, we identified a set of human ORs activated by methanethiol and hydrogen sulfide, two potent volatile sulfur malodors, through large-scale heterologous expression. Screening odorants that block OR activation in heterologous cells identified a set of antagonists, including β-ionone. Sensory evaluation in humans revealed that β-ionone reduced the odor intensity and unpleasantness of methanethiol. Additionally, suppression was not observed when methanethiol and β-ionone were introduced simultaneously to different nostrils. Our study supports the hypothesis that odor sensation is altered through antagonistic interactions at the OR level.
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Affiliation(s)
- Yosuke Fukutani
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
| | - Masashi Abe
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Haruka Saito
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Ryo Eguchi
- Research Section, R & D Division, S.T. Corporation, Shinjuku, Tokyo 161-0033, Japan
| | - Toshiaki Tazawa
- Research Section, R & D Division, S.T. Corporation, Shinjuku, Tokyo 161-0033, Japan
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Institute of Chemistry of the Natural Substances, Université Paris Saclay, CNRS UPR2301, Gif-sur-Yvette 91190, France
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
| | - Hiroaki Matsunami
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan; Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 27705, USA.
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18
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Zung JL, Kotb SM, McBride CS. Exploring natural odour landscapes: A case study with implications for human-biting insects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539789. [PMID: 37398328 PMCID: PMC10312452 DOI: 10.1101/2023.05.08.539789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The natural world is full of odours-blends of volatile chemicals emitted by potential sources of food, social partners, predators, and pathogens. Animals rely heavily on these signals for survival and reproduction. Yet we remain remarkably ignorant of the composition of the chemical world. How many compounds do natural odours typically contain? How often are those compounds shared across stimuli? What are the best statistical strategies for discrimination? Answering these questions will deliver crucial insight into how brains can most efficiently encode olfactory information. Here, we undertake the first large-scale survey of vertebrate body odours, a set of stimuli relevant to blood-feeding arthropods. We quantitatively characterize the odour of 64 vertebrate species (mostly mammals), representing 29 families and 13 orders. We confirm that these stimuli are complex blends of relatively common, shared compounds and show that they are much less likely to contain unique components than are floral odours-a finding with implications for olfactory coding in blood feeders and floral visitors. We also find that vertebrate body odours carry little phylogenetic information, yet show consistency within a species. Human odour is especially unique, even compared to the odour of other great apes. Finally, we use our newfound understanding of odour-space statistics to make specific predictions about olfactory coding, which align with known features of mosquito olfactory systems. Our work provides one of the first quantitative descriptions of a natural odour space and demonstrates how understanding the statistics of sensory environments can provide novel insight into sensory coding and evolution.
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Affiliation(s)
- Jessica L. Zung
- Department of Ecology and Evolutionary Biology and Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA 08544
| | | | - Carolyn S. McBride
- Department of Ecology and Evolutionary Biology and Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA 08544
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19
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Trimmer C, Arroyave R, Vuilleumier C, Wu L, Dumer A, DeLaura C, Kim J, Pierce GM, Borisovska M, De Nanteuil F, Emberger M, Varganov Y, Margot C, Rogers ME, Pfister P. Allosteric modulation of a human odorant receptor. Curr Biol 2023; 33:1523-1534.e4. [PMID: 36977419 DOI: 10.1016/j.cub.2023.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 12/02/2022] [Accepted: 03/06/2023] [Indexed: 03/29/2023]
Abstract
Odor perception is first determined by how the myriad of environmental volatiles are detected at the periphery of the olfactory system. The combinatorial activation of dedicated odorant receptors generates enough encoding power for the discrimination of tens of thousands of odorants. Recent studies have revealed that odorant receptors undergo widespread inhibitory modulation of their activity when presented with mixtures of odorants, a property likely required to maintain discrimination and ensure sparsity of the code for complex mixtures. Here, we establish the role of human OR5AN1 in the detection of musks and identify distinct odorants capable of enhancing its activity in binary mixtures. Chemical and pharmacological characterization indicate that specific α-β unsaturated aliphatic aldehydes act as positive allosteric modulators. Sensory experiments show decreased odor detection threshold in humans, suggesting that allosteric modulation of odorant receptors is perceptually relevant and likely adds another layer of complexity to how odors are encoded in the peripheral olfactory system.
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20
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Lin A, Qin S, Casademunt H, Wu M, Hung W, Cain G, Tan NZ, Valenzuela R, Lesanpezeshki L, Venkatachalam V, Pehlevan C, Zhen M, Samuel AD. Functional imaging and quantification of multineuronal olfactory responses in C. elegans. SCIENCE ADVANCES 2023; 9:eade1249. [PMID: 36857454 PMCID: PMC9977185 DOI: 10.1126/sciadv.ade1249] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 02/01/2023] [Indexed: 05/21/2023]
Abstract
Many animals perceive odorant molecules by collecting information from ensembles of olfactory neurons, where each neuron uses receptors that are tuned to recognize certain odorant molecules with different binding affinity. Olfactory systems are able, in principle, to detect and discriminate diverse odorants using combinatorial coding strategies. We have combined microfluidics and multineuronal imaging to study the ensemble-level olfactory representations at the sensory periphery of the nematode Caenorhabditis elegans. The collective activity of C. elegans chemosensory neurons reveals high-dimensional representations of olfactory information across a broad space of odorant molecules. We reveal diverse tuning properties and dose-response curves across chemosensory neurons and across odorants. We describe the unique contribution of each sensory neuron to an ensemble-level code for volatile odorants. We show that a natural stimuli, a set of nematode pheromones, are also encoded by the sensory ensemble. The integrated activity of the C. elegans chemosensory neurons contains sufficient information to robustly encode the intensity and identity of diverse chemical stimuli.
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Affiliation(s)
- Albert Lin
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Shanshan Qin
- Center for Brain Science, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Helena Casademunt
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Min Wu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Gregory Cain
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Nicolas Z. Tan
- Department of Physics, Northeastern University, Boston, MA, USA
| | | | - Leila Lesanpezeshki
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | | | - Cengiz Pehlevan
- Center for Brain Science, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Aravinthan D.T. Samuel
- Department of Physics, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
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21
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Nicoli A, Haag F, Marcinek P, He R, Kreißl J, Stein J, Marchetto A, Dunkel A, Hofmann T, Krautwurst D, Di Pizio A. Modeling the Orthosteric Binding Site of the G Protein-Coupled Odorant Receptor OR5K1. J Chem Inf Model 2023; 63:2014-2029. [PMID: 36696962 PMCID: PMC10091413 DOI: 10.1021/acs.jcim.2c00752] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
With approximately 400 encoding genes in humans, odorant receptors (ORs) are the largest subfamily of class A G protein-coupled receptors (GPCRs). Despite its high relevance and representation, the odorant-GPCRome is structurally poorly characterized: no experimental structures are available, and the low sequence identity of ORs to experimentally solved GPCRs is a significant challenge for their modeling. Moreover, the receptive range of most ORs is unknown. The odorant receptor OR5K1 was recently and comprehensively characterized in terms of cognate agonists. Here, we report two additional agonists and functional data of the most potent compound on two mutants, L1043.32 and L2556.51. Experimental data was used to guide the investigation of the binding modes of OR5K1 ligands into the orthosteric binding site using structural information from AI-driven modeling, as recently released in the AlphaFold Protein Structure Database, and from homology modeling. Induced-fit docking simulations were used to sample the binding site conformational space for ensemble docking. Mutagenesis data guided side chain residue sampling and model selection. We obtained models that could better rationalize the different activity of active (agonist) versus inactive molecules with respect to starting models and also capture differences in activity related to minor structural differences. Therefore, we provide a model refinement protocol that can be applied to model the orthosteric binding site of ORs as well as that of GPCRs with low sequence identity to available templates.
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Affiliation(s)
- Alessandro Nicoli
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Franziska Haag
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Patrick Marcinek
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Ruiming He
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany.,Department of Chemistry, Technical University of Munich, 85748 Garching, Germany
| | - Johanna Kreißl
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Jörg Stein
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Alessandro Marchetto
- Computational Biomedicine, Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.,Department of Biology, Faculty of Mathematics, Computer Science and Natural Sciences, RWTH Aachen University, 52074 Aachen, Germany
| | - Andreas Dunkel
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, 85354 Freising, Germany
| | - Dietmar Krautwurst
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Antonella Di Pizio
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
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22
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Ferguson ST, Bakis I, Edwards ND, Zwiebel LJ. Olfactory sensitivity differentiates morphologically distinct worker castes in Camponotus floridanus. BMC Biol 2023; 21:3. [PMID: 36617574 PMCID: PMC9827628 DOI: 10.1186/s12915-022-01505-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 12/08/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Camponotus floridanus ant colonies are comprised of a single reproductive queen and thousands of sterile female offspring that consist of two morphologically distinct castes: smaller minors and larger majors. Minors perform most of the tasks within the colony, including brood care and food collection, whereas majors have fewer clear roles and have been hypothesized to act as a specialized solider caste associated with colony defense. The allocation of workers to these different tasks depends, in part, on the detection and processing of local information including pheromones and other chemical blends such as cuticular hydrocarbons. However, the role peripheral olfactory sensitivity plays in establishing and maintaining morphologically distinct worker castes and their associated behaviors remains largely unexplored. RESULTS We examined the electrophysiological responses to general odorants, cuticular extracts, and a trail pheromone in adult minor and major C. floridanus workers, revealing that the repertoire of social behaviors is positively correlated with olfactory sensitivity. Minors in particular display primarily excitatory responses to olfactory stimuli, whereas major workers primarily manifest suppressed, sub-solvent responses. The notable exception to this paradigm is that both minors and majors display robust, dose-dependent excitatory responses to conspecific, non-nestmate cuticular extracts. Moreover, while both minors and majors actively aggress non-nestmate foes, the larger and physiologically distinct majors display significantly enhanced capabilities to rapidly subdue and kill their adversaries. CONCLUSIONS Our studies reveal the behavioral repertoire of minors and majors aligns with profound shifts in peripheral olfactory sensitivity and odor coding. The data reported here support the hypothesis that minors are multipotential workers with broad excitatory sensitivity, and majors are dedicated soldiers with a highly specialized olfactory system for distinguishing non-nestmate foes. Overall, we conclude that C. floridanus majors do indeed represent a physiologically and behaviorally specialized soldier caste in which caste-specific olfactory sensitivity plays an important role in task allocation and the regulation of social behavior in ant colonies.
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Affiliation(s)
- S. T. Ferguson
- grid.152326.10000 0001 2264 7217Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235 USA
| | - I. Bakis
- grid.152326.10000 0001 2264 7217Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235 USA
| | - N. D. Edwards
- grid.152326.10000 0001 2264 7217Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235 USA
| | - L. J. Zwiebel
- grid.152326.10000 0001 2264 7217Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235 USA
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23
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Dornburg A, Mallik R, Wang Z, Bernal MA, Thompson B, Bruford EA, Nebert DW, Vasiliou V, Yohe LR, Yoder JA, Townsend JP. Placing human gene families into their evolutionary context. Hum Genomics 2022; 16:56. [PMID: 36369063 PMCID: PMC9652883 DOI: 10.1186/s40246-022-00429-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/12/2022] [Indexed: 11/13/2022] Open
Abstract
Following the draft sequence of the first human genome over 20 years ago, we have achieved unprecedented insights into the rules governing its evolution, often with direct translational relevance to specific diseases. However, staggering sequence complexity has also challenged the development of a more comprehensive understanding of human genome biology. In this context, interspecific genomic studies between humans and other animals have played a critical role in our efforts to decode human gene families. In this review, we focus on how the rapid surge of genome sequencing of both model and non-model organisms now provides a broader comparative framework poised to empower novel discoveries. We begin with a general overview of how comparative approaches are essential for understanding gene family evolution in the human genome, followed by a discussion of analyses of gene expression. We show how homology can provide insights into the genes and gene families associated with immune response, cancer biology, vision, chemosensation, and metabolism, by revealing similarity in processes among distant species. We then explain methodological tools that provide critical advances and show the limitations of common approaches. We conclude with a discussion of how these investigations position us to gain fundamental insights into the evolution of gene families among living organisms in general. We hope that our review catalyzes additional excitement and research on the emerging field of comparative genomics, while aiding the placement of the human genome into its existentially evolutionary context.
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Affiliation(s)
- Alex Dornburg
- Department of Bioinformatics and Genomics, UNC-Charlotte, Charlotte, NC, USA.
| | - Rittika Mallik
- Department of Bioinformatics and Genomics, UNC-Charlotte, Charlotte, NC, USA
| | - Zheng Wang
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - Moisés A Bernal
- Department of Biological Sciences, College of Science and Mathematics, Auburn University, Auburn, AL, USA
| | - Brian Thompson
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Elspeth A Bruford
- Department of Haematology, University of Cambridge School of Clinical Medicine, Cambridge, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, UK
| | - Daniel W Nebert
- Department of Environmental Health, Center for Environmental Genetics, University of Cincinnati Medical Center, P.O. Box 670056, Cincinnati, OH, 45267, USA
- Department of Pediatrics and Molecular Developmental Biology, Division of Human Genetics, Cincinnati Children's Hospital, Cincinnati, OH, 45229, USA
| | - Vasilis Vasiliou
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Laurel R Yohe
- Department of Bioinformatics and Genomics, UNC-Charlotte, Charlotte, NC, USA
| | - Jeffrey A Yoder
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Jeffrey P Townsend
- Department of Bioinformatics and Genomics, UNC-Charlotte, Charlotte, NC, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
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24
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Frey T, Kwadha CA, Haag F, Pelletier J, Wallin EA, Holgersson E, Hedenström E, Bohman B, Bengtsson M, Becher PG, Krautwurst D, Witzgall P. The human odorant receptor OR10A6 is tuned to the pheromone of the commensal fruit fly Drosophila melanogaster. iScience 2022; 25:105269. [PMID: 36300000 PMCID: PMC9589189 DOI: 10.1016/j.isci.2022.105269] [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: 11/30/2021] [Revised: 04/10/2022] [Accepted: 09/29/2022] [Indexed: 12/03/2022] Open
Abstract
All living things speak chemistry. The challenge is to reveal the vocabulary, the odorants that enable communication across phylogenies and to translate them to physiological, behavioral, and ecological function. Olfactory receptors (ORs) interface animals with airborne odorants. Expression in heterologous cells makes it possible to interrogate single ORs and to identify cognate ligands. The cosmopolitan, anthropophilic strain of the vinegar fly Drosophila melanogaster depends on human resources and housing for survival. Curiously, humans sense the pheromone (Z)-4-undecenal (Z4-11Al) released by single fly females. A screening of all human ORs shows that the most highly expressed OR10A6 is tuned to Z4-11Al. Females of an ancestral African fly strain release a blend of Z4-11Al and Z4-9Al that produces a different aroma, which is how we distinguish these fly strains by nose. That flies and humans sense Z4-11Al via dedicated ORs shows how convergent evolution shapes communication channels between vertebrate and invertebrate animals. Humans sense the sex pheromone Z411-Al released by single Drosophila melanogaster females The most highly expressed human olfactory receptor OR10A6 is tuned to Z411-Al An African fly strain emits two aldehydes, which we distinguish from Z411-Al by nose Convergent evolution shapes chemical communication between phylogenies
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Affiliation(s)
- Tim Frey
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Charles A. Kwadha
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Franziska Haag
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Julien Pelletier
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Erika A. Wallin
- Department of Chemical Engineering, Mid Sweden University, Holmgatan 10, 85170 Sundsvall, Sweden
| | | | - Erik Hedenström
- Department of Chemical Engineering, Mid Sweden University, Holmgatan 10, 85170 Sundsvall, Sweden
| | - Björn Bohman
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Marie Bengtsson
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Paul G. Becher
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden
| | - Dietmar Krautwurst
- Leibniz-Institut für Lebensmittel-Systembiologie an der Technischen Universität München, Lise-Meitner Strasse 34, 85354 Freising, Germany
| | - Peter Witzgall
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 190, 234 22 Lomma, Sweden,Corresponding author
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25
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Burton SD, Brown A, Eiting TP, Youngstrom IA, Rust TC, Schmuker M, Wachowiak M. Mapping odorant sensitivities reveals a sparse but structured representation of olfactory chemical space by sensory input to the mouse olfactory bulb. eLife 2022; 11:e80470. [PMID: 35861321 PMCID: PMC9352350 DOI: 10.7554/elife.80470] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 07/20/2022] [Indexed: 11/17/2022] Open
Abstract
In olfactory systems, convergence of sensory neurons onto glomeruli generates a map of odorant receptor identity. How glomerular maps relate to sensory space remains unclear. We sought to better characterize this relationship in the mouse olfactory system by defining glomeruli in terms of the odorants to which they are most sensitive. Using high-throughput odorant delivery and ultrasensitive imaging of sensory inputs, we imaged responses to 185 odorants presented at concentrations determined to activate only one or a few glomeruli across the dorsal olfactory bulb. The resulting datasets defined the tuning properties of glomeruli - and, by inference, their cognate odorant receptors - in a low-concentration regime, and yielded consensus maps of glomerular sensitivity across a wide range of chemical space. Glomeruli were extremely narrowly tuned, with ~25% responding to only one odorant, and extremely sensitive, responding to their effective odorants at sub-picomolar to nanomolar concentrations. Such narrow tuning in this concentration regime allowed for reliable functional identification of many glomeruli based on a single diagnostic odorant. At the same time, the response spectra of glomeruli responding to multiple odorants was best predicted by straightforward odorant structural features, and glomeruli sensitive to distinct odorants with common structural features were spatially clustered. These results define an underlying structure to the primary representation of sensory space by the mouse olfactory system.
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Affiliation(s)
- Shawn D Burton
- Department of Neurobiology, University of Utah School of MedicineSalt Lake CityUnited States
| | - Audrey Brown
- Department of Neurobiology, University of Utah School of MedicineSalt Lake CityUnited States
| | - Thomas P Eiting
- Department of Neurobiology, University of Utah School of MedicineSalt Lake CityUnited States
| | - Isaac A Youngstrom
- Department of Neurobiology, University of Utah School of MedicineSalt Lake CityUnited States
| | - Thomas C Rust
- Department of Neurobiology, University of Utah School of MedicineSalt Lake CityUnited States
| | - Michael Schmuker
- Biocomputation Group, Centre of Data Innovation Research, Department of Computer Science, University of HertfordshireHertfordshireUnited Kingdom
| | - Matt Wachowiak
- Department of Neurobiology, University of Utah School of MedicineSalt Lake CityUnited States
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26
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Ghaninia M, Zhou Y, Knauer AC, Schiestl FP, Sharpee TO, Smith BH. Hyperbolic odorant mixtures as a basis for more efficient signaling between flowering plants and bees. PLoS One 2022; 17:e0270358. [PMID: 35830455 PMCID: PMC9278781 DOI: 10.1371/journal.pone.0270358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 06/08/2022] [Indexed: 11/19/2022] Open
Abstract
Animals use odors in many natural contexts, for example, for finding mates or food, or signaling danger. Most analyses of natural odors search for either the most meaningful components of a natural odor mixture, or they use linear metrics to analyze the mixture compositions. However, we have recently shown that the physical space for complex mixtures is ‘hyperbolic’, meaning that there are certain combinations of variables that have a disproportionately large impact on perception and that these variables have specific interpretations in terms of metabolic processes taking place inside the flower and fruit that produce the odors. Here we show that the statistics of odorants and odorant mixtures produced by inflorescences (Brassica rapa) are also better described with a hyperbolic rather than a linear metric, and that combinations of odorants in the hyperbolic space are better predictors of the nectar and pollen resources sought by bee pollinators than the standard Euclidian combinations. We also show that honey bee and bumble bee antennae can detect most components of the B. rapa odor space that we tested, and the strength of responses correlates with positions of odorants in the hyperbolic space. In sum, a hyperbolic representation can be used to guide investigation of how information is represented at different levels of processing in the CNS.
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Affiliation(s)
- Majid Ghaninia
- School of Life Sciences, Arizona State University, Tempe, AZ, United States of America
| | - Yuansheng Zhou
- The Salk Institute for Biological Studies, Computational Neurobiology Laboratory, La Jolla, CA, United States of America
- University of California, San Diego, La Jolla, CA, United States of America
| | - Anina C. Knauer
- Institute of Systematic and Evolutionary Botany University of Zurich, Zollikerstrasse, Zurich, Switzerland
| | - Florian P. Schiestl
- Institute of Systematic and Evolutionary Botany University of Zurich, Zollikerstrasse, Zurich, Switzerland
| | - Tatyana O. Sharpee
- The Salk Institute for Biological Studies, Computational Neurobiology Laboratory, La Jolla, CA, United States of America
- University of California, San Diego, La Jolla, CA, United States of America
- * E-mail: (TOS); , (BHS)
| | - Brian H. Smith
- School of Life Sciences, Arizona State University, Tempe, AZ, United States of America
- * E-mail: (TOS); , (BHS)
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27
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Xu R, Cong X, Zheng Q, Xu L, Ni MJ, de March CA, Matsunami H, Golebiowski J, Ma M, Yu Y. Interactions among key residues regulate mammalian odorant receptor trafficking. FASEB J 2022; 36:e22384. [PMID: 35639289 DOI: 10.1096/fj.202200116rr] [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: 01/20/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 11/11/2022]
Abstract
Odorant receptors (ORs) expressed in mammalian olfactory sensory neurons are essential for the sense of smell. However, structure-function studies of many ORs are hampered by unsuccessful heterologous expression. To understand and eventually overcome this bottleneck, we performed heterologous expression and functional assays of over 80 OR variants and chimeras. Combined with literature data and machine learning, we found that the transmembrane domain 4 (TM4) and its interactions with neighbor residues are important for OR functional expression. The data highlight critical roles of T4.62 therein. ORs that fail to reach the cell membrane can be rescued by modifications in TM4. Consequently, such modifications in MOR256-3 (Olfr124) also alter OR responses to odorants. T1614.62 P causes the retention of MOR256-3 in the endoplasmic reticulum (ER), while T1614.62 P/T1484.49 A reverses the retention and makes receptor trafficking to cell membrane. This study offers new clues toward wide-range functional studies of mammalian ORs.
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Affiliation(s)
- Rui Xu
- School of Life Sciences, Shanghai University, Shanghai, People's Republic of China
| | - Xiaojing Cong
- Institut de Chimie de Nice UMR7272, CNRS, Université Côte d'Azur, Nice, France.,Institut de Génomique Fonctionnelle, University of Montpellier, CNRS, INSERM, Montpellier Cedex 5, 34094, France
| | - Qian Zheng
- School of Life Sciences, Shanghai University, Shanghai, People's Republic of China
| | - Lun Xu
- Ear, Nose & Throat Institute, Department of Otolaryngology, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People's Republic of China
| | - Mengjue J Ni
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Jérôme Golebiowski
- Institut de Chimie de Nice UMR7272, CNRS, Université Côte d'Azur, Nice, France.,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Yiqun Yu
- Ear, Nose & Throat Institute, Department of Otolaryngology, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People's Republic of China.,Clinical and Research Center for Olfactory Disorders, Eye, Ear, Nose & Throat Hospital, Fudan University, Shanghai, People's Republic of China
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28
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Functional analysis of human olfactory receptors with a high basal activity using LNCaP cell line. PLoS One 2022; 17:e0267356. [PMID: 35446888 PMCID: PMC9022881 DOI: 10.1371/journal.pone.0267356] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 04/06/2022] [Indexed: 11/19/2022] Open
Abstract
Humans use a family of more than 400 olfactory receptors (ORs) to detect odorants. However, deorphanization of ORs is a critical issue because the functional properties of more than 80% of ORs remain unknown, thus, hampering our understanding of the relationship between receptor function and perception. HEK293 cells are the most commonly used heterologous expression system to determine the function of a given OR; however, they cannot functionally express a majority of ORs probably due to a lack of factor(s) required in cells in which ORs function endogenously. Interestingly, ORs have been known to be expressed in a variety of cells outside the nose and play critical physiological roles. These findings prompted us to test the capacity of cells to functionally express a specific repertoire of ORs. In this study, we selected three cell lines that endogenously express functional ORs. We demonstrated that human prostate carcinoma (LNCaP) cell lines successfully identified novel ligands for ORs that were not recognized when expressed in HEK293 cells. Further experiments suggested that the LNCaP cell line was effective for functional expression of ORs, especially with a high basal activity, which impeded the sensitive detection of ligand-mediated activity of ORs. This report provides an efficient functional assay system for a specific repertoire of ORs that cannot be characterized in current cell systems.
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29
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Cong X, Ren W, Pacalon J, Xu R, Xu L, Li X, de March CA, Matsunami H, Yu H, Yu Y, Golebiowski J. Large-Scale G Protein-Coupled Olfactory Receptor-Ligand Pairing. ACS CENTRAL SCIENCE 2022; 8:379-387. [PMID: 35350604 PMCID: PMC8949627 DOI: 10.1021/acscentsci.1c01495] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Indexed: 05/22/2023]
Abstract
G protein-coupled receptors (GPCRs) conserve common structural folds and activation mechanisms, yet their ligand spectra and functions are highly diverse. This work investigated how the amino-acid sequences of olfactory receptors (ORs)-the largest GPCR family-encode diversified responses to various ligands. We established a proteochemometric (PCM) model based on OR sequence similarities and ligand physicochemical features to predict OR responses to odorants using supervised machine learning. The PCM model was constructed with the aid of site-directed mutagenesis, in vitro functional assays, and molecular simulations. We found that the ligand selectivity of the ORs is mostly encoded in the residues up to 8 Å around the orthosteric pocket. Subsequent predictions using Random Forest (RF) showed a hit rate of up to 58%, as assessed by in vitro functional assays of 111 ORs and 7 odorants of distinct scaffolds. Sixty-four new OR-odorant pairs were discovered, and 25 ORs were deorphanized here. The best model demonstrated a 56% deorphanization rate. The PCM-RF approach will accelerate OR-odorant mapping and OR deorphanization.
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Affiliation(s)
- Xiaojing Cong
- Université
Côte d’Azur, CNRS, Institut de Chimie de Nice UMR7272, Nice 06108, France
- E-mail:
| | - Wenwen Ren
- Institutes
of Biomedical Sciences, Fudan University, Shanghai 200031, People’s Republic of China
| | - Jody Pacalon
- Université
Côte d’Azur, CNRS, Institut de Chimie de Nice UMR7272, Nice 06108, France
| | - Rui Xu
- School
of Life Sciences, Shanghai University, Shanghai 200444, People’s Republic of China
| | - Lun Xu
- Ear,
Nose & Throat Institute, Department of Otolaryngology, Eye, Ear,
Nose & Throat Hospital, Fudan University, Shanghai 200031, People’s Republic of China
| | - Xuewen Li
- School
of Life Sciences, Shanghai University, Shanghai 200444, People’s Republic of China
| | - Claire A. de March
- Department
of Molecular Genetics and Microbiology, and Department of Neurobiology,
and Duke Institute for Brain Sciences, Duke
University Medical Center, Research Drive, Durham, North Carolina 27710, United States
| | - Hiroaki Matsunami
- Department
of Molecular Genetics and Microbiology, and Department of Neurobiology,
and Duke Institute for Brain Sciences, Duke
University Medical Center, Research Drive, Durham, North Carolina 27710, United States
| | - Hongmeng Yu
- Ear,
Nose & Throat Institute, Department of Otolaryngology, Eye, Ear,
Nose & Throat Hospital, Fudan University, Shanghai 200031, People’s Republic of China
- Clinical
and Research Center for Olfactory Disorders, Eye, Ear, Nose &
Throat Hospital, Fudan University, Shanghai 200031, People’s Republic of China
- Research
Units of New Technologies of Endoscopic Surgery in Skull Base Tumor,
Chinese Academy of Medical Sciences, Beijing 100730, People’s
Republic of China
| | - Yiqun Yu
- Ear,
Nose & Throat Institute, Department of Otolaryngology, Eye, Ear,
Nose & Throat Hospital, Fudan University, Shanghai 200031, People’s Republic of China
- Clinical
and Research Center for Olfactory Disorders, Eye, Ear, Nose &
Throat Hospital, Fudan University, Shanghai 200031, People’s Republic of China
- E-mail:
| | - Jérôme Golebiowski
- Université
Côte d’Azur, CNRS, Institut de Chimie de Nice UMR7272, Nice 06108, France
- Department
of Brain and Cognitive Sciences, Daegu Gyeongbuk
Institute of Science and Technology, Daegu 711-873, South Korea
- E-mail:
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30
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Ruiz Tejada Segura ML, Abou Moussa E, Garabello E, Nakahara TS, Makhlouf M, Mathew LS, Wang L, Valle F, Huang SSY, Mainland JD, Caselle M, Osella M, Lorenz S, Reisert J, Logan DW, Malnic B, Scialdone A, Saraiva LR. A 3D transcriptomics atlas of the mouse nose sheds light on the anatomical logic of smell. Cell Rep 2022; 38:110547. [PMID: 35320714 PMCID: PMC8995392 DOI: 10.1016/j.celrep.2022.110547] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/26/2022] [Accepted: 03/01/2022] [Indexed: 12/26/2022] Open
Abstract
The sense of smell helps us navigate the environment, but its molecular architecture and underlying logic remain understudied. The spatial location of odorant receptor genes (Olfrs) in the nose is thought to be independent of the structural diversity of the odorants they detect. Using spatial transcriptomics, we create a genome-wide 3D atlas of the mouse olfactory mucosa (OM). Topographic maps of genes differentially expressed in space reveal that both Olfrs and non-Olfrs are distributed in a continuous and overlapping fashion over at least five broad zones in the OM. The spatial locations of Olfrs correlate with the mucus solubility of the odorants they recognize, providing direct evidence for the chromatographic theory of olfaction. This resource resolves the molecular architecture of the mouse OM and will inform future studies on mechanisms underlying Olfr gene choice, axonal pathfinding, patterning of the nervous system, and basic logic for the peripheral representation of smell.
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Affiliation(s)
- Mayra L Ruiz Tejada Segura
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany; Institute of Functional Epigenetics, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | | | - Elisa Garabello
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany; Physics Department, University of Turin and INFN, Via P. Giuria 1, 10125 Turin, Italy; Department of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Thiago S Nakahara
- Department of Biochemistry, University of São Paulo, São Paulo, Brazil
| | | | | | - Li Wang
- Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Filippo Valle
- Physics Department, University of Turin and INFN, Via P. Giuria 1, 10125 Turin, Italy
| | | | - Joel D Mainland
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA; Department of Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michele Caselle
- Physics Department, University of Turin and INFN, Via P. Giuria 1, 10125 Turin, Italy
| | - Matteo Osella
- Physics Department, University of Turin and INFN, Via P. Giuria 1, 10125 Turin, Italy
| | - Stephan Lorenz
- Sidra Medicine, P.O. Box 26999, Doha, Qatar; Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Johannes Reisert
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA
| | - Darren W Logan
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Bettina Malnic
- Department of Biochemistry, University of São Paulo, São Paulo, Brazil
| | - Antonio Scialdone
- Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München, Feodor-Lynen-Strasse 21, 81377 München, Germany; Institute of Functional Epigenetics, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
| | - Luis R Saraiva
- Sidra Medicine, P.O. Box 26999, Doha, Qatar; Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA; College of Health and Life Sciences, Hamad Bin Khalifa University, P.O. Box 34110, Doha, Qatar.
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31
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Wise PM, Ledyard A. Human Oral Sensitivity to and Taste Modulation by 3-Mercapto-2-Methylpentan-1-ol. CHEMOSENS PERCEPT 2022; 15:70-86. [PMID: 35233259 PMCID: PMC8873352 DOI: 10.1007/s12078-022-09295-w] [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: 07/24/2020] [Accepted: 02/01/2022] [Indexed: 01/11/2023]
Abstract
Introduction 3-Mercapto-2-methylpentan-1-ol (3 M) is a key onion flavor (aroma), but past sensory work has focused primarily on ortho-nasal presentation. A series of experiments was conducted to characterize human sensitivity to oral 3 M solutions, then determine how 3 M impacts perception of basic tastes. Methods Detection thresholds were measured for a food grade, racemic mixture using a forced-choice staircase procedure (n = 19). Recognition was measured by presenting a single stimulus per trial (3 M, vanillin, or water), with "onion," "vanilla," or "water" as responses (n = 18). Supra-threshold intensity (n = 20) was measured for various concentrations using the general labeled magnitude scale (gLMS). Odor-taste interactions were studied using mixtures of 3 M and exemplars of basic tastes. Participants rated the intensity of basic tastes, or both taste and aroma, using the gLMS (n ranged from 10 to 15). All stimuli were in aqueous solution. Results Participants detected oral 3 M at about 0.90 ppb and recognized 3 M as "onion" at about 5 ppb. Supra-threshold intensity increased roughly as a cumulative logistic function of concentration. 3 M enhanced the rated savory intensity of monosodium glutamate, but did not enhance the dominant qualities of exemplars of the other four basic tastes. Under a response-context more favorable to an analytic approach, savory enhancement was reduced but not eliminated. Savory enhancement was eliminated with nose-clips. Conclusions Oral sensitivity was lower than previous retronasal studies would suggest, but roughly consistent with concentrations in cooked allium varieties. Oral 3 M selectively enhanced savory intensity, an effect likely due to retronasal aroma rather than taste or mouthfeel. Implication 3 M is a promising candidate aroma to enhance or impart a savory flavor.
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Affiliation(s)
- Paul M. Wise
- grid.250221.60000 0000 9142 2735Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104-3308 USA
| | - Anne Ledyard
- grid.250221.60000 0000 9142 2735Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104-3308 USA
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Haag F, Di Pizio A, Krautwurst D. The key food odorant receptive range of broadly tuned receptor OR2W1. Food Chem 2021; 375:131680. [PMID: 34857413 DOI: 10.1016/j.foodchem.2021.131680] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/22/2021] [Accepted: 11/22/2021] [Indexed: 11/28/2022]
Abstract
Mammals perceive a multitude of odorants by their chemical sense of olfaction, a high-dimensional stimulus-detection system, with hundreds of narrowly or broadly tuned receptors, enabling pattern recognition by the brain. Cognate receptor-agonist information, however, is sparse, and the role of broadly tuned odorant receptors for encoding odor quality remains elusive. Here, we screened IL-6-HaloTag®-OR2W1 and haplotypes against 187 out of 230 defined key food odorants using the GloSensor™ system in HEK-293 cells, yielding 48 new agonists. Altogether, key food odorants represent about two-thirds of now 153 reported agonists of OR2W1, the highest number of agonists known for a mammalian odorant receptor. In summary, we characterized OR2W1 as a human odorant receptor, with a chemically diverse but exclusive receptive range, complementary to chemical subgroups covered by evolutionary younger, highly selective receptors. Our data suggest OR2W1 to be suited for participating in the detection of many foodborne odorants.
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Affiliation(s)
- Franziska Haag
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Antonella Di Pizio
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Dietmar Krautwurst
- Leibniz-Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany.
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33
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Imputation of sensory properties using deep learning. J Comput Aided Mol Des 2021; 35:1125-1140. [PMID: 34716833 DOI: 10.1007/s10822-021-00424-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 10/15/2021] [Indexed: 10/19/2022]
Abstract
Predicting the sensory properties of compounds is challenging due to the subjective nature of the experimental measurements. This testing relies on a panel of human participants and is therefore also expensive and time-consuming. We describe the application of a state-of-the-art deep learning method, Alchemite™, to the imputation of sparse physicochemical and sensory data and compare the results with conventional quantitative structure-activity relationship methods and a multi-target graph convolutional neural network. The imputation model achieved a substantially higher accuracy of prediction, with improvements in R2 between 0.26 and 0.45 over the next best method for each sensory property. We also demonstrate that robust uncertainty estimates generated by the imputation model enable the most accurate predictions to be identified and that imputation also more accurately predicts activity cliffs, where small changes in compound structure result in large changes in sensory properties. In combination, these results demonstrate that the use of imputation, based on data from less expensive, early experiments, enables better selection of compounds for more costly studies, saving experimental time and resources.
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34
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Ben Khemis I, Sagaama A, Issaoui N, Ben Lamine A. Steric and energetic characterizations of mouse and human musk receptors activated by nitro musk smelling compounds at molecular level: Statistical physics treatment and molecular docking analysis. Int J Biol Macromol 2021; 188:333-342. [PMID: 34389381 DOI: 10.1016/j.ijbiomac.2021.08.042] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/12/2021] [Accepted: 08/05/2021] [Indexed: 01/18/2023]
Abstract
Understanding olfaction process at a microscopic or molecular level needs more elucidation of the multiple stages involved in the olfaction mechanism. A worth full elucidation and a better understanding of this molecular mechanism, a necessary preamble should be achieved. The content of this work is a preamble for that. A study of the mouse and human olfactory receptors activation in response to two nitro musks stimuli, which are the musk xylol and the musk ketone, are considered here, first, for their wide expanded use in perfumery, but also to show some particular aspects of this process in the case of these two stimuli, which could help to deduce more details and more general aspects in the global olfactory mechanism. A statistical physics modeling using the monolayer model with two independent types of receptor binding sites of the response of the mouse olfactory receptor MOR215-1 and the human olfactory receptor OR5AN1, which are identified as specifically responding to musk compounds, is used to characterize the interaction between the two nitro musk molecules, the mouse and the human olfactory receptors and to determine the olfactory band of these two odorants through the determination of the molar adsorption energies and the adsorption energy distributions. The physico-chemical model parameters can be used for the steric characterization via the calculation of the receptor site size distributions. The docking computation between these two nitro musks and the human olfactory receptor OR5AN1 is performed demonstrating a large similarity in receptor-ligand detection process. Thus, docking finding results prove that the calculated binding affinities were belonging to the spectrum of adsorption energies.
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Affiliation(s)
- Ismahene Ben Khemis
- Laboratory of Quantum and Statistical Physics LR 18 ES 18, Faculty of Sciences of Monastir, Environnement Street, 5019 Monastir, Tunisia.
| | - Abir Sagaama
- Laboratory of Quantum and Statistical Physics LR 18 ES 18, Faculty of Sciences of Monastir, Environnement Street, 5019 Monastir, Tunisia
| | - Noureddine Issaoui
- Laboratory of Quantum and Statistical Physics LR 18 ES 18, Faculty of Sciences of Monastir, Environnement Street, 5019 Monastir, Tunisia
| | - Abdelmottaleb Ben Lamine
- Laboratory of Quantum and Statistical Physics LR 18 ES 18, Faculty of Sciences of Monastir, Environnement Street, 5019 Monastir, Tunisia.
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35
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Yohe LR, Leiser-Miller LB, Kaliszewska ZA, Donat P, Santana SE, Dávalos LM. Diversity in olfactory receptor repertoires is associated with dietary specialization in a genus of frugivorous bat. G3 (BETHESDA, MD.) 2021; 11:jkab260. [PMID: 34568918 PMCID: PMC8473985 DOI: 10.1093/g3journal/jkab260] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/19/2021] [Indexed: 11/30/2022]
Abstract
Mammalian olfactory receptor genes (ORs) are a diverse family of genes encoding proteins that directly interact with environmental chemical cues. ORs evolve via gene duplication in a birth-death fashion, neofunctionalizing and pseudogenizing over time. Olfaction is a primary sense used for food detection in plant-visiting bats, but the relationship between dietary specialization and OR repertoire diversity is unclear. Within neotropical Leaf-nosed bats (Phyllostomidae), many lineages are plant specialists, and some have a distinct OR repertoire compared to insectivorous species. Yet, whether specialization on particular plant genera is associated with the evolution of specialized, less diverse OR repertoires has never been tested. Using targeted sequence capture, we sequenced the OR repertoires of three sympatric species of short-tailed fruit bats (Carollia), which vary in their degree of specialization on the fruits of Piper plants. We characterized orthologous vs duplicated receptors among Carollia species, and explored the diversity and redundancy of the receptor gene repertoire. At the species level, the most dedicated Piper specialist, Carollia castanea, had lower OR diversity compared to the two generalists (C. sowelli and C. perspicillata), but we discovered a few unique sets of ORs within C. castanea with high redundancy of similar gene duplicates. These unique receptors potentially enable C. castanea to detect Piper fruit odorants better than its two congeners. Carollia perspicillata, the species with the most generalist diet, had a higher diversity of intact receptors, suggesting the ability to detect a wider range of odorant molecules. Variation among ORs may be a factor in the coexistence of these sympatric species, facilitating the exploitation of different plant resources. Our study sheds light on how gene duplication and changes in OR diversity may play a role in dietary adaptations and underlie ecological interactions between bats and plants.
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Affiliation(s)
- Laurel R Yohe
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT 06511, USA
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794, USA
| | | | | | - Paul Donat
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794, USA
| | - Sharlene E Santana
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98105, USA
| | - Liliana M Dávalos
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794, USA
- Consortium for Inter-Disciplinary Environmental Research, School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
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36
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E-Nose and Olfactory Assessment: Teamwork or a Challenge to the Last Data? The Case of Virgin Olive Oil Stability and Shelf Life. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11188453] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Electronic nose (E-nose) devices represent one of the most trailblazing innovations in current technological research, since mimicking the functioning of the biological sense of smell has always represented a fascinating challenge for technological development applied to life sciences and beyond. Sensor array tools are right now used in a plethora of applications, including, but not limited to, (bio-)medical, environmental, and food industry related. In particular, the food industry has seen a significant rise in the application of technological tools for determining the quality of edibles, progressively replacing human panelists, therefore changing the whole quality control chain in the field. To this end, the present review, conducted on PubMed, Science Direct and Web of Science, screening papers published between January 2010 and May 2021, sought to investigate the current trends in the usage of human panels and sensorized tools (E-nose and similar) in the food industry, comparing the performances between the two different approaches. In particular, the focus was mainly addressed towards the stability and shelf life assessment of olive oil, the main constituent of the renowned “Mediterranean diet”, and nowadays appreciated in cuisines from all around the world. The obtained results demonstrate that, despite the satisfying performances of both approaches, the best strategy merges the potentialities of human sensory panels and technological sensor arrays, (i.e., E-nose somewhat supported by E-tongue and/or E-eye). The current investigation can be used as a reference for future guidance towards the choice between human panelists and sensorized tools, to the benefit of food manufacturers.
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37
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Yohe LR, Fabbri M, Hanson M, Bhullar BAS. Olfactory receptor gene evolution is unusually rapid across Tetrapoda and outpaces chemosensory phenotypic change. Curr Zool 2021; 66:505-514. [PMID: 34484311 DOI: 10.1093/cz/zoaa051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/28/2020] [Indexed: 12/15/2022] Open
Abstract
Chemosensation is the most ubiquitous sense in animals, enacted by the products of complex gene families that detect environmental chemical cues and larger-scale sensory structures that process these cues. While there is a general conception that olfactory receptor (OR) genes evolve rapidly, the universality of this phenomenon across vertebrates, and its magnitude, are unclear. The supposed correlation between molecular rates of chemosensory evolution and phenotypic diversity of chemosensory systems is largely untested. We combine comparative genomics and sensory morphology to test whether OR genes and olfactory phenotypic traits evolve at faster rates than other genes or traits. Using published genomes, we identified ORs in 21 tetrapods, including amphibians, reptiles, birds, and mammals and compared their rates of evolution to those of orthologous non-OR protein-coding genes. We found that, for all clades investigated, most OR genes evolve nearly an order of magnitude faster than other protein-coding genes, with many OR genes showing signatures of diversifying selection across nearly all taxa in this study. This rapid rate of evolution suggests that chemoreceptor genes are in "evolutionary overdrive," perhaps evolving in response to the ever-changing chemical space of the environment. To obtain complementary morphological data, we stained whole fixed specimens with iodine, µCT-scanned the specimens, and digitally segmented chemosensory and nonchemosensory brain regions. We then estimated phenotypic variation within traits and among tetrapods. While we found considerable variation in chemosensory structures, they were no more diverse than nonchemosensory regions. We suggest chemoreceptor genes evolve quickly in reflection of an ever-changing chemical space, whereas chemosensory phenotypes and processing regions are more conserved because they use a standardized or constrained architecture to receive and process a range of chemical cues.
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Affiliation(s)
- Laurel R Yohe
- Department of Earth & Planetary Science, Peabody Museum of Natural History, Yale University, New Haven, CT, 06511, USA
| | - Matteo Fabbri
- Department of Earth & Planetary Science, Peabody Museum of Natural History, Yale University, New Haven, CT, 06511, USA
| | - Michael Hanson
- Department of Earth & Planetary Science, Peabody Museum of Natural History, Yale University, New Haven, CT, 06511, USA
| | - Bhart-Anjan S Bhullar
- Department of Earth & Planetary Science, Peabody Museum of Natural History, Yale University, New Haven, CT, 06511, USA
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38
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Liman ER. Insights into a receptor that lets insects sense scents. Nature 2021; 597:37-39. [PMID: 34349272 DOI: 10.1038/d41586-021-02076-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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39
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Francia S, Lodovichi C. The role of the odorant receptors in the formation of the sensory map. BMC Biol 2021; 19:174. [PMID: 34452614 PMCID: PMC8394594 DOI: 10.1186/s12915-021-01116-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
In the olfactory system, odorant receptors (ORs) expressed at the cell membrane of olfactory sensory neurons detect odorants and direct sensory axons toward precise target locations in the brain, reflected in the presence of olfactory sensory maps. This dual role of ORs is corroborated by their subcellular expression both in cilia, where they bind odorants, and at axon terminals, a location suitable for axon guidance cues. Here, we provide an overview and discuss previous work on the role of ORs in establishing the topographic organization of the olfactory system and recent findings on the mechanisms of activation and function of axonal ORs.
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Affiliation(s)
- Simona Francia
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy.,Veneto Institute of Molecular Medicine, Padua, Italy
| | - Claudia Lodovichi
- Veneto Institute of Molecular Medicine, Padua, Italy. .,Neuroscience Institute CNR, Via Orus 2, 35129, Padua, Italy. .,Department of Biomedical Sciences, University of Padua, Padua, Italy. .,Padova Neuroscience Center, Padua, Italy.
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40
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Ectopic Odorant Receptor Responding to Flavor Compounds: Versatile Roles in Health and Disease. Pharmaceutics 2021; 13:pharmaceutics13081314. [PMID: 34452275 PMCID: PMC8402194 DOI: 10.3390/pharmaceutics13081314] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/23/2022] Open
Abstract
Prompted by the ground-breaking discovery of the rodent odorant receptor (OR) gene family within the olfactory epithelium nearly 30 years ago, followed by that of OR genes in cells of the mammalian germ line, and potentiated by the identification of ORs throughout the body, our appreciation for ORs as general chemoreceptors responding to odorant compounds in the regulation of physiological or pathophysiological processes continues to expand. Ectopic ORs are now activated by a diversity of flavor compounds and are involved in diverse physiological phenomena varying from adipogenesis to myogenesis to hepatic lipid accumulation to serotonin secretion. In this review, we outline the key biological functions of the ectopic ORs responding to flavor compounds and the underlying molecular mechanisms. We also discuss research opportunities for utilizing ectopic ORs as therapeutic strategies in the treatment of human disease as well as challenges to be overcome in the future. The recognition of the potent function, signaling pathway, and pharmacology of ectopic ORs in diverse tissues and cell types, coupled with the fact that they belong to G protein-coupled receptors, a highly druggable protein family, unequivocally highlight the potential of ectopic ORs responding to flavor compounds, especially food-derived odorant compounds, as a promising therapeutic strategy for various diseases.
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41
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Mittermeier-Kleßinger VK, Hofmann T, Dawid C. Mitigating Off-Flavors of Plant-Based Proteins. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:9202-9207. [PMID: 34342446 DOI: 10.1021/acs.jafc.1c03398] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Proteins and, in particular, plant-based proteins are becoming more and more important in the face of future challenges, resulting from continuous population growth, the imbalance between malnutrition and overweight/obesity, and environmental changes. Recent developments open new avenues for improving the quality and sustainable production of plant proteins. Increasing knowledge on the key drivers of the off-flavor of plant proteins, which currently limit their use, supports new strategies to reach full flavor experience, thus enhancing consumer acceptance. Current limitations and future directions for improving the flavor profiles of plant-based proteins are discussed in this perspective.
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Affiliation(s)
| | - Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, D-85354 Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, D-85354 Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Technical University of Munich, D-85354 Freising, Germany
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42
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Abstract
Olfaction is fundamentally distinct from other sensory modalities. Natural odor stimuli are complex mixtures of volatile chemicals that interact in the nose with a receptor array that, in rodents, is built from more than 1,000 unique receptors. These interactions dictate a peripheral olfactory code, which in the brain is transformed and reformatted as it is broadcast across a set of highly interconnected olfactory regions. Here we discuss the problems of characterizing peripheral population codes for olfactory stimuli, of inferring the specific functions of different higher olfactory areas given their extensive recurrence, and of ultimately understanding how odor representations are linked to perception and action. We argue that, despite the differences between olfaction and other sensory modalities, addressing these specific questions will reveal general principles underlying brain function.
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Affiliation(s)
- David H Brann
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Sandeep Robert Datta
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA;
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43
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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: 30] [Impact Index Per Article: 7.5] [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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44
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Brown EB, Shah KD, Palermo J, Dey M, Dahanukar A, Keene AC. Ir56d-dependent fatty acid responses in Drosophila uncover taste discrimination between different classes of fatty acids. eLife 2021; 10:67878. [PMID: 33949306 PMCID: PMC8169106 DOI: 10.7554/elife.67878] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/04/2021] [Indexed: 11/24/2022] Open
Abstract
Chemosensory systems are critical for evaluating the caloric value and potential toxicity of food. While animals can discriminate between thousands of odors, much less is known about the discriminative capabilities of taste systems. Fats and sugars represent calorically potent and attractive food sources that contribute to hedonic feeding. Despite the differences in nutritional value between fats and sugars, the ability of the taste system to discriminate between different rewarding tastants is thought to be limited. In Drosophila, taste neurons expressing the ionotropic receptor 56d (IR56d) are required for reflexive behavioral responses to the medium-chain fatty acid, hexanoic acid. Here, we tested whether flies can discriminate between different classes of fatty acids using an aversive memory assay. Our results indicate that flies are able to discriminate medium-chain fatty acids from both short- and long-chain fatty acids, but not from other medium-chain fatty acids. While IR56d neurons are broadly responsive to short-, medium-, and long-chain fatty acids, genetic deletion of IR56d selectively disrupts response to medium-chain fatty acids. Further, IR56d+ GR64f+ neurons are necessary for proboscis extension response (PER) to medium-chain fatty acids, but both IR56d and GR64f neurons are dispensable for PER to short- and long-chain fatty acids, indicating the involvement of one or more other classes of neurons. Together, these findings reveal that IR56d is selectively required for medium-chain fatty acid taste, and discrimination of fatty acids occurs through differential receptor activation in shared populations of neurons. Our study uncovers a capacity for the taste system to encode tastant identity within a taste category.
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Affiliation(s)
- Elizabeth B Brown
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States
| | - Kreesha D Shah
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States.,Wilkes Honors College, Florida Atlantic University, Jupiter, United States
| | - Justin Palermo
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States
| | - Manali Dey
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, United States
| | - Anupama Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, United States.,Department of Molecular, Cell & Systems Biology, University of California, Riverside, Riverside, United States
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States
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Deconstructing the mouse olfactory percept through an ethological atlas. Curr Biol 2021; 31:2809-2818.e3. [PMID: 33957076 DOI: 10.1016/j.cub.2021.04.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/09/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022]
Abstract
Odor perception in non-humans is poorly understood. Here, we generated the most comprehensive mouse olfactory ethological atlas to date, consisting of behavioral responses to a diverse panel of 73 odorants, including 12 at multiple concentrations. These data revealed that mouse behavior is incredibly diverse and changes in response to odorant identity and concentration. Using only behavioral responses observed in other mice, we could predict which of two odorants was presented to a held-out mouse 82% of the time. Considering all 73 possible odorants, we could uniquely identify the target odorant from behavior on the first try 20% of the time and 46% within five attempts. Although mouse behavior is difficult to predict from human perception, they share three fundamental properties: first, odor valence parameters explained the highest variance of olfactory perception. Second, physicochemical properties of odorants can be used to predict the olfactory percept. Third, odorant concentration quantitatively and qualitatively impacts olfactory perception. These results increase our understanding of mouse olfactory behavior and how it compares to human odor perception and provide a template for future comparative studies of olfactory percepts among species.
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Joma M, Fovet CM, Seddiki N, Gressens P, Laforge M. COVID-19 and Pregnancy: Vertical Transmission and Inflammation Impact on Newborns. Vaccines (Basel) 2021; 9:391. [PMID: 33921113 PMCID: PMC8071483 DOI: 10.3390/vaccines9040391] [Citation(s) in RCA: 12] [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: 02/28/2021] [Revised: 04/08/2021] [Accepted: 04/10/2021] [Indexed: 12/18/2022] Open
Abstract
The COVID-19 pandemic is ongoing and we are still compiling new findings to decipher and understand SARS-CoV-2 infection during pregnancy. No reports encompass any conclusive confirmation of vertical transmission. Nevertheless, cases of fetal distress and multiple organ failure have been reported, as well as rare cases of fetal demise. While clinicians and scientists continue to seek proof of vertical transmission, they miss the greater point, namely the cause of preterm delivery. In this review, we suggest that the cause might not be due to the viral infection but the fetal exposure to maternal inflammation or cytokine storm that translates into a complication of COVID-19. This statement is extrapolated from previous experience with infections and inflammation which were reported to be fatal by increasing the risk of preterm delivery and causing abnormal neonatal brain development and resulting in neurological disorders like atypical behavioral phenotype or autistic syndrome. Given the potentially fatal consequences on neonate health, we highlight the urgent need for an animal model to study vertical transmission. The preclinical model will allow us to make the link between SARS-COV-2 infection, inflammation and long-term follow-up of child brain development.
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Affiliation(s)
- Mohamed Joma
- Université de Paris, NeuroDiderot, Inserm, 75019 Paris, France; (M.J.); (P.G.)
| | - Claire-Maelle Fovet
- INSERM U1184, CEA, IDMIT Department, Immunology of Viral, Auto-Immune, Hematological and Bacterial Diseases (IMVA-HB), Université Paris-Saclay, 92265 Fontenay-aux-Roses, France; (C.-M.F.); (N.S.)
| | - Nabila Seddiki
- INSERM U1184, CEA, IDMIT Department, Immunology of Viral, Auto-Immune, Hematological and Bacterial Diseases (IMVA-HB), Université Paris-Saclay, 92265 Fontenay-aux-Roses, France; (C.-M.F.); (N.S.)
| | - Pierre Gressens
- Université de Paris, NeuroDiderot, Inserm, 75019 Paris, France; (M.J.); (P.G.)
| | - Mireille Laforge
- Université de Paris, NeuroDiderot, Inserm, 75019 Paris, France; (M.J.); (P.G.)
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Qiu Q, Wu Y, Ma L, Yu CR. Encoding innately recognized odors via a generalized population code. Curr Biol 2021; 31:1813-1825.e4. [PMID: 33651991 PMCID: PMC8119320 DOI: 10.1016/j.cub.2021.01.094] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 12/25/2020] [Accepted: 01/27/2021] [Indexed: 01/19/2023]
Abstract
Odors carrying intrinsic values often trigger instinctive aversive or attractive responses. It is not known how innate valence is encoded. An intuitive model suggests that the information is conveyed through specific channels in hardwired circuits along the olfactory pathway, insulated from influences of other odors, to trigger innate responses. Here, we show that in mice, mixing innately aversive or attractive odors with a neutral odor and, surprisingly, mixing two odors with the same valence, abolish the innate behavioral responses. Recordings from the olfactory bulb indicate that odors are not masked at the level of peripheral activation and glomeruli independently encode components in the mixture. In contrast, crosstalk among the mitral and tufted (M/T) cells changes their patterns of activity such that those elicited by the mixtures can no longer be linearly decoded as separate components. The changes in behavioral and M/T cell responses are associated with reduced activation of brain areas linked to odor preferences. Thus, crosstalk among odor channels at the earliest processing stage in the olfactory pathway leads to re-coding of odor identity to abolish valence associated with the odors. These results are inconsistent with insulated labeled lines and support a model of a common mechanism of odor recognition for both innate and learned valence associations.
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Affiliation(s)
- Qiang Qiu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Yunming Wu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Limei Ma
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - C Ron Yu
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.
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Kurian SM, Naressi RG, Manoel D, Barwich AS, Malnic B, Saraiva LR. Odor coding in the mammalian olfactory epithelium. Cell Tissue Res 2021; 383:445-456. [PMID: 33409650 PMCID: PMC7873010 DOI: 10.1007/s00441-020-03327-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/27/2020] [Indexed: 12/31/2022]
Abstract
Noses are extremely sophisticated chemical detectors allowing animals to use scents to interpret and navigate their environments. Odor detection starts with the activation of odorant receptors (ORs), expressed in mature olfactory sensory neurons (OSNs) populating the olfactory mucosa. Different odorants, or different concentrations of the same odorant, activate unique ensembles of ORs. This mechanism of combinatorial receptor coding provided a possible explanation as to why different odorants are perceived as having distinct odors. Aided by new technologies, several recent studies have found that antagonist interactions also play an important role in the formation of the combinatorial receptor code. These findings mark the start of a new era in the study of odorant-receptor interactions and add a new level of complexity to odor coding in mammals.
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Affiliation(s)
| | | | | | | | - Bettina Malnic
- Department of Biochemistry, University of São Paulo, São Paulo, Brazil.
| | - Luis R Saraiva
- Sidra Medicine, Doha, Qatar.
- Monell Chemical Senses Center, Philadelphia, USA.
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
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Dewan A. Olfactory signaling via trace amine-associated receptors. Cell Tissue Res 2020; 383:395-407. [PMID: 33237477 DOI: 10.1007/s00441-020-03331-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/28/2020] [Indexed: 01/30/2023]
Abstract
Trace amine-associated receptors (TAARs) are a family of G protein-coupled receptors that function as odorant receptors in the main olfactory system of vertebrates. TAARs are monoallelically expressed in primary sensory neurons where they couple to the same transduction cascade as canonical olfactory receptors and are mapped onto glomeruli within a specific region of the olfactory bulb. TAARs have a high affinity for volatile amines, a class of chemicals that are generated during the decomposition of proteins and are ubiquitous physiological metabolites that are found in body fluids. Thus, amines are proposed to play an important role in intra- and interspecific communication such as signaling the sex of the conspecific, the quality of the food source, or even the proximity of a predator. TAARs have a crucial role in the perception of these behaviorally relevant compounds as the genetic deletion of all or even individual olfactory TAARs can alter the behavioral response and reduce the sensitivity to amines. The small size of this receptor family combined with the ethological relevance of their ligands makes the TAARs an attractive model system for probing olfactory perception. This review will summarize the current knowledge on the olfactory TAARs and discuss whether they represent a unique subsystem within the main olfactory system.
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Affiliation(s)
- Adam Dewan
- Department of Psychology, Florida State University, 1107 W. Call St, Tallahassee, FL, 32306, USA.
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McClintock TS, Khan N, Alimova Y, Aulisio M, Han DY, Breheny P. Encoding the Odor of Cigarette Smoke. J Neurosci 2020; 40:7043-7053. [PMID: 32801155 PMCID: PMC7480249 DOI: 10.1523/jneurosci.1144-20.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/23/2020] [Accepted: 08/09/2020] [Indexed: 11/21/2022] Open
Abstract
The encoding of odors is believed to begin as a combinatorial code consisting of distinct patterns of responses from odorant receptors (ORs), trace-amine associated receptors (TAARs), or both. To determine how specific response patterns arise requires detecting patterns in vivo and understanding how the components of an odor, which are nearly always mixtures of odorants, give rise to parts of the pattern. Cigarette smoke, a common and clinically relevant odor consisting of >400 odorants, evokes responses from 144 ORs and 3 TAARs in freely behaving male and female mice, the first example of in vivo responses of both ORs and TAARs to an odor. As expected, a simplified artificial mimic of cigarette smoke odor tested at low concentration to identify highly sensitive receptors evokes responses from four ORs, all also responsive to cigarette smoke. Human subjects of either sex identify 1-pentanethiol as the odorant most critical for perception of the artificial mimic; and in mice the OR response patterns to these two odors are significantly similar. Fifty-eight ORs respond to the headspace above 25% 1-pentanethiol, including 9 ORs responsive to cigarette smoke. The response patterns to both cigarette smoke and 1-pentanethiol have strongly responsive ORs spread widely across OR sequence diversity, consistent with most other combinatorial codes previously measured in vivo The encoding of cigarette smoke is accomplished by a broad receptor response pattern, and 1-pentanethiol is responsible for a small subset of the responsive ORs in this combinatorial code.SIGNIFICANCE STATEMENT Complex odors are usually perceived as distinct odor objects. Cigarette smoke is the first complex odor whose in vivo receptor response pattern has been measured. It is also the first pattern shown to include responses from both odorant receptors and trace-amine associated receptors, confirming that the encoding of complex odors can be enriched by signals coming through both families of receptors. Measures of human perception and mouse receptor physiology agree that 1-pentanethiol is a critical component of a simplified odorant mixture designed to mimic cigarette smoke odor. Its receptor response pattern helps to link those of the artificial mimic and real cigarette smoke, consistent with expectations about perceptual similarity arising from shared elements in receptor response patterns.
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Affiliation(s)
| | - Naazneen Khan
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536
| | - Yelena Alimova
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536
| | - Madeline Aulisio
- College of Public Health, University of Kentucky, Lexington, Kentucky 40536
| | - Dong Y Han
- Department of Neurology, University of Kentucky, Lexington, Kentucky 40536
| | - Patrick Breheny
- Department of Biostatistics, University of Iowa, Iowa City, Iowa 52242
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