1
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Leong LM, Storace DA. Imaging different cell populations in the mouse olfactory bulb using the genetically encoded voltage indicator ArcLight. NEUROPHOTONICS 2024; 11:033402. [PMID: 38288247 PMCID: PMC10823906 DOI: 10.1117/1.nph.11.3.033402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/30/2023] [Accepted: 12/14/2023] [Indexed: 01/31/2024]
Abstract
Genetically encoded voltage indicators (GEVIs) are protein-based optical sensors that allow for measurements from genetically defined populations of neurons. Although in vivo imaging in the mammalian brain with early generation GEVIs was difficult due to poor membrane expression and low signal-to-noise ratio, newer and more sensitive GEVIs have begun to make them useful for answering fundamental questions in neuroscience. We discuss principles of imaging using GEVIs and genetically encoded calcium indicators, both useful tools for in vivo imaging of neuronal activity, and review some of the recent mechanistic advances that have led to GEVI improvements. We provide an overview of the mouse olfactory bulb (OB) and discuss recent studies using the GEVI ArcLight to study different cell types within the bulb using both widefield and two-photon microscopy. Specific emphasis is placed on using GEVIs to begin to study the principles of concentration coding in the OB, how to interpret the optical signals from population measurements in the in vivo brain, and future developments that will push the field forward.
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Affiliation(s)
- Lee Min Leong
- Florida State University, Department of Biological Science, Tallahassee, Florida, United States
| | - Douglas A. Storace
- Florida State University, Department of Biological Science, Tallahassee, Florida, United States
- Florida State University, Program in Neuroscience, Tallahassee, Florida, United States
- Florida State University, Institute of Molecular Biophysics, Tallahassee, Florida, United States
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2
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Masuda M, Ihara S, Mori N, Koide T, Miyasaka N, Wakisaka N, Yoshikawa K, Watanabe H, Touhara K, Yoshihara Y. Identification of olfactory alarm substances in zebrafish. Curr Biol 2024; 34:1377-1389.e7. [PMID: 38423017 DOI: 10.1016/j.cub.2024.02.003] [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: 09/04/2023] [Revised: 12/08/2023] [Accepted: 02/01/2024] [Indexed: 03/02/2024]
Abstract
Escaping from danger is one of the most fundamental survival behaviors for animals. Most freshwater fishes display olfactory alarm reactions in which an injured fish releases putative alarm substances from the skin to notify its shoaling company about the presence of danger. Here, we identified two small compounds in zebrafish skin extract, designated as ostariopterin and daniol sulfate. Ostariopterin is a pterin derivative commonly produced in many freshwater fishes belonging to the Ostariophysi superorder. Daniol sulfate is a novel sulfated bile alcohol specifically present in the Danio species, including zebrafish. Ostariopterin and daniol sulfate activate distinct glomeruli in the olfactory bulb. Zebrafish display robust alarm reactions, composed of darting, freezing, and bottom dwelling, only when they are concomitantly stimulated with ostariopterin and daniol sulfate. These results demonstrate that the fish alarm reaction is driven through a coincidence detection mechanism of the two compounds along the olfactory neural circuitry.
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Affiliation(s)
- Miwa Masuda
- Laboratory for Systems Molecular Ethology, RIKEN Center for Brain Science, Saitama 351-0198, Japan; RIKEN CBS-KAO Collaboration Center, RIKEN Center for Brain Science, Saitama 351-0198, Japan; ERATO Touhara Chemosensory Signal Project, JST, Tokyo 113-8657, Japan
| | - Sayoko Ihara
- ERATO Touhara Chemosensory Signal Project, JST, Tokyo 113-8657, Japan; Laboratory of Biological Chemistry, Department of Applied Biological Chemistry, The University of Tokyo, Tokyo 113-8657, Japan
| | - Naoki Mori
- Laboratory of Organic Chemistry, Department of Applied Biological Chemistry, The University of Tokyo, Tokyo 113-8657, Japan
| | - Tetsuya Koide
- Laboratory for Systems Molecular Ethology, RIKEN Center for Brain Science, Saitama 351-0198, Japan
| | - Nobuhiko Miyasaka
- Laboratory for Systems Molecular Ethology, RIKEN Center for Brain Science, Saitama 351-0198, Japan; RIKEN CBS-KAO Collaboration Center, RIKEN Center for Brain Science, Saitama 351-0198, Japan
| | - Noriko Wakisaka
- Laboratory for Systems Molecular Ethology, RIKEN Center for Brain Science, Saitama 351-0198, Japan
| | - Keiichi Yoshikawa
- Laboratory of Biological Chemistry, Department of Applied Biological Chemistry, The University of Tokyo, Tokyo 113-8657, Japan
| | - Hidenori Watanabe
- Laboratory of Organic Chemistry, Department of Applied Biological Chemistry, The University of Tokyo, Tokyo 113-8657, Japan
| | - Kazushige Touhara
- ERATO Touhara Chemosensory Signal Project, JST, Tokyo 113-8657, Japan; Laboratory of Biological Chemistry, Department of Applied Biological Chemistry, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yoshihiro Yoshihara
- Laboratory for Systems Molecular Ethology, RIKEN Center for Brain Science, Saitama 351-0198, Japan; RIKEN CBS-KAO Collaboration Center, RIKEN Center for Brain Science, Saitama 351-0198, Japan; ERATO Touhara Chemosensory Signal Project, JST, Tokyo 113-8657, Japan.
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3
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Dieris M, Kowatschew D, Hassenklöver T, Manzini I, Korsching SI. Calcium imaging of adult olfactory epithelium reveals amines as important odor class in fish. Cell Tissue Res 2024; 396:95-102. [PMID: 38347202 PMCID: PMC10997700 DOI: 10.1007/s00441-024-03859-w] [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: 10/18/2023] [Accepted: 12/29/2023] [Indexed: 04/06/2024]
Abstract
The odor space of aquatic organisms is by necessity quite different from that of air-breathing animals. The recognized odor classes in teleost fish include amino acids, bile acids, reproductive hormones, nucleotides, and a limited number of polyamines. Conversely, a significant portion of the fish olfactory receptor repertoire is composed of trace amine-associated receptors, generally assumed to be responsible for detecting amines. Zebrafish possess over one hundred of these receptors, but the responses of olfactory sensory neurons to amines have not been known so far. Here we examined odor responses of zebrafish olfactory epithelial explants at the cellular level, employing calcium imaging. We report that amines elicit strong responses in olfactory sensory neurons, with a time course characteristically different from that of ATP-responsive (basal) cells. A quantitative analysis of the laminar height distribution shows amine-responsive cells undistinguishable from ciliated neurons positive for olfactory marker protein. This distribution is significantly different from those measured for microvillous neurons positive for transient receptor potential channel 2 and basal cells positive for proliferating cell nuclear antigen. Our results suggest amines as an important odor class for teleost fish.
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Affiliation(s)
- M Dieris
- Institute of Genetics, Faculty of Mathematics and Natural Sciences of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany
| | - D Kowatschew
- Institute of Genetics, Faculty of Mathematics and Natural Sciences of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany
| | - T Hassenklöver
- Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Göttingen Germany, and Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
- Current address: Department of Animal Physiology and Molecular Biomedicine, Institute of Animal Physiology, Justus-Liebig-University Gießen, Gießen, Germany
| | - I Manzini
- Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Göttingen Germany, and Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
- Current address: Department of Animal Physiology and Molecular Biomedicine, Institute of Animal Physiology, Justus-Liebig-University Gießen, Gießen, Germany
| | - S I Korsching
- Institute of Genetics, Faculty of Mathematics and Natural Sciences of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany.
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4
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Roy D, Subramaniam B, Chong WC, Bornhorst M, Packer RJ, Nazarian J. Zebrafish-A Suitable Model for Rapid Translation of Effective Therapies for Pediatric Cancers. Cancers (Basel) 2024; 16:1361. [PMID: 38611039 PMCID: PMC11010887 DOI: 10.3390/cancers16071361] [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: 03/15/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Pediatric cancers are the leading cause of disease-related deaths in children and adolescents. Most of these tumors are difficult to treat and have poor overall survival. Concerns have also been raised about drug toxicity and long-term detrimental side effects of therapies. In this review, we discuss the advantages and unique attributes of zebrafish as pediatric cancer models and their importance in targeted drug discovery and toxicity assays. We have also placed a special focus on zebrafish models of pediatric brain cancers-the most common and difficult solid tumor to treat.
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Affiliation(s)
- Debasish Roy
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC 20012, USA; (D.R.)
| | - Bavani Subramaniam
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC 20012, USA; (D.R.)
| | - Wai Chin Chong
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC 20012, USA; (D.R.)
| | - Miriam Bornhorst
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC 20012, USA; (D.R.)
| | - Roger J. Packer
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC 20012, USA; (D.R.)
| | - Javad Nazarian
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC 20012, USA; (D.R.)
- DIPG/DMG Research Center Zurich, Children’s Research Center, Department of Pediatrics, University Children’s Hospital Zürich, 8032 Zurich, Switzerland
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5
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Edwards T, Bouyoucos IA, Hasler CT, Fry M, Anderson WG. Understanding olfactory and behavioural responses to dietary cues in age-1 lake sturgeon Acipenser fulvescens. Comp Biochem Physiol A Mol Integr Physiol 2024; 288:111560. [PMID: 38056556 DOI: 10.1016/j.cbpa.2023.111560] [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: 08/26/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/08/2023]
Abstract
Detection of environmental cues is essential for all vertebrates and is typically established by the olfactory epithelium and olfactory sensory neurons (OSNs). In fishes, microvillous and ciliated OSNs are the principal types, typically detecting amino acids and bile salts, respectively. Activation of OSN receptors by specific ligands initiate downstream signal processing often leading to behavioural responses. In this study we used electrophysiological and behavioural techniques to evaluate olfactory detection and behaviour in juvenile lake sturgeon Acipenser fulvescens in response to hatchery- and natural dietary cues. We hypothesized that electro-olfactogram (EOG) and behavioural responses would be dependent on diet type. We predicted that inhibition of the phospholipase C/inositol 1,4,5-triphosphate (PLC/IP3) secondary transduction pathway would reduce EOG responses to dietary cues and, inhibition of the adenylyl cyclase/adenosine 3,5-cyclic monophosphate (cAMP) pathway, would have no effect. Furthermore, we predicted a strong EOG response would be manifested in a change in behaviour. We observed that both the PLC/IP3 and cAMP pathways were significantly involved in the detection of dietary cues. However, EOG responses did not manifest to behavioural responses, although the foraging activity to the hatchery cue was significantly greater compared to the control. Our results support the notion that lake sturgeon raised in a hatchery and fed a commercial pelleted diet may become accustomed to it prior to release into the wild. Further, this study suggests that, in conservation aquaculture settings, lake sturgeon should be exposed to natural dietary cues prior to release as one strategy to promote food recognition.
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Affiliation(s)
- Tyler Edwards
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road Winnipeg, Manitoba R3T 2N2, Canada.
| | - Ian A Bouyoucos
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road Winnipeg, Manitoba R3T 2N2, Canada
| | - Caleb T Hasler
- The University of Winnipeg, Department of Biology, 515 Portage Ave Winnipeg, Manitoba R3B 2E9, Canada
| | - Mark Fry
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road Winnipeg, Manitoba R3T 2N2, Canada
| | - W Gary Anderson
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road Winnipeg, Manitoba R3T 2N2, Canada
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6
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Rayamajhi D, Ege M, Ukhanov K, Ringers C, Zhang Y, Jung I, D’Gama PP, Li SS, Cosacak MI, Kizil C, Park HC, Yaksi E, Martens JR, Brody SL, Jurisch-Yaksi N, Roy S. The forkhead transcription factor Foxj1 controls vertebrate olfactory cilia biogenesis and sensory neuron differentiation. PLoS Biol 2024; 22:e3002468. [PMID: 38271330 PMCID: PMC10810531 DOI: 10.1371/journal.pbio.3002468] [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: 06/23/2023] [Accepted: 12/12/2023] [Indexed: 01/27/2024] Open
Abstract
In vertebrates, olfactory receptors localize on multiple cilia elaborated on dendritic knobs of olfactory sensory neurons (OSNs). Although olfactory cilia dysfunction can cause anosmia, how their differentiation is programmed at the transcriptional level has remained largely unexplored. We discovered in zebrafish and mice that Foxj1, a forkhead domain-containing transcription factor traditionally linked with motile cilia biogenesis, is expressed in OSNs and required for olfactory epithelium (OE) formation. In keeping with the immotile nature of olfactory cilia, we observed that ciliary motility genes are repressed in zebrafish, mouse, and human OSNs. Strikingly, we also found that besides ciliogenesis, Foxj1 controls the differentiation of the OSNs themselves by regulating their cell type-specific gene expression, such as that of olfactory marker protein (omp) involved in odor-evoked signal transduction. In line with this, response to bile acids, odors detected by OMP-positive OSNs, was significantly diminished in foxj1 mutant zebrafish. Taken together, our findings establish how the canonical Foxj1-mediated motile ciliogenic transcriptional program has been repurposed for the biogenesis of immotile olfactory cilia, as well as for the development of the OSNs.
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Affiliation(s)
- Dheeraj Rayamajhi
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Mert Ege
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Kirill Ukhanov
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, United States of America
| | - Christa Ringers
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Yiliu Zhang
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Inyoung Jung
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Biomedical Sciences, Korea University, Ansan, South Korea
| | - Percival P. D’Gama
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Summer Shijia Li
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Mehmet Ilyas Cosacak
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Helmholtz Association, Dresden, Germany
| | - Caghan Kizil
- Department of Neurology and The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York, United States of America
| | - Hae-Chul Park
- Department of Biomedical Sciences, Korea University, Ansan, South Korea
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
- Koç University Research Center for Translational Medicine, Koç University School of Medicine, Istanbul, Turkey
| | - Jeffrey R. Martens
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, United States of America
| | - Steven L. Brody
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Nathalie Jurisch-Yaksi
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Sudipto Roy
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
- Department of Paediatrics, National University of Singapore, Singapore
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7
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Offner T, Weiss L, Daume D, Berk A, Inderthal TJ, Manzini I, Hassenklöver T. Functional odor map heterogeneity is based on multifaceted glomerular connectivity in larval Xenopus olfactory bulb. iScience 2023; 26:107518. [PMID: 37636047 PMCID: PMC10448113 DOI: 10.1016/j.isci.2023.107518] [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: 09/13/2022] [Revised: 07/05/2023] [Accepted: 07/31/2023] [Indexed: 08/29/2023] Open
Abstract
Glomeruli are the functional units of the vertebrate olfactory bulb (OB) connecting olfactory receptor neuron (ORN) axons and mitral/tufted cell (MTC) dendrites. In amphibians, these two circuit elements regularly branch and innervate multiple, spatially distinct glomeruli. Using functional multiphoton-microscopy and single-cell tracing, we investigate the impact of this wiring on glomerular module organization and odor representations on multiple levels of the Xenopus laevis OB network. The glomerular odor map to amino acid odorants is neither stereotypic between animals nor chemotopically organized. Among the morphologically heterogeneous group of uni- and multi-glomerular MTCs, MTCs can selectively innervate glomeruli formed by axonal branches of individual ORNs. We conclude that odor map heterogeneity is caused by the coexistence of different intermingled glomerular modules. This demonstrates that organization of the amphibian main olfactory system is not strictly based on uni-glomerular connectivity.
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Affiliation(s)
- Thomas Offner
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Lukas Weiss
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Daniela Daume
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Anna Berk
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Tim Justin Inderthal
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Ivan Manzini
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Thomas Hassenklöver
- Institute of Animal Physiology, Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Giessen, 35392 Giessen, Germany
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8
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Bowers JM, Li CY, Parker CG, Westbrook ME, Juntti SA. Pheromone Perception in Fish: Mechanisms and Modulation by Internal Status. Integr Comp Biol 2023; 63:407-427. [PMID: 37263784 PMCID: PMC10445421 DOI: 10.1093/icb/icad049] [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: 02/28/2023] [Revised: 05/24/2023] [Accepted: 05/27/2023] [Indexed: 06/03/2023] Open
Abstract
Pheromones are chemical signals that facilitate communication between animals, and most animals use pheromones for reproduction and other forms of social behavior. The identification of key ligands and olfactory receptors used for pheromonal communication provides insight into the sensory processing of these important cues. An individual's responses to pheromones can be plastic, as physiological status modulates behavioral outputs. In this review, we outline the mechanisms for pheromone sensation and highlight physiological mechanisms that modify pheromone-guided behavior. We focus on hormones, which regulate pheromonal communication across vertebrates including fish, amphibians, and rodents. This regulation may occur in peripheral olfactory organs and the brain, but the mechanisms remain unclear. While this review centers on research in fish, we will discuss other systems to provide insight into how hormonal mechanisms function across taxa.
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Affiliation(s)
- Jessica M Bowers
- Department of Biology, University of Maryland, 2128 Bioscience Research Bldg, College Park, MD 20742, USA
| | - Cheng-Yu Li
- Department of Biology, University of Maryland, 2128 Bioscience Research Bldg, College Park, MD 20742, USA
| | - Coltan G Parker
- Department of Biology, University of Maryland, 2128 Bioscience Research Bldg, College Park, MD 20742, USA
| | - Molly E Westbrook
- Department of Biology, University of Maryland, 2128 Bioscience Research Bldg, College Park, MD 20742, USA
| | - Scott A Juntti
- Department of Biology, University of Maryland, 2128 Bioscience Research Bldg, College Park, MD 20742, USA
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9
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Venegas JP, Navarrete M, Orellana-Garcia L, Rojas M, Avello-Duarte F, Nunez-Parra A. Basal Forebrain Modulation of Olfactory Coding In Vivo. Int J Psychol Res (Medellin) 2023; 16:62-86. [PMID: 38106956 PMCID: PMC10723750 DOI: 10.21500/20112084.6486] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/23/2022] [Accepted: 12/07/2022] [Indexed: 12/19/2023] Open
Abstract
Sensory perception is one of the most fundamental brain functions, allowing individuals to properly interact and adapt to a constantly changing environment. This process requires the integration of bottom-up and topdown neuronal activity, which is centrally mediated by the basal forebrain, a brain region that has been linked to a series of cognitive processes such as attention and alertness. Here, we review the latest research using optogenetic approaches in rodents and in vivo electrophysiological recordings that are shedding light on the role of this region, in regulating olfactory processing and decisionmaking. Moreover, we summarize evidence highlighting the anatomical and physiological differences in the basal forebrain of individuals with autism spectrum disorder, which could underpin the sensory perception abnormalities they exhibit, and propose this research line as a potential opportunity to understand the neurobiological basis of this disorder.
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Affiliation(s)
- Juan Pablo Venegas
- Physiology Laboratory, Biology Department, Faculty of Science, University of Chile, Chile.Universidad de ChileUniversity of ChileChile
| | - Marcela Navarrete
- Physiology Laboratory, Biology Department, Faculty of Science, University of Chile, Chile.Universidad de ChileUniversity of ChileChile
| | - Laura Orellana-Garcia
- Physiology Laboratory, Biology Department, Faculty of Science, University of Chile, Chile.Universidad de ChileUniversity of ChileChile
| | - Marcelo Rojas
- Physiology Laboratory, Biology Department, Faculty of Science, University of Chile, Chile.Universidad de ChileUniversity of ChileChile
| | - Felipe Avello-Duarte
- Physiology Laboratory, Biology Department, Faculty of Science, University of Chile, Chile.Universidad de ChileUniversity of ChileChile
| | - Alexia Nunez-Parra
- Physiology Laboratory, Biology Department, Faculty of Science, University of Chile, Chile.Universidad de ChileUniversity of ChileChile
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10
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Zhu KW, Matsunami H. Target-Captured mRNA from Murine Olfactory Bulb. Methods Mol Biol 2023; 2710:149-170. [PMID: 37688731 DOI: 10.1007/978-1-0716-3425-7_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/11/2023]
Abstract
The external world is perceived via sensory receptors arranged in highly organized systems according to functional strategies, which in turn reflect features of critical importance to both the sense and the animal. Thus describing the receptor organization and functional strategies of olfaction, the sense of smell, is crucial for a concrete understanding of the fundamental principles of the system's architecture. Sensory processing in olfactory systems is organized across olfactory bulb (OB) glomeruli, wherein axons of peripheral sensory neurons expressing the same olfactory receptor (OR) co-terminate to transmit receptor-specific activity to mitral/tufted cells, projection neurons in the olfactory bulb. Understanding how receptors map to glomeruli is therefore critical to understanding olfaction.Here we describe a method to enrich low-abundant OR mRNAs from the mouse OB for spatial transcriptomics to generate high-throughput mapping of receptors to glomeruli [2]. Our method combines sequential sectioning along the anteroposterior, dorsoventral, and mediolateral axes with target capture enrichment sequencing to overcome low-abundance target expression. This strategy spatially mapped 86% of olfactory receptors across the olfactory bulb and uncovered a relationship between olfactory receptor sequence and glomerular position.
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Affiliation(s)
- Kevin W Zhu
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, USA
- Department of Neurobiology, Duke Institute for Brain Sciences, Durham, NC, USA
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11
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Birdal G, D'Gama PP, Jurisch-Yaksi N, Korsching SI. Expression of taste sentinels, T1R, T2R, and PLCβ2, on the passageway for olfactory signals in zebrafish. Chem Senses 2023; 48:bjad040. [PMID: 37843175 DOI: 10.1093/chemse/bjad040] [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: 07/28/2022] [Indexed: 10/17/2023] Open
Abstract
The senses of taste and smell detect overlapping sets of chemical compounds in fish, e.g. amino acids are detected by both senses. However, so far taste and smell organs appeared morphologically to be very distinct, with a specialized olfactory epithelium for detection of odors and taste buds located in the oral cavity and lip for detection of tastants. Here, we report dense clusters of cells expressing T1R and T2R receptors as well as their signal transduction molecule PLCβ2 in nostrils of zebrafish, i.e. on the entrance funnel through which odor molecules must pass to be detected by olfactory sensory neurons. Quantitative evaluation shows the density of these chemosensory cells in the nostrils to be as high or higher than that in the established taste organs oral cavity and lower lip. Hydrodynamic flow is maximal at the nostril rim enabling high throughput chemosensation in this organ. Taken together, our results suggest a sentinel function for these chemosensory cells in the nostril.
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Affiliation(s)
- Günes Birdal
- Institute for Genetics, Department of Biology, University of Cologne, Zülpicher Str. 47A, 50674 Cologne, Germany
| | - Percival P D'Gama
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Erling Skjalgsons Gate 1, 7491 Trondheim, Norway
| | - Nathalie Jurisch-Yaksi
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Erling Skjalgsons Gate 1, 7491 Trondheim, Norway
| | - Sigrun I Korsching
- Institute for Genetics, Department of Biology, University of Cologne, Zülpicher Str. 47A, 50674 Cologne, Germany
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12
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Zhu KW, Burton SD, Nagai MH, Silverman JD, de March CA, Wachowiak M, Matsunami H. Decoding the olfactory map through targeted transcriptomics links murine olfactory receptors to glomeruli. Nat Commun 2022; 13:5137. [PMID: 36050313 PMCID: PMC9437035 DOI: 10.1038/s41467-022-32267-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 07/21/2022] [Indexed: 12/12/2022] Open
Abstract
Sensory processing in olfactory systems is organized across olfactory bulb glomeruli, wherein axons of peripheral sensory neurons expressing the same olfactory receptor co-terminate to transmit receptor-specific activity to central neurons. Understanding how receptors map to glomeruli is therefore critical to understanding olfaction. High-throughput spatial transcriptomics is a rapidly advancing field, but low-abundance olfactory receptor expression within glomeruli has previously precluded high-throughput mapping of receptors to glomeruli in the mouse. Here we combined sequential sectioning along the anteroposterior, dorsoventral, and mediolateral axes with target capture enrichment sequencing to overcome low-abundance target expression. This strategy allowed us to spatially map 86% of olfactory receptors across the olfactory bulb and uncover a relationship between OR sequence and glomerular position.
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Affiliation(s)
- Kevin W Zhu
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Shawn D Burton
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, 18015, USA
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Maira H Nagai
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Justin D Silverman
- College of Information Science and Technology, Pennsylvania State University, University Park, PA, 16802, USA
- Department of Statistics, Pennsylvania State University, University Park, PA, 16802, USA
- Department of Medicine, Pennsylvania State University, Hershey, PA, 17033, USA
- Institute for Computational and Data Science, Pennsylvania State University, University Park, PA, 16802, USA
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Matt Wachowiak
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA.
- Duke Institute for Brain Sciences, Duke University, Durham, NC, 27710, USA.
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13
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Endo K, Kazama H. Central organization of a high-dimensional odor space. Curr Opin Neurobiol 2022; 73:102528. [DOI: 10.1016/j.conb.2022.102528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 11/03/2022]
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14
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Coureaud G, Thomas-Danguin T, Sandoz JC, Wilson DA. Biological constraints on configural odour mixture perception. J Exp Biol 2022; 225:274695. [PMID: 35285471 PMCID: PMC8996812 DOI: 10.1242/jeb.242274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animals, including humans, detect odours and use this information to behave efficiently in the environment. Frequently, odours consist of complex mixtures of odorants rather than single odorants, and mixtures are often perceived as configural wholes, i.e. as odour objects (e.g. food, partners). The biological rules governing this 'configural perception' (as opposed to the elemental perception of mixtures through their components) remain weakly understood. Here, we first review examples of configural mixture processing in diverse species involving species-specific biological signals. Then, we present the original hypothesis that at least certain mixtures can be processed configurally across species. Indeed, experiments conducted in human adults, newborn rabbits and, more recently, in rodents and honeybees show that these species process some mixtures in a remarkably similar fashion. Strikingly, a mixture AB (A, ethyl isobutyrate; B, ethyl maltol) induces configural processing in humans, who perceive a mixture odour quality (pineapple) distinct from the component qualities (A, strawberry; B, caramel). The same mixture is weakly configurally processed in rabbit neonates, which perceive a particular odour for the mixture in addition to the component odours. Mice and honeybees also perceive the AB mixture configurally, as they respond differently to the mixture compared with its components. Based on these results and others, including neurophysiological approaches, we propose that certain mixtures are convergently perceived across various species of vertebrates/invertebrates, possibly as a result of a similar anatomical organization of their olfactory systems and the common necessity to simplify the environment's chemical complexity in order to display adaptive behaviours.
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Affiliation(s)
- Gérard Coureaud
- Centre de Recherche en Neurosciences de Lyon, Team Sensory Neuroethology (ENES), CNRS/INSERM/UCBL1/UJM, 69500 Lyon, France
| | - Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, Team Flavor, Food Oral Processing and Perception, INRAE, CNRS, Institut Agro Dijon, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, CNRS, Université Paris-Saclay, IRD, 91190 Gif-sur-Yvette, France
| | - Donald A Wilson
- Department of Child & Adolescent Psychiatry, New York University Langone School of Medicine and Nathan S. Kline Institute for Psychiatric Research, New York, NY 10016, USA
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15
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Patel R, Hallem EA. Olfaction: One receptor drives opposite behaviors. Curr Biol 2022; 32:R93-R96. [PMID: 35077699 DOI: 10.1016/j.cub.2021.12.008] [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] [Indexed: 11/19/2022]
Abstract
Many odorants are attractive at low concentrations but repulsive at higher concentrations. A new study demonstrates that, in Caenorhabditis elegans, a single odorant receptor acts in two different neuron pairs to mediate both attractive and repulsive responses to an odorant.
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Affiliation(s)
- Ruhi Patel
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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16
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Cheng RP, Dang P, Taku AA, Moon YJ, Pham V, Sun X, Zhao E, Raper JA. Loss of Neuropilin2a/b or Sema3fa alters olfactory sensory axon dynamics and protoglomerular targeting. Neural Dev 2022; 17:1. [PMID: 34980234 PMCID: PMC8725463 DOI: 10.1186/s13064-021-00157-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/29/2021] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Olfactory Sensory Neuron (OSN) axons project from the zebrafish olfactory epithelium to reproducible intermediate target locations in the olfactory bulb called protoglomeruli at early stages in development. Two classes of OSNs expressing either OMP or TRPC2 exclusively target distinct, complementary protoglomeruli. Using RNAseq, we identified axon guidance receptors nrp2a and nrp2b, and their ligand sema3fa, as potential guidance factors that are differentially expressed between these two classes of OSNs. METHODS To investigate their role in OSN axon guidance, we assessed the protoglomerular targeting fidelity of OSNs labeled by OMP:RFP and TRPC2:Venus transgenes in nrp2a, nrp2b, or sema3fa mutants. We used double mutant and genetic interaction experiments to interrogate the relationship between the three genes. We used live time-lapse imaging to compare the dynamic behaviors of OSN growth cones during protoglomerular targeting in heterozygous and mutant larvae. RESULTS The fidelity of protoglomerular targeting of TRPC2-class OSNs is degraded in nrp2a, nrp2b, or sema3fa mutants, as axons misproject into OMP-specific protoglomeruli and other ectopic locations in the bulb. These misprojections are further enhanced in nrp2a;nrp2b double mutants suggesting that nrp2s work at least partially in parallel in the same guidance process. Results from genetic interaction experiments are consistent with sema3fa acting in the same biological pathway as both nrp2a and nrp2b. Live time-lapse imaging was used to examine the dynamic behavior of TRPC2-class growth cones in nrp2a mutants compared to heterozygous siblings. Some TRPC2-class growth cones ectopically enter the dorsal-medial region of the bulb in both groups, but in fully mutant embryos, they are less likely to correct the error through retraction. The same result was observed when TRPC2-class growth cone behavior was compared between sema3fa heterozygous and sema3fa mutant larvae. CONCLUSIONS Our results suggest that nrp2a and nrp2b expressed in TRPC2-class OSNs help prevent their mixing with axon projections in OMP-specific protoglomeruli, and further, that sema3fa helps to exclude TRPC2-class axons by repulsion from the dorsal-medial bulb.
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Affiliation(s)
- Ryan P Cheng
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
| | - Puneet Dang
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
| | - Alemji A Taku
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
| | - Yoon Ji Moon
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
| | - Vi Pham
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
| | - Xiaohe Sun
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
| | - Ethan Zhao
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
| | - Jonathan A Raper
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA.
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17
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Iseppon F, Linley JE, Wood JN. Calcium imaging for analgesic drug discovery. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2022; 11:100083. [PMID: 35079661 PMCID: PMC8777277 DOI: 10.1016/j.ynpai.2021.100083] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/17/2021] [Accepted: 12/27/2021] [Indexed: 11/24/2022]
Abstract
Somatosensation and pain are complex phenomena involving a rangeofspecialised cell types forming different circuits within the peripheral and central nervous systems. In recent decades, advances in the investigation of these networks, as well as their function in sensation, resulted from the constant evolution of electrophysiology and imaging techniques to allow the observation of cellular activity at the population level both in vitro and in vivo. Genetically encoded indicators of neuronal activity, combined with recent advances in DNA engineering and modern microscopy, offer powerful tools to dissect and visualise the activity of specific neuronal subpopulations with high spatial and temporal resolution. In recent years various groups developed in vivo imaging techniques to image calcium transients in the dorsal root ganglia, the spinal cord and the brain of anesthetised and awake, behaving animals to address fundamental questions in both the physiology and pathophysiology of somatosensation and pain. This approach, besides giving unprecedented details on the circuitry of innocuous and painful sensation, can be a very powerful tool for pharmacological research, from the characterisation of new potential drugs to the discovery of new, druggable targets within specific neuronal subpopulations. Here we summarise recent developments in calcium imaging for pain research, discuss technical challenges and advances, and examine the potential positive impact of this technique in early preclinical phases of the analgesic drug discovery process.
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Affiliation(s)
- Federico Iseppon
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, WC1E 6BT London, UK
- Discovery UK, Neuroscience, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - John E. Linley
- Discovery UK, Neuroscience, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - John N. Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, WC1E 6BT London, UK
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18
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Choi JH, Duboue ER, Macurak M, Chanchu JM, Halpern ME. Specialized neurons in the right habenula mediate response to aversive olfactory cues. eLife 2021; 10:e72345. [PMID: 34878403 PMCID: PMC8691842 DOI: 10.7554/elife.72345] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/07/2021] [Indexed: 12/27/2022] Open
Abstract
Hemispheric specializations are well studied at the functional level but less is known about the underlying neural mechanisms. We identified a small cluster of cholinergic neurons in the dorsal habenula (dHb) of zebrafish, defined by their expression of the lecithin retinol acyltransferase domain containing 2 a (lratd2a) gene and their efferent connections with a subregion of the ventral interpeduncular nucleus (vIPN). The lratd2a-expressing neurons in the right dHb are innervated by a subset of mitral cells from both the left and right olfactory bulb and are activated upon exposure to the odorant cadaverine that is repellent to adult zebrafish. Using an intersectional strategy to drive expression of the botulinum neurotoxin specifically in these neurons, we find that adults no longer show aversion to cadaverine. Mutants with left-isomerized dHb that lack these neurons are also less repelled by cadaverine and their behavioral response to alarm substance, a potent aversive cue, is diminished. However, mutants in which both dHb have right identity appear more reactive to alarm substance. The results implicate an asymmetric dHb-vIPN neural circuit in the processing of repulsive olfactory cues and in modulating the resultant behavioral response.
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Affiliation(s)
- Jung-Hwa Choi
- Carnegie Institution for Science, Department of EmbryologyBaltimoreUnited States
| | - Erik R Duboue
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
- Wilkes Honors College, Florida Atlantic UniversityJupiterUnited States
| | - Michelle Macurak
- Carnegie Institution for Science, Department of EmbryologyBaltimoreUnited States
| | - Jean-Michel Chanchu
- Carnegie Institution for Science, Department of EmbryologyBaltimoreUnited States
| | - Marnie E Halpern
- Carnegie Institution for Science, Department of EmbryologyBaltimoreUnited States
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19
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Koyama S, Kondo K, Ueha R, Kashiwadani H, Heinbockel T. Possible Use of Phytochemicals for Recovery from COVID-19-Induced Anosmia and Ageusia. Int J Mol Sci 2021; 22:8912. [PMID: 34445619 PMCID: PMC8396277 DOI: 10.3390/ijms22168912] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022] Open
Abstract
The year 2020 became the year of the outbreak of coronavirus, SARS-CoV-2, which escalated into a worldwide pandemic and continued into 2021. One of the unique symptoms of the SARS-CoV-2 disease, COVID-19, is the loss of chemical senses, i.e., smell and taste. Smell training is one of the methods used in facilitating recovery of the olfactory sense, and it uses essential oils of lemon, rose, clove, and eucalyptus. These essential oils were not selected based on their chemical constituents. Although scientific studies have shown that they improve recovery, there may be better combinations for facilitating recovery. Many phytochemicals have bioactive properties with anti-inflammatory and anti-viral effects. In this review, we describe the chemical compounds with anti- inflammatory and anti-viral effects, and we list the plants that contain these chemical compounds. We expand the review from terpenes to the less volatile flavonoids in order to propose a combination of essential oils and diets that can be used to develop a new taste training method, as there has been no taste training so far. Finally, we discuss the possible use of these in clinical settings.
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Affiliation(s)
- Sachiko Koyama
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Kenji Kondo
- Department of Otolaryngology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan;
| | - Rumi Ueha
- Department of Otolaryngology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan;
- Swallowing Center, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Hideki Kashiwadani
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan;
| | - Thomas Heinbockel
- Department of Anatomy, College of Medicine, Howard University, Washington, DC 20059, USA
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20
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Martelli C, Storace DA. Stimulus Driven Functional Transformations in the Early Olfactory System. Front Cell Neurosci 2021; 15:684742. [PMID: 34413724 PMCID: PMC8369031 DOI: 10.3389/fncel.2021.684742] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/06/2021] [Indexed: 11/17/2022] Open
Abstract
Olfactory stimuli are encountered across a wide range of odor concentrations in natural environments. Defining the neural computations that support concentration invariant odor perception, odor discrimination, and odor-background segmentation across a wide range of stimulus intensities remains an open question in the field. In principle, adaptation could allow the olfactory system to adjust sensory representations to the current stimulus conditions, a well-known process in other sensory systems. However, surprisingly little is known about how adaptation changes olfactory representations and affects perception. Here we review the current understanding of how adaptation impacts processing in the first two stages of the vertebrate olfactory system, olfactory receptor neurons (ORNs), and mitral/tufted cells.
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Affiliation(s)
- Carlotta Martelli
- Institute of Developmental Biology and Neurobiology, University of Mainz, Mainz, Germany
| | - Douglas Anthony Storace
- Department of Biological Science, Florida State University, Tallahassee, FL, United States
- Program in Neuroscience, Florida State University, Tallahassee, FL, United States
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21
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Heinbockel T, Straiker A. Cannabinoids Regulate Sensory Processing in Early Olfactory and Visual Neural Circuits. Front Neural Circuits 2021; 15:662349. [PMID: 34305536 PMCID: PMC8294086 DOI: 10.3389/fncir.2021.662349] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/11/2021] [Indexed: 12/25/2022] Open
Abstract
Our sensory systems such as the olfactory and visual systems are the target of neuromodulatory regulation. This neuromodulation starts at the level of sensory receptors and extends into cortical processing. A relatively new group of neuromodulators includes cannabinoids. These form a group of chemical substances that are found in the cannabis plant. Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main cannabinoids. THC acts in the brain and nervous system like the chemical substances that our body produces, the endogenous cannabinoids or endocannabinoids, also nicknamed the brain's own cannabis. While the function of the endocannabinoid system is understood fairly well in limbic structures such as the hippocampus and the amygdala, this signaling system is less well understood in the olfactory pathway and the visual system. Here, we describe and compare endocannabinoids as signaling molecules in the early processing centers of the olfactory and visual system, the olfactory bulb, and the retina, and the relevance of the endocannabinoid system for synaptic plasticity.
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Affiliation(s)
- Thomas Heinbockel
- Department of Anatomy, Howard University College of Medicine, Washington, DC, United States
| | - Alex Straiker
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States
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22
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Gronowitz ME, Liu A, Qiu Q, Yu CR, Cleland TA. A physicochemical model of odor sampling. PLoS Comput Biol 2021; 17:e1009054. [PMID: 34115747 PMCID: PMC8221795 DOI: 10.1371/journal.pcbi.1009054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 06/23/2021] [Accepted: 05/09/2021] [Indexed: 11/19/2022] Open
Abstract
We present a general physicochemical sampling model for olfaction, based on established pharmacological laws, in which arbitrary combinations of odorant ligands and receptors can be generated and their individual and collective effects on odor representations and olfactory performance measured. Individual odor ligands exhibit receptor-specific affinities and efficacies; that is, they may bind strongly or weakly to a given receptor, and can act as strong agonists, weak agonists, partial agonists, or antagonists. Ligands interacting with common receptors compete with one another for dwell time; these competitive interactions appropriately simulate the degeneracy that fundamentally defines the capacities and limitations of odorant sampling. The outcome of these competing ligand-receptor interactions yields a pattern of receptor activation levels, thereafter mapped to glomerular presynaptic activation levels based on the convergence of sensory neuron axons. The metric of greatest interest is the mean discrimination sensitivity, a measure of how effectively the olfactory system at this level is able to recognize a small change in the physicochemical quality of a stimulus. This model presents several significant outcomes, both expected and surprising. First, adding additional receptors reliably improves the system's discrimination sensitivity. Second, in contrast, adding additional ligands to an odorscene initially can improve discrimination sensitivity, but eventually will reduce it as the number of ligands increases. Third, the presence of antagonistic ligand-receptor interactions produced clear benefits for sensory system performance, generating higher absolute discrimination sensitivities and increasing the numbers of competing ligands that could be present before discrimination sensitivity began to be impaired. Finally, the model correctly reflects and explains the modest reduction in odor discrimination sensitivity exhibited by transgenic mice in which the specificity of glomerular targeting by primary olfactory neurons is partially disrupted.
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Affiliation(s)
- Mitchell E. Gronowitz
- Department of Psychology, Cornell University, Ithaca, New York, United States of America
| | - Adam Liu
- Department of Psychology, Cornell University, Ithaca, New York, United States of America
| | - Qiang Qiu
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - C. Ron Yu
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Thomas A. Cleland
- Department of Psychology, Cornell University, Ithaca, New York, United States of America
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23
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Policarpo M, Bemis KE, Tyler JC, Metcalfe CJ, Laurenti P, Sandoz JC, Rétaux S, Casane D. Evolutionary dynamics of the OR gene repertoire in teleost fishes: evidence of an association with changes in olfactory epithelium shape. Mol Biol Evol 2021; 38:3742-3753. [PMID: 33950257 PMCID: PMC8661438 DOI: 10.1093/molbev/msab145] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Teleost fishes perceive their environment through a range of sensory modalities, among which olfaction often plays an important role. Richness of the olfactory repertoire depends on the diversity of receptors coded by homologous genes classified into four families: OR, TAAR, VR1, and VR2. Herein, we focus on the OR gene repertoire. While independent large contractions of the OR gene repertoire associated with ecological transitions have been found in mammals, little is known about the diversity of the OR gene repertoire and its evolution in teleost fishes, a group that includes more than 34,000 living species. We analyzed genomes of 163 species representing diversity in this large group. We found a large range of variation in the number of functional OR genes, from 15 in the Broad-nose Pipefish Syngnathus typhle and the Ocean Sunfish Mola mola, to 429 in the Zig-zag Eel Mastacembelus armatus. The number of OR genes was higher in species when a multilamellar olfactory rosette was present. Moreover, the number of lamellae was correlated with the richness of the OR gene repertoire. While a slow and balanced birth-and-death process generally drives the evolution of the OR gene repertoire, we inferred several episodes of high rates of gene loss, sometimes followed by large gains in the number of OR genes. These gains coincide with morphological changes of the olfactory organ and suggest a strong functional association between changes in the morphology and the evolution of the OR gene repertoire.
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Affiliation(s)
- Maxime Policarpo
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement et Écologie, 91198, Gif-sur-Yvette, France
| | - Katherine E Bemis
- NOAA National Systematics Laboratory, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560, U.S.A
| | - James C Tyler
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, D.C., 20560, U.S.A
| | | | - Patrick Laurenti
- Université de Paris, Laboratoire Interdisciplinaire des Energies de Demain, Paris, France
| | - Jean-Christophe Sandoz
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement et Écologie, 91198, Gif-sur-Yvette, France
| | - Sylvie Rétaux
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Didier Casane
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement et Écologie, 91198, Gif-sur-Yvette, France.,Université de Paris, UFR Sciences du Vivant, F-75013 Paris, France
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24
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Costa KCM, Brigante TAV, Fernandes GG, Scomparin DS, Scarante FF, de Oliveira DP, Campos AC. Zebrafish as a Translational Model: An Experimental Alternative to Study the Mechanisms Involved in Anosmia and Possible Neurodegenerative Aspects of COVID-19? eNeuro 2021; 8:ENEURO.0027-21.2021. [PMID: 33952614 PMCID: PMC8174008 DOI: 10.1523/eneuro.0027-21.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/07/2021] [Accepted: 04/12/2021] [Indexed: 12/15/2022] Open
Abstract
The Coronavirus disease-2019 (COVID-19) presents a variability of clinical symptoms, ranging from asymptomatic to severe respiratory and systemic conditions. In a cohort of patients, the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2), beyond the classical respiratory manifestations, induces anosmia. Evidence has suggested SARS-CoV-2-induced anosmia can be the result of neurodegeneration of the olfactory pathway. Neurologic symptoms associated with COVID-19 have been reported; however, the precise mechanism and possible long-lasting effects remain poorly investigated. Preclinical models are valuable tools for describing and testing new possible treatments for neurologic disorders. In this way, the zebrafish (Danio rerio) organism model represents an attractive tool in the field of neuroscience, showing economic and logistic advantages besides genetic and physiologic similarities with mammalian, including the brain structure and functions. Besides, its external embryonic development, high availability of eggs, and fast development allows easy genetic manipulation and fast replications. In the present review, we suggest that the zebrafish model can be advantageous to investigate the neurologic features of COVID-19.
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Affiliation(s)
- Karla C M Costa
- Pharmacology of Neuroplasticity Laboratory, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil, 14049-900,
| | - Tamires A V Brigante
- Pharmacology of Neuroplasticity Laboratory, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil, 14049-900
| | - Gabriel G Fernandes
- Pharmacology of Neuroplasticity Laboratory, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil, 14049-900
| | - Davi S Scomparin
- Pharmacology of Neuroplasticity Laboratory, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil, 14049-900
| | - Franciele F Scarante
- Pharmacology of Neuroplasticity Laboratory, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil, 14049-900
| | - Danielle P de Oliveira
- EcoHumanTox Laboratory, Department of Clinical, Toxicological and Bromatological Analysis, School of Pharmaceutical Science of Ribeirão Preto, University of São Paulo, São Paulo, Brazil 14049-900
| | - Alline C Campos
- Pharmacology of Neuroplasticity Laboratory, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil, 14049-900
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25
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Friedrich RW, Wanner AA. Dense Circuit Reconstruction to Understand Neuronal Computation: Focus on Zebrafish. Annu Rev Neurosci 2021; 44:275-293. [PMID: 33730512 DOI: 10.1146/annurev-neuro-110220-013050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The dense reconstruction of neuronal wiring diagrams from volumetric electron microscopy data has the potential to generate fundamentally new insights into mechanisms of information processing and storage in neuronal circuits. Zebrafish provide unique opportunities for dynamical connectomics approaches that combine reconstructions of wiring diagrams with measurements of neuronal population activity and behavior. Such approaches have the power to reveal higher-order structure in wiring diagrams that cannot be detected by sparse sampling of connectivity and that is essential for neuronal computations. In the brain stem, recurrently connected neuronal modules were identified that can account for slow, low-dimensional dynamics in an integrator circuit. In the spinal cord, connectivity specifies functional differences between premotor interneurons. In the olfactory bulb, tuning-dependent connectivity implements a whitening transformation that is based on the selective suppression of responses to overrepresented stimulus features. These findings illustrate the potential of dynamical connectomics in zebrafish to analyze the circuit mechanisms underlying higher-order neuronal computations.
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Affiliation(s)
- Rainer W Friedrich
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland; .,Faculty of Natural Sciences, University of Basel, 4003 Basel, Switzerland
| | - Adrian A Wanner
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey 08544, USA;
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26
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Shahriari A, Khara LS, Allison WT, Tierney KB. Zebrafish (Danio rerio) behavioural response to an odorant mixture containing attracting and repelling odorants. BEHAVIOUR 2021. [DOI: 10.1163/1568539x-bja10070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Odorants guide essential activities such as foraging and fleeing predators. Studies usually examine behavioural and physiological effects of individual odorants, while animals in the environment are exposed to multiple stimuli simultaneously. In this study, we exposed zebrafish to a mixture of attraction-evoking and aversion-evoking amino acids, and behavioural responses were observed. Attraction to l-alanine and avoidance to l-cysteine were observed, and so these amino acids were used to make the mixture (zebrafish also avoided l-serine, but this was weaker than with l-cysteine exposures). When exposed to the mixture, fish responded with avoidance, which suggests that aversion-evoking stimuli outweigh attraction-evoking stimuli. Attraction towards the mixture was seen only when the concentration of l-cysteine was decreased from 0.1 to 0.001 mM. Olfactory ablation surgery confirmed that the behaviours were olfactory-mediated. Overall, this study demonstrated that odorant stimuli that repel outweigh stimuli that attract until their concentration decreases by as much as 100-fold.
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Affiliation(s)
- Arash Shahriari
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Lakhan S. Khara
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - W. Ted Allison
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Keith B. Tierney
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
- School of Public Health, University of Alberta, Edmonton, AB, Canada T6G 1C9
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27
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Braubach O, Croll RP. The glomerular network of the zebrafish olfactory bulb. Cell Tissue Res 2021; 383:255-271. [PMID: 33484356 DOI: 10.1007/s00441-020-03394-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/25/2020] [Indexed: 10/22/2022]
Abstract
Each zebrafish olfactory bulb contains ~ 140 glomeruli that are distinguishable based on size, location, neurochemistry and function. Here we examine the mitral cell innervation of differently sized glomeruli in adult zebrafish. Type 1 glomeruli had diameters of 80.9 ± 8.1 μm and were innervated by 5.9 ± 0.9 mitral cells. The Type 1 mediodorsal glomeruli (mdG) were innervated by both uniglomerular (innervating only single glomeruli) and multiglomerular mitral cells (innervating two or more glomeruli). In contrast, the Type 1 ventroposterior (vpG) and lateral glomeruli (lG) were only innervated by uniglomerular mitral cells. Type 2 ventral glomeruli were 46 ± 5.1 μm in diameter and were innervated by 3.3 ± 0.2 mitral cells. Type 2 ventromedial glomeruli (vmG) were innervated exclusively by uniglomerular mitral cells. Type 3 glomeruli had diameters of 17 ± 2.5 μm and were innervated by 1.1 ± 0.6 multiglomerular mitral cells each. Finally, Type 4 glomeruli were small, with average diameters of 4.8 ± 3.9 μm and were restricted to the lateral plexus. These glomeruli were innervated mainly by multiglomerular mitral cells with extensively branching dendrites. This study provides the first specific associations between uni- and multiglomerular mitral cells with known zebrafish glomeruli. Our results suggest that glomeruli are distinguishable based on their postsynaptic compartment and that distinct input-output computations occur in different types of zebrafish glomeruli.
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Affiliation(s)
- Oliver Braubach
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, B3H4R2, Canada.
| | - Roger P Croll
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, B3H4R2, Canada
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Suryanarayana SM, Pérez-Fernández J, Robertson B, Grillner S. Olfaction in Lamprey Pallium Revisited-Dual Projections of Mitral and Tufted Cells. Cell Rep 2021; 34:108596. [PMID: 33406414 DOI: 10.1016/j.celrep.2020.108596] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/19/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022] Open
Abstract
The presence of two separate afferent channels from the olfactory glomeruli to different targets in the brain is unravelled in the lamprey. The mitral-like cells send axonal projections directly to the piriform cortex in the ventral part of pallium, whereas the smaller tufted-like cells project separately and exclusively to a relay nucleus called the dorsomedial telencephalic nucleus (dmtn). This nucleus, located at the interface between the olfactory bulb and pallium, in turn projects to a circumscribed area in the anteromedial, ventral part of pallium. The tufted-like cells are activated with short latency from the olfactory nerve and terminate with mossy fibers on the dmtn cells, wherein they elicit large unitary excitatory postsynaptic potentials (EPSPs). In all synapses along this tufted-like cell pathway, there is no concurrent inhibition, in contrast to the mitral-like cell pathway. This is similar to recent findings in rodents establishing two separate exclusive projection patterns, suggesting an evolutionarily conserved organization.
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Affiliation(s)
| | - Juan Pérez-Fernández
- Department of Neuroscience, Karolinska Institutet, Solnavägen 9, 171 65 Solna, Sweden
| | - Brita Robertson
- Department of Neuroscience, Karolinska Institutet, Solnavägen 9, 171 65 Solna, Sweden
| | - Sten Grillner
- Department of Neuroscience, Karolinska Institutet, Solnavägen 9, 171 65 Solna, Sweden.
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Offner T, Daume D, Weiss L, Hassenklöver T, Manzini I. Whole-Brain Calcium Imaging in Larval Xenopus. Cold Spring Harb Protoc 2020; 2020:pdb.prot106815. [PMID: 33037078 DOI: 10.1101/pdb.prot106815] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Sensory systems detect environmental stimuli and transform them into electrical activity patterns interpretable by the central nervous system. En route to higher brain centers, the initial sensory input is successively transformed by interposed secondary processing centers. Mapping the neuronal activity patterns at all of those stages is essential to understand sensory information processing. Larval Xenopus laevis is very well-suited for whole-brain imaging of neuronal activity. This is mainly due to its small size, transparency, and the accessibility of both peripheral and central parts of sensory systems. Here we describe a protocol for calcium imaging at several levels of the olfactory system using focal injection of chemical calcium indicator dyes or a Xenopus transgenic line with neuronal GCaMP6s expression. In combination with fast volumetric multiphoton microscopy, the calcium imaging methods described can provide detailed insight into spatiotemporal activity of entire brain regions at different stages of sensory information processing. Although the methods are broadly applicable to the central nervous system, in this work we focus on protocols for calcium imaging of glomeruli in the olfactory bulb and odor-responsive neurons in the olfactory amygdala.
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Affiliation(s)
- Thomas Offner
- Department of Animal Physiology and Molecular Biomedicine, University of Giessen, 35392 Giessen, Germany
| | - Daniela Daume
- Department of Animal Physiology and Molecular Biomedicine, University of Giessen, 35392 Giessen, Germany
| | - Lukas Weiss
- Department of Animal Physiology and Molecular Biomedicine, University of Giessen, 35392 Giessen, Germany
| | - Thomas Hassenklöver
- Department of Animal Physiology and Molecular Biomedicine, University of Giessen, 35392 Giessen, Germany
| | - Ivan Manzini
- Department of Animal Physiology and Molecular Biomedicine, University of Giessen, 35392 Giessen, Germany
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Diving into the streams and waves of constitutive and regenerative olfactory neurogenesis: insights from zebrafish. Cell Tissue Res 2020; 383:227-253. [PMID: 33245413 DOI: 10.1007/s00441-020-03334-2] [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: 07/31/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023]
Abstract
The olfactory system is renowned for its functional and structural plasticity, with both peripheral and central structures displaying persistent neurogenesis throughout life and exhibiting remarkable capacity for regenerative neurogenesis after damage. In general, fish are known for their extensive neurogenic ability, and the zebrafish in particular presents an attractive model to study plasticity and adult neurogenesis in the olfactory system because of its conserved structure, relative simplicity, rapid cell turnover, and preponderance of neurogenic niches. In this review, we present an overview of the anatomy of zebrafish olfactory structures, with a focus on the neurogenic niches in the olfactory epithelium, olfactory bulb, and ventral telencephalon. Constitutive and regenerative neurogenesis in both the peripheral olfactory organ and central olfactory bulb of zebrafish is reviewed in detail, and a summary of current knowledge about the cellular origin and molecular signals involved in regulating these processes is presented. While some features of physiologic and injury-induced neurogenic responses are similar, there are differences that indicate that regeneration is not simply a reiteration of the constitutive proliferation process. We provide comparisons to mammalian neurogenesis that reveal similarities and differences between species. Finally, we present a number of open questions that remain to be answered.
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Endo K, Tsuchimoto Y, Kazama H. Synthesis of Conserved Odor Object Representations in a Random, Divergent-Convergent Network. Neuron 2020; 108:367-381.e5. [PMID: 32814018 DOI: 10.1016/j.neuron.2020.07.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 03/10/2020] [Accepted: 07/24/2020] [Indexed: 01/09/2023]
Abstract
Animals are capable of recognizing mixtures and groups of odors as a unitary object. However, how odor object representations are generated in the brain remains elusive. Here, we investigate sensory transformation between the primary olfactory center and its downstream region, the mushroom body (MB), in Drosophila and show that clustered representations for mixtures and groups of odors emerge in the MB at the population and single-cell levels. Decoding analyses demonstrate that neurons selective for mixtures and groups enhance odor generalization. Responses of these neurons and those selective for individual odors all emerge in an experimentally well-constrained model implementing divergent-convergent, random connectivity between the primary center and the MB. Furthermore, we found that relative odor representations are conserved across animals despite this random connectivity. Our results show that the generation of distinct representations for individual odors and groups and mixtures of odors in the MB can be understood in a unified computational and mechanistic framework.
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Affiliation(s)
- Keita Endo
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; RIKEN CBS-KAO Collaboration Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yoshiko Tsuchimoto
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hokto Kazama
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; RIKEN CBS-KAO Collaboration Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
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32
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Lieggi C, Kalueff AV, Lawrence C, Collymore C. The Influence of Behavioral, Social, and Environmental Factors on Reproducibility and Replicability in Aquatic Animal Models. ILAR J 2020; 60:270-288. [PMID: 32400880 PMCID: PMC7743897 DOI: 10.1093/ilar/ilz019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 08/08/2019] [Accepted: 09/11/2019] [Indexed: 12/17/2022] Open
Abstract
The publication of reproducible, replicable, and translatable data in studies utilizing animal models is a scientific, practical, and ethical necessity. This requires careful planning and execution of experiments and accurate reporting of results. Recognition that numerous developmental, environmental, and test-related factors can affect experimental outcomes is essential for a quality study design. Factors commonly considered when designing studies utilizing aquatic animal species include strain, sex, or age of the animal; water quality; temperature; and acoustic and light conditions. However, in the aquatic environment, it is equally important to consider normal species behavior, group dynamics, stocking density, and environmental complexity, including tank design and structural enrichment. Here, we will outline normal species and social behavior of 2 commonly used aquatic species: zebrafish (Danio rerio) and Xenopus (X. laevis and X. tropicalis). We also provide examples as to how these behaviors and the complexity of the tank environment can influence research results and provide general recommendations to assist with improvement of reproducibility and replicability, particularly as it pertains to behavior and environmental complexity, when utilizing these popular aquatic models.
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Affiliation(s)
- Christine Lieggi
- Center of Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and Hospital for Special Surgery, New York, New York
| | - Allan V Kalueff
- School of Pharmacy, Southwest University, Chongqing, China, and Ural Federal University, Ekaterinburg, Russia
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33
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Diversity of Olfactory Responses and Skills in Astyanax Mexicanus Cavefish Populations Inhabiting different Caves. DIVERSITY 2020. [DOI: 10.3390/d12100395] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Animals in many phyla are adapted to and thrive in the constant darkness of subterranean environments. To do so, cave animals have presumably evolved mechano- and chemosensory compensations to the loss of vision, as is the case for the blind characiform cavefish, Astyanax mexicanus. Here, we systematically assessed the olfactory capacities of cavefish and surface fish of this species in the lab as well as in the wild, in five different caves in northeastern Mexico, using an olfactory setup specially developed to test and record olfactory responses during fieldwork. Overall cavefish showed lower (i.e., better) olfactory detection thresholds than surface fish. However, wild adult cavefish from the Pachón, Sabinos, Tinaja, Chica and Subterráneo caves showed highly variable responses to the three different odorant molecules they were exposed to. Pachón and Subterráneo cavefish showed the highest olfactory capacities, and Chica cavefish showed no response to the odors presented. We discuss these data with regard to the environmental conditions in which these different cavefish populations live. Our experiments in natural settings document the diversity of cave environments inhabited by a single species of cavefish, A. mexicanus, and highlight the complexity of the plastic and genetic mechanisms that underlie cave adaptation.
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34
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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: 0.8] [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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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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36
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Kermen F, Darnet L, Wiest C, Palumbo F, Bechert J, Uslu O, Yaksi E. Stimulus-specific behavioral responses of zebrafish to a large range of odors exhibit individual variability. BMC Biol 2020; 18:66. [PMID: 32539727 PMCID: PMC7296676 DOI: 10.1186/s12915-020-00801-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 05/22/2020] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Odor-driven behaviors such as feeding, mating, and predator avoidance are crucial for animal survival. The neural pathways processing these behaviors have been well characterized in a number of species, and involve the activity of diverse brain regions following stimulation of the olfactory bulb by specific odors. However, while the zebrafish olfactory circuitry is well understood, a comprehensive characterization linking odor-driven behaviors to specific odors is needed to better relate olfactory computations to animal responses. RESULTS Here, we used a medium-throughput setup to measure the swimming trajectories of 10 zebrafish in response to 17 ecologically relevant odors. By selecting appropriate locomotor metrics, we constructed ethograms systematically describing odor-induced changes in the swimming trajectory. We found that adult zebrafish reacted to most odorants using different behavioral programs and that a combination of a few relevant behavioral metrics enabled us to capture most of the variance in these innate odor responses. We observed that individual components of natural food and alarm odors do not elicit the full behavioral response. Finally, we show that zebrafish blood elicits prominent defensive behaviors similar to those evoked by skin extract and activates spatially overlapping olfactory bulb domains. CONCLUSION Altogether, our results highlight a prominent intra- and inter-individual variability in zebrafish odor-driven behaviors and identify a small set of waterborne odors that elicit robust responses. Our behavioral setup and our results will be useful resources for future studies interested in characterizing innate olfactory behaviors in aquatic animals.
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Affiliation(s)
- Florence Kermen
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7030, Trondheim, Norway.
- Neuro-Electronics Research Flanders, Imec Campus, Kapeldreef 75, 3001, Leuven, Belgium.
- Department of Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 7491, Trondheim, Norway.
- KU Leuven, 3000, Leuven, Belgium.
| | - Lea Darnet
- Neuro-Electronics Research Flanders, Imec Campus, Kapeldreef 75, 3001, Leuven, Belgium
- KU Leuven, 3000, Leuven, Belgium
| | - Christoph Wiest
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7030, Trondheim, Norway
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 9DU, UK
| | - Fabrizio Palumbo
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7030, Trondheim, Norway
| | - Jack Bechert
- Neuro-Electronics Research Flanders, Imec Campus, Kapeldreef 75, 3001, Leuven, Belgium
- KU Leuven, 3000, Leuven, Belgium
| | - Ozge Uslu
- Neuro-Electronics Research Flanders, Imec Campus, Kapeldreef 75, 3001, Leuven, Belgium
- KU Leuven, 3000, Leuven, Belgium
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, 7030, Trondheim, Norway.
- Neuro-Electronics Research Flanders, Imec Campus, Kapeldreef 75, 3001, Leuven, Belgium.
- KU Leuven, 3000, Leuven, Belgium.
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McClintock TS, Wang Q, Sengoku T, Titlow WB, Breheny P. Mixture and concentration effects on odorant receptor response patterns in vivo. Chem Senses 2020; 45:bjaa032. [PMID: 32427281 DOI: 10.1093/chemse/bjaa032] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Indexed: 02/28/2024] Open
Abstract
Natural odors are mixtures of volatile chemicals (odorants). Odors are encoded as responses of distinct subsets of the hundreds of odorant receptors and trace amine-associated receptors expressed monogenically by olfactory sensory neurons. This is an elegantly simple mechanism for differentially encoding odors but it is susceptible to complex dose-response relationships and interactions between odorants at receptors, which may help explain olfactory phenomena such as mixture suppression, synthetic versus elemental odor processing, and poorly predictable perceptual outcomes of new odor mixtures. In this study in vivo tests in freely behaving mice confirm evidence of a characteristic receptor response pattern consisting of a few receptors with strong responses and a greater number of weakly responding receptors. Odorant receptors responsive to an odor are often unrelated and widely divergent in sequence, even when the odor consists of a single species of odorant. Odorant receptor response patterns to a citrus odor broaden with concentration. Some highly sensitive receptors respond only to a low concentration but others respond in proportion to concentration, a feature that may be critical for concentration-invariant perception. Other tests find evidence of interactions between odorants in vivo. All of the odorant receptor responses to a moderate concentration of the fecal malodor indole are suppressed by a high concentration of the floral odorant, α-ionone. Such suppressive effects are consistent with prior evidence that odorant interactions at individual odorant receptors are common.
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Affiliation(s)
| | - Qiang Wang
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | - Tomoko Sengoku
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | - William B Titlow
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | - Patrick Breheny
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA
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de March CA, Titlow WB, Sengoku T, Breheny P, Matsunami H, McClintock TS. Modulation of the combinatorial code of odorant receptor response patterns in odorant mixtures. Mol Cell Neurosci 2020; 104:103469. [PMID: 32061665 DOI: 10.1016/j.mcn.2020.103469] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 02/01/2023] Open
Abstract
The perception of odors relies on combinatorial codes consisting of odorant receptor (OR) response patterns to encode odor identity. Modulation of these patterns by odorant interactions at ORs potentially explains several olfactory phenomena: mixture suppression, unpredictable sensory outcomes, and the perception of odorant mixtures as unique objects. We determined OR response patterns to 4 odorants and 3 binary mixtures in vivo in mice, identifying 30 responsive ORs. These patterns typically had a few strongly responsive ORs and a greater number of weakly responsive ORs. ORs responsive to an odorant were often unrelated sequences distributed across several OR subfamilies. Mixture responses predicted pharmacological interactions between odorants, which were tested in vitro by heterologous expression of ORs in cultured cells, providing independent evidence confirming odorant agonists for 13 ORs and identifying both suppressive and additive effects. This included 11 instances of antagonism of ORs by an odorant, 1 instance of additive responses to a binary mixture, 1 instance of suppression of a strong agonist by a weak agonist, and the discovery of an inverse agonist for an OR. Interactions between odorants at ORs are common even when the odorants are not known to interact perceptually in humans, and in some cases interactions at mouse ORs correlate with the ability of humans to perceive an odorant in a mixture.
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Affiliation(s)
- Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - William B Titlow
- Department of Physiology, University of Kentucky, Lexington, KY 40536-0298, USA
| | - Tomoko Sengoku
- Department of Physiology, University of Kentucky, Lexington, KY 40536-0298, USA
| | - Patrick Breheny
- Department of Biostatistics, University of Iowa, Iowa City, IA 52242, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA; Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan; Duke Institute for Brain Sciences, Duke University, Durham, NC 27710, USA.
| | - Timothy S McClintock
- Department of Physiology, University of Kentucky, Lexington, KY 40536-0298, USA.
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39
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Perl O, Nahum N, Belelovsky K, Haddad R. The contribution of temporal coding to odor coding and odor perception in humans. eLife 2020; 9:49734. [PMID: 32031520 PMCID: PMC7007219 DOI: 10.7554/elife.49734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/15/2020] [Indexed: 11/17/2022] Open
Abstract
Whether neurons encode information through their spike rates, their activity times or both is an ongoing debate in systems neuroscience. Here, we tested whether humans can discriminate between a pair of temporal odor mixtures (TOMs) composed of the same two components delivered in rapid succession in either one temporal order or its reverse. These TOMs presumably activate the same olfactory neurons but at different times and thus differ mainly in the time of neuron activation. We found that most participants could hardly discriminate between TOMs, although they easily discriminated between a TOM and one of its components. By contrast, participants succeeded in discriminating between the TOMs when they were notified of their successive nature in advance. We thus suggest that the time of glomerulus activation can be exploited to extract odor-related information, although it does not change the odor perception substantially, as should be expected from an odor code per se.
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Affiliation(s)
- Ofer Perl
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Nahum Nahum
- Department of Psychology, Bar-Ilan University, Ramat-Gan, Israel
| | - Katya Belelovsky
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Rafi Haddad
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
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40
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Whitening of odor representations by the wiring diagram of the olfactory bulb. Nat Neurosci 2020; 23:433-442. [PMID: 31959937 PMCID: PMC7101160 DOI: 10.1038/s41593-019-0576-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 12/12/2019] [Indexed: 11/08/2022]
Abstract
Neuronal computations underlying higher brain functions depend on synaptic interactions among specific neurons. A mechanistic understanding of such computations requires wiring diagrams of neuronal networks. In this study, we examined how the olfactory bulb (OB) performs 'whitening', a fundamental computation that decorrelates activity patterns and supports their classification by memory networks. We measured odor-evoked activity in the OB of a zebrafish larva and subsequently reconstructed the complete wiring diagram by volumetric electron microscopy. The resulting functional connectome revealed an over-representation of multisynaptic connectivity motifs that mediate reciprocal inhibition between neurons with similar tuning. This connectivity suppressed redundant responses and was necessary and sufficient to reproduce whitening in simulations. Whitening of odor representations is therefore mediated by higher-order structure in the wiring diagram that is adapted to natural input patterns.
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41
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Abstract
The zebrafish (Danio rerio) has emerged as a widely used model system during the last four decades. The fact that the zebrafish larva is transparent enables sophisticated in vivo imaging, including calcium imaging of intracellular transients in many different tissues. While being a vertebrate, the reduced complexity of its nervous system and small size make it possible to follow large-scale activity in the whole brain. Its genome is sequenced and many genetic and molecular tools have been developed that simplify the study of gene function in health and disease. Since the mid 90's, the development and neuronal function of the embryonic, larval, and later, adult zebrafish have been studied using calcium imaging methods. This updated chapter is reviewing the advances in methods and research findings of zebrafish calcium imaging during the last decade. The choice of calcium indicator depends on the desired number of cells to study and cell accessibility. Synthetic calcium indicators, conjugated to dextrans and acetoxymethyl (AM) esters, are still used to label specific neuronal cell types in the hindbrain and the olfactory system. However, genetically encoded calcium indicators, such as aequorin and the GCaMP family of indicators, expressed in various tissues by the use of cell-specific promoters, are now the choice for most applications, including brain-wide imaging. Calcium imaging in the zebrafish has contributed greatly to our understanding of basic biological principles during development and adulthood, and the function of disease-related genes in a vertebrate system.
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42
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Olivares J, Schmachtenberg O. An update on anatomy and function of the teleost olfactory system. PeerJ 2019; 7:e7808. [PMID: 31579633 PMCID: PMC6768218 DOI: 10.7717/peerj.7808] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/01/2019] [Indexed: 12/16/2022] Open
Abstract
About half of all extant vertebrates are teleost fishes. Although our knowledge about anatomy and function of their olfactory systems still lags behind that of mammals, recent advances in cellular and molecular biology have provided us with a wealth of novel information about the sense of smell in this important animal group. Its paired olfactory organs contain up to five types of olfactory receptor neurons expressing OR, TAAR, VR1- and VR2-class odorant receptors associated with individual transduction machineries. The different types of receptor neurons are preferentially tuned towards particular classes of odorants, that are associated with specific behaviors, such as feeding, mating or migration. We discuss the connections of the receptor neurons in the olfactory bulb, the differences in bulbar circuitry compared to mammals, and the characteristics of second order projections to telencephalic olfactory areas, considering the everted ontogeny of the teleost telencephalon. The review concludes with a brief overview of current theories about odor coding and the prominent neural oscillations observed in the teleost olfactory system.
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Affiliation(s)
- Jesús Olivares
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile.,Universidad de Valparaíso, PhD Program in Neuroscience, Valparaíso, Chile
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
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43
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Storace DA, Cohen LB, Choi Y. Using Genetically Encoded Voltage Indicators (GEVIs) to Study the Input-Output Transformation of the Mammalian Olfactory Bulb. Front Cell Neurosci 2019; 13:342. [PMID: 31417362 PMCID: PMC6684792 DOI: 10.3389/fncel.2019.00342] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/11/2019] [Indexed: 12/19/2022] Open
Abstract
Genetically encoded voltage indicators (GEVIs) are fluorescent protein reporters of membrane potential. These tools can, in principle, be used to monitor the neural activity of genetically distinct cell types in the brain. Although introduced in 1997, they have been a challenge to use to study intact neural circuits due to a combination of small signal-to-noise ratio, slow kinetics, and poor membrane expression. New strategies have yielded novel GEVIs such as ArcLight, which have improved properties. Here, we compare the in vivo properties of ArcLight with Genetically Encoded Calcium Indicators (GECIs) in the mouse olfactory bulb. We show how voltage imaging can be combined with organic calcium sensitive dyes to measure the input-output transformation of the olfactory bulb. Finally, we demonstrate that ArcLight can be targeted to olfactory bulb interneurons. The olfactory bulb contributes substantially to the perception of the concentration invariance of odor recognition.
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Affiliation(s)
- Douglas A Storace
- Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Lawrence B Cohen
- Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States.,Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
| | - Yunsook Choi
- Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States.,Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
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44
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Chae H, Kepple DR, Bast WG, Murthy VN, Koulakov AA, Albeanu DF. Mosaic representations of odors in the input and output layers of the mouse olfactory bulb. Nat Neurosci 2019; 22:1306-1317. [PMID: 31332371 DOI: 10.1038/s41593-019-0442-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/30/2019] [Indexed: 11/09/2022]
Abstract
The elementary stimulus features encoded by the olfactory system remain poorly understood. We examined the relationship between 1,666 physical-chemical descriptors of odors and the activity of olfactory bulb inputs and outputs in awake mice. Glomerular and mitral and tufted cell responses were sparse and locally heterogeneous, with only a weak dependence of their positions on physical-chemical properties. Odor features represented by ensembles of mitral and tufted cells were overlapping but distinct from those represented in glomeruli, which is consistent with an extensive interplay between feedforward and feedback inputs to the bulb. This reformatting was well described as a rotation in odor space. The physical-chemical descriptors accounted for a small fraction in response variance, and the similarity of odors in the physical-chemical space was a poor predictor of similarity in neuronal representations. Our results suggest that commonly used physical-chemical properties are not systematically represented in bulbar activity and encourage further searches for better descriptors of odor space.
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Affiliation(s)
- Honggoo Chae
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Daniel R Kepple
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.,Watson School for Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Walter G Bast
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Alexei A Koulakov
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. .,Watson School for Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
| | - Dinu F Albeanu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. .,Watson School for Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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45
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Velez Z, Roggatz CC, Benoit DM, Hardege JD, Hubbard PC. Short- and Medium-Term Exposure to Ocean Acidification Reduces Olfactory Sensitivity in Gilthead Seabream. Front Physiol 2019; 10:731. [PMID: 31333474 PMCID: PMC6616109 DOI: 10.3389/fphys.2019.00731] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 05/27/2019] [Indexed: 12/21/2022] Open
Abstract
The effects of ocean acidification on fish are only partially understood. Studies on olfaction are mostly limited to behavioral alterations of coral reef fish; studies on temperate species and/or with economic importance are scarce. The current study evaluated the effects of short- and medium-term exposure to ocean acidification on the olfactory system of gilthead seabream (Sparus aurata), and attempted to explain observed differences in sensitivity by changes in the protonation state of amino acid odorants. Short-term exposure to elevated PCO2 decreased olfactory sensitivity to some odorants, such as L-serine, L-leucine, L-arginine, L-glutamate, and conspecific intestinal fluid, but not to others, such as L-glutamine and conspecific bile fluid. Seabream were unable to compensate for high PCO2 levels in the medium term; after 4 weeks exposure to high PCO2, the olfactory sensitivity remained lower in elevated PCO2 water. The decrease in olfactory sensitivity in high PCO2 water could be partly attributed to changes in the protonation state of the odorants and/or their receptor(s); we illustrate how protonation due to reduced pH causes changes in the charge distribution of odorant molecules, an essential component for ligand-receptor interaction. However, there are other mechanisms involved. At a histological level, the olfactory epithelium contained higher densities of mucus cells in fish kept in high CO2 water, and a shift in pH of the mucus they produced to more neutral. These differences suggest a physiological response of the olfactory epithelium to lower pH and/or high CO2 levels, but an inability to fully counteract the effects of acidification on olfactory sensitivity. Therefore, the current study provides evidence for a direct, medium term, global effect of ocean acidification on olfactory sensitivity in fish, and possibly other marine organisms, and suggests a partial explanatory mechanism.
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Affiliation(s)
| | - Christina C Roggatz
- Energy and Environment Institute, University of Hull, Hull, United Kingdom.,Department of Biological and Marine Science, University of Hull, Hull, United Kingdom
| | - David M Benoit
- E.A. Milne Centre for Astrophysics and G.W. Gray Centre for Advanced Material, University of Hull, Hull, United Kingdom
| | - Jörg D Hardege
- Department of Biological and Marine Science, University of Hull, Hull, United Kingdom
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46
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Kadakia N, Emonet T. Front-end Weber-Fechner gain control enhances the fidelity of combinatorial odor coding. eLife 2019; 8:e45293. [PMID: 31251174 PMCID: PMC6609331 DOI: 10.7554/elife.45293] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 06/26/2019] [Indexed: 11/13/2022] Open
Abstract
We showed previously (Gorur-Shandilya et al., 2017) that Drosophila olfactory receptor neurons (ORNs) expressing the co-receptor Orco scale their gain inversely with mean odor intensity according to Weber-Fechner's law. Here, we show that this front-end adaptation promotes the reconstruction of odor identity from dynamic odor signals, even in the presence of confounding background odors and rapid intensity fluctuations. These enhancements are further aided by known downstream transformations in the antennal lobe and mushroom body. Our results, which are applicable to various odor classification and reconstruction schemes, stem from the fact that this adaptation mechanism is not intrinsic to the identity of the receptor involved. Instead, a feedback mechanism adjusts receptor sensitivity based on the activity of the receptor-Orco complex, according to Weber-Fechner's law. Thus, a common scaling of the gain across Orco-expressing ORNs may be a key feature of ORN adaptation that helps preserve combinatorial odor codes in naturalistic landscapes.
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Affiliation(s)
- Nirag Kadakia
- Department of Molecular, Cellular and Developmental BiologyYale UniversityNew HavenUnited States
| | - Thierry Emonet
- Department of Molecular, Cellular and Developmental BiologyYale UniversityNew HavenUnited States
- Department of PhysicsYale UniversityNew HavenUnited States
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47
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Calvo-Ochoa E, Byrd-Jacobs CA. The Olfactory System of Zebrafish as a Model for the Study of Neurotoxicity and Injury: Implications for Neuroplasticity and Disease. Int J Mol Sci 2019; 20:ijms20071639. [PMID: 30986990 PMCID: PMC6480214 DOI: 10.3390/ijms20071639] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/26/2019] [Accepted: 03/29/2019] [Indexed: 12/30/2022] Open
Abstract
The olfactory system, composed of the olfactory organs and the olfactory bulb, allows organisms to interact with their environment and through the detection of odor signals. Olfaction mediates behaviors pivotal for survival, such as feeding, mating, social behavior, and danger assessment. The olfactory organs are directly exposed to the milieu, and thus are particularly vulnerable to damage by environmental pollutants and toxicants, such as heavy metals, pesticides, and surfactants, among others. Given the widespread occurrence of olfactory toxicants, there is a pressing need to understand the effects of these harmful compounds on olfactory function. Zebrafish (Danio rerio) is a valuable model for studying human physiology, disease, and toxicity. Additionally, the anatomical components of the zebrafish olfactory system are similar to those of other vertebrates, and they present a remarkable degree of regeneration and neuroplasticity, making it an ideal model for the study of regeneration, reorganization and repair mechanisms following olfactory toxicant exposure. In this review, we focus on (1) the anatomical, morphological, and functional organization of the olfactory system of zebrafish; (2) the adverse effects of olfactory toxicants and injury to the olfactory organ; and (3) remodeling and repair neuroplasticity mechanisms following injury and degeneration by olfactory toxicant exposure.
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Affiliation(s)
- Erika Calvo-Ochoa
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008-5410, USA.
| | - Christine A Byrd-Jacobs
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008-5410, USA.
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48
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Nikonov AA, Maruska KP. Male dominance status regulates odor-evoked processing in the forebrain of a cichlid fish. Sci Rep 2019; 9:5083. [PMID: 30911102 PMCID: PMC6433859 DOI: 10.1038/s41598-019-41521-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 03/11/2019] [Indexed: 02/07/2023] Open
Abstract
The ability to identify odors in the environment is crucial for survival and reproduction. However, whether olfactory processing in higher-order brain centers is influenced by an animal's physiological condition is unknown. We used in vivo neuron and local field potential (LFP) recordings from the ventral telencephalon of dominant and subordinate male cichlids to test the hypothesis that response properties of olfactory neurons differ with social status. Dominant males had a high percentage of neurons that responded to several odor types, suggesting broad tuning or differential sensitivity when males are reproductively active and defending a territory. A greater percentage of neurons in dominant males also responded to sex- and food-related odors, while a greater percentage of neurons in subordinate males responded to complex odors collected from behaving dominant males, possibly as a mechanism to mediate social suppression and allow subordinates to identify opportunities to rise in rank. Odor-evoked LFP spectral densities, indicative of synaptic inputs, were also 2-3-fold greater in dominant males, demonstrating status-dependent differences in processing possibly linking olfactory and other neural inputs to goal-directed behaviors. For the first time we reveal social and reproductive-state plasticity in olfactory processing neurons in the vertebrate forebrain that are associated with status-specific lifestyles.
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Affiliation(s)
- Alexandre A Nikonov
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg., Baton Rouge, LA, 70803, USA
| | - Karen P Maruska
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg., Baton Rouge, LA, 70803, USA.
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49
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Vaz R, Hofmeister W, Lindstrand A. Zebrafish Models of Neurodevelopmental Disorders: Limitations and Benefits of Current Tools and Techniques. Int J Mol Sci 2019; 20:ijms20061296. [PMID: 30875831 PMCID: PMC6471844 DOI: 10.3390/ijms20061296] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/26/2019] [Accepted: 03/11/2019] [Indexed: 12/13/2022] Open
Abstract
For the past few years there has been an exponential increase in the use of animal models to confirm the pathogenicity of candidate disease-causing genetic variants found in patients. One such animal model is the zebrafish. Despite being a non-mammalian animal, the zebrafish model has proven its potential in recapitulating the phenotypes of many different human genetic disorders. This review will focus on recent advances in the modeling of neurodevelopmental disorders in zebrafish, covering aspects from early brain development to techniques used for modulating gene expression, as well as how to best characterize the resulting phenotypes. We also review other existing models of neurodevelopmental disorders, and the current efforts in developing and testing compounds with potential therapeutic value.
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Affiliation(s)
- Raquel Vaz
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, 171 76 Stockholm, Sweden.
| | - Wolfgang Hofmeister
- Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, 5000 Odense, Denmark and the Novo Nordisk Foundation for Stem cell Biology (Danstem), University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine and Clinical Genetics, Karolinska University Laboratory, Karolinska University Hospital, 171 76 Stockholm, Sweden.
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50
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Gerlach G, Tietje K, Biechl D, Namekawa I, Schalm G, Sulmann A. Behavioural and neuronal basis of olfactory imprinting and kin recognition in larval fish. ACTA ACUST UNITED AC 2019; 222:222/Suppl_1/jeb189746. [PMID: 30728237 DOI: 10.1242/jeb.189746] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Imprinting is a specific form of long-term memory of a cue acquired during a sensitive phase of development. To ensure that organisms memorize the right cue, the learning process must happen during a specific short time period, mostly soon after hatching, which should end before irrelevant or misleading signals are encountered. A well-known case of olfactory imprinting in the aquatic environment is that of the anadromous Atlantic and Pacific salmon, which prefer the olfactory cues of natal rivers to which they return after migrating several years in the open ocean. Recent research has shown that olfactory imprinting and olfactory guided navigation in the marine realm are far more common than previously assumed. Here, we present evidence for the involvement of olfactory imprinting in the navigation behaviour of coral reef fish, which prefer their home reef odour over that of other reefs. Two main olfactory imprinting processes can be differentiated: (1) imprinting on environmental cues and (2) imprinting on chemical compounds released by kin, which is based on genetic relatedness among conspecifics. While the first process allows for plasticity, so that organisms can imprint on a variety of chemical signals, the latter seems to be restricted to specific genetically determined kin signals. We focus on the second, elucidating the behavioural and neuronal basis of the imprinting process on kin cues using larval zebrafish (Danio rerio) as a model. Our data suggest that the process of imprinting is not confined to the central nervous system but also triggers some changes in the olfactory epithelium.
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Affiliation(s)
- Gabriele Gerlach
- Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany .,Helmholtz Institute for Functional Marine Biodiversity Oldenburg (HIFMB), 26129 Oldenburg, Germany.,Centre of Excellence for Coral Reef Studies and School of Marine and Tropical Biology, James Cook University, QLD 4811, Australia
| | - Kristin Tietje
- Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
| | - Daniela Biechl
- Graduate School of Systemic Neurosciences & Department Biology II, Ludwig-Maximilians-Universität Munich, 82152 Planegg-Martinsried, Germany
| | - Iori Namekawa
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Gregor Schalm
- Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
| | - Astrid Sulmann
- Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
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