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Jiang X, Dimitriou E, Grabe V, Sun R, Chang H, Zhang Y, Gershenzon J, Rybak J, Hansson BS, Sachse S. Ring-shaped odor coding in the antennal lobe of migratory locusts. Cell 2024; 187:3973-3991.e24. [PMID: 38897195 DOI: 10.1016/j.cell.2024.05.036] [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: 12/01/2023] [Revised: 04/05/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024]
Abstract
The representation of odors in the locust antennal lobe with its >2,000 glomeruli has long remained a perplexing puzzle. We employed the CRISPR-Cas9 system to generate transgenic locusts expressing the genetically encoded calcium indicator GCaMP in olfactory sensory neurons. Using two-photon functional imaging, we mapped the spatial activation patterns representing a wide range of ecologically relevant odors across all six developmental stages. Our findings reveal a functionally ring-shaped organization of the antennal lobe composed of specific glomerular clusters. This configuration establishes an odor-specific chemotopic representation by encoding different chemical classes and ecologically distinct odors in the form of glomerular rings. The ring-shaped glomerular arrangement, which we confirm by selective targeting of OR70a-expressing sensory neurons, occurs throughout development, and the odor-coding pattern within the glomerular population is consistent across developmental stages. Mechanistically, this unconventional spatial olfactory code reflects the locust-specific and multiplexed glomerular innervation pattern of the antennal lobe.
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Affiliation(s)
- Xingcong Jiang
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany; Research Group Olfactory Coding, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Eleftherios Dimitriou
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Veit Grabe
- Microscopic Service Group, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Ruo Sun
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Hetan Chang
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Yifu Zhang
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Jürgen Rybak
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
| | - Silke Sachse
- Research Group Olfactory Coding, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
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2
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Brewer AA, Barton B. Cortical field maps across human sensory cortex. Front Comput Neurosci 2023; 17:1232005. [PMID: 38164408 PMCID: PMC10758003 DOI: 10.3389/fncom.2023.1232005] [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: 06/03/2023] [Accepted: 11/07/2023] [Indexed: 01/03/2024] Open
Abstract
Cortical processing pathways for sensory information in the mammalian brain tend to be organized into topographical representations that encode various fundamental sensory dimensions. Numerous laboratories have now shown how these representations are organized into numerous cortical field maps (CMFs) across visual and auditory cortex, with each CFM supporting a specialized computation or set of computations that underlie the associated perceptual behaviors. An individual CFM is defined by two orthogonal topographical gradients that reflect two essential aspects of feature space for that sense. Multiple adjacent CFMs are then organized across visual and auditory cortex into macrostructural patterns termed cloverleaf clusters. CFMs within cloverleaf clusters are thought to share properties such as receptive field distribution, cortical magnification, and processing specialization. Recent measurements point to the likely existence of CFMs in the other senses, as well, with topographical representations of at least one sensory dimension demonstrated in somatosensory, gustatory, and possibly olfactory cortical pathways. Here we discuss the evidence for CFM and cloverleaf cluster organization across human sensory cortex as well as approaches used to identify such organizational patterns. Knowledge of how these topographical representations are organized across cortex provides us with insight into how our conscious perceptions are created from our basic sensory inputs. In addition, studying how these representations change during development, trauma, and disease serves as an important tool for developing improvements in clinical therapies and rehabilitation for sensory deficits.
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Affiliation(s)
- Alyssa A. Brewer
- mindSPACE Laboratory, Departments of Cognitive Sciences and Language Science (by Courtesy), Center for Hearing Research, University of California, Irvine, Irvine, CA, United States
| | - Brian Barton
- mindSPACE Laboratory, Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, United States
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3
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Zavatone-Veth JA, Masset P, Tong WL, Zak JD, Murthy VN, Pehlevan C. Neural Circuits for Fast Poisson Compressed Sensing in the Olfactory Bulb. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.21.545947. [PMID: 37961548 PMCID: PMC10634677 DOI: 10.1101/2023.06.21.545947] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Within a single sniff, the mammalian olfactory system can decode the identity and concentration of odorants wafted on turbulent plumes of air. Yet, it must do so given access only to the noisy, dimensionally-reduced representation of the odor world provided by olfactory receptor neurons. As a result, the olfactory system must solve a compressed sensing problem, relying on the fact that only a handful of the millions of possible odorants are present in a given scene. Inspired by this principle, past works have proposed normative compressed sensing models for olfactory decoding. However, these models have not captured the unique anatomy and physiology of the olfactory bulb, nor have they shown that sensing can be achieved within the 100-millisecond timescale of a single sniff. Here, we propose a rate-based Poisson compressed sensing circuit model for the olfactory bulb. This model maps onto the neuron classes of the olfactory bulb, and recapitulates salient features of their connectivity and physiology. For circuit sizes comparable to the human olfactory bulb, we show that this model can accurately detect tens of odors within the timescale of a single sniff. We also show that this model can perform Bayesian posterior sampling for accurate uncertainty estimation. Fast inference is possible only if the geometry of the neural code is chosen to match receptor properties, yielding a distributed neural code that is not axis-aligned to individual odor identities. Our results illustrate how normative modeling can help us map function onto specific neural circuits to generate new hypotheses.
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Affiliation(s)
- Jacob A Zavatone-Veth
- Center for Brain Science, Harvard University Cambridge, MA 02138
- Department of Physics, Harvard University Cambridge, MA 02138
| | - Paul Masset
- Center for Brain Science, Harvard University Cambridge, MA 02138
- Department of Molecular and Cellular Biology, Harvard University Cambridge, MA 02138
| | - William L Tong
- Center for Brain Science, Harvard University Cambridge, MA 02138
- John A. Paulson School of Engineering and Applied Sciences, Harvard University Cambridge, MA 02138
- Kempner Institute for the Study of Natural and Artificial Intelligence, Harvard University Cambridge, MA 02138
| | - Joseph D Zak
- Department of Biological Sciences, University of Illinois at Chicago Chicago, IL 60607
| | - Venkatesh N Murthy
- Center for Brain Science, Harvard University Cambridge, MA 02138
- Department of Molecular and Cellular Biology, Harvard University Cambridge, MA 02138
| | - Cengiz Pehlevan
- Center for Brain Science, Harvard University Cambridge, MA 02138
- John A. Paulson School of Engineering and Applied Sciences, Harvard University Cambridge, MA 02138
- Kempner Institute for the Study of Natural and Artificial Intelligence, Harvard University Cambridge, MA 02138
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4
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Srinivasan S, Daste S, Modi MN, Turner GC, Fleischmann A, Navlakha S. Effects of stochastic coding on olfactory discrimination in flies and mice. PLoS Biol 2023; 21:e3002206. [PMID: 37906721 PMCID: PMC10618007 DOI: 10.1371/journal.pbio.3002206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/21/2023] [Indexed: 11/02/2023] Open
Abstract
Sparse coding can improve discrimination of sensory stimuli by reducing overlap between their representations. Two factors, however, can offset sparse coding's benefits: similar sensory stimuli have significant overlap and responses vary across trials. To elucidate the effects of these 2 factors, we analyzed odor responses in the fly and mouse olfactory regions implicated in learning and discrimination-the mushroom body (MB) and the piriform cortex (PCx). We found that neuronal responses fall along a continuum from extremely reliable across trials to extremely variable or stochastic. Computationally, we show that the observed variability arises from noise within central circuits rather than sensory noise. We propose this coding scheme to be advantageous for coarse- and fine-odor discrimination. More reliable cells enable quick discrimination between dissimilar odors. For similar odors, however, these cells overlap and do not provide distinguishing information. By contrast, more unreliable cells are decorrelated for similar odors, providing distinguishing information, though these benefits only accrue with extended training with more trials. Overall, we have uncovered a conserved, stochastic coding scheme in vertebrates and invertebrates, and we identify a candidate mechanism, based on variability in a winner-take-all (WTA) inhibitory circuit, that improves discrimination with training.
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Affiliation(s)
- Shyam Srinivasan
- Kavli Institute for Brain and Mind, University of California, San Diego, California, United States of America
- Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Simon Daste
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, Rhode Island, United States of America
- Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island, United States of America
| | - Mehrab N. Modi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Glenn C. Turner
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Alexander Fleischmann
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, Rhode Island, United States of America
- Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island, United States of America
| | - Saket Navlakha
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
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5
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Brandt S, Pavlichenko I, Shneidman AV, Patel H, Tripp A, Wong TSB, Lazaro S, Thompson E, Maltz A, Storwick T, Beggs H, Szendrei-Temesi K, Lotsch BV, Kaplan CN, Visser CW, Brenner MP, Murthy VN, Aizenberg J. Nonequilibrium sensing of volatile compounds using active and passive analyte delivery. Proc Natl Acad Sci U S A 2023; 120:e2303928120. [PMID: 37494398 PMCID: PMC10400973 DOI: 10.1073/pnas.2303928120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 06/22/2023] [Indexed: 07/28/2023] Open
Abstract
Although sensor technologies have allowed us to outperform the human senses of sight, hearing, and touch, the development of artificial noses is significantly behind their biological counterparts. This largely stems from the sophistication of natural olfaction, which relies on both fluid dynamics within the nasal anatomy and the response patterns of hundreds to thousands of unique molecular-scale receptors. We designed a sensing approach to identify volatiles inspired by the fluid dynamics of the nose, allowing us to extract information from a single sensor (here, the reflectance spectra from a mesoporous one-dimensional photonic crystal) rather than relying on a large sensor array. By accentuating differences in the nonequilibrium mass-transport dynamics of vapors and training a machine learning algorithm on the sensor output, we clearly identified polar and nonpolar volatile compounds, determined the mixing ratios of binary mixtures, and accurately predicted the boiling point, flash point, vapor pressure, and viscosity of a number of volatile liquids, including several that had not been used for training the model. We further implemented a bioinspired active sniffing approach, in which the analyte delivery was performed in well-controlled 'inhale-exhale' sequences, enabling an additional modality of differentiation and reducing the duration of data collection and analysis to seconds. Our results outline a strategy to build accurate and rapid artificial noses for volatile compounds that can provide useful information such as the composition and physical properties of chemicals, and can be applied in a variety of fields, including disease diagnosis, hazardous waste management, and healthy building monitoring.
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Affiliation(s)
- Soeren Brandt
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA02134
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Ida Pavlichenko
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA02134
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Anna V. Shneidman
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA02134
| | - Haritosh Patel
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA02134
| | - Austin Tripp
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Timothy S. B. Wong
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Sean Lazaro
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Ethan Thompson
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Aubrey Maltz
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Thomas Storwick
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Holden Beggs
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
| | - Katalin Szendrei-Temesi
- Max Planck Institute for Solid State Research, Stuttgart70569, Germany
- Department of Chemistry, Ludwig-Maximilians-Universität München, München81377, Germany
| | - Bettina V. Lotsch
- Max Planck Institute for Solid State Research, Stuttgart70569, Germany
- Department of Chemistry, Ludwig-Maximilians-Universität München, München81377, Germany
| | - C. Nadir Kaplan
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA24061
- Center for Soft Matter and Biological Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA24061
| | - Claas W. Visser
- Department of Thermal and Fluid Engineering, Faculty of Engineering Technology, University of Twente, Enschede7522 NB, Netherlands
| | - Michael P. Brenner
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA02134
| | - Venkatesh N. Murthy
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA02138
- Center for Brain Science, Harvard University, Cambridge, MA02138
| | - Joanna Aizenberg
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA02134
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA02138
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA02138
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6
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Rugard M, Audouze K, Tromelin A. Combining the Classification and Pharmacophore Approaches to Understand Homogeneous Olfactory Perceptions at Peripheral Level: Focus on Two Aroma Mixtures. Molecules 2023; 28:molecules28104028. [PMID: 37241770 DOI: 10.3390/molecules28104028] [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: 03/23/2023] [Revised: 04/20/2023] [Accepted: 05/03/2023] [Indexed: 05/28/2023] Open
Abstract
The mechanisms involved in the homogeneous perception of odorant mixtures remain largely unknown. With the aim of enhancing knowledge about blending and masking mixture perceptions, we focused on structure-odor relationships by combining the classification and pharmacophore approaches. We built a dataset of about 5000 molecules and their related odors and reduced the multidimensional space defined by 1014 fingerprints representing the structures to a tridimensional 3D space using uniform manifold approximation and projection (UMAP). The self-organizing map (SOM) classification was then performed using the 3D coordinates in the UMAP space that defined specific clusters. We explored the allocating in these clusters of the components of two aroma mixtures: a blended mixture (red cordial (RC) mixture, 6 molecules) and a masking binary mixture (isoamyl acetate/whiskey-lactone [IA/WL]). Focusing on clusters containing the components of the mixtures, we looked at the odor notes carried by the molecules belonging to these clusters and also at their structural features by pharmacophore modeling (PHASE). The obtained pharmacophore models suggest that WL and IA could have a common binding site(s) at the peripheral level, but that would be excluded for the components of RC. In vitro experiments will soon be carried out to assess these hypotheses.
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Affiliation(s)
- Marylène Rugard
- T3S, Inserm UMR S-1124, Université Paris Cité, F-75006 Paris, France
| | - Karine Audouze
- T3S, Inserm UMR S-1124, Université Paris Cité, F-75006 Paris, France
| | - Anne Tromelin
- Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
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7
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Application of artificial intelligence to decode the relationships between smell, olfactory receptors and small molecules. Sci Rep 2022; 12:18817. [PMID: 36335231 PMCID: PMC9637086 DOI: 10.1038/s41598-022-23176-y] [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: 12/24/2021] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
Deciphering the relationship between molecules, olfactory receptors (ORs) and corresponding odors remains a challenging task. It requires a comprehensive identification of ORs responding to a given odorant. With the recent advances in artificial intelligence and the growing research in decoding the human olfactory perception from chemical features of odorant molecules, the applications of advanced machine learning have been revived. In this study, Convolutional Neural Network (CNN) and Graphical Convolutional Network (GCN) models have been developed on odorant molecules-odors and odorant molecules-olfactory receptors using a large set of 5955 molecules, 160 odors and 106 olfactory receptors. The performance of such models is promising with a Precision/Recall Area Under Curve of 0.66 for the odorant-odor and 0.91 for the odorant-olfactory receptor GCN models respectively. Furthermore, based on the correspondence of odors and ORs associated for a set of 389 compounds, an odor-olfactory receptor pairwise score was computed for each odor-OR combination allowing to suggest a combinatorial relationship between olfactory receptors and odors. Overall, this analysis demonstrate that artificial intelligence may pave the way in the identification of the smell perception and the full repertoire of receptors for a given odorant molecule.
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8
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Kulason S, Ratnanather JT, Miller MI, Kamath V, Hua J, Yang K, Ma M, Ishizuka K, Sawa A. A comparative neuroimaging perspective of olfaction and higher-order olfactory processing: on health and disease. Semin Cell Dev Biol 2022; 129:22-30. [PMID: 34462249 PMCID: PMC9900497 DOI: 10.1016/j.semcdb.2021.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/18/2021] [Indexed: 02/08/2023]
Abstract
Olfactory dysfunction is often the earliest indicator of disease in a range of neurological and psychiatric disorders. One tempting working hypothesis is that pathological changes in the peripheral olfactory system where the body is exposed to many adverse environmental stressors may have a causal role for the brain alteration. Whether and how the peripheral pathology spreads to more central brain regions may be effectively studied in rodent models, and there is successful precedence in experimental models for Parkinson's disease. It is of interest to study whether a similar mechanism may underlie the pathology of psychiatric illnesses, such as schizophrenia. However, direct comparison between rodent models and humans includes challenges under light of comparative neuroanatomy and experimental methodologies used in these two distinct species. We believe that neuroimaging modality that has been the main methodology of human brain studies may be a useful viewpoint to address and fill the knowledge gap between rodents and humans in this scientific question. Accordingly, in the present review article, we focus on brain imaging studies associated with olfaction in healthy humans and patients with neurological and psychiatric disorders, and if available those in rodents. We organize this review article at three levels: 1) olfactory bulb (OB) and peripheral structures of the olfactory system, 2) primary olfactory cortical and subcortical regions, and 3) associated higher-order cortical regions. This research area is still underdeveloped, and we acknowledge that further validation with independent cohorts may be needed for many studies presented here, in particular those with human subjects. Nevertheless, whether and how peripheral olfactory disturbance impacts brain function is becoming even a hotter topic in the ongoing COVID-19 pandemic, given the risk of long-term changes of mental status associated with olfactory infection of SARS-CoV-2. Together, in this review article, we introduce this underdeveloped but important research area focusing on its implications in neurological and psychiatric disorders, with several pioneered publications.
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Affiliation(s)
- Sue Kulason
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - J Tilak Ratnanather
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Michael I Miller
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Vidyulata Kamath
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jun Hua
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Kun Yang
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Koko Ishizuka
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA
| | - Akira Sawa
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA; Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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9
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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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10
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Zak JD. Longitudinal imaging of individual olfactory sensory neurons in situ. Front Cell Neurosci 2022; 16:946816. [PMID: 35936493 PMCID: PMC9354957 DOI: 10.3389/fncel.2022.946816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/30/2022] [Indexed: 12/24/2022] Open
Abstract
Olfactory sensory neurons are found deep within the nasal cavity at a spatially restricted sheet of sensory epithelium. Due to their location behind the nasal turbinates, accessing these cells for physiological measurements in living animals is challenging, and until recently, not possible. As a further complication, damage to the overlying bone on the dorsal surface of the snout disrupts the negative pressure distribution throughout the nasal cavities, which fundamentally alters how odorants are delivered to the sensory epithelium and the inherent mechanosensory properties of olfactory sensory neurons in live animals. The approach described here circumvents these limitations and allows for optical access to olfactory sensory neurons in mice across time scales ranging from days to months.
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11
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Matsukawa M, Yoshikawa M, Katsuyama N, Aizawa S, Sato T. The Anterior Piriform Cortex and Predator Odor Responses: Modulation by Inhibitory Circuits. Front Behav Neurosci 2022; 16:896525. [PMID: 35571276 PMCID: PMC9097892 DOI: 10.3389/fnbeh.2022.896525] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
Rodents acquire more information from the sense of smell than humans because they have a nearly fourfold greater variety of olfactory receptors. They use olfactory information not only for obtaining food, but also for detecting environmental dangers. Predator-derived odor compounds provoke instinctive fear and stress reactions in animals. Inbred lines of experimental animals react in an innate stereotypical manner to predators even without prior exposure. Predator odors have also been used in models of various neuropsychiatric disorders, including post-traumatic stress disorder following a life-threatening event. Although several brain regions have been reported to be involved in predator odor-induced stress responses, in this mini review, we focus on the functional role of inhibitory neural circuits, especially in the anterior piriform cortex (APC). We also discuss the changes in these neural circuits following innate reactions to odor exposure. Furthermore, based on the three types of modulation of the stress response observed by our group using the synthetic fox odorant 2,5-dihydro-2,4,5-trimethylthiazoline, we describe how the APC interacts with other brain regions to regulate the stress response. Finally, we discuss the potential therapeutic application of odors in the treatment of stress-related disorders. A clearer understanding of the odor–stress response is needed to allow targeted modulation of the monoaminergic system and of the intracerebral inhibitory networks. It would be improved the quality of life of those who have stress-related conditions.
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Affiliation(s)
- Mutsumi Matsukawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Japan
- *Correspondence: Mutsumi Matsukawa,
| | - Masaaki Yoshikawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Japan
| | - Narumi Katsuyama
- Cognitive Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Japan
| | - Shin Aizawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Japan
| | - Takaaki Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ikeda, Japan
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12
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Bast WG, Albeanu DF. Mapping odorant receptors to their glomeruli. Nat Neurosci 2022; 25:405-407. [DOI: 10.1038/s41593-022-01045-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Jacobs LF. How the evolution of air breathing shaped hippocampal function. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200532. [PMID: 34957846 PMCID: PMC8710879 DOI: 10.1098/rstb.2020.0532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/15/2021] [Indexed: 12/25/2022] Open
Abstract
To make maps from airborne odours requires dynamic respiratory patterns. I propose that this constraint explains the modulation of memory by nasal respiration in mammals, including murine rodents (e.g. laboratory mouse, laboratory rat) and humans. My prior theories of limbic system evolution offer a framework to understand why this occurs. The answer begins with the evolution of nasal respiration in Devonian lobe-finned fishes. This evolutionary innovation led to adaptive radiations in chemosensory systems, including the emergence of the vomeronasal system and a specialization of the main olfactory system for spatial orientation. As mammals continued to radiate into environments hostile to spatial olfaction (air, water), there was a loss of hippocampal structure and function in lineages that evolved sensory modalities adapted to these new environments. Hence the independent evolution of echolocation in bats and toothed whales was accompanied by a loss of hippocampal structure (whales) and an absence of hippocampal theta oscillations during navigation (bats). In conclusion, models of hippocampal function that are divorced from considerations of ecology and evolution fall short of explaining hippocampal diversity across mammals and even hippocampal function in humans. This article is part of the theme issue 'Systems neuroscience through the lens of evolutionary theory'.
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Affiliation(s)
- Lucia F. Jacobs
- Department of Psychology, University of California, 2121 Berkeley Way, Berkeley, CA 94720-1650, USA
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14
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Noyes NC, Phan A, Davis RL. Memory suppressor genes: Modulating acquisition, consolidation, and forgetting. Neuron 2021; 109:3211-3227. [PMID: 34450024 PMCID: PMC8542634 DOI: 10.1016/j.neuron.2021.08.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/15/2021] [Accepted: 07/30/2021] [Indexed: 02/06/2023]
Abstract
The brain has a remarkable but underappreciated capacity to limit memory formation and expression. The term "memory suppressor gene" was coined in 1998 as an attempt to explain emerging reports that some genes appeared to limit memory. At that time, only a handful of memory suppressor genes were known, and they were understood to work by limiting cAMP-dependent consolidation. In the intervening decades, almost 100 memory suppressor genes with diverse functions have been discovered that affect not only consolidation but also acquisition and forgetting. Here we highlight the surprising extent to which biological limits are placed on memory formation through reviewing the literature on memory suppressor genes. In this review, we present memory suppressors within the framework of their actions on different memory operations: acquisition, consolidation, and forgetting. This is followed by a discussion of the reasons why there may be a biological need to limit memory formation.
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Affiliation(s)
- Nathaniel C Noyes
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Anna Phan
- Department of Biological Sciences, University of Alberta, 11355 Saskatchewan Drive, Edmonton, AB T6G 2E9, Canada
| | - Ronald L Davis
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA.
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15
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Olfactory Optogenetics: Light Illuminates the Chemical Sensing Mechanisms of Biological Olfactory Systems. BIOSENSORS-BASEL 2021; 11:bios11090309. [PMID: 34562900 PMCID: PMC8470751 DOI: 10.3390/bios11090309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/17/2021] [Accepted: 08/27/2021] [Indexed: 01/26/2023]
Abstract
The mammalian olfactory system has an amazing ability to distinguish thousands of odorant molecules at the trace level. Scientists have made great achievements on revealing the olfactory sensing mechanisms in decades; even though many issues need addressing. Optogenetics provides a novel technical approach to solve this dilemma by utilizing light to illuminate specific part of the olfactory system; which can be used in all corners of the olfactory system for revealing the olfactory mechanism. This article reviews the most recent advances in olfactory optogenetics devoted to elucidate the mechanisms of chemical sensing. It thus attempts to introduce olfactory optogenetics according to the structure of the olfactory system. It mainly includes the following aspects: the sensory input from the olfactory epithelium to the olfactory bulb; the influences of the olfactory bulb (OB) neuron activity patterns on olfactory perception; the regulation between the olfactory cortex and the olfactory bulb; and the neuromodulation participating in odor coding by dominating the olfactory bulb. Finally; current challenges and future development trends of olfactory optogenetics are proposed and discussed.
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16
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Francia S, Lodovichi C. The role of the odorant receptors in the formation of the sensory map. BMC Biol 2021; 19:174. [PMID: 34452614 PMCID: PMC8394594 DOI: 10.1186/s12915-021-01116-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
In the olfactory system, odorant receptors (ORs) expressed at the cell membrane of olfactory sensory neurons detect odorants and direct sensory axons toward precise target locations in the brain, reflected in the presence of olfactory sensory maps. This dual role of ORs is corroborated by their subcellular expression both in cilia, where they bind odorants, and at axon terminals, a location suitable for axon guidance cues. Here, we provide an overview and discuss previous work on the role of ORs in establishing the topographic organization of the olfactory system and recent findings on the mechanisms of activation and function of axonal ORs.
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Affiliation(s)
- Simona Francia
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy.,Veneto Institute of Molecular Medicine, Padua, Italy
| | - Claudia Lodovichi
- Veneto Institute of Molecular Medicine, Padua, Italy. .,Neuroscience Institute CNR, Via Orus 2, 35129, Padua, Italy. .,Department of Biomedical Sciences, University of Padua, Padua, Italy. .,Padova Neuroscience Center, Padua, Italy.
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17
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Abstract
Olfaction is fundamentally distinct from other sensory modalities. Natural odor stimuli are complex mixtures of volatile chemicals that interact in the nose with a receptor array that, in rodents, is built from more than 1,000 unique receptors. These interactions dictate a peripheral olfactory code, which in the brain is transformed and reformatted as it is broadcast across a set of highly interconnected olfactory regions. Here we discuss the problems of characterizing peripheral population codes for olfactory stimuli, of inferring the specific functions of different higher olfactory areas given their extensive recurrence, and of ultimately understanding how odor representations are linked to perception and action. We argue that, despite the differences between olfaction and other sensory modalities, addressing these specific questions will reveal general principles underlying brain function.
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Affiliation(s)
- David H Brann
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Sandeep Robert Datta
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA;
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18
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Manzini I, Schild D, Di Natale C. Principles of odor coding in vertebrates and artificial chemosensory systems. Physiol Rev 2021; 102:61-154. [PMID: 34254835 DOI: 10.1152/physrev.00036.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The biological olfactory system is the sensory system responsible for the detection of the chemical composition of the environment. Several attempts to mimic biological olfactory systems have led to various artificial olfactory systems using different technical approaches. Here we provide a parallel description of biological olfactory systems and their technical counterparts. We start with a presentation of the input to the systems, the stimuli, and treat the interface between the external world and the environment where receptor neurons or artificial chemosensors reside. We then delineate the functions of receptor neurons and chemosensors as well as their overall I-O relationships. Up to this point, our account of the systems goes along similar lines. The next processing steps differ considerably: while in biology the processing step following the receptor neurons is the "integration" and "processing" of receptor neuron outputs in the olfactory bulb, this step has various realizations in electronic noses. For a long period of time, the signal processing stages beyond the olfactory bulb, i.e., the higher olfactory centers were little studied. Only recently there has been a marked growth of studies tackling the information processing in these centers. In electronic noses, a third stage of processing has virtually never been considered. In this review, we provide an up-to-date overview of the current knowledge of both fields and, for the first time, attempt to tie them together. We hope it will be a breeding ground for better information, communication, and data exchange between very related but so far little connected fields.
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Affiliation(s)
- Ivan Manzini
- Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University Medical Center, University of Göttingen, Göttingen, Germany
| | - Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy
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19
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Resolving different presynaptic activity patterns within single olfactory glomeruli of Xenopus laevis larvae. Sci Rep 2021; 11:14258. [PMID: 34244587 PMCID: PMC8270923 DOI: 10.1038/s41598-021-93677-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 06/25/2021] [Indexed: 11/18/2022] Open
Abstract
Olfactory sensing is generally organized into groups of similarly sensing olfactory receptor neurons converging into their corresponding glomerulus, which is thought to behave as a uniform functional unit. It is however unclear to which degree axons within a glomerulus show identical activity, how many converge into a glomerulus, and to answer these questions, how it is possible to visually separate them in live imaging. Here we investigate activity of olfactory receptor neurons and their axon terminals throughout olfactory glomeruli using electrophysiological recordings and rapid 4D calcium imaging. While single olfactory receptor neurons responsive to the same odor stimulus show a diversity of responses in terms of sensitivity and spontaneous firing rate on the level of the somata, their pre-synaptic calcium activity in the glomerulus is homogeneous. In addition, we could not observe the correlated spontaneous calcium activity that is found on the post-synaptic side throughout mitral cell dendrites and has been used in activity correlation imaging. However, it is possible to induce spatio-temporal presynaptic response inhomogeneities by applying trains of olfactory stimuli with varying amino acid concentrations. Automated region-of-interest detection and correlation analysis then visually distinguishes at least two axon subgroups per glomerulus that differ in odor sensitivity.
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20
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Redolfi N, Lodovichi C. Spontaneous Afferent Activity Carves Olfactory Circuits. Front Cell Neurosci 2021; 15:637536. [PMID: 33767612 PMCID: PMC7985084 DOI: 10.3389/fncel.2021.637536] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/08/2021] [Indexed: 12/11/2022] Open
Abstract
Electrical activity has a key role in shaping neuronal circuits during development. In most sensory modalities, early in development, internally generated spontaneous activity sculpts the initial layout of neuronal wiring. With the maturation of the sense organs, the system relies more on sensory-evoked electrical activity. Stimuli-driven neuronal discharge is required for the transformation of immature circuits in the specific patterns of neuronal connectivity that subserve normal brain function. The olfactory system (OS) differs from this organizational plan. Despite the important role of odorant receptors (ORs) in shaping olfactory topography, odor-evoked activity does not have a prominent role in refining neuronal wiring. On the contrary, afferent spontaneous discharge is required to achieve and maintain the specific diagram of connectivity that defines the topography of the olfactory bulb (OB). Here, we provide an overview of the development of olfactory topography, with a focus on the role of afferent spontaneous discharge in the formation and maintenance of the specific synaptic contacts that result in the topographic organization of the OB.
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Affiliation(s)
- Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Claudia Lodovichi
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Neuroscience Institute CNR, Padua, Italy.,Veneto Institute of Molecular Medicine, Padua, Italy.,Padova Neuroscience Center, University of Padua, Padua, Italy
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21
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Chockanathan U, Crosier EJW, Waddle S, Lyman E, Gerkin RC, Padmanabhan K. Changes in pairwise correlations during running reshape global network state in the main olfactory bulb. J Neurophysiol 2021; 125:1612-1623. [PMID: 33656931 DOI: 10.1152/jn.00464.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neural codes for sensory inputs have been hypothesized to reside in a broader space defined by ongoing patterns of spontaneous activity. To understand the structure of this spontaneous activity in the olfactory system, we performed high-density recordings of neural populations in the main olfactory bulb of awake mice. We observed changes in pairwise correlations of spontaneous activity between mitral and tufted (M/T) cells when animals were running, which resulted in an increase in the entropy of the population. Surprisingly, pairwise maximum entropy models that described the population activity using only assumptions about the firing rates and correlations of neurons were better at predicting the global structure of activity when animals were stationary as compared to when they were running, implying that higher order (3rd, 4th order) interactions governed population activity during locomotion. Taken together, we found that locomotion alters the functional interactions that shape spontaneous population activity at the earliest stages of olfactory processing, one synapse away from the sensory receptors in the nasal epithelium. These data suggest that the coding space available for sensory representations responds adaptively to the animal's behavioral state.NEW & NOTEWORTHY The organization and structure of spontaneous population activity in the olfactory system places constraints of how odor information is represented. Using high-density electrophysiological recordings of mitral and tufted cells, we found that running increases the dimensionality of spontaneous activity, implicating higher order interactions among neurons during locomotion. Behavior, thus, flexibly alters neuronal activity at the earliest stages of sensory processing.
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Affiliation(s)
- Udaysankar Chockanathan
- Medical Scientist Training Program (MSTP), University of Rochester School of Medicine, Rochester, New York.,Department of Neuroscience and Neuroscience Graduate Program (NGP), University of Rochester School of Medicine, Rochester, New York
| | - Emily J W Crosier
- Department of Neuroscience and Neuroscience Graduate Program (NGP), University of Rochester School of Medicine, Rochester, New York
| | - Spencer Waddle
- Department of Physics, University of Delaware, Newark, Delaware
| | - Edward Lyman
- Department of Physics, University of Delaware, Newark, Delaware
| | - Richard C Gerkin
- School of Life Sciences, Arizona State University, Tempe, Arizona
| | - Krishnan Padmanabhan
- Medical Scientist Training Program (MSTP), University of Rochester School of Medicine, Rochester, New York.,Department of Neuroscience and Neuroscience Graduate Program (NGP), University of Rochester School of Medicine, Rochester, New York.,Center for Visual Sciences, University of Rochester School of Medicine, Rochester, New York
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22
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Furusawa K, Emoto K. Scrap and Build for Functional Neural Circuits: Spatiotemporal Regulation of Dendrite Degeneration and Regeneration in Neural Development and Disease. Front Cell Neurosci 2021; 14:613320. [PMID: 33505249 PMCID: PMC7829185 DOI: 10.3389/fncel.2020.613320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/04/2020] [Indexed: 01/01/2023] Open
Abstract
Dendrites are cellular structures essential for the integration of neuronal information. These elegant but complex structures are highly patterned across the nervous system but vary tremendously in their size and fine architecture, each designed to best serve specific computations within their networks. Recent in vivo imaging studies reveal that the development of mature dendrite arbors in many cases involves extensive remodeling achieved through a precisely orchestrated interplay of growth, degeneration, and regeneration of dendritic branches. Both degeneration and regeneration of dendritic branches involve precise spatiotemporal regulation for the proper wiring of functional networks. In particular, dendrite degeneration must be targeted in a compartmentalized manner to avoid neuronal death. Dysregulation of these developmental processes, in particular dendrite degeneration, is associated with certain types of pathology, injury, and aging. In this article, we review recent progress in our understanding of dendrite degeneration and regeneration, focusing on molecular and cellular mechanisms underlying spatiotemporal control of dendrite remodeling in neural development. We further discuss how developmental dendrite degeneration and regeneration are molecularly and functionally related to dendrite remodeling in pathology, disease, and aging.
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Affiliation(s)
- Kotaro Furusawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Kazuo Emoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, Tokyo, Japan
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23
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Reed DR, Alhadeff AL, Beauchamp GK, Chaudhari N, Duffy VB, Dus M, Fontanini A, Glendinning JI, Green BG, Joseph PV, Kyriazis GA, Lyte M, Maruvada P, McGann JP, McLaughlin JT, Moran TH, Murphy C, Noble EE, Pepino MY, Pluznick JL, Rother KI, Saez E, Spector AC, Sternini C, Mattes RD. NIH Workshop Report: sensory nutrition and disease. Am J Clin Nutr 2021; 113:232-245. [PMID: 33300030 PMCID: PMC7779223 DOI: 10.1093/ajcn/nqaa302] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022] Open
Abstract
In November 2019, the NIH held the "Sensory Nutrition and Disease" workshop to challenge multidisciplinary researchers working at the interface of sensory science, food science, psychology, neuroscience, nutrition, and health sciences to explore how chemosensation influences dietary choice and health. This report summarizes deliberations of the workshop, as well as follow-up discussion in the wake of the current pandemic. Three topics were addressed: A) the need to optimize human chemosensory testing and assessment, B) the plasticity of chemosensory systems, and C) the interplay of chemosensory signals, cognitive signals, dietary intake, and metabolism. Several ways to advance sensory nutrition research emerged from the workshop: 1) refining methods to measure chemosensation in large cohort studies and validating measures that reflect perception of complex chemosensations relevant to dietary choice; 2) characterizing interindividual differences in chemosensory function and how they affect ingestive behaviors, health, and disease risk; 3) defining circuit-level organization and function that link and interact with gustatory, olfactory, homeostatic, visceral, and cognitive systems; and 4) discovering new ligands for chemosensory receptors (e.g., those produced by the microbiome) and cataloging cell types expressing these receptors. Several of these priorities were made more urgent by the current pandemic because infection with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the ensuing coronavirus disease of 2019 has direct short- and perhaps long-term effects on flavor perception. There is increasing evidence of functional interactions between the chemosensory and nutritional sciences. Better characterization of this interface is expected to yield insights to promote health, mitigate disease risk, and guide nutrition policy.
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Affiliation(s)
| | - Amber L Alhadeff
- Monell Chemical Senses Center, Philadelphia, PA, USA
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Nirupa Chaudhari
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
- Program in Neurosciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Valerie B Duffy
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, USA
| | - Monica Dus
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Alfredo Fontanini
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
| | - John I Glendinning
- Department of Biology, Barnard College, Columbia University, New York, NY, USA
- Department of Neuroscience and Behavior, Barnard College, Columbia University, New York, NY, USA
| | - Barry G Green
- The John B Pierce Laboratory, New Haven, CT, USA
- Department of Surgery (Otolaryngology), Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Paule V Joseph
- National Institute of Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
- National Institute of Nursing, NIH, Bethesda, MD, USA
| | - George A Kyriazis
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Mark Lyte
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, USA
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA
| | - Padma Maruvada
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - John P McGann
- Behavioral and Systems Neuroscience, Department of Psychology, Rutgers University, Piscataway, NJ, USA
| | - John T McLaughlin
- Division of Diabetes, Endocrinology, & Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, United Kingdom
- Department of Gastroenterology, Salford Royal NHS Foundation Trust, Salford, United Kingdom
| | - Timothy H Moran
- Department of Psychiatry & Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Claire Murphy
- Department of Psychology, San Diego State University, San Diego, CA, USA
- Department of Psychiatry, University of California, San Diego, San Diego, CA, USA
| | - Emily E Noble
- Department of Foods and Nutrition, University of Georgia, Athens, GA, USA
| | - M Yanina Pepino
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jennifer L Pluznick
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kristina I Rother
- Intramural Research Program, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Enrique Saez
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Alan C Spector
- Department of Psychology, Florida State University, Tallahassee, FL, USA
- Program in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Catia Sternini
- Digestive Disease Division, Departments of Medicine and Neurobiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Richard D Mattes
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
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24
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Egger V, Kuner T. Olfactory bulb granule cells: specialized to link coactive glomerular columns for percept generation and discrimination of odors. Cell Tissue Res 2021; 383:495-506. [PMID: 33404844 PMCID: PMC7873091 DOI: 10.1007/s00441-020-03402-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/14/2020] [Indexed: 12/16/2022]
Abstract
The role of granule cells in olfactory processing is surrounded by several enigmatic observations, such as the purpose of reciprocal spines and the mechanisms for GABA release, the apparently low firing activity and recurrent inhibitory drive of granule cells, the missing proof for functional reciprocal connectivity, and the apparently negligible contribution to lateral inhibition. Here, we summarize recent results with regard to both the mechanisms of GABA release and the behavioral relevance of granule cell activity during odor discrimination. We outline a novel hypothesis that has the potential to resolve most of these enigmas and allows further predictions on the function of granule cells in odor processing. Briefly, recent findings imply that GABA release from the reciprocal spine requires a local spine action potential and the cooperative action of NMDA receptors and high voltage-activated Ca2+ channels. Thus, lateral inhibition is conditional on activity in the principal neurons connected to a granule cell and tightly intertwined with recurrent inhibition. This notion allows us to infer that lateral inhibition between principal neurons occurs "on demand," i.e., selectively on coactive mitral and tufted cells, and thus can provide directed, dynamically switched lateral inhibition in a sensory system with 1000 input channels organized in glomerular columns. The mechanistic underpinnings of this hypothesis concur with findings from odor discrimination behavior in mice with synaptic proteins deleted in granule cells. In summary, our hypothesis explains the unusual microcircuit of the granule cell reciprocal spine as a means of olfactory combinatorial coding.
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Affiliation(s)
- Veronica Egger
- Institute of Zoology, Regensburg University, Universitätsstr. 30, 93040, Regensburg, Germany.
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
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25
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Togashi K, Tsuji M, Takeuchi S, Nakahama R, Koizumi H, Emoto K. Adeno-Associated Virus-Mediated Single-Cell Labeling of Mitral Cells in the Mouse Olfactory Bulb: Insights into the Developmental Dynamics of Dendrite Remodeling. Front Cell Neurosci 2020; 14:572256. [PMID: 33362468 PMCID: PMC7756102 DOI: 10.3389/fncel.2020.572256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 11/16/2020] [Indexed: 12/28/2022] Open
Abstract
Neurons typically remodel axons/dendrites for functional refinement of neural circuits in the developing brain. Mitral cells in the mammalian olfactory system remodel their dendritic arbors in the perinatal development, but the underlying molecular and cellular mechanisms remain elusive in part due to a lack of convenient methods to label mitral cells with single-cell resolution. Here we report a novel method for single-cell labeling of mouse mitral cells using adeno-associated virus (AAV)-mediated gene delivery. We first demonstrated that AAV injection into the olfactory ventricle of embryonic day 14.5 (E14.5) mice preferentially labels mitral cells in the olfactory bulb (OB). Birthdate labeling indicated that AAV can transduce mitral cells independently of their birthdates. Furthermore, in combination with the Cre-mediated gene expression system, AAV injection allows visualization of mitral cells at single-cell resolution. Using this AAV-mediated single-cell labeling method, we investigated dendrite development of mitral cells and found that ~50% of mitral cells exhibited mature apical dendrites with a single thick and tufted branch before birth, suggesting that a certain population of mitral cells completes dendrite remodeling during embryonic stages. We also found an atypical subtype of mitral cells that have multiple dendritic shafts innervating the same glomeruli. Our data thus demonstrate that the AAV-mediated labeling method that we reported here provides an efficient way to visualize mitral cells with single-cell resolution and could be utilized to study dynamic aspects as well as functions of mitral cells in the olfactory circuits.
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Affiliation(s)
- Kazuya Togashi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Masato Tsuji
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Shunsuke Takeuchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ryota Nakahama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Koizumi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Kazuo Emoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, Tokyo, Japan
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26
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Lage-Rupprecht V, Zhou L, Bianchini G, Aghvami SS, Mueller M, Rózsa B, Sassoè-Pognetto M, Egger V. Presynaptic NMDARs cooperate with local spikes toward GABA release from the reciprocal olfactory bulb granule cell spine. eLife 2020; 9:e63737. [PMID: 33252329 PMCID: PMC7704106 DOI: 10.7554/elife.63737] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/10/2020] [Indexed: 12/16/2022] Open
Abstract
In the rodent olfactory bulb the smooth dendrites of the principal glutamatergic mitral cells (MCs) form reciprocal dendrodendritic synapses with large spines on GABAergic granule cells (GC), where unitary release of glutamate can trigger postsynaptic local activation of voltage-gated Na+-channels (Navs), that is a spine spike. Can such single MC input evoke reciprocal release? We find that unitary-like activation via two-photon uncaging of glutamate causes GC spines to release GABA both synchronously and asynchronously onto MC dendrites. This release indeed requires activation of Navs and high-voltage-activated Ca2+-channels (HVACCs), but also of NMDA receptors (NMDAR). Simulations show temporally overlapping HVACC- and NMDAR-mediated Ca2+-currents during the spine spike, and ultrastructural data prove NMDAR presence within the GABAergic presynapse. This cooperative action of presynaptic NMDARs allows to implement synapse-specific, activity-dependent lateral inhibition, and thus could provide an efficient solution to combinatorial percept synthesis in a sensory system with many receptor channels.
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Affiliation(s)
- Vanessa Lage-Rupprecht
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
- Department of Bioinformatics, Fraunhofer SCAISankt AugustinGermany
| | - Li Zhou
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
| | - Gaia Bianchini
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
| | - S Sara Aghvami
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
- School of Electrical and Computer Engineering, University of TehranTehranIslamic Republic of Iran
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM)TehranIslamic Republic of Iran
| | - Max Mueller
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
| | - Balázs Rózsa
- Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapestHungary
| | | | - Veronica Egger
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
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27
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Egger V, Diamond JS. A17 Amacrine Cells and Olfactory Granule Cells: Parallel Processors of Early Sensory Information. Front Cell Neurosci 2020; 14:600537. [PMID: 33250720 PMCID: PMC7674606 DOI: 10.3389/fncel.2020.600537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/05/2020] [Indexed: 12/16/2022] Open
Abstract
Neurons typically receive synaptic input in their dendritic arbor, integrate inputs in their soma, and send output action potentials through their axon, following Cajal's law of dynamic polarization. Two notable exceptions are retinal amacrine cells and olfactory granule cells (GCs), which flout Cajal's edict by providing synaptic output from the same dendrites that collect synaptic input. Amacrine cells, a diverse cell class comprising >60 subtypes, employ various dendritic input/output strategies, but A17 amacrine cells (A17s) in particular share further interesting functional characteristics with GCs: both receive excitatory synaptic input from neurons in the primary glutamatergic pathway and return immediate, reciprocal feedback via GABAergic inhibitory synapses to the same synaptic terminals that provided input. Both neurons thereby process signals locally within their dendrites, shaping many parallels, signaling pathways independently. The similarities between A17s and GCs cast into relief striking differences that may indicate distinct processing roles within their respective circuits: First, they employ partially dissimilar molecular mechanisms to transform excitatory input into inhibitory output; second, GCs fire action potentials, whereas A17s do not. Third, GC signals may be influenced by cortical feedback, whereas the mammalian retina receives no such retrograde input. Finally, A17s constitute just one subtype within a diverse class that is specialized in a particular task, whereas the more homogeneous GCs may play more diverse signaling roles via multiple processing modes. Here, we review these analogies and distinctions between A17 amacrine cells and granule cells, hoping to gain further insight into the operating principles of these two sensory circuits.
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Affiliation(s)
- Veronica Egger
- Department of Neurophysiology, Institute of Zoology, Universität Regensburg, Regensburg, Germany
| | - Jeffrey S. Diamond
- Synaptic Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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28
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Baig AM, Sanders EC. Potential neuroinvasive pathways of SARS-CoV-2: Deciphering the spectrum of neurological deficit seen in coronavirus disease-2019 (COVID-19). J Med Virol 2020; 92:1845-1857. [PMID: 32492193 PMCID: PMC7300748 DOI: 10.1002/jmv.26105] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 05/26/2020] [Indexed: 12/15/2022]
Abstract
Coronavirus disease-2019 (COVID-19) was declared a global pandemic on 11 March 2020. Scientists and clinicians must acknowledge that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the potential to attack the human body in multiple ways simultaneously and exploit any weaknesses of its host. A multipronged attack could potentially explain the severity and extensive variety of signs and symptoms observed in patients with COVID-19. Understanding the diverse tactics of this virus to infect the human body is both critical and incredibly complex. Although patients diagnosed with COVID-19 have primarily presented with pulmonary involvement, viral invasion, and injury to diverse end organs is also prevalent and well documented in these patients, but has been largely unheeded. Human organs known for angiotensin-converting enzyme 2 (ACE2) expression including the gastrointestinal tract, kidneys, heart, adrenals, brain, and testicles are examples of extra pulmonary tissues with confirmed invasion by SARS-CoV-2. Initial multiple organ involvement may present with vague signs and symptoms to alert health care professionals early in the course of COVID-19. Another example of an ongoing, yet neglected element of the syndromic features of COVID-19, are the reported findings of loss of smell, altered taste, ataxia, headache, dizziness, and loss of consciousness, which suggest a potential for neural involvement. In this review, we further deliberate on the neuroinvasive potential of SARS-CoV-2, the neurologic symptomology observed in COVID-19, the host-virus interaction, possible routes of SARS-CoV-2 to invade the central nervous system, other neurologic considerations for patients with COVID-19, and a collective call to action.
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Affiliation(s)
- Abdul Mannan Baig
- Department of Biological and Biomedical SciencesAga Khan UniversityKarachiSindhPakistan
| | - Erin C. Sanders
- Department of Obstetrics and GynecologyMount Auburn Hospital, Boston Urogynecology AssociatesCambridgeMassachusettsUnited States
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29
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Dalal T, Gupta N, Haddad R. Bilateral and unilateral odor processing and odor perception. Commun Biol 2020; 3:150. [PMID: 32238904 PMCID: PMC7113286 DOI: 10.1038/s42003-020-0876-6] [Citation(s) in RCA: 13] [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: 10/08/2019] [Accepted: 03/05/2020] [Indexed: 11/09/2022] Open
Abstract
Imagine smelling a novel perfume with only one nostril and then smelling it again with the other nostril. Clearly, you can tell that it is the same perfume both times. This simple experiment demonstrates that odor information is shared across both hemispheres to enable perceptual unity. In many sensory systems, perceptual unity is believed to be mediated by inter-hemispheric connections between iso-functional cortical regions. However, in the olfactory system, the underlying neural mechanisms that enable this coordination are unclear because the two olfactory cortices are not topographically organized and do not seem to have homotypic inter-hemispheric mapping. This review presents recent advances in determining which aspects of odor information are processed unilaterally or bilaterally, and how odor information is shared across the two hemispheres. We argue that understanding the mechanisms of inter-hemispheric coordination can provide valuable insights that are hard to achieve when focusing on one hemisphere alone.
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Affiliation(s)
- Tal Dalal
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Nitin Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Rafi Haddad
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 5290002, Israel.
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30
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Kozma MT, Ngo-Vu H, Wong YY, Shukla NS, Pawar SD, Senatore A, Schmidt M, Derby CD. Comparison of transcriptomes from two chemosensory organs in four decapod crustaceans reveals hundreds of candidate chemoreceptor proteins. PLoS One 2020; 15:e0230266. [PMID: 32163507 PMCID: PMC7067487 DOI: 10.1371/journal.pone.0230266] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/25/2020] [Indexed: 12/18/2022] Open
Abstract
Crustaceans express genes for at least three classes of putative chemosensory proteins. These are: Ionotropic Receptors (IRs), derived from the heterotetrameric ionotropic glutamate receptors (iGluRs); Transient Receptor Potential (TRP) channels, a diverse set of sensor-channels that include several families of chemoreceptor channels; and Gustatory Receptor Like receptors (GRLs), ionotropic receptors that are homologues of Gustatory Receptors (GRs) of insects and are expressed sparingly in most crustaceans so far studied. IRs are typically numerically the most dominant of these receptor proteins in crustaceans and include two classes: co-receptor IRs, which are necessary for making a functional receptor-channel; and tuning IRs, whose specific combination in the IR subunits in the heterotetramer confers chemical specificity. Previous work showed that the transcriptomes from two major chemosensory organs-the lateral flagellum of the antennule (LF) and the tips of the legs (dactyls)-of the Caribbean spiny lobster Panulirus argus express four co-receptor IRs and over 100 tuning IRs. In this paper, we examined and compared the transcriptomes from the LF and dactyls of P. argus and three other decapod crustaceans-the clawed lobster Homarus americanus, red swamp crayfish Procambarus clarkii, and the blue crab Callinectes sapidus. Each species has at least ca. 100 to 250 IRs, 1 to 4 GRLs, and ca. 15 TRP channels including those shown to be involved in chemoreception in other species. The IRs show different degrees of phylogenetic conservation: some are arthropod-conserved, others are pancrustacean-conserved, others appear to be crustacean-conserved, and some appear to be species-specific. Many IRs appear to be more highly expressed in the LF than dactyl. Our results show that decapod crustaceans express an abundance of genes for chemoreceptor proteins of different types, phylogenetic conservation, and expression patterns. An understanding of their functional roles awaits determining their expression patterns in individual chemosensory neurons and the central projections of those neurons.
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Affiliation(s)
- Mihika T. Kozma
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Hanh Ngo-Vu
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Yuen Yan Wong
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Neal S. Shukla
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Shrikant D. Pawar
- Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Adriano Senatore
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Manfred Schmidt
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Charles D. Derby
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
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31
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Seubert J, Kalpouzos G, Larsson M, Hummel T, Bäckman L, Laukka EJ. Temporolimbic cortical volume is associated with semantic odor memory performance in aging. Neuroimage 2020; 211:116600. [PMID: 32018003 DOI: 10.1016/j.neuroimage.2020.116600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/10/2020] [Accepted: 01/31/2020] [Indexed: 12/30/2022] Open
Abstract
Olfactory function, and specifically semantic olfactory memory (i.e., odor identification), has frequently been shown to predict cognitive functioning across multiple domains in old age. This observation suggests that olfactory function can serve as a marker for the integrity of temporolimbic cortical networks, but a clear delineation of this association is still missing. To address this issue, the present study employed voxel-based morphometry in a region of interest-based design to determine the extent to which gray matter volumes of core olfactory and memory areas are associated with olfactory memory performance in an aging population free from neurodegenerative disease. We further aimed to determine potential overlap in structural anatomical correlates, and differences in association strength, for semantic and episodic olfactory memory. Structural magnetic resonance imaging (MRI), episodic and semantic odor memory and episodic and semantic verbal memory data were collected in 422 participants from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), all aged ≥ 60 years. Controlling for age and education, semantic, but not episodic, olfactory memory was positively related to gray matter volume in a cluster extending from the anterior hippocampus and amygdala into the posterior piriform cortex. The observed associations remained even when verbal memory performance was controlled for, supporting a link between the olfactory memory domain and cortical volume over and above more generalized memory abilities. As such, our data provide evidence for distinct functional-structural associations for semantic odor memory, supporting the idea of temporolimbic integrity as a neurobiological substrate linking olfactory function to cognitive health in old age.
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Affiliation(s)
- Janina Seubert
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Department of Clinical Neuroscience, Psychology Division, Karolinska Institutet, Stockholm, Sweden.
| | - Grégoria Kalpouzos
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Maria Larsson
- Gösta Ekman's Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Thomas Hummel
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Lars Bäckman
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Erika J Laukka
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Stockholm Gerontology Research Center, Stockholm, Sweden
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32
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Matsukawa M, Katsuyama N, Imada M, Aizawa S, Sato T. Simultaneous activities in both mirror-image glomerular maps in the olfactory bulb may have an important role in stress-related neuronal responses in mice. Brain Res 2020; 1732:146676. [PMID: 31981677 DOI: 10.1016/j.brainres.2020.146676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/09/2020] [Accepted: 01/18/2020] [Indexed: 10/25/2022]
Abstract
In the mouse olfactory bulb (OB), odor input from the olfactory epithelium innervates topographically to form odorant maps, which are mirror-image arrangements of glomerular clusters with domain organization. However, the functional role of the mirror-image representation in the OB remains unknown. Predator odors induce stress responses, and the dorsal domain of the dorsolateral wall of the olfactory bulb (dlOB) is known to be involved in this process. However, it remains unclear whether the activities in the medial wall of the OB (mOB), the other mirror half, are also involved in stress responses. Therefore, in this study, we investigated whether the mOB and dlOB are required for the induction of stress responses using lesioning or electrical stimulation. Although there were no significant differences in the number of activated neurons in the bed nucleus of the stria terminalis, posterior piriform cortex or amygdalo-piriform transition area, fewer activated neurons were observed in the anterior piriform cortex (APC) following lesion of both the mOB and dlOB combined. No changes were observed in the density of activated cells in any examined brain region following stimulation of either the mOB or dlOB alone. However, activated neurons in the APC were significantly more numerous following simultaneous stimulation of the mOB and dlOB. Collectively, our results suggest that simultaneous activation in both the mOB and dlOB is needed to induce APC neural activities that produce stress-like behavior. These findings provide insight into olfactory information processing, and may also help in the development of therapies for odor-induced stress behaviors.
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Affiliation(s)
- Mutsumi Matsukawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, 30-1 Oyaguchi-Kamicho, Itabashi, Tokyo 173-8610, Japan.
| | - Narumi Katsuyama
- Cognitive Neuroscience Section, Primate Research Institute, Kyoto University, 41-2, Kanrin, Inuyama, Aichi 484-8506, Japan
| | - Masato Imada
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, 30-1 Oyaguchi-Kamicho, Itabashi, Tokyo 173-8610, Japan
| | - Shin Aizawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, 30-1 Oyaguchi-Kamicho, Itabashi, Tokyo 173-8610, Japan
| | - Takaaki Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
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33
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Homma R, Nagayama S. A Prism Method for Optical Glomerular Mapping of the Medial Olfactory Bulb in Mice. Front Neural Circuits 2020; 13:79. [PMID: 31920566 PMCID: PMC6933389 DOI: 10.3389/fncir.2019.00079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/06/2019] [Indexed: 11/13/2022] Open
Abstract
The processing of odor input in the brain begins in the olfactory bulb (OB), where odor information is represented by combinations of active glomeruli. Each glomerulus is associated with a specific odorant receptor type, of which there are ~1,000 in mice; thus different odors activate different subsets of glomeruli. Most receptor types have duplicate lateral and medial glomeruli in each of the left and right OBs. The two sets of glomeruli form separate but mirror-symmetric glomerular maps. It is not known whether the odor representations in these paired maps are exact copies of each other or potentially encode additional information. Previous studies of glomerular odor representations were mostly limited to the lateral map because the medial map is inaccessible with high-resolution activity mapping techniques, such as optical imaging. To address this, we developed a method for optical imaging of the medial bulb by replacing the contralateral bulb with a right-angle prism that has a mirror coating on the hypotenuse. With this method, we performed calcium imaging of corresponding subsets of glomeruli in the lateral map at the dorsal surface and the medial map at the medial wall. Thus, we demonstrate an experimental model system for comparing odor representations in these redundant sensory maps, enabling a better understanding of the role of paired maps and the neuronal coding of odor stimuli.
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Affiliation(s)
- Ryota Homma
- Department of Neurobiology & Anatomy, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Shin Nagayama
- Department of Neurobiology & Anatomy, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
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34
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Bhattarai JP, Schreck M, Moberly AH, Luo W, Ma M. Aversive Learning Increases Release Probability of Olfactory Sensory Neurons. Curr Biol 2019; 30:31-41.e3. [PMID: 31839448 DOI: 10.1016/j.cub.2019.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/04/2019] [Accepted: 11/01/2019] [Indexed: 10/25/2022]
Abstract
Predicting danger from previously associated sensory stimuli is essential for survival. Contributions from altered peripheral sensory inputs are implicated in this process, but the underlying mechanisms remain elusive. Here, we use the mammalian olfactory system to investigate such mechanisms. Primary olfactory sensory neurons (OSNs) project their axons directly to the olfactory bulb (OB) glomeruli, where their synaptic release is subject to local and cortical influence and neuromodulation. Pairing optogenetic activation of a single glomerulus with foot shock in mice induces freezing to light stimulation alone during fear retrieval. This is accompanied by an increase in OSN release probability and a reduction in GABAB receptor expression in the conditioned glomerulus. Furthermore, freezing time is positively correlated with the release probability of OSNs in fear-conditioned mice. These results suggest that aversive learning increases peripheral olfactory inputs at the first synapse, which may contribute to the behavioral outcome.
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Affiliation(s)
- Janardhan P Bhattarai
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 109 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Mary Schreck
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 109 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Andrew H Moberly
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 109 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Wenqin Luo
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 109 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 109 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
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35
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Qin S, Li Q, Tang C, Tu Y. Optimal compressed sensing strategies for an array of nonlinear olfactory receptor neurons with and without spontaneous activity. Proc Natl Acad Sci U S A 2019; 116:20286-20295. [PMID: 31548382 PMCID: PMC6789560 DOI: 10.1073/pnas.1906571116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
There are numerous different odorant molecules in nature but only a relatively small number of olfactory receptor neurons (ORNs) in brains. This "compressed sensing" challenge is compounded by the constraint that ORNs are nonlinear sensors with a finite dynamic range. Here, we investigate possible optimal olfactory coding strategies by maximizing mutual information between odor mixtures and ORNs' responses with respect to the bipartite odor-receptor interaction network (ORIN) characterized by sensitivities between all odorant-ORN pairs. For ORNs without spontaneous (basal) activity, we find that the optimal ORIN is sparse-a finite fraction of sensitives are zero, and the nonzero sensitivities follow a broad distribution that depends on the odor statistics. We show analytically that sparsity in the optimal ORIN originates from a trade-off between the broad tuning of ORNs and possible interference. Furthermore, we show that the optimal ORIN enhances performances of downstream learning tasks (reconstruction and classification). For ORNs with a finite basal activity, we find that having inhibitory odor-receptor interactions increases the coding capacity and the fraction of inhibitory interactions increases with the ORN basal activity. We argue that basal activities in sensory receptors in different organisms are due to the trade-off between the increase in coding capacity and the cost of maintaining the spontaneous basal activity. Our theoretical findings are consistent with existing experiments and predictions are made to further test our theory. The optimal coding model provides a unifying framework to understand the peripheral olfactory systems across different organisms.
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Affiliation(s)
- Shanshan Qin
- Center for Quantitative Biology, Peking University, Beijing 100871, China
| | - Qianyi Li
- Integrated Science Program, Yuanpei College, Peking University, Beijing 100871, China
| | - Chao Tang
- Center for Quantitative Biology, Peking University, Beijing 100871, China;
- School of Physics, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Yuhai Tu
- Physical Sciences Department, IBM T. J. Watson Research Center, Yorktown Heights, NY 10598
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36
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Chemosensory Perception: A Review on Electrophysiological Methods in “Cognitive Neuro-Olfactometry”. CHEMOSENSORS 2019. [DOI: 10.3390/chemosensors7030045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Various brain imaging techniques are available, but few are specifically designed to visualize chemical sensory and, in particular, olfactory processing. This review describes the results of quantitative and qualitative studies that have used electroencephalography (EEG) and magneto-encephalography (MEG) to evaluate responses to olfactory stimulation (OS). EEG and MEG are able to detect the components of chemosensory event-related potentials (CSERPs) and the cortical rhythms associated with different types of OS. Olfactory studies are filling the gaps in both the developmental field of the life cycle (from newborns to geriatric age) and the clinical and basic research fields, in a way that can be considered the modern “cognitive neuro-olfactometry”.
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37
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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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38
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Beyeler M, Rounds EL, Carlson KD, Dutt N, Krichmar JL. Neural correlates of sparse coding and dimensionality reduction. PLoS Comput Biol 2019; 15:e1006908. [PMID: 31246948 PMCID: PMC6597036 DOI: 10.1371/journal.pcbi.1006908] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Supported by recent computational studies, there is increasing evidence that a wide range of neuronal responses can be understood as an emergent property of nonnegative sparse coding (NSC), an efficient population coding scheme based on dimensionality reduction and sparsity constraints. We review evidence that NSC might be employed by sensory areas to efficiently encode external stimulus spaces, by some associative areas to conjunctively represent multiple behaviorally relevant variables, and possibly by the basal ganglia to coordinate movement. In addition, NSC might provide a useful theoretical framework under which to understand the often complex and nonintuitive response properties of neurons in other brain areas. Although NSC might not apply to all brain areas (for example, motor or executive function areas) the success of NSC-based models, especially in sensory areas, warrants further investigation for neural correlates in other regions.
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Affiliation(s)
- Michael Beyeler
- Department of Psychology, University of Washington, Seattle, Washington, United States of America
- Institute for Neuroengineering, University of Washington, Seattle, Washington, United States of America
- eScience Institute, University of Washington, Seattle, Washington, United States of America
- Department of Computer Science, University of California, Irvine, California, United States of America
| | - Emily L. Rounds
- Department of Cognitive Sciences, University of California, Irvine, California, United States of America
| | - Kristofor D. Carlson
- Department of Cognitive Sciences, University of California, Irvine, California, United States of America
- Sandia National Laboratories, Albuquerque, New Mexico, United States of America
| | - Nikil Dutt
- Department of Computer Science, University of California, Irvine, California, United States of America
- Department of Cognitive Sciences, University of California, Irvine, California, United States of America
| | - Jeffrey L. Krichmar
- Department of Computer Science, University of California, Irvine, California, United States of America
- Department of Cognitive Sciences, University of California, Irvine, California, United States of America
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39
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Bodaleo F, Tapia-Monsalves C, Cea-Del Rio C, Gonzalez-Billault C, Nunez-Parra A. Structural and Functional Abnormalities in the Olfactory System of Fragile X Syndrome Models. Front Mol Neurosci 2019; 12:135. [PMID: 31191246 PMCID: PMC6548058 DOI: 10.3389/fnmol.2019.00135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/09/2019] [Indexed: 12/18/2022] Open
Abstract
Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability. It is produced by mutation of the Fmr1 gene that encodes for the Fragile Mental Retardation Protein (FMRP), an important RNA-binding protein that regulates the expression of multiple proteins located in neuronal synapses. Individuals with FXS exhibit abnormal sensory information processing frequently leading to hypersensitivity across sensory modalities and consequently a wide array of behavioral symptoms. Insects and mammals engage primarily their sense of smell to create proper representations of the external world and guide adequate decision-making processes. This feature in combination with the exquisitely organized neuronal circuits found throughout the olfactory system (OS) and the wide expression of FMRP in brain regions that process olfactory information makes it an ideal model to study sensory alterations in FXS models. In the last decade several groups have taken advantage of these features and have used the OS of fruit fly and rodents to understand neuronal alteration giving rise to sensory perception issues. In this review article, we will discuss molecular, morphological and physiological aspects of the olfactory information processing in FXS models. We will highlight the decreased inhibitory/excitatory synaptic balance and the diminished synaptic plasticity found in this system resulting in behavioral alteration of individuals in the presence of odorant stimuli.
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Affiliation(s)
- Felipe Bodaleo
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | | | - Christian Cea-Del Rio
- Laboratory of Neurophysiopathology, Centro de Investigacion Biomedica y Aplicada (CIBAP), School of Medicine, Universidad de Santiago de Chile, Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, CA, United States
| | - Alexia Nunez-Parra
- Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Cell Physiology Center, Universidad de Chile, Santiago, Chile
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40
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Jacobs LF. The navigational nose: a new hypothesis for the function of the human external pyramid. ACTA ACUST UNITED AC 2019; 222:222/Suppl_1/jeb186924. [PMID: 30728230 DOI: 10.1242/jeb.186924] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
One of the outstanding questions in evolution is why Homo erectus became the first primate species to evolve the external pyramid, i.e. an external nose. The accepted hypothesis for this trait has been its role in respiration, to warm and humidify air as it is inspired. However, new studies testing the key assumptions of the conditioning hypothesis, such as the importance of turbulence to enhance heat and moisture exchange, have called this hypothesis into question. The human nose has two functions, however, respiration and olfaction. It is thus also possible that the external nose evolved in response to selection for olfaction. The genus Homo had many adaptations for long-distance locomotion, which allowed Homo erectus to greatly expand its species range, from Africa to Asia. Long-distance navigation in birds and other species is often accomplished by orientation to environmental odors. Such olfactory navigation, in turn, is enhanced by stereo olfaction, made possible by the separation of the olfactory sensors. By these principles, the human external nose could have evolved to separate olfactory inputs to enhance stereo olfaction. This could also explain why nose shape later became so variable: as humans became more sedentary in the Neolithic, a decreasing need for long-distance movements could have been replaced by selection for other olfactory functions, such as detecting disease, that would have been critical to survival in newly dense human settlements.
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Affiliation(s)
- Lucia F Jacobs
- Department of Psychology and Helen Wills Neuroscience Institute, University of California, 2121 Berkeley Way, Berkeley, CA 94720-1650, USA
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41
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Andonian A, Paseltiner D, Gould TJ, Castro JB. A deep learning based method for large-scale classification, registration, and clustering of in-situ hybridization experiments in the mouse olfactory bulb. J Neurosci Methods 2019; 312:162-168. [PMID: 30529409 PMCID: PMC6637410 DOI: 10.1016/j.jneumeth.2018.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND The Allen Mouse Brain Atlas allows study of the brain's molecular anatomy at cellular scale, for thousands genes. To fully leverage this resource, one must register histological images of brain tissue - a task made challenging by the brain's structural complexity and heterogeneity, as well as inter-experiment variability. NEW METHOD We have developed a deep-learning based methodology for classification and registration of thousands of sections of brain tissue, using the mouse olfactory bulb (OB) as a case study. RESULTS We trained a convolutional neural network (CNN) to derive an image similarity measure for in-situ hybridization experiments, and embedded these in a low-dimensional feature space to guide the design of registration templates. We then compiled a high quality, registered atlas of gene expression for the OB (the first such atlas for the OB, to our knowledge). As proof-of-principle, the atlas was clustered using non-negative matrix factorization to reveal canonical expression motifs, and to identify novel, lamina-specific marker genes. COMPARISON WITH EXISTING METHODS Our method leverages virtues of CNNs for a set of important problems in molecular neuroanatomy, with performance comparable to existing methods. CONCLUSION The atlas we have complied allows for intra- and inter-laminar comparisons of gene expression patterns in the OB across thousands of genes, as well identification of canonical expression profiles through clustering. We anticipate that this will be a useful resource for investigators studying the bulb's development and functional topography. Our methods are publicly available for those interested in extending them to other brain areas.
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Affiliation(s)
- Alexander Andonian
- Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Daniel Paseltiner
- Bates College, Program in Neuroscience, Lewiston, ME 04240, United States
| | - Travis J Gould
- Bates College, Physics Department, Lewiston, ME 04240, United States
| | - Jason B Castro
- Bates College, Program in Neuroscience, Lewiston, ME 04240, United States.
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42
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Olfactory marker protein (OMP) regulates formation and refinement of the olfactory glomerular map. Nat Commun 2018; 9:5073. [PMID: 30498219 PMCID: PMC6265328 DOI: 10.1038/s41467-018-07544-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 11/07/2018] [Indexed: 11/29/2022] Open
Abstract
Inputs from olfactory sensory neuron (OSN) axons expressing the same type of odorant receptor (OR) converge in the glomerulus of the main olfactory bulb. A key marker of mature OSNs is olfactory marker protein (OMP), whose deletion has been associated with deficits in OSN signal transduction and odor discrimination. Here, we investigate glomerular odor responses and anatomical architecture in mice in which one or both alleles of OMP are replaced by the fluorescent synaptic activity reporter, synaptopHluorin. Functionally heterogeneous glomeruli, that is, ones with microdomains with distinct odor responses, are rare in OMP+/– mice, but occur frequently in OMP–/– mice. Genetic targeting of single ORs reveals that these microdomains arise from co-innervation of individual glomeruli by OSNs expressing different ORs. This glomerular mistargeting is locally restricted to a few glomerular diameters. Our studies document functional heterogeneity in sensory input within individual glomeruli and uncover its anatomical correlate, revealing an unexpected role for OMP in the formation and refinement of the glomerular map. Olfactory marker protein (OMP) expressed in all olfactory sensory neurons (OSN) is required for proper signal transduction and odor discrimination. Here, the authors report that OMP deletion leads to formation of glomeruli with axons from heterogeneous OSNs due to local axonal mistargeting.
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Srinivasan S, Stevens CF. The distributed circuit within the piriform cortex makes odor discrimination robust. J Comp Neurol 2018; 526:2725-2743. [PMID: 30014545 DOI: 10.1002/cne.24492] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 05/30/2018] [Accepted: 06/01/2018] [Indexed: 12/14/2022]
Abstract
Distributed circuits wherein connections between subcircuit components seem randomly distributed are common to the olfactory circuit, hippocampus, and cerebellum. In such circuits, activation patterns seem random too, showing no detectable spatial preference, and contrast with regions that have topographic connections between subcircuits and topographic activation patterns. Quantitative studies of topographic circuits in the neocortex have yielded common principles of organization. Whether distributed circuits share similar principles of organization is unknown because similar quantitative information is missing and understanding the way they encode information remains a challenge. We addressed these needs by providing a quantitative description of the mouse piriform cortex, a paleocortical distributed circuit that subserves olfaction. The quantitative information provided two insights. First, with a nearly parameter-free model of the olfactory circuit, we show that the piriform cortex robustly maintains odor information and discrimination ability present in the olfactory bulb. Second, the paleocortex is quantitatively different from the neocortex: it has a lower surface area density, which decreases from the anterior to posterior paleocortex contrasting with the uniform neuronal density of the neocortex. These insights might also apply to other distributed circuits.
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Affiliation(s)
- Shyam Srinivasan
- Salk Institute for Biological Studies, La Jolla, California.,Kavli Institute for Brain and Mind, University of California, San Diego, California
| | - Charles F Stevens
- Salk Institute for Biological Studies, La Jolla, California.,Kavli Institute for Brain and Mind, University of California, San Diego, California
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44
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Kida H, Fukutani Y, Mainland JD, de March CA, Vihani A, Li YR, Chi Q, Toyama A, Liu L, Kameda M, Yohda M, Matsunami H. Vapor detection and discrimination with a panel of odorant receptors. Nat Commun 2018; 9:4556. [PMID: 30385742 PMCID: PMC6212438 DOI: 10.1038/s41467-018-06806-w] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 09/04/2018] [Indexed: 12/29/2022] Open
Abstract
Olfactory systems have evolved the extraordinary capability to detect and discriminate volatile odorous molecules (odorants) in the environment. Fundamentally, this process relies on the interaction of odorants and their cognate olfactory receptors (ORs) encoded in the genome. Here, we conducted a cell-based screen using over 800 mouse ORs against seven odorants, resulting in the identification of a set of high-affinity and/or broadly-tuned ORs. We then test whether heterologously expressed ORs respond to odors presented in vapor phase by individually expressing 31 ORs to measure cAMP responses against vapor phase odor stimulation. Comparison of response profiles demonstrates this platform is capable of discriminating between structural analogs. Lastly, co-expression of carboxyl esterase Ces1d expressed in olfactory mucosa resulted in marked changes in activation of specific odorant-OR combinations. Altogether, these results establish a cell-based volatile odor detection and discrimination platform and form the basis for an OR-based volatile odor sensor. Biomimetic “noses” have been proposed to replace trained animals for chemical detection. Here the authors select 31 mouse olfactory receptors (ORs), based on a large cell-based screen of >800 ORs against seven chemicals, to build an OR-based sensor able to discriminate structurally similar compounds.
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Affiliation(s)
- Hitoshi Kida
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Yosuke Fukutani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Joel D Mainland
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Monell Chemical Senses Center, Philadelphia, PA, 19104, USA.,Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Aashutosh Vihani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Neurobiology, Neurobiology graduate program, Duke University Medical Center, Durham, NC, 27710, USA
| | - Yun Rose Li
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Radiation Oncology, Helen Diller Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA
| | - Qiuyi Chi
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Akemi Toyama
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Linda Liu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Masaharu Kameda
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA. .,Department of Neurobiology, Neurobiology graduate program, Duke University Medical Center, 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.
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45
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Ikeda K, Suzuki N, Bekkers JM. Sodium and potassium conductances in principal neurons of the mouse piriform cortex: a quantitative description. J Physiol 2018; 596:5397-5414. [PMID: 30194865 DOI: 10.1113/jp275824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/21/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The primary olfactory (or piriform) cortex is a promising model system for understanding how the cerebral cortex processes sensory information, although an investigation of the piriform cortex is hindered by a lack of detailed information about the intrinsic electrical properties of its component neurons. In the present study, we quantify the properties of voltage-dependent sodium currents and voltage- and calcium-dependent potassium currents in two important classes of excitatory neurons in the main input layer of the piriform cortex. We identify several classes of these currents and show that their properties are similar to those found in better-studied cortical regions. Our detailed quantitative descriptions of these currents will be valuable to computational neuroscientists who aim to build models that explain how the piriform cortex encodes odours. ABSTRACT The primary olfactory cortex (or piriform cortex, PC) is an anatomically simple palaeocortex that is increasingly used as a model system for investigating cortical sensory processing. However, little information is available on the intrinsic electrical conductances in neurons of the PC, hampering efforts to build realistic computational models of this cortex. In the present study, we used nucleated macropatches and whole-cell recordings to rigorously quantify the biophysical properties of voltage-gated sodium (NaV ), voltage-gated potassium (KV ) and calcium-activated potassium (KCa ) conductances in two major classes of glutamatergic neurons in layer 2 of the PC, semilunar (SL) cells and superficial pyramidal (SP) cells. We found that SL and SP cells both express a fast-inactivating NaV current, two types of KV current (A-type and delayed rectifier-type) and three types of KCa current (fast-, medium- and slow-afterhyperpolarization currents). The kinetic and voltage-dependent properties of the NaV and KV conductances were, with some exceptions, identical in SL and SP cells and similar to those found in neocortical pyramidal neurons. The KCa conductances were also similar across the different types of neurons. Our results are summarized in a series of empirical equations that should prove useful to computational neuroscientists seeking to model the PC. More broadly, our findings indicate that, at the level of single-cell electrical properties, this palaeocortex is not so different from the neocortex, vindicating efforts to use the PC as a model of cortical sensory processing in general.
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Affiliation(s)
- Kaori Ikeda
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | | | - John M Bekkers
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
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46
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Kozma MT, Schmidt M, Ngo-Vu H, Sparks SD, Senatore A, Derby CD. Chemoreceptor proteins in the Caribbean spiny lobster, Panulirus argus: Expression of Ionotropic Receptors, Gustatory Receptors, and TRP channels in two chemosensory organs and brain. PLoS One 2018; 13:e0203935. [PMID: 30240423 PMCID: PMC6150509 DOI: 10.1371/journal.pone.0203935] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 08/30/2018] [Indexed: 12/22/2022] Open
Abstract
The spiny lobster, Panulirus argus, has two classes of chemosensilla representing “olfaction” and “distributed chemoreception,” as is typical for decapod crustaceans. Olfactory sensilla are found exclusively on antennular lateral flagella and are innervated only by olfactory receptor neurons (ORNs) that project into olfactory lobes organized into glomeruli in the brain. Distributed chemoreceptor sensilla are found on all body surfaces including the antennular lateral flagella (LF) and walking leg dactyls (dactyls), and are innervated by both chemoreceptor neurons (CRNs) and mechanoreceptor neurons that project into somatotopically organized neuropils. Here, we examined expression of three classes of chemosensory genes in transcriptomes of the LF (with ORNs and CRNs), dactyls (with only CRNs), and brain of P. argus: Ionotropic Receptors (IRs), which are related to ionotropic glutamate receptors and found in all protostomes including crustaceans; Gustatory Receptors (GRs), which are ionotropic receptors that are abundantly expressed in insects but more restricted in crustaceans; and Transient Receptor Potential (TRP) channels, a diverse set of sensor-channels that include several chemosensors in diverse animals. We identified 108 IRs, one GR, and 18 homologues representing all seven subfamilies of TRP channels. The number of IRs expressed in the LF is far greater than in dactyls, possibly reflecting the contribution of receptor proteins associated with the ORNs beyond those associated with CRNs. We found co-receptor IRs (IR8a, IR25a, IR76b, IR93a) and conserved IRs (IR21a, IR40a) in addition to the numerous divergent IRs in the LF, dactyl, and brain. Immunocytochemistry showed that IR25a is expressed in ORNs, CRNs, and a specific type of cell located in the brain near the olfactory lobes. While the function of IRs, TRP channels, and the GR was not explored, our results suggest that P. argus has an abundance of diverse putative chemoreceptor proteins that it may use in chemoreception.
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Affiliation(s)
- Mihika T. Kozma
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
| | - Manfred Schmidt
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Hanh Ngo-Vu
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Shea D. Sparks
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Adriano Senatore
- Department of Biology, University of Toronto Mississauga, Ontario, Canada
| | - Charles D. Derby
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
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47
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Loss of odor-induced c-Fos expression of juxtaglomerular activity following maintenance of mice on fatty diets. J Bioenerg Biomembr 2018; 51:3-13. [PMID: 30203289 DOI: 10.1007/s10863-018-9769-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/27/2018] [Indexed: 10/28/2022]
Abstract
Diet-induced obesity (DIO) decreases the number of OMP+ olfactory sensory neurons (OSN) in the olfactory epithelium by 25% and reduces correlate axonal projections to the olfactory bulb (OB). Whether surviving OSNs have equivalent odor responsivity is largely unknown. Herein, we utilized c-fos immediate-early gene expression to map neuronal activity and determine whether mice weaned to control (CF), moderately-high fat (MHF), or high-fat (HF) diet for a period of 6 months had changes in odor activation. Diet-challenged M72-IRES-tau-GFP mice were exposed to either a preferred M72 (Olfr160) ligand, isopropyl tiglate, or clean air in a custom-made Bell-jar infusion chamber using an alternating odor exposure pattern generated by a picosprizer™. Mice maintained on fatty diets weighed significantly more and cleared glucose less efficiently as determined by an intraperitoneal glucose tolerance test (IPGTT). The number of juxtaglomerular cells (JGs) decreased following maintenance of the mice on the MHF diet for cells surrounding the medial but not lateral M72 glomerulus within a 4 cell-column distance. The percentage of c-fos + JGs surrounding the lateral M72 glomerulus decreased in fat-challenged mice whereas those surrounding the medial glomerulus were not affected by diet. Altogether, these results show an asymmetry in the responsiveness of the 'mirror image' glomerular map for the M72 receptor that shows greater sensitivity of the lateral vs. medial glomerulus upon exposure to fatty diet.
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48
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Abstract
Since the first attempts to mimic the human nose with artificial devices, a variety of sensors have been developed, ranging from simple inorganic and organic gas detectors to biosensing elements incorporating proteins of the biological olfactory system. In order to design a device able to mimic the human nose, two major issues still need to be addressed regarding the complexity of olfactory coding and the extreme sensitivity of the biological system. So far, only 50 of the approximately 300–400 functioning olfactory receptors have been de-orphanized, still a long way from breaking the human olfactory code. On the other hand, the exceptional sensitivity of the human nose is based on amplification mechanisms difficult to reproduce with electronic circuits, and perhaps novel approaches are required to address this issue. Here, we review the recent literature on chemical sensing both in biological systems and artificial devices, and try to establish the state-of-the-art towards the design of an electronic nose.
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49
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Vinograd A, Fuchs-Shlomai Y, Stern M, Mukherjee D, Gao Y, Citri A, Davison I, Mizrahi A. Functional Plasticity of Odor Representations during Motherhood. Cell Rep 2018; 21:351-365. [PMID: 29020623 PMCID: PMC5643523 DOI: 10.1016/j.celrep.2017.09.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 06/21/2017] [Accepted: 09/11/2017] [Indexed: 01/24/2023] Open
Abstract
Motherhood is accompanied by new behaviors aimed at ensuring the wellbeing of the offspring. Olfaction plays a key role in guiding maternal behaviors during this transition. We studied functional changes in the main olfactory bulb (OB) of mothers in mice. Using in vivo two-photon calcium imaging, we studied the sensory representation of odors by mitral cells (MCs). We show that MC responses to monomolecular odors become sparser and weaker in mothers. In contrast, responses to biologically relevant odors are spared from sparsening or strengthen. MC responses to mixtures and to a range of concentrations suggest that these differences between odor responses cannot be accounted for by mixture suppressive effects or gain control mechanisms. In vitro whole-cell recordings show an increase in inhibitory synaptic drive onto MCs. The increase of inhibitory tone may contribute to the general decrease in responsiveness and concomitant enhanced representation of specific odors. MCs of mothers show sparser responses for pure odors MCs of mothers have stronger inhibitory drive onto MCs MCs of mothers show stronger responses to natural odors MC ensemble coding is improved for natural but not pure odors
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Affiliation(s)
- Amit Vinograd
- Department of Neurobiology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel; The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel
| | - Yael Fuchs-Shlomai
- Department of Neurobiology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel; The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel
| | - Merav Stern
- Department of Applied Mathematics, University of Washington, Seattle, WA, USA
| | - Diptendu Mukherjee
- Department of Chemical Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel; The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel
| | - Yuan Gao
- Department of Biology, Boston University, Boston, MA, USA
| | - Ami Citri
- Department of Chemical Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel; The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel
| | - Ian Davison
- Department of Biology, Boston University, Boston, MA, USA
| | - Adi Mizrahi
- Department of Neurobiology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel; The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel.
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50
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Galliano E, Franzoni E, Breton M, Chand AN, Byrne DJ, Murthy VN, Grubb MS. Embryonic and postnatal neurogenesis produce functionally distinct subclasses of dopaminergic neuron. eLife 2018; 7:e32373. [PMID: 29676260 PMCID: PMC5935487 DOI: 10.7554/elife.32373] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 04/04/2018] [Indexed: 11/13/2022] Open
Abstract
Most neurogenesis in the mammalian brain is completed embryonically, but in certain areas the production of neurons continues throughout postnatal life. The functional properties of mature postnatally generated neurons often match those of their embryonically produced counterparts. However, we show here that in the olfactory bulb (OB), embryonic and postnatal neurogenesis produce functionally distinct subpopulations of dopaminergic (DA) neurons. We define two subclasses of OB DA neuron by the presence or absence of a key subcellular specialisation: the axon initial segment (AIS). Large AIS-positive axon-bearing DA neurons are exclusively produced during early embryonic stages, leaving small anaxonic AIS-negative cells as the only DA subtype generated via adult neurogenesis. These populations are functionally distinct: large DA cells are more excitable, yet display weaker and - for certain long-latency or inhibitory events - more broadly tuned responses to odorant stimuli. Embryonic and postnatal neurogenesis can therefore generate distinct neuronal subclasses, placing important constraints on the functional roles of adult-born neurons in sensory processing.
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Affiliation(s)
- Elisa Galliano
- Centre for Developmental NeurobiologyInstitute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
- Department of Molecular and Cellular BiologyHarvard UniversityCambridgeUnited States
- Centre for Brain ScienceHarvard UniversityCambridgeUnited States
| | - Eleonora Franzoni
- Centre for Developmental NeurobiologyInstitute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | - Marine Breton
- Centre for Developmental NeurobiologyInstitute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | - Annisa N Chand
- Centre for Developmental NeurobiologyInstitute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | - Darren J Byrne
- Centre for Developmental NeurobiologyInstitute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | - Venkatesh N Murthy
- Department of Molecular and Cellular BiologyHarvard UniversityCambridgeUnited States
- Centre for Brain ScienceHarvard UniversityCambridgeUnited States
| | - Matthew S Grubb
- Centre for Developmental NeurobiologyInstitute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
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