1
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Ekanayake A, Yang Q, Kanekar S, Ahmed B, McCaslin S, Kalra D, Eslinger P, Karunanayaka P. Monorhinal and Birhinal Odor Processing in Humans: an fMRI investigation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551475. [PMID: 37577649 PMCID: PMC10418263 DOI: 10.1101/2023.08.01.551475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The olfactory nerve, also known as cranial nerve I, is known to have exclusive ipsilateral projections to primary olfactory cortical structures. It is still unclear whether these projections also correspond to functional pathways of odor processing. In an olfactory functional magnetic resonance imaging (fMRI) study of twenty young healthy subjects with a normal sense of smell, we tested whether nostril specific stimulation with phenyl ethyl alcohol (PEA), a pure olfactory stimulant, asymmetrically activates primary or secondary olfactory-related brain structures such as primary olfactory cortex, entorhinal cortex, and orbitofrontal cortex. The results indicated that without a challenging olfactory task, passive (no sniffing) and active (with sniffing) nostril-specific PEA stimulation did not produce asymmetrical fMRI activation in olfactory cortical structures.
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Affiliation(s)
- Anupa Ekanayake
- Grodno State Medical University, Grodno, Belarus
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Qing Yang
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
- Department of Neurosurgery, Penn State University College of Medicine, Hershey, PA, USA
| | - Sangam Kanekar
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Biyar Ahmed
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Silas McCaslin
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Deepak Kalra
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, USA
| | - Paul Eslinger
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, USA
| | - Prasanna Karunanayaka
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
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2
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Odor discrimination is immune to the effects of verbal labels. Sci Rep 2023; 13:1742. [PMID: 36720925 PMCID: PMC9889793 DOI: 10.1038/s41598-023-28134-w] [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: 01/20/2022] [Accepted: 01/13/2023] [Indexed: 02/01/2023] Open
Abstract
For many odors that we encounter in daily life, we perceive their qualities without being able to specifically identify their sources-an experience termed the "tip-of-the-nose" phenomenon. Does learning an odor's identity alter our experience of it? Past work has shown that labeling odors can alter how we describe and react to them, but it remains an open question whether such changes extend to the level of perception, making an odor actually smell different. Here, in a set of odor classification experiments we tested whether attaching labels to odors can alter their perceptual discriminability. We found that even for odors whose reported similarity changed markedly when their identities were revealed, their discriminability remained unchanged by labels. Our findings indicate that two critical functions of olfaction-parsing the odor environment and supporting the subjective experience of odor qualities-access distinct odor representations within the olfactory processing stream.
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3
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Lindroos R, Raj R, Pierzchajlo S, Hörberg T, Herman P, Challma S, Hummel T, Larsson M, Laukka EJ, Olofsson JK. Perceptual odor qualities predict successful odor identification in old age. Chem Senses 2022; 47:6806083. [PMID: 36334272 PMCID: PMC9636890 DOI: 10.1093/chemse/bjac025] [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] [Indexed: 11/06/2022] Open
Abstract
Odor identification is a common assessment of olfaction, and it is affected in a large number of diseases. Identification abilities decline with age, but little is known about whether there are perceptual odor features that can be used to predict identification. Here, we analyzed data from a large, population-based sample of 2,479 adults, aged 60 years or above, from the Swedish National study on Aging and Care in Kungsholmen. Participants performed both free and cued odor identification tests. In a separate experiment, we assessed perceived pleasantness, familiarity, intensity, and edibility of all odors in the first sample, and examined how odor identification performance is associated with these variables. The analysis showed that high-intensity odors are easier to identify than low-intensity odors overall, but also that they are more susceptible to the negative repercussions of old age. This result indicates that sensory decline is a major aspect of age-dependent odor identification impairment, and suggests a framework where identification likelihood is proportional to the perceived intensity of the odor. Additional analyses further showed that high-performing individuals can discriminate target odors from distractors along the pleasantness and edibility dimensions and that unpleasant and inedible odors show smaller age-related differences in identification. Altogether, these results may guide further development and optimization of brief and efficient odor identification tests as well as influence the design of odorous products targeted toward older consumers.
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Affiliation(s)
- Robert Lindroos
- Corresponding author: Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Albanovägen 12, 114 19 Stockholm, Sweden.
| | - Rohan Raj
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Stephen Pierzchajlo
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Thomas Hörberg
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Pawel Herman
- Division of Computational Science and Technology, KTH, Royal Institute of Technology and Digital Futures, Stockholm, Sweden
| | - Sandra Challma
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Maria Larsson
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Erika J Laukka
- Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karoliska institutet, Stockholm, Sweden
| | - Jonas K Olofsson
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
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4
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Tybur JM, Croijmans IM, van Huijstee D, Çınar Ç, Lal V, Smeets MA. Disgust sensitivity relates to affective responses to – but not ability to detect – olfactory cues to pathogens. EVOL HUM BEHAV 2022. [DOI: 10.1016/j.evolhumbehav.2022.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Patel R, Hallem EA. Olfaction: One receptor drives opposite behaviors. Curr Biol 2022; 32:R93-R96. [PMID: 35077699 DOI: 10.1016/j.cub.2021.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Many odorants are attractive at low concentrations but repulsive at higher concentrations. A new study demonstrates that, in Caenorhabditis elegans, a single odorant receptor acts in two different neuron pairs to mediate both attractive and repulsive responses to an odorant.
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Affiliation(s)
- Ruhi Patel
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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6
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Jennings L, Williams E, Avlas M, Dewan A. The behavioral sensitivity of mice to acetate esters. Chem Senses 2022; 47:6639759. [PMID: 35816188 PMCID: PMC9272796 DOI: 10.1093/chemse/bjac017] [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] [Indexed: 11/20/2022] Open
Abstract
Measures of behavioral sensitivity provide an important guide for choosing the stimulus concentrations used in functional experiments. This information is particularly valuable in the olfactory system as the neural representation of an odorant changes with concentration. This study focuses on acetate esters because they are commonly used to survey neural activity in a variety of olfactory regions, probe the behavioral limits of odor discrimination, and assess odor structure–activity relationships in mice. Despite their frequent use, the relative sensitivity of these odorants in mice is not available. Thus, we assayed the ability of C57BL/6J mice to detect seven different acetates (propyl acetate, butyl acetate, pentyl acetate, hexyl acetate, octyl acetate, isobutyl acetate, and isoamyl acetate) using a head-fixed Go/No-Go operant conditioning assay combined with highly reproducible stimulus delivery. To aid in the accessibility and applicability of our data, we have estimated the vapor-phase concentrations of these odorants in five different solvents using a photoionization detector-based approach. The resulting liquid-/vapor-phase equilibrium equations successfully corrected for behavioral sensitivity differences observed in animals tested with the same odorant in different solvents. We found that mice are most sensitive to isobutyl acetate and least sensitive to propyl acetate. These updated measures of sensitivity will hopefully guide experimenters in choosing appropriate stimulus concentrations for experiments using these odorants.
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Affiliation(s)
- Liam Jennings
- Department of Psychology, Florida State University, Tallahassee, FL, United States
| | - Ellie Williams
- Department of Psychology, Florida State University, Tallahassee, FL, United States
| | - Marta Avlas
- Department of Psychology, Florida State University, Tallahassee, FL, United States
| | - Adam Dewan
- Department of Psychology, Florida State University, Tallahassee, FL, United States
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7
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Noto T, Zhou G, Yang Q, Lane G, Zelano C. Human Primary Olfactory Amygdala Subregions Form Distinct Functional Networks, Suggesting Distinct Olfactory Functions. Front Syst Neurosci 2021; 15:752320. [PMID: 34955769 PMCID: PMC8695617 DOI: 10.3389/fnsys.2021.752320] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/08/2021] [Indexed: 12/02/2022] Open
Abstract
Three subregions of the amygdala receive monosynaptic projections from the olfactory bulb, making them part of the primary olfactory cortex. These primary olfactory areas are located at the anterior-medial aspect of the amygdala and include the medial amygdala (MeA), cortical amygdala (CoA), and the periamygdaloid complex (PAC). The vast majority of research on the amygdala has focused on the larger basolateral and basomedial subregions, which are known to be involved in implicit learning, threat responses, and emotion. Fewer studies have focused on the MeA, CoA, and PAC, with most conducted in rodents. Therefore, our understanding of the functions of these amygdala subregions is limited, particularly in humans. Here, we first conducted a review of existing literature on the MeA, CoA, and PAC. We then used resting-state fMRI and unbiased k-means clustering techniques to show that the anatomical boundaries of human MeA, CoA, and PAC accurately parcellate based on their whole-brain resting connectivity patterns alone, suggesting that their functional networks are distinct, relative both to each other and to the amygdala subregions that do not receive input from the olfactory bulb. Finally, considering that distinct functional networks are suggestive of distinct functions, we examined the whole-brain resting network of each subregion and speculated on potential roles that each region may play in olfactory processing. Based on these analyses, we speculate that the MeA could potentially be involved in the generation of rapid motor responses to olfactory stimuli (including fight/flight), particularly in approach/avoid contexts. The CoA could potentially be involved in olfactory-related reward processing, including learning and memory of approach/avoid responses. The PAC could potentially be involved in the multisensory integration of olfactory information with other sensory systems. These speculations can be used to form the basis of future studies aimed at clarifying the olfactory functions of these under-studied primary olfactory areas.
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Affiliation(s)
- Torben Noto
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Guangyu Zhou
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Qiaohan Yang
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Gregory Lane
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Christina Zelano
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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8
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Faour M, Magnan C, Gurden H, Martin C. Olfaction in the context of obesity and diabetes: Insights from animal models to humans. Neuropharmacology 2021; 206:108923. [PMID: 34919903 DOI: 10.1016/j.neuropharm.2021.108923] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 12/07/2021] [Accepted: 12/10/2021] [Indexed: 12/12/2022]
Abstract
The olfactory system is at the crossroad between sensory processing and metabolic sensing. In addition to being the center of detection and identification of food odors, it is a sensor for most of the hormones and nutrients responsible for feeding behavior regulation. The consequences of modifications in body homeostasis, nutrient overload and alteration of this brain network in the pathological condition of food-induced obesity and type 2 diabetes are still not elucidated. The aim of this review was first to use both humans and animal studies to report on the current knowledge of the consequences of obesity and type 2 diabetes on odorant threshold and olfactory perception including identification discrimination and memory. We then discuss how olfactory processing can be modified by an alteration of the metabolic homeostasis of the organism and available elements on pharmacological treatments that regulate olfaction. We focus on data within the olfactory system but also on the interactions between the olfactory system and other brain networks impacted by metabolic diseases.
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Affiliation(s)
- Maya Faour
- Université de Paris, BFA, UMR 8251, CNRS, F-75013, Paris, France
| | | | - Hirac Gurden
- Université de Paris, BFA, UMR 8251, CNRS, F-75013, Paris, France
| | - Claire Martin
- Université de Paris, BFA, UMR 8251, CNRS, F-75013, Paris, France.
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9
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Cheng H, Liu Y, Xue Y, Shao J, Tan Z, Liu S, Duan S, Kang L. Molecular Strategies for Intensity-Dependent Olfactory Processing in Caenorhabditis elegans. Front Mol Neurosci 2021; 14:748214. [PMID: 34803606 PMCID: PMC8600271 DOI: 10.3389/fnmol.2021.748214] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Various odorants trigger complex animal behaviors across species in both quality- and quantity-dependent manners. However, how the intensity of olfactory input is encoded remains largely unknown. Here we report that isoamyl alcohol (IAA) induces bi-directional currents through a Gα- guanylate cyclase (GC)- cGMP signaling pathway in Caenorhabditis elegans olfactory neuron amphid wing “C” cell (AWC), while two opposite cGMP signaling pathways are responsible for odor-sensing in olfactory neuron amphid wing “B” cell (AWB): (1) a depolarizing Gα (GPA-3)- phosphodiesterase (PDE) – cGMP pathway which can be activated by low concentrations of isoamyl alcohol (IAA), and (2) a hyperpolarizing Gα (ODR-3)- GC- cGMP pathway sensing high concentrations of IAA. Besides, IAA induces Gα (ODR-3)-TRPV(OSM-9)-dependent currents in amphid wing “A” cell (AWA) and amphid neuron “H” cell with single ciliated sensory ending (ASH) neurons with different thresholds. Our results demonstrate that an elaborate combination of multiple signaling machineries encode the intensity of olfactory input, shedding light on understanding the molecular strategies on sensory transduction.
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Affiliation(s)
- Hankui Cheng
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Yu Liu
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Yadan Xue
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiajie Shao
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhibing Tan
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Siyan Liu
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Shumin Duan
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.,Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lijun Kang
- Department of Neurobiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
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10
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Kluger DS, Gross J. Respiration modulates oscillatory neural network activity at rest. PLoS Biol 2021; 19:e3001457. [PMID: 34762645 PMCID: PMC8610250 DOI: 10.1371/journal.pbio.3001457] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/23/2021] [Accepted: 10/25/2021] [Indexed: 12/11/2022] Open
Abstract
Despite recent advances in understanding how respiration affects neural signalling to influence perception, cognition, and behaviour, it is yet unclear to what extent breathing modulates brain oscillations at rest. We acquired respiration and resting state magnetoencephalography (MEG) data from human participants to investigate if, where, and how respiration cyclically modulates oscillatory amplitudes (2 to 150 Hz). Using measures of phase-amplitude coupling, we show respiration-modulated brain oscillations (RMBOs) across all major frequency bands. Sources of these modulations spanned a widespread network of cortical and subcortical brain areas with distinct spectrotemporal modulation profiles. Globally, delta and gamma band modulations varied with distance to the head centre, with stronger modulations at distal (versus central) cortical sites. Overall, we provide the first comprehensive mapping of RMBOs across the entire brain, highlighting respiration-brain coupling as a fundamental mechanism to shape neural processing within canonical resting state and respiratory control networks (RCNs).
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Affiliation(s)
- Daniel S. Kluger
- Institute for Biomagnetism and Biosignal Analysis, University of Muenster, Muenster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster, Muenster, Germany
- * E-mail:
| | - Joachim Gross
- Institute for Biomagnetism and Biosignal Analysis, University of Muenster, Muenster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster, Muenster, Germany
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
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11
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The human olfactory bulb processes odor valence representation and cues motor avoidance behavior. Proc Natl Acad Sci U S A 2021; 118:2101209118. [PMID: 34645711 PMCID: PMC8545486 DOI: 10.1073/pnas.2101209118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2021] [Indexed: 11/18/2022] Open
Abstract
Determining the valence of an odor to guide rapid approach-avoidance behavior is thought to be one of the core tasks of the olfactory system, and yet little is known of the initial neural mechanisms supporting this process or of its subsequent behavioral manifestation in humans. In two experiments, we measured the functional processing of odor valence perception in the human olfactory bulb (OB)-the first processing stage of the olfactory system-using a noninvasive method as well as assessed the subsequent motor avoidance response. We demonstrate that odor valence perception is associated with both gamma and beta activity in the human OB. Moreover, we show that negative, but not positive, odors initiate an early beta response in the OB, a response that is linked to a preparatory neural motor response in the motor cortex. Finally, in a separate experiment, we show that negative odors trigger a full-body motor avoidance response, manifested as a rapid leaning away from the odor, within the time period predicted by the OB results. Taken together, these results demonstrate that the human OB processes odor valence in a sequential manner in both the gamma and beta frequency bands and suggest that rapid processing of unpleasant odors in the OB might underlie rapid approach-avoidance decisions.
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12
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Iravani B, Peter MG, Arshamian A, Olsson MJ, Hummel T, Kitzler HH, Lundström JN. Acquired olfactory loss alters functional connectivity and morphology. Sci Rep 2021; 11:16422. [PMID: 34385571 PMCID: PMC8361122 DOI: 10.1038/s41598-021-95968-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
Removing function from a developed and functional sensory system is known to alter both cerebral morphology and functional connections. To date, a majority of studies assessing sensory-dependent plasticity have focused on effects from either early onset or long-term sensory loss and little is known how the recent sensory loss affects the human brain. With the aim of determining how recent sensory loss affects cerebral morphology and functional connectivity, we assessed differences between individuals with acquired olfactory loss (duration 7-36 months) and matched healthy controls in their grey matter volume, using multivariate pattern analyses, and functional connectivity, using dynamic connectivity analyses, within and from the olfactory cortex. Our results demonstrate that acquired olfactory loss is associated with altered grey matter volume in, among others, posterior piriform cortex, a core olfactory processing area, as well as the inferior frontal gyrus and angular gyrus. In addition, compared to controls, individuals with acquired anosmia displayed significantly stronger dynamic functional connectivity from the posterior piriform cortex to, among others, the angular gyrus, a known multisensory integration area. When assessing differences in dynamic functional connectivity from the angular gyrus, individuals with acquired anosmia had stronger connectivity from the angular gyrus to areas primary responsible for basic visual processing. These results demonstrate that recently acquired sensory loss is associated with both changed cerebral morphology within core olfactory areas and increase dynamic functional connectivity from olfactory cortex to cerebral areas processing multisensory integration.
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Affiliation(s)
- Behzad Iravani
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 171 77, Stockholm, Sweden
| | - Moa G Peter
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 171 77, Stockholm, Sweden
| | - Artin Arshamian
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 171 77, Stockholm, Sweden
| | - Mats J Olsson
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 171 77, Stockholm, Sweden
| | - Thomas Hummel
- Department of Otorhinolaryngology, Smell and Taste Clinic, TU Dresden, Dresden, Germany
| | - Hagen H Kitzler
- Institute of Diagnostic and Interventional Neuroradiology, TU Dresden, Dresden, Germany
| | - Johan N Lundström
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 171 77, Stockholm, Sweden. .,Monell Chemical Senses Center, Philadelphia, PA, USA. .,Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA. .,Stockholm University Brain Imaging Centre, Stockholm University, Stockholm, Sweden.
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13
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Singh V, Tchernookov M, Balasubramanian V. What the odor is not: Estimation by elimination. Phys Rev E 2021; 104:024415. [PMID: 34525542 PMCID: PMC8892575 DOI: 10.1103/physreve.104.024415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 08/02/2021] [Indexed: 11/07/2022]
Abstract
Olfactory systems use a small number of broadly sensitive receptors to combinatorially encode a vast number of odors. We propose a method of decoding such distributed representations by exploiting a statistical fact: Receptors that do not respond to an odor carry more information than receptors that do because they signal the absence of all odorants that bind to them. Thus, it is easier to identify what the odor is not rather than what the odor is. For realistic numbers of receptors, response functions, and odor complexity, this method of elimination turns an underconstrained decoding problem into a solvable one, allowing accurate determination of odorants in a mixture and their concentrations. We construct a neural network realization of our algorithm based on the structure of the olfactory pathway.
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Affiliation(s)
- Vijay Singh
- Department of Physics, North Carolina A&T State University, Greensboro, NC, 27410, USA
- Department of Physics, & Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Martin Tchernookov
- Department of Physics, University of Wisconsin, Whitewater, WI, 53190, USA
| | - Vijay Balasubramanian
- Department of Physics, & Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, PA 19104, USA
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14
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Ma Y, Tang K, Xu Y, Thomas-Danguin T. Perceptual interactions among food odors: Major influences on odor intensity evidenced with a set of 222 binary mixtures of key odorants. Food Chem 2021; 353:129483. [PMID: 33740506 DOI: 10.1016/j.foodchem.2021.129483] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 02/01/2023]
Abstract
This study explored the impact of perceptual interactions on the odor intensity of 222 binary mixtures designed from 72 odorants found in food products. Odor intensity was rated by 30 trained subjects. The results showed that in most cases, the components' odor was perceived within the mixture and their intensity remained the same as in the unmixed situation in 54.3% of cases. Masking was the second major effect (44.8%) and occurred more frequently when components' pleasantness was significantly different. Synergy occurred in a small number of cases (0.9%) and only for four compounds. The overall odor intensity of the mixture was determined to be equal to the strongest component in most cases (73.9%), while partial addition was observed as the second most frequent effect (21.7%), especially when the components had equal intensity. Overall, this work provides general rules about the outcome to expect when mixing key components of food aromas.
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Affiliation(s)
- Yue Ma
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China; Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China; Centre des Sciences du Goût et de l'Alimentation, INRAE, CNRS, AgroSup Dijon, Université Bourgogne Franche-Comté, Dijon, France.
| | - Ke Tang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China; Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China.
| | - Yan Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China; Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, PR China.
| | - Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, INRAE, CNRS, AgroSup Dijon, Université Bourgogne Franche-Comté, Dijon, France.
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15
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Zhou G, Olofsson JK, Koubeissi MZ, Menelaou G, Rosenow J, Schuele SU, Xu P, Voss JL, Lane G, Zelano C. Human hippocampal connectivity is stronger in olfaction than other sensory systems. Prog Neurobiol 2021; 201:102027. [PMID: 33640412 DOI: 10.1016/j.pneurobio.2021.102027] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/20/2021] [Accepted: 02/21/2021] [Indexed: 12/17/2022]
Abstract
During mammalian evolution, primate neocortex expanded, shifting hippocampal functional networks away from primary sensory cortices, towards association cortices. Reflecting this rerouting, human resting hippocampal functional networks preferentially include higher association cortices, while those in rodents retained primary sensory cortices. Research on human visual, auditory and somatosensory systems shows evidence of this rerouting. Olfaction, however, is unique among sensory systems in its relative structural conservation throughout mammalian evolution, and it is unknown whether human primary olfactory cortex was subject to the same rerouting. We combined functional neuroimaging and intracranial electrophysiology to directly compare hippocampal functional networks across human sensory systems. We show that human primary olfactory cortex-including the anterior olfactory nucleus, olfactory tubercle and piriform cortex-has stronger functional connectivity with hippocampal networks at rest, compared to other sensory systems. This suggests that unlike other sensory systems, olfactory-hippocampal connectivity may have been retained in mammalian evolution. We further show that olfactory-hippocampal connectivity oscillates with nasal breathing. Our findings suggest olfaction might provide insight into how memory and cognition depend on hippocampal interactions.
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Affiliation(s)
- Guangyu Zhou
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Jonas K Olofsson
- Department of Psychology, Stockholm University, Stockholm, Sweden; Emotional Brain Institute, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Child and Adolescent Psychiatry, New York University School of Medicine, New York, NY, USA
| | | | | | - Joshua Rosenow
- Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Stephan U Schuele
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Pengfei Xu
- Beijing Key Laboratory of Applied Experimental Psychology, Faculty of Psychology, Beijing Normal University, Beijing, China; Center for Neuroimaging, Shenzhen Institute of Neuroscience, Shenzhen, China; Guangdong-Hong Kong-Macao Greater Bay Area Research Institute for Neuroscience and Neurotechnologies, Kwun Tong, Hong Kong, China
| | - Joel L Voss
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Gregory Lane
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Christina Zelano
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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16
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Losacco J, George NM, Hiratani N, Restrepo D. The Olfactory Bulb Facilitates Use of Category Bounds for Classification of Odorants in Different Intensity Groups. Front Cell Neurosci 2020; 14:613635. [PMID: 33362477 PMCID: PMC7759615 DOI: 10.3389/fncel.2020.613635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/16/2020] [Indexed: 11/22/2022] Open
Abstract
Signal processing of odor inputs to the olfactory bulb (OB) changes through top-down modulation whose shaping of neural rhythms in response to changes in stimulus intensity is not understood. Here we asked whether the representation of a high vs. low intensity odorant in the OB by oscillatory neural activity changed as the animal learned to discriminate odorant concentration ranges in a go-no go task. We trained mice to discriminate between high vs. low concentration odorants by learning to lick to the rewarded group (low or high). We recorded the local field potential (LFP) in the OB of these mice and calculated the theta-referenced beta or gamma oscillation power (theta phase-referenced power, or tPRP). We found that as the mouse learned to differentiate odorant concentrations, tPRP diverged between trials for the rewarded vs. the unrewarded concentration range. For the proficient animal, linear discriminant analysis was able to predict the rewarded odorant group and the performance of this classifier correlated with the percent correct behavior in the odor concentration discrimination task. Interestingly, the behavioral response and decoding accuracy were asymmetric as a function of concentration when the rewarded stimulus was shifted between the high and low odorant concentration ranges. A model for decision making motivated by the statistics of OB activity that uses a single threshold in a logarithmic concentration scale displays this asymmetry. Taken together with previous studies on the intensity criteria for decisions on odorant concentrations, our finding suggests that OB oscillatory events facilitate decision making to classify concentrations using a single intensity criterion.
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Affiliation(s)
- Justin Losacco
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Nicholas M. George
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Naoki Hiratani
- Gatsby Computational Neuroscience Unit, University College London, London, United Kingdom
| | - Diego Restrepo
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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17
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Coutens B, Rekik K, Harster A, Etienne P, Noirot V, Frances B, Moulédous L, Guiard BP. A Citrus Based Sensory Functional Food Ingredient Induces Antidepressant-like Effects: Possible Involvement of an Interplay between the Olfactory and the Serotonergic Systems. Neuroscience 2020; 451:149-163. [PMID: 33039523 DOI: 10.1016/j.neuroscience.2020.09.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 09/17/2020] [Accepted: 09/20/2020] [Indexed: 12/28/2022]
Abstract
In the present study, we examined the neurobehavioral effects of a sensory functional food ingredient mainly based on Citrus sinensis extracts (D11399) using a battery of tests recapitulating various endophenotypes of depression such as anxiety in the open field (OF), the elevated plus-maze (EPM), and the novelty suppressed feeding (NSF), self-care in the splash test (ST), despair in the forced swimming task (FST) but also anhedonia in the sucrose preference test (SPT) in mice. A one-week oral administration of D11399 promoted anxiolytic- and antidepressant-like responses in naïve mice subjected to the NSF and FST. In a marked contrast, the administration of D11399 by oral gavage or the inhibition of olfaction by methimazole prevented such beneficial effects. We further investigated the neurobehavioral properties of a ten-week oral administration of D11399 in the corticosterone (CORT) mouse model of depression. Interestingly, D11399 also elicited anxiolytic- and antidepressant-like effects in various paradigms. To characterize the putative underpinning neurobiological mechanisms in CORT mice, we investigated whether cellular and molecular processes commonly associated with antidepressant responses such as monoaminergic neurotransmission and neuronal maturation in the hippocampus were impacted. Although D11399 did not modify the hippocampal extracellular levels of monoamines (i.e. serotonin and norepinephrine), it reversed the ability of CORT to decrease serotonin neurons firing rate in the dorsal raphe and neuronal maturation in the hippocampus. These findings suggest that the anxiolytic- and antidepressant-like effects of this sensory functional food ingredient are closely related with olfaction and likely a concomitant change in the activity of the central serotonergic system. Further experiments are warranted to precise the neuronal circuits linking sensorial and emotional modalities and identify innovative therapeutic strategies aimed to relieve depressive endophenotypes.
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Affiliation(s)
- B Coutens
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - K Rekik
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - A Harster
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | | | | | - B Frances
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - L Moulédous
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - B P Guiard
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France; Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92290 Chatenay-Malabry, France.
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18
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Taylor AJ, Beauchamp JD, Briand L, Heer M, Hummel T, Margot C, McGrane S, Pieters S, Pittia P, Spence C. Factors affecting flavor perception in space: Does the spacecraft environment influence food intake by astronauts? Compr Rev Food Sci Food Saf 2020; 19:3439-3475. [PMID: 33337044 DOI: 10.1111/1541-4337.12633] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 12/11/2022]
Abstract
The intention to send a crewed mission to Mars involves a huge amount of planning to ensure a safe and successful mission. Providing adequate amounts of food for the crew is a major task, but 20 years of feeding astronauts on the International Space Station (ISS) have resulted in a good knowledge base. A crucial observation from the ISS is that astronauts typically consume only 80% of their daily calorie requirements when in space. This is despite daily exercise regimes that keep energy usage at very similar levels to those found on Earth. This calorie deficit seems to have little effect on astronauts who spend up to 12 months on the ISS, but given that a mission to Mars would take 30 to 36 months to complete, there is concern that a calorie deficit over this period may lead to adverse effects in crew members. The key question is why astronauts undereat when they have a supply of food designed to fully deliver their nutritional needs. This review focuses on evidence from astronauts that foods taste different in space, compared to on Earth. The underlying hypothesis is that conditions in space may change the perceived flavor of the food, and this flavor change may, in turn, lead to underconsumption by astronauts. The key areas investigated in this review for their potential impact on food intake are the effects of food shelf life, physiological changes, noise, air and water quality on the perception of food flavor, as well as the link between food flavor and food intake.
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Affiliation(s)
| | - Jonathan D Beauchamp
- Department of Sensory Analytics, Fraunhofer Institute for Process Engineering and Packaging IVV, Freising, Germany
| | - Loïc Briand
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRAE, Université de Bourgogne Franche-Comté, Dijon, France
| | - Martina Heer
- International University of Applied Sciences, Bad Honnef, Germany
| | - Thomas Hummel
- Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | | | - Scott McGrane
- Waltham Petcare Science Institute, Waltham on the Wolds, UK
| | - Serge Pieters
- Haute Ecole Léonard de Vinci, Institut Paul Lambin, Brussels, Belgium
| | - Paola Pittia
- Faculty of Bioscience and Technology for Food, Agriculture, and Environment, University of Teramo, Teramo, Italy
| | - Charles Spence
- Department of Experimental Psychology, University of Oxford, Oxford, UK
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19
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Functional Connectome Analyses Reveal the Human Olfactory Network Organization. eNeuro 2020; 7:ENEURO.0551-19.2020. [PMID: 32471848 PMCID: PMC7418535 DOI: 10.1523/eneuro.0551-19.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 01/24/2023] Open
Abstract
The olfactory system is uniquely heterogeneous, performing multifaceted functions (beyond basic sensory processing) across diverse, widely distributed neural substrates. While knowledge of human olfaction continues to grow, it remains unclear how the olfactory network is organized to serve this unique set of functions. The olfactory system is uniquely heterogeneous, performing multifaceted functions (beyond basic sensory processing) across diverse, widely distributed neural substrates. While knowledge of human olfaction continues to grow, it remains unclear how the olfactory network is organized to serve this unique set of functions. Leveraging a large and high-quality resting-state functional magnetic resonance imaging (rs-fMRI) dataset of nearly 900 participants from the Human Connectome Project (HCP), we identified a human olfactory network encompassing cortical and subcortical regions across the temporal and frontal lobes. Highlighting its reliability and generalizability, the connectivity matrix of this olfactory network mapped closely onto that extracted from an independent rs-fMRI dataset. Graph theoretical analysis further explicated the organizational principles of the network. The olfactory network exhibits a modular composition of three (i.e., the sensory, limbic, and frontal) subnetworks and demonstrates strong small-world properties, high in both global integration and local segregation (i.e., circuit specialization). This network organization thus ensures the segregation of local circuits, which are nonetheless integrated via connecting hubs [i.e., amygdala (AMY) and anterior insula (INSa)], thereby enabling the specialized, yet integrative, functions of olfaction. In particular, the degree of local segregation positively predicted olfactory discrimination performance in the independent sample, which we infer as a functional advantage of the network organization. In sum, an olfactory functional network has been identified through the large HCP dataset, affording a representative template of the human olfactory functional neuroanatomy. Importantly, the topological analysis of the olfactory network provides network-level insights into the remarkable functional specialization and spatial segregation of the olfactory system.
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20
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Zak JD, Reddy G, Vergassola M, Murthy VN. Antagonistic odor interactions in olfactory sensory neurons are widespread in freely breathing mice. Nat Commun 2020; 11:3350. [PMID: 32620767 PMCID: PMC7335155 DOI: 10.1038/s41467-020-17124-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 06/10/2020] [Indexed: 12/24/2022] Open
Abstract
Odor landscapes contain complex blends of molecules that each activate unique, overlapping populations of olfactory sensory neurons (OSNs). Despite the presence of hundreds of OSN subtypes in many animals, the overlapping nature of odor inputs may lead to saturation of neural responses at the early stages of stimulus encoding. Information loss due to saturation could be mitigated by normalizing mechanisms such as antagonism at the level of receptor-ligand interactions, whose existence and prevalence remains uncertain. By imaging OSN axon terminals in olfactory bulb glomeruli as well as OSN cell bodies within the olfactory epithelium in freely breathing mice, we find widespread antagonistic interactions in binary odor mixtures. In complex mixtures of up to 12 odorants, antagonistic interactions are stronger and more prevalent with increasing mixture complexity. Therefore, antagonism is a common feature of odor mixture encoding in OSNs and helps in normalizing activity to reduce saturation and increase information transfer.
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Affiliation(s)
- Joseph D Zak
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA, 02138, USA.
- Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA.
| | - Gautam Reddy
- NSF-Simons Center for Mathematical & Statistical Analysis of Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Massimo Vergassola
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, F-75005, France
| | - Venkatesh N Murthy
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA, 02138, USA.
- Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA.
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21
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Blazing RM, Franks KM. Odor coding in piriform cortex: mechanistic insights into distributed coding. Curr Opin Neurobiol 2020; 64:96-102. [PMID: 32422571 DOI: 10.1016/j.conb.2020.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 03/01/2020] [Indexed: 10/24/2022]
Abstract
Olfaction facilitates a large variety of animal behaviors such as feeding, mating, and communication. Recent work has begun to reveal the logic of odor transformations that occur throughout the olfactory system to form the odor percept. In this review, we describe the coding principles and mechanisms by which the piriform cortex and other olfactory areas encode three key odor features: odor identity, intensity, and valence. We argue that the piriform cortex produces a multiplexed odor code that allows non-interfering representations of distinct features of the odor stimulus to facilitate odor recognition and learning, which ultimately drives behavior.
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Affiliation(s)
- Robin M Blazing
- Department of Neurobiology, Duke University Medical School, Durham, NC, 27705, United States
| | - Kevin M Franks
- Department of Neurobiology, Duke University Medical School, Durham, NC, 27705, United States.
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22
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Hu XS, Ikegami K, Vihani A, Zhu KW, Zapata M, de March CA, Do M, Vaidya N, Kucera G, Bock C, Jiang Y, Yohda M, Matsunami H. Concentration-Dependent Recruitment of Mammalian Odorant Receptors. eNeuro 2020; 7:ENEURO.0103-19.2019. [PMID: 32015097 PMCID: PMC7189481 DOI: 10.1523/eneuro.0103-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 11/22/2019] [Accepted: 11/26/2019] [Indexed: 12/20/2022] Open
Abstract
A fundamental challenge in studying principles of organization used by the olfactory system to encode odor concentration information has been identifying comprehensive sets of activated odorant receptors (ORs) across a broad concentration range inside freely behaving animals. In mammals, this has recently become feasible with high-throughput sequencing-based methods that identify populations of activated ORs in vivo In this study, we characterized the mouse OR repertoires activated by the two odorants, acetophenone (ACT) and 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), from 0.01% to 100% (v/v) as starting concentrations using phosphorylated ribosomal protein S6 capture followed by RNA-Seq. We found Olfr923 to be one of the most sensitive ORs that is enriched by ACT. Using a mouse line that genetically labels Olfr923-positive axons, we provided evidence that ACT activates the Olfr923 glomeruli in the olfactory bulb. Through molecular dynamics stimulations, we identified amino acid residues in the Olfr923 binding cavity that facilitate ACT binding. This study sheds light on the active process by which unique OR repertoires may collectively facilitate the discrimination of odorant concentrations.
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Affiliation(s)
- Xiaoyang Serene Hu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Kentaro Ikegami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan
| | - Aashutosh Vihani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC 27710
| | - Kevin W Zhu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Marcelo Zapata
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Matthew Do
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Natasha Vaidya
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- North Carolina School of Science and Mathematics, Durham, NC 27705
| | - Gary Kucera
- DCI Rodent Cancer Models Shared Resource, Duke University Medical Center, Durham, NC 27710
| | - Cheryl Bock
- DCI Rodent Cancer Models Shared Resource, Duke University Medical Center, Durham, NC 27710
| | - Yue Jiang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Masafumi Yohda
- Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC 27710
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23
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Snitz K, Perl O, Honigstein D, Secundo L, Ravia A, Yablonka A, Endevelt-Shapira Y, Sobel N. SmellSpace: An Odor-Based Social Network as a Platform for Collecting Olfactory Perceptual Data. Chem Senses 2020; 44:267-278. [PMID: 30873534 PMCID: PMC6462760 DOI: 10.1093/chemse/bjz014] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A common goal in olfaction research is modeling the link between odorant structure and odor perception. Such modeling efforts require large data sets on olfactory perception, yet only a few of these are publicly and freely available. Given that individual odor perception may be informative on personal makeup and interpersonal relationships, we hypothesized that people would gladly provide olfactory perceptual estimates in the context of an odor-based social network. We developed a web-based infrastructure for such a network we called SmellSpace and distributed 10 000 scratch-and-sniff registration booklets each containing a subset of 12 out of 35 microencapsulated odorants. Within ~100 days, we obtained data from ~1000 participants who rated the odorants along 13 verbal descriptors. To verify that these estimates are comparable to lab-collected estimates we tested 26 participants in a controlled lab setting using the same odorants and descriptors. We observed remarkably high overall group correlations between lab and SmellSpace data, implying that this method provides for credible group-representations of odorants. We further estimated the usability of the data by applying to it two previously published models that used odorant structure alone to predict either odorant pleasantness or pairwise odorant perceptual similarity. We observed statistically significant predictions in both cases, thus further implying that the current data may be helpful toward future efforts of modeling olfactory perception from structure. We conclude that an odor-based social network is a potentially useful instrument for collecting extensive data on olfactory perception and here post the complete raw data set from the first ~1000 participants.
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Affiliation(s)
- Kobi Snitz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Ofer Perl
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | | | - Lavi Secundo
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Aharon Ravia
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Adi Yablonka
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | | | - Noam Sobel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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24
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Naudon L, François A, Mariadassou M, Monnoye M, Philippe C, Bruneau A, Dussauze M, Rué O, Rabot S, Meunier N. First step of odorant detection in the olfactory epithelium and olfactory preferences differ according to the microbiota profile in mice. Behav Brain Res 2020; 384:112549. [PMID: 32050097 DOI: 10.1016/j.bbr.2020.112549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/16/2020] [Accepted: 02/08/2020] [Indexed: 02/09/2023]
Abstract
We have previously provided the first evidence that the microbiota modulates the physiology of the olfactory epithelium using germfree mice. The extent to which changes to the olfactory system depend on the microbiota is still unknown. In the present work, we explored if different microbiota would differentially impact olfaction. We therefore studied the olfactory function of three groups of mice of the same genetic background, whose parents had been conventionalized before mating with microbiota from three different mouse strains. Caecal short chain fatty acids profiles and 16S rRNA gene sequencing ascertained that gut microbiota differed between the three groups. We then used a behavioural test to measure the attractiveness of various odorants and observed that the three groups of mice differed in their attraction towards odorants. Their olfactory epithelium properties, including electrophysiological responses recorded by electro-olfactograms and expression of genes related to the olfactory transduction pathway, also showed several differences. Overall, our data demonstrate that differences in gut microbiota profiles are associated with differences in olfactory preferences and in olfactory epithelium functioning.
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Affiliation(s)
- Laurent Naudon
- Université Paris-Saclay, INRAE, AgroParisTech, CNRS, Micalis Institute, 78350, Jouy-en-Josas, France.
| | - Adrien François
- Université Paris-Saclay, UVSQ, INRAE, NBO, 78350, Jouy-en-Josas, F-78350, France
| | | | - Magali Monnoye
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Catherine Philippe
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Aurélia Bruneau
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Marie Dussauze
- Université Paris-Saclay, UVSQ, INRAE, NBO, 78350, Jouy-en-Josas, F-78350, France
| | - Olivier Rué
- Université Paris-Saclay, INRAE, MaIAGE, 78350, Jouy-en-Josas, France
| | - Sylvie Rabot
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Nicolas Meunier
- Université Paris-Saclay, UVSQ, INRAE, NBO, 78350, Jouy-en-Josas, F-78350, France
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25
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Young BD, Escalon JA, Mathew D. Odors: from chemical structures to gaseous plumes. Neurosci Biobehav Rev 2020; 111:19-29. [PMID: 31931034 DOI: 10.1016/j.neubiorev.2020.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 01/07/2020] [Accepted: 01/07/2020] [Indexed: 10/25/2022]
Abstract
We are immersed within an odorous sea of chemical currents that we parse into individual odors with complex structures. Odors have been posited as determined by the structural relation between the molecules that compose the chemical compounds and their interactions with the receptor site. But, naturally occurring smells are parsed from gaseous odor plumes. To give a comprehensive account of the nature of odors the chemosciences must account for these large distributed entities as well. We offer a focused review of what is known about the perception of odor plumes for olfactory navigation and tracking, which we then connect to what is known about the role odorants play as properties of the plume in determining odor identity with respect to odor quality. We end by motivating our central claim that more research needs to be conducted on the role that odorants play within the odor plume in determining odor identity.
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Affiliation(s)
- Benjamin D Young
- Philosophy and Neuroscience, University of Nevada, 1664 N Virginia St, Reno, NV 89557, United States.
| | | | - Dennis Mathew
- Biology and Neuroscience, University of Nevada, Reno, United States.
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26
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Multisensory Enhancement of Odor Object Processing in Primary Olfactory Cortex. Neuroscience 2019; 418:254-265. [DOI: 10.1016/j.neuroscience.2019.08.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 08/22/2019] [Accepted: 08/23/2019] [Indexed: 01/06/2023]
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Fine LG, Riera CE. Sense of Smell as the Central Driver of Pavlovian Appetite Behavior in Mammals. Front Physiol 2019; 10:1151. [PMID: 31620009 PMCID: PMC6759725 DOI: 10.3389/fphys.2019.01151] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 08/26/2019] [Indexed: 01/07/2023] Open
Abstract
The seminal experiments of Ivan Petrovich Pavlov set the stage for an understanding of the physiological concomitants of appetite and feeding behavior. His findings, from careful and creative experimentation, have been uncontested for over a century. One of Pavlov's most fundamental observations was that activation of salivary, gastric and pancreatic secretions during feeding and sham-feeding, precedes entry of food into the mouth, generating signals to the brain from various sensory pathways. Pavlov referred to this as the "psychic" phase of digestion. However, quite surprisingly, he did not attempt to isolate any single sensory system as the main driver of this phenomenon. Herein we revisit Pavlov's findings and hypothesize that the evolutionarily-important sense of smell is the pathway most-likely determinant of feeding behavior in mammals. Substantial understandings of olfactory receptors and their neural pathways in the central nervous system have emerged over the past decade. Neurogenic signals, working in concert with hormonal inputs are described, illustrating the ways in which sense of smell determines food-seeking and food-preference. Additionally, we describe how sense of smell affects metabolic pathways relevant to energy metabolism, hunger and satiety as well as a broad range of human behaviors, thereby reinforcing its central biological role in mammals. Intriguing possibilities for future research, based upon this hypothesis, are raised.
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Affiliation(s)
- Leon G Fine
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Program in the History of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Celine E Riera
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States.,Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
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Abstract
This chapter focuses on the development of the human olfactory system. In this system, function does not require full neuroanatomical maturity. Thus, discrimination of odorous molecules, including a number within the mother's diet, occurs in amniotic fluid after 28-30 weeks of gestation, at which time the olfactory bulbs are identifiable by MRI. Hypoplasia/aplasia of the bulbs is documented in the third trimester and postnatally. Interestingly, olfactory axons project from the nasal epithelium to the telencephalon before formation of the olfactory bulbs and lack a peripheral ganglion, but the synaptic glomeruli of the future olfactory bulb serves this function. Histologic lamination of the olfactory bulb is present by 14 weeks, but maturation remains incomplete at term for neuronal differentiation, synaptogenesis, myelination, and persistence of the normal transitory fetal ventricular recess. Myelination occurs postnatally. Although olfaction is the only sensory system without direct thalamic projections, the olfactory bulb and anterior olfactory nucleus are, in effect, thalamic surrogates. For example, many dendro-dendritic synapses occur within the bulb between GABAergic granular neurons and periglomerular neurons. Moreover, bulbar synaptic glomeruli are analogous to peripheral ganglia of other sensory cranial nerves. The olfactory tract contains much gray as well as white matter. The olfactory epithelium and bulb both incorporate progenitor cells at all ages. Diverse malformations of the olfactory bulb can be detected by clinical examination, imaging, and neuropathology; indeed, olfactory reflexes of the neonate can be reliably tested. We recommend that such testing be routine in the neonatal neurologic examination, especially in children with brain malformations, endocrinopathies, chromosomopathies, genetic/metabolic disorders, and perinatal hypoxic/ischemic encephalopathy.
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Affiliation(s)
- Harvey B Sarnat
- Department of Paediatrics, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada; Department of Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada; Department of Pathology and Laboratory Medicine (Neuropathology), University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada.
| | - Laura Flores-Sarnat
- Department of Paediatrics, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada; Department of Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada
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Block E. Molecular Basis of Mammalian Odor Discrimination: A Status Report. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:13346-13366. [PMID: 30453735 DOI: 10.1021/acs.jafc.8b04471] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Humans have 396 unique, intact olfactory receptors (ORs), G-protein coupled receptors (GPCRs) containing receptor-specific binding sites; other mammals have more. Activation of these transmembrane proteins by an odorant initiates a signaling cascade, evoking an action potential leading to perception of a smell. Because the number of distinguishable odorants vastly exceeds the number of ORs, research has focused on mechanisms of recognition and signaling processes for classes of odorants. In this review, selected recent examples will be presented of "deorphaned" mammalian receptors, where the OR ligands (odorants) as well as key aspects of receptor-odorant interactions were identified using odorant-mediated receptor activation data together with site-directed mutagenesis and molecular modeling. Based on cumulative evidence from OR deorphaning and olfactory receptor neuron activation studies, a receptor-ligand docking model rather than an alternative bond vibration model is suggested to best explain the molecular basis of the exquisitely sensitive odor discrimination in mammals.
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Affiliation(s)
- Eric Block
- Department of Chemistry , University at Albany, SUNY , Albany , New York 12222 , United States
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Abstract
Sampling regulates stimulus intensity and temporal dynamics at the sense organ. Despite variations in sampling behavior, animals must make veridical perceptual judgments about external stimuli. In olfaction, odor sampling varies with respiration, which influences neural responses at the olfactory periphery. Nevertheless, rats were able to perform fine odor intensity judgments despite variations in sniff kinetics. To identify the features of neural activity supporting stable intensity perception, in awake mice we measured responses of mitral/tufted (MT) cells to different odors and concentrations across a range of sniff frequencies. Amplitude and latency of the MT cells' responses vary with sniff duration. A fluid dynamics (FD) model based on odor concentration kinetics in the intranasal cavity can account for this variability. Eliminating sniff waveform dependence of MT cell responses using the FD model allows for significantly better decoding of concentration. This suggests potential schemes for sniff waveform invariant odor concentration coding.
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Sniffing Fast: Paradoxical Effects on Odor Concentration Discrimination at the Levels of Olfactory Bulb Output and Behavior. eNeuro 2018; 5:eN-NWR-0148-18. [PMID: 30596145 PMCID: PMC6306510 DOI: 10.1523/eneuro.0148-18.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 08/07/2018] [Accepted: 08/11/2018] [Indexed: 12/03/2022] Open
Abstract
In awake mice, sniffing behavior is subject to complex contextual modulation. It has been hypothesized that variance in inhalation dynamics alters odor concentration profiles in the naris despite a constant environmental concentration. Using whole-cell recordings in the olfactory bulb of awake mice, we directly demonstrate that rapid sniffing mimics the effect of odor concentration increase at the level of both mitral and tufted cell (MTC) firing rate responses and temporal responses. Paradoxically, we find that mice are capable of discriminating fine concentration differences within short timescales despite highly variable sniffing behavior. One way that the olfactory system could differentiate between a change in sniffing and a change in concentration would be to receive information about the inhalation parameters in parallel with information about the odor. We find that the sniff-driven activity of MTCs without odor input is informative of the kind of inhalation that just occurred, allowing rapid detection of a change in inhalation. Thus, a possible reason for sniff modulation of the early olfactory system may be to directly inform downstream centers of nasal flow dynamics, so that an inference can be made about environmental concentration independent of sniff variance.
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Li H, Panwar B, Omenn GS, Guan Y. Accurate prediction of personalized olfactory perception from large-scale chemoinformatic features. Gigascience 2018; 7:4750780. [PMID: 29267859 PMCID: PMC5824779 DOI: 10.1093/gigascience/gix127] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022] Open
Abstract
Background The olfactory stimulus-percept problem has been studied for more than a century, yet it is still hard to precisely predict the odor given the large-scale chemoinformatic features of an odorant molecule. A major challenge is that the perceived qualities vary greatly among individuals due to different genetic and cultural backgrounds. Moreover, the combinatorial interactions between multiple odorant receptors and diverse molecules significantly complicate the olfaction prediction. Many attempts have been made to establish structure-odor relationships for intensity and pleasantness, but no models are available to predict the personalized multi-odor attributes of molecules. In this study, we describe our winning algorithm for predicting individual and population perceptual responses to various odorants in the DREAM Olfaction Prediction Challenge. Results We find that random forest model consisting of multiple decision trees is well suited to this prediction problem, given the large feature spaces and high variability of perceptual ratings among individuals. Integrating both population and individual perceptions into our model effectively reduces the influence of noise and outliers. By analyzing the importance of each chemical feature, we find that a small set of low- and nondegenerative features is sufficient for accurate prediction. Conclusions Our random forest model successfully predicts personalized odor attributes of structurally diverse molecules. This model together with the top discriminative features has the potential to extend our understanding of olfactory perception mechanisms and provide an alternative for rational odorant design.
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Affiliation(s)
- Hongyang Li
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Bharat Panwar
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Gilbert S Omenn
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA.,Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Yuanfang Guan
- Department of Computational Medicine and Bioinformatics and Departments of Internal Medicine and Human Genetics and School of Public Health, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
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33
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Carr R, Frings S. Neuropeptides in sensory signal processing. Cell Tissue Res 2018; 375:217-225. [PMID: 30377783 DOI: 10.1007/s00441-018-2946-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/09/2018] [Indexed: 12/21/2022]
Abstract
Peptides released from trigeminal fibers fulfill well-understood functions in neuroinflammatory processes and in the modulation of nociceptive signal processing. In particular, calcitonin gene-related peptide (CGRP) and substance P (SP), released from afferent nerve terminals, exert paracrine effects on the surrounding tissue and this has been recently highlighted by the prominent parcrine role of CGRP in the development of headache and migraine. Some recent communications suggest that these sensory neuropeptides may also modulate the workings of sensory organs and influence afferent signals from nose, tongue, eyes and ears. Here, we briefly review the evidence for modulatory effects of CGRP and SP in the sensory periphery.
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Affiliation(s)
- Richard Carr
- Department of Experimental Pain Research, Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Str. 13-17, 68167, Mannheim, Germany.
| | - Stephan Frings
- Department of Animal Physiology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
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34
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Hamakawa M, Okamoto T. The effect of different emotional states on olfactory perception: A preliminary study. FLAVOUR FRAG J 2018. [DOI: 10.1002/ffj.3469] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Masayuki Hamakawa
- Graduate School of Systems Life Sciences; Kyushu University; Fukuoka Japan
- Research Fellow of Japan Society for the Promotion of Science; Tokyo Japan
| | - Tsuyoshi Okamoto
- Graduate School of Systems Life Sciences; Kyushu University; Fukuoka Japan
- Faculty of Arts and Science; Kyushu University; Fukuoka Japan
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35
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Woodward MR, Hafeez MU, Qi Q, Riaz A, Benedict RHB, Yan L, Szigeti K. Odorant Item Specific Olfactory Identification Deficit May Differentiate Alzheimer Disease From Aging. Am J Geriatr Psychiatry 2018; 26:835-846. [PMID: 29858162 PMCID: PMC6086738 DOI: 10.1016/j.jagp.2018.02.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 02/23/2018] [Accepted: 02/25/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVES To explore whether the ability to recognize specific odorant items is differentially affected in aging versus Alzheimer disease (AD); to refine olfactory identification deficit (OID) as a biomarker of prodromal and early AD. DESIGN Prospective multicenter cross-sectional study with a longitudinal arm. SETTING Outpatient memory diagnostic clinics in New York and Texas. PARTICIPANTS Adults aged 65 and older with amnestic mild cognitive impairment (aMCI) and AD and healthy aging (HA) subjects in the comparison group. MEASUREMENTS Participants completed the University of Pennsylvania Smell Identification Test (UPSIT) and neuropsychological testing. AD-associated odorants (AD-10) were selected based on a model of ordinal logistic regression. Age-associated odorants (Age-10) were identified using a linear model. RESULTS For the 841 participants (234 HA, 192 aMCI, 415 AD), AD-10 was superior to Age-10 in separating HA and AD. AD-10 was associated with a more widespread cognitive deficit across multiple domains, in contrast to Age-10. The disease- and age-associated odorants clustered separately in age and AD. AD-10 predicted conversion from aMCI to AD. CONCLUSIONS Nonoverlapping UPSIT items were identified that were individually associated with age and disease. Despite a modest predictive value of the AD-specific items for conversion to AD, the AD-specific items may be useful in enriching samples to better identify those at risk for AD. Further studies are needed with monomolecular and unilateral stimulation and orthogonal biomarker validation to further refine disease- and age-associated signals.
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Affiliation(s)
- Matthew R. Woodward
- Alzheimer’s Disease and Memory Disorder Center, Department of Neurology, University at Buffalo, SUNY, Buffalo, NY
| | - Muhammad Ubaid Hafeez
- Alzheimer’s Disease and Memory Disorder Center, Department of Neurology, University at Buffalo, SUNY, Buffalo, NY
| | - Qianya Qi
- Roswell Park Cancer Institute, University at Buffalo, SUNY, Buffalo, NY
| | - Ahmed Riaz
- Alzheimer’s Disease and Memory Disorder Center, Department of Neurology, University at Buffalo, SUNY, Buffalo, NY
| | - Ralph HB Benedict
- Alzheimer’s Disease and Memory Disorder Center, Department of Neurology, University at Buffalo, SUNY, Buffalo, NY
| | - Li Yan
- Roswell Park Cancer Institute, University at Buffalo, SUNY, Buffalo, NY
| | - Kinga Szigeti
- Alzheimer's Disease and Memory Disorders Center, Department of Neurology, University at Buffalo, SUNY, Buffalo, NY.
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36
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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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37
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Zou LQ, Zhou HY, Zhuang Y, van Hartevelt TJ, Lui SSY, Cheung EFC, Møller A, Kringelbach ML, Chan RCK. Neural responses during the anticipation and receipt of olfactory reward and punishment in human. Neuropsychologia 2018; 111:172-179. [PMID: 29408479 DOI: 10.1016/j.neuropsychologia.2018.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 01/29/2018] [Accepted: 02/02/2018] [Indexed: 02/04/2023]
Abstract
Pleasure experience is an important part of normal healthy life and is essential for general and mental well-being. Many neuroimaging studies have investigated the underlying neural processing of verbal and visual modalities of reward. However, how the brain processes rewards in the olfactory modality is not fully understood. This study aimed to examine the neural basis of olfactory rewards in 25 healthy participants using functional magnetic resonance imaging (fMRI). We developed an Olfactory Incentive Delay (OLID) imaging task distinguishing between the anticipation and receipt of olfactory rewards and punishments. We found that the pallidum was activated during the anticipation of both olfactory rewards and punishments. The bilateral insula was activated independently from the odours' hedonic valence during the receipt phase. In addition, right caudate activation during the anticipation of unpleasant odours was correlated with self-reported anticipatory hedonic traits, whereas bilateral insular activation during the receipt of pleasant odours was correlated with self-reported consummatory hedonic traits. These findings suggest that activity in the insula and the caudate may be biomarkers of anhedonia. These findings also highlight a useful and valid paradigm to study the neural circuitry underlying reward processing in people with anhedonia.
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Affiliation(s)
- Lai-Quan Zou
- Department of Psychology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, Guangdong, China; Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Han-Yu Zhou
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Yuan Zhuang
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China; CAS Key Laboratory of Behavioural Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Tim J van Hartevelt
- University of Oxford, Department of Psychiatry, Warneford Hospital, Oxford, UK; Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Denmark; Aarhus University, Centre for Functionally Integrative Neuroscience (CFIN), Denmark
| | - Simon S Y Lui
- Castle Peak Hospital, Hong Kong Special Administration Region, China; Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Eric F C Cheung
- Castle Peak Hospital, Hong Kong Special Administration Region, China
| | - Arne Møller
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Denmark; Aarhus University, Centre for Functionally Integrative Neuroscience (CFIN), Denmark; Sino-Danish Center, University of Chinese Academy of Sciences, Beijing, China
| | - Morten L Kringelbach
- University of Oxford, Department of Psychiatry, Warneford Hospital, Oxford, UK; Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Denmark
| | - Raymond C K Chan
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China; Sino-Danish Center, University of Chinese Academy of Sciences, Beijing, China.
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38
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Hoffmann-Hensel SM, Sijben R, Rodriguez-Raecke R, Freiherr J. Cognitive Load Alters Neuronal Processing of Food Odors. Chem Senses 2017; 42:723-736. [PMID: 28968851 DOI: 10.1093/chemse/bjx046] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Obesity is a major health concern in modern societies. Although decreased physical activity and enhanced intake of high-caloric foods are important risk factors for developing obesity, human behavior during eating also plays a role. Previous studies have shown that distraction while eating increases food intake and leads to impaired processing of food stimuli. As olfaction is the most important sense involved in flavor perception, we used functional magnetic resonance imaging techniques to investigate the influence of cognitive memory load on olfactory perception and processing. Low- and high-caloric food odors were presented in combination with either low or high cognitive loads utilizing a memory task. The efficacy of the memory task was verified by a decrease in participant recall accuracy and an increase in skin conductance response during high cognitive load. Our behavioral data reveal a diminished perceived intensity for low- but not high-caloric food odors during high cognitive load. For low-caloric food odors, bilateral orbitofrontal (OFC) and piriform cortices (pirC) showed significantly lower activity during high compared with low cognitive load. For high-caloric food odors, a similar effect was established in pirC, but not in OFC. Insula activity correlates with higher intensity ratings found during the low cognitive load condition. We conclude lower activity in pirC and OFC to be responsible for diminished intensity perception, comparable to results in olfactory impaired patients and elderly. Further studies should investigate the influence of olfactory/gustatory intensities on food choices under distraction with special regards to low-caloric food.
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Affiliation(s)
- Sonja Maria Hoffmann-Hensel
- Diagnostic and Interventional Neuroradiology, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Rik Sijben
- Diagnostic and Interventional Neuroradiology, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Rea Rodriguez-Raecke
- Diagnostic and Interventional Neuroradiology, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany.,Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Str. 35, 85354 Freising, Germany
| | - Jessica Freiherr
- Diagnostic and Interventional Neuroradiology, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany.,Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Str. 35, 85354 Freising, Germany
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39
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Krautwurst T, Krautwurst D. “Hidden Scents – The Language of Smell in the Age of Approximation”. Chem Senses 2017. [DOI: 10.1093/chemse/bjx069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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40
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Sarnat HB, Flores-Sarnat L, Wei XC. Olfactory Development, Part 1: Function, From Fetal Perception to Adult Wine-Tasting. J Child Neurol 2017; 32:566-578. [PMID: 28424010 DOI: 10.1177/0883073817690867] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Discrimination of odorous molecules in amniotic fluid occur after 30 weeks' gestation; fetuses exhibit differential responses to maternal diet. Olfactory reflexes enable reliable neonatal testing. Olfactory bulbs can be demonstrated reliably by MRI after 30 weeks' gestation, and their hypoplasia or aplasia also documented by late prenatal and postnatal MRI. Olfactory axons project from nasal epithelium to telencephalon before olfactory bulbs form. Fetal olfactory maturation remains incomplete at term for neuronal differentiation, synaptogenesis, myelination, and persistence of the transitory fetal ventricular recess. Immaturity does not signify nonfunction. Olfaction is the only sensory system without thalamic projection because of its own intrinsic thalamic equivalent. Diverse malformations of the olfactory bulb can be diagnosed by clinical examination, imaging, and neuropathology. Some epileptic auras might be primarily generated in the olfactory bulb. Cranial nerve 1 should be tested in all neonates and especially in patients with brain malformations, endocrinopathies, chromosomopathies, and genetic/metabolic diseases.
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Affiliation(s)
- Harvey B Sarnat
- 1 Department of Paediatrics, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,2 Department of Clinical Neurosciences, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,3 Department of Pathology and Laboratory Medicine (Neuropathology), University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,5 Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Laura Flores-Sarnat
- 1 Department of Paediatrics, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,2 Department of Clinical Neurosciences, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,3 Department of Pathology and Laboratory Medicine (Neuropathology), University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,5 Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Xing-Chang Wei
- 4 Department of Radiology and Diagnostic Imaging, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,5 Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
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41
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Fjaeldstad A, Fernandes HM, Van Hartevelt TJ, Gleesborg C, Møller A, Ovesen T, Kringelbach ML. Brain fingerprints of olfaction: a novel structural method for assessing olfactory cortical networks in health and disease. Sci Rep 2017; 7:42534. [PMID: 28195241 PMCID: PMC5307346 DOI: 10.1038/srep42534] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/10/2017] [Indexed: 11/09/2022] Open
Abstract
Olfactory deficits are a common (often prodromal) symptom of neurodegenerative or psychiatric disorders. As such, olfaction could have great potential as an early biomarker of disease, for example using neuroimaging to investigate the breakdown of structural connectivity profile of the primary olfactory networks. We investigated the suitability for this purpose in two existing neuroimaging maps of olfactory networks. We found problems with both existing neuroimaging maps in terms of their structural connectivity to known secondary olfactory networks. Based on these findings, we were able to merge the existing maps to a new template map of olfactory networks with connections to all key secondary olfactory networks. We introduce a new method that combines diffusion tensor imaging with probabilistic tractography and pattern recognition techniques. This method can obtain comprehensive and reliable fingerprints of the structural connectivity underlying the neural processing of olfactory stimuli in normosmic adults. Combining the novel proposed method for structural fingerprinting with the template map of olfactory networks has great potential to be used for future neuroimaging investigations of olfactory function in disease. With time, the proposed method may even come to serve as structural biomarker for early detection of disease.
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Affiliation(s)
- A. Fjaeldstad
- Flavour Institute, Aarhus University, Aarhus, Denmark
- Department of Psychiatry, University of Oxford, Oxford, UK
- Department of Otorhinolaryngology, Regional Hospital Unit West Jutland, Holstebro, Denmark
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - H. M. Fernandes
- Flavour Institute, Aarhus University, Aarhus, Denmark
- Department of Psychiatry, University of Oxford, Oxford, UK
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Center for Music in the Brain, Aarhus University, Aarhus, Denmark
| | - T. J. Van Hartevelt
- Flavour Institute, Aarhus University, Aarhus, Denmark
- Department of Psychiatry, University of Oxford, Oxford, UK
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Center for Music in the Brain, Aarhus University, Aarhus, Denmark
| | - C. Gleesborg
- Flavour Institute, Aarhus University, Aarhus, Denmark
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - A. Møller
- Flavour Institute, Aarhus University, Aarhus, Denmark
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine & PET-Centre, Aarhus University Hospital, Aarhus, Denmark
| | - T. Ovesen
- Flavour Institute, Aarhus University, Aarhus, Denmark
- Department of Otorhinolaryngology, Regional Hospital Unit West Jutland, Holstebro, Denmark
| | - M. L. Kringelbach
- Flavour Institute, Aarhus University, Aarhus, Denmark
- Department of Psychiatry, University of Oxford, Oxford, UK
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Center for Music in the Brain, Aarhus University, Aarhus, Denmark
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42
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Chelminski Y, Magnan C, Luquet SH, Everard A, Meunier N, Gurden H, Martin C. Odor-Induced Neuronal Rhythms in the Olfactory Bulb Are Profoundly Modified in ob/ob Obese Mice. Front Physiol 2017; 8:2. [PMID: 28154537 PMCID: PMC5244437 DOI: 10.3389/fphys.2017.00002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/03/2017] [Indexed: 01/03/2023] Open
Abstract
Leptin, the product of the Ob(Lep) gene, is a peptide hormone that plays a major role in maintaining the balance between food intake and energy expenditure. In the brain, leptin receptors are expressed by hypothalamic cells but also in the olfactory bulb, the first central structure coding for odors, suggesting a precise function of this hormone in odor-evoked activities. Although olfaction plays a key role in feeding behavior, the ability of the olfactory bulb to integrate the energy-related signal leptin is still missing. Therefore, we studied the fate of odor-induced activity in the olfactory bulb in the genetic context of leptin deficiency using the obese ob/ob mice. By means of an odor discrimination task with concomitant local field potential recordings, we showed that ob/ob mice perform better than wild-type (WT) mice in the early stage of the task. This behavioral gain of function was associated in parallel with profound changes in neuronal oscillations in the olfactory bulb. The distribution of the peaks in the gamma frequency range was shifted toward higher frequencies in ob/ob mice compared to WT mice before learning. More notably, beta oscillatory activity, which has been shown previously to be correlated with olfactory discrimination learning, was longer and stronger in expert ob/ob mice after learning. Since oscillations in the olfactory bulb emerge from mitral to granule cell interactions, our results suggest that cellular dynamics in the olfactory bulb are deeply modified in ob/ob mice in the context of olfactory learning.
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Affiliation(s)
- Yan Chelminski
- UMR 8165 Centre National de la Recherche Scientifique, IMNC, Paris Sud University, Paris Diderot University Orsay, France
| | - Christophe Magnan
- UMR 8251 Centre National de la Recherche Scientifique, BFA, Paris Diderot University, Sorbonne Paris Cité University Paris, France
| | - Serge H Luquet
- UMR 8251 Centre National de la Recherche Scientifique, BFA, Paris Diderot University, Sorbonne Paris Cité University Paris, France
| | - Amandine Everard
- UMR 8251 Centre National de la Recherche Scientifique, BFA, Paris Diderot University, Sorbonne Paris Cité University Paris, France
| | - Nicolas Meunier
- INRA, UR1197 NeuroBiologie de l'OlfactionJouy-en-Josas, France; Université de Versailles St-Quentin en YvelinesVersailles, France
| | - Hirac Gurden
- UMR 8165 Centre National de la Recherche Scientifique, IMNC, Paris Sud University, Paris Diderot UniversityOrsay, France; UMR 8251 Centre National de la Recherche Scientifique, BFA, Paris Diderot University, Sorbonne Paris Cité UniversityParis, France
| | - Claire Martin
- UMR 8165 Centre National de la Recherche Scientifique, IMNC, Paris Sud University, Paris Diderot UniversityOrsay, France; UMR 8251 Centre National de la Recherche Scientifique, BFA, Paris Diderot University, Sorbonne Paris Cité UniversityParis, France
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43
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Cecchetto C, Rumiati RI, Parma V. Relative Contribution of Odour Intensity and Valence to Moral Decisions. Perception 2017; 46:447-474. [PMID: 28084905 DOI: 10.1177/0301006616689279] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Meta-analytic evidence showed that the chemical senses affect moral decisions. However, how odours impact on morality is currently unclear. Through a set of three studies, we assess whether and how odour intensity biases moral choices (Study 1a), its psychophysiological responses (Study 1b), as well as the behavioural and psychophysiological effects of odour valence on moral choices (Study 2). Study 1a suggests that the presence of an odour plays a role in shaping moral choice. Study 1b reveals that of two iso-pleasant versions of the same neutral odour, only the one presented sub-threshold (vs. supra-threshold) favours deontological moral choices, those based on the principle of not harming others even when such harm provides benefits. As expected, this odour intensity effect is tracked by skin conductance responses, whereas no difference in cardiac activity - proxy for the valence dimension - is revealed. Study 2 suggests that the same neutral odour presented sub-threshold increases deontological choices even when compared to iso-intense ambiguous odour, perceived as pleasant or unpleasant by half of the participants, respectively. Skin conductance responses, as expected, track odour pleasantness, but cardiac activity fails to do so. Results are discussed in the context of mechanisms alternative to disgust induction underlying moral choices.
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Affiliation(s)
- Cinzia Cecchetto
- SISSA - International School for Advanced Studies, Trieste, Italy
| | - Raffaella Ida Rumiati
- SISSA - International School for Advanced Studies, Trieste, Italy; ANVUR - Agenzia Nazionale della Valutazione del sistema Universitario e della Ricerca, Roma, Italy
| | - Valentina Parma
- SISSA - International School for Advanced Studies, Trieste, Italy; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Center for Autism Research, Philadelphia, PA, USA
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44
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Son M, Lee JY, Ko HJ, Park TH. Bioelectronic Nose: An Emerging Tool for Odor Standardization. Trends Biotechnol 2017; 35:301-307. [PMID: 28089199 DOI: 10.1016/j.tibtech.2016.12.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 12/08/2016] [Accepted: 12/15/2016] [Indexed: 12/18/2022]
Abstract
Odors are perceived differently as a function of individual human experience, and communicating about odors between individuals is therefore very difficult. There is a need to classify and standardize odors, but appropriate tools have not yet been developed. A bioelectronic nose mimics human olfaction and detects target molecules with high sensitivity and selectivity. This new tool has great potential in many applications and is expected to accelerate odor classification and standardization. In particular, a multiplexed bioelectronic nose can provide complex odor information using pattern recognition techniques, and could even reproduce odors via an integrated olfactory display system. We expect that a bioelectronic nose will be a useful tool for odor standardization by providing codes for odors that enable us to communicate odor information.
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Affiliation(s)
- Manki Son
- Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 151-742, Republic of Korea
| | - Ji Youn Lee
- Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Daejeon 34133, Korea
| | - Hwi Jin Ko
- Bio-MAX Institute, Seoul National University, Seoul 151-818, Korea
| | - Tai Hyun Park
- Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 151-742, Republic of Korea; School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742, Republic of Korea; Advanced Institutes of Convergence Technology, Suwon 443-270, Republic of Korea.
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45
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Olfactory Bulb Deep Short-Axon Cells Mediate Widespread Inhibition of Tufted Cell Apical Dendrites. J Neurosci 2016; 37:1117-1138. [PMID: 28003347 DOI: 10.1523/jneurosci.2880-16.2016] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/14/2016] [Accepted: 12/03/2016] [Indexed: 01/10/2023] Open
Abstract
In the main olfactory bulb (MOB), the first station of sensory processing in the olfactory system, GABAergic interneuron signaling shapes principal neuron activity to regulate olfaction. However, a lack of known selective markers for MOB interneurons has strongly impeded cell-type-selective investigation of interneuron function. Here, we identify the first selective marker of glomerular layer-projecting deep short-axon cells (GL-dSACs) and investigate systematically the structure, abundance, intrinsic physiology, feedforward sensory input, neuromodulation, synaptic output, and functional role of GL-dSACs in the mouse MOB circuit. GL-dSACs are located in the internal plexiform layer, where they integrate centrifugal cholinergic input with highly convergent feedforward sensory input. GL-dSAC axons arborize extensively across the glomerular layer to provide highly divergent yet selective output onto interneurons and principal tufted cells. GL-dSACs are thus capable of shifting the balance of principal tufted versus mitral cell activity across large expanses of the MOB in response to diverse sensory and top-down neuromodulatory input. SIGNIFICANCE STATEMENT The identification of cell-type-selective molecular markers has fostered tremendous insight into how distinct interneurons shape sensory processing and behavior. In the main olfactory bulb (MOB), inhibitory circuits regulate the activity of principal cells precisely to drive olfactory-guided behavior. However, selective markers for MOB interneurons remain largely unknown, limiting mechanistic understanding of olfaction. Here, we identify the first selective marker of a novel population of deep short-axon cell interneurons with superficial axonal projections to the sensory input layer of the MOB. Using this marker, together with immunohistochemistry, acute slice electrophysiology, and optogenetic circuit mapping, we reveal that this novel interneuron population integrates centrifugal cholinergic input with broadly tuned feedforward sensory input to modulate principal cell activity selectively.
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Abstract
The olfactory system removes correlations in natural odors using a network of inhibitory neurons in the olfactory bulb. It has been proposed that this network integrates the response from all olfactory receptors and inhibits them equally. However, how such global inhibition influences the neural representations of odors is unclear. Here, we study a simple statistical model of the processing in the olfactory bulb, which leads to concentration-invariant, sparse representations of the odor composition. We show that the inhibition strength can be tuned to obtain sparse representations that are still useful to discriminate odors that vary in relative concentration, size, and composition. The model reveals two generic consequences of global inhibition: (i) odors with many molecular species are more difficult to discriminate and (ii) receptor arrays with heterogeneous sensitivities perform badly. Comparing these predictions to experiments will help us to understand the role of global inhibition in shaping normalized odor representations in the olfactory bulb.
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Affiliation(s)
- David Zwicker
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States of America
- Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, MA 02138, United States of America
- * E-mail:
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47
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Cyclic-nucleotide-gated cation current and Ca2+-activated Cl current elicited by odorant in vertebrate olfactory receptor neurons. Proc Natl Acad Sci U S A 2016; 113:11078-11087. [PMID: 27647918 DOI: 10.1073/pnas.1613891113] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Olfactory transduction in vertebrate olfactory receptor neurons (ORNs) involves primarily a cAMP-signaling cascade that leads to the opening of cyclic-nucleotide-gated (CNG), nonselective cation channels. The consequent Ca2+ influx triggers adaptation but also signal amplification, the latter by opening a Ca2+-activated Cl channel (ANO2) to elicit, unusually, an inward Cl current. Hence the olfactory response has inward CNG and Cl components that are in rapid succession and not easily separable. We report here success in quantitatively separating these two currents with respect to amplitude and time course over a broad range of odorant strengths. Importantly, we found that the Cl current is the predominant component throughout the olfactory dose-response relation, down to the threshold of signaling to the brain. This observation is very surprising given a recent report by others that the olfactory-signal amplification effected by the Ca2+-activated Cl current does not influence the behavioral olfactory threshold in mice.
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Pietra G, Dibattista M, Menini A, Reisert J, Boccaccio A. The Ca2+-activated Cl- channel TMEM16B regulates action potential firing and axonal targeting in olfactory sensory neurons. J Gen Physiol 2016; 148:293-311. [PMID: 27619419 PMCID: PMC5037344 DOI: 10.1085/jgp.201611622] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/08/2016] [Indexed: 02/05/2023] Open
Abstract
TMEM16B is expressed in olfactory sensory neurons, but previous attempts to establish a physiological role in olfaction have been unsuccessful. Pietra et al. find that genetic ablation of TMEM16B results in defects in the olfactory behavior of mice and the cellular physiology of olfactory sensory neurons. The Ca2+-activated Cl− channel TMEM16B is highly expressed in the cilia of olfactory sensory neurons (OSNs). Although a large portion of the odor-evoked transduction current is carried by Ca2+-activated Cl− channels, their role in olfaction is still controversial. A previous report (Billig et al. 2011. Nat. Neurosci.http://dx.doi.org/10.1038/nn.2821) showed that disruption of the TMEM16b/Ano2 gene in mice abolished Ca2+-activated Cl− currents in OSNs but did not produce any major change in olfactory behavior. Here we readdress the role of TMEM16B in olfaction and show that TMEM16B knockout (KO) mice have behavioral deficits in odor-guided food-finding ability. Moreover, as the role of TMEM16B in action potential (AP) firing has not yet been studied, we use electrophysiological recording methods to measure the firing activity of OSNs. Suction electrode recordings from isolated olfactory neurons and on-cell loose-patch recordings from dendritic knobs of neurons in the olfactory epithelium show that randomly selected neurons from TMEM16B KO mice respond to stimulation with increased firing activity than those from wild-type (WT) mice. Because OSNs express different odorant receptors (ORs), we restrict variability by using a mouse line that expresses a GFP-tagged I7 OR, which is known to be activated by heptanal. In response to heptanal, we measure dramatic changes in the firing pattern of I7-expressing neurons from TMEM16B KO mice compared with WT: responses are prolonged and display a higher number of APs. Moreover, lack of TMEM16B causes a markedly reduced basal spiking activity in I7-expressing neurons, together with an alteration of axonal targeting to the olfactory bulb, leading to the appearance of supernumerary I7 glomeruli. Thus, TMEM16B controls AP firing and ensures correct glomerular targeting of OSNs expressing I7. Altogether, these results show that TMEM16B does have a relevant role in normal olfaction.
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Affiliation(s)
- Gianluca Pietra
- Neurobiology Group, International School for Advanced Studies (SISSA), 34136 Trieste, Italy
| | | | - Anna Menini
- Neurobiology Group, International School for Advanced Studies (SISSA), 34136 Trieste, Italy
| | | | - Anna Boccaccio
- Institute of Biophysics, National Research Council (CNR), 16149 Genova, Italy
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49
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Weiss T, Shushan S, Ravia A, Hahamy A, Secundo L, Weissbrod A, Ben-Yakov A, Holtzman Y, Cohen-Atsmoni S, Roth Y, Sobel N. From Nose to Brain: Un-Sensed Electrical Currents Applied in the Nose Alter Activity in Deep Brain Structures. Cereb Cortex 2016; 26:4180-4191. [PMID: 27591145 PMCID: PMC5066827 DOI: 10.1093/cercor/bhw222] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 05/16/2016] [Accepted: 06/27/2016] [Indexed: 01/02/2023] Open
Abstract
Rules linking patterns of olfactory receptor neuron activation in the nose to activity patterns in the brain and ensuing odor perception remain poorly understood. Artificially stimulating olfactory neurons with electrical currents and measuring ensuing perception may uncover these rules. We therefore inserted an electrode into the nose of 50 human volunteers and applied various currents for about an hour in each case. This induced assorted non-olfactory sensations but never once the perception of odor. To validate contact with the olfactory path, we used functional magnetic resonance imaging to measure resting-state brain activity in 18 subjects before and after un-sensed stimulation. We observed stimulation-induced neural decorrelation specifically in primary olfactory cortex, implying contact with the olfactory path. These results suggest that indiscriminate olfactory activation does not equate with odor perception. Moreover, this effort serendipitously uncovered a novel path for minimally invasive brain stimulation through the nose.
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Affiliation(s)
- Tali Weiss
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Sagit Shushan
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.,Department of Otolaryngology-Head and Neck Surgery, Edith Wolfson Medical Center, Holon 58100, Israel
| | - Aharon Ravia
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Avital Hahamy
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Lavi Secundo
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Aharon Weissbrod
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Aya Ben-Yakov
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yael Holtzman
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Smadar Cohen-Atsmoni
- Department of Otolaryngology-Head and Neck Surgery, Edith Wolfson Medical Center, Holon 58100, Israel
| | - Yehudah Roth
- Department of Otolaryngology-Head and Neck Surgery, Edith Wolfson Medical Center, Holon 58100, Israel
| | - Noam Sobel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
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50
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Keller A, Vosshall LB. Olfactory perception of chemically diverse molecules. BMC Neurosci 2016; 17:55. [PMID: 27502425 PMCID: PMC4977894 DOI: 10.1186/s12868-016-0287-2] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 07/08/2016] [Indexed: 11/10/2022] Open
Abstract
Background Understanding the relationship between a stimulus and how it is perceived reveals fundamental principles about the mechanisms of sensory perception. While this stimulus-percept problem is mostly understood for color vision and tone perception, it is not currently possible to predict how a given molecule smells. While there has been some progress in predicting the pleasantness and intensity of an odorant, perceptual data for a larger number of diverse molecules are needed to improve current predictions. Towards this goal, we tested the olfactory perception of 480 structurally and perceptually diverse molecules at two concentrations using a panel of 55 healthy human subjects. Results For each stimulus, we collected data on perceived intensity, pleasantness, and familiarity. In addition, subjects were asked to apply 20 semantic odor quality descriptors to these stimuli, and were offered the option to describe the smell in their own words. Using this dataset, we replicated several previous correlations between molecular features of the stimulus and olfactory perception. The number of sulfur atoms in a molecule was correlated with the odor quality descriptors “garlic,” “fish,” and “decayed,” and large and structurally complex molecules were perceived to be more pleasant. We discovered a number of correlations in intensity perception between molecules. We show that familiarity had a strong effect on the ability of subjects to describe a smell. Many subjects used commercial products to describe familiar odorants, highlighting the role of prior experience in verbal reports of olfactory perception. Nonspecific descriptors like “chemical” were applied frequently to unfamiliar odorants, and unfamiliar odorants were generally rated as neither pleasant nor unpleasant. Conclusions We present a very large psychophysical dataset and use this to correlate molecular features of a stimulus to olfactory percept. Our work reveals robust correlations between molecular features and perceptual qualities, and highlights the dominant role of familiarity and experience in assigning verbal descriptors to odorants. Electronic supplementary material The online version of this article (doi:10.1186/s12868-016-0287-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andreas Keller
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, 1230 York Avenue, Box 63, New York, NY, 10065, USA
| | - Leslie B Vosshall
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, 1230 York Avenue, Box 63, New York, NY, 10065, USA. .,Howard Hughes Medical Institute, New York, USA. .,Kavli Neural Systems Institute, The Rockefeller University, New York, USA.
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