1
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Joshi S, Haney S, Wang Z, Locatelli F, Smith B, Cao Y, Bazhenov M. Plasticity in inhibitory networks improves pattern separation in early olfactory processing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.24.576675. [PMID: 38328149 PMCID: PMC10849730 DOI: 10.1101/2024.01.24.576675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Distinguishing between nectar and non-nectar odors presents a challenge for animals due to shared compounds in complex mixtures, where changing ratios often signify differences in reward. Changes in nectar production throughout the day and potentially many times within a forager's lifetime add to the complexity. The honeybee olfactory system, containing less than a 1000 of principal neurons in the early olfactory relay, the antennal lobe (AL), must learn to associate diverse volatile blends with rewards. We used a computational network model and live imaging of the honeybee's AL to explore the neural mechanisms and functions of the AL plasticity. Our findings revealed that when trained with a set of rewarded and unrewarded odors, the AL inhibitory network suppresses shared chemical compounds while enhancing responses to distinct compounds. This results in improved pattern separation and a more concise and efficient neural code. Our Ca2+ imaging data support our model's predictions. Furthermore, we applied these contrast enhancement principles to a Graph Convolutional Network (GCN) and found that similar mechanisms could enhance the performance of artificial neural networks. Our model provides insights into how plasticity at the inhibitory network level reshapes coding for efficient learning of complex odors.
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Affiliation(s)
- Shruti Joshi
- Department of Electrical and Computer Engineering, University of California San Diego, USA
- Department of Medicine, University of California San Diego, USA
| | - Seth Haney
- Department of Medicine, University of California San Diego, USA
| | - Zhenyu Wang
- Department of Electrical, Computer and Energy Engineering, Arizona State University, USA
| | - Fernando Locatelli
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET, Buenos Aires, Argentina
| | - Brian Smith
- School of Life Science, Arizona State University, USA
| | - Yu Cao
- Department of Electrical and Computer Engineering, University of Minnesota, USA
| | - Maxim Bazhenov
- Department of Medicine, University of California San Diego, USA
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2
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Latshaw JS, Mazade RE, Petersen M, Mustard JA, Sinakevitch I, Wissler L, Guo X, Cook C, Lei H, Gadau J, Smith B. Tyramine and its Amtyr1 receptor modulate attention in honey bees ( Apis mellifera). eLife 2023; 12:e83348. [PMID: 37814951 PMCID: PMC10564449 DOI: 10.7554/elife.83348] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 08/14/2023] [Indexed: 10/11/2023] Open
Abstract
Animals must learn to ignore stimuli that are irrelevant to survival and attend to ones that enhance survival. When a stimulus regularly fails to be associated with an important consequence, subsequent excitatory learning about that stimulus can be delayed, which is a form of nonassociative conditioning called 'latent inhibition'. Honey bees show latent inhibition toward an odor they have experienced without association with food reinforcement. Moreover, individual honey bees from the same colony differ in the degree to which they show latent inhibition, and these individual differences have a genetic basis. To investigate the mechanisms that underly individual differences in latent inhibition, we selected two honey bee lines for high and low latent inhibition, respectively. We crossed those lines and mapped a Quantitative Trait Locus for latent inhibition to a region of the genome that contains the tyramine receptor gene Amtyr1 [We use Amtyr1 to denote the gene and AmTYR1 the receptor throughout the text.]. We then show that disruption of Amtyr1 signaling either pharmacologically or through RNAi qualitatively changes the expression of latent inhibition but has little or slight effects on appetitive conditioning, and these results suggest that AmTYR1 modulates inhibitory processing in the CNS. Electrophysiological recordings from the brain during pharmacological blockade are consistent with a model that AmTYR1 indirectly regulates at inhibitory synapses in the CNS. Our results therefore identify a distinct Amtyr1-based modulatory pathway for this type of nonassociative learning, and we propose a model for how Amtyr1 acts as a gain control to modulate hebbian plasticity at defined synapses in the CNS. We have shown elsewhere how this modulation also underlies potentially adaptive intracolonial learning differences among individuals that benefit colony survival. Finally, our neural model suggests a mechanism for the broad pleiotropy this gene has on several different behaviors.
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Affiliation(s)
- Joseph S Latshaw
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Reece E Mazade
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Mary Petersen
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Julie A Mustard
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | | | - Lothar Wissler
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Xiaojiao Guo
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Chelsea Cook
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Hong Lei
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Jürgen Gadau
- School of Life Sciences, Arizona State UniversityTempeUnited States
| | - Brian Smith
- School of Life Sciences, Arizona State UniversityTempeUnited States
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3
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Coureaud G, Thomas-Danguin T, Sandoz JC, Wilson DA. Biological constraints on configural odour mixture perception. J Exp Biol 2022; 225:274695. [PMID: 35285471 PMCID: PMC8996812 DOI: 10.1242/jeb.242274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animals, including humans, detect odours and use this information to behave efficiently in the environment. Frequently, odours consist of complex mixtures of odorants rather than single odorants, and mixtures are often perceived as configural wholes, i.e. as odour objects (e.g. food, partners). The biological rules governing this 'configural perception' (as opposed to the elemental perception of mixtures through their components) remain weakly understood. Here, we first review examples of configural mixture processing in diverse species involving species-specific biological signals. Then, we present the original hypothesis that at least certain mixtures can be processed configurally across species. Indeed, experiments conducted in human adults, newborn rabbits and, more recently, in rodents and honeybees show that these species process some mixtures in a remarkably similar fashion. Strikingly, a mixture AB (A, ethyl isobutyrate; B, ethyl maltol) induces configural processing in humans, who perceive a mixture odour quality (pineapple) distinct from the component qualities (A, strawberry; B, caramel). The same mixture is weakly configurally processed in rabbit neonates, which perceive a particular odour for the mixture in addition to the component odours. Mice and honeybees also perceive the AB mixture configurally, as they respond differently to the mixture compared with its components. Based on these results and others, including neurophysiological approaches, we propose that certain mixtures are convergently perceived across various species of vertebrates/invertebrates, possibly as a result of a similar anatomical organization of their olfactory systems and the common necessity to simplify the environment's chemical complexity in order to display adaptive behaviours.
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Affiliation(s)
- Gérard Coureaud
- Centre de Recherche en Neurosciences de Lyon, Team Sensory Neuroethology (ENES), CNRS/INSERM/UCBL1/UJM, 69500 Lyon, France
| | - Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, Team Flavor, Food Oral Processing and Perception, INRAE, CNRS, Institut Agro Dijon, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, CNRS, Université Paris-Saclay, IRD, 91190 Gif-sur-Yvette, France
| | - Donald A Wilson
- Department of Child & Adolescent Psychiatry, New York University Langone School of Medicine and Nathan S. Kline Institute for Psychiatric Research, New York, NY 10016, USA
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4
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Raka RN, Wu H, Xiao J, Hossen I, Cao Y, Huang M, Jin J. Human ectopic olfactory receptors and their food originated ligands: a review. Crit Rev Food Sci Nutr 2021; 62:5424-5443. [PMID: 33605814 DOI: 10.1080/10408398.2021.1885007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Ectopic olfactory receptors (EORs) are expressed in non-nasal tissues of human body. They belong to the G-protein coupled receptor (GPCR) superfamily. EORs may not be capable of differentiating odorants as nasal olfactory receptors (ORs), but still can be triggered by odorants and are involved in different biological processes such as anti-inflammation, energy metabolism, apoptosis etc. Consumption of strong flavored foods like celery, oranges, onions, and spices, is a good aid to attenuate inflammation and boost our immune system. During the digestion of these foods in human digestive system and the metabolization by gut microbiota, the odorants closely interacting with EORs, may play important roles in various bio-functions like serotonin release, appetite regulation etc., and ultimately impact health and diseases. Thus, EORs could be a potential target linking the ligands from food and their bioactivities. There have been related studies in different research fields of medicine and physiology, but still no systematic food oriented review. Our review portrays that EORs could be a potential target for functional food development. In this review, we summarized the EORs found in human tissues, their impacts on health and disease, ligands interacting with EORs exerting specific biological effects, and the mechanisms involved.
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Affiliation(s)
- Rifat Nowshin Raka
- Beijing Technology and Business University, Beijing, China.,Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing, China.,Beijing Laboratory for Food Quality and Safety, Beijing, China.,Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing, China
| | - Hua Wu
- Beijing Technology and Business University, Beijing, China.,Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing, China.,Beijing Key Lab of Plant Resource Research and Development, Beijing, China
| | - Junsong Xiao
- Beijing Technology and Business University, Beijing, China.,Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing, China.,Beijing Laboratory for Food Quality and Safety, Beijing, China.,Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing, China
| | - Imam Hossen
- Beijing Technology and Business University, Beijing, China.,Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing, China.,Beijing Laboratory for Food Quality and Safety, Beijing, China.,Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing, China
| | - Yanping Cao
- Beijing Technology and Business University, Beijing, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing, China
| | - Mingquan Huang
- Beijing Technology and Business University, Beijing, China.,Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing, China
| | - Jianming Jin
- Beijing Technology and Business University, Beijing, China.,Beijing Key Lab of Plant Resource Research and Development, Beijing, China
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5
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Aguiar JMRBV, Ferreira GDS, Sanches PA, Bento JMS, Sazima M. What pollinators see does not match what they smell: Absence of color-fragrance association in the deceptive orchid Ionopsis utricularioides. PHYTOCHEMISTRY 2021; 182:112591. [PMID: 33333335 DOI: 10.1016/j.phytochem.2020.112591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/13/2020] [Accepted: 11/14/2020] [Indexed: 06/12/2023]
Abstract
Many deceptive orchids present variation in floral color and fragrance. This might be advantageous for the plant, as it can disturb the associative avoidance learning of pollinators, promoting more visits to the flowers. Some studies have shown that color and fragrance can be correlated in polymorphic deceptive orchids, but these studies employed color traits based on the human visual system and not the visual perception of pollinators. Thus, we investigated the composition of the floral fragrance of Ionopsis utricularioides (Sw.) Lindl., a polymorphic deceptive orchid, and analyzed possible correlations with the floral color as seen by bees, Apis mellifera L. and Melipona quadrifasciata Lepeletier, using the color hexagon model. We found high color and fragrance intraspecific variation, as expected for deceptive species. However, we found no color-fragrance association in individuals, either by comparing fragrance profiles with the color variable saturation or by comparing them with the placement of individuals in the color hexagon for both bee species. This lack of correlation contradicts the biochemical pathway hypothesis, which proposes that associations between floral color and scent in polymorphic flowers arise from shared biochemical pathways. However, a complete absence of correlation between floral signals is consistent with selection arising through pollinator cognitive ecology. Lack of correlation would increase the floral variability perceived by bees, given their multimodal learning, and this variability could disrupt avoidance learning of deceptive flowers, thus enhancing the efficacy of the plant's deceptive pollination mechanism.
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Affiliation(s)
| | - Gabriel de Souza Ferreira
- Senckenberg Centre for Human Evolution and Palaeoenvironment (HEP) at the Eberhard Karls Universität Tübingen, Sigwartstr. 10, 72076, Tübingen, Germany
| | - Patricia Alessandra Sanches
- Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Departamento de Entomologia e Acarologia, Piracicaba, SP, 13418-900, Brazil; Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092, Zürich, Switzerland
| | - José Mauricio Simões Bento
- Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Departamento de Entomologia e Acarologia, Piracicaba, SP, 13418-900, Brazil
| | - Marlies Sazima
- Departamento de Botânica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, 13083-865, Brazil
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6
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Marachlian E, Klappenbach M, Locatelli F. Learning-dependent plasticity in the antennal lobe improves discrimination and recognition of odors in the honeybee. Cell Tissue Res 2021; 383:165-175. [PMID: 33511470 DOI: 10.1007/s00441-020-03396-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/11/2020] [Indexed: 12/22/2022]
Abstract
Honeybees are extensively used to study olfactory learning and memory processes thanks to their ability to discriminate and remember odors and because of their advantages for optophysiological recordings of the circuits involved in memory and odor perception. There are evidences that the encoding of odors in areas of primary sensory processing is not rigid, but undergoes changes caused by olfactory experience. The biological meaning of these changes is focus of intense discussions. Along this review, we present evidences of plasticity related to different forms of learning and discuss its function in the context of olfactory challenges that honeybees have to solve. So far, results in honeybees are consistent with a model in which changes in early olfactory processing contributes to the ability of an animal to recognize the presence of relevant odors and facilitates the discrimination of odors in a way adjusted to its own experience.
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Affiliation(s)
- Emiliano Marachlian
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Université Paris, Paris, France
| | - Martin Klappenbach
- Departamento de Fisiología, Biología Molecular y Celular e Instituto de Fisiología, Facultad de Ciencias Exactas y Naturales, Biología Molecular y Neurociencias, Universidad de Buenos Aires, C1428EHA, Buenos Aires, Argentina
| | - Fernando Locatelli
- Departamento de Fisiología, Biología Molecular y Celular e Instituto de Fisiología, Facultad de Ciencias Exactas y Naturales, Biología Molecular y Neurociencias, Universidad de Buenos Aires, C1428EHA, Buenos Aires, Argentina.
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7
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Abstract
With less than a million neurons, the western honeybee Apis mellifera is capable of complex olfactory behaviors and provides an ideal model for investigating the neurophysiology of the olfactory circuit and the basis of olfactory perception and learning. Here, we review the most fundamental aspects of honeybee's olfaction: first, we discuss which odorants dominate its environment, and how bees use them to communicate and regulate colony homeostasis; then, we describe the neuroanatomy and the neurophysiology of the olfactory circuit; finally, we explore the cellular and molecular mechanisms leading to olfactory memory formation. The vastity of histological, neurophysiological, and behavioral data collected during the last century, together with new technological advancements, including genetic tools, confirm the honeybee as an attractive research model for understanding olfactory coding and learning.
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Affiliation(s)
- Marco Paoli
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 31062, Toulouse, France.
| | - Giovanni C Galizia
- Department of Neuroscience, University of Konstanz, 78457, Konstanz, Germany.
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8
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Wycke MA, Coureaud G, Thomas-Danguin T, Sandoz JC. Configural perception of a binary olfactory mixture in honey bees, as in humans, rodents and newborn rabbits. J Exp Biol 2020; 223:jeb227611. [PMID: 33046568 DOI: 10.1242/jeb.227611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/06/2020] [Indexed: 11/20/2022]
Abstract
How animals perceive and learn complex stimuli, such as mixtures of odorants, is a difficult problem, for which the definition of general rules across the animal kingdom remains elusive. Recent experiments conducted in human and rodent adults as well as newborn rabbits suggested that these species process particular odor mixtures in a similar, configural manner. Thus, the binary mixture of ethyl isobutyrate (EI) and ethyl maltol (EM) induces configural processing in humans, who perceive a mixture odor quality (pineapple) that is distinct from the quality of each component (strawberry and caramel). Similarly, rabbit neonates treat the mixture differently, at least in part, from its components. In the present study, we asked whether the properties of the EI.EM mixture extend to an influential invertebrate model, the honey bee Apis mellifera. We used appetitive conditioning of the proboscis extension response to evaluate how bees perceive the EI.EM mixture. In a first experiment, we measured perceptual similarity between this mixture and its components in a generalization protocol. In a second experiment, we measured the ability of bees to differentiate between the mixture and both of its components in a negative patterning protocol. In each experimental series, the performance of bees with this mixture was compared with that obtained with four other mixtures, chosen from previous work in humans, newborn rabbits and bees. Our results suggest that when having to differentiate mixture and components, bees treat the EI.EM in a robust configural manner, similarly to mammals, suggesting the existence of common perceptual rules across the animal kindgdom.
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Affiliation(s)
- Marie-Anne Wycke
- Evolution, Genomes, Behavior and Ecology, CNRS, Université Paris-Saclay, IRD, 91190 Gif-sur-Yvette, France
| | - Gérard Coureaud
- Centre de Recherche en Neurosciences de Lyon, Equipe Codage et Mémoire Olfactive, CNRS/INSERM/UCBL1, 69500 Bron, France
| | - Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, CNRS, Université Paris-Saclay, IRD, 91190 Gif-sur-Yvette, France
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9
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Cleland TA, Borthakur A. A Systematic Framework for Olfactory Bulb Signal Transformations. Front Comput Neurosci 2020; 14:579143. [PMID: 33071767 PMCID: PMC7538604 DOI: 10.3389/fncom.2020.579143] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/17/2020] [Indexed: 11/13/2022] Open
Abstract
We describe an integrated theory of olfactory systems operation that incorporates experimental findings across scales, stages, and methods of analysis into a common framework. In particular, we consider the multiple stages of olfactory signal processing as a collective system, in which each stage samples selectively from its antecedents. We propose that, following the signal conditioning operations of the nasal epithelium and glomerular-layer circuitry, the plastic external plexiform layer of the olfactory bulb effects a process of category learning-the basis for extracting meaningful, quasi-discrete odor representations from the metric space of undifferentiated olfactory quality. Moreover, this early categorization process also resolves the foundational problem of how odors of interest can be recognized in the presence of strong competitive interference from simultaneously encountered background odorants. This problem is fundamentally constraining on early-stage olfactory encoding strategies and must be resolved if these strategies and their underlying mechanisms are to be understood. Multiscale general theories of olfactory systems operation are essential in order to leverage the analytical advantages of engineered approaches together with our expanding capacity to interrogate biological systems.
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Affiliation(s)
- Thomas A. Cleland
- Computational Physiology Laboratory, Department of Psychology, Cornell University, Ithaca, NY, United States
| | - Ayon Borthakur
- Computational Physiology Laboratory, Field of Computational Biology, Cornell University, Ithaca, NY, United States
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10
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Sprayberry JDH. Compounds without borders: A mechanism for quantifying complex odors and responses to scent-pollution in bumblebees. PLoS Comput Biol 2020; 16:e1007765. [PMID: 32320390 PMCID: PMC7197864 DOI: 10.1371/journal.pcbi.1007765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 05/04/2020] [Accepted: 03/02/2020] [Indexed: 11/21/2022] Open
Abstract
Bumblebees are critical pollinators whose populations have been experiencing troubling declines over the past several decades. Successful foraging improves colony fitness, thus understanding how anthropogenic influences modulate foraging behavior may aid conservation efforts. Odor pollution can have negative impacts on bumble- and honey-bees foraging behavior. However, given the vast array of potential scent contaminants, individually testing pollutants is an ineffective approach. The ability to quantitatively measure how much scent-pollution of a floral-odor bumblebees can tolerate would represent a paradigm shift in odor-pollution studies. Current statistical methods for analyzing complex odors have poor predictive power because statistically-derived odor-spaces are rewritten when new odors are added. This study presents an alternative method of analyzing complex odor blends based on the encoding properties of insect olfactory systems. This “Compounds Without Borders” (CWB) method vectorizes odors in a multidimensional space representing relevant functional group and carbon characteristics of their component odorants. A single vector can be built for any scent, which allows the angular distance between any two odors to be calculated–including a learned odor and its polluted counterpart. Data presented here indicate that CWB-angles are capable of both describing and predicting bumblebee odor-discrimination behavior: odor pairs with angular distances in the 20–29° range appear to be generalized, while odor pairs over 30 degrees are differentiated. The neurophysiological properties underlying CWB-vectorization of odors are not unique to bumblebees; CWB-angle analysis of a small sample of published odor-data supports the idea that this method may have broader applications.
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Affiliation(s)
- Jordanna D H Sprayberry
- Departments of Biology & Neuroscience, Muhlenberg College, Allentown, Pennsylvania, United States of America
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11
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Smith BH, Cook CN. Experimental psychology meets behavioral ecology: what laboratory studies of learning polymorphisms mean for learning under natural conditions, and vice versa. J Neurogenet 2020; 34:178-183. [PMID: 32024408 DOI: 10.1080/01677063.2020.1718674] [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] [Indexed: 02/07/2023]
Abstract
Behavior genetics, and specifically the study of learning and memory, has benefitted immensely from the development of powerful forward- and reverse-genetic methods for investigating the relationships between genes and behavior. Application of these methods in controlled laboratory settings has led to insights into gene-behavior relationships. In this perspective article, we argue that the field is now poised to make significant inroads into understanding the adaptive value of heritable variation in behavior in natural populations. Studies of natural variation with several species, in particular, are now in a position to complement laboratory studies of mechanisms, and sometimes this work can lead to counterintuitive insights into the mechanism of gene action on behavior. We make this case using a recent example from work with the honey bee, Apis mellifera.
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Affiliation(s)
- Brian H Smith
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Chelsea N Cook
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
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12
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Jernigan CM, Halby R, Gerkin RC, Sinakevitch I, Locatelli F, Smith BH. Experience-dependent tuning of early olfactory processing in the adult honey bee, Apis mellifera. ACTA ACUST UNITED AC 2020; 223:jeb.206748. [PMID: 31767739 DOI: 10.1242/jeb.206748] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 11/19/2019] [Indexed: 11/20/2022]
Abstract
Experience-dependent plasticity in the central nervous system allows an animal to adapt its responses to stimuli over different time scales. In this study, we explored the impacts of adult foraging experience on early olfactory processing by comparing naturally foraging honey bees, Apis mellifera, with those that experienced a chronic reduction in adult foraging experience. We placed age-matched sets of sister honey bees into two different olfactory conditions, in which animals were allowed to forage ad libitum In one condition, we restricted foraging experience by placing honey bees in a tent in which both sucrose and pollen resources were associated with a single odor. In the second condition, honey bees were allowed to forage freely and therefore encounter a diversity of naturally occurring resource-associated olfactory experiences. We found that honey bees with restricted foraging experiences had altered antennal lobe development. We measured the glomerular responses to odors using calcium imaging in the antennal lobe, and found that natural olfactory experience also enhanced the inter-individual variation in glomerular response profiles to odors. Additionally, we found that honey bees with adult restricted foraging experience did not distinguish relevant components of an odor mixture in a behavioral assay as did their freely foraging siblings. This study highlights the impacts of individual experience on early olfactory processing at multiple levels.
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Affiliation(s)
| | - Rachael Halby
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Richard C Gerkin
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Irina Sinakevitch
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Fernando Locatelli
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET) and Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA Buenos Aires, Argentina
| | - Brian H Smith
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
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13
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Chan HK, Hersperger F, Marachlian E, Smith BH, Locatelli F, Szyszka P, Nowotny T. Odorant mixtures elicit less variable and faster responses than pure odorants. PLoS Comput Biol 2018; 14:e1006536. [PMID: 30532147 PMCID: PMC6287832 DOI: 10.1371/journal.pcbi.1006536] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/29/2018] [Indexed: 11/18/2022] Open
Abstract
In natural environments, odors are typically mixtures of several different chemical compounds. However, the implications of mixtures for odor processing have not been fully investigated. We have extended a standard olfactory receptor model to mixtures and found through its mathematical analysis that odorant-evoked activity patterns are more stable across concentrations and first-spike latencies of receptor neurons are shorter for mixtures than for pure odorants. Shorter first-spike latencies arise from the nonlinear dependence of binding rate on odorant concentration, commonly described by the Hill coefficient, while the more stable activity patterns result from the competition between different ligands for receptor sites. These results are consistent with observations from numerical simulations and physiological recordings in the olfactory system of insects. Our results suggest that mixtures allow faster and more reliable olfactory coding, which could be one of the reasons why animals often use mixtures in chemical signaling.
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Affiliation(s)
- Ho Ka Chan
- Sussex Neuroscience, School of Engineering and Informatics, University of Sussex, Falmer, Brighton, United Kingdom
| | - Fabian Hersperger
- Department of Neuroscience, University of Konstanz, Konstanz, Germany
| | - Emiliano Marachlian
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET) and Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Brian H. Smith
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Fernando Locatelli
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-UBA-CONICET) and Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Paul Szyszka
- Department of Neuroscience, University of Konstanz, Konstanz, Germany
| | - Thomas Nowotny
- Sussex Neuroscience, School of Engineering and Informatics, University of Sussex, Falmer, Brighton, United Kingdom
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Aguiar JMRBV, Roselino AC, Sazima M, Giurfa M. Can honey bees discriminate between floral-fragrance isomers? J Exp Biol 2018; 221:jeb.180844. [DOI: 10.1242/jeb.180844] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/18/2018] [Indexed: 11/20/2022]
Abstract
Many flowering plants present variable complex fragrances, which usually include different isomers of the same molecule. As fragrance is an essential cue for flower recognition by pollinators, we ask if honey bees discriminate between floral-fragrance isomers in an appetitive context. We used the olfactory conditioning of the proboscis extension response (PER), which allows training a restrained bee to an odor paired with sucrose solution. Bees were trained under an absolute (a single odorant rewarded) or a differential conditioning regime (a rewarded vs. a non-rewarded odorant) using four different pairs of isomers. One hour after training, discrimination and generalization between pairs of isomers were tested. Bees trained under absolute conditioning exhibited high generalization between isomers and discriminated only one out of four isomer pairs; after differential conditioning, they learned to differentiate between two out of four pairs of isomers but in all cases generalization responses to the non-rewarding isomer remained high. Adding an aversive taste to the non-rewarded isomer facilitated discrimination of isomers that otherwise seemed non-discriminable, but generalization remained high. Although honey bees discriminated isomers under certain conditions, they achieved the task with difficulty and tended to generalize between them, thus showing that these molecules were perceptually similar to them. We conclude that the presence of isomers within floral fragrances might not necessarily contribute to a dramatic extent to floral odor diversity.
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Affiliation(s)
- João Marcelo Robazzi Bignelli Valente Aguiar
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, France
- Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Ana Carolina Roselino
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Marlies Sazima
- Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Martin Giurfa
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, France
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Münch D, Galizia CG. Take time: odor coding capacity across sensory neurons increases over time in Drosophila. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:959-972. [PMID: 28852844 PMCID: PMC5696509 DOI: 10.1007/s00359-017-1209-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 08/11/2017] [Accepted: 08/14/2017] [Indexed: 11/25/2022]
Abstract
Due to the highly efficient olfactory code, olfactory sensory systems are able to reliably encode enormous numbers of olfactory stimuli. The olfactory code consists of combinatorial activation patterns across sensory neurons, thus its capacity exceeds the number of involved classes of sensory neurons by a manifold. Activation patterns are not static but vary over time, caused by the temporally complex response dynamics of the individual sensory neuron responses. We systematically analyzed the temporal dynamics of olfactory sensory neuron responses to a diverse set of odorants. We find that response dynamics depend on the combination of sensory neuron and odorant and that information about odorant identity can be extracted from the time course of the response. We also show that new response dynamics can arise when mixing two odorants. Our data show that temporal dynamics of odorant responses are able to significantly enhance the coding capacity of olfactory sensory systems.
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Affiliation(s)
- Daniel Münch
- Neurobiology, University of Konstanz, 78457, Konstanz, Germany. .,Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Av. Brasília, 1400-038, Lisbon, Portugal.
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