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Abstract
Simple innate behavior is often described as hard-wired and largely inflexible. Here, we show that the avoidance of hot temperature, a simple innate behavior, contains unexpected plasticity in Drosophila. First, we demonstrate that hot receptor neurons of the antenna and their molecular heat sensor, Gr28B.d, are essential for flies to produce escape turns away from heat. High-resolution fly tracking combined with a 3D simulation of the thermal environment shows that, in steep thermal gradients, the direction of escape turns is determined by minute temperature differences between the antennae (0.1°-1 °C). In parallel, live calcium imaging confirms that such small stimuli reliably activate both peripheral thermosensory neurons and central circuits. Next, based on our measurements, we evolve a fly/vehicle model with two symmetrical sensors and motors (a "Braitenberg vehicle") which closely approximates basic fly thermotaxis. Critical differences between real flies and the hard-wired vehicle reveal that fly heat avoidance involves decision-making, relies on rapid learning, and is robust to new conditions, features generally associated with more complex behavior.
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52
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Abstract
Flying insects track turbulent odor plumes to find mates, food and egg-laying sites. To maintain contact with the plume, insects are thought to adapt their flight control according to the distribution of odor in the plume using the timing of odor onsets and intervals between odor encounters. Although timing cues are important, few studies have addressed whether insects are capable of deriving spatial information about odor distribution from bilateral comparisons between their antennae in flight. The proboscis extension reflex (PER) associative learning protocol, originally developed to study odor learning in honeybees, was used as a tool to ask if hawkmoths, Manduca sexta, can discriminate between odor stimuli arriving on either antenna. We show moths discriminated the odor arrival side with an accuracy of >70%. Information about spatial distribution of odor stimuli may be available to moths searching for odor sources, opening the possibility that they use both spatial and temporal odor information.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | - M A Willis
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106-7080, U.S.A
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53
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Jain K, Lavista-Llanos S, Grabe V, Hansson BS, Wicher D. Calmodulin regulates the olfactory performance in Drosophila melanogaster. Sci Rep 2021; 11:3747. [PMID: 33580172 PMCID: PMC7881240 DOI: 10.1038/s41598-021-83296-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 02/01/2021] [Indexed: 12/01/2022] Open
Abstract
Insect odorant receptors (ORs) detect volatile chemical cues with high sensitivity. These ORs operate as ligand-gated ion channels and are formed by heptahelical OrX and Orco (co-receptor) proteins. A highly conserved calmodulin (CaM) binding site (CBS) 336SAIKYWVER344 within the second intracellular loop of Drosophila melanogaster Orco constitutes a target for regulating OR performance. Here we asked how a point mutation K339N in this CBS affects the olfactory performance of Drosophila melanogaster. We first asked how this mutation would affect the odor responses of olfactory sensory neurons (OSNs). Using Ca2+ imaging in an ex-vivo antenna preparation, we activated all OR (OrX/Orco) expressing neurons using the synthetic agonist VUAA1. In a next attempt, we restricted the OR spectrum to Or22a expressing neurons (Or22a/Orco) and stimulated these OSNs with the ligand ethyl hexanoate. In both approaches, we found that flies carrying the K339N point mutation in Orco display a reduced olfactory response. We also found that the mutation abolishes the capability of OSNs to sensitize by repeated weak odor stimuli. Next, we asked whether OrcoK339N might affect the odor localization performance. Using a wind tunnel bioassay, we found that odor localization in flies carrying the OrcoK339N mutation was severely diminished.
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Affiliation(s)
- Kalpana Jain
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Sofia Lavista-Llanos
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Veit Grabe
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany
| | - Dieter Wicher
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745, Jena, Germany.
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54
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Flanigan KAS, Wiegmann DD, Hebets EA, Bingman VP. Multisensory integration supports configural learning of a home refuge in the whip spider Phrynus marginemaculatus. J Exp Biol 2021; 224:jeb.238444. [PMID: 33436366 DOI: 10.1242/jeb.238444] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/04/2021] [Indexed: 12/31/2022]
Abstract
Whip spiders (Amblypygi) reside in structurally complex habitats and are nocturnally active yet display notable navigational abilities. From the theory that uncertainty in sensory inputs should promote multisensory representations to guide behavior, we hypothesized that their navigation is supported by a multisensory and perhaps configural representation of navigational inputs, an ability documented in a few insects and never reported in arachnids. We trained Phrynus marginemaculatus to recognize a home shelter characterized by both discriminative olfactory and tactile stimuli. In tests, subjects readily discriminated between shelters based on the paired stimuli. However, subjects failed to recognize the shelter in tests with either of the component stimuli alone. This result is consistent with the hypothesis that the terminal phase of their navigational behavior, shelter recognition, can be supported by the integration of multisensory stimuli as an enduring, configural representation. We hypothesize that multisensory learning occurs in the whip spiders' extraordinarily large mushroom bodies, which may functionally resemble the hippocampus of vertebrates.
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Affiliation(s)
- Kaylyn A S Flanigan
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0001, USA.,J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, OH 43403-0001, USA
| | - Daniel D Wiegmann
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0001, USA.,J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, OH 43403-0001, USA
| | - Eileen A Hebets
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118, USA
| | - Verner P Bingman
- J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, OH 43403-0001, USA .,Department of Psychology, Bowling Green State University, Bowling Green, OH 43403-0001, USA
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55
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Hernandez-Reyes CA, Fukushima S, Shigaki S, Kurabayashi D, Sakurai T, Kanzaki R, Sezutsu H. Identification of Exploration and Exploitation Balance in the Silkmoth Olfactory Search Behavior by Information-Theoretic Modeling. Front Comput Neurosci 2021; 15:629380. [PMID: 33597856 PMCID: PMC7882484 DOI: 10.3389/fncom.2021.629380] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 01/08/2020] [Indexed: 11/13/2022] Open
Abstract
Insects search for and find odor sources as their basic behaviors, such as when looking for food or a mate. This has motivated research to describe how they achieve such behavior under turbulent odor plumes with a small number of neurons. Among different insects, the silk moth has been studied owing to its clear motor response to olfactory input. In past studies, the "programmed behavior" of the silk moth has been modeled as the average duration of a sequence of maneuvers based on the duration of periods without odor hits. However, this model does not fully represent the fine variations in their behavior. In this study, we used silk moth olfactory search trajectories from an experimental virtual reality device. We achieved an accurate input by using optogenetic silk moths that react to blue light. We then modeled such trajectories as a probabilistic learning agent with a belief of possible source locations. We found that maneuvers mismatching the programmed behavior are related to larger entropy decrease, that is, they are more likely to increase the certainty of the belief. This implies that silkmoths include some stochasticity in their search policy to balance the exploration and exploitation of olfactory information by matching or mismatching the programmed behavior model. We believe that this information-theoretic representation of insect behavior is important for the future implementation of olfactory searches in artificial agents such as robots.
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Affiliation(s)
| | - Shumpei Fukushima
- Department of Systems and Control Engineering, Tokyo Institute of Technology, Tokyo, Japan.,MHPS Ltd., Takasago, Japan
| | - Shunsuke Shigaki
- Department of Systems Innovation, Osaka University, Osaka, Japan
| | - Daisuke Kurabayashi
- Department of Systems and Control Engineering, Tokyo Institute of Technology, Tokyo, Japan
| | - Takeshi Sakurai
- Department of Agricultural Innovation for Sustainability, Tokyo University of Agriculture, Atsugi, Japan
| | - Ryohei Kanzaki
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Hideki Sezutsu
- Transgenic Silkworm Research Unit, National Agriculture and Food Research Organization, Tsukuba, Japan
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56
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Cardé RT. Navigation Along Windborne Plumes of Pheromone and Resource-Linked Odors. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:317-336. [PMID: 32926790 DOI: 10.1146/annurev-ento-011019-024932] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Many insects locate resources such as a mate, a host, or food by flying upwind along the odor plumes that these resources emit to their source. A windborne plume has a turbulent structure comprised of odor filaments interspersed with clean air. As it propagates downwind, the plume becomes more dispersed and dilute, but filaments with concentrations above the threshold required to elicit a behavioral response from receiving organisms can persist for long distances. Flying insects orient along plumes by steering upwind, triggered by the optomotor reaction. Sequential measurements of differences in odor concentration are unreliable indicators of distance to or direction of the odor source. Plume intermittency and the plume's fine-scale structure can play a role in setting an insect's upwind course. The prowess of insects in navigating to odor sources has spawned bioinspired virtual models and even odor-seeking robots, although some of these approaches use mechanisms that are unnecessarily complex and probably exceed an insect's processing capabilities.
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Affiliation(s)
- Ring T Cardé
- Department of Entomology, University of California, Riverside, California 92521, USA;
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57
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Abstract
The olfactory system translates chemical signals into neuronal signals that inform behavioral decisions of the animal. Odors are cues for source identity, but if monitored long enough, they can also be used to localize the source. Odor representations should therefore be robust to changing conditions and flexible in order to drive an appropriate behavior. In this review, we aim at discussing the main computations that allow robust and flexible encoding of odor information in the olfactory neural pathway.
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58
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Currier TA, Matheson AMM, Nagel KI. Encoding and control of orientation to airflow by a set of Drosophila fan-shaped body neurons. eLife 2020; 9:e61510. [PMID: 33377868 PMCID: PMC7793622 DOI: 10.7554/elife.61510] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/29/2020] [Indexed: 12/25/2022] Open
Abstract
The insect central complex (CX) is thought to underlie goal-oriented navigation but its functional organization is not fully understood. We recorded from genetically-identified CX cell types in Drosophila and presented directional visual, olfactory, and airflow cues known to elicit orienting behavior. We found that a group of neurons targeting the ventral fan-shaped body (ventral P-FNs) are robustly tuned for airflow direction. Ventral P-FNs did not generate a 'map' of airflow direction. Instead, cells in each hemisphere were tuned to 45° ipsilateral, forming a pair of orthogonal bases. Imaging experiments suggest that ventral P-FNs inherit their airflow tuning from neurons that provide input from the lateral accessory lobe (LAL) to the noduli (NO). Silencing ventral P-FNs prevented flies from selecting appropriate corrective turns following changes in airflow direction. Our results identify a group of CX neurons that robustly encode airflow direction and are required for proper orientation to this stimulus.
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Affiliation(s)
- Timothy A Currier
- Neuroscience Institute, New York University Langone Medical CenterNew YorkUnited States
- Center for Neural Science, New York UniversityNew YorkUnited States
| | - Andrew MM Matheson
- Neuroscience Institute, New York University Langone Medical CenterNew YorkUnited States
| | - Katherine I Nagel
- Neuroscience Institute, New York University Langone Medical CenterNew YorkUnited States
- Center for Neural Science, New York UniversityNew YorkUnited States
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59
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Renou M, Anton S. Insect olfactory communication in a complex and changing world. CURRENT OPINION IN INSECT SCIENCE 2020; 42:1-7. [PMID: 32485594 DOI: 10.1016/j.cois.2020.04.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/17/2020] [Accepted: 04/24/2020] [Indexed: 06/11/2023]
Abstract
Insect intraspecific olfactory communication occurs in a complex sensory environment. Here we present recent results on how the olfactory system extracts specific information from a sensory background, and integrates it with complementary information to improve odor source localization. Recent advances on mechanisms of olfactory mixture processing, multi-modal integration, as well as plasticity of sensory processing are reviewed. Significant progress in the understanding of neural coding and molecular bases of olfaction reinforce our perception of the tremendous adaptability of insects to a changing environment. However several reports demonstrate that anthropogenic environmental perturbations interfere with insect olfactory communication and might as a consequence significantly alter the functioning of ecosystems and agroecosystems.
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Affiliation(s)
- Michel Renou
- Institut d'Ecologie et des Sciences de l'Environnement de Paris (iEES-Paris). INRAE, Sorbonne Université, CNRS, IRD, UPEC, Univ. P7. Versailles, France
| | - Sylvia Anton
- Institute for Genetics, Environment and Plant Protection - EGI, INRAE-Institut Agro-Université de Rennes 1, Angers, France.
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60
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Rapp H, Nawrot MP. A spiking neural program for sensorimotor control during foraging in flying insects. Proc Natl Acad Sci U S A 2020; 117:28412-28421. [PMID: 33122439 PMCID: PMC7668073 DOI: 10.1073/pnas.2009821117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Foraging is a vital behavioral task for living organisms. Behavioral strategies and abstract mathematical models thereof have been described in detail for various species. To explore the link between underlying neural circuits and computational principles, we present how a biologically detailed neural circuit model of the insect mushroom body implements sensory processing, learning, and motor control. We focus on cast and surge strategies employed by flying insects when foraging within turbulent odor plumes. Using a spike-based plasticity rule, the model rapidly learns to associate individual olfactory sensory cues paired with food in a classical conditioning paradigm. We show that, without retraining, the system dynamically recalls memories to detect relevant cues in complex sensory scenes. Accumulation of this sensory evidence on short time scales generates cast-and-surge motor commands. Our generic systems approach predicts that population sparseness facilitates learning, while temporal sparseness is required for dynamic memory recall and precise behavioral control. Our work successfully combines biological computational principles with spike-based machine learning. It shows how knowledge transfer from static to arbitrary complex dynamic conditions can be achieved by foraging insects and may serve as inspiration for agent-based machine learning.
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Affiliation(s)
- Hannes Rapp
- Computational Systems Neuroscience, Institute of Zoology, University of Cologne, Cologne 50674, Germany
| | - Martin Paul Nawrot
- Computational Systems Neuroscience, Institute of Zoology, University of Cologne, Cologne 50674, Germany
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61
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Demir M, Kadakia N, Anderson HD, Clark DA, Emonet T. Walking Drosophila navigate complex plumes using stochastic decisions biased by the timing of odor encounters. eLife 2020; 9:e57524. [PMID: 33140723 PMCID: PMC7609052 DOI: 10.7554/elife.57524] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/15/2020] [Indexed: 11/16/2022] Open
Abstract
How insects navigate complex odor plumes, where the location and timing of odor packets are uncertain, remains unclear. Here we imaged complex odor plumes simultaneously with freely-walking flies, quantifying how behavior is shaped by encounters with individual odor packets. We found that navigation was stochastic and did not rely on the continuous modulation of speed or orientation. Instead, flies turned stochastically with stereotyped saccades, whose direction was biased upwind by the timing of prior odor encounters, while the magnitude and rate of saccades remained constant. Further, flies used the timing of odor encounters to modulate the transition rates between walks and stops. In more regular environments, flies continuously modulate speed and orientation, even though encounters can still occur randomly due to animal motion. We find that in less predictable environments, where encounters are random in both space and time, walking flies navigate with random walks biased by encounter timing.
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Affiliation(s)
- Mahmut Demir
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| | - Nirag Kadakia
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
- Swartz Foundation Fellow, Yale UniversityNew HavenUnited States
| | - Hope D Anderson
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| | - Damon A Clark
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
- Interdepartmental Neuroscience Program, Yale UniversityNew HavenUnited States
- Department of Physics, Yale UniversityNew HavenUnited States
| | - Thierry Emonet
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
- Interdepartmental Neuroscience Program, Yale UniversityNew HavenUnited States
- Department of Physics, Yale UniversityNew HavenUnited States
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62
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Cribellier A, Spitzen J, Fairbairn H, van de Geer C, van Leeuwen JL, Muijres FT. Lure, retain, and catch malaria mosquitoes. How heat and humidity improve odour-baited trap performance. Malar J 2020; 19:357. [PMID: 33028362 PMCID: PMC7542916 DOI: 10.1186/s12936-020-03403-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/31/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND When seeking a human for a blood meal, mosquitoes use several cues to detect and find their hosts. From this knowledge, counter-flow odour-baited traps have been developed that use a combination of CO2, human-mimicking odour, visual cues and circulating airflow to attract and capture mosquitoes. Initially developed for monitoring, these traps are now also being considered as promising vector control tools. The traps are attractive to host-seeking mosquitoes, but their capture efficiency is low. It has been hypothesized that the lack of short-range host cues, such as heat and increased local humidity, often prevent mosquitoes from getting close enough to get caught; this lack might even trigger avoidance manoeuvres near the capture region. METHODS This study investigated how close-range host cues affect the flight behaviour of Anopheles female malaria mosquitoes around odour-baited traps, and how this affects trap capture performance. For this, a novel counter-flow odour-baited trap was developed, the M-Tego. In addition to the usual CO2 and odour-blend, this trap can provide the short-range host cues, heat and humidity. Systematically adding or removing these two cues tested how this affected the trap capture percentages and flight behaviour. First, capture percentages of the M-Tego with and without short-range host cues to the BG-Suna trap were compared, in both laboratory and semi-field testing. Then, machine-vision techniques were used to track the three-dimensional flight movements of mosquitoes around the M-Tego. RESULTS With heat and humidity present, the M-Tego captured significantly more mosquitoes as capture percentages almost doubled. Comparing the flight behaviour around the M-Tego with variable close-range host cues showed that when these cues were present, flying mosquitoes were more attracted to the trap and spent more time there. In addition, the M-Tego was found to have a better capture mechanism than the BG-Suna, most likely because it does not elicit previously observed upward avoiding manoeuvres. CONCLUSIONS Results suggest that adding heat and humidity to an odour-baited trap lures more mosquitoes close to the trap and retains them there longer, resulting in higher capture performance. These findings support the development of control tools for fighting mosquito-borne diseases such as malaria.
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Affiliation(s)
- Antoine Cribellier
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Jeroen Spitzen
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands
| | - Henry Fairbairn
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands.,Faculty of Industrial Design Engineering, Delft University of Technology, Delft, The Netherlands
| | - Cedric van de Geer
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands.,Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands.,Faculty of Industrial Design Engineering, Delft University of Technology, Delft, The Netherlands.,Ifakara Health Institute, Ifakara, Tanzania
| | - Johan L van Leeuwen
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Florian T Muijres
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands.
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63
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Fan S, Hao D, Sun X, Sultan YM, Li Z, Xia K. A Study of Modified Infotaxis Algorithms in 2D and 3D Turbulent Environments. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2020; 2020:4159241. [PMID: 32908473 PMCID: PMC7468623 DOI: 10.1155/2020/4159241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/16/2020] [Accepted: 07/06/2020] [Indexed: 11/17/2022]
Abstract
Emergency response to hazardous gases in the environment is an important research field in environmental monitoring. In recent years, with the rapid development of sensor technology and mobile device technology, more autonomous search algorithms for hazardous gas emission sources are proposed in uncertain environment, which can avoid emergency personnel from contacting hazardous gas in a short distance. Infotaxis is an autonomous search strategy without a concentration gradient, which uses scattered sensor data to track the location of the release source in turbulent environment. This paper optimizes the imbalance of exploitation and exploration in the reward function of Infotaxis algorithm and proposes a mobile strategy for the three-dimensional scene. In two-dimensional and three-dimensional scenes, the average steps of search tasks are used as the evaluation criteria to analyze the information trend algorithm combined with different reward functions and mobile strategies. The results show that the balance between the exploitation item and exploration item of the reward function proposed in this paper is better than that of the reward function in the Infotaxis algorithm, no matter in the two-dimensional scenes or in the three-dimensional scenes.
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Affiliation(s)
- Shurui Fan
- Tianjin Key Laboratory of Electronic Materials Devices, School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Dongxia Hao
- Tianjin Key Laboratory of Electronic Materials Devices, School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Xudong Sun
- Tianjin Key Laboratory of Electronic Materials Devices, School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Yusuf Mohamed Sultan
- Tianjin Key Laboratory of Electronic Materials Devices, School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Zirui Li
- Tianjin Key Laboratory of Electronic Materials Devices, School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Kewen Xia
- Tianjin Key Laboratory of Electronic Materials Devices, School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China
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64
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Multimodal interactions in insect navigation. Anim Cogn 2020; 23:1129-1141. [PMID: 32323027 PMCID: PMC7700066 DOI: 10.1007/s10071-020-01383-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 01/06/2023]
Abstract
Animals travelling through the world receive input from multiple sensory modalities that could be important for the guidance of their journeys. Given the availability of a rich array of cues, from idiothetic information to input from sky compasses and visual information through to olfactory and other cues (e.g. gustatory, magnetic, anemotactic or thermal) it is no surprise to see multimodality in most aspects of navigation. In this review, we present the current knowledge of multimodal cue use during orientation and navigation in insects. Multimodal cue use is adapted to a species’ sensory ecology and shapes navigation behaviour both during the learning of environmental cues and when performing complex foraging journeys. The simultaneous use of multiple cues is beneficial because it provides redundant navigational information, and in general, multimodality increases robustness, accuracy and overall foraging success. We use examples from sensorimotor behaviours in mosquitoes and flies as well as from large scale navigation in ants, bees and insects that migrate seasonally over large distances, asking at each stage how multiple cues are combined behaviourally and what insects gain from using different modalities.
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65
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Betkiewicz R, Lindner B, Nawrot MP. Circuit and Cellular Mechanisms Facilitate the Transformation from Dense to Sparse Coding in the Insect Olfactory System. eNeuro 2020; 7:ENEURO.0305-18.2020. [PMID: 32132095 PMCID: PMC7294456 DOI: 10.1523/eneuro.0305-18.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 10/31/2019] [Accepted: 02/19/2020] [Indexed: 11/21/2022] Open
Abstract
Transformations between sensory representations are shaped by neural mechanisms at the cellular and the circuit level. In the insect olfactory system, the encoding of odor information undergoes a transition from a dense spatiotemporal population code in the antennal lobe to a sparse code in the mushroom body. However, the exact mechanisms shaping odor representations and their role in sensory processing are incompletely identified. Here, we investigate the transformation from dense to sparse odor representations in a spiking model of the insect olfactory system, focusing on two ubiquitous neural mechanisms: spike frequency adaptation at the cellular level and lateral inhibition at the circuit level. We find that cellular adaptation is essential for sparse representations in time (temporal sparseness), while lateral inhibition regulates sparseness in the neuronal space (population sparseness). The interplay of both mechanisms shapes spatiotemporal odor representations, which are optimized for the discrimination of odors during stimulus onset and offset. Response pattern correlation across different stimuli showed a nonmonotonic dependence on the strength of lateral inhibition with an optimum at intermediate levels, which is explained by two counteracting mechanisms. In addition, we find that odor identity is stored on a prolonged timescale in the adaptation levels but not in the spiking activity of the principal cells of the mushroom body, providing a testable hypothesis for the location of the so-called odor trace.
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Affiliation(s)
- Rinaldo Betkiewicz
- Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
- Computational Systems Neuroscience, Institute of Zoology, University of Cologne, 50674 Cologne, Germany
- Department of Physics, Humboldt University Berlin, 12489 Berlin, Germany
| | - Benjamin Lindner
- Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
- Department of Physics, Humboldt University Berlin, 12489 Berlin, Germany
| | - Martin P Nawrot
- Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
- Computational Systems Neuroscience, Institute of Zoology, University of Cologne, 50674 Cologne, Germany
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66
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Buehlmann C, Aussel A, Graham P. Dynamic multimodal interactions in navigating wood ants: what do path details tell us about cue integration? J Exp Biol 2020; 223:jeb221036. [PMID: 32139472 DOI: 10.1242/jeb.221036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 02/28/2020] [Indexed: 01/24/2023]
Abstract
Ants are expert navigators, using multimodal information to navigate successfully. Here, we present the results of systematic studies of multimodal cue use in navigating wood ants, Formica rufa Ants learnt to navigate to a feeder that was defined by an olfactory cue (O), visual cue (V) and airflow (A) presented together. When the feeder, olfactory cue and airflow were all placed at the centre of the visual cue (VOACentre), ants did not directly approach the learnt feeder when either the olfactory or visual cue was removed. This confirms that some form of cue binding has taken place. However, in a visually simpler task with the feeder located at the edge of the visual cue (VOAEdge), ants still approached the feeder directly when individual cue components were removed. Hence, cue binding is flexible and depends on the navigational context. In general, cues act additively in determining the ants' path accuracy, i.e. the use of multiple cues increased navigation performance. Moreover, across different training conditions, we saw different motor patterns in response to different sensory cues. For instance, ants had more sinuous paths with more turns when they followed an odour plume but did not have any visual cues. Having visual information together with the odour enhanced performance and therefore positively impacted on plume following. Interestingly, path characteristics of ants from the different multimodal groups (VOACentre versus VOAEdge) were different, suggesting that the observed flexibility in cue binding may be a result of ants' movement characteristics.
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Affiliation(s)
| | | | - Paul Graham
- University of Sussex, School of Life Sciences, Brighton BN1 9QG, UK
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67
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Mechanisms underlying attraction to odors in walking Drosophila. PLoS Comput Biol 2020; 16:e1007718. [PMID: 32226007 PMCID: PMC7105121 DOI: 10.1371/journal.pcbi.1007718] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 02/07/2020] [Indexed: 11/19/2022] Open
Abstract
Mechanisms that control movements range from navigational mechanisms, in which the animal employs directional cues to reach a specific destination, to search movements during which there are little or no environmental cues. Even though most real-world movements result from an interplay between these mechanisms, an experimental system and theoretical framework for the study of interplay of these mechanisms is not available. Here, we rectify this deficit. We create a new method to stimulate the olfactory system in Drosophila or fruit flies. As flies explore a circular arena, their olfactory receptor neuron (ORNs) are optogenetically activated within a central region making this region attractive to the flies without emitting any clear directional signals outside this central region. In the absence of ORN activation, the fly’s locomotion can be described by a random walk model where a fly’s movement is described by its speed and turn-rate (or kinematics). Upon optogenetic stimulation, the fly’s behavior changes dramatically in two respects. First, there are large kinematic changes. Second, there are more turns at the border between light-zone and no-light-zone and these turns have an inward bias. Surprisingly, there is no increase in turn-rate, rather a large decrease in speed that makes it appear that the flies are turning at the border. Similarly, the inward bias of the turns is a result of the increase in turn angle. These two mechanisms entirely account for the change in a fly’s locomotion. No complex mechanisms such as path-integration or a careful evaluation of gradients are necessary. The strategy an animal employs to explore the environment and to find and return to the location where it has previously found food or mates is an important part of its behavior. In nature, animals have incomplete information about their environment, and must use this incomplete information to navigate. In most laboratory experiments, there is usually clear directional information making it difficult to infer an animal’s real strategy from laboratory behavioral experiments. In this study, we devise a new behavioral task wherein we remotely activate olfactory neurons when fruit flies are in a given location. This activation makes a given location attractive to the flies without providing any directional information and allows us to assess how flies navigate under these conditions. We find that flies navigate towards the activated location using two simple mechanisms: First, its speed in the activated region and its turn rate is much lower than it is elsewhere. Second, at the boundary of the odor-zone, its speed decreases dramatically and its turns become much sharper. Essentially, these simple mechanisms appear to be extremely robust.
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A Comparison between Mouse, In Silico, and Robot Odor Plume Navigation Reveals Advantages of Mouse Odor Tracking. eNeuro 2020; 7:ENEURO.0212-19.2019. [PMID: 31924732 PMCID: PMC7004486 DOI: 10.1523/eneuro.0212-19.2019] [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] [Received: 06/04/2019] [Revised: 11/04/2019] [Accepted: 12/19/2019] [Indexed: 11/26/2022] Open
Abstract
Localization of odors is essential to animal survival, and thus animals are adept at odor navigation. In natural conditions animals encounter odor sources in which odor is carried by air flow varying in complexity. We sought to identify potential minimalist strategies that can effectively be used for odor-based navigation and asses their performance in an increasingly chaotic environment. Localization of odors is essential to animal survival, and thus animals are adept at odor navigation. In natural conditions animals encounter odor sources in which odor is carried by air flow varying in complexity. We sought to identify potential minimalist strategies that can effectively be used for odor-based navigation and asses their performance in an increasingly chaotic environment. To do so, we compared mouse, in silico model, and Arduino-based robot odor-localization behavior in a standardized odor landscape. Mouse performance remains robust in the presence of increased complexity, showing a shift in strategy towards faster movement with increased environmental complexity. Implementing simple binaral and temporal models of tropotaxis and klinotaxis, an in silico model and Arduino robot, in the same environment as the mice, are equally successful in locating the odor source within a plume of low complexity. However, performance of these algorithms significantly drops when the chaotic nature of the plume is increased. Additionally, both algorithm-driven systems show more successful performance when using a strictly binaral model at a larger sensor separation distance and more successful performance when using a temporal and binaral model when using a smaller sensor separation distance. This suggests that with an increasingly chaotic odor environment, mice rely on complex strategies that allow for robust odor localization that cannot be resolved by minimal algorithms that display robust performance at low levels of complexity. Thus, highlighting that an animal’s ability to modulate behavior with environmental complexity is beneficial for odor localization.
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69
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Currier TA, Nagel KI. Multisensory control of navigation in the fruit fly. Curr Opin Neurobiol 2019; 64:10-16. [PMID: 31841944 DOI: 10.1016/j.conb.2019.11.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/23/2019] [Accepted: 11/25/2019] [Indexed: 01/16/2023]
Abstract
Spatial navigation is influenced by cues from nearly every sensory modality and thus provides an excellent model for understanding how different sensory streams are integrated to drive behavior. Here we review recent work on multisensory control of navigation in the model organism Drosophila melanogaster, which allows for detailed circuit dissection. We identify four modes of integration that have been described in the literature-suppression, gating, summation, and association-and describe regions of the larval and adult brain that have been implicated in sensory integration. Finally we discuss what circuit architectures might support these different forms of integration. We argue that Drosophila is an excellent model to discover these circuit and biophysical motifs.
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Affiliation(s)
- Timothy A Currier
- Neuroscience Institute, New York University Medical Center, 435 E 30th St., New York, NY 10016, USA; Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA
| | - Katherine I Nagel
- Neuroscience Institute, New York University Medical Center, 435 E 30th St., New York, NY 10016, USA; Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
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70
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Amin H, Lin AC. Neuronal mechanisms underlying innate and learned olfactory processing in Drosophila. CURRENT OPINION IN INSECT SCIENCE 2019; 36:9-17. [PMID: 31280185 DOI: 10.1016/j.cois.2019.06.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 06/03/2019] [Indexed: 06/09/2023]
Abstract
Olfaction allows animals to adapt their behavior in response to different chemical cues in their environment. How does the brain efficiently discriminate different odors to drive appropriate behavior, and how does it flexibly assign value to odors to adjust behavior according to experience? This review traces neuronal mechanisms underlying these processes in adult Drosophila melanogaster from olfactory receptors to higher brain centers. We highlight neural circuit principles such as lateral inhibition, segregation and integration of olfactory channels, temporal accumulation of sensory evidence, and compartmentalized synaptic plasticity underlying associative memory.
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Affiliation(s)
- Hoger Amin
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Andrew C Lin
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom.
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71
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Mahishi D, Huetteroth W. The prandial process in flies. CURRENT OPINION IN INSECT SCIENCE 2019; 36:157-166. [PMID: 31765996 DOI: 10.1016/j.cois.2019.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/03/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Feeding is fundamental to any heterotroph organism; in its role to quell hunger it overrides most other motivational states. But feeding also literally opens the door to harmful risks, especially for a saprophagous animal like Drosophila; ingestion of poisonous substrate can lead to irreversible damage. Thus feeding incorporates a series of steps with several checkpoints to guarantee that the ingestion remains beneficial and provides a balanced diet, or the feeding process is interrupted. Subsequently, we will summarize and describe the feeding process in Drosophila in a comprehensive manner. We propose eleven distinct steps for feeding, grouped into four categories, to address our current knowledge of prandial regulatory mechanisms in Drosophila.
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Affiliation(s)
- Deepthi Mahishi
- Department of Biology, University of Leipzig, Leipzig, Germany
| | - Wolf Huetteroth
- Department of Biology, University of Leipzig, Leipzig, Germany.
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72
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Gorur-Shandilya S, Martelli C, Demir M, Emonet T. Controlling and measuring dynamic odorant stimuli in the laboratory. ACTA ACUST UNITED AC 2019; 222:jeb.207787. [PMID: 31672728 DOI: 10.1242/jeb.207787] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/24/2019] [Indexed: 12/28/2022]
Abstract
Animals experience complex odorant stimuli that vary widely in composition, intensity and temporal properties. However, stimuli used to study olfaction in the laboratory are much simpler. This mismatch arises from the challenges in measuring and controlling them precisely and accurately. Even simple pulses can have diverse kinetics that depend on their molecular identity. Here, we introduce a model that describes how stimulus kinetics depend on the molecular identity of the odorant and the geometry of the delivery system. We describe methods to deliver dynamic odorant stimuli of several types, including broadly distributed stimuli that reproduce some of the statistics of naturalistic plumes, in a reproducible and precise manner. Finally, we introduce a method to calibrate a photo-ionization detector to any odorant it can detect, using no additional components. Our approaches are affordable and flexible and can be used to advance our understanding of how olfactory neurons encode real-world odor signals.
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Affiliation(s)
- Srinivas Gorur-Shandilya
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA.,Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Carlotta Martelli
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA.,Department of Biology, University of Konstanz, Konstanz 78457, Germany
| | - Mahmut Demir
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Thierry Emonet
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA .,Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA.,Department of Physics, Yale University, New Haven, CT 06511, USA
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73
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Pannunzi M, Nowotny T. Odor Stimuli: Not Just Chemical Identity. Front Physiol 2019; 10:1428. [PMID: 31827441 PMCID: PMC6890726 DOI: 10.3389/fphys.2019.01428] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/04/2019] [Indexed: 01/14/2023] Open
Abstract
In most sensory modalities the underlying physical phenomena are well understood, and stimulus properties can be precisely controlled. In olfaction, the situation is different. The presence of specific chemical compounds in the air (or water) is the root cause for perceived odors, but it remains unknown what organizing principles, equivalent to wavelength for light, determine the dimensions of odor space. Equally important, but less in the spotlight, odor stimuli are also complex with respect to their physical properties, including concentration and time-varying spatio-temporal distribution. We still lack a complete understanding or control over these properties, in either experiments or theory. In this review, we will concentrate on two important aspects of the physical properties of odor stimuli beyond the chemical identity of the odorants: (1) The amplitude of odor stimuli and their temporal dynamics. (2) The spatio-temporal structure of odor plumes in a natural environment. Concerning these issues, we ask the following questions: (1) Given any particular experimental protocol for odor stimulation, do we have a realistic estimate of the odorant concentration in the air, and at the olfactory receptor neurons? Can we control, or at least know, the dynamics of odorant concentration at olfactory receptor neurons? (2) What do we know of the spatio-temporal structure of odor stimuli in a natural environment both from a theoretical and experimental perspective? And how does this change if we consider mixtures of odorants? For both topics, we will briefly summarize the underlying principles of physics and review the experimental and theoretical Neuroscience literature, focusing on the aspects that are relevant to animals’ physiology and behavior. We hope that by bringing the physical principles behind odor plume landscapes to the fore we can contribute to promoting a new generation of experiments and models.
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74
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Lan B, Kanzaki R, Ando N. Dropping Counter: A Detection Algorithm for Identifying Odour-Evoked Responses from Noisy Electroantennograms Measured by a Flying Robot. SENSORS 2019; 19:s19204574. [PMID: 31640187 PMCID: PMC6832354 DOI: 10.3390/s19204574] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/12/2019] [Accepted: 10/18/2019] [Indexed: 11/30/2022]
Abstract
The electroantennogram (EAG) is a technique used for measuring electrical signals from the antenna of an insect. Its rapid response time, quick recovery speed, and high sensitivity make it suitable for odour-tracking tasks employing mobile robots. However, its application to flying robots has not been extensively studied owing to the electrical and mechanical noises generated. In this study, we investigated the characteristics of the EAG mounted on a tethered flying quadcopter and developed a special counter-based algorithm for detecting the odour-generated responses. As the EAG response is negative, the algorithm creates a window and compares the values inside it. Once a value is smaller than the first one, the counter will increase by one and finally turns the whole signal into a clearer odour stimulated result. By experimental evaluation, the new algorithm gives a higher cross-correlation coefficient when compared with the fixed-threshold method. The result shows that the accuracy of this novel algorithm for recognising odour-evoked EAG signals from noise exceeds that of the traditional method; furthermore, the use of insect antennae as odour sensors for flying robots is demonstrated to be feasible.
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Affiliation(s)
- Bluest Lan
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Meguro-ku, Komaba, Tokyo 153-8904, Japan.
| | - Ryohei Kanzaki
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Meguro-ku, Komaba, Tokyo 153-8904, Japan.
| | - Noriyasu Ando
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Meguro-ku, Komaba, Tokyo 153-8904, Japan.
- Department of Systems Life Engineering, Faculty of Engineering, Maebashi Institute of Technology, 460-1 Kamisadori-cho, Maebashi, Gunma 371-0816, Japan.
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75
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Vinauger C, Lahondère C, Wolff GH, Locke LT, Liaw JE, Parrish JZ, Akbari OS, Dickinson MH, Riffell JA. Modulation of Host Learning in Aedes aegypti Mosquitoes. Curr Biol 2019; 28:333-344.e8. [PMID: 29395917 DOI: 10.1016/j.cub.2017.12.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/07/2017] [Accepted: 12/07/2017] [Indexed: 12/27/2022]
Abstract
How mosquitoes determine which individuals to bite has important epidemiological consequences. This choice is not random; most mosquitoes specialize in one or a few vertebrate host species, and some individuals in a host population are preferred over others. Mosquitoes will also blood feed from other hosts when their preferred is no longer abundant, but the mechanisms mediating these shifts between hosts, and preferences for certain individuals within a host species, remain unclear. Here, we show that olfactory learning may contribute to Aedes aegypti mosquito biting preferences and host shifts. Training and testing to scents of humans and other host species showed that mosquitoes can aversively learn the scent of specific humans and single odorants and learn to avoid the scent of rats (but not chickens). Using pharmacological interventions, RNAi, and CRISPR gene editing, we found that modification of the dopamine-1 receptor suppressed their learning abilities. We further show through combined electrophysiological and behavioral recordings from tethered flying mosquitoes that these odors evoke changes in both behavior and antennal lobe (AL) neuronal responses and that dopamine strongly modulates odor-evoked responses in AL neurons. Not only do these results provide direct experimental evidence that olfactory learning in mosquitoes can play an epidemiological role, but collectively, they also provide neuroanatomical and functional demonstration of the role of dopamine in mediating this learning-induced plasticity, for the first time in a disease vector insect.
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Affiliation(s)
- Clément Vinauger
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Chloé Lahondère
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Gabriella H Wolff
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Lauren T Locke
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Jessica E Liaw
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Omar S Akbari
- Department of Entomology, University of California, Riverside, Riverside, CA 92521, USA
| | - Michael H Dickinson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jeffrey A Riffell
- Department of Biology, University of Washington, Seattle, WA 98195, USA.
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76
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Liu MZ, Vosshall LB. General Visual and Contingent Thermal Cues Interact to Elicit Attraction in Female Aedes aegypti Mosquitoes. Curr Biol 2019; 29:2250-2257.e4. [PMID: 31257144 DOI: 10.1016/j.cub.2019.06.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 04/29/2019] [Accepted: 06/03/2019] [Indexed: 01/31/2023]
Abstract
Female Aedes aegypti mosquitoes use multiple sensory modalities to hunt human hosts and obtain a blood meal for egg production. Attractive cues include carbon dioxide (CO2), a major component of exhaled breath [1, 2]; heat elevated above ambient temperature, signifying warm-blooded skin [3, 4]; and dark visual contrast [5, 6], proposed to bridge long-range olfactory and short-range thermal cues [7]. Any of these sensory cues in isolation is an incomplete signal of a human host, and so a mosquito must integrate multimodal sensory information before committing to approaching and biting a person [8]. Here, we study the interaction of visual cues, heat, and CO2 to investigate the contributions of human-associated stimuli to host-seeking decisions. We show that tethered flying mosquitoes strongly orient toward dark visual contrast, regardless of CO2 stimulation and internal host-seeking status. This suggests that attraction to visual contrast is general and not contingent on other host cues. In free-flight experiments with CO2, adding a dark contrasting visual cue to a warmed surface enhanced attraction. Moderate warmth became more attractive to mosquitoes, and mosquitoes aggregated on the cue at all non-noxious temperatures. Gr3 mutants, unable to detect CO2, were lured to the visual cue at ambient temperatures but fled and did not return when the surface was warmed to host-like temperatures. This suggests that attraction to thermal cues is contingent on the presence of the additional sensory cue CO2. Our results illustrate that mosquitoes integrate general attractive visual stimuli with context-dependent thermal stimuli to seek promising sites for blood feeding.
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Affiliation(s)
- Molly Z Liu
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Leslie B Vosshall
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, New York, NY 10065, USA; Kavli Neural Systems Institute, New York, NY 10065, USA.
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77
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Collett M, Graham P, Collett TS. Insect Navigation: What Backward Walking Reveals about the Control of Movement. Curr Biol 2019; 27:R141-R144. [PMID: 28222290 DOI: 10.1016/j.cub.2016.12.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Ants often walk backwards to drag large prey to their nest. New experiments show how they can use information from retinotopically encoded views to follow visual routes even while moving backwards. The mechanisms enabling ants to decouple body orientation and the control of travel direction are likely to be shared with other, flying, insects.
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Affiliation(s)
- Matthew Collett
- Psychology, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QG, UK.
| | - Paul Graham
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
| | - Thomas S Collett
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
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78
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Dolan MJ, Frechter S, Bates AS, Dan C, Huoviala P, Roberts RJV, Schlegel P, Dhawan S, Tabano R, Dionne H, Christoforou C, Close K, Sutcliffe B, Giuliani B, Li F, Costa M, Ihrke G, Meissner GW, Bock DD, Aso Y, Rubin GM, Jefferis GSXE. Neurogenetic dissection of the Drosophila lateral horn reveals major outputs, diverse behavioural functions, and interactions with the mushroom body. eLife 2019; 8:e43079. [PMID: 31112130 PMCID: PMC6529221 DOI: 10.7554/elife.43079] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/07/2019] [Indexed: 01/26/2023] Open
Abstract
Animals exhibit innate behaviours to a variety of sensory stimuli including olfactory cues. In Drosophila, one higher olfactory centre, the lateral horn (LH), is implicated in innate behaviour. However, our structural and functional understanding of the LH is scant, in large part due to a lack of sparse neurogenetic tools for this region. We generate a collection of split-GAL4 driver lines providing genetic access to 82 LH cell types. We use these to create an anatomical and neurotransmitter map of the LH and link this to EM connectomics data. We find ~30% of LH projections converge with outputs from the mushroom body, site of olfactory learning and memory. Using optogenetic activation, we identify LH cell types that drive changes in valence behavior or specific locomotor programs. In summary, we have generated a resource for manipulating and mapping LH neurons, providing new insights into the circuit basis of innate and learned olfactory behavior.
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Affiliation(s)
- Michael-John Dolan
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
- Division of NeurobiologyMRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Shahar Frechter
- Division of NeurobiologyMRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | - Chuntao Dan
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Paavo Huoviala
- Division of NeurobiologyMRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | - Philipp Schlegel
- Division of NeurobiologyMRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Department of ZoologyUniversity of CambridgeCambridgeUnited Kingdom
| | - Serene Dhawan
- Division of NeurobiologyMRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Department of ZoologyUniversity of CambridgeCambridgeUnited Kingdom
| | - Remy Tabano
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Heather Dionne
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | | | - Kari Close
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Ben Sutcliffe
- Division of NeurobiologyMRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Bianca Giuliani
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Feng Li
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Marta Costa
- Department of ZoologyUniversity of CambridgeCambridgeUnited Kingdom
| | - Gudrun Ihrke
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | | | - Davi D Bock
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Yoshinori Aso
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Gerald M Rubin
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Gregory SXE Jefferis
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
- Division of NeurobiologyMRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Department of ZoologyUniversity of CambridgeCambridgeUnited Kingdom
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79
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Corfas RA, Sharma T, Dickinson MH. Diverse Food-Sensing Neurons Trigger Idiothetic Local Search in Drosophila. Curr Biol 2019; 29:1660-1668.e4. [PMID: 31056390 DOI: 10.1016/j.cub.2019.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/21/2019] [Accepted: 03/06/2019] [Indexed: 01/14/2023]
Abstract
Foraging animals may benefit from remembering the location of a newly discovered food patch while continuing to explore nearby [1, 2]. For example, after encountering a drop of yeast or sugar, hungry flies often perform a local search [3, 4]. That is, rather than remaining on the food or simply walking away, flies execute a series of exploratory excursions during which they repeatedly depart and return to the resource. Fruit flies, Drosophila melanogaster, can perform this food-centered search behavior in the absence of external landmarks, instead relying on internal (idiothetic) cues [5]. This path-integration behavior may represent a deeply conserved navigational capacity in insects [6, 7], but its underlying neural basis remains unknown. Here, we used optogenetic activation to screen candidate cell classes and found that local searches can be initiated by diverse sensory neurons. Optogenetically induced searches resemble those triggered by actual food, are modulated by starvation state, and exhibit key features of path integration. Flies perform tightly centered searches around the fictive food site, even within a constrained maze, and they can return to the fictive food site after long excursions. Together, these results suggest that flies enact local searches in response to a wide variety of food-associated cues and that these sensory pathways may converge upon a common neural system for navigation. Using a virtual reality system, we demonstrate that local searches can be optogenetically induced in tethered flies walking on a spherical treadmill, laying the groundwork for future studies to image the brain during path integration. VIDEO ABSTRACT.
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Affiliation(s)
- Román A Corfas
- Division of Biology & Bioengineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - Tarun Sharma
- Division of Biology & Bioengineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - Michael H Dickinson
- Division of Biology & Bioengineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA.
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80
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Onodera Y, Ichikawa R, Terao K, Tanimoto H, Yamagata N. Courtship behavior induced by appetitive olfactory memory. J Neurogenet 2019; 33:143-151. [PMID: 30955396 DOI: 10.1080/01677063.2019.1593978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Reinforcement signals such as food reward and noxious punishment can change diverse behaviors. This holds true in fruit flies, Drosophila melanogaster, which can be conditioned by an odor and sugar reward or electric shock punishment. Despite a wide variety of behavior modulated by learning, conditioned responses have been traditionally measured by altered odor preference in a choice, and other memory-guided behaviors have been only scarcely investigated. Here, we analyzed detailed conditioned odor responses of flies after sugar associative learning by employing a video recording and semi-automated processing pipeline. Trajectory analyses revealed that multiple behavioral components were altered along with conditioned approach to the rewarded odor. Notably, we found that lateral wing extension, a hallmark of courtship behavior of D. melanogaster, was robustly increased specifically in the presence of the rewarded odor. Strikingly, genetic disruption of the mushroom body output did not impair conditioned courtship increase, while markedly weakening conditioned odor approach. Our results highlight the complexity of conditioned responses and their distinct regulatory mechanisms that may underlie coordinated yet complex memory-guided behaviors in flies.
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Affiliation(s)
- Yuya Onodera
- a Graduate School of Life Sciences , Tohoku University , Sendai 980-8577 , Japan
| | - Rino Ichikawa
- a Graduate School of Life Sciences , Tohoku University , Sendai 980-8577 , Japan
| | - Kanta Terao
- a Graduate School of Life Sciences , Tohoku University , Sendai 980-8577 , Japan
| | - Hiromu Tanimoto
- a Graduate School of Life Sciences , Tohoku University , Sendai 980-8577 , Japan
| | - Nobuhiro Yamagata
- a Graduate School of Life Sciences , Tohoku University , Sendai 980-8577 , Japan
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81
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Olfactory Navigation and the Receptor Nonlinearity. J Neurosci 2019; 39:3713-3727. [PMID: 30846614 DOI: 10.1523/jneurosci.2512-18.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/29/2019] [Accepted: 02/23/2019] [Indexed: 11/21/2022] Open
Abstract
The demands on a sensory system depend not only on the statistics of its inputs but also on the task. In olfactory navigation, for example, the task is to find the plume source; allocation of sensory resources may therefore be driven by aspects of the plume that are informative about source location, rather than concentration per se. Here we explore the implications of this idea for encoding odor concentration. To formalize the notion that sensory resources are limited, we considered coding strategies that partitioned the odor concentration range into a set of discriminable intervals. We developed a dynamic programming algorithm that, given the distribution of odor concentrations at several locations, determines the partitioning that conveys the most information about location. We applied this analysis to planar laser-induced fluorescence measurements of spatiotemporal odor fields with realistic advection speeds (5-20 cm/s), with or without a nearby boundary or obstacle. Across all environments, the optimal coding strategy allocated more resources (i.e., more and finer discriminable intervals) to the upper end of the concentration range than would be expected from histogram equalization, the optimal strategy if the goal were to reconstruct the plume, rather than to navigate. Finally, we show that ligand binding, as captured by the Hill equation, transforms odorant concentration into response levels in a way that approximates information maximization for navigation. This behavior occurs when the Hill dissociation constant is near the mean odor concentration, an adaptive set-point that has been observed in the olfactory system of flies.SIGNIFICANCE STATEMENT The first step of olfactory processing is receptor binding, and the resulting relationship between odorant concentration and the bound receptor fraction is a saturating one. While this Hill nonlinearity can be viewed as a distortion that is imposed by the biophysics of receptor binding, here we show that it also plays an important information-processing role in olfactory navigation. Specifically, by combining a novel dynamic-programming algorithm with physical measurements of turbulent plumes, we determine the optimal strategy for encoding odor concentration when the goal is to determine location. This strategy is distinct from histogram equalization, the strategy that maximizes information about plume concentration, and is closely approximated by the Hill nonlinearity when the binding constant is near the ambient mean.
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82
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Houot B, Cazalé-Debat L, Fraichard S, Everaerts C, Saxena N, Sane SP, Ferveur JF. Gene Regulation and Species-Specific Evolution of Free Flight Odor Tracking in Drosophila. Mol Biol Evol 2019; 35:3-15. [PMID: 28961885 DOI: 10.1093/molbev/msx241] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The flying ability of insects has coevolved with the development of organs necessary to take-off from the ground, generate, and modulate lift during flight in complex environments. Flight orientation to the appropriate food source and mating partner depends on the perception and integration of multiple chemical signals. We used a wind tunnel-based assay to investigate the natural and molecular evolution of free flight odor tracking in Drosophila. First, the comparison of female and male flies of several populations and species revealed substantial sex-, inter-, and intra-specific variations for distinct flight features. In these flies, we compared the molecular structure of desat1, a fast-evolving gene involved in multiple aspects of Drosophila pheromonal communication. We manipulated desat1 regulation and found that both neural and nonneural tissues affect distinct flight features. Together, our data suggest that desat1 is one of the genes involved in the evolution of free-flight odor tracking behaviors in Drosophila.
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Affiliation(s)
- Benjamin Houot
- Centre des Sciences du Goût et de l'Alimentation, UMR6265 CNRS, UMR1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
- Division of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Laurie Cazalé-Debat
- Centre des Sciences du Goût et de l'Alimentation, UMR6265 CNRS, UMR1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
| | - Stéphane Fraichard
- Centre des Sciences du Goût et de l'Alimentation, UMR6265 CNRS, UMR1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
| | - Claude Everaerts
- Centre des Sciences du Goût et de l'Alimentation, UMR6265 CNRS, UMR1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
| | - Nitesh Saxena
- Insect Flight Laboratory, National Center for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore, India
| | - Sanjay P Sane
- Insect Flight Laboratory, National Center for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore, India
| | - Jean-François Ferveur
- Centre des Sciences du Goût et de l'Alimentation, UMR6265 CNRS, UMR1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
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83
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Markow TA. Host use and host shifts in Drosophila. CURRENT OPINION IN INSECT SCIENCE 2019; 31:139-145. [PMID: 31109667 DOI: 10.1016/j.cois.2019.01.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 01/14/2019] [Accepted: 01/15/2019] [Indexed: 05/28/2023]
Abstract
Over a thousand Drosophila species have radiated onto a wide range of feeding and breeding sites. These radiations involve adaptations for locating, accepting, and growing in hosts with highly differing characteristics. In a number of species, owing to the availability of sequenced genomes, particular steps in host specialization and genes that control them, are being identified. Many cases of specialization involve the ability to detoxify some component of the host. Examples include Drosophila sechellia and the octanoic acid in Morinda citrifolia, alpha-amanitin in mycophagous drosophilids, and the alkaloids in cactophilic species. Owing to the known ecologies of many species for which genomes exist, the Drosophila model system provides an unprecedented opportunity to simultaneously examine the genes underlying HOST LOCATION, HOST ACCEPTANCE and HOST USE, the types of selection acting upon them and any coevolutionary interactions among the genes underlying these steps.
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Affiliation(s)
- Therese Ann Markow
- National Laboratory for the Genomics of Biodiversity, CINVESTAV, Irapuato, Mexico; Division of Biological Sciences, University of California at San Diego, La Jolla, CA, USA.
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84
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Tao L, Ozarkar S, Beck JM, Bhandawat V. Statistical structure of locomotion and its modulation by odors. eLife 2019; 8:e41235. [PMID: 30620334 PMCID: PMC6361587 DOI: 10.7554/elife.41235] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 01/05/2019] [Indexed: 11/22/2022] Open
Abstract
Most behaviors such as making tea are not stereotypical but have an obvious structure. However, analytical methods to objectively extract structure from non-stereotyped behaviors are immature. In this study, we analyze the locomotion of fruit flies and show that this non-stereotyped behavior is well-described by a Hierarchical Hidden Markov Model (HHMM). HHMM shows that a fly's locomotion can be decomposed into a few locomotor features, and odors modulate locomotion by altering the time a fly spends performing different locomotor features. Importantly, although all flies in our dataset use the same set of locomotor features, individual flies vary considerably in how often they employ a given locomotor feature, and how this usage is modulated by odor. This variation is so large that the behavior of individual flies is best understood as being grouped into at least three to five distinct clusters, rather than variations around an average fly.
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Affiliation(s)
- Liangyu Tao
- Department of BiologyDuke UniversityDurhamUnited States
| | | | - Jeffrey M Beck
- Department of NeurobiologyDuke UniversityDurhamUnited States
| | - Vikas Bhandawat
- Department of BiologyDuke UniversityDurhamUnited States
- Department of NeurobiologyDuke UniversityDurhamUnited States
- Duke Institute for Brain SciencesDuke UniversityDurhamUnited States
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85
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Abstract
In most sensory modalities the underlying physical phenomena are well understood, and stimulus properties can be precisely controlled. In olfaction, the situation is different. The presence of specific chemical compounds in the air (or water) is the root cause for perceived odors, but it remains unknown what organizing principles, equivalent to wavelength for light, determine the dimensions of odor space. Equally important, but less in the spotlight, odor stimuli are also complex with respect to their physical properties, including concentration and time-varying spatio-temporal distribution. We still lack a complete understanding or control over these properties, in either experiments or theory. In this review, we will concentrate on two important aspects of the physical properties of odor stimuli beyond the chemical identity of the odorants: (1) The amplitude of odor stimuli and their temporal dynamics. (2) The spatio-temporal structure of odor plumes in a natural environment. Concerning these issues, we ask the following questions: (1) Given any particular experimental protocol for odor stimulation, do we have a realistic estimate of the odorant concentration in the air, and at the olfactory receptor neurons? Can we control, or at least know, the dynamics of odorant concentration at olfactory receptor neurons? (2) What do we know of the spatio-temporal structure of odor stimuli in a natural environment both from a theoretical and experimental perspective? And how does this change if we consider mixtures of odorants? For both topics, we will briefly summarize the underlying principles of physics and review the experimental and theoretical Neuroscience literature, focusing on the aspects that are relevant to animals' physiology and behavior. We hope that by bringing the physical principles behind odor plume landscapes to the fore we can contribute to promoting a new generation of experiments and models.
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86
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Tastekin I, Khandelwal A, Tadres D, Fessner ND, Truman JW, Zlatic M, Cardona A, Louis M. Sensorimotor pathway controlling stopping behavior during chemotaxis in the Drosophila melanogaster larva. eLife 2018; 7:e38740. [PMID: 30465650 PMCID: PMC6264072 DOI: 10.7554/elife.38740] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 11/07/2018] [Indexed: 02/02/2023] Open
Abstract
Sensory navigation results from coordinated transitions between distinct behavioral programs. During chemotaxis in the Drosophila melanogaster larva, the detection of positive odor gradients extends runs while negative gradients promote stops and turns. This algorithm represents a foundation for the control of sensory navigation across phyla. In the present work, we identified an olfactory descending neuron, PDM-DN, which plays a pivotal role in the organization of stops and turns in response to the detection of graded changes in odor concentrations. Artificial activation of this descending neuron induces deterministic stops followed by the initiation of turning maneuvers through head casts. Using electron microscopy, we reconstructed the main pathway that connects the PDM-DN neuron to the peripheral olfactory system and to the pre-motor circuit responsible for the actuation of forward peristalsis. Our results set the stage for a detailed mechanistic analysis of the sensorimotor conversion of graded olfactory inputs into action selection to perform goal-oriented navigation.
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Affiliation(s)
- Ibrahim Tastekin
- EMBL-CRG Systems Biology Research UnitCentre for Genomic Regulation, The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu FabraBarcelonaSpain
| | - Avinash Khandelwal
- EMBL-CRG Systems Biology Research UnitCentre for Genomic Regulation, The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - David Tadres
- EMBL-CRG Systems Biology Research UnitCentre for Genomic Regulation, The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu FabraBarcelonaSpain
- Institute of Molecular Life SciencesUniversity of ZurichZurichSwitzerland
- Department of Molecular, Cellular and Developmental Biology & Neuroscience Research InstituteUniversity of CaliforniaSanta BarbaraUnited States
| | - Nico D Fessner
- EMBL-CRG Systems Biology Research UnitCentre for Genomic Regulation, The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu FabraBarcelonaSpain
| | - James W Truman
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Marta Zlatic
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
- Department of ZoologyUniversity of CambridgeCambridgeUnited Kingdom
| | - Albert Cardona
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Matthieu Louis
- EMBL-CRG Systems Biology Research UnitCentre for Genomic Regulation, The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu FabraBarcelonaSpain
- Department of Molecular, Cellular and Developmental Biology & Neuroscience Research InstituteUniversity of CaliforniaSanta BarbaraUnited States
- Department of PhysicsUniversity of California Santa BarbaraCaliforniaUnited States
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87
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Distinct activity-gated pathways mediate attraction and aversion to CO 2 in Drosophila. Nature 2018; 564:420-424. [PMID: 30464346 PMCID: PMC6314688 DOI: 10.1038/s41586-018-0732-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 10/11/2018] [Indexed: 12/18/2022]
Abstract
Carbon dioxide is produced by many organic processes, and is a convenient volatile cue for insects1 searching for blood hosts2, flowers3, communal nests4, fruit5, and wildfires6. Curiously, although Drosophila melanogaster feed on yeast that produce CO2 and ethanol during fermentation, laboratory experiments suggest that walking flies avoid CO27–12. Here, we resolve this paradox by showing that both flying and walking Drosophila find CO2 attractive, but only when in an active state associated with foraging. Aversion at low activity levels may be an adaptation to avoid CO2-seeking-parasites, or succumbing to respiratory acidosis in the presence of high concentrations of CO2 that exist in nature13,14. In contrast to CO2, flies are attracted to ethanol in all behavioral states, and invest twice the time searching near ethanol compared to CO2. These behavioral differences reflect the fact that whereas CO2 is generated by many natural processes, ethanol is a unique signature of yeast fermentation. Using genetic tools, we determined that the evolutionarily ancient ionotropic co-receptor IR25a is required for CO2 attraction, and that the receptors necessary for CO2 avoidance are not involved. Our study lays the foundation for future research to determine the neural circuits underlying both state- and odorant- dependent decision making in Drosophila.
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88
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Draft RW, McGill MR, Kapoor V, Murthy VN. Carpenter ants use diverse antennae sampling strategies to track odor trails. ACTA ACUST UNITED AC 2018; 221:jeb.185124. [PMID: 30266788 DOI: 10.1242/jeb.185124] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/20/2018] [Indexed: 12/20/2022]
Abstract
Directed and meaningful animal behavior depends on the ability to sense key features in the environment. Among the different environmental signals, olfactory cues are critically important for foraging, navigation and social communication in many species, including ants. Ants use their two antennae to explore the olfactory world, but how they do so remains largely unknown. In this study, we used high-resolution videography to characterize the antennae dynamics of carpenter ants (Camponotus pennsylvanicus). Antennae are highly active during both odor tracking and exploratory behavior. When tracking, ants used several distinct behavioral strategies with stereotyped antennae sampling patterns (which we call 'sinusoidal', 'probing' and 'trail following'). In all behaviors, left and right antennae movements were anti-correlated, and tracking ants exhibited biases in the use of left versus right antenna to sample the odor trail. These results suggest non-redundant roles for the two antennae. In one of the behavioral modules (trail following), ants used both antennae to detect trail edges and direct subsequent turns, suggesting a specialized form of tropotaxis. Lastly, removal of an antenna resulted not only in less accurate tracking but also in changes in the sampling pattern of the remaining antenna. Our quantitative characterization of odor trail tracking lays a foundation to build better models of olfactory sensory processing and sensorimotor behavior in terrestrial insects.
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Affiliation(s)
- Ryan W Draft
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA .,Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Matthew R McGill
- Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Vikrant Kapoor
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.,Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Venkatesh N Murthy
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.,Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA
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89
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Baker KL, Dickinson M, Findley TM, Gire DH, Louis M, Suver MP, Verhagen JV, Nagel KI, Smear MC. Algorithms for Olfactory Search across Species. J Neurosci 2018; 38:9383-9389. [PMID: 30381430 PMCID: PMC6209839 DOI: 10.1523/jneurosci.1668-18.2018] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/15/2018] [Accepted: 09/18/2018] [Indexed: 11/21/2022] Open
Abstract
Localizing the sources of stimuli is essential. Most organisms cannot eat, mate, or escape without knowing where the relevant stimuli originate. For many, if not most, animals, olfaction plays an essential role in search. While microorganismal chemotaxis is relatively well understood, in larger animals the algorithms and mechanisms of olfactory search remain mysterious. In this symposium, we will present recent advances in our understanding of olfactory search in flies and rodents. Despite their different sizes and behaviors, both species must solve similar problems, including meeting the challenges of turbulent airflow, sampling the environment to optimize olfactory information, and incorporating odor information into broader navigational systems.
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Affiliation(s)
- Keeley L Baker
- Department of Neuroscience, Yale School of Medicine, New Haven 06519, Connecticut
- John B. Pierce Laboratory, New Haven 06519, Connecticut
| | - Michael Dickinson
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena 91125, California
| | - Teresa M Findley
- Institute of Neuroscience, University of Oregon, Eugene 97403, Oregon
- Department of Biology, University of Oregon, Eugene 97403, Oregon
| | - David H Gire
- Department of Psychology, University of Washington, Seattle 98195, Washington
| | - Matthieu Louis
- Neuroscience Research Institute, University of Santa Barbara, Santa Barbara 93106, California
- Department of Molecular, Cellular, and Developmental Biology, University of Santa Barbara, Santa Barbara 93106, California
- Department of Physics, University of Santa Barbara, Santa Barbara 93106, California
| | - Marie P Suver
- Neuroscience Institute, New York University Langone Medical Center, New York 10016, New York, and
| | - Justus V Verhagen
- Department of Neuroscience, Yale School of Medicine, New Haven 06519, Connecticut
- John B. Pierce Laboratory, New Haven 06519, Connecticut
| | - Katherine I Nagel
- Neuroscience Institute, New York University Langone Medical Center, New York 10016, New York, and
| | - Matthew C Smear
- Institute of Neuroscience, University of Oregon, Eugene 97403, Oregon,
- Department of Psychology, University of Oregon, Eugene 97403, Oregon
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90
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Álvarez-Salvado E, Licata AM, Connor EG, McHugh MK, King BMN, Stavropoulos N, Victor JD, Crimaldi JP, Nagel KI. Elementary sensory-motor transformations underlying olfactory navigation in walking fruit-flies. eLife 2018; 7:e37815. [PMID: 30129438 PMCID: PMC6103744 DOI: 10.7554/elife.37815] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/16/2018] [Indexed: 12/25/2022] Open
Abstract
Odor attraction in walking Drosophila melanogaster is commonly used to relate neural function to behavior, but the algorithms underlying attraction are unclear. Here, we develop a high-throughput assay to measure olfactory behavior in response to well-controlled sensory stimuli. We show that odor evokes two behaviors: an upwind run during odor (ON response), and a local search at odor offset (OFF response). Wind orientation requires antennal mechanoreceptors, but search is driven solely by odor. Using dynamic odor stimuli, we measure the dependence of these two behaviors on odor intensity and history. Based on these data, we develop a navigation model that recapitulates the behavior of flies in our apparatus, and generates realistic trajectories when run in a turbulent boundary layer plume. The ability to parse olfactory navigation into quantifiable elementary sensori-motor transformations provides a foundation for dissecting neural circuits that govern olfactory behavior.
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Affiliation(s)
- Efrén Álvarez-Salvado
- Neuroscience InstituteNew York University Langone Medical CenterNew YorkUnited States
| | - Angela M Licata
- Neuroscience InstituteNew York University Langone Medical CenterNew YorkUnited States
| | - Erin G Connor
- Department of Civil, Environmental and Architectural EngineeringUniversity of Colorado BoulderBoulderUnited States
| | - Margaret K McHugh
- Department of Civil, Environmental and Architectural EngineeringUniversity of Colorado BoulderBoulderUnited States
| | - Benjamin MN King
- Neuroscience InstituteNew York University Langone Medical CenterNew YorkUnited States
| | - Nicholas Stavropoulos
- Neuroscience InstituteNew York University Langone Medical CenterNew YorkUnited States
| | - Jonathan D Victor
- Institute for Computational BiomedicineWeill Cornell Medical CollegeNew YorkUnited States
- Feil Family Brain and Mind Research InstituteWeill Cornell Medical CollegeNew YorkUnited States
| | - John P Crimaldi
- Department of Civil, Environmental and Architectural EngineeringUniversity of Colorado BoulderBoulderUnited States
| | - Katherine I Nagel
- Neuroscience InstituteNew York University Langone Medical CenterNew YorkUnited States
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91
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A balance between aerodynamic and olfactory performance during flight in Drosophila. Nat Commun 2018; 9:3215. [PMID: 30097572 PMCID: PMC6086917 DOI: 10.1038/s41467-018-05708-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/05/2018] [Indexed: 11/08/2022] Open
Abstract
The ability to track odor plumes to their source (food, mate, etc.) is key to the survival of many insects. During this odor-guided navigation, flapping wings could actively draw odorants to the antennae to enhance olfactory sensitivity, but it is unclear if improving olfactory function comes at a cost to aerodynamic performance. Here, we computationally quantify the odor plume features around a fruit fly in forward flight and confirm that the antenna is well positioned to receive a significant increase of odor mass flux (peak 1.8 times), induced by wing flapping, vertically from below the body but not horizontally. This anisotropic odor spatial sampling may have important implications for behavior and the algorithm during plume tracking. Further analysis also suggests that, because both aerodynamic and olfactory functions are indispensable during odor-guided navigation, the wing shape and size may be a balance between the two functions.
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92
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Morphology of visual projection neurons supplying premotor area in the brain of the silkmoth Bombyx mori. Cell Tissue Res 2018; 374:497-515. [DOI: 10.1007/s00441-018-2892-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 07/05/2018] [Indexed: 12/14/2022]
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93
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Cribellier A, van Erp JA, Hiscox A, Lankheet MJ, van Leeuwen JL, Spitzen J, Muijres FT. Flight behaviour of malaria mosquitoes around odour-baited traps: capture and escape dynamics. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180246. [PMID: 30225014 PMCID: PMC6124112 DOI: 10.1098/rsos.180246] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
Host-seeking mosquitoes rely on a range of sensory cues to find and approach blood hosts, as well as to avoid host detection. By using odour blends and visual cues that attract anthropophilic mosquitoes, odour-baited traps have been developed to monitor and control human pathogen-transmitting vectors. Although long-range attraction of such traps has already been studied thoroughly, close-range response of mosquitoes to these traps has been largely ignored. Here, we studied the flight behaviour of female malaria mosquitoes (Anopheles coluzzii) in the immediate vicinity of a commercially available odour-baited trap, positioned in a hanging and standing orientation. By analysing more than 2500 three-dimensional flight tracks, we elucidated how mosquitoes reacted to the trap, and how this led to capture. The measured flight dynamics revealed two distinct stereotypical behaviours: (i) mosquitoes that approached a trap tended to simultaneously fly downward towards the ground; (ii) mosquitoes that came close to a trap changed their flight direction by rapidly accelerating upward. The combination of these behaviours led to strikingly different flight patterns and capture dynamics, resulting in contrasting short-range attractiveness and capture mechanism of the oppositely oriented traps. These new insights may help in improving odour-baited traps, and consequently their contribution in global vector control strategies.
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Affiliation(s)
- Antoine Cribellier
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Jens A. van Erp
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | - Alexandra Hiscox
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands
| | - Martin J. Lankheet
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
| | | | - Jeroen Spitzen
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands
| | - Florian T. Muijres
- Experimental Zoology Group, Wageningen University, Wageningen, The Netherlands
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94
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Information-theoretic analysis of realistic odor plumes: What cues are useful for determining location? PLoS Comput Biol 2018; 14:e1006275. [PMID: 29990365 PMCID: PMC6054425 DOI: 10.1371/journal.pcbi.1006275] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 07/20/2018] [Accepted: 05/31/2018] [Indexed: 01/30/2023] Open
Abstract
Many species rely on olfaction to navigate towards food sources or mates. Olfactory navigation is a challenging task since odor environments are typically turbulent. While time-averaged odor concentration varies smoothly with the distance to the source, instaneous concentrations are intermittent and obtaining stable averages takes longer than the typical intervals between animals’ navigation decisions. How to effectively sample from the odor distribution to determine sampling location is the focus in this article. To investigate which sampling strategies are most informative about the location of an odor source, we recorded three naturalistic stimuli with planar lased-induced fluorescence and used an information-theoretic approach to quantify the information that different sampling strategies provide about sampling location. Specifically, we compared multiple sampling strategies based on a fixed number of coding bits for encoding the olfactory stimulus. When the coding bits were all allocated to representing odor concentration at a single sensor, information rapidly saturated. Using the same number of coding bits in two sensors provides more information, as does coding multiple samples at different times. When accumulating multiple samples at a fixed location, the temporal sequence does not yield a large amount of information and can be averaged with minimal loss. Furthermore, we show that histogram-equalization is not the most efficient way to use coding bits when using the olfactory sample to determine location. Navigating towards a food source or mating partner based on an animals’ sense of smell is a difficult task due to the complex spatiotemporal distribution of odor molecules. The most basic aspect of this task is the acquisition of samples from the environment. It is clear that odor concentration does not vary smoothly across space in many natural foraging environments. Using data from three different naturalistic environments, we compare different sampling strategies and assess their efficacy in determining the sources’ location. Our findings show that coarsely encoding the concentration of samples at separate sensors and/or multiple times provides more information than encoding fewer samples with higher resolution. Furthermore, coding resources should be focused on discriminating rare high-concentration odor samples, which are very informative about the sampling location. Such a nonlinear transformation can be implemented biologically by the receptor binding kinetics that bind odorants as a first stage of the sampling process. A further implication is that animals as well as computational models of algorithms can operate efficiently with a coarse representation of the odor concentration.
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95
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Namiki S, Wada S, Kanzaki R. Descending neurons from the lateral accessory lobe and posterior slope in the brain of the silkmoth Bombyx mori. Sci Rep 2018; 8:9663. [PMID: 29941958 PMCID: PMC6018430 DOI: 10.1038/s41598-018-27954-5] [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: 01/19/2018] [Accepted: 04/24/2018] [Indexed: 11/17/2022] Open
Abstract
A population of descending neurons connect the brain and thoracic motor center, playing a critical role in controlling behavior. We examined the anatomical organization of descending neurons (DNs) in the brain of the silkmoth Bombyx mori. Moth pheromone orientation is a good model to investigate neuronal mechanisms of behavior. Based on mass staining and single-cell staining, we evaluated the anatomical organization of neurite distribution by DNs in the brain. Dense innervation was observed in the posterior-ventral part of the brain called the posterior slope (PS). We analyzed the morphology of DNs innervating the lateral accessory lobe (LAL), which is considered important for moth olfactory behavior. We observed that all LAL DNs also innervate the PS, suggesting the integration of signals from the LAL and PS. We also identified a set of DNs innervating the PS but not the LAL. These DNs were sensitive to the sex pheromone, suggesting a role of the PS in motor control for pheromone processing. Here we discuss the organization of descending pathways for pheromone orientation.
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Affiliation(s)
- Shigehiro Namiki
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8904, Japan.
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96
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Faruque IA, Muijres FT, Macfarlane KM, Kehlenbeck A, Humbert JS. Identification of optimal feedback control rules from micro-quadrotor and insect flight trajectories. BIOLOGICAL CYBERNETICS 2018; 112:165-179. [PMID: 29299686 DOI: 10.1007/s00422-017-0742-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 12/08/2017] [Indexed: 06/07/2023]
Abstract
This paper presents "optimal identification," a framework for using experimental data to identify the optimality conditions associated with the feedback control law implemented in the measurements. The technique compares closed loop trajectory measurements against a reduced order model of the open loop dynamics, and uses linear matrix inequalities to solve an inverse optimal control problem as a convex optimization that estimates the controller optimality conditions. In this study, the optimal identification technique is applied to two examples, that of a millimeter-scale micro-quadrotor with an engineered controller on board, and the example of a population of freely flying Drosophila hydei maneuvering about forward flight. The micro-quadrotor results show that the performance indices used to design an optimal flight control law for a micro-quadrotor may be recovered from the closed loop simulated flight trajectories, and the Drosophila results indicate that the combined effect of the insect longitudinal flight control sensing and feedback acts principally to regulate pitch rate.
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Affiliation(s)
- Imraan A Faruque
- School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK, USA.
| | | | - Kenneth M Macfarlane
- Department of Aerospace Engineering, University of Maryland, College Park, MD, USA
| | - Andrew Kehlenbeck
- Department of Aerospace Engineering, University of Maryland, College Park, MD, USA
| | - J Sean Humbert
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA
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97
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High Precision of Spike Timing across Olfactory Receptor Neurons Allows Rapid Odor Coding in Drosophila. iScience 2018; 4:76-83. [PMID: 30240755 PMCID: PMC6147046 DOI: 10.1016/j.isci.2018.05.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/19/2018] [Accepted: 05/14/2018] [Indexed: 01/10/2023] Open
Abstract
In recent years, it has become evident that olfaction is a fast sense, and millisecond short differences in stimulus onsets are used by animals to analyze their olfactory environment. In contrast, olfactory receptor neurons are thought to be relatively slow and temporally imprecise. These observations have led to a conundrum: how, then, can an animal resolve fast stimulus dynamics and smell with high temporal acuity? Using parallel recordings from olfactory receptor neurons in Drosophila, we found hitherto unknown fast and temporally precise odorant-evoked spike responses, with first spike latencies (relative to odorant arrival) down to 3 ms and with a SD below 1 ms. These data provide new upper bounds for the speed of olfactory processing and suggest that the insect olfactory system could use the precise spike timing for olfactory coding and computation, which can explain insects' rapid processing of temporal stimuli when encountering turbulent odor plumes. Olfactory receptor neuron responses are fast and temporally precise Odor-evoked spikes can occur 3 ms after odorant arrival and jitter less than 1 ms First-spike timing varies over a wider concentration range than spike rate Neural network model demonstrates the plausibility of a spike-timing code for odors
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98
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Lüdke A, Raiser G, Nehrkorn J, Herz AVM, Galizia CG, Szyszka P. Calcium in Kenyon Cell Somata as a Substrate for an Olfactory Sensory Memory in Drosophila. Front Cell Neurosci 2018; 12:128. [PMID: 29867361 PMCID: PMC5960692 DOI: 10.3389/fncel.2018.00128] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022] Open
Abstract
Animals can form associations between temporally separated stimuli. To do so, the nervous system has to retain a neural representation of the first stimulus until the second stimulus appears. The neural substrate of such sensory stimulus memories is unknown. Here, we search for a sensory odor memory in the insect olfactory system and characterize odorant-evoked Ca2+ activity at three consecutive layers of the olfactory system in Drosophila: in olfactory receptor neurons (ORNs) and projection neurons (PNs) in the antennal lobe, and in Kenyon cells (KCs) in the mushroom body. We show that the post-stimulus responses in ORN axons, PN dendrites, PN somata, and KC dendrites are odor-specific, but they are not predictive of the chemical identity of past olfactory stimuli. However, the post-stimulus responses in KC somata carry information about the identity of previous olfactory stimuli. These findings show that the Ca2+ dynamics in KC somata could encode a sensory memory of odorant identity and thus might serve as a basis for associations between temporally separated stimuli.
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Affiliation(s)
- Alja Lüdke
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
| | - Georg Raiser
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
- International Max Planck Research School for Organismal Biology, Konstanz, Germany
| | - Johannes Nehrkorn
- Fakultät für Biologie, Ludwig-Maximilians-Universität München, Martinsried, Germany
- Bernstein Center for Computational Neuroscience, Munich, Germany
| | - Andreas V. M. Herz
- Fakultät für Biologie, Ludwig-Maximilians-Universität München, Martinsried, Germany
- Bernstein Center for Computational Neuroscience, Munich, Germany
| | - C. Giovanni Galizia
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
| | - Paul Szyszka
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
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99
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Flight motor networks modulate primary olfactory processing in the moth Manduca sexta. Proc Natl Acad Sci U S A 2018; 115:5588-5593. [PMID: 29735707 PMCID: PMC6003457 DOI: 10.1073/pnas.1722379115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Across vertebrates and invertebrates, corollary discharge circuits (CDCs) project to and inform sensory networks about an animal’s movements, which directly impact sensory processing. Failure of CDCs likely underlie sensory hallucinations in schizophrenia, Parkinson’s disease, and dyspnea, highlighting the fundamental importance of CDCs for successfully interpreting sensory cues to adaptively interact with the external world. Ultimately, understanding the role of CDCs in integrating sensory motor function will be vital to understand these diseases, but mechanistically little is known about how CDCs function. CDCs have been identified in most sensory domains except olfaction. Our findings indicate that a histaminergic CDC enhances the ability of the olfactory system to more precisely encode stimulus temporal structure, resulting in enhanced olfactory acuity. Nervous systems must distinguish sensory signals derived from an animal’s own movements (reafference) from environmentally derived sources (exafference). To accomplish this, motor networks producing reafference transmit motor information, via a corollary discharge circuit (CDC), to affected sensory networks, modulating sensory function during behavior. While CDCs have been described in most sensory modalities, none have been observed projecting to an olfactory pathway. In moths, two mesothoracic to deutocerebral histaminergic neurons (MDHns) project from flight sensorimotor centers in the mesothoracic neuromere to the antennal lobe (AL), where they provide the sole source of histamine (HA), but whether they represent a CDC is unknown. We demonstrate that MDHn spiking activity is positively correlated with wing-motor output and increased before bouts of motor activity, suggesting that MDHns communicate global locomotor state, rather than providing a precisely timed motor copy. Within the AL, HA application sharpened entrainment of projection neuron responses to odor stimuli embedded within simulated wing-beat–induced flows, whereas MDHn axotomy or AL HA receptor (HA-r) blockade reduced entrainment. This finding is consistent with higher-order CDCs, as the MDHns enhanced rather than filtered entrainment of AL projection neurons. Finally, HA-r blockade increased odor detection and discrimination thresholds in behavior assays. These results establish MDHns as a CDC that modulates AL temporal resolution, enhancing odor-guided behavior. MDHns thus appear to represent a higher-order CDC to an insect olfactory pathway; this CDC’s unique nature highlights the importance of motor-to-sensory signaling as a context-specific mechanism that fine-tunes sensory function.
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100
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Baggett V, Mishra A, Kehrer AL, Robinson AO, Shaw P, Zars T. Place learning overrides innate behaviors in Drosophila. ACTA ACUST UNITED AC 2018; 25:122-128. [PMID: 29449456 PMCID: PMC5817280 DOI: 10.1101/lm.046136.117] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 12/19/2017] [Indexed: 11/24/2022]
Abstract
Animals in a natural environment confront many sensory cues. Some of these cues bias behavioral decisions independent of experience, and action selection can reveal a stimulus–response (S–R) connection. However, in a changing environment it would be a benefit for an animal to update behavioral action selection based on experience, and learning might modify even strong S–R relationships. How animals use learning to modify S–R relationships is a largely open question. Three sensory stimuli, air, light, and gravity sources were presented to individual Drosophila melanogaster in both naïve and place conditioning situations. Flies were tested for a potential modification of the S–R relationships of anemotaxis, phototaxis, and negative gravitaxis by a contingency that associated place with high temperature. With two stimuli, significant S–R relationships were abandoned when the cue was in conflict with the place learning contingency. The role of the dunce (dnc) cAMP-phosphodiesterase and the rutabaga (rut) adenylyl cyclase were examined in all conditions. Both dnc1 and rut2080 mutant flies failed to display significant S–R relationships with two attractive cues, and have characteristically lower conditioning scores under most conditions. Thus, learning can have profound effects on separate native S–R relationships in multiple contexts, and mutation of the dnc and rut genes reveal complex effects on behavior.
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Affiliation(s)
- Vincent Baggett
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA
| | - Aditi Mishra
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA
| | - Abigail L Kehrer
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA
| | - Abbey O Robinson
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA
| | - Paul Shaw
- Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Troy Zars
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA
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