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Kheradmand B, Richardson-Ramos I, Chan S, Nelson C, Nieh JC. Honey Bees Can Use Sequence Learning to Predict Rewards from a Prior Unrewarded Visual Stimulus. INSECTS 2025; 16:358. [PMID: 40332847 PMCID: PMC12027691 DOI: 10.3390/insects16040358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2025] [Revised: 02/02/2025] [Accepted: 03/27/2025] [Indexed: 05/08/2025]
Abstract
Learning to anticipate upcoming events can increase fitness by allowing animals to choose the best course of action, and many species can learn sequences of events and anticipate rewards. To date, most studies have focused on sequences over short time scales such as a few seconds. Whereas events separated by a few seconds are easily learned, events separated by longer delays are typically more difficult to learn. Here, we show that honey bees (Apis mellifera) can learn a sequence of two visually distinct food sources alternating in profitability every few minutes. Bees were challenged to learn that the rewarded pattern was the one that was non-rewarded on the prior visit. We show that bees can predict and choose the feeder that will be rewarding upon their next approach more frequently than predicted by chance, and they improve with experience, with 64% correct choices made in the second half of their visit sequence (N = 320 visits by 20 different bees). These results increase our understanding of honey bee visual sequential learning and further demonstrate the flexibility of foragers' learning strategies.
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Affiliation(s)
- Bahram Kheradmand
- Section of Ecology, Behavior, and Evolution, Division of Biological Sciences, University of California San Diego, 9500 Gilman Dr, MC0116, La Jolla, CA 92093, USA; (I.R.-R.); (S.C.); (C.N.); (J.C.N.)
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2
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Sonter CA, Tighe M, Rader R, Wilson SC. Can Bees Detect Perfluorooctane Sulfonate (PFOS)? ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024; 43:1638-1647. [PMID: 38721889 DOI: 10.1002/etc.5881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/14/2023] [Accepted: 04/01/2024] [Indexed: 06/27/2024]
Abstract
The European honey bee (Apis mellifera) is an important crop pollinator threatened by multiple stressors, including exposure to contaminants. Perfluorooctane sulfonate (PFOS) is a persistent global contaminant that accumulates and biomagnifies in food chains and is detected in honey. Even sublethal exposure to PFOS is detrimental to bee health, but exposure routes are unclear and nothing is known about bee response (detection, avoidance, or attraction) to PFOS. Using Y-mazes, we studied the response of individual bees to PFOS-spiked sugar syrup at four concentrations, 0.02, 30, 61 and 103 µg L-1. Bee activity, choice behavior, and drink duration for unspiked and spiked sugar syrup was recorded for 10 min in the Y-maze system. Most bees (≥80%) tasted and then drank the sugar syrup solutions, including the PFOS-contaminated syrup. Only at 61 and 103 µg L-1 did bees significantly avoid drinking PFOS-spiked syrup, and only when given a choice with unspiked syrup. When the choice of consuming unspiked syrup was removed, the bees drank PFOS-spiked syrup at all the PFOS concentrations tested, and avoidance was not evident. Avoidance was not observed in any treatment at 0.02 or 30 µg L-1 PFOS, concentrations that are frequently reported in environmental waters in contaminated areas. These findings confirm that bees will access PFOS-contaminated resources at concentrations detrimental to the colony health, and provide evidence of potential exposure pathways that may threaten crop pollination services and also human health via food chain transfer in PFOS-contaminated areas. Environ Toxicol Chem 2024;43:1638-1647. © 2024 SETAC.
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Affiliation(s)
- Carolyn A Sonter
- School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
| | - Matthew Tighe
- School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
| | - Romina Rader
- School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
| | - Susan C Wilson
- School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
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3
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Zanola D, Czaczkes TJ, Josens R. Ants evade harmful food by active abandonment. Commun Biol 2024; 7:84. [PMID: 38216747 PMCID: PMC10786876 DOI: 10.1038/s42003-023-05729-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/19/2023] [Indexed: 01/14/2024] Open
Abstract
Invasive ants, such as the Argentine ant, pose a severe economic and ecological threat. Despite advancements in baiting techniques, effectively managing established ant populations remains a daunting challenge, often ending in failure. Ant colonies employ behavioural immunity against pathogens, raising the question of whether ants can collectively respond to toxic baits. This study investigates whether ant colonies actively abandon palatable but harmful food sources. We provided two sucrose feeders, each generating a new foraging trail, with one transitioning to offering toxic food. Six hours later, ant activity on that path decreases, while activity on the non-toxic food and the trunk trail remains unaffected, excluding factors like population decline or satiation as reasons for the activity decline. Laboratory experiments confirmed that ants remained alive six hours after ingesting toxic food. Ant presence remains low on the toxic food path for days, gradually decreasing along the nearest section of the trunk trail. This abandonment behaviour minimises the entry of harmful food into the nest, acting as a protective social mechanism. The evasion of toxic bait-treated areas likely contributes considerably to control failures. Understanding the behavioural response to toxic baits is essential for developing effective strategies to combat invasive ant species.
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Affiliation(s)
- Daniel Zanola
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina
| | - Tomer J Czaczkes
- Animal Comparative Economics Laboratory, Faculty of Biology and Preclinical Medicine, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany
| | - Roxana Josens
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina.
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4
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Lafon G, Geng H, Avarguès-Weber A, Buatois A, Massou I, Giurfa M. The Neural Signature of Visual Learning Under Restrictive Virtual-Reality Conditions. Front Behav Neurosci 2022; 16:846076. [PMID: 35250505 PMCID: PMC8888666 DOI: 10.3389/fnbeh.2022.846076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 01/21/2022] [Indexed: 11/22/2022] Open
Abstract
Honey bees are reputed for their remarkable visual learning and navigation capabilities. These capacities can be studied in virtual reality (VR) environments, which allow studying performances of tethered animals in stationary flight or walk under full control of the sensory environment. Here, we used a 2D VR setup in which a tethered bee walking stationary under restrictive closed-loop conditions learned to discriminate vertical rectangles differing in color and reinforcing outcome. Closed-loop conditions restricted stimulus control to lateral displacements. Consistently with prior VR analyses, bees learned to discriminate the trained stimuli. Ex vivo analyses on the brains of learners and non-learners showed that successful learning led to a downregulation of three immediate early genes in the main regions of the visual circuit, the optic lobes (OLs) and the calyces of the mushroom bodies (MBs). While Egr1 was downregulated in the OLs, Hr38 and kakusei were coincidently downregulated in the calyces of the MBs. Our work thus reveals that color discrimination learning induced a neural signature distributed along the sequential pathway of color processing that is consistent with an inhibitory trace. This trace may relate to the motor patterns required to solve the discrimination task, which are different from those underlying pathfinding in 3D VR scenarios allowing for navigation and exploratory learning and which lead to IEG upregulation.
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Affiliation(s)
- Gregory Lafon
- Research Center on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Haiyang Geng
- Research Center on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou, China
| | - Aurore Avarguès-Weber
- Research Center on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Alexis Buatois
- Research Center on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Isabelle Massou
- Research Center on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Martin Giurfa
- Research Center on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou, China
- Institut Universitaire de France, Paris, France
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5
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Visual learning in a virtual reality environment upregulates immediate early gene expression in the mushroom bodies of honey bees. Commun Biol 2022; 5:130. [PMID: 35165405 PMCID: PMC8844430 DOI: 10.1038/s42003-022-03075-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 01/26/2022] [Indexed: 11/08/2022] Open
Abstract
Free-flying bees learn efficiently to solve numerous visual tasks. Yet, the neural underpinnings of this capacity remain unexplored. We used a 3D virtual reality (VR) environment to study visual learning and determine if it leads to changes in immediate early gene (IEG) expression in specific areas of the bee brain. We focused on kakusei, Hr38 and Egr1, three IEGs that have been related to bee foraging and orientation, and compared their relative expression in the calyces of the mushroom bodies, the optic lobes and the rest of the brain after color discrimination learning. Bees learned to discriminate virtual stimuli displaying different colors and retained the information learned. Successful learners exhibited Egr1 upregulation only in the calyces of the mushroom bodies, thus uncovering a privileged involvement of these brain regions in associative color learning and the usefulness of Egr1 as a marker of neural activity induced by this phenomenon.
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Motion cues from the background influence associative color learning of honey bees in a virtual-reality scenario. Sci Rep 2021; 11:21127. [PMID: 34702914 PMCID: PMC8548521 DOI: 10.1038/s41598-021-00630-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/13/2021] [Indexed: 11/21/2022] Open
Abstract
Honey bees exhibit remarkable visual learning capacities, which can be studied using virtual reality (VR) landscapes in laboratory conditions. Existing VR environments for bees are imperfect as they provide either open-loop conditions or 2D displays. Here we achieved a true 3D environment in which walking bees learned to discriminate a rewarded from a punished virtual stimulus based on color differences. We included ventral or frontal background cues, which were also subjected to 3D updating based on the bee movements. We thus studied if and how the presence of such motion cues affected visual discrimination in our VR landscape. Our results showed that the presence of frontal, and to a lesser extent, of ventral background motion cues impaired the bees' performance. Whenever these cues were suppressed, color discrimination learning became possible. We analyzed the specific contribution of foreground and background cues and discussed the role of attentional interference and differences in stimulus salience in the VR environment to account for these results. Overall, we show how background and target cues may interact at the perceptual level and influence associative learning in bees. In addition, we identify issues that may affect decision-making in VR landscapes, which require specific control by experimenters.
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Adipokinetic hormone (AKH), energy budget and their effect on feeding and gustatory processes of foraging honey bees. Sci Rep 2021; 11:18311. [PMID: 34526585 PMCID: PMC8443544 DOI: 10.1038/s41598-021-97851-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 08/31/2021] [Indexed: 02/08/2023] Open
Abstract
The adipokinetic hormone (AKH) of insects is considered an equivalent of the mammalian hormone glucagon as it induces fast mobilization of carbohydrates and lipids from the fat body upon starvation. Yet, in foraging honey bees, which lack fat body storage for carbohydrates, it was suggested that AKH may have lost its original function. Here we manipulated the energy budget of bee foragers to determine the effect of AKH on appetitive responses. As AKH participates in a cascade leading to acceptance of unpalatable substances in starved Drosophila, we also assessed its effect on foragers presented with sucrose solution spiked with salicin. Starved and partially-fed bees were topically exposed with different doses of AKH to determine if this hormone modifies food ingestion and sucrose responsiveness. We found a significant effect of the energy budget (i.e. starved vs. partially-fed) on the decision to ingest or respond to both pure sucrose solution and sucrose solution spiked with salicin, but no effect of AKH per se. These results are consistent with a loss of function of AKH in honey bee foragers, in accordance with a social life that implies storing energy resources in the hive, in amounts that exceed individual needs.
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Wada-Katsumata A, Schal C. Olfactory Learning Supports an Adaptive Sugar-Aversion Gustatory Phenotype in the German Cockroach. INSECTS 2021; 12:724. [PMID: 34442290 PMCID: PMC8397102 DOI: 10.3390/insects12080724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/09/2021] [Accepted: 08/09/2021] [Indexed: 11/16/2022]
Abstract
An association of food sources with odors prominently guides foraging behavior in animals. To understand the interaction of olfactory memory and food preferences, we used glucose-averse (GA) German cockroaches. Multiple populations of cockroaches evolved a gustatory polymorphism where glucose is perceived as a deterrent and enables GA cockroaches to avoid eating glucose-containing toxic baits. Comparative behavioral analysis using an operant conditioning paradigm revealed that learning and memory guide foraging decisions. Cockroaches learned to associate specific food odors with fructose (phagostimulant, reward) within only a 1 h conditioning session, and with caffeine (deterrent, punishment) after only three 1 h conditioning sessions. Glucose acted as reward in wild type (WT) cockroaches, but GA cockroaches learned to avoid an innately attractive odor that was associated with glucose. Olfactory memory was retained for at least 3 days after three 1 h conditioning sessions. Our results reveal that specific tastants can serve as potent reward or punishment in olfactory associative learning, which reinforces gustatory food preferences. Olfactory learning, therefore, reinforces behavioral resistance of GA cockroaches to sugar-containing toxic baits. Cockroaches may also generalize their olfactory learning to baits that contain the same or similar attractive odors even if they do not contain glucose.
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Affiliation(s)
- Ayako Wada-Katsumata
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| | - Coby Schal
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
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9
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Nectar non-protein amino acids (NPAAs) do not change nectar palatability but enhance learning and memory in honey bees. Sci Rep 2021; 11:11721. [PMID: 34083559 PMCID: PMC8175726 DOI: 10.1038/s41598-021-90895-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/17/2021] [Indexed: 02/04/2023] Open
Abstract
Floral nectar is a pivotal element of the intimate relationship between plants and pollinators. Nectars are composed of a plethora of nutritionally valuable compounds but also hundreds of secondary metabolites (SMs) whose function remains elusive. Here we performed a set of behavioural experiments to study whether five ubiquitous nectar non-protein amino acids (NPAAs: β-alanine, GABA, citrulline, ornithine and taurine) interact with gustation, feeding preference, and learning and memory in Apis mellifera. We showed that foragers were unable to discriminate NPAAs from water when only accessing antennal chemo-tactile information and that freely moving bees did not exhibit innate feeding preferences for NPAAs. Also, NPAAs did not alter food consumption or longevity in caged bees over 10 days. Taken together our data suggest that natural concentrations of NPAAs did not alter nectar palatability to bees. Olfactory conditioning assays showed that honey bees were more likely to learn a scent when it signalled a sucrose reward containing either β-alanine or GABA, and that GABA enhanced specific memory retention. Conversely, when ingested two hours prior to conditioning, GABA, β-alanine, and taurine weakened bees' acquisition performances but not specific memory retention, which was enhanced in the case of β-alanine and taurine. Neither citrulline nor ornithine affected learning and memory. NPAAs in nectars may represent a cooperative strategy adopted by plants to attract beneficial pollinators.
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Bestea L, Réjaud A, Sandoz JC, Carcaud J, Giurfa M, de Brito Sanchez MG. Peripheral taste detection in honey bees: What do taste receptors respond to? Eur J Neurosci 2021; 54:4417-4444. [PMID: 33934411 DOI: 10.1111/ejn.15265] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 11/30/2022]
Abstract
Understanding the neural principles governing taste perception in species that bear economic importance or serve as research models for other sensory modalities constitutes a strategic goal. Such is the case of the honey bee (Apis mellifera), which is environmentally and socioeconomically important, given its crucial role as pollinator agent in agricultural landscapes and which has served as a traditional model for visual and olfactory neurosciences and for research on communication, navigation, and learning and memory. Here we review the current knowledge on honey bee gustatory receptors to provide an integrative view of peripheral taste detection in this insect, highlighting specificities and commonalities with other insect species. We describe behavioral and electrophysiological responses to several tastant categories and relate these responses, whenever possible, to known molecular receptor mechanisms. Overall, we adopted an evolutionary and comparative perspective to understand the neural principles of honey bee taste and define key questions that should be answered in future gustatory research centered on this insect.
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Affiliation(s)
- Louise Bestea
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS (UMR 5169), University of Toulouse, Toulouse, France
| | - Alexandre Réjaud
- Laboratoire Evolution et Diversité Biologique, CNRS, IRD (UMR 5174), University of Toulouse, Toulouse, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, CNRS, IRD (UMR 9191, University Paris Saclay, Gif-sur-Yvette, France
| | - Julie Carcaud
- Evolution, Genomes, Behavior and Ecology, CNRS, IRD (UMR 9191, University Paris Saclay, Gif-sur-Yvette, France
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS (UMR 5169), University of Toulouse, Toulouse, France.,College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou, China.,Institut Universitaire de France (IUF), Paris, France
| | - Maria Gabriela de Brito Sanchez
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS (UMR 5169), University of Toulouse, Toulouse, France
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11
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Competition and pollen wars: simulations reveal the dynamics of competition mediated through heterospecific pollen transfer by non-flower constant insects. THEOR ECOL-NETH 2020. [DOI: 10.1007/s12080-020-00490-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Lai Y, Despouy E, Sandoz JC, Su S, de Brito Sanchez MG, Giurfa M. Degradation of an appetitive olfactory memory via devaluation of sugar reward is mediated by 5-HT signaling in the honey bee. Neurobiol Learn Mem 2020; 173:107278. [PMID: 32652234 DOI: 10.1016/j.nlm.2020.107278] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/29/2020] [Accepted: 07/06/2020] [Indexed: 02/06/2023]
Abstract
Conditioned taste aversion (CTA) learning induces the devaluation of a preferred food through its pairing with a stimulus inducing internal illness. In invertebrates, it is still unclear how this aversive learning impairs the memories of stimuli that had been associated with the appetitive food prior to its devaluation. Here we studied this phenomenon in the honey bee and characterized its neural underpinnings. We first trained bees to associate an odorant (conditioned stimulus, CS) with appetitive fructose solution (unconditioned stimulus, US) using a Pavlovian olfactory conditioning. We then subjected the bees that learned the association to a CTA training during which the antennal taste of fructose solution was contingent or not to the ingestion of quinine solution, which induces malaise a few hours after ingestion. Only the group experiencing contingent fructose stimulation and quinine-based malaise exhibited a decrease in responses to the fructose and a concomitant decrease in odor-specific retention in tests performed 23 h after the original odor conditioning. Furthermore, injection of dopamine- and serotonin-receptor antagonists after CTA learning revealed that this long-term decrease was mediated by serotonergic signaling as its blockade rescued both the responses to fructose and the odor-specific memory 23 h after conditioning. The impairment of a prior CS memory by subsequent CTA conditioning confirms that bees retrieve a devaluated US representation when presented with the CS. Our findings further highlight the importance of serotonergic signaling in aversive learning in the bee and uncover mechanisms underlying aversive memories induced by internal illness in invertebrates.
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Affiliation(s)
- Yuan Lai
- College of Animal Science (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China; Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse, France
| | - Elodie Despouy
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, Université Paris-Saclay, CNRS, IRD, 1 avenue de la Terrasse, F-91198 Gif-sur-Yvette, France
| | - Songkun Su
- College of Animal Science (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Maria Gabriela de Brito Sanchez
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse, France.
| | - Martin Giurfa
- College of Animal Science (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China; Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse, France; Institut Universitaire de France (IUF), France.
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13
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Hostachy C, Couzi P, Hanafi-Portier M, Portemer G, Halleguen A, Murmu M, Deisig N, Dacher M. Responsiveness to Sugar Solutions in the Moth Agrotis ipsilon: Parameters Affecting Proboscis Extension. Front Physiol 2019; 10:1423. [PMID: 31849694 PMCID: PMC6888557 DOI: 10.3389/fphys.2019.01423] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/04/2019] [Indexed: 12/05/2022] Open
Abstract
Adult moths need energy and nutrients for reproducing and obtain them mainly by consuming flower nectar (a solution of sugars and other compounds). Gustatory perception gives them information on the plants they feed on. Feeding and food perception are integrated in the proboscis extension response, which occurs when their antennae touch a sugar solution. We took advantage of this reflex to explore moth sugar responsiveness depending on different parameters (i.e., sex, age, satiety, site of presentation, and composition of the solution). We observed that starvation but not age induced higher response rates to sucrose. Presentation of sucrose solutions in a randomized order confirmed that repeated sugar stimulations did not affect the response rate; however, animals were sometimes sensitized to water, indicating sucrose presentation might induce non-associative plasticity. Leg stimulation was much less efficient than antennal stimulation to elicit a response. Quinine prevented and terminated sucrose-elicited proboscis extension. Males but not females responded slightly more to sucrose than to fructose. Animals of either sex rarely reacted to glucose, but curiously, mixtures in which half sucrose or fructose were replaced by glucose elicited the same response rate than sucrose or fructose alone. Fructose synergized the response when mixed with sucrose in male but not female moths. This is consistent with the fact that nectars consumed by moths in nature are mixtures of these three sugars, which suggests an adaptation to nectar perception.
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Affiliation(s)
| | | | | | | | | | | | | | - Matthieu Dacher
- Sorbonne Université, Université Paris Est Créteil, INRA, CNRS, IRD – Institute for Ecology and Environmental Sciences of Paris (iEES Paris), Paris, France
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14
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Buatois A, Flumian C, Schultheiss P, Avarguès-Weber A, Giurfa M. Transfer of Visual Learning Between a Virtual and a Real Environment in Honey Bees: The Role of Active Vision. Front Behav Neurosci 2018; 12:139. [PMID: 30057530 PMCID: PMC6053632 DOI: 10.3389/fnbeh.2018.00139] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/18/2018] [Indexed: 01/19/2023] Open
Abstract
To study visual learning in honey bees, we developed a virtual reality (VR) system in which the movements of a tethered bee walking stationary on a spherical treadmill update the visual panorama presented in front of it (closed-loop conditions), thus creating an experience of immersion within a virtual environment. In parallel, we developed a small Y-maze with interchangeable end-boxes, which allowed replacing repeatedly a freely walking bee into the starting point of the maze for repeated decision recording. Using conditioning and transfer experiments between the VR setup and the Y-maze, we studied the extent to which movement freedom and active vision are crucial for learning a simple color discrimination. Approximately 57% of the bees learned the visual discrimination in both conditions. Transfer from VR to the maze improved significantly the bees’ performances: 75% of bees having chosen the CS+ continued doing so and 100% of bees having chosen the CS− reverted their choice in favor of the CS+. In contrast, no improvement was seen for these two groups of bees during the reciprocal transfer from the Y-maze to VR. In this case, bees exhibited inconsistent choices in the VR setup. The asymmetric transfer between contexts indicates that the information learned in each environment may be different despite the similar learning success. Moreover, it shows that reducing the possibility of active vision and movement freedom in the passage from the maze to the VR impairs the expression of visual learning while increasing them in the reciprocal transfer improves it. Our results underline the active nature of visual processing in bees and allow discussing the developments required for immersive VR experiences in insects.
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Affiliation(s)
- Alexis Buatois
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Clara Flumian
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Patrick Schultheiss
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Aurore Avarguès-Weber
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, Toulouse, France
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15
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Guiraud M, Hotier L, Giurfa M, de Brito Sanchez MG. Aversive gustatory learning and perception in honey bees. Sci Rep 2018; 8:1343. [PMID: 29358592 PMCID: PMC5778057 DOI: 10.1038/s41598-018-19715-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/08/2018] [Indexed: 11/09/2022] Open
Abstract
Taste perception allows discriminating edible from non-edible items and is crucial for survival. In the honey bee, the gustatory sense has remained largely unexplored, as tastants have been traditionally used as reinforcements rather than as stimuli to be learned and discriminated. Here we provide the first characterization of antennal gustatory perception in this insect using a novel conditioning protocol in which tastants are dissociated from their traditional food-reinforcement role to be learned as predictors of punishment. We found that bees have a limited gustatory repertoire via their antennae: they discriminate between broad gustatory modalities but not within modalities, and are unable to differentiate bitter substances from water. Coupling gustatory conditioning with blockade of aminergic pathways in the bee brain revealed that these pathways are not restricted to encode reinforcements but may also encode conditioned stimuli. Our results reveal unknown aspects of honey bee gustation, and bring new elements for comparative analyses of gustatory perception in animals.
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Affiliation(s)
- Marie Guiraud
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, 31062, Toulouse cedex 9, France.,Queen Mary University of London, School of Biological and Chemical Sciences, Biological and Experimental Psychology, Mile End Road, London, E1 4NS, United Kingdom
| | - Lucie Hotier
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, 31062, Toulouse cedex 9, France
| | - Martin Giurfa
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, 31062, Toulouse cedex 9, France.
| | - María Gabriela de Brito Sanchez
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, 31062, Toulouse cedex 9, France.
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16
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Aguiar JMRBV, Roselino AC, Sazima M, Giurfa M. Can honey bees discriminate between floral-fragrance isomers? J Exp Biol 2018; 221:jeb.180844. [DOI: 10.1242/jeb.180844] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/18/2018] [Indexed: 11/20/2022]
Abstract
Many flowering plants present variable complex fragrances, which usually include different isomers of the same molecule. As fragrance is an essential cue for flower recognition by pollinators, we ask if honey bees discriminate between floral-fragrance isomers in an appetitive context. We used the olfactory conditioning of the proboscis extension response (PER), which allows training a restrained bee to an odor paired with sucrose solution. Bees were trained under an absolute (a single odorant rewarded) or a differential conditioning regime (a rewarded vs. a non-rewarded odorant) using four different pairs of isomers. One hour after training, discrimination and generalization between pairs of isomers were tested. Bees trained under absolute conditioning exhibited high generalization between isomers and discriminated only one out of four isomer pairs; after differential conditioning, they learned to differentiate between two out of four pairs of isomers but in all cases generalization responses to the non-rewarding isomer remained high. Adding an aversive taste to the non-rewarded isomer facilitated discrimination of isomers that otherwise seemed non-discriminable, but generalization remained high. Although honey bees discriminated isomers under certain conditions, they achieved the task with difficulty and tended to generalize between them, thus showing that these molecules were perceptually similar to them. We conclude that the presence of isomers within floral fragrances might not necessarily contribute to a dramatic extent to floral odor diversity.
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Affiliation(s)
- João Marcelo Robazzi Bignelli Valente Aguiar
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, France
- Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Ana Carolina Roselino
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Marlies Sazima
- Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Martin Giurfa
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, France
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17
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Liao LH, Wu WY, Berenbaum MR. Behavioral responses of honey bees (Apis mellifera) to natural and synthetic xenobiotics in food. Sci Rep 2017; 7:15924. [PMID: 29162843 PMCID: PMC5698444 DOI: 10.1038/s41598-017-15066-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/16/2017] [Indexed: 01/01/2023] Open
Abstract
While the natural foods of the western honey bee (Apis mellifera) contain diverse phytochemicals, in contemporary agroecosystems honey bees also encounter pesticides as floral tissue contaminants. Whereas some ubiquitous phytochemicals in bee foods up-regulate detoxification and immunity genes, thereby benefiting nestmates, many agrochemical pesticides adversely affect bee health even at sublethal levels. How honey bees assess xenobiotic risk to nestmates as they forage is poorly understood. Accordingly, we tested nine phytochemicals ubiquitous in nectar, pollen, or propolis, as well as five synthetic xenobiotics that frequently contaminate hives—two herbicides (atrazine and glyphosate) and three fungicides (boscalid, chlorothalonil, and prochloraz). In semi-field free-flight experiments, bees were offered a choice between paired sugar water feeders amended with either a xenobiotic or solvent only (control). Among the phytochemicals, foragers consistently preferred quercetin at all five concentrations tested, as evidenced by both visitation frequency and consumption rates. This preference may reflect the long evolutionary association between honey bees and floral tissues. Of pesticides eliciting a response, bees displayed a preference at specific concentrations for glyphosate and chlorothalonil. This paradoxical preference may account for the frequency with which these pesticides occur as hive contaminants and suggests that they present a greater risk factor for honey bee health than previously suspected.
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Affiliation(s)
- Ling-Hsiu Liao
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801-3795, USA
| | - Wen-Yen Wu
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801-3795, USA
| | - May R Berenbaum
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801-3795, USA.
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18
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de Premorel G, Giurfa M, Andraud C, Gomez D. Higher iridescent-to-pigment optical effect in flowers facilitates learning, memory and generalization in foraging bumblebees. Proc Biol Sci 2017; 284:20171097. [PMID: 29070719 PMCID: PMC5666091 DOI: 10.1098/rspb.2017.1097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 09/26/2017] [Indexed: 11/12/2022] Open
Abstract
Iridescence-change of colour with changes in the angle of view or of illumination-is widespread in the living world, but its functions remain poorly understood. The presence of iridescence has been suggested in flowers where diffraction gratings generate iridescent colours. Such colours have been suggested to serve plant-pollinator communication. Here we tested whether a higher iridescence relative to corolla pigmentation would facilitate discrimination, learning and retention of iridescent visual targets. We conditioned bumblebees (Bombus terrestris) to discriminate iridescent from non-iridescent artificial flowers and we varied iridescence detectability by varying target iridescent relative to pigment optical effect. We show that bees rewarded on targets with higher iridescent relative to pigment effect required fewer choices to complete learning, showed faster generalization to novel targets exhibiting the same iridescence-to-pigment level and had better long-term memory retention. Along with optical measurements, behavioural results thus demonstrate that bees can learn iridescence-related cues as bona fide signals for flower reward. They also suggest that floral advertising may be shaped by competition between iridescence and corolla pigmentation, a fact that has important evolutionary implications for pollinators. Optical measurements narrow down the type of cues that bees may have used for learning. Beyond pollinator-plant communication, our experiments help understanding how receivers influence the evolution of iridescence signals generated by gratings.
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Affiliation(s)
| | - Martin Giurfa
- Research Centre on Animal Cognition, Centre for Integrative Biology, University of Toulouse; CNRS, UPS, France
| | | | - Doris Gomez
- UMR 7179, CNRS, National Museum of Natural History, Brunoy, France
- UMR 7588 CNRS, Institute of NanoSciences of Paris, University of Paris 6, Paris, France
- UMR 5175 CNRS, Centre for Evolutionary and Functional Ecology, Montpellier, France
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19
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Buatois A, Pichot C, Schultheiss P, Sandoz JC, Lazzari CR, Chittka L, Avarguès-Weber A, Giurfa M. Associative visual learning by tethered bees in a controlled visual environment. Sci Rep 2017; 7:12903. [PMID: 29018218 PMCID: PMC5635106 DOI: 10.1038/s41598-017-12631-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/08/2017] [Indexed: 11/22/2022] Open
Abstract
Free-flying honeybees exhibit remarkable cognitive capacities but the neural underpinnings of these capacities cannot be studied in flying insects. Conversely, immobilized bees are accessible to neurobiological investigation but display poor visual learning. To overcome this limitation, we aimed at establishing a controlled visual environment in which tethered bees walking on a spherical treadmill learn to discriminate visual stimuli video projected in front of them. Freely flying bees trained to walk into a miniature Y-maze displaying these stimuli in a dark environment learned the visual discrimination efficiently when one of them (CS+) was paired with sucrose and the other with quinine solution (CS−). Adapting this discrimination to the treadmill paradigm with a tethered, walking bee was successful as bees exhibited robust discrimination and preferred the CS+ to the CS− after training. As learning was better in the maze, movement freedom, active vision and behavioral context might be important for visual learning. The nature of the punishment associated with the CS− also affects learning as quinine and distilled water enhanced the proportion of learners. Thus, visual learning is amenable to a controlled environment in which tethered bees learn visual stimuli, a result that is important for future neurobiological studies in virtual reality.
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Affiliation(s)
- Alexis Buatois
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse cedex 09, France
| | - Cécile Pichot
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse cedex 09, France
| | - Patrick Schultheiss
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse cedex 09, France
| | - Jean-Christophe Sandoz
- Laboratory Evolution Genomes Behavior and Ecology, CNRS, Univ Paris-Sud, IRD, University Paris Saclay, F-91198, Gif-sur-Yvette, France
| | - Claudio R Lazzari
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261 CNRS, University François Rabelais of Tours, F-37200, Tours, France
| | - Lars Chittka
- Queen Mary University of London, School of Biological and Chemical Sciences, Biological and Experimental Psychology, Mile End Road, London, E1 4NS, United Kingdom
| | - Aurore Avarguès-Weber
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse cedex 09, France.
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062, Toulouse cedex 09, France.
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20
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21
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Muth F, Cooper TR, Bonilla RF, Leonard AS. A novel protocol for studying bee cognition in the wild. Methods Ecol Evol 2017. [DOI: 10.1111/2041-210x.12852] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Felicity Muth
- Department of Biology University of Nevada Reno NV USA
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22
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Barlow SE, Wright GA, Ma C, Barberis M, Farrell IW, Marr EC, Brankin A, Pavlik BM, Stevenson PC. Distasteful Nectar Deters Floral Robbery. Curr Biol 2017; 27:2552-2558.e3. [DOI: 10.1016/j.cub.2017.07.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/23/2017] [Accepted: 07/04/2017] [Indexed: 10/19/2022]
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Roper M, Fernando C, Chittka L. Insect Bio-inspired Neural Network Provides New Evidence on How Simple Feature Detectors Can Enable Complex Visual Generalization and Stimulus Location Invariance in the Miniature Brain of Honeybees. PLoS Comput Biol 2017; 13:e1005333. [PMID: 28158189 PMCID: PMC5291356 DOI: 10.1371/journal.pcbi.1005333] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 12/23/2016] [Indexed: 11/20/2022] Open
Abstract
The ability to generalize over naturally occurring variation in cues indicating food or predation risk is highly useful for efficient decision-making in many animals. Honeybees have remarkable visual cognitive abilities, allowing them to classify visual patterns by common features despite having a relatively miniature brain. Here we ask the question whether generalization requires complex visual recognition or whether it can also be achieved with relatively simple neuronal mechanisms. We produced several simple models inspired by the known anatomical structures and neuronal responses within the bee brain and subsequently compared their ability to generalize achromatic patterns to the observed behavioural performance of honeybees on these cues. Neural networks with just eight large-field orientation-sensitive input neurons from the optic ganglia and a single layer of simple neuronal connectivity within the mushroom bodies (learning centres) show performances remarkably similar to a large proportion of the empirical results without requiring any form of learning, or fine-tuning of neuronal parameters to replicate these results. Indeed, a model simply combining sensory input from both eyes onto single mushroom body neurons returned correct discriminations even with partial occlusion of the patterns and an impressive invariance to the location of the test patterns on the eyes. This model also replicated surprising failures of bees to discriminate certain seemingly highly different patterns, providing novel and useful insights into the inner workings facilitating and limiting the utilisation of visual cues in honeybees. Our results reveal that reliable generalization of visual information can be achieved through simple neuronal circuitry that is biologically plausible and can easily be accommodated in a tiny insect brain. We present two very simple neural network models based directly on the neural circuitry of honeybees. These models, using just four large-field visual input neurons from each eye that sparsely connect to a single layer of interneurons within the bee brain learning centres, are able to discriminate complex achromatic patterns without the need for an internal image representation. One model combining the visual input from both eyes showed an impressive invariance to the location of the test patterns on the retina and even succeeded with the partial occlusion of these cues, which would obviously be advantageous for free-flying bees. We show that during generalization experiments, where the models have to distinguish between two novel stimuli, one more similar to a training set of patterns, that both simple models have performances very similar to the empirical honeybee results. Our models only failed to generalize to the correct test pattern when the distractor pattern contained only a few small differences; we discuss how the protocols employed during training enable honeybees to still distinguish these stimuli. This research provides new insights into the surprisingly limited neurobiological complexity that is required for specific cognitive abilities, and how these mechanisms may be employed within the tiny brain of the bee.
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Affiliation(s)
- Mark Roper
- Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
- * E-mail:
| | - Chrisantha Fernando
- Google DeepMind, London, United Kingdom
- School of Electronic Engineering and Computer Science, Queen Mary University of London, London, United Kingdom
| | - Lars Chittka
- Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
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24
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Desmedt L, Baracchi D, Devaud JM, Giurfa M, d'Ettorre P. Aversive learning of odor-heat associations in ants. J Exp Biol 2017; 220:4661-4668. [DOI: 10.1242/jeb.161737] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 10/27/2017] [Indexed: 11/20/2022]
Abstract
Ants have recently emerged as useful models for the study of olfactory learning. In this framework, the development of a protocol for the appetitive conditioning of the maxilla-labium extension response (MaLER) provided the possibility of studying Pavlovian odor-food learning in a controlled environment. Here we extend these studies by introducing the first Pavlovian aversive learning protocol for harnessed ants in the laboratory. We worked with carpenter ants Camponotus aethiops and first determined the capacity of different temperatures applied to the body surface to elicit the typical aversive mandible opening response (MOR). We determined that 75°C is the optimal temperature to induce MOR and chose the hind legs as the stimulated body region due to their high sensitivity. We then studied the ability of ants to learn and remember odor-heat associations using 75°C as unconditioned stimulus. We studied learning and short-term retention after absolute (one odor paired with heat) and differential conditioning (a punished odor versus an unpunished odor). Our results show that ants successfully learn the odor-heat association under a differential-conditioning regime and thus exhibit conditioned MOR to the punished odor. Yet, their performance under an absolute-conditioning regime is poor. These results demonstrate that ants are capable of aversive learning and confirm previous findings about the different attentional resources solicited by differential and absolute conditioning in general.
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Affiliation(s)
- Lucie Desmedt
- Laboratory of Experimental and Comparative Ethology, University of Paris 13, Sorbonne Paris Cité, France
| | - David Baracchi
- Laboratory of Experimental and Comparative Ethology, University of Paris 13, Sorbonne Paris Cité, France
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 09, France
| | - Jean-Marc Devaud
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 09, France
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 09, France
| | - Patrizia d'Ettorre
- Laboratory of Experimental and Comparative Ethology, University of Paris 13, Sorbonne Paris Cité, France
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 09, France
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25
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Perez M, Nowotny T, d'Ettorre P, Giurfa M. Olfactory experience shapes the evaluation of odour similarity in ants: a behavioural and computational analysis. Proc Biol Sci 2016; 283:20160551. [PMID: 27581883 PMCID: PMC5013785 DOI: 10.1098/rspb.2016.0551] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/12/2016] [Indexed: 11/26/2022] Open
Abstract
Perceptual similarity between stimuli is often assessed via generalization, the response to stimuli that are similar to the one which was previously conditioned. Although conditioning procedures are variable, studies on how this variation may affect perceptual similarity remain scarce. Here, we use a combination of behavioural and computational analyses to investigate the influence of olfactory conditioning procedures on odour generalization in ants. Insects were trained following either absolute conditioning, in which a single odour (an aldehyde) was rewarded with sucrose, or differential conditioning, in which one odour (the same aldehyde) was similarly rewarded and another odour (an aldehyde differing in carbon-chain length) was punished with quinine. The response to the trained odours and generalization to other aldehydes were assessed. We show that olfactory similarity, rather than being immutable, varies with the conditioning procedure. Compared with absolute conditioning, differential conditioning enhances olfactory discrimination. This improvement is best described by a multiplicative interaction between two independent processes, the excitatory and inhibitory generalization gradients induced by the rewarded and the punished odour, respectively. We show that olfactory similarity is dramatically shaped by an individual's perceptual experience and suggest a new hypothesis for the nature of stimulus interactions underlying experience-dependent changes in perceptual similarity.
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Affiliation(s)
- Margot Perez
- Laboratory of Experimental and Comparative Ethology (LEEC), University Paris 13, Sorbonne Paris Cité, Villetaneuse, France Centre National de la Recherche Scientifique (CNRS), Research Centre on Animal Cognition (UMR5169), Toulouse, France Research Centre on Animal Cognition (UMR5169), University Paul-Sabatier, Toulouse, France
| | - Thomas Nowotny
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, UK
| | - Patrizia d'Ettorre
- Laboratory of Experimental and Comparative Ethology (LEEC), University Paris 13, Sorbonne Paris Cité, Villetaneuse, France Centre National de la Recherche Scientifique (CNRS), Research Centre on Animal Cognition (UMR5169), Toulouse, France Research Centre on Animal Cognition (UMR5169), University Paul-Sabatier, Toulouse, France
| | - Martin Giurfa
- Centre National de la Recherche Scientifique (CNRS), Research Centre on Animal Cognition (UMR5169), Toulouse, France Research Centre on Animal Cognition (UMR5169), University Paul-Sabatier, Toulouse, France
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26
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Lichtenstein L, Sommerlandt FMJ, Spaethe J. Dumb and Lazy? A Comparison of Color Learning and Memory Retrieval in Drones and Workers of the Buff-Tailed Bumblebee, Bombus terrestris, by Means of PER Conditioning. PLoS One 2015; 10:e0134248. [PMID: 26230643 PMCID: PMC4521843 DOI: 10.1371/journal.pone.0134248] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 07/07/2015] [Indexed: 11/19/2022] Open
Abstract
More than 100 years ago, Karl von Frisch showed that honeybee workers learn and discriminate colors. Since then, many studies confirmed the color learning capabilities of females from various hymenopteran species. Yet, little is known about visual learning and memory in males despite the fact that in most bee species males must take care of their own needs and must find rewarding flowers to obtain food. Here we used the proboscis extension response (PER) paradigm to study the color learning capacities of workers and drones of the bumblebee, Bombus terrestris. Light stimuli were paired with sucrose reward delivered to the insects' antennae and inducing a reflexive extension of the proboscis. We evaluated color learning (i.e. conditioned PER to color stimuli) in absolute and differential conditioning protocols and mid-term memory retention was measured two hours after conditioning. Different monochromatic light stimuli in combination with neutral density filters were used to ensure that the bumblebees could only use chromatic and not achromatic (e.g. brightness) information. Furthermore, we tested if bees were able to transfer the learned information from the PER conditioning to a novel discrimination task in a Y-maze. Both workers and drones were capable of learning and discriminating between monochromatic light stimuli and retrieved the learned stimulus after two hours. Drones performed as well as workers during conditioning and in the memory test, but failed in the transfer test in contrast to workers. Our data clearly show that bumblebees can learn to associate a color stimulus with a sugar reward in PER conditioning and that both workers and drones reach similar acquisition and mid-term retention performances. Additionally, we provide evidence that only workers transfer the learned information from a Pavlovian to an operant situation.
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Affiliation(s)
- Leonie Lichtenstein
- Department of Behavioral Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
- * E-mail:
| | - Frank M. J. Sommerlandt
- Department of Behavioral Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
| | - Johannes Spaethe
- Department of Behavioral Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
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27
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Boitard C, Devaud JM, Isabel G, Giurfa M. GABAergic feedback signaling into the calyces of the mushroom bodies enables olfactory reversal learning in honey bees. Front Behav Neurosci 2015; 9:198. [PMID: 26283938 PMCID: PMC4518197 DOI: 10.3389/fnbeh.2015.00198] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 07/13/2015] [Indexed: 11/26/2022] Open
Abstract
In reversal learning, subjects first learn to respond to a reinforced stimulus A and not to a non-reinforced stimulus B (A+ vs. B−) and then have to learn the opposite when stimulus contingencies are reversed (A− vs. B+). This change in stimulus valence generates a transitory ambiguity at the level of stimulus outcome that needs to be overcome to solve the second discrimination. Honey bees (Apis mellifera) efficiently master reversal learning in the olfactory domain. The mushroom bodies (MBs), higher-order structures of the insect brain, are required to solve this task. Here we aimed at uncovering the neural circuits facilitating reversal learning in honey bees. We trained bees using the olfactory conditioning of the proboscis extension reflex (PER) coupled with localized pharmacological inhibition of Gamma-AminoButyric Acid (GABA)ergic signaling in the MBs. We show that inhibition of ionotropic but not metabotropic GABAergic signaling into the MB calyces impairs reversal learning, but leaves intact the capacity to perform two consecutive elemental olfactory discriminations with ambiguity of stimulus valence. On the contrary, inhibition of ionotropic GABAergic signaling into the MB lobes had no effect on reversal learning. Our results are thus consistent with a specific requirement of the feedback neurons (FNs) providing ionotropic GABAergic signaling from the MB lobes to the calyces for counteracting ambiguity of stimulus valence in reversal learning.
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Affiliation(s)
- Constance Boitard
- Research Center on Animal Cognition (UMR 5169), Centre National de la Recherche Scientifique (CNRS) Toulouse, France ; Research Center on Animal Cognition (UMR 5169), Université Paul Sabatier Toulouse, France
| | - Jean-Marc Devaud
- Research Center on Animal Cognition (UMR 5169), Centre National de la Recherche Scientifique (CNRS) Toulouse, France ; Research Center on Animal Cognition (UMR 5169), Université Paul Sabatier Toulouse, France
| | - Guillaume Isabel
- Research Center on Animal Cognition (UMR 5169), Centre National de la Recherche Scientifique (CNRS) Toulouse, France ; Research Center on Animal Cognition (UMR 5169), Université Paul Sabatier Toulouse, France
| | - Martin Giurfa
- Research Center on Animal Cognition (UMR 5169), Centre National de la Recherche Scientifique (CNRS) Toulouse, France ; Research Center on Animal Cognition (UMR 5169), Université Paul Sabatier Toulouse, France
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Farnier K, Dyer AG, Taylor GS, Peters RA, Steinbauer MJ. Visual acuity trade-offs and microhabitat-driven adaptation of searching behaviour in psyllids (Hemiptera: Psylloidea: Aphalaridae). ACTA ACUST UNITED AC 2015; 218:1564-71. [PMID: 25827835 DOI: 10.1242/jeb.120808] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 03/19/2015] [Indexed: 11/20/2022]
Abstract
Insects have evolved morphological and physiological adaptations in response to selection pressures inherent to their ecology. Consequently, visual performance and acuity often significantly vary between different insect species. Whilst psychophysics has allowed for the accurate determination of visual acuity for some Lepidoptera and Hymenoptera, very little is known about other insect taxa that cannot be trained to positively respond to a given stimulus. In this study, we demonstrate that prior knowledge of insect colour preferences can be used to facilitate acuity testing. We focused on four psyllid species (Hemiptera: Psylloidea: Aphalaridae), namely Ctenarytaina eucalypti, Ctenarytaina bipartita, Anoeconeossa bundoorensis and Glycaspis brimblecombei, that differ in their colour preferences and utilization of different host-plant modules (e.g. apical buds, stems, leaf lamellae) and tested their visual acuity in a modified Y-maze adapted to suit psyllid searching behaviour. Our study revealed that psyllids have visual acuity ranging from 6.3 to 8.7 deg. Morphological measurements for different species showed a close match between inter-ommatidial angles and behaviourally determined visual angles (between 5.5 and 6.6 deg) suggesting detection of colour stimuli at the single ommatidium level. Whilst our data support isometric scaling of psyllids' eyes for C. eucalypti, C. bipartita and G. brimblecombei, a morphological trade-off between light sensitivity and spatial resolution was found in A. bundoorensis. Overall, species whose microhabitat preferences require more movement between modules appear to possess superior visual acuity. The psyllid searching behaviours that we describe with the help of tracking software depict species-specific strategies that presumably evolved to optimize searching for food and oviposition sites.
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Affiliation(s)
- Kevin Farnier
- Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, VIC 3086, Australia
| | - Adrian G Dyer
- School of Media and Communication, RMIT, Melbourne, VIC 3001, Australia
| | - Gary S Taylor
- Australian Centre for Evolutionary Biology and Biodiversity, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Richard A Peters
- Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, VIC 3086, Australia
| | - Martin J Steinbauer
- Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, VIC 3086, Australia
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