1
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Zhang T, Zhang X, Sun D, Kim WJ. Exploring the Asymmetric Body's Influence on Interval Timing Behaviors of Drosophila melanogaster. Behav Genet 2024; 54:416-425. [PMID: 39133418 DOI: 10.1007/s10519-024-10193-y] [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: 05/02/2024] [Accepted: 08/05/2024] [Indexed: 08/13/2024]
Abstract
The roles of brain asymmetry in Drosophila are diverse, encompassing the regulation of behavior, the creation of memory, neurodevelopment, and evolution. A comprehensive examination of the Drosophila brain has the potential to enhance our understanding of the functional significance of brain asymmetry in cognitive and behavioral processes, as well as its role in evolutionary perspectives. This study explores the influence of brain asymmetry on interval timing behaviors in Drosophila, with a specific focus on the asymmetric body (AB) structure. Despite being bilaterally symmetric, the AB exhibits functional asymmetry and is located within the central complex of the fly brain. Interval timing behaviors, such as rival-induced prolonged mating duration: longer mating duration behavior (LMD) and sexual experience-mediated shorter mating duration behavior (SMD), are essential for Drosophila. We utilize genetic manipulations to selectively activate or inhibit AB neurons and evaluates their impact on LMD and SMD behaviors. The results indicate that specific populations of AB neurons play unique roles in orchestrating these interval timing behaviors. Notably, inhibiting GAL4R38D01-labeled AB neurons disrupts both LMD and SMD, while GAL4R42C09 neuron inhibition affects only LMD. Moreover, hyperexcitation of GAL4R72A10-labeled AB neurons perturbs SMD. Our study identifies NetrinB (NetB) and Abdominal-B (Abd-B) are important genes for AB neurons in LMD and highlights the role of 5-HT1B neurons in generating LMD through peptidergic Pigment-dispersing factor (PDF) signaling. In summary, this study underscores the importance of AB neuron asymmetry in mediating interval timing behaviors and provides insights into the underlying mechanisms of memory formation and function in Drosophila.
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Affiliation(s)
- Tianmu Zhang
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China
| | - Xiaoli Zhang
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China
| | - Dongyu Sun
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China
| | - Woo Jae Kim
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China.
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2
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Thornton-Kolbe EM, Ahmed M, Gordon FR, Sieriebriennikov B, Williams DL, Kurmangaliyev YZ, Clowney EJ. Spatial constraints and cell surface molecule depletion structure a randomly connected learning circuit. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.17.603956. [PMID: 39071296 PMCID: PMC11275898 DOI: 10.1101/2024.07.17.603956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
The brain can represent almost limitless objects to "categorize an unlabeled world" (Edelman, 1989). This feat is supported by expansion layer circuit architectures, in which neurons carrying information about discrete sensory channels make combinatorial connections onto much larger postsynaptic populations. Combinatorial connections in expansion layers are modeled as randomized sets. The extent to which randomized wiring exists in vivo is debated, and how combinatorial connectivity patterns are generated during development is not understood. Non-deterministic wiring algorithms could program such connectivity using minimal genomic information. Here, we investigate anatomic and transcriptional patterns and perturb partner availability to ask how Kenyon cells, the expansion layer neurons of the insect mushroom body, obtain combinatorial input from olfactory projection neurons. Olfactory projection neurons form their presynaptic outputs in an orderly, predictable, and biased fashion. We find that Kenyon cells accept spatially co-located but molecularly heterogeneous inputs from this orderly map, and ask how Kenyon cell surface molecule expression impacts partner choice. Cell surface immunoglobulins are broadly depleted in Kenyon cells, and we propose that this allows them to form connections with molecularly heterogeneous partners. This model can explain how developmentally identical neurons acquire diverse wiring identities.
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Affiliation(s)
- Emma M. Thornton-Kolbe
- Neurosciences Graduate Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Maria Ahmed
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Finley R. Gordon
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | | | - Donnell L. Williams
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | | | - E. Josephine Clowney
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Michigan Neuroscience Institute, Ann Arbor, MI, USA
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3
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Selcho M. Octopamine in the mushroom body circuitry for learning and memory. Learn Mem 2024; 31:a053839. [PMID: 38862169 PMCID: PMC11199948 DOI: 10.1101/lm.053839.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/20/2024] [Indexed: 06/13/2024]
Abstract
Octopamine, the functional analog of noradrenaline, modulates many different behaviors and physiological processes in invertebrates. In the central nervous system, a few octopaminergic neurons project throughout the brain and innervate almost all neuropils. The center of memory formation in insects, the mushroom bodies, receive octopaminergic innervations in all insects investigated so far. Different octopamine receptors, either increasing or decreasing cAMP or calcium levels in the cell, are localized in Kenyon cells, further supporting the release of octopamine in the mushroom bodies. In addition, different mushroom body (MB) output neurons, projection neurons, and dopaminergic PAM cells are targets of octopaminergic neurons, enabling the modulation of learning circuits at different neural sites. For some years, the theory persisted that octopamine mediates rewarding stimuli, whereas dopamine (DA) represents aversive stimuli. This simple picture has been challenged by the finding that DA is required for both appetitive and aversive learning. Furthermore, octopamine is also involved in aversive learning and a rather complex interaction between these biogenic amines seems to modulate learning and memory. This review summarizes the role of octopamine in MB function, focusing on the anatomical principles and the role of the biogenic amine in learning and memory.
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Affiliation(s)
- Mareike Selcho
- Department of Animal Physiology, Institute of Biology, Leipzig University, 04103 Leipzig, Germany
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4
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Larnerd C, Kachewar N, Wolf FW. Drosophila learning and memory centers and the actions of drugs of abuse. Learn Mem 2024; 31:a053815. [PMID: 38862166 PMCID: PMC11199947 DOI: 10.1101/lm.053815.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 03/27/2024] [Indexed: 06/13/2024]
Abstract
Drug addiction and the circuitry for learning and memory are intimately intertwined. Drugs of abuse create strong, inappropriate, and lasting memories that contribute to many of their destructive properties, such as continued use despite negative consequences and exceptionally high rates of relapse. Studies in Drosophila melanogaster are helping us understand how drugs of abuse, especially alcohol, create memories at the level of individual neurons and in the circuits where they function. Drosophila is a premier organism for identifying the mechanisms of learning and memory. Drosophila also respond to drugs of abuse in ways that remarkably parallel humans and rodent models. An emerging consensus is that, for alcohol, the mushroom bodies participate in the circuits that control acute drug sensitivity, not explicitly associative forms of plasticity such as tolerance, and classical associative memories of their rewarding and aversive properties. Moreover, it is becoming clear that drugs of abuse use the mushroom body circuitry differently from other behaviors, potentially providing a basis for their addictive properties.
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Affiliation(s)
- Caleb Larnerd
- Quantitative and Systems Biology Graduate Group, University of California, Merced, California 95343, USA
| | - Neha Kachewar
- Department of Molecular and Cell Biology, University of California, Merced, California 95343, USA
- Health Sciences Research Institute, University of California, Merced, California 95343, USA
| | - Fred W Wolf
- Quantitative and Systems Biology Graduate Group, University of California, Merced, California 95343, USA
- Department of Molecular and Cell Biology, University of California, Merced, California 95343, USA
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5
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Mancini N, Thoener J, Tafani E, Pauls D, Mayseless O, Strauch M, Eichler K, Champion A, Kobler O, Weber D, Sen E, Weiglein A, Hartenstein V, Chytoudis-Peroudis CC, Jovanic T, Thum AS, Rohwedder A, Schleyer M, Gerber B. Rewarding Capacity of Optogenetically Activating a Giant GABAergic Central-Brain Interneuron in Larval Drosophila. J Neurosci 2023; 43:7393-7428. [PMID: 37734947 PMCID: PMC10621887 DOI: 10.1523/jneurosci.2310-22.2023] [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: 12/17/2022] [Revised: 07/19/2023] [Accepted: 08/26/2023] [Indexed: 09/23/2023] Open
Abstract
Larvae of the fruit fly Drosophila melanogaster are a powerful study case for understanding the neural circuits underlying behavior. Indeed, the numerical simplicity of the larval brain has permitted the reconstruction of its synaptic connectome, and genetic tools for manipulating single, identified neurons allow neural circuit function to be investigated with relative ease and precision. We focus on one of the most complex neurons in the brain of the larva (of either sex), the GABAergic anterior paired lateral neuron (APL). Using behavioral and connectomic analyses, optogenetics, Ca2+ imaging, and pharmacology, we study how APL affects associative olfactory memory. We first provide a detailed account of the structure, regional polarity, connectivity, and metamorphic development of APL, and further confirm that optogenetic activation of APL has an inhibiting effect on its main targets, the mushroom body Kenyon cells. All these findings are consistent with the previously identified function of APL in the sparsening of sensory representations. To our surprise, however, we found that optogenetically activating APL can also have a strong rewarding effect. Specifically, APL activation together with odor presentation establishes an odor-specific, appetitive, associative short-term memory, whereas naive olfactory behavior remains unaffected. An acute, systemic inhibition of dopamine synthesis as well as an ablation of the dopaminergic pPAM neurons impair reward learning through APL activation. Our findings provide a study case of complex circuit function in a numerically simple brain, and suggest a previously unrecognized capacity of central-brain GABAergic neurons to engage in dopaminergic reinforcement.SIGNIFICANCE STATEMENT The single, identified giant anterior paired lateral (APL) neuron is one of the most complex neurons in the insect brain. It is GABAergic and contributes to the sparsening of neuronal activity in the mushroom body, the memory center of insects. We provide the most detailed account yet of the structure of APL in larval Drosophila as a neurogenetically accessible study case. We further reveal that, contrary to expectations, the experimental activation of APL can exert a rewarding effect, likely via dopaminergic reward pathways. The present study both provides an example of unexpected circuit complexity in a numerically simple brain, and reports an unexpected effect of activity in central-brain GABAergic circuits.
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Affiliation(s)
- Nino Mancini
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, Magdeburg, 39118, Germany
| | - Juliane Thoener
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, Magdeburg, 39118, Germany
| | - Esmeralda Tafani
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, Magdeburg, 39118, Germany
| | - Dennis Pauls
- Department of Animal Physiology, Institute of Biology, Leipzig University, Leipzig, 04103, Germany
| | - Oded Mayseless
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Martin Strauch
- Institute of Imaging and Computer Vision, RWTH Aachen University, Aachen, 52074, Germany
| | - Katharina Eichler
- Institute of Neurobiology, University of Puerto Rico Medical Science Campus, Old San Juan, Puerto Rico, 00901
| | - Andrew Champion
- Department of Physiology, Development and Neuroscience, Cambridge University, Cambridge, CB2 3EL, United Kingdom
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, 20147, Virginia
| | - Oliver Kobler
- Leibniz Institute for Neurobiology, Combinatorial Neuroimaging Core Facility, Magdeburg, 39118, Germany
| | - Denise Weber
- Department of Genetics, Institute of Biology, Leipzig University, Leipzig, 04103, Germany
| | - Edanur Sen
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, Magdeburg, 39118, Germany
| | - Aliće Weiglein
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, Magdeburg, 39118, Germany
| | - Volker Hartenstein
- University of California, Department of Molecular, Cell and Developmental Biology, Los Angeles, California 90095-1606
| | | | - Tihana Jovanic
- Université Paris-Saclay, Centre National de la Recherche Scientifique, Institut des neurosciences Paris-Saclay, Saclay, 91400, France
| | - Andreas S Thum
- Department of Genetics, Institute of Biology, Leipzig University, Leipzig, 04103, Germany
| | - Astrid Rohwedder
- Department of Genetics, Institute of Biology, Leipzig University, Leipzig, 04103, Germany
| | - Michael Schleyer
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, Magdeburg, 39118, Germany
| | - Bertram Gerber
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, Magdeburg, 39118, Germany
- Center for Behavioral Brain Sciences, Magdeburg, 39106, Germany
- Institute for Biology, Otto von Guericke University, Magdeburg, 39120, Germany
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6
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Jovanoski KD, Duquenoy L, Mitchell J, Kapoor I, Treiber CD, Croset V, Dempsey G, Parepalli S, Cognigni P, Otto N, Felsenberg J, Waddell S. Dopaminergic systems create reward seeking despite adverse consequences. Nature 2023; 623:356-365. [PMID: 37880370 PMCID: PMC10632144 DOI: 10.1038/s41586-023-06671-8] [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: 07/04/2022] [Accepted: 09/22/2023] [Indexed: 10/27/2023]
Abstract
Resource-seeking behaviours are ordinarily constrained by physiological needs and threats of danger, and the loss of these controls is associated with pathological reward seeking1. Although dysfunction of the dopaminergic valuation system of the brain is known to contribute towards unconstrained reward seeking2,3, the underlying reasons for this behaviour are unclear. Here we describe dopaminergic neural mechanisms that produce reward seeking despite adverse consequences in Drosophila melanogaster. Odours paired with optogenetic activation of a defined subset of reward-encoding dopaminergic neurons become cues that starved flies seek while neglecting food and enduring electric shock punishment. Unconstrained seeking of reward is not observed after learning with sugar or synthetic engagement of other dopaminergic neuron populations. Antagonism between reward-encoding and punishment-encoding dopaminergic neurons accounts for the perseverance of reward seeking despite punishment, whereas synthetic engagement of the reward-encoding dopaminergic neurons also impairs the ordinary need-dependent dopaminergic valuation of available food. Connectome analyses reveal that the population of reward-encoding dopaminergic neurons receives highly heterogeneous input, consistent with parallel representation of diverse rewards, and recordings demonstrate state-specific gating and satiety-related signals. We propose that a similar dopaminergic valuation system dysfunction is likely to contribute to maladaptive seeking of rewards by mammals.
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Affiliation(s)
| | - Lucille Duquenoy
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Jessica Mitchell
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Ishaan Kapoor
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | | | - Vincent Croset
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
- Department of Biosciences, Durham University, Durham, UK
| | - Georgia Dempsey
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Sai Parepalli
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Paola Cognigni
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
- Northern Medical Physics and Clinical Engineering, Newcastle upon Tyne Hospitals NHS Trust, Newcastle upon Tyne, UK
| | - Nils Otto
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Münster, Germany
| | - Johannes Felsenberg
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK.
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7
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Mohamed A, Malekou I, Sim T, O'Kane CJ, Maait Y, Scullion B, Masuda-Nakagawa LM. Mushroom body output neurons MBON-a1/a2 define an odor intensity channel that regulates behavioral odor discrimination learning in larval Drosophila. Front Physiol 2023; 14:1111244. [PMID: 37256074 PMCID: PMC10225628 DOI: 10.3389/fphys.2023.1111244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 05/02/2023] [Indexed: 06/01/2023] Open
Abstract
The sensitivity of animals to sensory input must be regulated to ensure that signals are detected and also discriminable. However, how circuits regulate the dynamic range of sensitivity to sensory stimuli is not well understood. A given odor is represented in the insect mushroom bodies (MBs) by sparse combinatorial coding by Kenyon cells (KCs), forming an odor quality representation. To address how intensity of sensory stimuli is processed at the level of the MB input region, the calyx, we characterized a set of novel mushroom body output neurons that respond preferentially to high odor concentrations. We show that a pair of MB calyx output neurons, MBON-a1/2, are postsynaptic in the MB calyx, where they receive extensive synaptic inputs from KC dendrites, the inhibitory feedback neuron APL, and octopaminergic sVUM1 neurons, but relatively few inputs from projection neurons. This pattern is broadly consistent in the third-instar larva as well as in the first instar connectome. MBON-a1/a2 presynaptic terminals innervate a region immediately surrounding the MB medial lobe output region in the ipsilateral and contralateral brain hemispheres. By monitoring calcium activity using jRCamP1b, we find that MBON-a1/a2 responses are odor-concentration dependent, responding only to ethyl acetate (EA) concentrations higher than a 200-fold dilution, in contrast to MB neurons which are more concentration-invariant and respond to EA dilutions as low as 10-4. Optogenetic activation of the calyx-innervating sVUM1 modulatory neurons originating in the SEZ (Subesophageal zone), did not show a detectable effect on MBON-a1/a2 odor responses. Optogenetic activation of MBON-a1/a2 using CsChrimson impaired odor discrimination learning compared to controls. We propose that MBON-a1/a2 form an output channel of the calyx, summing convergent sensory and modulatory input, firing preferentially to high odor concentration, and might affect the activity of downstream MB targets.
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8
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Marquand K, Roselli C, Cervantes-Sandoval I, Boto T. Sleep benefits different stages of memory in Drosophila. Front Physiol 2023; 14:1087025. [PMID: 36744027 PMCID: PMC9892949 DOI: 10.3389/fphys.2023.1087025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/06/2023] [Indexed: 01/20/2023] Open
Abstract
Understanding the physiological mechanisms that modulate memory acquisition and consolidation remains among the most ambitious questions in neuroscience. Massive efforts have been dedicated to deciphering how experience affects behavior, and how different physiological and sensory phenomena modulate memory. Our ability to encode, consolidate and retrieve memories depends on internal drives, and sleep stands out among the physiological processes that affect memory: one of the most relatable benefits of sleep is the aiding of memory that occurs in order to both prepare the brain to learn new information, and after a learning task, to consolidate those new memories. Drosophila lends itself to the study of the interactions between memory and sleep. The fruit fly provides incomparable genetic resources, a mapped connectome, and an existing framework of knowledge on the molecular, cellular, and circuit mechanisms of memory and sleep, making the fruit fly a remarkable model to decipher the sophisticated regulation of learning and memory by the quantity and quality of sleep. Research in Drosophila has stablished not only that sleep facilitates learning in wild-type and memory-impaired animals, but that sleep deprivation interferes with the acquisition of new memories. In addition, it is well-accepted that sleep is paramount in memory consolidation processes. Finally, studies in Drosophila have shown that that learning itself can promote sleep drive. Nevertheless, the molecular and network mechanisms underlying this intertwined relationship are still evasive. Recent remarkable work has shed light on the neural substrates that mediate sleep-dependent memory consolidation. In a similar way, the mechanistic insights of the neural switch control between sleep-dependent and sleep-independent consolidation strategies were recently described. This review will discuss the regulation of memory by sleep in Drosophila, focusing on the most recent advances in the field and pointing out questions awaiting to be investigated.
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Affiliation(s)
- Katie Marquand
- Department of Physiology, School of Medicine, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Camilla Roselli
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Isaac Cervantes-Sandoval
- Department of Biology, Georgetown University, Washington, DC, United States
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States
| | - Tamara Boto
- Department of Physiology, School of Medicine, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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9
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Dvořáček J, Kodrík D. Drug effect and addiction research with insects - From Drosophila to collective reward in honeybees. Neurosci Biobehav Rev 2022; 140:104816. [PMID: 35940307 DOI: 10.1016/j.neubiorev.2022.104816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/29/2022] [Accepted: 08/01/2022] [Indexed: 10/16/2022]
Abstract
Animals and humans share similar reactions to the effects of addictive substances, including those of their brain networks to drugs. Our review focuses on simple invertebrate models, particularly the honeybee (Apis mellifera), and on the effects of drugs on bee behaviour and brain functions. The drug effects in bees are very similar to those described in humans. Furthermore, the honeybee community is a superorganism in which many collective functions outperform the simple sum of individual functions. The distribution of reward functions in this superorganism is unique - although sublimated at the individual level, community reward functions are of higher quality. This phenomenon of collective reward may be extrapolated to other animal species living in close and strictly organised societies, i.e. humans. The relationship between sociality and reward, based on use of similar parts of the neural network (social decision-making network in mammals, mushroom body in bees), suggests a functional continuum of reward and sociality in animals.
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Affiliation(s)
- Jiří Dvořáček
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budĕjovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budĕjovice, Czech Republic.
| | - Dalibor Kodrík
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budĕjovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budĕjovice, Czech Republic
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10
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Naganos S, Ueno K, Horiuchi J, Saitoe M. Dopamine activity in projection neurons regulates short-lasting olfactory approach memory in Drosophila. Eur J Neurosci 2022; 56:4558-4571. [PMID: 35815601 PMCID: PMC9540629 DOI: 10.1111/ejn.15766] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 11/27/2022]
Abstract
Survival in many animals requires the ability to associate certain cues with danger and others with safety. In a Drosophila melanogaster aversive olfactory conditioning paradigm, flies are exposed to two odours, one presented coincidentally with electrical shocks, and a second presented 45 s after shock cessation. When flies are later given a choice between these two odours, they avoid the shock‐paired odour and prefer the unpaired odour. While many studies have examined how flies learn to avoid the shock‐paired odour through formation of odour‐fear associations, here we demonstrate that conditioning also causes flies to actively approach the second odour. In contrast to fear memories, which are longer lasting and requires activity of D1‐like dopamine receptors only in the mushroom bodies, approach memory is short‐lasting and requires activity of D1‐like dopamine receptors in projection neurons originating from the antennal lobes, primary olfactory centers. Further, while recall of fear memories requires activity of the mushroom bodies, recall of approach memories does not. Our data suggest that olfactory approach memory is formed using different mechanisms in different brain locations compared to aversive and appetitive olfactory memories.
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Affiliation(s)
| | - Kohei Ueno
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | | | - Minoru Saitoe
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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11
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Israel S, Rozenfeld E, Weber D, Huetteroth W, Parnas M. Olfactory stimuli and moonwalker SEZ neurons can drive backward locomotion in Drosophila. Curr Biol 2022; 32:1131-1149.e7. [PMID: 35139358 PMCID: PMC8926844 DOI: 10.1016/j.cub.2022.01.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 10/31/2021] [Accepted: 01/12/2022] [Indexed: 01/05/2023]
Abstract
How different sensory stimuli are collected, processed, and further transformed into a coordinated motor response is a fundamental question in neuroscience. In particular, the internal and external conditions that drive animals to switch to backward walking and the mechanisms by which the nervous system supports such behavior are still unknown. In fruit flies, moonwalker descending neurons (MDNs) are considered command-type neurons for backward locomotion as they receive visual and mechanosensory inputs and transmit motor-related signals to downstream neurons to elicit backward locomotion. Whether other modalities converge onto MDNs, which central brain neurons activate MDNs, and whether other retreat-driving pathways exist is currently unknown. Here, we show that olfactory stimulation can elicit MDN-mediated backward locomotion. Moreover, we identify the moonwalker subesophageal zone neurons (MooSEZs), a pair of bilateral neurons, which can trigger straight and rotational backward locomotion. MooSEZs act via postsynaptic MDNs and via other descending neurons. Although they respond to olfactory input, they are not required for odor-induced backward walking. Thus, this work reveals an important modality input to MDNs, a novel set of neurons presynaptic to MDNs driving backward locomotion and an MDN-independent backward locomotion pathway.
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Affiliation(s)
- Shai Israel
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Eyal Rozenfeld
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Denise Weber
- Institute for Biology, University of Leipzig, Talstraße 33, 04103 Leipzig, Germany
| | - Wolf Huetteroth
- Institute for Biology, University of Leipzig, Talstraße 33, 04103 Leipzig, Germany
| | - Moshe Parnas
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel.
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12
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Prisco L, Deimel SH, Yeliseyeva H, Fiala A, Tavosanis G. The anterior paired lateral neuron normalizes odour-evoked activity in the Drosophila mushroom body calyx. eLife 2021; 10:e74172. [PMID: 34964714 PMCID: PMC8741211 DOI: 10.7554/elife.74172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/28/2021] [Indexed: 11/25/2022] Open
Abstract
To identify and memorize discrete but similar environmental inputs, the brain needs to distinguish between subtle differences of activity patterns in defined neuronal populations. The Kenyon cells (KCs) of the Drosophila adult mushroom body (MB) respond sparsely to complex olfactory input, a property that is thought to support stimuli discrimination in the MB. To understand how this property emerges, we investigated the role of the inhibitory anterior paired lateral (APL) neuron in the input circuit of the MB, the calyx. Within the calyx, presynaptic boutons of projection neurons (PNs) form large synaptic microglomeruli (MGs) with dendrites of postsynaptic KCs. Combining electron microscopy (EM) data analysis and in vivo calcium imaging, we show that APL, via inhibitory and reciprocal synapses targeting both PN boutons and KC dendrites, normalizes odour-evoked representations in MGs of the calyx. APL response scales with the PN input strength and is regionalized around PN input distribution. Our data indicate that the formation of a sparse code by the KCs requires APL-driven normalization of their MG postsynaptic responses. This work provides experimental insights on how inhibition shapes sensory information representation in a higher brain centre, thereby supporting stimuli discrimination and allowing for efficient associative memory formation.
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Affiliation(s)
- Luigi Prisco
- Dynamics of neuronal circuits, German Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | | | - Hanna Yeliseyeva
- Dynamics of neuronal circuits, German Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | - André Fiala
- Department of Molecular Neurobiology of Behavior, University of GöttingenGöttingenGermany
| | - Gaia Tavosanis
- Dynamics of neuronal circuits, German Center for Neurodegenerative Diseases (DZNE)BonnGermany
- LIMES, Rheinische Friedrich Wilhelms Universität BonnBonnGermany
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13
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Weiss JT, Donlea JM. Sleep deprivation results in diverse patterns of synaptic scaling across the Drosophila mushroom bodies. Curr Biol 2021; 31:3248-3261.e3. [PMID: 34107302 PMCID: PMC8355077 DOI: 10.1016/j.cub.2021.05.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 03/22/2021] [Accepted: 05/11/2021] [Indexed: 11/19/2022]
Abstract
Sleep is essential for a variety of plastic processes, including learning and memory. However, the consequences of insufficient sleep on circuit connectivity remain poorly understood. To better appreciate the effects of sleep loss on synaptic connectivity across a memory-encoding circuit, we examined changes in the distribution of synaptic markers in the Drosophila mushroom body (MB). Protein-trap tags for active zone components indicate that recent sleep time is inversely correlated with Bruchpilot (BRP) abundance in the MB lobes; sleep loss elevates BRP while sleep induction reduces BRP across the MB. Overnight sleep deprivation also elevated levels of dSyd-1 and Cacophony, but not other pre-synaptic proteins. Cell-type-specific genetic reporters show that MB-intrinsic Kenyon cells (KCs) exhibit increased pre-synaptic BRP throughout the axonal lobes after sleep deprivation; similar increases were not detected in projections from large interneurons or dopaminergic neurons that innervate the MB. These results indicate that pre-synaptic plasticity in KCs is responsible for elevated levels of BRP in the MB lobes of sleep-deprived flies. Because KCs provide synaptic inputs to several classes of post-synaptic partners, we next used a fluorescent reporter for synaptic contacts to test whether each class of KC output connections is scaled uniformly by sleep loss. The KC output synapses that we observed here can be divided into three classes: KCs to MB interneurons; KCs to dopaminergic neurons; and KCs to MB output neurons. No single class showed uniform scaling across each constituent member, indicating that different rules may govern plasticity during sleep loss across cell types.
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Affiliation(s)
- Jacqueline T Weiss
- Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA; Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA.
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14
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Dvořáček J, Kodrík D. Drosophila reward system - A summary of current knowledge. Neurosci Biobehav Rev 2021; 123:301-319. [PMID: 33421541 DOI: 10.1016/j.neubiorev.2020.12.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 12/16/2020] [Accepted: 12/27/2020] [Indexed: 01/19/2023]
Abstract
The fruit fly Drosophila melanogaster brain is the most extensively investigated model of a reward system in insects. Drosophila can discriminate between rewarding and punishing environmental stimuli and consequently undergo associative learning. Functional models, especially those modelling mushroom bodies, are constantly being developed using newly discovered information, adding to the complexity of creating a simple model of the reward system. This review aims to clarify whether its reward system also includes a hedonic component. Neurochemical systems that mediate the 'wanting' component of reward in the Drosophila brain are well documented, however, the systems that mediate the pleasure component of reward in mammals, including those involving the endogenous opioid and endocannabinoid systems, are unlikely to be present in insects. The mushroom body components exhibit differential developmental age and different functional processes. We propose a hypothetical hierarchy of the levels of reinforcement processing in response to particular stimuli, and the parallel processes that take place concurrently. The possible presence of activity-silencing and meta-satiety inducing levels in Drosophila should be further investigated.
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Affiliation(s)
- Jiří Dvořáček
- Institute of Entomology, Biology Centre, CAS, and Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
| | - Dalibor Kodrík
- Institute of Entomology, Biology Centre, CAS, and Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
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15
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Chvilicek MM, Titos I, Rothenfluh A. The Neurotransmitters Involved in Drosophila Alcohol-Induced Behaviors. Front Behav Neurosci 2020; 14:607700. [PMID: 33384590 PMCID: PMC7770116 DOI: 10.3389/fnbeh.2020.607700] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Alcohol is a widely used and abused substance with numerous negative consequences for human health and safety. Historically, alcohol's widespread, non-specific neurobiological effects have made it a challenge to study in humans. Therefore, model organisms are a critical tool for unraveling the mechanisms of alcohol action and subsequent effects on behavior. Drosophila melanogaster is genetically tractable and displays a vast behavioral repertoire, making it a particularly good candidate for examining the neurobiology of alcohol responses. In addition to being experimentally amenable, Drosophila have high face and mechanistic validity: their alcohol-related behaviors are remarkably consistent with humans and other mammalian species, and they share numerous conserved neurotransmitters and signaling pathways. Flies have a long history in alcohol research, which has been enhanced in recent years by the development of tools that allow for manipulating individual Drosophila neurotransmitters. Through advancements such as the GAL4/UAS system and CRISPR/Cas9 mutagenesis, investigation of specific neurotransmitters in small subsets of neurons has become ever more achievable. In this review, we describe recent progress in understanding the contribution of seven neurotransmitters to fly behavior, focusing on their roles in alcohol response: dopamine, octopamine, tyramine, serotonin, glutamate, GABA, and acetylcholine. We chose these small-molecule neurotransmitters due to their conservation in mammals and their importance for behavior. While neurotransmitters like dopamine and octopamine have received significant research emphasis regarding their contributions to behavior, others, like glutamate, GABA, and acetylcholine, remain relatively unexplored. Here, we summarize recent genetic and behavioral findings concerning these seven neurotransmitters and their roles in the behavioral response to alcohol, highlighting the fitness of the fly as a model for human alcohol use.
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Affiliation(s)
- Maggie M. Chvilicek
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
| | - Iris Titos
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
| | - Adrian Rothenfluh
- Department of Psychiatry, University of Utah, Salt Lake City, UT, United States
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, United States
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT, United States
- Department of Human Genetics, University of Utah, Salt Lake City, UT, United States
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16
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Li F, Lindsey JW, Marin EC, Otto N, Dreher M, Dempsey G, Stark I, Bates AS, Pleijzier MW, Schlegel P, Nern A, Takemura SY, Eckstein N, Yang T, Francis A, Braun A, Parekh R, Costa M, Scheffer LK, Aso Y, Jefferis GSXE, Abbott LF, Litwin-Kumar A, Waddell S, Rubin GM. The connectome of the adult Drosophila mushroom body provides insights into function. eLife 2020; 9:e62576. [PMID: 33315010 PMCID: PMC7909955 DOI: 10.7554/elife.62576] [Citation(s) in RCA: 174] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022] Open
Abstract
Making inferences about the computations performed by neuronal circuits from synapse-level connectivity maps is an emerging opportunity in neuroscience. The mushroom body (MB) is well positioned for developing and testing such an approach due to its conserved neuronal architecture, recently completed dense connectome, and extensive prior experimental studies of its roles in learning, memory, and activity regulation. Here, we identify new components of the MB circuit in Drosophila, including extensive visual input and MB output neurons (MBONs) with direct connections to descending neurons. We find unexpected structure in sensory inputs, in the transfer of information about different sensory modalities to MBONs, and in the modulation of that transfer by dopaminergic neurons (DANs). We provide insights into the circuitry used to integrate MB outputs, connectivity between the MB and the central complex and inputs to DANs, including feedback from MBONs. Our results provide a foundation for further theoretical and experimental work.
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Affiliation(s)
- Feng Li
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Jack W Lindsey
- Department of Neuroscience, Columbia University, Zuckerman InstituteNew YorkUnited States
| | - Elizabeth C Marin
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Nils Otto
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Centre for Neural Circuits & Behaviour, University of OxfordOxfordUnited Kingdom
| | - Marisa Dreher
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Georgia Dempsey
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Ildiko Stark
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Alexander S Bates
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | - Philipp Schlegel
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Aljoscha Nern
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Shin-ya Takemura
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Nils Eckstein
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Tansy Yang
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Audrey Francis
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Amalia Braun
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Ruchi Parekh
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Marta Costa
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Louis K Scheffer
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gregory SXE Jefferis
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Larry F Abbott
- Department of Neuroscience, Columbia University, Zuckerman InstituteNew YorkUnited States
| | - Ashok Litwin-Kumar
- Department of Neuroscience, Columbia University, Zuckerman InstituteNew YorkUnited States
| | - Scott Waddell
- Centre for Neural Circuits & Behaviour, University of OxfordOxfordUnited Kingdom
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
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17
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Flyer-Adams JG, Rivera-Rodriguez EJ, Yu J, Mardovin JD, Reed ML, Griffith LC. Regulation of Olfactory Associative Memory by the Circadian Clock Output Signal Pigment-Dispersing Factor (PDF). J Neurosci 2020; 40:9066-9077. [PMID: 33106351 PMCID: PMC7673005 DOI: 10.1523/jneurosci.0782-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 08/10/2020] [Accepted: 09/07/2020] [Indexed: 01/19/2023] Open
Abstract
Dissociation between the output of the circadian clock and external environmental cues is a major cause of human cognitive dysfunction. While the effects of ablation of the molecular clock on memory have been studied in many systems, little has been done to test the role of specific clock circuit output signals. To address this gap, we examined the effects of mutations of Pigment-dispersing factor (Pdf) and its receptor, Pdfr, on associative memory in male and female Drosophila Loss of PDF signaling significantly decreases the ability to form associative memory. Appetitive short-term memory (STM), which in wild-type (WT) is time-of-day (TOD) independent, is decreased across the day by mutation of Pdf or Pdfr, but more substantially in the morning than in the evening. This defect is because of PDFR expression in adult neurons outside the core clock circuit and the mushroom body (MB) Kenyon cells (KCs). The acquisition of a TOD difference in mutants implies the existence of multiple oscillators that act to normalize memory formation across the day for appetitive processes. Interestingly, aversive STM requires PDF but not PDFR, suggesting that there are valence-specific pathways downstream of PDF that regulate memory formation. These data argue that the circadian clock uses circuit-specific and molecularly diverse output pathways to enhance the ability of animals to optimize responses to changing conditions.SIGNIFICANCE STATEMENT From humans to invertebrates, cognitive processes are influenced by organisms' internal circadian clocks, the pace of which is linked to the solar cycle. Disruption of this link is increasingly common (e.g., jetlag, social jetlag disorders) and causes cognitive impairments that are costly and long lasting. A detailed understanding of how the internal clock regulates cognition is critical for the development of therapeutic methods. Here, we show for the first time that olfactory associative memory in Drosophila requires signaling by Pigment-dispersing factor (PDF), a neuromodulatory signaling peptide produced only by circadian clock circuit neurons. We also find a novel role for the clock circuit in stabilizing appetitive sucrose/odor memory across the day.
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Affiliation(s)
- Johanna G Flyer-Adams
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Emmanuel J Rivera-Rodriguez
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Junwei Yu
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Jacob D Mardovin
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Martha L Reed
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Leslie C Griffith
- Department of Biology, Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
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18
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Amin H, Apostolopoulou AA, Suárez-Grimalt R, Vrontou E, Lin AC. Localized inhibition in the Drosophila mushroom body. eLife 2020; 9:56954. [PMID: 32955437 PMCID: PMC7541083 DOI: 10.7554/elife.56954] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 08/02/2020] [Indexed: 12/12/2022] Open
Abstract
Many neurons show compartmentalized activity, in which activity does not spread readily across the cell, allowing input and output to occur locally. However, the functional implications of compartmentalized activity for the wider neural circuit are often unclear. We addressed this problem in the Drosophila mushroom body, whose principal neurons, Kenyon cells, receive feedback inhibition from a non-spiking interneuron called the anterior paired lateral (APL) neuron. We used local stimulation and volumetric calcium imaging to show that APL inhibits Kenyon cells’ dendrites and axons, and that both activity in APL and APL’s inhibitory effect on Kenyon cells are spatially localized (the latter somewhat less so), allowing APL to differentially inhibit different mushroom body compartments. Applying these results to the Drosophila hemibrain connectome predicts that individual Kenyon cells inhibit themselves via APL more strongly than they inhibit other individual Kenyon cells. These findings reveal how cellular physiology and detailed network anatomy can combine to influence circuit function.
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Affiliation(s)
- Hoger Amin
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom.,Neuroscience Institute, University of Sheffield, Sheffield, United Kingdom
| | - Anthi A Apostolopoulou
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom.,Neuroscience Institute, University of Sheffield, Sheffield, United Kingdom
| | - Raquel Suárez-Grimalt
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Eleftheria Vrontou
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, United Kingdom
| | - Andrew C Lin
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom.,Neuroscience Institute, University of Sheffield, Sheffield, United Kingdom
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19
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Li J, Mahoney BD, Jacob MS, Caron SJC. Visual Input into the Drosophila melanogaster Mushroom Body. Cell Rep 2020; 32:108138. [PMID: 32937130 PMCID: PMC8252886 DOI: 10.1016/j.celrep.2020.108138] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/09/2020] [Accepted: 08/20/2020] [Indexed: 11/28/2022] Open
Abstract
The patterns of neuronal connectivity underlying multisensory integration, a fundamental property of many brains, remain poorly characterized. The Drosophila melanogaster mushroom body-an associative center-is an ideal system to investigate how different sensory channels converge in higher order brain centers. The neurons connecting the mushroom body to the olfactory system have been described in great detail, but input from other sensory systems remains poorly defined. Here, we use a range of anatomical and genetic techniques to identify two types of input neuron that connect visual processing centers-the lobula and the posterior lateral protocerebrum-to the dorsal accessory calyx of the mushroom body. Together with previous work that described a pathway conveying visual information from the medulla to the ventral accessory calyx of the mushroom body, our study defines a second, parallel pathway that is anatomically poised to convey information from the visual system to the dorsal accessory calyx.
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Affiliation(s)
- Jinzhi Li
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84103, USA
| | - Brennan Dale Mahoney
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84103, USA
| | - Miles Solomon Jacob
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84103, USA
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20
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Behavioral and neuronal underpinnings of safety in numbers in fruit flies. Nat Commun 2020; 11:4182. [PMID: 32826882 PMCID: PMC7442810 DOI: 10.1038/s41467-020-17856-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 07/20/2020] [Indexed: 11/08/2022] Open
Abstract
Living in a group allows individuals to decrease their defenses, enabling other beneficial behaviors such as foraging. The detection of a threat through social cues is widely reported, however, the safety cues that guide animals to break away from a defensive behavior and resume alternate activities remain elusive. Here we show that fruit flies display a graded decrease in freezing behavior, triggered by an inescapable threat, with increasing group sizes. Furthermore, flies use the cessation of movement of other flies as a cue of threat and its resumption as a cue of safety. Finally, we find that lobula columnar neurons, LC11, mediate the propensity for freezing flies to resume moving in response to the movement of others. By identifying visual motion cues, and the neurons involved in their processing, as the basis of a social safety cue this study brings new insights into the neuronal basis of safety in numbers.
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21
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Mariano V, Achsel T, Bagni C, Kanellopoulos AK. Modelling Learning and Memory in Drosophila to Understand Intellectual Disabilities. Neuroscience 2020; 445:12-30. [PMID: 32730949 DOI: 10.1016/j.neuroscience.2020.07.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 07/19/2020] [Accepted: 07/20/2020] [Indexed: 12/24/2022]
Abstract
Neurodevelopmental disorders (NDDs) include a large number of conditions such as Fragile X syndrome, autism spectrum disorders and Down syndrome, among others. They are characterized by limitations in adaptive and social behaviors, as well as intellectual disability (ID). Whole-exome and whole-genome sequencing studies have highlighted a large number of NDD/ID risk genes. To dissect the genetic causes and underlying biological pathways, in vivo experimental validation of the effects of these mutations is needed. The fruit fly, Drosophila melanogaster, is an ideal model to study NDDs, with highly tractable genetics, combined with simple behavioral and circuit assays, permitting rapid medium-throughput screening of NDD/ID risk genes. Here, we review studies where the use of well-established assays to study mechanisms of learning and memory in Drosophila has permitted insights into molecular mechanisms underlying IDs. We discuss how technologies in the fly model, combined with a high degree of molecular and physiological conservation between flies and mammals, highlight the Drosophila system as an ideal model to study neurodevelopmental disorders, from genetics to behavior.
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Affiliation(s)
- Vittoria Mariano
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1005, Switzerland; Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Tilmann Achsel
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1005, Switzerland
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1005, Switzerland; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome 00133, Italy.
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22
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Apostolopoulou AA, Lin AC. Mechanisms underlying homeostatic plasticity in the Drosophila mushroom body in vivo. Proc Natl Acad Sci U S A 2020; 117:16606-16615. [PMID: 32601210 PMCID: PMC7368247 DOI: 10.1073/pnas.1921294117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Neural network function requires an appropriate balance of excitation and inhibition to be maintained by homeostatic plasticity. However, little is known about homeostatic mechanisms in the intact central brain in vivo. Here, we study homeostatic plasticity in the Drosophila mushroom body, where Kenyon cells receive feedforward excitation from olfactory projection neurons and feedback inhibition from the anterior paired lateral neuron (APL). We show that prolonged (4-d) artificial activation of the inhibitory APL causes increased Kenyon cell odor responses after the artificial inhibition is removed, suggesting that the mushroom body compensates for excess inhibition. In contrast, there is little compensation for lack of inhibition (blockade of APL). The compensation occurs through a combination of increased excitation of Kenyon cells and decreased activation of APL, with differing relative contributions for different Kenyon cell subtypes. Our findings establish the fly mushroom body as a model for homeostatic plasticity in vivo.
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Affiliation(s)
- Anthi A Apostolopoulou
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, United Kingdom
- Neuroscience Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Andrew C Lin
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, United Kingdom;
- Neuroscience Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
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23
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Lerner H, Rozenfeld E, Rozenman B, Huetteroth W, Parnas M. Differential Role for a Defined Lateral Horn Neuron Subset in Naïve Odor Valence in Drosophila. Sci Rep 2020; 10:6147. [PMID: 32273557 PMCID: PMC7145822 DOI: 10.1038/s41598-020-63169-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 03/26/2020] [Indexed: 11/09/2022] Open
Abstract
Value coding of external stimuli in general, and odor valence in particular, is crucial for survival. In flies, odor valence is thought to be coded by two types of neurons: mushroom body output neurons (MBONs) and lateral horn (LH) neurons. MBONs are classified as neurons that promote either attraction or aversion, but not both, and they are dynamically activated by upstream neurons. This dynamic activation updates the valence values. In contrast, LH neurons receive scaled, but non-dynamic, input from their upstream neurons. It remains unclear how such a non-dynamic system generates differential valence values. Recently, PD2a1/b1 LH neurons were demonstrated to promote approach behavior at low odor concentration in starved flies. Here, we demonstrate that at high odor concentrations, these same neurons contribute to avoidance in satiated flies. The contribution of PD2a1/b1 LH neurons to aversion is context dependent. It is diminished in starved flies, although PD2a1/b1 neural activity remains unchanged, and at lower odor concentration. In addition, PD2a1/b1 aversive effect develops over time. Thus, our results indicate that, even though PD2a1/b1 LH neurons transmit hard-wired output, their effect on valence can change. Taken together, we suggest that the valence model described for MBONs does not hold for LH neurons.
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Affiliation(s)
- Hadas Lerner
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Eyal Rozenfeld
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Bar Rozenman
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Wolf Huetteroth
- Institute for Biology, University of Leipzig, Talstraße 33, 04103, Leipzig, Germany
| | - Moshe Parnas
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel. .,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 69978, Israel.
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24
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Elkahlah NA, Rogow JA, Ahmed M, Clowney EJ. Presynaptic developmental plasticity allows robust sparse wiring of the Drosophila mushroom body. eLife 2020; 9:e52278. [PMID: 31913123 PMCID: PMC7028369 DOI: 10.7554/elife.52278] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 01/07/2020] [Indexed: 01/29/2023] Open
Abstract
In order to represent complex stimuli, principle neurons of associative learning regions receive combinatorial sensory inputs. Density of combinatorial innervation is theorized to determine the number of distinct stimuli that can be represented and distinguished from one another, with sparse innervation thought to optimize the complexity of representations in networks of limited size. How the convergence of combinatorial inputs to principle neurons of associative brain regions is established during development is unknown. Here, we explore the developmental patterning of sparse olfactory inputs to Kenyon cells of the Drosophila melanogaster mushroom body. By manipulating the ratio between pre- and post-synaptic cells, we find that postsynaptic Kenyon cells set convergence ratio: Kenyon cells produce fixed distributions of dendritic claws while presynaptic processes are plastic. Moreover, we show that sparse odor responses are preserved in mushroom bodies with reduced cellular repertoires, suggesting that developmental specification of convergence ratio allows functional robustness.
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Affiliation(s)
- Najia A Elkahlah
- Department of Molecular, Cellular and Developmental BiologyThe University of MichiganAnn ArborUnited States
| | - Jackson A Rogow
- Laboratory of Neurophysiology and BehaviorThe Rockefeller UniversityNew YorkUnited States
| | - Maria Ahmed
- Department of Molecular, Cellular and Developmental BiologyThe University of MichiganAnn ArborUnited States
| | - E Josephine Clowney
- Department of Molecular, Cellular and Developmental BiologyThe University of MichiganAnn ArborUnited States
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25
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Higham JP, Hidalgo S, Buhl E, Hodge JJL. Restoration of Olfactory Memory in Drosophila Overexpressing Human Alzheimer's Disease Associated Tau by Manipulation of L-Type Ca 2+ Channels. Front Cell Neurosci 2019; 13:409. [PMID: 31551716 PMCID: PMC6746915 DOI: 10.3389/fncel.2019.00409] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 08/26/2019] [Indexed: 01/13/2023] Open
Abstract
The cellular underpinnings of memory deficits in Alzheimer’s disease (AD) are poorly understood. We utilized the tractable neural circuits sub-serving memory in Drosophila to investigate the role of impaired Ca2+ handling in memory deficits caused by expression of human 0N4R isoform of tau which is associated with AD. Expression of tau in mushroom body neuropils, or a subset of mushroom body output neurons, led to impaired memory. By using the Ca2+ reporter GCaMP6f, we observed changes in Ca2+ signaling when tau was expressed in these neurons, an effect that could be blocked by the L-type Ca2+ channel antagonist nimodipine or reversed by RNAi knock-down of the L-type channel gene. The L-type Ca2+ channel itself is required for memory formation, however, RNAi knock-down of the L-type Ca2+ channel in neurons overexpressing human tau resulted in flies whose memory is restored to levels equivalent to wild-type. Expression data suggest that Drosophila L-type Ca2+ channel mRNA levels are increased upon tau expression in neurons, thus contributing to the effects observed on memory and intracellular Ca2+ homeostasis. Together, our Ca2+ imaging and memory experiments suggest that expression of the 0N4R isoform of human tau increases the number of L-type Ca2+ channels in the membrane resulting in changes in neuronal excitability that can be ameliorated by RNAi knockdown or pharmacological blockade of L-type Ca2+ channels. This highlights a role for L-type Ca2+ channels in tauopathy and their potential as a therapeutic target for AD.
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Affiliation(s)
- James P Higham
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Sergio Hidalgo
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Edgar Buhl
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - James J L Hodge
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
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26
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Sengupta S, Crowe LB, You S, Roberts MA, Jackson FR. A Secreted Ig-Domain Protein Required in Both Astrocytes and Neurons for Regulation of Drosophila Night Sleep. Curr Biol 2019; 29:2547-2554.e2. [PMID: 31353186 DOI: 10.1016/j.cub.2019.06.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/20/2019] [Accepted: 06/19/2019] [Indexed: 12/29/2022]
Abstract
Endogenous rhythmic behaviors are evolutionarily conserved and essential for life. In mammalian and invertebrate models, well-characterized neuronal circuits and evolutionarily conserved mechanisms regulate circadian behavior and sleep [1-4]. In Drosophila, neuronal populations located in multiple brain regions mediate arousal, sleep drive, and homeostasis (reviewed in [3, 5-7]). Similar to mammals [8], there is also evidence that fly glial cells modulate the neuronal circuits controlling rhythmic behaviors, including sleep [1]. Here, we describe a novel gene (CG14141; aka Nkt) that is required for normal sleep. NKT is a 162-amino-acid protein with a single IgC2 immunoglobulin (Ig) domain and a high-quality signal peptide [9], and we show evidence that it is secreted, similar to its C. elegans ortholog (OIG-4) [10]. We demonstrate that Nkt-null flies or those with selective knockdown in either neurons or glia have decreased and fragmented night sleep, indicative of a non-redundant requirement in both cell types. We show that Nkt is required in fly astrocytes and in a specific set of wake-promoting neurons-the mushroom body (MB) α'β' cells that link sleep to memory consolidation [11]. Importantly, Nkt gene expression is required in the adult nervous system for normal sleep, consistent with a physiological rather than developmental function for the Ig-domain protein.
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Affiliation(s)
- Sukanya Sengupta
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Lauren B Crowe
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Samantha You
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Mary A Roberts
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - F Rob Jackson
- Department of Neuroscience, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA.
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27
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Stern U, Srivastava H, Chen HL, Mohammad F, Claridge-Chang A, Yang CH. Learning a Spatial Task by Trial and Error in Drosophila. Curr Biol 2019; 29:2517-2525.e5. [PMID: 31327716 DOI: 10.1016/j.cub.2019.06.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 04/29/2019] [Accepted: 06/13/2019] [Indexed: 12/17/2022]
Abstract
The ability to use memory to return to specific locations for foraging is advantageous for survival. Although recent reports have demonstrated that the fruit flies Drosophila melanogaster are capable of visual cue-driven place learning and idiothetic path integration [1-4], the depth and flexibility of Drosophila's ability to solve spatial tasks and the underlying neural substrate and genetic basis have not been extensively explored. Here, we show that Drosophila can remember a reward-baited location through reinforcement learning and do so quickly and without requiring vision. After gaining genetic access to neurons (through 0273-GAL4) with properties reminiscent of the vertebrate medial forebrain bundle (MFB) and developing a high-throughput closed-loop stimulation system, we found that both sighted and blind flies can learn-by trial and error-to repeatedly return to an unmarked location (in a rectangularly shaped arena) where a brief stimulation of the 0273-GAL4 neurons was available for each visit. We found that optogenetic stimulation of these neurons enabled learning by employing both a cholinergic pathway that promoted self-stimulation and a dopaminergic pathway that likely promoted association of relevant cues with reward. Lastly, inhibiting activities of specific neurons time-locked with stimulation of 0273-GAL4 neurons showed that mushroom bodies (MB) and central complex (CX) both play a role in promoting learning of our task. Our work uncovered new depth in flies' ability to learn a spatial task and established an assay with a level of throughput that permits a systematic genetic interrogation of flies' ability to learn spatial tasks.
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Affiliation(s)
- Ulrich Stern
- Department of Neurobiology, Duke University Medical School, 311 Research Drive, Durham, NC 27710, USA.
| | - Hemant Srivastava
- Department of Neurobiology, Duke University Medical School, 311 Research Drive, Durham, NC 27710, USA
| | - Hsueh-Ling Chen
- Department of Neurobiology, Duke University Medical School, 311 Research Drive, Durham, NC 27710, USA
| | - Farhan Mohammad
- NBD Program, Duke-NUS Medical School, 61 Biopolis Drive, 08-05, Singapore 138673, Singapore
| | - Adam Claridge-Chang
- NBD Program, Duke-NUS Medical School, 61 Biopolis Drive, 08-05, Singapore 138673, Singapore
| | - Chung-Hui Yang
- Department of Neurobiology, Duke University Medical School, 311 Research Drive, Durham, NC 27710, USA.
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28
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Bielopolski N, Amin H, Apostolopoulou AA, Rozenfeld E, Lerner H, Huetteroth W, Lin AC, Parnas M. Inhibitory muscarinic acetylcholine receptors enhance aversive olfactory learning in adult Drosophila. eLife 2019; 8:48264. [PMID: 31215865 PMCID: PMC6641838 DOI: 10.7554/elife.48264] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 06/18/2019] [Indexed: 11/13/2022] Open
Abstract
Olfactory associative learning in Drosophila is mediated by synaptic plasticity between the Kenyon cells of the mushroom body and their output neurons. Both Kenyon cells and their inputs from projection neurons are cholinergic, yet little is known about the physiological function of muscarinic acetylcholine receptors in learning in adult flies. Here, we show that aversive olfactory learning in adult flies requires type A muscarinic acetylcholine receptors (mAChR-A), particularly in the gamma subtype of Kenyon cells. mAChR-A inhibits odor responses and is localized in Kenyon cell dendrites. Moreover, mAChR-A knockdown impairs the learning-associated depression of odor responses in a mushroom body output neuron. Our results suggest that mAChR-A function in Kenyon cell dendrites is required for synaptic plasticity between Kenyon cells and their output neurons.
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Affiliation(s)
- Noa Bielopolski
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hoger Amin
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | | | - Eyal Rozenfeld
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hadas Lerner
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Wolf Huetteroth
- Institute for Biology, University of Leipzig, Leipzig, Germany
| | - Andrew C Lin
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Moshe Parnas
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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29
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Horiuchi J. Recurrent loops: Incorporating prediction error and semantic/episodic theories into Drosophila associative memory models. GENES BRAIN AND BEHAVIOR 2019; 18:e12567. [PMID: 30891930 PMCID: PMC6900151 DOI: 10.1111/gbb.12567] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/27/2019] [Accepted: 03/16/2019] [Indexed: 12/01/2022]
Abstract
In 2003, Martin Heisenberg et al. presented a model of how associative memories could be encoded and stored in the insect brain. This model was extremely influential in the Drosophila memory field, but did not incorporate several important mammalian concepts, including ideas of separate episodic and semantic types of memory and prediction error hypotheses. In addition, at that time, the concept of memory traces recurrently entering and exiting the mushroom bodies, brain areas where associative memories are formed and stored, was unknown. In this review, I present a simple updated model incorporating these ideas, which may be useful for future studies.
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Affiliation(s)
- Junjiro Horiuchi
- Department of higher brain functions and dementias, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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30
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Suppression of GABAergic neurons through D2-like receptor secures efficient conditioning in Drosophila aversive olfactory learning. Proc Natl Acad Sci U S A 2019; 116:5118-5125. [PMID: 30796183 DOI: 10.1073/pnas.1812342116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The GABAergic system serves as a vital negative modulator in cognitive functions, such as learning and memory, while the mechanisms governing this inhibitory system remain to be elucidated. In Drosophila, the GABAergic anterior paired lateral (APL) neurons mediate a negative feedback essential for odor discrimination; however, their activity is suppressed by learning via unknown mechanisms. In aversive olfactory learning, a group of dopaminergic (DA) neurons is activated on electric shock (ES) and modulates the Kenyon cells (KCs) in the mushroom body, the center of olfactory learning. Here we find that the same group of DA neurons also form functional synaptic connections with the APL neurons, thereby emitting a suppressive signal to the latter through Drosophila dopamine 2-like receptor (DD2R). Knockdown of either DD2R or its downstream molecules in the APL neurons results in impaired olfactory learning at the behavioral level. Results obtained from in vivo functional imaging experiments indicate that this DD2R-dependent DA-to-APL suppression occurs during odor-ES conditioning and discharges the GABAergic inhibition on the KCs specific to the conditioned odor. Moreover, the decrease in odor response of the APL neurons persists to the postconditioning phase, and this change is also absent in DD2R knockdown flies. Taken together, our findings show that DA-to-GABA suppression is essential for restraining the GABAergic inhibition during conditioning, as well as for inducing synaptic modification in this learning circuit. Such circuit mechanisms may play conserved roles in associative learning across species.
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31
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Crittenden JR, Skoulakis EMC, Goldstein ES, Davis RL. Drosophila mef2 is essential for normal mushroom body and wing development. Biol Open 2018; 7:bio.035618. [PMID: 30115617 PMCID: PMC6176937 DOI: 10.1242/bio.035618] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
MEF2 (myocyte enhancer factor 2) transcription factors are found in the brain and muscle of insects and vertebrates and are essential for the differentiation of multiple cell types. We show that in the fruit fly Drosophila, MEF2 is essential for the formation of mushroom bodies in the embryonic brain and for the normal development of wings in the adult. In embryos mutant for mef2, there is a striking reduction in the number of mushroom body neurons and their axon bundles are not detectable. The onset of MEF2 expression in neurons of the mushroom bodies coincides with their formation in the embryo and, in larvae, expression is restricted to post-mitotic neurons. In flies with a mef2 point mutation that disrupts nuclear localization, we find that MEF2 is restricted to a subset of Kenyon cells that project to the α/β, and γ axonal lobes of the mushroom bodies, but not to those forming the α’/β’ lobes. Summary:Drosophila mef2 expression is restricted to subsets of mushroom body neurons, from the time of their differentiation to adulthood, and is essential for mushroom body formation.
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Affiliation(s)
- Jill R Crittenden
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Efthimios M C Skoulakis
- Division of Neuroscience, Biomedical Sciences Research Centre 'Alexander Fleming', Vari, 16672, Greece
| | - Elliott S Goldstein
- School of Life Science, Cellular, Molecular and Bioscience Program, Arizona State University, Tempe, AZ, 85287, USA
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
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32
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Diesner M, Neupert S. Quantification of Biogenic Amines from Individual GFP-Labeled Drosophila Cells by MALDI-TOF Mass Spectrometry. Anal Chem 2018; 90:8035-8043. [DOI: 10.1021/acs.analchem.8b00961] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Max Diesner
- University of Cologne, Department of Biology, Institute for Zoology, Zülpicher Strasse 47b, 50674 Cologne, Germany
| | - Susanne Neupert
- University of Cologne, Department of Biology, Institute for Zoology, Zülpicher Strasse 47b, 50674 Cologne, Germany
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33
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Pavlowsky A, Schor J, Plaçais PY, Preat T. A GABAergic Feedback Shapes Dopaminergic Input on the Drosophila Mushroom Body to Promote Appetitive Long-Term Memory. Curr Biol 2018; 28:1783-1793.e4. [PMID: 29779874 PMCID: PMC5988562 DOI: 10.1016/j.cub.2018.04.040] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 03/02/2018] [Accepted: 04/13/2018] [Indexed: 01/11/2023]
Abstract
Memory consolidation is a crucial step for long-term memory (LTM) storage. However, we still lack a clear picture of how memory consolidation is regulated at the neuronal circuit level. Here, we took advantage of the well-described anatomy of the Drosophila olfactory memory center, the mushroom body (MB), to address this question in the context of appetitive LTM. The MB lobes, which are made by the fascicled axons of the MB intrinsic neurons, are organized into discrete anatomical modules, each covered by the terminals of a defined type of dopaminergic neuron (DAN) and the dendrites of a corresponding type of MB output neuron (MBON). We previously revealed the essential role of one DAN, the MP1 neuron, in the formation of appetitive LTM. The MP1 neuron is anatomically matched to the GABAergic MBON MVP2, which has been attributed feedforward inhibitory functions recently. Here, we used behavior experiments and in vivo imaging to challenge the existence of MP1-MVP2 synapses and investigate their role in appetitive LTM consolidation. We show that MP1 and MVP2 neurons form an anatomically and functionally recurrent circuit, which features a feedback inhibition that regulates consolidation of appetitive memory. This circuit involves two opposite type 1 and type 2 dopamine receptors in MVP2 neurons and the metabotropic GABAB-R1 receptor in MP1 neurons. We propose that this dual-receptor feedback supports a bidirectional self-regulation of MP1 input to the MB. This mechanism displays striking similarities with the mammalian reward system, in which modulation of the dopaminergic signal is primarily assigned to inhibitory neurons.
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Affiliation(s)
- Alice Pavlowsky
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Johann Schor
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Pierre-Yves Plaçais
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Thomas Preat
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France.
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34
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Diesner M, Predel R, Neupert S. Neuropeptide Mapping of Dimmed Cells of Adult Drosophila Brain. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:890-902. [PMID: 29372551 DOI: 10.1007/s13361-017-1870-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/29/2017] [Accepted: 12/16/2017] [Indexed: 06/07/2023]
Abstract
Neuropeptides are structurally highly diverse messenger molecules that act as regulators of many physiological processes such as development, metabolism, reproduction or behavior in general. Differentiation of neuropeptidergic cells often corresponds with the presence of the transcription factor DIMMED. In the central nervous system of the fruit fly Drosophila melanogaster, DIMMED commonly occurs in neuroendocrine neurons that release peptides as neurohormones but also in interneurons with complex branching patterns. Fly strains with green fluorescence protein (GFP)-expressing dimmed cells make it possible to systematically analyze the processed neuropeptides in these cells. In this study, we mapped individual GFP-expressing neurons of adult D. melanogaster from the dimmed (c929)>GFP line. Using single cell mass spectrometry, we analyzed 10 types of dimmed neurons from the brain/gnathal ganglion. These cells included neuroendocrine cells with projection into the retrocerebral complex but also a number of large interneurons. Resulting mass spectra not only provided comprehensive data regarding mature products from 13 neuropeptide precursors but also evidence for the cellular co-localization of neuropeptides from different neuropeptide genes. The results can be implemented in a neuroanatomical map of the D. melanogaster brain. Graphical Abstract ᅟ.
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Affiliation(s)
- Max Diesner
- Department for Biology, Zoological Institute, University of Cologne, Zuelpicher Strasse 47b, 50674, Cologne, Germany
| | - Reinhard Predel
- Department for Biology, Zoological Institute, University of Cologne, Zuelpicher Strasse 47b, 50674, Cologne, Germany
| | - Susanne Neupert
- Department for Biology, Zoological Institute, University of Cologne, Zuelpicher Strasse 47b, 50674, Cologne, Germany.
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35
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Cognigni P, Felsenberg J, Waddell S. Do the right thing: neural network mechanisms of memory formation, expression and update in Drosophila. Curr Opin Neurobiol 2018; 49:51-58. [PMID: 29258011 PMCID: PMC5981003 DOI: 10.1016/j.conb.2017.12.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/02/2022]
Abstract
When animals learn, plasticity in brain networks that respond to specific cues results in a change in the behavior that these cues elicit. Individual network components in the mushroom bodies of the fruit fly Drosophila melanogaster represent cues, learning signals and behavioral outcomes of learned experience. Recent findings have highlighted the importance of dopamine-driven plasticity and activity in feedback and feedforward connections, between various elements of the mushroom body neural network. These computational motifs have been shown to be crucial for long term olfactory memory consolidation, integration of internal states, re-evaluation and updating of learned information. The often recurrent circuit anatomy and a prolonged requirement for activity in parts of these underlying networks, suggest that self-sustained and precisely timed activity is a fundamental feature of network computations in the insect brain. Together these processes allow flies to continuously adjust the content of their learned knowledge and direct their behavior in a way that best represents learned expectations and serves their most pressing current needs.
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Affiliation(s)
- Paola Cognigni
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom
| | - Johannes Felsenberg
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom
| | - Scott Waddell
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom.
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36
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Musso PY, Lampin-Saint-Amaux A, Tchenio P, Preat T. Ingestion of artificial sweeteners leads to caloric frustration memory in Drosophila. Nat Commun 2017; 8:1803. [PMID: 29180783 PMCID: PMC5703724 DOI: 10.1038/s41467-017-01989-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 10/30/2017] [Indexed: 11/09/2022] Open
Abstract
Non-caloric artificial sweeteners (NAS) are widely used in modern human food, raising the question about their health impact. Here we have asked whether NAS consumption is a neutral experience at neural and behavioral level, or if NAS can be interpreted and remembered as negative experience. We used behavioral and imaging approaches to demonstrate that Drosophila melanogaster learn the non-caloric property of NAS through post-ingestion process. These results show that sweet taste is predictive of an energy value, and its absence leads to the formation of what we call Caloric Frustration Memory (CFM) that devalues the NAS or its caloric enantiomer. CFM formation involves activity of the associative memory brain structure, the mushroom bodies (MBs). In vivo calcium imaging of MB-input dopaminergic neurons that respond to sugar showed a reduced response to NAS after CFM formation. Altogether, these findings demonstrate that NAS are a negative experience for the brain. While non-caloric artificial sweeteners (NAS) are used as food additives, it’s unclear whether animals perceive NAS as positive or negative percept. Here, Musso and colleagues show in Drosophila that NAS is a negative percept, encoded in a new type of memory.
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Affiliation(s)
- Pierre-Yves Musso
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.,Department of Zoology, Cell and Developmental Biology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
| | - Aurélie Lampin-Saint-Amaux
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France
| | - Paul Tchenio
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.,Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, 91400, Orsay, France
| | - Thomas Preat
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.
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37
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Žurauskas M, Barnstedt O, Frade-Rodriguez M, Waddell S, Booth MJ. Rapid adaptive remote focusing microscope for sensing of volumetric neural activity. BIOMEDICAL OPTICS EXPRESS 2017; 8:4369-4379. [PMID: 29082071 PMCID: PMC5654786 DOI: 10.1364/boe.8.004369] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/15/2017] [Accepted: 08/15/2017] [Indexed: 05/04/2023]
Abstract
The ability to record neural activity in the brain of a living organism at cellular resolution is of great importance for defining the neural circuit mechanisms that direct behavior. Here we present an adaptive two-photon microscope optimized for extraction of neural signals over volumes in intact Drosophila brains, even in the presence of specimen motion. High speed volume imaging was made possible through reduction of spatial resolution while maintaining the light collection efficiency of a high resolution, high numerical aperture microscope. This enabled simultaneous recording of odor-evoked calcium transients in a defined volume of mushroom body Kenyon cell bodies in a live fruit fly.
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Affiliation(s)
- Mantas Žurauskas
- Centre for Neural Circuits and Behaviour, University of Oxford, Mansfield Road, Oxford OX1 3SR, UK
| | - Oliver Barnstedt
- Centre for Neural Circuits and Behaviour, University of Oxford, Mansfield Road, Oxford OX1 3SR, UK
| | - Maria Frade-Rodriguez
- Centre for Neural Circuits and Behaviour, University of Oxford, Mansfield Road, Oxford OX1 3SR, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of Oxford, Mansfield Road, Oxford OX1 3SR, UK
| | - Martin J. Booth
- Centre for Neural Circuits and Behaviour, University of Oxford, Mansfield Road, Oxford OX1 3SR, UK
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
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38
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Drosophila Neprilysin 1 Rescues Memory Deficits Caused by Amyloid-β Peptide. J Neurosci 2017; 37:10334-10345. [PMID: 28931572 DOI: 10.1523/jneurosci.1634-17.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/07/2017] [Accepted: 09/15/2017] [Indexed: 02/02/2023] Open
Abstract
Neprilysins are Type II metalloproteinases known to degrade and inactivate a number of small peptides, in particular the mammalian amyloid-β peptide (Aβ). In Drosophila, several neprilysins expressed in the brain are required for middle-term (MTM) and long-term memory (LTM) in the dorsal paired medial (DPM) neurons, a pair of large neurons that broadly innervate the mushroom bodies (MB), the center of olfactory memory. These data indicate that one or several peptides need to be degraded for MTM and LTM. We have previously shown that the fly amyloid precursor protein (APPL) is required for memory in the MB. We show here that APPL is also required in adult DPM neurons for MTM and LTM formation. This finding prompted us to search for an interaction between neprilysins and Drosophila Aβ (dAβ), a cleavage product of APPL. To find out whether dAβ was a neprilysin's target, we used inducible drivers to modulate neprilysin 1 (Nep1) and dAβ expression in adult DPM neurons. Experiments were conducted either in both sexes or in females. We show that Nep1 inhibition makes dAβ expression detrimental to both MTM and LTM. Conversely, memory deficits displayed by dAβ-expressing flies are rescued by Nep1 overexpression. Consistent with behavioral data, biochemical analyses confirmed that Nep1 degrades dAβ. Together, our findings establish that Nep1 and dAβ expressed in DPM neurons are functionally linked for memory processes, suggesting that dAβ is a physiological target for Nep1.SIGNIFICANCE STATEMENT Neprilysins are endopeptidases known to degrade a number of small peptides and in particular the amyloid peptide. We previously showed that all four neprilysins expressed in the Drosophila brain are involved in specific phases of olfactory memory. Here we show that an increase in the level of the neprilysin 1 peptidase overcomes memory deficits induced by amyloid peptide in young flies. Together, the data reveal a functional interaction between neprilysin 1 and amyloid peptide, suggesting that neprilysin 1 degrades amyloid peptide. These findings raise the possibility that, under nonpathological conditions, mammalian neprilysins degrade amyloid peptide to ensure memory formation.
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Origins of Cell-Type-Specific Olfactory Processing in the Drosophila Mushroom Body Circuit. Neuron 2017; 95:357-367.e4. [PMID: 28728024 DOI: 10.1016/j.neuron.2017.06.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/23/2017] [Accepted: 06/23/2017] [Indexed: 11/23/2022]
Abstract
How cell-type-specific physiological properties shape neuronal functions in a circuit remains poorly understood. We addressed this issue in the Drosophila mushroom body (MB), a higher olfactory circuit, where neurons belonging to distinct glomeruli in the antennal lobe feed excitation to three types of intrinsic neurons, α/β, α'/β', and γ Kenyon cells (KCs). Two-photon optogenetics and intracellular recording revealed that whereas glomerular inputs add similarly in all KCs, spikes were generated most readily in α'/β' KCs. This cell type was also the most competent in recruiting GABAergic inhibition fed back by anterior paired lateral neuron, which responded to odors either locally within a lobe or globally across all lobes depending on the strength of stimuli. Notably, as predicted from these physiological properties, α'/β' KCs had the highest odor detection speed, sensitivity, and discriminability. This enhanced discrimination required proper GABAergic inhibition. These results link cell-type-specific mechanisms and functions in the MB circuit.
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Takemura SY, Aso Y, Hige T, Wong A, Lu Z, Xu CS, Rivlin PK, Hess H, Zhao T, Parag T, Berg S, Huang G, Katz W, Olbris DJ, Plaza S, Umayam L, Aniceto R, Chang LA, Lauchie S, Ogundeyi O, Ordish C, Shinomiya A, Sigmund C, Takemura S, Tran J, Turner GC, Rubin GM, Scheffer LK. A connectome of a learning and memory center in the adult Drosophila brain. eLife 2017; 6. [PMID: 28718765 PMCID: PMC5550281 DOI: 10.7554/elife.26975] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 07/17/2017] [Indexed: 12/12/2022] Open
Abstract
Understanding memory formation, storage and retrieval requires knowledge of the underlying neuronal circuits. In Drosophila, the mushroom body (MB) is the major site of associative learning. We reconstructed the morphologies and synaptic connections of all 983 neurons within the three functional units, or compartments, that compose the adult MB’s α lobe, using a dataset of isotropic 8 nm voxels collected by focused ion-beam milling scanning electron microscopy. We found that Kenyon cells (KCs), whose sparse activity encodes sensory information, each make multiple en passant synapses to MB output neurons (MBONs) in each compartment. Some MBONs have inputs from all KCs, while others differentially sample sensory modalities. Only 6% of KC>MBON synapses receive a direct synapse from a dopaminergic neuron (DAN). We identified two unanticipated classes of synapses, KC>DAN and DAN>MBON. DAN activation produces a slow depolarization of the MBON in these DAN>MBON synapses and can weaken memory recall. DOI:http://dx.doi.org/10.7554/eLife.26975.001
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Affiliation(s)
- Shin-Ya Takemura
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Toshihide Hige
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Allan Wong
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Zhiyuan Lu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - C Shan Xu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Patricia K Rivlin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Harald Hess
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ting Zhao
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Toufiq Parag
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Stuart Berg
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Gary Huang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - William Katz
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Donald J Olbris
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Stephen Plaza
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Lowell Umayam
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Roxanne Aniceto
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Lei-Ann Chang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Shirley Lauchie
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Omotara Ogundeyi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Christopher Ordish
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Aya Shinomiya
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Christopher Sigmund
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Satoko Takemura
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Julie Tran
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Glenn C Turner
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Louis K Scheffer
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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Circuit Analysis of a Drosophila Dopamine Type 2 Receptor That Supports Anesthesia-Resistant Memory. J Neurosci 2017; 36:7936-45. [PMID: 27466338 DOI: 10.1523/jneurosci.4475-15.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 06/07/2016] [Indexed: 01/11/2023] Open
Abstract
UNLABELLED Dopamine is central to reinforcement processing and exerts this function in species ranging from humans to fruit flies. It can do so via two different types of receptors (i.e., D1 or D2) that mediate either augmentation or abatement of cellular cAMP levels. Whereas D1 receptors are known to contribute to Drosophila aversive odor learning per se, we here show that D2 receptors are specific for support of a consolidated form of odor memory known as anesthesia-resistant memory. By means of genetic mosaicism, we localize this function to Kenyon cells, the mushroom body intrinsic neurons, as well as GABAergic APL neurons and local interneurons of the antennal lobes, suggesting that consolidated anesthesia-resistant memory requires widespread dopaminergic modulation within the olfactory circuit. Additionally, dopaminergic neurons themselves require D2R, suggesting a critical role in dopamine release via its recognized autoreceptor function. Considering the dual role of dopamine in balancing memory acquisition (proactive function of dopamine) and its "forgetting" (retroactive function of dopamine), our analysis suggests D2R as central player of either process. SIGNIFICANCE STATEMENT Dopamine provides different information; while it mediates reinforcement during the learning act (proactive function), it balances memory performance between two antithetic processes thereafter (retroactive function) (i.e., forgetting and augmentation). Such bidirectional design can also be found at level of dopamine receptors, where augmenting D1 and abating D2 receptors are engaged to balance cellular cAMP levels. Here, we report that consolidated anesthesia-resistant memory (ARM), but not other concomitant memory phases, are sensitive to bidirectional dopaminergic signals. By means of genetic mosaicism, we identified widespread dopaminergic modulation within the olfactory circuit that suggests nonredundant and reiterating functions of D2R in support of ARM. Our results oppose ARM to its concomitant memory phases that localize to mushroom bodies and propose a decentralized organization of consolidated ARM.
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Shyu WH, Chiu TH, Chiang MH, Cheng YC, Tsai YL, Fu TF, Wu T, Wu CL. Neural circuits for long-term water-reward memory processing in thirsty Drosophila. Nat Commun 2017; 8:15230. [PMID: 28504254 PMCID: PMC5440665 DOI: 10.1038/ncomms15230] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 03/03/2017] [Indexed: 12/14/2022] Open
Abstract
The intake of water is important for the survival of all animals and drinking water can be used as a reward in thirsty animals. Here we found that thirsty Drosophila melanogaster can associate drinking water with an odour to form a protein-synthesis-dependent water-reward long-term memory (LTM). Furthermore, we found that the reinforcement of LTM requires water-responsive dopaminergic neurons projecting to the restricted region of mushroom body (MB) β′ lobe, which are different from the neurons required for the reinforcement of learning and short-term memory (STM). Synaptic output from α′β′ neurons is required for consolidation, whereas the output from γ and αβ neurons is required for the retrieval of LTM. Finally, two types of MB efferent neurons retrieve LTM from γ and αβ neurons by releasing glutamate and acetylcholine, respectively. Our results therefore cast light on the cellular and molecular mechanisms responsible for processing water-reward LTM in Drosophila. Distinct subsets of dopaminergic PAM neurons have been shown to be involved in short-term and long-term memory for sugar reward. Here the authors report the neural circuits and the cellular and molecular mechanisms for short-term and long-term memory for water reward in thirsty Drosophila.
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Affiliation(s)
- Wei-Huan Shyu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Tai-Hsiang Chiu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Meng-Hsuan Chiang
- Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Yu-Chin Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Ya-Lun Tsai
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Tsai-Feng Fu
- Department of Applied Chemistry, National Chi-Nan University, Nantou 54561, Taiwan
| | - Tony Wu
- Department of Neurology, Linkou Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
| | - Chia-Lin Wu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.,Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.,Department of Neurology, Linkou Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
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Facilitating Neuron-Specific Genetic Manipulations in Drosophila melanogaster Using a Split GAL4 Repressor. Genetics 2017; 206:775-784. [PMID: 28363977 PMCID: PMC5499185 DOI: 10.1534/genetics.116.199687] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 03/28/2017] [Indexed: 12/22/2022] Open
Abstract
Efforts to map neural circuits have been galvanized by the development of genetic technologies that permit the manipulation of targeted sets of neurons in the brains of freely behaving animals. The success of these efforts relies on the experimenter’s ability to target arbitrarily small subsets of neurons for manipulation, but such specificity of targeting cannot routinely be achieved using existing methods. In Drosophila melanogaster, a widely-used technique for refined cell type-specific manipulation is the Split GAL4 system, which augments the targeting specificity of the binary GAL4-UAS (Upstream Activating Sequence) system by making GAL4 transcriptional activity contingent upon two enhancers, rather than one. To permit more refined targeting, we introduce here the “Killer Zipper” (KZip+), a suppressor that makes Split GAL4 targeting contingent upon a third enhancer. KZip+ acts by disrupting both the formation and activity of Split GAL4 heterodimers, and we show how this added layer of control can be used to selectively remove unwanted cells from a Split GAL4 expression pattern or to subtract neurons of interest from a pattern to determine their requirement in generating a given phenotype. To facilitate application of the KZip+ technology, we have developed a versatile set of LexAop-KZip+ fly lines that can be used directly with the large number of LexA driver lines with known expression patterns. KZip+ significantly sharpens the precision of neuronal genetic control available in Drosophila and may be extended to other organisms where Split GAL4-like systems are used.
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Second-Generation Drosophila Chemical Tags: Sensitivity, Versatility, and Speed. Genetics 2017; 205:1399-1408. [PMID: 28209589 PMCID: PMC5378102 DOI: 10.1534/genetics.116.199281] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/10/2017] [Indexed: 11/22/2022] Open
Abstract
Thick tissue specimens present major challenges for labeling cells and subcellular structures in a rapid and reliable manner. Sutcliffe et al. present... Labeling and visualizing cells and subcellular structures within thick tissues, whole organs, and even intact animals is key to studying biological processes. This is particularly true for studies of neural circuits where neurons form submicron synapses but have arbors that may span millimeters in length. Traditionally, labeling is achieved by immunofluorescence; however, diffusion of antibody molecules (>100 kDa) is slow and often results in uneven labeling with very poor penetration into the center of thick specimens; these limitations can be partially addressed by extending staining protocols to over a week (Drosophila brain) and months (mice). Recently, we developed an alternative approach using genetically encoded chemical tags CLIP, SNAP, Halo, and TMP for tissue labeling; this resulted in >100-fold increase in labeling speed in both mice and Drosophila, at the expense of a considerable drop in absolute sensitivity when compared to optimized immunofluorescence staining. We now present a second generation of UAS- and LexA-responsive CLIPf, SNAPf, and Halo chemical labeling reagents for flies. These multimerized tags, with translational enhancers, display up to 64-fold increase in sensitivity over first-generation reagents. In addition, we developed a suite of conditional reporters (4xSNAPf tag and CLIPf-SNAPf-Halo2) that are activated by the DNA recombinase Bxb1. Our new reporters can be used with weak and strong GAL4 and LexA drivers and enable stochastic, intersectional, and multicolor Brainbow labeling. These improvements in sensitivity and experimental versatility, while still retaining the substantial speed advantage that is a signature of chemical labeling, should significantly increase the scope of this technology.
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Takahashi N, Katoh K, Watanabe H, Nakayama Y, Iwasaki M, Mizunami M, Nishino H. Complete identification of four giant interneurons supplying mushroom body calyces in the cockroach Periplaneta americana. J Comp Neurol 2016; 525:204-230. [PMID: 27573362 DOI: 10.1002/cne.24108] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 10/21/2022]
Abstract
Global inhibition is a fundamental physiological mechanism that has been proposed to shape odor representation in higher-order olfactory centers. A pair of mushroom bodies (MBs) in insect brains, an analog of the mammalian olfactory cortex, are implicated in multisensory integration and associative memory formation. With the use of single/multiple intracellular recording and staining in the cockroach Periplaneta americana, we succeeded in unambiguous identification of four tightly bundled GABA-immunoreactive giant interneurons that are presumably involved in global inhibitory control of the MB. These neurons, including three spiking neurons and one nonspiking neuron, possess dendrites in termination fields of MB output neurons and send axon terminals back to MB input sites, calyces, suggesting feedback roles onto the MB. The largest spiking neuron innervates almost exclusively the basal region of calyces, while the two smaller spiking neurons and the second-largest nonspiking neuron innervate more profusely the peripheral (lip) region of the calyces than the basal region. This subdivision corresponds well to the calycal zonation made by axon terminals of two populations of uniglomerular projection neurons with dendrites in distinct glomerular groups in the antennal lobe. The four giant neurons exhibited excitatory responses to every odor tested in a neuron-specific fashion, and two of the neurons also exhibited inhibitory responses in some recording sessions. Our results suggest that two parallel olfactory inputs to the MB undergo different forms of inhibitory control by the giant neurons, which may, in turn, be involved in different aspects of odor discrimination, plasticity, and state-dependent gain control. J. Comp. Neurol. 525:204-230, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Naomi Takahashi
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Ko Katoh
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Hidehiro Watanabe
- Division of Biology, Department of Earth System Science, Fukuoka University, Fukuoka, Japan
| | - Yuta Nakayama
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Masazumi Iwasaki
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | | | - Hiroshi Nishino
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
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Additive Expression of Consolidated Memory through Drosophila Mushroom Body Subsets. PLoS Genet 2016; 12:e1006061. [PMID: 27195782 PMCID: PMC4873240 DOI: 10.1371/journal.pgen.1006061] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 04/27/2016] [Indexed: 01/15/2023] Open
Abstract
Associative olfactory memory in Drosophila has two components called labile anesthesia-sensitive memory and consolidated anesthesia-resistant memory (ARM). Mushroom body (MB) is a brain region critical for the olfactory memory and comprised of 2000 neurons that can be classified into αβ, α′β′, and γ neurons. Previously we demonstrated that two parallel pathways mediated ARM consolidation: the serotonergic dorsal paired medial (DPM)–αβ neurons and the octopaminergic anterior paired lateral (APL)–α′β′ neurons. This finding prompted us to ask how this composite ARM is retrieved. Here, we showed that blocking the output of αβ neurons and that of α′β′ neurons each impaired ARM retrieval, and blocking both simultaneously had an additive effect. Knockdown of radish and octβ2R in αβ and α′β′ neurons, respectively, impaired ARM. A combinatorial assay of radish mutant background rsh1 and neurotransmission blockade confirmed that ARM retrieved from α′β′ neuron output is independent of radish. We identified MBON-β2β′2a and MBON-β′2mp as the MB output neurons downstream of αβ and α′β′ neurons, respectively, whose glutamatergic transmissions also additively contribute to ARM retrieval. Finally, we showed that α′β′ neurons could be functionally subdivided into α′β′m neurons required for ARM retrieval, and α′β′ap neurons required for ARM consolidation. Our work demonstrated that two parallel neural pathways mediating ARM consolidation in Drosophila MB additively contribute to ARM expression during retrieval. One of tantalizing questions in neuroscience is how the brain processes memory. Studies in animal models such as fruit fly have brought innovations addressing the general principles underlying memory processing such as acquisition, consolidation, and retrieval. Here, we revealed an additive expression of aversive consolidated memory through fly mushroom body (MB) subsets. By thermogenetic blockade of neurotransmission, we identified the necessity of MB αβ and α′β′ neurons, and their respective downstream neurons, for consolidated memory retrieval. We also showed that MB αβ and α′β′ neurons harbor distinct signaling pathways for memory consolidation by genetic manipulation. Notably, the combinatorial assays of neurotransmission blockade and genetic manipulations confirmed the independency between the two sets of double-layered parallel circuits. Our work, together with previous finding of two respective modulatory neurons upstream of αβ and α′β′ neurons, favor the notion that memory is consolidated in different brain regions/circuits in parallel and later additively retrieved for behavioral outcome.
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Williams ZM. Transgenerational influence of sensorimotor training on offspring behavior and its neural basis in Drosophila. Neurobiol Learn Mem 2016; 131:166-75. [PMID: 27044678 DOI: 10.1016/j.nlm.2016.03.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/23/2016] [Accepted: 03/30/2016] [Indexed: 01/01/2023]
Abstract
Whether specific learning experiences by parents influence the behavior of subsequent generations remains unclear. This study examines whether and what aspects of parental sensorimotor training prior to conception affect the behavior of subsequent generations and identifies the neural circuitries in Drosophila responsible for mediating these effects. Using genetic and anatomic techniques, I find that both first- and second-generation offspring of parents who underwent prolonged olfactory training over many days displayed a weak but selective approach bias to the same trained odors. However, I also find that the offspring did not differentiate between orders based on whether parental training was aversive or appetitive. Disruption of both olfactory-receptor and dorsal-paired-medial neuron input into the mushroom bodies abolished this change in offspring response, but disrupting synaptic output from α/β neurons of the mushroom body themselves had little effect on behavior even though they remained necessary for enacting newly trained conditioned responses. This study provides a circuit-based understanding of how specific sensory experiences in Drosophila may bias the behavior of subsequent generations, and identifies a transgenerational dissociation between the effects of conditioned and unconditioned sensory stimuli.
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Affiliation(s)
- Ziv M Williams
- Harvard-MIT Health Sciences and Technology, Boston, MA, United States; Harvard Medical School Program in Neuroscience, Boston, MA, United States; Department of Neurosurgery, MGH-HMS Center for Nervous System Repair, Harvard Medical School, Boston, MA, United States.
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Barnstedt O, Owald D, Felsenberg J, Brain R, Moszynski JP, Talbot CB, Perrat PN, Waddell S. Memory-Relevant Mushroom Body Output Synapses Are Cholinergic. Neuron 2016; 89:1237-1247. [PMID: 26948892 PMCID: PMC4819445 DOI: 10.1016/j.neuron.2016.02.015] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 01/04/2016] [Accepted: 01/27/2016] [Indexed: 11/17/2022]
Abstract
Memories are stored in the fan-out fan-in neural architectures of the mammalian cerebellum and hippocampus and the insect mushroom bodies. However, whereas key plasticity occurs at glutamatergic synapses in mammals, the neurochemistry of the memory-storing mushroom body Kenyon cell output synapses is unknown. Here we demonstrate a role for acetylcholine (ACh) in Drosophila. Kenyon cells express the ACh-processing proteins ChAT and VAChT, and reducing their expression impairs learned olfactory-driven behavior. Local ACh application, or direct Kenyon cell activation, evokes activity in mushroom body output neurons (MBONs). MBON activation depends on VAChT expression in Kenyon cells and is blocked by ACh receptor antagonism. Furthermore, reducing nicotinic ACh receptor subunit expression in MBONs compromises odor-evoked activation and redirects odor-driven behavior. Lastly, peptidergic corelease enhances ACh-evoked responses in MBONs, suggesting an interaction between the fast- and slow-acting transmitters. Therefore, olfactory memories in Drosophila are likely stored as plasticity of cholinergic synapses. Mushroom body Kenyon cell function requires ChAT and VAChT expression Kenyon cell-released acetylcholine drives mushroom body output neurons Blocking nicotinic receptors impairs mushroom body output neuron activation Acetylcholine interacts with coreleased neuropeptide
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Affiliation(s)
- Oliver Barnstedt
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - David Owald
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
| | - Johannes Felsenberg
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Ruth Brain
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - John-Paul Moszynski
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Clifford B Talbot
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Paola N Perrat
- Department of Neurobiology, UMass Medical School, Worcester, MA 01605, USA
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
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Guven-Ozkan T, Busto GU, Schutte SS, Cervantes-Sandoval I, O'Dowd DK, Davis RL. MiR-980 Is a Memory Suppressor MicroRNA that Regulates the Autism-Susceptibility Gene A2bp1. Cell Rep 2016; 14:1698-1709. [PMID: 26876166 DOI: 10.1016/j.celrep.2016.01.040] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/26/2015] [Accepted: 01/09/2016] [Indexed: 01/07/2023] Open
Abstract
MicroRNAs have been associated with many different biological functions, but little is known about their roles in conditioned behavior. We demonstrate that Drosophila miR-980 is a memory suppressor gene functioning in multiple regions of the adult brain. Memory acquisition and stability were both increased by miR-980 inhibition. Whole cell recordings and functional imaging experiments indicated that miR-980 regulates neuronal excitability. We identified the autism susceptibility gene, A2bp1, as an mRNA target for miR-980. A2bp1 levels varied inversely with miR-980 expression; memory performance was directly related to A2bp1 levels. In addition, A2bp1 knockdown reversed the memory gains produced by miR-980 inhibition, consistent with A2bp1 being a downstream target of miR-980 responsible for the memory phenotypes. Our results indicate that miR-980 represses A2bp1 expression to tune the excitable state of neurons, and the overall state of excitability translates to memory impairment or improvement.
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Affiliation(s)
- Tugba Guven-Ozkan
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Germain U Busto
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Soleil S Schutte
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA 92697, USA
| | | | - Diane K O'Dowd
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA 92697, USA
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA.
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Abstract
Binary expression systems are flexible and versatile genetic tools in Drosophila. The Q-system is a recently developed repressible binary expression system that offers new possibilities for transgene expression and genetic manipulations. In this review chapter, we focus on current state-of-the-art Q-system tools and reagents. We also discuss in vivo applications of the Q-system, together with GAL4/UAS and LexA/LexAop systems, for simultaneous expression of multiple effectors, intersectional labeling, and clonal analysis.
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