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Comyn T, Preat T, Pavlowsky A, Plaçais PY. PKCδ is an activator of neuronal mitochondrial metabolism that mediates the spacing effect on memory consolidation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.06.561186. [PMID: 38948698 PMCID: PMC11212906 DOI: 10.1101/2023.10.06.561186] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Relevance-based selectivity and high energy cost are two distinct features of long-term memory (LTM) formation that warrant its default inhibition. Spaced repetition of learning is a highly conserved cognitive mechanism that can lift this inhibition. Here, we questioned how the spacing effect integrates experience selection and energy efficiency at the cellular and molecular levels. We showed in Drosophila that spaced training triggers LTM formation by extending over several hours an increased mitochondrial metabolic activity in neurons of the associative memory center, the mushroom bodies (MBs). We found that this effect is mediated by PKCδ, a member of the so-called 'novel PKC' family of enzymes, which uncovers the critical function of PKCδ in neurons as a regulator of mitochondrial metabolism for LTM. Additionally, PKCδ activation and translocation to mitochondria result from LTM-specific dopamine signaling on MB neurons. By bridging experience-dependent neuronal circuit activity with metabolic modulation of memory-encoding neurons, PKCδ signaling binds the cognitive and metabolic constraints underlying LTM formation into a unified gating mechanism.
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Affiliation(s)
- Typhaine Comyn
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Thomas Preat
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Alice Pavlowsky
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
- Co-corresponding authors
| | - Pierre-Yves Plaçais
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
- Co-corresponding authors
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2
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Ho DM, Shaban M, Mahmood F, Ganguly P, Todeschini L, Van Vactor D, Artavanis-Tsakonas S. cAMP/PKA signaling regulates TDP-43 aggregation and mislocalization. Proc Natl Acad Sci U S A 2024; 121:e2400732121. [PMID: 38838021 PMCID: PMC11181030 DOI: 10.1073/pnas.2400732121] [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: 01/12/2024] [Accepted: 05/03/2024] [Indexed: 06/07/2024] Open
Abstract
Cytoplasmic mislocalization and aggregation of TDP-43 protein are hallmarks of amyotrophic lateral sclerosis (ALS) and are observed in the vast majority of both familial and sporadic cases. How these two interconnected processes are regulated on a molecular level, however, remains enigmatic. Genome-wide screens for modifiers of the ALS-associated genes TDP-43 and FUS have identified the phospholipase D (Pld) pathway as a key regulator of ALS-related phenotypes in the fruit fly Drosophila melanogaster [M. W. Kankel et al., Genetics 215, 747-766 (2020)]. Here, we report the results of our search for downstream targets of the enzymatic product of Pld, phosphatidic acid. We identify two conserved negative regulators of the cAMP/PKA signaling pathway, the phosphodiesterase dunce and the inhibitory subunit PKA-R2, as modifiers of pathogenic phenotypes resulting from overexpression of the Drosophila TDP-43 ortholog TBPH. We show that knockdown of either of these genes results in a mitigation of both TBPH aggregation and mislocalization in larval motor neuron cell bodies, as well as an amelioration of adult-onset motor defects and shortened lifespan induced by TBPH. We determine that PKA kinase activity is downstream of both TBPH and Pld and that overexpression of the PKA target CrebA can rescue TBPH mislocalization. These findings suggest a model whereby increasing cAMP/PKA signaling can ameliorate the molecular and functional effects of pathological TDP-43.
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Affiliation(s)
- Diana M. Ho
- Department of Cell Biology, Harvard Medical School, Boston, MA02115
| | - Muhammad Shaban
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA02114
- Cancer Data Science Program, Dana-Farber Cancer Institute, Boston, MA02115
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, MA02142
| | - Faisal Mahmood
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA02115
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA02114
- Cancer Data Science Program, Dana-Farber Cancer Institute, Boston, MA02115
- Cancer Program, Broad Institute of Harvard and MIT, Cambridge, MA02142
| | - Payel Ganguly
- Department of Cell Biology, Harvard Medical School, Boston, MA02115
| | | | - David Van Vactor
- Department of Cell Biology, Harvard Medical School, Boston, MA02115
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3
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Boto T, Tomchik SM. Functional Imaging of Learning-Induced Plasticity in the Central Nervous System with Genetically Encoded Reporters in Drosophila. Cold Spring Harb Protoc 2024; 2024:pdb.top107799. [PMID: 37197830 DOI: 10.1101/pdb.top107799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Learning and memory allow animals to adjust their behavior based on the predictive value of their past experiences. Memories often exist in complex representations, spread across numerous cells and synapses in the brain. Studying relatively simple forms of memory provides insights into the fundamental processes that underlie multiple forms of memory. Associative learning occurs when an animal learns the relationship between two previously unrelated sensory stimuli, such as when a hungry animal learns that a particular odor is followed by a tasty reward. Drosophila is a particularly powerful model to study how this type of memory works. The fundamental principles are widely shared among animals, and there is a wide range of genetic tools available to study circuit function in flies. In addition, the olfactory structures that mediate associative learning in flies, such as the mushroom body and its associated neurons, are anatomically organized, relatively well-characterized, and readily accessible to imaging. Here, we review the olfactory anatomy and physiology of the olfactory system, describe how plasticity in the olfactory pathway mediates learning and memory, and explain the general principles underlying calcium imaging approaches.
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Affiliation(s)
- Tamara Boto
- Department of Physiology, Trinity College Dublin, Dublin 2, Ireland
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Seth M Tomchik
- Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
- Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
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4
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Pribbenow C, Owald D. Skewing information flow through pre- and postsynaptic plasticity in the mushroom bodies of Drosophila. Learn Mem 2024; 31:a053919. [PMID: 38876487 PMCID: PMC11199954 DOI: 10.1101/lm.053919.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/26/2024] [Indexed: 06/16/2024]
Abstract
Animal brains need to store information to construct a representation of their environment. Knowledge of what happened in the past allows both vertebrates and invertebrates to predict future outcomes by recalling previous experience. Although invertebrate and vertebrate brains share common principles at the molecular, cellular, and circuit-architectural levels, there are also obvious differences as exemplified by the use of acetylcholine versus glutamate as the considered main excitatory neurotransmitters in the respective central nervous systems. Nonetheless, across central nervous systems, synaptic plasticity is thought to be a main substrate for memory storage. Therefore, how brain circuits and synaptic contacts change following learning is of fundamental interest for understanding brain computations tied to behavior in any animal. Recent progress has been made in understanding such plastic changes following olfactory associative learning in the mushroom bodies (MBs) of Drosophila A current framework of memory-guided behavioral selection is based on the MB skew model, in which antagonistic synaptic pathways are selectively changed in strength. Here, we review insights into plasticity at dedicated Drosophila MB output pathways and update what is known about the plasticity of both pre- and postsynaptic compartments of Drosophila MB neurons.
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Affiliation(s)
- Carlotta Pribbenow
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - David Owald
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
- Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
- NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
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5
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Suárez-Grimalt R, Grunwald Kadow IC, Scheunemann L. An integrative sensor of body states: how the mushroom body modulates behavior depending on physiological context. Learn Mem 2024; 31:a053918. [PMID: 38876486 PMCID: PMC11199956 DOI: 10.1101/lm.053918.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/08/2024] [Indexed: 06/16/2024]
Abstract
The brain constantly compares past and present experiences to predict the future, thereby enabling instantaneous and future behavioral adjustments. Integration of external information with the animal's current internal needs and behavioral state represents a key challenge of the nervous system. Recent advancements in dissecting the function of the Drosophila mushroom body (MB) at the single-cell level have uncovered its three-layered logic and parallel systems conveying positive and negative values during associative learning. This review explores a lesser-known role of the MB in detecting and integrating body states such as hunger, thirst, and sleep, ultimately modulating motivation and sensory-driven decisions based on the physiological state of the fly. State-dependent signals predominantly affect the activity of modulatory MB input neurons (dopaminergic, serotoninergic, and octopaminergic), but also induce plastic changes directly at the level of the MB intrinsic and output neurons. Thus, the MB emerges as a tightly regulated relay station in the insect brain, orchestrating neuroadaptations due to current internal and behavioral states leading to short- but also long-lasting changes in behavior. While these adaptations are crucial to ensure fitness and survival, recent findings also underscore how circuit motifs in the MB may reflect fundamental design principles that contribute to maladaptive behaviors such as addiction or depression-like symptoms.
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Affiliation(s)
- Raquel Suárez-Grimalt
- Institute for Biology/Genetics, Freie Universität Berlin, 14195 Berlin, Germany
- Institut für Neurophysiologie and NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | | | - Lisa Scheunemann
- Institute for Biology/Genetics, Freie Universität Berlin, 14195 Berlin, Germany
- Institut für Neurophysiologie and NeuroCure Cluster of Excellence, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
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6
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Yamada D, Davidson AM, Hige T. Cyclic nucleotide-induced bidirectional long-term synaptic plasticity in Drosophila mushroom body. J Physiol 2024; 602:2019-2045. [PMID: 38488688 PMCID: PMC11068490 DOI: 10.1113/jp285745] [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: 09/30/2023] [Accepted: 02/21/2024] [Indexed: 03/26/2024] Open
Abstract
Activation of the cAMP pathway is one of the common mechanisms underlying long-term potentiation (LTP). In the Drosophila mushroom body, simultaneous activation of odour-coding Kenyon cells (KCs) and reinforcement-coding dopaminergic neurons activates adenylyl cyclase in KC presynaptic terminals, which is believed to trigger synaptic plasticity underlying olfactory associative learning. However, learning induces long-term depression (LTD) at these synapses, contradicting the universal role of cAMP as a facilitator of transmission. Here, we developed a system to electrophysiologically monitor both short-term and long-term synaptic plasticity at KC output synapses and demonstrated that they are indeed an exception in which activation of the cAMP-protein kinase A pathway induces LTD. Contrary to the prevailing model, our cAMP imaging found no evidence for synergistic action of dopamine and KC activity on cAMP synthesis. Furthermore, we found that forskolin-induced cAMP increase alone was insufficient for plasticity induction; it additionally required simultaneous KC activation to replicate the presynaptic LTD induced by pairing with dopamine. On the other hand, activation of the cGMP pathway paired with KC activation induced slowly developing LTP, proving antagonistic actions of the two second-messenger pathways predicted by behavioural study. Finally, KC subtype-specific interrogation of synapses revealed that different KC subtypes exhibit distinct plasticity duration even among synapses on the same postsynaptic neuron. Thus, our work not only revises the role of cAMP in synaptic plasticity by uncovering the unexpected convergence point of the cAMP pathway and neuronal activity, but also establishes the methods to address physiological mechanisms of synaptic plasticity in this important model. KEY POINTS: Although presynaptic cAMP increase generally facilitates synapses, olfactory associative learning in Drosophila, which depends on dopamine and cAMP signalling genes, induces long-term depression (LTD) at the mushroom body output synapses. By combining electrophysiology, pharmacology and optogenetics, we directly demonstrate that these synapses are an exception where activation of the cAMP-protein kinase A pathway leads to presynaptic LTD. Dopamine- or forskolin-induced cAMP increase alone is not sufficient for LTD induction; neuronal activity, which has been believed to trigger cAMP synthesis in synergy with dopamine input, is required in the downstream pathway of cAMP. In contrast to cAMP, activation of the cGMP pathway paired with neuronal activity induces presynaptic long-term potentiation, which explains behaviourally observed opposing actions of transmitters co-released by dopaminergic neurons. Our work not only revises the role of cAMP in synaptic plasticity, but also provides essential methods to address physiological mechanisms of synaptic plasticity in this important model system.
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Affiliation(s)
- Daichi Yamada
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Andrew M. Davidson
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Toshihide Hige
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, United States
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7
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Mallick A, Tan HL, Epstein JM, Gaudry Q, Dacks AM. Serotonin acts through multiple cellular targets during an olfactory critical period. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.14.589413. [PMID: 38645269 PMCID: PMC11030346 DOI: 10.1101/2024.04.14.589413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Serotonin (5-HT) is known to modulate early development during critical periods when experience drives heightened levels of plasticity in neurons. Here, we take advantage of the genetically tractable olfactory system of Drosophila to investigate how 5-HT modulates critical period plasticity in the CO2 sensing circuit of fruit flies. Our study reveals that 5HT modulation of multiple neuronal targets is necessary for experience-dependent structural changes in an odor processing circuit. The olfactory CPP is known to involve local inhibitory networks and consistent with this we found that knocking down 5-HT7 receptors in a subset of GABAergic local interneurons was sufficient to block CPP, as was knocking down GABA receptors expressed by olfactory sensory neurons (OSNs). Additionally, direct modulation of OSNs via 5-HT2B expression in the cognate OSNs sensing CO2 is also essential for CPP. Furthermore, 5-HT1B expression by serotonergic neurons in the olfactory system is also required during the critical period. Our study reveals that 5-HT modulation of multiple neuronal targets is necessary for experience-dependent structural changes in an odor processing circuit.
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Affiliation(s)
- Ahana Mallick
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Hua Leonhard Tan
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | | | - Quentin Gaudry
- Department of Biology, University of Maryland, College Park, MD 20742, USA
- Senior Author: These authors contributed equally
| | - Andrew M Dacks
- Departments of Biology and Neuroscience, West Virginia University, Morgantown, WV 26505, USA
- Senior Author: These authors contributed equally
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8
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Yamada D, Davidson AM, Hige T. Cyclic nucleotide-induced bidirectional long-term synaptic plasticity in Drosophila mushroom body. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.28.560058. [PMID: 37808762 PMCID: PMC10557778 DOI: 10.1101/2023.09.28.560058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Activation of the cAMP pathway is one of the common mechanisms underlying long-term potentiation (LTP). In the Drosophila mushroom body, simultaneous activation of odor-coding Kenyon cells (KCs) and reinforcement-coding dopaminergic neurons activates adenylyl cyclase in KC presynaptic terminals, which is believed to trigger synaptic plasticity underlying olfactory associative learning. However, learning induces long-term depression (LTD) at these synapses, contradicting the universal role of cAMP as a facilitator of transmission. Here, we develop a system to electrophysiologically monitor both short-term and long-term synaptic plasticity at KC output synapses and demonstrate that they are indeed an exception where activation of the cAMP/protein kinase A pathway induces LTD. Contrary to the prevailing model, our cAMP imaging finds no evidence for synergistic action of dopamine and KC activity on cAMP synthesis. Furthermore, we find that forskolin-induced cAMP increase alone is insufficient for plasticity induction; it additionally requires simultaneous KC activation to replicate the presynaptic LTD induced by pairing with dopamine. On the other hand, activation of the cGMP pathway paired with KC activation induces slowly developing LTP, proving antagonistic actions of the two second-messenger pathways predicted by behavioral study. Finally, KC subtype-specific interrogation of synapses reveals that different KC subtypes exhibit distinct plasticity duration even among synapses on the same postsynaptic neuron. Thus, our work not only revises the role of cAMP in synaptic plasticity by uncovering the unexpected convergence point of the cAMP pathway and neuronal activity, but also establishes the methods to address physiological mechanisms of synaptic plasticity in this important model.
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Affiliation(s)
- Daichi Yamada
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Andrew M. Davidson
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Toshihide Hige
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, United States
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9
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Piette C, Gervasi N, Venance L. Synaptic plasticity through a naturalistic lens. Front Synaptic Neurosci 2023; 15:1250753. [PMID: 38145207 PMCID: PMC10744866 DOI: 10.3389/fnsyn.2023.1250753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023] Open
Abstract
From the myriad of studies on neuronal plasticity, investigating its underlying molecular mechanisms up to its behavioral relevance, a very complex landscape has emerged. Recent efforts have been achieved toward more naturalistic investigations as an attempt to better capture the synaptic plasticity underpinning of learning and memory, which has been fostered by the development of in vivo electrophysiological and imaging tools. In this review, we examine these naturalistic investigations, by devoting a first part to synaptic plasticity rules issued from naturalistic in vivo-like activity patterns. We next give an overview of the novel tools, which enable an increased spatio-temporal specificity for detecting and manipulating plasticity expressed at individual spines up to neuronal circuit level during behavior. Finally, we put particular emphasis on works considering brain-body communication loops and macroscale contributors to synaptic plasticity, such as body internal states and brain energy metabolism.
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Affiliation(s)
- Charlotte Piette
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | | | - Laurent Venance
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
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10
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Jelen M, Musso PY, Junca P, Gordon MD. Optogenetic induction of appetitive and aversive taste memories in Drosophila. eLife 2023; 12:e81535. [PMID: 37750673 PMCID: PMC10561975 DOI: 10.7554/elife.81535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/22/2023] [Indexed: 09/27/2023] Open
Abstract
Tastes typically evoke innate behavioral responses that can be broadly categorized as acceptance or rejection. However, research in Drosophila melanogaster indicates that taste responses also exhibit plasticity through experience-dependent changes in mushroom body circuits. In this study, we develop a novel taste learning paradigm using closed-loop optogenetics. We find that appetitive and aversive taste memories can be formed by pairing gustatory stimuli with optogenetic activation of sensory neurons or dopaminergic neurons encoding reward or punishment. As with olfactory memories, distinct dopaminergic subpopulations drive the parallel formation of short- and long-term appetitive memories. Long-term memories are protein synthesis-dependent and have energetic requirements that are satisfied by a variety of caloric food sources or by direct stimulation of MB-MP1 dopaminergic neurons. Our paradigm affords new opportunities to probe plasticity mechanisms within the taste system and understand the extent to which taste responses depend on experience.
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Affiliation(s)
- Meghan Jelen
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
| | - Pierre-Yves Musso
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
| | - Pierre Junca
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
| | - Michael D Gordon
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
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11
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Nöbel S, Danchin E, Isabel G. Mate copying requires the coincidence detector Rutabaga in the mushroom bodies of Drosophila melanogaster. iScience 2023; 26:107682. [PMID: 37694137 PMCID: PMC10484988 DOI: 10.1016/j.isci.2023.107682] [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: 03/28/2023] [Revised: 07/03/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023] Open
Abstract
Mate choice constitutes a major fitness-affecting decision often involving social learning leading to copying the preference of other individuals (i.e., mate copying). While mate copying exists in many taxa, its underlying neurobiological mechanisms remain virtually unknown. Here, we show in Drosophila melanogaster that the rutabaga gene is necessary to support mate copying. Rutabaga encodes an adenylyl cyclase (AC-Rut+) acting as a coincidence detector in associative learning. Since the brain localization requirements for AC-Rut+ expression differ in classical and operant learning, we determine the functional localization of AC-Rut+ for mate copying by artificially rescuing the expression of AC-Rut+ in neural subsets of a rutabaga mutant. We found that AC-Rut+ has to be expressed in the mushroom bodies' Kenyon cells (KCs), specifically in the γ-KCs subset. Thus, this form of discriminative social learning requires the same KCs as non-social Pavlovian learning, suggesting that pathways of social and asocial learning overlap significantly.
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Affiliation(s)
- Sabine Nöbel
- Department of Zoology, Animal Ecology, Martin-Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
- Université Toulouse 1 Capitole and Institute for Advanced Study in Toulouse (IAST), Toulouse, France
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Etienne Danchin
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 118 route de Narbonne, 31062 Toulouse, France
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), CNRS UMR 5169, Université de Toulouse Midi-Pyrénées, Toulouse, France
| | - Guillaume Isabel
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), CNRS UMR 5169, Université de Toulouse Midi-Pyrénées, Toulouse, France
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12
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Paoli M, Macri C, Giurfa M. A cognitive account of trace conditioning in insects. CURRENT OPINION IN INSECT SCIENCE 2023; 57:101034. [PMID: 37044245 DOI: 10.1016/j.cois.2023.101034] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 05/07/2023]
Abstract
Trace conditioning is a form of Pavlovian learning in which the conditioned stimulus (CS) and the unconditioned stimulus (US) are separated by a temporal gap. Insects learn trace associations of variable nature (appetitive, aversive) and involving CSs of different sensory modalities (olfactory, visual). The accessibility of the insect neural system in behaving animals allowed identifying neural processes driving trace conditioning: the existence of prolonged neural responses to the CS after stimulus offset and the anticipation of US responses during the free-stimulus gap. Specific brain structures, such as the mushroom bodies seem to be allocated to this learning form. Here, we posit that a further component facilitating trace conditioning in insects relates to neuromodulatory mechanisms underlying enhanced attention. We thus propose a model based on different types of mushroom-body neurons, which provides a cognitive account of trace conditioning in insects.
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Affiliation(s)
- Marco Paoli
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse cedex 9, France
| | - Catherine Macri
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse cedex 9, France
| | - Martin Giurfa
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse cedex 9, France; Institut Universitaire de France (IUF), Paris, France.
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13
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Zeng J, Li X, Zhang R, Lv M, Wang Y, Tan K, Xia X, Wan J, Jing M, Zhang X, Li Y, Yang Y, Wang L, Chu J, Li Y, Li Y. Local 5-HT signaling bi-directionally regulates the coincidence time window for associative learning. Neuron 2023; 111:1118-1135.e5. [PMID: 36706757 PMCID: PMC11152601 DOI: 10.1016/j.neuron.2022.12.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 10/03/2022] [Accepted: 12/30/2022] [Indexed: 01/27/2023]
Abstract
The coincidence between conditioned stimulus (CS) and unconditioned stimulus (US) is essential for associative learning; however, the mechanism regulating the duration of this temporal window remains unclear. Here, we found that serotonin (5-HT) bi-directionally regulates the coincidence time window of olfactory learning in Drosophila and affects synaptic plasticity of Kenyon cells (KCs) in the mushroom body (MB). Utilizing GPCR-activation-based (GRAB) neurotransmitter sensors, we found that KC-released acetylcholine (ACh) activates a serotonergic dorsal paired medial (DPM) neuron, which in turn provides inhibitory feedback to KCs. Physiological stimuli induce spatially heterogeneous 5-HT signals, which proportionally gate the intrinsic coincidence time windows of different MB compartments. Artificially reducing or increasing the DPM neuron-released 5-HT shortens or prolongs the coincidence window, respectively. In a sequential trace conditioning paradigm, this serotonergic neuromodulation helps to bridge the CS-US temporal gap. Altogether, we report a model circuitry for perceiving the temporal coincidence and determining the causal relationship between environmental events.
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Affiliation(s)
- Jianzhi Zeng
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China; Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, Anhui, China.
| | - Xuelin Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China
| | - Renzimo Zhang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China; Yuanpei College, Peking University, Beijing 100871, China
| | - Mingyue Lv
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China
| | - Yipan Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China
| | - Ke Tan
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Xiju Xia
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China; PKU-THU-NIBS Joint Graduate Program, Beijing 100871, China
| | - Jinxia Wan
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China
| | - Miao Jing
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Xiuning Zhang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China
| | - Yu Li
- School of Medicine, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Yang Yang
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liang Wang
- Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology & Center for Biomedical Optics and Molecular Imaging & CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jun Chu
- Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology & Center for Biomedical Optics and Molecular Imaging & CAS Key Laboratory of Health Informatics, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yan Li
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China; Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518132, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China; Yuanpei College, Peking University, Beijing 100871, China; PKU-THU-NIBS Joint Graduate Program, Beijing 100871, China; Chinese Institute for Brain Research, Beijing 102206, China.
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14
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Noyes NC, Davis RL. Innate and learned odor-guided behaviors utilize distinct molecular signaling pathways in a shared dopaminergic circuit. Cell Rep 2023; 42:112026. [PMID: 36701232 PMCID: PMC10366338 DOI: 10.1016/j.celrep.2023.112026] [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: 06/03/2022] [Revised: 11/16/2022] [Accepted: 01/10/2023] [Indexed: 01/26/2023] Open
Abstract
Odor-based learning and innate odor-driven behavior have been hypothesized to require separate neuronal circuitry. Contrary to this notion, innate behavior and olfactory learning were recently shown to share circuitry that includes the Drosophila mushroom body (MB). But how a single circuit drives two discrete behaviors remains unknown. Here, we define an MB circuit responsible for both olfactory learning and innate odor avoidance and the distinct dDA1 dopamine receptor-dependent signaling pathways that mediate these behaviors. Associative learning and learning-induced MB plasticity require rutabaga-encoded adenylyl cyclase activity in the MB. In contrast, innate odor preferences driven by naive MB neurotransmission are rutabaga independent, requiring the adenylyl cyclase ACXD. Both learning and innate odor preferences converge on PKA and the downstream MBON-γ2α'1. Importantly, the utilization of this shared circuitry for innate behavior only becomes apparent with hunger, indicating that hardwired innate behavior becomes more flexible during states of stress.
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Affiliation(s)
- Nathaniel C Noyes
- Department of Neuroscience, UF Scripps Biomedical Research, 130 Scripps Way #3C2, Jupiter, FL 33458, USA
| | - Ronald L Davis
- Department of Neuroscience, UF Scripps Biomedical Research, 130 Scripps Way #3C2, Jupiter, FL 33458, USA.
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15
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Neurogenetics of Memory, Learning, and Forgetting. Neurogenetics 2023. [DOI: 10.1007/978-3-031-07793-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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16
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Adel M, Chen N, Zhang Y, Reed ML, Quasney C, Griffith LC. Pairing-Dependent Plasticity in a Dissected Fly Brain Is Input-Specific and Requires Synaptic CaMKII Enrichment and Nighttime Sleep. J Neurosci 2022; 42:4297-4310. [PMID: 35474278 PMCID: PMC9145224 DOI: 10.1523/jneurosci.0144-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/23/2022] [Accepted: 04/19/2022] [Indexed: 11/21/2022] Open
Abstract
In Drosophila, in vivo functional imaging studies revealed that associative memory formation is coupled to a cascade of neural plasticity events in distinct compartments of the mushroom body (MB). In-depth investigation of the circuit dynamics, however, will require an ex vivo model that faithfully mirrors these events to allow direct manipulations of circuit elements that are inaccessible in the intact fly. The current ex vivo models have been able to reproduce the fundamental plasticity of aversive short-term memory, a potentiation of the MB intrinsic neuron (Kenyon cells [KCs]) responses after artificial learning ex vivo However, this potentiation showed different localization and encoding properties from those reported in vivo and failed to generate the previously reported suppression plasticity in the MB output neurons (MBONs). Here, we develop an ex vivo model using the female Drosophila brain that recapitulates behaviorally evoked plasticity in the KCs and MBONs. We demonstrate that this plasticity accurately localizes to the MB α'3 compartment and is encoded by a coincidence between KC activation and dopaminergic input. The formed plasticity is input-specific, requiring pairing of the conditioned stimulus and unconditioned stimulus pathways; hence, we name it pairing-dependent plasticity. Pairing-dependent plasticity formation requires an intact CaMKII gene and is blocked by previous-night sleep deprivation but is rescued by rebound sleep. In conclusion, we show that our ex vivo preparation recapitulates behavioral and imaging results from intact animals and can provide new insights into mechanisms of memory formation at the level of molecules, circuits, and brain state.SIGNIFICANCE STATEMENT The mammalian ex vivo LTP model enabled in-depth investigation of the hippocampal memory circuit. We develop a parallel model to study the Drosophila mushroom body (MB) memory circuit. Pairing activation of the conditioned stimulus and unconditioned stimulus pathways in dissected brains induces a potentiation pairing-dependent plasticity (PDP) in the axons of α'β' Kenyon cells and a suppression PDP in the dendrites of their postsynaptic MB output neurons, localized in the MB α'3 compartment. This PDP is input-specific and requires the 3' untranslated region of CaMKII Interestingly, ex vivo PDP carries information about the animal's experience before dissection; brains from sleep-deprived animals fail to form PDP, whereas those from animals who recovered 2 h of their lost sleep form PDP.
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Affiliation(s)
- Mohamed Adel
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Nannan Chen
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Yunpeng Zhang
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Martha L Reed
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Christina Quasney
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
| | - Leslie C Griffith
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454-9110
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17
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Sears JC, Broadie K. Temporally and Spatially Localized PKA Activity within Learning and Memory Circuitry Regulated by Network Feedback. eNeuro 2022; 9:ENEURO.0450-21.2022. [PMID: 35301221 PMCID: PMC8982635 DOI: 10.1523/eneuro.0450-21.2022] [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: 10/24/2021] [Revised: 02/18/2022] [Accepted: 03/12/2022] [Indexed: 12/02/2022] Open
Abstract
Dynamic functional connectivity within brain circuits requires coordination of intercellular signaling and intracellular signal transduction. Critical roles for cAMP-dependent protein kinase A (PKA) signaling are well established in the Drosophila mushroom body (MB) learning and memory circuitry, but local PKA activity within this well-mapped neuronal network is uncharacterized. Here, we use an in vivo PKA activity sensor (PKA-SPARK) to test spatiotemporal regulatory requirements in the MB axon lobes. We find immature animals have little detectable PKA activity, whereas postcritical period adults show high field-selective activation primarily in just 3/16 defined output regions. In addition to the age-dependent PKA activity in distinct α'/β' lobe nodes, females show sex-dependent elevation compared with males in these same restricted regions. Loss of neural cell body Fragile X mental retardation protein (FMRP) and Rugose [human Neurobeachin (NBEA)] suppresses localized PKA activity, whereas overexpression (OE) of MB lobe PKA-synergist Meng-Po (human SBK1) promotes PKA activity. Elevated Meng-Po subverts the PKA age-dependence, with elevated activity in immature animals, and spatial-restriction, with striking γ lobe activity. Testing circuit signaling requirements with temperature-sensitive shibire (human Dynamin) blockade, we find broadly expanded PKA activity within the MB lobes. Using transgenic tetanus toxin to block MB synaptic output, we find greatly heightened PKA activity in virtually all MB lobe fields, although the age-dependence is maintained. We conclude spatiotemporally restricted PKA activity signaling within this well-mapped learning/memory circuit is age-dependent and sex-dependent, driven by FMRP-Rugose pathway activation, temporally promoted by Meng-Po kinase function, and restricted by output neurotransmission providing network feedback.
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Affiliation(s)
- James C Sears
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN 37235
- Department of Pharmacology, Vanderbilt University and Medical Center, Nashville, TN 37235
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18
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Saitoe M, Naganos S, Miyashita T, Matsuno M, Ueno K. A non-canonical on-demand dopaminergic transmission underlying olfactory aversive learning. Neurosci Res 2021; 178:1-9. [PMID: 34973292 DOI: 10.1016/j.neures.2021.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 11/16/2021] [Accepted: 12/27/2021] [Indexed: 10/19/2022]
Abstract
Dopamine (DA) is involved in various brain functions including associative learning. However, it is unclear how a small number of DA neurons appropriately regulates various brain functions. DA neurons have a large number of release sites and release DA non-specifically to a large number of target neurons in the projection area in response to the activity of DA neurons. In contrast to this "broad transmission", recent studies in Drosophila ex vivo functional imaging studies have identified "on-demand transmission" that occurs independent on activity of DA neurons and releases DA specifically onto the target neurons that have produced carbon monoxide (CO) as a retrograde signal for DA release. Whereas broad transmission modulates the global function of the target area, on-demand transmission is suitable for modulating the function of specific circuits, neurons, or synapses. In Drosophila olfactory aversive conditioning, odor and shock information are associated in the brain region called mushroom body (MB) to form olfactory aversive memory. It has been suggested that DA neurons projecting to the MB mediate the transmission of shock information and reinforcement simultaneously. However, the circuit model based on on-demand transmission proposes that transmission of shock information and reinforcement are mediated by distinct neural mechanisms; while shock transmission is glutamatergic, DA neurons mediates reinforcement. On-demand transmission provides mechanical insights into how DA neurons regulate various brain functions.
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Affiliation(s)
- Minoru Saitoe
- Learning and Memory Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.
| | - Shintaro Naganos
- Learning and Memory Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan
| | - Tomoyuki Miyashita
- Learning and Memory Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan
| | - Motomi Matsuno
- Learning and Memory Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan
| | - Kohei Ueno
- Learning and Memory Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan
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19
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Scheffer LK, Meinertzhagen IA. A connectome is not enough - what is still needed to understand the brain of Drosophila? J Exp Biol 2021; 224:272599. [PMID: 34695211 DOI: 10.1242/jeb.242740] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Understanding the structure and operation of any nervous system has been a subject of research for well over a century. A near-term opportunity in this quest is to understand the brain of a model species, the fruit fly Drosophila melanogaster. This is an enticing target given its relatively small size (roughly 200,000 neurons), coupled with the behavioral richness that this brain supports, and the wide variety of techniques now available to study both brain and behavior. It is clear that within a few years we will possess a connectome for D. melanogaster: an electron-microscopy-level description of all neurons and their chemical synaptic connections. Given what we will soon have, what we already know and the research that is currently underway, what more do we need to know to enable us to understand the fly's brain? Here, we itemize the data we will need to obtain, collate and organize in order to build an integrated model of the brain of D. melanogaster.
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Affiliation(s)
- Louis K Scheffer
- Howard Hughes Medical Institute, 19741 Smith Circle, Ashburn, VA 20147, USA
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20
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Noyes NC, Phan A, Davis RL. Memory suppressor genes: Modulating acquisition, consolidation, and forgetting. Neuron 2021; 109:3211-3227. [PMID: 34450024 PMCID: PMC8542634 DOI: 10.1016/j.neuron.2021.08.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/15/2021] [Accepted: 07/30/2021] [Indexed: 02/06/2023]
Abstract
The brain has a remarkable but underappreciated capacity to limit memory formation and expression. The term "memory suppressor gene" was coined in 1998 as an attempt to explain emerging reports that some genes appeared to limit memory. At that time, only a handful of memory suppressor genes were known, and they were understood to work by limiting cAMP-dependent consolidation. In the intervening decades, almost 100 memory suppressor genes with diverse functions have been discovered that affect not only consolidation but also acquisition and forgetting. Here we highlight the surprising extent to which biological limits are placed on memory formation through reviewing the literature on memory suppressor genes. In this review, we present memory suppressors within the framework of their actions on different memory operations: acquisition, consolidation, and forgetting. This is followed by a discussion of the reasons why there may be a biological need to limit memory formation.
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Affiliation(s)
- Nathaniel C Noyes
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Anna Phan
- Department of Biological Sciences, University of Alberta, 11355 Saskatchewan Drive, Edmonton, AB T6G 2E9, Canada
| | - Ronald L Davis
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA.
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21
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Wiggin TD, Hsiao Y, Liu JB, Huber R, Griffith LC. Rest Is Required to Learn an Appetitively-Reinforced Operant Task in Drosophila. Front Behav Neurosci 2021; 15:681593. [PMID: 34220464 PMCID: PMC8250850 DOI: 10.3389/fnbeh.2021.681593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/21/2021] [Indexed: 11/13/2022] Open
Abstract
Maladaptive operant conditioning contributes to development of neuropsychiatric disorders. Candidate genes have been identified that contribute to this maladaptive plasticity, but the neural basis of operant conditioning in genetic model organisms remains poorly understood. The fruit fly Drosophila melanogaster is a versatile genetic model organism that readily forms operant associations with punishment stimuli. However, operant conditioning with a food reward has not been demonstrated in flies, limiting the types of neural circuits that can be studied. Here we present the first sucrose-reinforced operant conditioning paradigm for flies. In the paradigm, flies walk along a Y-shaped track with reward locations at the terminus of each hallway. When flies turn in the reinforced direction at the center of the track, they receive a sucrose reward at the end of the hallway. Only flies that rest early in training learn the reward contingency normally. Flies rewarded independently of their behavior do not form a learned association but have the same amount of rest as trained flies, showing that rest is not driven by learning. Optogenetically-induced sleep does not promote learning, indicating that sleep itself is not sufficient for learning the operant task. We validated the sensitivity of this assay to detect the effect of genetic manipulations by testing the classic learning mutant dunce. Dunce flies are learning-impaired in the Y-Track task, indicating a likely role for cAMP in the operant coincidence detector. This novel training paradigm will provide valuable insight into the molecular mechanisms of disease and the link between sleep and learning.
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Affiliation(s)
- Timothy D. Wiggin
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Yungyi Hsiao
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Jeffrey B. Liu
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Robert Huber
- Radcliffe Institute for Advanced Studies, Harvard University, Cambridge, MA, United States
- Juvatech, Toledo, MA, United States
| | - Leslie C. Griffith
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
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22
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Melnattur K, Kirszenblat L, Morgan E, Militchin V, Sakran B, English D, Patel R, Chan D, van Swinderen B, Shaw PJ. A conserved role for sleep in supporting Spatial Learning in Drosophila. Sleep 2021; 44:5909488. [PMID: 32959053 DOI: 10.1093/sleep/zsaa197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/18/2020] [Indexed: 01/25/2023] Open
Abstract
Sleep loss and aging impair hippocampus-dependent Spatial Learning in mammalian systems. Here we use the fly Drosophila melanogaster to investigate the relationship between sleep and Spatial Learning in healthy and impaired flies. The Spatial Learning assay is modeled after the Morris Water Maze. The assay uses a "thermal maze" consisting of a 5 × 5 grid of Peltier plates maintained at 36-37°C and a visual panorama. The first trial begins when a single tile that is associated with a specific visual cue is cooled to 25°C. For subsequent trials, the cold tile is heated, the visual panorama is rotated and the flies must find the new cold tile by remembering its association with the visual cue. Significant learning was observed with two different wild-type strains-Cs and 2U, validating our design. Sleep deprivation prior to training impaired Spatial Learning. Learning was also impaired in the classic learning mutant rutabaga (rut); enhancing sleep restored learning to rut mutants. Further, we found that flies exhibited a dramatic age-dependent cognitive decline in Spatial Learning starting at 20-24 days of age. These impairments could be reversed by enhancing sleep. Finally, we find that Spatial Learning requires dopaminergic signaling and that enhancing dopaminergic signaling in aged flies restored learning. Our results are consistent with the impairments seen in rodents and humans. These results thus demonstrate a critical conserved role for sleep in supporting Spatial Learning, and suggest potential avenues for therapeutic intervention during aging.
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Affiliation(s)
- Krishna Melnattur
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO
| | - Leonie Kirszenblat
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia.,RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Ellen Morgan
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO
| | - Valentin Militchin
- Department of Otolaryngology, Washington University School of Medicine, St Louis, MO
| | - Blake Sakran
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO
| | - Denis English
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO
| | - Rushi Patel
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO
| | - Dorothy Chan
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia
| | - Paul J Shaw
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO
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23
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Delhaye S, Bardoni B. Role of phosphodiesterases in the pathophysiology of neurodevelopmental disorders. Mol Psychiatry 2021; 26:4570-4582. [PMID: 33414502 PMCID: PMC8589663 DOI: 10.1038/s41380-020-00997-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022]
Abstract
Phosphodiesterases (PDEs) are enzymes involved in the homeostasis of both cAMP and cGMP. They are members of a family of proteins that includes 11 subfamilies with different substrate specificities. Their main function is to catalyze the hydrolysis of cAMP, cGMP, or both. cAMP and cGMP are two key second messengers that modulate a wide array of intracellular processes and neurobehavioral functions, including memory and cognition. Even if these enzymes are present in all tissues, we focused on those PDEs that are expressed in the brain. We took into consideration genetic variants in patients affected by neurodevelopmental disorders, phenotypes of animal models, and pharmacological effects of PDE inhibitors, a class of drugs in rapid evolution and increasing application to brain disorders. Collectively, these data indicate the potential of PDE modulators to treat neurodevelopmental diseases characterized by learning and memory impairment, alteration of behaviors associated with depression, and deficits in social interaction. Indeed, clinical trials are in progress to treat patients with Alzheimer's disease, schizophrenia, depression, and autism spectrum disorders. Among the most recent results, the application of some PDE inhibitors (PDE2A, PDE3, PDE4/4D, and PDE10A) to treat neurodevelopmental diseases, including autism spectrum disorders and intellectual disability, is a significant advance, since no specific therapies are available for these disorders that have a large prevalence. In addition, to highlight the role of several PDEs in normal and pathological neurodevelopment, we focused here on the deregulation of cAMP and/or cGMP in Down Syndrome, Fragile X Syndrome, Rett Syndrome, and intellectual disability associated with the CC2D1A gene.
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Affiliation(s)
- Sébastien Delhaye
- grid.429194.30000 0004 0638 0649Université Côte d’Azur, CNRS UMR7275, Institute of Molecular and Cellular Pharmacology, 06560 Valbonne, France
| | - Barbara Bardoni
- Université Côte d'Azur, Inserm, CNRS UMR7275, Institute of Molecular and Cellular Pharmacology, 06560, Valbonne, France.
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24
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Serotonin receptor 5-HT7 in Drosophila mushroom body neurons mediates larval appetitive olfactory learning. Sci Rep 2020; 10:21267. [PMID: 33277559 PMCID: PMC7718245 DOI: 10.1038/s41598-020-77910-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 11/09/2020] [Indexed: 11/29/2022] Open
Abstract
Serotonin (5-HT) and dopamine are critical neuromodulators known to regulate a range of behaviors in invertebrates and mammals, such as learning and memory. Effects of both serotonin and dopamine are mediated largely through their downstream G-protein coupled receptors through cAMP-PKA signaling. While the role of dopamine in olfactory learning in Drosophila is well described, the function of serotonin and its downstream receptors on Drosophila olfactory learning remain largely unexplored. In this study we show that the output of serotonergic neurons, possibly through points of synaptic contacts on the mushroom body (MB), is essential for training during olfactory associative learning in Drosophila larvae. Additionally, we demonstrate that the regulation of olfactory associative learning by serotonin is mediated by its downstream receptor (d5-HT7) in a cAMP-dependent manner. We show that d5-HT7 expression specifically in the MB, an anatomical structure essential for olfactory learning in Drosophila, is critical for olfactory associative learning. Importantly our work shows that spatio-temporal restriction of d5-HT7 expression to the MB is sufficient to rescue olfactory learning deficits in a d5-HT7 null larvae. In summary, our results establish a critical, and previously unknown, role of d5-HT7 in olfactory learning.
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25
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Boto T, Stahl A, Zhang X, Louis T, Tomchik SM. Independent Contributions of Discrete Dopaminergic Circuits to Cellular Plasticity, Memory Strength, and Valence in Drosophila. Cell Rep 2020; 27:2014-2021.e2. [PMID: 31091441 PMCID: PMC6585410 DOI: 10.1016/j.celrep.2019.04.069] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 02/18/2019] [Accepted: 04/11/2019] [Indexed: 01/13/2023] Open
Abstract
Dopaminergic neurons play a key role in encoding associative memories, but little is known about how these circuits modulate memory strength. Here we report that different sets of dopaminergic neurons projecting to the Drosophila mushroom body (MB) differentially regulate valence and memory strength. PPL2 neurons increase odor-evoked calcium re- sponses to a paired odor in the MB and enhance behavioral memory strength when activated during olfactory classical conditioning. When paired with odor alone, they increase MB responses to the paired odor but do not drive behavioral approach or avoidance, suggesting that they increase the salience of the odor without encoding strong valence. This contrasts with the role of dopaminergic PPL1 neurons, which drive behavioral reinforcement but do not alter odor-evoked calcium responses in the MB when stimulated. These data suggest that different sets of dopaminergic neurons modulate olfactory valence and memory strength via independent actions on a memory-encoding brain region. Boto et al. investigated the roles of two sets of dopaminergic neurons that converge on a memory-encoding brain region in flies. While one set, PPL1, drives aversive reinforcement (valence), PPL2 neurons enhance memory strength via modulation of Ca2+ response plasticity in memory-encoding mushroom body neurons.
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Affiliation(s)
- Tamara Boto
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Aaron Stahl
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Xiaofan Zhang
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Thierry Louis
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
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26
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Wakabayashi Y, Telu S, Dick RM, Fujita M, Ooms M, Morse CL, Liow JS, Hong JS, Gladding RL, Manly LS, Zoghbi SS, Mo X, D’Amato EC, Sindac JA, Nugent RA, Marron BE, Gurney ME, Innis RB, Pike VW. Discovery, Radiolabeling, and Evaluation of Subtype-Selective Inhibitors for Positron Emission Tomography Imaging of Brain Phosphodiesterase-4D. ACS Chem Neurosci 2020; 11:1311-1323. [PMID: 32212718 DOI: 10.1021/acschemneuro.0c00077] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We aimed to develop radioligands for PET imaging of brain phosphodiesterase subtype 4D (PDE4D), a potential target for developing cognition enhancing or antidepressive drugs. Exploration of several chemical series gave four leads with high PDE4D inhibitory potency and selectivity, optimal lipophilicity, and good brain uptake. These leads featured alkoxypyridinyl cores. They were successfully labeled with carbon-11 (t1/2 = 20.4 min) for evaluation with PET in monkey. Whereas two of these radioligands did not provide PDE4D-specific signal in monkey brain, two others, [11C]T1660 and [11C]T1650, provided sizable specific signal, as judged by pharmacological challenge using rolipram or a selective PDE4D inhibitor (BPN14770) and subsequent biomathematical analysis. Specific binding was highest in prefrontal cortex, temporal cortex, and hippocampus, regions that are important for cognitive function. [11C]T1650 was progressed to evaluation in humans with PET, but the output measure of brain enzyme density (VT) increased with scan duration. This instability over time suggests that radiometabolite(s) were accumulating in the brain. BPN14770 blocked PDE4D uptake in human brain after a single dose, but the percentage occupancy was difficult to estimate because of the unreliability of measuring VT. Overall, these results show that imaging of PDE4D in primate brain is feasible but that further radioligand refinement is needed, most likely to avoid problematic radiometabolites.
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Affiliation(s)
- Yuichi Wakabayashi
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Sanjay Telu
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Rachel M. Dick
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Masahiro Fujita
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Maarten Ooms
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Cheryl L. Morse
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Jeih-San Liow
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Jinsoo S. Hong
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Robert L. Gladding
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Lester S. Manly
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Sami S. Zoghbi
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Xuesheng Mo
- Tetra Therapeutics, Grand Rapids, Michigan 49506, United States
| | | | | | | | - Brian E. Marron
- Tetra Therapeutics, Grand Rapids, Michigan 49506, United States
| | - Mark E. Gurney
- Tetra Therapeutics, Grand Rapids, Michigan 49506, United States
| | - Robert B. Innis
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
| | - Victor W. Pike
- National Institute of Mental Health, Bethesda, Maryland 20892-9663, United States
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27
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Drosophila Middle-Term Memory: Amnesiac is Required for PKA Activation in the Mushroom Bodies, a Function Modulated by Neprilysin 1. J Neurosci 2020; 40:4219-4229. [PMID: 32303647 DOI: 10.1523/jneurosci.2311-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 03/30/2020] [Accepted: 04/05/2020] [Indexed: 11/21/2022] Open
Abstract
In Drosophila, the mushroom bodies (MB) constitute the central brain structure for olfactory associative memory. As in mammals, the cAMP/PKA pathway plays a key role in memory formation. In the MB, Rutabaga (Rut) adenylate cyclase acts as a coincidence detector during associative conditioning to integrate calcium influx resulting from acetylcholine stimulation and G-protein activation resulting from dopaminergic stimulation. Amnesiac encodes a secreted neuropeptide required in the MB for two phases of aversive olfactory memory. Previous sequence analysis has revealed strong homology with the mammalian pituitary adenylate cyclase-activating peptide (PACAP). Here, we examined whether amnesiac is involved in cAMP/PKA dynamics in response to dopamine and acetylcholine co-stimulation in living flies. Experiments were conducted with both sexes, or with either sex. Our data show that amnesiac is necessary for the PKA activation process that results from coincidence detection in the MB. Since PACAP peptide is cleaved by the human membrane neprilysin hNEP, we searched for an interaction between Amnesiac and Neprilysin 1 (Nep1), a fly neprilysin involved in memory. We show that when Nep1 expression is acutely knocked down in adult MB, memory deficits displayed by amn hypomorphic mutants are rescued. Consistently, Nep1 inhibition also restores normal PKA activation in amn mutant flies. Taken together, the results suggest that Nep1 targets Amnesiac degradation to terminate its signaling function. Our work thus highlights a key role for Amnesiac in establishing within the MB the PKA dynamics that sustain middle-term memory (MTM) formation, a function modulated by Nep1.SIGNIFICANCE STATEMENT The Drosophila amnesiac gene encodes a secreted neuropeptide whose expression is required for specific memory phases in the mushroom bodies (MB), the olfactory memory center. Here, we show that Amnesiac is required for PKA activation resulting from coincidence detection, a mechanism by which the MB integrate two spatially distinct stimuli to encode associative memory. Furthermore, our results uncover a functional relationship between Amnesiac and Neprilysin 1 (Nep1), a membrane peptidase involved in memory and expressed in the MB. These results suggest that Nep1 modulates Amnesiac levels. We propose that on conditioning, Amnesiac release from the MB allows, via an autocrine process, the sustaining of PKA activation-mediating memory, which subsequently is inactivated by Nep1 degradation.
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Modi MN, Shuai Y, Turner GC. The Drosophila Mushroom Body: From Architecture to Algorithm in a Learning Circuit. Annu Rev Neurosci 2020; 43:465-484. [PMID: 32283995 DOI: 10.1146/annurev-neuro-080317-0621333] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Drosophila brain contains a relatively simple circuit for forming Pavlovian associations, yet it achieves many operations common across memory systems. Recent advances have established a clear framework for Drosophila learning and revealed the following key operations: a) pattern separation, whereby dense combinatorial representations of odors are preprocessed to generate highly specific, nonoverlapping odor patterns used for learning; b) convergence, in which sensory information is funneled to a small set of output neurons that guide behavioral actions; c) plasticity, where changing the mapping of sensory input to behavioral output requires a strong reinforcement signal, which is also modulated by internal state and environmental context; and d) modularization, in which a memory consists of multiple parallel traces, which are distinct in stability and flexibility and exist in anatomically well-defined modules within the network. Cross-module interactions allow for higher-order effects where past experience influences future learning. Many of these operations have parallels with processes of memory formation and action selection in more complex brains.
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Affiliation(s)
- Mehrab N Modi
- Janelia Research Campus, Ashburn, Virginia 20147, USA;
| | - Yichun Shuai
- Janelia Research Campus, Ashburn, Virginia 20147, USA;
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29
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Concerted Actions of Octopamine and Dopamine Receptors Drive Olfactory Learning. J Neurosci 2020; 40:4240-4250. [PMID: 32277043 DOI: 10.1523/jneurosci.1756-19.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 03/12/2020] [Accepted: 03/29/2020] [Indexed: 11/21/2022] Open
Abstract
Aminergic signaling modulates associative learning and memory. Substantial advance has been made in Drosophila on the dopamine receptors and circuits mediating olfactory learning; however, our knowledge of other aminergic modulation lags behind. To address this knowledge gap, we investigated the role of octopamine in olfactory conditioning. Here, we report that octopamine activity through the β-adrenergic-like receptor Octβ1R drives aversive and appetitive learning: Octβ1R in the mushroom body αβ neurons processes aversive learning, whereas Octβ1R in the projection neurons mediates appetitive learning. Our genetic interaction and imaging studies pinpoint cAMP signaling as a key downstream effector for Octβ1R function. The rutabaga-adenylyl cyclase synthesizes cAMP in a Ca2+/calmodulin-dependent manner, serving as a coincidence detector for associative learning and likely representing a downstream target for Octβ1R. Supporting this notion, the double heterozygous rutabaga/+;octβ1r/+ flies perform poorly in both aversive and appetitive conditioning, while individual heterozygous rutabaga/+ and octβ1r/+ flies behave like the wild-type control. Consistently, the mushroom body and projection neurons in the octβ1r brain exhibit blunted responses to octopamine when cAMP levels are monitored through the cAMP sensor. We previously demonstrated the pivotal functions of the D1 receptor dDA1 in aversive and appetitive learning, and the α1 adrenergic-like receptor OAMB in appetitive learning. As expected, octβ1r genetically interacts with dumb (dDA1 mutant) in aversive and appetitive learning, but it interacts with oamb only in appetitive learning. This study uncovers the indispensable contributions of dopamine and octopamine signaling to aversive and appetitive learning. All experiments were performed on mixed sex unless otherwise noted.SIGNIFICANCE STATEMENT Animals make flexible behavioral choices that are constantly shaped by experience. This plasticity is vital for animals to appropriately respond to the cues predicting benefit or harm. In Drosophila, dopamine is known to mediate both reward-based and punishment-based learning while octopamine function is important only for reward. Here, we demonstrate that the octopamine-Octβ1R-cAMP pathway processes both aversive and appetitive learning in distinct neural sites of the olfactory circuit. Furthermore, we show that the octopamine-Octβ1R and dopamine-dDA1 signals together drive both aversive and appetitive learning, whereas the octopamine-Octβ1R and octopamine-OAMB pathways jointly facilitate appetitive, but not aversive, learning. This study identifies the cognate actions of octopamine and dopamine signaling as a key neural mechanism for associative learning.
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Zamberlan DC, Halmenschelager PT, Silva LFO, da Rocha JBT. Copper decreases associative learning and memory in Drosophila melanogaster. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 710:135306. [PMID: 31926406 DOI: 10.1016/j.scitotenv.2019.135306] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 06/10/2023]
Abstract
Copper is an essential element to all living organisms. Repeated use of metal-enriched chemicals, fertilizers, and organic substances may cause contamination at a large scale. Altered levels of Cu2+ may result in harmful effects and can be associated with memory and cognitive dysfunction. Studying simple, genetically tractable organisms such as Drosophila melanogaster, can reveal important data on the neural basis of conditioning. D. melanogaster is an important alternative experimental model to assess the toxic response to metals. In the present study, the effects of copper on flies' development and in learning and memory retention in male and female adult flies were investigated. We paired an odorant to pain perception and observed the aversion behavior over time. Exposure of D. melanogaster eggs to Cu2+ increased mortality of larvae, pupae, and adults and decreased memory retention in adults. Moreover, male flies demonstrated to be more susceptible to Cu2+ toxicity than females. The results therefore, reinforce the importance of controlling the anthropogenic heavy-metals soil contamination given their hazardous effects to living organisms.
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Affiliation(s)
- D C Zamberlan
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - P T Halmenschelager
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - L F O Silva
- Department of Civil and Environmental, Universidad De La Costa, Calle 58 #55-66, 080002 Barranquilla, Atlantico, Colombia
| | - J B T da Rocha
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
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31
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Boto T, Stahl A, Tomchik SM. Cellular and circuit mechanisms of olfactory associative learning in Drosophila. J Neurogenet 2020; 34:36-46. [PMID: 32043414 DOI: 10.1080/01677063.2020.1715971] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent years have witnessed significant progress in understanding how memories are encoded, from the molecular to the cellular and the circuit/systems levels. With a good compromise between brain complexity and behavioral sophistication, the fruit fly Drosophila melanogaster is one of the preeminent animal models of learning and memory. Here we review how memories are encoded in Drosophila, with a focus on short-term memory and an eye toward future directions. Forward genetic screens have revealed a large number of genes and transcripts necessary for learning and memory, some acting cell-autonomously. Further, the relative numerical simplicity of the fly brain has enabled the reverse engineering of learning circuits with remarkable precision, in some cases ascribing behavioral phenotypes to single neurons. Functional imaging and physiological studies have localized and parsed the plasticity that occurs during learning at some of the major loci. Connectomics projects are significantly expanding anatomical knowledge of the nervous system, filling out the roadmap for ongoing functional/physiological and behavioral studies, which are being accelerated by simultaneous tool development. These developments have provided unprecedented insight into the fundamental neural principles of learning, and lay the groundwork for deep understanding in the near future.
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Affiliation(s)
- Tamara Boto
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
| | - Aaron Stahl
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
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32
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Abstract
The Mushroom Body (MB) is the primary location of stored associative memories in the Drosophila brain. We discuss recent advances in understanding the MB's neuronal circuits made using advanced light microscopic methods and cell-type-specific genetic tools. We also review how the compartmentalized nature of the MB's organization allows this brain area to form and store memories with widely different dynamics.
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Affiliation(s)
- Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
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33
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Williams-Simon PA, Ganesan M, King EG. Learning to collaborate: bringing together behavior and quantitative genomics. J Neurogenet 2020; 34:28-35. [PMID: 31920134 DOI: 10.1080/01677063.2019.1710145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The genetic basis of complex trait like learning and memory have been well studied over the decades. Through those groundbreaking findings, we now have a better understanding about some of the genes and pathways that are involved in learning and/or memory. However, few of these findings identified the naturally segregating variants that are influencing learning and/or memory within populations. In this special issue honoring the legacy of Troy Zars, we review some of the traditional approaches that have been used to elucidate the genetic basis of learning and/or memory, specifically in fruit flies. We highlight some of his contributions to the field, and specifically describe his vision to bring together behavior and quantitative genomics with the aim of expanding our knowledge of the genetic basis of both learning and memory. Finally, we present some of our recent work in this area using a multiparental population (MPP) as a case study and describe the potential of this approach to advance our understanding of neurogenetics.
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Affiliation(s)
| | - Mathangi Ganesan
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
| | - Elizabeth G King
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA
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34
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Aso Y, Ray RP, Long X, Bushey D, Cichewicz K, Ngo TT, Sharp B, Christoforou C, Hu A, Lemire AL, Tillberg P, Hirsh J, Litwin-Kumar A, Rubin GM. Nitric oxide acts as a cotransmitter in a subset of dopaminergic neurons to diversify memory dynamics. eLife 2019; 8:49257. [PMID: 31724947 PMCID: PMC6948953 DOI: 10.7554/elife.49257] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 11/13/2019] [Indexed: 12/31/2022] Open
Abstract
Animals employ diverse learning rules and synaptic plasticity dynamics to record temporal and statistical information about the world. However, the molecular mechanisms underlying this diversity are poorly understood. The anatomically defined compartments of the insect mushroom body function as parallel units of associative learning, with different learning rates, memory decay dynamics and flexibility (Aso and Rubin, 2016). Here, we show that nitric oxide (NO) acts as a neurotransmitter in a subset of dopaminergic neurons in Drosophila. NO's effects develop more slowly than those of dopamine and depend on soluble guanylate cyclase in postsynaptic Kenyon cells. NO acts antagonistically to dopamine; it shortens memory retention and facilitates the rapid updating of memories. The interplay of NO and dopamine enables memories stored in local domains along Kenyon cell axons to be specialized for predicting the value of odors based only on recent events. Our results provide key mechanistic insights into how diverse memory dynamics are established in parallel memory systems.
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Affiliation(s)
- Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Robert P Ray
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Xi Long
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Daniel Bushey
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Karol Cichewicz
- Department of Biology, University of Virginia, Charlottesville, United States
| | - Teri-Tb Ngo
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Brandi Sharp
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | | | - Amy Hu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Andrew L Lemire
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Paul Tillberg
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Jay Hirsh
- Department of Biology, University of Virginia, Charlottesville, United States
| | - Ashok Litwin-Kumar
- Department of Neuroscience, Columbia University, New York, United States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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35
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Scheunemann L, Lampin-Saint-Amaux A, Schor J, Preat T. A sperm peptide enhances long-term memory in female Drosophila. SCIENCE ADVANCES 2019; 5:eaax3432. [PMID: 31799390 PMCID: PMC6867886 DOI: 10.1126/sciadv.aax3432] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 09/25/2019] [Indexed: 06/10/2023]
Abstract
Can mating influence cognitive functions such as learning and memory in a permanent way? We have addressed this question using a combined behavioral and in vivo imaging approach, finding that aversive long-term memory performance strongly increases in Drosophila females in response to sperm transfer following mating. A peptide in the male sperm, the sex peptide, is known to cause marked changes in female reproductive behavior, as well as other behaviors such as dietary preference. Here, we demonstrate that this sex peptide enhances memory by acting on a single pair of serotonergic brain neurons, in which activation of the sex peptide receptor stimulates the cyclic adenosine monophosphate/protein kinase A pathway. We thus reveal a strong effect of mating on memory via the neuromodulatory action of a sperm peptide on the female brain.
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36
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Cui SY, Yang MX, Zhang YH, Zheng V, Zhang HT, Gurney ME, Xu Y, O'Donnell JM. Protection from Amyloid β Peptide-Induced Memory, Biochemical, and Morphological Deficits by a Phosphodiesterase-4D Allosteric Inhibitor. J Pharmacol Exp Ther 2019; 371:250-259. [PMID: 31488603 PMCID: PMC6815937 DOI: 10.1124/jpet.119.259986] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/26/2019] [Indexed: 11/22/2022] Open
Abstract
Recent imaging studies of amyloid and tau in cognitively normal elderly subjects imply that Alzheimer's pathology can be tolerated by the brain to some extent due to compensatory mechanisms operating at the cellular and synaptic levels. The present study investigated the effects of an allosteric inhibitor of phosphodiesterase-4D (PDE4D), known as BPN14770 (2-(4-((2-(3-Chlorophenyl)-6-(trifluoromethyl)pyridin-4-yl)methyl)phenyl)acetic Acid), on impairment of memory, dendritic structure, and synaptic proteins induced by bilateral microinjection of oligomeric amyloid beta (Aβ 1-42 into the hippocampus of humanized PDE4D (hPDE4D) mice. The hPDE4D mice provide a unique and powerful genetic tool for assessing PDE4D target engagement. Behavioral studies showed that treatment with BPN14770 significantly improved memory acquisition and retrieval in the Morris water maze test and the percentage of alternations in the Y-maze test in the model of Aβ impairment. Microinjection of oligomeric Aβ 1-42 caused decreases in the number of dendrites, dendritic length, and spine density of pyramid neurons in the hippocampus. These changes were prevented by BPN14770 in a dose-dependent manner. Furthermore, molecular studies showed that BPN14770 prevented Aβ-induced decreases in synaptophysin, postsynaptic density protein 95, phosphorylated cAMP-response element binding protein (CREB)/CREB, brain-derived neurotrophic factor, and nerve growth factor inducible protein levels in the hippocampus. The protective effects of BPN14770 against Aβ-induced memory deficits, synaptic damage, and the alteration in the cAMP-meditated cell signaling cascade were blocked by H-89 (N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride), an inhibitor of protein kinase A. These results suggest that BPN14770 may activate compensatory mechanisms that support synaptic health even with the onset of amyloid pathology in Alzheimer's disease. SIGNIFICANCE STATEMENT: This study demonstrates that a phosphodiesterase-4D allosteric inhibitor, BPN14770, protects against memory loss and neuronal atrophy induced by oligomeric Aβ 1-42. The study provides useful insight into the potential role of compensatory mechanisms in Alzheimer's disease in a model of oligomeric Aβ 1-42 neurotoxicity.
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Affiliation(s)
- Su-Ying Cui
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
| | - Ming-Xin Yang
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
| | - Yong-He Zhang
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
| | - Victor Zheng
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
| | - Han-Ting Zhang
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
| | - Mark E Gurney
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
| | - Ying Xu
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
| | - James M O'Donnell
- Department of Pharmacology, School of Basic Medical Science, Peking University, Beijing, China (S.-Y.C., Y.-H.Z.); Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, New York (S.-Y.C., M.-X.Y., V.Z., Y.X., J.M.O.); Departments of Behavioral Medicine and Psychiatry, Physiology and Pharmacology, and Neuroscience, The Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, West Virginia (H.-T.Z.); and Tetra Discovery Partners Inc., Grand Rapids, Michigan (M.E.G.)
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Williams-Simon PA, Posey C, Mitchell S, Ng'oma E, Mrkvicka JA, Zars T, King EG. Multiple genetic loci affect place learning and memory performance in Drosophila melanogaster. GENES, BRAIN, AND BEHAVIOR 2019; 18:e12581. [PMID: 31095869 PMCID: PMC6718298 DOI: 10.1111/gbb.12581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 12/25/2022]
Abstract
Learning and memory are critical functions for all animals, giving individuals the ability to respond to changes in their environment. Within populations, individuals vary, however the mechanisms underlying this variation in performance are largely unknown. Thus, it remains to be determined what genetic factors cause an individual to have high learning ability and what factors determine how well an individual will remember what they have learned. To genetically dissect learning and memory performance, we used the Drosophila synthetic population resource (DSPR), a multiparent mapping resource in the model system Drosophila melanogaster, consisting of a large set of recombinant inbred lines (RILs) that naturally vary in these and other traits. Fruit flies can be trained in a "heat box" to learn to remain on one side of a chamber (place learning) and can remember this (place memory) over short timescales. Using this paradigm, we measured place learning and memory for ~49 000 individual flies from over 700 DSPR RILs. We identified 16 different loci across the genome that significantly affect place learning and/or memory performance, with 5 of these loci affecting both traits. To identify transcriptomic differences associated with performance, we performed RNA-Seq on pooled samples of seven high performing and seven low performing RILs for both learning and memory and identified hundreds of genes with differences in expression in the two sets. Integrating our transcriptomic results with the mapping results allowed us to identify nine promising candidate genes, advancing our understanding of the genetic basis underlying natural variation in learning and memory performance.
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Affiliation(s)
| | - Christopher Posey
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Samuel Mitchell
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Enoch Ng'oma
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - James A Mrkvicka
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Troy Zars
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Elizabeth G King
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
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Scheunemann L, Plaçais PY, Dromard Y, Schwärzel M, Preat T. Dunce Phosphodiesterase Acts as a Checkpoint for Drosophila Long-Term Memory in a Pair of Serotonergic Neurons. Neuron 2019; 98:350-365.e5. [PMID: 29673482 PMCID: PMC5919781 DOI: 10.1016/j.neuron.2018.03.032] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 12/19/2017] [Accepted: 03/16/2018] [Indexed: 01/08/2023]
Abstract
A key function of the brain is to filter essential information and store it in the form of stable, long-term memory (LTM). We demonstrate here that the Dunce (Dnc) phosphodiesterase, an important enzyme that degrades cAMP, acts as a molecular switch that controls LTM formation in Drosophila. We show that, during LTM formation, Dnc is inhibited in the SPN, a pair of newly characterized serotonergic neurons, which stimulates the cAMP/PKA pathway. As a consequence, the SPN activates downstream dopaminergic neurons, opening the gate for LTM formation in the olfactory memory center, the mushroom body. Strikingly, transient inhibition of Dnc in the SPN by RNAi was sufficient to induce LTM formation with a training protocol that normally generates only short-lived memory. Thus, Dnc activity in the SPN acts as a memory checkpoint to guarantee that only the most relevant learned experiences are consolidated into stable memory. Dunce phosphodiesterase is a default inhibitor of long-term memory (LTM) formation Dunce acts in a pair of newly identified serotonergic projection neurons These serotonergic neurons control the activity of LTM-gating dopaminergic neurons
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Affiliation(s)
- Lisa Scheunemann
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, ESPCI Paris, PSL Research University, CNRS, 10 rue Vauquelin, 75005 Paris, France
| | - Pierre-Yves Plaçais
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, ESPCI Paris, PSL Research University, CNRS, 10 rue Vauquelin, 75005 Paris, France
| | - Yann Dromard
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, ESPCI Paris, PSL Research University, CNRS, 10 rue Vauquelin, 75005 Paris, France
| | - Martin Schwärzel
- Freie Universität Berlin, Department of Biology/Neurobiology, Königin-Luise Str. 28-30, Berlin 14195, Germany
| | - Thomas Preat
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, ESPCI Paris, PSL Research University, CNRS, 10 rue Vauquelin, 75005 Paris, France.
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39
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Handler A, Graham TGW, Cohn R, Morantte I, Siliciano AF, Zeng J, Li Y, Ruta V. Distinct Dopamine Receptor Pathways Underlie the Temporal Sensitivity of Associative Learning. Cell 2019; 178:60-75.e19. [PMID: 31230716 PMCID: PMC9012144 DOI: 10.1016/j.cell.2019.05.040] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 02/19/2019] [Accepted: 05/20/2019] [Indexed: 12/28/2022]
Abstract
Animals rely on the relative timing of events in their environment to form and update predictive associations, but the molecular and circuit mechanisms for this temporal sensitivity remain incompletely understood. Here, we show that olfactory associations in Drosophila can be written and reversed on a trial-by-trial basis depending on the temporal relationship between an odor cue and dopaminergic reinforcement. Through the synchronous recording of neural activity and behavior, we show that reversals in learned odor attraction correlate with bidirectional neural plasticity in the mushroom body, the associative olfactory center of the fly. Two dopamine receptors, DopR1 and DopR2, contribute to this temporal sensitivity by coupling to distinct second messengers and directing either synaptic depression or potentiation. Our results reveal how dopamine-receptor signaling pathways can detect the order of events to instruct opposing forms of synaptic and behavioral plasticity, allowing animals to flexibly update their associations in a dynamic environment.
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Affiliation(s)
- Annie Handler
- Laboratory of Neurophysiology and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Thomas G W Graham
- Laboratory of Neurophysiology and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Raphael Cohn
- Laboratory of Neurophysiology and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Ianessa Morantte
- Laboratory of Neurophysiology and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Andrew F Siliciano
- Laboratory of Neurophysiology and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Jianzhi Zeng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, 100871 Beijing, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, 100871 Beijing, China
| | - Vanessa Ruta
- Laboratory of Neurophysiology and Behavior, The Rockefeller University, New York, NY 10065, USA.
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40
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Tanimoto H. Bodily Awareness: How Flies Learn Their Own Body Size. Curr Biol 2019; 29:R572-R574. [PMID: 31211976 DOI: 10.1016/j.cub.2019.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Animals need to perceive their own body size to apprehend their relationship to the environment. A new study shows that the fruit fly Drosophila acquires the requisite information on its body size from visual feedback during walking, and has further identified a subset of neurons responsible for maintenance of body-size memory.
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Affiliation(s)
- Hiromu Tanimoto
- Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, 980-8577 Sendai, Japan.
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41
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Mariani LL, Longueville S, Girault JA, Hervé D, Gervasi N. Differential enhancement of ERK, PKA and Ca 2+ signaling in direct and indirect striatal neurons of Parkinsonian mice. Neurobiol Dis 2019; 130:104506. [PMID: 31220556 DOI: 10.1016/j.nbd.2019.104506] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/06/2019] [Accepted: 06/13/2019] [Indexed: 12/29/2022] Open
Abstract
Parkinson's disease (PD) is characterized by severe locomotor deficits due to the disappearance of dopamine (DA) from the dorsal striatum. The development of PD symptoms and treatment-related complications such as dyskinesia have been proposed to result from complex alterations in intracellular signaling in both direct and indirect pathway striatal projection neurons (dSPNs and iSPNs, respectively) following loss of DA afferents. To identify cell-specific and dynamical modifications of signaling pathways associated with PD, we used a hemiparkinsonian mouse model with 6-hydroxydopamine (6-OHDA) lesion combined with two-photon fluorescence biosensors imaging in adult corticostriatal slices. After DA lesion, extracellular signal-regulated kinase (ERK) activation was increased in response to DA D1 receptor (D1R) or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) stimulation. The cAMP-dependent protein kinase (PKA) pathway contributing to ERK activation displayed supersensitive responses to D1R stimulation after 6-OHDA lesion. This cAMP/PKA supersensitivity was specific of D1R-responding SPNs and resulted from Gαolf upregulation and deficient phosphodiesterase activity. In lesioned striatum, the number of D1R-SPNs with spontaneous Ca2+ transients augmented while Ca2+ response to AMPA receptor stimulation specifically increased in iSPNs. Our work reveals distinct cell type-specific signaling alterations in the striatum after DA denervation. It suggests that over-activation of ERK pathway, observed in PD striatum, known to contribute to dyskinesia, may be linked to the combined dysregulation of DA and glutamate signaling pathways in the two populations of SPNs. These findings bring new insights into the implication of these respective neuronal populations in PD motor symptoms and the occurrence of PD treatment complications.
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Affiliation(s)
- Louise-Laure Mariani
- Inserm UMR-S 1270, Paris, France; Sorbonne Université, Science and Engineering Faculty, Paris, France; Institut du Fer à Moulin, Paris, France
| | - Sophie Longueville
- Inserm UMR-S 1270, Paris, France; Sorbonne Université, Science and Engineering Faculty, Paris, France; Institut du Fer à Moulin, Paris, France
| | - Jean-Antoine Girault
- Inserm UMR-S 1270, Paris, France; Sorbonne Université, Science and Engineering Faculty, Paris, France; Institut du Fer à Moulin, Paris, France
| | - Denis Hervé
- Inserm UMR-S 1270, Paris, France; Sorbonne Université, Science and Engineering Faculty, Paris, France; Institut du Fer à Moulin, Paris, France.
| | - Nicolas Gervasi
- Inserm UMR-S 1270, Paris, France; Sorbonne Université, Science and Engineering Faculty, Paris, France; Institut du Fer à Moulin, Paris, France.
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42
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Gurney ME, Nugent RA, Mo X, Sindac JA, Hagen TJ, Fox D, O'Donnell JM, Zhang C, Xu Y, Zhang HT, Groppi VE, Bailie M, White RE, Romero DL, Vellekoop AS, Walker JR, Surman MD, Zhu L, Campbell RF. Design and Synthesis of Selective Phosphodiesterase 4D (PDE4D) Allosteric Inhibitors for the Treatment of Fragile X Syndrome and Other Brain Disorders. J Med Chem 2019; 62:4884-4901. [PMID: 31013090 DOI: 10.1021/acs.jmedchem.9b00193] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Novel pyridine- and pyrimidine-based allosteric inhibitors are reported that achieve PDE4D subtype selectivity through recognition of a single amino acid difference on a key regulatory domain, known as UCR2, that opens and closes over the catalytic site for cAMP hydrolysis. The design and optimization of lead compounds was based on iterative analysis of X-ray crystal structures combined with metabolite identification. Selectivity for the activated, dimeric form of PDE4D provided potent memory enhancing effects in a mouse model of novel object recognition with improved tolerability and reduced vascular toxicity over earlier PDE4 inhibitors that lack subtype selectivity. The lead compound, 28 (BPN14770), has entered midstage, human phase 2 clinical trials for the treatment of Fragile X Syndrome.
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Affiliation(s)
- Mark E Gurney
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Richard A Nugent
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Xuesheng Mo
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Janice A Sindac
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Timothy J Hagen
- Department of Chemistry and Biochemistry , Northern Illinois University , 1425 West Lincoln Highway , DeKalb , Illinois 60115 , United States
| | - David Fox
- Beryllium Discovery Corp. , 7869 NE Day Road West , Bainbridge Island , Washington 98110 , United States
| | - James M O'Donnell
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences , University at Buffalo, The State University of New York , Buffalo , New York 14214-8033 , United States
| | - Chong Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences , University at Buffalo, The State University of New York , Buffalo , New York 14214-8033 , United States
| | - Ying Xu
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences , University at Buffalo, The State University of New York , Buffalo , New York 14214-8033 , United States
| | - Han-Ting Zhang
- Departments of Behavioral Medicine & Psychiatry and Physiology, Pharmacology & Neuroscience, Rockefeller Neurosciences Institute , West Virginia University Health Sciences Center , 1 Medical Center Drive , Morgantown , West Virginia 26506 , United States
| | - Vincent E Groppi
- Michigan Drug Discovery, Life Sciences Institute , University of Michigan , 210 Washtenaw Avenue , Ann Arbor , Michigan 48103 , United States
| | - Marc Bailie
- INDS Inc. , 6111 Jackson Road, Suite 100 , Ann Arbor , Michigan 48103 , United States
| | - Ronald E White
- White Global Pharma Consultants , 31 Kinglet Drive , South Cranbury , New Jersey 08512 , United States
| | - Donna L Romero
- Pharma-Vation Consulting, LLC , 1201 Turnberry Ridge Court , Chesterfield , Missouri 63005 , United States
| | - A Samuel Vellekoop
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Joel R Walker
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Matthew D Surman
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Lei Zhu
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Robert F Campbell
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
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43
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Gurney ME. Genetic Association of Phosphodiesterases With Human Cognitive Performance. Front Mol Neurosci 2019; 12:22. [PMID: 30800055 PMCID: PMC6376954 DOI: 10.3389/fnmol.2019.00022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/21/2019] [Indexed: 01/03/2023] Open
Abstract
Recent, large-scale, genome-wide association studies (GWAS) provide a first view of the genetic fine structure of cognitive performance in healthy individuals. These studies have pooled data from up to 1.1 million subjects based on simple measures of cognitive performance including educational attainment, self-reported math ability, highest math class taken, and pooled, normalized scores from cognitive tests. These studies now allow the genome-wide interrogation of genes and pathways for their potential impact on human cognitive performance. The phosphodiesterase (PDE) enzymes regulate key cyclic nucleotide signaling pathways. Many are expressed in the brain and have been the targets of CNS drug discovery. Genetic variation in PDE1C, PDE4B and PDE4D associates with multiple measures of human cognitive function. The large size of the human PDE4B and PDE4D genes allows genetic fine structure mapping to transcripts encoding dimeric (long) forms of the enzymes. Upstream and downstream effectors of the cAMP pathway modulated by PDE4D [adenylate cyclase 1 (ADCY1), ADCY8, PRKAR1A, CREB1, or CREBBP] did not show genetic association with cognitive performance, however, genetic association was seen with brain derived neurotrophic factor (BDNF), a gene whose expression is modulated by cAMP. Notably absent was genetic association in healthy subjects to targets of CNS drug discovery designed to improve cognition in disease states by the modulation of cholinergic [acetylcholinesterase (ACHE), choline acetyltransferase (CHAT), nicotinic alpha 7 acetylcholine receptor (CHRNA7)], serotonergic (HTR6), histaminergic (HRH3), or glutamatergic (GRM5) pathways. These new data provide a rationale for exploring the therapeutic benefit of selective inhibitors of PDE1C, PDE4B and PDE4D in CNS disorders affecting cognition.
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Affiliation(s)
- Mark E Gurney
- Tetra Discovery Partners, Grand Rapids, MI, United States
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44
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Connectomics and function of a memory network: the mushroom body of larval Drosophila. Curr Opin Neurobiol 2018; 54:146-154. [PMID: 30368037 DOI: 10.1016/j.conb.2018.10.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/04/2018] [Indexed: 11/20/2022]
Abstract
The Drosophila larva is a relatively simple, 10 000-neuron study case for learning and memory with enticing analytical power, combining genetic tractability, the availability of robust behavioral assays, the opportunity for single-cell transgenic manipulation, and an emerging synaptic connectome of its complete central nervous system. Indeed, although the insect mushroom body is a much-studied memory network, the connectome revealed that more than half of the classes of connection within the mushroom body had escaped attention. The connectome also revealed circuitry that integrates, both within and across brain hemispheres, higher-order sensory input, intersecting valence signals, and output neurons that instruct behavior. Further, it was found that activating individual dopaminergic mushroom body input neurons can have a rewarding or a punishing effect on olfactory stimuli associated with it, depending on the relative timing of this activation, and that larvae form molecularly dissociable short-term, long-term, and amnesia-resistant memories. Together, the larval mushroom body is a suitable study case to achieve a nuanced account of molecular function in a behaviorally meaningful memory network.
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45
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Memory enhancing effects of BPN14770, an allosteric inhibitor of phosphodiesterase-4D, in wild-type and humanized mice. Neuropsychopharmacology 2018; 43:2299-2309. [PMID: 30131563 PMCID: PMC6135860 DOI: 10.1038/s41386-018-0178-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 07/05/2018] [Accepted: 07/29/2018] [Indexed: 11/21/2022]
Abstract
Inhibitors of phosphodiesterase-4 (PDE4) have beneficial effects on memory in preclinical and clinical studies. Development of these drugs has stalled due to dose-limiting side effects of nausea and emesis. While use of subtype-selective inhibitors (i.e., for PDE4A, B, or D) could overcome this issue, conservation of the catalytic region, to which classical inhibitors bind, limits this approach. The present study examined the effects of BPN14770, an allosteric inhibitor of PDE4D, which binds to a primate-specific, N-terminal region. In mice engineered to express PDE4D with this primate-specific sequence, BPN14770 was 100-fold more potent for improving memory than in wild-type mice; meanwhile, it exhibited low potency in a mouse surrogate model for emesis. BPN14770 also antagonized the amnesic effects of scopolamine, increased cAMP signaling in brain, and increased BDNF and markers of neuronal plasticity associated with memory. These data establish a relationship between PDE4D target engagement and effects on memory for BPN14770 and suggest clinical potential for PDE4D-selective inhibitors.
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46
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Amnesiac Is Required in the Adult Mushroom Body for Memory Formation. J Neurosci 2018; 38:9202-9214. [PMID: 30201766 DOI: 10.1523/jneurosci.0876-18.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/08/2018] [Accepted: 08/30/2018] [Indexed: 11/21/2022] Open
Abstract
It was proposed that the Drosophila amnesiac gene (amn) is required for consolidation of aversive memory in the dorsal paired medial (DPM) neurons, a pair of large neurons that broadly innervate the mushroom bodies (MB), the fly center for olfactory learning and memory (Waddell et al., 2000). Yet, a conditional analysis showed that it was not possible to rescue the memory deficit of amnX8 null mutant flies when amn expression was restored only in the adult (DeZazzo et al., 1999), which led the authors to suggest that amn might be involved in the development of brain structures that normally promote adult olfactory memory. To further investigate temporal and spatial requirements of Amnesiac (AMN) peptide in memory, we used RNA interference in combination with conditional drivers. Experiments were conducted either in both sexes, or in either sexes. Our data show that acute modulation of amn expression in adult DPM neurons does not impact memory. We further show that amn expression is required for normal development of DPM neurons. Detailed enhancer trap analyses suggest that amn transcription unit contains two distinct enhancers, one specific of DPM neurons, and the other specific of α/β MB neurons. This prompted us to investigate extensively the role of AMN in the adult MB. Together, our results demonstrate that amn is acutely required in adult α/β MB neurons for middle-term and long-term memory. The data thus establish that amn plays two distinct roles. Its expression is required in DPM neurons for their development, and in adult MB for olfactory memory.SIGNIFICANCE STATEMENT The Drosophila amnesiac gene encodes a neuropeptide whose expression was proposed to be required for consolidation of aversive memory in the dorsal paired medial (DPM) neurons, a pair of large neurons that broadly innervate the mushroom bodies (MB), the olfactory memory center. Here, we investigated amnesiac temporal and spatial requirement using conditional tools that allowed us to manipulate its expression in selected neurons. This work leads to a complete reassessment of the role of amnesiac in brain development and memory. We show that amnesiac is required for two distinct processes: for normal development of DPM neurons, and in adult MB for memory.
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47
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Mizunami M, Terao K, Alvarez B. Application of a Prediction Error Theory to Pavlovian Conditioning in an Insect. Front Psychol 2018; 9:1272. [PMID: 30083125 PMCID: PMC6064870 DOI: 10.3389/fpsyg.2018.01272] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/03/2018] [Indexed: 12/01/2022] Open
Abstract
Elucidation of the conditions in which associative learning occurs is a critical issue in neuroscience and comparative psychology. In Pavlovian conditioning in mammals, it is thought that the discrepancy, or error, between the actual reward and the predicted reward determines whether learning occurs. This theory stems from the finding of Kamin’s blocking effect, in which after pairing of a stimulus with an unconditioned stimulus (US), conditioning of a second stimulus is blocked when the two stimuli are presented in compound and paired with the same US. Whether this theory is applicable to any species of invertebrates, however, has remained unknown. We first showed blocking and one-trial blocking of Pavlovian conditioning in the cricket Gryllus bimaculatus, which supported the Rescorla–Wagner model but not attentional theories, the major competitive error-correction learning theories to account for blocking. To match the prediction error theory, a neural circuit model was proposed, and prediction from the model was tested: the results were consistent with the Rescorla–Wagner model but not with the retrieval theory, another competitive theory to account for blocking. The findings suggest that the Rescorla–Wagner model best accounts for Pavlovian conditioning in crickets and that the basic computation rule underlying Pavlovian conditioning in crickets is the same to those suggested in mammals. Moreover, results of pharmacological studies in crickets suggested that octopamine and dopamine mediate prediction error signals in appetitive and aversive conditioning, respectively. This was in contrast to the notion that dopamine mediates appetitive prediction error signals in mammals. The functional significance and evolutionary implications of these findings are discussed.
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Affiliation(s)
| | - Kanta Terao
- Graduate School of Life Sciences, Hokkaido University, Sapporo, Japan
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48
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König C, Khalili A, Ganesan M, Nishu AP, Garza AP, Niewalda T, Gerber B, Aso Y, Yarali A. Reinforcement signaling of punishment versus relief in fruit flies. ACTA ACUST UNITED AC 2018; 25:247-257. [PMID: 29764970 PMCID: PMC5959229 DOI: 10.1101/lm.047308.118] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/06/2018] [Indexed: 01/21/2023]
Abstract
Painful events establish opponent memories: cues that precede pain are remembered negatively, whereas cues that follow pain, thus coinciding with relief are recalled positively. How do individual reinforcement-signaling neurons contribute to this “timing-dependent valence-reversal?” We addressed this question using an optogenetic approach in the fruit fly. Two types of fly dopaminergic neuron, each comprising just one paired cell, indeed established learned avoidance of odors that preceded their photostimulation during training, and learned approach to odors that followed the photostimulation. This is in striking parallel to punishment versus relief memories reinforced by a real noxious event. For only one of these neuron types, both effects were strong enough for further analyses. Notably, interfering with dopamine biosynthesis in these neurons partially impaired the punishing effect, but not the relieving after-effect of their photostimulation. We discuss how this finding constraints existing computational models of punishment versus relief memories and introduce a new model, which also incorporates findings from mammals. Furthermore, whether using dopaminergic neuron photostimulation or a real noxious event, more prolonged punishment led to stronger relief. This parametric feature of relief may also apply to other animals and may explain particular aspects of related behavioral dysfunction in humans.
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Affiliation(s)
- Christian König
- Leibniz Institute for Neurobiology, Research Group Molecular Systems Biology of Learning, Magdeburg 39118, Germany.,Institute of Pharmacology and Toxicology, Otto von Guericke University Magdeburg 39118, Germany
| | - Afshin Khalili
- Leibniz Institute for Neurobiology, Research Group Molecular Systems Biology of Learning, Magdeburg 39118, Germany
| | - Mathangi Ganesan
- Leibniz Institute for Neurobiology, Research Group Molecular Systems Biology of Learning, Magdeburg 39118, Germany
| | - Amrita P Nishu
- Leibniz Institute for Neurobiology, Research Group Molecular Systems Biology of Learning, Magdeburg 39118, Germany
| | - Alejandra P Garza
- Leibniz Institute for Neurobiology, Research Group Molecular Systems Biology of Learning, Magdeburg 39118, Germany
| | - Thomas Niewalda
- 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.,Otto von Guericke University, Institute for Biology, Behavioural Genetics, Magdeburg 39118, Germany.,Center for Behavioral Brain Sciences, Magdeburg 39118, Germany
| | - Yoshinori Aso
- HHMI, Janelia Research Campus, Ashburn, Virginia 20147, USA
| | - Ayse Yarali
- Leibniz Institute for Neurobiology, Research Group Molecular Systems Biology of Learning, Magdeburg 39118, Germany.,Center for Behavioral Brain Sciences, Magdeburg 39118, Germany
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49
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Lüdke A, Raiser G, Nehrkorn J, Herz AVM, Galizia CG, Szyszka P. Calcium in Kenyon Cell Somata as a Substrate for an Olfactory Sensory Memory in Drosophila. Front Cell Neurosci 2018; 12:128. [PMID: 29867361 PMCID: PMC5960692 DOI: 10.3389/fncel.2018.00128] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022] Open
Abstract
Animals can form associations between temporally separated stimuli. To do so, the nervous system has to retain a neural representation of the first stimulus until the second stimulus appears. The neural substrate of such sensory stimulus memories is unknown. Here, we search for a sensory odor memory in the insect olfactory system and characterize odorant-evoked Ca2+ activity at three consecutive layers of the olfactory system in Drosophila: in olfactory receptor neurons (ORNs) and projection neurons (PNs) in the antennal lobe, and in Kenyon cells (KCs) in the mushroom body. We show that the post-stimulus responses in ORN axons, PN dendrites, PN somata, and KC dendrites are odor-specific, but they are not predictive of the chemical identity of past olfactory stimuli. However, the post-stimulus responses in KC somata carry information about the identity of previous olfactory stimuli. These findings show that the Ca2+ dynamics in KC somata could encode a sensory memory of odorant identity and thus might serve as a basis for associations between temporally separated stimuli.
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Affiliation(s)
- Alja Lüdke
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
| | - Georg Raiser
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
- International Max Planck Research School for Organismal Biology, Konstanz, Germany
| | - Johannes Nehrkorn
- Fakultät für Biologie, Ludwig-Maximilians-Universität München, Martinsried, Germany
- Bernstein Center for Computational Neuroscience, Munich, Germany
| | - Andreas V. M. Herz
- Fakultät für Biologie, Ludwig-Maximilians-Universität München, Martinsried, Germany
- Bernstein Center for Computational Neuroscience, Munich, Germany
| | - C. Giovanni Galizia
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
| | - Paul Szyszka
- Department of Biology, Neurobiology, University of Konstanz, Konstanz, Germany
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50
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Widmann A, Eichler K, Selcho M, Thum AS, Pauls D. Odor-taste learning in Drosophila larvae. JOURNAL OF INSECT PHYSIOLOGY 2018; 106:47-54. [PMID: 28823531 DOI: 10.1016/j.jinsphys.2017.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/07/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
The Drosophila larva is an attractive model system to study fundamental questions in the field of neuroscience. Like the adult fly, the larva offers a seemingly unlimited genetic toolbox, which allows one to visualize, silence or activate neurons down to the single cell level. This, combined with its simplicity in terms of cell numbers, offers a useful system to study the neuronal correlates of complex processes including associative odor-taste learning and memory formation. Here, we summarize the current knowledge about odor-taste learning and memory at the behavioral level and integrate the recent progress on the larval connectome to shed light on the sub-circuits that allow Drosophila larvae to integrate present sensory input in the context of past experience and to elicit an appropriate behavioral response.
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Affiliation(s)
| | - Katharina Eichler
- Department of Biology, University of Konstanz, D-78464 Konstanz, Germany; HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Mareike Selcho
- Department of Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, D-97074 Würzburg, Germany
| | - Andreas S Thum
- Department of Biology, University of Konstanz, D-78464 Konstanz, Germany; Department of Genetics, University of Leipzig, D-04103 Leipzig, Germany.
| | - Dennis Pauls
- Department of Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, D-97074 Würzburg, Germany.
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