1
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Kuhn BN, Cannella N, Chitre AS, Nguyen KMH, Cohen K, Chen D, Peng B, Ziegler KS, Lin B, Johnson BB, Missfeldt Sanches T, Crow AD, Lunerti V, Gupta A, Dereschewitz E, Soverchia L, Hopkins JL, Roberts AT, Ubaldi M, Abdulmalek S, Kinen A, Hardiman G, Chung D, Polesskaya O, Solberg Woods LC, Ciccocioppo R, Kalivas PW, Palmer AA. Genome-wide association study reveals multiple loci for nociception and opioid consumption behaviors associated with heroin vulnerability in outbred rats. Mol Psychiatry 2025:10.1038/s41380-025-02922-4. [PMID: 40000848 DOI: 10.1038/s41380-025-02922-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Revised: 12/20/2024] [Accepted: 02/07/2025] [Indexed: 02/27/2025]
Abstract
The increased prevalence of opioid use disorder (OUD) makes it imperative to disentangle the biological mechanisms contributing to individual differences in OUD vulnerability. OUD shows strong heritability, however genetic variants contributing to vulnerability remain poorly defined. We performed a genome-wide association study using over 850 male and female heterogeneous stock (HS) rats to identify genes underlying behaviors associated with OUD such as nociception, as well as heroin-taking, extinction and seeking behaviors. By using an animal model of OUD, we were able to identify genetic variants associated with distinct OUD behaviors while maintaining a uniform environment, an experimental design not easily achieved in humans. Furthermore, we used a novel non-linear network-based clustering approach to characterize rats based on OUD vulnerability to assess genetic variants associated with OUD susceptibility. Our findings confirm the heritability of several OUD-like behaviors, including OUD susceptibility. Additionally, several genetic variants associated with nociceptive threshold prior to heroin experience, heroin consumption, escalation of intake, and motivation to obtain heroin were identified. Tom1, a microglial component, was implicated for nociception. Several genes involved in dopaminergic signaling, neuroplasticity and substance use disorders, including Brwd1, Pcp4, Phb1l2 and Mmp15 were implicated for the heroin traits. Additionally, an OUD vulnerable phenotype was associated with genetic variants for consumption and break point, suggesting a specific genetic contribution for OUD-like traits contributing to vulnerability. Together, these findings identify novel genetic markers related to the susceptibility to OUD-relevant behaviors in HS rats.
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Affiliation(s)
- Brittany N Kuhn
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
| | - Nazzareno Cannella
- School of Pharmacy, Center for Neuroscience, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Apurva S Chitre
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Khai-Minh H Nguyen
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Katarina Cohen
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Denghui Chen
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Beverly Peng
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Kendra S Ziegler
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Bonnie Lin
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Benjamin B Johnson
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | | | - Ayteria D Crow
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Veronica Lunerti
- School of Pharmacy, Center for Neuroscience, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Arkobrato Gupta
- The Interdisciplinary Ph.D. Program in Biostatistics, The Ohio State University, Columbus, OH, USA
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
- Pelotonia Institute for Immuno-Oncology, The James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - Eric Dereschewitz
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Laura Soverchia
- School of Pharmacy, Center for Neuroscience, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Jordan L Hopkins
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Analyse T Roberts
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Massimo Ubaldi
- School of Pharmacy, Center for Neuroscience, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Sarah Abdulmalek
- School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Analia Kinen
- School of Pharmacy, Center for Neuroscience, Pharmacology Unit, University of Camerino, Camerino, Italy
- School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Gary Hardiman
- School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK
- Departments of Medicine and Public Health Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Dongjun Chung
- The Interdisciplinary Ph.D. Program in Biostatistics, The Ohio State University, Columbus, OH, USA
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
- Pelotonia Institute for Immuno-Oncology, The James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - Oksana Polesskaya
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | | | - Roberto Ciccocioppo
- School of Pharmacy, Center for Neuroscience, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Peter W Kalivas
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Abraham A Palmer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, USA
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2
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Larnerd C, Nolazco M, Valdez A, Sanchez V, Wolf FW. Memory-like states created by the first ethanol experience are encoded into the Drosophila mushroom body learning and memory circuitry in an ethanol-specific manner. PLoS Genet 2025; 21:e1011582. [PMID: 39899623 PMCID: PMC11801723 DOI: 10.1371/journal.pgen.1011582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2024] [Revised: 02/06/2025] [Accepted: 01/17/2025] [Indexed: 02/05/2025] Open
Abstract
A first ethanol exposure creates three memory-like states in Drosophila. Ethanol memory-like states appear genetically and behaviorally paralleled to the canonical learning and memory traces anesthesia-sensitive, anesthesia-resistant, and long-term memory ASM, ARM, and LTM. It is unknown if these ethanol memory-like states are also encoded by the canonical learning and memory circuitry that is centered on the mushroom bodies. We show that the three ethanol memory-like states, anesthesia-sensitive tolerance (AST) and anesthesia resistant tolerance (ART) created by ethanol sedation to a moderately high ethanol exposure, and chronic tolerance created by a longer low concentration ethanol exposure, each engage the mushroom body circuitry differently. Moreover, critical encoding steps for ethanol memory-like states reside outside the mushroom body circuitry, and within the mushroom body circuitry they are markedly distinct from classical memory traces. Thus, the first ethanol exposure creates distinct memory-like states in ethanol-specific circuits and impacts the function of learning and memory circuitry in ways that might influence the formation and retention of other memories.
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Affiliation(s)
- Caleb Larnerd
- Quantitative and Systems Biology Graduate Program, University of California, Merced, California, United States of America
| | - Maria Nolazco
- Biological Sciences Undergraduate Program, University of California, Merced, California, United States of America
| | - Ashley Valdez
- Biological Sciences Undergraduate Program, University of California, Merced, California, United States of America
| | - Vanessa Sanchez
- Quantitative and Systems Biology Graduate Program, University of California, Merced, California, United States of America
| | - Fred W. Wolf
- Quantitative and Systems Biology Graduate Program, University of California, Merced, California, United States of America
- Department of Molecular and Cell Biology, University of California, Merced, California, United States of America
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3
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Kuhn BN, Cannella NN, Chitre A, Nguyen KMH, Cohen K, Chen D, Peng B, Ziegler KS, Lin B, Johnson B, Missfeldt Sanchez T, Crow AD, Lunerti V, Gupta A, Dereschewitz E, Soverchia L, Hopkins JL, Roberts AT, Ubaldi M, Abdulmalek S, Kinen A, Hardiman G, Chung D, Polesskaya O, Solberg-Woods L, Ciccocioppo R, Kalivas P, Palmer AA. Genome-wide association study reveals multiple loci for nociception and opioid consumption behaviors associated with heroin vulnerability in outbred rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.582340. [PMID: 38712202 PMCID: PMC11071306 DOI: 10.1101/2024.02.27.582340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The increased prevalence of opioid use disorder (OUD) makes it imperative to disentangle the biological mechanisms contributing to individual differences in OUD vulnerability. OUD shows strong heritability, however genetic variants contributing toward vulnerability remain poorly defined. We performed a genome-wide association study using over 850 male and female heterogeneous stock (HS) rats to identify genes underlying behaviors associated with OUD such as nociception, as well as heroin-taking, extinction and seeking behaviors. By using an animal model of OUD, we were able to identify genetic variants associated with distinct OUD behaviors while maintaining a uniform environment, an experimental design not easily achieved in humans. Furthermore, we used a novel non-linear network-based clustering approach to characterize rats based on OUD vulnerability to assess genetic variants associated with OUD susceptibility. Our findings confirm the heritability of several OUD-like behaviors, including OUD susceptibility. Additionally, several genetic variants associated with nociceptive threshold prior to heroin experience, heroin consumption, escalation of intake, and motivation to obtain heroin were identified. Tom1, a microglial component, was implicated for nociception. Several genes involved in dopaminergic signaling, neuroplasticity and substance use disorders, including Brwd1, Pcp4, Phb1l2 and Mmp15 were implicated for the heroin traits. Additionally, an OUD vulnerable phenotype was associated with genetic variants for consumption and break point, suggesting a specific genetic contribution for OUD-like traits contributing to vulnerability. Together, these findings identify novel genetic markers related to the susceptibility to OUD-relevant behaviors in HS rats.
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4
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Yan L, Wu L, Wiggin TD, Su X, Yan W, Li H, Li L, Lu Z, Li Y, Meng Z, Guo F, Li F, Griffith LC, Liu C. Brief disruption of activity in a subset of dopaminergic neurons during consolidation impairs long-term memory by fragmenting sleep. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.23.563499. [PMID: 37961167 PMCID: PMC10634733 DOI: 10.1101/2023.10.23.563499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Sleep disturbances are associated with poor long-term memory (LTM) formation, yet the underlying cell types and neural circuits involved have not been fully decoded. Dopamine neurons (DANs) are involved in memory processing at multiple stages. Here, using both male and female flies, Drosophila melanogaster , we show that, during the first few hours of memory consolidation, disruption of basal activity of a small subset of protocerebral anterior medial DANs (PAM-DANs), by either brief activation or inhibition of the two dorsal posterior medial (DPM) neurons, impairs 24 h LTM. Interestingly, these brief changes in activity using female flies result in sleep loss and fragmentation, especially at night. Pharmacological rescue of sleep after manipulation restores LTM. A specific subset of PAM-DANs (PAM-α1) that synapse onto DPM neurons specify the microcircuit that links sleep and memory. PAM-DANs, including PAM-α1, form functional synapses onto DPM mainly via multiple dopamine receptor subtypes. This PAM-α1 to DPM microcircuit exhibits a synchronized, transient, post-training increase in activity during the critical memory consolidation window, suggesting an effect of this microcircuit on maintaining the sleep necessary for LTM consolidation. Our results provide a new cellular and circuit basis for the complex relationship between sleep and memory.
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5
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Lin YC, Wu T, Wu CL. The Neural Correlations of Olfactory Associative Reward Memories in Drosophila. Cells 2024; 13:1716. [PMID: 39451234 PMCID: PMC11506542 DOI: 10.3390/cells13201716] [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: 09/20/2024] [Revised: 10/08/2024] [Accepted: 10/15/2024] [Indexed: 10/26/2024] Open
Abstract
Advancing treatment to resolve human cognitive disorders requires a comprehensive understanding of the molecular signaling pathways underlying learning and memory. While most organ systems evolved to maintain homeostasis, the brain developed the capacity to perceive and adapt to environmental stimuli through the continuous modification of interactions within a gene network functioning within a broader neural network. This distinctive characteristic enables significant neural plasticity, but complicates experimental investigations. A thorough examination of the mechanisms underlying behavioral plasticity must integrate multiple levels of biological organization, encompassing genetic pathways within individual neurons, interactions among neural networks providing feedback on gene expression, and observable phenotypic behaviors. Model organisms, such as Drosophila melanogaster, which possess more simple and manipulable nervous systems and genomes than mammals, facilitate such investigations. The evolutionary conservation of behavioral phenotypes and the associated genetics and neural systems indicates that insights gained from flies are pertinent to understanding human cognition. Rather than providing a comprehensive review of the entire field of Drosophila memory research, we focus on olfactory associative reward memories and their related neural circuitry in fly brains, with the objective of elucidating the underlying neural mechanisms, thereby advancing our understanding of brain mechanisms linked to cognitive systems.
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Affiliation(s)
- Yu-Chun Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan;
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Tony Wu
- Department of Neurology, New Taipei Municipal TuCheng Hospital, Chang Gung Memorial Hospital, New Taipei City 23652, Taiwan;
| | - Chia-Lin Wu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan;
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Neurology, New Taipei Municipal TuCheng Hospital, Chang Gung Memorial Hospital, New Taipei City 23652, Taiwan;
- Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
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6
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Delescluse J, Simonnet MM, Ziegler AB, Piffaretti K, Alves G, Grosjean Y, Manière G. A LAT1-Like Amino Acid Transporter Regulates Neuronal Activity in the Drosophila Mushroom Bodies. Cells 2024; 13:1340. [PMID: 39195231 PMCID: PMC11352668 DOI: 10.3390/cells13161340] [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: 03/08/2024] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 08/29/2024] Open
Abstract
The proper functioning of neural circuits that integrate sensory signals is essential for individual adaptation to an ever-changing environment. Many molecules can modulate neuronal activity, including neurotransmitters, receptors, and even amino acids. Here, we ask whether amino acid transporters expressed by neurons can influence neuronal activity. We found that minidiscs (mnd), which encodes a light chain of a heterodimeric amino acid transporter, is expressed in different cell types of the adult Drosophila brain: in mushroom body neurons (MBs) and in glial cells. Using live calcium imaging, we found that MND expressed in α/β MB neurons is essential for sensitivity to the L-amino acids: Leu, Ile, Asp, Glu, Lys, Thr, and Arg. We found that the Target Of Rapamycin (TOR) pathway but not the Glutamate Dehydrogenase (GDH) pathway is involved in the Leucine-dependent response of α/β MB neurons. This study strongly supports the key role of MND in regulating MB activity in response to amino acids.
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Affiliation(s)
- Julie Delescluse
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Mégane M. Simonnet
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Anna B. Ziegler
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
- Institute for Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Kévin Piffaretti
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Georges Alves
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Yael Grosjean
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
| | - Gérard Manière
- Centre des Sciences du Goût et de l’Alimentation, CNRS, INRAe, Institut Agro, Université de Bourgogne, F-21000 Dijon, France
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7
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Ali MZ, Anushree, Ahsan A, Ola MS, Haque R, Ahsan J. Ionotropic receptors mediate olfactory learning and memory in Drosophila. INSECT SCIENCE 2024; 31:1249-1269. [PMID: 38114448 DOI: 10.1111/1744-7917.13308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/16/2023] [Accepted: 10/27/2023] [Indexed: 12/21/2023]
Abstract
Phenylacetaldehyde (PAH), an aromatic compound, is present in a diverse range of fruits including overripe bananas and prickly pear cactus, the two major host fruits for Drosophila melanogaster. PAH acts as a potent ligand for the ionotropic receptor 84a (IR84a) in the adult fruit fly and it is detected by the IR84a/IR8a heterotetrameric complex. Its role in the male courtship behavior through IR84a as an environmental aphrodisiac is of additional importance. In D. melanogaster, two distinct kinds of olfactory receptors, that is, odorant receptors (ORs) and ionotropic receptors (IRs), perceive the odorant stimuli. They display unique structural, molecular, and functional characteristics in addition to having different evolutionary origins. Traditionally, olfactory cues detected by the ORs such as ethyl acetate, 1-butanol, isoamyl acetate, 1-octanol, 4-methylcyclohexanol, etc. classified as aliphatic esters and alcohols have been employed in olfactory classical conditioning using fruit flies. This underlines the participation of OR-activated olfactory pathways in learning and memory formation. Our study elucidates that likewise ethyl acetate (EA) (an OR-responsive odorant), PAH (an IR-responsive aromatic compound) too can form learning and memory when associated with an appetitive gustatory reinforcer. The association of PAH with sucrose (PAH/SUC) led to learning and formation of the long-term memory (LTM). Additionally, the Orco1, Ir84aMI00501, and Ir8a1 mutant flies were used to confirm the exclusive participation of the IR84a/IR8a complex in PAH/SUC olfactory associative conditioning. These results highlight the involvement of IRs via an IR-activated pathway in facilitating robust olfactory behavior.
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Affiliation(s)
- Md Zeeshan Ali
- Department of Biotechnology, Central University of South Bihar, Gaya, Bihar, India
| | - Anushree
- Department of Biotechnology, Central University of South Bihar, Gaya, Bihar, India
| | - Aarif Ahsan
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mohammad Shamsul Ola
- Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Rizwanul Haque
- Department of Biotechnology, Central University of South Bihar, Gaya, Bihar, India
| | - Jawaid Ahsan
- Department of Biotechnology, Central University of South Bihar, Gaya, Bihar, India
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8
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Meschi E, Duquenoy L, Otto N, Dempsey G, Waddell S. Compensatory enhancement of input maintains aversive dopaminergic reinforcement in hungry Drosophila. Neuron 2024; 112:2315-2332.e8. [PMID: 38795709 DOI: 10.1016/j.neuron.2024.04.035] [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: 08/21/2023] [Revised: 03/12/2024] [Accepted: 04/30/2024] [Indexed: 05/28/2024]
Abstract
Hungry animals need compensatory mechanisms to maintain flexible brain function, while modulation reconfigures circuits to prioritize resource seeking. In Drosophila, hunger inhibits aversively reinforcing dopaminergic neurons (DANs) to permit the expression of food-seeking memories. Multitasking the reinforcement system for motivation potentially undermines aversive learning. We find that chronic hunger mildly enhances aversive learning and that satiated-baseline and hunger-enhanced learning require endocrine adipokinetic hormone (AKH) signaling. Circulating AKH influences aversive learning via its receptor in four neurons in the ventral brain, two of which are octopaminergic. Connectomics revealed AKH receptor-expressing neurons to be upstream of several classes of ascending neurons, many of which are presynaptic to aversively reinforcing DANs. Octopaminergic modulation of and output from at least one of these ascending pathways is required for shock- and bitter-taste-reinforced aversive learning. We propose that coordinated enhancement of input compensates for hunger-directed inhibition of aversive DANs to preserve reinforcement when required.
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Affiliation(s)
- Eleonora Meschi
- University of Oxford, Centre for Neural Circuits and Behaviour, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Lucille Duquenoy
- University of Oxford, Centre for Neural Circuits and Behaviour, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Nils Otto
- University of Oxford, Centre for Neural Circuits and Behaviour, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Georgia Dempsey
- University of Oxford, Centre for Neural Circuits and Behaviour, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Scott Waddell
- University of Oxford, Centre for Neural Circuits and Behaviour, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK.
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9
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Mou W, Tang Y, Huang Y, Wu Z, Cui Y. Upregulation of neuronal ER-phagy improves organismal fitness and alleviates APP toxicity. Cell Rep 2024; 43:114255. [PMID: 38761376 DOI: 10.1016/j.celrep.2024.114255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/31/2024] [Accepted: 05/04/2024] [Indexed: 05/20/2024] Open
Abstract
ER-phagy, a selective autophagy targeting the endoplasmic reticulum (ER) for lysosomal degradation through cargo receptors, plays a critical role in ER quality control and is linked to various diseases. However, its physiological and pathological roles remain largely unclear due to a lack of animal model studies. This study establishes Drosophila as an in vivo ER-phagy model. Starvation triggers ER-phagy across multiple fly tissues. Disturbing ER-phagy by either globally upregulating or downregulating ER-phagy receptors, Atl or Rtnl1, harms the fly. Notably, moderate upregulation of ER-phagy in fly brains by overexpressing Atl or Rtnl1 significantly attenuates age-associated neurodegenerations. Furthermore, in a Drosophila model of Alzheimer's disease expressing human amyloid precursor protein (APP), impaired ER-phagy is observed. Enhancing ER-phagy in the APP-expressing fly brain facilitates APP degradation, significantly alleviating disease symptoms. Therefore, our findings suggest that modulating ER-phagy may offer a therapeutic strategy to treat aging and diseases associated with ER protein aggregation.
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Affiliation(s)
- Wenqing Mou
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Yinglu Tang
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX 75275, USA
| | - Yunpeng Huang
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Zhihao Wu
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX 75275, USA.
| | - Yixian Cui
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China.
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10
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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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11
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Parnas M, Manoim JE, Lin AC. Sensory encoding and memory in the mushroom body: signals, noise, and variability. Learn Mem 2024; 31:a053825. [PMID: 38862174 PMCID: PMC11199953 DOI: 10.1101/lm.053825.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/21/2023] [Indexed: 06/13/2024]
Abstract
To survive in changing environments, animals need to learn to associate specific sensory stimuli with positive or negative valence. How do they form stimulus-specific memories to distinguish between positively/negatively associated stimuli and other irrelevant stimuli? Solving this task is one of the functions of the mushroom body, the associative memory center in insect brains. Here we summarize recent work on sensory encoding and memory in the Drosophila mushroom body, highlighting general principles such as pattern separation, sparse coding, noise and variability, coincidence detection, and spatially localized neuromodulation, and placing the mushroom body in comparative perspective with mammalian memory systems.
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Affiliation(s)
- Moshe Parnas
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Julia E Manoim
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Andrew C Lin
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom
- Neuroscience Institute, University of Sheffield, Sheffield S10 2TN, United Kingdom
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12
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Yamazaki D, Maeyama Y, Tabata T. Combinatory Actions of Co-transmitters in Dopaminergic Systems Modulate Drosophila Olfactory Memories. J Neurosci 2023; 43:8294-8305. [PMID: 37429719 PMCID: PMC10711700 DOI: 10.1523/jneurosci.2152-22.2023] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 04/30/2023] [Accepted: 05/27/2023] [Indexed: 07/12/2023] Open
Abstract
Dopamine neurons (DANs) are extensively studied in the context of associative learning, in both vertebrates and invertebrates. In the acquisition of male and female Drosophila olfactory memory, the PAM cluster of DANs provides the reward signal, and the PPL1 cluster of DANs sends the punishment signal to the Kenyon cells (KCs) of mushroom bodies, the center for memory formation. However, thermo-genetical activation of the PPL1 DANs after memory acquisition impaired aversive memory, and that of the PAM DANs impaired appetitive memory. We demonstrate that the knockdown of glutamate decarboxylase, which catalyzes glutamate conversion to GABA in PAM DANs, potentiated the appetitive memory. In addition, the knockdown of glutamate transporter in PPL1 DANs potentiated aversive memory, suggesting that GABA and glutamate co-transmitters act in an inhibitory manner in olfactory memory formation. We also found that, in γKCs, the Rdl receptor for GABA and the mGluR DmGluRA mediate the inhibition. Although multiple-spaced training is required to form long-term aversive memory, a single cycle of training was sufficient to develop long-term memory when the glutamate transporter was knocked down, in even a single subset of PPL1 DANs. Our results suggest that the mGluR signaling pathway may set a threshold for memory acquisition to allow the organisms' behaviors to adapt to changing physiological conditions and environments.SIGNIFICANCE STATEMENT In the acquisition of olfactory memory in Drosophila, the PAM cluster of dopamine neurons (DANs) mediates the reward signal, while the PPL1 cluster of DANs conveys the punishment signal to the Kenyon cells of the mushroom bodies, which serve as the center for memory formation. We found that GABA co-transmitters in the PAM DANs and glutamate co-transmitters in the PPL1 DANs inhibit olfactory memory formation. Our findings demonstrate that long-term memory acquisition, which typically necessitates multiple-spaced training sessions to establish aversive memory, can be triggered with a single training cycle in cases where the glutamate co-transmission is inhibited, even within a single subset of PPL1 DANs, suggesting that the glutamate co-transmission may modulate the threshold for memory acquisition.
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Affiliation(s)
- Daisuke Yamazaki
- Institute of Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Yuko Maeyama
- Institute of Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Tetsuya Tabata
- Institute of Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
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13
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Wu L, Liu C. Integrated neural circuits of sleep and memory regulation in Drosophila. CURRENT OPINION IN INSECT SCIENCE 2023; 59:101105. [PMID: 37625641 DOI: 10.1016/j.cois.2023.101105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 07/16/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023]
Abstract
Sleep and memory are highly intertwined, yet the integrative neural network of these two fundamental physiological behaviors remains poorly understood. Multiple cell types and structures of the Drosophila brain have been shown involved in the regulation of sleep and memory, and recent efforts are focusing on bridging them at molecular and circuit levels. Here, we briefly review 1) identified neurons as key nodes of olfactory-associative memory circuits involved in different memory processes; 2) how neurons of memory circuits participate in sleep regulation; and 3) other cell types and circuits besides the mushroom body in linking sleep and memory. We also attempt to provide the remaining gaps of circuitry integration of sleep and memory, which may spark some new thinking for future efforts.
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Affiliation(s)
- Litao Wu
- CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518000, China
| | - Chang Liu
- CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518000, China; Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518000, China.
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14
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Davis RL. Learning and memory using Drosophila melanogaster: a focus on advances made in the fifth decade of research. Genetics 2023; 224:iyad085. [PMID: 37212449 PMCID: PMC10411608 DOI: 10.1093/genetics/iyad085] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 05/03/2023] [Indexed: 05/23/2023] Open
Abstract
In the last decade, researchers using Drosophila melanogaster have made extraordinary progress in uncovering the mysteries underlying learning and memory. This progress has been propelled by the amazing toolkit available that affords combined behavioral, molecular, electrophysiological, and systems neuroscience approaches. The arduous reconstruction of electron microscopic images resulted in a first-generation connectome of the adult and larval brain, revealing complex structural interconnections between memory-related neurons. This serves as substrate for future investigations on these connections and for building complete circuits from sensory cue detection to changes in motor behavior. Mushroom body output neurons (MBOn) were discovered, which individually forward information from discrete and non-overlapping compartments of the axons of mushroom body neurons (MBn). These neurons mirror the previously discovered tiling of mushroom body axons by inputs from dopamine neurons and have led to a model that ascribes the valence of the learning event, either appetitive or aversive, to the activity of different populations of dopamine neurons and the balance of MBOn activity in promoting avoidance or approach behavior. Studies of the calyx, which houses the MBn dendrites, have revealed a beautiful microglomeruluar organization and structural changes of synapses that occur with long-term memory (LTM) formation. Larval learning has advanced, positioning it to possibly lead in producing new conceptual insights due to its markedly simpler structure over the adult brain. Advances were made in how cAMP response element-binding protein interacts with protein kinases and other transcription factors to promote the formation of LTM. New insights were made on Orb2, a prion-like protein that forms oligomers to enhance synaptic protein synthesis required for LTM formation. Finally, Drosophila research has pioneered our understanding of the mechanisms that mediate permanent and transient active forgetting, an important function of the brain along with acquisition, consolidation, and retrieval. This was catalyzed partly by the identification of memory suppressor genes-genes whose normal function is to limit memory formation.
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Affiliation(s)
- Ronald L Davis
- Department of Neuroscience, Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, 130 Scripps Way, Jupiter, FL 33458, USA
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15
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Okray Z, Jacob PF, Stern C, Desmond K, Otto N, Talbot CB, Vargas-Gutierrez P, Waddell S. Multisensory learning binds neurons into a cross-modal memory engram. Nature 2023; 617:777-784. [PMID: 37100911 PMCID: PMC10208976 DOI: 10.1038/s41586-023-06013-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 03/24/2023] [Indexed: 04/28/2023]
Abstract
Associating multiple sensory cues with objects and experience is a fundamental brain process that improves object recognition and memory performance. However, neural mechanisms that bind sensory features during learning and augment memory expression are unknown. Here we demonstrate multisensory appetitive and aversive memory in Drosophila. Combining colours and odours improved memory performance, even when each sensory modality was tested alone. Temporal control of neuronal function revealed visually selective mushroom body Kenyon cells (KCs) to be required for enhancement of both visual and olfactory memory after multisensory training. Voltage imaging in head-fixed flies showed that multisensory learning binds activity between streams of modality-specific KCs so that unimodal sensory input generates a multimodal neuronal response. Binding occurs between regions of the olfactory and visual KC axons, which receive valence-relevant dopaminergic reinforcement, and is propagated downstream. Dopamine locally releases GABAergic inhibition to permit specific microcircuits within KC-spanning serotonergic neurons to function as an excitatory bridge between the previously 'modality-selective' KC streams. Cross-modal binding thereby expands the KCs representing the memory engram for each modality into those representing the other. This broadening of the engram improves memory performance after multisensory learning and permits a single sensory feature to retrieve the memory of the multimodal experience.
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Affiliation(s)
- Zeynep Okray
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford, UK.
| | - Pedro F Jacob
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford, UK
| | - Ciara Stern
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford, UK
| | - Kieran Desmond
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford, UK
| | - Nils Otto
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford, UK
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Clifford B Talbot
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford, UK
| | | | - Scott Waddell
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford, UK.
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16
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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: 25] [Impact Index Per Article: 12.5] [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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17
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Yan W, Lin H, Yu J, Wiggin TD, Wu L, Meng Z, Liu C, Griffith LC. Subtype-Specific Roles of Ellipsoid Body Ring Neurons in Sleep Regulation in Drosophila. J Neurosci 2023; 43:764-786. [PMID: 36535771 PMCID: PMC9899086 DOI: 10.1523/jneurosci.1350-22.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/22/2022] [Accepted: 10/26/2022] [Indexed: 12/23/2022] Open
Abstract
The ellipsoid body (EB) is a major structure of the central complex of the Drosophila melanogaster brain. Twenty-two subtypes of EB ring neurons have been identified based on anatomic and morphologic characteristics by light-level microscopy and EM connectomics. A few studies have associated ring neurons with the regulation of sleep homeostasis and structure. However, cell type-specific and population interactions in the regulation of sleep remain unclear. Using an unbiased thermogenetic screen of EB drivers using female flies, we found the following: (1) multiple ring neurons are involved in the modulation of amount of sleep and structure in a synergistic manner; (2) analysis of data for ΔP(doze)/ΔP(wake) using a mixed Gaussian model detected 5 clusters of GAL4 drivers which had similar effects on sleep pressure and/or depth: lines driving arousal contained R4m neurons, whereas lines that increased sleep pressure had R3m cells; (3) a GLM analysis correlating ring cell subtype and activity-dependent changes in sleep parameters across all lines identified several cell types significantly associated with specific sleep effects: R3p was daytime sleep-promoting, and R4m was nighttime wake-promoting; and (4) R3d cells present in 5HT7-GAL4 and in GAL4 lines, which exclusively affect sleep structure, were found to contribute to fragmentation of sleep during both day and night. Thus, multiple subtypes of ring neurons distinctively control sleep amount and/or structure. The unique highly interconnected structure of the EB suggests a local-network model worth future investigation; understanding EB subtype interactions may provide insight how sleep circuits in general are structured.SIGNIFICANCE STATEMENT How multiple brain regions, with many cell types, can coherently regulate sleep remains unclear, but identification of cell type-specific roles can generate opportunities for understanding the principles of integration and cooperation. The ellipsoid body (EB) of the fly brain exhibits a high level of connectivity and functional heterogeneity yet is able to tune multiple behaviors in real-time, including sleep. Leveraging the powerful genetic tools available in Drosophila and recent progress in the characterization of the morphology and connectivity of EB ring neurons, we identify several EB subtypes specifically associated with distinct aspects of sleep. Our findings will aid in revealing the rules of coding and integration in the brain.
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Affiliation(s)
- Wei Yan
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518000, China
| | - Hai Lin
- Central Research Institute, United Imaging Healthcare, Shanghai, 200032, China
| | - Junwei Yu
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02453
| | - Timothy D Wiggin
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02453
| | - Litao Wu
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518000, China
| | - Zhiqiang Meng
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518000, China
- CAS Key Laboratory of Brain Connectome and Manipulation, Shenzhen, 518000, China
- Shenzhen Key Laboratory of Drug Addiction, Shenzhen, 518000, China
| | - Chang Liu
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518000, China
- CAS Key Laboratory of Brain Connectome and Manipulation, Shenzhen, 518000, China
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, Shenzhen, 518000, China
| | - Leslie C Griffith
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02453
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18
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Marquand K, Roselli C, Cervantes-Sandoval I, Boto T. Sleep benefits different stages of memory in Drosophila. Front Physiol 2023; 14:1087025. [PMID: 36744027 PMCID: PMC9892949 DOI: 10.3389/fphys.2023.1087025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/06/2023] [Indexed: 01/20/2023] Open
Abstract
Understanding the physiological mechanisms that modulate memory acquisition and consolidation remains among the most ambitious questions in neuroscience. Massive efforts have been dedicated to deciphering how experience affects behavior, and how different physiological and sensory phenomena modulate memory. Our ability to encode, consolidate and retrieve memories depends on internal drives, and sleep stands out among the physiological processes that affect memory: one of the most relatable benefits of sleep is the aiding of memory that occurs in order to both prepare the brain to learn new information, and after a learning task, to consolidate those new memories. Drosophila lends itself to the study of the interactions between memory and sleep. The fruit fly provides incomparable genetic resources, a mapped connectome, and an existing framework of knowledge on the molecular, cellular, and circuit mechanisms of memory and sleep, making the fruit fly a remarkable model to decipher the sophisticated regulation of learning and memory by the quantity and quality of sleep. Research in Drosophila has stablished not only that sleep facilitates learning in wild-type and memory-impaired animals, but that sleep deprivation interferes with the acquisition of new memories. In addition, it is well-accepted that sleep is paramount in memory consolidation processes. Finally, studies in Drosophila have shown that that learning itself can promote sleep drive. Nevertheless, the molecular and network mechanisms underlying this intertwined relationship are still evasive. Recent remarkable work has shed light on the neural substrates that mediate sleep-dependent memory consolidation. In a similar way, the mechanistic insights of the neural switch control between sleep-dependent and sleep-independent consolidation strategies were recently described. This review will discuss the regulation of memory by sleep in Drosophila, focusing on the most recent advances in the field and pointing out questions awaiting to be investigated.
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Affiliation(s)
- Katie Marquand
- Department of Physiology, School of Medicine, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Camilla Roselli
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Isaac Cervantes-Sandoval
- Department of Biology, Georgetown University, Washington, DC, United States
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States
| | - Tamara Boto
- Department of Physiology, School of Medicine, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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19
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Mohandasan R, Thakare M, Sunke S, Iqbal FM, Sridharan M, Das G. Enhanced olfactory memory detection in trap-design Y-mazes allows the study of imperceptible memory traces in Drosophila. Learn Mem 2022; 29:355-366. [PMID: 36180129 PMCID: PMC9536757 DOI: 10.1101/lm.053545.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 07/08/2022] [Indexed: 11/25/2022]
Abstract
The neural basis of behavior is identified by systematically manipulating the activity of specific neurons and screening for loss or gain of phenotype. Therefore, robust, high-scoring behavioral assays are necessary for determining the neural circuits of novel behaviors. We report a simple Y-maze design for Drosophila olfactory learning and memory assay. Memory scores in our Y-mazes are considerably better and longer-lasting than scores obtained with commonly used T-mazes. Our results suggest that trapping flies to an odor choice in a Y-maze could improve scores. We postulated that the improved scores could reveal previously undetectable memory traces, enabling the study of underlying neural mechanisms. Indeed, we identified unreported protein synthesis-dependent long-term memories (LTMs), reinforced by ingestion of (1) an aversive compound and (2) a sweet but nonnutritious sugar, both 24 h after training. We also used Y-mazes to probe how using a greater reward may change memory dynamics. Our findings predict that a greater sugar reward may extend existing memory traces or reinforce additional novel ones.
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Affiliation(s)
- Radhika Mohandasan
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
- Savitribai Phule Pune University, Ganeshkhind, Pune 411007, India
| | - Manikrao Thakare
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
- Savitribai Phule Pune University, Ganeshkhind, Pune 411007, India
| | - Suhas Sunke
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Fathima Mukthar Iqbal
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Madhav Sridharan
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Gaurav Das
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
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20
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Aranha MM, Ramaswami M. Emotional states: Sweet relief for depressed flies. Curr Biol 2022; 32:R954-R957. [PMID: 36167044 DOI: 10.1016/j.cub.2022.08.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mammals and insects appear to have emotional states with features characteristic of human depression. A new study has defined a neural circuit including serotonergic neurons that drive sugar-induced relief from a depression-like-state in Drosophila.
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Affiliation(s)
- Marcia M Aranha
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland.
| | - Mani Ramaswami
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland.
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21
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Dvořáček J, Kodrík D. Drug effect and addiction research with insects - From Drosophila to collective reward in honeybees. Neurosci Biobehav Rev 2022; 140:104816. [PMID: 35940307 DOI: 10.1016/j.neubiorev.2022.104816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/29/2022] [Accepted: 08/01/2022] [Indexed: 10/16/2022]
Abstract
Animals and humans share similar reactions to the effects of addictive substances, including those of their brain networks to drugs. Our review focuses on simple invertebrate models, particularly the honeybee (Apis mellifera), and on the effects of drugs on bee behaviour and brain functions. The drug effects in bees are very similar to those described in humans. Furthermore, the honeybee community is a superorganism in which many collective functions outperform the simple sum of individual functions. The distribution of reward functions in this superorganism is unique - although sublimated at the individual level, community reward functions are of higher quality. This phenomenon of collective reward may be extrapolated to other animal species living in close and strictly organised societies, i.e. humans. The relationship between sociality and reward, based on use of similar parts of the neural network (social decision-making network in mammals, mushroom body in bees), suggests a functional continuum of reward and sociality in animals.
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Affiliation(s)
- Jiří Dvořáček
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budĕjovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budĕjovice, Czech Republic.
| | - Dalibor Kodrík
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budĕjovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budĕjovice, Czech Republic
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22
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Hermanns T, Graf-Boxhorn S, Poeck B, Strauss R. Octopamine mediates sugar relief from a chronic-stress-induced depression-like state in Drosophila. Curr Biol 2022; 32:4048-4056.e3. [PMID: 35914533 DOI: 10.1016/j.cub.2022.07.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/15/2022] [Accepted: 07/07/2022] [Indexed: 12/30/2022]
Abstract
Chronic, uncontrollable stress can result in psychiatric syndromes, including anxiety and major depressive disorder, in humans and mammalian disease models.1,2 Similarly, several days of chronic stress can induce depression-associated behavioral alteration in Drosophila accompanied by changes in biogenic amine levels in the adult brain.3-6 In our chronic stress paradigm, flies are subjected to 3 days of repetitive phases of 300 Hz vibrations combined with overcrowding and food deprivation. This treatment reduces voluntary behavioral activity, including the motivation to climb wide gaps (risk taking) and to stop for sweets (anhedonia), suggesting a depression-like state (DLS). These behavioral changes correlate with decreased serotonin release to the mushroom body (MB), a major behavioral control center in the central brain of the fly.7,8 Stressed flies are relieved from the DLS by feeding the anti-depressant serotonin precursor 5-HTP or the selective serotonin reuptake inhibitor fluoxetine. Notably, feeding sucrose to stressed flies results in elevated serotonin levels in the brain and ameliorates the DLS.3 Here, we show that this sugar relief is mediated by the neurotransmitter octopamine signaled from ventral unpaired medial neurons located in the subesophageal ganglion. The octopamine signaling of sweet sensation is transmitted to the MB via the dopaminergic PAM neurons. In addition, neuronal-silencing experiments reveal that the serotonergic dorsal paired medial (DPM) neurons innervating the MB are essential for sugar relief. Conversely, thermogenetic or optogenetic activation of DPMs can replace sweet sensation, elucidating that serotonergic signaling from DPMs takes part in positively modulating DLS-related behavioral changes.
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Affiliation(s)
- Tim Hermanns
- Institut für Entwicklungsbiologie und Neurobiologie, Johannes Gutenberg Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Sonja Graf-Boxhorn
- Institut für Entwicklungsbiologie und Neurobiologie, Johannes Gutenberg Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Burkhard Poeck
- Institut für Entwicklungsbiologie und Neurobiologie, Johannes Gutenberg Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Roland Strauss
- Institut für Entwicklungsbiologie und Neurobiologie, Johannes Gutenberg Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany.
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23
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Lee WP, Chiang MH, Chang LY, Shyu WH, Chiu TH, Fu TF, Wu T, Wu CL. Serotonin Signals Modulate Mushroom Body Output Neurons for Sustaining Water-Reward Long-Term Memory in Drosophila. Front Cell Dev Biol 2021; 9:755574. [PMID: 34858982 PMCID: PMC8631865 DOI: 10.3389/fcell.2021.755574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/26/2021] [Indexed: 11/27/2022] Open
Abstract
Memory consolidation is a time-dependent process through which an unstable learned experience is transformed into a stable long-term memory; however, the circuit and molecular mechanisms underlying this process are poorly understood. The Drosophila mushroom body (MB) is a huge brain neuropil that plays a crucial role in olfactory memory. The MB neurons can be generally classified into three subsets: γ, αβ, and α′β′. Here, we report that water-reward long-term memory (wLTM) consolidation requires activity from α′β′-related mushroom body output neurons (MBONs) in a specific time window. wLTM consolidation requires neurotransmission in MBON-γ3β′1 during the 0–2 h period after training, and neurotransmission in MBON-α′2 is required during the 2–4 h period after training. Moreover, neurotransmission in MBON-α′1α′3 is required during the 0–4 h period after training. Intriguingly, blocking neurotransmission during consolidation or inhibiting serotonin biosynthesis in serotoninergic dorsal paired medial (DPM) neurons also disrupted the wLTM, suggesting that wLTM consolidation requires serotonin signals from DPM neurons. The GFP Reconstitution Across Synaptic Partners (GRASP) data showed the connectivity between DPM neurons and MBON-γ3β′1, MBON-α′2, and MBON-α′1α′3, and RNAi-mediated silencing of serotonin receptors in MBON-γ3β′1, MBON-α′2, or MBON-α′1α′3 disrupted wLTM. Taken together, our results suggest that serotonin released from DPM neurons modulates neuronal activity in MBON-γ3β′1, MBON-α′2, and MBON-α′1α′3 at specific time windows, which is critical for the consolidation of wLTM in Drosophila.
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Affiliation(s)
- Wang-Pao Lee
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Meng-Hsuan Chiang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Li-Yun Chang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Wei-Huan Shyu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Tai-Hsiang Chiu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Tsai-Feng Fu
- Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan
| | - Tony Wu
- Department of Neurology, Chang Gung Memorial Hospital, Linkou, Taiwan.,Department of Neurology, New Taipei Municipal Tucheng Hospital, Tucheng, Taiwan.,Department of Neurology, Xiamen Chang Gung Hospital, Xiamen, China
| | - Chia-Lin Wu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Neurology, Chang Gung Memorial Hospital, Linkou, Taiwan.,Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan
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24
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Weiss JT, Donlea JM. Sleep deprivation results in diverse patterns of synaptic scaling across the Drosophila mushroom bodies. Curr Biol 2021; 31:3248-3261.e3. [PMID: 34107302 PMCID: PMC8355077 DOI: 10.1016/j.cub.2021.05.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 03/22/2021] [Accepted: 05/11/2021] [Indexed: 11/19/2022]
Abstract
Sleep is essential for a variety of plastic processes, including learning and memory. However, the consequences of insufficient sleep on circuit connectivity remain poorly understood. To better appreciate the effects of sleep loss on synaptic connectivity across a memory-encoding circuit, we examined changes in the distribution of synaptic markers in the Drosophila mushroom body (MB). Protein-trap tags for active zone components indicate that recent sleep time is inversely correlated with Bruchpilot (BRP) abundance in the MB lobes; sleep loss elevates BRP while sleep induction reduces BRP across the MB. Overnight sleep deprivation also elevated levels of dSyd-1 and Cacophony, but not other pre-synaptic proteins. Cell-type-specific genetic reporters show that MB-intrinsic Kenyon cells (KCs) exhibit increased pre-synaptic BRP throughout the axonal lobes after sleep deprivation; similar increases were not detected in projections from large interneurons or dopaminergic neurons that innervate the MB. These results indicate that pre-synaptic plasticity in KCs is responsible for elevated levels of BRP in the MB lobes of sleep-deprived flies. Because KCs provide synaptic inputs to several classes of post-synaptic partners, we next used a fluorescent reporter for synaptic contacts to test whether each class of KC output connections is scaled uniformly by sleep loss. The KC output synapses that we observed here can be divided into three classes: KCs to MB interneurons; KCs to dopaminergic neurons; and KCs to MB output neurons. No single class showed uniform scaling across each constituent member, indicating that different rules may govern plasticity during sleep loss across cell types.
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Affiliation(s)
- Jacqueline T Weiss
- Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA; Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA.
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25
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Dvořáček J, Kodrík D. Drosophila reward system - A summary of current knowledge. Neurosci Biobehav Rev 2021; 123:301-319. [PMID: 33421541 DOI: 10.1016/j.neubiorev.2020.12.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 12/16/2020] [Accepted: 12/27/2020] [Indexed: 01/19/2023]
Abstract
The fruit fly Drosophila melanogaster brain is the most extensively investigated model of a reward system in insects. Drosophila can discriminate between rewarding and punishing environmental stimuli and consequently undergo associative learning. Functional models, especially those modelling mushroom bodies, are constantly being developed using newly discovered information, adding to the complexity of creating a simple model of the reward system. This review aims to clarify whether its reward system also includes a hedonic component. Neurochemical systems that mediate the 'wanting' component of reward in the Drosophila brain are well documented, however, the systems that mediate the pleasure component of reward in mammals, including those involving the endogenous opioid and endocannabinoid systems, are unlikely to be present in insects. The mushroom body components exhibit differential developmental age and different functional processes. We propose a hypothetical hierarchy of the levels of reinforcement processing in response to particular stimuli, and the parallel processes that take place concurrently. The possible presence of activity-silencing and meta-satiety inducing levels in Drosophila should be further investigated.
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Affiliation(s)
- Jiří Dvořáček
- Institute of Entomology, Biology Centre, CAS, and Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
| | - Dalibor Kodrík
- Institute of Entomology, Biology Centre, CAS, and Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
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26
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Li F, Lindsey JW, Marin EC, Otto N, Dreher M, Dempsey G, Stark I, Bates AS, Pleijzier MW, Schlegel P, Nern A, Takemura SY, Eckstein N, Yang T, Francis A, Braun A, Parekh R, Costa M, Scheffer LK, Aso Y, Jefferis GSXE, Abbott LF, Litwin-Kumar A, Waddell S, Rubin GM. The connectome of the adult Drosophila mushroom body provides insights into function. eLife 2020; 9:e62576. [PMID: 33315010 PMCID: PMC7909955 DOI: 10.7554/elife.62576] [Citation(s) in RCA: 208] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022] Open
Abstract
Making inferences about the computations performed by neuronal circuits from synapse-level connectivity maps is an emerging opportunity in neuroscience. The mushroom body (MB) is well positioned for developing and testing such an approach due to its conserved neuronal architecture, recently completed dense connectome, and extensive prior experimental studies of its roles in learning, memory, and activity regulation. Here, we identify new components of the MB circuit in Drosophila, including extensive visual input and MB output neurons (MBONs) with direct connections to descending neurons. We find unexpected structure in sensory inputs, in the transfer of information about different sensory modalities to MBONs, and in the modulation of that transfer by dopaminergic neurons (DANs). We provide insights into the circuitry used to integrate MB outputs, connectivity between the MB and the central complex and inputs to DANs, including feedback from MBONs. Our results provide a foundation for further theoretical and experimental work.
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Affiliation(s)
- Feng Li
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Jack W Lindsey
- Department of Neuroscience, Columbia University, Zuckerman InstituteNew YorkUnited States
| | - Elizabeth C Marin
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Nils Otto
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Centre for Neural Circuits & Behaviour, University of OxfordOxfordUnited Kingdom
| | - Marisa Dreher
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Georgia Dempsey
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Ildiko Stark
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Alexander S Bates
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | - Philipp Schlegel
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Aljoscha Nern
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Shin-ya Takemura
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Nils Eckstein
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Tansy Yang
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Audrey Francis
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Amalia Braun
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Ruchi Parekh
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Marta Costa
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Louis K Scheffer
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gregory SXE Jefferis
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Larry F Abbott
- Department of Neuroscience, Columbia University, Zuckerman InstituteNew YorkUnited States
| | - Ashok Litwin-Kumar
- Department of Neuroscience, Columbia University, Zuckerman InstituteNew YorkUnited States
| | - Scott Waddell
- Centre for Neural Circuits & Behaviour, University of OxfordOxfordUnited Kingdom
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
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27
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Wu Y, Funato Y, Meschi E, Jovanoski KD, Miki H, Waddell S. Magnesium efflux from Drosophila Kenyon cells is critical for normal and diet-enhanced long-term memory. eLife 2020; 9:61339. [PMID: 33242000 PMCID: PMC7843133 DOI: 10.7554/elife.61339] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/25/2020] [Indexed: 12/12/2022] Open
Abstract
Dietary magnesium (Mg2+) supplementation can enhance memory in young and aged rats. Memory-enhancing capacity was largely ascribed to increases in hippocampal synaptic density and elevated expression of the NR2B subunit of the NMDA-type glutamate receptor. Here we show that Mg2+ feeding also enhances long-term memory in Drosophila. Normal and Mg2+-enhanced fly memory appears independent of NMDA receptors in the mushroom body and instead requires expression of a conserved CNNM-type Mg2+-efflux transporter encoded by the unextended (uex) gene. UEX contains a putative cyclic nucleotide-binding homology domain and its mutation separates a vital role for uex from a function in memory. Moreover, UEX localization in mushroom body Kenyon cells (KCs) is altered in memory-defective flies harboring mutations in cAMP-related genes. Functional imaging suggests that UEX-dependent efflux is required for slow rhythmic maintenance of KC Mg2+. We propose that regulated neuronal Mg2+ efflux is critical for normal and Mg2+-enhanced memory. The proverbial saying ‘you are what you eat’ perfectly summarizes the concept that our diet can influence both our mental and physical health. We know that foods that are good for the heart, such as nuts, oily fish and berries, are also good for the brain. We know too that vitamins and minerals are essential for overall good health. But is there any evidence that increasing your intake of specific vitamins or minerals could help boost your brain power? While it might sound almost too good to be true, there is some evidence that this is the case for at least one mineral, magnesium. Studies in rodents have shown that adding magnesium supplements to food improves how well the animals perform on memory tasks. Both young and old animals benefit from additional magnesium. Even elderly rodents with a condition similar to Alzheimer’s disease show less memory loss when given magnesium supplements. But what about other species? Wu et al. now show that magnesium supplements also boost memory performance in fruit flies. One group of flies was fed with standard cornmeal for several days, while the other group received cornmeal supplemented with magnesium. Both groups were then trained to associate an odor with a food reward. Flies that had received the extra magnesium showed better memory for the odor when tested 24 hours after training. Wu et al. show that magnesium improves memory in the flies via a different mechanism to that reported previously for rodents. In rodents, magnesium increased levels of a receptor protein for a brain chemical called glutamate. In fruit flies, by contrast, the memory boost depended on a protein that transports magnesium out of neurons. Mutant flies that lacked this transporter showed memory impairments. Unlike normal flies, those without the transporter showed no memory improvement after eating magnesium-enriched food. The results suggest that the transporter may help adjust magnesium levels inside brain cells in response to neural activity. Humans produce four variants of this magnesium transporter, each encoded by a different gene. One of these transporters has already been implicated in brain development. The findings of Wu et al. suggest that the transporters may also act in the adult brain to influence cognition. Further studies are needed to test whether targeting the magnesium transporter could ultimately hold promise for treating memory impairments.
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Affiliation(s)
- Yanying Wu
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Oxford, United Kingdom
| | - Yosuke Funato
- Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Eleonora Meschi
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Oxford, United Kingdom
| | - Kristijan D Jovanoski
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Oxford, United Kingdom
| | - Hiroaki Miki
- Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Tinsley Building, Oxford, United Kingdom
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28
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Lee WP, Chiang MH, Chang LY, Lee JY, Tsai YL, Chiu TH, Chiang HC, Fu TF, Wu T, Wu CL. Mushroom body subsets encode CREB2-dependent water-reward long-term memory in Drosophila. PLoS Genet 2020; 16:e1008963. [PMID: 32780743 PMCID: PMC7418956 DOI: 10.1371/journal.pgen.1008963] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/29/2020] [Indexed: 11/18/2022] Open
Abstract
Long-term memory (LTM) formation depends on the conversed cAMP response element-binding protein (CREB)-dependent gene transcription followed by de novo protein synthesis. Thirsty fruit flies can be trained to associate an odor with water reward to form water-reward LTM (wLTM), which can last for over 24 hours without a significant decline. The role of de novo protein synthesis and CREB-regulated gene expression changes in neural circuits that contribute to wLTM remains unclear. Here, we show that acute inhibition of protein synthesis in the mushroom body (MB) αβ or γ neurons during memory formation using a cold-sensitive ribosome-inactivating toxin disrupts wLTM. Furthermore, adult stage-specific expression of dCREB2b in αβ or γ neurons also disrupts wLTM. The MB αβ and γ neurons can be further classified into five different neuronal subsets including αβ core, αβ surface, αβ posterior, γ main, and γ dorsal. We observed that the neurotransmission from αβ surface and γ dorsal neuron subsets is required for wLTM retrieval, whereas the αβ core, αβ posterior, and γ main are dispensable. Adult stage-specific expression of dCREB2b in αβ surface and γ dorsal neurons inhibits wLTM formation. In vivo calcium imaging revealed that αβ surface and γ dorsal neurons form wLTM traces with different dynamic properties, and these memory traces are abolished by dCREB2b expression. Our results suggest that a small population of neurons within the MB circuits support long-term storage of water-reward memory in Drosophila.
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Affiliation(s)
- Wang-Pao Lee
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taiwan
| | - Meng-Hsuan Chiang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taiwan
| | - Li-Yun Chang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taiwan
| | - Jhen-Yi Lee
- School of Medicine, College of Medicine, Chang Gung University, Taiwan
| | - Ya-Lun Tsai
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taiwan
| | - Tai-Hsiang Chiu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taiwan
| | | | - Tsai-Feng Fu
- Department of Applied Chemistry, National Chi Nan University, Taiwan
| | - Tony Wu
- Department of Neurology, Chang Gung Memorial Hospital, Taiwan
| | - Chia-Lin Wu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taiwan
- Department of Neurology, Chang Gung Memorial Hospital, Taiwan
- Department of Biochemistry, College of Medicine, Chang Gung University, Taiwan
- * E-mail:
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29
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Appetitive Memory with Survival Benefit Is Robust Across Aging in Drosophila. J Neurosci 2020; 40:2296-2304. [PMID: 31992587 DOI: 10.1523/jneurosci.2045-19.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 11/21/2022] Open
Abstract
The formation of memory declines with advancing age. However, susceptibility to memory impairments depends on several factors, including the robustness of memory, the responsible neural circuits, and the internal state of aged individuals. How age-dependent changes in internal states and neural circuits affect memory formation remains unclear. Here, we show in Drosophila melanogaster that aged flies of both sexes form robust appetitive memory conditioned with nutritious sugar, which suppresses their high mortality rates during starvation. In contrast, aging impairs the formation of appetitive memory conditioned with non-nutritious sugar that lacks survival benefits for the flies. We found that aging enhanced the preference for nutritious sugar over non-nutritious sugar correlated with an age-dependent increase in the expression of Drosophila neuropeptide F, an ortholog of mammalian neuropeptide Y. Furthermore, a subset of dopaminergic neurons that signal the sweet taste of sugar decreases its function with aging, while a subset of dopaminergic neurons that signal the nutritional value of sugar maintains its function with age. Our results suggest that aging impairs the ability to form memories without survival benefits; however, the ability to form memories with survival benefits is maintained through age-dependent changes in the neural circuits and neuropeptides.SIGNIFICANCE STATEMENT The susceptibility to age-dependent memory impairments depends on the strength of the memory, changes in the responsible neurons, and internal states of aged individuals. How age-dependent changes in such internal states affect neural activity and memory formation remains unclear. We show in Drosophila melanogaster that aged flies of both sexes form robust appetitive memory conditioned with nutritious sugar, which has survival benefits for aged flies. In contrast, aging impairs the formation of appetitive memory conditioned with non-nutritious sugar that lacks survival benefits for the flies. Aging changes the neural circuits including dopamine neurons and neuropeptide F-expressing neurons, leading to the age-dependent impairment in memory with insufficient survival benefits and the preservation of the ability to form memory with survival benefits.
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30
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Rapid single-wavelength lightsheet localization microscopy for clarified tissue. Nat Commun 2019; 10:4762. [PMID: 31628310 PMCID: PMC6800451 DOI: 10.1038/s41467-019-12715-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 09/27/2019] [Indexed: 02/02/2023] Open
Abstract
Optical super-resolution microscopy allows nanoscale imaging of protein molecules in intact biological tissues. However, it is still challenging to perform large volume super-resolution imaging for entire animal organs. Here we develop a single-wavelength Bessel lightsheet method, optimized for refractive-index matching with clarified specimens to overcome the aberrations encountered in imaging thick tissues. Using spontaneous blinking fluorophores to label proteins of interest, we resolve the morphology of most, if not all, dopaminergic neurons in the whole adult brain (3.64 × 107 µm3) of Drosophila melanogaster at the nanometer scale with high imaging speed (436 µm3 per second) for localization. Quantitative single-molecule localization reveals the subcellular distribution of a monoamine transporter protein in the axons of a single, identified serotonergic Dorsal Paired Medial (DPM) neuron. Large datasets are obtained from imaging one brain per day to provide a robust statistical analysis of these imaging data.
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31
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Lyutova R, Selcho M, Pfeuffer M, Segebarth D, Habenstein J, Rohwedder A, Frantzmann F, Wegener C, Thum AS, Pauls D. Reward signaling in a recurrent circuit of dopaminergic neurons and peptidergic Kenyon cells. Nat Commun 2019; 10:3097. [PMID: 31308381 PMCID: PMC6629635 DOI: 10.1038/s41467-019-11092-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 06/20/2019] [Indexed: 11/09/2022] Open
Abstract
Dopaminergic neurons in the brain of the Drosophila larva play a key role in mediating reward information to the mushroom bodies during appetitive olfactory learning and memory. Using optogenetic activation of Kenyon cells we provide evidence that recurrent signaling exists between Kenyon cells and dopaminergic neurons of the primary protocerebral anterior (pPAM) cluster. Optogenetic activation of Kenyon cells paired with odor stimulation is sufficient to induce appetitive memory. Simultaneous impairment of the dopaminergic pPAM neurons abolishes appetitive memory expression. Thus, we argue that dopaminergic pPAM neurons mediate reward information to the Kenyon cells, and in turn receive feedback from Kenyon cells. We further show that this feedback signaling is dependent on short neuropeptide F, but not on acetylcholine known to be important for odor-shock memories in adult flies. Our data suggest that recurrent signaling routes within the larval mushroom body circuitry may represent a mechanism subserving memory stabilization.
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Affiliation(s)
- Radostina Lyutova
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - Mareike Selcho
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - Maximilian Pfeuffer
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - Dennis Segebarth
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany.,Institute of Clinical Neurobiology, University Hospital of Würzburg, D-97078, Würzburg, Germany
| | - Jens Habenstein
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany.,Department of Behavioral Physiology and Sociobiology, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - Astrid Rohwedder
- Department of Genetics, University of Leipzig, D-04103, Leipzig, Germany
| | - Felix Frantzmann
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - Christian Wegener
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - Andreas S Thum
- Department of Genetics, University of Leipzig, D-04103, Leipzig, Germany
| | - Dennis Pauls
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, D-97074, Würzburg, Germany.
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32
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Yamazaki D, Hiroi M, Abe T, Shimizu K, Minami-Ohtsubo M, Maeyama Y, Horiuchi J, Tabata T. Two Parallel Pathways Assign Opposing Odor Valences during Drosophila Memory Formation. Cell Rep 2019; 22:2346-2358. [PMID: 29490271 DOI: 10.1016/j.celrep.2018.02.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/13/2017] [Accepted: 02/01/2018] [Indexed: 11/15/2022] Open
Abstract
During olfactory associative learning in Drosophila, odors activate specific subsets of intrinsic mushroom body (MB) neurons. Coincident exposure to either rewards or punishments is thought to activate extrinsic dopaminergic neurons, which modulate synaptic connections between odor-encoding MB neurons and MB output neurons to alter behaviors. However, here we identify two classes of intrinsic MB γ neurons based on cAMP response element (CRE)-dependent expression, γCRE-p and γCRE-n, which encode aversive and appetitive valences. γCRE-p and γCRE-n neurons act antagonistically to maintain neutral valences for neutral odors. Activation or inhibition of either cell type upsets this balance, toggling odor preferences to either positive or negative values. The mushroom body output neurons, MBON-γ5β'2a/β'2mp and MBON-γ2α'1, mediate the actions of γCRE-p and γCRE-n neurons. Our data indicate that MB neurons encode valence information, as well as odor information, and this information is integrated through a process involving MBONs to regulate learning and memory.
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Affiliation(s)
- Daisuke Yamazaki
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Tokyo 113-0032, Japan.
| | - Makoto Hiroi
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Tokyo 113-0032, Japan
| | - Takashi Abe
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Tokyo 113-0032, Japan
| | - Kazumichi Shimizu
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Tokyo 113-0032, Japan
| | - Maki Minami-Ohtsubo
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Tokyo 113-0032, Japan
| | - Yuko Maeyama
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Tokyo 113-0032, Japan
| | - Junjiro Horiuchi
- Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, Japan
| | - Tetsuya Tabata
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Tokyo 113-0032, Japan.
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Suppression of GABAergic neurons through D2-like receptor secures efficient conditioning in Drosophila aversive olfactory learning. Proc Natl Acad Sci U S A 2019; 116:5118-5125. [PMID: 30796183 DOI: 10.1073/pnas.1812342116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The GABAergic system serves as a vital negative modulator in cognitive functions, such as learning and memory, while the mechanisms governing this inhibitory system remain to be elucidated. In Drosophila, the GABAergic anterior paired lateral (APL) neurons mediate a negative feedback essential for odor discrimination; however, their activity is suppressed by learning via unknown mechanisms. In aversive olfactory learning, a group of dopaminergic (DA) neurons is activated on electric shock (ES) and modulates the Kenyon cells (KCs) in the mushroom body, the center of olfactory learning. Here we find that the same group of DA neurons also form functional synaptic connections with the APL neurons, thereby emitting a suppressive signal to the latter through Drosophila dopamine 2-like receptor (DD2R). Knockdown of either DD2R or its downstream molecules in the APL neurons results in impaired olfactory learning at the behavioral level. Results obtained from in vivo functional imaging experiments indicate that this DD2R-dependent DA-to-APL suppression occurs during odor-ES conditioning and discharges the GABAergic inhibition on the KCs specific to the conditioned odor. Moreover, the decrease in odor response of the APL neurons persists to the postconditioning phase, and this change is also absent in DD2R knockdown flies. Taken together, our findings show that DA-to-GABA suppression is essential for restraining the GABAergic inhibition during conditioning, as well as for inducing synaptic modification in this learning circuit. Such circuit mechanisms may play conserved roles in associative learning across species.
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Donlea JM. Roles for sleep in memory: insights from the fly. Curr Opin Neurobiol 2018; 54:120-126. [PMID: 30366270 DOI: 10.1016/j.conb.2018.10.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/04/2018] [Indexed: 01/10/2023]
Abstract
Sleep has been universally conserved across animal species. The basic functions of sleep remain unclear, but insufficient sleep impairs memory acquisition and retention in both vertebrates and invertebrates. Sleep is also a homeostatic process that is influenced not only by the amount of time awake, but also by neural activity and plasticity. Because of the breadth and precision of available genetic tools, the fruit fly has become a powerful model system to understand sleep regulation and function. Importantly, these tools enable the dissection of memory-encoding circuits at the level of individual neurons, and have allowed the development of genetic tools to induce sleep on-demand. This review describes recent investigations of the role for sleep in memory using Drosophila and current hypotheses of sleep's functions for supporting plasticity, learning, and memory.
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Affiliation(s)
- Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095-1763, USA.
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35
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Cognigni P, Felsenberg J, Waddell S. Do the right thing: neural network mechanisms of memory formation, expression and update in Drosophila. Curr Opin Neurobiol 2018; 49:51-58. [PMID: 29258011 PMCID: PMC5981003 DOI: 10.1016/j.conb.2017.12.002] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/02/2022]
Abstract
When animals learn, plasticity in brain networks that respond to specific cues results in a change in the behavior that these cues elicit. Individual network components in the mushroom bodies of the fruit fly Drosophila melanogaster represent cues, learning signals and behavioral outcomes of learned experience. Recent findings have highlighted the importance of dopamine-driven plasticity and activity in feedback and feedforward connections, between various elements of the mushroom body neural network. These computational motifs have been shown to be crucial for long term olfactory memory consolidation, integration of internal states, re-evaluation and updating of learned information. The often recurrent circuit anatomy and a prolonged requirement for activity in parts of these underlying networks, suggest that self-sustained and precisely timed activity is a fundamental feature of network computations in the insect brain. Together these processes allow flies to continuously adjust the content of their learned knowledge and direct their behavior in a way that best represents learned expectations and serves their most pressing current needs.
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Affiliation(s)
- Paola Cognigni
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom
| | - Johannes Felsenberg
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom
| | - Scott Waddell
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom.
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Musso PY, Lampin-Saint-Amaux A, Tchenio P, Preat T. Ingestion of artificial sweeteners leads to caloric frustration memory in Drosophila. Nat Commun 2017; 8:1803. [PMID: 29180783 PMCID: PMC5703724 DOI: 10.1038/s41467-017-01989-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 10/30/2017] [Indexed: 11/09/2022] Open
Abstract
Non-caloric artificial sweeteners (NAS) are widely used in modern human food, raising the question about their health impact. Here we have asked whether NAS consumption is a neutral experience at neural and behavioral level, or if NAS can be interpreted and remembered as negative experience. We used behavioral and imaging approaches to demonstrate that Drosophila melanogaster learn the non-caloric property of NAS through post-ingestion process. These results show that sweet taste is predictive of an energy value, and its absence leads to the formation of what we call Caloric Frustration Memory (CFM) that devalues the NAS or its caloric enantiomer. CFM formation involves activity of the associative memory brain structure, the mushroom bodies (MBs). In vivo calcium imaging of MB-input dopaminergic neurons that respond to sugar showed a reduced response to NAS after CFM formation. Altogether, these findings demonstrate that NAS are a negative experience for the brain. While non-caloric artificial sweeteners (NAS) are used as food additives, it’s unclear whether animals perceive NAS as positive or negative percept. Here, Musso and colleagues show in Drosophila that NAS is a negative percept, encoded in a new type of memory.
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Affiliation(s)
- Pierre-Yves Musso
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.,Department of Zoology, Cell and Developmental Biology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
| | - Aurélie Lampin-Saint-Amaux
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France
| | - Paul Tchenio
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.,Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, 91400, Orsay, France
| | - Thomas Preat
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.
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Drosophila Neprilysins Are Involved in Middle-Term and Long-Term Memory. J Neurosci 2017; 36:9535-46. [PMID: 27629706 DOI: 10.1523/jneurosci.3730-15.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 07/25/2016] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Neprilysins are type II metalloproteinases known to degrade and inactivate a number of small peptides. Neprilysins in particular are the major amyloid-β peptide-degrading enzymes. In mouse models of Alzheimer's disease, neprilysin overexpression improves learning and memory deficits, whereas neprilysin deficiency aggravates the behavioral phenotypes. However, whether these enzymes are involved in memory in nonpathological conditions is an open question. Drosophila melanogaster is a well suited model system with which to address this issue. Several memory phases have been characterized in this organism and the neuronal circuits involved are well described. The fly genome contains five neprilysin-encoding genes, four of which are expressed in the adult. Using conditional RNA interference, we show here that all four neprilysins are involved in middle-term and long-term memory. Strikingly, all four are required in a single pair of neurons, the dorsal paired medial (DPM) neurons that broadly innervate the mushroom bodies (MBs), the center of olfactory memory. Neprilysins are also required in the MB, reflecting the functional relationship between the DPM neurons and the MB, a circuit believed to stabilize memories. Together, our data establish a role for neprilysins in two specific memory phases and further show that DPM neurons play a critical role in the proper targeting of neuropeptides involved in these processes. SIGNIFICANCE STATEMENT Neprilysins are endopeptidases known to degrade a number of small peptides. Neprilysin research has essentially focused on their role in Alzheimer's disease and heart failure. Here, we use Drosophila melanogaster to study whether neprilysins are involved in memory. Drosophila can form several types of olfactory memory and the neuronal structures involved are well described. Four neprilysin genes are expressed in adult Drosophila Using conditional RNA interference, we show that all four are specifically involved in middle-term memory (MTM) and long-term memory (LTM) and that their expression is required in the mushroom bodies and also in a single pair of closely connected neurons. The data show that these two neurons play a critical role in targeting neuropeptides essential for MTM and LTM.
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Takemura SY, Aso Y, Hige T, Wong A, Lu Z, Xu CS, Rivlin PK, Hess H, Zhao T, Parag T, Berg S, Huang G, Katz W, Olbris DJ, Plaza S, Umayam L, Aniceto R, Chang LA, Lauchie S, Ogundeyi O, Ordish C, Shinomiya A, Sigmund C, Takemura S, Tran J, Turner GC, Rubin GM, Scheffer LK. A connectome of a learning and memory center in the adult Drosophila brain. eLife 2017; 6. [PMID: 28718765 PMCID: PMC5550281 DOI: 10.7554/elife.26975] [Citation(s) in RCA: 235] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 07/17/2017] [Indexed: 12/12/2022] Open
Abstract
Understanding memory formation, storage and retrieval requires knowledge of the underlying neuronal circuits. In Drosophila, the mushroom body (MB) is the major site of associative learning. We reconstructed the morphologies and synaptic connections of all 983 neurons within the three functional units, or compartments, that compose the adult MB’s α lobe, using a dataset of isotropic 8 nm voxels collected by focused ion-beam milling scanning electron microscopy. We found that Kenyon cells (KCs), whose sparse activity encodes sensory information, each make multiple en passant synapses to MB output neurons (MBONs) in each compartment. Some MBONs have inputs from all KCs, while others differentially sample sensory modalities. Only 6% of KC>MBON synapses receive a direct synapse from a dopaminergic neuron (DAN). We identified two unanticipated classes of synapses, KC>DAN and DAN>MBON. DAN activation produces a slow depolarization of the MBON in these DAN>MBON synapses and can weaken memory recall. DOI:http://dx.doi.org/10.7554/eLife.26975.001
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Affiliation(s)
- Shin-Ya Takemura
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Toshihide Hige
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Allan Wong
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Zhiyuan Lu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - C Shan Xu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Patricia K Rivlin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Harald Hess
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ting Zhao
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Toufiq Parag
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Stuart Berg
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Gary Huang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - William Katz
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Donald J Olbris
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Stephen Plaza
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Lowell Umayam
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Roxanne Aniceto
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Lei-Ann Chang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Shirley Lauchie
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Omotara Ogundeyi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Christopher Ordish
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Aya Shinomiya
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Christopher Sigmund
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Satoko Takemura
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Julie Tran
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Glenn C Turner
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Louis K Scheffer
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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Shyu WH, Chiu TH, Chiang MH, Cheng YC, Tsai YL, Fu TF, Wu T, Wu CL. Neural circuits for long-term water-reward memory processing in thirsty Drosophila. Nat Commun 2017; 8:15230. [PMID: 28504254 PMCID: PMC5440665 DOI: 10.1038/ncomms15230] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 03/03/2017] [Indexed: 12/14/2022] Open
Abstract
The intake of water is important for the survival of all animals and drinking water can be used as a reward in thirsty animals. Here we found that thirsty Drosophila melanogaster can associate drinking water with an odour to form a protein-synthesis-dependent water-reward long-term memory (LTM). Furthermore, we found that the reinforcement of LTM requires water-responsive dopaminergic neurons projecting to the restricted region of mushroom body (MB) β′ lobe, which are different from the neurons required for the reinforcement of learning and short-term memory (STM). Synaptic output from α′β′ neurons is required for consolidation, whereas the output from γ and αβ neurons is required for the retrieval of LTM. Finally, two types of MB efferent neurons retrieve LTM from γ and αβ neurons by releasing glutamate and acetylcholine, respectively. Our results therefore cast light on the cellular and molecular mechanisms responsible for processing water-reward LTM in Drosophila. Distinct subsets of dopaminergic PAM neurons have been shown to be involved in short-term and long-term memory for sugar reward. Here the authors report the neural circuits and the cellular and molecular mechanisms for short-term and long-term memory for water reward in thirsty Drosophila.
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Affiliation(s)
- Wei-Huan Shyu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Tai-Hsiang Chiu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Meng-Hsuan Chiang
- Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Yu-Chin Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Ya-Lun Tsai
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Tsai-Feng Fu
- Department of Applied Chemistry, National Chi-Nan University, Nantou 54561, Taiwan
| | - Tony Wu
- Department of Neurology, Linkou Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
| | - Chia-Lin Wu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.,Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.,Department of Neurology, Linkou Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
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40
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Two Components of Aversive Memory in Drosophila, Anesthesia-Sensitive and Anesthesia-Resistant Memory, Require Distinct Domains Within the Rgk1 Small GTPase. J Neurosci 2017; 37:5496-5510. [PMID: 28416593 DOI: 10.1523/jneurosci.3648-16.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 03/12/2017] [Accepted: 04/12/2017] [Indexed: 12/17/2022] Open
Abstract
Multiple components have been identified that exhibit different stabilities for aversive olfactory memory in Drosophila These components have been defined by behavioral and genetic studies and genes specifically required for a specific component have also been identified. Intermediate-term memory generated after single cycle conditioning is divided into anesthesia-sensitive memory (ASM) and anesthesia-resistant memory (ARM), with the latter being more stable. We determined that the ASM and ARM pathways converged on the Rgk1 small GTPase and that the N-terminal domain-deleted Rgk1 was sufficient for ASM formation, whereas the full-length form was required for ARM formation. Rgk1 is specifically accumulated at the synaptic site of the Kenyon cells (KCs), the intrinsic neurons of the mushroom bodies, which play a pivotal role in olfactory memory formation. A higher than normal Rgk1 level enhanced memory retention, which is consistent with the result that Rgk1 suppressed Rac-dependent memory decay; these findings suggest that rgk1 bolsters ASM via the suppression of forgetting. We propose that Rgk1 plays a pivotal role in the regulation of memory stabilization by serving as a molecular node that resides at KC synapses, where the ASM and ARM pathway may interact.SIGNIFICANCE STATEMENT Memory consists of multiple components. Drosophila olfactory memory serves as a fundamental model with which to investigate the mechanisms that underlie memory formation and has provided genetic and molecular means to identify the components of memory, namely short-term, intermediate-term, and long-term memory, depending on how long the memory lasts. Intermediate memory is further divided into anesthesia-sensitive memory (ASM) and anesthesia-resistant memory (ARM), with the latter being more stable. We have identified a small GTPase in Drosophila, Rgk1, which plays a pivotal role in the regulation of olfactory memory stability. Rgk1 is required for both ASM and ARM. Moreover, N-terminal domain-deleted Rgk1 was sufficient for ASM formation, whereas the full-length form was required for ARM formation.
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Perry S, Kiragasi B, Dickman D, Ray A. The Role of Histone Deacetylase 6 in Synaptic Plasticity and Memory. Cell Rep 2017; 18:1337-1345. [PMID: 28178513 PMCID: PMC5387061 DOI: 10.1016/j.celrep.2017.01.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 10/28/2016] [Accepted: 01/12/2017] [Indexed: 02/02/2023] Open
Abstract
Histone deacetylases (HDACs) have been extensively studied as drug targets in neurodegenerative diseases, but less is known about their role in healthy neurons. We tested zinc-dependent HDACs using RNAi in Drosophila melanogaster and found memory deficits with RPD3 and HDAC6. We demonstrate that HDAC6 is required in both the larval and adult stages for normal olfactory memory retention. Neuronal expression of HDAC6 rescued memory deficits, and we demonstrate that the N-terminal deacetylase (DAC) domain is required for this ability. This suggests that deacetylation of synaptic targets associated with the first DAC domain, such as the active-zone scaffold Bruchpilot, is required for memory retention. Finally, electrophysiological experiments at the neuromuscular junction reveal that HDAC6 mutants exhibit a partial block of homeostatic plasticity, suggesting that HDAC6 may be required for the stabilization of synaptic strength. The learning deficit we observe in HDAC6 mutants could be a behavioral consequence of these synaptic defects.
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Affiliation(s)
- Sarah Perry
- Graduate Program in Genetics, Genomics, and Bioinformatics, University of California, Riverside, Riverside, CA 92521, USA
| | - Beril Kiragasi
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Anandasankar Ray
- Graduate Program in Genetics, Genomics, and Bioinformatics, University of California, Riverside, Riverside, CA 92521, USA; Center for Disease Vector Research, University of California, Riverside, Riverside, CA 92521, USA.
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42
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Owald D, Lin S, Waddell S. Light, heat, action: neural control of fruit fly behaviour. Philos Trans R Soc Lond B Biol Sci 2016; 370:20140211. [PMID: 26240426 PMCID: PMC4528823 DOI: 10.1098/rstb.2014.0211] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The fruit fly Drosophila melanogaster has emerged as a popular model to investigate fundamental principles of neural circuit operation. The sophisticated genetics and small brain permit a cellular resolution understanding of innate and learned behavioural processes. Relatively recent genetic and technical advances provide the means to specifically and reproducibly manipulate the function of many fly neurons with temporal resolution. The same cellular precision can also be exploited to express genetically encoded reporters of neural activity and cell-signalling pathways. Combining these approaches in living behaving animals has great potential to generate a holistic view of behavioural control that transcends the usual molecular, cellular and systems boundaries. In this review, we discuss these approaches with particular emphasis on the pioneering studies and those involving learning and memory.
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Affiliation(s)
- David Owald
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Suewei Lin
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK
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43
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Short and long-lasting behavioral consequences of agonistic encounters between male Drosophila melanogaster. Proc Natl Acad Sci U S A 2016; 113:4818-23. [PMID: 27071097 DOI: 10.1073/pnas.1520953113] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
In many animal species, learning and memory have been found to play important roles in regulating intra- and interspecific behavioral interactions in varying environments. In such contexts, aggression is commonly used to obtain desired resources. Previous defeats or victories during aggressive interactions have been shown to influence the outcome of later contests, revealing loser and winner effects. In this study, we asked whether short- and/or long-term behavioral consequences accompany victories and defeats in dyadic pairings between male Drosophila melanogaster and how long those effects remain. The results demonstrated that single fights induced important behavioral changes in both combatants and resulted in the formation of short-term loser and winner effects. These decayed over several hours, with the duration depending on the level of familiarity of the opponents. Repeated defeats induced a long-lasting loser effect that was dependent on de novo protein synthesis, whereas repeated victories had no long-term behavioral consequences. This suggests that separate mechanisms govern the formation of loser and winner effects. These studies aim to lay a foundation for future investigations exploring the molecular mechanisms and circuitry underlying the nervous system changes induced by winning and losing bouts during agonistic encounters.
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44
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Williams ZM. Transgenerational influence of sensorimotor training on offspring behavior and its neural basis in Drosophila. Neurobiol Learn Mem 2016; 131:166-75. [PMID: 27044678 DOI: 10.1016/j.nlm.2016.03.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/23/2016] [Accepted: 03/30/2016] [Indexed: 01/01/2023]
Abstract
Whether specific learning experiences by parents influence the behavior of subsequent generations remains unclear. This study examines whether and what aspects of parental sensorimotor training prior to conception affect the behavior of subsequent generations and identifies the neural circuitries in Drosophila responsible for mediating these effects. Using genetic and anatomic techniques, I find that both first- and second-generation offspring of parents who underwent prolonged olfactory training over many days displayed a weak but selective approach bias to the same trained odors. However, I also find that the offspring did not differentiate between orders based on whether parental training was aversive or appetitive. Disruption of both olfactory-receptor and dorsal-paired-medial neuron input into the mushroom bodies abolished this change in offspring response, but disrupting synaptic output from α/β neurons of the mushroom body themselves had little effect on behavior even though they remained necessary for enacting newly trained conditioned responses. This study provides a circuit-based understanding of how specific sensory experiences in Drosophila may bias the behavior of subsequent generations, and identifies a transgenerational dissociation between the effects of conditioned and unconditioned sensory stimuli.
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Affiliation(s)
- Ziv M Williams
- Harvard-MIT Health Sciences and Technology, Boston, MA, United States; Harvard Medical School Program in Neuroscience, Boston, MA, United States; Department of Neurosurgery, MGH-HMS Center for Nervous System Repair, Harvard Medical School, Boston, MA, United States.
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45
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Androschuk A, Al-Jabri B, Bolduc FV. From Learning to Memory: What Flies Can Tell Us about Intellectual Disability Treatment. Front Psychiatry 2015; 6:85. [PMID: 26089803 PMCID: PMC4453272 DOI: 10.3389/fpsyt.2015.00085] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 05/19/2015] [Indexed: 01/13/2023] Open
Abstract
Intellectual disability (ID), previously known as mental retardation, affects 3% of the population and remains without pharmacological treatment. ID is characterized by impaired general mental abilities associated with defects in adaptive function in which onset occurs before 18 years of age. Genetic factors are increasing and being recognized as the causes of severe ID due to increased use of genome-wide screening tools. Unfortunately drug discovery for treatment of ID has not followed the same pace as gene discovery, leaving clinicians, patients, and families without the ability to ameliorate symptoms. Despite this, several model organisms have proven valuable in developing and screening candidate drugs. One such model organism is the fruit fly Drosophila. First, we review the current understanding of memory in human and its model in Drosophila. Second, we describe key signaling pathways involved in ID and memory such as the cyclic adenosine 3',5'-monophosphate (cAMP)-cAMP response element binding protein (CREB) pathway, the regulation of protein synthesis, the role of receptors and anchoring proteins, the role of neuronal proliferation, and finally the role of neurotransmitters. Third, we characterize the types of memory defects found in patients with ID. Finally, we discuss how important insights gained from Drosophila learning and memory could be translated in clinical research to lead to better treatment development.
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Affiliation(s)
- Alaura Androschuk
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Basma Al-Jabri
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Francois V. Bolduc
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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Wu CL, Fu TF, Chou YY, Yeh SR. A single pair of neurons modulates egg-laying decisions in Drosophila. PLoS One 2015; 10:e0121335. [PMID: 25781933 PMCID: PMC4363143 DOI: 10.1371/journal.pone.0121335] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/10/2015] [Indexed: 11/19/2022] Open
Abstract
Animals have to judge environmental cues and choose the most suitable option for them from many different options. Female fruit flies selecting an optimum site to deposit their eggs is a biologically important reproductive behavior. When given the direct choice between ovipositing their eggs in a sucrose-containing medium or a caffeine-containing medium, female flies prefer the latter. However, the neural circuits and molecules that regulate this decision-making processes during egg-laying site selection remain poorly understood. In the present study, we found that amnesiac (amn) mutant flies show significant defects in egg-laying decisions, and such defects can be reversed by expressing the wild-type amn transgene in two dorsal paired medial (DPM) neurons in the brain. Silencing neuronal activity with an inward rectifier potassium channel (Kir2.1) in DPM neurons also impairs egg-laying decisions. Finally, the activity in mushroom body αβ neurons is required for the egg-laying behavior, suggesting a possible “DPM-αβ neurons” brain circuit modulating egg-laying decisions. Our results highlight the brain circuits and molecular mechanisms of egg-laying decisions in Drosophila.
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Affiliation(s)
- Chia-Lin Wu
- Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Medical Research, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- * E-mail:
| | - Tsai-Feng Fu
- Department of Applied Chemistry, National Chi-Nan University, Nantou, Taiwan
| | - Yen-Yun Chou
- Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Sheng-Rong Yeh
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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Haynes PR, Christmann BL, Griffith LC. A single pair of neurons links sleep to memory consolidation in Drosophila melanogaster. eLife 2015; 4:e03868. [PMID: 25564731 PMCID: PMC4305081 DOI: 10.7554/elife.03868] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 01/07/2015] [Indexed: 12/17/2022] Open
Abstract
Sleep promotes memory consolidation in humans and many other species, but the physiological and anatomical relationships between sleep and memory remain unclear. Here, we show the dorsal paired medial (DPM) neurons, which are required for memory consolidation in Drosophila, are sleep-promoting inhibitory neurons. DPMs increase sleep via release of GABA onto wake-promoting mushroom body (MB) α'/β' neurons. Functional imaging demonstrates that DPM activation evokes robust increases in chloride in MB neurons, but is unable to cause detectable increases in calcium or cAMP. Downregulation of α'/β' GABAA and GABABR3 receptors results in sleep loss, suggesting these receptors are the sleep-relevant targets of DPM-mediated inhibition. Regulation of sleep by neurons necessary for consolidation suggests that these brain processes may be functionally interrelated via their shared anatomy. These findings have important implications for the mechanistic relationship between sleep and memory consolidation, arguing for a significant role of inhibitory neurotransmission in regulating these processes.
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Affiliation(s)
- Paula R Haynes
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
| | - Bethany L Christmann
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
| | - Leslie C Griffith
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University, Waltham, United States
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Abstract
It is now almost forty years since the first description of learning in the fruit fly Drosophila melanogaster. Various incarnations of the classic mutagenesis approach envisaged in the early days have provided around one hundred learning defective mutant fly strains. Recent technological advances permit temporal control of neural function in the behaving fly. These approaches have radically changed experiments in the field and have provided a neural circuit perspective of memory formation, consolidation and retrieval. Combining neural perturbations with more classical mutant intervention allows investigators to interrogate the molecular and cellular processes of memory within the defined neural circuits. Here, we summarize some of the progress made in the last ten years that indicates a remarkable conservation of the neural mechanisms of memory formation between flies and mammals. We emphasize that considering an ethologically-relevant viewpoint might provide additional experimental power in studies of Drosophila memory.
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Gerber B, Yarali A, Diegelmann S, Wotjak CT, Pauli P, Fendt M. Pain-relief learning in flies, rats, and man: basic research and applied perspectives. Learn Mem 2014; 21:232-52. [PMID: 24643725 PMCID: PMC3966540 DOI: 10.1101/lm.032995.113] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Memories relating to a painful, negative event are adaptive and can be stored for a lifetime to support preemptive avoidance, escape, or attack behavior. However, under unfavorable circumstances such memories can become overwhelmingly powerful. They may trigger excessively negative psychological states and uncontrollable avoidance of locations, objects, or social interactions. It is therefore obvious that any process to counteract such effects will be of value. In this context, we stress from a basic-research perspective that painful, negative events are "Janus-faced" in the sense that there are actually two aspects about them that are worth remembering: What made them happen and what made them cease. We review published findings from fruit flies, rats, and man showing that both aspects, respectively related to the onset and the offset of the negative event, induce distinct and oppositely valenced memories: Stimuli experienced before an electric shock acquire negative valence as they signal upcoming punishment, whereas stimuli experienced after an electric shock acquire positive valence because of their association with the relieving cessation of pain. We discuss how memories for such punishment- and relief-learning are organized, how this organization fits into the threat-imminence model of defensive behavior, and what perspectives these considerations offer for applied psychology in the context of trauma, panic, and nonsuicidal self-injury.
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Affiliation(s)
- Bertram Gerber
- Leibniz Institut für Neurobiologie (LIN), Abteilung Genetik von Lernen und Gedächtnis, 39118 Magdeburg, Germany
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Franklin S, Madl T, D'Mello S, Snaider J. LIDA: A Systems-level Architecture for Cognition, Emotion, and Learning. ACTA ACUST UNITED AC 2014. [DOI: 10.1109/tamd.2013.2277589] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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