1
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Pribbenow C, Owald D. Skewing information flow through pre- and postsynaptic plasticity in the mushroom bodies of Drosophila. Learn Mem 2024; 31:a053919. [PMID: 38876487 PMCID: PMC11199954 DOI: 10.1101/lm.053919.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/26/2024] [Indexed: 06/16/2024]
Abstract
Animal brains need to store information to construct a representation of their environment. Knowledge of what happened in the past allows both vertebrates and invertebrates to predict future outcomes by recalling previous experience. Although invertebrate and vertebrate brains share common principles at the molecular, cellular, and circuit-architectural levels, there are also obvious differences as exemplified by the use of acetylcholine versus glutamate as the considered main excitatory neurotransmitters in the respective central nervous systems. Nonetheless, across central nervous systems, synaptic plasticity is thought to be a main substrate for memory storage. Therefore, how brain circuits and synaptic contacts change following learning is of fundamental interest for understanding brain computations tied to behavior in any animal. Recent progress has been made in understanding such plastic changes following olfactory associative learning in the mushroom bodies (MBs) of Drosophila A current framework of memory-guided behavioral selection is based on the MB skew model, in which antagonistic synaptic pathways are selectively changed in strength. Here, we review insights into plasticity at dedicated Drosophila MB output pathways and update what is known about the plasticity of both pre- and postsynaptic compartments of Drosophila MB neurons.
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Affiliation(s)
- Carlotta Pribbenow
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - David Owald
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
- Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
- NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
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2
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Davidson AM, Hige T. Roles of feedback and feed-forward networks of dopamine subsystems: insights from Drosophila studies. Learn Mem 2024; 31:a053807. [PMID: 38862171 PMCID: PMC11199952 DOI: 10.1101/lm.053807.123] [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: 08/30/2023] [Accepted: 11/10/2023] [Indexed: 06/13/2024]
Abstract
Across animal species, dopamine-operated memory systems comprise anatomically segregated, functionally diverse subsystems. Although individual subsystems could operate independently to support distinct types of memory, the logical interplay between subsystems is expected to enable more complex memory processing by allowing existing memory to influence future learning. Recent comprehensive ultrastructural analysis of the Drosophila mushroom body revealed intricate networks interconnecting the dopamine subsystems-the mushroom body compartments. Here, we review the functions of some of these connections that are beginning to be understood. Memory consolidation is mediated by two different forms of network: A recurrent feedback loop within a compartment maintains sustained dopamine activity required for consolidation, whereas feed-forward connections across compartments allow short-term memory formation in one compartment to open the gate for long-term memory formation in another compartment. Extinction and reversal of aversive memory rely on a similar feed-forward circuit motif that signals omission of punishment as a reward, which triggers plasticity that counteracts the original aversive memory trace. Finally, indirect feed-forward connections from a long-term memory compartment to short-term memory compartments mediate higher-order conditioning. Collectively, these emerging studies indicate that feedback control and hierarchical connectivity allow the dopamine subsystems to work cooperatively to support diverse and complex forms of learning.
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Affiliation(s)
- Andrew M Davidson
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Toshihide Hige
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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3
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Wang CM, Wu CY, Lin CE, Hsu MC, Lin JC, Huang CC, Lien TY, Lin HK, Chang TW, Chiang HC. Forgotten memory storage and retrieval in Drosophila. Nat Commun 2023; 14:7153. [PMID: 37935667 PMCID: PMC10630420 DOI: 10.1038/s41467-023-42753-x] [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: 09/28/2022] [Accepted: 10/20/2023] [Indexed: 11/09/2023] Open
Abstract
Inaccessibility of stored memory in ensemble cells through the forgetting process causes animals to be unable to respond to natural recalling cues. While accumulating evidence has demonstrated that reactivating memory-stored cells can switch cells from an inaccessible state to an accessible form and lead to recall of previously learned information, the underlying cellular and molecular mechanisms remain elusive. The current study used Drosophila as a model to demonstrate that the memory of one-trial aversive olfactory conditioning, although inaccessible within a few hours after learning, is stored in KCαβ and retrievable after mild retraining. One-trial aversive conditioning triggers protein synthesis to form a long-lasting cellular memory trace, approximately 20 days, via creb in KCαβ, and a transient cellular memory trace, approximately one day, via orb in MBON-α3. PPL1-α3 negatively regulates forgotten one-trial conditioning memory retrieval. The current study demonstrated that KCαβ, PPL1-α3, and MBON-α3 collaboratively regulate the formation of forgotten one-cycle aversive conditioning memory formation and retrieval.
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Affiliation(s)
- Chih-Ming Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan, ROC
| | - Chun-Yuan Wu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Chen-En Lin
- Department of Medicine, National Cheng-Kung University, Tainan, Taiwan, ROC
| | - Ming-Chi Hsu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan, ROC
| | - Jing-Chun Lin
- Department of Medicine, National Cheng-Kung University, Tainan, Taiwan, ROC
| | - Chuan-Chin Huang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan, ROC
| | - Ting-Yu Lien
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan, ROC
| | - Hsin-Kai Lin
- Department of Medicine, National Cheng-Kung University, Tainan, Taiwan, ROC
| | - Ting-Wei Chang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
- Brain Research Center, National Tsing Hua University, Hsinchu, Taiwan, ROC
| | - Hsueh-Cheng Chiang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC.
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan, ROC.
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4
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Chen CC, Lin HW, Feng KL, Tseng DW, de Belle JS, Chiang AS. A subset of cholinergic mushroom body neurons blocks long-term memory formation in Drosophila. Cell Rep 2023; 42:112974. [PMID: 37590142 DOI: 10.1016/j.celrep.2023.112974] [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: 07/23/2022] [Revised: 12/22/2022] [Accepted: 07/29/2023] [Indexed: 08/19/2023] Open
Abstract
Long-term memory (LTM) requires learning-induced synthesis of new proteins allocated to specific neurons and synapses in a neural circuit. Not all learned information, however, becomes permanent memory. How the brain gates relevant information into LTM remains unclear. In Drosophila adults, weak learning after a single training session in an olfactory aversive task typically does not induce protein-synthesis-dependent LTM. Instead, strong learning after multiple spaced training sessions is required. Here, we report that pre-synaptic active-zone protein synthesis and cholinergic signaling from the early α/β subset of mushroom body (MB) neurons produce a downstream inhibitory effect on LTM formation. When we eliminated inhibitory signaling from these neurons, weak learning was then sufficient to form LTM. This bidirectional circuit mechanism modulates the transition between distinct memory phase functions in different subpopulations of MB neurons in the olfactory memory circuit.
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Affiliation(s)
- Chun-Chao Chen
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Hsuan-Wen Lin
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Kuan-Lin Feng
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Der-Wan Tseng
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - J Steven de Belle
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan; School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA; Department of Psychological Sciences, University of San Diego, San Diego, CA 92110, USA; School of Life Sciences, University of Nevada, Las Vegas, NV 89154, USA; MnemOdyssey LLC, Escondido, CA 92027, USA
| | - Ann-Shyn Chiang
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan; Institute of Systems Neuroscience and Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan; Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80780, Taiwan; Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli 35053, Taiwan; Graduate Institute of Clinical Medical Science, China Medical University, Taichung 40402, Taiwan; Kavli Institute for Brain and Mind, University of California at San Diego, La Jolla, CA 92093-0526, USA.
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5
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [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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6
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Turrel O, Ramesh N, Escher MJF, Pooryasin A, Sigrist SJ. Transient active zone remodeling in the Drosophila mushroom body supports memory. Curr Biol 2022; 32:4900-4913.e4. [PMID: 36327980 DOI: 10.1016/j.cub.2022.10.017] [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: 12/16/2021] [Revised: 08/15/2022] [Accepted: 10/06/2022] [Indexed: 11/22/2022]
Abstract
Elucidating how the distinct components of synaptic plasticity dynamically orchestrate the distinct stages of memory acquisition and maintenance within neuronal networks remains a major challenge. Specifically, plasticity processes tuning the functional and also structural state of presynaptic active zone (AZ) release sites are widely observed in vertebrates and invertebrates, but their behavioral relevance remains mostly unclear. We here provide evidence that a transient upregulation of presynaptic AZ release site proteins supports aversive olfactory mid-term memory in the Drosophila mushroom body (MB). Upon paired aversive olfactory conditioning, AZ protein levels (ELKS-family BRP/(m)unc13-family release factor Unc13A) increased for a few hours with MB-lobe-specific dynamics. Kenyon cell (KC, intrinsic MB neurons)-specific knockdown (KD) of BRP did not affect aversive olfactory short-term memory (STM) but strongly suppressed aversive mid-term memory (MTM). Different proteins crucial for the transport of AZ biosynthetic precursors (transport adaptor Aplip1/Jip-1; kinesin motor IMAC/Unc104; small GTPase Arl8) were also specifically required for the formation of aversive olfactory MTM. Consistent with the merely transitory increase of AZ proteins, BRP KD did not interfere with the formation of aversive olfactory long-term memory (LTM; i.e., 1 day). Our data suggest that the remodeling of presynaptic AZ refines the MB circuitry after paired aversive conditioning, over a time window of a few hours, to display aversive olfactory memories.
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Affiliation(s)
- Oriane Turrel
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Niraja Ramesh
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Marc J F Escher
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Atefeh Pooryasin
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Stephan J Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany.
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7
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Naganos S, Ueno K, Horiuchi J, Saitoe M. Dopamine activity in projection neurons regulates short-lasting olfactory approach memory in Drosophila. Eur J Neurosci 2022; 56:4558-4571. [PMID: 35815601 PMCID: PMC9540629 DOI: 10.1111/ejn.15766] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 11/27/2022]
Abstract
Survival in many animals requires the ability to associate certain cues with danger and others with safety. In a Drosophila melanogaster aversive olfactory conditioning paradigm, flies are exposed to two odours, one presented coincidentally with electrical shocks, and a second presented 45 s after shock cessation. When flies are later given a choice between these two odours, they avoid the shock‐paired odour and prefer the unpaired odour. While many studies have examined how flies learn to avoid the shock‐paired odour through formation of odour‐fear associations, here we demonstrate that conditioning also causes flies to actively approach the second odour. In contrast to fear memories, which are longer lasting and requires activity of D1‐like dopamine receptors only in the mushroom bodies, approach memory is short‐lasting and requires activity of D1‐like dopamine receptors in projection neurons originating from the antennal lobes, primary olfactory centers. Further, while recall of fear memories requires activity of the mushroom bodies, recall of approach memories does not. Our data suggest that olfactory approach memory is formed using different mechanisms in different brain locations compared to aversive and appetitive olfactory memories.
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Affiliation(s)
| | - Kohei Ueno
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | | | - Minoru Saitoe
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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8
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Stahl A, Noyes NC, Boto T, Botero V, Broyles CN, Jing M, Zeng J, King LB, Li Y, Davis RL, Tomchik SM. Associative learning drives longitudinally graded presynaptic plasticity of neurotransmitter release along axonal compartments. eLife 2022; 11:76712. [PMID: 35285796 PMCID: PMC8956283 DOI: 10.7554/elife.76712] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/11/2022] [Indexed: 12/27/2022] Open
Abstract
Anatomical and physiological compartmentalization of neurons is a mechanism to increase the computational capacity of a circuit, and a major question is what role axonal compartmentalization plays. Axonal compartmentalization may enable localized, presynaptic plasticity to alter neuronal output in a flexible, experience-dependent manner. Here, we show that olfactory learning generates compartmentalized, bidirectional plasticity of acetylcholine release that varies across the longitudinal compartments of Drosophila mushroom body (MB) axons. The directionality of the learning-induced plasticity depends on the valence of the learning event (aversive vs. appetitive), varies linearly across proximal to distal compartments following appetitive conditioning, and correlates with learning-induced changes in downstream mushroom body output neurons (MBONs) that modulate behavioral action selection. Potentiation of acetylcholine release was dependent on the CaV2.1 calcium channel subunit cacophony. In addition, contrast between the positive conditioned stimulus and other odors required the inositol triphosphate receptor, which maintained responsivity to odors upon repeated presentations, preventing adaptation. Downstream from the MB, a set of MBONs that receive their input from the γ3 MB compartment were required for normal appetitive learning, suggesting that they represent a key node through which reward learning influences decision-making. These data demonstrate that learning drives valence-correlated, compartmentalized, bidirectional potentiation, and depression of synaptic neurotransmitter release, which rely on distinct mechanisms and are distributed across axonal compartments in a learning circuit.
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Affiliation(s)
- Aaron Stahl
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Nathaniel C Noyes
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Tamara Boto
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Valentina Botero
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Connor N Broyles
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Miao Jing
- Chinese Institute for Brain Research, Beijing, China
| | - Jianzhi Zeng
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU IDG/McGovern Institute for Brain Research, Beijing, China
| | - Lanikea B King
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Yulong Li
- Chinese Institute for Brain Research, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.,PKU IDG/McGovern Institute for Brain Research, Beijing, China
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Seth M Tomchik
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
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9
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Shrestha P, Klann E. Spatiotemporally resolved protein synthesis as a molecular framework for memory consolidation. Trends Neurosci 2022; 45:297-311. [PMID: 35184897 PMCID: PMC8930706 DOI: 10.1016/j.tins.2022.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 01/25/2023]
Abstract
De novo protein synthesis is required for long-term memory consolidation. Dynamic regulation of protein synthesis occurs via a complex interplay of translation factors and modulators. Many components of the protein synthesis machinery have been targeted either pharmacologically or genetically to establish its requirement for memory. The combination of ligand/light-gating and genetic strategies, that is, chemogenetics and optogenetics, has begun to reveal the spatiotemporal resolution of protein synthesis in specific cell types during memory consolidation. This review summarizes current knowledge of the macroscopic and microscopic neural substrates for protein synthesis in memory consolidation. In addition, we highlight future directions for determining the localization and timing of de novo protein synthesis for memory consolidation with tools that permit unprecedented spatiotemporal precision.
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Affiliation(s)
- Prerana Shrestha
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY 10012, USA; NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
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10
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Pribbenow C, Chen YC, Heim MM, Laber D, Reubold S, Reynolds E, Balles I, Fernández-d V Alquicira T, Suárez-Grimalt R, Scheunemann L, Rauch C, Matkovic T, Rösner J, Lichtner G, Jagannathan SR, Owald D. Postsynaptic plasticity of cholinergic synapses underlies the induction and expression of appetitive and familiarity memories in Drosophila. eLife 2022; 11:80445. [PMID: 36250621 PMCID: PMC9733945 DOI: 10.7554/elife.80445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022] Open
Abstract
In vertebrates, several forms of memory-relevant synaptic plasticity involve postsynaptic rearrangements of glutamate receptors. In contrast, previous work indicates that Drosophila and other invertebrates store memories using presynaptic plasticity of cholinergic synapses. Here, we provide evidence for postsynaptic plasticity at cholinergic output synapses from the Drosophila mushroom bodies (MBs). We find that the nicotinic acetylcholine receptor (nAChR) subunit α5 is required within specific MB output neurons for appetitive memory induction but is dispensable for aversive memories. In addition, nAChR α2 subunits mediate memory expression and likely function downstream of α5 and the postsynaptic scaffold protein discs large (Dlg). We show that postsynaptic plasticity traces can be induced independently of the presynapse, and that in vivo dynamics of α2 nAChR subunits are changed both in the context of associative and non-associative (familiarity) memory formation, underlying different plasticity rules. Therefore, regardless of neurotransmitter identity, key principles of postsynaptic plasticity support memory storage across phyla.
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Affiliation(s)
- Carlotta Pribbenow
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Yi-chun Chen
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - M-Marcel Heim
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Desiree Laber
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Silas Reubold
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Eric Reynolds
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Isabella Balles
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Tania Fernández-d V Alquicira
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Raquel Suárez-Grimalt
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany,Einstein Center for Neurosciences BerlinBerlinGermany
| | - Lisa Scheunemann
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany,NeuroCure, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany,Institut für Biologie, Freie Universität BerlinBerlinGermany
| | - Carolin Rauch
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Tanja Matkovic
- Institut für Biologie, Freie Universität BerlinBerlinGermany
| | - Jörg Rösner
- NWFZ, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthGreifswaldGermany
| | - Gregor Lichtner
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany,Universitätsmedizin Greifswald, Department of Anesthesia, Critical Care, Emergency and Pain MedicineGreifswaldGermany
| | - Sridhar R Jagannathan
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - David Owald
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany,Einstein Center for Neurosciences BerlinBerlinGermany,NeuroCure, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
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11
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Feng KL, Weng JY, Chen CC, Abubaker MB, Lin HW, Charng CC, Lo CC, de Belle JS, Tully T, Lien CC, Chiang AS. Neuropeptide F inhibits dopamine neuron interference of long-term memory consolidation in Drosophila. iScience 2021; 24:103506. [PMID: 34934925 DOI: 10.1016/j.isci.2021.103506] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/13/2021] [Accepted: 11/22/2021] [Indexed: 11/28/2022] Open
Abstract
Long-term memory (LTM) formation requires consolidation processes to overcome interfering signals that erode memory formation. Olfactory memory in Drosophila involves convergent projection neuron (PN; odor) and dopaminergic neuron (DAN; reinforcement) input to the mushroom body (MB). How post-training DAN activity in the posterior lateral protocerebrum (PPL1) continues to regulate memory consolidation remains unknown. Here we address this question using targeted transgenes in behavior and electrophysiology experiments to show that (1) persistent post-training activity of PPL1-α2α'2 and PPL1-α3 DANs interferes with aversive LTM formation; (2) neuropeptide F (NPF) signaling blocks this interference in PPL1-α2α'2 and PPL1-α3 DANs after spaced training to enable LTM formation; and (3) training-induced NPF release and neurotransmission from two upstream dorsal-anterior-lateral (DAL2) neurons are required to form LTM. Thus, NPF signals from DAL2 neurons to specific PPL1 DANs disinhibit the memory circuit, ensuring that periodic events are remembered as consolidated LTM.
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Affiliation(s)
- Kuan-Lin Feng
- Institute of Biotechnology, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ju-Yun Weng
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chun-Chao Chen
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | | | - Hsuan-Wen Lin
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ching-Che Charng
- Institute of Systems Neuroscience and Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chung-Chuan Lo
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan.,Institute of Systems Neuroscience and Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - J Steven de Belle
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan.,Department of Psychological Sciences, University of San Diego, San Diego, CA 92110, USA.,School of Life Sciences, University of Nevada, Las Vegas, NV 89154, USA.,MnemOdyssey LLC, Escondido, CA 92027, USA
| | - Tim Tully
- Institute of Biotechnology, National Tsing Hua University, Hsinchu 30013, Taiwan.,Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Cheng-Chang Lien
- Institute of Neuroscience and Brain Research Center, National Yang Ming Chiao Tung University, Taipei 11221, Taiwan
| | - Ann-Shyn Chiang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu 30013, Taiwan.,Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan.,Institute of Systems Neuroscience and Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan.,Kaohsiung Medical University, Kaohsiung 80708, Taiwan.,National Health Research Institutes, Zhunan 35053, Taiwan.,China Medical University, Taichung 40402, Taiwan.,Kavli Institute for Brain and Mind, University of California at San Diego, La Jolla, CA 92093-0526, USA
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12
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Lesar A, Tahir J, Wolk J, Gershow M. Switch-like and persistent memory formation in individual Drosophila larvae. eLife 2021; 10:e70317. [PMID: 34636720 PMCID: PMC8510578 DOI: 10.7554/elife.70317] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/27/2021] [Indexed: 11/15/2022] Open
Abstract
Associative learning allows animals to use past experience to predict future events. The circuits underlying memory formation support immediate and sustained changes in function, often in response to a single example. Larval Drosophila is a genetic model for memory formation that can be accessed at molecular, synaptic, cellular, and circuit levels, often simultaneously, but existing behavioral assays for larval learning and memory do not address individual animals, and it has been difficult to form long-lasting memories, especially those requiring synaptic reorganization. We demonstrate a new assay for learning and memory capable of tracking the changing preferences of individual larvae. We use this assay to explore how activation of a pair of reward neurons changes the response to the innately aversive gas carbon dioxide (CO2). We confirm that when coupled to CO2 presentation in appropriate temporal sequence, optogenetic reward reduces avoidance of CO2. We find that learning is switch-like: all-or-none and quantized in two states. Memories can be extinguished by repeated unrewarded exposure to CO2 but are stabilized against extinction by repeated training or overnight consolidation. Finally, we demonstrate long-lasting protein synthesis dependent and independent memory formation.
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Affiliation(s)
- Amanda Lesar
- Department of Physics, New York UniversityNew YorkUnited States
| | - Javan Tahir
- Department of Physics, New York UniversityNew YorkUnited States
| | - Jason Wolk
- Department of Physics, New York UniversityNew YorkUnited States
| | - Marc Gershow
- Department of Physics, New York UniversityNew YorkUnited States
- Center for Neural Science, New York UniversityNew YorkUnited States
- NYU Neuroscience Institute, New York University Langone Medical CenterNew YorkUnited States
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13
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CREBA and CREBB in two identified neurons gate long-term memory formation in Drosophila. Proc Natl Acad Sci U S A 2021; 118:2100624118. [PMID: 34507985 PMCID: PMC8449312 DOI: 10.1073/pnas.2100624118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2021] [Indexed: 11/18/2022] Open
Abstract
Episodic events are frequently consolidated into labile memory but are not necessarily transferred to persistent long-term memory (LTM). Regulatory mechanisms leading to LTM formation are poorly understood, however, especially at the resolution of identified neurons. Here, we demonstrate enhanced LTM following aversive olfactory conditioning in Drosophila when the transcription factor cyclic AMP response element binding protein A (CREBA) is induced in just two dorsal-anterior-lateral (DAL) neurons. Our experiments show that this process is regulated by protein-gene interactions in DAL neurons: (1) crebA transcription is induced by training and repressed by crebB overexpression, (2) CREBA bidirectionally modulates LTM formation, (3) crebA overexpression enhances training-induced gene transcription, and (4) increasing membrane excitability enhances LTM formation and gene expression. These findings suggest that activity-dependent gene expression in DAL neurons during LTM formation is regulated by CREB proteins.
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14
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Swarnkar S, Avchalumov Y, Espadas I, Grinman E, Liu XA, Raveendra BL, Zucca A, Mediouni S, Sadhu A, Valente S, Page D, Miller K, Puthanveettil SV. Molecular motor protein KIF5C mediates structural plasticity and long-term memory by constraining local translation. Cell Rep 2021; 36:109369. [PMID: 34260917 PMCID: PMC8319835 DOI: 10.1016/j.celrep.2021.109369] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 02/16/2021] [Accepted: 06/18/2021] [Indexed: 12/20/2022] Open
Abstract
Synaptic structural plasticity, key to long-term memory storage, requires translation of localized RNAs delivered by long-distance transport from the neuronal cell body. Mechanisms and regulation of this system remain elusive. Here, we explore the roles of KIF5C and KIF3A, two members of kinesin superfamily of molecular motors (Kifs), and find that loss of function of either kinesin decreases dendritic arborization and spine density whereas gain of function of KIF5C enhances it. KIF5C function is a rate-determining component of local translation and is associated with ∼650 RNAs, including EIF3G, a regulator of translation initiation, and plasticity-associated RNAs. Loss of function of KIF5C in dorsal hippocampal CA1 neurons constrains both spatial and contextual fear memory, whereas gain of function specifically enhances spatial memory and extinction of contextual fear. KIF5C-mediated long-distance transport of local translation substrates proves a key mechanism underlying structural plasticity and memory.
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Affiliation(s)
- Supriya Swarnkar
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Yosef Avchalumov
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Isabel Espadas
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Eddie Grinman
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Xin-An Liu
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Bindu L Raveendra
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Aya Zucca
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Sonia Mediouni
- Department of Immunology and Microbiology, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Abhishek Sadhu
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Susana Valente
- Department of Immunology and Microbiology, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Damon Page
- Department of Neuroscience, Scripps Florida, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Kyle Miller
- Department of Integrative Biology, Michigan State University, East Lansing, MI, USA
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15
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Dai SM, Huang CY, Chang C. Introduction of a cold sensitivity-conferring mutation into the RTA-Bddsx hybrid system of Bactrocera dorsalis for establishment of a thermally controllable homozygous line. PEST MANAGEMENT SCIENCE 2021; 77:3547-3553. [PMID: 33840145 DOI: 10.1002/ps.6408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 04/08/2021] [Accepted: 04/10/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND For efficient control of the economically important fruit pest Bactrocera dorsalis, a hybrid system combining ricin toxicity and sex-related alternative splicing of the doublesex gene has been developed. This system exhibits the expected female-specific lethal effect; however, the transgenic females do not survive, making it difficult to raise stable homozygous lines. Since modification of ricin toxin A chain (RTA) through a single-residue change (Gly212 > Arg212 ) leads to cold-sensitive posttranslational repression of its toxicity, we utilized this unique property to obtain RTA-Bddsx females that survive at low temperature for line maintenance. RESULTS In transient expression experiments using embryonic injection, two groups treated with RTAcs-derived DNA (LERQcs and RTAcs) exhibited temperature-dependent effects. The toxicity was higher at 29 °C than at 18 °C. The proportion of males was close to 50% at 18 °C in all the tested groups except LERQcs-treated flies, which exhibited a high proportion of males (over 70%) at 29 °C. The results indicate the cold-sensitive responses of RTA and further suggest a female-specific lethal effect. Subsequently, 14 putative RTAcs-Bddsx transgenic Ds-Red+ G1 males were identified, and female-specific lethal effects were observed in Ds-Red+ G2 and G3 lines under cultivation at 29 °C but not at 18 °C. The male ratio can be increased to up to 95% in G3 line 001, indicating that RTAcs functions well in B. dorsalis. CONCLUSION The improved RTAcs-Bddsx system with conditional toxicity represents a novel and promising step toward the practical control of B. dorsalis. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Shu-Mei Dai
- Department of Entomology, National Chung-Hsing University, Taichung, Taiwan
| | - Chun-Yen Huang
- Biotechnology Center, National Chung-Hsing University, Taichung, Taiwan
- Department of Medical Research, E-Da Hospital, Kaohsiung, Taiwan
| | - Cheng Chang
- Biotechnology Center, National Chung-Hsing University, Taichung, Taiwan
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16
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Roselli C, Ramaswami M, Boto T, Cervantes-Sandoval I. The Making of Long-Lasting Memories: A Fruit Fly Perspective. Front Behav Neurosci 2021; 15:662129. [PMID: 33859556 PMCID: PMC8042140 DOI: 10.3389/fnbeh.2021.662129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/08/2021] [Indexed: 11/25/2022] Open
Abstract
Understanding the nature of the molecular mechanisms underlying memory formation, consolidation, and forgetting are some of the fascinating questions in modern neuroscience. The encoding, stabilization and elimination of memories, rely on the structural reorganization of synapses. These changes will enable the facilitation or depression of neural activity in response to the acquisition of new information. In other words, these changes affect the weight of specific nodes within a neural network. We know that these plastic reorganizations require de novo protein synthesis in the context of Long-term memory (LTM). This process depends on neural activity triggered by the learned experience. The use of model organisms like Drosophila melanogaster has been proven essential for advancing our knowledge in the field of neuroscience. Flies offer an optimal combination of a more straightforward nervous system, composed of a limited number of cells, and while still displaying complex behaviors. Studies in Drosophila neuroscience, which expanded over several decades, have been critical for understanding the cellular and molecular mechanisms leading to the synaptic and behavioral plasticity occurring in the context of learning and memory. This is possible thanks to sophisticated technical approaches that enable precise control of gene expression in the fruit fly as well as neural manipulation, like chemogenetics, thermogenetics, or optogenetics. The search for the identity of genes expressed as a result of memory acquisition has been an active interest since the origins of behavioral genetics. From screenings of more or less specific candidates to broader studies based on transcriptome analysis, our understanding of the genetic control behind LTM has expanded exponentially in the past years. Here we review recent literature regarding how the formation of memories induces a rapid, extensive and, in many cases, transient wave of transcriptional activity. After a consolidation period, transcriptome changes seem more stable and likely represent the synthesis of new proteins. The complexity of the circuitry involved in memory formation and consolidation is such that there are localized changes in neural activity, both regarding temporal dynamics and the nature of neurons and subcellular locations affected, hence inducing specific temporal and localized changes in protein expression. Different types of neurons are recruited at different times into memory traces. In LTM, the synthesis of new proteins is required in specific subsets of cells. This de novo translation can take place in the somatic cytoplasm and/or locally in distinct zones of compartmentalized synaptic activity, depending on the nature of the proteins and the plasticity-inducing processes that occur. We will also review recent advances in understanding how localized changes are confined to the relevant synapse. These recent studies have led to exciting discoveries regarding proteins that were not previously involved in learning and memory processes. This invaluable information will lead to future functional studies on the roles that hundreds of new molecular actors play in modulating neural activity.
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Affiliation(s)
- 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
| | - Mani Ramaswami
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland.,National Centre for Biological Sciences, TIFR, Bengaluru, India
| | - Tamara Boto
- Trinity College Institute of Neuroscience, Department of Physiology, School of Medicine, 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
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17
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Scaplen KM, Talay M, Fisher JD, Cohn R, Sorkaç A, Aso Y, Barnea G, Kaun KR. Transsynaptic mapping of Drosophila mushroom body output neurons. eLife 2021; 10:e63379. [PMID: 33570489 PMCID: PMC7877909 DOI: 10.7554/elife.63379] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/26/2021] [Indexed: 11/13/2022] Open
Abstract
The mushroom body (MB) is a well-characterized associative memory structure within the Drosophila brain. Analyzing MB connectivity using multiple approaches is critical for understanding the functional implications of this structure. Using the genetic anterograde transsynaptic tracing tool, trans-Tango, we identified divergent projections across the brain and convergent downstream targets of the MB output neurons (MBONs). Our analysis revealed at least three separate targets that receive convergent input from MBONs: other MBONs, the fan-shaped body (FSB), and the lateral accessory lobe (LAL). We describe, both anatomically and functionally, a multilayer circuit in which inhibitory and excitatory MBONs converge on the same genetic subset of FSB and LAL neurons. This circuit architecture enables the brain to update and integrate information with previous experience before executing appropriate behavioral responses. Our use of trans-Tango provides a genetically accessible anatomical framework for investigating the functional relevance of components within these complex and interconnected circuits.
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Affiliation(s)
- Kristin M Scaplen
- Department of Neuroscience, Brown UniversityProvidenceUnited States
- Department of Psychology, Bryant UniversitySmithfieldUnited States
- Center for Health and Behavioral Sciences, Bryant UniversitySmithfieldUnited States
| | - Mustafa Talay
- Department of Neuroscience, Brown UniversityProvidenceUnited States
| | - John D Fisher
- Department of Neuroscience, Brown UniversityProvidenceUnited States
| | - Raphael Cohn
- Laboratory of Neurophysiology and Behavior, The Rockefeller UniversityNew YorkUnited States
| | - Altar Sorkaç
- Department of Neuroscience, Brown UniversityProvidenceUnited States
| | - Yoshi Aso
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gilad Barnea
- Department of Neuroscience, Brown UniversityProvidenceUnited States
| | - Karla R Kaun
- Department of Neuroscience, Brown UniversityProvidenceUnited States
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18
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Rpd3/CoRest-mediated activity-dependent transcription regulates the flexibility in memory updating in Drosophila. Nat Commun 2021; 12:628. [PMID: 33504795 PMCID: PMC7840730 DOI: 10.1038/s41467-021-20898-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 12/23/2020] [Indexed: 01/30/2023] Open
Abstract
Consolidated memory can be preserved or updated depending on the environmental change. Although such conflicting regulation may happen during memory updating, the flexibility of memory updating may have already been determined in the initial memory consolidation process. Here, we explored the gating mechanism for activity-dependent transcription in memory consolidation, which is unexpectedly linked to the later memory updating in Drosophila. Through proteomic analysis, we discovered that the compositional change in the transcriptional repressor, which contains the histone deacetylase Rpd3 and CoRest, acts as the gating mechanism that opens and closes the time window for activity-dependent transcription. Opening the gate through the compositional change in Rpd3/CoRest is required for memory consolidation, but closing the gate through Rpd3/CoRest is significant to limit future memory updating. Our data indicate that the flexibility of memory updating is determined through the initial activity-dependent transcription, providing a mechanism involved in defining memory state.
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19
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Schleyer M, Weiglein A, Thoener J, Strauch M, Hartenstein V, Kantar Weigelt M, Schuller S, Saumweber T, Eichler K, Rohwedder A, Merhof D, Zlatic M, Thum AS, Gerber B. Identification of Dopaminergic Neurons That Can Both Establish Associative Memory and Acutely Terminate Its Behavioral Expression. J Neurosci 2020; 40:5990-6006. [PMID: 32586949 PMCID: PMC7392503 DOI: 10.1523/jneurosci.0290-20.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/14/2020] [Accepted: 05/19/2020] [Indexed: 02/01/2023] Open
Abstract
An adaptive transition from exploring the environment in search of vital resources to exploiting these resources once the search was successful is important to all animals. Here we study the neuronal circuitry that allows larval Drosophila melanogaster of either sex to negotiate this exploration-exploitation transition. We do so by combining Pavlovian conditioning with high-resolution behavioral tracking, optogenetic manipulation of individually identified neurons, and EM data-based analyses of synaptic organization. We find that optogenetic activation of the dopaminergic neuron DAN-i1 can both establish memory during training and acutely terminate learned search behavior in a subsequent recall test. Its activation leaves innate behavior unaffected, however. Specifically, DAN-i1 activation can establish associative memories of opposite valence after paired and unpaired training with odor, and its activation during the recall test can terminate the search behavior resulting from either of these memories. Our results further suggest that in its behavioral significance DAN-i1 activation resembles, but does not equal, sugar reward. Dendrogram analyses of all the synaptic connections between DAN-i1 and its two main targets, the Kenyon cells and the mushroom body output neuron MBON-i1, further suggest that the DAN-i1 signals during training and during the recall test could be delivered to the Kenyon cells and to MBON-i1, respectively, within previously unrecognized, locally confined branching structures. This would provide an elegant circuit motif to terminate search on its successful completion.SIGNIFICANCE STATEMENT In the struggle for survival, animals have to explore their environment in search of food. Once food is found, however, it is adaptive to prioritize exploiting it over continuing a search that would now be as pointless as searching for the glasses you are wearing. This exploration-exploitation trade-off is important for animals and humans, as well as for technical search devices. We investigate which of the only 10,000 neurons of a fruit fly larva can tip the balance in this trade-off, and identify a single dopamine neuron called DAN-i1 that can do so. Given the similarities in dopamine neuron function across the animal kingdom, this may reflect a general principle of how search is terminated once it is successful.
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Affiliation(s)
- Michael Schleyer
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Aliće Weiglein
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Juliane Thoener
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Martin Strauch
- Institute of Imaging & Computer Vision, RWTH Aachen University, 52056 Aachen, Germany
| | - Volker Hartenstein
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California 90095-1606
| | - Melisa Kantar Weigelt
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Sarah Schuller
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Timo Saumweber
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
| | - Katharina Eichler
- University of Konstanz, Institute for Biology, 78464 Konstanz, Germany
- HHMI Janelia Research Campus, Ashburn, Virginia 20147
- Institute of Neurobiology, University of Puerto Rico Medical Science Campus, Old San Juan, Puerto Rico 00901
| | - Astrid Rohwedder
- University of Konstanz, Institute for Biology, 78464 Konstanz, Germany
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, United Kingdom
| | - Dorit Merhof
- Institute of Imaging & Computer Vision, RWTH Aachen University, 52056 Aachen, Germany
| | - Marta Zlatic
- HHMI Janelia Research Campus, Ashburn, Virginia 20147
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, United Kingdom
| | - Andreas S Thum
- University of Konstanz, Institute for Biology, 78464 Konstanz, Germany
- University Leipzig, Institute for Biology, 04103 Leipzig, Germany
| | - Bertram Gerber
- Leibniz Institute for Neurobiology, Department Genetics of Learning and Memory, 39118 Magdeburg, Germany
- Centre for Behavioural Brain Sciences, 39108 Magdeburg, Germany
- Institute for Biology, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany
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20
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Jacob PF, Waddell S. Spaced Training Forms Complementary Long-Term Memories of Opposite Valence in Drosophila. Neuron 2020; 106:977-991.e4. [PMID: 32289250 PMCID: PMC7302427 DOI: 10.1016/j.neuron.2020.03.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/25/2020] [Accepted: 03/16/2020] [Indexed: 12/30/2022]
Abstract
Forming long-term memory (LTM) often requires repetitive experience spread over time. Studies in Drosophila suggest aversive olfactory LTM is optimal after spaced training, multiple trials of differential odor conditioning with rest intervals. Memory after spaced training is frequently compared to that after the same number of trials without intervals. Here we show that, after spaced training, flies acquire additional information and form an aversive memory for the shock-paired odor and a slowly emerging and more persistent "safety-memory" for the explicitly unpaired odor. Safety-memory acquisition requires repetition, order, and spacing of the training trials and relies on triggering specific rewarding dopaminergic neurons. Co-existence of aversive and safety memories is evident as depression of odor-specific responses at different combinations of junctions in the mushroom body output network; combining two outputs appears to signal relative safety. Having complementary aversive and safety memories augments LTM performance after spaced training by making the odor preference more certain.
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Affiliation(s)
- Pedro F Jacob
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford OX1 3TA, UK.
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21
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Multiple network properties overcome random connectivity to enable stereotypic sensory responses. Nat Commun 2020; 11:1023. [PMID: 32094345 PMCID: PMC7039968 DOI: 10.1038/s41467-020-14836-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 02/03/2020] [Indexed: 02/08/2023] Open
Abstract
Connections between neuronal populations may be genetically hardwired or random. In the insect olfactory system, projection neurons of the antennal lobe connect randomly to Kenyon cells of the mushroom body. Consequently, while the odor responses of the projection neurons are stereotyped across individuals, the responses of the Kenyon cells are variable. Surprisingly, downstream of Kenyon cells, mushroom body output neurons show stereotypy in their responses. We found that the stereotypy is enabled by the convergence of inputs from many Kenyon cells onto an output neuron, and does not require learning. The stereotypy emerges in the total response of the Kenyon cell population using multiple odor-specific features of the projection neuron responses, benefits from the nonlinearity in the transfer function, depends on the convergence:randomness ratio, and is constrained by sparseness. Together, our results reveal the fundamental mechanisms and constraints with which convergence enables stereotypy in sensory responses despite random connectivity.
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22
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Olesnicky EC, Killian DJ. The cytoplasmic polyadenylation element binding protein (CPEB), Orb, is important for dendrite development and neuron fate specification in Drosophila melanogaster. Gene 2020; 738:144473. [PMID: 32057929 DOI: 10.1016/j.gene.2020.144473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 12/14/2022]
Abstract
Cytoplasmic polyadenylation element binding proteins (CPEBs) are widely conserved proteins that regulate the length of poly(A) tails in the cytoplasm, regulate translation, and regulate mRNA transport. While CPEBs are best known for regulating maternal messages in oocytes, CPEBs also have roles in many other cell types including neurons. Here we extend our knowledge of the roles of CPEBs in neurons by showing that the Drosophila CPEB-encoding gene, orb, is required for proper dendrite development in larval sensory dendritic arborization neurons. Furthermore, we provide evidence that orb is important for neuron cell fate specification.
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Affiliation(s)
- Eugenia C Olesnicky
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, 80918, United States.
| | - Darrell J Killian
- Department of Molecular Biology, Colorado College, Colorado Springs, CO 80903, United States
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23
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Aso Y, Ray RP, Long X, Bushey D, Cichewicz K, Ngo TT, Sharp B, Christoforou C, Hu A, Lemire AL, Tillberg P, Hirsh J, Litwin-Kumar A, Rubin GM. Nitric oxide acts as a cotransmitter in a subset of dopaminergic neurons to diversify memory dynamics. eLife 2019; 8:49257. [PMID: 31724947 PMCID: PMC6948953 DOI: 10.7554/elife.49257] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 11/13/2019] [Indexed: 12/31/2022] Open
Abstract
Animals employ diverse learning rules and synaptic plasticity dynamics to record temporal and statistical information about the world. However, the molecular mechanisms underlying this diversity are poorly understood. The anatomically defined compartments of the insect mushroom body function as parallel units of associative learning, with different learning rates, memory decay dynamics and flexibility (Aso and Rubin, 2016). Here, we show that nitric oxide (NO) acts as a neurotransmitter in a subset of dopaminergic neurons in Drosophila. NO's effects develop more slowly than those of dopamine and depend on soluble guanylate cyclase in postsynaptic Kenyon cells. NO acts antagonistically to dopamine; it shortens memory retention and facilitates the rapid updating of memories. The interplay of NO and dopamine enables memories stored in local domains along Kenyon cell axons to be specialized for predicting the value of odors based only on recent events. Our results provide key mechanistic insights into how diverse memory dynamics are established in parallel memory systems.
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Affiliation(s)
- Yoshinori Aso
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Robert P Ray
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Xi Long
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Daniel Bushey
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Karol Cichewicz
- Department of Biology, University of Virginia, Charlottesville, United States
| | - Teri-Tb Ngo
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Brandi Sharp
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | | | - Amy Hu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Andrew L Lemire
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Paul Tillberg
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Jay Hirsh
- Department of Biology, University of Virginia, Charlottesville, United States
| | - Ashok Litwin-Kumar
- Department of Neuroscience, Columbia University, New York, United States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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von Hadeln J, Hensgen R, Bockhorst T, Rosner R, Heidasch R, Pegel U, Quintero Pérez M, Homberg U. Neuroarchitecture of the central complex of the desert locust: Tangential neurons. J Comp Neurol 2019; 528:906-934. [PMID: 31625611 DOI: 10.1002/cne.24796] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 12/11/2022]
Abstract
The central complex (CX) comprises a group of midline neuropils in the insect brain, consisting of the protocerebral bridge (PB), the upper (CBU) and lower division (CBL) of the central body and a pair of globular noduli. It receives prominent input from the visual system and plays a major role in spatial orientation of the animals. Vertical slices and horizontal layers of the CX are formed by columnar, tangential, and pontine neurons. While pontine and columnar neurons have been analyzed in detail, especially in the fruit fly and desert locust, understanding of the organization of tangential cells is still rudimentary. As a basis for future functional studies, we have studied the morphologies of tangential neurons of the CX of the desert locust Schistocerca gregaria. Intracellular dye injections revealed 43 different types of tangential neuron, 8 of the PB, 5 of the CBL, 24 of the CBU, 2 of the noduli, and 4 innervating multiple substructures. Cell bodies of these neurons were located in 11 different clusters in the cell body rind. Judging from the presence of fine versus beaded terminals, the vast majority of these neurons provide input into the CX, especially from the lateral complex (LX), the superior protocerebrum, the posterior slope, and other surrounding brain areas, but not directly from the mushroom bodies. Connections are largely subunit- and partly layer-specific. No direct connections were found between the CBU and the CBL. Instead, both subdivisions are connected in parallel with the PB and distinct layers of the noduli.
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Affiliation(s)
- Joss von Hadeln
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Ronja Hensgen
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Tobias Bockhorst
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Ronny Rosner
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Ronny Heidasch
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Uta Pegel
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Manuel Quintero Pérez
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Uwe Homberg
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
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25
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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: 3.6] [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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26
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Horiuchi J. Recurrent loops: Incorporating prediction error and semantic/episodic theories into Drosophila associative memory models. GENES BRAIN AND BEHAVIOR 2019; 18:e12567. [PMID: 30891930 PMCID: PMC6900151 DOI: 10.1111/gbb.12567] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/27/2019] [Accepted: 03/16/2019] [Indexed: 12/01/2022]
Abstract
In 2003, Martin Heisenberg et al. presented a model of how associative memories could be encoded and stored in the insect brain. This model was extremely influential in the Drosophila memory field, but did not incorporate several important mammalian concepts, including ideas of separate episodic and semantic types of memory and prediction error hypotheses. In addition, at that time, the concept of memory traces recurrently entering and exiting the mushroom bodies, brain areas where associative memories are formed and stored, was unknown. In this review, I present a simple updated model incorporating these ideas, which may be useful for future studies.
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Affiliation(s)
- Junjiro Horiuchi
- Department of higher brain functions and dementias, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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27
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Widmer YF, Fritsch C, Jungo MM, Almeida S, Egger B, Sprecher SG. Multiple neurons encode CrebB dependent appetitive long-term memory in the mushroom body circuit. eLife 2018; 7:39196. [PMID: 30346271 PMCID: PMC6234028 DOI: 10.7554/elife.39196] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/19/2018] [Indexed: 11/28/2022] Open
Abstract
Lasting changes in gene expression are critical for the formation of long-term memories (LTMs), depending on the conserved CrebB transcriptional activator. While requirement of distinct neurons in defined circuits for different learning and memory phases have been studied in detail, only little is known regarding the gene regulatory changes that occur within these neurons. We here use the fruit fly as powerful model system to study the neural circuits of CrebB-dependent appetitive olfactory LTM. We edited the CrebB locus to create a GFP-tagged CrebB conditional knockout allele, allowing us to generate mutant, post-mitotic neurons with high spatial and temporal precision. Investigating CrebB-dependence within the mushroom body (MB) circuit we show that MB α/β and α’/β’ neurons as well as MBON α3, but not in dopaminergic neurons require CrebB for LTM. Thus, transcriptional memory traces occur in different neurons within the same neural circuit. Our brains can store different types of memories. You may have forgotten what you had for lunch yesterday, but still be able to remember a song from your childhood. Short-term memories and long-term memories form via different mechanisms. To establish long-term memories, the brain must produce new proteins, many of which are common to all members of the animal kingdom. By studying these proteins in organisms such as fruit flies, we can learn more about their role in our own memories. Widmer et al. used this approach to explore how a protein called CrebB helps fruit flies to remember for several days that a specific odor is associated with a sugary reward. These odor-reward memories form in a brain region called the mushroom body, which has three lobes. Input neurons supply information about the odor and the reward to the region, while output neurons pass on information to other parts of the fly brain. CrebB regulates the production of new proteins required to form these long-term odor-reward memories: but where exactly does CrebB act during this process? Using a gene editing technique called CRISPR, Widmer et al. generated mutant flies. In these insects CrebB could be easily deactivated ‘at will’ in either the entire brain, the whole mushroom body, each of the three lobes or in specific output neurons. The flies were then trained on the odor-reward task, and their memory tested 24 hours later. The results revealed that for the memories to form, CrebB is only required in two of the three lobes of the mushroom body, and in certain output neurons. Future studies can now focus on the cells shown to need CrebB to create long-term memories, and identify the other proteins involved in this process. In humans, defects in CrebB are associated with intellectual disability, addiction and depression. The mutant fly created by Widmer et al. could be a useful model in which to investigate how the protein may play a role in these conditions.
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Affiliation(s)
- Yves F Widmer
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Cornelia Fritsch
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Magali M Jungo
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Silvia Almeida
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Boris Egger
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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28
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Olesnicky EC, Antonacci S, Popitsch N, Lybecker MC, Titus MB, Valadez R, Derkach PG, Marean A, Miller K, Mathai SK, Killian DJ. Shep interacts with posttranscriptional regulators to control dendrite morphogenesis in sensory neurons. Dev Biol 2018; 444:116-128. [PMID: 30352216 DOI: 10.1016/j.ydbio.2018.09.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/20/2018] [Accepted: 09/09/2018] [Indexed: 10/28/2022]
Abstract
RNA binding proteins (RBPs) mediate posttranscriptional gene regulatory events throughout development. During neurogenesis, many RBPs are required for proper dendrite morphogenesis within Drosophila sensory neurons. Despite their fundamental role in neuronal morphogenesis, little is known about the molecular mechanisms in which most RBPs participate during neurogenesis. In Drosophila, alan shepard (shep) encodes a highly conserved RBP that regulates dendrite morphogenesis in sensory neurons. Moreover, the C. elegans ortholog sup-26 has also been implicated in sensory neuron dendrite morphogenesis. Nonetheless, the molecular mechanism by which Shep/SUP-26 regulate dendrite development is not understood. Here we show that Shep interacts with the RBPs Trailer Hitch (Tral), Ypsilon schachtel (Yps), Belle (Bel), and Poly(A)-Binding Protein (PABP), to direct dendrite morphogenesis in Drosophila sensory neurons. Moreover, we identify a conserved set of Shep/SUP-26 target RNAs that include regulators of cell signaling, posttranscriptional gene regulators, and known regulators of dendrite development.
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Affiliation(s)
- Eugenia C Olesnicky
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, United States.
| | - Simona Antonacci
- Department of Molecular Biology, Colorado College, Colorado Springs, CO 80903, United States
| | - Niko Popitsch
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, A-1090 Vienna, Austria
| | - Meghan C Lybecker
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, United States
| | - M Brandon Titus
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, United States
| | - Racquel Valadez
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, United States
| | - Paul G Derkach
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO 80918, United States
| | - Amber Marean
- Department of Molecular Biology, Colorado College, Colorado Springs, CO 80903, United States
| | - Katherine Miller
- Department of Molecular Biology, Colorado College, Colorado Springs, CO 80903, United States
| | - Samuel K Mathai
- Department of Molecular Biology, Colorado College, Colorado Springs, CO 80903, United States
| | - Darrell J Killian
- Department of Molecular Biology, Colorado College, Colorado Springs, CO 80903, United States
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29
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Cognigni P, Felsenberg J, Waddell S. Do the right thing: neural network mechanisms of memory formation, expression and update in Drosophila. Curr Opin Neurobiol 2018; 49:51-58. [PMID: 29258011 PMCID: PMC5981003 DOI: 10.1016/j.conb.2017.12.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/02/2022]
Abstract
When animals learn, plasticity in brain networks that respond to specific cues results in a change in the behavior that these cues elicit. Individual network components in the mushroom bodies of the fruit fly Drosophila melanogaster represent cues, learning signals and behavioral outcomes of learned experience. Recent findings have highlighted the importance of dopamine-driven plasticity and activity in feedback and feedforward connections, between various elements of the mushroom body neural network. These computational motifs have been shown to be crucial for long term olfactory memory consolidation, integration of internal states, re-evaluation and updating of learned information. The often recurrent circuit anatomy and a prolonged requirement for activity in parts of these underlying networks, suggest that self-sustained and precisely timed activity is a fundamental feature of network computations in the insect brain. Together these processes allow flies to continuously adjust the content of their learned knowledge and direct their behavior in a way that best represents learned expectations and serves their most pressing current needs.
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Affiliation(s)
- Paola Cognigni
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom
| | - Johannes Felsenberg
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom
| | - Scott Waddell
- Centre for Neural Circuit and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, United Kingdom.
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