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Voglewede MM, Ozsen EN, Ivak N, Bernabucci M, Tang R, Sun M, Pang ZP, Zhang H. Loss of the polarity protein Par3 promotes dendritic spine neoteny and enhances learning and memory. iScience 2024; 27:110308. [PMID: 39045101 PMCID: PMC11263792 DOI: 10.1016/j.isci.2024.110308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 03/25/2024] [Accepted: 06/17/2024] [Indexed: 07/25/2024] Open
Abstract
The Par3 polarity protein is critical for subcellular compartmentalization in different developmental processes. Variants of PARD3, encoding PAR3, are associated with intelligence and neurodevelopmental disorders. However, the role of Par3 in glutamatergic synapse formation and cognitive functions in vivo remains unknown. Here, we show that forebrain-specific Par3 conditional knockout leads to increased long, thin dendritic spines in vivo. In addition, we observed a decrease in the amplitude of miniature excitatory postsynaptic currents. Surprisingly, loss of Par3 enhances hippocampal-dependent spatial learning and memory and repetitive behavior. Phosphoproteomic analysis revealed proteins regulating cytoskeletal dynamics are significantly dysregulated downstream of Par3. Mechanistically, we found Par3 deletion causes increased Rac1 activation and dysregulated microtubule dynamics through CAMSAP2. Together, our data reveal an unexpected role for Par3 as a molecular gatekeeper in regulating the pool of immature dendritic spines, a rate-limiting step of learning and memory, through modulating Rac1 activation and microtubule dynamics in vivo.
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Affiliation(s)
- Mikayla M. Voglewede
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Elif Naz Ozsen
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Noah Ivak
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Matteo Bernabucci
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- The Child Health Institute of New Jersey, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Ruizhe Tang
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Miao Sun
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Zhiping P. Pang
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- The Child Health Institute of New Jersey, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Huaye Zhang
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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2
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Abstract
The brain is designed not only with molecules and cellular processes that help to form memories but also with molecules and cellular processes that suppress the formation and retention of memory. The latter processes are critical for an efficient memory management system, given the vast amount of information that each person experiences in their daily activities and that most of this information becomes irrelevant with time. Thus, efficiency dictates that the brain should have processes for selecting the most critical information for storage and suppressing the irrelevant or forgetting it later should it escape the initial filters. Such memory suppressor molecules and processes are revealed by genetic or pharmacologic insults that lead to enhanced memory expression. We review here the predominant memory suppressor molecules and processes that have recently been discovered. They are diverse, as expected, because the brain is complex and employs many different strategies and mechanisms to form memories. They include the gene-repressive actions of small noncoding RNAs, repressors of protein synthesis, cAMP-mediated gene expression pathways, inter- and intracellular signaling pathways for normal forgetting, and others. A deep understanding of memory suppressor molecules and processes is necessary to fully comprehend how the brain forms, stabilizes, and retrieves memories and to reveal how brain disorders disrupt memory.
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Affiliation(s)
- Nathaniel C. Noyes
- Department of Neuroscience, University of Florida Scripps Biomedical Research, Jupiter, FL, USA
| | - Ronald L. Davis
- Department of Neuroscience, University of Florida Scripps Biomedical Research, Jupiter, FL, USA
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3
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Bullard MR, Cervantes JCM, Quaicoe NB, Jin A, Adams DA, Lin JM, Iliadis E, Seidler TM, Cervantes-Sandoval I, He HY. Accelerated protein retention expansion microscopy using microwave radiation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.11.593228. [PMID: 38766072 PMCID: PMC11100821 DOI: 10.1101/2024.05.11.593228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Protein retention expansion microscopy (ExM) retains genetically encoded fluorescent proteins or antibody-conjugated fluorescent probes in fixed tissue and isotropically expands the tissue through a swellable polymer network to allow nanoscale (<70 nm) resolution on diffraction-limited confocal microscopes. Despite numerous advantages ExM brings to biological studies, the full protocol is time-consuming and can take multiple days to complete. Here, we adapted the ExM protocol to the vibratome-sectioned brain tissue of Xenopus laevis tadpoles and implemented a microwave-assisted protocol to reduce the workflow from days to hours. In addition to the significantly accelerated processing time, our microwave-assisted ExM (M/WExM) protocol maintains the superior resolution and signal-to-noise ratio of the original ExM protocol. Furthermore, the M/WExM protocol yields higher magnitude of expansion, suggesting that in addition to accelerating the process through increased diffusion rate of reagents, microwave radiation may also facilitate the expansion process. To demonstrate the applicability of this method to other specimens and protocols, we adapted the microwave-accelerated protocol to whole mount adult brain tissue of Drosophila melanogaster fruit flies, and successfully reduced the total processing time of a widely-used Drosophila IHC-ExM protocol from 6 days to 2 days. Our results demonstrate that with appropriate adjustment of the microwave parameters (wattage, pulse duration, interval, and number of cycles), this protocol can be readily adapted to different model organisms and tissue types to greatly increase the efficiency of ExM experiments.
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Affiliation(s)
| | | | | | - Amanda Jin
- Department of Biology, Georgetown University, Washington, DC 20057
| | - Danya A. Adams
- Department of Biology, Georgetown University, Washington, DC 20057
| | - Jessica M. Lin
- Department of Biology, Georgetown University, Washington, DC 20057
| | - Elena Iliadis
- Department of Biology, Georgetown University, Washington, DC 20057
| | - Tess M. Seidler
- Department of Biology, Georgetown University, Washington, DC 20057
| | | | - Hai-yan He
- Department of Biology, Georgetown University, Washington, DC 20057
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4
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Pribbenow C, Owald D. Skewing information flow through pre- and postsynaptic plasticity in the mushroom bodies of Drosophila. Learn Mem 2024; 31:a053919. [PMID: 38876487 PMCID: PMC11199954 DOI: 10.1101/lm.053919.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/26/2024] [Indexed: 06/16/2024]
Abstract
Animal brains need to store information to construct a representation of their environment. Knowledge of what happened in the past allows both vertebrates and invertebrates to predict future outcomes by recalling previous experience. Although invertebrate and vertebrate brains share common principles at the molecular, cellular, and circuit-architectural levels, there are also obvious differences as exemplified by the use of acetylcholine versus glutamate as the considered main excitatory neurotransmitters in the respective central nervous systems. Nonetheless, across central nervous systems, synaptic plasticity is thought to be a main substrate for memory storage. Therefore, how brain circuits and synaptic contacts change following learning is of fundamental interest for understanding brain computations tied to behavior in any animal. Recent progress has been made in understanding such plastic changes following olfactory associative learning in the mushroom bodies (MBs) of Drosophila A current framework of memory-guided behavioral selection is based on the MB skew model, in which antagonistic synaptic pathways are selectively changed in strength. Here, we review insights into plasticity at dedicated Drosophila MB output pathways and update what is known about the plasticity of both pre- and postsynaptic compartments of Drosophila MB neurons.
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Affiliation(s)
- Carlotta Pribbenow
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - David Owald
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
- Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
- NeuroCure, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
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5
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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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6
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Berry JA, Guhle DC, Davis RL. Active forgetting and neuropsychiatric diseases. Mol Psychiatry 2024:10.1038/s41380-024-02521-9. [PMID: 38532011 DOI: 10.1038/s41380-024-02521-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 03/04/2024] [Accepted: 03/06/2024] [Indexed: 03/28/2024]
Abstract
Recent and pioneering animal research has revealed the brain utilizes a variety of molecular, cellular, and network-level mechanisms used to forget memories in a process referred to as "active forgetting". Active forgetting increases behavioral flexibility and removes irrelevant information. Individuals with impaired active forgetting mechanisms can experience intrusive memories, distressing thoughts, and unwanted impulses that occur in neuropsychiatric diseases. The current evidence indicates that active forgetting mechanisms degrade, or mask, molecular and cellular memory traces created in synaptic connections of "engram cells" that are specific for a given memory. Combined molecular genetic/behavioral studies using Drosophila have uncovered a complex system of cellular active-forgetting pathways within engram cells that is regulated by dopamine neurons and involves dopamine-nitric oxide co-transmission and reception, endoplasmic reticulum Ca2+ signaling, and cytoskeletal remodeling machinery regulated by small GTPases. Some of these molecular cellular mechanisms have already been found to be conserved in mammals. Interestingly, some pathways independently regulate forgetting of distinct memory types and temporal phases, suggesting a multi-layering organization of forgetting systems. In mammals, active forgetting also involves modulation of memory trace synaptic strength by altering AMPA receptor trafficking. Furthermore, active-forgetting employs network level mechanisms wherein non-engram neurons, newly born-engram neurons, and glial cells regulate engram synapses in a state and experience dependent manner. Remarkably, there is evidence for potential coordination between the network and cellular level forgetting mechanisms. Finally, subjects with several neuropsychiatric diseases have been tested and shown to be impaired in active forgetting. Insights obtained from research on active forgetting in animal models will continue to enrich our understanding of the brain dysfunctions that occur in neuropsychiatric diseases.
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Affiliation(s)
- Jacob A Berry
- Department of Biological Sciences, University of Alberta, Edmonton, AL, T6G 2E9, Canada.
| | - Dana C Guhle
- Department of Biological Sciences, University of Alberta, Edmonton, AL, T6G 2E9, Canada
| | - Ronald L Davis
- Department of Neuroscience, UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL, 33458, USA.
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7
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Zhuravlev AV, Vetrovoy OV, Zalomaeva ES, Egozova ES, Nikitina EA, Savvateeva-Popova EV. Overexpression of the limk1 Gene in Drosophila melanogaster Can Lead to Suppression of Courtship Memory in Males. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:393-406. [PMID: 38648760 DOI: 10.1134/s0006297924030015] [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: 10/30/2023] [Revised: 12/06/2023] [Accepted: 12/08/2023] [Indexed: 04/25/2024]
Abstract
Courtship suppression is a behavioral adaptation of the fruit fly. When majority of the females in a fly population are fertilized and non-receptive for mating, a male, after a series of failed attempts, decreases its courtship activity towards all females, saving its energy and reproductive resources. The time of courtship decrease depends on both duration of unsuccessful courtship and genetically determined features of the male nervous system. Thereby, courtship suppression paradigm can be used for studying molecular mechanisms of learning and memory. p-Cofilin, a component of the actin remodeling signaling cascade and product of LIM-kinase 1 (LIMK1), regulates Drosophila melanogaster forgetting in olfactory learning paradigm. Previously, we have shown that limk1 suppression in the specific types of nervous cells differently affects fly courtship memory. Here, we used Gal4 > UAS system to induce limk1 overexpression in the same types of neurons. limk1 activation in the mushroom body, glia, and fruitless neurons decreased learning index compared to the control strain or the strain with limk1 knockdown. In cholinergic and dopaminergic/serotoninergic neurons, both overexpression and knockdown of limk1 impaired Drosophila short-term memory. Thus, proper balance of the limk1 activity is crucial for normal cognitive activity of the fruit fly.
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Affiliation(s)
- Aleksandr V Zhuravlev
- Pavlov Institute of Physiology, Russian Academy of Sciences, Saint Petersburg, 199034, Russia.
| | - Oleg V Vetrovoy
- Pavlov Institute of Physiology, Russian Academy of Sciences, Saint Petersburg, 199034, Russia.
| | - Ekaterina S Zalomaeva
- Pavlov Institute of Physiology, Russian Academy of Sciences, Saint Petersburg, 199034, Russia.
- Herzen State Pedagogical University of Russia, Saint Petersburg, 191186, Russia
| | - Ekaterina S Egozova
- Herzen State Pedagogical University of Russia, Saint Petersburg, 191186, Russia.
| | - Ekaterina A Nikitina
- Pavlov Institute of Physiology, Russian Academy of Sciences, Saint Petersburg, 199034, Russia.
- Herzen State Pedagogical University of Russia, Saint Petersburg, 191186, Russia
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8
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Takakura M, Lam YH, Nakagawa R, Ng MY, Hu X, Bhargava P, Alia AG, Gu Y, Wang Z, Ota T, Kimura Y, Morimoto N, Osakada F, Lee AY, Leung D, Miyashita T, Du J, Okuno H, Hirano Y. Differential second messenger signaling via dopamine neurons bidirectionally regulates memory retention. Proc Natl Acad Sci U S A 2023; 120:e2304851120. [PMID: 37639608 PMCID: PMC10483633 DOI: 10.1073/pnas.2304851120] [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: 03/24/2023] [Accepted: 07/10/2023] [Indexed: 08/31/2023] Open
Abstract
Memory formation and forgetting unnecessary memory must be balanced for adaptive animal behavior. While cyclic AMP (cAMP) signaling via dopamine neurons induces memory formation, here we report that cyclic guanine monophosphate (cGMP) signaling via dopamine neurons launches forgetting of unconsolidated memory in Drosophila. Genetic screening and proteomic analyses showed that neural activation induces the complex formation of a histone H3K9 demethylase, Kdm4B, and a GMP synthetase, Bur, which is necessary and sufficient for forgetting unconsolidated memory. Kdm4B/Bur is activated by phosphorylation through NO-dependent cGMP signaling via dopamine neurons, inducing gene expression, including kek2 encoding a presynaptic protein. Accordingly, Kdm4B/Bur activation induced presynaptic changes. Our data demonstrate a link between cGMP signaling and synapses via gene expression in forgetting, suggesting that the opposing functions of memory are orchestrated by distinct signaling via dopamine neurons, which affects synaptic integrity and thus balances animal behavior.
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Affiliation(s)
- Mai Takakura
- SK Project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto606-8507, Japan
| | - Yu Hong Lam
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Reiko Nakagawa
- Laboratory for Cell-Free Protein Synthesis, RIKEN Center for Biosystems Dynamics Research, Kobe650-0047, Japan
| | - Man Yung Ng
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Xinyue Hu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Priyanshu Bhargava
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Abdalla G. Alia
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Yuzhe Gu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Zigao Wang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Takeshi Ota
- SHIONOGI & CO., LTD, Analysis and Evaluation Laboratory, Bio Analytical 1, Shionogi Pharmaceutical Research Center, Toyonaka-shi, Osaka561-0825, Japan
| | - Yoko Kimura
- SK Project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto606-8507, Japan
| | - Nao Morimoto
- Laboratory of Molecular Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido060-0815, Japan
| | - Fumitaka Osakada
- Laboratory of Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi464-8601, Japan
| | - Ah Young Lee
- Center for Epigenomics Research, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Danny Leung
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
- Center for Epigenomics Research, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Tomoyuki Miyashita
- Learning and Memory Project, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa, Setagaya, Tokyo156-8506, Japan
| | - Juan Du
- Department of Entomology, Ministry of Agriculture and Rural Affairs Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing100193, China
| | - Hiroyuki Okuno
- SK Project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto606-8507, Japan
- Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima890-8544, Japan
| | - Yukinori Hirano
- SK Project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto606-8507, Japan
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
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9
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Dalto JF, Medina JH. Time-dependent inhibition of Rac1 in the VTA enhances long-term aversive memory: implications in active forgetting mechanisms. Sci Rep 2023; 13:13507. [PMID: 37598223 PMCID: PMC10439914 DOI: 10.1038/s41598-023-40434-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/10/2023] [Indexed: 08/21/2023] Open
Abstract
The fate of memories depends mainly on two opposing forces: the mechanisms required for the storage and maintenance of memory and the mechanisms underlying forgetting, being the latter much less understood. Here, we show the effect of inhibiting the small Rho GTPase Rac1 on the fate of inhibitory avoidance memory in male rats. The immediate post-training micro-infusion of the specific Rac1 inhibitor NSC23766 (150 ng/0.5 µl/ side) into the ventral tegmental area (VTA) enhanced long-term memory at 1, 7, and 14 days after a single training. Additionally, an opposed effect occurred when the inhibitor was infused at 12 h after training while no effect was observed immediately after testing animals at 1 day. Control experiments ruled out the possibility that post-training memory enhancement was due to facilitation of memory formation since no effect was found when animals were tested at 1 h after acquisition and no memory enhancement was observed after the formation of a weak memory. Immediate post-training micro-infusion of Rac1 inhibitor into the dorsal hippocampus, or the amygdala did not affect memory. Our findings support the idea of a Rac1-dependent time-specific active forgetting mechanism in the VTA controlling the strength of a long-term aversive memory.
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Affiliation(s)
- Juliana F Dalto
- Instituto de Biología Celular y Neurociencias "Prof. Eduardo de Robertis", Facultad de Medicina, Universidad de Buenos Aires-CONICET, Paraguay 2155, 3rd Floor, C1121ABG, Buenos Aires, Argentina
| | - Jorge H Medina
- Instituto de Biología Celular y Neurociencias "Prof. Eduardo de Robertis", Facultad de Medicina, Universidad de Buenos Aires-CONICET, Paraguay 2155, 3rd Floor, C1121ABG, Buenos Aires, Argentina.
- Instituto Tecnológico de Buenos Aires, Buenos Aires, Argentina.
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10
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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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11
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Guskjolen A, Cembrowski MS. Engram neurons: Encoding, consolidation, retrieval, and forgetting of memory. Mol Psychiatry 2023; 28:3207-3219. [PMID: 37369721 PMCID: PMC10618102 DOI: 10.1038/s41380-023-02137-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023]
Abstract
Tremendous strides have been made in our understanding of the neurobiological substrates of memory - the so-called memory "engram". Here, we integrate recent progress in the engram field to illustrate how engram neurons transform across the "lifespan" of a memory - from initial memory encoding, to consolidation and retrieval, and ultimately to forgetting. To do so, we first describe how cell-intrinsic properties shape the initial emergence of the engram at memory encoding. Second, we highlight how these encoding neurons preferentially participate in synaptic- and systems-level consolidation of memory. Third, we describe how these changes during encoding and consolidation guide neural reactivation during retrieval, and facilitate memory recall. Fourth, we describe neurobiological mechanisms of forgetting, and how these mechanisms can counteract engram properties established during memory encoding, consolidation, and retrieval. Motivated by recent experimental results across these four sections, we conclude by proposing some conceptual extensions to the traditional view of the engram, including broadening the view of cell-type participation within engrams and across memory stages. In collection, our review synthesizes general principles of the engram across memory stages, and describes future avenues to further understand the dynamic engram.
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Affiliation(s)
- Axel Guskjolen
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
| | - Mark S Cembrowski
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada.
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada.
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12
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Wang W, Wang Z, Cao J, Dong Y, Chen Y. Roles of Rac1-Dependent Intrinsic Forgetting in Memory-Related Brain Disorders: Demon or Angel. Int J Mol Sci 2023; 24:10736. [PMID: 37445914 DOI: 10.3390/ijms241310736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Animals are required to handle daily massive amounts of information in an ever-changing environment, and the resulting memories and experiences determine their survival and development, which is critical for adaptive evolution. However, intrinsic forgetting, which actively deletes irrelevant information, is equally important for memory acquisition and consolidation. Recently, it has been shown that Rac1 activity plays a key role in intrinsic forgetting, maintaining the balance of the brain's memory management system in a controlled manner. In addition, dysfunctions of Rac1-dependent intrinsic forgetting may contribute to memory deficits in neurological and neurodegenerative diseases. Here, these new findings will provide insights into the neurobiology of memory and forgetting, pathological mechanisms and potential therapies for brain disorders that alter intrinsic forgetting mechanisms.
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Affiliation(s)
- Wei Wang
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zixu Wang
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Jing Cao
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yulan Dong
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yaoxing Chen
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
- Key Laboratory of Precision Nutrition and Food Quality, Key Laboratory of Functional Dairy, Ministry of Education, Beijing Laboratory of Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China
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13
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Zhuravlev AV, Zalomaeva ES, Egozova ES, Sokurova VV, Nikitina EA, Savvateeva-Popova EV. LIM-kinase 1 effects on memory abilities and male courtship song in Drosophila depend on the neuronal type. Vavilovskii Zhurnal Genet Selektsii 2023; 27:250-263. [PMID: 37293442 PMCID: PMC10244584 DOI: 10.18699/vjgb-23-31] [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: 06/09/2022] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 06/10/2023] Open
Abstract
The signal pathway of actin remodeling, including LIM-kinase 1 (LIMK1) and its substrate cofilin, regulates multiple processes in neurons of vertebrates and invertebrates. Drosophila melanogaster is widely used as a model object for studying mechanisms of memory formation, storage, retrieval and forgetting. Previously, active forgetting in Drosophila was investigated in the standard Pavlovian olfactory conditioning paradigm. The role of specific dopaminergic neurons (DAN) and components of the actin remodeling pathway in different forms of forgetting was shown. In our research, we investigated the role of LIMK1 in Drosophila memory and forgetting in the conditioned courtship suppression paradigm (CCSP). In the Drosophila brain, LIMK1 and p-cofilin levels appeared to be low in specific neuropil structures, including the mushroom body (MB) lobes and the central complex. At the same time, LIMK1 was observed in cell bodies, such as DAN clusters regulating memory formation in CCSP. We applied GAL4 × UAS binary system to induce limk1 RNA interference in different types of neurons. The hybrid strain with limk1 interference in MB lobes and glia showed an increase in 3-h short-term memory (STM), without significant effects on long-term memory. limk1 interference in cholinergic neurons (CHN) impaired STM, while its interference in DAN and serotoninergic neurons (SRN) also dramatically impaired the flies' learning ability. By contrast, limk1 interference in fruitless neurons (FRN) resulted in increased 15-60 min STM, indicating a possible LIMK1 role in active forgetting. Males with limk1 interference in CHN and FRN also showed the opposite trends of courtship song parameters changes. Thus, LIMK1 effects on the Drosophila male memory and courtship song appeared to depend on the neuronal type or brain structure.
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Affiliation(s)
- A V Zhuravlev
- Pavlov Institute of Physiology of the Russian Academy of Sciences, St. Petersburg, Russia
| | - E S Zalomaeva
- Pavlov Institute of Physiology of the Russian Academy of Sciences, St. Petersburg, RussiaHerzen State Pedagogical University of Russia, St. Petersburg, Russia
| | - E S Egozova
- Herzen State Pedagogical University of Russia, St. Petersburg, Russia
| | - V V Sokurova
- Herzen State Pedagogical University of Russia, St. Petersburg, Russia
| | - E A Nikitina
- Pavlov Institute of Physiology of the Russian Academy of Sciences, St. Petersburg, Russia Herzen State Pedagogical University of Russia, St. Petersburg, Russia
| | - E V Savvateeva-Popova
- Pavlov Institute of Physiology of the Russian Academy of Sciences, St. Petersburg, Russia
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14
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Yang Q, Zhou J, Wang L, Hu W, Zhong Y, Li Q. Spontaneous recovery of reward memory through active forgetting of extinction memory. Curr Biol 2023; 33:838-848.e3. [PMID: 36731465 DOI: 10.1016/j.cub.2023.01.022] [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: 08/07/2022] [Revised: 12/16/2022] [Accepted: 01/11/2023] [Indexed: 02/04/2023]
Abstract
Learned behavior can be suppressed by the extinction procedure. Such extinguished memory often returns spontaneously over time, making it difficult to treat diseases such as addiction. However, the biological mechanisms underlying such spontaneous recovery remain unclear. Here, we report that the extinguished reward memory in Drosophila recovers spontaneously because extinction training forms an aversive memory that can be actively forgotten via the Rac1/Dia pathway. Manipulating Rac1 activity does not affect sugar-reward memory and its immediate extinction effect but bidirectionally regulates spontaneous recovery-the decay process of extinction. Experiments using thermogenetic inhibition and functional imaging support that such extinction appears to be coded as an aversive experience. Genetic and pharmacological inhibition of formin Dia, a downstream effector of Rac1, specifically prevents spontaneous recovery after extinction in both behavioral performance and corresponding physiological traces. Together, our data suggest that spontaneous recovery is caused by active forgetting of the opposing extinction memory.
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Affiliation(s)
- Qi Yang
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Jun Zhou
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Lingling Wang
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Wantong Hu
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Yi Zhong
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
| | - Qian Li
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
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15
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Zhao J, Zhang X, Zhao B, Hu W, Diao T, Wang L, Zhong Y, Li Q. Genetic dissection of mutual interference between two consecutive learning tasks in Drosophila. eLife 2023; 12:83516. [PMID: 36897069 PMCID: PMC10030115 DOI: 10.7554/elife.83516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 03/09/2023] [Indexed: 03/11/2023] Open
Abstract
Animals can continuously learn different tasks to adapt to changing environments and, therefore, have strategies to effectively cope with inter-task interference, including both proactive interference (Pro-I) and retroactive interference (Retro-I). Many biological mechanisms are known to contribute to learning, memory, and forgetting for a single task, however, mechanisms involved only when learning sequential different tasks are relatively poorly understood. Here, we dissect the respective molecular mechanisms of Pro-I and Retro-I between two consecutive associative learning tasks in Drosophila. Pro-I is more sensitive to an inter-task interval (ITI) than Retro-I. They occur together at short ITI (<20 min), while only Retro-I remains significant at ITI beyond 20 min. Acutely overexpressing Corkscrew (CSW), an evolutionarily conserved protein tyrosine phosphatase SHP2, in mushroom body (MB) neurons reduces Pro-I, whereas acute knockdown of CSW exacerbates Pro-I. Such function of CSW is further found to rely on the γ subset of MB neurons and the downstream Raf/MAPK pathway. In contrast, manipulating CSW does not affect Retro-I as well as a single learning task. Interestingly, manipulation of Rac1, a molecule that regulates Retro-I, does not affect Pro-I. Thus, our findings suggest that learning different tasks consecutively triggers distinct molecular mechanisms to tune proactive and retroactive interference.
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Affiliation(s)
- Jianjian Zhao
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Xuchen Zhang
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Bohan Zhao
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Wantong Hu
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Tongxin Diao
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Liyuan Wang
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Yi Zhong
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Qian Li
- School of Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
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16
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Neurogenetics of Memory, Learning, and Forgetting. Neurogenetics 2023. [DOI: 10.1007/978-3-031-07793-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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17
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Active forgetting requires Sickie function in a dedicated dopamine circuit in Drosophila. Proc Natl Acad Sci U S A 2022; 119:e2204229119. [PMID: 36095217 PMCID: PMC9499536 DOI: 10.1073/pnas.2204229119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Forgetting is an essential component of the brain's memory management system, providing a balance to memory formation processes by removing unused or unwanted memories, or by suppressing their expression. However, the molecular, cellular, and circuit mechanisms underlying forgetting are poorly understood. Here we show that the memory suppressor gene, sickie, functions in a single dopamine neuron (DAn) by supporting the process of active forgetting in Drosophila. RNAi knockdown (KD) of sickie impairs forgetting by reducing the Ca2+ influx and DA release from the DAn that promotes forgetting. Coimmunoprecipitation/mass spectrometry analyses identified cytoskeletal and presynaptic active zone (AZ) proteins as candidates that physically interact with Sickie, and a focused RNAi screen of the candidates showed that Bruchpilot (Brp)-a presynaptic AZ protein that regulates calcium channel clustering and neurotransmitter release-impairs active forgetting like sickie KD. In addition, overexpression of brp rescued the impaired forgetting of sickie KD, providing evidence that they function in the same process. Moreover, we show that sickie KD in the DAn reduces the abundance and size of AZ markers but increases their number, suggesting that Sickie controls DAn activity for forgetting by modulating the presynaptic AZ structure. Our results identify a molecular and circuit mechanism for normal levels of active forgetting and reveal a surprising role of Sickie in maintaining presynaptic AZ structure for neurotransmitter release.
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18
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Bourouliti A, Skoulakis EMC. Anesthesia Resistant Memories in Drosophila, a Working Perspective. Int J Mol Sci 2022; 23:ijms23158527. [PMID: 35955662 PMCID: PMC9369046 DOI: 10.3390/ijms23158527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 12/10/2022] Open
Abstract
Memories are lasting representations over time of associations between stimuli or events. In general, the relatively slow consolidation of memories requires protein synthesis with a known exception being the so-called Anesthesia Resistant Memory (ARM) in Drosophila. This protein synthesis-independent memory type survives amnestic shocks after a short, sensitive window post training, and can also emerge after repeated cycles of training in a negatively reinforced olfactory conditioning task, without rest between cycles (massed conditioning—MC). We discussed operational and molecular mechanisms that mediate ARM and differentiate it from protein synthesis-dependent long-term memory (LTM) in Drosophila. Based on the notion that ARM is unlikely to specifically characterize Drosophila, we examined protein synthesis and MC-elicited memories in other species and based on intraspecies shared molecular components and proposed potential relationships of ARM with established memory types in Drosophila and vertebrates.
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Affiliation(s)
- Anna Bourouliti
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16674 Vari, Greece;
- Department of Molecular Biology and Genetics, Democritus University of Thrace, 68100 Alexandroupolis, Greece
| | - Efthimios M. C. Skoulakis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16674 Vari, Greece;
- Correspondence:
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19
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Córdova-García G, Esquivel CJ, Pérez-Staples D, Ruiz-May E, Herrera-Cruz M, Reyes-Hernández M, Abraham S, Aluja M, Sirot L. Characterization of reproductive proteins in the Mexican fruit fly points towards the evolution of novel functions. Proc Biol Sci 2022; 289:20212806. [PMID: 35765836 PMCID: PMC9240691 DOI: 10.1098/rspb.2021.2806] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Seminal fluid proteins (Sfps) modify female phenotypes and have wide-ranging evolutionary implications on fitness in many insects. However, in the Mexican fruit fly, Anastrepha ludens, a highly destructive agricultural pest, the functions of Sfps are still largely unknown. To gain insights into female phenotypes regulated by Sfps, we used nano-liquid chromatography mass spectrometry to conduct a proteomic analysis of the soluble proteins from reproductive organs of A. ludens. The proteins predicted to be transferred from males to females during copulation were 100 proteins from the accessory glands, 69 from the testes and 20 from the ejaculatory bulb, resulting in 141 unique proteins after accounting for redundancies from multiple tissues. These 141 included orthologues to Drosophila melanogaster proteins involved mainly in oogenesis, spermatogenesis, immune response, lifespan and fecundity. In particular, we found one protein associated with female olfactory response to repellent stimuli (Scribble), and two related to memory formation (aPKC and Shibire). Together, these results raise the possibility that A. ludens Sfps could play a role in regulating female olfactory responses and memory formation and could be indicative of novel evolutionary functions in this important agricultural pest.
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Affiliation(s)
- Guadalupe Córdova-García
- INBIOTECA, Universidad Veracruzana, Av. de las Culturas Veracruzanas 101, Col. E. Zapata, Xalapa, CP 91090 Veracruz, México
| | | | - Diana Pérez-Staples
- INBIOTECA, Universidad Veracruzana, Av. de las Culturas Veracruzanas 101, Col. E. Zapata, Xalapa, CP 91090 Veracruz, México
| | - Eliel Ruiz-May
- Red de Manejo Biorracional de Plagas y Vectores, Clúster Científico y Tecnológico BioMimic®, Instituto de Ecología A.C. (INECOL), Antigua Carretera a Coatepec 351, Xalapa, Veracruz, México
| | - Mariana Herrera-Cruz
- Facultad de Medicina y Cirugía, Universidad Autónoma Benito Juárez de Oaxaca, Ex-Hda de Aguilera S/N, C.P. 68020, Oaxaca, Oaxaca, México
| | - Martha Reyes-Hernández
- Universidad Autónoma de Guadalajara, Av. Patria 1201, Col. Lomas del Valle, CP 45129 Zapopan, Jalisco, México
| | - Solana Abraham
- Laboratorio de Investigaciones Ecoetológicas de Moscas de la Fruta y sus Enemigos Naturales (LIEMEN), PROIMI-Biotecnología, CONICET, Avenida Belgrano y Pasaje Caseros s/n, CP 4000 San Miguel de Tucumán, Tucumán, Argentina
| | - Martín Aluja
- Red de Manejo Biorracional de Plagas y Vectores, Clúster Científico y Tecnológico BioMimic®, Instituto de Ecología A.C. (INECOL), Antigua Carretera a Coatepec 351, Xalapa, Veracruz, México
| | - Laura Sirot
- Department of Biology, College of Wooster, 931 College Mall, Wooster, OH 44691, USA
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20
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The signaling pathway of levamisole-sensitive-acetylcholine receptors involved in short-term forgetting of Caenorhabditis elegans. Mol Genet Genomics 2022; 297:1027-1038. [PMID: 35585325 DOI: 10.1007/s00438-022-01901-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/16/2022] [Indexed: 10/18/2022]
Abstract
In contrast to the popular opinion that forgetting is only the opposite of learning and memory, active forgetting explains the intrinsic instability of a labile memory that lasts for hours and has its own signal transduction pathways. However, the detailed mechanisms underlying forgetting are still lacking, though the investigations available in this field offer the first insights into their regulation. To identify the alternative signaling pathways that control the process of forgetting, we used the short-term forgetting model of Caenorhabditis elegans and discovered the involvement of lev-10, a scaffolded transmembrane protein of L-AChR, by screening the candidate genes that potentially functioned in synaptic plasticity. The LEV-9/LEV-10/L-AChR functional complex was confirmed to participate in forgetting occurrence. Furthermore, EGL-9 functioned upstream of LEV-10 and negatively regulated the latter during forgetting. Meanwhile, EGL-9 was also the target of miR-51, and hence the mutation of miR-51 similarly affected the function of L-AChR and delayed the short-term forgetting. Our findings have identified an integrated signaling pathway responsible for active forgetting, which provides the new experimental evidence on the cholinergic forgetting signal.
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21
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Ryan TJ, Frankland PW. Forgetting as a form of adaptive engram cell plasticity. Nat Rev Neurosci 2022; 23:173-186. [PMID: 35027710 DOI: 10.1038/s41583-021-00548-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2021] [Indexed: 12/30/2022]
Abstract
One leading hypothesis suggests that memories are stored in ensembles of neurons (or 'engram cells') and that successful recall involves reactivation of these ensembles. A logical extension of this idea is that forgetting occurs when engram cells cannot be reactivated. Forms of 'natural forgetting' vary considerably in terms of their underlying mechanisms, time course and reversibility. However, we suggest that all forms of forgetting involve circuit remodelling that switches engram cells from an accessible state (where they can be reactivated by natural recall cues) to an inaccessible state (where they cannot). In many cases, forgetting rates are modulated by environmental conditions and we therefore propose that forgetting is a form of neuroplasticity that alters engram cell accessibility in a manner that is sensitive to mismatches between expectations and the environment. Moreover, we hypothesize that disease states associated with forgetting may hijack natural forgetting mechanisms, resulting in reduced engram cell accessibility and memory loss.
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Affiliation(s)
- Tomás J Ryan
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland. .,Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland. .,Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, Victoria, Australia. .,Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada.
| | - Paul W Frankland
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada. .,Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada. .,Department of Psychology, University of Toronto, Toronto, Ontario, Canada. .,Department of Physiology, University of Toronto, Toronto, Ontario, Canada. .,Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.
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22
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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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23
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Noyes NC, Phan A, Davis RL. Memory suppressor genes: Modulating acquisition, consolidation, and forgetting. Neuron 2021; 109:3211-3227. [PMID: 34450024 PMCID: PMC8542634 DOI: 10.1016/j.neuron.2021.08.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/15/2021] [Accepted: 07/30/2021] [Indexed: 02/06/2023]
Abstract
The brain has a remarkable but underappreciated capacity to limit memory formation and expression. The term "memory suppressor gene" was coined in 1998 as an attempt to explain emerging reports that some genes appeared to limit memory. At that time, only a handful of memory suppressor genes were known, and they were understood to work by limiting cAMP-dependent consolidation. In the intervening decades, almost 100 memory suppressor genes with diverse functions have been discovered that affect not only consolidation but also acquisition and forgetting. Here we highlight the surprising extent to which biological limits are placed on memory formation through reviewing the literature on memory suppressor genes. In this review, we present memory suppressors within the framework of their actions on different memory operations: acquisition, consolidation, and forgetting. This is followed by a discussion of the reasons why there may be a biological need to limit memory formation.
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Affiliation(s)
- Nathaniel C Noyes
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Anna Phan
- Department of Biological Sciences, University of Alberta, 11355 Saskatchewan Drive, Edmonton, AB T6G 2E9, Canada
| | - Ronald L Davis
- Department of Neuroscience, Scripps Research Institute Florida, Jupiter, FL 33458, USA.
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24
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Castillo Díaz F, Caffino L, Fumagalli F. Bidirectional role of dopamine in learning and memory-active forgetting. Neurosci Biobehav Rev 2021; 131:953-963. [PMID: 34655655 DOI: 10.1016/j.neubiorev.2021.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/05/2021] [Accepted: 10/11/2021] [Indexed: 12/15/2022]
Abstract
Dopaminergic neurons projecting from the Substantia Nigra to the Striatum play a critical role in motor functions while dopaminergic neurons originating in the Ventral Tegmental Area (VTA) and projecting to the Nucleus Accumbens, Hippocampus and other cortical structures regulate rewarding learning. While VTA mainly consists of dopaminergic neurons, excitatory (glutamate) and inhibitory (GABA) VTA-neurons have also been described: these neurons may also modulate and contribute to shape the final dopaminergic response, which is critical for memory formation. However, given the large amount of information that is handled daily by our brain, it is essential that irrelevant information be deleted. Recently, apart from the well-established role of dopamine (DA) in learning, it has been shown that DA plays a critical role in the intrinsic active forgetting mechanisms that control storage information, contributing to the deletion of a consolidated memory. These new insights may be instrumental to identify therapies for those disorders that involve memory alterations.
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Affiliation(s)
- Fernando Castillo Díaz
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy.
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy
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25
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Zhang H, Ben Zablah Y, Zhang H, Jia Z. Rho Signaling in Synaptic Plasticity, Memory, and Brain Disorders. Front Cell Dev Biol 2021; 9:729076. [PMID: 34671600 PMCID: PMC8520953 DOI: 10.3389/fcell.2021.729076] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/03/2021] [Indexed: 12/12/2022] Open
Abstract
Memory impairments are associated with many brain disorders such as autism, Alzheimer's disease, and depression. Forming memories involves modifications of synaptic transmission and spine morphology. The Rho family small GTPases are key regulators of synaptic plasticity by affecting various downstream molecules to remodel the actin cytoskeleton. In this paper, we will review recent studies on the roles of Rho proteins in the regulation of hippocampal long-term potentiation (LTP) and long-term depression (LTD), the most extensively studied forms of synaptic plasticity widely regarded as cellular mechanisms for learning and memory. We will also discuss the involvement of Rho signaling in spine morphology, the structural basis of synaptic plasticity and memory formation. Finally, we will review the association between brain disorders and abnormalities of Rho function. It is expected that studying Rho signaling at the synapse will contribute to the understanding of how memory is formed and disrupted in diseases.
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Affiliation(s)
- Haorui Zhang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Youssif Ben Zablah
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Haiwang Zhang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Zhengping Jia
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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26
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Ezan J, Moreau MM, Mamo TM, Shimbo M, Decroo M, Richter M, Peyroutou R, Rachel R, Tissir F, de Anda FC, Sans N, Montcouquiol M. Early loss of Scribble affects cortical development, interhemispheric connectivity and psychomotor activity. Sci Rep 2021; 11:9106. [PMID: 33907211 PMCID: PMC8079449 DOI: 10.1038/s41598-021-88147-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 04/01/2021] [Indexed: 12/03/2022] Open
Abstract
Neurodevelopmental disorders arise from combined defects in processes including cell proliferation, differentiation, migration and commissure formation. The evolutionarily conserved tumor-suppressor protein Scribble (Scrib) serves as a nexus to transduce signals for the establishment of apicobasal and planar cell polarity during these processes. Human SCRIB gene mutations are associated with neural tube defects and this gene is located in the minimal critical region deleted in the rare Verheij syndrome. In this study, we generated brain-specific conditional cKO mouse mutants and assessed the impact of the Scrib deletion on brain morphogenesis and behavior. We showed that embryonic deletion of Scrib in the telencephalon leads to cortical thickness reduction (microcephaly) and partial corpus callosum and hippocampal commissure agenesis. We correlated these phenotypes with a disruption in various developmental mechanisms of corticogenesis including neurogenesis, neuronal migration and axonal connectivity. Finally, we show that Scrib cKO mice have psychomotor deficits such as locomotor activity impairment and memory alterations. Altogether, our results show that Scrib is essential for early brain development due to its role in several developmental cellular mechanisms that could underlie some of the deficits observed in complex neurodevelopmental pathologies.
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Affiliation(s)
- Jerome Ezan
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France.
| | - Maité M Moreau
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France
| | - Tamrat M Mamo
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France
| | - Miki Shimbo
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France
| | - Maureen Decroo
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France
| | - Melanie Richter
- Germany Center for Molecular Neurobiology Hamburg (ZMNH), Research Group Neuronal Development, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ronan Peyroutou
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France
| | - Rivka Rachel
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, NIH, Bethesda, MD, 20892, USA
| | - Fadel Tissir
- Developmental Neurobiology Group, Institute of Neuroscience, University of Louvain, Avenue Mounier 73, Box B1.73.16, 1200, Brussels, Belgium
| | - Froylan Calderon de Anda
- Germany Center for Molecular Neurobiology Hamburg (ZMNH), Research Group Neuronal Development, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nathalie Sans
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France
| | - Mireille Montcouquiol
- Université de Bordeaux, INSERM, Neurocentre Magendie, U1215, 33077, Bordeaux, France.
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27
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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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28
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Costanzi M, Cianfanelli B, Santirocchi A, Lasaponara S, Spataro P, Rossi-Arnaud C, Cestari V. Forgetting Unwanted Memories: Active Forgetting and Implications for the Development of Psychological Disorders. J Pers Med 2021; 11:jpm11040241. [PMID: 33810436 PMCID: PMC8066077 DOI: 10.3390/jpm11040241] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
Intrusive memories are a common feature of many psychopathologies, and suppression-induced forgetting of unwanted memories appears as a critical ability to preserve mental health. In recent years, biological and cognitive studies converged in revealing that forgetting is due to active processes. Recent neurobiological studies provide evidence on the active role of main neurotransmitter systems in forgetting, suggesting that the brain actively works to suppress retrieval of unwanted memories. On the cognitive side, there is evidence that voluntary and involuntary processes (here termed "intentional" and "incidental" forgetting, respectively) contribute to active forgetting. In intentional forgetting, an inhibitory control mechanism suppresses awareness of unwanted memories at encoding or retrieval. In incidental forgetting, retrieval practice of some memories involuntarily suppresses the retrieval of other related memories. In this review we describe recent findings on deficits in active forgetting observed in psychopathologies, like post-traumatic stress disorder, depression, schizophrenia, and obsessive-compulsive disorder. Moreover, we report studies in which the role of neurotransmitter systems, known to be involved in the pathogenesis of mental disorders, has been investigated in active forgetting paradigms. The possibility that biological and cognitive mechanisms of active forgetting could be considered as hallmarks of the early onset of psychopathologies is also discussed.
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Affiliation(s)
- Marco Costanzi
- Department of Human Sciences, Lumsa University, 00193 Rome, Italy; (B.C.); (S.L.)
- Correspondence:
| | - Beatrice Cianfanelli
- Department of Human Sciences, Lumsa University, 00193 Rome, Italy; (B.C.); (S.L.)
| | - Alessandro Santirocchi
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
| | - Stefano Lasaponara
- Department of Human Sciences, Lumsa University, 00193 Rome, Italy; (B.C.); (S.L.)
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
| | - Pietro Spataro
- Department of Economy, Universitas Mercatorum, 00100 Rome, Italy;
| | - Clelia Rossi-Arnaud
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
| | - Vincenzo Cestari
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
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29
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Zhang Y, Zhou Y, Zhang X, Wang L, Zhong Y. Clock neurons gate memory extinction in Drosophila. Curr Biol 2021; 31:1337-1343.e4. [PMID: 33545046 DOI: 10.1016/j.cub.2021.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/15/2020] [Accepted: 01/06/2021] [Indexed: 11/25/2022]
Abstract
Memory forms when a previously neutral stimulus (CS+) becomes competent to predict a biologically potent stimulus (US). However, if the CS+ is repeatedly presented without the US after the memory formation, this memory will be suppressed by newly formed extinction memory.1,2 The striking feature of extinction learning is that it requires repeated trials to robustly form extinction. Extended repetition only yields memories that remain transient in nature,3 thus imposing challenges in understanding the underlying mechanisms of extinction learning. Here, we took advantage of the versatile genetic tools4 and the well-characterized circadian system of Drosophila5,6 to link these unique features to clock neurons. We report that inhibiting the activity of clock neurons blocks the formation of extinction memory. Further investigation attributes this role to a subset of cryptochrome-positive dorsal neurons 1 (DN1s) and their downstream SIFamide neurons. The requirement of clock neurons from a gating mechanism of extinction for a single extinction learning trial robustly causes typical extinction when coupled with acute activation of DN1s, as marked by the initially enhanced but eventually diminished memory suppression. Accordingly, we detected specific neural responses to extinction training in a few DN1s via calcium imaging fulfilled by the TRIC tool,7 but not in dorsal neurons 2 or dorsolateral neurons. Based on these findings, we propose that in extinction of appetitive long-term memory, multiple trials of extinction learning robustly activate DN1 clock neurons to open the gate of extinction, which may contribute to the transient nature of extinction memory.
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Affiliation(s)
- Yunchuan Zhang
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Yinzhong Zhou
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Xuchen Zhang
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Lingling Wang
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Yi Zhong
- School of Life Science, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
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30
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Abstract
Active forgetting is an essential component of the brain’s memory management system1. Forgetting can be permanent, in which prior memory is lost completely; or transient, in which memory exists in a temporary state of impaired retrieval. Such temporary blocks on memory seem universal, and can disrupt an individual’s plans, social interactions, and ability to make rapid, flexible and appropriate choices. However, the neurobiological mechanisms that cause transient forgetting are unknown. Here we identify a single dopamine neuron in Drosophila that mediates memory suppression resulting in transient forgetting. Artificially activating this neuron failed to abolish the expression of long-term memory. Rather, it briefly suppressed memory retrieval, with memory becoming accessible with time. The dopamine neuron modulates memory retrieval by stimulating a unique dopamine receptor expressed in a restricted physical compartment of the axons of mushroom body neurons. This mechanism for transient forgetting is triggered by interfering stimuli presented just prior to retrieval.
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31
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Gamoran A, Greenwald-Levin M, Siton S, Halunga D, Sadeh T. It's about time: Delay-dependent forgetting of item- and contextual-information. Cognition 2020; 205:104437. [PMID: 32861981 DOI: 10.1016/j.cognition.2020.104437] [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: 12/04/2019] [Revised: 08/05/2020] [Accepted: 08/09/2020] [Indexed: 11/18/2022]
Abstract
Once fiercely rejected, the notion of delay-dependent forgetting from long-term memory has recently resurfaced. By this notion, the duration of the study-test delay predicts the magnitude of memory degradation. Our Representation Theory of Forgetting adopts the notion of delay-dependent forgetting, alongside interference due to similarity of representations as an additional cause of forgetting-rather than its sole cause, as has been largely argued in the past. This theory maintains that the causes of forgetting depend on the underlying memory representations. Because hippocampus-based memory representations are relatively distinct from one another, by the virtue of being associated with distinct contexts, they are not as likely as non-hippocampus representations to be forgotten due to interference from similar memories. Instead, as neurobiological evidence suggests, these representations may be forgotten over the passage of time. Thus, contextual-information should be particularly sensitive to delay-dependent forgetting in comparison to item-information. In the current study we tested this hypothesis by comparing the effects of short study-test delay (~2 min) to long delay (~15 min) on forgetting. In three experiments using three different memory paradigms, we obtained various measures of item- and contextual-information. Results converged to support our predictions: whereas most measures of contextual-information showed forgetting over time, item-information was less affected by delay and, at times, was not affected at all. Finally, different patterns of time-dependent forgetting of contextual-information were observed in recall and recognition, in line with the different roles of context in these tests. Our results provide novel evidence for the specific effects of delay on hippocampus-based, contextual memory representations.
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Affiliation(s)
- Avi Gamoran
- Department of Psychology, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | | | - Stav Siton
- The Department of Cognitive and Brain Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel; Department of Psychology, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Dan Halunga
- Department of Psychology, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Talya Sadeh
- The Department of Cognitive and Brain Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel; Department of Psychology, Ben-Gurion University of the Negev, Beer Sheva, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva, Israel.
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32
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Cervantes-Sandoval I, Davis RL, Berry JA. Rac1 Impairs Forgetting-Induced Cellular Plasticity in Mushroom Body Output Neurons. Front Cell Neurosci 2020; 14:258. [PMID: 33061890 PMCID: PMC7477079 DOI: 10.3389/fncel.2020.00258] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/24/2020] [Indexed: 12/02/2022] Open
Abstract
Active memory forgetting is a well-regulated biological process thought to be adaptive and to allow proper cognitive functions. Recent efforts have elucidated several molecular players involved in the regulation of olfactory forgetting in Drosophila, including the small G protein Rac1, the dopamine receptor DAMB, and the scaffold protein Scribble. Similarly, we recently reported that dopaminergic neurons mediate both learning- and forgetting-induced plasticity in the mushroom body output neuron MBON-γ2α′1. Two open questions remain: how does forgetting affect plasticity in other, highly plastic, mushroom body compartments and how do genes that regulate forgetting affect this cellular plasticity? Here, we show that forgetting reverses short-term synaptic depression induced by aversive conditioning in the highly plastic mushroom body output neuron MBON-γ1pedc>α/β. In addition, our results indicate that genetic tampering with normal forgetting by inhibition of small G protein Rac1 impairs restoration of depressed odor responses to learned odor by intrinsic forgetting through time passing and forgetting induced acutely by shock stimulation after conditioning or reversal learning. These data further indicate that some forms of forgetting truly erase physiological changes generated by memory encoding.
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Affiliation(s)
- Isaac Cervantes-Sandoval
- Department of Biology, Georgetown University, Washington, DC, United States.,Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL, United States
| | - Jacob A Berry
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL, United States
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33
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miR-92a Suppresses Mushroom Body-Dependent Memory Consolidation in Drosophila. eNeuro 2020; 7:ENEURO.0224-20.2020. [PMID: 32737186 PMCID: PMC7642123 DOI: 10.1523/eneuro.0224-20.2020] [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: 05/26/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 12/14/2022] Open
Abstract
MicroRNAs (miRNAs) fine tune gene expression to regulate many aspects of nervous system physiology. Here, we show that miR-92a suppresses memory consolidation that occurs in the αβ and γ mushroom body neurons (MBns) of Drosophila, making miR-92a a memory suppressor miRNA. Bioinformatics analyses suggested that mRNAs encoding kinesin heavy chain 73 (KHC73), a protein that belongs to Kinesin-3 family of anterograde motor proteins, may be a functional target of miR-92a. Behavioral studies that employed expression of khc73 with and without its 3' untranslated region (UTR) containing miR-92a target sites, luciferase assays in HEK cells with reporters containing wild-type and mutant target sequences in the khc73 3'UTR, and immunohistochemistry experiments involving KHC73 expression with and without the wild-type khc73 3'UTR, all point to the conclusion that khc73 is a major target of miR-92a in its functional role as a miRNA memory suppressor gene.
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34
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Costa JF, Dines M, Lamprecht R. The Role of Rac GTPase in Dendritic Spine Morphogenesis and Memory. Front Synaptic Neurosci 2020; 12:12. [PMID: 32362820 PMCID: PMC7182350 DOI: 10.3389/fnsyn.2020.00012] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/04/2020] [Indexed: 11/21/2022] Open
Abstract
The ability to form memories in the brain is needed for daily functions, and its impairment is associated with human mental disorders. Evidence indicates that long-term memory (LTM)-related processes such as its consolidation, extinction and forgetting involve changes of synaptic efficacy produced by alterations in neural transmission and morphology. Modulation of the morphology and number of dendritic spines has been proposed to contribute to changes in neuronal transmission mediating such LTM-related processes. Rac GTPase activity is regulated by synaptic activation and it can affect spine morphology by controlling actin-regulatory proteins. Recent evidence shows that changes in Rac GTPase activity affect memory consolidation, extinction, erasure and forgetting and can affect spine morphology in brain areas that mediate these behaviors. Altered Rac GTPase activity is associated with abnormal spine morphology and brain disorders. By affecting Rac GTPase activity we can further understand the roles of spine morphogenesis in memory. Moreover, manipulation of Rac GTPase activity may serve as a therapeutic tool for the treatment of memory-related brain diseases.
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Affiliation(s)
| | | | - Raphael Lamprecht
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
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35
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Modi MN, Shuai Y, Turner GC. The Drosophila Mushroom Body: From Architecture to Algorithm in a Learning Circuit. Annu Rev Neurosci 2020; 43:465-484. [PMID: 32283995 DOI: 10.1146/annurev-neuro-080317-0621333] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Drosophila brain contains a relatively simple circuit for forming Pavlovian associations, yet it achieves many operations common across memory systems. Recent advances have established a clear framework for Drosophila learning and revealed the following key operations: a) pattern separation, whereby dense combinatorial representations of odors are preprocessed to generate highly specific, nonoverlapping odor patterns used for learning; b) convergence, in which sensory information is funneled to a small set of output neurons that guide behavioral actions; c) plasticity, where changing the mapping of sensory input to behavioral output requires a strong reinforcement signal, which is also modulated by internal state and environmental context; and d) modularization, in which a memory consists of multiple parallel traces, which are distinct in stability and flexibility and exist in anatomically well-defined modules within the network. Cross-module interactions allow for higher-order effects where past experience influences future learning. Many of these operations have parallels with processes of memory formation and action selection in more complex brains.
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Affiliation(s)
- Mehrab N Modi
- Janelia Research Campus, Ashburn, Virginia 20147, USA;
| | - Yichun Shuai
- Janelia Research Campus, Ashburn, Virginia 20147, USA;
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36
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Xia X, Gui L, He G, Wei B, Zhang Y, Yu F, Wu H, Zhan ZH. An expanded particle swarm optimization based on multi-exemplar and forgetting ability. Inf Sci (N Y) 2020. [DOI: 10.1016/j.ins.2019.08.065] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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37
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Dopamine D 1 and D 2 Receptors Differentially Regulate Rac1 and Cdc42 Signaling in the Nucleus Accumbens to Modulate Behavioral and Structural Plasticity After Repeated Methamphetamine Treatment. Biol Psychiatry 2019; 86:820-835. [PMID: 31060803 DOI: 10.1016/j.biopsych.2019.03.966] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/21/2019] [Accepted: 03/03/2019] [Indexed: 11/21/2022]
Abstract
BACKGROUND Methamphetamine (METH) is a highly addictive psychostimulant that strongly activates dopamine receptor signaling in the nucleus accumbens (NAc). However, how dopamine D1 and D2 receptors (D1Rs and D2Rs, respectively) as well as downstream signaling pathways, such as those involving Rac1 and Cdc42, modulate METH-induced behavioral and structural plasticity is largely unknown. METHODS Using NAc conditional D1R and D2R deletion mice, Rac1 and Cdc42 mutant viruses, and a series of behavioral and morphological methods, we assessed the effects of D1Rs and D2Rs on Rac1 and Cdc42 in modulating METH-induced behavioral and structural plasticity in the NAc. RESULTS D1Rs and D2Rs in the NAc consistently regulated METH-induced conditioned place preference, locomotor activation, and dendritic and spine remodeling of medium spiny neurons but differentially regulated METH withdrawal-induced spatial learning and memory impairment and anxiety. Interestingly, Rac1 and Cdc42 signaling were oppositely modulated by METH, and suppression of Rac1 signaling and activation of Cdc42 signaling were crucial to METH-induced conditioned place preference and structural plasticity but not to locomotor activation. D1Rs activated Rac1 and Cdc42 signaling, while D2Rs inhibited Rac1 signaling but activated Cdc42 signaling to mediate METH-induced conditioned place preference and structural plasticity but not locomotor activation. In addition, NAc D1R deletion aggravated METH withdrawal-induced spatial learning and memory impairment by suppressing Rac1 signaling but not Cdc42 signaling, while NAc D2R deletion aggravated METH withdrawal-induced anxiety without affecting Rac1 or Cdc42 signaling. CONCLUSIONS D1Rs and D2Rs differentially regulate Rac1 and Cdc42 signaling to modulate METH-induced behavioral plasticity and the structural remodeling of medium spiny neurons in the NAc.
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38
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Amin H, Lin AC. Neuronal mechanisms underlying innate and learned olfactory processing in Drosophila. CURRENT OPINION IN INSECT SCIENCE 2019; 36:9-17. [PMID: 31280185 DOI: 10.1016/j.cois.2019.06.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 06/03/2019] [Indexed: 06/09/2023]
Abstract
Olfaction allows animals to adapt their behavior in response to different chemical cues in their environment. How does the brain efficiently discriminate different odors to drive appropriate behavior, and how does it flexibly assign value to odors to adjust behavior according to experience? This review traces neuronal mechanisms underlying these processes in adult Drosophila melanogaster from olfactory receptors to higher brain centers. We highlight neural circuit principles such as lateral inhibition, segregation and integration of olfactory channels, temporal accumulation of sensory evidence, and compartmentalized synaptic plasticity underlying associative memory.
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Affiliation(s)
- Hoger Amin
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Andrew C Lin
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom.
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39
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Stan RC, Bhatt DK, Camargo MM. Cellular Adaptation Relies on Regulatory Proteins Having Episodic Memory. Bioessays 2019; 42:e1900115. [DOI: 10.1002/bies.201900115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/06/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Razvan C. Stan
- Cantacuzino National Military‐Medical Institute for Research‐Development Bucharest 050096 Romania
- Department of ImmunologyUniversity of São Paulo São Paulo 05508‐900 Brazil
| | - Darshak K. Bhatt
- Faculty of Medical SciencesGroningen University Groningen 9700 AB The Netherlands
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40
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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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Altered Actin Filament Dynamics in the Drosophila Mushroom Bodies Lead to Fast Acquisition of Alcohol Consumption Preference. J Neurosci 2019; 39:8877-8884. [PMID: 31558618 DOI: 10.1523/jneurosci.0973-19.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/22/2019] [Accepted: 09/13/2019] [Indexed: 01/12/2023] Open
Abstract
Alcohol use is highly prevalent in the United States and across the world, and every year millions of people suffer from alcohol use disorders (AUDs). Although the genetic contribution to developing AUDs is estimated to be 50-60%, many of the underlying molecular mechanisms remain unclear. Previous studies from our laboratory revealed that Drosophila melanogaster lacking RhoGAP18B and Ras Suppressor 1 (Rsu1) display reduced sensitivity to ethanol-induced sedation. Both Rsu1 and RhoGAP18B are negative regulators of the small Rho-family GTPase, Rac1, a modulator of actin dynamics. Here we investigate the role of Rac1 and its downstream target, the actin-severing protein cofilin, in alcohol consumption preference. We show that these two regulators of actin dynamics can alter male experience-dependent alcohol preference in a bidirectional manner: expressing either activated Rac1 or dominant-negative cofilin in the mushroom bodies (MBs) abolishes experience-dependent alcohol preference. Conversely, dominant-negative Rac1 or activated cofilin MB expression lead to faster acquisition of alcohol preference. Our data show that Rac1 and cofilin activity are key to determining the rate of acquisition of alcohol preference, revealing a critical role of actin dynamics regulation in the development of voluntary self-administration in Drosophila SIGNIFICANCE STATEMENT The risks for developing an alcohol use disorder (AUD) are strongly determined by genetic factors. Understanding the genes and molecular mechanisms that contribute to that risk is therefore a necessary first step for the development of targeted therapeutic intervention. Here we show that regulators of actin cytoskeleton dynamics can bidirectionally determine the acquisition rate of alcohol self-administration, highlighting this process as a key mechanism contributing to the risk of AUD development.
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Zhao J, Ying L, Liu Y, Liu N, Tu G, Zhu M, Wu Y, Xiao B, Ye L, Li J, Guo F, Zhang L, Wang H, Zhang L. Different roles of Rac1 in the acquisition and extinction of methamphetamine-associated contextual memory in the nucleus accumbens. Am J Cancer Res 2019; 9:7051-7071. [PMID: 31660086 PMCID: PMC6815963 DOI: 10.7150/thno.34655] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/30/2019] [Indexed: 02/03/2023] Open
Abstract
Rationale: Repeated methamphetamine (METH) exposure induces long-term cognitive deficits and pathological drug-associated memory that can be disrupted by manipulating memory reconsolidation and extinction. The nucleus accumbens (NAc) is the key region of the brain reward system and predominantly consists of two subtypes of medium spiny neurons (MSNs) based on the expression of D1 or D2 dopamine receptors (D1-MSNs or D2-MSNs). Spine structural plasticity in the NAc is critical for the acquisition, reconsolidation and extinction of drug-associated memory. However, the molecular mechanisms underlying METH-associated memory and spine remodelling in each type of MSNs in the NAc remain unknown. Here, we explored whether Rac1 in the NAc mediates METH-associated contextual memory and spine remodelling. Methods: Pharmacological and genetic manipulations of Rac1 were used to investigate its role during the acquisition, reconsolidation and extinction of METH-associated contextual memory. Recombinant adeno-associated viruses expressing mCherry under the control of the dopamine D1 receptor gene promoter (Drd1-mCherry) or dopamine D2 receptor gene promoter (Drd2-mCherry) were used to specifically label D1-MSNs or D2-MSNs. Results: Using viral-mediated gene transfer, we demonstrated that decreased Rac1 activity was required for the acquisition of METH-associated contextual memory and the METH-induced increase in thin spine density, whereas increased Rac1 signalling was important for the extinction of METH-associated contextual memory and the related elimination of thin spines. Moreover, the increase of dendritic spines was both found in D1-MSNs and D2-MSNs during the acquisition process, but extinction training selectively decreased the spine density in D1-MSNs. Interestingly, Rac1 was responsible for METH-induced spine plasticity in D1-MSNs but not in D2-MSNs. Additionally, we found that microinjection of a Rac1 inhibitor or activator into the NAc was not sufficient to disrupt reconsolidation, and the pharmacological activation of Rac1 in the NAc facilitated the extinction of METH-associated contextual memory. Regarding cognitive memory, decreased Rac1 activity improved the METH-induced impairment in object recognition memory. Conclusion: Our findings indicate that Rac1 plays opposing roles in the acquisition and extinction of METH-associated contextual memory and reveal the cell-specific role of Rac1 in METH-associated spine remodelling, suggesting that Rac1 is a potential therapeutic target for reducing relapse in METH addiction and remediating METH-induced recognition memory impairment.
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Drosophila Tau Negatively Regulates Translation and Olfactory Long-Term Memory, But Facilitates Footshock Habituation and Cytoskeletal Homeostasis. J Neurosci 2019; 39:8315-8329. [PMID: 31488613 DOI: 10.1523/jneurosci.0391-19.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/24/2019] [Accepted: 08/07/2019] [Indexed: 01/07/2023] Open
Abstract
Although the involvement of pathological tau in neurodegenerative dementias is indisputable, its physiological roles have remained elusive in part because its abrogation has been reported without overt phenotypes in mice and Drosophila This was addressed using the recently described Drosophila tauKO and Mi{MIC} mutants and focused on molecular and behavioral analyses. Initially, we show that Drosophila tau (dTau) loss precipitates dynamic cytoskeletal changes in the adult Drosophila CNS and translation upregulation. Significantly, we demonstrate for the first time distinct roles for dTau in adult mushroom body (MB)-dependent neuroplasticity as its downregulation within α'β'neurons impairs habituation. In accord with its negative regulation of translation, dTau loss specifically enhances protein synthesis-dependent long-term memory (PSD-LTM), but not anesthesia-resistant memory. In contrast, elevation of the protein in the MBs yielded premature habituation and depressed PSD-LTM. Therefore, tau loss in Drosophila dynamically alters brain cytoskeletal dynamics and profoundly affects neuronal proteostasis and plasticity.SIGNIFICANCE STATEMENT We demonstrate that despite modest sequence divergence, the Drosophila tau (dTau) is a true vertebrate tau ortholog as it interacts with the neuronal microtubule and actin cytoskeleton. Novel physiological roles for dTau in regulation of translation, long-term memory, and footshock habituation are also revealed. These emerging insights on tau physiological functions are invaluable for understanding the molecular pathways and processes perturbed in tauopathies.
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44
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Genetic dissection of active forgetting in labile and consolidated memories in Drosophila. Proc Natl Acad Sci U S A 2019; 116:21191-21197. [PMID: 31488722 PMCID: PMC6800343 DOI: 10.1073/pnas.1903763116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Different memory components are forgotten through distinct molecular mechanisms. In Drosophila, the activation of 2 Rho GTPases (Rac1 and Cdc42), respectively, underlies the forgetting of an early labile memory (anesthesia-sensitive memory, ASM) and a form of consolidated memory (anesthesia-resistant memory, ARM). Here, we dissected the molecular mechanisms that tie Rac1 and Cdc42 to the different types of memory forgetting. We found that 2 WASP family proteins, SCAR/WAVE and WASp, act downstream of Rac1 and Cdc42 separately to regulate ASM and ARM forgetting in mushroom body neurons. Arp2/3 complex, which organizes branched actin polymerization, is a canonical downstream effector of WASP family proteins. However, we found that Arp2/3 complex is required in Cdc42/WASp-mediated ARM forgetting but not in Rac1/SCAR-mediated ASM forgetting. Instead, we identified that Rac1/SCAR may function with formin Diaphanous (Dia), a nucleator that facilitates linear actin polymerization, in ASM forgetting. The present study, complementing the previously identified Rac1/cofilin pathway that regulates actin depolymerization, suggests that Rho GTPases regulate forgetting by recruiting both actin polymerization and depolymerization pathways. Moreover, Rac1 and Cdc42 may regulate different types of memory forgetting by tapping into different actin polymerization mechanisms.
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Mariottini C, Munari L, Gunzel E, Seco JM, Tzavaras N, Hansen J, Stern SA, Gao V, Aleyasin H, Sharma A, Azeloglu EU, Hodes GE, Russo SJ, Huff V, Birtwistle MR, Blitzer RD, Alberini CM, Iyengar R. Wilm's tumor 1 promotes memory flexibility. Nat Commun 2019; 10:3756. [PMID: 31434897 PMCID: PMC6704057 DOI: 10.1038/s41467-019-11781-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 07/31/2019] [Indexed: 02/06/2023] Open
Abstract
Under physiological conditions, strength and persistence of memory must be regulated in order to produce behavioral flexibility. In fact, impairments in memory flexibility are associated with pathologies such as post-traumatic stress disorder or autism; however, the underlying mechanisms that enable memory flexibility are still poorly understood. Here, we identify transcriptional repressor Wilm's Tumor 1 (WT1) as a critical synaptic plasticity regulator that decreases memory strength, promoting memory flexibility. WT1 is activated in the hippocampus following induction of long-term potentiation (LTP) or learning. WT1 knockdown enhances CA1 neuronal excitability, LTP and long-term memory whereas its overexpression weakens memory retention. Moreover, forebrain WT1-deficient mice show deficits in both reversal, sequential learning tasks and contextual fear extinction, exhibiting impaired memory flexibility. We conclude that WT1 limits memory strength or promotes memory weakening, thus enabling memory flexibility, a process that is critical for learning from new experiences.
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Affiliation(s)
- Chiara Mariottini
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA.
- Systems Biology Center, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA.
| | - Leonardo Munari
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Ellen Gunzel
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
- Systems Biology Center, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Joseph M Seco
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Nikos Tzavaras
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Jens Hansen
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
- Systems Biology Center, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Sarah A Stern
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
- Center for Neural Science, New York University, New York, 10003, NY, USA
| | - Virginia Gao
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
- Center for Neural Science, New York University, New York, 10003, NY, USA
| | - Hossein Aleyasin
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Ali Sharma
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Evren U Azeloglu
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Georgia E Hodes
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Scott J Russo
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Vicki Huff
- Department of Genetics, M.D. Anderson Cancer Center, University of Texas, Houston, 77030, TX, USA
| | - Marc R Birtwistle
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
- Systems Biology Center, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Robert D Blitzer
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA
| | - Cristina M Alberini
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA.
- Center for Neural Science, New York University, New York, 10003, NY, USA.
| | - Ravi Iyengar
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA.
- Systems Biology Center, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, 10029, NY, USA.
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Inhibition of Rac1-dependent forgetting alleviates memory deficits in animal models of Alzheimer's disease. Protein Cell 2019; 10:745-759. [PMID: 31321704 PMCID: PMC6776562 DOI: 10.1007/s13238-019-0641-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/23/2019] [Indexed: 01/08/2023] Open
Abstract
Accelerated forgetting has been identified as a feature of Alzheimer's disease (AD), but the therapeutic efficacy of the manipulation of biological mechanisms of forgetting has not been assessed in AD animal models. Ras-related C3 botulinum toxin substrate 1 (Rac1), a small GTPase, has been shown to regulate active forgetting in Drosophila and mice. Here, we showed that Rac1 activity is aberrantly elevated in the hippocampal tissues of AD patients and AD animal models. Moreover, amyloid-beta 42 could induce Rac1 activation in cultured cells. The elevation of Rac1 activity not only accelerated 6-hour spatial memory decay in 3-month-old APP/PS1 mice, but also significantly contributed to severe memory loss in aged APP/PS1 mice. A similar age-dependent Rac1 activity-based memory loss was also observed in an AD fly model. Moreover, inhibition of Rac1 activity could ameliorate cognitive defects and synaptic plasticity in AD animal models. Finally, two novel compounds, identified through behavioral screening of a randomly selected pool of brain permeable small molecules for their positive effect in rescuing memory loss in both fly and mouse models, were found to be capable of inhibiting Rac1 activity. Thus, multiple lines of evidence corroborate in supporting the idea that inhibition of Rac1 activity is effective for treating AD-related memory loss.
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Pilarzyk K, Klett J, Pena EA, Porcher L, Smith AJ, Kelly MP. Loss of Function of Phosphodiesterase 11A4 Shows that Recent and Remote Long-Term Memories Can Be Uncoupled. Curr Biol 2019; 29:2307-2321.e5. [PMID: 31303492 DOI: 10.1016/j.cub.2019.06.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 03/06/2019] [Accepted: 06/07/2019] [Indexed: 12/19/2022]
Abstract
Systems consolidation is a process by which memories initially require the hippocampus for recent long-term memory (LTM) but then become increasingly independent of the hippocampus and more dependent on the cortex for remote LTM. Here, we study the role of phosphodiesterase 11A4 (PDE11A4) in systems consolidation. PDE11A4, which degrades cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), is preferentially expressed in neurons of CA1, the subiculum, and the adjacently connected amygdalohippocampal region. In male and female mice, deletion of PDE11A enhances remote LTM for social odor recognition and social transmission of food preference (STFP) despite eliminating or silencing recent LTM for those same social events. Measurement of a surrogate marker of neuronal activation (i.e., Arc mRNA) suggests the recent LTM deficits observed in Pde11 knockout mice correspond with decreased activation of ventral CA1 relative to wild-type littermates. In contrast, the enhanced remote LTM observed in Pde11a knockout mice corresponds with increased activation and altered functional connectivity of anterior cingulate cortex, frontal association cortex, parasubiculum, and the superficial layer of medial entorhinal cortex. The apparent increased neural activation observed in prefrontal cortex of Pde11a knockout mice during remote LTM retrieval may be related to an upregulation of the N-methyl-D-aspartate receptor subunits NR1 and NR2A. Viral restoration of PDE11A4 to vCA1 alone is sufficient to rescue both the LTM phenotypes and upregulation of NR1 exhibited by Pde11a knockout mice. Together, our findings suggest remote LTM can be decoupled from recent LTM, which may have relevance for cognitive deficits associated with aging, temporal lobe epilepsy, or transient global amnesia.
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Affiliation(s)
- Katy Pilarzyk
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, 6439 Garners Ferry Road, Columbia, SC 29209, USA
| | - Jennifer Klett
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, 6439 Garners Ferry Road, Columbia, SC 29209, USA
| | - Edsel A Pena
- Department of Statistics, University of South Carolina, 1523 Green Street, Columbia, SC 29201, USA
| | - Latarsha Porcher
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, 6439 Garners Ferry Road, Columbia, SC 29209, USA
| | - Abigail J Smith
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, 6439 Garners Ferry Road, Columbia, SC 29209, USA
| | - Michy P Kelly
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, 6439 Garners Ferry Road, Columbia, SC 29209, USA.
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48
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Karam CS, Jones SK, Javitch JA. Come Fly with Me: An overview of dopamine receptors in Drosophila melanogaster. Basic Clin Pharmacol Toxicol 2019; 126 Suppl 6:56-65. [PMID: 31219669 DOI: 10.1111/bcpt.13277] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/17/2019] [Indexed: 12/23/2022]
Abstract
Dopamine (DA) receptors play critical roles in a wide range of behaviours, including sensory processing, motor function, reward and arousal. As such, aberrant DA signalling is associated with numerous neurological and psychiatric disorders. Therefore, understanding the mechanisms by which DA neurotransmission drives intracellular signalling pathways that modulate behaviour can provide critical insights to guide the development of targeted therapeutics. Drosophila melanogaster has emerged as a powerful model with unique advantages to study the mechanisms underlying DA neurotransmission and associated behaviours in a controlled and systematic manner. Many regions in the fly brain innervated by dopaminergic neurons have been mapped and linked to specific behaviours, including associative learning and arousal. Here, we provide an overview of the homology between human and Drosophila dopaminergic systems and review the current literature on the pharmacology, molecular signalling mechanisms and behavioural outcome of DA receptor activation in the Drosophila brain.
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Affiliation(s)
- Caline S Karam
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York City, New York, USA.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York City, New York, USA
| | - Sandra K Jones
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York City, New York, USA.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York City, New York, USA
| | - Jonathan A Javitch
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York City, New York, USA.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York City, New York, USA.,Department of Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, New York City, New York, USA
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49
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Castillo Díaz F, Hernandez MA, Capellá T, Medina JH. Dopamine Neurotransmission in the Ventral Tegmental Area Promotes Active Forgetting of Cocaine-Associated Memory. Mol Neurobiol 2019; 56:6206-6217. [DOI: 10.1007/s12035-019-1516-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 01/28/2019] [Indexed: 10/27/2022]
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50
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Bonello TT, Peifer M. Scribble: A master scaffold in polarity, adhesion, synaptogenesis, and proliferation. J Cell Biol 2018; 218:742-756. [PMID: 30598480 PMCID: PMC6400555 DOI: 10.1083/jcb.201810103] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/26/2018] [Accepted: 12/14/2018] [Indexed: 02/08/2023] Open
Abstract
Key events ranging from cell polarity to proliferation regulation to neuronal signaling rely on the assembly of multiprotein adhesion or signaling complexes at particular subcellular sites. Multidomain scaffolding proteins nucleate assembly and direct localization of these complexes, and the protein Scribble and its relatives in the LAP protein family provide a paradigm for this. Scribble was originally identified because of its role in apical-basal polarity and epithelial integrity in Drosophila melanogaster It is now clear that Scribble acts to assemble and position diverse multiprotein complexes in processes ranging from planar polarity to adhesion to oriented cell division to synaptogenesis. Here, we explore what we have learned about the mechanisms of action of Scribble in the context of its multiple known interacting partners and discuss how this knowledge opens new questions about the full range of Scribble protein partners and their structural and signaling roles.
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Affiliation(s)
- Teresa T Bonello
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Mark Peifer
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC .,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
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