1
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Dalto JF, Medina JH, Pastor V. Molecular Underpinnings of Memory Persistence and Forgetting. J Neurochem 2025; 169:e70089. [PMID: 40411122 DOI: 10.1111/jnc.70089] [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: 02/19/2025] [Revised: 05/07/2025] [Accepted: 05/08/2025] [Indexed: 05/26/2025]
Abstract
The fate of memories depends mainly on external and internal factors affecting cellular and systems consolidation on the one hand and the decay or weakening of the memory trace on the other hand. Over the past 40 years, research has focused on the mechanisms of memory consolidation, retrieval, and its consequences: extinction and reconsolidation. In contrast, much less is known about the molecular mechanisms required for the maintenance of memory storage and forgetting. These opposing forces are both activity- and time-dependent. Here, we summarize the molecular signatures and inherent mechanisms involved in memory persistence and active forgetting, highlighting recent findings on the role of dopamine neurotransmission, intracellular signaling cascades, and actin cytoskeleton dynamics in these processes.
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Affiliation(s)
- Juliana F Dalto
- Instituto Tecnológico de Buenos Aires (ITBA), Buenos Aires, Argentina
| | - Jorge H Medina
- Instituto Tecnológico de Buenos Aires (ITBA), Buenos Aires, Argentina
- Instituto de Biología Celular y Neurociencias "Prof. Eduardo De Robertis", CONICET-UBA, Buenos Aires, Argentina
| | - Verónica Pastor
- Instituto de Biología Celular y Neurociencias "Prof. Eduardo De Robertis", CONICET-UBA, Buenos Aires, Argentina
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2
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Larner AJ. An "Engram-Centric" Approach to Transient Global Amnesia (TGA) and Other Acute-Onset Amnesias. Neurol Int 2025; 17:8. [PMID: 39852772 PMCID: PMC11767542 DOI: 10.3390/neurolint17010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2024] [Revised: 01/04/2025] [Accepted: 01/09/2025] [Indexed: 01/26/2025] Open
Abstract
The differential diagnosis of acute-onset amnesia includes transient global amnesia (TGA), transient epileptic amnesia (TEA), and functional (or psychogenic) amnesia. The most common of these, TGA, is a rare but well-described condition characterised by a self-limited episode of dense anterograde amnesia with variable retrograde amnesia. Although the clinical phenomenology of TGA is well described, its pathogenesis is not currently understood, thus preventing the development of evidence-based therapeutic recommendations. Here, TGA, TEA, and functional amnesia are considered in light of the historical engram conception of memory, now informed by recent experimental research, as disturbances in distributed ensembles of engram neurones active during memory formation and recall. This analysis affords therapeutic implications for these conditions, should interventions to reactivate latent or silent engrams become available.
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Affiliation(s)
- Andrew J Larner
- Department of Brain Repair & Rehabilitation, Institute of Neurology, University College London, London WC1E 6BT, UK
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3
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Jiao JJ, Hu Y, Cui YJ, Tuo CM, Wang YX, Li XY, Zhang Y, Wu MN. Anisomycin alleviates cognitive impairments and pathological features in 3xTg-AD mice. Neuropharmacology 2024; 261:110159. [PMID: 39303856 DOI: 10.1016/j.neuropharm.2024.110159] [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: 07/28/2024] [Revised: 08/29/2024] [Accepted: 09/12/2024] [Indexed: 09/22/2024]
Abstract
Neuroinflammation plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). Anisomycin is a pyrrolidine antibiotic isolated from Streptomyces griseolus, which is an efficient anti-inflammatory agent that functions both in vivo and in vitro. However, it is not clear whether anisomycin can exert neuroprotective effect in AD. In the present study, anisomycin was intragastrically administrated to female triple-transgenic AD (3xTg-AD) model mice, then Morris water maze test was used to observe the long-term spatial memory of mice, the in vivo hippocampal field potential recording was performed to evaluate the synaptic plasticity, the Western blot and immunofluorescence were employed to detect pathological changes, and the bioinformatics analysis was used to predict the potential target of anisomycin exerting effects in AD. The results showed that anisomycin ameliorated the long-term spatial memory deficits, improved LTP depression and increased the expression of PSD-95, reduced the Aβ and tau pathologies, and alleviated the activation of microglia and astrocytes in the brains of 3xTg-AD mice. In addition, the results from bioinformatics analysis showed that the potential target of anisomycin focused on inflammatory pathway. These results indicated that anisomycin exerts neuroprotective effects in 3xTg-AD mice by alleviating neuroinflammation, but the potential mechanism of anisomycin exerting neuroprotective effects needs to be further investigated.
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Affiliation(s)
- Juan-Juan Jiao
- Department of Physiology Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology in Shanxi Province, Shanxi Medical University, Taiyuan, China
| | - Yang Hu
- Department of Pharmacology, Shanxi Medical University, Taiyuan, China
| | - Yu-Jia Cui
- Department of Physiology Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology in Shanxi Province, Shanxi Medical University, Taiyuan, China
| | - Chun-Mei Tuo
- Department of Physiology Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology in Shanxi Province, Shanxi Medical University, Taiyuan, China
| | - Yi-Xuan Wang
- School of Basic Medicine, Shanxi Medical University, Taiyuan, China
| | - Xin-Yi Li
- Department of Neurology, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences Tongji Shanxi Hospital, Taiyuan, China
| | - Yi Zhang
- Department of Pharmacology, Shanxi Medical University, Taiyuan, China.
| | - Mei-Na Wu
- Department of Physiology Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China; Key Laboratory of Cellular Physiology in Shanxi Province, Shanxi Medical University, Taiyuan, China.
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4
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Abstract
Memories are stored as ensembles of engram neurons and their successful recall involves the reactivation of these cellular networks. However, significant gaps remain in connecting these cell ensembles with the process of forgetting. Here, we utilized a mouse model of object memory and investigated the conditions in which a memory could be preserved, retrieved, or forgotten. Direct modulation of engram activity via optogenetic stimulation or inhibition either facilitated or prevented the recall of an object memory. In addition, through behavioral and pharmacological interventions, we successfully prevented or accelerated forgetting of an object memory. Finally, we showed that these results can be explained by a computational model in which engrams that are subjectively less relevant for adaptive behavior are more likely to be forgotten. Together, these findings suggest that forgetting may be an adaptive form of engram plasticity which allows engrams to switch from an accessible state to an inaccessible state.
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Affiliation(s)
- James D O'Leary
- School of Biochemistry and Immunology, Trinity College DublinDublinIreland
- Trinity College Institute of Neuroscience, Trinity College DublinDublinIreland
| | - Rasmus Bruckner
- Trinity College Institute of Neuroscience, Trinity College DublinDublinIreland
- Department of Education and Psychology, Freie Universität BerlinBerlinGermany
- Max Planck Research Group NeuroCode, Max Planck Institute for Human DevelopmentBerlinGermany
| | - Livia Autore
- School of Biochemistry and Immunology, Trinity College DublinDublinIreland
- Trinity College Institute of Neuroscience, Trinity College DublinDublinIreland
| | - Tomás J Ryan
- School of Biochemistry and Immunology, Trinity College DublinDublinIreland
- Trinity College Institute of Neuroscience, Trinity College DublinDublinIreland
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of MelbourneMelbourneAustralia
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR)TorontoCanada
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5
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Berry JA, Guhle DC, Davis RL. Active forgetting and neuropsychiatric diseases. Mol Psychiatry 2024; 29:2810-2820. [PMID: 38532011 PMCID: PMC11420092 DOI: 10.1038/s41380-024-02521-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [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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6
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Pomi A, Lin J, Mizraji E. A memory access gate controlled by dynamic contexts. Biosystems 2024; 241:105232. [PMID: 38754622 DOI: 10.1016/j.biosystems.2024.105232] [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: 03/05/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024]
Abstract
Temporary difficulties in accessing the contents of memories are a common experience in everyday life, for example, when we try to recognize a known person in an unusual context. In addition, recent experiments seem to indicate that retrograde amnesia in the early stages of Alzheimer's disease is due to disorders in accessing memories that were installed normally. These facts suggest the existence of an intermediate step between the stimulus arrival and the associative recognition. In this work, a multimodular neurocomputational model is presented postulating the existence of a neural gate that controls the access of the stimulus with its context to the consolidated memory. If recognition is not achieved, a random search is initiated in a contextual network aroused by the initial context. The search continues until the appropriate context that allows for recognition is found or until the process is turned off because the initial stimulus is no longer maintained in the working memory. The model is based on vector patterns of neural activity and context-dependent matrix memories. Simple Markov chain simulations are presented to exemplify possible search scenarios in the contextual network. Finally, we discuss some of the characteristics of the model and the phenomenon under study.
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Affiliation(s)
- Andrés Pomi
- Group of Cognitive Systems Modeling, Biophysics and Systems Biology Section, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay.
| | - Juan Lin
- Group of Cognitive Systems Modeling, Biophysics and Systems Biology Section, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay; Physics Department, Washington College, Chestertown, MD, 21620, USA
| | - Eduardo Mizraji
- Group of Cognitive Systems Modeling, Biophysics and Systems Biology Section, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
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7
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Lazarov O, Gupta M, Kumar P, Morrissey Z, Phan T. Memory circuits in dementia: The engram, hippocampal neurogenesis and Alzheimer's disease. Prog Neurobiol 2024; 236:102601. [PMID: 38570083 PMCID: PMC11221328 DOI: 10.1016/j.pneurobio.2024.102601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 03/20/2024] [Accepted: 03/22/2024] [Indexed: 04/05/2024]
Abstract
Here, we provide an in-depth consideration of our current understanding of engrams, spanning from molecular to network levels, and hippocampal neurogenesis, in health and Alzheimer's disease (AD). This review highlights novel findings in these emerging research fields and future research directions for novel therapeutic avenues for memory failure in dementia. Engrams, memory in AD, and hippocampal neurogenesis have each been extensively studied. The integration of these topics, however, has been relatively less deliberated, and is the focus of this review. We primarily focus on the dentate gyrus (DG) of the hippocampus, which is a key area of episodic memory formation. Episodic memory is significantly impaired in AD, and is also the site of adult hippocampal neurogenesis. Advancements in technology, especially opto- and chemogenetics, have made sophisticated manipulations of engram cells possible. Furthermore, innovative methods have emerged for monitoring neurons, even specific neuronal populations, in vivo while animals engage in tasks, such as calcium imaging. In vivo calcium imaging contributes to a more comprehensive understanding of engram cells. Critically, studies of the engram in the DG using these technologies have shown the important contribution of hippocampal neurogenesis for memory in both health and AD. Together, the discussion of these topics provides a holistic perspective that motivates questions for future research.
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Affiliation(s)
- Orly Lazarov
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA.
| | - Muskan Gupta
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Pavan Kumar
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Zachery Morrissey
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Trongha Phan
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
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8
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O'Sullivan FM, Ryan TJ. If Engrams Are the Answer, What Is the Question? ADVANCES IN NEUROBIOLOGY 2024; 38:273-302. [PMID: 39008021 DOI: 10.1007/978-3-031-62983-9_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Engram labelling and manipulation methodologies are now a staple of contemporary neuroscientific practice, giving the impression that the physical basis of engrams has been discovered. Despite enormous progress, engrams have not been clearly identified, and it is unclear what they should look like. There is an epistemic bias in engram neuroscience toward characterizing biological changes while neglecting the development of theory. However, the tools of engram biology are exciting precisely because they are not just an incremental step forward in understanding the mechanisms of plasticity and learning but because they can be leveraged to inform theory on one of the fundamental mysteries in neuroscience-how and in what format the brain stores information. We do not propose such a theory here, as we first require an appreciation for what is lacking. We outline a selection of issues in four sections from theoretical biology and philosophy that engram biology and systems neuroscience generally should engage with in order to construct useful future theoretical frameworks. Specifically, what is it that engrams are supposed to explain? How do the different building blocks of the brain-wide engram come together? What exactly are these component parts? And what information do they carry, if they carry anything at all? Asking these questions is not purely the privilege of philosophy but a key to informing scientific hypotheses that make the most of the experimental tools at our disposal. The risk for not engaging with these issues is high. Without a theory of what engrams are, what they do, and the wider computational processes they fit into, we may never know when they have been found.
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Affiliation(s)
- Fionn M O'Sullivan
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Tomás J Ryan
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland.
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia.
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada.
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9
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Brosens N, Lesuis SL, Rao-Ruiz P, van den Oever MC, Krugers HJ. Shaping Memories Via Stress: A Synaptic Engram Perspective. Biol Psychiatry 2023:S0006-3223(23)01720-1. [PMID: 37977215 DOI: 10.1016/j.biopsych.2023.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 10/09/2023] [Accepted: 11/05/2023] [Indexed: 11/19/2023]
Abstract
Stress modulates the activity of various memory systems and can thereby guide behavioral interaction with the environment in an adaptive or maladaptive manner. At the cellular level, a large body of evidence indicates that (nor)adrenaline and glucocorticoid release induced by acute stress exposure affects synapse function and synaptic plasticity, which are critical substrates for learning and memory. Recent evidence suggests that memories are supported in the brain by sparsely distributed neurons within networks, termed engram cell ensembles. While the physiological and molecular effects of stress on the synapse are increasingly well characterized, how these synaptic modifications shape the multiscale dynamics of engram cell ensembles is still poorly understood. In this review, we discuss and integrate recent information on how acute stress affects synapse function and how this may alter engram cell ensembles and their synaptic connectivity to shape memory strength and memory precision. We provide a mechanistic framework of a synaptic engram under stress and put forward outstanding questions that address knowledge gaps in our understanding of the mechanisms that underlie stress-induced memory modulation.
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Affiliation(s)
- Niek Brosens
- Brain Plasticity Group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands.
| | - Sylvie L Lesuis
- Brain Plasticity Group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands; Cellular and Cognitive Neuroscience group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands
| | - Priyanka Rao-Ruiz
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Harm J Krugers
- Brain Plasticity Group, Swammerdam Institute for Life Sciences-Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands.
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10
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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: 5] [Impact Index Per Article: 2.5] [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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11
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Li M, Wang L, Guo S, Huang N, Ai H. Cordycepin buffers anisomycin-induced fear memory deficit by restoring hippocampal BDNF. Biochem Biophys Res Commun 2023; 665:118-123. [PMID: 37156049 DOI: 10.1016/j.bbrc.2023.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/23/2023] [Accepted: 05/02/2023] [Indexed: 05/10/2023]
Abstract
The process of memory consolidation involves the synthesis of new proteins, and interfering with protein synthesis through anisomycin can impair memory. Memory deficits due to aging and sleep disorders may also result from a reduction in protein synthesis. Rescuing memory deficits caused by protein synthesis deficiency is therefore an important issue that needs to be addressed. Our study focused on the effects of cordycepin on fear memory deficits induced by anisomycin using contextual fear conditioning. We observed that cordycepin was able to attenuate these deficits and restore BDNF levels in the hippocampus. The behavioral effects of cordycepin were dependent on the BDNF/TrkB pathway, as demonstrated by the use of ANA-12. Cordycepin had no significant impact on locomotor activity, anxiety or fear memory. Our findings provide the first evidence that cordycepin can prevent anisomycin-induced memory deficits by regulating BDNF expression in the hippocampus.
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Affiliation(s)
- Minghao Li
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Li Wang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Siyuan Guo
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Nan Huang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Heng Ai
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, China.
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12
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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: 6] [Impact Index Per Article: 3.0] [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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13
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Gatica S, Aravena C, Prado Y, Aravena D, Echeverría C, Santibanez JF, Riedel CA, Stehberg J, Simon F. Appraisal of the Neuroprotective Effect of Dexmedetomidine: A Meta-Analysis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1408:163-181. [PMID: 37093427 DOI: 10.1007/978-3-031-26163-3_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Dexmedetomidine is an adrenergic receptor agonist that has been regarded as neuroprotective in several studies without an objective measure to it. Thus, the aim of this meta-analysis was to analyze and quantify the current evidence for the neuroprotective effects of dexmedetomidine in animals. The search was performed by querying the National Library of Medicine. Studies were included based on their language, significancy of their results, and complete availability of data on animal characteristics and interventions. Risk of bias was assessed using SYRCLE's risk of bias tool and certainty was assessed using the ARRIVE Guidelines 2.0. Synthesis was performed by calculating pooled standardized mean difference and presented in forest plots and tables. The number of eligible records included per outcome is the following: 22 for IL-1β, 13 for IL-6, 19 for apoptosis, 7 for oxidative stress, 7 for Escape Latency, and 4 for Platform Crossings. At the cellular level, dexmedetomidine was found protective against production of IL-1β (standardized mean difference (SMD) = - 4.3 [- 4.8; - 3.7]) and IL-6 (SMD = - 5.6 [- 6.7; - 4.6]), apoptosis (measured through TUNEL, SMD = - 6.0 [- 6.8; - 4.6]), and oxidative stress (measured as MDA production, SMD = - 2.0 [- 2.4; - 1.4]) exclusively in the central nervous system. At the organism level, dexmedetomidine improved behavioral outcomes measuring escape latency (SMD = - 2.4 [- 3.3; - 1.6]) and number of platform crossings (SMD = 9.1 [- 6.8; - 11.5]). No eligible study had high risk of bias and certainty was satisfactory for reproducibility in all cases. This meta-analysis highlights the complexity of adrenergic stimulation and sheds light into the mechanisms potentiated by dexmedetomidine, which could be exploited for improving current neuroprotective formulations.
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Affiliation(s)
- Sebastian Gatica
- Laboratory of Integrative Physiopathology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile.
| | - Cristobal Aravena
- Laboratory of Integrative Physiopathology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Yolanda Prado
- Laboratory of Integrative Physiopathology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Diego Aravena
- Laboratory of Integrative Physiopathology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Cesar Echeverría
- Laboratory of Molecular Biology, Nanomedicine and Genomics, Faculty of Medicine, University of Atacama, Copiapo, Chile
| | - Juan F Santibanez
- Institute for Medical Research, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
- Integrative Center for Biology and Applied Chemistry (CIBQA), Bernardo O'Higgins University, Santiago, Chile
| | - Claudia A Riedel
- Laboratory of Integrative Physiopathology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Jimmy Stehberg
- Laboratory of Neurobiology, Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Felipe Simon
- Laboratory of Integrative Physiopathology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile.
- Millennium Nucleus of Ion Channel-Associated Diseases, Universidad de Chile, Santiago, Chile.
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14
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Bailly C, Beignet J, Loirand G, Sauzeau V. Rac1 as a therapeutic anticancer target: Promises and limitations. Biochem Pharmacol 2022; 203:115180. [PMID: 35853497 DOI: 10.1016/j.bcp.2022.115180] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/13/2022] [Accepted: 07/13/2022] [Indexed: 11/16/2022]
Abstract
Small molecule inhibitors of GTPases are increasingly considered for the treatment of multiple human pathologies. The GTPase Rac1 (Ras-related C3 botulinum toxin substrate 1) plays major roles in vital cellular processes, notably in the control cell motility and dynamic, the regulation of oxidative stress, and in inflammatory and immune surveillance. As such, Rac1 is viewed as a potential target to combat cancers but also diverse inflammatory, metabolic, neurodegenerative, respiratory, cardiovascular, viral, and parasitic diseases. Potent and selective Rac1 inhibitors have been identified and designed, such as compounds GYS32661 and MBQ-167 both in preclinical development for the treatment of advanced solid tumors. The pleiotropic roles and ubiquitous expression of the protein can be viewed as limitations for anticancer approaches. However, the frequent overexpression and/or hyperactivation of the Rac1 in difficult-to-treat chemoresistant cancers, make Rac1 an attractive target in oncology. The key roles of Rac1 in multiple cellular pathways, together with its major implications in carcinogenesis, tumor proliferation and metastasis, support the development of small molecule inhibitors. The challenge is high and the difficulty shall not be underestimated, but the target is innovative and promising in combination with chemo- and/or immuno-therapy. Opportunities and challenges associated with the targeting of Rac1 are discussed.
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Affiliation(s)
- Christian Bailly
- OncoWitan, Scientific Consulting Office, Lille (Wasquehal), 59290, France.
| | - Julien Beignet
- SATT Ouest Valorisation, 30 boulevard Vincent Gâche, CS 70211, 44202 Nantes cedex, France
| | - Gervaise Loirand
- Université de Nantes, CHU Nantes, CNRS, INSERM, Institut du thorax, Nantes, France
| | - Vincent Sauzeau
- Université de Nantes, CHU Nantes, CNRS, INSERM, Institut du thorax, Nantes, France
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