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Almaguer-Melian W, Mercerón-Martínez D, Alacán-Ricardo L, Piña AEV, Hsieh C, Bergado-Rosado JA, Sacktor TC. Amygdala stimulation transforms short-term memory into remote memory by persistent activation of atypical protein kinase C in the anterior cingulate cortex. Neuroscience 2025; 569:288-297. [PMID: 39900220 DOI: 10.1016/j.neuroscience.2025.01.065] [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: 09/17/2024] [Revised: 12/16/2024] [Accepted: 01/31/2025] [Indexed: 02/05/2025]
Abstract
Although many studies have addressed the role of the amygdala in modulating long-term memory, it is not known whether weak training plus amygdala stimulation can transform a short-term memory into a remote memory. Object place recognition (OPR) memory after strong training remains hippocampus-dependent through the persistent action of protein kinase Mzeta (PKMζ) for at least 6 days, but it is unknown whether weak training plus amygdala stimulation can transform short-term memory into an even longer memory, and whether such memory is stored through more persistent action of PKMζ in hippocampus. We trained male rats (150 total in our study) to acquire OPR and 15 min or 5 h later induced a brief pattern of electrical stimulation in basolateral amygdala (BLA). Our results reveal that a short-term memory lasting < 4h can be converted into remote memory lasting at least 3 weeks if the BLA is activated 15 min, but not 5 h after learning. To examine how this remote memory is maintained, we injected ZIP, an inhibitor of atypical protein kinase Cs (aPKCs), PKMζ and PKCι/λ, into either hippocampal CA1, dentate gyrus (DG), or anterior cingulate cortex (ACC). Our data reveal amygdala stimulation produces consolidation into remote memory, not by persistent aPKC activation in the hippocampal formation, but in ACC. Our data establish a powerful modulating role of the BLA in forming remote memory and open a path in the search for neurological restoration of memory, based on enhancing synaptic plasticity in aging or neurodegenerative disorders such as Alzheimer's disease.
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Affiliation(s)
- William Almaguer-Melian
- Laboratorio de Electrofisiología Experimental del Centro Internacional de Restauración Neurológica CIREN La Habana Cuba
| | - Daymara Mercerón-Martínez
- Laboratorio de Electrofisiología Experimental del Centro Internacional de Restauración Neurológica CIREN La Habana Cuba
| | - Laura Alacán-Ricardo
- Facultad de Medicina Victoria de Girón Universidad Médica de La Habana La Habana Cuba
| | | | - Changchi Hsieh
- Department of Physiology and Pharmacology, State University of New York Downstate Health Sciences University NY USA
| | | | - Todd Charlton Sacktor
- Department of Physiology and Pharmacology, State University of New York Downstate Health Sciences University NY USA; Departments of Neurology and Anesthesiology, State University of New York Downstate Health Sciences University NY USA.
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2
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Yang X, Miao X, Schweiggart F, Großmann S, Rauss K, Hallschmid M, Born J, Lutz ND. The effect of fasting on human memory consolidation. Neurobiol Learn Mem 2025; 218:108034. [PMID: 39938634 DOI: 10.1016/j.nlm.2025.108034] [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: 08/16/2024] [Revised: 12/17/2024] [Accepted: 02/08/2025] [Indexed: 02/14/2025]
Abstract
The consolidation of long-term memory is thought to critically rely on sleep. However, first evidence from a study in Drosophila suggests that hunger, as another brain state, can benefit memory consolidation as well. Here, we report two human (within-subjects crossover) experiments examining the effects of fasting (versus satiated conditions) during a 10-hour post-encoding consolidation period on subsequent recall of declarative and procedural memories in healthy men. In Experiment 1, participants (n = 16), after an 18.5-hour fasting period, encoded 3 memory tasks (word paired associates, a visual version of the Deese-Roediger-McDermott task, finger tapping) and subsequently either continued to fast or received standardized meals. Recall was tested 48 h later in a satiated state. Experiment 2 (n = 16 participants) differed from Experiment 1 in that a What-Where-When episodic memory task replaced the Deese-Roediger-McDermott task and recall was tested only 24 h later in a fasted state. Compared with the satiated state, fasting enhanced cued recall of word paired associates (more correct and faster responses) and item recognition in the What-Where-When task. By contrast, fasting impaired recall of episodic context memory, i.e., spatial context in the Deese-Roediger-McDermott task, and temporal-spatial context in the What-Where-When task. Procedural memory (finger tapping) remained unaffected. This pattern suggests a differential effect of fasting selectively promoting consolidation of semantic-like representations in cortical networks whereas hippocampal representations of episodic context are weakened. We speculate that hunger strengthens cortical representations by suppressing hippocampal interference during wake consolidation. Yet, the underlying mechanism remains to be clarified.
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Affiliation(s)
- Xuefeng Yang
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany; Graduate School of Neural & Behavioural Science, International Max Planck Research School, Tübingen, Germany
| | - Xiu Miao
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany; Graduate School of Neural & Behavioural Science, International Max Planck Research School, Tübingen, Germany
| | - Franziska Schweiggart
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Sophia Großmann
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Karsten Rauss
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Manfred Hallschmid
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany; German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research & Metabolic Diseases of the Helmholtz Center Munich at the University Tübingen (IDM), Germany; German Center for Mental Health (DZPG), Tübingen, Germany
| | - Jan Born
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany; German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research & Metabolic Diseases of the Helmholtz Center Munich at the University Tübingen (IDM), Germany; German Center for Mental Health (DZPG), Tübingen, Germany; Werner Reichert Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany.
| | - Nicolas D Lutz
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany; Institute of Medical Psychology, LMU Munich, Munich, Germany
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Loetscher KB, Goldfarb EV. Integrating and fragmenting memories under stress and alcohol. Neurobiol Stress 2024; 30:100615. [PMID: 38375503 PMCID: PMC10874731 DOI: 10.1016/j.ynstr.2024.100615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/03/2024] [Accepted: 02/06/2024] [Indexed: 02/21/2024] Open
Abstract
Stress can powerfully influence the way we form memories, particularly the extent to which they are integrated or situated within an underlying spatiotemporal and broader knowledge architecture. These different representations in turn have significant consequences for the way we use these memories to guide later behavior. Puzzlingly, although stress has historically been argued to promote fragmentation, leading to disjoint memory representations, more recent work suggests that stress can also facilitate memory binding and integration. Understanding the circumstances under which stress fosters integration will be key to resolving this discrepancy and unpacking the mechanisms by which stress can shape later behavior. Here, we examine memory integration at multiple levels: linking together the content of an individual experience, threading associations between related but distinct events, and binding an experience into a pre-existing schema or sense of causal structure. We discuss neural and cognitive mechanisms underlying each form of integration as well as findings regarding how stress, aversive learning, and negative affect can modulate each. In this analysis, we uncover that stress can indeed promote each level of integration. We also show how memory integration may apply to understanding effects of alcohol, highlighting extant clinical and preclinical findings and opportunities for further investigation. Finally, we consider the implications of integration and fragmentation for later memory-guided behavior, and the importance of understanding which type of memory representation is potentiated in order to design appropriate interventions.
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Affiliation(s)
| | - Elizabeth V. Goldfarb
- Department of Psychiatry, Yale University, USA
- Department of Psychology, Yale University, USA
- Wu Tsai Institute, Yale University, USA
- National Center for PTSD, West Haven VA, USA
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4
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Xu S, Momin M, Ahmed S, Hossain A, Veeramuthu L, Pandiyan A, Kuo CC, Zhou T. Illuminating the Brain: Advances and Perspectives in Optoelectronics for Neural Activity Monitoring and Modulation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303267. [PMID: 37726261 DOI: 10.1002/adma.202303267] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/30/2023] [Indexed: 09/21/2023]
Abstract
Optogenetic modulation of brain neural activity that combines optical and electrical modes in a unitary neural system has recently gained robust momentum. Controlling illumination spatial coverage, designing light-activated modulators, and developing wireless light delivery and data transmission are crucial for maximizing the use of optical neuromodulation. To this end, biocompatible electrodes with enhanced optoelectrical performance, device integration for multiplexed addressing, wireless transmission, and multimodal operation in soft systems have been developed. This review provides an outlook for uniformly illuminating large brain areas while spatiotemporally imaging the neural responses upon optoelectrical stimulation with little artifacts. Representative concepts and important breakthroughs, such as head-mounted illumination, multiple implanted optical fibers, and micro-light-delivery devices, are discussed. Examples of techniques that incorporate electrophysiological monitoring and optoelectrical stimulation are presented. Challenges and perspectives are posed for further research efforts toward high-density optoelectrical neural interface modulation, with the potential for nonpharmacological neurological disease treatments and wireless optoelectrical stimulation.
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Affiliation(s)
- Shumao Xu
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Marzia Momin
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Salahuddin Ahmed
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Arafat Hossain
- Department of Electrical Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
| | - Loganathan Veeramuthu
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei, 10608, Republic of China
| | - Archana Pandiyan
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei, 10608, Republic of China
| | - Chi-Ching Kuo
- Department of Molecular Science and Engineering, National Taipei University of Technology, Taipei, 10608, Republic of China
| | - Tao Zhou
- Department of Engineering Science and Mechanics, Center for Neural Engineering, The Pennsylvania State University, Pennsylvania, 16802, USA
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Gao TT, Oh T, Mehta K, Huang YA, Camp T, Fan H, Han JW, Barnes CM, Zhang K. The clinical potential of optogenetic interrogation of pathogenesis. Clin Transl Med 2023; 13:e1243. [PMID: 37132114 PMCID: PMC10154842 DOI: 10.1002/ctm2.1243] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/05/2023] [Accepted: 04/13/2023] [Indexed: 05/04/2023] Open
Abstract
BACKGROUND Opsin-based optogenetics has emerged as a powerful biomedical tool using light to control protein conformation. Such capacity has been initially demonstrated to control ion flow across the cell membrane, enabling precise control of action potential in excitable cells such as neurons or muscle cells. Further advancement in optogenetics incorporates a greater variety of photoactivatable proteins and results in flexible control of biological processes, such as gene expression and signal transduction, with commonly employed light sources such as LEDs or lasers in optical microscopy. Blessed by the precise genetic targeting specificity and superior spatiotemporal resolution, optogenetics offers new biological insights into physiological and pathological mechanisms underlying health and diseases. Recently, its clinical potential has started to be capitalized, particularly for blindness treatment, due to the convenient light delivery into the eye. AIMS AND METHODS This work summarizes the progress of current clinical trials and provides a brief overview of basic structures and photophysics of commonly used photoactivable proteins. We highlight recent achievements such as optogenetic control of the chimeric antigen receptor, CRISPR-Cas system, gene expression, and organelle dynamics. We discuss conceptual innovation and technical challenges faced by current optogenetic research. CONCLUSION In doing so, we provide a framework that showcases ever-growing applications of optogenetics in biomedical research and may inform novel precise medicine strategies based on this enabling technology.
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Affiliation(s)
- Tianyu Terry Gao
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
| | - Teak‐Jung Oh
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
| | - Kritika Mehta
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
| | - Yu‐En Andrew Huang
- University of Illinois at Urbana‐ChampaignCenter for Biophysics and Quantitative BiologyUrbanaIllinoisUSA
| | - Tyler Camp
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
| | - Huaxun Fan
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
| | - Jeong Won Han
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
| | - Collin Michael Barnes
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
| | - Kai Zhang
- University of Illinois at Urbana‐ChampaignDepartment of BiochemistryUrbanaIllinoisUSA
- University of Illinois at Urbana‐ChampaignCenter for Biophysics and Quantitative BiologyUrbanaIllinoisUSA
- Cancer Center at IllinoisUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
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6
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Moscovitch M, Gilboa A. Has the concept of systems consolidation outlived its usefulness? Identification and evaluation of premises underlying systems consolidation. Fac Rev 2022; 11:33. [PMID: 36532709 PMCID: PMC9720899 DOI: 10.12703/r/11-33] [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] [Indexed: 10/15/2023] Open
Abstract
Systems consolidation has mostly been treated as a neural construct defined by the time-dependent change in memory representation from the hippocampus (HPC) to other structures, primarily the neocortex. Here, we identify and evaluate the explicit and implicit premises that underlie traditional or standard models and theories of systems consolidation based on evidence from research on humans and other animals. We use the principle that changes in neural representation over time and experience are accompanied by corresponding changes in psychological representations, and vice versa, to argue that each of the premises underlying traditional or standard models and theories of systems consolidation is found wanting. One solution is to modify or abandon the premises or theories and models. This is reflected in moderated models of systems consolidation that emphasize the early role of the HPC in training neocortical memories until they stabilize. The fault, however, may lie in the very concept of systems consolidation and its defining feature. We propose that the concept be replaced by one of memory systems reorganization, which does not carry the theoretical baggage of systems consolidation and is flexible enough to capture the dynamic nature of memory from inception to very long-term retention and retrieval at a psychological and neural level. The term "memory system reorganization" implies that memory traces are not fixed, even after they are presumably consolidated. Memories can continue to change as a result of experience and interactions among memory systems across the lifetime. As will become clear, hippocampal training of neocortical memories is only one type of such interaction, and not always the most important one, even at inception. We end by suggesting some principles of memory reorganization that can help guide research on dynamic memory processes that capture corresponding changes in memory at the psychological and neural levels.
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Affiliation(s)
- Morris Moscovitch
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Rotman Research Institute, Baycrest, Toronto, ON, Canada
| | - Asaf Gilboa
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Rotman Research Institute, Baycrest, Toronto, ON, Canada
- Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada
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7
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Zorzo C, Arias JL, Méndez M. Functional neuroanatomy of allocentric remote spatial memory in rodents. Neurosci Biobehav Rev 2022; 136:104609. [PMID: 35278596 DOI: 10.1016/j.neubiorev.2022.104609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/03/2022] [Accepted: 03/06/2022] [Indexed: 12/12/2022]
Abstract
Successful spatial cognition involves learning, consolidation, storage, and later retrieval of a spatial memory trace. The functional contributions of specific brain areas and their interactions during retrieval of past spatial events are unclear. This systematic review collects studies about allocentric remote spatial retrieval assessed at least two weeks post-acquisition in rodents. Results including non-invasive interventions, brain lesion and inactivation experiments, pharmacological treatments, chemical agent administration, and genetic manipulations revealed that there is a normal forgetting when time-periods are close to or exceed one month. Moreover, changes in the morphology and functionality of neocortical areas, hippocampus, and other subcortical structures, such as the thalamus, have been extensively observed as a result of spatial memory retrieval. In conclusion, apart from an increasingly neocortical recruitment in remote spatial retrieval, the hippocampus seems to participate in the retrieval of fine spatial details. These results help to better understand the timing of memory maintenance and normal forgetting, outlining the underlying brain areas implicated.
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Affiliation(s)
- Candela Zorzo
- Department of Psychology, University of Oviedo, Faculty of Psychology, Plaza Feijoo s/n, 33003 Oviedo, Asturias, Spain; Neuroscience Institute of Principado de Asturias (INEUROPA).
| | - Jorge L Arias
- Department of Psychology, University of Oviedo, Faculty of Psychology, Plaza Feijoo s/n, 33003 Oviedo, Asturias, Spain; Neuroscience Institute of Principado de Asturias (INEUROPA).
| | - Marta Méndez
- Department of Psychology, University of Oviedo, Faculty of Psychology, Plaza Feijoo s/n, 33003 Oviedo, Asturias, Spain; Neuroscience Institute of Principado de Asturias (INEUROPA).
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8
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Olfactory Optogenetics: Light Illuminates the Chemical Sensing Mechanisms of Biological Olfactory Systems. BIOSENSORS-BASEL 2021; 11:bios11090309. [PMID: 34562900 PMCID: PMC8470751 DOI: 10.3390/bios11090309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/17/2021] [Accepted: 08/27/2021] [Indexed: 01/26/2023]
Abstract
The mammalian olfactory system has an amazing ability to distinguish thousands of odorant molecules at the trace level. Scientists have made great achievements on revealing the olfactory sensing mechanisms in decades; even though many issues need addressing. Optogenetics provides a novel technical approach to solve this dilemma by utilizing light to illuminate specific part of the olfactory system; which can be used in all corners of the olfactory system for revealing the olfactory mechanism. This article reviews the most recent advances in olfactory optogenetics devoted to elucidate the mechanisms of chemical sensing. It thus attempts to introduce olfactory optogenetics according to the structure of the olfactory system. It mainly includes the following aspects: the sensory input from the olfactory epithelium to the olfactory bulb; the influences of the olfactory bulb (OB) neuron activity patterns on olfactory perception; the regulation between the olfactory cortex and the olfactory bulb; and the neuromodulation participating in odor coding by dominating the olfactory bulb. Finally; current challenges and future development trends of olfactory optogenetics are proposed and discussed.
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9
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Roesler R, Parent MB, LaLumiere RT, McIntyre CK. Amygdala-hippocampal interactions in synaptic plasticity and memory formation. Neurobiol Learn Mem 2021; 184:107490. [PMID: 34302951 DOI: 10.1016/j.nlm.2021.107490] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/14/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022]
Abstract
Memories of emotionally arousing events tend to endure longer than other memories. This review compiles findings from several decades of research investigating the role of the amygdala in modulating memories of emotional experiences. Episodic memory is a kind of declarative memory that depends upon the hippocampus, and studies suggest that the basolateral complex of the amygdala (BLA) modulates episodic memory consolidation through interactions with the hippocampus. Although many studies in rodents and imaging studies in humans indicate that the amygdala modulates memory consolidation and plasticity processes in the hippocampus, the anatomical pathways through which the amygdala affects hippocampal regions that are important for episodic memories were unresolved until recent optogenetic advances made it possible to visualize and manipulate specific BLA efferent pathways during memory consolidation. Findings indicate that the BLA influences hippocampal-dependent memories, as well as synaptic plasticity, histone modifications, gene expression, and translation of synaptic plasticity associated proteins in the hippocampus. More recent findings from optogenetic studies suggest that the BLA modulates spatial memory via projections to the medial entorhinal cortex, and that the frequency of activity in this pathway is a critical element of this modulation.
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Affiliation(s)
- Rafael Roesler
- Cancer and Neurobiology Laboratory, Experimental Research Center, Clinical Hospital (CPE-HCPA), Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil; Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500 (ICBS, Campus Centro/UFRGS), 90050-170 Porto Alegre, RS, Brazil.
| | - Marise B Parent
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA; Department of Psychology, Georgia State University, Atlanta, GA 30303, USA.
| | - Ryan T LaLumiere
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, 52242, USA; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA.
| | - Christa K McIntyre
- School of Behavior and Brain Sciences, The University of Texas at Dallas, Richardson, TX 75080-3021, USA.
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10
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Gilboa A, Moscovitch M. No consolidation without representation: Correspondence between neural and psychological representations in recent and remote memory. Neuron 2021; 109:2239-2255. [PMID: 34015252 DOI: 10.1016/j.neuron.2021.04.025] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 03/24/2021] [Accepted: 04/26/2021] [Indexed: 10/21/2022]
Abstract
Memory systems consolidation is often conceived as the linear, time-dependent, neurobiological shift of memory from hippocampal-cortical to cortico-cortical dependency. We argue that contrary to this unidirectional view of memory reorganization, information about events may be retained in multiple forms (e.g., event-specific sensory-near episodic memory, event-specific gist information, event-general schematic information, or abstract semantic memory). These representations can all form at the time of the event and may continue to coexist for long durations. Their relative strength, composition, and dominance of expression change with time and experience, with task demands, and through their dynamic interaction with one another. These different psychological mnemonic representations depend on distinct functional and structural neurobiological substrates such that there is a neural-psychological representation correspondence (NPRC) among them. We discuss how the dynamics of psychological memory representations are reflected in multiple levels of neurobiological markers and their interactions. By this view, there are only variations of synaptic consolidation and memory dynamics without assuming a distinct systems consolidation process.
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Affiliation(s)
- Asaf Gilboa
- Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, ON M6A 2E1, Canada; Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3, Canada.
| | - Morris Moscovitch
- Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, ON M6A 2E1, Canada; Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3, Canada.
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11
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Memories are not written in stone: Re-writing fear memories by means of non-invasive brain stimulation and optogenetic manipulations. Neurosci Biobehav Rev 2021; 127:334-352. [PMID: 33964307 DOI: 10.1016/j.neubiorev.2021.04.036] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/29/2021] [Accepted: 04/29/2021] [Indexed: 11/21/2022]
Abstract
The acquisition of fear associative memory requires brain processes of coordinated neural activity within the amygdala, prefrontal cortex (PFC), hippocampus, thalamus and brainstem. After fear consolidation, a suppression of fear memory in the absence of danger is crucial to permit adaptive coping behavior. Acquisition and maintenance of fear extinction critically depend on amygdala-PFC projections. The robust correspondence between the brain networks encompassed cortical and subcortical hubs involved into fear processing in humans and in other species underscores the potential utility of comparing the modulation of brain circuitry in humans and animals, as a crucial step to inform the comprehension of fear mechanisms and the development of treatments for fear-related disorders. The present review is aimed at providing a comprehensive description of the literature on recent clinical and experimental researches regarding the noninvasive brain stimulation and optogenetics. These innovative manipulations applied over specific hubs of fear matrix during fear acquisition, consolidation, reconsolidation and extinction allow an accurate characterization of specific brain circuits and their peculiar interaction within the specific fear processing.
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12
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Oh TJ, Fan H, Skeeters SS, Zhang K. Steering Molecular Activity with Optogenetics: Recent Advances and Perspectives. Adv Biol (Weinh) 2021; 5:e2000180. [PMID: 34028216 PMCID: PMC8218620 DOI: 10.1002/adbi.202000180] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/14/2020] [Indexed: 12/24/2022]
Abstract
Optogenetics utilizes photosensitive proteins to manipulate the localization and interaction of molecules in living cells. Because light can be rapidly switched and conveniently confined to the sub-micrometer scale, optogenetics allows for controlling cellular events with an unprecedented resolution in time and space. The past decade has witnessed an enormous progress in the field of optogenetics within the biological sciences. The ever-increasing amount of optogenetic tools, however, can overwhelm the selection of appropriate optogenetic strategies. Considering that each optogenetic tool may have a distinct mode of action, a comparative analysis of the current optogenetic toolbox can promote the further use of optogenetics, especially by researchers new to this field. This review provides such a compilation that highlights the spatiotemporal accuracy of current optogenetic systems. Recent advances of optogenetics in live cells and animal models are summarized, the emerging work that interlinks optogenetics with other research fields is presented, and exciting clinical and industrial efforts to employ optogenetic strategy toward disease intervention are reported.
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Affiliation(s)
- Teak-Jung Oh
- 600 South Mathews Avenue, 314 B Roger Adams Laboratory, Urbana, IL, 61801, USA
| | - Huaxun Fan
- 600 South Mathews Avenue, 314 B Roger Adams Laboratory, Urbana, IL, 61801, USA
| | - Savanna S Skeeters
- 600 South Mathews Avenue, 314 B Roger Adams Laboratory, Urbana, IL, 61801, USA
| | - Kai Zhang
- 600 South Mathews Avenue, 314 B Roger Adams Laboratory, Urbana, IL, 61801, USA
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13
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Kurzina NP, Volnova AB, Aristova IY, Gainetdinov RR. A New Paradigm for Training Hyperactive Dopamine Transporter Knockout Rats: Influence of Novel Stimuli on Object Recognition. Front Behav Neurosci 2021; 15:654469. [PMID: 33967714 PMCID: PMC8100052 DOI: 10.3389/fnbeh.2021.654469] [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: 01/18/2021] [Accepted: 03/04/2021] [Indexed: 01/07/2023] Open
Abstract
Attention deficit hyperactivity disorder (ADHD) is believed to be connected with a high level of hyperactivity caused by alterations of the control of dopaminergic transmission in the brain. The strain of hyperdopaminergic dopamine transporter knockout (DAT-KO) rats represents an optimal model for investigating ADHD-related pathological mechanisms. The goal of this work was to study the influence of the overactivated dopamine system in the brain on a motor cognitive task fulfillment. The DAT-KO rats were trained to learn an object recognition task and store it in long-term memory. We found that DAT-KO rats can learn to move an object and retrieve food from the rewarded familiar objects and not to move the non-rewarded novel objects. However, we observed that the time of task performance and the distances traveled were significantly increased in DAT-KO rats in comparison with wild-type controls. Both groups of rats explored the novel objects longer than the familiar cubes. However, unlike controls, DAT-KO rats explored novel objects significantly longer and with fewer errors, since they preferred not to move the non-rewarded novel objects. After a 3 months' interval that followed the training period, they were able to retain the learned skills in memory and to efficiently retrieve them. The data obtained indicate that DAT-KO rats have a deficiency in learning the cognitive task, but their hyperactivity does not prevent the ability to learn a non-spatial cognitive task under the presentation of novel stimuli. The longer exploration of novel objects during training may ensure persistent learning of the task paradigm. These findings may serve as a base for developing new ADHD learning paradigms.
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Affiliation(s)
- Natalia P. Kurzina
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Anna B. Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
- Department of Physiology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Irina Y. Aristova
- Department of Physiology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Raul R. Gainetdinov
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
- Saint Petersburg State University Hospital, Saint Petersburg State University, Saint Petersburg, Russia
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14
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15
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Laricchiuta D, Sciamanna G, Gimenez J, Termine A, Fabrizio C, Caioli S, Balsamo F, Panuccio A, De Bardi M, Saba L, Passarello N, Cutuli D, Mattioni A, Zona C, Orlando V, Petrosini L. Optogenetic Stimulation of Prelimbic Pyramidal Neurons Maintains Fear Memories and Modulates Amygdala Pyramidal Neuron Transcriptome. Int J Mol Sci 2021; 22:ijms22020810. [PMID: 33467450 PMCID: PMC7830910 DOI: 10.3390/ijms22020810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/12/2021] [Accepted: 01/12/2021] [Indexed: 12/26/2022] Open
Abstract
Fear extinction requires coordinated neural activity within the amygdala and medial prefrontal cortex (mPFC). Any behavior has a transcriptomic signature that is modified by environmental experiences, and specific genes are involved in functional plasticity and synaptic wiring during fear extinction. Here, we investigated the effects of optogenetic manipulations of prelimbic (PrL) pyramidal neurons and amygdala gene expression to analyze the specific transcriptional pathways associated to adaptive and maladaptive fear extinction. To this aim, transgenic mice were (or not) fear-conditioned and during the extinction phase they received optogenetic (or sham) stimulations over photo-activable PrL pyramidal neurons. At the end of behavioral testing, electrophysiological (neural cellular excitability and Excitatory Post-Synaptic Currents) and morphological (spinogenesis) correlates were evaluated in the PrL pyramidal neurons. Furthermore, transcriptomic cell-specific RNA-analyses (differential gene expression profiling and functional enrichment analyses) were performed in amygdala pyramidal neurons. Our results show that the optogenetic activation of PrL pyramidal neurons in fear-conditioned mice induces fear extinction deficits, reflected in an increase of cellular excitability, excitatory neurotransmission, and spinogenesis of PrL pyramidal neurons, and associated to strong modifications of the transcriptome of amygdala pyramidal neurons. Understanding the electrophysiological, morphological, and transcriptomic architecture of fear extinction may facilitate the comprehension of fear-related disorders.
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Affiliation(s)
- Daniela Laricchiuta
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
- Correspondence:
| | - Giuseppe Sciamanna
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
| | - Juliette Gimenez
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
| | - Andrea Termine
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
- Department of Systems Medicine, Tor Vergata University of Rome, 00133 Rome, Italy;
| | - Carlo Fabrizio
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
- Department of Systems Medicine, Tor Vergata University of Rome, 00133 Rome, Italy;
| | - Silvia Caioli
- Unit of Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy;
| | - Francesca Balsamo
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
| | - Anna Panuccio
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
- Department of Psychology, University “Sapienza” of Rome, 00185 Rome, Italy
| | - Marco De Bardi
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
| | - Luana Saba
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
| | - Noemi Passarello
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
| | - Debora Cutuli
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
- Department of Psychology, University “Sapienza” of Rome, 00185 Rome, Italy
| | - Anna Mattioni
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
| | - Cristina Zona
- Department of Systems Medicine, Tor Vergata University of Rome, 00133 Rome, Italy;
| | - Valerio Orlando
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
- Biological Environmental Science and Engineering Division, KAUST Environmental Epigenetics Program, Thuwal 23955-6900, Saudi Arabia
| | - Laura Petrosini
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; (G.S.); (J.G.); (A.T.); (C.F.); (F.B.); (A.P.); (M.D.B.); (L.S.); (N.P.); (D.C.); (A.M.); (V.O.); (L.P.)
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16
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Nadel L, Maurer AP. Recalling Lashley and reconsolidating Hebb. Hippocampus 2020; 30:776-793. [PMID: 30216593 PMCID: PMC6417981 DOI: 10.1002/hipo.23027] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/20/2018] [Accepted: 09/02/2018] [Indexed: 12/26/2022]
Abstract
Many of the foundational theoretical ideas in the field of learning and memory are traced to Donald Hebb. Examination of these ideas and their evolution suggest that Karl Lashley might have significantly influenced their development. Here, we discuss the relationship between Hebb and Lashley, and the parallels between them. Many now investigating the neurobiological basis of memory may be unaware both of Hebb's original descriptions, and the likely substantial contributions of Lashley. Many of their concerns remain with us today, and by clarifying the history we hope to strengthen the foundations of our field.
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Affiliation(s)
- L Nadel
- Department of Psychology, University of Arizona, Tucson, Arizona
| | - A P Maurer
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida
- Department of Civil and Coastal Engineering, University of Florida, Gainesville, Florida
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17
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Xiao Z, Lin K, Fellous JM. Conjunctive reward-place coding properties of dorsal distal CA1 hippocampus cells. BIOLOGICAL CYBERNETICS 2020; 114:285-301. [PMID: 32266474 DOI: 10.1007/s00422-020-00830-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
Autonomous motivated spatial navigation in animals or robots requires the association between spatial location and value. Hippocampal place cells are involved in goal-directed spatial navigation and the consolidation of spatial memories. Recently, Gauthier and Tank (Neuron 99(1):179-193, 2018. https://doi.org/10.1016/j.neuron.2018.06.008) have identified a subpopulation of hippocampal cells selectively activated in relation to rewarded goals. However, the relationship between these cells' spiking activity and goal representation remains elusive. We analyzed data from experiments in which rats underwent five consecutive tasks in which reward locations and spatial context were manipulated. We found CA1 populations with properties continuously ranging from place cells to reward cells. Specifically, we found typical place cells insensitive to reward locations, reward cells that only fired at correct rewarded feeders in each task regardless of context, and "hybrid cells" that responded to spatial locations and change of reward locations. Reward cells responded mostly to the reward delivery rather than to its expectation. In addition, we found a small group of neurons that transitioned between place and reward cells properties within the 5-task session. We conclude that some pyramidal cells (if not all) integrate both spatial and reward inputs to various degrees. These results provide insights into the integrative coding properties of CA1 pyramidal cells, focusing on their abilities to carry both spatial and reward information in a mixed and plastic manner. This conjunctive coding property prompts a re-thinking of current computational models of spatial navigation in which hippocampal spatial and subcortical value representations are independent.
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Affiliation(s)
- Zhuocheng Xiao
- Program in Applied Mathematics, University of Arizona, Tucson, AZ, 85721, USA
| | - Kevin Lin
- Program in Applied Mathematics, University of Arizona, Tucson, AZ, 85721, USA
- Department of Mathematics, University of Arizona, Tucson, AZ, 85721, USA
- Neuroscience Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, 85721, USA
| | - Jean-Marc Fellous
- Program in Applied Mathematics, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Psychology, University of Arizona, 1503 E University Blvd, Suite 312, Tucson, AZ, 85721, USA.
- Neuroscience Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, 85721, USA.
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18
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Abstract
In this review we briefly outline how lesion studies, temporary inactivation and neural activity assays have helped update functional models of the retrosplenial cortex, a region critical for episodic and spatial memory. We advocate for the continued importance of appropriately designed behavioural studies in the context of novel experimental methods, such as optogenetic and chemogenetic manipulations. At the same time, we caution against the overreliance on any given level of analysis or experimental technique. Complementary, multimodal strategies are required for understanding how the retrosplenial cortex contributes to the formation and storage of memories both at a structural and systems-level.
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19
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Miller TD, Chong TTJ, Aimola Davies AM, Johnson MR, Irani SR, Husain M, Ng TWC, Jacob S, Maddison P, Kennard C, Gowland PA, Rosenthal CR. Human hippocampal CA3 damage disrupts both recent and remote episodic memories. eLife 2020; 9:e41836. [PMID: 31976861 PMCID: PMC6980860 DOI: 10.7554/elife.41836] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/05/2019] [Indexed: 12/31/2022] Open
Abstract
Neocortical-hippocampal interactions support new episodic (event) memories, but there is conflicting evidence about the dependence of remote episodic memories on the hippocampus. In line with systems consolidation and computational theories of episodic memory, evidence from model organisms suggests that the cornu ammonis 3 (CA3) hippocampal subfield supports recent, but not remote, episodic retrieval. In this study, we demonstrated that recent and remote memories were susceptible to a loss of episodic detail in human participants with focal bilateral damage to CA3. Graph theoretic analyses of 7.0-Tesla resting-state fMRI data revealed that CA3 damage disrupted functional integration across the medial temporal lobe (MTL) subsystem of the default network. The loss of functional integration in MTL subsystem regions was predictive of autobiographical episodic retrieval performance. We conclude that human CA3 is necessary for the retrieval of episodic memories long after their initial acquisition and functional integration of the default network is important for autobiographical episodic memory performance.
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Affiliation(s)
- Thomas D Miller
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Department of NeurologyRoyal Free HospitalLondonUnited Kingdom
| | - Trevor T-J Chong
- Monash Institute of Cognitive and Clinical NeurosciencesMonash UniversityClaytonAustralia
| | - Anne M Aimola Davies
- Department of Experimental PsychologyUniversity of OxfordOxfordUnited Kingdom
- Research School of PsychologyAustralian National UniversityCanberraAustralia
| | - Michael R Johnson
- Division of Brain SciencesImperial College LondonLondonUnited Kingdom
| | - Sarosh R Irani
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Masud Husain
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Department of Experimental PsychologyUniversity of OxfordOxfordUnited Kingdom
| | - Tammy WC Ng
- Department of AnaesthesticsRoyal Free HospitalLondonUnited Kingdom
| | - Saiju Jacob
- Neurology Department, Queen Elizabeth Neuroscience CentreUniversity Hospitals of BirminghamBirminghamUnited Kingdom
| | - Paul Maddison
- Neurology DepartmentQueen’s Medical CentreNottinghamUnited Kingdom
| | - Christopher Kennard
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Penny A Gowland
- Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and AstronomyUniversity of NottinghamNottinghamUnited Kingdom
| | - Clive R Rosenthal
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
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20
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Hardt O, Sossin WS. Terminological and Epistemological Issues in Current Memory Research. Front Mol Neurosci 2020; 12:336. [PMID: 32038166 PMCID: PMC6987036 DOI: 10.3389/fnmol.2019.00336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/30/2019] [Indexed: 12/12/2022] Open
Abstract
A number of observations in recent years demonstrates that across all levels of organization, memory is inherently fluid. On the cognitive-behavioral level, the innocent act of remembering can irrevocably alter the contents of established long-term memories, while the content of dormant long-term memories that is deemed irrelevant, superfluous, or limiting may be pragmatically erased or suppressed. On the cellular level, the proteins implementing the molecular alterations underpinning memories are in a constant state of flux, with proteins being turned over, translocated, reconfigured, substituted, and replaced. Yet, the general perception of memory, and the words used to describe it, suggest a static system characterized by the goal of preserving records of past experiences with high fidelity, in contrast to the reality of an inherently adaptive system purposed to enable survival in a changing world with a pragmatic disregard for the fate of acquired memories. Here, we examine present memory terminology and how it corresponds to our actual understanding of the molecules, cells, and systems underlying memory. We will identify where terms lead us astray and line out possible ways to reform memory nomenclature to better fit the true nature of memory as we begin to know it.
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Affiliation(s)
- Oliver Hardt
- Department of Psychology, McGill University, Montreal, QC, Canada.,The Simons Initiative for the Developing Brain and The Patrick Wild Centre, The University of Edinburgh, Edinburgh, United Kingdom
| | - Wayne S Sossin
- The Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
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21
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Helfer P, Shultz TR. A computational model of systems memory consolidation and reconsolidation. Hippocampus 2019; 30:659-677. [PMID: 31872960 DOI: 10.1002/hipo.23187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 10/05/2019] [Accepted: 12/04/2019] [Indexed: 12/27/2022]
Abstract
In the mammalian brain, newly acquired memories depend on the hippocampus (HPC) for maintenance and recall, but over time, the neocortex takes over these functions, rendering memories HPC-independent. The process responsible for this transformation is called systems memory consolidation. Reactivation of a well-consolidated memory can trigger a temporary return to a HPC-dependent state, a phenomenon known as systems memory reconsolidation. The neural mechanisms underlying systems memory consolidation and reconsolidation are not well understood. Here, we propose a neural model based on well-documented mechanisms of synaptic plasticity and stability and describe a computational implementation that demonstrates the model's ability to account for a range of findings from the systems consolidation and reconsolidation literature. We derive several predictions from the computational model and suggest experiments that may test its validity.
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Affiliation(s)
- Peter Helfer
- Department of Psychology, McGill University, 2001 McGill College, Montreal, QC, Canada
| | - Thomas R Shultz
- Department of Psychology, McGill University, 2001 McGill College, Montreal, QC, Canada
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22
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Sekeres MJ, Moscovitch M, Grady CL, Sullens DG, Winocur G. Reminders reinstate context-specificity to generalized remote memories in rats: relation to activity in the hippocampus and aCC. ACTA ACUST UNITED AC 2019; 27:1-5. [PMID: 31843976 PMCID: PMC6919192 DOI: 10.1101/lm.050161.119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/15/2019] [Indexed: 01/23/2023]
Abstract
Conditioned fear memories that are context-specific shortly after conditioning generalize over time. We exposed rats to a context reminder 30 d after conditioning, which served to reinstate context-specificity, and investigated how this reminder alters retrieval-induced activity in the hippocampus and anterior cingulate cortex (aCC) relative to a no reminder condition. c-Fos expression in dorsal CA1 was observed following retrieval in the original context, but not in a novel context, whether or not the memory was reactivated, suggesting that dCA1 retains the context-specific representation. c-Fos was highly expressed in aCC following remote memory testing in both contexts, regardless of reminder condition, indicating that aCC develops generalized representations that are insensitive to memory reactivation.
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Affiliation(s)
- Melanie J Sekeres
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas 76798, USA
| | - Morris Moscovitch
- Rotman Research Institute, Baycrest, Toronto, Ontario M6A 2E1, Canada.,Department of Psychology, Baycrest, Toronto, Ontario M6A 2E1, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario M5S 3G3, Canada
| | - Cheryl L Grady
- Rotman Research Institute, Baycrest, Toronto, Ontario M6A 2E1, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario M5S 3G3, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario M5S 3G3, Canada
| | - D Gregory Sullens
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas 76798, USA
| | - Gordon Winocur
- Rotman Research Institute, Baycrest, Toronto, Ontario M6A 2E1, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario M5S 3G3, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario M5S 3G3, Canada.,Department of Psychology, Trent University, Peterborough, Ontario K9J 7B8, Canada
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23
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Cutsuridis V. Memory Prosthesis: Is It Time for a Deep Neuromimetic Computing Approach? Front Neurosci 2019; 13:667. [PMID: 31333399 PMCID: PMC6624412 DOI: 10.3389/fnins.2019.00667] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/11/2019] [Indexed: 11/13/2022] Open
Abstract
Memory loss, one of the most dreaded afflictions of the human condition, presents considerable burden on the world's health care system and it is recognized as a major challenge in the elderly. There are only a few neuromodulation treatments for memory dysfunctions. Open loop deep brain stimulation is such a treatment for memory improvement, but with limited success and conflicting results. In recent years closed-loop neuroprosthesis systems able to simultaneously record signals during behavioral tasks and generate with the use of internal neural factors the precise timing of stimulation patterns are presented as attractive alternatives and show promise in memory enhancement and restoration. A few such strides have already been made in both animals and humans, but with limited insights into their mechanisms of action. Here, I discuss why a deep neuromimetic computing approach linking multiple levels of description, mimicking the dynamics of brain circuits, interfaced with recording and stimulating electrodes could enhance the performance of current memory prosthesis systems, shed light into the neurobiology of learning and memory and accelerate the progress of memory prosthesis research. I propose what the necessary components (nodes, structure, connectivity, learning rules, and physiological responses) of such a deep neuromimetic model should be and what type of data are required to train/test its performance, so it can be used as a true substitute of damaged brain areas capable of restoring/enhancing their missing memory formation capabilities. Considerations to neural circuit targeting, tissue interfacing, electrode placement/implantation, and multi-network interactions in complex cognition are also provided.
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24
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Argyropoulos GPD, Loane C, Roca-Fernandez A, Lage-Martinez C, Gurau O, Irani SR, Butler CR. Network-wide abnormalities explain memory variability in hippocampal amnesia. eLife 2019; 8:e46156. [PMID: 31282861 PMCID: PMC6639076 DOI: 10.7554/elife.46156] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 07/05/2019] [Indexed: 01/11/2023] Open
Abstract
Patients with hippocampal amnesia play a central role in memory neuroscience but the neural underpinnings of amnesia are hotly debated. We hypothesized that focal hippocampal damage is associated with changes across the extended hippocampal system and that these, rather than hippocampal atrophy per se, would explain variability in memory between patients. We assessed this hypothesis in a uniquely large cohort of patients (n = 38) after autoimmune limbic encephalitis, a syndrome associated with focal structural hippocampal pathology. These patients showed impaired recall, recognition and maintenance of new information, and remote autobiographical amnesia. Besides hippocampal atrophy, we observed correlatively reduced thalamic and entorhinal cortical volume, resting-state inter-hippocampal connectivity and activity in posteromedial cortex. Associations of hippocampal volume with recall, recognition, and remote memory were fully mediated by wider network abnormalities, and were only direct in forgetting. Network abnormalities may explain the variability across studies of amnesia and speak to debates in memory neuroscience.
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Affiliation(s)
- Georgios PD Argyropoulos
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Clare Loane
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUnited Kingdom
| | - Adriana Roca-Fernandez
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Carmen Lage-Martinez
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Valdecilla Biomedical Research InstituteUniversity Hospital Marqués de ValdecillaSantanderSpain
| | - Oana Gurau
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Christopher R Butler
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
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25
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Vetere G, Borreca A, Pignataro A, Conforto G, Giustizieri M, Marinelli S, Ammassari-Teule M. Coincident Pre- and Post-Synaptic Cortical Remodelling Disengages Episodic Memory from Its Original Context. Mol Neurobiol 2019; 56:8513-8523. [PMID: 31267371 DOI: 10.1007/s12035-019-01652-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/15/2019] [Indexed: 11/28/2022]
Abstract
The view that the neocortex is remotely recruited for long-term episodic memory recall is challenged by data showing that an intense transcriptional and synaptic activity is detected in this region immediately after training. By measuring markers of synaptic activity at recent and remote time points from contextual fear conditioning (CFC), we could show that pre-synaptic changes are selectively detected 1 day post-training when the memory is anchored to the training context. Differently, pre- and post-synaptic changes are detected 14 days post-training when the memory generalizes to other contexts. Confirming that coincident pre- and post-synaptic remodelling mediates the disengagement of memory from its original context, DREADDs-mediated enhancement of cortical neuron activity during CFC training anticipates expression of a schematic memory and observation of bilateral synaptic remodelling. Together, our data show that the plastic properties of cortical synapses vary over time and specialise in relation to the quality of memory.
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Affiliation(s)
- Gisella Vetere
- Department of Experimental Neuroscience, Laboratory of Psychobiology, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy.,Laboratoire Plasticité du Cerveau, ESPCI-Ecole Supérieure de Physique et Chimie Industrielle, Paris, France
| | - Antonella Borreca
- Department of Experimental Neuroscience, Laboratory of Psychobiology, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy.,Consiglio Nazionale delle Ricerche, Istituto di Biologia Cellulare e Neurobiologia, Rome, Italy.,Consiglio Nazionale delle Ricerche, Istituto di Neuroscienze, Milan, Italy
| | - Annabella Pignataro
- Department of Experimental Neuroscience, Laboratory of Psychobiology, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy.,Consiglio Nazionale delle Ricerche, Istituto di Biologia Cellulare e Neurobiologia, Rome, Italy
| | - Giulia Conforto
- Department of Experimental Neuroscience, Laboratory of Psychobiology, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy
| | | | | | - Martine Ammassari-Teule
- Department of Experimental Neuroscience, Laboratory of Psychobiology, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy. .,Consiglio Nazionale delle Ricerche, Istituto di Biologia Cellulare e Neurobiologia, Rome, Italy.
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26
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Genzel L, Schut E, Schröder T, Eichler R, Khamassi M, Gomez A, Navarro Lobato I, Battaglia F. The object space task shows cumulative memory expression in both mice and rats. PLoS Biol 2019; 17:e3000322. [PMID: 31206519 PMCID: PMC6597117 DOI: 10.1371/journal.pbio.3000322] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 06/27/2019] [Accepted: 05/29/2019] [Indexed: 01/03/2023] Open
Abstract
Declarative memory encompasses representations of specific events as well as knowledge extracted by accumulation over multiple episodes. To investigate how these different sorts of memories are created, we developed a new behavioral task in rodents. The task consists of 3 distinct conditions (stable, overlapping, and random). Rodents are exposed to multiple sample trials, in which they explore objects in specific spatial arrangements, with object identity changing from trial to trial. In the stable condition, the locations are constant during all sample trials even though the objects themselves change; in the test trial, 1 object’s location is changed. In the random condition, object locations are presented in the sample phase without a specific spatial pattern. In the overlapping condition, 1 location is shared (overlapping) between all trials, while the other location changes during sample trials. We show that in the overlapping condition, instead of only remembering the last sample trial, rodents form a cumulative memory of the sample trials. Here, we could show that both mice and rats can accumulate information across multiple trials and express a long-term abstracted memory. Memories are stored and retrieved in different ways, depending on the age of memory and the character of the information, but many tasks for rodent subjects cannot differentiate between them. A new training paradigm for rats and mice enables testing for abstracted memory representation while controlling for memory recency.
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Affiliation(s)
- Lisa Genzel
- Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
- RadboudUMC, Nijmegen, the Netherlands
- * E-mail:
| | - Evelien Schut
- Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
- RadboudUMC, Nijmegen, the Netherlands
| | - Tim Schröder
- Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Ronny Eichler
- Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
- RadboudUMC, Nijmegen, the Netherlands
| | - Mehdi Khamassi
- Institute of Intelligent Systems and Robotics, Sorbonne Université, CNRS, Paris, France
| | - Angela Gomez
- Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Irene Navarro Lobato
- Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Francesco Battaglia
- Donders Institute for Brain Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
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27
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Langille JJ. Remembering to Forget: A Dual Role for Sleep Oscillations in Memory Consolidation and Forgetting. Front Cell Neurosci 2019; 13:71. [PMID: 30930746 PMCID: PMC6425990 DOI: 10.3389/fncel.2019.00071] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/13/2019] [Indexed: 12/20/2022] Open
Abstract
It has been known since the time of patient H. M. and Karl Lashley's equipotentiality studies that the hippocampus and cortex serve mnestic functions. Current memory models maintain that these two brain structures accomplish unique, but interactive, memory functions. Specifically, most modeling suggests that memories are rapidly acquired during waking experience by the hippocampus, before being later consolidated into the cortex for long-term storage. Sleep has been shown to be critical for the transfer and consolidation of memories in the cortex. Like memory consolidation, a role for sleep in adaptive forgetting has both historical precedent, as Francis Crick suggested in 1983 that sleep was for "reverse-learning," and recent empirical support. In this article I review the evidence indicating that the same brain activity involved in sleep replay associated memory consolidation is responsible for sleep-dependent forgetting. In reviewing the literature, it became clear that both a cellular mechanism for systems consolidation and an agreed upon general, as well as cellular, mechanism for sleep-dependent forgetting is seldom discussed or is lacking. I advocate here for a candidate cellular systems consolidation mechanism wherein changes in calcium kinetics and the activation of consolidative signaling cascades arise from the triple phase locking of non-rapid eye movement sleep (NREMS) slow oscillation, sleep spindle and sharp-wave ripple rhythms. I go on to speculatively consider several sleep stage specific forgetting mechanisms and conclude by discussing a notional function of NREM-rapid eye movement sleep (REMS) cycling. The discussed model argues that the cyclical organization of sleep functions to first lay down and edit and then stabilize and integrate engrams. All things considered, it is increasingly clear that hallmark sleep stage rhythms, including several NREMS oscillations and the REMS hippocampal theta rhythm, serve the dual function of enabling simultaneous memory consolidation and adaptive forgetting. Specifically, the same sleep rhythms that consolidate new memories, in the cortex and hippocampus, simultaneously organize the adaptive forgetting of older memories in these brain regions.
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Affiliation(s)
- Jesse J Langille
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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28
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Quillfeldt JA. Temporal Flexibility of Systems Consolidation and the Synaptic Occupancy/Reset Theory (SORT): Cues About the Nature of the Engram. Front Synaptic Neurosci 2019; 11:1. [PMID: 30814946 PMCID: PMC6381034 DOI: 10.3389/fnsyn.2019.00001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 01/14/2019] [Indexed: 11/24/2022] Open
Abstract
The ability to adapt to new situations involves behavioral changes expressed either from an innate repertoire, or by acquiring experience through memory consolidation mechanisms, by far a much richer and flexible source of adaptation. Memory formation consists of two interrelated processes that take place at different spatial and temporal scales, Synaptic Consolidation, local plastic changes in the recruited neurons, and Systems Consolidation, a process of gradual reorganization of the explicit/declarative memory trace between hippocampus and the neocortex. In this review, we summarize some converging experimental results from our lab that support a normal temporal framework of memory systems consolidation as measured both from the anatomical and the psychological points of view, and propose a hypothetical model that explains these findings while predicting other phenomena. Then, the same experimental design was repeated interposing additional tasks between the training and the remote test to verify for any interference: we found that (a) when the animals were subject to a succession of new learnings, systems consolidation was accelerated, with the disengagement of the hippocampus taking place before the natural time point of this functional switch, but (b) when a few reactivation sessions reexposed the animal to the training context without the shock, systems consolidation was delayed, with the hippocampus prolonging its involvement in retrieval. We hypothesize that new learning recruits from a fixed number of plastic synapses in the CA1 area to store the engram index, while reconsolidation lead to a different outcome, in which additional synapses are made available. The first situation implies the need of a reset mechanism in order to free synapses needed for further learning, and explains the acceleration observed under intense learning activity, while the delay might be explained by a different process, able to generate extra free synapses: depending on the cognitive demands, it deals either with a fixed or a variable pool of available synapses. The Synaptic Occupancy/Reset Theory (SORT) emerged as an explanation for the temporal flexibility of systems consolidation, to encompass the two different dynamics of explicit memories, as well as to bridge both synaptic and systems consolidation in one single mechanism.
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Affiliation(s)
- Jorge Alberto Quillfeldt
- Psychobiology and Neurocomputation Lab, Department of Biophysics, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Department of Psychology, McGill University, Montreal, QC, Canada
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29
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Balbinot G, Schuch CP. Compensatory Relearning Following Stroke: Cellular and Plasticity Mechanisms in Rodents. Front Neurosci 2019; 12:1023. [PMID: 30766468 PMCID: PMC6365459 DOI: 10.3389/fnins.2018.01023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/18/2018] [Indexed: 11/13/2022] Open
Abstract
von Monakow’s theory of diaschisis states the functional ‘standstill’ of intact brain regions that are remote from a damaged area, often implied in recovery of function. Accordingly, neural plasticity and activity patterns related to recovery are also occurring at the same regions. Recovery relies on plasticity in the periinfarct and homotopic contralesional regions and involves relearning to perform movements. Seeking evidence for a relearning mechanism following stroke, we found that rodents display many features that resemble classical learning and memory mechanisms. Compensatory relearning is likely to be accompanied by gradual shaping of these regions and pathways, with participating neurons progressively adapting cortico-striato-thalamic activity and synaptic strengths at different cortico-thalamic loops – adapting function relayed by the striatum. Motor cortex functional maps are progressively reinforced and shaped by these loops as the striatum searches for different functional actions. Several cortical and striatal cellular mechanisms that influence motor learning may also influence post-stroke compensatory relearning. Future research should focus on how different neuromodulatory systems could act before, during or after rehabilitation to improve stroke recovery.
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Affiliation(s)
- Gustavo Balbinot
- Brain Institute, Universidade Federal do Rio Grande do Norte, Natal, Brazil
| | - Clarissa Pedrini Schuch
- Graduate Program in Rehabilitation Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, Brazil
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30
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Duszkiewicz AJ, McNamara CG, Takeuchi T, Genzel L. Novelty and Dopaminergic Modulation of Memory Persistence: A Tale of Two Systems. Trends Neurosci 2018; 42:102-114. [PMID: 30455050 PMCID: PMC6352318 DOI: 10.1016/j.tins.2018.10.002] [Citation(s) in RCA: 190] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/26/2018] [Accepted: 10/01/2018] [Indexed: 11/10/2022]
Abstract
Adaptation to the ever-changing world is critical for survival, and our brains are particularly tuned to remember events that differ from previous experiences. Novel experiences induce dopamine release in the hippocampus, a process which promotes memory persistence. While axons from the ventral tegmental area (VTA) were generally thought to be the exclusive source of hippocampal dopamine, recent studies have demonstrated that noradrenergic neurons in the locus coeruleus (LC) corelease noradrenaline and dopamine in the hippocampus and that their dopamine release boosts memory retention as well. In this opinion article, we propose that the projections originating from the VTA and the LC belong to two distinct systems that enhance memory of novel events. Novel experiences that share some commonality with past ones (‘common novelty’) activate the VTA and promote semantic memory formation via systems memory consolidation. By contrast, experiences that bear only a minimal relationship to past experiences (‘distinct novelty’) activate the LC to trigger strong initial memory consolidation in the hippocampus, resulting in vivid and long-lasting episodic memories. Novelty induces dopamine release in the hippocampus, triggering memory consolidation to boost memory persistence. Two dopaminergic systems (the ventral tegmental area- and locus coeruleus-hippocampus systems) can stabilise memory through novelty-induced dopamine release in the hippocampus. Novel experiences can be viewed as a spectrum, from experiences that, while clearly novel, share some commonality with past experiences (‘common novelty’), to more fundamentally distinct experiences that bear minimal relationships to past experiences (‘distinct novelty’). We propose that events characterised by ‘common novelty’ boost memory retention via activation of the ventral tegmental area-hippocampus system, resulting in initial consolidation followed by systems consolidation to create neocortical, semantic, long-term memories. We further propose that events characterised by ‘distinct novelty’ lead to the boost of detailed hippocampal, episodic, long-term memory via activation of the locus coeruleus-hippocampus system through strong upregulation of the synaptic tagging and capture mechanism.
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Affiliation(s)
- Adrian J Duszkiewicz
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada; Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Colin G McNamara
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford, UK
| | - Tomonori Takeuchi
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark; Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus, Denmark.
| | - Lisa Genzel
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University and Radboudumc, Nijmegen, The Netherlands.
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31
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Devan BD, Berger K, McDonald RJ. The Emergent Engram: A Historical Legacy and Contemporary Discovery. Front Behav Neurosci 2018; 12:168. [PMID: 30131682 PMCID: PMC6090515 DOI: 10.3389/fnbeh.2018.00168] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 07/16/2018] [Indexed: 01/10/2023] Open
Affiliation(s)
- Bryan D Devan
- Laboratory of Comparative Neuropsychology, Psychology Department, Towson University, Towson, MD, United States
| | - Kyle Berger
- Laboratory of Comparative Neuropsychology, Psychology Department, Towson University, Towson, MD, United States
| | - Robert J McDonald
- Canadian Center for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
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33
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Sekeres MJ, Winocur G, Moscovitch M. The hippocampus and related neocortical structures in memory transformation. Neurosci Lett 2018; 680:39-53. [DOI: 10.1016/j.neulet.2018.05.006] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 12/23/2022]
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34
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Pollack GA, Bezek JL, Lee SH, Scarlata MJ, Weingast LT, Bergstrom HC. Cued fear memory generalization increases over time. Learn Mem 2018; 25:298-308. [PMID: 29907637 PMCID: PMC6004064 DOI: 10.1101/lm.047555.118] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 04/13/2018] [Indexed: 01/04/2023]
Abstract
Fear memory is a highly stable and durable form of memory, even over vast (remote) time frames. Nevertheless, some elements of fear memory can be forgotten, resulting in generalization. The purpose of this study is to determine how cued fear memory generalizes over time and measure underlying patterns of cortico-amygdala synaptic plasticity. We established generalization gradients at recent (1-d) and remote (30-d) retention intervals following auditory cued fear conditioning in adult male C57BL/6 mice. Results revealed a flattening of the generalization gradient (increased generalization) that was dissociated from contextual fear generalization, indicating a specific influence of time on cued fear memory performance. This effect reversed after a brief exposure to the novel stimulus soon after learning. Measurements from cortico-amygdala imaging of the activity-regulated cytoskeletal Arc/arg 3.1 (Arc) protein using immunohistochemistry after cued fear memory retrieval revealed a stable pattern of Arc expression in the dorsolateral amygdala, but temporally dynamic expression in the cortex. Over time, increased fear memory generalization was associated with a reduction in Arc expression in the agranular insular and infralimbic cortices while discrimination learning was associated with increased Arc expression in the prelimbic cortex. These data identify the dorsolateral amygdala, medial prefrontal, and insular cortices as loci for synaptic plasticity underlying cued fear memory generalization over time.
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Affiliation(s)
- Gabrielle A Pollack
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Jessica L Bezek
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Serena H Lee
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Miranda J Scarlata
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Leah T Weingast
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Hadley C Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
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35
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Milczarek MM, Vann SD, Sengpiel F. Spatial Memory Engram in the Mouse Retrosplenial Cortex. Curr Biol 2018; 28:1975-1980.e6. [PMID: 29887312 PMCID: PMC6013279 DOI: 10.1016/j.cub.2018.05.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 01/19/2023]
Abstract
Memory relies on lasting adaptations of neuronal properties elicited by stimulus-driven plastic changes [1]. The strengthening (and weakening) of synapses results in the establishment of functional ensembles. It is presumed that such ensembles (or engrams) are activated during memory acquisition and re-activated upon memory retrieval. The retrosplenial cortex (RSC) has emerged as a key brain area supporting memory [2], including episodic and topographical memory in humans [3, 4, 5], as well as spatial memory in rodents [6, 7]. Dysgranular RSC is densely connected with dorsal stream visual areas [8] and contains place-like and head-direction cells, making it a prime candidate for integrating navigational information [9]. While previous reports [6, 10] describe the recruitment of RSC ensembles during navigational tasks, such ensembles have never been tracked long enough to provide evidence of stable engrams and have not been related to the retention of long-term memory. Here, we used in vivo 2-photon imaging to analyze patterns of activity of over 6,000 neurons within dysgranular RSC. Eight mice were trained on a spatial memory task. Learning was accompanied by the gradual emergence of a context-specific pattern of neuronal activity over a 3-week period, which was re-instated upon retrieval more than 3 weeks later. The stability of this memory engram was predictive of the degree of forgetting; more stable engrams were associated with better performance. This provides direct evidence for the interdependence of spatial memory consolidation and RSC engram formation. Our results demonstrate the participation of RSC in spatial memory storage at the level of neuronal ensembles. Longitudinal C-fos imaging reveals retrosplenial spatial memory engrams in mice Engrams become progressively more stable with learning and are maintained over weeks The degree of memory retention is related to the stability of the engrams
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