101
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Dixsaut L, Gräff J. Brain-wide screen of prelimbic cortex inputs reveals a functional shift during early fear memory consolidation. eLife 2022; 11:78542. [PMID: 35838139 PMCID: PMC9286739 DOI: 10.7554/elife.78542] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Memory formation and storage rely on multiple interconnected brain areas, the contribution of which varies during memory consolidation. The medial prefrontal cortex, in particular the prelimbic cortex (PL), was traditionally found to be involved in remote memory storage, but recent evidence points toward its implication in early consolidation as well. Nevertheless, the inputs to the PL governing these dynamics remain unknown. Here, we first performed a brain-wide, rabies-based retrograde tracing screen of PL engram cells activated during contextual fear memory formation in male mice to identify relevant PL input regions. Next, we assessed the specific activity pattern of these inputs across different phases of memory consolidation, from fear memory encoding to recent and remote memory recall. Using projection-specific chemogenetic inhibition, we then tested their functional role in memory consolidation, which revealed a hitherto unknown contribution of claustrum to PL inputs at encoding, and of insular cortex to PL inputs at recent memory recall. Both of these inputs further impacted how PL engram cells were reactivated at memory recall, testifying to their relevance for establishing a memory trace in the PL. Collectively, these data identify a spatiotemporal shift in PL inputs important for early memory consolidation, and thereby help to refine the working model of memory formation.
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Affiliation(s)
- Lucie Dixsaut
- Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Johannes Gräff
- Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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102
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Leal Santos S, Chen BK, Pereira GR, Pham V, Denny CA. Propranolol Administration Modulates Neural Activity in the Hippocampal Hilus During Fear Retrieval. Front Behav Neurosci 2022; 16:919831. [PMID: 35874651 PMCID: PMC9301278 DOI: 10.3389/fnbeh.2022.919831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/13/2022] [Indexed: 11/23/2022] Open
Abstract
Altered fear learning is a strong behavioral component of anxiety disorders such as post-traumatic stress disorder (PTSD). Recent efforts have attempted to combine exposure therapies with drugs that target fear memory retrieval and memory reconsolidation, in order to improve treatment efficacy. The noradrenergic (NA) signaling system is of particular interest, due to its role in regulating the stress response and its involvement in fear and learning processes. Importantly, propranolol (P), a non-selective β-adrenergic antagonist, has shown the potential in decreasing exaggerated fear in both humans and animal models. In a previous study, we utilized an activity-dependent tagging murine model to determine the neural mechanisms by which propranolol attenuates learned fear. We found that propranolol acutely decreased memory trace reactivation specifically in the dorsal dentate gyrus (dDG), but not in CA3 or CA1. Here, we extended our previous study by investigating whether propranolol additionally altered activity in the hilus, a polymorphic layer that consists of neurons, mossy cells, and GABAergic interneurons. We found that propranolol acutely reduced overall hilar activity in both the dorsal and ventral hilus. Moreover, we report that propranolol significantly altered the activity of parvalbumin (PV)+ cells in the ventral (vDG), but not dorsal DG (dDG). Together, these results suggest that a β-adrenergic blockade may affect the activity of excitatory and inhibitory cell types in the hilar layer of the DG, and that these alterations may contribute to manipulating fear memory traces.
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Affiliation(s)
- Sofia Leal Santos
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, United States
- Division of Systems Neuroscience, Research Foundation for Mental Hygiene, Inc. (RFMH)/New York State Psychiatric Institute (NYSPI), New York, NY, United States
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- Instituto de Investigação em Ciências da Vida e da Saúde (ICVS)/3Bs - PT Government Associate Laboratory, Guimarães, Portugal
| | - Briana K. Chen
- Neurobiology and Behavior (NB&B) Graduate Program, Columbia University, New York, NY, United States
| | - Guilherme R. Pereira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- Instituto de Investigação em Ciências da Vida e da Saúde (ICVS)/3Bs - PT Government Associate Laboratory, Guimarães, Portugal
| | - Vananh Pham
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, United States
- Division of Systems Neuroscience, Research Foundation for Mental Hygiene, Inc. (RFMH)/New York State Psychiatric Institute (NYSPI), New York, NY, United States
| | - Christine A. Denny
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, United States
- Division of Systems Neuroscience, Research Foundation for Mental Hygiene, Inc. (RFMH)/New York State Psychiatric Institute (NYSPI), New York, NY, United States
- *Correspondence: Christine A. Denny,
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103
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Redman WT, Wolcott NS, Montelisciani L, Luna G, Marks TD, Sit KK, Yu CH, Smith S, Goard MJ. Long-term transverse imaging of the hippocampus with glass microperiscopes. eLife 2022; 11:75391. [PMID: 35775393 PMCID: PMC9249394 DOI: 10.7554/elife.75391] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 06/12/2022] [Indexed: 11/19/2022] Open
Abstract
The hippocampus consists of a stereotyped neuronal circuit repeated along the septal-temporal axis. This transverse circuit contains distinct subfields with stereotyped connectivity that support crucial cognitive processes, including episodic and spatial memory. However, comprehensive measurements across the transverse hippocampal circuit in vivo are intractable with existing techniques. Here, we developed an approach for two-photon imaging of the transverse hippocampal plane in awake mice via implanted glass microperiscopes, allowing optical access to the major hippocampal subfields and to the dendritic arbor of pyramidal neurons. Using this approach, we tracked dendritic morphological dynamics on CA1 apical dendrites and characterized spine turnover. We then used calcium imaging to quantify the prevalence of place and speed cells across subfields. Finally, we measured the anatomical distribution of spatial information, finding a non-uniform distribution of spatial selectivity along the DG-to-CA1 axis. This approach extends the existing toolbox for structural and functional measurements of hippocampal circuitry.
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Affiliation(s)
- William T Redman
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara, United States
| | - Nora S Wolcott
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States
| | - Luca Montelisciani
- Cognitive and Systems Neuroscience Group, University of Amsterdam, Amsterdam, Netherlands
| | - Gabriel Luna
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Tyler D Marks
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Kevin K Sit
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
| | - Che-Hang Yu
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Spencer Smith
- Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Michael J Goard
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States.,Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
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104
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Nambu MF, Lin YJ, Reuschenbach J, Tanaka KZ. What does engram encode?: Heterogeneous memory engrams for different aspects of experience. Curr Opin Neurobiol 2022; 75:102568. [PMID: 35660988 DOI: 10.1016/j.conb.2022.102568] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/26/2022] [Accepted: 05/01/2022] [Indexed: 01/03/2023]
Abstract
Long-lasting synaptic changes within the neuronal network mediate memory. Neurons bearing such physical traces of memory (memory engram cells) are often equated with neurons expressing immediate early genes (IEGs) during a specific experience. However, past studies observed the expression of different IEGs in non-overlapping neurons or synaptic plasticity in neurons that do not express a particular IEG. Importantly, recent studies revealed that distinct subsets of neurons expressing different IEGs or even IEG negative-(yet active) neurons support different aspects of memory or computation, suggesting a more complex nature of memory engram cells than previously thought. In this short review, we introduce studies revealing such heterogeneous composition of the memory engram and discuss how the memory system benefits from it.
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Affiliation(s)
- Miyu F Nambu
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan. https://twitter.com/meowmiyu
| | - Yu-Ju Lin
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan. https://twitter.com/linyuru25199808
| | - Josefine Reuschenbach
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan. https://twitter.com/Jausefine
| | - Kazumasa Z Tanaka
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
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105
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Alexandrov YI, Pletnikov MV. Neuronal metabolism in learning and memory: The anticipatory activity perspective. Neurosci Biobehav Rev 2022; 137:104664. [PMID: 35439520 DOI: 10.1016/j.neubiorev.2022.104664] [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: 11/16/2021] [Revised: 03/30/2022] [Accepted: 04/10/2022] [Indexed: 12/20/2022]
Abstract
Current research on the molecular mechanisms of learning and memory is based on the "stimulus-response" paradigm, in which the neural circuits connecting environmental events with behavioral responses are strengthened. By contrast, cognitive and systems neuroscience emphasize the intrinsic activity of the brain that integrates information, establishes anticipatory actions, executes adaptive actions, and assesses the outcome via regulatory feedback mechanisms. We believe that the difference in the perspectives of systems and molecular studies is a major roadblock to further progress toward understanding the mechanisms of learning and memory. Here, we briefly overview the current studies in molecular mechanisms of learning and memory and propose that studying the predictive properties of neuronal metabolism will significantly advance our knowledge of how intrinsic, predictive activity of neurons shapes a new learning event. We further suggest that predictive metabolic changes in the brain may also take place in non-neuronal cells, including those of peripheral tissues. Finally, we present a path forward toward more in-depth studies of the role of cell metabolism in learning and memory.
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Affiliation(s)
- Yuri I Alexandrov
- V. B. Shvyrkov Laboratory for the Neural Bases of the Mind, Institute of Psychology, the Russian Academy of Sciences, Moscow, Russia; Department of Psychology, Institute for Cognitive Neuroscience, HSE University, Moscow, Russia.
| | - Mikhail V Pletnikov
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York, University at Buffalo, Buffalo, NY 14203, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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106
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Barykina NV, Karasev MM, Verkhusha VV, Shcherbakova DM. Technologies for large-scale mapping of functional neural circuits active during a user-defined time window. Prog Neurobiol 2022; 216:102290. [PMID: 35654210 DOI: 10.1016/j.pneurobio.2022.102290] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/15/2022] [Accepted: 05/25/2022] [Indexed: 11/25/2022]
Abstract
The mapping of neural circuits activated during behavior down to individual neurons is crucial for decoding how the brain processes information. Technologies allowing activity-dependent labeling of neurons during user-defined restricted time windows are rapidly developing. Precise marking of the time window with light, in addition to chemicals, is now possible. In these technologies, genetically encoded molecules integrate molecular events resulting from neuronal activity with light/drug-dependent events. The outputs are either changes in fluorescence or activation of gene expression. Molecular reporters allow labeling of activated neurons for visualization and cell-type identification. The transcriptional readout also allows further control of activated neuronal populations using optogenetic tools as reporters. Here we review the design of these technologies and discuss their demonstrated applications to reveal previously unknown connections in the mammalian brain. We also consider the strengths and weaknesses of the current approaches and provide a perspective for the future.
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Affiliation(s)
- Natalia V Barykina
- P.K. Anokhin Institute of Normal Physiology, Moscow 125315, Russia; Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Maksim M Karasev
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Vladislav V Verkhusha
- Department of Genetics, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Daria M Shcherbakova
- Department of Genetics, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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107
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Ortega-de San Luis C, Ryan TJ. Understanding the physical basis of memory: Molecular mechanisms of the engram. J Biol Chem 2022; 298:101866. [PMID: 35346687 PMCID: PMC9065729 DOI: 10.1016/j.jbc.2022.101866] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 12/18/2022] Open
Abstract
Memory, defined as the storage and use of learned information in the brain, is necessary to modulate behavior and critical for animals to adapt to their environments and survive. Despite being a cornerstone of brain function, questions surrounding the molecular and cellular mechanisms of how information is encoded, stored, and recalled remain largely unanswered. One widely held theory is that an engram is formed by a group of neurons that are active during learning, which undergoes biochemical and physical changes to store information in a stable state, and that are later reactivated during recall of the memory. In the past decade, the development of engram labeling methodologies has proven useful to investigate the biology of memory at the molecular and cellular levels. Engram technology allows the study of individual memories associated with particular experiences and their evolution over time, with enough experimental resolution to discriminate between different memory processes: learning (encoding), consolidation (the passage from short-term to long-term memories), and storage (the maintenance of memory in the brain). Here, we review the current understanding of memory formation at a molecular and cellular level by focusing on insights provided using engram technology.
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Affiliation(s)
- Clara Ortega-de San Luis
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
| | - Tomás J Ryan
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Victoria, Australia; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada.
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108
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Cho HY, Lee HS, Jeong Y, Han J, Yoo M, Han JH. Excitability-Independent Memory Allocation for Repeated Event. Front Behav Neurosci 2022; 16:860027. [PMID: 35571275 PMCID: PMC9094695 DOI: 10.3389/fnbeh.2022.860027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
How memory is organized in cell ensembles when an event is repeated is not well-understood. Recently, we found that retraining 24 h after the initial fear conditioning (FC) event induces turnover of neurons in the lateral amygdala (LA) that encodes fear memory. Excitability-dependent competition between eligible neurons has been suggested as a rule that governs memory allocation. However, it remains undetermined whether excitability is also involved in the allocation of a repeated event. By increasing excitability in a subset of neurons in the LA before FC, we confirmed that these neurons preferentially participated in encoding fear memory as previously reported. These neurons, however, became unnecessary for memory recall after retraining 24 h following initial FC. Consistently, the initial memory-encoding neurons became less likely to be reactivated during recall. This reorganization in cell ensembles, however, was not induced and memory was co-allocated when retraining occurred 6 h after the initial FC. In 24-h retraining condition, artificially increasing excitability right before retraining failed to drive memory co-allocation. These results suggest a distinct memory allocation mechanism for repeated events distantly separated in time.
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Affiliation(s)
- Hye-Yeon Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Han-Sol Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Yire Jeong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Junho Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Miran Yoo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Jin-Hee Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
- *Correspondence: Jin-Hee Han
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109
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Terranova JI, Yokose J, Osanai H, Marks WD, Yamamoto J, Ogawa SK, Kitamura T. Hippocampal-amygdala memory circuits govern experience-dependent observational fear. Neuron 2022; 110:1416-1431.e13. [PMID: 35139362 PMCID: PMC9035063 DOI: 10.1016/j.neuron.2022.01.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 12/10/2021] [Accepted: 01/13/2022] [Indexed: 11/28/2022]
Abstract
The empathic ability to vicariously experience the other's fearful situation, a process called observational fear (OF), is critical to survive in nature and function in society. OF can be facilitated by both prior similar fear experience in the observer and social familiarity with the demonstrator. However, the neural circuit mechanisms of experience-dependent OF (Exp OF) remain unknown. Here, we demonstrate that hippocampal-basolateral amygdala (HPC-BLA) circuits in mice without involving the anterior cingulate cortex, considered a center of OF, mediate Exp OF. Dorsal HPC neurons generate fear memory engram cells in BLA encoding prior similar fear experiences, which are essential for Exp OF. On the other hand, ventral HPC neurons respond to the familiar demonstrator's aversive situation during Exp OF, which reactivates the fear memory engram cells in BLA to elicit Exp OF. Our study provides new insights into the memory engram-dependent perception-action coupling that underlies empathic behaviors like Exp OF.
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Affiliation(s)
- Joseph I Terranova
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jun Yokose
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Hisayuki Osanai
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - William D Marks
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jun Yamamoto
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sachie K Ogawa
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Takashi Kitamura
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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110
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Lei B, Lv L, Hu S, Tang Y, Zhong Y. Social experiences switch states of memory engrams through regulating hippocampal Rac1 activity. Proc Natl Acad Sci U S A 2022; 119:e2116844119. [PMID: 35377811 PMCID: PMC9169661 DOI: 10.1073/pnas.2116844119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 02/06/2022] [Indexed: 11/18/2022] Open
Abstract
In pathological or artificial conditions, memory can be formed as silenced engrams that are unavailable for retrieval by presenting conditioned stimuli but can be artificially switched into the latent state so that natural recall is allowed. However, it remains unclear whether such different states of engrams bear any physiological significance and can be switched through physiological mechanisms. Here, we show that an acute social reward experience switches the silent memory engram into the latent state. Conversely, an acute social stress causes transient forgetting via turning a latent memory engram into a silent state. Such emotion-driven bidirectional switching between latent and silent states of engrams is mediated through regulation of Rac1 activity–dependent reversible forgetting in the hippocampus, as stress-activated Rac1 suppresses retrieval, while reward recovers silenced memory under amnesia by inhibiting Rac1. Thus, data presented reveal hippocampal Rac1 activity as the basis for emotion-mediated switching between latent and silent engrams to achieve emotion-driven behavioral flexibility.
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Affiliation(s)
- Bo Lei
- School of Life Sciences, Tsinghua University, Beijing 100084, People’s Republic of China
- McGovern Institute of Brain Research, Tsinghua University, Beijing 100084, People’s Republic of China
| | - Li Lv
- School of Life Sciences, Tsinghua University, Beijing 100084, People’s Republic of China
- McGovern Institute of Brain Research, Tsinghua University, Beijing 100084, People’s Republic of China
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, People’s Republic of China
- Peking University–Tsinghua University–National Institute Biological Science Joint Graduate Program, Beijing 100084, People's Republic of China
| | - Shiqiang Hu
- School of Life Sciences, Tsinghua University, Beijing 100084, People’s Republic of China
- McGovern Institute of Brain Research, Tsinghua University, Beijing 100084, People’s Republic of China
- Peking University–Tsinghua University–National Institute Biological Science Joint Graduate Program, Beijing 100084, People's Republic of China
| | - Yikai Tang
- School of Life Sciences, Tsinghua University, Beijing 100084, People’s Republic of China
- McGovern Institute of Brain Research, Tsinghua University, Beijing 100084, People’s Republic of China
| | - Yi Zhong
- School of Life Sciences, Tsinghua University, Beijing 100084, People’s Republic of China
- McGovern Institute of Brain Research, Tsinghua University, Beijing 100084, People’s Republic of China
- Peking University–Tsinghua University–National Institute Biological Science Joint Graduate Program, Beijing 100084, People's Republic of China
- Tsinghua–Peking Center for Life Sciences, Beijing 100084, People’s Republic of China
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua University, Beijing 100084, People’s Republic of China
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111
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Roy DS, Park YG, Kim ME, Zhang Y, Ogawa SK, DiNapoli N, Gu X, Cho JH, Choi H, Kamentsky L, Martin J, Mosto O, Aida T, Chung K, Tonegawa S. Brain-wide mapping reveals that engrams for a single memory are distributed across multiple brain regions. Nat Commun 2022; 13:1799. [PMID: 35379803 PMCID: PMC8980018 DOI: 10.1038/s41467-022-29384-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/10/2022] [Indexed: 11/28/2022] Open
Abstract
Neuronal ensembles that hold specific memory (memory engrams) have been identified in the hippocampus, amygdala, or cortex. However, it has been hypothesized that engrams of a specific memory are distributed among multiple brain regions that are functionally connected, referred to as a unified engram complex. Here, we report a partial map of the engram complex for contextual fear conditioning memory by characterizing encoding activated neuronal ensembles in 247 regions using tissue phenotyping in mice. The mapping was aided by an engram index, which identified 117 cFos+ brain regions holding engrams with high probability, and brain-wide reactivation of these neuronal ensembles by recall. Optogenetic manipulation experiments revealed engram ensembles, many of which were functionally connected to hippocampal or amygdala engrams. Simultaneous chemogenetic reactivation of multiple engram ensembles conferred a greater level of memory recall than reactivation of a single engram ensemble, reflecting the natural memory recall process. Overall, our study supports the unified engram complex hypothesis for memory storage.
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Affiliation(s)
- Dheeraj S Roy
- RIKEN-MIT Laboratory for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
| | - Young-Gyun Park
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Minyoung E Kim
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ying Zhang
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Sachie K Ogawa
- RIKEN-MIT Laboratory for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Nicholas DiNapoli
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Xinyi Gu
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jae H Cho
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Heejin Choi
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Lee Kamentsky
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jared Martin
- RIKEN-MIT Laboratory for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Olivia Mosto
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Tomomi Aida
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Kwanghun Chung
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
- Institute for Medical Engineering and Science, Picower Institute for Learning and Memory, Department of Chemical Engineering and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Yonsei-IBS Institute, Yonsei University, Seoul, 03722, Republic of Korea.
| | - Susumu Tonegawa
- RIKEN-MIT Laboratory for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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112
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Luo W, Yun D, Hu Y, Tian M, Yang J, Xu Y, Tang Y, Zhan Y, Xie H, Guan JS. Acquiring new memories in neocortex of hippocampal-lesioned mice. Nat Commun 2022; 13:1601. [PMID: 35332120 PMCID: PMC8948206 DOI: 10.1038/s41467-022-29208-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 03/04/2022] [Indexed: 12/26/2022] Open
Abstract
The hippocampus interacts with the neocortical network for memory retrieval and consolidation. Here, we found the lateral entorhinal cortex (LEC) modulates learning-induced cortical long-range gamma synchrony (20–40 Hz) in a hippocampal-dependent manner. The long-range gamma synchrony, which was coupled to the theta (7–10 Hz) rhythm and enhanced upon learning and recall, was mediated by inter-cortical projections from layer 5 neurons of the LEC to layer 2 neurons of the sensory and association cortices. Artificially induced cortical gamma synchrony across cortical areas improved memory encoding in hippocampal lesioned mice for originally hippocampal-dependent tasks. Mechanistically, we found that activities of cortical c-Fos labeled neurons, which showed egocentric map properties, were modulated by LEC-mediated gamma synchrony during memory recall, implicating a role of cortical synchrony to generate an integrative memory representation from disperse features. Our findings reveal the hippocampal mediated organization of cortical memories and suggest brain-machine interface approaches to improve cognitive function. Hippocampal lesioned mice form new memories. Here, the authors show the lateral entorhinal cortex modulates learning-induced cortical long-range gamma synchrony in a hippocampal-dependent manner and artificially induced cortical gamma synchrony across cortical areas improved memory encoding in hippocampal lesioned mice.
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Affiliation(s)
- Wenhan Luo
- School of Life Science and Technology, Shanghai Tech University, 201210, Shanghai, China
| | - Di Yun
- School of Life Science and Technology, Shanghai Tech University, 201210, Shanghai, China
| | - Yi Hu
- School of Life Science and Technology, Shanghai Tech University, 201210, Shanghai, China
| | - Miaomiao Tian
- School of Life Science and Technology, Shanghai Tech University, 201210, Shanghai, China
| | - Jiajun Yang
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Yifan Xu
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Yong Tang
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518055, Shenzhen, China
| | - Yang Zhan
- Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518055, Shenzhen, China
| | - Hong Xie
- Institute of Photonic Chips, University of Shanghai for Science and Technology, 200093, Shanghai, China.,Centre for Artificial-Intelligence Nanophotonics, School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Ji-Song Guan
- School of Life Science and Technology, Shanghai Tech University, 201210, Shanghai, China. .,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 200031, Shanghai, China.
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113
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Brain-wide projection reconstruction of single functionally defined neurons. Nat Commun 2022; 13:1531. [PMID: 35318336 PMCID: PMC8940919 DOI: 10.1038/s41467-022-29229-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/04/2022] [Indexed: 12/23/2022] Open
Abstract
Reconstructing axonal projections of single neurons at the whole-brain level is currently a converging goal of the neuroscience community that is fundamental for understanding the logic of information flow in the brain. Thousands of single neurons from different brain regions have recently been morphologically reconstructed, but the corresponding physiological functional features of these reconstructed neurons are unclear. By combining two-photon Ca2+ imaging with targeted single-cell plasmid electroporation, we reconstruct the brain-wide morphologies of single neurons that are defined by a sound-evoked response map in the auditory cortices (AUDs) of awake mice. Long-range interhemispheric projections can be reliably labelled via co-injection with an adeno-associated virus, which enables enhanced expression of indicator protein in the targeted neurons. Here we show that this method avoids the randomness and ambiguity of conventional methods of neuronal morphological reconstruction, offering an avenue for developing a precise one-to-one map of neuronal projection patterns and physiological functional features. Brain-wide axonal projections of single neurons have been extensively reconstructed without any functional characterization. The authors present a method that allows for developing a precise one-to-one map of both projection patterns and functional features of single neurons in mice.
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114
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Miyawaki H, Mizuseki K. De novo inter-regional coactivations of preconfigured local ensembles support memory. Nat Commun 2022; 13:1272. [PMID: 35277492 PMCID: PMC8917150 DOI: 10.1038/s41467-022-28929-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 02/21/2022] [Indexed: 12/31/2022] Open
Abstract
Neuronal ensembles in the amygdala, ventral hippocampus, and prefrontal cortex are involved in fear memory; however, how inter-regional ensemble interactions support memory remains elusive. Using multi-regional large-scale electrophysiology in the aforementioned structures of fear-conditioned rats, we found that the local ensembles activated during fear memory acquisition are inter-regionally coactivated during the subsequent sleep period, which relied on brief bouts of fast network oscillations. During memory retrieval, the coactivations reappeared, together with fast oscillations. Coactivation-participating-ensembles were configured prior to memory acquisition in the amygdala and prefrontal cortex but developed through experience in the hippocampus. Our findings suggest that elements of a given memory are instantly encoded within various brain regions in a preconfigured manner, whereas hippocampal ensembles and the network for inter-regional integration of the distributed information develop in an experience-dependent manner to form a new memory, which is consistent with the hippocampal memory index hypothesis. The authors show that fear-memory-related cell-ensembles in the amygdala, hippocampus, and prefrontal cortex are inter-regionally co-activated in post-learning sleep. The co-activations are hosted by fast network oscillations and re-appear during recall.
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Affiliation(s)
- Hiroyuki Miyawaki
- Department of Physiology, Osaka City University Graduate School of Medicine, Asahimachi 1-4-3, Abeno-ku, Osaka, 545-8585, Japan.
| | - Kenji Mizuseki
- Department of Physiology, Osaka City University Graduate School of Medicine, Asahimachi 1-4-3, Abeno-ku, Osaka, 545-8585, Japan.
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115
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Tomé DF, Sadeh S, Clopath C. Coordinated hippocampal-thalamic-cortical communication crucial for engram dynamics underneath systems consolidation. Nat Commun 2022; 13:840. [PMID: 35149680 PMCID: PMC8837777 DOI: 10.1038/s41467-022-28339-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 01/13/2022] [Indexed: 11/09/2022] Open
Abstract
Systems consolidation refers to the time-dependent reorganization of memory representations or engrams across brain regions. Despite recent advancements in unravelling this process, the exact mechanisms behind engram dynamics and the role of associated pathways remain largely unknown. Here we propose a biologically-plausible computational model to address this knowledge gap. By coordinating synaptic plasticity timescales and incorporating a hippocampus-thalamus-cortex circuit, our model is able to couple engram reactivations across these regions and thereby reproduce key dynamics of cortical and hippocampal engram cells along with their interdependencies. Decoupling hippocampal-thalamic-cortical activity disrupts systems consolidation. Critically, our model yields testable predictions regarding hippocampal and thalamic engram cells, inhibitory engrams, thalamic inhibitory input, and the effect of thalamocortical synaptic coupling on retrograde amnesia induced by hippocampal lesions. Overall, our results suggest that systems consolidation emerges from coupled reactivations of engram cells in distributed brain regions enabled by coordinated synaptic plasticity timescales in multisynaptic subcortical-cortical circuits.
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Affiliation(s)
| | - Sadra Sadeh
- Department of Bioengineering, Imperial College London, London, UK
| | - Claudia Clopath
- Department of Bioengineering, Imperial College London, London, UK.
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116
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Shrestha P, Klann E. Spatiotemporally resolved protein synthesis as a molecular framework for memory consolidation. Trends Neurosci 2022; 45:297-311. [PMID: 35184897 PMCID: PMC8930706 DOI: 10.1016/j.tins.2022.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 01/25/2023]
Abstract
De novo protein synthesis is required for long-term memory consolidation. Dynamic regulation of protein synthesis occurs via a complex interplay of translation factors and modulators. Many components of the protein synthesis machinery have been targeted either pharmacologically or genetically to establish its requirement for memory. The combination of ligand/light-gating and genetic strategies, that is, chemogenetics and optogenetics, has begun to reveal the spatiotemporal resolution of protein synthesis in specific cell types during memory consolidation. This review summarizes current knowledge of the macroscopic and microscopic neural substrates for protein synthesis in memory consolidation. In addition, we highlight future directions for determining the localization and timing of de novo protein synthesis for memory consolidation with tools that permit unprecedented spatiotemporal precision.
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Affiliation(s)
- Prerana Shrestha
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY 10012, USA; NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
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117
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Yan Y, Aierken A, Wang C, Jin W, Quan Z, Wang Z, Qing H, Ni J, Zhao J. Neuronal Circuits Associated with Fear Memory: Potential Therapeutic Targets for Posttraumatic Stress Disorder. Neuroscientist 2022; 29:332-351. [PMID: 35057666 DOI: 10.1177/10738584211069977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Posttraumatic stress disorder (PTSD) is a psychiatric disorder that is associated with long-lasting memories of traumatic experiences. Extinction and discrimination of fear memory have become therapeutic targets for PTSD. Newly developed optogenetics and advanced in vivo imaging techniques have provided unprecedented spatiotemporal tools to characterize the activity, connectivity, and functionality of specific cell types in complicated neuronal circuits. The use of such tools has offered mechanistic insights into the exquisite organization of the circuitry underlying the extinction and discrimination of fear memory. This review focuses on the acquisition of more detailed, comprehensive, and integrated neural circuits to understand how the brain regulates the extinction and discrimination of fear memory. A future challenge is to translate these researches into effective therapeutic treatment for PTSD from the perspective of precise regulation of the neural circuits associated with the extinction and discrimination of fear memories.
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Affiliation(s)
- Yan Yan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Ailikemu Aierken
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Chunjian Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Wei Jin
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhe Wang
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
- The National Clinical Research Center for Geriatric Disease, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Juan Zhao
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China
- Aerospace Medical Center, Aerospace Center Hospital, Beijing, China
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118
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Ryan TJ, Frankland PW. Forgetting as a form of adaptive engram cell plasticity. Nat Rev Neurosci 2022; 23:173-186. [PMID: 35027710 DOI: 10.1038/s41583-021-00548-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2021] [Indexed: 12/30/2022]
Abstract
One leading hypothesis suggests that memories are stored in ensembles of neurons (or 'engram cells') and that successful recall involves reactivation of these ensembles. A logical extension of this idea is that forgetting occurs when engram cells cannot be reactivated. Forms of 'natural forgetting' vary considerably in terms of their underlying mechanisms, time course and reversibility. However, we suggest that all forms of forgetting involve circuit remodelling that switches engram cells from an accessible state (where they can be reactivated by natural recall cues) to an inaccessible state (where they cannot). In many cases, forgetting rates are modulated by environmental conditions and we therefore propose that forgetting is a form of neuroplasticity that alters engram cell accessibility in a manner that is sensitive to mismatches between expectations and the environment. Moreover, we hypothesize that disease states associated with forgetting may hijack natural forgetting mechanisms, resulting in reduced engram cell accessibility and memory loss.
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Affiliation(s)
- Tomás J Ryan
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland. .,Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland. .,Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, Victoria, Australia. .,Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada.
| | - Paul W Frankland
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada. .,Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada. .,Department of Psychology, University of Toronto, Toronto, Ontario, Canada. .,Department of Physiology, University of Toronto, Toronto, Ontario, Canada. .,Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.
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119
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Merten JE, Villarrubia SA, Holly KS, Kemp AS, Kumler AC, Larson-Prior LJ, Murray TA. The use of rodent models to better characterize the relationship among epilepsy, sleep, and memory. Epilepsia 2022; 63:525-536. [PMID: 34985784 DOI: 10.1111/epi.17161] [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: 08/24/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 11/28/2022]
Abstract
Epilepsy, a neurological disorder characterized by recurrent seizures, is known to be associated with impaired sleep and memory. Although the specific mechanisms underlying these impairments are uncertain, the known role of sleep in memory consolidation suggests a potential relationship may exist between seizure activity, disrupted sleep, and memory impairment. A possible mediator in this relationship is the sleep spindle, the characteristic electroencephalographic (EEG) feature of non-rapid-eye-movement (NREM) sleep in humans and other mammals. Growing evidence supports the idea that sleep spindles, having thalamic origin, may mediate the process of long-term memory storage and plasticity by generating neuronal conditions that favor these processes. To study this potential relationship, a single model in which memory, sleep, and epilepsy can be simultaneously observed is of necessity. Rodent models of epilepsy appear to fulfill this requirement. Not only do rodents express both sleep spindles and seizure-induced sleep disruptions, but they also allow researchers to invasively study neurobiological processes both pre- and post- epileptic onset via the artificial induction of epilepsy (a practice that cannot be carried out in human subjects). However, the degree to which sleep architecture differs between rodents and humans makes direct comparisons between the two challenging. This review addresses these challenges and concludes that rodent sleep studies are useful in observing the functional roles of sleep and how they are affected by epilepsy.
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Affiliation(s)
- John E Merten
- College of Medicine, University of Arkansas for Medical Sciences (UAMS), Little Rock, Arkansas, USA
| | | | - Kevin S Holly
- Biomedical Engineering, Louisiana Tech University, Ruston, Louisina, USA
| | - Aaron S Kemp
- Departments of Psychiatry and Biomedical Informatics, UAMS, Little Rock, Arkansas, USA
| | - Allison C Kumler
- Biomedical Engineering, Louisiana Tech University, Ruston, Louisina, USA
| | - Linda J Larson-Prior
- Departments of Psychiatry and Biomedical Informatics, UAMS, Little Rock, Arkansas, USA.,Departments of Neurology, Neurobiology & Developmental Sciences, Pediatrics, UAMS, Little Rock, Arkansas, USA
| | - Teresa A Murray
- Biomedical Engineering, Louisiana Tech University, Ruston, Louisina, USA
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120
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Smith DM, Yang YY, Subramanian DL, Miller AMP, Bulkin DA, Law LM. The limbic memory circuit and the neural basis of contextual memory. Neurobiol Learn Mem 2022; 187:107557. [PMID: 34808337 PMCID: PMC8755583 DOI: 10.1016/j.nlm.2021.107557] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 01/03/2023]
Abstract
The hippocampus, retrosplenial cortex and anterior thalamus are key components of a neural circuit known to be involved in a variety of memory functions, including spatial, contextual and episodic memory. In this review, we focus on the role of this circuit in contextual memory processes. The background environment, or context, is a powerful cue for memory retrieval, and neural representations of the context provide a mechanism for efficiently retrieving relevant memories while avoiding interference from memories that belong to other contexts. Data from experimental lesions and neural manipulation techniques indicate that each of these regions is critical for contextual memory. Neurophysiological evidence from the hippocampus and retrosplenial cortex suggest that contextual information is represented within this circuit by population-level neural firing patterns that reliably differentiate each context a subject encounters. These findings indicate that encoding contextual information to support context-dependent memory retrieval is a key function of this circuit.
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Affiliation(s)
- David M Smith
- Department of Psychology, Cornell University, Ithaca, NY, United States.
| | - Yan Yu Yang
- Department of Psychology, Cornell University, Ithaca, NY, United States
| | | | - Adam M P Miller
- Department of Psychology, Cornell University, Ithaca, NY, United States
| | - David A Bulkin
- Department of Psychology, Cornell University, Ithaca, NY, United States
| | - L Matthew Law
- Department of Psychology, Cornell University, Ithaca, NY, United States
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121
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Conklin BD. Spectral characteristics of visual working memory in the monkey frontoparietal network. PSYCHOLOGY OF LEARNING AND MOTIVATION 2022. [DOI: 10.1016/bs.plm.2022.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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122
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De Garrido L. Conceptual Design of a Creative Artificial Intelligence System Based on the Neurocognitive Bases of Human Creativity in the Brain. CREATIVITY RESEARCH JOURNAL 2021. [DOI: 10.1080/10400419.2021.2005309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Luis De Garrido
- Universitat de València
- Universidad Complutense de Madrid
- National Association of Sustainable Creative Architecture Researh
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123
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Marcondes LA, de C Myskiw J, Nachtigall EG, Narvaes RF, Izquierdo I, Furini CRG. PKMζ maintains remote contextual fear memory by inhibiting GluA2-dependent AMPA receptor endocytosis in the prelimbic cortex. Neuroscience 2021; 497:97-106. [PMID: 34968669 DOI: 10.1016/j.neuroscience.2021.12.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/10/2021] [Accepted: 12/21/2021] [Indexed: 10/19/2022]
Abstract
Fear memories allow animals to recognize and adequately respond to dangerous situations. The prelimbic cortex (PrL) is a crucial node in the circuitry that encodes contextual fear memory, and its activity is central for fear memory expression over time. However, while PrL has been implicated in contextual fear memory storage, the molecular mechanisms underlying its maintenance remain unclear. Protein kinase M zeta (PKMζ) is a persistently active enzyme which has been shown to maintain many forms of memories by inhibiting the endocytosis of GluA2-containing AMPA receptors. Therefore, we hypothesized that PKMζ action upon GluA2-containing AMPARs could be a mechanism for contextual fear memory maintenance in the PrL. To test this hypothesis, we trained rats in a contextual fear conditioning (CFC) paradigm and administered intra-PrL infusions of the PKMζ inhibitor ZIP, the GluA2-dependent endocytosis inhibitor GluA23Y or the inactive peptide GluA23Y(s), either two or twenty days after conditioning, and assessed long-term memory retention twenty-four hours later. We found that acute inhibition of GluA2-dependent AMPAR endocytosis in the PrL does not affect recent or remote contextual fear memory maintenance. Also, PKMζ inhibition in the PrL does not impair the maintenance of recent contextual fear memory. However, we found that inhibition of prelimbic PKMζ at a remote time point disrupted contextual fear memory maintenance, and that blocking GluA2-dependent removal of AMPARs prevents this impairment. Our results confirm the central role of PrL in fear memory and identify PKMζ-induced inhibition of GluA2-containing AMPAR endocytosis as a key mechanism governing remote contextual fear memory maintenance.
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Affiliation(s)
- Lucas A Marcondes
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3(rd) floor, 90610-000, Porto Alegre, RS, Brazil; Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2(nd) floor - HSL, 90610-000, Porto Alegre, RS, Brazil
| | - Jociane de C Myskiw
- Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2(nd) floor - HSL, 90610-000, Porto Alegre, RS, Brazil
| | - Eduarda G Nachtigall
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3(rd) floor, 90610-000, Porto Alegre, RS, Brazil; Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2(nd) floor - HSL, 90610-000, Porto Alegre, RS, Brazil
| | - Rodrigo F Narvaes
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3(rd) floor, 90610-000, Porto Alegre, RS, Brazil; Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2(nd) floor - HSL, 90610-000, Porto Alegre, RS, Brazil
| | - Ivan Izquierdo
- Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2(nd) floor - HSL, 90610-000, Porto Alegre, RS, Brazil
| | - Cristiane R G Furini
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3(rd) floor, 90610-000, Porto Alegre, RS, Brazil; Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2(nd) floor - HSL, 90610-000, Porto Alegre, RS, Brazil.
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124
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Learning and memory: Shuffling memory traces by relearning. Curr Biol 2021; 31:R1588-R1591. [PMID: 34932971 DOI: 10.1016/j.cub.2021.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Memory engram cells are a subpopulation of neurons activated during learning, and are necessary and sufficient for memory recall. New findings show that relearning induces the turnover of the memory engram cell population involved in fear memory recall.
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125
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Silent Synapses in Cocaine-Associated Memory and Beyond. J Neurosci 2021; 41:9275-9285. [PMID: 34759051 DOI: 10.1523/jneurosci.1559-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/22/2021] [Accepted: 09/27/2021] [Indexed: 11/21/2022] Open
Abstract
Glutamatergic synapses are key cellular sites where cocaine experience creates memory traces that subsequently promote cocaine craving and seeking. In addition to making across-the-board synaptic adaptations, cocaine experience also generates a discrete population of new synapses that selectively encode cocaine memories. These new synapses are glutamatergic synapses that lack functionally stable AMPARs, often referred to as AMPAR-silent synapses or, simply, silent synapses. They are generated de novo in the NAc by cocaine experience. After drug withdrawal, some of these synapses mature by recruiting AMPARs, contributing to the consolidation of cocaine-associated memory. After cue-induced retrieval of cocaine memories, matured silent synapses alternate between two dynamic states (AMPAR-absent vs AMPAR-containing) that correspond with the behavioral manifestations of destabilization and reconsolidation of these memories. Here, we review the molecular mechanisms underlying silent synapse dynamics during behavior, discuss their contributions to circuit remodeling, and analyze their role in cocaine-memory-driven behaviors. We also propose several mechanisms through which silent synapses can form neuronal ensembles as well as cross-region circuit engrams for cocaine-specific behaviors. These perspectives lead to our hypothesis that cocaine-generated silent synapses stand as a distinct set of synaptic substrates encoding key aspects of cocaine memory that drive cocaine relapse.
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126
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The Medial Prefrontal Cortex and Fear Memory: Dynamics, Connectivity, and Engrams. Int J Mol Sci 2021; 22:ijms222212113. [PMID: 34830009 PMCID: PMC8619965 DOI: 10.3390/ijms222212113] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 01/08/2023] Open
Abstract
It is becoming increasingly apparent that long-term memory formation relies on a distributed network of brain areas. While the hippocampus has been at the center of attention for decades, it is now clear that other regions, in particular the medial prefrontal cortex (mPFC), are taking an active part as well. Recent evidence suggests that the mPFC-traditionally implicated in the long-term storage of memories-is already critical for the early phases of memory formation such as encoding. In this review, we summarize these findings, relate them to the functional importance of the mPFC connectivity, and discuss the role of the mPFC during memory consolidation with respect to the different theories of memory storage. Owing to its high functional connectivity to other brain areas subserving memory formation and storage, the mPFC emerges as a central hub across the lifetime of a memory, although much still remains to be discovered.
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127
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Willems T, Henke K. Imaging human engrams using 7 Tesla magnetic resonance imaging. Hippocampus 2021; 31:1257-1270. [PMID: 34739173 PMCID: PMC9298259 DOI: 10.1002/hipo.23391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 12/15/2022]
Abstract
The investigation of the physical traces of memories (engrams) has made significant progress in the last decade due to optogenetics and fluorescent cell tagging applied in rodents. Engram cells were identified. The ablation of engram cells led to the loss of the associated memory, silent memories were reactivated, and artificial memories were implanted in the brain. Human engram research lags behind engram research in rodents due to methodological and ethical constraints. However, advances in multivariate analysis techniques of functional magnetic resonance imaging (fMRI) data and machine learning algorithms allowed the identification of stable engram patterns in humans. In addition, MRI scanners with an ultrahigh field strength of 7 Tesla (T) have left their prototype state and became more common around the world to assist human engram research. Although most engram research in humans is still being performed with a field strength of 3T, fMRI at 7T will push engram research. Here, we summarize the current state and findings of human engram research and discuss the advantages and disadvantages of applying 7 versus 3T fMRI to image human memory traces.
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Affiliation(s)
- Tom Willems
- Institute of Psychology, University of Bern, Bern, Switzerland
| | - Katharina Henke
- Institute of Psychology, University of Bern, Bern, Switzerland
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128
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Bowden DM, German DC. Mapping reward mechanisms by intracerebral self-stimulation in the rhesus monkey (Macaca mulatta). J Comp Neurol 2021; 529:3564-3592. [PMID: 33978232 PMCID: PMC8920750 DOI: 10.1002/cne.25188] [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: 12/08/2020] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 11/08/2022]
Abstract
The objective of the study was to identify brain structures that mediate reward as evidenced by positive reinforcing effects of stimuli on behavior. Testing by intracerebral self-stimulation enabled monkeys to inform whether activation of ~2900 sites in 74 structures of 4 sensorimotor pathways and 4 modulatory loop pathways was positive, negative or neutral. Stimulation was rewarding at 30% of sites, negative at 17%, neutral at 52%. Virtually all (99%) structures yielded some positive or negative sites, suggesting a ubiquitous distribution of pathways transmitting valence information. Mapping of sites to structures with dense versus sparse dopaminergic (DA) or noradrenergic (NA) innervation showed that stimulation of DA-pathways was rewarding or neutral. Stimulation of NA-pathways was not rewarding. Stimulation of association areas was generally rewarding; stimulation of purely sensory or motor structures was generally negative. Reward related more to structures' sensorimotor function than to density of DA-innervation. Stimulation of basal ganglia loop pathways was rewarding except in lateral globus pallidus, an inhibitory structure in the negative feedback loop; stimulation of the cerebellar loop was rewarding in anterior vermis and the spinocerebellar pathway; and stimulation of the hippocampal CA1 loop was rewarding. While most positive sites were in the DA reward system, numerous sites in sparsely DA-innervated posterior cingulate and parietal cortices may represent a separate reward system. DA-density represents concentrations of plastic synapses that mediate acquisition of new synaptic connections. DA-sparse areas may represent innate, genetically programmed reward-associated pathways. Implications of findings in regard to response habituation and addiction are discussed.
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Affiliation(s)
- Douglas M. Bowden
- Department of Psychiatry and Behavioral Sciences and National Primate Research Center, University of Washington, Seattle, Washington
| | - Dwight C. German
- Department of Psychiatry and Behavioral Sciences and National Primate Research Center, University of Washington, Seattle, Washington
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
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129
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Wang G, Xie H, Hu Y, Chen Q, Liu C, Liu K, Yan Y, Guan JS. Egr1-EGFP transgenic mouse allows in vivo recording of Egr1 expression and neural activity. J Neurosci Methods 2021; 363:109350. [PMID: 34487772 DOI: 10.1016/j.jneumeth.2021.109350] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/29/2021] [Accepted: 08/31/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Immediate-early genes (IEGs) have been serving as markers of active neurons for their rapid responses to stimulation. With the development of IEG-EGFP reporters by the GENSAT project, application of the IEGs have been greatly expanded. However, detailed validations for these systems are still lacking, causing trouble in the interpretation of the fluorescence signals. NEW METHOD In this work, taken Egr1-EGFP transgenic mice as an example, we proposed an improvement for the usage of the Egr1-EGFP reporter system based on detailed validation of its fluorescence signals. RESULTS Firstly, the exogenous EGFP mRNA levels were linearly correlated with the endogenous Egr1 mRNA levels in neurons. Secondly, the 3-hr-changes of the Egr1-EGFP signals before and after the stimulus were positively correlated with the stimulus-induced neuronal activities. Interestingly, persistent neuronal activity patterns in the post-stimulus phase also showed correlation with the stimulus-induced Egr1-EGFP signal changes. Furthermore, enriched environments engaged dramatic neuronal activations, allowing detailed characterization of Egr1-EGFP expression dynamics. COMPARISON WITH EXISTING METHOD(S) People used to infer the neuronal activities based on the raw fluorescence signals of IEG-EGFP reporter system, which was strongly obstructed by distinct protein regulation or dynamic properties between the EGFP and the IEGs. We demonstrated a better way for data analysis and experimental design. CONCLUSIONS Taken together, this work proves that Egr1-EGFP signal is weakly but significantly correlated to task-induced neural activity and gives detailed characterization of the signal dynamics. It not only provides basis for the understanding of the IEG-EGFP fluorescence signals but also offers instructions for proper experimental design with IEG-EGFP reporter systems.
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Affiliation(s)
- Guangyu Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Shanghai Research Center for Brain Science and Brain-Inspired Intelligence Institute of Brain Intelligence Science and Technology, Shanghai 201210, China
| | - Hong Xie
- Centre for Artificial-Intelligence Nanophotonics, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Yi Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Qinan Chen
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Chenhui Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Kaiyuan Liu
- MOE Key Laboratory of Protein Sciences, IDG/McGovern institute for Brain Research at Tsinghua, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yuze Yan
- MOE Key Laboratory of Protein Sciences, IDG/McGovern institute for Brain Research at Tsinghua, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ji-Song Guan
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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130
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Kislinger L. Photographs of Actions: What Makes Them Special Cues to Social Perception. Brain Sci 2021; 11:brainsci11111382. [PMID: 34827381 PMCID: PMC8615998 DOI: 10.3390/brainsci11111382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/18/2021] [Accepted: 10/18/2021] [Indexed: 11/16/2022] Open
Abstract
I have reviewed studies on neural responses to pictured actions in the action observation network (AON) and the cognitive functions of these responses. Based on this review, I have analyzed the specific representational characteristics of action photographs. There has been consensus that AON responses provide viewers with knowledge of observed or pictured actions, but there has been controversy about the properties of this knowledge. Is this knowledge causally provided by AON activities or is it dependent on conceptual processing? What elements of actions does it refer to, and how generalized or specific is it? The answers to these questions have come from studies that used transcranial magnetic stimulation (TMS) to stimulate motor or somatosensory cortices. In conjunction with electromyography (EMG), TMS allows researchers to examine changes of the excitability in the corticospinal tract and muscles of people viewing pictured actions. The timing of these changes and muscle specificity enable inferences to be drawn about the cognitive products of processing pictured actions in the AON. Based on a review of studies using TMS and other neuroscience methods, I have proposed a novel hypothetical account that describes the characteristics of action photographs that make them effective cues to social perception. This account includes predictions that can be tested experimentally.
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131
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Cho HY, Shin W, Lee HS, Lee Y, Kim M, Oh JP, Han J, Jeong Y, Suh B, Kim E, Han JH. Turnover of fear engram cells by repeated experience. Curr Biol 2021; 31:5450-5461.e4. [PMID: 34687608 DOI: 10.1016/j.cub.2021.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/07/2021] [Accepted: 10/01/2021] [Indexed: 10/20/2022]
Abstract
A sparse population of neurons active during a learning event has been identified as memory engram cells. However, cells that are recruited to support memory when experience is repeated have been scarcely explored. Evidence from previous studies provides contradictory views. To address these questions, we employed learning-dependent cell labeling in the lateral amygdala (LA) and applied electrophysiological recording, spine imaging, and optogenetic tools to the labeled neurons with or without retraining. We found that engram cells established from original fear learning became dispensable for memory retrieval specifically with relearning, and this correlated with a reduction of synaptic transmission and loss of dendritic spines in these neurons. Despite such decreased connectivity, direct activation of these neurons resulted in fear-memory recall. We further identified that repeated memory was encoded in neurons active during relearning. These results suggest a shift in neuronal ensembles encoding fear memory in the LA by relearning through disconnection of the existing engram neurons established from original experience.
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Affiliation(s)
- Hye-Yeon Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Wangyong Shin
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Han-Sol Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Yeji Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Mujun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Jung-Pyo Oh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Junho Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Yire Jeong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Boin Suh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Jin-Hee Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea; KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Korea.
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132
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Stamatakis AM, Resendez SL, Chen KS, Favero M, Liang-Guallpa J, Nassi JJ, Neufeld SQ, Visscher K, Ghosh KK. Miniature microscopes for manipulating and recording in vivo brain activity. Microscopy (Oxf) 2021; 70:399-414. [PMID: 34283242 PMCID: PMC8491619 DOI: 10.1093/jmicro/dfab028] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/02/2021] [Accepted: 07/19/2021] [Indexed: 12/23/2022] Open
Abstract
Here we describe the development and application of miniature integrated microscopes (miniscopes) paired with microendoscopes that allow for the visualization and manipulation of neural circuits in superficial and subcortical brain regions in freely behaving animals. Over the past decade the miniscope platform has expanded to include simultaneous optogenetic capabilities, electrically-tunable lenses that enable multi-plane imaging, color-corrected optics, and an integrated data acquisition platform that streamlines multimodal experiments. Miniscopes have given researchers an unprecedented ability to monitor hundreds to thousands of genetically-defined neurons from weeks to months in both healthy and diseased animal brains. Sophisticated algorithms that take advantage of constrained matrix factorization allow for background estimation and reliable cell identification, greatly improving the reliability and scalability of source extraction for large imaging datasets. Data generated from miniscopes have empowered researchers to investigate the neural circuit underpinnings of a wide array of behaviors that cannot be studied under head-fixed conditions, such as sleep, reward seeking, learning and memory, social behaviors, and feeding. Importantly, the miniscope has broadened our understanding of how neural circuits can go awry in animal models of progressive neurological disorders, such as Parkinson's disease. Continued miniscope development, including the ability to record from multiple populations of cells simultaneously, along with continued multimodal integration of techniques such as electrophysiology, will allow for deeper understanding into the neural circuits that underlie complex and naturalistic behavior.
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Affiliation(s)
| | | | - Kai-Siang Chen
- Inscopix Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA
| | - Morgana Favero
- Inscopix Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA
| | | | | | - Shay Q Neufeld
- Inscopix Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA
| | - Koen Visscher
- Inscopix Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA
| | - Kunal K Ghosh
- Inscopix Inc., 2462 Embarcadero Way, Palo Alto, CA 94303, USA
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133
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Grella SL, Gomes SM, Lackie RE, Renda B, Marrone DF. Norepinephrine as a spatial memory reset signal. Behav Pharmacol 2021; 32:531-548. [PMID: 34417358 DOI: 10.1097/fbp.0000000000000648] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Contextual information is represented in the hippocampus (HPC) partially through the recruitment of distinct neuronal ensembles. It is believed that reactivation of these ensembles underlies memory retrieval processes. Recently, we showed that norepinephrine input from phasic locus coeruleus activation induces hippocampal plasticity resulting in the recruitment of new neurons and disengagement from previously established representations. We hypothesize that norepinephrine may provide a neuromodulatory mnemonic switch signaling the HPC to move from a state of retrieval to encoding in the presence of novelty, and therefore, plays a role in memory updating. Here, we tested whether bilateral dorsal dentate gyrus (dDG) infusions of the β-adrenergic receptor (BAR) agonist isoproterenol (ISO), administered prior to encoding or retrieval, would impair spatial working and reference memory by reverting, the system to encoding (thereby recruiting new neurons) potentially interfering with the retrieval of the previously established spatial ensemble. We also investigated whether dDG infusions of ISO could promote cognitive flexibility by switching the system to encoding when it is adaptive (ie, when new information is presented, eg, reversal learning). We found that intra-dDG infusions of ISO given prior to retrieval caused deficits in working and reference memory which was blocked by pretreatment with the BAR-antagonist, propranolol (PRO). In contrast, ISO administered prior to reversal learning led to improved performance. These data support our hypothesis that norepinephrine serves as a novelty signal to update HPC contextual representations via BAR activation-facilitated recruitment of new neurons. This can be both maladaptive and adaptive depending on the situation.
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Affiliation(s)
- Stephanie L Grella
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Department of Psychological & Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Sarah M Gomes
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Faculty of Health Sciences, School of Medicine, Queen's University, Kingston
| | - Rachel E Lackie
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Program in Neuroscience, Robarts Research Institute, University of Western Ontario, London
| | - Briana Renda
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Department of Psychology, University of Guelph, Guelph, Ontario, Canada
| | - Diano F Marrone
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- McKnight Brain Institute, University of Arizona, Tucson, Arizona, USA
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134
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Zheng J, Suo L, Zhou Y, Jia L, Li J, Kuang Y, Cui D, Zhang X, Wu Q. Pyk2 suppresses contextual fear memory in an autophosphorylation-independent manner. J Mol Cell Biol 2021; 13:808-821. [PMID: 34529077 PMCID: PMC8782590 DOI: 10.1093/jmcb/mjab057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 11/13/2022] Open
Abstract
Clustered protocadherins (Pcdhs) are a large family of cadherin-like cell adhesion proteins that are central for neurite self-avoidance and neuronal connectivity in the brain. Their downstream non-receptor tyrosine kinase Pyk2 (proline-rich tyrosine kinase 2, also known as Ptk2b, Cakb, Raftk, Fak2, and Cadtk) is predominantly expressed in the hippocampus. We constructed Pyk2 null mouse lines and found that these mutant mice showed enhancement in contextual fear memory, without any change in auditory-cued and spatial-referenced learning and memory. In addition, by preparing Y402F mutant mice, we observed that Pyk2 suppressed contextual fear memory in an autophosphorylation-independent manner. Moreover, using high-throughput RNA sequencing, we found that immediate early genes, such as Npas4, cFos, Zif268/Egr1, Arc, and Nr4a1, were enhanced in Pyk2 null mice. We further showed that Pyk2 disruption affected pyramidal neuronal complexity and spine dynamics. Thus, we demonstrated that Pyk2 is a novel fear memory suppressor molecule and Pyk2 null mice provide a model for understanding fear-related disorders. These findings have interesting implications regarding dysregulation of the Pcdh‒Pyk2 axis in neuropsychiatric disorders.
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Affiliation(s)
- Jin Zheng
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Lun Suo
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Yuxiao Zhou
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Liling Jia
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Jingwei Li
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
| | - Yanping Kuang
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Donghong Cui
- Shanghai Mental Health Center, Shanghai Key Laboratory of Psychotic Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Xuehong Zhang
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiang Wu
- Center for Comparative Biomedicine, Ministry of Education Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Joint International Research Laboratory of Metabolic and Developmental Sciences, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,WLA Laboratories, Shanghai, China
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135
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Nagayach A, Ghafari M, Zhao Y, Collins GS, Singh A, Geller AI. Connected neurons in multiple neocortical areas, comprising parallel circuits, encode essential information for visual shape learning. J Chem Neuroanat 2021; 118:102024. [PMID: 34492329 DOI: 10.1016/j.jchemneu.2021.102024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 08/28/2021] [Accepted: 09/02/2021] [Indexed: 11/25/2022]
Abstract
Neocortical areas comprised of multiple neuronal circuits which are encoded with innumerable advanced cognitive tasks. Studies focused on neuronal network and synaptic plasticity has hypothesized that every specific neuron and the circuit process the explicit essential information for the specific tasks. However, the structure of these circuits and the involved critical neurons remain to be elucidated. Considering our previous studies, showing the specificity of rat postrhinal cortex comprising specific neuronal circuit for encoding both the learning and recall of shape discrimination through a fast neurotransmitter release from the transduced neurons, here we have demonstrated that postsynaptic neurons in two distinct areas, perirhinal cortex and the ventral temporal association areas are required for the specific visual shape discriminations learning. The constitutively active PKC was delivered into neuronal cells in postrhinal cortex, and the animals were allowed to learn the new shape discriminations, and then the silencing siRNA was delivered into postsynaptic neurons in either perirhinal cortex or ventral temporal association areas, using a novel technology for gene transfer into connected neurons. We observed that expression of the siRNA caused the deficits in visual performance, via blocking the activity in the neurons, as displayed by activity-dependent gene imaging, and also subsequently obstructed the activation of specific signaling pathways required for further learning, and dendritic protein synthesis and CREB. Thus, ratifying the conclusion that the two parallel circuits are both required for the visual shape discrimination learning.
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Affiliation(s)
- Aarti Nagayach
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States.
| | - Maryam Ghafari
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States
| | - Yinghong Zhao
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States
| | - Grant S Collins
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States
| | - Anshuman Singh
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States
| | - Alfred I Geller
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States; Department of Pharmacology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, United States
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136
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Li X, Zeng P, Wang F, Zhang D, Zhou Y, Liang R, Ou Q, Wu X, Zhang S. A nanoimprinted artificial engram device. NANOSCALE HORIZONS 2021; 6:718-728. [PMID: 34259291 DOI: 10.1039/d1nh00064k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
At present, mainstream neuromorphic hardware is based on artificial synapses; however, an engram, instead of a synapse, has recently been confirmed as the basic unit of memory, which verifies the engram theory proposed by Richard Semon in 1904. Here, we demonstrate an artificial engram device based on a nanoimprinted curable resin. The variation in the relative diffraction efficiency based on the asymmetric reversible topological change of the nanoimprinted resin enables the device to meet all the requirements for artificial engrams, including synaptic plasticity, long memory storage time, asymmetric memorizing-forgetting behaviour and measurable changes and responses. On this basis, we demonstrate the concept of realizing memory formation, memory manipulation and implantation, and memory consolidation using our artificial engram device in comparison with its biological counterpart.
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Affiliation(s)
- Xuesong Li
- Institute for Electric Light Sources, Department of Light Sources and Illuminating Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, P. R. China.
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137
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Cummings KA, Lacagnina AF, Clem RL. GABAergic microcircuitry of fear memory encoding. Neurobiol Learn Mem 2021; 184:107504. [PMID: 34425220 DOI: 10.1016/j.nlm.2021.107504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 12/30/2022]
Abstract
The paradigm of fear conditioning is largely responsible for our current understanding of how memories are encoded at the cellular level. Its most fundamental underlying mechanism is considered to be plasticity of synaptic connections between excitatory projection neurons (PNs). However, recent studies suggest that while PNs execute critical memory functions, their activity at key stages of learning and recall is extensively orchestrated by a diverse array of GABAergic interneurons (INs). Here we review the contributions of genetically-defined INs to processing of threat-related stimuli in fear conditioning, with a particular focus on how synaptic interactions within interconnected networks of INs modulates PN activity through both inhibition and disinhibition. Furthermore, we discuss accumulating evidence that GABAergic microcircuits are an important locus for synaptic plasticity during fear learning and therefore a viable substrate for long-term memory. These findings suggest that further investigation of INs could unlock unique conceptual insights into the organization and function of fear memory networks.
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Affiliation(s)
- Kirstie A Cummings
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; Department of Neurobiology, University of Alabama Birmingham School of Medicine, Birmingham, AL 35294, United States
| | - Anthony F Lacagnina
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Roger L Clem
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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138
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Subramaniyan M, Manivannan S, Chelur V, Tsetsenis T, Jiang E, Dani JA. Fear conditioning potentiates the hippocampal CA1 commissural pathway in vivo and increases awake phase sleep. Hippocampus 2021; 31:1154-1175. [PMID: 34418215 PMCID: PMC9290090 DOI: 10.1002/hipo.23381] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/10/2021] [Accepted: 07/24/2021] [Indexed: 11/24/2022]
Abstract
The hippocampus is essential for spatial learning and memory. To assess learning we used contextual fear conditioning (cFC), where animals learn to associate a place with aversive events like foot‐shocks. Candidate memory mechanisms for cFC are long‐term potentiation (LTP) and long‐term depression (LTD), but there is little direct evidence of them operating in the hippocampus in vivo following cFC. Also, little is known about the behavioral state changes induced by cFC. To address these issues, we recorded local field potentials in freely behaving mice by stimulating in the left dorsal CA1 region and recording in the right dorsal CA1 region. Synaptic strength in the commissural pathway was monitored by measuring field excitatory postsynaptic potentials (fEPSPs) before and after cFC. After cFC, the commissural pathway's synaptic strength was potentiated. Although recordings occurred during the wake phase of the light/dark cycle, the mice slept more in the post‐conditioning period than in the pre‐conditioning period. Relative to awake periods, in non‐rapid eye movement (NREM) sleep the fEPSPs were larger in both pre‐ and post‐conditioning periods. We also found a significant negative correlation between the animal's speed and fEPSP size. Therefore, to avoid confounds in the fEFSP potentiation estimates, we controlled for speed‐related and sleep‐related fEPSP changes and still found that cFC induced long‐term potentiation, but no significant long‐term depression. Synaptic strength changes were not found in the control group that simply explored the fear‐conditioning chamber, indicating that exploration of the novel place did not produce the measurable effects caused by cFC. These results show that following cFC, the CA1 commissural pathway is potentiated, likely contributing to the functional integration of the left and right hippocampi in fear memory consolidation. In addition, the cFC paradigm produces significant changes in an animal's behavioral state, which are observable as proximal changes in sleep patterns.
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Affiliation(s)
- Manivannan Subramaniyan
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sumithrra Manivannan
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Vikas Chelur
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Theodoros Tsetsenis
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Evan Jiang
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John A Dani
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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139
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Ko SY, Frankland PW. Neurogenesis-dependent transformation of hippocampal engrams. Neurosci Lett 2021; 762:136176. [PMID: 34400284 DOI: 10.1016/j.neulet.2021.136176] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 07/29/2021] [Accepted: 08/11/2021] [Indexed: 11/29/2022]
Abstract
In humans and other mammals, memories of events are encoded by neuronal ensembles (or engrams) in the hippocampus. The mnemonic information stored in these engrams can then be used to guide future behavior, including prediction- and decision-making in dynamic environments. While some hippocampal engrams may be persistently stored, others are modified over time, suggesting that the represented memories may also be transformed. How might hippocampal engrams be modified through time? Adult hippocampal neurogenesis represents one process that continuously rewires hippocampal circuitry, presumably including stored hippocampal engrams. At intermediate stages, we propose that neurogenesis-mediated rewiring of hippocampal engram circuitry induces forgetting of specific stimulus attributes, and this less precise engram allows for generalization. At more advanced stages, we propose that neurogenesis-mediated rewiring of hippocampal engram circuitry leads to silencing of hippocampal engrams, rendering them no longer accessible by natural retrieval cues.
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Affiliation(s)
- Sangyoon Y Ko
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Temerty Centre for AI Research and Education in Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Paul W Frankland
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada; Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada; Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada.
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140
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Choi DI, Kim J, Lee H, Kim JI, Sung Y, Choi JE, Venkat SJ, Park P, Jung H, Kaang BK. Synaptic correlates of associative fear memory in the lateral amygdala. Neuron 2021; 109:2717-2726.e3. [PMID: 34363751 DOI: 10.1016/j.neuron.2021.07.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 04/16/2021] [Accepted: 07/01/2021] [Indexed: 01/25/2023]
Abstract
Successful adaptation to the environment requires an accurate response to external threats by recalling specific memories. Memory formation and recall require engram cell activity and synaptic strengthening among activated neuronal ensembles. However, elucidation of the underlying neural substrates of associative fear memory has remained limited without a direct interrogation of extinction-induced changes of specific synapses that encode a specific auditory fear memory. Using dual-eGRASP (enhanced green fluorescent protein reconstitution across synaptic partners), we found that synapses among activated neuronal ensembles or activated synaptic ensembles showed a significantly larger spine morphology at auditory cortex (AC)-to-lateral amygdala (LA) projections after auditory fear conditioning in mice. Fear extinction reversed these enhanced synaptic ensemble spines, whereas re-conditioning with the same tone and shock restored the spine size of the synaptic ensemble. We suggest that synaptic ensembles encode and represent different fear memory states.
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Affiliation(s)
- Dong Il Choi
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Jooyoung Kim
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Hoonwon Lee
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Ji-Il Kim
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Yongmin Sung
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Ja Eun Choi
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - S Jayakumar Venkat
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Pojeong Park
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Hyunsu Jung
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Bong-Kiun Kaang
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea.
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141
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Wichert N, Witt M, Blume C, Scheper T. Clinical applicability of optogenetic gene regulation. Biotechnol Bioeng 2021; 118:4168-4185. [PMID: 34287844 DOI: 10.1002/bit.27895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 05/27/2021] [Accepted: 07/13/2021] [Indexed: 11/10/2022]
Abstract
The field of optogenetics is rapidly growing in relevance and number of developed tools. Among other things, the optogenetic repertoire includes light-responsive ion channels and methods for gene regulation. This review will be confined to the optogenetic control of gene expression in mammalian cells as suitable models for clinical applications. Here optogenetic gene regulation might offer an excellent method for spatially and timely regulated gene and protein expression in cell therapeutic approaches. Well-known systems for gene regulation, such as the LOV-, CRY2/CIB-, PhyB/PIF-systems, as well as other, in mammalian cells not yet fully established systems, will be described. Advantages and disadvantages with regard to clinical applications are outlined in detail. Among the many unanswered questions concerning the application of optogenetics, we discuss items such as the use of exogenous chromophores and their effects on the biology of the cells and methods for a gentle, but effective gene transfection method for optogenetic tools for in vivo applications.
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Affiliation(s)
- Nina Wichert
- Insitute of Technical Chemistry, Leibniz University of Hannover, Hannover, Germany
| | - Martin Witt
- Insitute of Technical Chemistry, Leibniz University of Hannover, Hannover, Germany
| | - Cornelia Blume
- Insitute of Technical Chemistry, Leibniz University of Hannover, Hannover, Germany
| | - Thomas Scheper
- Insitute of Technical Chemistry, Leibniz University of Hannover, Hannover, Germany
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142
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Jeong Y, Cho HY, Kim M, Oh JP, Kang MS, Yoo M, Lee HS, Han JH. Synaptic plasticity-dependent competition rule influences memory formation. Nat Commun 2021; 12:3915. [PMID: 34168140 PMCID: PMC8225794 DOI: 10.1038/s41467-021-24269-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 06/10/2021] [Indexed: 11/08/2022] Open
Abstract
Memory is supported by a specific collection of neurons distributed in broad brain areas, an engram. Despite recent advances in identifying an engram, how the engram is created during memory formation remains elusive. To explore the relation between a specific pattern of input activity and memory allocation, here we target a sparse subset of neurons in the auditory cortex and thalamus. The synaptic inputs from these neurons to the lateral amygdala (LA) are not potentiated by fear conditioning. Using an optogenetic priming stimulus, we manipulate these synapses to be potentiated by the learning. In this condition, fear memory is preferentially encoded in the manipulated cell ensembles. This change, however, is abolished with optical long-term depression (LTD) delivered shortly after training. Conversely, delivering optical long-term potentiation (LTP) alone shortly after fear conditioning is sufficient to induce the preferential memory encoding. These results suggest a synaptic plasticity-dependent competition rule underlying memory formation.
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Affiliation(s)
- Yire Jeong
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
| | - Hye-Yeon Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
| | - Mujun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
| | - Jung-Pyo Oh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
| | - Min Soo Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
| | - Miran Yoo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
| | - Han-Sol Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea
| | - Jin-Hee Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea.
- KAIST Institute for the BioCentury (KIB), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, Korea.
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143
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Leal Santos S, Stackmann M, Muñoz Zamora A, Mastrodonato A, De Landri AV, Vaughan N, Chen BK, Lanio M, Denny CA. Propranolol Decreases Fear Expression by Modulating Fear Memory Traces. Biol Psychiatry 2021; 89:1150-1161. [PMID: 33766406 PMCID: PMC8201901 DOI: 10.1016/j.biopsych.2021.01.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 01/27/2023]
Abstract
BACKGROUND Posttraumatic stress disorder can develop after a traumatic event and results in heightened, inappropriate fear and anxiety. Although approximately 8% of the U.S. population is affected by posttraumatic stress disorder, only two drugs have been approved by the Food and Drug Administration to treat it, both with limited efficacy. Propranolol, a nonselective β-adrenergic antagonist, has shown efficacy in decreasing exaggerated fear, and there has been renewed interest in using it to treat fear disorders. METHODS Here, we sought to determine the mechanisms by which propranolol attenuates fear by utilizing an activity-dependent tagging system, ArcCreERT2 x eYFP mice. 129S6/SvEv mice were administered a 4-shock contextual fear conditioning paradigm followed by immediate or delayed context reexposures. Saline or propranolol was administered either before or after the first context reexposure. To quantify hippocampal, prefrontal, and amygdalar memory traces, ArcCreERT2 x eYFP mice were administered a delayed context reexposure with either a saline or propranolol injection before context reexposure. RESULTS Propranolol decreased fear expression only when administered before a delayed context reexposure. Fear memory traces were affected in the dorsal dentate gyrus and basolateral amygdala after propranolol administration in the ArcCreERT2 x eYFP mice. Propranolol acutely altered functional connectivity between the hippocampal, cortical, and amygdalar regions. CONCLUSIONS These data indicate that propranolol may decrease fear expression by altering network-correlated activity and by weakening the reactivation of the initial traumatic memory trace. This work contributes to the understanding of noradrenergic drugs as therapeutic aids for patients with posttraumatic stress disorder.
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Affiliation(s)
- Sofia Leal Santos
- Department of Psychiatry, Columbia University Irving Medical Center, New York, New York; Division of Systems Neuroscience, Research Foundation for Mental Hygiene Inc/New York State Psychiatric Institute, New York, New York; Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Michelle Stackmann
- Neurobiology and Behavior Graduate Program, Columbia University, New York, New York
| | - Andrea Muñoz Zamora
- Division of Systems Neuroscience, Research Foundation for Mental Hygiene Inc/New York State Psychiatric Institute, New York, New York
| | - Alessia Mastrodonato
- Department of Psychiatry, Columbia University Irving Medical Center, New York, New York; Division of Systems Neuroscience, Research Foundation for Mental Hygiene Inc/New York State Psychiatric Institute, New York, New York
| | - Allegra V De Landri
- Division of Systems Neuroscience, Research Foundation for Mental Hygiene Inc/New York State Psychiatric Institute, New York, New York; Columbia College, Columbia University, New York, New York
| | - Nick Vaughan
- Columbia College, Columbia University, New York, New York
| | - Briana K Chen
- Neurobiology and Behavior Graduate Program, Columbia University, New York, New York
| | - Marcos Lanio
- Medical Scientist Training Program, Columbia University Irving Medical Center, New York, New York; Neurobiology and Behavior Graduate Program, Columbia University, New York, New York
| | - Christine A Denny
- Department of Psychiatry, Columbia University Irving Medical Center, New York, New York; Division of Systems Neuroscience, Research Foundation for Mental Hygiene Inc/New York State Psychiatric Institute, New York, New York.
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144
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Kislinger L, Kotrschal K. Hunters and Gatherers of Pictures: Why Photography Has Become a Human Universal. Front Psychol 2021; 12:654474. [PMID: 34168589 PMCID: PMC8217823 DOI: 10.3389/fpsyg.2021.654474] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 05/11/2021] [Indexed: 11/13/2022] Open
Abstract
Photography is ubiquitous worldwide. We analyzed why people take, share, and use personal photographs, independent of their specific cultural background. These behaviors are still poorly understood. Experimental research on them is scarce. Smartphone technology and social media have pushed the success of photography, but cannot explain it, as not all smartphone features are widely used just because they are available. We analyzed properties of human nature that have made taking and using photographs functional behaviors. We did this based on the four levels, which Nikolaas Tinbergen suggested for analyzing why animals behave in a particular way. Including findings from multiple disciplines, we developed a novel conceptual framework-the "Mental Utilization Hypothesis of Photography." It suggests that people adopt photography because it matches with core human mental mechanisms mainly from the social domain, and people use photography as a cognitive, primarily social coping strategy. Our framework comprises a range of testable predictions, provides a new theoretical basis for future empirical investigations into photography, and has practical implications. We conclude that photography has become a human universal, which is based on context-sensitive mental predispositions and differentiates itself in the social and societal environment.
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Affiliation(s)
| | - Kurt Kotrschal
- Department of Behavioral Biology and Konrad Lorenz Forschungsstelle, University of Vienna, Vienna, Austria
- Domestication Lab at the Konrad-Lorenz Institute of Ethology, Wolf Science Center, University of Veterinary Medicine, Ernstbrunn, Austria
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145
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Li XH, Xue C, Liu MQ, Zhang MY, Zhou Y, Xiao X, Wang J, Xu XJ, Shi Y, Zhang WN. Attractin Gene Deficiency in Rats Leads to Impairments in Both Activity and Spatial Learning and Memory. Neuroscience 2021; 466:101-108. [PMID: 34000322 DOI: 10.1016/j.neuroscience.2021.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/04/2021] [Accepted: 05/06/2021] [Indexed: 01/03/2023]
Abstract
Attractin (ATRN), an autosomal recessive gene that is widely distributed in the brain, is involved in the execution of a variety of brain functions and associated with certain neuropsychiatric disorders. Here, we introduce a novel rat strain harboring a mutation in ATRN that was generated by knocking in ATRN-G505C via the CRISPR/Cas9 system. We assessed the behavioral performance of these mutant ATRN knock-in rats. The G505C mutation was introduced into exon 9, and a synthetic primer was inserted into introns 8-9 for genotyping. The 505th amino acid, a Gly (G) residue, was mutated to a Cys (C) residue, i.e., GGC was mutated to TGC. Behavioral experiments showed that homozygous ATRN rats spent significantly more time searching for the escape platform in the acquisition trial and significantly less time in the target area in the probe trial in the Morris water maze (MWM) test and traveled a significantly shorter distance in the open field test (OFT) than wild-type rats. In addition, Western blot analysis and immunohistochemistry showed that rats with the mutant ATRN gene exhibited significantly reduced expression of brain-derived neurotrophic factor (BDNF). In summary, our results indicate that mutations in the ATRN gene directly lead to learning and memory impairments and slight motor deficits. These findings provide new clues for the mechanism by which mutant ATRN induces neurodegenerative changes.
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Affiliation(s)
- Xiao-Hui Li
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China
| | - Cheng Xue
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China; Department of Clinical Laboratory, Affiliated Changzhou No.2 People's Hospital, Nanjing Medical University, Changzhou 213003, PR China
| | - Meng-Qi Liu
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China
| | - Meng-Yu Zhang
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China
| | - Yang Zhou
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China
| | - Xu Xiao
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China
| | - Jia Wang
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China
| | - Xi-Jia Xu
- Department of Psychiatry, Affiliated Nanjing Brain Hospital, Nanjing Medical University, Nanjing, PR China.
| | - Yun Shi
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210032, PR China.
| | - Wei-Ning Zhang
- School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu Province, PR China.
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146
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Missaire M, Fraize N, Comte JC, Truchet B, Parmentier R, Salin PA, Malleret G. Working and Reference Memory Tasks Trigger Opposed Long-Term Synaptic Changes in the Rat Dentate Gyrus. Cereb Cortex 2021; 31:2980-2992. [PMID: 33506269 DOI: 10.1093/cercor/bhaa405] [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: 08/29/2020] [Revised: 12/16/2020] [Accepted: 12/16/2020] [Indexed: 11/13/2022] Open
Abstract
Long-term storage of information into memory is supposed to rely on long-term synaptic plasticity processes. The detection of such synaptic changes after training in long-term/reference memory (RM) tasks has yet been scarce, variable and only studied on a short time scale. Short-term or working memory (WM) is largely known to depend on persistent neuronal activity or short-term plasticity. However, processing information into WM could also involve long-term synaptic changes that could be responsible for the erasure/forgetting of items previously stored in WM and acting as proactive interference. In order to study long-term synaptic changes associated with RM or WM, we trained chronically implanted rats in 3 different radial maze tasks: a classical RM task and 2 WM tasks involving different levels of proactive interference. Synaptic responses in the dentate gyrus were recorded during 2 × 24 h in freely moving rats after training. We found that consolidation of long-term information leads first to a delayed synaptic potentiation, occurring 9 h after RM training that is replaced by a synaptic depression once the RM rule is fully acquired. In contrast, optimal information processing into WM triggers a synaptic depression immediately after training and lasting 3 h that could act as a mechanism for interference erasure/forgetting.
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Affiliation(s)
- Mégane Missaire
- FORGETTING 'Forgetting Processes and Cortical Dynamics' Team, Lyon Neuroscience Research Center (CRNL), University Lyon 1, Lyon F-69008, France
| | - Nicolas Fraize
- FORGETTING 'Forgetting Processes and Cortical Dynamics' Team, Lyon Neuroscience Research Center (CRNL), University Lyon 1, Lyon F-69008, France
| | - Jean-Christophe Comte
- FORGETTING 'Forgetting Processes and Cortical Dynamics' Team, Lyon Neuroscience Research Center (CRNL), University Lyon 1, Lyon F-69008, France.,Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Lyon F-69000, France
| | - Bruno Truchet
- Laboratory of Cognitive Neuroscience, CNRS and Aix-Marseille University, Marseille F-13331, France
| | - Régis Parmentier
- FORGETTING 'Forgetting Processes and Cortical Dynamics' Team, Lyon Neuroscience Research Center (CRNL), University Lyon 1, Lyon F-69008, France.,Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Lyon F-69000, France
| | - Paul-Antoine Salin
- FORGETTING 'Forgetting Processes and Cortical Dynamics' Team, Lyon Neuroscience Research Center (CRNL), University Lyon 1, Lyon F-69008, France.,Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Lyon F-69000, France
| | - Gaël Malleret
- FORGETTING 'Forgetting Processes and Cortical Dynamics' Team, Lyon Neuroscience Research Center (CRNL), University Lyon 1, Lyon F-69008, France.,Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Lyon F-69000, France
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147
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Mandwal A, Orlandi JG, Simon C, Davidsen J. A biochemical mechanism for time-encoding memory formation within individual synapses of Purkinje cells. PLoS One 2021; 16:e0251172. [PMID: 33961660 PMCID: PMC8104431 DOI: 10.1371/journal.pone.0251172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 04/21/2021] [Indexed: 11/18/2022] Open
Abstract
Within the classical eye-blink conditioning, Purkinje cells within the cerebellum are known to suppress their tonic firing rates for a well defined time period in response to the conditional stimulus after training. The temporal profile of the drop in tonic firing rate, i.e., the onset and the duration, depend upon the time interval between the onsets of the conditional and unconditional training stimuli. Direct stimulation of parallel fibers and climbing fiber by electrodes was found to be sufficient to reproduce the same characteristic drop in the firing rate of the Purkinje cell. In addition, the specific metabotropic glutamate-based receptor type 7 (mGluR7) was found responsible for the initiation of the response, suggesting an intrinsic mechanism within the Purkinje cell for the temporal learning. In an attempt to look for a mechanism for time-encoding memory formation within individual Purkinje cells, we propose a biochemical mechanism based on recent experimental findings. The proposed mechanism tries to answer key aspects of the “Coding problem” of Neuroscience by focusing on the Purkinje cell’s ability to encode time intervals through training. According to the proposed mechanism, the time memory is encoded within the dynamics of a set of proteins—mGluR7, G-protein, G-protein coupled Inward Rectifier Potassium ion channel, Protein Kinase A, Protein Phosphatase 1 and other associated biomolecules—which self-organize themselves into a protein complex. The intrinsic dynamics of these protein complexes can differ and thus can encode different time durations. Based on their amount and their collective dynamics within individual synapses, the Purkinje cell is able to suppress its own tonic firing rate for a specific time interval. The time memory is encoded within the effective dynamics of the biochemical reactions and altering these dynamics means storing a different time memory. The proposed mechanism is verified by both a minimal and a more comprehensive mathematical model of the conditional response behavior of the Purkinje cell and corresponding dynamical simulations of the involved biomolecules, yielding testable experimental predictions.
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Affiliation(s)
- Ayush Mandwal
- Complexity Science Group, Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
- * E-mail: (AM); (JD)
| | - Javier G. Orlandi
- Complexity Science Group, Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jörn Davidsen
- Complexity Science Group, Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
- * E-mail: (AM); (JD)
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Lovett-Barron M. Learning-dependent neuronal activity across the larval zebrafish brain. Curr Opin Neurobiol 2021; 67:42-49. [PMID: 32861055 PMCID: PMC7907282 DOI: 10.1016/j.conb.2020.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/29/2020] [Accepted: 07/31/2020] [Indexed: 11/30/2022]
Abstract
Learning changes the activity of neurons across multiple brain regions, but the significance of this distributed organization remains poorly understood, owing in part to the difficulty of observing brain-wide activity patterns in commonly used mammalian model systems. This review discusses the promise of using the small and optically accessible nervous system of larval zebrafish to study the brain-wide networks that encode experience. I discuss the opportunities and challenges of studying learning and memory in the larval zebrafish, the lessons learned from recent studies of brain-wide imaging during experience-dependent behavior, and the potential for using zebrafish neurotechnology to understand the physiological principles and behavioral significance of distributed memory networks.
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Affiliation(s)
- Matthew Lovett-Barron
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
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149
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Ryan TJ, Ortega-de San Luis C, Pezzoli M, Sen S. Engram cell connectivity: an evolving substrate for information storage. Curr Opin Neurobiol 2021; 67:215-225. [PMID: 33812274 DOI: 10.1016/j.conb.2021.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 01/02/2023]
Abstract
Understanding memory requires an explanation for how information can be stored in the brain in a stable state. The change in the brain that accounts for a given memory is referred to as an engram. In recent years, the term engram has been operationalized as the cells that are activated by a learning experience, undergoes plasticity, and are sufficient and necessary for memory recall. Using this framework, and a growing toolbox of related experimental techniques, engram manipulation has become a central topic in behavioral, systems, and molecular neuroscience. Recent research on the topic has provided novel insights into the mechanisms of long-term memory storage, and its overlap with instinct. We propose that memory and instinct may be embodied as isomorphic topological structures within the brain's microanatomical circuitry.
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Affiliation(s)
- Tomás J Ryan
- School of Biochemistry and Immunology and Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland; Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC 3052, Australia; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1M1, Canada.
| | - Clara Ortega-de San Luis
- School of Biochemistry and Immunology and Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Maurizio Pezzoli
- School of Biochemistry and Immunology and Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Siddhartha Sen
- Centre for Research on Adaptive Nanostructures and Nanodevices and School of Physics, Trinity College Dublin, D02 PN40, Ireland
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150
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Rao-Ruiz P, Visser E, Mitrić M, Smit AB, van den Oever MC. A Synaptic Framework for the Persistence of Memory Engrams. Front Synaptic Neurosci 2021; 13:661476. [PMID: 33841124 PMCID: PMC8024575 DOI: 10.3389/fnsyn.2021.661476] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 02/26/2021] [Indexed: 12/31/2022] Open
Abstract
The ability to store and retrieve learned information over prolonged periods of time is an essential and intriguing property of the brain. Insight into the neurobiological mechanisms that underlie memory consolidation is of utmost importance for our understanding of memory persistence and how this is affected in memory disorders. Recent evidence indicates that a given memory is encoded by sparsely distributed neurons that become highly activated during learning, so-called engram cells. Research by us and others confirms the persistent nature of cortical engram cells by showing that these neurons are required for memory expression up to at least 1 month after they were activated during learning. Strengthened synaptic connectivity between engram cells is thought to ensure reactivation of the engram cell network during retrieval. However, given the continuous integration of new information into existing neuronal circuits and the relatively rapid turnover rate of synaptic proteins, it is unclear whether a lasting learning-induced increase in synaptic connectivity is mediated by stable synapses or by continuous dynamic turnover of synapses of the engram cell network. Here, we first discuss evidence for the persistence of engram cells and memory-relevant adaptations in synaptic plasticity, and then propose models of synaptic adaptations and molecular mechanisms that may support memory persistence through the maintenance of enhanced synaptic connectivity within an engram cell network.
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Affiliation(s)
- Priyanka Rao-Ruiz
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Esther Visser
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Miodrag Mitrić
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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