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Josselyn SA, Tonegawa S. Memory engrams: Recalling the past and imagining the future. Science 2020; 367:367/6473/eaaw4325. [PMID: 31896692 DOI: 10.1126/science.aaw4325] [Citation(s) in RCA: 406] [Impact Index Per Article: 101.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In 1904, Richard Semon introduced the term "engram" to describe the neural substrate for storing memories. An experience, Semon proposed, activates a subset of cells that undergo off-line, persistent chemical and/or physical changes to become an engram. Subsequent reactivation of this engram induces memory retrieval. Although Semon's contributions were largely ignored in his lifetime, new technologies that allow researchers to image and manipulate the brain at the level of individual neurons has reinvigorated engram research. We review recent progress in studying engrams, including an evaluation of evidence for the existence of engrams, the importance of intrinsic excitability and synaptic plasticity in engrams, and the lifetime of an engram. Together, these findings are beginning to define an engram as the basic unit of memory.
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Affiliation(s)
- Sheena A Josselyn
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada. .,Department of Psychology, University of Toronto, Toronto, Ontario M5S 3G3, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5G 1X8, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Brain, Mind & Consciousness Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1M1, Canada
| | - 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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52
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Yang X, Bao Y, Xu J, Gong R, Zhang N, Cai L, Xia M, Wang J, Lu W. Long-Lasting Somatic Modifications of Convergent Dendritic Inputs in Hippocampal Neurons. Cereb Cortex 2020; 30:1436-1446. [PMID: 31504279 DOI: 10.1093/cercor/bhz177] [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] [Indexed: 11/14/2022] Open
Abstract
Integrated neural inputs from different dendrites converge at the soma for action potential generation. However, it is unclear how the convergent dendritic inputs interact at the soma and whether they can be further modified there. We report here an entirely new plasticity rule in hippocampal neurons in which repetitive pairing of subthreshold excitatory inputs from proximal apical and basal dendrites at a precise interval induces persistent bidirectional modifications of the two dendritic inputs. Strikingly, the modification of the dendritic inputs specially occurs at soma in the absence of somatic action potential and requires activation of somatic N-methyl-D-aspartate receptors (NMDARs). Once induced, the somatic modification can also be observed in other unpaired dendritic inputs upon their arrival at the soma. We further reveal that the soma can employ an active mechanism to potentiate the dendritic inputs by promoting sustained activation of somatic NMDARs and subsequent down-regulating of the fast inactivating A-type potassium current (IA) at the soma. Thus, the input-timing-dependent somatic plasticity we uncovered here is in sharp contrast to conventional forms of synaptic plasticity that occur at the dendrites and is important to somatic action potential generation.
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Affiliation(s)
- Xin Yang
- State Key Laboratory of Bioelectronics, Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China
| | - Yifei Bao
- State Key Laboratory of Bioelectronics, Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China
| | - Jindong Xu
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province 226001, People's Republic of China
| | - Ru Gong
- State Key Laboratory of Bioelectronics, Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China
| | - Nan Zhang
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province 226001, People's Republic of China
| | - Lei Cai
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province 226001, People's Republic of China
| | - Mingmei Xia
- State Key Laboratory of Bioelectronics, Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China
| | - Jingjing Wang
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province 226001, People's Republic of China.,Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200011, China
| | - Wei Lu
- State Key Laboratory of Bioelectronics, Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province 226001, People's Republic of China.,Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
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53
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Amygdala Reward Neurons Form and Store Fear Extinction Memory. Neuron 2020; 105:1077-1093.e7. [DOI: 10.1016/j.neuron.2019.12.025] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/29/2019] [Accepted: 12/18/2019] [Indexed: 12/14/2022]
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54
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Locating the engram: Should we look for plastic synapses or information-storing molecules? Neurobiol Learn Mem 2020; 169:107164. [PMID: 31945459 DOI: 10.1016/j.nlm.2020.107164] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/18/2019] [Accepted: 01/10/2020] [Indexed: 12/12/2022]
Abstract
Karl Lashley began the search for the engram nearly seventy years ago. In the time since, much has been learned but divisions remain. In the contemporary neurobiology of learning and memory, two profoundly different conceptions contend: the associative/connectionist (A/C) conception and the computational/representational (C/R) conception. Both theories ground themselves in the belief that the mind is emergent from the properties and processes of a material brain. Where these theories differ is in their description of what the neurobiological substrate of memory is and where it resides in the brain. The A/C theory of memory emphasizes the need to distinguish memory cognition from the memory engram and postulates that memory cognition is an emergent property of patterned neural activity routed through engram circuits. In this model, learning re-organizes synapse association strengths to guide future neural activity. Importantly, the version of the A/C theory advocated for here contends that synaptic change is not symbolic and, despite normally being necessary, is not sufficient for memory cognition. Instead, synaptic change provides the capacity and a blueprint for reinstating symbolic patterns of neural activity. Unlike the A/C theory, which posits that memory emerges at the circuit level, the C/R conception suggests that memory manifests at the level of intracellular molecular structures. In C/R theory, these intracellular structures are information-conveying and have properties compatible with the view that brain computation utilizes a read/write memory, functionally similar to that in a computer. New research has energized both sides and highlighted the need for new discussion. Both theories, the key questions each theory has yet to resolve and several potential paths forward are presented here.
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55
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Mishra P, Narayanan R. Heterogeneities in intrinsic excitability and frequency-dependent response properties of granule cells across the blades of the rat dentate gyrus. J Neurophysiol 2020; 123:755-772. [PMID: 31913748 PMCID: PMC7052640 DOI: 10.1152/jn.00443.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The dentate gyrus (DG), the input gate to the hippocampus proper, is anatomically segregated into three different sectors, namely, the suprapyramidal blade, the crest region, and the infrapyramidal blade. Although there are well-established differences between these sectors in terms of neuronal morphology, connectivity patterns, and activity levels, differences in electrophysiological properties of granule cells within these sectors have remained unexplored. Here, employing somatic whole cell patch-clamp recordings from the rat DG, we demonstrate that granule cells in these sectors manifest considerable heterogeneities in their intrinsic excitability, temporal summation, action potential characteristics, and frequency-dependent response properties. Across sectors, these neurons showed positive temporal summation of their responses to inputs mimicking excitatory postsynaptic currents and showed little to no sag in their voltage responses to pulse currents. Consistently, the impedance amplitude profile manifested low-pass characteristics and the impedance phase profile lacked positive phase values at all measured frequencies and voltages and for all sectors. Granule cells in all sectors exhibited class I excitability, with broadly linear firing rate profiles, and granule cells in the crest region fired significantly fewer action potentials compared with those in the infrapyramidal blade. Finally, we found weak pairwise correlations across the 18 different measurements obtained individually from each of the three sectors, providing evidence that these measurements are indeed reporting distinct aspects of neuronal physiology. Together, our analyses show that granule cells act as integrators of afferent information and emphasize the need to account for the considerable physiological heterogeneities in assessing their roles in information encoding and processing.NEW & NOTEWORTHY We employed whole cell patch-clamp recordings from granule cells in the three subregions of the rat dentate gyrus to demonstrate considerable heterogeneities in their intrinsic excitability, temporal summation, action potential characteristics, and frequency-dependent response properties. Across sectors, granule cells did not express membrane potential resonance, and their impedance profiles lacked inductive phase leads at all measured frequencies. Our analyses also show that granule cells manifest class I excitability characteristics, categorizing them as integrators of afferent information.
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Affiliation(s)
- Poonam Mishra
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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56
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Kastellakis G, Poirazi P. Synaptic Clustering and Memory Formation. Front Mol Neurosci 2019; 12:300. [PMID: 31866824 PMCID: PMC6908852 DOI: 10.3389/fnmol.2019.00300] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/25/2019] [Indexed: 01/12/2023] Open
Abstract
In the study of memory engrams, synaptic memory allocation is a newly emerged theme that focuses on how specific synapses are engaged in the storage of a given memory. Cumulating evidence from imaging and molecular experiments indicates that the recruitment of synapses that participate in the encoding and expression of memory is neither random nor uniform. A hallmark observation is the emergence of groups of synapses that share similar response properties and/or similar input properties and are located within a stretch of a dendritic branch. This grouping of synapses has been termed "synapse clustering" and has been shown to emerge in many different memory-related paradigms, as well as in in vitro studies. The clustering of synapses may emerge from synapses receiving similar input, or via many processes which allow for cross-talk between nearby synapses within a dendritic branch, leading to cooperative plasticity. Clustered synapses can act in concert to maximally exploit the nonlinear integration potential of the dendritic branches in which they reside. Their main contribution is to facilitate the induction of dendritic spikes and dendritic plateau potentials, which provide advanced computational and memory-related capabilities to dendrites and single neurons. This review focuses on recent evidence which investigates the role of synapse clustering in dendritic integration, sensory perception, learning, and memory as well as brain dysfunction. We also discuss recent theoretical work which explores the computational advantages provided by synapse clustering, leading to novel and revised theories of memory. As an eminent phenomenon during memory allocation, synapse clustering both shapes memory engrams and is also shaped by the parallel plasticity mechanisms upon which it relies.
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Affiliation(s)
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, Greece
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57
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Yetton BD, Cai DJ, Spoormaker VI, Silva AJ, Mednick SC. Human Memories Can Be Linked by Temporal Proximity. Front Hum Neurosci 2019; 13:315. [PMID: 31572150 PMCID: PMC6753892 DOI: 10.3389/fnhum.2019.00315] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/23/2019] [Indexed: 11/13/2022] Open
Abstract
Real-world memories involve the integration of multiple events across time, yet the mechanisms underlying this integration is unknown. Recent rodent studies show that distinct memories encoded within a few hours, but not several days, share a common neural ensemble, and a common fate whereby later fear conditioning can transfer from one memory to the other. Here, we tested if distinct memories could be linked by temporal proximity in humans. 74 young adults encoded two memories (A and B) close (3-h) or far apart (7-day) in time. One day after encoding the second memory (B), Memory A was updated by pairing it with electric shock (i.e., fear conditioning). We tested whether the memory and fear associated with Memory B would be stronger in the 3-h, compared with the 7-day condition. Results were generally consistent with rodent studies, where we found heightened Memory B fear expression when the two memories were encoded close, but not far apart, in time. Furthermore, there was less forgetting of Memory B in the 3-h compared to 7-day condition. Our results suggest that temporally proximal memories may be linked, such that updating one experience updates the other.
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Affiliation(s)
- Benjamin D Yetton
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, United States
| | - Denise J Cai
- Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | | | - Alcino J Silva
- Department of Neurobiology, Department of Psychology, Department of Psychiatry and Biobehavioral Sciences, Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Sara C Mednick
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, United States
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58
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Krajcovic B, Fajnerova I, Horacek J, Kelemen E, Kubik S, Svoboda J, Stuchlik A. Neural and neuronal discoordination in schizophrenia: From ensembles through networks to symptoms. Acta Physiol (Oxf) 2019; 226:e13282. [PMID: 31002202 DOI: 10.1111/apha.13282] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/27/2019] [Accepted: 04/12/2019] [Indexed: 12/22/2022]
Abstract
Despite the substantial knowledge accumulated by past research, the exact mechanisms of the pathogenesis of schizophrenia and causal treatments still remain unclear. Deficits of cognition and information processing in schizophrenia are today often viewed as the primary and core symptoms of this devastating disorder. These deficits likely result from disruptions in the coordination of neuronal and neural activity. The aim of this review is to bring together convergent evidence of discoordinated brain circuits in schizophrenia at multiple levels of resolution, ranging from principal cells and interneurons, neuronal ensembles and local circuits, to large-scale brain networks. We show how these aberrations could underlie deficits in cognitive control and other higher order cognitive-behavioural functions. Converging evidence from both animal models and patients with schizophrenia is presented in an effort to gain insight into common features of deficits in the brain information processing in this disorder, marked by disruption of several neurotransmitter and signalling systems and severe behavioural outcomes.
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Affiliation(s)
- Branislav Krajcovic
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Third Faculty of Medicine Charles University Prague Czech Republic
| | - Iveta Fajnerova
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Jiri Horacek
- Third Faculty of Medicine Charles University Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Eduard Kelemen
- Research Programme 1 - Experimental Neurobiology National Institute of Mental Health Klecany Czech Republic
| | - Stepan Kubik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Jan Svoboda
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Ales Stuchlik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
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Parra-Damas A, Saura CA. Synapse-to-Nucleus Signaling in Neurodegenerative and Neuropsychiatric Disorders. Biol Psychiatry 2019; 86:87-96. [PMID: 30846302 DOI: 10.1016/j.biopsych.2019.01.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/18/2018] [Accepted: 01/04/2019] [Indexed: 01/07/2023]
Abstract
Synapse-to-nucleus signaling is critical for converting signals received at synapses into transcriptional programs essential for cognition, memory, and emotion. This neuronal mechanism usually involves activity-dependent translocation of synaptonuclear factors from synapses to the nucleus resulting in regulation of transcriptional programs underlying synaptic plasticity. Acting as synapse-to-nucleus messengers, amyloid precursor protein intracellular domain associated-1 protein, cAMP response element binding protein (CREB)-regulated transcription coactivator-1, Jacob, nuclear factor kappa-light-chain-enhancer of activated B cells, RING finger protein 10, and SH3 and multiple ankyrin repeat domains 3 play essential roles in synapse remodeling and plasticity, which are considered the cellular basis of memory. Other synaptic proteins, such as extracellular signal-regulated kinase, calcium/calmodulin-dependent protein kinase II gamma, and CREB2, translocate from dendrites or cytosol to the nucleus upon synaptic activity, suggesting that they could contribute to synapse-to-nucleus signaling. Notably, some synaptonuclear factors converge on the transcription factor CREB, indicating that CREB signaling is a key hub mediating integration of synaptic signals into transcriptional programs required for neuronal function and plasticity. Although major efforts have been focused on identification and regulatory mechanisms of synaptonuclear factors, the relevance of synapse-to-nucleus communication in brain physiology and pathology is still unclear. Recent evidence, however, indicates that synaptonuclear factors are implicated in neuropsychiatric, neurodevelopmental, and neurodegenerative disorders, suggesting that uncoupling synaptic activity from nuclear signaling may prompt synapse pathology, contributing to a broad spectrum of brain disorders. This review summarizes current knowledge of synapse-to-nucleus signaling in neuron survival, synaptic function and plasticity, and memory. Finally, we discuss how altered synapse-to-nucleus signaling may lead to memory and emotional disturbances, which is relevant for clinical and therapeutic strategies in neurodegenerative and neuropsychiatric diseases.
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Affiliation(s)
- Arnaldo Parra-Damas
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Carlos A Saura
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas, Universitat Autònoma de Barcelona, Barcelona, Spain.
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60
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Sakaguchi H, Ozaki Y, Ashida T, Matsubara T, Oishi N, Kihara S, Takahashi J. Self-Organized Synchronous Calcium Transients in a Cultured Human Neural Network Derived from Cerebral Organoids. Stem Cell Reports 2019; 13:458-473. [PMID: 31257131 PMCID: PMC6739638 DOI: 10.1016/j.stemcr.2019.05.029] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 05/30/2019] [Accepted: 05/30/2019] [Indexed: 12/19/2022] Open
Abstract
The cerebrum is a major center for brain function, and its activity is derived from the assembly of activated cells in neural networks. It is currently difficult to study complex human cerebral neuronal network activity. Here, using cerebral organoids, we report self-organized and complex human neural network activities that include synchronized and non-synchronized patterns. Self-organized neuronal network formation was observed following a dissociation culture of human embryonic stem cell-derived cerebral organoids. The spontaneous individual and synchronized activity of the network was measured via calcium imaging, and subsequent analysis enabled the examination of detailed cell activity patterns, providing simultaneous raster plots, cluster analyses, and cell distribution data. Finally, we demonstrated the feasibility of our system to assess drug-inducible dynamic changes of the network activity. The comprehensive functional analysis of human neuronal networks using this system may offer a powerful tool to access human brain function. Cerebral organoids can recapitulate cerebral characters in 3D order A functional neural network was efficiently formed after dissociation of organoids Calcium activity patterns were examined with clustering and the cell distribution A powerful system for the functional analysis of human neuronal networks
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Affiliation(s)
- Hideya Sakaguchi
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan.
| | - Yuki Ozaki
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Tomoka Ashida
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Takayoshi Matsubara
- Life Science Center, MB HQ, Yokogawa Electric Corporation, Ishikawa 920-0177, Japan
| | - Naotaka Oishi
- Informatics Japan, PerkinElmer Japan Co., Ltd., Tokyo 101-0024, Japan
| | - Shunsuke Kihara
- Department of Fundamental Cell Technology, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Jun Takahashi
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan.
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Drieu C, Zugaro M. Hippocampal Sequences During Exploration: Mechanisms and Functions. Front Cell Neurosci 2019; 13:232. [PMID: 31263399 PMCID: PMC6584963 DOI: 10.3389/fncel.2019.00232] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/08/2019] [Indexed: 12/13/2022] Open
Abstract
Although the hippocampus plays a critical role in spatial and episodic memories, the mechanisms underlying memory formation, stabilization, and recall for adaptive behavior remain relatively unknown. During exploration, within single cycles of the ongoing theta rhythm that dominates hippocampal local field potentials, place cells form precisely ordered sequences of activity. These neural sequences result from the integration of both external inputs conveying sensory-motor information, and intrinsic network dynamics possibly related to memory processes. Their endogenous replay during subsequent sleep is critical for memory consolidation. The present review discusses possible mechanisms and functions of hippocampal theta sequences during exploration. We present several lines of evidence suggesting that these neural sequences play a key role in information processing and support the formation of initial memory traces, and discuss potential functional distinctions between neural sequences emerging during theta vs. awake sharp-wave ripples.
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Affiliation(s)
- Céline Drieu
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U 1050, PSL Research University, Paris, France
| | - Michaël Zugaro
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U 1050, PSL Research University, Paris, France
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Biane JS, Takashima Y, Scanziani M, Conner JM, Tuszynski MH. Reorganization of Recurrent Layer 5 Corticospinal Networks Following Adult Motor Training. J Neurosci 2019; 39:4684-4693. [PMID: 30948479 PMCID: PMC6561695 DOI: 10.1523/jneurosci.3442-17.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 03/28/2019] [Accepted: 04/01/2019] [Indexed: 01/27/2023] Open
Abstract
Recurrent synaptic connections between neighboring neurons are a key feature of mammalian cortex, accounting for the vast majority of cortical inputs. Although computational models indicate that reorganization of recurrent connectivity is a primary driver of experience-dependent cortical tuning, the true biological features of recurrent network plasticity are not well identified. Indeed, whether rewiring of connections between cortical neurons occurs during behavioral training, as is widely predicted, remains unknown. Here, we probe M1 recurrent circuits following motor training in adult male rats and find robust synaptic reorganization among functionally related layer 5 neurons, resulting in a 2.5-fold increase in recurrent connection probability. This reorganization is specific to the neuronal subpopulation most relevant for executing the trained motor skill, and behavioral performance was impaired following targeted molecular inhibition of this subpopulation. In contrast, recurrent connectivity is unaffected among neighboring layer 5 neurons largely unrelated to the trained behavior. Training-related corticospinal cells also express increased excitability following training. These findings establish the presence of selective modifications in recurrent cortical networks in adulthood following training.SIGNIFICANCE STATEMENT Recurrent synaptic connections between neighboring neurons are characteristic of cortical architecture, and modifications to these circuits are thought to underlie in part learning in the adult brain. We now show that there are robust changes in recurrent connections in the rat motor cortex upon training on a novel motor task. Motor training results in a 2.5-fold increase in recurrent connectivity, but only within the neuronal subpopulation most relevant for executing the new motor behavior; recurrent connectivity is unaffected among adjoining neurons that do not execute the trained behavior. These findings demonstrate selective reorganization of recurrent synaptic connections in the adult neocortex following novel motor experience, and illuminate fundamental properties of cortical function and plasticity.
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Affiliation(s)
| | | | - Massimo Scanziani
- Neurobiology, University of California, San Diego, California 92093
- Howard Hughes Medical Institute, San Diego, California, 92093, and
| | | | - Mark H Tuszynski
- Departments of Neurosciences,
- Veterans Administration Medical Center, San Diego, California 92161
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63
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Matos MR, Visser E, Kramvis I, van der Loo RJ, Gebuis T, Zalm R, Rao-Ruiz P, Mansvelder HD, Smit AB, van den Oever MC. Memory strength gates the involvement of a CREB-dependent cortical fear engram in remote memory. Nat Commun 2019; 10:2315. [PMID: 31127098 PMCID: PMC6534583 DOI: 10.1038/s41467-019-10266-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/29/2019] [Indexed: 12/22/2022] Open
Abstract
Encoding and retrieval of contextual memories is initially mediated by sparsely activated neurons, so-called engram cells, in the hippocampus. Subsequent memory persistence is thought to depend on network-wide changes involving progressive contribution of cortical regions, a process referred to as systems consolidation. Using a viral-based TRAP (targeted recombination in activated populations) approach, we studied whether consolidation of contextual fear memory by neurons in the medial prefrontal cortex (mPFC) is modulated by memory strength and CREB function. We demonstrate that activity of a small subset of mPFC neurons is sufficient and necessary for remote memory expression, but their involvement depends on the strength of conditioning. Furthermore, selective disruption of CREB function in mPFC engram cells after mild conditioning impairs remote memory expression. Together, our data demonstrate that memory consolidation by mPFC engram cells requires CREB-mediated transcription, with the functionality of this network hub being gated by memory strength. Little is known about mechanisms that regulate the involvement of cortical engram cells in remote memory. Here, authors demonstrate that memory consolidation by mPFC engram cells requires CREB-mediated transcription, with the functionality of this network hub being gated by memory strength.
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Affiliation(s)
- Mariana R Matos
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Esther Visser
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Ioannis Kramvis
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Rolinka J van der Loo
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Titia Gebuis
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Robbert Zalm
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Priyanka Rao-Ruiz
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands.
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Engram-specific transcriptome profiling of contextual memory consolidation. Nat Commun 2019; 10:2232. [PMID: 31110186 PMCID: PMC6527697 DOI: 10.1038/s41467-019-09960-x] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 03/29/2019] [Indexed: 12/20/2022] Open
Abstract
Sparse populations of neurons in the dentate gyrus (DG) of the hippocampus are causally implicated in the encoding of contextual fear memories. However, engram-specific molecular mechanisms underlying memory consolidation remain largely unknown. Here we perform unbiased RNA sequencing of DG engram neurons 24 h after contextual fear conditioning to identify transcriptome changes specific to memory consolidation. DG engram neurons exhibit a highly distinct pattern of gene expression, in which CREB-dependent transcription features prominently (P = 6.2 × 10−13), including Atf3 (P = 2.4 × 10−41), Penk (P = 1.3 × 10−15), and Kcnq3 (P = 3.1 × 10−12). Moreover, we validate the functional relevance of the RNAseq findings by establishing the causal requirement of intact CREB function specifically within the DG engram during memory consolidation, and identify a novel group of CREB target genes involved in the encoding of long-term memory. The molecular mechanisms underlying contextual fear memory consolidation by sparse dentate gyrus (DG) neuronal populations remain unclear. Here using unbiased RNA sequencing of DG engram neurons the authors identify persistent transcriptome modifications during memory consolidation, in which CREB-dependent transcription features prominently
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65
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Increased neuronal signatures of targeted memory reactivation during slow-wave up states. Sci Rep 2019; 9:2715. [PMID: 30804371 PMCID: PMC6389952 DOI: 10.1038/s41598-019-39178-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/18/2019] [Indexed: 11/29/2022] Open
Abstract
It is assumed that slow oscillatory up-states represent crucial time windows for memory reactivation and consolidation during sleep. We tested this assumption by utilizing closed-loop targeted memory reactivation: Participants were re-exposed to prior learned foreign vocabulary during up- and down-states of slow oscillations. While presenting memory cues during slow oscillatory up-states improved recall performance, down-state cueing did not result in a clear behavioral benefit. Still, no robust behavioral benefit of up- as compared to down-state cueing was observable. At the electrophysiological level however, successful memory reactivation during up-states was associated with a characteristic power increase in the theta and sleep spindle band. No oscillatory changes were observable for down-state cues. Our findings provide experimental support for the assumption that slow oscillatory up-states may represent privileged time windows for memory reactivation, while the interplay of slow oscillations, theta and sleep spindle activity promotes successful memory consolidation during sleep.
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66
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Seibt J, Frank MG. Primed to Sleep: The Dynamics of Synaptic Plasticity Across Brain States. Front Syst Neurosci 2019; 13:2. [PMID: 30774586 PMCID: PMC6367653 DOI: 10.3389/fnsys.2019.00002] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/09/2019] [Indexed: 11/13/2022] Open
Abstract
It is commonly accepted that brain plasticity occurs in wakefulness and sleep. However, how these different brain states work in concert to create long-lasting changes in brain circuitry is unclear. Considering that wakefulness and sleep are profoundly different brain states on multiple levels (e.g., cellular, molecular and network activation), it is unlikely that they operate exactly the same way. Rather it is probable that they engage different, but coordinated, mechanisms. In this article we discuss how plasticity may be divided across the sleep-wake cycle, and how synaptic changes in each brain state are linked. Our working model proposes that waking experience triggers short-lived synaptic events that are necessary for transient plastic changes and mark (i.e., 'prime') circuits and synapses for further processing in sleep. During sleep, synaptic protein synthesis at primed synapses leads to structural changes necessary for long-term information storage.
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Affiliation(s)
- Julie Seibt
- Surrey Sleep Research Centre, University of Surrey, Guildford, United Kingdom
| | - Marcos G. Frank
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University Spokane, Spokane, WA, United States
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67
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Gabitov E, Boutin A, Pinsard B, Censor N, Fogel SM, Albouy G, King BR, Carrier J, Cohen LG, Karni A, Doyon J. Susceptibility of consolidated procedural memory to interference is independent of its active task-based retrieval. PLoS One 2019; 14:e0210876. [PMID: 30653576 PMCID: PMC6336251 DOI: 10.1371/journal.pone.0210876] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 01/03/2019] [Indexed: 11/18/2022] Open
Abstract
Reconsolidation theory posits that upon retrieval, consolidated memories are destabilized and need to be restabilized in order to persist. It has been suggested that experience with a competitive task immediately after memory retrieval may interrupt these restabilization processes leading to memory loss. Indeed, using a motor sequence learning paradigm, we have recently shown that, in humans, interference training immediately after active task-based retrieval of the consolidated motor sequence knowledge may negatively affect its performance levels. Assessing changes in tapping pattern before and after interference training, we also demonstrated that this performance deficit more likely indicates a genuine memory loss rather than an initial failure of memory retrieval. Here, applying a similar approach, we tested the necessity of the hypothetical retrieval-induced destabilization of motor memory to allow its impairment. The impact of memory retrieval on performance of a new motor sequence knowledge acquired during the interference training was also evaluated. Similar to the immediate post-retrieval interference, interference training alone without the preceding active task-based memory retrieval was also associated with impairment of the pre-established motor sequence memory. Performance levels of the sequence trained during the interference training, on the other hand, were impaired only if this training was given immediately after memory retrieval. Noteworthy, an 8-hour interval between memory retrieval and interference allowed to express intact performance levels for both sequences. The current results suggest that susceptibility of the consolidated motor memory to behavioral interference is independent of its active task-based retrieval. Differential effects of memory retrieval on performance levels of the new motor sequence encoded during the interference training further suggests that memory retrieval may influence the way new information is stored by facilitating its integration within the retrieved memory trace. Thus, impairment of the pre-established motor memory may reflect interference from a competing memory trace rather than involve interruption of reconsolidation.
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Affiliation(s)
- Ella Gabitov
- Functional Neuroimaging Unit, C.R.I.U.G.M., Montreal, Quebec, Canada
- McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, Quebec, Canada
- * E-mail: (EG); (JD)
| | - Arnaud Boutin
- Functional Neuroimaging Unit, C.R.I.U.G.M., Montreal, Quebec, Canada
- McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Basile Pinsard
- Functional Neuroimaging Unit, C.R.I.U.G.M., Montreal, Quebec, Canada
- McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, Quebec, Canada
- Sorbonne Université, CNRS, INSERM, Laboratoire d’Imagerie Biomédicale, LIB, Paris, France
| | - Nitzan Censor
- School of Psychological Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Stuart M. Fogel
- School of Psychology, University of Ottawa, Ottawa, Ontario, Canada
| | - Geneviève Albouy
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium
| | - Bradley R. King
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium
| | - Julie Carrier
- Functional Neuroimaging Unit, C.R.I.U.G.M., Montreal, Quebec, Canada
- Research Center of Sacré-Cœur Hospital of Montreal, Montreal, Quebec, Canada
| | - Leonardo G. Cohen
- Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Avi Karni
- Laboratory for Human Brain & Learning, Sagol Department of Neurobiology & the E.J. Safra Brain Research Center, University of Haifa, Haifa, Israel
| | - Julien Doyon
- McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, Quebec, Canada
- * E-mail: (EG); (JD)
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68
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Pereira LM, de Castro CM, Guerra LTL, Queiroz TM, Marques JT, Pereira GS. Hippocampus and Prefrontal Cortex Modulation of Contextual Fear Memory Is Dissociated by Inhibiting De Novo Transcription During Late Consolidation. Mol Neurobiol 2019; 56:5507-5519. [DOI: 10.1007/s12035-018-1463-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/18/2018] [Indexed: 11/28/2022]
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69
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Oishi N, Nomoto M, Ohkawa N, Saitoh Y, Sano Y, Tsujimura S, Nishizono H, Matsuo M, Muramatsu SI, Inokuchi K. Artificial association of memory events by optogenetic stimulation of hippocampal CA3 cell ensembles. Mol Brain 2019; 12:2. [PMID: 30621738 PMCID: PMC6323779 DOI: 10.1186/s13041-018-0424-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/26/2018] [Indexed: 11/10/2022] Open
Abstract
Previous gain-of-function studies using an optogenetic technique showed that manipulation of the hippocampal dentate gyrus or CA1 cell ensembles is important for memory reactivation and to generate synthetic or false memory. However, gain-of-function study manipulating CA3 cell ensembles has not been reported. The CA3 area of the hippocampus comprises a recurrent excitatory circuit, which is thought to be important for the generation of associations among the stored information within one brain region. We investigated whether the coincident firing of cell ensembles in one brain region, hippocampal CA3, associates distinct events. CA3 cell ensembles responding to context exploration and during contextual fear conditioning were labeled with channelrhodopsin-2 (ChR2)-mCherry. The synchronous activation of these ensembles induced freezing behavior in mice in a neutral context, in which a foot shock had never been delivered. The recall of this artificial associative fear memory was context specific. In vivo electrophysiological recordings showed that 20-Hz optical stimulation of ChR2-mCherry-expressing CA3 neurons, which is the same stimulation protocol used in behavioral experiment, induced long-term potentiation at CA3-CA3 synapses. Altogether, these results demonstrate that the synchronous activation of ensembles in one brain region, CA3 of the hippocampus, is sufficient for the association of distinct events. The results of our electrophysiology potentially suggest that this artificial association of memory events might be induced by the strengthening of synaptic efficacy between CA3 ensembles via recurrent circuit.
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Affiliation(s)
- Naoya Oishi
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan
| | - Masanori Nomoto
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan
| | - Noriaki Ohkawa
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), JST, University of Toyama, Toyama, 930-0194, Japan
| | - Yoshito Saitoh
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan
| | - Yoshitake Sano
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan.,Present address: Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, 278-8510, Japan
| | - Shuhei Tsujimura
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan
| | - Hirofumi Nishizono
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan.,Division of Animal Experimental Laboratory, Life Science Research Center, University of Toyama, Toyama, 930-0194, Japan
| | - Mina Matsuo
- Division of Animal Experimental Laboratory, Life Science Research Center, University of Toyama, Toyama, 930-0194, Japan
| | - Shin-Ichi Muramatsu
- Division of Neurology, Department of Medicine, Jichi Medical University, Tochigi, 329-0498, Japan.,Center for Gene and Cell Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Kaoru Inokuchi
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan. .,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, Toyama, 930-0194, Japan.
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70
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Hearing M. Prefrontal-accumbens opioid plasticity: Implications for relapse and dependence. Pharmacol Res 2018; 139:158-165. [PMID: 30465850 DOI: 10.1016/j.phrs.2018.11.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/05/2018] [Accepted: 11/07/2018] [Indexed: 01/12/2023]
Abstract
In addiction, an individual's ability to inhibit drug seeking and drug taking is thought to reflect a pathological strengthening of drug-seeking behaviors or impairments in the capacity to control maladaptive behavior. These processes are not mutually exclusive and reflect drug-induced modifications within prefrontal cortical and nucleus accumbens circuits, however unlike psychostimulants such as cocaine, far less is known about the temporal, anatomical, and cellular dynamics of these changes. We discuss what is known regarding opioid-induced adaptations in intrinsic membrane physiology and pre-/postsynaptic neurotransmission in principle pyramidal and medium spiny neurons in the medial prefrontal cortex and nucleus accumbens from electrophysiological studies and explore how circuit specific adaptations may contribute to unique facets of opioid addiction.
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Affiliation(s)
- Matthew Hearing
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, 53233, USA.
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71
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Zhang JJ, Haubrich J, Bernabo M, Finnie PS, Nader K. Limits on lability: Boundaries of reconsolidation and the relationship to metaplasticity. Neurobiol Learn Mem 2018; 154:78-86. [DOI: 10.1016/j.nlm.2018.02.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/08/2018] [Accepted: 02/19/2018] [Indexed: 02/07/2023]
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72
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Mansvelder HD, Verhoog MB, Goriounova NA. Synaptic plasticity in human cortical circuits: cellular mechanisms of learning and memory in the human brain? Curr Opin Neurobiol 2018; 54:186-193. [PMID: 30017789 DOI: 10.1016/j.conb.2018.06.013] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/19/2018] [Accepted: 06/30/2018] [Indexed: 12/18/2022]
Abstract
Synaptic plasticity is the cellular basis of learning and memory, but to what extent this holds for the adult human brain is not known. To study synaptic plasticity in human neuronal circuits poses a huge challenge, since live human neurons and synapses are not readily accessible. Despite this, various lines of research have provided insights in properties of adult human synapses and their plasticity both in vitro and in vivo, with some unexpected surprises. We first discuss the experimental approaches to study activity-dependent plasticity of adult human synapses, and then highlight rules and mechanisms of Hebbian spike timing-dependent plasticity (STDP) found in these synapses. Finally, we conclude with thoughts on how these synaptic principles can underlie human learning and memory.
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Affiliation(s)
- Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Amsterdam, VU University Amsterdam, The Netherlands.
| | - Matthijs B Verhoog
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Amsterdam, VU University Amsterdam, The Netherlands; Division of Cell Biology, Department of Human Biology, Neuroscience Institute, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Natalia A Goriounova
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Amsterdam, VU University Amsterdam, The Netherlands
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73
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Abstract
Memories for events are thought to be represented in sparse, distributed neuronal ensembles (or engrams). In this article, we review how neurons are chosen to become part of a particular engram, via a process of neuronal allocation. Experiments in rodents indicate that eligible neurons compete for allocation to a given engram, with more excitable neurons winning this competition. Moreover, fluctuations in neuronal excitability determine how engrams interact, promoting either memory integration (via coallocation to overlapping engrams) or separation (via disallocation to nonoverlapping engrams). In parallel with rodent studies, recent findings in humans verify the importance of this memory integration process for linking memories that occur close in time or share related content. A deeper understanding of allocation promises to provide insights into the logic underlying how knowledge is normally organized in the brain and the disorders in which this process has gone awry.
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Affiliation(s)
- Sheena A Josselyn
- Department of Psychology, University of Toronto, Ontario M5S 3G3, Canada; ,
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Physiology, University of Toronto, Ontario M5S 1A8, Canada
- Institute of Medical Sciences, University of Toronto, Ontario M5S 1A8, Canada
- Brain, Mind & Consciousness Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1M1, Canada
| | - Paul W Frankland
- Department of Psychology, University of Toronto, Ontario M5S 3G3, Canada; ,
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Physiology, University of Toronto, Ontario M5S 1A8, Canada
- Institute of Medical Sciences, University of Toronto, Ontario M5S 1A8, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1M1, Canada
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74
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Doron A, Goshen I. Investigating the transition from recent to remote memory using advanced tools. Brain Res Bull 2018; 141:35-43. [DOI: 10.1016/j.brainresbull.2017.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 08/27/2017] [Accepted: 09/11/2017] [Indexed: 11/30/2022]
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75
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Abdou K, Shehata M, Choko K, Nishizono H, Matsuo M, Muramatsu SI, Inokuchi K. Synapse-specific representation of the identity of overlapping memory engrams. Science 2018; 360:1227-1231. [DOI: 10.1126/science.aat3810] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/26/2018] [Indexed: 12/17/2022]
Abstract
Memories are integrated into interconnected networks; nevertheless, each memory has its own identity. How the brain defines specific memory identity out of intermingled memories stored in a shared cell ensemble has remained elusive. We found that after complete retrograde amnesia of auditory fear conditioning in mice, optogenetic stimulation of the auditory inputs to the lateral amygdala failed to induce memory recall, implying that the memory engram no longer existed in that circuit. Complete amnesia of a given fear memory did not affect another linked fear memory encoded in the shared ensemble. Optogenetic potentiation or depotentiation of the plasticity at synapses specific to one memory affected the recall of only that memory. Thus, the sharing of engram cells underlies the linkage between memories, whereas synapse-specific plasticity guarantees the identity and storage of individual memories.
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76
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Lee AK, Brecht M. Elucidating Neuronal Mechanisms Using Intracellular Recordings during Behavior. Trends Neurosci 2018; 41:385-403. [DOI: 10.1016/j.tins.2018.03.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/19/2018] [Accepted: 03/23/2018] [Indexed: 12/17/2022]
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77
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Ohline SM, Wake KL, Hawkridge MV, Dinnunhan MF, Hegemann RU, Wilson A, Schoderboeck L, Logan BJ, Jungenitz T, Schwarzacher SW, Hughes SM, Abraham WC. Adult-born dentate granule cell excitability depends on the interaction of neuron age, ontogenetic age and experience. Brain Struct Funct 2018; 223:3213-3228. [PMID: 29796923 DOI: 10.1007/s00429-018-1685-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 05/15/2018] [Indexed: 12/11/2022]
Abstract
Early during their maturation, adult-born dentate granule cells (aDGCs) are particularly excitable, but eventually develop the electrophysiologically quiet properties of mature cells. However, the stability versus plasticity of this quiet state across time and experience remains unresolved. By birthdating two populations of aDGCs across different animal ages, we found for 10-month-old rats the expected reduction in excitability across cells aged 4-12 weeks, as determined by Egr1 immunoreactivity. Unexpectedly, cells 35 weeks old (after genesis at an animal age of 2 months) were as excitable as 4-week-old cells, in the dorsal hippocampus. This high level of excitability at maturity was specific for cells born in animals 2 months of age, as cells born later in life did not show this effect. Importantly, excitability states were not fixed once maturity was gained, but were enhanced by enriched environment exposure or LTP induction, indicating that any maturational decrease in excitability can be compensated by experience. These data reveal the importance of the animal's age for aDGC excitability, and emphasize their prolonged capability for plasticity during adulthood.
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Affiliation(s)
- S M Ohline
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - K L Wake
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - M-V Hawkridge
- Institute of Clinical Neuroanatomy, Goethe-University of Frankfurt, Frankfurt am Main, Germany
| | - M F Dinnunhan
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - R U Hegemann
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - A Wilson
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - L Schoderboeck
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Department of Biochemistry, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - B J Logan
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - T Jungenitz
- Institute of Clinical Neuroanatomy, Goethe-University of Frankfurt, Frankfurt am Main, Germany
| | - S W Schwarzacher
- Institute of Clinical Neuroanatomy, Goethe-University of Frankfurt, Frankfurt am Main, Germany
| | - S M Hughes
- Department of Biochemistry, University of Otago, Dunedin, New Zealand.,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - W C Abraham
- Department of Psychology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand. .,Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, New Zealand.
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78
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Kredlow MA, Eichenbaum H, Otto MW. Memory creation and modification: Enhancing the treatment of psychological disorders. AMERICAN PSYCHOLOGIST 2018; 73:269-285. [PMID: 29494172 PMCID: PMC5897133 DOI: 10.1037/amp0000185] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Modification of the ongoing influence of maladaptive cognitive, emotional, and behavioral patterns is a fundamental feature of many psychological treatments. Accordingly, a clear understanding of the nature of memory adaptation and accommodation to therapeutic learning becomes an important issue for (1) understanding the impact of clinical interventions, and (2) considering innovations in treatment strategies. In this article, we consider advances in the conceptualization of memory processes and memory modification research relative to clinical treatment. We review basic research on the formation of memories, the way in which new learning is integrated within memory structures, and strategies to influence the nature and degree to which new learning is integrated. We then discuss cognitive/behavioral and pharmacological strategies for influencing memory formation in relation to disorder prevention or treatment. Our goal is to foster awareness of current strategies for enhancing therapeutic learning and to encourage research on potential new avenues for memory enhancement in service of the treatment of mental health disorders. (PsycINFO Database Record
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Affiliation(s)
| | | | - Michael W Otto
- Department of Psychological and Brain Sciences, Boston University
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79
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Kowiański P, Lietzau G, Steliga A, Czuba E, Ludkiewicz B, Waśkow M, Spodnik JH, Moryś J. Nicotine-induced CREB and DeltaFosB activity is modified by caffeine in the brain reward system of the rat. J Chem Neuroanat 2018; 88:1-12. [PMID: 29100904 DOI: 10.1016/j.jchemneu.2017.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 10/30/2017] [Accepted: 10/31/2017] [Indexed: 12/21/2022]
Abstract
Coffee and nicotine consumption are frequently combined, indicating possible intensifying effect of caffeine on smoking behavior, although neurobiological background of this phenomenon remains unknown. We aimed at determining the effect of caffeine and nicotine, applied separately or simultaneously, on activation of six structures of the brain reward system: nucleus accumbens (NAc), ventral tegmental area (VTA), amygdala (Amg), hippocampus (Hip), medial prefrontal cortex (mPfr) and dorsal striatum (CdP) in the adult male Wistar rats. Activation of two transcription factors, the phosphorylated form of cyclic AMP-response element binding protein (pCREB) and DeltaFosB (ΔFosB) was assessed by immunohistochemistry after multiple-dose five-days psychostimulants administration followed by 20min and 24h survival, respectively. Nicotine evoked the highest increase of pCREB-immunoreactivity (-ir) in NAc, while caffeine exerted the weakest effect in mPfr and CdP. Nicotine/caffeine co-administration resulted in decrease of pCREB-ir in NAc and increase in Amg, compared with the effect of each psychostimulant used separately. Nicotine was the strongest psychostimulant activating ΔFosB-ir in Amg, whereas caffeine - in Hip. Nicotine/caffeine-exerted effect upon ΔFosB-ir in Amg was weaker, whereas in mPfr stronger, than nicotine-evoked effect in these structures. In summary, pCREB and ΔFosB activation is dependent on the type of stimulus, brain structure and functional context. Activation of both transcription factors is responsible for caffeine's modifying effect upon nicotine-related behaviors and must be taken into account while quitting cigarette smoking.
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Affiliation(s)
- Przemysław Kowiański
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Str., 80-211 Gdansk, Poland; Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200 Slupsk, Poland.
| | - Grażyna Lietzau
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Str., 80-211 Gdansk, Poland; Department of Clinical Science and Education, Södersjukhuset, Internal Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Aleksandra Steliga
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200 Slupsk, Poland
| | - Ewelina Czuba
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Str., 80-211 Gdansk, Poland
| | - Beata Ludkiewicz
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Str., 80-211 Gdansk, Poland
| | - Monika Waśkow
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200 Slupsk, Poland
| | - Jan H Spodnik
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Str., 80-211 Gdansk, Poland
| | - Janusz Moryś
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Str., 80-211 Gdansk, Poland
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80
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Lisman J, Cooper K, Sehgal M, Silva AJ. Memory formation depends on both synapse-specific modifications of synaptic strength and cell-specific increases in excitability. Nat Neurosci 2018; 21:309-314. [PMID: 29434376 PMCID: PMC5915620 DOI: 10.1038/s41593-018-0076-6] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 12/08/2017] [Indexed: 11/09/2022]
Abstract
The modification of synaptic strength produced by long-term potentiation (LTP) is widely thought to underlie memory storage. Indeed, given that hippocampal pyramidal neurons have >10,000 independently modifiable synapses, the potential for information storage by synaptic modification is enormous. However, recent work suggests that CREB-mediated global changes in neuronal excitability also play a critical role in memory formation. Because these global changes have a modest capacity for information storage compared with that of synaptic plasticity, their importance for memory function has been unclear. Here we review the newly emerging evidence for CREB-dependent control of excitability and discuss two possible mechanisms. First, the CREB-dependent transient change in neuronal excitability performs a memory-allocation function ensuring that memory is stored in ways that facilitate effective linking of events with temporal proximity (hours). Second, these changes may promote cell-assembly formation during the memory-consolidation phase. It has been unclear whether such global excitability changes and local synaptic mechanisms are complementary. Here we argue that the two mechanisms can work together to promote useful memory function.
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Affiliation(s)
- John Lisman
- Department of Biology, Brandeis University, Waltham, MA, USA
| | | | - Megha Sehgal
- Department of Neurobiology, Department of Psychology, Department of Psychiatry and Biobehavioral Sciences, Integrative Center for Learning and Memory, and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Alcino J Silva
- Department of Biology, Brandeis University, Waltham, MA, USA.
- Department of Neurobiology, Department of Psychology, Department of Psychiatry and Biobehavioral Sciences, Integrative Center for Learning and Memory, and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA.
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81
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Memory allocation mechanisms underlie memory linking across time. Neurobiol Learn Mem 2018; 153:21-25. [PMID: 29496645 DOI: 10.1016/j.nlm.2018.02.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/14/2018] [Accepted: 02/19/2018] [Indexed: 11/22/2022]
Abstract
Memories are dynamic in nature. A cohesive representation of the world requires memories to be altered over time, linked with other memories and eventually integrated into a larger framework of sematic knowledge. Although there is a considerable literature on how single memories are encoded, retrieved and updated, little is known about the mechanisms that govern memory linking, e.g., linking and integration of various memories across hours or days. In this review, we present evidence that specific memory allocation mechanisms, such as changes in CREB and intrinsic excitability, ensure memory storage in ways that facilitate effective recall and linking at a later time. Beyond CREB and intrinsic excitability, we also review a number of other phenomena with potential roles in memory linking.
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82
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Eagle AL, Gajewski PA, Robison AJ. Role of hippocampal activity-induced transcription in memory consolidation. Rev Neurosci 2018; 27:559-73. [PMID: 27180338 DOI: 10.1515/revneuro-2016-0010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 03/26/2016] [Indexed: 01/15/2023]
Abstract
Experience-dependent changes in the strength of connections between neurons in the hippocampus (HPC) are critical for normal learning and memory consolidation, and disruption of this process drives a variety of neurological and psychiatric diseases. Proper HPC function relies upon discrete changes in gene expression driven by transcription factors (TFs) induced by neuronal activity. Here, we describe the induction and function of many of the most well-studied HPC TFs, including cyclic-AMP response element binding protein, serum-response factor, AP-1, and others, and describe their role in the learning process. We also discuss the known target genes of many of these TFs and the purported mechanisms by which they regulate long-term changes in HPC synaptic strength. Moreover, we propose that future research in this field will depend upon unbiased identification of additional gene targets for these activity-dependent TFs and subsequent meta-analyses that identify common genes or pathways regulated by multiple TFs in the HPC during learning or disease.
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83
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Kastellakis G, Silva AJ, Poirazi P. Linking Memories across Time via Neuronal and Dendritic Overlaps in Model Neurons with Active Dendrites. Cell Rep 2017; 17:1491-1504. [PMID: 27806290 PMCID: PMC5149530 DOI: 10.1016/j.celrep.2016.10.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/17/2016] [Accepted: 10/04/2016] [Indexed: 11/29/2022] Open
Abstract
Memories are believed to be stored in distributed neuronal assemblies through activity-induced changes in synaptic and intrinsic properties. However, the specific mechanisms by which different memories become associated or linked remain a mystery. Here, we develop a simplified, biophysically inspired network model that incorporates multiple plasticity processes and explains linking of information at three different levels: (1) learning of a single associative memory, (2) rescuing of a weak memory when paired with a strong one, and (3) linking of multiple memories across time. By dissecting synaptic from intrinsic plasticity and neuron-wide from dendritically restricted protein capture, the model reveals a simple, unifying principle: linked memories share synaptic clusters within the dendrites of overlapping populations of neurons. The model generates numerous experimentally testable predictions regarding the cellular and sub-cellular properties of memory engrams as well as their spatiotemporal interactions. Network model with active dendrites and synaptic, somatic, homeostatic plasticity Linked memories are stored in overlapping populations of neurons Linked memories share synaptic clusters in common dendritic branches The locus of protein synthesis or capture shapes the structure of the memory trace
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Affiliation(s)
- George Kastellakis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology, Hellas (FORTH), N. Plastira 100, P.O. Box 1385, Heraklion, Crete 70013, Greece; Department of Biology, University of Crete, P.O. Box 2208, Heraklion, Crete 70013, Greece
| | - Alcino J Silva
- Integrative Center for Learning and Memory, Departments of Neurobiology, Psychology, and Psychiatry, and Brain Research Institute, UCLA, 2554 Gonda Center, Los Angeles, CA 90095, USA
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology, Hellas (FORTH), N. Plastira 100, P.O. Box 1385, Heraklion, Crete 70013, Greece.
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84
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Parsons RG. Behavioral and neural mechanisms by which prior experience impacts subsequent learning. Neurobiol Learn Mem 2017; 154:22-29. [PMID: 29155095 DOI: 10.1016/j.nlm.2017.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 11/05/2017] [Accepted: 11/16/2017] [Indexed: 10/18/2022]
Abstract
Memory is often thought about in terms of its ability to recollect and store information about the past, but its function likely rests with the fact that it permits adaptation to ongoing and future experience. Thus, the brain circuitry that encodes memory must act as if stored information is likely to be modified by subsequent experience. Considerable progress has been made in identifying the behavioral and neural mechanisms supporting the acquisition and consolidation of memories, but this knowledge comes largely from studies in laboratory animals in which the training experience is presented in isolation from prior experimentally-controlled events. Given that memories are unlikely to be formed upon a clean slate, there is a clear need to understand how learning occurs upon the background of prior experience. This article reviews recent studies from an emerging body of work on metaplasticity, memory allocation, and synaptic tagging and capture, all of which demonstrate that prior experience can have a profound effect on subsequent learning. Special attention will be given to discussion of the neural mechanisms that allow past experience to affect future learning and to the time course by which past learning events can alter subsequent learning. Finally, consideration will be given to the possible significance of a non-synaptic component of the memory trace, which in some cases is likely responsible for the priming of subsequent learning and may be involved in the recovery from amnestic treatments in which the synaptic mechanisms of memory have been impaired.
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Affiliation(s)
- Ryan G Parsons
- Stony Brook University, Department of Psychology, 100 Nicolls Rd., Stony Brook, NY 11794, United States.
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85
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Schmidt-Hieber C, Nolan MF. Synaptic integrative mechanisms for spatial cognition. Nat Neurosci 2017; 20:1483-1492. [PMID: 29073648 DOI: 10.1038/nn.4652] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/22/2017] [Indexed: 12/11/2022]
Abstract
Synaptic integrative mechanisms have profound effects on electrical signaling in the brain that, although largely hidden from recording methods that observe the spiking activity of neurons, may be critical for the encoding, storage and retrieval of information. Here we review roles for synaptic integrative mechanisms in the selection, generation and plasticity of place and grid fields, and in related temporal codes for the representation of space. We outline outstanding questions and challenges in the testing of hypothesized models for spatial computation and memory.
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Affiliation(s)
| | - Matthew F Nolan
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
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86
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Lei Z, Wang D, Chen N, Ma K, Lu W, Song Z, Cui S, Wang JH. Synapse Innervation and Associative Memory Cell Are Recruited for Integrative Storage of Whisker and Odor Signals in the Barrel Cortex through miRNA-Mediated Processes. Front Cell Neurosci 2017; 11:316. [PMID: 29118695 PMCID: PMC5661269 DOI: 10.3389/fncel.2017.00316] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 09/26/2017] [Indexed: 11/13/2022] Open
Abstract
Associative learning is a common way for information acquisition, and the integrative storage of multiple associated signals is essential for associative thinking and logical reasoning. In terms of the cellular mechanism for associative memory, our studies by behavioral task and cellular imaging demonstrate that paired whisker and odor stimulations lead to odorant-induced whisker motion and associative memory cell recruitment in the barrel cortex (BC), which is driven presumably by synapse innervation from co-activated sensory cortices. To confirm these associative memory cells and synapse innervations essential for associative memory and to examine their potential mechanisms, we studied a causal relationship between epigenetic process and memory cell/synapse recruitment by manipulating miRNAs and observing the changes from the recruitments of associative memory cells and synapse innervations to associative memory. Anti-miRNA-324 and anti-miRNA-133a in the BC significantly downregulate new synapse innervation, associative memory cell recruitment and odorant-induced whisker motion, where Tau-tubulin kinase-1 expression is increased. Therefore, the upregulated miRNA-324 in associative learning knocks down Ttbk1-mediated Tau phosphorylation and microtubule depolymerization, which drives the balance between polymerization and depolymerization toward the axon prolongation and spine stabilization to initiate new synapse innervations and to recruit associative memory cells.
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Affiliation(s)
- Zhuofan Lei
- School of Pharmacy, Qingdao University, Dengzhou, China.,Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,Department of Biology, University of Chinese Academy of Sciences, Beijing, China
| | - Dangui Wang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Na Chen
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Ke Ma
- School of Pharmacy, Qingdao University, Dengzhou, China
| | - Wei Lu
- School of Pharmacy, Qingdao University, Dengzhou, China.,Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Zhenhua Song
- School of Pharmacy, Qingdao University, Dengzhou, China
| | - Shan Cui
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jin-Hui Wang
- School of Pharmacy, Qingdao University, Dengzhou, China.,Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,Department of Biology, University of Chinese Academy of Sciences, Beijing, China
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87
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Du J, Koffman EE. Labeling Aversive Memory Trace in Mouse Using a Doxycycline-inducible Expression System. Bio Protoc 2017; 7:e2578. [PMID: 34595260 DOI: 10.21769/bioprotoc.2578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 09/02/2017] [Accepted: 09/25/2017] [Indexed: 11/02/2022] Open
Abstract
A memory trace, also known as a memory engram, is theorized to be a mechanism for physical memory storage in the brain ( Silva et al., 2009 ; Josselyn, 2010) and memory trace is associated with a specific population of neurons ( Liu et al., 2012 ; Ramirez et al., 2013 ). Labeling and stimulating those neurons will activate the memory trace ( Liu et al., 2012 ; Ramirez et al., 2013 ). Memory appears to be spread over different regions of the brain rather than being localized to one area. Therefore, the methods used to trace memory have the ability to improve our understanding of neuronal circuits. In this protocol, we introduce a doxycycline-inducible expression system to label the specific neurons associated with the original memory trace.
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Affiliation(s)
- Jianyang Du
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Erin E Koffman
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
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88
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89
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Zhou QG, Liu MY, Lee HW, Ishikawa F, Devkota S, Shen XR, Jin X, Wu HY, Liu Z, Liu X, Jin X, Zhou HH, Ro EJ, Zhang J, Zhang Y, Lin YH, Suh H, Zhu DY. Hippocampal TERT Regulates Spatial Memory Formation through Modulation of Neural Development. Stem Cell Reports 2017; 9:543-556. [PMID: 28757168 PMCID: PMC5550029 DOI: 10.1016/j.stemcr.2017.06.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 01/29/2023] Open
Abstract
The molecular mechanism of memory formation remains a mystery. Here, we show that TERT, the catalytic subunit of telomerase, gene knockout (Tert−/−) causes extremely poor ability in spatial memory formation. Knockdown of TERT in the dentate gyrus of adult hippocampus impairs spatial memory processes, while overexpression facilitates it. We find that TERT plays a critical role in neural development including dendritic development and neuritogenesis of hippocampal newborn neurons. A monosynaptic pseudotyped rabies virus retrograde tracing method shows that TERT is required for neural circuit integration of hippocampal newborn neurons. Interestingly, TERT regulated neural development and spatial memory formation in a reverse transcription activity-independent manner. Using X-ray irradiation, we find that hippocampal newborn neurons mediate the modulation of spatial memory processes by TERT. These observations reveal an important function of TERT through a non-canonical pathway and encourage the development of a TERT-based strategy to treat neurological disease-associated memory impairment. Tert gene knockout causes extremely poor ability in spatial memory formation Dendritic development and neuritogenesis are impaired in Tert−/− mice TERT is required for neural circuit integration of hippocampal newborn neurons TERT regulates spatial memory formation in an activity-independent manner
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Affiliation(s)
- Qi-Gang Zhou
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China; Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| | - Meng-Ying Liu
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei Laboratory Animal Research Center, Yonsei University, Seoul 120-749, Korea
| | - Fuyuki Ishikawa
- Departments of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Kyoto 606-850, Japan
| | - Sushil Devkota
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei Laboratory Animal Research Center, Yonsei University, Seoul 120-749, Korea
| | - Xin-Ru Shen
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Xin Jin
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Hai-Yin Wu
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Zhigang Liu
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Xiao Liu
- Department of Chinese Medicine, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China
| | - Xun Jin
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Neurosurgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325015 Zhejiang, P.R. China
| | - Hai-Hui Zhou
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Eun Jeoung Ro
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jing Zhang
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Yu Zhang
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Yu-Hui Lin
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China
| | - Hoonkyo Suh
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| | - Dong-Ya Zhu
- Department of Clinical Pharmacology, Institution of Stem Cells and Neuroregeneration, Pharmacy College, Nanjing Medical University, Nanjing 211166, P.R. China.
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90
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Park Y, Choi W, Paik SB. Symmetry of learning rate in synaptic plasticity modulates formation of flexible and stable memories. Sci Rep 2017; 7:5671. [PMID: 28720795 PMCID: PMC5516032 DOI: 10.1038/s41598-017-05929-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 06/06/2017] [Indexed: 01/06/2023] Open
Abstract
Spike-timing-dependent plasticity (STDP) is considered critical to learning and memory functions in the human brain. Across various types of synapse, STDP is observed as different profiles of Hebbian and anti-Hebbian learning rules. However, the specific roles of diverse STDP profiles in memory formation still remain elusive. Here, we show that the symmetry of the learning rate profile in STDP is crucial to determining the character of stored memory. Using computer simulations, we found that an asymmetric learning rate generates flexible memory that is volatile and easily overwritten by newly appended information. Moreover, a symmetric learning rate generates stable memory that can coexist with newly appended information. In addition, by combining these two conditions, we could realize a hybrid memory type that operates in a way intermediate between stable and flexible memory. Our results demonstrate that various attributes of memory functions may originate from differences in the synaptic stability.
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Affiliation(s)
- Youngjin Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Woochul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.,Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Se-Bum Paik
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea. .,Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.
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91
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Skill Learning Modulates RNA Pol II Poising at Immediate Early Genes in the Adult Striatum. eNeuro 2017; 4:eN-NWR-0074-17. [PMID: 28451632 PMCID: PMC5392706 DOI: 10.1523/eneuro.0074-17.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 03/10/2017] [Indexed: 12/14/2022] Open
Abstract
A multilayered complexity of epigenetic and transcriptional regulatory mechanisms underlies neuronal activity-dependent gene transcription. The regulation of RNA Pol II progression along the transcription cycle, from promoter-proximal poising (with RNA Pol II paused at promoter-proximal regions, characterized by a Ser5P+-rich and Ser2P+-poor RPB1 CTD) to active elongation, has emerged as a major step in transcriptional regulation across several organisms, tissues, and developmental stages, including the nervous system. However, it is not known whether this mechanism is modulated by experience. We investigated the impact of learning a motor skill on RNA Pol II phosphorylation dynamics in the adult mouse striatum. We uncovered that learning modulates the in vivo striatal phosphorylation dynamics of the CTD of the RNA Pol II RPB1 subunit, leading to an increased poising index in trained mice. We found that this modulation occurs at immediate early genes (IEGs), with increased poising of RNA Pol II at both Arc and Fos genes but not at constitutively expressed genes. Furthermore, we confirmed that this was learning dependent, and not just regulated by context or motor activity. These experiments demonstrate a novel phenomenon of learning induced transcriptional modulation in adult brain, which may have implications for our understanding of learning, memory allocation, and consolidation.
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92
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Zeithamova D, Preston AR. Temporal Proximity Promotes Integration of Overlapping Events. J Cogn Neurosci 2017; 29:1311-1323. [PMID: 28253077 DOI: 10.1162/jocn_a_01116] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Events with overlapping elements can be encoded as two separate representations or linked into an integrated representation, yet we know little about the conditions that promote one form of representation over the other. Here, we tested the hypothesis that the proximity of overlapping events would increase the probability of integration. Participants first established memories for house-object and face-object pairs; half of the pairs were learned 24 hr before an fMRI session, and the other half 30 min before the session. During scanning, participants encoded object-object pairs that overlapped with the initial pairs acquired on the same or prior day. Participants were also scanned as they made inference judgments about the relationships among overlapping pairs learned on the same or different day. Participants were more accurate and faster when inferring relationships among memories learned on the same day relative to those acquired across days, suggesting that temporal proximity promotes integration. Evidence for reactivation of existing memories-as measured by a visual content classifier-was equivalent during encoding of overlapping pairs from the two temporal conditions. In contrast, evidence for integration-as measured by a mnemonic strategy classifier from an independent study [Richter, F. R., Chanales, A. J. H., & Kuhl, B. A. Predicting the integration of overlapping memories by decoding mnemonic processing states during learning. Neuroimage, 124, 323-335, 2016]-was greater for same-day overlapping events, paralleling the behavioral results. During inference itself, activation patterns further differentiated when participants were making inferences about events acquired on the same day versus across days. These findings indicate that temporal proximity of events promotes integration and further influences the neural mechanisms engaged during inference.
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93
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Owens MT, Tanner KD. Teaching as Brain Changing: Exploring Connections between Neuroscience and Innovative Teaching. CBE LIFE SCIENCES EDUCATION 2017; 16:16/2/fe2. [PMID: 28450442 PMCID: PMC5459260 DOI: 10.1187/cbe.17-01-0005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
One would hope that of the many ways to conceptualize teaching and learning, scientists would view these processes as driving biological changes in the brain. Here, the authors draw connections between innovative teaching techniques and neuroscience that may support our understanding of why innovative teaching is so effective at promoting learning.
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Affiliation(s)
- Melinda T Owens
- Science Education Partnership and Assessment Laboratory, San Francisco State University, San Francisco, CA 94132
| | - Kimberly D Tanner
- Science Education Partnership and Assessment Laboratory, San Francisco State University, San Francisco, CA 94132
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94
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Mechanisms of Memory Consolidation and Transformation. COGNITIVE NEUROSCIENCE OF MEMORY CONSOLIDATION 2017. [DOI: 10.1007/978-3-319-45066-7_2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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95
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Fernández RS, Bavassi L, Kaczer L, Forcato C, Pedreira ME. Interference Conditions of the Reconsolidation Process in Humans: The Role of Valence and Different Memory Systems. Front Hum Neurosci 2016; 10:641. [PMID: 28066212 PMCID: PMC5167735 DOI: 10.3389/fnhum.2016.00641] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/02/2016] [Indexed: 12/03/2022] Open
Abstract
Following the presentation of a reminder, consolidated memories become reactivated followed by a process of re-stabilization, which is referred to as reconsolidation. The most common behavioral tool used to reveal this process is interference produced by new learning shortly after memory reactivation. Memory interference is defined as a decrease in memory retrieval, the effect is generated when new information impairs an acquired memory. In general, the target memory and the interference task used are the same. Here we investigated how different memory systems and/or their valence could produce memory reconsolidation interference. We showed that a reactivated neutral declarative memory could be interfered by new learning of a different neutral declarative memory. Then, we revealed that an aversive implicit memory could be interfered by the presentation of a reminder followed by a threatening social event. Finally, we showed that the reconsolidation of a neutral declarative memory is unaffected by the acquisition of an aversive implicit memory and conversely, this memory remains intact when the neutral declarative memory is used as interference. These results suggest that the interference of memory reconsolidation is effective when two task rely on the same memory system or both evoke negative valence.
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Affiliation(s)
- Rodrigo S. Fernández
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología y Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos Aires, Argentina
| | - Luz Bavassi
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología y Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos Aires, Argentina
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos Aires, Argentina
| | - Laura Kaczer
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología y Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos Aires, Argentina
| | - Cecilia Forcato
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología y Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos Aires, Argentina
| | - María E. Pedreira
- Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología y Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos Aires, Argentina
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96
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Growth hormone biases amygdala network activation after fear learning. Transl Psychiatry 2016; 6:e960. [PMID: 27898076 PMCID: PMC5290350 DOI: 10.1038/tp.2016.203] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 07/07/2016] [Accepted: 07/18/2016] [Indexed: 01/27/2023] Open
Abstract
Prolonged stress exposure is a risk factor for developing posttraumatic stress disorder, a disorder characterized by the 'over-encoding' of a traumatic experience. A potential mechanism by which this occurs is through upregulation of growth hormone (GH) in the amygdala. Here we test the hypotheses that GH promotes the over-encoding of fearful memories by increasing the number of neurons activated during memory encoding and biasing the allocation of neuronal activation, one aspect of the process by which neurons compete to encode memories, to favor neurons that have stronger inputs. Viral overexpression of GH in the amygdala increased the number of amygdala cells activated by fear memory formation. GH-overexpressing cells were especially biased to express the immediate early gene c-Fos after fear conditioning, revealing strong autocrine actions of GH in the amygdala. In addition, we observed dramatically enhanced dendritic spine density in GH-overexpressing neurons. These data elucidate a previously unrecognized autocrine role for GH in the regulation of amygdala neuron function and identify specific mechanisms by which chronic stress, by enhancing GH in the amygdala, may predispose an individual to excessive fear memory formation.
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97
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Functional and structural underpinnings of neuronal assembly formation in learning. Nat Neurosci 2016; 19:1553-1562. [PMID: 27749830 DOI: 10.1038/nn.4418] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 09/14/2016] [Indexed: 02/07/2023]
Abstract
Learning and memory are associated with the formation and modification of neuronal assemblies: populations of neurons that encode what has been learned and mediate memory retrieval upon recall. Functional studies of neuronal assemblies have progressed dramatically thanks to recent technological advances. Here we discuss how a focus on assembly formation and consolidation has provided a powerful conceptual framework to relate mechanistic studies of synaptic and circuit plasticity to behaviorally relevant aspects of learning and memory. Neurons are likely recruited to particular learning-related assemblies as a function of their relative excitabilities and synaptic activation, followed by selective strengthening of pre-existing synapses, formation of new connections and elimination of outcompeted synapses to ensure memory formation. Mechanistically, these processes involve linking transcription to circuit modification. They include the expression of immediate early genes and specific molecular and cellular events, supported by network-wide activities that are shaped and modulated by local inhibitory microcircuits.
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98
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Choi KY, Kim YK. Plasticity-augmented psychotherapy for refractory depressive and anxiety disorders. Prog Neuropsychopharmacol Biol Psychiatry 2016; 70:134-47. [PMID: 27072378 DOI: 10.1016/j.pnpbp.2016.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 12/28/2022]
Abstract
Psychotherapy and pharmacotherapy have been the mainstays of treatment for depression and anxiety disorders during the last century. However, treatment response has not improved in the last few decades, with only half of all patients responding satisfactorily to typical antidepressants. To fulfill the needs of the remaining patients, new treatments with better efficacy are in demand. The addition of psychotherapy to antidepressant treatment has been shown to be superior to pharmacotherapy alone. However, the time costs of psychotherapy limit its use for clinicians and patients. Advancements in neuroscience have contributed to an improved understanding of the pathogenesis of depressive and anxiety disorders. In particular, recent advances in the field of fear conditioning have provided valuable insight into the treatment of refractory depressive and anxiety disorders. In this review, we studied the reconsolidation-updating paradigm and the concept of epigenetic modification, which has been shown to permanently attenuate remote fear memory. This has implications for drug-augmented, e.g. antidepressant and valproic acid, psychotherapy. Future research on more sophisticated psychotherapy techniques will increase the desirability of this treatment modality for both clinicians and patients.
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Affiliation(s)
- Kwang-Yeon Choi
- Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea
| | - Yong-Ku Kim
- Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea.
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99
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Eichenbaum H, Amaral DG, Buffalo EA, Buzsáki G, Cohen N, Davachi L, Frank L, Heckers S, Morris RGM, Moser EI, Nadel L, O'Keefe J, Preston A, Ranganath C, Silva A, Witter M. Hippocampus at 25. Hippocampus 2016; 26:1238-49. [PMID: 27399159 PMCID: PMC5367855 DOI: 10.1002/hipo.22616] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 07/08/2016] [Indexed: 11/08/2022]
Abstract
The journal Hippocampus has passed the milestone of 25 years of publications on the topic of a highly studied brain structure, and its closely associated brain areas. In a recent celebration of this event, a Boston memory group invited 16 speakers to address the question of progress in understanding the hippocampus that has been achieved. Here we present a summary of these talks organized as progress on four main themes: (1) Understanding the hippocampus in terms of its interactions with multiple cortical areas within the medial temporal lobe memory system, (2) understanding the relationship between memory and spatial information processing functions of the hippocampal region, (3) understanding the role of temporal organization in spatial and memory processing by the hippocampus, and (4) understanding how the hippocampus integrates related events into networks of memories. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Howard Eichenbaum
- Center for Memory and Brain and Department of Psychological and Brain Sciences, Boston University, Boston, MA.
| | - David G Amaral
- Department of Psychiatry and Behavioral Sciences and UC Davis Mind Institute, Davis, CA
| | - Elizabeth A Buffalo
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - György Buzsáki
- Deparment of Neuroscience and Physiology and NYU Neuroscience Institute, New York University Medical School, New York, NY
| | - Neal Cohen
- Psychology Department and Beckman Institute, University of Illinois at Urbana Champaign, Champaign, IL
| | - Lila Davachi
- Department of Psychology, New York Institute, New York, NY
| | - Loren Frank
- Department of Physiology and Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA
| | - Stephan Heckers
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University School of Medicine, Nashville, TN
| | - Richard G M Morris
- Centre for Cognitive and Neural Systems,The University of Edinburgh, Edinburgh, UK
| | - Edvard I Moser
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
| | - Lynn Nadel
- Department of Psychology, University of Arizona, Tucson, AZ
| | - John O'Keefe
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour and Department of Cell and Developmental Biology, University College London, UK
| | - Alison Preston
- Center for Learning and Memory, Department of Psychology and Neuroscience, University of Texas at Austin, Austin, TX
| | - Charan Ranganath
- Department of Psychiatry and Behavioral Sciences and UC Davis Mind Institute, Davis, CA
| | - Alcino Silva
- Department of Psychology and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA
| | - Menno Witter
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Trondheim, Norway
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100
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Optogenetic Inhibitor of the Transcription Factor CREB. ACTA ACUST UNITED AC 2016; 22:1531-1539. [PMID: 26590638 DOI: 10.1016/j.chembiol.2015.09.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/11/2015] [Accepted: 09/24/2015] [Indexed: 01/28/2023]
Abstract
Current approaches for optogenetic control of transcription do not mimic the activity of endogenous transcription factors, which act at numerous sites in the genome in a complex interplay with other factors. Optogenetic control of dominant negative versions of endogenous transcription factors provides a mechanism for mimicking the natural regulation of gene expression. Here we describe opto-DN-CREB, a blue-light-controlled inhibitor of the transcription factor CREB created by fusing the dominant negative inhibitor A-CREB to photoactive yellow protein (PYP). A light-driven conformational change in PYP prevents coiled-coil formation between A-CREB and CREB, thereby activating CREB. Optogenetic control of CREB function was characterized in vitro, in HEK293T cells, and in neurons where blue light enabled control of expression of the CREB targets NR4A2 and c-Fos. Dominant negative inhibitors exist for numerous transcription factors; linking these to optogenetic domains offers a general approach for spatiotemporal control of native transcriptional events.
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