101
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Thielen JW, Hong D, Rohani Rankouhi S, Wiltfang J, Fernández G, Norris DG, Tendolkar I. The increase in medial prefrontal glutamate/glutamine concentration during memory encoding is associated with better memory performance and stronger functional connectivity in the human medial prefrontal-thalamus-hippocampus network. Hum Brain Mapp 2018; 39:2381-2390. [PMID: 29488277 PMCID: PMC5969297 DOI: 10.1002/hbm.24008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 12/22/2017] [Accepted: 02/08/2018] [Indexed: 12/15/2022] Open
Abstract
The classical model of the declarative memory system describes the hippocampus and its interactions with representational brain areas in posterior neocortex as being essential for the formation of long‐term episodic memories. However, new evidence suggests an extension of this classical model by assigning the medial prefrontal cortex (mPFC) a specific, yet not fully defined role in episodic memory. In this study, we utilized 1H magnetic resonance spectroscopy (MRS) and psychophysiological interaction (PPI) analysis to lend further support for the idea of a mnemonic role of the mPFC in humans. By using MRS, we measured mPFC γ‐aminobutyric acid (GABA) and glutamate/glutamine (GLx) concentrations before and after volunteers memorized face–name association. We demonstrate that mPFC GLx but not GABA levels increased during the memory task, which appeared to be related to memory performance. Regarding functional connectivity, we used the subsequent memory paradigm and found that the GLx increase was associated with stronger mPFC connectivity to thalamus and hippocampus for associations subsequently recognized with high confidence as opposed to subsequently recognized with low confidence/forgotten. Taken together, we provide new evidence for an mPFC involvement in episodic memory by showing a memory‐related increase in mPFC excitatory neurotransmitter levels that was associated with better memory and stronger memory‐related functional connectivity in a medial prefrontal–thalamus–hippocampus network.
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Affiliation(s)
- Jan-Willem Thielen
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany.,Donders Institute for Brain Cognition and Behavior, Radboud University and Radboud University Medical Center, Nijmegen, the Netherlands.,Department for Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Donghyun Hong
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany
| | | | - Jens Wiltfang
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Guillén Fernández
- Donders Institute for Brain Cognition and Behavior, Radboud University and Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, the Netherlands
| | - David G Norris
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany.,Donders Institute for Brain Cognition and Behavior, Radboud University and Radboud University Medical Center, Nijmegen, the Netherlands.,MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands
| | - Indira Tendolkar
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany.,Donders Institute for Brain Cognition and Behavior, Radboud University and Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Psychiatry, Radboud University Medical Center, Nijmegen, the Netherlands
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102
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Schönauer M, Brodt S, Pöhlchen D, Breßmer A, Danek AH, Gais S. Sleep Does Not Promote Solving Classical Insight Problems and Magic Tricks. Front Hum Neurosci 2018; 12:72. [PMID: 29535620 PMCID: PMC5834438 DOI: 10.3389/fnhum.2018.00072] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/09/2018] [Indexed: 11/13/2022] Open
Abstract
During creative problem solving, initial solution attempts often fail because of self-imposed constraints that prevent us from thinking out of the box. In order to solve a problem successfully, the problem representation has to be restructured by combining elements of available knowledge in novel and creative ways. It has been suggested that sleep supports the reorganization of memory representations, ultimately aiding problem solving. In this study, we systematically tested the effect of sleep and time on problem solving, using classical insight tasks and magic tricks. Solving these tasks explicitly requires a restructuring of the problem representation and may be accompanied by a subjective feeling of insight. In two sessions, 77 participants had to solve classical insight problems and magic tricks. The two sessions either occurred consecutively or were spaced 3 h apart, with the time in between spent either sleeping or awake. We found that sleep affected neither general solution rates nor the number of solutions accompanied by sudden subjective insight. Our study thus adds to accumulating evidence that sleep does not provide an environment that facilitates the qualitative restructuring of memory representations and enables problem solving.
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Affiliation(s)
- Monika Schönauer
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Svenja Brodt
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Dorothee Pöhlchen
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Anja Breßmer
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Amory H. Danek
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Steffen Gais
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
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103
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Bonasia K, Sekeres MJ, Gilboa A, Grady CL, Winocur G, Moscovitch M. Prior knowledge modulates the neural substrates of encoding and retrieving naturalistic events at short and long delays. Neurobiol Learn Mem 2018; 153:26-39. [PMID: 29474955 DOI: 10.1016/j.nlm.2018.02.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/26/2018] [Accepted: 02/19/2018] [Indexed: 12/18/2022]
Abstract
Congruence with prior knowledge and incongruence/novelty have long been identified as two prominent factors that, despite their opposing characteristics, can both enhance episodic memory. Using narrative film clip stimuli, this study investigated these effects in naturalistic event memories - examining behaviour and neural activation to help explain this paradox. Furthermore, we examined encoding, immediate retrieval, and one-week delayed retrieval to determine how these effects evolve over time. Behaviourally, both congruence with prior knowledge and incongruence/novelty enhanced memory for events, though incongruent events were recalled with more errors over time. During encoding, greater congruence with prior knowledge was correlated with medial prefrontal cortex (mPFC) and parietal activation, suggesting that these areas may play a key role in linking current episodic processing with prior knowledge. Encoding of increasingly incongruent events, on the other hand, was correlated with increasing activation in, and functional connectivity between, the medial temporal lobe (MTL) and posterior sensory cortices. During immediate and delayed retrieval the mPFC and MTL each demonstrated functional connectivity that varied based on the congruence of events with prior knowledge; with connectivity between the MTL and occipital regions found for incongruent events, while congruent events were associated with functional connectivity between the mPFC and the inferior parietal lobules and middle frontal gyri. These results demonstrate patterns of neural activity and connectivity that shift based on the nature of the event being experienced or remembered, and that evolve over time. Furthermore, they suggest potential mechanisms by which both congruence with prior knowledge and incongruence/novelty may enhance memory, through mPFC and MTL functional connectivity, respectively.
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Affiliation(s)
- Kyra Bonasia
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada; Geisel School of Medicine, Dartmouth College, 1 Rope Ferry Road, Hanover, NH 03755, USA.
| | - Melanie J Sekeres
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada; Department of Psychology and Neuroscience, Baylor University, 101 Bagby Ave., Waco, TX 76706, USA; Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, Ontario M6A 2E1, Canada
| | - Asaf Gilboa
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada; Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, Ontario M6A 2E1, Canada
| | - Cheryl L Grady
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada; Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, Ontario M6A 2E1, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada
| | - Gordon Winocur
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada; Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, Ontario M6A 2E1, Canada; Department of Psychology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L 0G2, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada
| | - Morris Moscovitch
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada; Rotman Research Institute, Baycrest Health Sciences, 3560 Bathurst Street, Toronto, Ontario M6A 2E1, Canada
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104
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Ohki T, Takei Y. Neural mechanisms of mental schema: a triplet of delta, low beta/spindle and ripple oscillations. Eur J Neurosci 2018; 48:2416-2430. [PMID: 29405470 DOI: 10.1111/ejn.13844] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 12/14/2022]
Abstract
Schemas are higher-level knowledge structures that integrate and organise lower-level representations. As internal templates, schemas are formed according to how events are perceived, interpreted and remembered. Although these higher-level units are assumed to play a fundamental role in our daily life from an early age, the neuronal basis and mechanisms of schema formation and use remain largely unknown. It is important to elucidate how the brain constructs and maintains these higher-level units. In order to examine the possible neural underpinnings of schema, we recapitulate previous work and discuss their findings related to schemas as the brain template. We specifically focused on low beta/spindle oscillations, which are assumed to be the key components of schemas, and propose that the brain template is implemented with a triplet of neural oscillations, that is delta, low beta/spindle and ripple oscillations.
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Affiliation(s)
- Takefumi Ohki
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan.,Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yuichi Takei
- Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
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105
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Bonnici HM, Maguire EA. Two years later - Revisiting autobiographical memory representations in vmPFC and hippocampus. Neuropsychologia 2018; 110:159-169. [PMID: 28502632 PMCID: PMC5825381 DOI: 10.1016/j.neuropsychologia.2017.05.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/09/2017] [Accepted: 05/11/2017] [Indexed: 11/04/2022]
Abstract
A long-standing question in memory neuroscience concerns how and where autobiographical memories of personal experiences are represented in the brain. In a previous high resolution multivoxel pattern analysis fMRI study, we examined two week old (recent) and ten year old (remote) autobiographical memories (Bonnici et al., 2012, J. Neurosci. 32:16982-16991). We found that remote memories were particularly well represented in ventromedial prefrontal cortex (vmPFC) compared to recent memories. Moreover, while both types of memory were represented within anterior and posterior hippocampus, remote memories were more easily distinguished in the posterior portion. These findings suggested that a change of some kind had occurred between two weeks and ten years in terms of where autobiographical memories were represented in the brain. In order to examine this further, here participants from the original study returned two years later and recalled the memories again. We found that there was no difference in the detectability of memory representations within vmPFC for the now 2 year old and 12 year old memories, and this was also the case for the posterior hippocampus. Direct comparison of the two week old memories (original study) with themselves two years later (present study) confirmed that their representation within vmPFC had become more evident. Overall, this within-subjects longitudinal fMRI study extends our understanding of autobiographical memory representations by allowing us to narrow the window within which their consolidation is likely to occur. We conclude that after a memory is initially encoded, its representation within vmPFC has stablised by, at most, two years later.
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Affiliation(s)
- Heidi M Bonnici
- School of Psychology, University of East Anglia, Norwich NR4 7TJ, UK
| | - Eleanor A Maguire
- Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK.
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106
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Ahuja S, Chen RK, Kam K, Pettibone WD, Osorio RS, Varga AW. Role of normal sleep and sleep apnea in human memory processing. Nat Sci Sleep 2018; 10:255-269. [PMID: 30214331 PMCID: PMC6128282 DOI: 10.2147/nss.s125299] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A fundamental problem in the field of obstructive sleep apnea (OSA) and memory is that it has historically minimized the basic neurobiology of sleep's role in memory. Memory formation has been classically divided into phases of encoding, processing/consolidation, and retrieval. An abundance of evidence suggests that sleep plays a critical role specifically in the processing/consolidation phase, but may do so differentially for memories that were encoded using particular brain circuits. In this review, we discuss some of the more established evidence for sleep's function in the processing of declarative, spatial navigational, emotional, and motor/procedural memories and more emerging evidence highlighting sleep's importance in higher order functions such as probabilistic learning, transitive inference, and category/gist learning. Furthermore, we discuss sleep's capacity for memory augmentation through targeted/cued memory reactivation. OSA - by virtue of its associated sleep fragmentation, intermittent hypoxia, and potential brain structural effects - is well positioned to specifically impact the processing/consolidation phase, but testing this possibility requires experimental paradigms in which memory encoding and retrieval are separated by a period of sleep with and without the presence of OSA. We argue that such paradigms should focus on the specific types of memory tasks for which sleep has been shown to have a significant effect. We discuss the small number of studies in which this has been done, in which OSA nearly uniformly negatively impacts offline memory processing. When periods of offline processing are minimal or absent and do not contain sleep, as is the case in the broad literature on OSA and memory, the effects of OSA on memory are far less consistent.
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Affiliation(s)
- Shilpi Ahuja
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Rebecca K Chen
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Korey Kam
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Ward D Pettibone
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Ricardo S Osorio
- Center for Brain Health, Department of Psychiatry, NYU School of Medicine, New York, NY, USA
| | - Andrew W Varga
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
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107
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Shaw JJ, Monaghan P. Lateralised sleep spindles relate to false memory generation. Neuropsychologia 2017; 107:60-67. [DOI: 10.1016/j.neuropsychologia.2017.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 11/26/2022]
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108
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Leminen MM, Virkkala J, Saure E, Paajanen T, Zee PC, Santostasi G, Hublin C, Müller K, Porkka-Heiskanen T, Huotilainen M, Paunio T. Enhanced Memory Consolidation Via Automatic Sound Stimulation During Non-REM Sleep. Sleep 2017; 40:2965202. [PMID: 28364428 PMCID: PMC5806588 DOI: 10.1093/sleep/zsx003] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Introduction: Slow-wave sleep (SWS) slow waves and sleep spindle activity have been shown to be crucial for memory consolidation. Recently, memory consolidation has been causally facilitated in human participants via auditory stimuli phase-locked to SWS slow waves. Aims: Here, we aimed to develop a new acoustic stimulus protocol to facilitate learning and to validate it using different memory tasks. Most importantly, the stimulation setup was automated to be applicable for ambulatory home use. Methods: Fifteen healthy participants slept 3 nights in the laboratory. Learning was tested with 4 memory tasks (word pairs, serial finger tapping, picture recognition, and face-name association). Additional questionnaires addressed subjective sleep quality and overnight changes in mood. During the stimulus night, auditory stimuli were adjusted and targeted by an unsupervised algorithm to be phase-locked to the negative peak of slow waves in SWS. During the control night no sounds were presented. Results: Results showed that the sound stimulation increased both slow wave (p = .002) and sleep spindle activity (p < .001). When overnight improvement of memory performance was compared between stimulus and control nights, we found a significant effect in word pair task but not in other memory tasks. The stimulation did not affect sleep structure or subjective sleep quality. Conclusions: We showed that the memory effect of the SWS-targeted individually triggered single-sound stimulation is specific to verbal associative memory. Moreover, the ambulatory and automated sound stimulus setup was promising and allows for a broad range of potential follow-up studies in the future.
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Affiliation(s)
- Miika M Leminen
- Finnish Institute of Occupational Health, Helsinki, Finland.,Cognitive Brain Research Unit, Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jussi Virkkala
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Emma Saure
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Teemu Paajanen
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Phyllis C Zee
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL
| | - Giovanni Santostasi
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL
| | | | - Kiti Müller
- Finnish Institute of Occupational Health, Helsinki, Finland
| | | | - Minna Huotilainen
- Finnish Institute of Occupational Health, Helsinki, Finland.,Cognitive Brain Research Unit, Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Cicero Learning Network, University of Helsinki, Helsinki, Finland
| | - Tiina Paunio
- Finnish Institute of Occupational Health, Helsinki, Finland.,Department of Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland.,Department of Health, National Institute for Health and Welfare, Helsinki, Finland
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109
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Tompary A, Davachi L. Consolidation Promotes the Emergence of Representational Overlap in the Hippocampus and Medial Prefrontal Cortex. Neuron 2017; 96:228-241.e5. [PMID: 28957671 DOI: 10.1016/j.neuron.2017.09.005] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 08/10/2017] [Accepted: 09/07/2017] [Indexed: 02/08/2023]
Abstract
Structured knowledge is thought to form, in part, through the extraction and representation of regularities across overlapping experiences. However, little is known about how consolidation processes may transform novel episodic memories to reflect such regularities. In a multi-day fMRI study, participants encoded trial-unique associations that shared features with other trials. Multi-variate pattern analyses were used to measure neural similarity across overlapping and non-overlapping memories during immediate and 1-week retrieval of these associations. We found that neural patterns in the hippocampus and medial prefrontal cortex represented the featural overlap across memories, but only after a week. Furthermore, after a week, the strength of a memory's unique episodic reinstatement during retrieval was inversely related to its representation of overlap, suggesting a trade-off between the integration of related memories and recovery of episodic details. These findings suggest that consolidation-related changes in neural representations support the gradual organization of discrete episodes into structured knowledge.
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Affiliation(s)
- Alexa Tompary
- Department of Psychology, New York University, New York, NY, 10003, USA
| | - Lila Davachi
- Department of Psychology, New York University, New York, NY, 10003, USA; Center for Neural Science, New York University, New York, NY, 10003, USA.
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110
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111
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Angular Gyrus Involvement at Encoding and Retrieval Is Associated with Durable But Less Specific Memories. J Neurosci 2017; 37:9474-9485. [PMID: 28871031 PMCID: PMC6596768 DOI: 10.1523/jneurosci.3603-16.2017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 08/12/2017] [Accepted: 08/17/2017] [Indexed: 01/24/2023] Open
Abstract
After consolidation, information belonging to a mental schema is better remembered, but such memory can be less specific when it comes to details. A neuronal mechanism consistent with this behavioral pattern could result from a dynamic interaction that entails mediation by a specific cortical network with associated hippocampal disengagement. We now report that, in male and female adult human subjects, encoding and later consolidation of a series of objects embedded in a semantic schema was associated with a buildup of activity in the angular gyrus (AG) that predicted memory 24 h later. In parallel, the posterior hippocampus became less involved as schema objects were encoded successively. Hippocampal disengagement was related to an increase in falsely remembering objects that were not presented at encoding. During both encoding and retrieval, the AG and lateral occipital complex (LOC) became functionally connected and this interaction was beneficial for successful retrieval. Therefore, a network including the AG and LOC enhances the overnight retention of schema-related memories and their simultaneous detachment from the hippocampus reduces the specificity of the memory.SIGNIFICANCE STATEMENT This study provides the first empirical evidence on how the hippocampus and the neocortex interact dynamically when acquiring and then effectively retaining durable knowledge that is associated to preexisting knowledge, but they do so at the cost of memory specificity. This interaction is a fundamental mnemonic operation that has thus far been largely overlooked in memory research.
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112
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Cousins JN, Sasmita K, Chee MWL. Memory encoding is impaired after multiple nights of partial sleep restriction. J Sleep Res 2017; 27:138-145. [PMID: 28677325 DOI: 10.1111/jsr.12578] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/29/2017] [Indexed: 01/19/2023]
Abstract
Sleep is important for normative cognitive functioning. A single night of total sleep deprivation can reduce the capacity to encode new memories. However, it is unclear how sleep restriction during several consecutive nights affects memory encoding. To explore this, we employed a parallel-group design with 59 adolescents randomized into sleep-restricted (SR) and control groups. Both groups were afforded 9 h time in bed (TIB) for 2 baseline nights, followed by 5 consecutive nights of 5 h TIB for the SR group (n = 29) and 9 h TIB for the control group (n = 30). Participants then performed a picture-encoding task. Encoding ability was measured with a recognition test after 3 nights of 9 h TIB recovery sleep for both groups, allowing the assessment of encoding ability without the confounding effects of fatigue at retrieval. Memory was significantly worse in the sleep-restricted group (P = 0.001), and this impairment was not correlated with decline in vigilance. We conclude that memory-encoding deteriorates after several nights of partial sleep restriction, and this typical pattern of sleep negatively affects adolescents' ability to learn declarative information.
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Affiliation(s)
- James N Cousins
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Karen Sasmita
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Michael W L Chee
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
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113
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Neurobiology of Schemas and Schema-Mediated Memory. Trends Cogn Sci 2017; 21:618-631. [PMID: 28551107 DOI: 10.1016/j.tics.2017.04.013] [Citation(s) in RCA: 283] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 02/05/2023]
Abstract
Schemas are superordinate knowledge structures that reflect abstracted commonalities across multiple experiences, exerting powerful influences over how events are perceived, interpreted, and remembered. Activated schema templates modulate early perceptual processing, as they get populated with specific informational instances (schema instantiation). Instantiated schemas, in turn, can enhance or distort mnemonic processing from the outset (at encoding), impact offline memory transformation and accelerate neocortical integration. Recent studies demonstrate distinctive neurobiological processes underlying schema-related learning. Interactions between the ventromedial prefrontal cortex (vmPFC), hippocampus, angular gyrus (AG), and unimodal associative cortices support context-relevant schema instantiation and schema mnemonic effects. The vmPFC and hippocampus may compete (as suggested by some models) or synchronize (as suggested by others) to optimize schema-related learning depending on the specific operationalization of schema memory. This highlights the need for more precise definitions of memory schemas.
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114
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Dallé E, Daniels WMU, Mabandla MV. Fluvoxamine maleate effects on dopamine signaling in the prefrontal cortex of stressed Parkinsonian rats: Implications for learning and memory. Brain Res Bull 2017; 132:75-81. [PMID: 28549887 DOI: 10.1016/j.brainresbull.2017.05.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/09/2017] [Accepted: 05/22/2017] [Indexed: 10/19/2022]
Abstract
Parkinson's disease (PD) is also associated with cognitive impairment and reduced extrinsic supply of dopamine (DA) to the prefrontal cortex (PFC). In the present study, we looked at whether exposure to early life stress reduces DA and serotonin (5-HT) concentration in the PFC thus leading to enhanced cognitive impairment in a Parkinsonian rat model. Maternal separation was the stressor used to develop an animal model for early life stress that has chronic effects on brain and behavior. Sprague-Dawley rats were treated with the antidepressant Fluvoxamine maleate (FM) prior to a unilateral 6-hydroxydopamine (6-OHDA) lesion to model motor deficits in rats. The Morris water maze (MWM) and the forelimb use asymmetry (cylinder) tests were used to assess learning and memory impairment and motor deficits respectively. Blood plasma was used to measure corticosterone concentration and prefrontal tissue was collected for lipid peroxidation, DA, and 5-HT analysis. Our results show that animals exposed to early life stress displayed learning and memory impairment as well as elevated basal plasma corticosterone concentration which were attenuated by treatment with FM. A 6-OHDA lesion effect was evidenced by impairment in the cylinder test as well as decreased DA and 5-HT concentration in the PFC. These effects were attenuated by FM treatment resulting in higher DA concentration in the PFC of treated animals than in non-treated animals. This study suggests that DA and 5-HT signaling in the PFC are responsive to FM and may reduce stress-induced cognitive impairment in PD.
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Affiliation(s)
- Ernest Dallé
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Willie M U Daniels
- School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Musa V Mabandla
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa.
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115
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Yang Q, Song D, Qing H. Neural changes in Alzheimer's disease from circuit to molecule: Perspective of optogenetics. Neurosci Biobehav Rev 2017; 79:110-118. [PMID: 28522119 DOI: 10.1016/j.neubiorev.2017.05.015] [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: 12/20/2016] [Revised: 04/21/2017] [Accepted: 05/12/2017] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD), as a crucial neurodegenerative disorder, affects neural activities at many levels. Synaptic plasticity and neural circuits are most susceptible in AD, but the detailed mechanism is unclear. Optogenetic tools provide unprecedented spatio-temporal specificity to stimulate specific neural circuits or synaptic molecules to reveal the precise function of normal brain and mechanism of deficits in AD models. Furthermore, using optogenetics to stimulate neurons can rescue learning and memory loss caused by AD. It also has possibility to use light to control the Neurotransmitter receptors and their downstream signal pathway. These technical methods have broad therapeutic application prospect.
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Affiliation(s)
- Qinghu Yang
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Da Song
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Hong Qing
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China.
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116
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Mander BA, Winer JR, Walker MP. Sleep and Human Aging. Neuron 2017; 94:19-36. [PMID: 28384471 PMCID: PMC5810920 DOI: 10.1016/j.neuron.2017.02.004] [Citation(s) in RCA: 577] [Impact Index Per Article: 82.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/02/2017] [Accepted: 02/03/2017] [Indexed: 12/13/2022]
Abstract
Older adults do not sleep as well as younger adults. Why? What alterations in sleep quantity and quality occur as we age, and are there functional consequences? What are the underlying neural mechanisms that explain age-related sleep disruption? This review tackles these questions. First, we describe canonical changes in human sleep quantity and quality in cognitively normal older adults. Second, we explore the underlying neurobiological mechanisms that may account for these human sleep alterations. Third, we consider the functional consequences of age-related sleep disruption, focusing on memory impairment as an exemplar. We conclude with a discussion of a still-debated question: do older adults simply need less sleep, or rather, are they unable to generate the sleep that they still need?
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Affiliation(s)
- Bryce A Mander
- Sleep and Neuroimaging Laboratory, Department of Psychology, University of California, Berkeley, Berkeley, CA 94720-1650, USA
| | - Joseph R Winer
- Sleep and Neuroimaging Laboratory, Department of Psychology, University of California, Berkeley, Berkeley, CA 94720-1650, USA
| | - Matthew P Walker
- Sleep and Neuroimaging Laboratory, Department of Psychology, University of California, Berkeley, Berkeley, CA 94720-1650, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720-1650, USA.
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117
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Sterpenich V, Ceravolo L, Schwartz S. Sleep deprivation disrupts the contribution of the hippocampus to the formation of novel lexical associations. BRAIN AND LANGUAGE 2017; 167:61-71. [PMID: 28173964 DOI: 10.1016/j.bandl.2016.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 06/06/2023]
Abstract
Sleep is involved in the mechanisms underlying memory consolidation and brain plasticity. Consolidation refers to a process through which labile memories are reorganized into more stable ones. An intriguing but often neglected question concerns how pre-existing knowledge is modified when new information enters memory, and whether sleep can influence this process. We investigated how nonword learning may modify the neural representations of closely-related existing words. We also tested whether sleep contributes to any such effect by comparing a group of participants who slept during the night following a first encoding session to a sleep deprived group. Thirty participants were first intensively trained at writing nonwords on Day 1 (remote nonwords) and Day 4 (recent nonwords), following which they underwent functional MRI. This session consisted of a word lexical decision task including words orthographically-close to the trained nonwords, followed by an incidental memory task on the nonwords. Participants who slept detected real words related to remote nonwords faster than those related to recent nonwords, and showed better explicit memory for the remote nonwords. Although the full interaction comparing both groups for these effects was not significant, we found that participants from the sleep-deprivation group did not display such differences between remote and recent conditions. Imaging results revealed that the functional interplay between hippocampus and frontal regions critically mediated these behavioral effects. This study demonstrates that sleep may not only strengthen memory for recently learned items but also promotes a constant reorganization of existing networks of word representations, allowing facilitated access to orthographically-close words.
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Affiliation(s)
- Virginie Sterpenich
- Neurology and Imaging of Cognition Laboratory, Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland; Swiss Center for Affective Sciences, University of Geneva, Switzerland; Department of Neuroscience, University Medical Center, Geneva, Switzerland
| | - Leonardo Ceravolo
- Swiss Center for Affective Sciences, University of Geneva, Switzerland; Neuroscience of Emotion and Affective Dynamics laboratory, Department of Psychology, University of Geneva, Switzerland
| | - Sophie Schwartz
- Neurology and Imaging of Cognition Laboratory, Department of Neuroscience, Faculty of Medicine, University of Geneva, Switzerland; Swiss Center for Affective Sciences, University of Geneva, Switzerland; Department of Neuroscience, University Medical Center, Geneva, Switzerland
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118
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James E, Gaskell MG, Weighall A, Henderson L. Consolidation of vocabulary during sleep: The rich get richer? Neurosci Biobehav Rev 2017; 77:1-13. [PMID: 28274725 DOI: 10.1016/j.neubiorev.2017.01.054] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/16/2016] [Accepted: 01/31/2017] [Indexed: 01/10/2023]
Abstract
Sleep plays a role in strengthening new words and integrating them with existing vocabulary knowledge, consistent with neural models of learning in which sleep supports hippocampal transfer to neocortical memory. Such models are based on adult research, yet neural maturation may mean that the mechanisms supporting word learning vary across development. Here, we propose a model in which children may capitalise on larger amounts of slow-wave sleep to support a greater demand on learning and neural reorganisation, whereas adults may benefit from a richer knowledge base to support consolidation. Such an argument is reinforced by the well-reported "Matthew effect", whereby rich vocabulary knowledge is associated with better acquisition of new vocabulary. We present a meta-analysis that supports this association between children's existing vocabulary knowledge and their integration of new words overnight. Whilst multiple mechanisms likely contribute to vocabulary consolidation and neural reorganisation across the lifespan, we propose that contributions of existing knowledge should be rigorously examined in developmental studies. Such research has potential to greatly enhance neural models of learning.
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Affiliation(s)
- Emma James
- Department of Psychology, University of York, York, YO10 5DD, United Kingdom
| | - M Gareth Gaskell
- Department of Psychology, University of York, York, YO10 5DD, United Kingdom
| | - Anna Weighall
- School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Lisa Henderson
- Department of Psychology, University of York, York, YO10 5DD, United Kingdom.
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119
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Berkers RMWJ, van der Linden M, de Almeida RF, Müller NCJ, Bovy L, Dresler M, Morris RGM, Fernández G. Transient medial prefrontal perturbation reduces false memory formation. Cortex 2017; 88:42-52. [PMID: 28068640 DOI: 10.1016/j.cortex.2016.12.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 11/06/2016] [Accepted: 12/19/2016] [Indexed: 01/25/2023]
Abstract
Knowledge extracted across previous experiences, or schemas, benefit encoding and retention of congruent information. However, they can also reduce specificity and augment memory for semantically related, but false information. A demonstration of the latter is given by the Deese-Roediger-McDermott (DRM) paradigm, where the studying of words that fit a common semantic schema are found to induce false memories for words that are congruent with the given schema, but were not studied. The medial prefrontal cortex (mPFC) has been ascribed the function of leveraging prior knowledge to influence encoding and retrieval, based on imaging and patient studies. Here, we used transcranial magnetic stimulation (TMS) to transiently perturb ongoing mPFC processing immediately before participants performed the DRM-task. We observed the predicted reduction in false recall of critical lures after mPFC perturbation, compared to two control groups, whereas veridical recall and recognition memory performance remained similar across groups. These data provide initial causal evidence for a role of the mPFC in biasing the assimilation of new memories and their consolidation as a function of prior knowledge.
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Affiliation(s)
- Ruud M W J Berkers
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany.
| | - Marieke van der Linden
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Rafael F de Almeida
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - Nils C J Müller
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Leonore Bovy
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Richard G M Morris
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, United Kingdom
| | - Guillén Fernández
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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120
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I know I've seen you before: Distinguishing recent-single-exposure-based familiarity from pre-existing familiarity. Brain Res 2017; 1658:11-24. [PMID: 28073651 DOI: 10.1016/j.brainres.2017.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 12/21/2016] [Accepted: 01/04/2017] [Indexed: 11/22/2022]
Abstract
This study examines how individuals differentiate recent-single-exposure-based familiarity from pre-existing familiarity. If these are two distinct cognitive processes, are they supported by the same neural bases? This study examines how recent-single-exposure-based familiarity and multiple-previous-exposure-based familiarity are supported and represented in the brain using functional MRI. In a novel approach, we first behaviorally show that subjects can divide retrieval of items in pre-existing memory into judgments of recollection and familiarity. Then, using functional magnetic resonance imaging, we examine the differences in blood oxygen level dependent activity and regional connectivity during judgments of recent-single-exposure-based and pre-existing familiarity. Judgments of these two types of familiarity showed distinct regions of activation in a whole-brain analysis, in medial temporal lobe (MTL) substructures, and in MTL substructure functional-correlations with other brain regions. Specifically, within the MTL, perirhinal cortex showed increased activation during recent-single-exposure-based familiarity while parahippocampal cortex showed increased activation during judgments of pre-existing familiarity. We find that recent-single-exposure-based and pre-existing familiarity are represented as distinct neural processes in the brain; this is supported by differing patterns of brain activation and regional correlations. This spatially distinct regional brain involvement suggests that the two separate experiences of familiarity, recent-exposure-based familiarity and pre-existing familiarity, may be cognitively distinct.
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121
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Morrissey MD, Insel N, Takehara-Nishiuchi K. Generalizable knowledge outweighs incidental details in prefrontal ensemble code over time. eLife 2017; 6. [PMID: 28195037 PMCID: PMC5308892 DOI: 10.7554/elife.22177] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/17/2017] [Indexed: 02/02/2023] Open
Abstract
Memories for recent experiences are rich in incidental detail, but with time the brain is thought to extract latent rules and structures common across past experiences. We show that over weeks following the acquisition of two distinct associative memories, neuron firing in the rat prelimbic prefrontal cortex (mPFC) became less selective for perceptual features unique to each association and, with an apparently different time-course, became more selective for common relational features. We further found that during exposure to a novel experimental context, memory expression and neuron selectivity for relational features immediately generalized to the new situation. These neural patterns offer a window into the network-level processes by which the mPFC develops a knowledge structure of the world that can be adaptively applied to new experiences.
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Affiliation(s)
- Mark D Morrissey
- Department of Psychology, University or Toronto, Toronto, Canada.,Collaborative Program in Neuroscience, University of Toronto, Toronto, Canada
| | - Nathan Insel
- Department of Psychology, University or Toronto, Toronto, Canada
| | - Kaori Takehara-Nishiuchi
- Department of Psychology, University or Toronto, Toronto, Canada.,Collaborative Program in Neuroscience, University of Toronto, Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
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122
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van Ekert J, Wegman J, Jansen C, Takashima A, Janzen G. The dynamics of memory consolidation of landmarks. Hippocampus 2017; 27:393-404. [DOI: 10.1002/hipo.22698] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2016] [Indexed: 01/09/2023]
Affiliation(s)
- Janneke van Ekert
- Radboud University Nijmegen Behavioural Science Institute, P.O. Box 91046500 HENijmegen The Netherlands
- Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, P.O. Box 91016500 HBNijmegen The Netherlands
| | - Joost Wegman
- Radboud University Nijmegen Behavioural Science Institute, P.O. Box 91046500 HENijmegen The Netherlands
- Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, P.O. Box 91016500 HBNijmegen The Netherlands
| | - Clemens Jansen
- Radboud University Nijmegen Behavioural Science Institute, P.O. Box 91046500 HENijmegen The Netherlands
- Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, P.O. Box 91016500 HBNijmegen The Netherlands
| | - Atsuko Takashima
- Radboud University Nijmegen Behavioural Science Institute, P.O. Box 91046500 HENijmegen The Netherlands
- Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, P.O. Box 91016500 HBNijmegen The Netherlands
- Max Planck Institute for Psycholinguistics, P.O. Box 3106500 AHNijmegen The Netherlands
| | - Gabriele Janzen
- Radboud University Nijmegen Behavioural Science Institute, P.O. Box 91046500 HENijmegen The Netherlands
- Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, P.O. Box 91016500 HBNijmegen The Netherlands
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123
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The Yin and Yang of Memory Consolidation: Hippocampal and Neocortical. PLoS Biol 2017; 15:e2000531. [PMID: 28085883 PMCID: PMC5234779 DOI: 10.1371/journal.pbio.2000531] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 12/14/2016] [Indexed: 01/06/2023] Open
Abstract
While hippocampal and cortical mechanisms of memory consolidation have long been studied, their interaction is poorly understood. We sought to investigate potential interactions with respect to trace dominance, strengthening, and interference associated with postencoding novelty or sleep. A learning procedure was scheduled in a watermaze that placed the impact of novelty and sleep in opposition. Distinct behavioural manipulations-context preexposure or interference during memory retrieval-differentially affected trace dominance and trace survival, respectively. Analysis of immediate early gene expression revealed parallel up-regulation in the hippocampus and cortex, sustained in the hippocampus in association with novelty but in the cortex in association with sleep. These findings shed light on dynamically interacting mechanisms mediating the stabilization of hippocampal and neocortical memory traces. Hippocampal memory traces followed by novelty were more dominant by default but liable to interference, whereas sleep engaged a lasting stabilization of cortical traces and consequent trace dominance after preexposure.
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124
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Himmer L, Müller E, Gais S, Schönauer M. Sleep-mediated memory consolidation depends on the level of integration at encoding. Neurobiol Learn Mem 2017; 137:101-106. [DOI: 10.1016/j.nlm.2016.11.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/23/2016] [Accepted: 11/29/2016] [Indexed: 11/26/2022]
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125
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The Effect of Sleep on Multiple Memory Systems. COGNITIVE NEUROSCIENCE OF MEMORY CONSOLIDATION 2017. [DOI: 10.1007/978-3-319-45066-7_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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126
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Wagner IC, van Buuren M, Bovy L, Morris RG, Fernández G. Methylphenidate during early consolidation affects long-term associative memory retrieval depending on baseline catecholamines. Psychopharmacology (Berl) 2017; 234:657-669. [PMID: 28013352 PMCID: PMC5263224 DOI: 10.1007/s00213-016-4502-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 12/05/2016] [Indexed: 12/03/2022]
Abstract
RATIONALE Synaptic memory consolidation is thought to rely on catecholaminergic signaling. Eventually, it is followed by systems consolidation, which embeds memories in a neocortical network. Although this sequence was demonstrated in rodents, it is unclear how catecholamines affect memory consolidation in humans. OBJECTIVES Here, we tested the effects of catecholaminergic modulation on synaptic and subsequent systems consolidation. We expected enhanced memory performance and increased neocortical engagement during delayed retrieval. Additionally, we tested if this effect was modulated by individual differences in a cognitive proxy measure of baseline catecholamine synthesis capacity. METHODS Fifty-three healthy males underwent a between-subjects, double-blind, placebo-controlled procedure across 2 days. On day 1, subjects studied and retrieved object-location associations and received 20 mg of methylphenidate or placebo. Drug intake was timed so that methylphenidate was expected to affect early consolidation but not encoding or retrieval. Memory was tested again while subjects were scanned three days later. RESULTS Methylphenidate did not facilitate memory performance, and there was no significant group difference in activation during delayed retrieval. However, memory representations differed between groups depending on baseline catecholamines. The placebo group showed increased activation in occipito-temporal regions but decreased connectivity with the hippocampus, associated with lower baseline catecholamine synthesis capacity. The methylphenidate group showed stronger activation in the postcentral gyrus, associated with higher baseline catecholamine synthesis capacity. CONCLUSIONS Altogether, methylphenidate during early consolidation did not foster long-term memory performance, but it affected retrieval-related neural processes depending on individual levels of baseline catecholamines.
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Affiliation(s)
- Isabella C Wagner
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands.
| | - Mariët van Buuren
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands
| | - Leonore Bovy
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands
| | - Richard G Morris
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, EH8 9JZ, UK
| | - Guillén Fernández
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands
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127
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A Role of Sleep in Forming Predictive Codes. COGNITIVE NEUROSCIENCE OF MEMORY CONSOLIDATION 2017. [DOI: 10.1007/978-3-319-45066-7_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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128
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Asken BM, Sullan MJ, Snyder AR, Houck ZM, Bryant VE, Hizel LP, McLaren ME, Dede DE, Jaffee MS, DeKosky ST, Bauer RM. Factors Influencing Clinical Correlates of Chronic Traumatic Encephalopathy (CTE): a Review. Neuropsychol Rev 2016; 26:340-363. [PMID: 27561662 PMCID: PMC5507554 DOI: 10.1007/s11065-016-9327-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 08/08/2016] [Indexed: 12/14/2022]
Abstract
Chronic traumatic encephalopathy (CTE) is a neuropathologically defined disease reportedly linked to a history of repetitive brain trauma. As such, retired collision sport athletes are likely at heightened risk for developing CTE. Researchers have described distinct pathological features of CTE as well a wide range of clinical symptom presentations, recently termed traumatic encephalopathy syndrome (TES). These clinical symptoms are highly variable, non-specific to individuals described as having CTE pathology in case reports, and are often associated with many other factors. This review describes the cognitive, emotional, and behavioral changes associated with 1) developmental and demographic factors, 2) neurodevelopmental disorders, 3) normal aging, 4) adjusting to retirement, 5) drug and alcohol abuse, 6) surgeries and anesthesia, and 7) sleep difficulties, as well as the relationship between these factors and risk for developing dementia-related neurodegenerative disease. We discuss why some professional athletes may be particularly susceptible to many of these effects and the importance of choosing appropriate controls groups when designing research protocols. We conclude that these factors should be considered as modifiers predominantly of the clinical outcomes associated with repetitive brain trauma within a broader biopsychosocial framework when interpreting and attributing symptom development, though also note potential effects on neuropathological outcomes. Importantly, this could have significant treatment implications for improving quality of life.
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Affiliation(s)
- Breton M Asken
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA.
| | - Molly J Sullan
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Aliyah R Snyder
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Zachary M Houck
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Vaughn E Bryant
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Loren P Hizel
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Molly E McLaren
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Duane E Dede
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Michael S Jaffee
- Department of Neurology, University of Florida, Gainesville, FL, USA
| | - Steven T DeKosky
- Department of Neurology, University of Florida, Gainesville, FL, USA
| | - Russell M Bauer
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
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129
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Memory consolidation reconfigures neural pathways involved in the suppression of emotional memories. Nat Commun 2016; 7:13375. [PMID: 27898050 PMCID: PMC5141344 DOI: 10.1038/ncomms13375] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 09/27/2016] [Indexed: 12/02/2022] Open
Abstract
The ability to suppress unwanted emotional memories is crucial for human mental health. Through consolidation over time, emotional memories often become resistant to change. However, how consolidation impacts the effectiveness of emotional memory suppression is still unknown. Using event-related fMRI while concurrently recording skin conductance, we investigated the neurobiological processes underlying the suppression of aversive memories before and after overnight consolidation. Here we report that consolidated aversive memories retain their emotional reactivity and become more resistant to suppression. Suppression of consolidated memories involves higher prefrontal engagement, and less concomitant hippocampal and amygdala disengagement. In parallel, we show a shift away from hippocampal-dependent representational patterns to distributed neocortical representational patterns in the suppression of aversive memories after consolidation. These findings demonstrate rapid changes in emotional memory organization with overnight consolidation, and suggest possible neurobiological bases underlying the resistance to suppression of emotional memories in affective disorders. As memories consolidate over time, they become resistant to change, though how this impacts the volitional suppression of memories is not known. Liu and colleagues show that, after overnight consolidation, aversive memories exhibit distributed prefrontal representations and are harder to suppress.
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130
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Hales JB, Ocampo AC, Broadbent NJ, Clark RE. Consolidation of spatial memory in the rat: Findings using zeta-inhibitory peptide. Neurobiol Learn Mem 2016; 136:220-227. [PMID: 27818270 DOI: 10.1016/j.nlm.2016.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 10/20/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
Abstract
Whether or not spatial memories reorganize in the rodent brain is an unanswered question that carries the importance of whether the rodent provides a suitable animal model of human retrograde amnesia. The finding of equally impaired recent and remote spatial memory could reflect the continued importance of the hippocampus for spatial memory or a performance deficit (for example, hippocampal lesions may impair the rat's ability to use distal spatial cues to navigate to a specific point in space). In the current study, we tested recent and remote spatial memory in rats following hippocampal ZIP (zeta-pseudosubstrate inhibitory peptide) infusion to inhibit PKMzeta. Hippocampal ZIP infusion has previously been shown to impair spatial and nonspatial memory soon after learning, presumably by reversing late-phase long-term potentiation, allowing us to disrupt memory without damaging hippocampal tissue. We used a stereotaxic approach for infusing ZIP throughout the dorsal, intermediate, and ventral hippocampus following spatial memory training. Although rats showed intact memory retrieval on the standard Morris watermaze task and trace fear conditioning, rats infused with ZIP 24h after training on the annular watermaze task exhibited impaired spatial memory compared to control rats (those infused with aCSF) and performed no different than chance. In contrast, rats infused with ZIP 1month after training performed similar to control rats and both groups performed above chance. Additionally, the ability to form new memories after ZIP infusions remained intact. Thus, ZIP infusions into the hippocampus after learning impaired retrieval of recently formed spatial memories while sparing remote spatial memories.
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Affiliation(s)
- Jena B Hales
- Department of Psychological Sciences, University of San Diego, San Diego, CA 92110, USA
| | - Amber C Ocampo
- Department of Psychology, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Robert E Clark
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA; Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA.
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131
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Abstract
Previous evidence indicates that the brain stores memory in two complementary systems, allowing both rapid plasticity and stable representations at different sites. For memory to be established in a long-lasting neocortical store, many learning repetitions are considered necessary after initial encoding into hippocampal circuits. To elucidate the dynamics of hippocampal and neocortical contributions to the early phases of memory formation, we closely followed changes in human functional brain activity while volunteers navigated through two different, initially unknown virtual environments. In one condition, they were able to encode new information continuously about the spatial layout of the maze. In the control condition, no information could be learned because the layout changed constantly. Our results show that the posterior parietal cortex (PPC) encodes memories for spatial locations rapidly, beginning already with the first visit to a location and steadily increasing activity with each additional encounter. Hippocampal activity and connectivity between the PPC and hippocampus, on the other hand, are strongest during initial encoding, and both decline with additional encounters. Importantly, stronger PPC activity related to higher memory-based performance. Compared with the nonlearnable control condition, PPC activity in the learned environment remained elevated after a 24-h interval, indicating a stable change. Our findings reflect the rapid creation of a memory representation in the PPC, which belongs to a recently proposed parietal memory network. The emerging parietal representation is specific for individual episodes of experience, predicts behavior, and remains stable over offline periods, and must therefore hold a mnemonic function.
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132
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Two Distinct Scene-Processing Networks Connecting Vision and Memory. eNeuro 2016; 3:eN-NWR-0178-16. [PMID: 27822493 PMCID: PMC5075944 DOI: 10.1523/eneuro.0178-16.2016] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/02/2016] [Accepted: 09/30/2016] [Indexed: 11/21/2022] Open
Abstract
A number of regions in the human brain are known to be involved in processing natural scenes, but the field has lacked a unifying framework for understanding how these different regions are organized and interact. We provide evidence from functional connectivity and meta-analyses for a new organizational principle, in which scene processing relies upon two distinct networks that split the classically defined parahippocampal place area (PPA). The first network of strongly connected regions consists of the occipital place area/transverse occipital sulcus and posterior PPA, which contain retinotopic maps and are not strongly coupled to the hippocampus at rest. The second network consists of the caudal inferior parietal lobule, retrosplenial complex, and anterior PPA, which connect to the hippocampus (especially anterior hippocampus), and are implicated in both visual and nonvisual tasks, including episodic memory and navigation. We propose that these two distinct networks capture the primary functional division among scene-processing regions, between those that process visual features from the current view of a scene and those that connect information from a current scene view with a much broader temporal and spatial context. This new framework for understanding the neural substrates of scene-processing bridges results from many lines of research, and makes specific functional predictions.
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133
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Khan I, Tantray MA, Alam MS, Hamid H. Natural and synthetic bioactive inhibitors of glycogen synthase kinase. Eur J Med Chem 2016; 125:464-477. [PMID: 27689729 DOI: 10.1016/j.ejmech.2016.09.058] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/26/2016] [Accepted: 09/18/2016] [Indexed: 01/19/2023]
Abstract
Glycogen synthase kinase-3 is a multi-functional serine-threonine kinase and is involved in diverse physiological processes, including metabolism, cell cycle, and gene expression by regulating a wide variety of known substrates like glycogen synthase, tau-protein and β-catenin. Aberrant GSK-3 has been involved in diabetes, inflammation, cancer, Alzheimer's and bipolar disorder. In this review, we present an overview of the involvement of GSK-3 in various signalling pathways, resulting in a number of adverse pathologies due to its dysregulation. In addition, a detailed description of the small molecule inhibitors of GSK-3 with different mode of action discovered or specifically developed for GSK-3 has been presented. Furthermore, some clues for the future optimization of these promising molecules to develop specific drugs inhibiting GSK-3, for the treatment of associated disease conditions have also been discussed.
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Affiliation(s)
- Imran Khan
- Department of Chemistry, Faculty of Science, Jamia Hamdard (Hamdard University), New Delhi 110 062, India
| | - Mushtaq A Tantray
- Department of Chemistry, Faculty of Science, Jamia Hamdard (Hamdard University), New Delhi 110 062, India
| | - Mohammad Sarwar Alam
- Department of Chemistry, Faculty of Science, Jamia Hamdard (Hamdard University), New Delhi 110 062, India
| | - Hinna Hamid
- Department of Chemistry, Faculty of Science, Jamia Hamdard (Hamdard University), New Delhi 110 062, India.
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134
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de Voogd LD, Fernández G, Hermans EJ. Disentangling the roles of arousal and amygdala activation in emotional declarative memory. Soc Cogn Affect Neurosci 2016; 11:1471-80. [PMID: 27217115 PMCID: PMC5015804 DOI: 10.1093/scan/nsw055] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 02/26/2016] [Accepted: 04/18/2016] [Indexed: 01/27/2023] Open
Abstract
A large body of evidence in animals and humans implicates the amygdala in promoting memory for arousing experiences. Although the amygdala can trigger threat-related noradrenergic-sympathetic arousal, in humans amygdala activation and noradrenergic-sympathetic arousal do not always concur. This raises the question how these two processes play a role in enhancing emotional declarative memory. This study was designed to disentangle these processes in a combined subsequent-memory/fear-conditioning paradigm with neutral items belonging to two conceptual categories as conditioned stimuli. Functional MRI, skin conductance (index of sympathetic activity), and pupil dilation (indirect index of central noradrenergic activity) were acquired throughout procedures. Recognition memory for individual items was tested 24 h later. We found that pupil dilation and skin conductance responses were higher on CS+ (associated with a shock) compared with CS- trials, irrespective of later memory for those items. By contrast, amygdala activity was only higher for CS+ items that were later confidently remembered compared with CS+ items that were later forgotten. Thus, amygdala activity and not noradrenergic-sympathetic arousal, predicted enhanced declarative item memory. This dissociation is in line with animal models stating that the amygdala integrates arousal-related neuromodulatory changes to alter mnemonic processes elsewhere in the brain.
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Affiliation(s)
- Lycia D de Voogd
- Donders Institute for Brain, Cognition and Behaviour Department for Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Guillén Fernández
- Donders Institute for Brain, Cognition and Behaviour Department for Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Erno J Hermans
- Donders Institute for Brain, Cognition and Behaviour Department for Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, The Netherlands
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135
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Vogel S, Schwabe L. Stress in the zoo: Tracking the impact of stress on memory formation over time. Psychoneuroendocrinology 2016; 71:64-72. [PMID: 27240149 DOI: 10.1016/j.psyneuen.2016.04.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 04/28/2016] [Accepted: 04/28/2016] [Indexed: 12/17/2022]
Abstract
Although stress is well known to modulate human memory, precisely how memory formation is altered by a stressful encounter remains unclear. Stress effects on cognition are mainly mediated by the rapidly acting sympathetic nervous system, resulting in the release of catecholamines, and the slower acting hypothalamus-pituitary-adrenal axis secreting cortisol, which induces its effects on cognition through fast, non-genomic actions and delayed, genomic actions. Importantly, these different waves of the physiological stress response are thought to dynamically alter neural processing in brain regions important for memory such as the amygdala and the hippocampus. However, the precise time course of stress effects on memory formation is still unclear. To track the development of stress effects on memory over time, we tested individuals who underwent a stressful experience or a control procedure before a 2-h walk through a zoo, while an automatic camera continuously photographed the events they encoded. In a recognition memory test one week later, participants were presented with target photographs of their own zoo tour and lure photographs from an alternate tour. Stressed participants showed better memory for the experimental treatment than control participants, and this memory enhancement for the stressful encounter itself was directly linked to the sympathetic stress response. Moreover, stress enhanced memory for events encoded 41-65min after stressor onset, which was associated with the cortisol stress response, most likely arising from non-genomic cortisol actions. However, memory for events encoded long after the stressor, when genomic cortisol actions had most likely developed, remained unchanged. Our findings provide novel insights into how stress effects on memory formation develop over time, depending on the activity of major physiological stress response systems.
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Affiliation(s)
- Susanne Vogel
- Department of Cognitive Psychology, Institute of Psychology, University of Hamburg, Von-Melle-Park 5, 20146 Hamburg, Germany.
| | - Lars Schwabe
- Department of Cognitive Psychology, Institute of Psychology, University of Hamburg, Von-Melle-Park 5, 20146 Hamburg, Germany.
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136
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Urbain C, De Tiège X, Op De Beeck M, Bourguignon M, Wens V, Verheulpen D, Van Bogaert P, Peigneux P. Sleep in children triggers rapid reorganization of memory-related brain processes. Neuroimage 2016; 134:213-222. [DOI: 10.1016/j.neuroimage.2016.03.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 03/21/2016] [Indexed: 10/22/2022] Open
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137
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Rissman J, Chow TE, Reggente N, Wagner AD. Decoding fMRI Signatures of Real-world Autobiographical Memory Retrieval. J Cogn Neurosci 2016; 28:604-20. [DOI: 10.1162/jocn_a_00920] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Abstract
Extant neuroimaging data implicate frontoparietal and medial-temporal lobe regions in episodic retrieval, and the specific pattern of activity within and across these regions is diagnostic of an individual's subjective mnemonic experience. For example, in laboratory-based paradigms, memories for recently encoded faces can be accurately decoded from single-trial fMRI patterns [Uncapher, M. R., Boyd-Meredith, J. T., Chow, T. E., Rissman, J., & Wagner, A. D. Goal-directed modulation of neural memory patterns: Implications for fMRI-based memory detection. Journal of Neuroscience, 35, 8531–8545, 2015; Rissman, J., Greely, H. T., & Wagner, A. D. Detecting individual memories through the neural decoding of memory states and past experience. Proceedings of the National Academy of Sciences, U.S.A., 107, 9849–9854, 2010]. Here, we investigated the neural patterns underlying memory for real-world autobiographical events, probed at 1- to 3-week retention intervals as well as whether distinct patterns are associated with different subjective memory states. For 3 weeks, participants (n = 16) wore digital cameras that captured photographs of their daily activities. One week later, they were scanned while making memory judgments about sequences of photos depicting events from their own lives or events captured by the cameras of others. Whole-brain multivoxel pattern analysis achieved near-perfect accuracy at distinguishing correctly recognized events from correctly rejected novel events, and decoding performance did not significantly vary with retention interval. Multivoxel pattern classifiers also differentiated recollection from familiarity and reliably decoded the subjective strength of recollection, of familiarity, or of novelty. Classification-based brain maps revealed dissociable neural signatures of these mnemonic states, with activity patterns in hippocampus, medial PFC, and ventral parietal cortex being particularly diagnostic of recollection. Finally, a classifier trained on previously acquired laboratory-based memory data achieved reliable decoding of autobiographical memory states. We discuss the implications for neuroscientific accounts of episodic retrieval and comment on the potential forensic use of fMRI for probing experiential knowledge.
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138
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Baran B, Mantua J, Spencer RMC. Age-related Changes in the Sleep-dependent Reorganization of Declarative Memories. J Cogn Neurosci 2016; 28:792-802. [PMID: 26918588 DOI: 10.1162/jocn_a_00938] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Consolidation of declarative memories has been associated with slow wave sleep in young adults. Previous work suggests that, in spite of changes in sleep, sleep-dependent consolidation of declarative memories may be preserved with aging, although reduced relative to young adults. Previous work on young adults shows that, with consolidation, retrieval of declarative memories gradually becomes independent of the hippocampus. To investigate whether memories are similarly reorganized over sleep at the neural level, we compared functional brain activation associated with word pair recall following a nap and equivalent wake in young and older adults. SWS during the nap predicted better subsequent memory recall and was negatively associated with retrieval-related hippocampal activation in young adults. In contrast, in older adults there was no relationship between sleep and memory performance or with retrieval-related hippocampal activation. Furthermore, compared with young adults, postnap memory retrieval in older adults required strong functional connectivity of the hippocampus with the PFC, whereas there were no differences between young and older adults in the functional connectivity of the hippocampus following wakefulness. These results suggest that, although neural reorganization takes place over sleep in older adults, the shift is unique from that seen in young adults, perhaps reflecting memories at an earlier stage of stabilization.
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139
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Sommer T. The Emergence of Knowledge and How it Supports the Memory for Novel Related Information. Cereb Cortex 2016; 27:1906-1921. [DOI: 10.1093/cercor/bhw031] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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140
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Taylor CJ, Ohline SM, Moss T, Ulrich K, Abraham WC. The persistence of long-term potentiation in the projection from ventral hippocampus to medial prefrontal cortex in awake rats. Eur J Neurosci 2016; 43:811-22. [PMID: 26750170 DOI: 10.1111/ejn.13167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 12/07/2015] [Accepted: 12/22/2015] [Indexed: 12/12/2022]
Abstract
A potentially vital pathway in the processing of spatial memory is the pathway from ventral hippocampus to medial prefrontal cortex (vHPC-mPFC). To assess long-term potentiation (LTP) induction and maintenance across days in this pathway, the effects of several induction paradigms were compared in awake, freely moving rats. Two different high-frequency stimulation (HFS) protocols generated LTP lasting no longer than 1 week. However, after delivering HFS on three consecutive days, LTP lasted an average of 20 days, due mainly to the greater initial induction. Thus the pathway does not require extensive multi-day stimulation to induce LTP, as for other intra-neocortical pathways, but also it does not exhibit the extremely long-lasting and stable LTP previously observed in area CA1 and the dentate gyrus. By using bilaterally placed stimulating and recording electrodes, we found that HFS in one vHPC generated responses and LTP in the contralateral mPFC, even when the ipsilateral mPFC was inactivated by CNQX. We attribute this crossed response to a polysynaptic pathway from the vHPC to the contralateral mPFC. Finally, we found that repeated overnight exposure to an enriched environment also potentiated the vHPC-mPFC response, but this too was a transient effect lasting < 9 days, declining to baseline even before the enriched environment treatment was completed. Overall, these findings are consistent with the view that potentiation of vHPC-mPFC pathway may play a key role in promoting the hippocampus-mPFC interplay that, over days, leads to long-term storage in the frontal cortex of memories that are independent of the hippocampus.
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Affiliation(s)
- Chanel J Taylor
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Shane M Ohline
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Research New Zealand, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Timothy Moss
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Katharina Ulrich
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Research New Zealand, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
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141
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Malle C, Eustache F, Rauchs G. [The role of sleep in memory consolidation: effects of age and Alzheimer's disease]. Biol Aujourdhui 2016; 209:261-272. [PMID: 26820832 DOI: 10.1051/jbio/2015024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Indexed: 06/05/2023]
Abstract
Sleep favors memory consolidation. Studies conducted in recent years allowed to reveal the neurobiological underpinnings underlying the beneficial effect of sleep on memory. They also have led to the proposal of two theoretical models: the "hippocampo-neocortical dialogue" and the "synaptic downscaling hypothesis". Normal ageing and, even more markedly Alzheimer's disease, are associated with sleep changes that may alter sleep-dependent memory consolidation. This paper presents a review of studies investigating the relationships between sleep and memory and how these links are affected by ageing and Alzheimer's disease.
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Affiliation(s)
- Carine Malle
- Inserm U1077, GIP Cyceron, Bd Becquerel, BP 5229, 14074 Caen Cedex 5, France - Université de Caen Normandie, UMR-S1077, Caen, France - École Pratique des Hautes Études, UMR-S1077, Caen, France - CHU de Caen, U1077, Caen, France
| | - Francis Eustache
- Inserm U1077, GIP Cyceron, Bd Becquerel, BP 5229, 14074 Caen Cedex 5, France - Université de Caen Normandie, UMR-S1077, Caen, France - École Pratique des Hautes Études, UMR-S1077, Caen, France - CHU de Caen, U1077, Caen, France
| | - Géraldine Rauchs
- Inserm U1077, GIP Cyceron, Bd Becquerel, BP 5229, 14074 Caen Cedex 5, France - Université de Caen Normandie, UMR-S1077, Caen, France - École Pratique des Hautes Études, UMR-S1077, Caen, France - CHU de Caen, U1077, Caen, France
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142
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Carcaud J, Giurfa M, Sandoz JC. Parallel Olfactory Processing in the Honey Bee Brain: Odor Learning and Generalization under Selective Lesion of a Projection Neuron Tract. Front Integr Neurosci 2016; 9:75. [PMID: 26834589 PMCID: PMC4717326 DOI: 10.3389/fnint.2015.00075] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/22/2015] [Indexed: 11/30/2022] Open
Abstract
The function of parallel neural processing is a fundamental problem in Neuroscience, as it is found across sensory modalities and evolutionary lineages, from insects to humans. Recently, parallel processing has attracted increased attention in the olfactory domain, with the demonstration in both insects and mammals that different populations of second-order neurons encode and/or process odorant information differently. Among insects, Hymenoptera present a striking olfactory system with a clear neural dichotomy from the periphery to higher-order centers, based on two main tracts of second-order (projection) neurons: the medial and lateral antennal lobe tracts (m-ALT and l-ALT). To unravel the functional role of these two pathways, we combined specific lesions of the m-ALT tract with behavioral experiments, using the classical conditioning of the proboscis extension response (PER conditioning). Lesioned and intact bees had to learn to associate an odorant (1-nonanol) with sucrose. Then the bees were subjected to a generalization procedure with a range of odorants differing in terms of their carbon chain length or functional group. We show that m-ALT lesion strongly affects acquisition of an odor-sucrose association. However, lesioned bees that still learned the association showed a normal gradient of decreasing generalization responses to increasingly dissimilar odorants. Generalization responses could be predicted to some extent by in vivo calcium imaging recordings of l-ALT neurons. The m-ALT pathway therefore seems necessary for normal classical olfactory conditioning performance.
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Affiliation(s)
- Julie Carcaud
- Evolution, Genomes, Behavior and Ecology, Centre National de la Recherche Scientifique, Univ Paris-Sud, IRD, Université Paris-SaclayGif-sur-Yvette, France; Research Center on Animal Cognition, Université Toulouse III - Paul SabatierToulouse, France; Research Center on Animal Cognition, Centre National de la Recherche ScientifiqueToulouse, France
| | - Martin Giurfa
- Research Center on Animal Cognition, Université Toulouse III - Paul SabatierToulouse, France; Research Center on Animal Cognition, Centre National de la Recherche ScientifiqueToulouse, France
| | - Jean Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, Centre National de la Recherche Scientifique, Univ Paris-Sud, IRD, Université Paris-Saclay Gif-sur-Yvette, France
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143
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Dede AJO, Smith CN. The Functional and Structural Neuroanatomy of Systems Consolidation for Autobiographical and Semantic Memory. Curr Top Behav Neurosci 2016; 37:119-150. [PMID: 27677778 DOI: 10.1007/7854_2016_452] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It is well established that patients with memory impairment have more difficulty retrieving memories from the recent past relative to the remote past and that damage to the medial temporal lobe (MTL) plays a key role in this pattern of impairment. The precise role of the MTL and how it may interact with other brain regions remains an area of active research. We investigated the role of structures in a memory network that supports remembering. Our chapter focuses on two types of memory: episodic memory and semantic memory. Findings from studies of patients with brain damage and neuroimaging studies in patients and healthy individuals were considered together to identify the functional and structural neuroanatomy of past remembrance.
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Affiliation(s)
- Adam J O Dede
- Department of Psychology, University of California San Diego, San Diego, CA, 92093, USA
- Veteran Affairs San Diego Healthcare System, 3350 La Jolla Village Drive (116A), San Diego, CA, 92161, USA
| | - Christine N Smith
- Department of Psychiatry, University of California San Diego, San Diego, CA, 92093, USA.
- Veteran Affairs San Diego Healthcare System, 3350 La Jolla Village Drive (116A), San Diego, CA, 92161, USA.
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144
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Bakker I, Takashima A, van Hell JG, Janzen G, McQueen JM. Tracking lexical consolidation with ERPs: Lexical and semantic-priming effects on N400 and LPC responses to newly-learned words. Neuropsychologia 2015; 79:33-41. [DOI: 10.1016/j.neuropsychologia.2015.10.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 07/29/2015] [Accepted: 10/12/2015] [Indexed: 11/30/2022]
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145
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Wagner IC, van Buuren M, Kroes MCW, Gutteling TP, van der Linden M, Morris RG, Fernández G. Schematic memory components converge within angular gyrus during retrieval. eLife 2015; 4:e09668. [PMID: 26575291 PMCID: PMC4709269 DOI: 10.7554/elife.09668] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 11/16/2015] [Indexed: 11/13/2022] Open
Abstract
Mental schemas form associative knowledge structures that can promote the encoding and consolidation of new and related information. Schemas are facilitated by a distributed system that stores components separately, presumably in the form of inter-connected neocortical representations. During retrieval, these components need to be recombined into one representation, but where exactly such recombination takes place is unclear. Thus, we asked where different schema components are neuronally represented and converge during retrieval. Subjects acquired and retrieved two well-controlled, rule-based schema structures during fMRI on consecutive days. Schema retrieval was associated with midline, medial-temporal, and parietal processing. We identified the multi-voxel representations of different schema components, which converged within the angular gyrus during retrieval. Critically, convergence only happened after 24-hour-consolidation and during a transfer test where schema material was applied to novel but related trials. Therefore, the angular gyrus appears to recombine consolidated schema components into one memory representation. DOI:http://dx.doi.org/10.7554/eLife.09668.001 To make sense of the world around us, we constantly try to work out the relationship of new information to other things that we already know, and sort our knowledge into pre-existing mental frameworks, or “schemas”. This makes learning new things that are related to a schema, as well as remembering this knowledge, easier. The process of making these mental connections is thought to involve an extensive brain network. Separate types of information are stored in different brain regions within this network, yet to link this information together, the brain must combine them into a single representation. Wagner et al. have now investigated which brain regions are involved in recombining separate information. Human volunteers were trained to interpret the positions or colors of pairs of circles with different rules. The combination of these separate types of information formed a mental schema that could be used as a “weather forecast”. The design of the experiment meant that measuring the brain activity of the volunteers during the task (using a technique called functional magnetic resonance imaging) allowed the brain regions involved in retrieving the different parts of such a schema to be distinguished. Twenty-four hours later volunteers returned to use the mental schemas that they had learned to predict the weather. Retrieving which weather conditions the circle pairs represented activated a network of regions in the volunteers’ brains. Further analysis revealed that some of these regions showed specific activity patterns in response to remembering information about only one element of the task (for example, only the rules or only the visual information). However, the different aspects of the task all appeared to be integrated by a brain region called the angular gyrus. This suggests that the angular gyrus is responsible for combining separate memory parts and pieces of information into a single representation. It is able to do so by connecting to brain regions that code for such specific aspects, although this only occurs 24 hours after the mental schemas have been established. Future studies could investigate the result of damage to the angular gyrus: different pieces of information might not be combined, or could result in an incorrect memory during retrieval. Finally, since the angular gyrus has been related to a wealth of different mental processes, it remains a challenge for future research to "converge" these findings and to understand the underlying computations. DOI:http://dx.doi.org/10.7554/eLife.09668.002
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Affiliation(s)
- Isabella C Wagner
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Mariët van Buuren
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
| | - Marijn C W Kroes
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands.,Center for Neural Science, New York University, New York, United States.,Department of Psychology, New York University, New York, United States
| | - Tjerk P Gutteling
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Marieke van der Linden
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
| | - Richard G Morris
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, United Kingdom
| | - Guillén Fernández
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
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146
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Mitra A, Snyder AZ, Tagliazucchi E, Laufs H, Raichle ME. Propagated infra-slow intrinsic brain activity reorganizes across wake and slow wave sleep. eLife 2015; 4:e10781. [PMID: 26551562 PMCID: PMC4737658 DOI: 10.7554/elife.10781] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/06/2015] [Indexed: 12/14/2022] Open
Abstract
Propagation of slow intrinsic brain activity has been widely observed in electrophysiogical studies of slow wave sleep (SWS). However, in human resting state fMRI (rs-fMRI), intrinsic activity has been understood predominantly in terms of zero-lag temporal synchrony (functional connectivity) within systems known as resting state networks (RSNs). Prior rs-fMRI studies have found that RSNs are generally preserved across wake and sleep. Here, we use a recently developed analysis technique to study propagation of infra-slow intrinsic blood oxygen level dependent (BOLD) signals in normal adults during wake and SWS. This analysis reveals marked changes in propagation patterns in SWS vs. wake. Broadly, ordered propagation is preserved within traditionally defined RSNs but lost between RSNs. Additionally, propagation between cerebral cortex and subcortical structures reverses directions, and intra-cortical propagation becomes reorganized, especially in visual and sensorimotor cortices. These findings show that propagated rs-fMRI activity informs theoretical accounts of the neural functions of sleep.
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Affiliation(s)
- Anish Mitra
- Department of Radiology, Washington University in St. Louis, St. Louis, United States
| | - Abraham Z Snyder
- Department of Radiology, Washington University in St. Louis, St. Louis, United States
- Department of Neurology, Washington University in St. Louis, St. Louis, United States
| | - Enzo Tagliazucchi
- Institute for Medical Psychology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Department of Neurology, Brain Imaging Center, Goethe-Universität Frankfurt am Main, Frankfurt, Germany
| | - Helmut Laufs
- Department of Neurology, Brain Imaging Center, Goethe-Universität Frankfurt am Main, Frankfurt, Germany
- Department of Neurology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Marcus E Raichle
- Department of Radiology, Washington University in St. Louis, St. Louis, United States
- Department of Neurology, Washington University in St. Louis, St. Louis, United States
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147
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Tsivilis D, Allan K, Roberts J, Williams N, Downes JJ, El-Deredy W. Old-new ERP effects and remote memories: the late parietal effect is absent as recollection fails whereas the early mid-frontal effect persists as familiarity is retained. Front Hum Neurosci 2015; 9:532. [PMID: 26528163 PMCID: PMC4604239 DOI: 10.3389/fnhum.2015.00532] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 09/14/2015] [Indexed: 01/09/2023] Open
Abstract
Understanding the electrophysiological correlates of recognition memory processes has been a focus of research in recent years. This study investigated the effects of retention interval on recognition memory by comparing memory for objects encoded four weeks (remote) or 5 min (recent) before testing. In Experiment 1, event related potentials (ERPs) were acquired while participants performed a yes-no recognition memory task involving remote, recent and novel objects. Relative to correctly rejected new items, remote and recent hits showed an attenuated frontal negativity from 300–500 ms post-stimulus. This effect, also known as the FN400, has been previously associated with familiarity memory. Recent and remote recognition ERPs did not differ from each other at this time-window. By contrast, recent but not remote recognition showed increased parietal positivity from around 500 ms post-stimulus. This late parietal effect (LPE), which is considered a correlate of recollection-related processes, also discriminated between recent and remote memories. A second, behavioral experiment confirmed that remote memories unlike recent memories were based almost exclusively on familiarity. These findings support the idea that the FN400 and LPE are indices of familiarity and recollection memory, respectively and show that remote and recent memories are functionally and anatomically distinct.
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Affiliation(s)
| | - Kevin Allan
- School of Psychology, University of Aberdeen Aberdeen, UK
| | - Jenna Roberts
- School of Psychological Sciences, University of Manchester Manchester, UK
| | | | | | - Wael El-Deredy
- School of Psychological Sciences, University of Manchester Manchester, UK ; School of Biomedical Engineering, University of Valparaiso Valparaiso, Chile
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149
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Buzsáki G. Hippocampal sharp wave-ripple: A cognitive biomarker for episodic memory and planning. Hippocampus 2015; 25:1073-188. [PMID: 26135716 PMCID: PMC4648295 DOI: 10.1002/hipo.22488] [Citation(s) in RCA: 905] [Impact Index Per Article: 100.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 06/30/2015] [Indexed: 12/23/2022]
Abstract
Sharp wave ripples (SPW-Rs) represent the most synchronous population pattern in the mammalian brain. Their excitatory output affects a wide area of the cortex and several subcortical nuclei. SPW-Rs occur during "off-line" states of the brain, associated with consummatory behaviors and non-REM sleep, and are influenced by numerous neurotransmitters and neuromodulators. They arise from the excitatory recurrent system of the CA3 region and the SPW-induced excitation brings about a fast network oscillation (ripple) in CA1. The spike content of SPW-Rs is temporally and spatially coordinated by a consortium of interneurons to replay fragments of waking neuronal sequences in a compressed format. SPW-Rs assist in transferring this compressed hippocampal representation to distributed circuits to support memory consolidation; selective disruption of SPW-Rs interferes with memory. Recently acquired and pre-existing information are combined during SPW-R replay to influence decisions, plan actions and, potentially, allow for creative thoughts. In addition to the widely studied contribution to memory, SPW-Rs may also affect endocrine function via activation of hypothalamic circuits. Alteration of the physiological mechanisms supporting SPW-Rs leads to their pathological conversion, "p-ripples," which are a marker of epileptogenic tissue and can be observed in rodent models of schizophrenia and Alzheimer's Disease. Mechanisms for SPW-R genesis and function are discussed in this review.
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Affiliation(s)
- György Buzsáki
- The Neuroscience Institute, School of Medicine and Center for Neural Science, New York University, New York, New York
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150
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Thielen JW, Takashima A, Rutters F, Tendolkar I, Fernández G. Transient relay function of midline thalamic nuclei during long-term memory consolidation in humans. ACTA ACUST UNITED AC 2015; 22:527-31. [PMID: 26373833 PMCID: PMC4579360 DOI: 10.1101/lm.038372.115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 06/22/2015] [Indexed: 11/24/2022]
Abstract
To test the hypothesis that thalamic midline nuclei play a transient role in memory consolidation, we reanalyzed a prospective functional MRI study, contrasting recent and progressively more remote memory retrieval. We revealed a transient thalamic connectivity increase with the hippocampus, the medial prefrontal cortex (mPFC), and a parahippocampal area, which decreased with time. In turn, mPFC-parahippocampal connectivity increased progressively. These findings support a model in which thalamic midline nuclei serve as a hub linking hippocampus, mPFC, and posterior representational areas during memory retrieval at an early (2 h) stage of consolidation, extending classical systems consolidation models by attributing a transient role to midline thalamic nuclei.
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Affiliation(s)
- Jan-Willem Thielen
- Donders Institute for Brain Cognition and Behavior, Radboud University Medical Center, 6537 Nijmegen, The Netherlands Department for Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, 45127 Essen, Germany Erwin L. Hahn Institute for Magnetic Resonance Imaging, 45127 Essen, Germany
| | - Atsuko Takashima
- Donders Institute for Brain Cognition and Behavior, Radboud University Medical Center, 6537 Nijmegen, The Netherlands Behavioural Science Institute, Radboud University, 6537 Nijmegen, The Netherlands
| | - Femke Rutters
- Department of Epidemiology and Biostatistics, VU University Medical Center, 1081 Amsterdam, The Netherlands
| | - Indira Tendolkar
- Donders Institute for Brain Cognition and Behavior, Radboud University Medical Center, 6537 Nijmegen, The Netherlands Department for Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, 45127 Essen, Germany Department of Psychiatry, Radboud University Medical Center, 6537 Nijmegen, The Netherlands
| | - Guillén Fernández
- Donders Institute for Brain Cognition and Behavior, Radboud University Medical Center, 6537 Nijmegen, The Netherlands Department of Cognitive Neuroscience, Radboud University Medical Center, 6537 Nijmegen, The Netherlands
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