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Dubinsky JM, Hamid AA. The neuroscience of active learning and direct instruction. Neurosci Biobehav Rev 2024; 163:105737. [PMID: 38796122 DOI: 10.1016/j.neubiorev.2024.105737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/13/2024] [Accepted: 05/20/2024] [Indexed: 05/28/2024]
Abstract
Throughout the educational system, students experiencing active learning pedagogy perform better and fail less than those taught through direct instruction. Can this be ascribed to differences in learning from a neuroscientific perspective? This review examines mechanistic, neuroscientific evidence that might explain differences in cognitive engagement contributing to learning outcomes between these instructional approaches. In classrooms, direct instruction comprehensively describes academic content, while active learning provides structured opportunities for learners to explore, apply, and manipulate content. Synaptic plasticity and its modulation by arousal or novelty are central to all learning and both approaches. As a form of social learning, direct instruction relies upon working memory. The reinforcement learning circuit, associated agency, curiosity, and peer-to-peer social interactions combine to enhance motivation, improve retention, and build higher-order-thinking skills in active learning environments. When working memory becomes overwhelmed, additionally engaging the reinforcement learning circuit improves retention, providing an explanation for the benefits of active learning. This analysis provides a mechanistic examination of how emerging neuroscience principles might inform pedagogical choices at all educational levels.
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Affiliation(s)
- Janet M Dubinsky
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA.
| | - Arif A Hamid
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
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2
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Savelli F. Spontaneous Dynamics of Hippocampal Place Fields in a Model of Combinatorial Competition among Stable Inputs. J Neurosci 2024; 44:e1663232024. [PMID: 38316560 PMCID: PMC10977031 DOI: 10.1523/jneurosci.1663-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 01/16/2024] [Accepted: 01/21/2024] [Indexed: 02/07/2024] Open
Abstract
We present computer simulations illustrating how the plastic integration of spatially stable inputs could contribute to the dynamic character of hippocampal spatial representations. In novel environments of slightly larger size than typical apparatus, the emergence of well-defined place fields in real place cells seems to rely on inputs from normally functioning grid cells. Theoretically, the grid-to-place transformation is possible if a place cell is able to respond selectively to a combination of suitably aligned grids. We previously identified the functional characteristics that allow a synaptic plasticity rule to accomplish this selection by synaptic competition during rat foraging behavior. Here, we show that the synaptic competition can outlast the formation of place fields, contributing to their spatial reorganization over time, when the model is run in larger environments and the topographical/modular organization of grid inputs is taken into account. Co-simulated cells that differ only by their randomly assigned grid inputs display different degrees and kinds of spatial reorganization-ranging from place-field remapping to more subtle in-field changes or lapses in firing. The model predicts a greater number of place fields and propensity for remapping in place cells recorded from more septal regions of the hippocampus and/or in larger environments, motivating future experimental standardization across studies and animal models. In sum, spontaneous remapping could arise from rapid synaptic learning involving inputs that are functionally homogeneous, spatially stable, and minimally stochastic.
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Affiliation(s)
- Francesco Savelli
- Department of Neuroscience, Developmental and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
- Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas 78249
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, Texas 78249
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3
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Krasne FB, Fanselow MS. Remote memory in a Bayesian model of context fear conditioning (BaconREM). Front Behav Neurosci 2024; 17:1295969. [PMID: 38515786 PMCID: PMC10955142 DOI: 10.3389/fnbeh.2023.1295969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 12/13/2023] [Indexed: 03/23/2024] Open
Abstract
Here, we propose a model of remote memory (BaconREM), which is an extension of a previously published Bayesian model of context fear learning (BACON) that accounts for many aspects of recently learned context fear. BaconREM simulates most known phenomenology of remote context fear as studied in rodents and makes new predictions. In particular, it predicts the well-known observation that fear that was conditioned to a recently encoded context becomes hippocampus-independent and shows much-enhanced generalization ("hyper-generalization") when systems consolidation occurs (i.e., when memory becomes remote). However, the model also predicts that there should be circumstances under which the generalizability of remote fear may not increase or even decrease. It also predicts the established finding that a "reminder" exposure to a feared context can abolish hyper-generalization while at the same time making remote fear again hippocampus-dependent. This observation has in the past been taken to suggest that reminders facilitate access to detail memory that remains permanently in the hippocampus even after systems consolidation is complete. However, the present model simulates this result even though it totally moves all the contextual memory that it retains to the neo-cortex when context fear becomes remote.
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Affiliation(s)
- Franklin B. Krasne
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Michael S. Fanselow
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
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4
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Bein O, Davachi L. Event Integration and Temporal Differentiation: How Hierarchical Knowledge Emerges in Hippocampal Subfields through Learning. J Neurosci 2024; 44:e0627232023. [PMID: 38129134 PMCID: PMC10919070 DOI: 10.1523/jneurosci.0627-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 11/10/2023] [Accepted: 11/16/2023] [Indexed: 12/23/2023] Open
Abstract
Everyday life is composed of events organized by changes in contexts, with each event containing an unfolding sequence of occurrences. A major challenge facing our memory systems is how to integrate sequential occurrences within events while also maintaining their details and avoiding over-integration across different contexts. We asked if and how distinct hippocampal subfields come to hierarchically and, in parallel, represent both event context and subevent occurrences with learning. Female and male human participants viewed sequential events defined as sequences of objects superimposed on shared color frames while undergoing high-resolution fMRI. Importantly, these events were repeated to induce learning. Event segmentation, as indexed by increased reaction times at event boundaries, was observed in all repetitions. Temporal memory decisions were quicker for items from the same event compared to across different events, indicating that events shaped memory. With learning, hippocampal CA3 multivoxel activation patterns clustered to reflect the event context, with more clustering correlated with behavioral facilitation during event transitions. In contrast, in the dentate gyrus (DG), temporally proximal items that belonged to the same event became associated with more differentiated neural patterns. A computational model explained these results by dynamic inhibition in the DG. Additional similarity measures support the notion that CA3 clustered representations reflect shared voxel populations, while DG's distinct item representations reflect different voxel populations. These findings suggest an interplay between temporal differentiation in the DG and attractor dynamics in CA3. They advance our understanding of how knowledge is structured through integration and separation across time and context.
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Affiliation(s)
- Oded Bein
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey 08540
| | - Lila Davachi
- Department of Psychology, Columbia University, New York, New York 10027
- Center for Clinical Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962
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5
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Spens E, Burgess N. A generative model of memory construction and consolidation. Nat Hum Behav 2024; 8:526-543. [PMID: 38242925 PMCID: PMC10963272 DOI: 10.1038/s41562-023-01799-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 12/05/2023] [Indexed: 01/21/2024]
Abstract
Episodic memories are (re)constructed, share neural substrates with imagination, combine unique features with schema-based predictions and show schema-based distortions that increase with consolidation. Here we present a computational model in which hippocampal replay (from an autoassociative network) trains generative models (variational autoencoders) to (re)create sensory experiences from latent variable representations in entorhinal, medial prefrontal and anterolateral temporal cortices via the hippocampal formation. Simulations show effects of memory age and hippocampal lesions in agreement with previous models, but also provide mechanisms for semantic memory, imagination, episodic future thinking, relational inference and schema-based distortions including boundary extension. The model explains how unique sensory and predictable conceptual elements of memories are stored and reconstructed by efficiently combining both hippocampal and neocortical systems, optimizing the use of limited hippocampal storage for new and unusual information. Overall, we believe hippocampal replay training generative models provides a comprehensive account of memory construction, imagination and consolidation.
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Affiliation(s)
- Eleanor Spens
- UCL Institute of Cognitive Neuroscience, University College London, London, UK.
| | - Neil Burgess
- UCL Institute of Cognitive Neuroscience, University College London, London, UK.
- UCL Queen Square Institute of Neurology, University College London, London, UK.
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6
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Király B, Domonkos A, Jelitai M, Lopes-Dos-Santos V, Martínez-Bellver S, Kocsis B, Schlingloff D, Joshi A, Salib M, Fiáth R, Barthó P, Ulbert I, Freund TF, Viney TJ, Dupret D, Varga V, Hangya B. The medial septum controls hippocampal supra-theta oscillations. Nat Commun 2023; 14:6159. [PMID: 37816713 PMCID: PMC10564782 DOI: 10.1038/s41467-023-41746-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/15/2023] [Indexed: 10/12/2023] Open
Abstract
Hippocampal theta oscillations orchestrate faster beta-to-gamma oscillations facilitating the segmentation of neural representations during navigation and episodic memory. Supra-theta rhythms of hippocampal CA1 are coordinated by local interactions as well as inputs from the entorhinal cortex (EC) and CA3 inputs. However, theta-nested gamma-band activity in the medial septum (MS) suggests that the MS may control supra-theta CA1 oscillations. To address this, we performed multi-electrode recordings of MS and CA1 activity in rodents and found that MS neuron firing showed strong phase-coupling to theta-nested supra-theta episodes and predicted changes in CA1 beta-to-gamma oscillations on a cycle-by-cycle basis. Unique coupling patterns of anatomically defined MS cell types suggested that indirect MS-to-CA1 pathways via the EC and CA3 mediate distinct CA1 gamma-band oscillations. Optogenetic activation of MS parvalbumin-expressing neurons elicited theta-nested beta-to-gamma oscillations in CA1. Thus, the MS orchestrates hippocampal network activity at multiple temporal scales to mediate memory encoding and retrieval.
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Affiliation(s)
- Bálint Király
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary
- Department of Biological Physics, Institute of Physics, Eötvös Loránd University, Budapest, Hungary
| | - Andor Domonkos
- Subcortical Modulation Research Group, Institute of Experimental Medicine, Budapest, Hungary
| | - Márta Jelitai
- Subcortical Modulation Research Group, Institute of Experimental Medicine, Budapest, Hungary
| | - Vítor Lopes-Dos-Santos
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sergio Martínez-Bellver
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary
- Department of Anatomy and Human Embryology, Faculty of Medicine and Odontology, University of Valencia, Valencia, Spain
| | - Barnabás Kocsis
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Dániel Schlingloff
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary
| | - Abhilasha Joshi
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Minas Salib
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Richárd Fiáth
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Péter Barthó
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
| | - István Ulbert
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Tamás F Freund
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Tim J Viney
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - David Dupret
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Viktor Varga
- Subcortical Modulation Research Group, Institute of Experimental Medicine, Budapest, Hungary
| | - Balázs Hangya
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, Hungary.
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7
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Bein O, Gasser C, Amer T, Maril A, Davachi L. Predictions transform memories: How expected versus unexpected events are integrated or separated in memory. Neurosci Biobehav Rev 2023; 153:105368. [PMID: 37619645 PMCID: PMC10591973 DOI: 10.1016/j.neubiorev.2023.105368] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 08/13/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
Our brains constantly generate predictions about the environment based on prior knowledge. Many of the events we experience are consistent with these predictions, while others might be inconsistent with prior knowledge and thus violate our predictions. To guide future behavior, the memory system must be able to strengthen, transform, or add to existing knowledge based on the accuracy of our predictions. We synthesize recent evidence suggesting that when an event is consistent with our predictions, it leads to neural integration between related memories, which is associated with enhanced associative memory, as well as memory biases. Prediction errors, in turn, can promote both neural integration and separation, and lead to multiple mnemonic outcomes. We review these findings and how they interact with factors such as memory reactivation, prediction error strength, and task goals, to offer insight into what determines memory for events that violate our predictions. In doing so, this review brings together recent neural and behavioral research to advance our understanding of how predictions shape memory, and why.
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Affiliation(s)
- Oded Bein
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, United States.
| | - Camille Gasser
- Department of Psychology, Columbia University, New York, NY, United States.
| | - Tarek Amer
- Department of Psychology, University of Victoria, Victoria, Canada
| | - Anat Maril
- Department of Psychology, The Hebrew University of Jerusalem, Jerusalem, Israel; Department of Cognitive Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lila Davachi
- Center for Clinical Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States
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8
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Savelli F. Spontaneous dynamics of hippocampal place fields in a model of combinatorial competition among stable inputs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.04.556254. [PMID: 37732194 PMCID: PMC10508775 DOI: 10.1101/2023.09.04.556254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
We present computer simulations illustrating how the plastic integration of spatially stable inputs could contribute to the dynamic character of hippocampal spatial representations. In novel environments of slightly larger size than typical apparatus, the emergence of well-defined place fields in real place cells seems to rely on inputs from normally functioning grid cells. Theoretically, the grid-to-place transformation is possible if a place cell is able to respond selectively to a combination of suitably aligned grids. We previously identified the functional characteristics that allow a synaptic plasticity rule to accomplish this selection by synaptic competition during rat foraging behavior. Here, we show that the synaptic competition can outlast the formation of place fields, contributing to their spatial reorganization over time, when the model is run in larger environments and the topographical/modular organization of grid inputs is taken into account. Co-simulated cells that differ only by their randomly assigned grid inputs display different degrees and kinds of spatial reorganization-ranging from place-field remapping to more subtle in-field changes or lapses in firing. The model predicts a greater number of place fields and propensity for remapping in place cells recorded from more septal regions of the hippocampus and/or in larger environments, motivating future experimental standardization across studies and animal models. In sum, spontaneous remapping could arise from rapid synaptic learning involving inputs that are functionally homogeneous, spatially stable, and minimally stochastic. Significance Statement In both AI and theoretical neuroscience, learning systems often rely on the asymptotic convergence of slow-acting learning rules applied to input spaces that are presumed to be sampled repeatedly, for example over developmental timescales. Place cells of the hippocampus testify to a neural system capable of rapidly encoding cognitive variables-such as the animal's position in space-from limited experience. These internal representations undergo "spontaneous" changes over time, spurring much interest in their cognitive significance and underlying mechanisms. We investigate a model suggesting that some of these changes could be a tradeoff of rapid learning.
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Li YP, Wang Y, Turk-Browne NB, Kuhl BA, Hutchinson JB. Perception and memory retrieval states are reflected in distributed patterns of background functional connectivity. Neuroimage 2023; 276:120221. [PMID: 37290674 PMCID: PMC10484747 DOI: 10.1016/j.neuroimage.2023.120221] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/19/2023] [Accepted: 06/06/2023] [Indexed: 06/10/2023] Open
Abstract
The same visual input can serve as the target of perception or as a trigger for memory retrieval depending on whether cognitive processing is externally oriented (perception) or internally oriented (memory retrieval). While numerous human neuroimaging studies have characterized how visual stimuli are differentially processed during perception versus memory retrieval, perception and memory retrieval may also be associated with distinct neural states that are independent of stimulus-evoked neural activity. Here, we combined human fMRI with full correlation matrix analysis (FCMA) to reveal potential differences in "background" functional connectivity across perception and memory retrieval states. We found that perception and retrieval states could be discriminated with high accuracy based on patterns of connectivity across (1) the control network, (2) the default mode network (DMN), and (3) retrosplenial cortex (RSC). In particular, clusters in the control network increased connectivity with each other during the perception state, whereas clusters in the DMN were more strongly coupled during the retrieval state. Interestingly, RSC switched its coupling between networks as the cognitive state shifted from retrieval to perception. Finally, we show that background connectivity (1) was fully independent from stimulus-related variance in the signal and, further, (2) captured distinct aspects of cognitive states compared to traditional classification of stimulus-evoked responses. Together, our results reveal that perception and memory retrieval are associated with sustained cognitive states that manifest as distinct patterns of connectivity among large-scale brain networks.
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Affiliation(s)
- Y Peeta Li
- Department of Psychology, University of Oregon, Eugene, OR, United States.
| | - Yida Wang
- Amazon Web Services, Palo Alto, CA, United States
| | - Nicholas B Turk-Browne
- Department of Psychology, Yale University, New Haven, CT, United States; Wu Tsai Institute, Yale University, New Haven, CT, United States
| | - Brice A Kuhl
- Department of Psychology, University of Oregon, Eugene, OR, United States
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Kanagamani T, Chakravarthy VS, Ravindran B, Menon RN. A deep network-based model of hippocampal memory functions under normal and Alzheimer's disease conditions. Front Neural Circuits 2023; 17:1092933. [PMID: 37416627 PMCID: PMC10320296 DOI: 10.3389/fncir.2023.1092933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 06/02/2023] [Indexed: 07/08/2023] Open
Abstract
We present a deep network-based model of the associative memory functions of the hippocampus. The proposed network architecture has two key modules: (1) an autoencoder module which represents the forward and backward projections of the cortico-hippocampal projections and (2) a module that computes familiarity of the stimulus and implements hill-climbing over the familiarity which represents the dynamics of the loops within the hippocampus. The proposed network is used in two simulation studies. In the first part of the study, the network is used to simulate image pattern completion by autoassociation under normal conditions. In the second part of the study, the proposed network is extended to a heteroassociative memory and is used to simulate picture naming task in normal and Alzheimer's disease (AD) conditions. The network is trained on pictures and names of digits from 0 to 9. The encoder layer of the network is partly damaged to simulate AD conditions. As in case of AD patients, under moderate damage condition, the network recalls superordinate words ("odd" instead of "nine"). Under severe damage conditions, the network shows a null response ("I don't know"). Neurobiological plausibility of the model is extensively discussed.
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Affiliation(s)
- Tamizharasan Kanagamani
- Laboratory for Computational Neuroscience, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, TN, India
| | - V. Srinivasa Chakravarthy
- Laboratory for Computational Neuroscience, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, TN, India
| | - Balaraman Ravindran
- Department of Computer Science and Engineering, Robert Bosch Centre for Data Science and AI, Indian Institute of Technology Madras, Chennai, TN, India
| | - Ramshekhar N. Menon
- Cognition and Behavioural Neurology Section, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
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Nazari M, Karimi SA, Komaki S, Kourosh Arami M, Komaki A. Underlying mechanisms of long-term potentiation during the inhibition of the cannabinoid CB1 and GABAB receptors in the dentate gyrus of hippocampus. BMC Neurosci 2023; 24:3. [PMID: 36635629 PMCID: PMC9835329 DOI: 10.1186/s12868-022-00767-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 12/13/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The release of various neurotransmitters and thereby the excitability of neuronal circuits are regulated by the endocannabinoid system in an activity-dependent manner. Hippocampal long-term potentiation (LTP) is augmented in cannabinoid type 1 (CB1) receptor-deficient mice. CB1 receptors exist on GABAergic axon terminals in the hippocampus. In our previous work, we showed that CB1 antagonists increased the population spike (PS) amplitude, field excitatory post-synaptic potential (fEPSP), and the LTP induction in the dentate gyrus (DG) of the rat hippocampus while the GABAB antagonist decreased these parameters. Determining the underlying mechanisms of the pre- and/or postsynaptic locus of LTP expression is of great importance. In this study, we investigated whether LTP alteration acutely caused by CB1 and GABAB receptor antagonists (AM251 and CGP55845, respectively) happens at the postsynaptic or presynaptic regions, or at both. Therefore, the paired-pulse ratio (PPR) was assessed prior to and following the LTP induction in the studied groups. METHODS Male Wistar rats were randomly assigned to the groups of control, AM251, CGP55845, CGP55845 + AM251. A high-frequency stimulation (HFS) of the perforant path (PP) was used to induce LTP in the DG region. RESULTS Statistical analysis revealed that AM251 produced significant increase in excitatory postsynaptic potential (EPSP) slope and amplitude of PS. Conversely, administration of CGP55845 produced decrease in slope of EPSP. The current results indicated that the PPR was not influenced by LTP induction in the presence of AM251 or CGP55845 either alone or their combination. CONCLUSIONS It can be concluded that the site causing LTP expression is, at least in part, the postsynaptic site because PPR was not influenced by LTP induction in the presence of AM251 or CGP55845 either alone or their combination.
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Affiliation(s)
- Masoumeh Nazari
- grid.411950.80000 0004 0611 9280Department of Physiology, School of Medicine, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 65178/518 Hamadan, Iran
| | - Seyed Asaad Karimi
- grid.411950.80000 0004 0611 9280Department of Physiology, School of Medicine, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 65178/518 Hamadan, Iran ,grid.411950.80000 0004 0611 9280Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Somayeh Komaki
- grid.411950.80000 0004 0611 9280Department of Physiology, School of Medicine, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 65178/518 Hamadan, Iran
| | - Masoumeh Kourosh Arami
- grid.411746.10000 0004 4911 7066Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Alireza Komaki
- grid.411950.80000 0004 0611 9280Department of Physiology, School of Medicine, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 65178/518 Hamadan, Iran ,grid.411950.80000 0004 0611 9280Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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12
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Shin J, Lee HW, Jin SW, Lee I. Subtle visual change in a virtual environment induces heterogeneous remapping systematically in CA1, but not CA3. Cell Rep 2022; 41:111823. [PMID: 36516763 DOI: 10.1016/j.celrep.2022.111823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 08/10/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Environmental change may lead to new memories or modify old ones, but the underlying neural mechanisms are largely unclear. We recorded hippocampal place cells simultaneously from CA1 and CA3 in a virtual reality environment. Compared with CA1, place cells in CA3 are more tolerant of individual landmark changes but undergo orthogonal changes to code distinctively different environments. As visual noise (virtual fog) is introduced to a visually enriched environment, place cells in CA1 split into two subpopulations: in one, place cells maintain their field locations while changing their firing rates to reflect sensory changes; in the other, place cells exhibit global remapping in response to the contextual change. In contrast, place cells in CA3 exhibit mainly rate remapping under the same conditions. Our results suggest that CA1 may simultaneously represent heterogeneous maps of the same environment when subtle visual noise induces both sensory and contextual changes.
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Affiliation(s)
- Jhoseph Shin
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Hyun-Woo Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Seung-Woo Jin
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea.
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13
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Poh JH, Vu MAT, Stanek JK, Hsiung A, Egner T, Adcock RA. Hippocampal convergence during anticipatory midbrain activation promotes subsequent memory formation. Nat Commun 2022; 13:6729. [PMID: 36344524 PMCID: PMC9640528 DOI: 10.1038/s41467-022-34459-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/25/2022] [Indexed: 11/09/2022] Open
Abstract
The hippocampus has been a focus of memory research since H.M's surgery abolished his ability to form new memories, yet its mechanistic role in memory remains debated. Here, we identify a candidate memory mechanism: an anticipatory hippocampal "convergence state", observed while awaiting valuable information, and which predicts subsequent learning. During fMRI, participants viewed trivia questions eliciting high or low curiosity, followed seconds later by its answer. We reasoned that encoding success requires a confluence of conditions, so that hippocampal states more conducive to memory formation should converge in state space. To operationalize convergence of neural states, we quantified the typicality of multivoxel patterns in the medial temporal lobes during anticipation and encoding of trivia answers. We found that the typicality of anticipatory hippocampal patterns increased during high curiosity. Crucially, anticipatory hippocampal pattern typicality increased with dopaminergic midbrain activation and uniquely accounted for the association between midbrain activation and subsequent recall. We propose that hippocampal convergence states may complete a cascade from motivation and midbrain activation to memory enhancement, and may be a general predictor of memory formation.
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Affiliation(s)
- Jia-Hou Poh
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA.
| | - Mai-Anh T Vu
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA
- Department of Neurobiology, Duke University, Durham, NC, USA
- Department of Psychological & Brain Sciences, Boston University, Boston, MA, USA
| | - Jessica K Stanek
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA
- Department of Psychology & Neuroscience, Duke University, Durham, NC, USA
| | - Abigail Hsiung
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA
- Department of Psychology & Neuroscience, Duke University, Durham, NC, USA
| | - Tobias Egner
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA
- Department of Psychology & Neuroscience, Duke University, Durham, NC, USA
| | - R Alison Adcock
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA.
- Department of Neurobiology, Duke University, Durham, NC, USA.
- Department of Psychology & Neuroscience, Duke University, Durham, NC, USA.
- Department of Psychiatry & Behavioral Sciences, Duke University, Durham, NC, USA.
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14
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Polykretis I, Michmizos KP. The role of astrocytes in place cell formation: A computational modeling study. J Comput Neurosci 2022; 50:505-518. [PMID: 35840871 PMCID: PMC9671849 DOI: 10.1007/s10827-022-00828-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 05/20/2022] [Accepted: 07/12/2022] [Indexed: 11/30/2022]
Abstract
Place cells develop spatially-tuned receptive fields during the early stages of novel environment exploration. The generative mechanism underlying these spatially-selective responses remains largely elusive, but has been associated with theta rhythmicity. An important factor implicating the transformation of silent cells to place cells is a spatially-uniform depolarization that is mediated by a persistent sodium current. This neuronal current is modulated by extracellular calcium concentration, which, in turn, is actively controlled by astrocytes. However, there is no established relationship between the neuronal depolarization and astrocytic activity. To consider this link, we designed a bioplausible computational model of a neuronal-astrocytic network, where astrocytes induced the transient emergence of place fields in silent cells, and accelerated the plasticity-induced consolidation of place cells. Interestingly, theta oscillations emerged naturally at the network level, resulting from the astrocytic modulation of subcellular neuronal properties. Our results suggest that astrocytes participate in spatial mapping and exploration, and further highlight the computational roles of these cells in the brain.
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Affiliation(s)
- Ioannis Polykretis
- Computational Brain Lab, Department of Computer Science, Rutgers University, New Brunswick, New Jersey, USA
| | - Konstantinos P Michmizos
- Computational Brain Lab, Department of Computer Science, Rutgers University, New Brunswick, New Jersey, USA.
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15
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Aitken F, Kok P. Hippocampal representations switch from errors to predictions during acquisition of predictive associations. Nat Commun 2022; 13:3294. [PMID: 35676285 PMCID: PMC9178037 DOI: 10.1038/s41467-022-31040-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 05/11/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractWe constantly exploit the statistical regularities in our environment to help guide our perception. The hippocampus has been suggested to play a pivotal role in both learning environmental statistics, as well as exploiting them to generate perceptual predictions. However, it is unclear how the hippocampus balances encoding new predictive associations with the retrieval of existing ones. Here, we present the results of two high resolution human fMRI studies (N = 24 for both experiments) directly investigating this. Participants were exposed to auditory cues that predicted the identity of an upcoming visual shape (with 75% validity). Using multivoxel decoding analysis, we find that the hippocampus initially preferentially represents unexpected shapes (i.e., those that violate the cue regularities), but later switches to representing the cue-predicted shape regardless of which was actually presented. These findings demonstrate that the hippocampus is involved both acquiring and exploiting predictive associations, and is dominated by either errors or predictions depending on whether learning is ongoing or complete.
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16
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Wilmerding LK, Yazdanbakhsh A, Hasselmo ME. Impact of optogenetic pulse design on CA3 learning and replay: A neural model. CELL REPORTS METHODS 2022; 2:100208. [PMID: 35637904 PMCID: PMC9142690 DOI: 10.1016/j.crmeth.2022.100208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 10/22/2021] [Accepted: 04/11/2022] [Indexed: 11/23/2022]
Abstract
Optogenetic manipulation of hippocampal circuitry is an important tool for investigating learning in vivo. Numerous approaches to pulse design have been employed to elicit desirable circuit and behavioral outcomes. Here, we systematically test the outcome of different single-pulse waveforms in a rate-based model of hippocampal memory function at the level of mnemonic replay extension and de novo synaptic weight formation in CA3 and CA1. Lower-power waveforms with long forward or forward and backward ramps yield more natural sequence replay dynamics and induce synaptic plasticity that allows for more natural memory replay timing, in contrast to square or backward ramps. These differences between waveform shape and amplitude are preserved with the addition of noise in membrane potential, light scattering, and protein expression, improving the potential validity of predictions for in vivo work. These results inform future optogenetic experimental design choices in the field of learning and memory.
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Affiliation(s)
- Lucius K. Wilmerding
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Arash Yazdanbakhsh
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Michael E. Hasselmo
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
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17
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Grossman CD, Cohen JY. Neuromodulation and Neurophysiology on the Timescale of Learning and Decision-Making. Annu Rev Neurosci 2022; 45:317-337. [PMID: 35363533 DOI: 10.1146/annurev-neuro-092021-125059] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nervous systems evolved to effectively navigate the dynamics of the environment to achieve their goals. One framework used to study this fundamental problem arose in the study of learning and decision-making. In this framework, the demands of effective behavior require slow dynamics-on the scale of seconds to minutes-of networks of neurons. Here, we review the phenomena and mechanisms involved. Using vignettes from a few species and areas of the nervous system, we view neuromodulators as key substrates for temporal scaling of neuronal dynamics. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Cooper D Grossman
- The Solomon H. Snyder Department of Neuroscience, Brain Science Institute, and Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | - Jeremiah Y Cohen
- The Solomon H. Snyder Department of Neuroscience, Brain Science Institute, and Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
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18
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Lu Q, Hasson U, Norman KA. A neural network model of when to retrieve and encode episodic memories. eLife 2022; 11:e74445. [PMID: 35142289 PMCID: PMC9000961 DOI: 10.7554/elife.74445] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/09/2022] [Indexed: 11/23/2022] Open
Abstract
Recent human behavioral and neuroimaging results suggest that people are selective in when they encode and retrieve episodic memories. To explain these findings, we trained a memory-augmented neural network to use its episodic memory to support prediction of upcoming states in an environment where past situations sometimes reoccur. We found that the network learned to retrieve selectively as a function of several factors, including its uncertainty about the upcoming state. Additionally, we found that selectively encoding episodic memories at the end of an event (but not mid-event) led to better subsequent prediction performance. In all of these cases, the benefits of selective retrieval and encoding can be explained in terms of reducing the risk of retrieving irrelevant memories. Overall, these modeling results provide a resource-rational account of why episodic retrieval and encoding should be selective and lead to several testable predictions.
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Affiliation(s)
- Qihong Lu
- Department of Psychology, Princeton UniversityPrincetonUnited States
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Uri Hasson
- Department of Psychology, Princeton UniversityPrincetonUnited States
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Kenneth A Norman
- Department of Psychology, Princeton UniversityPrincetonUnited States
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
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19
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Hauer BE, Pagliardini S, Dickson CT. Prefrontal-Hippocampal Pathways Through the Nucleus Reuniens Are Functionally Biased by Brain State. Front Neuroanat 2022; 15:804872. [PMID: 35173588 PMCID: PMC8842257 DOI: 10.3389/fnana.2021.804872] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/13/2021] [Indexed: 11/13/2022] Open
Abstract
Circuit-level communication between disparate brain regions is fundamental for the complexities of the central nervous system operation. Co-ordinated bouts of rhythmic activity between the prefrontal cortex (PFC) and hippocampus (HPC), in particular, are important for mnemonic processes. This is true during awake behavior, as well as during offline states like sleep. We have recently shown that the anatomically interposed thalamic nucleus reuniens (RE) has a role in coordinating slow-wave activity between the PFC and HPC. Here, we took advantage of spontaneous brain state changes occurring during urethane anesthesia in order to assess if PFC-HPC communication was modified during activated (theta) vs. deactivated (slow oscillation: SO) states. These forebrain states are highly similar to those expressed during rapid eye movement (REM) and non-REM stages of natural sleep, respectively. Evoked potentials and excitatory current sinks in the HPC were consistently larger during SO states, regardless of whether PFC or RE afferents were stimulated. Interestingly, PFC stimulation during theta appeared to preferentially use a cortico-cortical pathway, presumably involving the entorhinal cortex as opposed to the more direct RE to HPC conduit. Optogenetic and chemogenetic manipulations of the RE suggested that this state-dependent biasing was mediated by responding in the RE itself. Finally, the phase of both ongoing rhythms also appeared to be an important factor in modulating HPC responses, with maximal field excitatory postsynaptic potentials (EPSPs) occurring during the negative-going phase of both rhythms. Thus, forebrain state plays an important role in how communication takes place across the PFC and HPC, with the RE as a determining factor in how this is shaped. Furthermore, ongoing sleep-like rhythms influence the coordination and perhaps potentiate excitatory processing in this extended episodic memory circuit. Our results have direct implications for activity-dependent processes relevant to sleep-dependent memory consolidation.
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Affiliation(s)
- Brandon E. Hauer
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Silvia Pagliardini
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Department of Physiology, University of Alberta, Edmonton, AB, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
| | - Clayton T. Dickson
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Department of Physiology, University of Alberta, Edmonton, AB, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB, Canada
- Department of Psychology, University of Alberta, Edmonton, AB, Canada
- *Correspondence: Clayton T. Dickson
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20
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Prediction errors disrupt hippocampal representations and update episodic memories. Proc Natl Acad Sci U S A 2021; 118:2117625118. [PMID: 34911768 DOI: 10.1073/pnas.2117625118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2021] [Indexed: 11/18/2022] Open
Abstract
The brain supports adaptive behavior by generating predictions, learning from errors, and updating memories to incorporate new information. Prediction error, or surprise, triggers learning when reality contradicts expectations. Prior studies have shown that the hippocampus signals prediction errors, but the hypothesized link to memory updating has not been demonstrated. In a human functional MRI study, we elicited mnemonic prediction errors by interrupting familiar narrative videos immediately before the expected endings. We found that prediction errors reversed the relationship between univariate hippocampal activation and memory: greater hippocampal activation predicted memory preservation after expected endings, but memory updating after surprising endings. In contrast to previous studies, we show that univariate activation was insufficient for understanding hippocampal prediction error signals. We explain this surprising finding by tracking both the evolution of hippocampal activation patterns and the connectivity between the hippocampus and neuromodulatory regions. We found that hippocampal activation patterns stabilized as each narrative episode unfolded, suggesting sustained episodic representations. Prediction errors disrupted these sustained representations and the degree of disruption predicted memory updating. The relationship between hippocampal activation and subsequent memory depended on concurrent basal forebrain activation, supporting the idea that cholinergic modulation regulates attention and memory. We conclude that prediction errors create conditions that favor memory updating, prompting the hippocampus to abandon ongoing predictions and make memories malleable.
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21
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Humphries R, Mellor JR, O'Donnell C. Acetylcholine Boosts Dendritic NMDA Spikes in a CA3 Pyramidal Neuron Model. Neuroscience 2021; 489:69-83. [PMID: 34780920 DOI: 10.1016/j.neuroscience.2021.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 10/12/2021] [Accepted: 11/05/2021] [Indexed: 11/25/2022]
Abstract
Acetylcholine has been proposed to facilitate the formation of memory ensembles within the hippocampal CA3 network, by enhancing plasticity at CA3-CA3 recurrent synapses. Regenerative NMDA receptor (NMDAR) activation in CA3 neuron dendrites (NMDA spikes) increase synaptic Ca2+ influx and can trigger this synaptic plasticity. Acetylcholine inhibits potassium channels which enhances dendritic excitability and therefore could facilitate NMDA spike generation. Here, we investigate NMDAR-mediated nonlinear synaptic integration in stratum radiatum (SR) and stratum lacunosum moleculare (SLM) dendrites in a reconstructed CA3 neuron computational model and study the effect of cholinergic inhibition of potassium conductances on this nonlinearity. We found that distal SLM dendrites, with a higher input resistance, had a lower threshold for NMDA spike generation compared to SR dendrites. Simulating acetylcholine by blocking potassium channels (M-type, A-type, Ca2+-activated, and inwardly-rectifying) increased dendritic excitability and reduced the number of synapses required to generate NMDA spikes, particularly in the SR dendrites. The magnitude of this effect was heterogeneous across different dendritic branches within the same neuron. These results predict that acetylcholine facilitates dendritic integration and NMDA spike generation in selected CA3 dendrites which could strengthen connections between specific CA3 neurons to form memory ensembles.
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Affiliation(s)
- Rachel Humphries
- Center for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Bristol BS8 1TD, UK; Computational Neuroscience Unit, School of Computer Science, Electrical and Electronic Engineering, and Engineering Mathematics, University of Bristol, Bristol BS8 1UB, UK
| | - Jack R Mellor
- Center for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Cian O'Donnell
- Computational Neuroscience Unit, School of Computer Science, Electrical and Electronic Engineering, and Engineering Mathematics, University of Bristol, Bristol BS8 1UB, UK; School of Computing, Engineering and Intelligent Systems, Ulster University, Magee Campus, Northland Road, Derry/Londonderry BT48 7JL, UK.
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22
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Do Q, Hasselmo ME. Neural circuits and symbolic processing. Neurobiol Learn Mem 2021; 186:107552. [PMID: 34763073 PMCID: PMC10121157 DOI: 10.1016/j.nlm.2021.107552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 10/14/2021] [Accepted: 11/02/2021] [Indexed: 11/29/2022]
Abstract
The ability to use symbols is a defining feature of human intelligence. However, neuroscience has yet to explain the fundamental neural circuit mechanisms for flexibly representing and manipulating abstract concepts. This article will review the research on neural models for symbolic processing. The review first focuses on the question of how symbols could possibly be represented in neural circuits. The review then addresses how neural symbolic representations could be flexibly combined to meet a wide range of reasoning demands. Finally, the review assesses the research on program synthesis and proposes that the most flexible neural representation of symbolic processing would involve the capacity to rapidly synthesize neural operations analogous to lambda calculus to solve complex cognitive tasks.
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Affiliation(s)
- Quan Do
- Center for Systems Neuroscience, Boston University, 610 Commonwealth Ave, Boston, MA 02215, United States.
| | - Michael E Hasselmo
- Center for Systems Neuroscience, Boston University, 610 Commonwealth Ave, Boston, MA 02215, United States.
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23
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Bein O, Plotkin NA, Davachi L. Mnemonic prediction errors promote detailed memories. Learn Mem 2021; 28:422-434. [PMID: 34663695 PMCID: PMC8525423 DOI: 10.1101/lm.053410.121] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 08/16/2021] [Indexed: 12/19/2022]
Abstract
When our experience violates our predictions, it is adaptive to update our knowledge to promote a more accurate representation of the world and facilitate future predictions. Theoretical models propose that these mnemonic prediction errors should be encoded into a distinct memory trace to prevent interference with previous, conflicting memories. We investigated this proposal by repeatedly exposing participants to pairs of sequentially presented objects (A → B), thus evoking expectations. Then, we violated participants' expectations by replacing the second object in the pairs with a novel object (A → C). The following item memory test required participants to discriminate between identical old items and similar lures, thus testing detailed and distinctive item memory representations. In two experiments, mnemonic prediction errors enhanced item memory: Participants correctly identified more old items as old when those items violated expectations during learning, compared with items that did not violate expectations. This memory enhancement for C items was only observed when participants later showed intact memory for the related A → B pairs, suggesting that strong predictions are required to facilitate memory for violations. Following up on this, a third experiment reduced prediction strength prior to violation and subsequently eliminated the memory advantage of violations. Interestingly, mnemonic prediction errors did not increase gist-based mistakes of identifying old items as similar lures or identifying similar lures as old. Enhanced item memory in the absence of gist-based mistakes suggests that violations enhanced memory for items' details, which could be mediated via distinct memory traces. Together, these results advance our knowledge of how mnemonic prediction errors promote memory formation.
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Affiliation(s)
- Oded Bein
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey 08540, USA
| | - Natalie A Plotkin
- Department of Psychology, Columbia University, New York, New York 10027, USA
| | - Lila Davachi
- Department of Psychology, Columbia University, New York, New York 10027, USA
- Center for Clinical Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA
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24
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Grande X, Berron D, Maass A, Bainbridge WA, Düzel E. Content-specific vulnerability of recent episodic memories in Alzheimer's disease. Neuropsychologia 2021; 160:107976. [PMID: 34314781 PMCID: PMC8434425 DOI: 10.1016/j.neuropsychologia.2021.107976] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 11/21/2022]
Abstract
Endel Tulving's episodic memory framework emphasizes the multifaceted re-experiencing of personal events. Indeed, decades of research focused on the experiential nature of episodic memories, usually treating recent episodic memory as a coherent experiential quality. However, recent insights into the functional architecture of the medial temporal lobe show that different types of mnemonic information are segregated into distinct neural pathways in brain circuits empirically associated with episodic memory. Moreover, recent memories do not fade as a whole under conditions of progressive neurodegeneration in these brain circuits, notably in Alzheimer's disease. Instead, certain memory content seem particularly vulnerable from the moment of their encoding while other content can remain memorable consistently across individuals and contexts. We propose that these observations are related to the content-specific functional architecture of the medial temporal lobe and consequently to a content-specific impairment of memory at different stages of the neurodegeneration. To develop Endel Tulving's inspirational legacy further and to advance our understanding of how memory function is affected by neurodegenerative conditions such as Alzheimer's disease, we postulate that it is compelling to focus on the representational content of recent episodic memories. The functional anatomy of episodic memory segregates different memory content. Alzheimer's disease may cause content-specific loss of recent memories Content-specific memorability across individuals changes with Alzheimer's disease. Content-specific assessment could provide new insights into episodic memory in health and disease
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Affiliation(s)
- Xenia Grande
- German Center for Neurodegenerative Diseases, Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University Magdeburg, Germany.
| | - David Berron
- German Center for Neurodegenerative Diseases, Magdeburg, Germany; Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
| | - Anne Maass
- German Center for Neurodegenerative Diseases, Magdeburg, Germany
| | | | - Emrah Düzel
- German Center for Neurodegenerative Diseases, Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University Magdeburg, Germany; Institute of Cognitive Neuroscience, University College London, United Kingdom.
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25
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Santos-Pata D, Amil AF, Raikov IG, Rennó-Costa C, Mura A, Soltesz I, Verschure PFMJ. Epistemic Autonomy: Self-supervised Learning in the Mammalian Hippocampus. Trends Cogn Sci 2021; 25:582-595. [PMID: 33906817 PMCID: PMC10631471 DOI: 10.1016/j.tics.2021.03.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 01/05/2023]
Abstract
Biological cognition is based on the ability to autonomously acquire knowledge, or epistemic autonomy. Such self-supervision is largely absent in artificial neural networks (ANN) because they depend on externally set learning criteria. Yet training ANN using error backpropagation has created the current revolution in artificial intelligence, raising the question of whether the epistemic autonomy displayed in biological cognition can be achieved with error backpropagation-based learning. We present evidence suggesting that the entorhinal-hippocampal complex combines epistemic autonomy with error backpropagation. Specifically, we propose that the hippocampus minimizes the error between its input and output signals through a modulatory counter-current inhibitory network. We further discuss the computational emulation of this principle and analyze it in the context of autonomous cognitive systems.
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Affiliation(s)
- Diogo Santos-Pata
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
| | - Adrián F Amil
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | | | - César Rennó-Costa
- Digital Metropolis Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Anna Mura
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
| | - Ivan Soltesz
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Paul F M J Verschure
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
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26
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Theta Oscillations Gate the Transmission of Reliable Sequences in the Medial Entorhinal Cortex. eNeuro 2021; 8:ENEURO.0059-20.2021. [PMID: 33820802 PMCID: PMC8208650 DOI: 10.1523/eneuro.0059-20.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 11/21/2022] Open
Abstract
Stability and precision of sequential activity in the entorhinal cortex (EC) is crucial for encoding spatially guided behavior and memory. These sequences are driven by constantly evolving sensory inputs and persist despite a noisy background. In a realistic computational model of a medial EC (MEC) microcircuit, we show that intrinsic neuronal properties and network mechanisms interact with theta oscillations to generate reliable outputs. In our model, sensory inputs activate interneurons near their most excitable phase during each theta cycle. As the inputs change, different interneurons are recruited and postsynaptic stellate cells are released from inhibition. This causes a sequence of rebound spikes. The rebound time scale of stellate cells, because of an h–current, matches that of theta oscillations. This fortuitous similarity of time scales ensures that stellate spikes get relegated to the least excitable phase of theta and the network encodes the external drive but ignores recurrent excitation. In contrast, in the absence of theta, rebound spikes compete with external inputs and disrupt the sequence that follows. Further, the same mechanism where theta modulates the gain of incoming inputs, can be used to select between competing inputs to create transient functionally connected networks. Our results concur with experimental data that show, subduing theta oscillations disrupts the spatial periodicity of grid cell receptive fields. In the bat MEC where grid cell receptive fields persist even in the absence of continuous theta oscillations, we argue that other low frequency fluctuations play the role of theta.
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27
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Lockhofen DEL, Mulert C. Neurochemistry of Visual Attention. Front Neurosci 2021; 15:643597. [PMID: 34025339 PMCID: PMC8133366 DOI: 10.3389/fnins.2021.643597] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/12/2021] [Indexed: 11/25/2022] Open
Abstract
Visual attention is the cognitive process that mediates the selection of important information from the environment. This selection is usually controlled by bottom-up and top-down attentional biasing. Since for most humans vision is the dominant sense, visual attention is critically important for higher-order cognitive functions and related deficits are a core symptom of many neuropsychiatric and neurological disorders. Here, we summarize the importance and relative contributions of different neuromodulators and neurotransmitters to the neural mechanisms of top-down and bottom-up attentional control. We will not only review the roles of widely accepted neuromodulators, such as acetylcholine, dopamine and noradrenaline, but also the contributions of other modulatory substances. In doing so, we hope to shed some light on the current understanding of the role of neurochemistry in shaping neuron properties contributing to the allocation of attention in the visual field.
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Affiliation(s)
| | - Christoph Mulert
- Center for Psychiatry and Psychotherapy, Justus-Liebig University, Hessen, Germany
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28
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Lehr AB, Kumar A, Tetzlaff C, Hafting T, Fyhn M, Stöber TM. CA2 beyond social memory: Evidence for a fundamental role in hippocampal information processing. Neurosci Biobehav Rev 2021; 126:398-412. [PMID: 33775693 DOI: 10.1016/j.neubiorev.2021.03.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 01/16/2023]
Abstract
Hippocampal region CA2 has received increased attention due to its importance in social recognition memory. While its specific function remains to be identified, there are indications that CA2 plays a major role in a variety of situations, widely extending beyond social memory. In this targeted review, we highlight lines of research which have begun to converge on a more fundamental role for CA2 in hippocampus-dependent memory processing. We discuss recent proposals that speak to the computations CA2 may perform within the hippocampal circuit.
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Affiliation(s)
- Andrew B Lehr
- Department of Computational Neuroscience, University of Göttingen, Germany; Bernstein Center for Computational Neuroscience, University of Göttingen, Germany; Department of Computational Physiology, Simula Research Laboratory, Lysaker, Norway; Centre for Integrative Neuroplasticity, University of Oslo, Norway.
| | - Arvind Kumar
- Department of Computational Science and Technology, KTH Royal Institute of Technology, Sweden
| | - Christian Tetzlaff
- Department of Computational Neuroscience, University of Göttingen, Germany; Bernstein Center for Computational Neuroscience, University of Göttingen, Germany
| | - Torkel Hafting
- Centre for Integrative Neuroplasticity, University of Oslo, Norway; Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Marianne Fyhn
- Centre for Integrative Neuroplasticity, University of Oslo, Norway; Department of Biosciences, University of Oslo, Norway
| | - Tristan M Stöber
- Department of Computational Physiology, Simula Research Laboratory, Lysaker, Norway; Centre for Integrative Neuroplasticity, University of Oslo, Norway; Department of Informatics, University of Oslo, Norway.
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Alcantara-Gonzalez D, Chartampila E, Criscuolo C, Scharfman HE. Early changes in synaptic and intrinsic properties of dentate gyrus granule cells in a mouse model of Alzheimer's disease neuropathology and atypical effects of the cholinergic antagonist atropine. Neurobiol Dis 2021; 152:105274. [PMID: 33484828 DOI: 10.1016/j.nbd.2021.105274] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/09/2021] [Accepted: 01/16/2021] [Indexed: 12/19/2022] Open
Abstract
It has been reported that hyperexcitability occurs in a subset of patients with Alzheimer's disease (AD) and hyperexcitability could contribute to the disease. Several studies have suggested that the hippocampal dentate gyrus (DG) may be an important area where hyperexcitability occurs. Therefore, we tested the hypothesis that the principal DG cell type, granule cells (GCs), would exhibit changes at the single-cell level which would be consistent with hyperexcitability and might help explain it. We used the Tg2576 mouse, where it has been shown that hyperexcitability is robust at 2-3 months of age. GCs from 2 to 3-month-old Tg2576 mice were compared to age-matched wild type (WT) mice. Effects of muscarinic cholinergic antagonism were tested because previously we found that Tg2576 mice exhibited hyperexcitability in vivo that was reduced by the muscarinic cholinergic antagonist atropine, counter to the dogma that in AD one needs to boost cholinergic function. The results showed that GCs from Tg2576 mice exhibited increased frequency of spontaneous excitatory postsynaptic potentials/currents (sEPSP/Cs) and reduced frequency of spontaneous inhibitory synaptic events (sIPSCs) relative to WT, increasing the excitation:inhibition (E:I) ratio. There was an inward NMDA receptor-dependent current that we defined here as a novel synaptic current (nsC) in Tg2576 mice because it was very weak in WT mice. Intrinsic properties were distinct in Tg2576 GCs relative to WT. In summary, GCs of the Tg2576 mouse exhibit early electrophysiological alterations that are consistent with increased synaptic excitation, reduced inhibition, and muscarinic cholinergic dysregulation. The data support previous suggestions that the DG contributes to hyperexcitability and there is cholinergic dysfunction early in life in AD mouse models.
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Affiliation(s)
- David Alcantara-Gonzalez
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Elissavet Chartampila
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Chiara Criscuolo
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Helen E Scharfman
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Child & Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, New York University Langone Health, New York, NY 10016, USA; Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA.
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Prajapati SK, Krishnamurthy S. Development and treatment of cognitive inflexibility in sub-chronic stress–re-stress (SRS) model of PTSD. Pharmacol Rep 2021; 73:464-479. [DOI: 10.1007/s43440-020-00198-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 10/22/2022]
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31
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Bein O, Reggev N, Maril A. Prior knowledge promotes hippocampal separation but cortical assimilation in the left inferior frontal gyrus. Nat Commun 2020; 11:4590. [PMID: 32929067 PMCID: PMC7490707 DOI: 10.1038/s41467-020-18364-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 08/10/2020] [Indexed: 12/11/2022] Open
Abstract
An adaptive memory system rarely learns information tabula rasa, but rather builds on prior knowledge to facilitate learning. How prior knowledge influences the neural representation of novel associations remains unknown. Here, participants associated pairs of faces in two conditions: a famous, highly familiar face with a novel face or two novel faces while undergoing fMRI. We examine multivoxel activity patterns corresponding to individual faces before and after learning. The activity patterns representing members of famous-novel pairs becomes separated in the hippocampus, that is, more distinct from one another through learning, in striking contrast to paired novel faces that become similar. In the left inferior frontal gyrus, however, prior knowledge leads to integration, and in a specific direction: the representation of the novel face becomes similar to that of the famous face after learning, suggesting assimilation of new into old memories. We propose that hippocampal separation might resolve interference between existing and newly learned information, allowing cortical assimilation. Thus, associative learning with versus without prior knowledge relies on radically different computations. Prior knowledge strongly impacts new learning, but its influence on the neural representation of novel information is unknown. Here, the authors show multiple neural codes for learning: prior knowledge leads to integrated cortical representations, while promoting hippocampal separation.
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Affiliation(s)
- Oded Bein
- Department of Psychology, New York University, 6 Washington Pl, New York, NY, 10003, USA
| | - Niv Reggev
- Psychology Department, Ben Gurion University of the Negev, 1 Shderot Ben Gurion, Be'er Sheva, 8410501, Israel
| | - Anat Maril
- Department of Psychology, The Hebrew University of Jerusalem, Mount Scopus, Jerusalem, 91905, Israel. .,Department of Cognitive Science, The Hebrew University of Jerusalem, Mount Scopus, Jerusalem, 91905, Israel.
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32
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Geschwill P, Kaiser ME, Grube P, Lehmann N, Thome C, Draguhn A, Hollnagel JO, Both M. Synchronicity of excitatory inputs drives hippocampal networks to distinct oscillatory patterns. Hippocampus 2020; 30:1044-1057. [PMID: 32412680 DOI: 10.1002/hipo.23214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/21/2020] [Accepted: 04/25/2020] [Indexed: 11/11/2022]
Abstract
The rodent hippocampus expresses a variety of neuronal network oscillations depending on the behavioral state of the animal. Locomotion and active exploration are accompanied by theta-nested gamma oscillations while resting states and slow-wave sleep are dominated by intermittent sharp wave-ripple complexes. It is believed that gamma rhythms create a framework for efficient acquisition of information whereas sharp wave-ripples are thought to be involved in consolidation and retrieval of memory. While not strictly mutually exclusive, one of the two patterns usually dominates in a given behavioral state. Here we explore how different input patterns induce either of the two network states, using an optogenetic stimulation approach in hippocampal brain slices of mice. We report that the pattern of the evoked oscillation depends strongly on the initial synchrony of activation of excitatory cells within CA3. Short, synchronous activation favors the emergence of sharp wave-ripple complexes while persistent but less synchronous activity-as typical for sensory input during exploratory behavior-supports the generation of gamma oscillations. This dichotomy is reflected by different degrees of synchrony of excitatory and inhibitory synaptic currents within these two states. Importantly, the induction of these two fundamental network patterns does not depend on the presence of any neuromodulatory transmitter like acetylcholine, but is merely based on a different synchrony in the initial activation pattern.
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Affiliation(s)
- Pascal Geschwill
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
| | - Martin E Kaiser
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
| | - Paul Grube
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
| | - Nadja Lehmann
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
| | - Christian Thome
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
| | - Andreas Draguhn
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
| | - Martin Both
- Intitute for Physiology and Pathophysiology, University Heidelberg, Heidelberg, Germany
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33
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Günseli E, Aly M. Preparation for upcoming attentional states in the hippocampus and medial prefrontal cortex. eLife 2020; 9:e53191. [PMID: 32255423 PMCID: PMC7237206 DOI: 10.7554/elife.53191] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/07/2020] [Indexed: 12/23/2022] Open
Abstract
Goal-directed attention is usually studied by providing individuals with explicit instructions on what they should attend to. But in daily life, we often use past experiences to guide our attentional states. Given the importance of memory for predicting upcoming events, we hypothesized that memory-guided attention is supported by neural preparation for anticipated attentional states. We examined preparatory coding in the human hippocampus and mPFC, two regions that are important for memory-guided behaviors, in two tasks: one where attention was guided by memory and another in which attention was explicitly instructed. Hippocampus and mPFC exhibited higher activity for memory-guided vs. explicitly instructed attention. Furthermore, representations in both regions contained information about upcoming attentional states. In the hippocampus, this preparation was stronger for memory-guided attention, and occurred alongside stronger coupling with visual cortex during attentional guidance. These results highlight the mechanisms by which memories are used to prepare for upcoming attentional goals.
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Affiliation(s)
- Eren Günseli
- Department of Psychology, Columbia UniversityNew YorkUnited States
- Department of Psychology, Sabanci UniversityIstanbulTurkey
| | - Mariam Aly
- Department of Psychology, Columbia UniversityNew YorkUnited States
- Affiliate Member, Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
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34
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Decker AL, Duncan K. Acetylcholine and the complex interdependence of memory and attention. Curr Opin Behav Sci 2020. [DOI: 10.1016/j.cobeha.2020.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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35
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Tarder-Stoll H, Jayakumar M, Dimsdale-Zucker HR, Günseli E, Aly M. Dynamic internal states shape memory retrieval. Neuropsychologia 2020; 138:107328. [DOI: 10.1016/j.neuropsychologia.2019.107328] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 12/13/2019] [Accepted: 12/22/2019] [Indexed: 12/30/2022]
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36
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Maier M, Ballester BR, Verschure PFMJ. Principles of Neurorehabilitation After Stroke Based on Motor Learning and Brain Plasticity Mechanisms. Front Syst Neurosci 2019; 13:74. [PMID: 31920570 PMCID: PMC6928101 DOI: 10.3389/fnsys.2019.00074] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 11/19/2019] [Indexed: 01/19/2023] Open
Abstract
What are the principles underlying effective neurorehabilitation? The aim of neurorehabilitation is to exploit interventions based on human and animal studies about learning and adaptation, as well as to show that the activation of experience-dependent neuronal plasticity augments functional recovery after stroke. Instead of teaching compensatory strategies that do not reduce impairment but allow the patient to return home as soon as possible, functional recovery might be more sustainable as it ensures a long-term reduction in impairment and an improvement in quality of life. At the same time, neurorehabilitation permits the scientific community to collect valuable data, which allows inferring about the principles of brain organization. Hence neuroscience sheds light on the mechanisms of learning new functions or relearning lost ones. However, current rehabilitation methods lack the exact operationalization of evidence gained from skill learning literature, leading to an urgent need to bridge motor learning theory and present clinical work in order to identify a set of ingredients and practical applications that could guide future interventions. This work aims to unify the neuroscientific literature relevant to the recovery process and rehabilitation practice in order to provide a synthesis of the principles that constitute an effective neurorehabilitation approach. Previous attempts to achieve this goal either focused on a subset of principles or did not link clinical application to the principles of motor learning and recovery. We identified 15 principles of motor learning based on existing literature: massed practice, spaced practice, dosage, task-specific practice, goal-oriented practice, variable practice, increasing difficulty, multisensory stimulation, rhythmic cueing, explicit feedback/knowledge of results, implicit feedback/knowledge of performance, modulate effector selection, action observation/embodied practice, motor imagery, and social interaction. We comment on trials that successfully implemented these principles and report evidence from experiments with healthy individuals as well as clinical work.
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Affiliation(s)
- Martina Maier
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems, Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Belén Rubio Ballester
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems, Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Paul F. M. J. Verschure
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems, Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Institucio Catalana de Recerca I Estudis Avançats, Barcelona, Spain
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37
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Abstract
Mammals have evolved specialized brain systems to support efficient navigation within diverse habitats and over varied distances, but while navigational strategies and sensory mechanisms vary across species, core spatial components appear to be widely shared. This review presents common elements found in mammalian spatial mapping systems, focusing on the cells in the hippocampal formation representing orientational and locational spatial information, and 'core' mammalian hippocampal circuitry. Mammalian spatial mapping systems make use of both allothetic cues (space-defining cues in the external environment) and idiothetic cues (cues derived from self-motion). As examples of each cue type, we discuss: environmental boundaries, which control both orientational and locational neuronal activity and behaviour; and 'path integration', a process that allows the estimation of linear translation from velocity signals, thought to depend upon grid cells in the entorhinal cortex. Building cognitive maps entails sampling environments: we consider how the mapping system controls exploration to acquire spatial information, and how exploratory strategies may integrate idiothetic with allothetic information. We discuss how 'replay' may act to consolidate spatial maps, and simulate trajectories to aid navigational planning. Finally, we discuss grid cell models of vector navigation.
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Affiliation(s)
| | - Tom Hartley
- Department of Psychology, University of York, YO10 5DD, UK
| | - Colin Lever
- Psychology Department, Durham University, DH1 3LE, UK.
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38
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Duncan K, Semmler A, Shohamy D. Modulating the Use of Multiple Memory Systems in Value-based Decisions with Contextual Novelty. J Cogn Neurosci 2019; 31:1455-1467. [PMID: 31322467 DOI: 10.1162/jocn_a_01447] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
With multiple learning and memory systems at its disposal, the human brain can represent the past in many ways, from extracting regularities across similar experiences (incremental learning) to storing rich, idiosyncratic details of individual events (episodic memory). The unique information carried by these neurologically distinct forms of memory can bias our behavior in different directions, raising crucial questions about how these memory systems interact to guide choice and the factors that cause one to dominate. Here, we devised a new approach to estimate how decisions are independently influenced by episodic memories and incremental learning. Furthermore, we identified a biologically motivated factor that biases the use of different memory types-the detection of novelty versus familiarity. Consistent with computational models of cholinergic memory modulation, we find that choices are more influenced by episodic memories following the recognition of an unrelated familiar image but more influenced by incrementally learned values after the detection of a novel image. Together this work provides a new behavioral tool enabling the disambiguation of key memory behaviors thought to be supported by distinct neural systems while also identifying a theoretically important and broadly applicable manipulation to bias the arbitration between these two sources of memories.
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39
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Baraban SC. Viral tracing of presynaptic inputs to newly born dentate granule cells in a rodent model of mesial temporal lobe epilepsy. Ann Neurol 2019; 81:769-771. [PMID: 28470692 DOI: 10.1002/ana.24945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 04/17/2017] [Accepted: 04/26/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Scott C Baraban
- Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco San Francisco, CA
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40
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Bayati M, Neher T, Melchior J, Diba K, Wiskott L, Cheng S. Storage fidelity for sequence memory in the hippocampal circuit. PLoS One 2018; 13:e0204685. [PMID: 30286147 PMCID: PMC6171846 DOI: 10.1371/journal.pone.0204685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 09/11/2018] [Indexed: 12/24/2022] Open
Abstract
Episodic memories have been suggested to be represented by neuronal sequences, which are stored and retrieved from the hippocampal circuit. A special difficulty is that realistic neuronal sequences are strongly correlated with each other since computational memory models generally perform poorly when correlated patterns are stored. Here, we study in a computational model under which conditions the hippocampal circuit can perform this function robustly. During memory encoding, CA3 sequences in our model are driven by intrinsic dynamics, entorhinal inputs, or a combination of both. These CA3 sequences are hetero-associated with the input sequences, so that the network can retrieve entire sequences based on a single cue pattern. We find that overall memory performance depends on two factors: the robustness of sequence retrieval from CA3 and the circuit's ability to perform pattern completion through the feedforward connectivity, including CA3, CA1 and EC. The two factors, in turn, depend on the relative contribution of the external inputs and recurrent drive on CA3 activity. In conclusion, memory performance in our network model critically depends on the network architecture and dynamics in CA3.
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Affiliation(s)
- Mehdi Bayati
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
| | - Torsten Neher
- Mental Health Research and Treatment Center, Department of Clinical Child and Adolescent Psychology, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany
| | - Jan Melchior
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
| | - Kamran Diba
- Department of Anesthesiology, University of Michigan, Ann Arbor, United States of America
| | - Laurenz Wiskott
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
| | - Sen Cheng
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
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41
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Coppi E, Lana D, Cherchi F, Fusco I, Buonvicino D, Urru M, Ranieri G, Muzzi M, Iovino L, Giovannini MG, Pugliese AM, Chiarugi A. Dexpramipexole enhances hippocampal synaptic plasticity and memory in the rat. Neuropharmacology 2018; 143:306-316. [PMID: 30291939 DOI: 10.1016/j.neuropharm.2018.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/19/2018] [Accepted: 10/02/2018] [Indexed: 01/22/2023]
Abstract
Even though pharmacological approaches able to counteract age-dependent cognitive impairment have been highly investigated, drugs improving cognition and memory are still an unmet need. It has been hypothesized that sustaining energy dynamics within the aged hippocampus can boost memory storage by sustaining synaptic functioning and long term potentiation (LTP). Dexpramipexole (DEX) is the first-in-class compound able to sustain neuronal bioenergetics by interacting with mitochondrial F1Fo-ATP synthase. In the present study, for the first time we evaluated the effects of DEX on synaptic fatigue, LTP induction, learning and memory retention. We report that DEX improved LTP maintenance in CA1 neurons of acute hippocampal slices from aged but not young rats. However, we found no evidence that DEX counteracted two classic parameters of synaptic fatigue such as fEPSP reduction or the train area during the high frequency stimulation adopted to induce LTP. Interestingly, patch-clamp recordings in rat hippocampal neurons revealed that DEX dose-dependently inhibited (IC50 814 nM) the IA current, a rapidly-inactivating K+ current that negatively regulates neuronal excitability as well as cognition and memory processes. In keeping with this, DEX counteracted both scopolamine-induced spatial memory loss in rats challenged in Morris Water Maze test and memory retention in rats undergoing Novel Object Recognition. Overall, the present study discloses the ability of DEX to boost hippocampal synaptic plasticity, learning and memory. In light of the good safety profile of DEX in humans, our findings may have a realistic translational potential to treatment of cognitive disorders.
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Affiliation(s)
- Elisabetta Coppi
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Italy.
| | - Daniele Lana
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Italy
| | - Federica Cherchi
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Italy
| | - Irene Fusco
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Italy
| | - Daniela Buonvicino
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Italy
| | - Matteo Urru
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Italy
| | - Giuseppe Ranieri
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Italy
| | - Mirko Muzzi
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Italy
| | - Ludovica Iovino
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Italy
| | - Maria Grazia Giovannini
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Italy
| | - Anna Maria Pugliese
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Italy
| | - Alberto Chiarugi
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Italy
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42
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Abstract
We present a model of how neural representations of egocentric spatial experiences in parietal cortex interface with viewpoint-independent representations in medial temporal areas, via retrosplenial cortex, to enable many key aspects of spatial cognition. This account shows how previously reported neural responses (place, head-direction and grid cells, allocentric boundary- and object-vector cells, gain-field neurons) can map onto higher cognitive function in a modular way, and predicts new cell types (egocentric and head-direction-modulated boundary- and object-vector cells). The model predicts how these neural populations should interact across multiple brain regions to support spatial memory, scene construction, novelty-detection, 'trace cells', and mental navigation. Simulated behavior and firing rate maps are compared to experimental data, for example showing how object-vector cells allow items to be remembered within a contextual representation based on environmental boundaries, and how grid cells could update the viewpoint in imagery during planning and short-cutting by driving sequential place cell activity.
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Affiliation(s)
- Andrej Bicanski
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUnited Kingdom
| | - Neil Burgess
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUnited Kingdom
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43
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Tucker MA, Taylor K, Merchant R, George S, Stoddard C, Kopera K. Scopolamine does not impact declarative and motor memory consolidation across a night of sleep or a day of wakefulness. Neurobiol Learn Mem 2018; 155:371-378. [PMID: 30172950 DOI: 10.1016/j.nlm.2018.08.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/14/2018] [Accepted: 08/29/2018] [Indexed: 10/28/2022]
Abstract
It has been proposed that normal waking levels of acetylcholine (ACH) are important for initial memory acquisition, and that decreased ACH is critical for memory consolidation. Sleep is thought to benefit memory consolidation in part due to the predominance of low ACH levels observed during non-rapid eye movement sleep. Here we examined whether sleep and ACH suppression with the cholinergic antagonist scopolamine impact declarative and motor memory consolidation across a night of sleep or a day of wakefulness. Eighty-seven participants trained on a declarative and motor memory task in the morning or evening. Following training, participants were administered a scopolamine (0.4 mg) or placebo capsule. Participants were retested on the tasks 12 h later after a day of wake or a night of sleep. Reducing ACH levels with scopolamine provided no consolidation benefit for either task. Additionally, we found that sleep had a pronounced beneficial effect for declarative, but not motor memory consolidation. Lastly, in an exploratory analysis of the relationship between motivation and memory performance, we found that indices of intrinsic motivation were associated with improved memory acquisition and consolidation. Our findings show that reducing ACH levels after memory acquisition has no impact on the consolidation of declarative or motor memories. Additionally, sleep benefitted declarative memory but not motor memory consolidation, which highlights the interesting, though uncommon, finding that performance on some tasks might not benefit from sleep. Interestingly, the future study of intrinsic motivation may be warranted given its relationship to memory acquisition and consolidation. These findings add to our understanding of how sleep and acetylcholine impact memory consolidation, and may provide some insight about the role of ACH in memory disorders such as Alzheimer's disease.
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Affiliation(s)
- Matthew A Tucker
- University of South Carolina School of Medicine Greenville, United States.
| | - Kathryn Taylor
- University of South Carolina School of Medicine Greenville, United States
| | - Rozina Merchant
- University of South Carolina School of Medicine Greenville, United States
| | - Sharon George
- University of South Carolina School of Medicine Greenville, United States
| | - Caroline Stoddard
- University of South Carolina School of Medicine Greenville, United States
| | - Kevin Kopera
- University of South Carolina School of Medicine Greenville, United States
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44
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Gu Z, Alexander GM, Dudek SM, Yakel JL. Hippocampus and Entorhinal Cortex Recruit Cholinergic and NMDA Receptors Separately to Generate Hippocampal Theta Oscillations. Cell Rep 2018; 21:3585-3595. [PMID: 29262336 DOI: 10.1016/j.celrep.2017.11.080] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/10/2017] [Accepted: 11/21/2017] [Indexed: 11/25/2022] Open
Abstract
Although much progress has been made in understanding type II theta rhythm generation under urethane anesthesia, less is known about the mechanisms underlying type I theta generation during active exploration. To better understand the contributions of cholinergic and NMDA receptor activation to type I theta generation, we recorded hippocampal theta oscillations from freely moving mice with local infusion of cholinergic or NMDA receptor antagonists to either the hippocampus or the entorhinal cortex (EC). We found that cholinergic receptors in the hippocampus, but not the EC, and NMDA receptors in the EC, but not the hippocampus, are critical for open-field theta generation and Y-maze performance. We further found that muscarinic M1 receptors located on pyramidal neurons, but not interneurons, are critical for cholinergic modulation of hippocampal synapses, theta generation, and Y-maze performance. These results suggest that hippocampus and EC neurons recruit cholinergic-dependent and NMDA-receptor-dependent mechanisms, respectively, to generate theta oscillations to support behavioral performance.
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Affiliation(s)
- Zhenglin Gu
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, US Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Georgia M Alexander
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, US Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, US Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Jerrel L Yakel
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, US Department of Health and Human Services, Research Triangle Park, NC 27709, USA.
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45
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Words-In-Sequence Memory Formed by Eye Movement Sequences During Reading: A Network Model Based on Theta Phase Coding. Neural Process Lett 2018. [DOI: 10.1007/s11063-017-9632-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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46
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Kassab R, Alexandre F. Pattern separation in the hippocampus: distinct circuits under different conditions. Brain Struct Funct 2018; 223:2785-2808. [PMID: 29637298 DOI: 10.1007/s00429-018-1659-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 03/26/2018] [Indexed: 10/17/2022]
Abstract
Pattern separation is a fundamental hippocampal process thought to be critical for distinguishing similar episodic memories, and has long been recognized as a natural function of the dentate gyrus (DG), supporting autoassociative learning in CA3. Understanding how neural circuits within the DG-CA3 network mediate this process has received much interest, yet the exact mechanisms behind remain elusive. Here, we argue for the case that sparse coding is necessary but not sufficient to ensure efficient separation and, alternatively, propose a possible interaction of distinct circuits which, nevertheless, act in synergy to produce a unitary function of pattern separation. The proposed circuits involve different functional granule-cell populations, a primary population mediates sparsification and provides recurrent excitation to the other populations which are related to additional pattern separation mechanisms with higher degrees of robustness against interference in CA3. A variety of top-down and bottom-up factors, such as motivation, emotion, and pattern similarity, control the selection of circuitry depending on circumstances. According to this framework, a computational model is implemented and tested against model variants in a series of numerical simulations and biological experiments. The results demonstrate that the model combines fast learning, robust pattern separation and high storage capacity. It also accounts for the controversy around the involvement of the DG during memory recall, explains other puzzling findings, and makes predictions that can inform future investigations.
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Affiliation(s)
- Randa Kassab
- INRIA, Bordeaux Sud-Ouest, Talence, France. .,Institut des Maladies Neurodégénératives, University of Bordeaux, CNRS UMR 5293-Case 28, Centre Broca Nouvelle-Aquitaine, 146 rue Léo Saignat, 33076, Bordeaux, France. .,LaBRI, UMR 5800, CNRS, Bordeaux INP, University of Bordeaux, Talence, France.
| | - Frédéric Alexandre
- INRIA, Bordeaux Sud-Ouest, Talence, France.,Institut des Maladies Neurodégénératives, University of Bordeaux, CNRS UMR 5293-Case 28, Centre Broca Nouvelle-Aquitaine, 146 rue Léo Saignat, 33076, Bordeaux, France.,LaBRI, UMR 5800, CNRS, Bordeaux INP, University of Bordeaux, Talence, France
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47
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Duncan KD, Schlichting ML. Hippocampal representations as a function of time, subregion, and brain state. Neurobiol Learn Mem 2018. [PMID: 29535044 DOI: 10.1016/j.nlm.2018.03.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
How does the hippocampus represent interrelated experiences in memory? We review prominent yet seemingly contradictory theoretical perspectives, which propose that the hippocampus distorts experiential representations to either emphasize their distinctiveness or highlight common elements. These fundamentally different kinds of memory representations may be instantiated in the brain via conjunctive separated codes and adaptively differentiated codes on the one hand, or integrated relational codes on the other. After reviewing empirical support for these different coding schemes within the hippocampus, we outline two organizing principles which may explain the conflicting findings in the literature. First focusing on where the memories are formed and stored, we argue that distinct hippocampal regions represent experiences at multiple levels of abstraction and may transmit them to distinct cortical networks. Then focusing on when memories are formed, we identify several factors that can open and maintain specialized time windows, during which the very same hippocampal network is biased toward one coding scheme over the others. Specifically, we discuss evidence for (1) excitability-mediated integration windows, maintained by persistently elevated CREB levels following encoding of a specific memory, (2) fleeting cholinergically-mediated windows favoring memory separation, and (3) sustained dopaminergically-mediated windows favoring memory integration. By presenting a broad overview of different hippocampal coding schemes across species, we hope to inspire future empirical and modeling research to consider how factors surrounding memory formation shape the representations in which they are stored.
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Affiliation(s)
- Katherine D Duncan
- Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada.
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48
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Korotkova T, Ponomarenko A, Monaghan CK, Poulter SL, Cacucci F, Wills T, Hasselmo ME, Lever C. Reconciling the different faces of hippocampal theta: The role of theta oscillations in cognitive, emotional and innate behaviors. Neurosci Biobehav Rev 2018; 85:65-80. [DOI: 10.1016/j.neubiorev.2017.09.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 08/22/2017] [Accepted: 09/02/2017] [Indexed: 12/30/2022]
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49
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Loh E, Kurth-Nelson Z, Berron D, Dayan P, Duzel E, Dolan R, Guitart-Masip M. Parsing the Role of the Hippocampus in Approach-Avoidance Conflict. Cereb Cortex 2018; 27:201-215. [PMID: 27993819 PMCID: PMC5939226 DOI: 10.1093/cercor/bhw378] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 11/11/2016] [Indexed: 01/07/2023] Open
Abstract
The hippocampus plays a central role in the approach-avoidance conflict that is central to the genesis of anxiety. However, its exact functional contribution has yet to be identified. We designed a novel gambling task that generated approach-avoidance conflict while controlling for spatial processing. We fit subjects' behavior using a model that quantified the subjective values of choice options, and recorded neural signals using functional magnetic resonance imaging (fMRI). Distinct functional signals were observed in anterior hippocampus, with inferior hippocampus selectively recruited when subjects rejected a gamble, to a degree that covaried with individual differences in anxiety. The superior anterior hippocampus, in contrast, uniquely demonstrated value signals that were potentiated in the context of approach-avoidance conflict. These results implicate the anterior hippocampus in behavioral avoidance and choice monitoring, in a manner relevant to understanding its role in anxiety. Our findings highlight interactions between subregions of the hippocampus as an important focus for future study.
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Affiliation(s)
- Eleanor Loh
- Wellcome Trust Centre for Neuroimaging, University College London, London WC1n 3BG, UK
| | - Zeb Kurth-Nelson
- Wellcome Trust Centre for Neuroimaging, University College London, London WC1n 3BG, UK.,Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London WC1B 5EH, UK
| | - David Berron
- Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, D-39120 Magdeburg, Germany
| | - Peter Dayan
- Gatsby Computational Neuroscience Unit, University College London, London W1T 4JG, UK
| | - Emrah Duzel
- Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, D-39120 Magdeburg, Germany.,Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK
| | - Ray Dolan
- Wellcome Trust Centre for Neuroimaging, University College London, London WC1n 3BG, UK.,Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London WC1B 5EH, UK
| | - Marc Guitart-Masip
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London WC1B 5EH, UK.,Ageing Research Centre, Karolinska Institute Stockholm, SE-11330 Stockholm, Sweden
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50
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Unfolding the cognitive map: The role of hippocampal and extra-hippocampal substrates based on a systems analysis of spatial processing. Neurobiol Learn Mem 2018; 147:90-119. [DOI: 10.1016/j.nlm.2017.11.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/17/2017] [Accepted: 11/21/2017] [Indexed: 01/03/2023]
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