1
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Chen S, Cheng N, Chen X, Wang C. Integration and competition between space and time in the hippocampus. Neuron 2024:S0896-6273(24)00579-8. [PMID: 39241779 DOI: 10.1016/j.neuron.2024.08.007] [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: 03/12/2024] [Revised: 07/11/2024] [Accepted: 08/09/2024] [Indexed: 09/09/2024]
Abstract
Episodic memory is organized in both spatial and temporal contexts. The hippocampus is crucial for episodic memory and has been demonstrated to encode spatial and temporal information. However, how the representations of space and time interact in the hippocampal memory system is still unclear. Here, we recorded the activity of hippocampal CA1 neurons in mice in a variety of one-dimensional navigation tasks while systematically varying the speed of the animals. For all tasks, we found neurons simultaneously represented space and elapsed time. There was a negative correlation between the preferred space and lap duration, e.g., the preferred spatial position shifted more toward the origin when the lap duration became longer. A similar relationship between the preferred time and traveled distance was also observed. The results strongly suggest a competitive and integrated representation of space-time by single hippocampal neurons, which may provide the neural basis for spatiotemporal contexts.
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Affiliation(s)
- Shijie Chen
- Brain Research Centre, Department of Neuroscience, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Ning Cheng
- Shenzhen Key Laboratory of Precision Diagnosis and Treatment of Depression, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Xiaojing Chen
- Brain Research Centre, Department of Neuroscience, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Cheng Wang
- Shenzhen Key Laboratory of Precision Diagnosis and Treatment of Depression, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Key Laboratory of Brain Cognition and Brain-inspired Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.
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2
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Wang Y, Wang X, Wang L, Zheng L, Meng S, Zhu N, An X, Wang L, Yang J, Zheng C, Ming D. Dynamic prediction of goal location by coordinated representation of prefrontal-hippocampal theta sequences. Curr Biol 2024; 34:1866-1879.e6. [PMID: 38608677 DOI: 10.1016/j.cub.2024.03.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/20/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024]
Abstract
Prefrontal (PFC) and hippocampal (HPC) sequences of neuronal firing modulated by theta rhythms could represent upcoming choices during spatial memory-guided decision-making. How the PFC-HPC network dynamically coordinates theta sequences to predict specific goal locations and how it is interrupted in memory impairments induced by amyloid beta (Aβ) remain unclear. Here, we detected theta sequences of firing activities of PFC neurons and HPC place cells during goal-directed spatial memory tasks. We found that PFC ensembles exhibited predictive representation of the specific goal location since the starting phase of memory retrieval, earlier than the hippocampus. High predictive accuracy of PFC theta sequences existed during successful memory retrieval and positively correlated with memory performance. Coordinated PFC-HPC sequences showed PFC-dominant prediction of goal locations during successful memory retrieval. Furthermore, we found that theta sequences of both regions still existed under Aβ accumulation, whereas their predictive representation of goal locations was weakened with disrupted spatial representation of HPC place cells and PFC neurons. These findings highlight the essential role of coordinated PFC-HPC sequences in successful memory retrieval of a precise goal location.
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Affiliation(s)
- Yimeng Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Xueling Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Ling Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
| | - Li Zheng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Shuang Meng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Nan Zhu
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Xingwei An
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
| | - Lei Wang
- School of Statistics and Data Science, Nankai University, Tianjin 300071, China.
| | - Jiajia Yang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
| | - Chenguang Zheng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
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3
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Herber CS, Pratt KJ, Shea JM, Villeda SA, Giocomo LM. Spatial Coding Dysfunction and Network Instability in the Aging Medial Entorhinal Cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.12.588890. [PMID: 38659809 PMCID: PMC11042240 DOI: 10.1101/2024.04.12.588890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Across species, spatial memory declines with age, possibly reflecting altered hippocampal and medial entorhinal cortex (MEC) function. However, the integrity of cellular and network-level spatial coding in aged MEC is unknown. Here, we leveraged in vivo electrophysiology to assess MEC function in young, middle-aged, and aged mice navigating virtual environments. In aged grid cells, we observed impaired stabilization of context-specific spatial firing, correlated with spatial memory deficits. Additionally, aged grid networks shifted firing patterns often but with poor alignment to context changes. Aged spatial firing was also unstable in an unchanging environment. In these same mice, we identified 458 genes differentially expressed with age in MEC, 61 of which had expression correlated with spatial firing stability. These genes were enriched among interneurons and related to synaptic transmission. Together, these findings identify coordinated transcriptomic, cellular, and network changes in MEC implicated in impaired spatial memory in aging.
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Affiliation(s)
- Charlotte S. Herber
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
| | - Karishma J.B. Pratt
- Department of Anatomy, University of California San Francisco, 513 Parnassus Avenue, Box 0452, San Francisco, CA, 94143, USA
- These authors contributed equally
| | - Jeremy M. Shea
- Department of Anatomy, University of California San Francisco, 513 Parnassus Avenue, Box 0452, San Francisco, CA, 94143, USA
- These authors contributed equally
| | - Saul A. Villeda
- Department of Anatomy, University of California San Francisco, 513 Parnassus Avenue, Box 0452, San Francisco, CA, 94143, USA
- Bakar Aging Research Institute, San Francisco, CA, 94143, USA
| | - Lisa M. Giocomo
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
- Lead contact
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4
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Politi A, Torcini A. A robust balancing mechanism for spiking neural networks. CHAOS (WOODBURY, N.Y.) 2024; 34:041102. [PMID: 38639569 DOI: 10.1063/5.0199298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 02/03/2024] [Indexed: 04/20/2024]
Abstract
Dynamical balance of excitation and inhibition is usually invoked to explain the irregular low firing activity observed in the cortex. We propose a robust nonlinear balancing mechanism for a random network of spiking neurons, which works also in the absence of strong external currents. Biologically, the mechanism exploits the plasticity of excitatory-excitatory synapses induced by short-term depression. Mathematically, the nonlinear response of the synaptic activity is the key ingredient responsible for the emergence of a stable balanced regime. Our claim is supported by a simple self-consistent analysis accompanied by extensive simulations performed for increasing network sizes. The observed regime is essentially fluctuation driven and characterized by highly irregular spiking dynamics of all neurons.
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Affiliation(s)
- Antonio Politi
- Institute for Complex Systems and Mathematical Biology and Department of Physics, Aberdeen AB24 3UE, United Kingdom
- CNR-Consiglio Nazionale delle Ricerche-Istituto dei Sistemi Complessi, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
| | - Alessandro Torcini
- CNR-Consiglio Nazionale delle Ricerche-Istituto dei Sistemi Complessi, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
- Laboratoire de Physique Théorique et Modélisation, CY Cergy Paris Université, CNRS UMR 8089, 95302 Cergy-Pontoise cedex, France
- INFN Sezione di Firenze, Via Sansone 1 50019 Sesto Fiorentino, Italy
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5
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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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6
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Ding SS, Fox JL, Gordus A, Joshi A, Liao JC, Scholz M. Fantastic beasts and how to study them: rethinking experimental animal behavior. J Exp Biol 2024; 227:jeb247003. [PMID: 38372042 PMCID: PMC10911175 DOI: 10.1242/jeb.247003] [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] [Indexed: 02/20/2024]
Abstract
Humans have been trying to understand animal behavior at least since recorded history. Recent rapid development of new technologies has allowed us to make significant progress in understanding the physiological and molecular mechanisms underlying behavior, a key goal of neuroethology. However, there is a tradeoff when studying animal behavior and its underlying biological mechanisms: common behavior protocols in the laboratory are designed to be replicable and controlled, but they often fail to encompass the variability and breadth of natural behavior. This Commentary proposes a framework of 10 key questions that aim to guide researchers in incorporating a rich natural context into their experimental design or in choosing a new animal study system. The 10 questions cover overarching experimental considerations that can provide a template for interspecies comparisons, enable us to develop studies in new model organisms and unlock new experiments in our quest to understand behavior.
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Affiliation(s)
- Siyu Serena Ding
- Max Planck Institute of Animal Behavior, 78464 Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, 78464 Konstanz, Germany
| | - Jessica L. Fox
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Andrew Gordus
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Abhilasha Joshi
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA 94158, USA
| | - James C. Liao
- Department of Biology, The Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
| | - Monika Scholz
- Max Planck Research Group Neural Information Flow, Max Planck Institute for Neurobiology of Behavior – caesar, 53175 Bonn, Germany
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7
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Sloin HE, Spivak L, Levi A, Gattegno R, Someck S, Stark E. Local activation of CA1 pyramidal cells induces theta-phase precession. Science 2024; 383:551-558. [PMID: 38301006 DOI: 10.1126/science.adk2456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 12/21/2023] [Indexed: 02/03/2024]
Abstract
Hippocampal theta-phase precession is involved in spatiotemporal coding and in generating multineural spike sequences, but how precession originates remains unresolved. To determine whether precession can be generated directly in hippocampal area CA1 and disambiguate multiple competing mechanisms, we used closed-loop optogenetics to impose artificial place fields in pyramidal cells of mice running on a linear track. More than one-third of the CA1 artificial fields exhibited synthetic precession that persisted for a full theta cycle. By contrast, artificial fields in the parietal cortex did not exhibit synthetic precession. These findings are incompatible with precession models based on inheritance, dual-input, spreading activation, inhibition-excitation summation, or somato-dendritic competition. Thus, a precession generator resides locally within CA1.
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Affiliation(s)
- Hadas E Sloin
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Lidor Spivak
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Amir Levi
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roni Gattegno
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Shirly Someck
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Eran Stark
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Sagol Department of Neurobiology, Haifa University, Haifa 3103301, Israel
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8
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Dragoi G. The generative grammar of the brain: a critique of internally generated representations. Nat Rev Neurosci 2024; 25:60-75. [PMID: 38036709 DOI: 10.1038/s41583-023-00763-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2023] [Indexed: 12/02/2023]
Abstract
The past decade of progress in neurobiology has uncovered important organizational principles for network preconfiguration and neuronal selection that suggest a generative grammar exists in the brain. In this Perspective, I discuss the competence of the hippocampal neural network to generically express temporally compressed sequences of neuronal firing that represent novel experiences, which is envisioned as a form of generative neural syntax supporting a neurobiological perspective on brain function. I compare this neural competence with the hippocampal network performance that represents specific experiences with higher fidelity after new learning during replay, which is envisioned as a form of neural semantic that supports a complementary neuropsychological perspective. I also demonstrate how the syntax of network competence emerges a priori during early postnatal life and is followed by the later development of network performance that enables rapid encoding and memory consolidation. Thus, I propose that this generative grammar of the brain is essential for internally generated representations, which are crucial for the cognitive processes underlying learning and memory, prospection, and inference, which ultimately underlie our reason and representation of the world.
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Affiliation(s)
- George Dragoi
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.
- Wu Tsai Institute, Yale University, New Haven, CT, USA.
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9
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Prince SM, Yassine TA, Katragadda N, Roberts TC, Singer AC. New information triggers prospective codes to adapt for flexible navigation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.31.564814. [PMID: 37961524 PMCID: PMC10634986 DOI: 10.1101/2023.10.31.564814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Navigating a dynamic world requires rapidly updating choices by integrating past experiences with new information. In hippocampus and prefrontal cortex, neural activity representing future goals is theorized to support planning. However, it remains unknown how prospective goal representations incorporate new, pivotal information. Accordingly, we designed a novel task that precisely introduces new information using virtual reality, and we recorded neural activity as mice flexibly adapted their planned destinations. We found that new information triggered increased hippocampal prospective representations of both possible goals; while in prefrontal cortex, new information caused prospective representations of choices to rapidly shift to the new choice. When mice did not flexibly adapt, prefrontal choice codes failed to switch, despite relatively intact hippocampal goal representations. Prospective code updating depended on the commitment to the initial choice and degree of adaptation needed. Thus, we show how prospective codes update with new information to flexibly adapt ongoing navigational plans.
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Affiliation(s)
- Stephanie M. Prince
- Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, 30332, United States
| | - Teema A. Yassine
- Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, 30332, United States
| | - Navya Katragadda
- Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, 30332, United States
| | - Tyler C. Roberts
- Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, 30332, United States
| | - Annabelle C. Singer
- Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, 30332, United States
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10
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Liu C, Todorova R, Tang W, Oliva A, Fernandez-Ruiz A. Associative and predictive hippocampal codes support memory-guided behaviors. Science 2023; 382:eadi8237. [PMID: 37856604 PMCID: PMC10894649 DOI: 10.1126/science.adi8237] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/21/2023] [Indexed: 10/21/2023]
Abstract
Episodic memory involves learning and recalling associations between items and their spatiotemporal context. Those memories can be further used to generate internal models of the world that enable predictions to be made. The mechanisms that support these associative and predictive aspects of memory are not yet understood. In this study, we used an optogenetic manipulation to perturb the sequential structure, but not global network dynamics, of place cells as rats traversed specific spatial trajectories. This perturbation abolished replay of those trajectories and the development of predictive representations, leading to impaired learning of new optimal trajectories during memory-guided navigation. However, place cell assembly reactivation and reward-context associative learning were unaffected. Our results show a mechanistic dissociation between two complementary hippocampal codes: an associative code (through coactivity) and a predictive code (through sequences).
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Affiliation(s)
| | | | - Wenbo Tang
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
| | - Azahara Oliva
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
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11
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Seger SE, Kriegel JLS, Lega BC, Ekstrom AD. Memory-related processing is the primary driver of human hippocampal theta oscillations. Neuron 2023; 111:3119-3130.e4. [PMID: 37467749 PMCID: PMC10685603 DOI: 10.1016/j.neuron.2023.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 05/01/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
Decades of work in rodents suggest that movement is a powerful driver of hippocampal low-frequency "theta" oscillations. Puzzlingly, such movement-related theta increases in primates are less sustained and of lower frequency, leading to questions about their functional relevance. Verbal memory encoding and retrieval lead to robust increases in low-frequency oscillations in humans, and one possibility is that memory might be a stronger driver of hippocampal theta oscillations in humans than navigation. Here, neurosurgical patients navigated routes and then immediately mentally simulated the same routes while undergoing intracranial recordings. We found that mentally simulating the same route that was just navigated elicited oscillations that were of greater power, higher frequency, and longer duration than those involving navigation. Our findings suggest that memory is a more potent driver of human hippocampal theta oscillations than navigation, supporting models of internally generated theta oscillations in the human hippocampus.
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Affiliation(s)
- Sarah E Seger
- Neuroscience Interdisciplinary Program, University of Arizona, 1503 E. University Blvd., Tucson, AZ 85719, USA
| | - Jennifer L S Kriegel
- Department of Neurosurgery, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Brad C Lega
- Department of Neurosurgery, University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Arne D Ekstrom
- Neuroscience Interdisciplinary Program, University of Arizona, 1503 E. University Blvd., Tucson, AZ 85719, USA; Psychology Department, University of Arizona, 1503 E. University Blvd., Tucson, AZ 85719, USA; Evelyn McKnight Brain Institute, University of Arizona, 1503 E. University Blvd., Tucson, AZ 85719, USA.
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12
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Robbe D. Lost in time: Relocating the perception of duration outside the brain. Neurosci Biobehav Rev 2023; 153:105312. [PMID: 37467906 DOI: 10.1016/j.neubiorev.2023.105312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/08/2023] [Indexed: 07/21/2023]
Abstract
It is well-accepted in neuroscience that animals process time internally to estimate the duration of intervals lasting between one and several seconds. More than 100 years ago, Henri Bergson nevertheless remarked that, because animals have memory, their inner experience of time is ever-changing, making duration impossible to measure internally and time a source of change. Bergson proposed that quantifying the inner experience of time requires its externalization in movements (observed or self-generated), as their unfolding leaves measurable traces in space. Here, studies across species are reviewed and collectively suggest that, in line with Bergson's ideas, animals spontaneously solve time estimation tasks through a movement-based spatialization of time. Moreover, the well-known scalable anticipatory responses of animals to regularly spaced rewards can be explained by the variable pressure of time on reward-oriented actions. Finally, the brain regions linked with time perception overlap with those implicated in motor control, spatial navigation and motivation. Thus, instead of considering time as static information processed by the brain, it might be fruitful to conceptualize it as a kind of force to which animals are more or less sensitive depending on their internal state and environment.
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Affiliation(s)
- David Robbe
- Institut de Neurobiologie de la Méditerranée (INMED), INSERM, Marseille, France; Aix-Marseille Université, Marseille, France.
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13
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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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14
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Robinson JC, Wilmot JH, Hasselmo ME. Septo-hippocampal dynamics and the encoding of space and time. Trends Neurosci 2023; 46:712-725. [PMID: 37479632 PMCID: PMC10538955 DOI: 10.1016/j.tins.2023.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 05/12/2023] [Accepted: 06/27/2023] [Indexed: 07/23/2023]
Abstract
Encoding an event in memory requires neural activity to represent multiple dimensions of behavioral experience in space and time. Recent experiments have explored the influence of neural dynamics regulated by the medial septum on the functional encoding of space and time by neurons in the hippocampus and associated structures. This review addresses these dynamics, focusing on the role of theta rhythm, the differential effects of septal inactivation and activation on the functional coding of space and time by individual neurons, and the influence on phase coding that appears as phase precession. We also discuss data indicating that theta rhythm plays a role in timing the internal dynamics of memory encoding and retrieval, as well as the behavioral influences of these neuronal manipulations with regard to memory function.
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Affiliation(s)
- Jennifer C Robinson
- Center for Systems Neuroscience, Boston University, 610 Commonwealth Avenue, Boston, MA 02215, USA.
| | - Jacob H Wilmot
- Center for Systems Neuroscience, Boston University, 610 Commonwealth Avenue, Boston, MA 02215, USA.
| | - Michael E Hasselmo
- Center for Systems Neuroscience, Boston University, 610 Commonwealth Avenue, Boston, MA 02215, USA.
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15
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Etter G, Carmichael JE, Williams S. Linking temporal coordination of hippocampal activity to memory function. Front Cell Neurosci 2023; 17:1233849. [PMID: 37720546 PMCID: PMC10501408 DOI: 10.3389/fncel.2023.1233849] [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: 06/02/2023] [Accepted: 08/01/2023] [Indexed: 09/19/2023] Open
Abstract
Oscillations in neural activity are widespread throughout the brain and can be observed at the population level through the local field potential. These rhythmic patterns are associated with cycles of excitability and are thought to coordinate networks of neurons, in turn facilitating effective communication both within local circuits and across brain regions. In the hippocampus, theta rhythms (4-12 Hz) could contribute to several key physiological mechanisms including long-range synchrony, plasticity, and at the behavioral scale, support memory encoding and retrieval. While neurons in the hippocampus appear to be temporally coordinated by theta oscillations, they also tend to fire in sequences that are developmentally preconfigured. Although loss of theta rhythmicity impairs memory, these sequences of spatiotemporal representations persist in conditions of altered hippocampal oscillations. The focus of this review is to disentangle the relative contribution of hippocampal oscillations from single-neuron activity in learning and memory. We first review cellular, anatomical, and physiological mechanisms underlying the generation and maintenance of hippocampal rhythms and how they contribute to memory function. We propose candidate hypotheses for how septohippocampal oscillations could support memory function while not contributing directly to hippocampal sequences. In particular, we explore how theta rhythms could coordinate the integration of upstream signals in the hippocampus to form future decisions, the relevance of such integration to downstream regions, as well as setting the stage for behavioral timescale synaptic plasticity. Finally, we leverage stimulation-based treatment in Alzheimer's disease conditions as an opportunity to assess the sufficiency of hippocampal oscillations for memory function.
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Affiliation(s)
| | | | - Sylvain Williams
- Department of Psychiatry, Douglas Mental Health Research Institute, McGill University, Montreal, QC, Canada
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16
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Aoki Y, Yokoi T, Morikawa S, Kuga N, Ikegaya Y, Sasaki T. Effects of theta phase precessing optogenetic intervention on hippocampal neuronal reactivation and spatial maps. iScience 2023; 26:107233. [PMID: 37534136 PMCID: PMC10392074 DOI: 10.1016/j.isci.2023.107233] [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: 05/04/2023] [Revised: 06/04/2023] [Accepted: 06/23/2023] [Indexed: 08/04/2023] Open
Abstract
As animals explore environments, hippocampal place cells sequentially fire at progressively earlier phases of theta oscillations in hippocampal local field potentials. In this study, we evaluated the network-level significance of theta phase-entrained neuronal activity in organizing place cell spike patterns. A closed-loop system was developed in which optogenetic stimulation with a temporal pattern replicating theta phase precession is delivered to hippocampal CA1 neurons when rats traversed a particular region on a linear track. Place cells that had place fields during phase precessing stimulation, but not random phase stimulation, showed stronger reactivation during hippocampal sharp-wave ripples in a subsequent rest period. After the rest period, place cells with place fields that emerged during phase precessing stimulation showed more stable place fields. These results imply that neuronal reactivation and stability of spatial maps are mediated by theta phase precession in the hippocampus.
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Affiliation(s)
- Yuki Aoki
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Taiki Yokoi
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-Ku, Sendai 980-8578, Japan
| | - Shota Morikawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo 113-0033, Japan
| | - Nahoko Kuga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-Ku, Sendai 980-8578, Japan
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo 113-0033, Japan
- Center for Information and Neural Networks, 1-4 Yamadaoka, Suita City, Osaka 565-0871, Japan
| | - Takuya Sasaki
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-Ku, Sendai 980-8578, Japan
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17
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Ma W, Si T, Wang Z, Wen P, Zhu Z, Liu Q, Wang J, Xu F, Li Q. Astrocytic α4-containing nAChR signaling in the hippocampus governs the formation of temporal association memory. Cell Rep 2023; 42:112674. [PMID: 37352098 DOI: 10.1016/j.celrep.2023.112674] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 03/24/2023] [Accepted: 06/06/2023] [Indexed: 06/25/2023] Open
Abstract
Everyday episodic memories involve linking together related events that are temporally separated. However, the mechanisms of forming this temporal association have remained unclear. Here, using astrocyte-specific manipulations, we show that potentiating astrocyte Ca2+ signaling in the hippocampal cornu ammonis 1 (CA1) enhances the strength of such temporal association, in parallel with long-term potentiation (LTP) enhancement of temporoammonic pathway to CA1, whereas attenuation of astrocyte Ca2+ signaling has the opposite effect. Moreover, we identify that these effects are mediated by astrocytic α4 subunit-containing nicotinic acetylcholine receptors (α4-nAChRs) via mechanisms involving NMDAR co-agonist supply. Finally, astrocytic α4-nAChRs underlie the cognitive enhancer nicotine's physiological effects. Together, these findings highlight the importance of astrocyte Ca2+ signaling in cognitive behavior and reveal a mechanism in governing the temporal association of episodic memory formation that operates through α4-nAChRs on hippocampal astrocytes.
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Affiliation(s)
- Wenyu Ma
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tengxiao Si
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zan Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengjie Wen
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zhenxiang Zhu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qing Liu
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fuqiang Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Qin Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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18
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Parra-Barrero E, Cheng S. Learning to predict future locations with internally generated theta sequences. PLoS Comput Biol 2023; 19:e1011101. [PMID: 37172053 DOI: 10.1371/journal.pcbi.1011101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 05/24/2023] [Accepted: 04/13/2023] [Indexed: 05/14/2023] Open
Abstract
Representing past, present and future locations is key for spatial navigation. Indeed, within each cycle of the theta oscillation, the population of hippocampal place cells appears to represent trajectories starting behind the current position of the animal and sweeping ahead of it. In particular, we reported recently that the position represented by CA1 place cells at a given theta phase corresponds to the location where animals were or will be located at a fixed time interval into the past or future assuming the animal ran at its typical, not the current, speed through that part of the environment. This coding scheme leads to longer theta trajectories, larger place fields and shallower phase precession in areas where animals typically run faster. Here we present a mechanistic computational model that accounts for these experimental observations. The model consists of a continuous attractor network with short-term synaptic facilitation and depression that internally generates theta sequences that advance at a fixed pace. Spatial locations are then mapped onto the active units via modified Hebbian plasticity. As a result, neighboring units become associated with spatial locations further apart where animals run faster, reproducing our earlier experimental results. The model also accounts for the higher density of place fields generally observed where animals slow down, such as around rewards. Furthermore, our modeling results reveal that an artifact of the decoding analysis might be partly responsible for the observation that theta trajectories start behind the animal's current position. Overall, our results shed light on how the hippocampal code might arise from the interplay between behavior, sensory input and predefined network dynamics.
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Affiliation(s)
- Eloy Parra-Barrero
- Institute for Neural Computation, Faculty of Computer Science, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Sen Cheng
- Institute for Neural Computation, Faculty of Computer Science, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
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19
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Joshi A, Denovellis EL, Mankili A, Meneksedag Y, Davidson TJ, Gillespie AK, Guidera JA, Roumis D, Frank LM. Dynamic synchronization between hippocampal representations and stepping. Nature 2023; 617:125-131. [PMID: 37046088 PMCID: PMC10156593 DOI: 10.1038/s41586-023-05928-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 03/07/2023] [Indexed: 04/14/2023]
Abstract
The hippocampus is a mammalian brain structure that expresses spatial representations1 and is crucial for navigation2,3. Navigation, in turn, intricately depends on locomotion; however, current accounts suggest a dissociation between hippocampal spatial representations and the details of locomotor processes. Specifically, the hippocampus is thought to represent mainly higher-order cognitive and locomotor variables such as position, speed and direction of movement4-7, whereas the limb movements that propel the animal can be computed and represented primarily in subcortical circuits, including the spinal cord, brainstem and cerebellum8-11. Whether hippocampal representations are actually decoupled from the detailed structure of locomotor processes remains unknown. To address this question, here we simultaneously monitored hippocampal spatial representations and ongoing limb movements underlying locomotion at fast timescales. We found that the forelimb stepping cycle in freely behaving rats is rhythmic and peaks at around 8 Hz during movement, matching the approximately 8 Hz modulation of hippocampal activity and spatial representations during locomotion12. We also discovered precisely timed coordination between the time at which the forelimbs touch the ground ('plant' times of the stepping cycle) and the hippocampal representation of space. Notably, plant times coincide with hippocampal representations that are closest to the actual position of the nose of the rat, whereas between these plant times, the hippocampal representation progresses towards possible future locations. This synchronization was specifically detectable when rats approached spatial decisions. Together, our results reveal a profound and dynamic coordination on a timescale of tens of milliseconds between central cognitive representations and peripheral motor processes. This coordination engages and disengages rapidly in association with cognitive demands and is well suited to support rapid information exchange between cognitive and sensory-motor circuits.
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Affiliation(s)
- Abhilasha Joshi
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA.
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA, USA.
| | - Eric L Denovellis
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA, USA
| | - Abhijith Mankili
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA, USA
| | - Yagiz Meneksedag
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
- Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Thomas J Davidson
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| | - Anna K Gillespie
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA, USA
| | - Jennifer A Guidera
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA, USA
| | - Demetris Roumis
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA, USA
| | - Loren M Frank
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA.
- Departments of Physiology and Psychiatry, University of California, San Francisco, CA, USA.
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA, USA.
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20
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Liu J, Chen D, Xiao X, Zhang H, Zhou W, Liang S, Kunz L, Schulze-Bonhage A, Axmacher N, Wang L. Multi-scale goal distance representations in human hippocampus during virtual spatial navigation. Curr Biol 2023; 33:2024-2033.e3. [PMID: 37148875 DOI: 10.1016/j.cub.2023.04.033] [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: 12/29/2022] [Revised: 03/17/2023] [Accepted: 04/14/2023] [Indexed: 05/08/2023]
Abstract
Goal-directed navigation relies on both coarse and fine-grained coding of spatial distance between the current position of a navigating subject and a goal destination. However, the neural signatures underlying goal distance coding remain poorly understood. Using intracranial EEG recordings from the hippocampus of drug-resistant epilepsy patients who performed a virtual spatial navigation task, we found that the right hippocampal theta power was significantly modulated by goal distance and decreased with goal proximity. This modulation varied along the hippocampal longitudinal axis such that theta power in the posterior hippocampus decreased more strongly with goal proximity. Similarly, neural timescale, reflecting the duration across which information can be maintained, increased gradually from the posterior to anterior hippocampus. Taken together, this study provides empirical evidence for multi-scale spatial representations of goal distance in the human hippocampus and links the hippocampal processing of spatial information to its intrinsic temporal dynamics.
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Affiliation(s)
- Jiali Liu
- CAS Key Laboratory of Mental Health, Institute of Psychology, 16 Lincui Rd, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, 1 Yanqihu East Rd, Beijing 101408, China
| | - Dong Chen
- CAS Key Laboratory of Mental Health, Institute of Psychology, 16 Lincui Rd, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, 1 Yanqihu East Rd, Beijing 101408, China
| | - Xue Xiao
- CAS Key Laboratory of Mental Health, Institute of Psychology, 16 Lincui Rd, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, 1 Yanqihu East Rd, Beijing 101408, China
| | - Hui Zhang
- Department of Neuropsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Universitätsstraße 150, Bochum 44801, Germany
| | - Wenjing Zhou
- Department of Epilepsy Center, Tsinghua University Yuquan Hospital, 5 Shijingshan Rd, Beijing 100040, China
| | - Shuli Liang
- Functional Neurosurgery Department, Beijing Children's Hospital, Capital Medical University, 56 Nanlishi Rd, Beijing 100045, China
| | - Lukas Kunz
- Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Ave, New York, NY 10027, USA
| | - Andreas Schulze-Bonhage
- Epilepsy Center, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 64, Freiburg im Breisgau 79106, Germany
| | - Nikolai Axmacher
- Department of Neuropsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Universitätsstraße 150, Bochum 44801, Germany
| | - Liang Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, 16 Lincui Rd, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, 1 Yanqihu East Rd, Beijing 101408, China.
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21
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Layfield D, Sidell N, Blankenberger K, Newman EL. Hippocampal inactivation during rearing on hind legs impairs spatial memory. Sci Rep 2023; 13:6136. [PMID: 37061540 PMCID: PMC10105745 DOI: 10.1038/s41598-023-33209-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 04/09/2023] [Indexed: 04/17/2023] Open
Abstract
Spatial memory requires an intact hippocampus. Hippocampal function during epochs of locomotion and quiet rest (e.g., grooming and reward consumption) has been the target of extensive study. However, during navigation rats frequently rear up onto their hind legs, and the importance of hippocampal activity during these periods of attentive sampling for spatial memory is unknown. To address this, we tested the necessity of dorsal hippocampal activity during rearing epochs in the study phase of a delayed win-shift task for memory performance in the subsequent test phase. Hippocampal activity was manipulated with closed-loop, bilateral, optogenetic inactivation. Spatial memory accuracy was significantly and selectively reduced when the dorsal hippocampus was inactivated during rearing epochs at encoding. These data show that hippocampal activity during periods of rearing can be important for spatial memory, revealing a novel link between hippocampal function during epochs of rearing and spatial memory.
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Affiliation(s)
- Dylan Layfield
- Program in Neuroscience, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA.
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA.
| | - Nathan Sidell
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
| | - Kevin Blankenberger
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
| | - Ehren Lee Newman
- Program in Neuroscience, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
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22
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Heldman R, Pang D, Zhao X, Wang Y. A CA1 circuit motif that signals the start of information integration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.12.532295. [PMID: 36993346 PMCID: PMC10054991 DOI: 10.1101/2023.03.12.532295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Integrating information from the recent past is critical for guiding predictions and shaping behavior. The process of integrating information, such as tracking distance traveled or time elapsed, begins with establishing a starting point. Yet, the mechanisms by which neural circuits utilize relevant cues to initiate integration remain unknown. Our study sheds light on this question by identifying a subpopulation of CA1 pyramidal neurons called PyrDown. These neurons shut down their activity at the beginning of distance or time integration and then gradually ramp up their firing as the animal approaches the reward. PyrDown neurons provide a mechanism for representing integrated information through ramping activity, complementing the well-known place/time cells that respond to specific distances or time points. Our findings also reveal that parvalbumin inhibitory interneurons mediate the shutdown of PyrDown neurons, uncovering a circuit motif that enables the initiation of subsequent information integration to improve future predictions.
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23
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Leprince E, Dard RF, Mortet S, Filippi C, Giorgi-Kurz M, Bourboulou R, Lenck-Santini PP, Picardo MA, Bocchio M, Baude A, Cossart R. Extrinsic control of the early postnatal CA1 hippocampal circuits. Neuron 2023; 111:888-902.e8. [PMID: 36608692 DOI: 10.1016/j.neuron.2022.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 10/18/2022] [Accepted: 12/08/2022] [Indexed: 01/07/2023]
Abstract
The adult CA1 region of the hippocampus produces coordinated neuronal dynamics with minimal reliance on its extrinsic inputs. By contrast, neonatal CA1 is tightly linked to externally generated sensorimotor activity, but the circuit mechanisms underlying early synchronous activity in CA1 remain unclear. Here, using a combination of in vivo and ex vivo circuit mapping, calcium imaging, and electrophysiological recordings in mouse pups, we show that early dynamics in the ventro-intermediate CA1 are under the mixed influence of entorhinal (EC) and thalamic (VMT) inputs. Both VMT and EC can drive internally generated synchronous events ex vivo. However, movement-related population bursts detected in vivo are exclusively driven by the EC. These differential effects on synchrony reflect the different intrahippocampal targets of these inputs. Hence, cortical and subcortical pathways act differently on the neonatal CA1, implying distinct contributions to the development of the hippocampal microcircuit and related cognitive maps.
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Affiliation(s)
- Erwan Leprince
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France
| | - Robin F Dard
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France
| | - Salomé Mortet
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France
| | - Caroline Filippi
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France
| | - Marie Giorgi-Kurz
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France
| | - Romain Bourboulou
- Department of Cell and Developmental Biology, University College London, London, UK
| | | | - Michel A Picardo
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France
| | - Marco Bocchio
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France; Department of Psychology, Durham University, Durham, UK
| | - Agnès Baude
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France
| | - Rosa Cossart
- Aix Marseille University, INSERM, INMED (UMR1249), Turing Centre for Living systems, Marseille, France.
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24
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Hines M, Poulter S, Douchamps V, Pibiri F, McGregor A, Lever C. Frequency matters: how changes in hippocampal theta frequency can influence temporal coding, anxiety-reduction, and memory. Front Syst Neurosci 2023; 16:998116. [PMID: 36817946 PMCID: PMC9936826 DOI: 10.3389/fnsys.2022.998116] [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: 07/19/2022] [Accepted: 12/30/2022] [Indexed: 02/05/2023] Open
Abstract
Hippocampal theta frequency is a somewhat neglected topic relative to theta power, phase, coherence, and cross-frequency coupling. Accordingly, here we review and present new data on variation in hippocampal theta frequency, focusing on functional associations (temporal coding, anxiety reduction, learning, and memory). Taking the rodent hippocampal theta frequency to running-speed relationship as a model, we identify two doubly-dissociable frequency components: (a) the slope component of the theta frequency-to-stimulus-rate relationship ("theta slope"); and (b) its y-intercept frequency ("theta intercept"). We identify three tonic determinants of hippocampal theta frequency. (1) Hotter temperatures increase theta frequency, potentially consistent with time intervals being judged as shorter when hot. Initial evidence suggests this occurs via the "theta slope" component. (2) Anxiolytic drugs with widely-different post-synaptic and pre-synaptic primary targets share the effect of reducing the "theta intercept" component, supporting notions of a final common pathway in anxiety reduction involving the hippocampus. (3) Novelty reliably decreases, and familiarity increases, theta frequency, acting upon the "theta slope" component. The reliability of this latter finding, and the special status of novelty for learning, prompts us to propose a Novelty Elicits Slowing of Theta frequency (NEST) hypothesis, involving the following elements: (1) Theta frequency slowing in the hippocampal formation is a generalised response to novelty of different types and modalities; (2) Novelty-elicited theta slowing is a hippocampal-formation-wide adaptive response functioning to accommodate the additional need for learning entailed by novelty; (3) Lengthening the theta cycle enhances associativity; (4) Even part-cycle lengthening may boost associativity; and (5) Artificial theta stimulation aimed at enhancing learning should employ low-end theta frequencies.
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25
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Morris G, Derdikman D. The chicken and egg problem of grid cells and place cells. Trends Cogn Sci 2023; 27:125-138. [PMID: 36437188 DOI: 10.1016/j.tics.2022.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 11/26/2022]
Abstract
Place cells and grid cells are major building blocks of the hippocampal cognitive map. The prominent forward model postulates that grid-cell modules are generated by a continuous attractor network; that a velocity signal evoked during locomotion moves entorhinal activity bumps; and that place-cell activity constitutes summation of entorhinal grid-cell modules. Experimental data support the first postulate, but not the latter two. Several families of solutions that depart from these postulates have been put forward. We suggest a modified model (spatial modulation continuous attractor network; SCAN), whereby place cells are generated from spatially selective nongrid cells. Locomotion causes these cells to move the hippocampal activity bump, leading to movement of the entorhinal manifolds. Such inversion accords with the shift of hippocampal thought from navigation to more abstract functions.
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Affiliation(s)
- Genela Morris
- Department of Neuroscience, Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel; Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
| | - Dori Derdikman
- Department of Neuroscience, Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel.
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26
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Omer DB, Las L, Ulanovsky N. Contextual and pure time coding for self and other in the hippocampus. Nat Neurosci 2023; 26:285-294. [PMID: 36585486 DOI: 10.1038/s41593-022-01226-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 10/31/2022] [Indexed: 12/31/2022]
Abstract
Navigation and episodic memory depend critically on representing temporal sequences. Hippocampal 'time cells' form temporal sequences, but it is unknown whether they represent context-dependent experience or time per se. Here we report on time cells in bat hippocampal area CA1, which, surprisingly, formed two distinct populations. One population of time cells generated different temporal sequences when the bat hung at different locations, thus conjunctively encoding spatial context and time-'contextual time cells'. A second population exhibited similar preferred times across different spatial contexts, thus purely encoding elapsed time. When examining neural responses after the landing moment of another bat, in a social imitation task, we found time cells that encoded temporal sequences aligned to the other's landing. We propose that these diverse time codes may support the perception of interval timing, episodic memory and temporal coordination between self and others.
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Affiliation(s)
- David B Omer
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Liora Las
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Nachum Ulanovsky
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
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27
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Etter G, van der Veldt S, Choi J, Williams S. Optogenetic frequency scrambling of hippocampal theta oscillations dissociates working memory retrieval from hippocampal spatiotemporal codes. Nat Commun 2023; 14:410. [PMID: 36697399 PMCID: PMC9877037 DOI: 10.1038/s41467-023-35825-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 01/03/2023] [Indexed: 01/26/2023] Open
Abstract
The precise temporal coordination of activity in the brain is thought to be fundamental for memory function. Inhibitory neurons in the medial septum provide a prominent source of innervation to the hippocampus and play a major role in controlling hippocampal theta (~8 Hz) oscillations. While pharmacological inhibition of medial septal neurons is known to disrupt memory, the exact role of septal inhibitory neurons in regulating hippocampal representations and memory is not fully understood. Here, we dissociate the role of theta rhythms in spatiotemporal coding and memory using an all-optical interrogation and recording approach. We find that optogenetic frequency scrambling stimulations abolish theta oscillations and modulate a portion of neurons in the hippocampus. Such stimulation decreased episodic and working memory retrieval while leaving hippocampal spatiotemporal codes intact. Our study suggests that theta rhythms play an essential role in memory but may not be necessary for hippocampal spatiotemporal codes.
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Affiliation(s)
- Guillaume Etter
- McGill University & Douglas Mental Health University Institute, Montreal, Canada.
| | | | - Jisoo Choi
- McGill University & Douglas Mental Health University Institute, Montreal, Canada
| | - Sylvain Williams
- McGill University & Douglas Mental Health University Institute, Montreal, Canada.
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28
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Alexander AS, Place R, Starrett MJ, Chrastil ER, Nitz DA. Rethinking retrosplenial cortex: Perspectives and predictions. Neuron 2023; 111:150-175. [PMID: 36460006 DOI: 10.1016/j.neuron.2022.11.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 08/09/2022] [Accepted: 11/06/2022] [Indexed: 12/03/2022]
Abstract
The last decade has produced exciting new ideas about retrosplenial cortex (RSC) and its role in integrating diverse inputs. Here, we review the diversity in forms of spatial and directional tuning of RSC activity, temporal organization of RSC activity, and features of RSC interconnectivity with other brain structures. We find that RSC anatomy and dynamics are more consistent with roles in multiple sensorimotor and cognitive processes than with any isolated function. However, two more generalized categories of function may best characterize roles for RSC in complex cognitive processes: (1) shifting and relating perspectives for spatial cognition and (2) prediction and error correction for current sensory states with internal representations of the environment. Both functions likely take advantage of RSC's capacity to encode conjunctions among sensory, motor, and spatial mapping information streams. Together, these functions provide the scaffold for intelligent actions, such as navigation, perspective taking, interaction with others, and error detection.
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Affiliation(s)
- Andrew S Alexander
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
| | - Ryan Place
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael J Starrett
- Department of Neurobiology & Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Elizabeth R Chrastil
- Department of Neurobiology & Behavior, University of California, Irvine, Irvine, CA 92697, USA; Department of Cognitive Sciences, University of California, Irvine, Irvine, CA 92697, USA.
| | - Douglas A Nitz
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA 92093, USA.
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29
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Mysin I, Shubina L. Hippocampal non-theta state: The "Janus face" of information processing. Front Neural Circuits 2023; 17:1134705. [PMID: 36960401 PMCID: PMC10027749 DOI: 10.3389/fncir.2023.1134705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 02/14/2023] [Indexed: 03/09/2023] Open
Abstract
The vast majority of studies on hippocampal rhythms have been conducted on animals or humans in situations where their attention was focused on external stimuli or solving cognitive tasks. These studies formed the basis for the idea that rhythmical activity coordinates the work of neurons during information processing. However, at rest, when attention is not directed to external stimuli, brain rhythms do not disappear, although the parameters of oscillatory activity change. What is the functional load of rhythmical activity at rest? Hippocampal oscillatory activity during rest is called the non-theta state, as opposed to the theta state, a characteristic activity during active behavior. We dedicate our review to discussing the present state of the art in the research of the non-theta state. The key provisions of the review are as follows: (1) the non-theta state has its own characteristics of oscillatory and neuronal activity; (2) hippocampal non-theta state is possibly caused and maintained by change of rhythmicity of medial septal input under the influence of raphe nuclei; (3) there is no consensus in the literature about cognitive functions of the non-theta-non-ripple state; and (4) the antagonistic relationship between theta and delta rhythms observed in rodents is not always observed in humans. Most attention is paid to the non-theta-non-ripple state, since this aspect of hippocampal activity has not been investigated properly and discussed in reviews.
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30
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Viney TJ, Sarkany B, Ozdemir AT, Hartwich K, Schweimer J, Bannerman D, Somogyi P. Spread of pathological human Tau from neurons to oligodendrocytes and loss of high-firing pyramidal neurons in aging mice. Cell Rep 2022; 41:111646. [PMID: 36384116 PMCID: PMC9681663 DOI: 10.1016/j.celrep.2022.111646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 08/23/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022] Open
Abstract
Intracellular aggregation of hyperphosphorylated Tau (pTau) in the brain is associated with cognitive and motor impairments, and ultimately neurodegeneration. We investigate how human pTau affects cells and network activity in the hippocampal formation of the THY-Tau22 tauopathy model mice in vivo. We find that pTau preferentially accumulates in deep-layer pyramidal neurons, leading to neurodegeneration, and we establish that pTau spreads to oligodendrocytes. During goal-directed virtual navigation in aged transgenic mice, we detect fewer high-firing prosubicular pyramidal cells, but the firing population retains its coupling to theta oscillations. Analysis of network oscillations and firing patterns of pyramidal and GABAergic neurons recorded in head-fixed and freely moving mice suggests preserved neuronal coordination. In spatial memory tests, transgenic mice have reduced short-term familiarity, but spatial working and reference memory are surprisingly normal. We hypothesize that unimpaired subcortical network mechanisms maintain cortical neuronal coordination, counteracting the widespread pTau aggregation, loss of high-firing cells, and neurodegeneration.
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Affiliation(s)
- Tim J Viney
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK.
| | - Barbara Sarkany
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - A Tugrul Ozdemir
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Katja Hartwich
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Judith Schweimer
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - David Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford OX2 6GG, UK
| | - Peter Somogyi
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
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31
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Mao D. Neural Correlates of Spatial Navigation in Primate Hippocampus. Neurosci Bull 2022; 39:315-327. [PMID: 36319893 PMCID: PMC9905402 DOI: 10.1007/s12264-022-00968-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 06/16/2022] [Indexed: 11/07/2022] Open
Abstract
The hippocampus has been extensively implicated in spatial navigation in rodents and more recently in bats. Numerous studies have revealed that various kinds of spatial information are encoded across hippocampal regions. In contrast, investigations of spatial behavioral correlates in the primate hippocampus are scarce and have been mostly limited to head-restrained subjects during virtual navigation. However, recent advances made in freely-moving primates suggest marked differences in spatial representations from rodents, albeit some similarities. Here, we review empirical studies examining the neural correlates of spatial navigation in the primate (including human) hippocampus at the levels of local field potentials and single units. The lower frequency theta oscillations are often intermittent. Single neuron responses are highly mixed and task-dependent. We also discuss neuronal selectivity in the eye and head coordinates. Finally, we propose that future studies should focus on investigating both intrinsic and extrinsic population activity and examining spatial coding properties in large-scale hippocampal-neocortical networks across tasks.
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Affiliation(s)
- Dun Mao
- Center for Excellence in Brain Science and Intelligent Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
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32
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Lehr AB, Luboeinski J, Tetzlaff C. Neuromodulator-dependent synaptic tagging and capture retroactively controls neural coding in spiking neural networks. Sci Rep 2022; 12:17772. [PMID: 36273097 PMCID: PMC9588040 DOI: 10.1038/s41598-022-22430-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/14/2022] [Indexed: 01/19/2023] Open
Abstract
Events that are important to an individual's life trigger neuromodulator release in brain areas responsible for cognitive and behavioral function. While it is well known that the presence of neuromodulators such as dopamine and norepinephrine is required for memory consolidation, the impact of neuromodulator concentration is, however, less understood. In a recurrent spiking neural network model featuring neuromodulator-dependent synaptic tagging and capture, we study how synaptic memory consolidation depends on the amount of neuromodulator present in the minutes to hours after learning. We find that the storage of rate-based and spike timing-based information is controlled by the level of neuromodulation. Specifically, we find better recall of temporal information for high levels of neuromodulation, while we find better recall of rate-coded spatial patterns for lower neuromodulation, mediated by the selection of different groups of synapses for consolidation. Hence, our results indicate that in minutes to hours after learning, the level of neuromodulation may alter the process of synaptic consolidation to ultimately control which type of information becomes consolidated in the recurrent neural network.
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Affiliation(s)
- Andrew B. Lehr
- grid.7450.60000 0001 2364 4210Department of Computational Neuroscience, University of Göttingen, Göttingen, Germany ,grid.7450.60000 0001 2364 4210Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany ,grid.7450.60000 0001 2364 4210Department of Computational Synaptic Physiology, University of Göttingen, Göttingen, Germany
| | - Jannik Luboeinski
- grid.7450.60000 0001 2364 4210Department of Computational Neuroscience, University of Göttingen, Göttingen, Germany ,grid.7450.60000 0001 2364 4210Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany ,grid.7450.60000 0001 2364 4210Department of Computational Synaptic Physiology, University of Göttingen, Göttingen, Germany
| | - Christian Tetzlaff
- grid.7450.60000 0001 2364 4210Department of Computational Neuroscience, University of Göttingen, Göttingen, Germany ,grid.7450.60000 0001 2364 4210Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany ,grid.7450.60000 0001 2364 4210Department of Computational Synaptic Physiology, University of Göttingen, Göttingen, Germany
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33
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Behaviourally modulated hippocampal theta oscillations in the ferret persist during both locomotion and immobility. Nat Commun 2022; 13:5905. [PMID: 36207304 PMCID: PMC9547075 DOI: 10.1038/s41467-022-33507-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 09/21/2022] [Indexed: 11/09/2022] Open
Abstract
Theta oscillations are a hallmark of hippocampal activity across mammals and play a critical role in many hippocampal models of memory and spatial navigation. To reconcile the cross-species differences observed in the presence and properties of theta, we recorded hippocampal local field potentials in rats and ferrets during auditory and visual localisation tasks designed to vary locomotion and sensory attention. Here, we show that theta oscillations occur during locomotion in both ferrets and rats, however during periods of immobility, theta oscillations persist in the ferret, contrasting starkly with the switch to large irregular activity (LIA) in the rat. Theta during immobility in the ferret is identified as analogous to Type 2 theta that has been observed in rodents due to its sensitivity to atropine, and is modulated by behavioural state with the strongest theta observed during reward epochs. These results demonstrate that even under similar behavioural conditions, differences exist between species in the relationship between theta and behavioural state.
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34
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Abstract
When navigating through space, we must maintain a representation of our position in real time; when recalling a past episode, a memory can come back in a flash. Interestingly, the brain's spatial representation system, including the hippocampus, supports these two distinct timescale functions. How are neural representations of space used in the service of both real-world navigation and internal mnemonic processes? Recent progress has identified sequences of hippocampal place cells, evolving at multiple timescales in accordance with either navigational behaviors or internal oscillations, that underlie these functions. We review experimental findings on experience-dependent modulation of these sequential representations and consider how they link real-world navigation to time-compressed memories. We further discuss recent work suggesting the prevalence of these sequences beyond hippocampus and propose that these multiple-timescale mechanisms may represent a general algorithm for organizing cell assemblies, potentially unifying the dual roles of the spatial representation system in memory and navigation.
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Affiliation(s)
- Wenbo Tang
- Graduate Program in Neuroscience, Brandeis University, Waltham, Massachusetts, USA;
| | - Shantanu P Jadhav
- Neuroscience Program, Department of Psychology, and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts, USA;
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35
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Totty MS, Maren S. Neural Oscillations in Aversively Motivated Behavior. Front Behav Neurosci 2022; 16:936036. [PMID: 35846784 PMCID: PMC9284508 DOI: 10.3389/fnbeh.2022.936036] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Fear and anxiety-based disorders are highly debilitating and among the most prevalent psychiatric disorders. These disorders are associated with abnormal network oscillations in the brain, yet a comprehensive understanding of the role of network oscillations in the regulation of aversively motivated behavior is lacking. In this review, we examine the oscillatory correlates of fear and anxiety with a particular focus on rhythms in the theta and gamma-range. First, we describe neural oscillations and their link to neural function by detailing the role of well-studied theta and gamma rhythms to spatial and memory functions of the hippocampus. We then describe how theta and gamma oscillations act to synchronize brain structures to guide adaptive fear and anxiety-like behavior. In short, that hippocampal network oscillations act to integrate spatial information with motivationally salient information from the amygdala during states of anxiety before routing this information via theta oscillations to appropriate target regions, such as the prefrontal cortex. Moreover, theta and gamma oscillations develop in the amygdala and neocortical areas during the encoding of fear memories, and interregional synchronization reflects the retrieval of both recent and remotely encoded fear memories. Finally, we argue that the thalamic nucleus reuniens represents a key node synchronizing prefrontal-hippocampal theta dynamics for the retrieval of episodic extinction memories in the hippocampus.
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36
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Speers LJ, Schmidt R, Bilkey DK. Aberrant Phase Precession of Lateral Septal Cells in a Maternal Immune Activation Model of Schizophrenia Risk May Disrupt the Integration of Location with Reward. J Neurosci 2022; 42:4187-4201. [PMID: 35396329 PMCID: PMC9121831 DOI: 10.1523/jneurosci.0039-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/16/2022] [Accepted: 04/03/2022] [Indexed: 11/21/2022] Open
Abstract
Spatial memory and reward processing are known to be disrupted in schizophrenia. Since the lateral septum (LS) may play an important role in the integration of location and reward, we examined the effect of maternal immune activation (MIA), a known schizophrenia risk factor, on spatial representation in the rat LS. In support of a previous study, we found that spatial location is represented as a phase code in the rostral LS of adult male rats, so that LS cell spiking shifts systematically against the phase of the hippocampal, theta-frequency, local field potential as an animal moves along a track toward a reward (phase precession). Whereas shallow precession slopes were observed in control group cells, they were steeper in the MIA animals, such that firing frequently precessed across several theta cycles as the animal moved along the length of the apparatus, with subsequent ambiguity in the phase representation of location. Furthermore, an analysis of the phase trajectories of the control group cells revealed that the population tended to converge toward a common firing phase as the animal approached the reward location. This suggested that phase coding in these cells might signal both reward location and the distance to reward. By comparison, the degree of phase convergence in the MIA-group cells was weak, and the region of peak convergence was distal to the reward location. These findings suggest that a schizophrenia risk factor disrupts the phase-based encoding of location-reward relationships in the LS, potentially smearing reward representations across space.SIGNIFICANCE STATEMENT It is unclear how spatial or contextual information generated by hippocampal cells is converted to a code that can be used to signal reward location in regions, such as the VTA. Here we provide evidence that the firing phase of cells in the lateral septum, a region that links the two areas, may code reward location in the firing phase of cells. This phase coding is disrupted in a maternal immune activation model of schizophrenia risk such that representations of reward may be smeared across space in maternal immune activation animals. This could potentially underlie erroneous reward processing and misattribution of salience in schizophrenia.
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Affiliation(s)
- Lucinda J Speers
- Psychology Department, Otago University, Dunedin 9054, New Zealand
| | - Robert Schmidt
- Psychology Department, University of Sheffield, Sheffield, United Kingdom
| | - David K Bilkey
- Psychology Department, Otago University, Dunedin 9054, New Zealand
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37
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Shelley LE, Barr CI, Nitz DA. Cortical and Hippocampal Dynamics Under Logical Fragmentation of Environmental Space. Neurobiol Learn Mem 2022; 189:107597. [DOI: 10.1016/j.nlm.2022.107597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 01/18/2022] [Accepted: 02/01/2022] [Indexed: 10/19/2022]
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Abstract
By linking the past with the future, our memories define our sense of identity. Because human memory engages the conscious realm, its examination has historically been approached from language and introspection and proceeded largely along separate parallel paths in humans and other animals. Here, we first highlight the achievements and limitations of this mind-based approach and make the case for a new brain-based understanding of declarative memory with a focus on hippocampal physiology. Next, we discuss the interleaved nature and common physiological mechanisms of navigation in real and mental spacetime. We suggest that a distinguishing feature of memory types is whether they subserve actions for single or multiple uses. Finally, in contrast to the persisting view of the mind as a highly plastic blank slate ready for the world to make its imprint, we hypothesize that neuronal networks are endowed with a reservoir of neural trajectories, and the challenge faced by the brain is how to select and match preexisting neuronal trajectories with events in the world.
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Affiliation(s)
- György Buzsáki
- Neuroscience Institute and Department of Neurology, NYU Grossman School of Medicine, New York University, New York, NY 10016, USA;
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - Sam McKenzie
- Department of Neurosciences, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Lila Davachi
- Department of Psychology, Columbia University, New York, NY 10027, USA
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA
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39
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Cao L, Varga V, Chen ZS. Uncovering spatial representations from spatiotemporal patterns of rodent hippocampal field potentials. CELL REPORTS METHODS 2021; 1:100101. [PMID: 34888543 PMCID: PMC8654278 DOI: 10.1016/j.crmeth.2021.100101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/27/2021] [Accepted: 09/28/2021] [Indexed: 12/23/2022]
Abstract
Spatiotemporal patterns of large-scale spiking and field potentials of the rodent hippocampus encode spatial representations during maze runs, immobility, and sleep. Here, we show that multisite hippocampal field potential amplitude at ultra-high-frequency band (FPAuhf), a generalized form of multiunit activity, provides not only a fast and reliable reconstruction of the rodent's position when awake, but also a readout of replay content during sharp-wave ripples. This FPAuhf feature may serve as a robust real-time decoding strategy from large-scale recordings in closed-loop experiments. Furthermore, we develop unsupervised learning approaches to extract low-dimensional spatiotemporal FPAuhf features during run and ripple periods and to infer latent dynamical structures from lower-rank FPAuhf features. We also develop an optical flow-based method to identify propagating spatiotemporal LFP patterns from multisite array recordings, which can be used as a decoding application. Finally, we develop a prospective decoding strategy to predict an animal's future decision in goal-directed navigation.
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Affiliation(s)
- Liang Cao
- The Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Physics, East China Normal University, Shanghai 200241, China
| | - Viktor Varga
- The Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, USA
- Institute of Experimental Medicine, 43 Szigony Street, 1083 Budapest, Hungary
| | - Zhe S. Chen
- The Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Psychiatry, Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY 10016, USA
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40
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Quirk CR, Zutshi I, Srikanth S, Fu ML, Marciano ND, Wright MK, Parsey DF, Liu S, Siretskiy RE, Huynh TL, Leutgeb JK, Leutgeb S. Precisely timed theta oscillations are selectively required during the encoding phase of memory. Nat Neurosci 2021; 24:1614-1627. [PMID: 34608335 PMCID: PMC8556344 DOI: 10.1038/s41593-021-00919-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 08/02/2021] [Indexed: 11/12/2022]
Abstract
Brain oscillations have been hypothesized to support cognitive function by coordinating spike timing within and across brain regions, yet it is often not known when timing is either critical for neural computations or an epiphenomenon. The entorhinal cortex and hippocampus are necessary for learning and memory and exhibit prominent theta oscillations (6-9 Hz), which are controlled by pacemaker cells in the medial septal area. Here we show that entorhinal and hippocampal neuronal activity patterns were strongly entrained by rhythmic optical stimulation of parvalbumin-positive medial septal area neurons in mice. Despite strong entrainment, memory impairments in a spatial working memory task were not observed with pacing frequencies at or below the endogenous theta frequency and only emerged at frequencies ≥10 Hz, and specifically when pacing was targeted to maze segments where encoding occurs. Neural computations during the encoding phase were therefore selectively disrupted by perturbations of the timing of neuronal firing patterns.
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Affiliation(s)
- Clare R. Quirk
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ipshita Zutshi
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sunandha Srikanth
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Maylin L. Fu
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Naomie Devico Marciano
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Morgan K. Wright
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Darian F. Parsey
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stanley Liu
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rachel E. Siretskiy
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Tiffany L. Huynh
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jill K. Leutgeb
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stefan Leutgeb
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA,Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, CA 92093, USA,Correspondence should be addressed to S.L. ()
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41
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Zhao X, Hsu CL, Spruston N. Rapid synaptic plasticity contributes to a learned conjunctive code of position and choice-related information in the hippocampus. Neuron 2021; 110:96-108.e4. [PMID: 34678146 DOI: 10.1016/j.neuron.2021.10.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/30/2021] [Accepted: 10/01/2021] [Indexed: 01/04/2023]
Abstract
To successfully perform goal-directed navigation, animals must know where they are and what they are doing-e.g., looking for water, bringing food back to the nest, or escaping from a predator. Hippocampal neurons code for these critical variables conjunctively, but little is known about how this "where/what" code is formed or flexibly routed to other brain regions. To address these questions, we performed intracellular whole-cell recordings in mouse CA1 during a cued, two-choice virtual navigation task. We demonstrate that plateau potentials in CA1 pyramidal neurons rapidly strengthen synaptic inputs carrying conjunctive information about position and choice. Plasticity-induced response fields were modulated by cues only in animals previously trained to collect rewards based on available cues. Thus, we reveal that gradual learning is required for the formation of a conjunctive population code, upstream of CA1, while plateau-potential-induced synaptic plasticity in CA1 enables flexible routing of the code to downstream brain regions.
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Affiliation(s)
- Xinyu Zhao
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Ching-Lung Hsu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Nelson Spruston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
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42
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Robinson JC, Brandon MP. Skipping ahead: A circuit for representing the past, present, and future. eLife 2021; 10:e68795. [PMID: 34647521 PMCID: PMC8516414 DOI: 10.7554/elife.68795] [Citation(s) in RCA: 6] [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: 03/26/2021] [Accepted: 09/28/2021] [Indexed: 01/02/2023] Open
Abstract
Envisioning the future is intuitively linked to our ability to remember the past. Within the memory system, substantial work has demonstrated the involvement of the prefrontal cortex and the hippocampus in representing the past and present. Recent data shows that both the prefrontal cortex and the hippocampus encode future trajectories, which are segregated in time by alternating cycles of the theta rhythm. Here, we discuss how information is temporally organized by these brain regions supported by the medial septum, nucleus reuniens, and parahippocampal regions. Finally, we highlight a brain circuit that we predict is essential for the temporal segregation of future scenarios.
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Affiliation(s)
- Jennifer C Robinson
- Department of Psychological and Brain Sciences, Rajen Kilachand Center for Integrated Life Sciences and Engineering, Boston UniversityBostonUnited States
| | - Mark P Brandon
- Department of Psychiatry, Douglas Hospital Research Centre, McGill UniversityMontrealCanada
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43
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Speers LJ, Bilkey DK. Disorganization of Oscillatory Activity in Animal Models of Schizophrenia. Front Neural Circuits 2021; 15:741767. [PMID: 34675780 PMCID: PMC8523827 DOI: 10.3389/fncir.2021.741767] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/16/2021] [Indexed: 01/02/2023] Open
Abstract
Schizophrenia is a chronic, debilitating disorder with diverse symptomatology, including disorganized cognition and behavior. Despite considerable research effort, we have only a limited understanding of the underlying brain dysfunction. In this article, we review the potential role of oscillatory circuits in the disorder with a particular focus on the hippocampus, a region that encodes sequential information across time and space, as well as the frontal cortex. Several mechanistic explanations of schizophrenia propose that a loss of oscillatory synchrony between and within these brain regions may underlie some of the symptoms of the disorder. We describe how these oscillations are affected in several animal models of schizophrenia, including models of genetic risk, maternal immune activation (MIA) models, and models of NMDA receptor hypofunction. We then critically discuss the evidence for disorganized oscillatory activity in these models, with a focus on gamma, sharp wave ripple, and theta activity, including the role of cross-frequency coupling as a synchronizing mechanism. Finally, we focus on phase precession, which is an oscillatory phenomenon whereby individual hippocampal place cells systematically advance their firing phase against the background theta oscillation. Phase precession is important because it allows sequential experience to be compressed into a single 120 ms theta cycle (known as a 'theta sequence'). This time window is appropriate for the induction of synaptic plasticity. We describe how disruption of phase precession could disorganize sequential processing, and thereby disrupt the ordered storage of information. A similar dysfunction in schizophrenia may contribute to cognitive symptoms, including deficits in episodic memory, working memory, and future planning.
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Affiliation(s)
| | - David K. Bilkey
- Department of Psychology, Otago University, Dunedin, New Zealand
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44
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Marks WD, Yamamoto N, Kitamura T. Complementary roles of differential medial entorhinal cortex inputs to the hippocampus for the formation and integration of temporal and contextual memory (Systems Neuroscience). Eur J Neurosci 2021; 54:6762-6779. [PMID: 32277786 PMCID: PMC8187108 DOI: 10.1111/ejn.14737] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/28/2020] [Accepted: 03/30/2020] [Indexed: 11/29/2022]
Abstract
In humans and rodents, the entorhinal cortical (EC)-hippocampal (HPC) circuit is crucial for the formation and recall of memory, preserving both spatial information and temporal information about the occurrence of past events. Both modeling and experimental studies have revealed circuits within this network that play crucial roles in encoding space and context. However, our understanding about the time-related aspects of memory is just beginning to be understood. In this review, we first describe updates regarding recent anatomical discoveries for the EC-HPC network, as several important neural circuits critical for memory formation have been discovered by newly developed neural tracing technologies. Second, we examine the complementary roles of multiple medial entorhinal cortical inputs, including newly discovered circuits, into the hippocampus for the temporal and spatial aspects of memory. Finally, we will discuss how temporal and contextual memory information is integrated in HPC cornu ammonis 1 cells. We provide new insights into the neural circuit mechanisms for anatomical and functional segregation and integration of the temporal and spatial aspects of memory encoding in the EC-HPC networks.
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Affiliation(s)
- William D. Marks
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Naoki Yamamoto
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Takashi Kitamura
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
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45
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Rueckemann JW, Sosa M, Giocomo LM, Buffalo EA. The grid code for ordered experience. Nat Rev Neurosci 2021; 22:637-649. [PMID: 34453151 PMCID: PMC9371942 DOI: 10.1038/s41583-021-00499-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2021] [Indexed: 02/07/2023]
Abstract
Entorhinal cortical grid cells fire in a periodic pattern that tiles space, which is suggestive of a spatial coordinate system. However, irregularities in the grid pattern as well as responses of grid cells in contexts other than spatial navigation have presented a challenge to existing models of entorhinal function. In this Perspective, we propose that hippocampal input provides a key informative drive to the grid network in both spatial and non-spatial circumstances, particularly around salient events. We build on previous models in which neural activity propagates through the entorhinal-hippocampal network in time. This temporal contiguity in network activity points to temporal order as a necessary characteristic of representations generated by the hippocampal formation. We advocate that interactions in the entorhinal-hippocampal loop build a topological representation that is rooted in the temporal order of experience. In this way, the structure of grid cell firing supports a learned topology rather than a rigid coordinate frame that is bound to measurements of the physical world.
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Affiliation(s)
- Jon W Rueckemann
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, USA
- Washington National Primate Research Center, Seattle, WA, USA
| | - Marielena Sosa
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lisa M Giocomo
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Elizabeth A Buffalo
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, USA.
- Washington National Primate Research Center, Seattle, WA, USA.
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46
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Lehr AB, Stöber TM. Differential involvement of CA2 in internally vs. externally driven hippocampal sequences. Proc Natl Acad Sci U S A 2021; 118:e2110671118. [PMID: 34518233 PMCID: PMC8463789 DOI: 10.1073/pnas.2110671118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2021] [Indexed: 11/18/2022] Open
Affiliation(s)
- Andrew B Lehr
- Department of Computational Neuroscience, University of Göttingen, 37073 Göttingen, Germany;
- Bernstein Center for Computational Neuroscience, University of Göttingen, 37073 Göttingen, Germany
| | - Tristan M Stöber
- Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main, Germany;
- Centre for Integrative Neuroplasticity, University of Oslo, 0315 Oslo, Norway
- Department of Informatics, University of Oslo, 0315 Oslo, Norway
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47
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Gemzik ZM, Donahue MM, Griffin AL. Optogenetic suppression of the medial septum impairs working memory maintenance. ACTA ACUST UNITED AC 2021; 28:361-370. [PMID: 34526381 PMCID: PMC8456985 DOI: 10.1101/lm.053348.120] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 07/30/2021] [Indexed: 01/14/2023]
Abstract
Spatial working memory (SWM) is the ability to encode, maintain, and retrieve spatial information over a temporal gap, and relies on a network of structures including the medial septum (MS), which provides critical input to the hippocampus. Although the role of the MS in SWM is well-established, up until recently, we have been unable to use temporally precise circuit manipulation techniques to examine the specific role of the MS in SWM, particularly to distinguish between encoding, maintenance, and retrieval. Here, we test the hypothesis that the MS supports the maintenance of spatial information over a temporal gap using precisely timed optogenetic suppression delivered during specific portions of three different tasks, two of which rely on SWM and one that does not. In experiment 1, we found that MS optogenetic suppression impaired choice accuracy of a SWM dependent conditional discrimination task. Moreover, this deficit was only observed when MS suppression was delivered during the cue-sampling, but not the cue-retrieval, portion of the trial. There was also no deficit when MS neurons were optogenetically suppressed as rats performed a SWM-independent variant of the task. In experiment 2, we tested whether MS suppression affected choice accuracy on a delayed nonmatch to position (DNMP) task when suppression was limited to the sample, delay, and choice phases of the task. We found that MS suppression delivery during the delay phase of the DNMP task, but not during the sample or choice phases, impaired choice accuracy. Our results collectively suggest that the MS plays an important role in SWM by maintaining task-relevant information over a temporal delay.
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Affiliation(s)
- Zachary M Gemzik
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19711, USA
| | - Margaret M Donahue
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19711, USA
| | - Amy L Griffin
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19711, USA
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48
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Numan R. The Prefrontal-Hippocampal Comparator: Volition and Episodic Memory. Percept Mot Skills 2021; 128:2421-2447. [PMID: 34424092 DOI: 10.1177/00315125211041341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This review describes recent research that is relevant to the prefrontal-hippocampal comparator model with the following conclusions: 1. Hippocampal area CA1 serves, at least in part, as an associative match-mismatch comparator. 2. Voluntary movement strengthens episodic memories for goal-directed behavior. 3. Hippocampal theta power serves as a prediction error signal during hippocampal dependent tasks. 4. The self-referential component of episodic memory in humans is mediated by the corollary discharge (the efference copy of the action plan developed by prefrontal cortex and transmitted to hippocampus where it is stored as a working memory; CA1 uses this efference copy to compare the expected consequences of action to the actual consequences of action). 5. Impairments in the production or transmission of this corollary discharge may contribute to some of the symptoms of schizophrenia. Unresolved issues and suggestions for future research are discussed.
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Affiliation(s)
- Robert Numan
- Department of Psychology, Santa Clara University, Santa Clara, California, United States
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49
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Speers LJ, Cheyne KR, Cavani E, Hayward T, Schmidt R, Bilkey DK. Hippocampal Sequencing Mechanisms Are Disrupted in a Maternal Immune Activation Model of Schizophrenia Risk. J Neurosci 2021; 41:6954-6965. [PMID: 34253630 PMCID: PMC8360689 DOI: 10.1523/jneurosci.0730-21.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/07/2021] [Accepted: 07/04/2021] [Indexed: 01/02/2023] Open
Abstract
Episodic memory requires information to be stored and recalled in sequential order, and these processes are disrupted in schizophrenia. Hippocampal phase precession and theta sequences are thought to provide a biological mechanism for sequential ordering of experience at timescales suitable for plasticity. These phenomena have not previously been examined in any models of schizophrenia risk. Here, we examine these phenomena in a maternal immune activation (MIA) rodent model. We show that while individual pyramidal cells in the CA1 region continue to precess normally in MIA animals, the starting phase of precession as an animal enters a new place field is considerably more variable in MIA animals than in controls. A critical consequence of this change is a disorganization of the ordered representation of experience via theta sequences. These results provide the first evidence of a biological-level mechanism that, if it occurs in schizophrenia, may explain aspects of disorganized sequential processing that contribute to the cognitive symptoms of the disorder.SIGNIFICANCE STATEMENT Hippocampal phase precession and theta sequences have been proposed as biophysical mechanisms by which the sequential structure of cognition might be ordered. Disturbances of sequential processing have frequently been observed in schizophrenia. Here, we show for the first time that phase precession and theta sequences are disrupted in a maternal immune activation (MIA) model of schizophrenia risk. This is a result of greater variability in the starting phase of precession, indicating that the mechanisms that coordinate precession at the assembly level are disrupted. We propose that this disturbance in phase precession underlies some of the disorganized cognitive symptoms that occur in schizophrenia. These findings could have important preclinical significance for the identification and treatment of schizophrenia risk factors.
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Affiliation(s)
- Lucinda J Speers
- Psychology Department, Otago University, Dunedin 9016, New Zealand
| | - Kirsten R Cheyne
- Psychology Department, Otago University, Dunedin 9016, New Zealand
| | - Elena Cavani
- Psychology Department, Otago University, Dunedin 9016, New Zealand
- University of Tübingen, Tübingen 72076, Germany
| | - Tara Hayward
- Psychology Department, Otago University, Dunedin 9016, New Zealand
| | - Robert Schmidt
- Psychology Department, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - David K Bilkey
- Psychology Department, Otago University, Dunedin 9016, New Zealand
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50
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Ying Y, Wang JZ. Illuminating Neural Circuits in Alzheimer's Disease. Neurosci Bull 2021; 37:1203-1217. [PMID: 34089505 PMCID: PMC8353043 DOI: 10.1007/s12264-021-00716-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/06/2021] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and there is currently no cure. Neural circuit dysfunction is the fundamental mechanism underlying the learning and memory deficits in patients with AD. Therefore, it is important to understand the structural features and mechanisms underlying the deregulated circuits during AD progression, by which new tools for intervention can be developed. Here, we briefly summarize the most recently established cutting-edge experimental approaches and key techniques that enable neural circuit tracing and manipulation of their activity. We also discuss the advantages and limitations of these approaches. Finally, we review the applications of these techniques in the discovery of circuit mechanisms underlying β-amyloid and tau pathologies during AD progression, and as well as the strategies for targeted AD treatments.
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Affiliation(s)
- Yang Ying
- Department of Pathophysiology, School of Basic Medicine, Ministry of Education Key Laboratory for Neurological Disorders, Hubei Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Ministry of Education Key Laboratory for Neurological Disorders, Hubei Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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