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Vöröslakos M, Zhang Y, McClain K, Huszár R, Rothstein A, Buzsáki G. ThermoMaze: A behavioral paradigm for readout of immobility-related brain events. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.25.550518. [PMID: 37546818 PMCID: PMC10402115 DOI: 10.1101/2023.07.25.550518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Brain states fluctuate between exploratory and consummatory phases of behavior. These state changes affect both internal computation and the organism's responses to sensory inputs. Understanding neuronal mechanisms supporting exploratory and consummatory states and their switching requires experimental control of behavioral shifts and collecting sufficient amounts of brain data. To achieve this goal, we developed the ThermoMaze, which exploits the animal's natural warmth-seeking homeostatic behavior. By decreasing the floor temperature and selectively heating unmarked areas, mice avoid the aversive state by exploring the maze and finding the warm spot. In its design, the ThermoMaze is analogous to the widely used water maze but without the inconvenience of a wet environment and, therefore, allows the collection of physiological data in many trials. We combined the ThermoMaze with electrophysiology recording, and report that spiking activity of hippocampal CA1 neurons during sharp-wave ripple events encode the position of the animal. Thus, place-specific firing is not confined to locomotion and associated theta oscillations but persist during waking immobility and sleep at the same location. The ThermoMaze will allow for detailed studies of brain correlates of immobility, preparatory-consummatory transitions and open new options for studying behavior-mediated temperature homeostasis.
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Affiliation(s)
- Mihály Vöröslakos
- Neuroscience Institute and New York University, New York, NY 10016, USA
| | - Yunchang Zhang
- Neuroscience Institute and New York University, New York, NY 10016, USA
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Kathryn McClain
- Neuroscience Institute and New York University, New York, NY 10016, USA
| | - Roman Huszár
- Neuroscience Institute and New York University, New York, NY 10016, USA
| | - Aryeh Rothstein
- Neuroscience Institute and New York University, New York, NY 10016, USA
| | - György Buzsáki
- Neuroscience Institute and New York University, New York, NY 10016, USA
- Department of Neurology, School of Medicine, New York University, New York, NY 10016, USA
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2
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Coulter ME, Gillespie AK, Chu J, Denovellis EL, Nguyen TTK, Liu DF, Wadhwani K, Sharma B, Wang K, Deng X, Eden UT, Kemere C, Frank LM. Closed-loop modulation of remote hippocampal representations with neurofeedback. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593085. [PMID: 38766135 PMCID: PMC11100667 DOI: 10.1101/2024.05.08.593085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Humans can remember specific events without acting on them and can influence which memories are retrieved based on internal goals. However, current animal models of memory typically present sensory cues to trigger retrieval and assess retrieval based on action 1-5 . As a result, it is difficult to determine whether measured patterns of neural activity relate to the cue(s), the retrieved memory, or the behavior. We therefore asked whether we could develop a paradigm to isolate retrieval-related neural activity in animals without retrieval cues or the requirement of a behavioral report. To do this, we focused on hippocampal "place cells." These cells primarily emit spiking patterns that represent the animal's current location (local representations), but they can also generate representations of previously visited locations distant from the animal's current location (remote representations) 6-13 . It is not known whether animals can deliberately engage specific remote representations, and if so, whether this engagement would occur during specific brain states. So, we used a closed-loop neurofeedback system to reward expression of remote representations that corresponded to uncued, experimenter-selected locations, and found that rats could increase the prevalence of these specific remote representations over time; thus, demonstrating memory retrieval modulated by internal goals in an animal model. These representations occurred predominately during periods of immobility but outside of hippocampal sharp-wave ripple (SWR) 13-15 events. This paradigm enables future direct studies of memory retrieval mechanisms in the healthy brain and in models of neurological disorders.
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Raut RV, Rosenthal ZP, Wang X, Miao H, Zhang Z, Lee JM, Raichle ME, Bauer AQ, Brunton SL, Brunton BW, Kutz JN. Arousal as a universal embedding for spatiotemporal brain dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.06.565918. [PMID: 38187528 PMCID: PMC10769245 DOI: 10.1101/2023.11.06.565918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Neural activity in awake organisms shows widespread and spatiotemporally diverse correlations with behavioral and physiological measurements. We propose that this covariation reflects in part the dynamics of a unified, arousal-related process that regulates brain-wide physiology on the timescale of seconds. Taken together with theoretical foundations in dynamical systems, this interpretation leads us to a surprising prediction: that a single, scalar measurement of arousal (e.g., pupil diameter) should suffice to reconstruct the continuous evolution of multimodal, spatiotemporal measurements of large-scale brain physiology. To test this hypothesis, we perform multimodal, cortex-wide optical imaging and behavioral monitoring in awake mice. We demonstrate that spatiotemporal measurements of neuronal calcium, metabolism, and blood-oxygen can be accurately and parsimoniously modeled from a low-dimensional state-space reconstructed from the time history of pupil diameter. Extending this framework to behavioral and electrophysiological measurements from the Allen Brain Observatory, we demonstrate the ability to integrate diverse experimental data into a unified generative model via mappings from an intrinsic arousal manifold. Our results support the hypothesis that spontaneous, spatially structured fluctuations in brain-wide physiology-widely interpreted to reflect regionally-specific neural communication-are in large part reflections of an arousal-related process. This enriched view of arousal dynamics has broad implications for interpreting observations of brain, body, and behavior as measured across modalities, contexts, and scales.
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Affiliation(s)
- Ryan V. Raut
- Allen Institute, Seattle, WA, USA
- Department of Physiology & Biophysics, University of Washington, Seattle, WA, USA
| | - Zachary P. Rosenthal
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Xiaodan Wang
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Hanyang Miao
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Zhanqi Zhang
- Department of Computer Science & Engineering, University of California San Diego, La Jolla, CA, USA
| | - Jin-Moo Lee
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Marcus E. Raichle
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Adam Q. Bauer
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Steven L. Brunton
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | | | - J. Nathan Kutz
- Department of Applied Mathematics, University of Washington, Seattle, WA, USA
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4
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Wang F, Chen X, Bo B, Zhang T, Liu K, Jiang J, Wang Y, Xie H, Liang Z, Guan JS. State-dependent memory retrieval: insights from neural dynamics and behavioral perspectives. Learn Mem 2023; 30:325-337. [PMID: 38114331 PMCID: PMC10750866 DOI: 10.1101/lm.053893.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 11/28/2023] [Indexed: 12/21/2023]
Abstract
Memory retrieval is strikingly susceptible to external states (environment) and internal states (mood states and alcohol), yet we know little about the underlying mechanisms. We examined how internally generated states influence successful memory retrieval using the functional magnetic resonance imaging (fMRI) of laboratory mice during memory retrieval. Mice exhibited a strong tendency to perform memory retrieval correctly only in the reinstated mammillary body-inhibited state, in which mice were trained to discriminate auditory stimuli in go/no-go tasks. fMRI revealed that distinct auditory cues engaged differential brain regions, which were primed by internal state. Specifically, a cue associated with a reward activated the lateral amygdala, while a cue signaling no reward predominantly activated the postsubiculum. Modifying these internal states significantly altered the neural activity balance between these regions. Optogenetic inhibition of those regions in the precue period blocked the retrieval of type-specific memories. Our findings suggest that memory retrieval is under the control of two interrelated neural circuits underlying the neural basis of state-dependent memory retrieval.
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Affiliation(s)
- Fei Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Cerebrovascular Disease Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Xu Chen
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Binshi Bo
- Institute of Neuroscience, CAS Center for Excellence in Brain Sciences and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Tianfu Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Kaiyuan Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Life of Science, Tsinghua University, Beijing 100084, China
| | - Jun Jiang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yonggang Wang
- Headache Center, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Headache Center, China National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Hong Xie
- Institute of Photonic Chips, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Zhifeng Liang
- Institute of Neuroscience, CAS Center for Excellence in Brain Sciences and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ji-Song Guan
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
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5
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Hong Y, Moore IL, Smith DE, Long NM. Spatiotemporal Dynamics of Memory Encoding and Memory Retrieval States. J Cogn Neurosci 2023; 35:1463-1477. [PMID: 37348133 PMCID: PMC10513765 DOI: 10.1162/jocn_a_02022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Memory encoding and memory retrieval are neurally distinct brain states that can be differentiated on the basis of cortical network activity. However, it is unclear whether sustained engagement of one network or fluctuations between multiple networks give rise to these memory states. The spatiotemporal dynamics of memory states may have important implications for memory behavior and cognition; however, measuring temporally resolved signals of cortical networks poses a challenge. Here, we recorded scalp electroencephalography from participants performing a mnemonic state task in which they were biased toward memory encoding or retrieval. We performed a microstate analysis to measure the temporal dynamics of cortical networks throughout this mnemonic state task. We find that Microstate E, a putative analog of the default mode network, shows temporally sustained dissociations between memory encoding and retrieval, with greater engagement during retrieve compared with encode trials. We further show that decreased engagement of Microstate E is a general property of encoding, rather than a reflection of retrieval suppression. Thus, memory success, as well as cognition more broadly, may be influenced by the ability to engage or disengage Microstate E in a goal-dependent manner.
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Affiliation(s)
- Yuju Hong
- University of Virginia, Charlottesville
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6
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Long NM. The intersection of the retrieval state and internal attention. Nat Commun 2023; 14:3861. [PMID: 37386043 PMCID: PMC10310828 DOI: 10.1038/s41467-023-39609-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 06/21/2023] [Indexed: 07/01/2023] Open
Abstract
Large-scale brain states or distributed patterns of brain activity modulate downstream processing and behavior. Sustained attention and memory retrieval states impact subsequent memory, yet how these states relate to one another is unclear. I hypothesize that internal attention is a central process of the retrieval state. The alternative is that the retrieval state specifically reflects a controlled, episodic retrieval mode, engaged only when intentionally accessing events situated within a spatiotemporal context. To test my hypothesis, I developed a mnemonic state classifier independently trained to measure retrieval state evidence and applied this classifier to a spatial attention task. I find that retrieval state evidence increases during delay and response intervals when participants are maintaining spatial information. Critically, retrieval state evidence is positively related to the amount of maintained spatial location information and predicts target detection reaction times. Together, these findings support the hypothesis that internal attention is a central process of the retrieval state.
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Affiliation(s)
- Nicole M Long
- Department of Psychology, University of Virginia, 22904, Charlottesville, VA, USA.
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7
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Etemadi L, Enander JM, Jörntell H. Hippocampal output profoundly impacts the interpretation of tactile input patterns in SI cortical neurons. iScience 2023; 26:106885. [PMID: 37260754 PMCID: PMC10227419 DOI: 10.1016/j.isci.2023.106885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 04/13/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023] Open
Abstract
Due to continuous state variations in neocortical circuits, individual somatosensory cortex (SI) neurons in vivo display a variety of intracellular responses to the exact same spatiotemporal tactile input pattern. To manipulate the internal cortical state, we here used brief electrical stimulation of the output region of the hippocampus, which preceded the delivery of specific tactile afferent input patterns to digit 2 of the anesthetized rat. We find that hippocampal output had a diversified, remarkably strong impact on the intracellular response types displayed by each neuron in the primary SI to each given tactile input pattern. Qualitatively, this impact was comparable to that previously described for cortical output, which was surprising given the widely assumed specific roles of the hippocampus, such as in cortical memory formation. The findings show that hippocampal output can profoundly impact the state-dependent interpretation of tactile inputs and hence influence perception, potentially with affective and semantic components.
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Affiliation(s)
- Leila Etemadi
- Neural Basis of Sensorimotor Control, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Jonas M.D. Enander
- Center for Social and Affective Neuroscience, Linköping University, Linköping, Sweden
| | - Henrik Jörntell
- Neural Basis of Sensorimotor Control, Department of Experimental Medical Science, Lund University, Lund, Sweden
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Acero VP, Das S, Rivellini O, Purvis EM, Adewole DO, Cullen DK. Emergent structural and functional properties of hippocampal multi-cellular aggregates. Front Neurosci 2023; 17:1171115. [PMID: 37397454 PMCID: PMC10311220 DOI: 10.3389/fnins.2023.1171115] [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: 02/21/2023] [Accepted: 05/24/2023] [Indexed: 07/04/2023] Open
Abstract
Hippocampal neural networks are distinctly capable of integrating multi-modal sensory inputs to drive memory formation. Neuroscientific investigations using simplified in vitro models have greatly relied on planar (2D) neuronal cultures made from dissociated tissue. While these models have served as simple, cost-effective, and high-throughput tools for examining various morphological and electrophysiological characteristics of hippocampal networks, 2D cultures fail to reconstitute critical elements of the brain microenvironment that may be necessary for the emergence of sophisticated integrative network properties. To address this, we utilized a forced aggregation technique to generate high-density (>100,000 cells/mm3) multi-cellular three-dimensional aggregates using rodent embryonic hippocampal tissue. We contrasted the emergent structural and functional properties of aggregated (3D) and dissociated (2D) cultures over 28 days in vitro (DIV). Hippocampal aggregates displayed robust axonal fasciculation across large distances and significant neuronal polarization, i.e., spatial segregation of dendrites and axons, at earlier time points compared to dissociated cultures. Moreover, we found that astrocytes in aggregate cultures self-organized into non-overlapping quasi-domains and developed highly stellate morphologies resembling astrocyte structures in vivo. We maintained cultures on multi-electrode arrays (MEAs) to assess spontaneous electrophysiological activity for up to 28 DIV. We found that 3D networks of aggregated cultures developed highly synchronized networks and with high burstiness by 28 DIV. We also demonstrated that dual-aggregate networks became active by 7 DIV, in contrast to single-aggregate networks which became active and developed synchronous bursting activity with repeating motifs by 14 DIV. Taken together, our findings demonstrate that the high-density, multi-cellular, 3D microenvironment of hippocampal aggregates supports the recapitulation of emergent biofidelic morphological and functional properties. Our findings suggest that neural aggregates may be used as segregated, modular building blocks for the development of complex, multi-nodal neural network topologies.
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Affiliation(s)
- Victor P. Acero
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States
| | - Suradip Das
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Olivia Rivellini
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Erin M. Purvis
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Dayo O. Adewole
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States
| | - Daniel Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, United States
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, United States
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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9
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Inayat S, McAllister BB, Whishaw IQ, Mohajerani MH. Hippocampal conjunctive and complementary CA1 populations relate sensory events to movement. iScience 2023; 26:106481. [PMID: 37096033 PMCID: PMC10121467 DOI: 10.1016/j.isci.2023.106481] [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: 09/09/2022] [Revised: 02/27/2023] [Accepted: 03/18/2023] [Indexed: 04/26/2023] Open
Abstract
Hippocampal CA1 neurons respond to sensory stimuli during enforced immobility, movement, and their transitions in a new conveyor belt task. Head-fixed mice were exposed to light flashes or air streams while at rest, spontaneously moving, or running a fixed distance. Two-photon calcium imaging of CA1 neurons revealed that 62% of 3341 imaged cells were active during one or more of 20 sensorimotor events. Of these active cells, 17% were active for any given sensorimotor event, with a higher proportion during locomotion. The study found two types of cells: Conjunctive cells that were active across multiple events, and complementary cells that were active only during individual events, encoding novel sensorimotor events or their delayed repetitions. The configuration of these cells across changing sensorimotor events may signify the role of hippocampus in functional networks integrating sensory information with ongoing movement making it suitable for movement guidance.
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Affiliation(s)
- Samsoon Inayat
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
| | - Brendan B McAllister
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
| | - Ian Q Whishaw
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
| | - Majid H Mohajerani
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
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Rampon M, Carponcy J, Missaire M, Bouet R, Parmentier R, Comte JC, Malleret G, Salin PA. Synapse-Specific Modulation of Synaptic Responses by Brain States in Hippocampal Pathways. J Neurosci 2023; 43:1191-1210. [PMID: 36631268 PMCID: PMC9962785 DOI: 10.1523/jneurosci.0772-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 01/13/2023] Open
Abstract
Synaptic changes play a major role in memory processes. Modulation of synaptic responses by brain states remains, however, poorly understood in hippocampal networks, even in basal conditions. We recorded evoked synaptic responses at five hippocampal pathways in freely moving male rats. We showed that, at the perforant path to dentate gyrus (PP-DG) synapse, responses increase during wakefulness compared with sleep. At the Schaffer collaterals to CA1 (SC-CA1) synapse, responses increase during non-REM sleep (NREM) compared with the other states. During REM sleep (REM), responses decreased at the PP-DG and SC-CA1 synapses compared with NREM, while they increased at the fornix to nucleus accumbens synapse (Fx-NAc) during REM compared with the other states. In contrast, responses at the fornix to medial PFC synapse (Fx-PFC) and at the fornix to amygdala synapse (Fx-Amy) were weakly modulated by vigilance states. Extended sleep periods led to synaptic changes at PP-DG and Fx-Amy synapses but not at the other synapses. Synaptic responses were also linked to local oscillations and were highly correlated between Fx-PFC and Fx-NAc but not between Fx-Amy and these synapses. These results reveal synapse-specific modulations that may contribute to memory consolidation during the sleep-wake cycle.SIGNIFICANCE STATEMENT Surprisingly, the cortical network dynamics remains poorly known at the synaptic level. We tested the hypothesis that brain states would modulate synaptic changes in the same way at different cortical connections. To tackle this issue, we implemented an approach to explore the synaptic behavior of five connections upstream and downstream the rat hippocampus. Our study reveals that synaptic responses are modulated in a highly synapse-specific manner by wakefulness and sleep states as well as by local oscillations at these connections. Moreover, we found rapid synaptic changes during wake and sleep transitions as well as synaptic down and upregulations after extended periods of sleep. These synaptic changes are likely related to the mechanisms of sleep-dependent memory consolidation.
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Affiliation(s)
- Manon Rampon
- Forgetting processes and cortical dynamics' team, Centre de Recherche en Neurosciences de Lyon, University Claude Bernard Lyon 1, Bron, F-69500, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
| | - Julien Carponcy
- Forgetting processes and cortical dynamics' team, Centre de Recherche en Neurosciences de Lyon, University Claude Bernard Lyon 1, Bron, F-69500, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
- Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, OX1 3TH, United Kingdom
| | - Mégane Missaire
- Forgetting processes and cortical dynamics' team, Centre de Recherche en Neurosciences de Lyon, University Claude Bernard Lyon 1, Bron, F-69500, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
| | - Romain Bouet
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
| | - Regis Parmentier
- Forgetting processes and cortical dynamics' team, Centre de Recherche en Neurosciences de Lyon, University Claude Bernard Lyon 1, Bron, F-69500, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
| | - Jean-Christophe Comte
- Forgetting processes and cortical dynamics' team, Centre de Recherche en Neurosciences de Lyon, University Claude Bernard Lyon 1, Bron, F-69500, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
| | - Gael Malleret
- Forgetting processes and cortical dynamics' team, Centre de Recherche en Neurosciences de Lyon, University Claude Bernard Lyon 1, Bron, F-69500, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
| | - Paul A Salin
- Forgetting processes and cortical dynamics' team, Centre de Recherche en Neurosciences de Lyon, University Claude Bernard Lyon 1, Bron, F-69500, France
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale U1028, Bron, F-69500, France
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11
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Ghatak S, Nakamura T, Lipton SA. Aberrant protein S-nitrosylation contributes to hyperexcitability-induced synaptic damage in Alzheimer's disease: Mechanistic insights and potential therapies. Front Neural Circuits 2023; 17:1099467. [PMID: 36817649 PMCID: PMC9932935 DOI: 10.3389/fncir.2023.1099467] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Alzheimer's disease (AD) is arguably the most common cause of dementia in the elderly and is marked by progressive synaptic degeneration, which in turn leads to cognitive decline. Studies in patients and in various AD models have shown that one of the early signatures of AD is neuronal hyperactivity. This excessive electrical activity contributes to dysregulated neural network function and synaptic damage. Mechanistically, evidence suggests that hyperexcitability accelerates production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) that contribute to neural network impairment and synapse loss. This review focuses on the pathways and molecular changes that cause hyperexcitability and how RNS-dependent posttranslational modifications, represented predominantly by protein S-nitrosylation, mediate, at least in part, the deleterious effects of hyperexcitability on single neurons and the neural network, resulting in synaptic loss in AD.
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Affiliation(s)
- Swagata Ghatak
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India
| | - Tomohiro Nakamura
- Neurodegeneration New Medicines Center and Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States,*Correspondence: Tomohiro Nakamura,
| | - Stuart A. Lipton
- Neurodegeneration New Medicines Center and Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States,Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA, United States,Stuart A. Lipton,
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12
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van den Berg M, Toen D, Verhoye M, Keliris GA. Alterations in theta-gamma coupling and sharp wave-ripple, signs of prodromal hippocampal network impairment in the TgF344-AD rat model. Front Aging Neurosci 2023; 15:1081058. [PMID: 37032829 PMCID: PMC10075364 DOI: 10.3389/fnagi.2023.1081058] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Alzheimer's disease (AD) is a severe neurodegenerative disorder caused by the accumulation of toxic proteins, amyloid-beta (Aβ) and tau, which eventually leads to dementia. Disease-modifying therapies are still lacking, due to incomplete insights into the neuropathological mechanisms of AD. Synaptic dysfunction is known to occur before cognitive symptoms become apparent and recent studies have demonstrated that imbalanced synaptic signaling drives the progression of AD, suggesting that early synaptic dysfunction could be an interesting therapeutic target. Synaptic dysfunction results in altered oscillatory activity, which can be detected with electroencephalography and electrophysiological recordings. However, the majority of these studies have been performed at advanced stages of AD, when extensive damage and cognitive symptoms are already present. The current study aimed to investigate if the hippocampal oscillatory activity is altered at pre-plaque stages of AD. The rats received stereotactic surgery to implant a laminar electrode in the CA1 layer of the right hippocampus. Electrophysiological recordings during two consecutive days in an open field were performed in 4-5-month-old TgF344-AD rats when increased concentrations of soluble Aβ species were observed in the brain, in the absence of Aβ-plaques. We observed a decreased power of high theta oscillations in TgF344-AD rats compared to wild-type littermates. Sharp wave-ripple (SWR) analysis revealed an increased SWR power and a decreased duration of SWR during quiet wake in TgF344-AD rats. The alterations in properties of SWR and the increased power of fast oscillations are suggestive of neuronal hyperexcitability, as has been demonstrated to occur during presymptomatic stages of AD. In addition, decreased strength of theta-gamma coupling, an important neuronal correlate of memory encoding, was observed in the TgF344-AD rats. Theta-gamma phase amplitude coupling has been associated with memory encoding and the execution of cognitive functions. Studies have demonstrated that mild cognitive impairment patients display decreased coupling strength, similar to what is described here. The current study demonstrates altered hippocampal network activity occurring at pre-plaque stages of AD and provides insights into prodromal network dysfunction in AD. The alterations observed could aid in the detection of AD during presymptomatic stages.
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Affiliation(s)
- Monica van den Berg
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- *Correspondence: Monica van den Berg, ; Georgios A. Keliris,
| | - Daniëlle Toen
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Marleen Verhoye
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Georgios A. Keliris
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- Institute of Computer Science, Foundation for Research and Technology – Hellas, Heraklion, Crete, Greece
- *Correspondence: Monica van den Berg, ; Georgios A. Keliris,
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13
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He H, Guan H, McHugh TJ. The expanded circuitry of hippocampal ripples and replay. Neurosci Res 2022; 189:13-19. [PMID: 36572253 DOI: 10.1016/j.neures.2022.12.010] [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: 12/15/2022] [Revised: 12/01/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
The place cells and well-defined oscillatory population rhythms of the rodent hippocampus have served as a powerful model system in linking cells and circuits to memory function. While the initial three decades of place cell research primarily focused on the activity of neurons during exploration, the last twenty-five years have seen growing interest in the physiology of the hippocampus at rest. During slow-wave sleep and quiet wakefulness the hippocampus exhibits sharp-wave ripples (SWRs), short high-frequency, high-amplitude oscillations, that organize the reactivation or 'replay' of sequences of place cells, and interventions that disrupt SWRs impair learning. While the canonical model of SWRs generation have emphasized CA3 input to CA1 as the source of excitatory drive, recent work suggests there are multiple circuits, including the CA2 region, that can both influence, generate and organize SWRs, both from the oscillatory and information content perspectives in a task and state-dependent manner. This extended circuitry and its function must be considered for a true understanding of the role of the hippocampus in off-line processes such as planning and consolidation.
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Affiliation(s)
- Hongshen He
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan
| | - Hefei Guan
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan.
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14
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Whitebirch AC, LaFrancois JJ, Jain S, Leary P, Santoro B, Siegelbaum SA, Scharfman HE. Enhanced excitability of the hippocampal CA2 region and its contribution to seizure activity in a mouse model of temporal lobe epilepsy. Neuron 2022; 110:3121-3138.e8. [PMID: 35987207 PMCID: PMC9547935 DOI: 10.1016/j.neuron.2022.07.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/26/2022] [Accepted: 07/19/2022] [Indexed: 11/25/2022]
Abstract
The hippocampal CA2 region, an area important for social memory, has been suspected to play a role in temporal lobe epilepsy (TLE) because of its resistance to degeneration observed in neighboring CA1 and CA3 regions in both humans and rodent models of TLE. However, little is known about whether alterations in CA2 properties promote seizure generation or propagation. Here, we addressed the role of CA2 using the pilocarpine-induced status epilepticus model of TLE. Ex vivo electrophysiological recordings from acute hippocampal slices revealed a set of coordinated changes that enhance CA2 PC intrinsic excitability, reduce CA2 inhibitory input, and increase CA2 excitatory output to its major CA1 synaptic target. Moreover, selective chemogenetic silencing of CA2 pyramidal cells caused a significant decrease in the frequency of spontaneous seizures measured in vivo. These findings provide the first evidence that CA2 actively contributes to TLE seizure activity and may thus be a promising therapeutic target.
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Affiliation(s)
- Alexander C Whitebirch
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, NY 10027, USA
| | - John J LaFrancois
- The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Swati Jain
- The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Paige Leary
- Department of Neuroscience and Physiology, New York University Langone Health, New York, NY 10016, USA
| | - Bina Santoro
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, NY 10027, USA
| | - Steven A Siegelbaum
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, NY 10027, USA.
| | - Helen E Scharfman
- Department of Child Psychiatry, New York University Langone Health, New York, NY 10016, USA; Department of Neuroscience and Physiology, New York University Langone Health, New York, NY 10016, USA; Department of Psychiatry, New York University Langone Health, New York, NY 10016, USA; The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
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15
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Deng X, Chen S, Sosa M, Karlsson MP, Wei XX, Frank LM. A Variable Clock Underlies Internally Generated Hippocampal Sequences. J Neurosci 2022; 42:3797-3810. [PMID: 35351831 PMCID: PMC9087812 DOI: 10.1523/jneurosci.1120-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/23/2021] [Accepted: 01/01/2022] [Indexed: 11/21/2022] Open
Abstract
Humans have the ability to store and retrieve memories with various degrees of specificity, and recent advances in reinforcement learning have identified benefits to learning when past experience is represented at different levels of temporal abstraction. How this flexibility might be implemented in the brain remains unclear. We analyzed the temporal organization of male rat hippocampal population spiking to identify potential substrates for temporally flexible representations. We examined activity both during locomotion and during memory-associated population events known as sharp-wave ripples (SWRs). We found that spiking during SWRs is rhythmically organized with higher event-to-event variability than spiking during locomotion-associated population events. Decoding analyses using clusterless methods further indicate that a similar spatial experience can be replayed in multiple SWRs, each time with a different rhythmic structure whose periodicity is sampled from a log-normal distribution. This variability increases with experience despite the decline in SWR rates that occurs as environments become more familiar. We hypothesize that the variability in temporal organization of hippocampal spiking provides a mechanism for storing experiences with various degrees of specificity.SIGNIFICANCE STATEMENT One of the most remarkable properties of memory is its flexibility: the brain can retrieve stored representations at varying levels of detail where, for example, we can begin with a memory of an entire extended event and then zoom in on a particular episode. The neural mechanisms that support this flexibility are not understood. Here we show that hippocampal sharp-wave ripples, which mark the times of memory replay and are important for memory storage, have a highly variable temporal structure that is well suited to support the storage of memories at different levels of detail.
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Affiliation(s)
- Xinyi Deng
- Department of Data Science, Beijing University of Technology, Beijing 100124, People's Republic of China
| | - Shizhe Chen
- Department of Statistics, University of California, Davis, Davis, California 95616
| | - Marielena Sosa
- Center for Integrative Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, California 94158
| | - Mattias P Karlsson
- Center for Integrative Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, California 94158
| | - Xue-Xin Wei
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78751
| | - Loren M Frank
- Center for Integrative Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, California 94158
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California 94158
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, California 94158
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16
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Jones EAA, Rao A, Zilberter M, Djukic B, Bant JS, Gillespie AK, Koutsodendris N, Nelson M, Yoon SY, Huang K, Yuan H, Gill TM, Huang Y, Frank LM. Dentate gyrus and CA3 GABAergic interneurons bidirectionally modulate signatures of internal and external drive to CA1. Cell Rep 2021; 37:110159. [PMID: 34965435 PMCID: PMC9069800 DOI: 10.1016/j.celrep.2021.110159] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 10/04/2021] [Accepted: 12/01/2021] [Indexed: 01/19/2023] Open
Abstract
Specific classes of GABAergic neurons play specific roles in regulating information processing in the brain. In the hippocampus, two major classes, parvalbumin-expressing (PV+) and somatostatin-expressing (SST+), differentially regulate endogenous firing patterns and target subcellular compartments of principal cells. How these classes regulate the flow of information throughout the hippocampus is poorly understood. We hypothesize that PV+ and SST+ interneurons in the dentate gyrus (DG) and CA3 differentially modulate CA3 patterns of output, thereby altering the influence of CA3 on CA1. We find that while suppressing either interneuron class increases DG and CA3 output, the effects on CA1 were very different. Suppressing PV+ interneurons increases local field potential signatures of coupling from CA3 to CA1 and decreases signatures of coupling from entorhinal cortex to CA1; suppressing SST+ interneurons has the opposite effect. Thus, DG and CA3 PV+ and SST+ interneurons bidirectionally modulate the flow of information through the hippocampal circuit.
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Affiliation(s)
- Emily A. Aery Jones
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Antara Rao
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Misha Zilberter
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Jason S. Bant
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Anna K. Gillespie
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, CA 94143, USA
| | - Nicole Koutsodendris
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Maxine Nelson
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Seo Yeon Yoon
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Ky Huang
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Heidi Yuan
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Theodore M. Gill
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA,Departments of Neurology and Pathology, University of California, San Francisco, CA 94143, USA,Gladstone Center for Translational Advancement, San Francisco, CA 94158, USA,Correspondence should be addressed to: Loren Frank () or Yadong Huang ()
| | - Loren M. Frank
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, CA 94143, USA,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA,Lead contact,Correspondence should be addressed to: Loren Frank () or Yadong Huang ()
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17
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Ross TW, Easton A. The Hippocampal Horizon: Constructing and Segmenting Experience for Episodic Memory. Neurosci Biobehav Rev 2021; 132:181-196. [PMID: 34826509 DOI: 10.1016/j.neubiorev.2021.11.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 12/29/2022]
Abstract
How do we recollect specific events that have occurred during continuous ongoing experience? There is converging evidence from non-human animals that spatially modulated cellular activity of the hippocampal formation supports the construction of ongoing events. On the other hand, recent human oriented event cognition models have outlined that our experience is segmented into discrete units, and that such segmentation can operate on shorter or longer timescales. Here, we describe a unification of how these dynamic physiological mechanisms of the hippocampus relate to ongoing externally and internally driven event segmentation, facilitating the demarcation of specific moments during experience. Our cross-species interdisciplinary approach offers a novel perspective in the way we construct and remember specific events, leading to the generation of many new hypotheses for future research.
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Affiliation(s)
- T W Ross
- Department of Psychology, Durham University, South Road, Durham, DH1 3LE, United Kingdom; Centre for Learning and Memory Processes, Durham University, United Kingdom.
| | - A Easton
- Department of Psychology, Durham University, South Road, Durham, DH1 3LE, United Kingdom; Centre for Learning and Memory Processes, Durham University, United Kingdom
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18
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He H, Boehringer R, Huang AJY, Overton ETN, Polygalov D, Okanoya K, McHugh TJ. CA2 inhibition reduces the precision of hippocampal assembly reactivation. Neuron 2021; 109:3674-3687.e7. [PMID: 34555316 DOI: 10.1016/j.neuron.2021.08.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 07/02/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022]
Abstract
The structured reactivation of hippocampal neuronal ensembles during fast synchronous oscillatory events, termed sharp-wave ripples (SWRs), has been suggested to play a crucial role in the storage and use of memory. Activity in both the CA2 and CA3 subregions can precede this population activity in CA1, and chronic inhibition of either region alters SWR oscillations. However, the precise contribution of CA2 to the oscillation, as well as to the reactivation of CA1 neurons within it, remains unclear. Here, we employ chemogenetics to transiently silence CA2 pyramidal cells in mice, and we observe that although SWRs still occur, the reactivation of CA1 pyramidal cell ensembles within the events lose both temporal and informational precision. These observations suggest that CA2 activity contributes to the fidelity of experience-dependent hippocampal replay.
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Affiliation(s)
- Hongshen He
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan; Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Roman Boehringer
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Arthur J Y Huang
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Eric T N Overton
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Denis Polygalov
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Kazuo Okanoya
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan; Cognition and Behavior Joint Laboratory, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan; Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
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19
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Hsu SY, Jura B, Shih MH, Meyrand P, Tsai FS, Bem T. Recognition of post-learning alteration of hippocampal ripples by convolutional neural network differs in the wild-type and AD mice. Sci Rep 2021; 11:21241. [PMID: 34711860 PMCID: PMC8553820 DOI: 10.1038/s41598-021-00598-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/11/2021] [Indexed: 11/09/2022] Open
Abstract
Evidence indicates that sharp-wave ripples (SWRs) are primary network events supporting memory processes. However, some studies demonstrate that even after disruption of awake SWRs the animal can still learn spatial task or that SWRs may be not necessary to establish a cognitive map of the environment. Moreover, we have found recently that despite a deficit of sleep SWRs the APP/PS1 mice, a model of Alzheimer’s disease, show undisturbed spatial reference memory. Searching for a learning-related alteration of SWRs that could account for the efficiency of memory in these mice we use convolutional neural networks (CNN) to discriminate pre- and post-learning 256 ms samples of LFP signals, containing individual SWRs. We found that the fraction of samples that were correctly recognized by CNN in majority of discrimination sessions was equal to ~ 50% in the wild-type (WT) and only 14% in APP/PS1 mice. Moreover, removing signals generated in a close vicinity of SWRs significantly diminished the number of such highly recognizable samples in the WT but not in APP/PS1 group. These results indicate that in WT animals a large subset of SWRs and signals generated in their proximity may contain learning-related information whereas such information seem to be limited in the AD mice.
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Affiliation(s)
- Sheng-Yi Hsu
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, 40402, Taiwan.,Research Center for Interneural Computing, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Bartosz Jura
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109, Warsaw, Poland.,Institute of Applied Psychology, Jagiellonian University, Cracow, Poland
| | - Mau-Hsiang Shih
- Research Center for Interneural Computing, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Pierre Meyrand
- Neurocentre Magendie, INSERM U1215, University Bordeaux, Bordeaux, France
| | - Feng-Sheng Tsai
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, 40402, Taiwan.,Research Center for Interneural Computing, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Tiaza Bem
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109, Warsaw, Poland.
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20
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Divergence in Population Coding for Space between Dorsal and Ventral CA1. eNeuro 2021; 8:ENEURO.0211-21.2021. [PMID: 34433573 PMCID: PMC8425966 DOI: 10.1523/eneuro.0211-21.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 11/25/2022] Open
Abstract
Molecular, anatomic, and behavioral studies show that the hippocampus is structurally and functionally heterogeneous, with dorsal hippocampus implicated in mnemonic processes and spatial navigation and ventral hippocampus involved in affective processes. By performing electrophysiological recordings of large neuronal populations in dorsal and ventral CA1 in head-fixed mice navigating a virtual environment, we found that this diversity resulted in different strategies for population coding of space. Populations of neurons in dorsal CA1 showed more complex patterns of activity, which resulted in a higher dimensionality of neural representations that translated to more information being encoded, as compared ensembles in vCA1. Furthermore, a pairwise maximum entropy model was better at predicting the structure of these global patterns of activity in ventral CA1 as compared with dorsal CA1. Taken together, the different coding strategies we uncovered likely emerge from anatomic and physiological differences along the longitudinal axis of hippocampus and that may, in turn, underpin the divergent ethological roles of dorsal and ventral CA1.
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21
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Stability of ripple events during task engagement in human hippocampus. Cell Rep 2021; 35:109304. [PMID: 34192546 PMCID: PMC8288441 DOI: 10.1016/j.celrep.2021.109304] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 04/02/2021] [Accepted: 06/03/2021] [Indexed: 11/23/2022] Open
Abstract
High-frequency activity bursts in the hippocampus, known as ripples, are thought to support memory consolidation during “offline” states, such as sleep. Recently, human hippocampal ripples have been observed during “online” episodic memory tasks. It remains unclear whether similar ripple activity occurs during other cognitive states, including different types of episodic memory. However, identifying genuine ripple events in the human hippocampus is challenging. To address these questions, spectro-temporal ripple identification was applied to human hippocampal recordings across a variety of cognitive tasks. Overall, ripple attributes were stable across tasks of visual perception and associative memory, with mean rates lower than offline states of rest and sleep. In contrast, while more complex visual attention tasks did not modulate ripple attributes, rates were enhanced for more complex autobiographical memory conditions. Therefore, hippocampal ripples reliably occur across cognitive states but are specifically enhanced during offline states and complex memory processes, consistent with a role in consolidation. Hippocampal ripples are high-frequency activity bursts proposed to support “offline” memory consolidation. Chen et al. identify that human hippocampal ripples occur with stable properties across tasks of visual perception and associative memory but are enhanced for autobiographical memory retrieval and non-REM sleep, supporting their “online” role in establishing and strengthening memory traces.
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22
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O'Callaghan C, Walpola IC, Shine JM. Neuromodulation of the mind-wandering brain state: the interaction between neuromodulatory tone, sharp wave-ripples and spontaneous thought. Philos Trans R Soc Lond B Biol Sci 2020; 376:20190699. [PMID: 33308063 DOI: 10.1098/rstb.2019.0699] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mind-wandering has become a captivating topic for cognitive neuroscientists. By now, it is reasonably well described in terms of its phenomenology and the large-scale neural networks that support it. However, we know very little about what neurobiological mechanisms trigger a mind-wandering episode and sustain the mind-wandering brain state. Here, we focus on the role of ascending neuromodulatory systems (i.e. acetylcholine, noradrenaline, serotonin and dopamine) in shaping mind-wandering. We advance the hypothesis that the hippocampal sharp wave-ripple (SWR) is a compelling candidate for a brain state that can trigger mind-wandering episodes. This hippocampal rhythm, which occurs spontaneously in quiescent behavioural states, is capable of propagating widespread activity in the default network and is functionally associated with recollective, associative, imagination and simulation processes. The occurrence of the SWR is heavily dependent on hippocampal neuromodulatory tone. We describe how the interplay of neuromodulators may promote the hippocampal SWR and trigger mind-wandering episodes. We then identify the global neuromodulatory signatures that shape the evolution of the mind-wandering brain state. Under our proposed framework, mind-wandering emerges due to the interplay between neuromodulatory systems that influence the transitions between brain states, which either facilitate, or impede, a wandering mind. This article is part of the theme issue 'Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation'.
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Affiliation(s)
- Claire O'Callaghan
- Brain and Mind Centre and School of Medical Sciences, Faculty of Medicine, University of Sydney, Sydney, Australia.,Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - Ishan C Walpola
- Brain and Mind Centre and School of Medical Sciences, Faculty of Medicine, University of Sydney, Sydney, Australia
| | - James M Shine
- Brain and Mind Centre and School of Medical Sciences, Faculty of Medicine, University of Sydney, Sydney, Australia
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23
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Ozawa M, Davis P, Ni J, Maguire J, Papouin T, Reijmers L. Experience-dependent resonance in amygdalo-cortical circuits supports fear memory retrieval following extinction. Nat Commun 2020; 11:4358. [PMID: 32868768 PMCID: PMC7459312 DOI: 10.1038/s41467-020-18199-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/06/2020] [Indexed: 11/08/2022] Open
Abstract
Learned fear and safety are associated with distinct oscillatory states in the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC). To determine if and how these network states support the retrieval of competing memories, we mimicked endogenous oscillatory activity through optogenetic stimulation of parvalbumin-expressing interneurons in mice during retrieval of contextual fear and extinction memories. We found that exogenously induced 4 Hz and 8 Hz oscillatory activity in the BLA exerts bi-directional control over conditioned freezing behavior in an experience- and context-specific manner, and that these oscillations have an experience-dependent ability to recruit distinct functional neuronal ensembles. At the network level we demonstrate, via simultaneous manipulation of BLA and mPFC, that experience-dependent 4 Hz resonance across BLA-mPFC circuitry supports post-extinction fear memory retrieval. Our findings reveal that post-extinction fear memory retrieval is supported by local and interregional experience-dependent resonance, and suggest novel approaches for interrogation and therapeutic manipulation of acquired fear circuitry.
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Affiliation(s)
- Minagi Ozawa
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, USA
| | - Patrick Davis
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, USA
- Medical Scientist Training Program, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, USA
- Boston Combined Residency Program (Child Neurology), Boston Children's Hospital, Boston, MA, USA
| | - Jianguang Ni
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
| | - Jamie Maguire
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
| | - Thomas Papouin
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
| | - Leon Reijmers
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA.
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24
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Bein O, Duncan K, Davachi L. Mnemonic prediction errors bias hippocampal states. Nat Commun 2020; 11:3451. [PMID: 32651370 PMCID: PMC7351776 DOI: 10.1038/s41467-020-17287-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 06/16/2020] [Indexed: 11/10/2022] Open
Abstract
When our experience violates our predictions, it is adaptive to upregulate encoding of novel information, while down-weighting retrieval of erroneous memory predictions to promote an updated representation of the world. We asked whether mnemonic prediction errors promote hippocampal encoding versus retrieval states, as marked by distinct network connectivity between hippocampal subfields. During fMRI scanning, participants were cued to internally retrieve well-learned complex room-images and were then presented with either an identical or a modified image (0-4 changes). In the left hemisphere, we find that CA1-entorhinal connectivity increases, and CA1-CA3 connectivity decreases, with the number of changes. Further, in the left CA1, the similarity between activity patterns during cued-retrieval of the learned room and during the image is lower when the image includes changes, consistent with a prediction error signal in CA1. Our findings provide a mechanism by which mnemonic prediction errors may drive memory updating—by biasing hippocampal states. When our expectations are violated, it is adaptive to update our internal models to improve predictions in the future. Here, the authors show that during mnemonic violations, hippocampal networks are biased towards an encoding state and away from a retrieval state to potentially update these predictions.
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Affiliation(s)
- Oded Bein
- Department of Psychology, New York University, New York, NY, 10003, USA.
| | - Katherine Duncan
- Department of Psychology, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - Lila Davachi
- Department of Psychology, Columbia University, New York, NY, 10027, USA. .,Center for Biomedical Imaging and Neuromodulation, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA.
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25
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Gwilt M, Bauer M, Bast T. Frequency- and state-dependent effects of hippocampal neural disinhibition on hippocampal local field potential oscillations in anesthetized rats. Hippocampus 2020; 30:1021-1043. [PMID: 32396678 DOI: 10.1002/hipo.23212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/09/2020] [Accepted: 04/09/2020] [Indexed: 11/11/2022]
Abstract
Reduced inhibitory GABA function, so-called neural disinhibition, has been implicated in cognitive disorders, including schizophrenia and age-related cognitive decline. We previously showed in rats that hippocampal disinhibition by local microinfusion of the GABA-A receptor antagonist picrotoxin disrupted memory and attention and enhanced hippocampal multi-unit burst firing recorded around the infusion site under isoflurane anesthesia. Here, we analyzed the hippocampal local field potential (LFP) recorded alongside the multi-unit data. We predicted frequency-specific LFP changes, based on previous studies implicating GABA in hippocampal oscillations, with the weight of evidence suggesting that disinhibition would facilitate theta and disrupt gamma oscillations. Using a new semi-automated method based on the kurtosis of the LFP peak-amplitude distribution as well as on amplitude envelope thresholding, we separated three distinct hippocampal LFP states under isoflurane anesthesia: "burst" and "suppression" states-high-amplitude LFP spike bursts and the interspersed low-amplitudeperiods-and a medium-amplitude "continuous" state. The burst state showed greater overall power than suppression and continuous states and higher relative delta/theta power, but lower relative beta/gamma power. The burst state also showed reduced functional connectivity across the hippocampal recording area, especially around theta and beta frequencies. Overall neuronal firing was higher in the burst than the other two states, whereas the proportion of burst firing was higher in burst and continuous states than the suppression state. Disinhibition caused state- and frequency-dependent LFP changes, tending to increase power at lower frequencies (<20 Hz), but to decrease power and connectivity at higher frequencies (>20 Hz) in burst and suppression states. The disinhibition-induced enhancement of multi-unit bursting was also state-dependent, tending to be more pronounced in burst and suppression states than the continuous state. Overall, we characterized three distinct hippocampal LFP states in isoflurane-anesthetized rats. Disinhibition changed hippocampal LFP oscillations in a state- and frequency-dependent way. Moreover, the disinhibition-induced enhancement of multi-unit bursting was also LFP state-dependent.
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Affiliation(s)
- Miriam Gwilt
- School of Psychology and Neuroscience@Nottingham, University of Nottingham, Nottingham, UK
| | - Markus Bauer
- School of Psychology and Neuroscience@Nottingham, University of Nottingham, Nottingham, UK
| | - Tobias Bast
- School of Psychology and Neuroscience@Nottingham, University of Nottingham, Nottingham, UK
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26
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Tukker JJ, Beed P, Schmitz D, Larkum ME, Sachdev RNS. Up and Down States and Memory Consolidation Across Somatosensory, Entorhinal, and Hippocampal Cortices. Front Syst Neurosci 2020; 14:22. [PMID: 32457582 PMCID: PMC7227438 DOI: 10.3389/fnsys.2020.00022] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/03/2020] [Indexed: 01/01/2023] Open
Abstract
In the course of a day, brain states fluctuate, from conscious awake information-acquiring states to sleep states, during which previously acquired information is further processed and stored as memories. One hypothesis is that memories are consolidated and stored during "offline" states such as sleep, a process thought to involve transfer of information from the hippocampus to other cortical areas. Up and Down states (UDS), patterns of activity that occur under anesthesia and sleep states, are likely to play a role in this process, although the nature of this role remains unclear. Here we review what is currently known about these mechanisms in three anatomically distinct but interconnected cortical areas: somatosensory cortex, entorhinal cortex, and the hippocampus. In doing so, we consider the role of this activity in the coordination of "replay" during sleep states, particularly during hippocampal sharp-wave ripples. We conclude that understanding the generation and propagation of UDS may provide key insights into the cortico-hippocampal dialogue linking archi- and neocortical areas during memory formation.
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Affiliation(s)
- John J Tukker
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Neuroscience Research Center, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Prateep Beed
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Neuroscience Research Center, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Neuroscience Research Center, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,Cluster of Excellence NeuroCure, Berlin, Germany.,Einstein Center for Neurosciences Berlin, Berlin, Germany
| | - Matthew E Larkum
- Cluster of Excellence NeuroCure, Berlin, Germany.,Einstein Center for Neurosciences Berlin, Berlin, Germany.,Institut für Biologie, Humboldt Universität, Berlin, Germany
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27
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Nitzan N, McKenzie S, Beed P, English DF, Oldani S, Tukker JJ, Buzsáki G, Schmitz D. Propagation of hippocampal ripples to the neocortex by way of a subiculum-retrosplenial pathway. Nat Commun 2020; 11:1947. [PMID: 32327634 PMCID: PMC7181800 DOI: 10.1038/s41467-020-15787-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 03/27/2020] [Indexed: 02/07/2023] Open
Abstract
Bouts of high frequency activity known as sharp wave ripples (SPW-Rs) facilitate communication between the hippocampus and neocortex. However, the paths and mechanisms by which SPW-Rs broadcast their content are not well understood. Due to its anatomical positioning, the granular retrosplenial cortex (gRSC) may be a bridge for this hippocampo-cortical dialogue. Using silicon probe recordings in awake, head-fixed mice, we show the existence of SPW-R analogues in gRSC and demonstrate their coupling to hippocampal SPW-Rs. gRSC neurons reliably distinguished different subclasses of hippocampal SPW-Rs according to ensemble activity patterns in CA1. We demonstrate that this coupling is brain state-dependent, and delineate a topographically-organized anatomical pathway via VGlut2-expressing, bursty neurons in the subiculum. Optogenetic stimulation or inhibition of bursty subicular cells induced or reduced responses in superficial gRSC, respectively. These results identify a specific path and underlying mechanisms by which the hippocampus can convey neuronal content to the neocortex during SPW-Rs.
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Affiliation(s)
- Noam Nitzan
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
| | - Sam McKenzie
- Neuroscience Institute and Department of Neurology New York University Langone Medical Center, New York, NY, 10016, USA
| | - Prateep Beed
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
| | - Daniel Fine English
- Neuroscience Institute and Department of Neurology New York University Langone Medical Center, New York, NY, 10016, USA
- School of Neuroscience, College of Science, Virginia Tech, VA, 24061, USA
| | - Silvia Oldani
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
- Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - John J Tukker
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany
- Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - György Buzsáki
- Neuroscience Institute and Department of Neurology New York University Langone Medical Center, New York, NY, 10016, USA.
- Center for Neural Science, New York University, New York, NY, 10016, USA.
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, Berlin, Germany.
- Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.
- Cluster of Excellence NeuroCure, Berlin, Germany.
- Einstein Center for Neurosciences, Berlin, Germany.
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28
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Kay K, Chung JE, Sosa M, Schor JS, Karlsson MP, Larkin MC, Liu DF, Frank LM. Constant Sub-second Cycling between Representations of Possible Futures in the Hippocampus. Cell 2020; 180:552-567.e25. [PMID: 32004462 DOI: 10.1016/j.cell.2020.01.014] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/17/2019] [Accepted: 01/09/2020] [Indexed: 02/07/2023]
Abstract
Cognitive faculties such as imagination, planning, and decision-making entail the ability to represent hypothetical experience. Crucially, animal behavior in natural settings implies that the brain can represent hypothetical future experience not only quickly but also constantly over time, as external events continually unfold. To determine how this is possible, we recorded neural activity in the hippocampus of rats navigating a maze with multiple spatial paths. We found neural activity encoding two possible future scenarios (two upcoming maze paths) in constant alternation at 8 Hz: one scenario per ∼125-ms cycle. Further, we found that the underlying dynamics of cycling (both inter- and intra-cycle dynamics) generalized across qualitatively different representational correlates (location and direction). Notably, cycling occurred across moving behaviors, including during running. These findings identify a general dynamic process capable of quickly and continually representing hypothetical experience, including that of multiple possible futures.
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Affiliation(s)
- Kenneth Kay
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Jason E Chung
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Marielena Sosa
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jonathan S Schor
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Mattias P Karlsson
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Margaret C Larkin
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Daniel F Liu
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Loren M Frank
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
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29
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Tokuda K, Katori Y, Aihara K. Chaotic dynamics as a mechanism of rapid transition of hippocampal local field activity between theta and non-theta states. CHAOS (WOODBURY, N.Y.) 2019; 29:113115. [PMID: 31779345 DOI: 10.1063/1.5110327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 10/21/2019] [Indexed: 06/10/2023]
Abstract
We propose a dynamical model of the local hippocampal circuit realizing the transition between the theta and non-theta states. We model the interaction between hippocampal local rhythm generators and the external periodic input from the medial septum and diagonal band of Broca (MS-DBB). With our model, bifurcation of the nonlinear dynamics serves as a mechanism that realizes two distinctive oscillations in the hippocampus, where the amplitude of the oscillatory input from the MS-DBB works as a bifurcation parameter. We model the network of the hippocampal interneurons with a network of simple class 1 neuron models connected mutually with gap junctions. The model neurons exhibit highly synchronous periodic oscillations under the existence of an external force from the MS-DBB, just as the real hippocampus shows theta oscillation under the rhythmic input from the MS-DBB. The model shows diffusion-induced chaotic dynamics under an aperiodic MS-DBB activity, just as the large amplitude irregular activity appears following the disappearance of the rhythmicity of the MS-DBB neurons in the real brain. The model is consistent with both previous experimental findings reporting the existence of local rhythm generators in the hippocampus and the executive role of the MS-DBB in synchronizing theta oscillation in vivo. Our model also replicates the traveling waves of theta oscillations in two-dimensionally coupled networks.
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Affiliation(s)
- Keita Tokuda
- Department of Pharmacy, Faculty of Medicine, The University of Tokyo Hospital, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Yuichi Katori
- School of Systems Information Science, Future University Hakodate, 116-2 Kamedanakano-cho, Hakodate, Hokkaido 041-8655, Japan
| | - Kazuyuki Aihara
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
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30
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Iqubal A, Sharma S, Najmi AK, Syed MA, Ali J, Alam MM, Haque SE. Nerolidol ameliorates cyclophosphamide-induced oxidative stress, neuroinflammation and cognitive dysfunction: Plausible role of Nrf2 and NF- κB. Life Sci 2019; 236:116867. [PMID: 31520598 DOI: 10.1016/j.lfs.2019.116867] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/31/2019] [Accepted: 09/10/2019] [Indexed: 12/27/2022]
Abstract
AIM Cyclophosphamide (CP) is a potent anticancer and immunosuppressant drug. Studies have shown significant oxidative stress and cognitive impairment but neuroinflammatory and histological aberrations with its administration is underexplored. Nerolidol (NER) is a lipophilic bioactive molecule with antioxidant and anti-inflammatory properties but it has not been explored for neuroprotective potential in CP-induced neurotoxic manifestations. Therefore, in the present study, we aimed to evaluate the neuroprotective potential of NER in CP-induced neuroinflammation and associated comorbid conditions like depression and cognitive dysfunctions. MATERIALS AND METHOD In-silico study using Schrödinger software was used to assess the binding affinity of NER with Nrf2. In the In vivo study, NER 200 and 400 mg/kg p.o. were given from 1st day to 14th day. CP 200 mg/kg, i.p., was administered on the 7th day. After 24 h of the last dosing, neurobehavioral tests like spontaneous body alternation, passive avoidance and forced swim test were performed. On completion of study, mice were sacrificed, hippocampus and cortex were removed for biochemical estimations, histopathology and immunohistochemistry of p65 NF- κB and Nrf2. KEY FINDINGS In-silico study showed significant binding of NER into the pocket domain of Nrf2. In-vivo study showed protective effect of NER against CP-induced neuroinflammation, oxidative stress, cognitive impairment and structural abnormalities in the hippocampus and cortex regions. SIGNIFICANCE Findings of the study suggested that NER is a potential therapeutic molecule which can mitigate CP-induced neurotoxic manifestations via Nrf2 and NF-κB pathway. However, more detailed studies are needed to explicate the mechanism underlying its neuroprotective effect.
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Affiliation(s)
- Ashif Iqubal
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Sumit Sharma
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Abul Kalam Najmi
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Mansoor Ali Syed
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India
| | - Javed Ali
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - M Mumtaz Alam
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Syed Ehtaishamul Haque
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India.
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31
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The hippocampal sharp wave-ripple in memory retrieval for immediate use and consolidation. Nat Rev Neurosci 2019; 19:744-757. [PMID: 30356103 DOI: 10.1038/s41583-018-0077-1] [Citation(s) in RCA: 204] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Various cognitive functions have long been known to require the hippocampus. Recently, progress has been made in identifying the hippocampal neural activity patterns that implement these functions. One such pattern is the sharp wave-ripple (SWR), an event associated with highly synchronous neural firing in the hippocampus and modulation of neural activity in distributed brain regions. Hippocampal spiking during SWRs can represent past or potential future experience, and SWR-related interventions can alter subsequent memory performance. These findings and others suggest that SWRs support both memory consolidation and memory retrieval for processes such as decision-making. In addition, studies have identified distinct types of SWR based on representational content, behavioural state and physiological features. These various findings regarding SWRs suggest that different SWR types correspond to different cognitive functions, such as retrieval and consolidation. Here, we introduce another possibility - that a single SWR may support more than one cognitive function. Taking into account classic psychological theories and recent molecular results that suggest that retrieval and consolidation share mechanisms, we propose that the SWR mediates the retrieval of stored representations that can be utilized immediately by downstream circuits in decision-making, planning, recollection and/or imagination while simultaneously initiating memory consolidation processes.
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32
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Hay I, Hynes KL, Burgess JR. Mild-to-Moderate Gestational Iodine Deficiency Processing Disorder. Nutrients 2019; 11:E1974. [PMID: 31443337 PMCID: PMC6770179 DOI: 10.3390/nu11091974] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/12/2019] [Accepted: 08/15/2019] [Indexed: 12/28/2022] Open
Abstract
This synopsis paper aims to identify if a common pattern of learning and social difficulties can be conceptualized across recent longitudinal studies investigating the influence of mild-to-moderate gestational iodine deficiency (GID) on offspring's optimal cognitive and psycho-social development. The main studies investigated are: The Southampton Women's Study (SWS)-United Kingdom; the Avon Longitudinal Study of Parents and Children (ALSPAC)-United Kingdom; the Gestational Iodine Cohort Longitudinal Study-Tasmania, Australia, and the Danish National Birth Cohort Case-Control Study-Denmark. In contrast to severe GID where there is a global negative impact on neurodevelopment, mild-to-moderate intrauterine iodine deficiency has subtler, but nonetheless important, permanent cognitive and psycho-social consequences on the offspring. This paper links the results from each study and maintains that mild-to-moderate GID is associated with a disorder that is characterized by speed of neural transmitting difficulties that are typically associated with working memory capacity difficulties and attention and response inhibition. The authors maintain that this disorder is better identified as Gestational Iodine Deficiency Processing Disorder (GIDPD), rather than, what to date has often been identified as 'suboptimal development'. The Autistic Spectrum Disorder (ASD), Attention Deficit, Hyperactivity Disorder (ADHD), language and literacy disorders (learning disabilities and dyslexia) are the main manifestations associated with GIDPD. GIDPD is identified on IQ measures, but selectively and mainly on verbal reasoning IQ subtests, with individuals with GIDPD still operating within the 'normal' full-scale IQ range. Greater consideration needs to be given by public health professionals, policy makers and educators about the important and preventable consequences of GID. Specifically, more emphasis should be placed on adequate iodine intake in women prior to pregnancy, as well as during pregnancy and when lactating. Secondly, researchers and others need to further extend, refine and clarify whether GIDPD, as a nosological (medical classification) entity, is a valid disorder and concept for consideration.
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Affiliation(s)
- Ian Hay
- Faculty of Education, University of Tasmania, Launceston 7250, Australia.
| | - Kristen L Hynes
- Menzies Institute for Medical Research, University of Tasmania, Hobart 7001, Australia
| | - John R Burgess
- Department of Endocrinology, Royal Hobart Hospital, Hobart 7001, Australia
- School of Medicine, University of Tasmania, Hobart 7000, Australia
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