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Koukaroudi D, Qiu Z, Fransén E, Gokhale R, Bulovaite E, Komiyama NH, Seibt J, Grant SGN. Sleep maintains excitatory synapse diversity in the cortex and hippocampus. Curr Biol 2024; 34:3836-3843.e5. [PMID: 39096907 DOI: 10.1016/j.cub.2024.07.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/17/2024] [Accepted: 07/05/2024] [Indexed: 08/05/2024]
Abstract
Insufficient sleep is a global problem with serious consequences for cognition and mental health.1 Synapses play a central role in many aspects of cognition, including the crucial function of memory consolidation during sleep.2 Interference with the normal expression or function of synapse proteins is a cause of cognitive, mood, and other behavioral problems in over 130 brain disorders.3 Sleep deprivation (SD) has also been reported to alter synapse protein composition and synapse number, although with conflicting results.4,5,6,7 In our study, we conducted synaptome mapping of excitatory synapses in 125 regions of the mouse brain and found that sleep deprivation selectively reduces synapse diversity in the cortex and in the CA1 region of the hippocampus. Sleep deprivation targeted specific types and subtypes of excitatory synapses while maintaining total synapse density (synapse number/area). Synapse subtypes with longer protein lifetimes exhibited resilience to sleep deprivation, similar to observations in aging and genetic perturbations. Moreover, the altered synaptome architecture affected the responses to neural oscillations, suggesting that sleep plays a vital role in preserving cognitive function by maintaining the brain's synaptome architecture.
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Affiliation(s)
- Dimitra Koukaroudi
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Zhen Qiu
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; School of Science and Engineering, University of Dundee, Dundee DD1 4HN, UK
| | - Erik Fransén
- Department of Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, 10044 Stockholm, Sweden; Science for Life Laboratory, KTH Royal Institute of Technology, 171 65 Solna, Sweden
| | - Ragini Gokhale
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Edita Bulovaite
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Noboru H Komiyama
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK; The Patrick Wild Centre for Research into Autism, Fragile X Syndrome & Intellectual Disabilities, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK; Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Julie Seibt
- Surrey Sleep Research Centre, School of Biosciences, University of Surrey, Guildford, Surrey GU2 7XP, UK
| | - Seth G N Grant
- Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK.
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2
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Méndez P, de la Vega-Ruiz R, Montes-Mellado A. Estrogenic regulation of hippocampal inhibitory system across lifespan. J Neuroendocrinol 2024:e13441. [PMID: 39143852 DOI: 10.1111/jne.13441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/08/2024] [Accepted: 08/01/2024] [Indexed: 08/16/2024]
Abstract
Estrogens produced in peripheral tissues and locally in the brain are potent neuromodulators. The function of the hippocampus, a brain region essential for episodic memory and spatial navigation, relies on the activity of ensembles of excitatory neurons whose activity is temporally and spatially coordinated by a wide diversity of inhibitory neurons (INs) types. Over the last years, we have accumulated evidence that indicates that estrogens regulate the function of hippocampal INs through different mechanisms, including transcriptional regulation and rapid nongenomic signaling. Here, we argue that the well-documented influence of estrogens on episodic memory may be related to the actions of local and peripheral estrogens on the heterogenous populations of hippocampal INs. We discuss how physiological changes in peripheral sex hormone levels throughout lifespan may interact with local brain sources to regulate IN function at different stages of life, from early hippocampal development to the aging brain. We conclude that considering INs as mediators of sex hormone actions in the hippocampus across the healthy life span will benefit our understanding of sex-biased neurodevelopmental disorders and physiological aging.
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3
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Schlafly ED, Carbonero D, Chu CJ, Kramer MA. A data augmentation procedure to improve detection of spike ripples in brain voltage recordings. Neurosci Res 2024:S0168-0102(24)00096-8. [PMID: 39102943 DOI: 10.1016/j.neures.2024.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Revised: 06/04/2024] [Accepted: 07/30/2024] [Indexed: 08/07/2024]
Abstract
Epilepsy is a major neurological disorder characterized by recurrent, spontaneous seizures. For patients with drug-resistant epilepsy, treatments include neurostimulation or surgical removal of the epileptogenic zone (EZ), the brain region responsible for seizure generation. Precise targeting of the EZ requires reliable biomarkers. Spike ripples - high-frequency oscillations that co-occur with large amplitude epileptic discharges - have gained prominence as a candidate biomarker. However, spike ripple detection remains a challenge. The gold-standard approach requires an expert manually visualize and interpret brain voltage recordings, which limits reproducibility and high-throughput analysis. Addressing these limitations requires more objective, efficient, and automated methods for spike ripple detection, including approaches that utilize deep neural networks. Despite advancements, dataset heterogeneity and scarcity severely limit machine learning performance. Our study explores long-short term memory (LSTM) neural network architectures for spike ripple detection, leveraging data augmentation to improve classifier performance. We highlight the potential of combining training on augmented and in vivo data for enhanced spike ripple detection and ultimately improving diagnostic accuracy in epilepsy treatment.
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Affiliation(s)
- Emily D Schlafly
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA.
| | - Daniel Carbonero
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA; Center for Systems Neuroscience, Boston University, Boston, MA, USA.
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4
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Coelho CA, Mocle AJ, Jacob AD, Ramsaran AI, Rashid AJ, Köhler S, Josselyn SA, Frankland PW. Dentate gyrus ensembles gate context-dependent neural states and memory retrieval. SCIENCE ADVANCES 2024; 10:eadn9815. [PMID: 39093976 PMCID: PMC11296340 DOI: 10.1126/sciadv.adn9815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 06/28/2024] [Indexed: 08/04/2024]
Abstract
Memories of events are linked to the contexts in which they were encoded. This contextual linking ensures enhanced access to those memories that are most relevant to the context at hand, including specific associations that were previously learned in that context. This principle, referred to as encoding specificity, predicts that context-specific neural states should bias retrieval of particular associations over others, potentially allowing for the disambiguation of retrieval cues that may have multiple associations or meanings. Using a context-odor paired associate learning paradigm in mice, here, we show that chemogenetic manipulation of dentate gyrus ensembles corresponding to specific contexts reinstates context-specific neural states in downstream CA1 and biases retrieval toward context-specific associations.
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Affiliation(s)
- Cesar A.O. Coelho
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
| | - Andrew J. Mocle
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Alex D. Jacob
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Adam I. Ramsaran
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Asim J. Rashid
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
| | - Stefan Köhler
- Department of Psychology, University of Western Ontario, London, ON, Canada
| | - Sheena A. Josselyn
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Paul W. Frankland
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research, Toronto, ON, Canada
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5
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Löffler H, Gupta DS, Bahmer A. Neural coding of space by time. BIOLOGICAL CYBERNETICS 2024; 118:215-227. [PMID: 38844579 DOI: 10.1007/s00422-024-00992-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 05/24/2024] [Indexed: 07/31/2024]
Abstract
The intertwining of space and time poses a significant scientific challenge, transcending disciplines from philosophy and physics to neuroscience. Deciphering neural coding, marked by its inherent spatial and temporal dimensions, has proven to be a complex task. In this paper, we present insights into temporal and spatial modes of neural coding and their intricate interplay, drawn from neuroscientific findings. We illustrate the conversion of a purely spatial input into the temporal form of a singular spike train, demonstrating storage, transmission to remote locations, and recall through spike bursts corresponding to Sharp Wave Ripples. Moreover, the converted temporal representation can be transformed back into a spatiotemporal pattern. The principles of the transformation process are illustrated using a simple feed-forward spiking neural network. The frequencies and phases of Subthreshold Membrane potential Oscillations play a pivotal role in this framework. The model offers insights into information multiplexing and phenomena such as stretching or compressing time of spike patterns.
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Affiliation(s)
| | | | - Andreas Bahmer
- RheinMain University of Applied Sciences, Ruesselsheim Campus, 65197, Wiesbaden, Germany
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6
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Fayed MR, Ghandour K, Inokuchi K. Sleep and quiet wakefulness signify an idling brain hub for creative insights. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230226. [PMID: 38853559 PMCID: PMC11343221 DOI: 10.1098/rstb.2023.0226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 03/12/2024] [Accepted: 04/09/2024] [Indexed: 06/11/2024] Open
Abstract
Long-term potentiation of synaptic strength is a fundamental aspect of learning and memory. Memories are believed to be stored within specific populations of neurons known as engram cells, which are subsequently reactivated during sleep, facilitating the consolidation of stored information. However, sleep and offline reactivations are associated not only with past experiences but also with anticipation of future events. During periods of offline reactivation, which occur during sleep and quiet wakefulness, the brain exhibits a capability to form novel connections. This process links various past experiences, often leading to the emergence of qualitatively new information that was not initially available. Brain activity during sleep and quiet wakefulness is referred to as the 'idling brain'. Idling brain activity is believed to play a pivotal role in abstracting essential information, comprehending underlying rules, generating creative ideas and fostering insightful thoughts. In this review, we will explore the current state of research and future directions in understanding how sleep and idling brain activity are interconnected with various cognitive functions, especially creative insights. These insights have profound implications for our daily lives, impacting our ability to process information, make decisions and navigate complex situations effectively. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Mostafa R. Fayed
- Research Centre for Idling Brain Science, University of Toyama, Toyama930-0194, Japan
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama930-0194, Japan
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh33516, Egypt
| | - Khaled Ghandour
- Research Centre for Idling Brain Science, University of Toyama, Toyama930-0194, Japan
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama930-0194, Japan
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Cairo11562, Egypt
| | - Kaoru Inokuchi
- Research Centre for Idling Brain Science, University of Toyama, Toyama930-0194, Japan
- Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama930-0194, Japan
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7
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Jones EAA, Low IIC, Cho FS, Giocomo LM. Entorhinal cortex represents task-relevant remote locations independent of CA1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.23.604815. [PMID: 39091781 PMCID: PMC11291150 DOI: 10.1101/2024.07.23.604815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Neurons can collectively represent the current sensory experience while an animal is exploring its environment or remote experiences while the animal is immobile. These remote representations can reflect learned associations1-3 and be required for learning4. Neurons in the medial entorhinal cortex (MEC) reflect the animal's current location during movement5, but little is known about what MEC neurons collectively represent during immobility. Here, we recorded thousands of neurons in superficial MEC and dorsal CA1 as mice learned to associate two pairs of rewarded locations. We found that during immobility, the MEC neural population frequently represented positions far from the animal's location, which we defined as 'non-local coding'. Cells with spatial firing fields at remote locations drove non-local coding, even as cells representing the current position remained active. While MEC non-local coding has been reported during sharp-wave ripples in downstream CA16, we observed non-local coding more often outside of ripples. In fact, CA1 activity was less coordinated with MEC during non-local coding. We further observed that non-local coding was pertinent to the task, as MEC preferentially represented remote task-relevant locations at appropriate times, while rarely representing task-irrelevant locations. Together, this work raises the possibility that MEC non-local coding could strengthen associations between locations independently from CA1.
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Affiliation(s)
- Emily A. Aery Jones
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Isabel I. C. Low
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Frances S. Cho
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Lisa M. Giocomo
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305
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8
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Xiang LY, Chen XY, Lu LM, Kong MH, Ji Q, Xiong Y, Xie MM, Jian XL, Zhu ZR. Mechanisms of Neuronal Reactivation in Memory Consolidation: A Perspective from Pathological Conditions. Neuroscience 2024; 551:196-204. [PMID: 38810690 DOI: 10.1016/j.neuroscience.2024.05.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 05/19/2024] [Accepted: 05/23/2024] [Indexed: 05/31/2024]
Abstract
Memory consolidation refers to a process by which labile newly formed memory traces are progressively strengthened into long term memories and become more resistant to interference. Recent work has revealed that spontaneous hippocampal activity during rest, commonly referred to as "offline" activity, plays a critical role in the process of memory consolidation. Hippocampal reactivation occurs during sharp-wave ripples (SWRs), which are events associated with highly synchronous neural firing in the hippocampus and modulation of neural activity in distributed brain regions. Memory consolidation occurs primarily through a coordinated communication between hippocampus and neocortex. Cortical slow oscillations drive the repeated reactivation of hippocampal memory representations together with SWRs and thalamo-cortical spindles, inducing long-lasting cellular and network modifications responsible for memory stabilization.In this review, we aim to comprehensively cover the field of "reactivation and memory consolidation" research by detailing the physiological mechanisms of neuronal reactivation and firing patterns during SWRs and providing a discussion of more recent key findings. Several mechanistic explanations of neuropsychiatric diseases propose that impaired neural replay may underlie some of the symptoms of the disorders. Abnormalities in neuronal reactivation are a common phenomenon and cause pathological impairment in several diseases, such as Alzheimer's disease (AD), epilepsy and schizophrenia. However, the specific pathological changes and mechanisms of reactivation in each disease are different. Recent work has also enlightened some of the underlying pathological mechanisms of neuronal reactivation in these diseases. In this review, we further describe how SWRs, ripples and slow oscillations are affected in Alzheimer's disease, epilepsy, and schizophrenia. We then compare the differences of neuronal reactivation and discuss how different reactivation abnormalities cause pathological changes in these diseases. Aberrant neural reactivation provides insights into disease pathogenesis and may even serve as biomarkers for early disease progression and treatment response.
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Affiliation(s)
- Lei-Ying Xiang
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Xiao-Yi Chen
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Li-Ming Lu
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Ming-Hui Kong
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Qi Ji
- Department of Medical Psychology, Army Medical University, Chongqing, PR China
| | - Yu Xiong
- Department of Stomatology, Southwest Hospital, Chongqing, PR China
| | - Mei-Ming Xie
- Chinese People's Liberation Army Western Theater General Hospital, Chengdu, PR China
| | - Xin-Ling Jian
- No. 950 Hospital of the Chinese People's Liberation Army, Yecheng, PR China
| | - Zhi-Ru Zhu
- Department of Medical Psychology, Army Medical University, Chongqing, PR China.
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9
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Young RA, Shin JD, Guo Z, Jadhav SP. Hippocampal-prefrontal communication subspaces align with behavioral and network patterns in a spatial memory task. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.08.601617. [PMID: 39026752 PMCID: PMC11257456 DOI: 10.1101/2024.07.08.601617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Rhythmic network states have been theorized to facilitate communication between brain regions, but how these oscillations influence communication subspaces, i.e, the low-dimensional neural activity patterns that mediate inter-regional communication, and in turn how subspaces impact behavior remains unclear. Using a spatial memory task in rats, we simultaneously recorded ensembles from hippocampal CA1 and the prefrontal cortex (PFC) to address this question. We found that task behaviors best aligned with low-dimensional, shared subspaces between these regions, rather than local activity in either region. Critically, both network oscillations and speed modulated the structure and performance of this communication subspace. Contrary to expectations, theta coherence did not better predict CA1-PFC shared activity, while theta power played a more significant role. To understand the communication space, we visualized shared CA1-PFC communication geometry using manifold techniques and found ring-like structures. We hypothesize that these shared activity manifolds are utilized to mediate the task behavior. These findings suggest that memory-guided behaviors are driven by shared CA1-PFC interactions that are dynamically modulated by oscillatory states, offering a novel perspective on the interplay between rhythms and behaviorally relevant neural communication.
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10
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Shin JD, Jadhav SP. Prefrontal cortical ripples mediate top-down suppression of hippocampal reactivation during sleep memory consolidation. Curr Biol 2024; 34:2801-2811.e9. [PMID: 38834064 PMCID: PMC11233241 DOI: 10.1016/j.cub.2024.05.018] [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: 02/13/2024] [Revised: 04/17/2024] [Accepted: 05/09/2024] [Indexed: 06/06/2024]
Abstract
Consolidation of initially encoded hippocampal representations in the neocortex through reactivation is crucial for long-term memory formation and is facilitated by the coordination of hippocampal sharp-wave ripples (SWRs) with cortical slow and spindle oscillations during non-REM sleep. Recent evidence suggests that high-frequency cortical ripples can also coordinate with hippocampal SWRs in support of consolidation; however, the contribution of cortical ripples to reactivation remains unclear. We used high-density, continuous recordings in the hippocampus (area CA1) and prefrontal cortex (PFC) over the course of spatial learning and show that independent PFC ripples dissociated from SWRs are prevalent in NREM sleep and predominantly suppress hippocampal activity. PFC ripples paradoxically mediate top-down suppression of hippocampal reactivation rather than coordination, and this suppression is stronger for assemblies that are reactivated during coordinated CA1-PFC ripples for consolidation of recent experiences. Further, we show non-canonical, serial coordination of independent cortical ripples with slow and spindle oscillations, which are known signatures of memory consolidation. These results establish a role for prefrontal cortical ripples in top-down regulation of behaviorally relevant hippocampal representations during consolidation.
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Affiliation(s)
- Justin D Shin
- Neuroscience Program, Department of Psychology, and Volen National Center for Complex Systems, Brandeis University, 415 South Street, Waltham, MA 02453, USA
| | - Shantanu P Jadhav
- Neuroscience Program, Department of Psychology, and Volen National Center for Complex Systems, Brandeis University, 415 South Street, Waltham, MA 02453, USA.
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11
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Gillespie AK, Astudillo Maya D, Denovellis EL, Desse S, Frank LM. Neurofeedback training can modulate task-relevant memory replay rate in rats. eLife 2024; 12:RP90944. [PMID: 38958562 PMCID: PMC11221834 DOI: 10.7554/elife.90944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024] Open
Abstract
Hippocampal replay - the time-compressed, sequential reactivation of ensembles of neurons related to past experience - is a key neural mechanism of memory consolidation. Replay typically coincides with a characteristic pattern of local field potential activity, the sharp-wave ripple (SWR). Reduced SWR rates are associated with cognitive impairment in multiple models of neurodegenerative disease, suggesting that a clinically viable intervention to promote SWRs and replay would prove beneficial. We therefore developed a neurofeedback paradigm for rat subjects in which SWR detection triggered rapid positive feedback in the context of a memory-dependent task. This training protocol increased the prevalence of task-relevant replay during the targeted neurofeedback period by changing the temporal dynamics of SWR occurrence. This increase was also associated with neural and behavioral forms of compensation after the targeted period. These findings reveal short-timescale regulation of SWR generation and demonstrate that neurofeedback is an effective strategy for modulating hippocampal replay.
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Affiliation(s)
- Anna K Gillespie
- Departments of Biological Structure and Lab Medicine & Pathology, University of WashingtonSeattleUnited States
- Departments of Physiology and Psychiatry and the Kavli Institute for Fundamental Neuroscience, University of California, San FranciscoSan FranciscoUnited States
| | - Daniela Astudillo Maya
- Departments of Physiology and Psychiatry and the Kavli Institute for Fundamental Neuroscience, University of California, San FranciscoSan FranciscoUnited States
| | - Eric L Denovellis
- Departments of Physiology and Psychiatry and the Kavli Institute for Fundamental Neuroscience, University of California, San FranciscoSan FranciscoUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Sachi Desse
- Departments of Physiology and Psychiatry and the Kavli Institute for Fundamental Neuroscience, University of California, San FranciscoSan FranciscoUnited States
| | - Loren M Frank
- Departments of Physiology and Psychiatry and the Kavli Institute for Fundamental Neuroscience, University of California, San FranciscoSan FranciscoUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
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12
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Walia V, Wal P, Mishra S, Agrawal A, Kosey S, Dilipkumar Patil A. Potential role of oxytocin in the regulation of memories and treatment of memory disorders. Peptides 2024; 177:171222. [PMID: 38649032 DOI: 10.1016/j.peptides.2024.171222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/03/2024] [Accepted: 04/13/2024] [Indexed: 04/25/2024]
Abstract
Oxytocin (OXT) is an "affiliative" hormone or neurohormone or neuropeptide consists of nine amino acids, synthesized in magnocellular neurons of paraventricular (PVN) and supraoptic nuclei (SON) of hypothalamus. OXT receptors are widely distributed in various region of brain and OXT has been shown to regulate various social and nonsocial behavior. Hippocampus is the main region which regulates the learning and memory. Hippocampus particularly regulates the acquisition of new memories and retention of acquired memories. OXT has been shown to regulate the synaptic plasticity, neurogenesis, and consolidation of memories. Further, findings from both preclinical and clinical studies have suggested that the OXT treatment improves performance in memory related task. Various trials have suggested the positive impact of intranasal OXT in the dementia patients. However, these studies are limited in number. In the present study authors have highlighted the role of OXT in the formation and retrieval of memories. Further, the study demonstrated the outcome of OXT treatment in various memory and related disorders.
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Affiliation(s)
- Vaibhav Walia
- SGT College of Pharmacy, SGT University, Gurugram, Haryana, India.
| | - Pranay Wal
- PSIT-Pranveer Singh Institute of Technology (Pharmacy), Kanpur, UP 209305, India
| | - Shweta Mishra
- SGT College of Pharmacy, SGT University, Gurugram, Haryana, India
| | - Ankur Agrawal
- Jai Institute of Pharmaceutical Sciences and Research, Gwalior, MP, India
| | - Sourabh Kosey
- Department of Pharmacy Practice, ISF College of Pharmacy, Moga, Punjab, India
| | - Aditya Dilipkumar Patil
- Founder, Tech Hom Research Solutions (THRS), Plot no. 38, 1st floor, opposite to biroba mandir, near ST stand, Satara, Maharashtra 415110, India
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13
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Rangel Guerrero DK, Balueva K, Barayeu U, Baracskay P, Gridchyn I, Nardin M, Roth CN, Wulff P, Csicsvari J. Hippocampal cholecystokinin-expressing interneurons regulate temporal coding and contextual learning. Neuron 2024; 112:2045-2061.e10. [PMID: 38636524 DOI: 10.1016/j.neuron.2024.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 10/03/2023] [Accepted: 03/18/2024] [Indexed: 04/20/2024]
Abstract
Cholecystokinin-expressing interneurons (CCKIs) are hypothesized to shape pyramidal cell-firing patterns and regulate network oscillations and related network state transitions. To directly probe their role in the CA1 region, we silenced their activity using optogenetic and chemogenetic tools in mice. Opto-tagged CCKIs revealed a heterogeneous population, and their optogenetic silencing triggered wide disinhibitory network changes affecting both pyramidal cells and other interneurons. CCKI silencing enhanced pyramidal cell burst firing and altered the temporal coding of place cells: theta phase precession was disrupted, whereas sequence reactivation was enhanced. Chemogenetic CCKI silencing did not alter the acquisition of spatial reference memories on the Morris water maze but enhanced the recall of contextual fear memories and enabled selective recall when similar environments were tested. This work suggests the key involvement of CCKIs in the control of place-cell temporal coding and the formation of contextual memories.
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Affiliation(s)
- Dámaris K Rangel Guerrero
- Information and Systems Sciences, Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.
| | - Kira Balueva
- Institute of Physiology, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Uladzislau Barayeu
- Information and Systems Sciences, Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Peter Baracskay
- Information and Systems Sciences, Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Igor Gridchyn
- Information and Systems Sciences, Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Michele Nardin
- Information and Systems Sciences, Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Chiara Nina Roth
- Information and Systems Sciences, Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Peer Wulff
- Institute of Physiology, Christian-Albrechts-University Kiel, 24118 Kiel, Germany.
| | - Jozsef Csicsvari
- Information and Systems Sciences, Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.
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14
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Schreiner T, Griffiths BJ, Kutlu M, Vollmar C, Kaufmann E, Quach S, Remi J, Noachtar S, Staudigl T. Spindle-locked ripples mediate memory reactivation during human NREM sleep. Nat Commun 2024; 15:5249. [PMID: 38898100 PMCID: PMC11187142 DOI: 10.1038/s41467-024-49572-8] [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: 10/30/2023] [Accepted: 06/11/2024] [Indexed: 06/21/2024] Open
Abstract
Memory consolidation relies in part on the reactivation of previous experiences during sleep. The precise interplay of sleep-related oscillations (slow oscillations, spindles and ripples) is thought to coordinate the information flow between relevant brain areas, with ripples mediating memory reactivation. However, in humans empirical evidence for a role of ripples in memory reactivation is lacking. Here, we investigated the relevance of sleep oscillations and specifically ripples for memory reactivation during human sleep using targeted memory reactivation. Intracranial electrophysiology in epilepsy patients and scalp EEG in healthy participants revealed that elevated levels of slow oscillation - spindle activity coincided with the read-out of experimentally induced memory reactivation. Importantly, spindle-locked ripples recorded intracranially from the medial temporal lobe were found to be correlated with the identification of memory reactivation during non-rapid eye movement sleep. Our findings establish ripples as key-oscillation for sleep-related memory reactivation in humans and emphasize the importance of the coordinated interplay of the cardinal sleep oscillations.
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Affiliation(s)
- Thomas Schreiner
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Benjamin J Griffiths
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Merve Kutlu
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Vollmar
- Epilepsy Center, Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elisabeth Kaufmann
- Epilepsy Center, Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stefanie Quach
- Department of Neurosurgery, University Hospital Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jan Remi
- Epilepsy Center, Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Soheyl Noachtar
- Epilepsy Center, Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Tobias Staudigl
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
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15
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Laham BJ, Gore IR, Brown CJ, Gould E. Adult-born granule cells modulate CA2 network activity during retrieval of developmental memories of the mother. eLife 2024; 12:RP90600. [PMID: 38833278 PMCID: PMC11149928 DOI: 10.7554/elife.90600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024] Open
Abstract
Adult-born granule cells (abGCs) project to the CA2 region of the hippocampus, but it remains unknown how this circuit affects behavioral function. Here, we show that abGC input to the CA2 of adult mice is involved in the retrieval of remote developmental memories of the mother. Ablation of abGCs impaired the ability to discriminate between a caregiving mother and a novel mother, and this ability returned after abGCs were regenerated. Chemogenetic inhibition of projections from abGCs to the CA2 also temporarily prevented the retrieval of remote mother memories. These findings were observed when abGCs were inhibited at 4-6 weeks old, but not when they were inhibited at 10-12 weeks old. We also found that abGCs are necessary for differentiating features of CA2 network activity, including theta-gamma coupling and sharp wave ripples, in response to novel versus familiar social stimuli. Taken together, these findings suggest that abGCs are necessary for neuronal oscillations associated with discriminating between social stimuli, thus enabling retrieval of remote developmental memories of the mother by their adult offspring.
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Affiliation(s)
- Blake J Laham
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Isha R Gore
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Casey J Brown
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Elizabeth Gould
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
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16
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Giri B, Kinsky N, Kaya U, Maboudi K, Abel T, Diba K. Sleep loss diminishes hippocampal reactivation and replay. Nature 2024; 630:935-942. [PMID: 38867049 DOI: 10.1038/s41586-024-07538-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/07/2024] [Indexed: 06/14/2024]
Abstract
Memories benefit from sleep1, and the reactivation and replay of waking experiences during hippocampal sharp-wave ripples (SWRs) are considered to be crucial for this process2. However, little is known about how these patterns are impacted by sleep loss. Here we recorded CA1 neuronal activity over 12 h in rats across maze exploration, sleep and sleep deprivation, followed by recovery sleep. We found that SWRs showed sustained or higher rates during sleep deprivation but with lower power and higher frequency ripples. Pyramidal cells exhibited sustained firing during sleep deprivation and reduced firing during sleep, yet their firing rates were comparable during SWRs regardless of sleep state. Despite the robust firing and abundance of SWRs during sleep deprivation, we found that the reactivation and replay of neuronal firing patterns was diminished during these periods and, in some cases, completely abolished compared to ad libitum sleep. Reactivation partially rebounded after recovery sleep but failed to reach the levels found in natural sleep. These results delineate the adverse consequences of sleep loss on hippocampal function at the network level and reveal a dissociation between the many SWRs elicited during sleep deprivation and the few reactivations and replays that occur during these events.
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Affiliation(s)
- Bapun Giri
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Nathaniel Kinsky
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Utku Kaya
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kourosh Maboudi
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Ted Abel
- Department of Neuroscience and Pharmacology, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, USA
| | - Kamran Diba
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA.
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA.
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17
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Choucry A, Nomoto M, Inokuchi K. Engram mechanisms of memory linking and identity. Nat Rev Neurosci 2024; 25:375-392. [PMID: 38664582 DOI: 10.1038/s41583-024-00814-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2024] [Indexed: 05/25/2024]
Abstract
Memories are thought to be stored in neuronal ensembles referred to as engrams. Studies have suggested that when two memories occur in quick succession, a proportion of their engrams overlap and the memories become linked (in a process known as prospective linking) while maintaining their individual identities. In this Review, we summarize the key principles of memory linking through engram overlap, as revealed by experimental and modelling studies. We describe evidence of the involvement of synaptic memory substrates, spine clustering and non-linear neuronal capacities in prospective linking, and suggest a dynamic somato-synaptic model, in which memories are shared between neurons yet remain separable through distinct dendritic and synaptic allocation patterns. We also bring into focus retrospective linking, in which memories become associated after encoding via offline reactivation, and discuss key temporal and mechanistic differences between prospective and retrospective linking, as well as the potential differences in their cognitive outcomes.
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Affiliation(s)
- Ali Choucry
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Masanori Nomoto
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan
- Japan Agency for Medical Research and Development (AMED), Tokyo, Japan
| | - Kaoru Inokuchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan.
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18
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Li H, Zhao Z, Fassini A, Lee HK, Green RJ, Gomperts SN. Impaired Hippocampal Reactivation Preceding Robust Aβ Deposition in a Model of Alzheimer's Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.26.595168. [PMID: 38853978 PMCID: PMC11160633 DOI: 10.1101/2024.05.26.595168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Current therapeutic strategies for Alzheimer's disease (AD) target amyloid-beta (Aβ) fibrils and high molecular weight protofibrils associated with plaques, but other bioactive species may directly contribute to neural systems failure in AD. Employing hippocampal electrophysiological recordings and dynamic calcium imaging across the sleep-wake cycle in young mice expressing human Aβ and Aβ oligomers, we reveal marked impairments of hippocampal function long before amyloid plaques predominate. In slow wave sleep (SWS), Aβ increased the proportion of hypoactive cells and reduced place-cell reactivation. During awake behavior, Aβ impaired theta-gamma phase-amplitude coupling (PAC) and drove excessive synchronization of place cell calcium fluctuations with hippocampal theta. Remarkably, the on-line impairment of hippocampal theta-gamma PAC correlated with the SWS impairment of place-cell reactivation. Together, these results identify toxic effects of Aβ on memory encoding and consolidation processes before robust plaque deposition and support targeting soluble Aβ-related species to treat and prevent AD.
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Affiliation(s)
- Hanyan Li
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Zhuoyang Zhao
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Aline Fassini
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Han K. Lee
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Reese J. Green
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Stephen N. Gomperts
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
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19
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Karimani F, Asgari Taei A, Abolghasemi-Dehaghani MR, Safari MS, Dargahi L. Impairment of entorhinal cortex network activity in Alzheimer's disease. Front Aging Neurosci 2024; 16:1402573. [PMID: 38882526 PMCID: PMC11176617 DOI: 10.3389/fnagi.2024.1402573] [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: 03/17/2024] [Accepted: 05/20/2024] [Indexed: 06/18/2024] Open
Abstract
The entorhinal cortex (EC) stands out as a critical brain region affected in the early phases of Alzheimer's disease (AD), with some of the disease's pathological processes originating from this area, making it one of the most crucial brain regions in AD. Recent research highlights disruptions in the brain's network activity, characterized by heightened excitability and irregular oscillations, may contribute to cognitive impairment. These disruptions are proposed not only as potential therapeutic targets but also as early biomarkers for AD. In this paper, we will begin with a review of the anatomy and function of EC, highlighting its selective vulnerability in AD. Subsequently, we will discuss the disruption of EC network activity, exploring changes in excitability and neuronal oscillations in this region during AD and hypothesize that, considering the advancements in neuromodulation techniques, addressing the disturbances in the network activity of the EC could offer fresh insights for both the diagnosis and treatment of AD.
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Affiliation(s)
- Farnaz Karimani
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Afsaneh Asgari Taei
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Mir-Shahram Safari
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Leila Dargahi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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20
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Iwata T, Yanagisawa T, Ikegaya Y, Smallwood J, Fukuma R, Oshino S, Tani N, Khoo HM, Kishima H. Hippocampal sharp-wave ripples correlate with periods of naturally occurring self-generated thoughts in humans. Nat Commun 2024; 15:4078. [PMID: 38778048 PMCID: PMC11111804 DOI: 10.1038/s41467-024-48367-1] [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: 06/21/2023] [Accepted: 04/29/2024] [Indexed: 05/25/2024] Open
Abstract
Core features of human cognition highlight the importance of the capacity to focus on information distinct from events in the here and now, such as mind wandering. However, the brain mechanisms that underpin these self-generated states remain unclear. An emerging hypothesis is that self-generated states depend on the process of memory replay, which is linked to sharp-wave ripples (SWRs), which are transient high-frequency oscillations originating in the hippocampus. Local field potentials were recorded from the hippocampus of 10 patients with epilepsy for up to 15 days, and experience sampling was used to describe their association with ongoing thought patterns. The SWR rates were higher during extended periods of time when participants' ongoing thoughts were more vivid, less desirable, had more imaginable properties, and exhibited fewer correlations with an external task. These data suggest a role for SWR in the patterns of ongoing thoughts that humans experience in daily life.
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Affiliation(s)
- Takamitsu Iwata
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Takufumi Yanagisawa
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan.
- Institute for Advanced Co-Creation Studies, Osaka University, Osaka, 565-0871, Japan.
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, 113-0033, Japan
- National Institute of Information and Communications Technology, Center for Information and Neural Networks, Suita City, Osaka, 565-0871, Japan
| | - Jonathan Smallwood
- Department of Psychology, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Ryohei Fukuma
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
- Institute for Advanced Co-Creation Studies, Osaka University, Osaka, 565-0871, Japan
| | - Satoru Oshino
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Naoki Tani
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Hui Ming Khoo
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Haruhiko Kishima
- Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
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21
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Tononi G, Boly M, Cirelli C. Consciousness and sleep. Neuron 2024; 112:1568-1594. [PMID: 38697113 PMCID: PMC11105109 DOI: 10.1016/j.neuron.2024.04.011] [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: 03/07/2024] [Revised: 04/04/2024] [Accepted: 04/10/2024] [Indexed: 05/04/2024]
Abstract
Sleep is a universal, essential biological process. It is also an invaluable window on consciousness. It tells us that consciousness can be lost but also that it can be regained, in all its richness, when we are disconnected from the environment and unable to reflect. By considering the neurophysiological differences between dreaming and dreamless sleep, we can learn about the substrate of consciousness and understand why it vanishes. We also learn that the ongoing state of the substrate of consciousness determines the way each experience feels regardless of how it is triggered-endogenously or exogenously. Dreaming consciousness is also a window on sleep and its functions. Dreams tell us that the sleeping brain is remarkably lively, recombining intrinsic activation patterns from a vast repertoire, freed from the requirements of ongoing behavior and cognitive control.
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Affiliation(s)
- Giulio Tononi
- Department of Psychiatry, University of Wisconsin, Madison, WI 53719, USA.
| | - Melanie Boly
- Department of Neurology, University of Wisconsin, Madison, WI 53719, USA
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin, Madison, WI 53719, USA
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22
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Chen HT, van der Meer MAA. Paradoxical replay can protect contextual task representations from destructive interference when experience is unbalanced. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593332. [PMID: 38766204 PMCID: PMC11100794 DOI: 10.1101/2024.05.09.593332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Experience replay is a powerful mechanism to learn efficiently from limited experience. Despite several decades of compelling experimental results, the factors that determine which experiences are selected for replay remain unclear. A particular challenge for current theories is that on tasks that feature unbalanced experience, rats paradoxically replay the less-experienced trajectory. To understand why, we simulated a feedforward neural network with two regimes: rich learning (structured representations tailored to task demands) and lazy learning (unstructured, task-agnostic representations). Rich, but not lazy, representations degraded following unbalanced experience, an effect that could be reversed with paradoxical replay. To test if this computational principle can account for the experimental data, we examined the relationship between paradoxical replay and learned task representations in the rat hippocampus. Strikingly, we found a strong association between the richness of learned task representations and the paradoxicality of replay. Taken together, these results suggest that paradoxical replay specifically serves to protect rich representations from the destructive effects of unbalanced experience, and more generally demonstrate a novel interaction between the nature of task representations and the function of replay in artificial and biological systems.
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Affiliation(s)
- Hung-Tu Chen
- Department of Psychological & Brain Sciences, Dartmouth College, Hanover, NH 03755
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23
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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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24
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Gonzalez DA, Peel JH, Pagadala T, McHail DG, Cressman JR, Dumas TC. Analysis of hippocampal local field potentials by diffusion mapped delay coordinates. J Comput Neurosci 2024; 52:133-144. [PMID: 38581476 PMCID: PMC11035132 DOI: 10.1007/s10827-024-00870-6] [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: 06/21/2022] [Revised: 07/13/2023] [Accepted: 03/15/2024] [Indexed: 04/08/2024]
Abstract
Spatial navigation through novel spaces and to known goal locations recruits multiple integrated structures in the mammalian brain. Within this extended network, the hippocampus enables formation and retrieval of cognitive spatial maps and contributes to decision making at choice points. Exploration and navigation to known goal locations produce synchronous activity of hippocampal neurons resulting in rhythmic oscillation events in local networks. Power of specific oscillatory frequencies and numbers of these events recorded in local field potentials correlate with distinct cognitive aspects of spatial navigation. Typically, oscillatory power in brain circuits is analyzed with Fourier transforms or short-time Fourier methods, which involve assumptions about the signal that are likely not true and fail to succinctly capture potentially informative features. To avoid such assumptions, we applied a method that combines manifold discovery techniques with dynamical systems theory, namely diffusion maps and Takens' time-delay embedding theory, that avoids limitations seen in traditional methods. This method, called diffusion mapped delay coordinates (DMDC), when applied to hippocampal signals recorded from juvenile rats freely navigating a Y-maze, replicates some outcomes seen with standard approaches and identifies age differences in dynamic states that traditional analyses are unable to detect. Thus, DMDC may serve as a suitable complement to more traditional analyses of LFPs recorded from behaving subjects that may enhance information yield.
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Affiliation(s)
- D A Gonzalez
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA, 22030, USA
| | - J H Peel
- Department of Physics and Astronomy, George Mason University, Fairfax, VA, 22030, USA
| | - T Pagadala
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA, 22030, USA
| | - D G McHail
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA, 22030, USA
| | - J R Cressman
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA, 22030, USA
- Department of Physics and Astronomy, George Mason University, Fairfax, VA, 22030, USA
| | - T C Dumas
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA, 22030, USA.
- Psychology Department, George Mason University, 4400 University Drive, MS 2A1, Fairfax, VA, 22030, USA.
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25
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Seenivasan P, Basak R, Narayanan R. Cross-strata co-occurrence of ripples with theta-frequency oscillations in the hippocampus of foraging rats. J Physiol 2024; 602:2315-2341. [PMID: 38654581 PMCID: PMC7615956 DOI: 10.1113/jp284629] [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: 03/02/2023] [Accepted: 04/04/2024] [Indexed: 04/26/2024] Open
Abstract
Brain rhythms have been postulated to play central roles in animal cognition. A prominently reported dichotomy of hippocampal rhythms links theta-frequency oscillations (4-12 Hz) and ripples (120-250 Hz) exclusively to preparatory and consummatory behaviours, respectively. However, because of the differential power expression of these two signals across hippocampal strata, such exclusivity requires validation through analyses of simultaneous multi-strata recordings. We assessed co-occurrence of theta-frequency oscillations with ripples in multi-channel recordings of extracellular potentials across hippocampal strata from foraging rats. We detected all ripple events from an identified stratum pyramidale (SP) channel. We then defined theta epochs based on theta oscillations detected from the stratum lacunosum-moleculare (SLM) or the stratum radiatum (SR). We found ∼20% of ripple events (in SP) to co-occur with theta epochs identified from SR/SLM channels, defined here as theta ripples. Strikingly, when theta epochs were instead identified from the SP channel, such co-occurrences were significantly reduced because of a progressive reduction in theta power along the SLM-SR-SP axis. Behaviourally, we found most theta ripples to occur during immobile periods, with comparable theta power during exploratory and immobile theta epochs. Furthermore, the progressive reduction in theta power along the SLM-SR-SP axis was common to exploratory and immobile periods. Finally, we found a strong theta-phase preference of theta ripples within the fourth quadrant [3π/2 - 2π] of the associated theta oscillation. The prevalence of theta ripples expands the potential roles of ripple-frequency oscillations to span the continuum of encoding, retrieval and consolidation, achieved through interactions with theta oscillations. KEY POINTS: The brain manifests oscillations in recorded electrical potentials, with different frequencies of oscillation associated with distinct behavioural states. A prominently reported dichotomy assigns theta-frequency oscillations (4-12 Hz) and ripples (120-250 Hz) recorded in the hippocampus to be exclusively associated with preparatory and consummatory behaviours, respectively. Our multi-strata recordings from the rodent hippocampus coupled with cross-strata analyses provide direct quantitative evidence for the occurrence of ripple events nested within theta oscillations. These results highlight the need for an analysis pipeline that explicitly accounts for the specific strata where individual oscillatory power is high, in analysing simultaneously recorded data from multiple strata. Our observations open avenues for investigations involving cross-strata interactions between theta oscillations and ripples across different behavioural states.
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Affiliation(s)
- Pavithraa Seenivasan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Reshma Basak
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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26
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Blanco I, Caccavano A, Wu JY, Vicini S, Glasgow E, Conant K. Coupling of Sharp Wave Events between Zebrafish Hippocampal and Amygdala Homologs. J Neurosci 2024; 44:e1467232024. [PMID: 38508712 PMCID: PMC11044098 DOI: 10.1523/jneurosci.1467-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 03/01/2024] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
The mammalian hippocampus exhibits spontaneous sharp wave events (1-30 Hz) with an often-present superimposed fast ripple oscillation (120-220 Hz) to form a sharp wave ripple (SWR) complex. During slow-wave sleep or quiet restfulness, SWRs result from the sequential spiking of hippocampal cell assemblies initially activated during learned or imagined experiences. Additional cortical/subcortical areas exhibit SWR events that are coupled to hippocampal SWRs, and studies in mammals suggest that coupling may be critical for the consolidation and recall of specific memories. In the present study, we have examined juvenile male and female zebrafish and show that SWR events are intrinsically generated and maintained within the telencephalon and that their hippocampal homolog, the anterodorsolateral lobe (ADL), exhibits SW events with ∼9% containing an embedded ripple (SWR). Single-cell calcium imaging coupled to local field potential recordings revealed that ∼10% of active cells in the dorsal telencephalon participate in any given SW event. Furthermore, fluctuations in cholinergic tone modulate SW events consistent with mammalian studies. Moreover, the basolateral amygdala (BLA) homolog exhibits SW events with ∼5% containing an embedded ripple. Computing the SW peak coincidence difference between the ADL and BLA showed bidirectional communication. Simultaneous coupling occurred more frequently within the same hemisphere, and in coupled events across hemispheres, the ADL more commonly preceded BLA. Together, these data suggest conserved mechanisms across species by which SW and SWR events are modulated, and memories may be transferred and consolidated through regional coupling.
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Affiliation(s)
- Ismary Blanco
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20057
| | - Adam Caccavano
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20057
| | - Jian-Young Wu
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20057
- Departments of Neuroscience, Georgetown University Medical Center, Washington, DC 20057
| | - Stefano Vicini
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20057
- Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057
| | - Eric Glasgow
- Oncology, Georgetown University Medical Center, Washington, DC 20057
| | - Katherine Conant
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20057
- Departments of Neuroscience, Georgetown University Medical Center, Washington, DC 20057
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Yadav N, Toader A, Rajasethupathy P. Beyond hippocampus: Thalamic and prefrontal contributions to an evolving memory. Neuron 2024; 112:1045-1059. [PMID: 38272026 DOI: 10.1016/j.neuron.2023.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 11/07/2023] [Accepted: 12/22/2023] [Indexed: 01/27/2024]
Abstract
The hippocampus has long been at the center of memory research, and rightfully so. However, with emerging technological capabilities, we can increasingly appreciate memory as a more dynamic and brain-wide process. In this perspective, our goal is to begin developing models to understand the gradual evolution, reorganization, and stabilization of memories across the brain after their initial formation in the hippocampus. By synthesizing studies across the rodent and human literature, we suggest that as memory representations initially form in hippocampus, parallel traces emerge in frontal cortex that cue memory recall, and as they mature, with sustained support initially from limbic then diencephalic then cortical circuits, they become progressively independent of hippocampus and dependent on a mature cortical representation. A key feature of this model is that, as time progresses, memory representations are passed on to distinct circuits with progressively longer time constants, providing the opportunity to filter, forget, update, or reorganize memories in the process of committing to long-term storage.
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Affiliation(s)
- Nakul Yadav
- Laboratory of Neural Dynamics & Cognition, The Rockefeller University, New York, NY, USA
| | - Andrew Toader
- Laboratory of Neural Dynamics & Cognition, The Rockefeller University, New York, NY, USA
| | - Priya Rajasethupathy
- Laboratory of Neural Dynamics & Cognition, The Rockefeller University, New York, NY, USA.
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28
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Staresina BP. Coupled sleep rhythms for memory consolidation. Trends Cogn Sci 2024; 28:339-351. [PMID: 38443198 DOI: 10.1016/j.tics.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 02/02/2024] [Accepted: 02/02/2024] [Indexed: 03/07/2024]
Abstract
How do passing moments turn into lasting memories? Sheltered from external tasks and distractions, sleep constitutes an optimal state for the brain to reprocess and consolidate previous experiences. Recent work suggests that consolidation is governed by the intricate interaction of slow oscillations (SOs), spindles, and ripples - electrophysiological sleep rhythms that orchestrate neuronal processing and communication within and across memory circuits. This review describes how sequential SO-spindle-ripple coupling provides a temporally and spatially fine-tuned mechanism to selectively strengthen target memories across hippocampal and cortical networks. Coupled sleep rhythms might be harnessed not only to enhance overnight memory retention, but also to combat memory decline associated with healthy ageing and neurodegenerative diseases.
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Affiliation(s)
- Bernhard P Staresina
- Department of Experimental Psychology, University of Oxford, Oxford, UK; Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, UK.
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29
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Fu Y, Zhang J, Cao Y, Ye L, Zheng R, Li Q, Shen B, Shi Y, Cao J, Fang J. Recognition memory deficits detected through eye-tracking in well-controlled children with self-limited epilepsy with centrotemporal spikes. Epilepsia 2024; 65:1128-1140. [PMID: 38299621 DOI: 10.1111/epi.17902] [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: 10/04/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 02/02/2024]
Abstract
OBJECTIVE Children with self-limited epilepsy characterized by centrotemporal spikes (SeLECTS) exhibit cognitive deficits in memory during the active phase, but there is currently a lack of studies and techniques to assess their memory development after well-controlled seizures. In this study, we employed eye-tracking techniques to investigate visual memory and its association with clinical factors and global intellectual ability, aiming to identify potential risk factors by examining encoding and recognition processes. METHODS A total of 26 recruited patients diagnosed with SeLECTS who had been seizure-free for at least 2 years, along with 24 control subjects, underwent Wechsler cognitive assessment and an eye-movement-based memory task while video-electroencephalographic (EEG) data were recorded. Fixation and pupil data related to eye movements were utilized to detect distinct memory processes and subsequently to compare the cognitive performance of patients exhibiting different regression patterns on EEG. RESULTS The findings revealed persistent impairments in visual memory among children with SeLECTS after being well controlled, primarily observed in the recognition stage rather than the encoding phase. Furthermore, the age at onset, frequency of seizures, and interictal epileptiform discharges exhibited significant correlations with eye movement data. SIGNIFICANCE Children with SeLECTS exhibit persistent recognition memory impairment after being well controlled for the disease. Controlling the frequency of seizures and reducing prolonged epileptiform activity may improve memory cognitive development. The application of the eye-tracking technique may provide novel insights into exploring memory cognition as well as underlying mechanisms associated with pediatric epilepsy.
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Affiliation(s)
- Yanlu Fu
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Jingxin Zhang
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Yina Cao
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Linmei Ye
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Runze Zheng
- Artificial Intelligence Institute, Hangzhou Dianzi University School of Automation, Hangzhou, Zhejiang, China
| | - Qiwei Li
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Beibei Shen
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Yi Shi
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Jiuwen Cao
- Artificial Intelligence Institute, Hangzhou Dianzi University School of Automation, Hangzhou, Zhejiang, China
| | - Jiajia Fang
- Department of Neurology, Fourth Affiliated Hospital Zhejiang University School of Medicine, Yiwu, Zhejiang, China
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30
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Yang Y, Leopold DA, Duyn JH, Liu X. Hippocampal replay sequence governed by spontaneous brain-wide dynamics. PNAS NEXUS 2024; 3:pgae078. [PMID: 38562584 PMCID: PMC10983782 DOI: 10.1093/pnasnexus/pgae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/01/2024] [Indexed: 04/04/2024]
Abstract
Neurons in the hippocampus exhibit spontaneous spiking activity during rest that appears to recapitulate previously experienced events. While this replay activity is frequently linked to memory consolidation and learning, the underlying mechanisms are not well understood. Recent large-scale neural recordings in mice have demonstrated that resting-state spontaneous activity is expressed as quasi-periodic cascades of spiking activity that pervade the forebrain, with each cascade engaging a high proportion of recorded neurons. Hippocampal ripples are known to be coordinated with cortical dynamics; however, less is known about the occurrence of replay activity relative to other brain-wide spontaneous events. Here we analyzed responses across the mouse brain to multiple viewings of natural movies, as well as subsequent patterns of neural activity during rest. We found that hippocampal neurons showed time-selectivity, with individual neurons responding consistently during particular moments of the movie. During rest, the population of time-selective hippocampal neurons showed both forward and time-reversed replay activity that matched the sequence observed in the movie. Importantly, these replay events were strongly time-locked to brain-wide spiking cascades, with forward and time-reversed replay activity associated with distinct cascade types. Thus, intrinsic hippocampal replay activity is temporally structured according to large-scale spontaneous physiology affecting areas throughout the forebrain. These findings shed light on the coordination between hippocampal and cortical circuits thought to be critical for memory consolidation.
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Affiliation(s)
- Yifan Yang
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - David A Leopold
- Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, and National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Section on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeff H Duyn
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiao Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Institute for Computational and Data Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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31
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Yang W, Sun C, Huszár R, Hainmueller T, Kiselev K, Buzsáki G. Selection of experience for memory by hippocampal sharp wave ripples. Science 2024; 383:1478-1483. [PMID: 38547293 PMCID: PMC11068097 DOI: 10.1126/science.adk8261] [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: 09/12/2023] [Accepted: 02/23/2024] [Indexed: 04/02/2024]
Abstract
Experiences need to be tagged during learning for further consolidation. However, neurophysiological mechanisms that select experiences for lasting memory are not known. By combining large-scale neural recordings in mice with dimensionality reduction techniques, we observed that successive maze traversals were tracked by continuously drifting populations of neurons, providing neuronal signatures of both places visited and events encountered. When the brain state changed during reward consumption, sharp wave ripples (SPW-Rs) occurred on some trials, and their specific spike content decoded the trial blocks that surrounded them. During postexperience sleep, SPW-Rs continued to replay those trial blocks that were reactivated most frequently during waking SPW-Rs. Replay content of awake SPW-Rs may thus provide a neurophysiological tagging mechanism to select aspects of experience that are preserved and consolidated for future use.
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Affiliation(s)
- Wannan Yang
- Neuroscience Institute and Department of Neurology, NYU Grossman School of Medicine, New York University, New York City, NY, USA
- Center for Neural Science, New York University, New York City, NY, USA
| | - Chen Sun
- Mila - Quebec AI Institute, Montréal, Quebec, Canada
| | - Roman Huszár
- Neuroscience Institute and Department of Neurology, NYU Grossman School of Medicine, New York University, New York City, NY, USA
- Center for Neural Science, New York University, New York City, NY, USA
| | - Thomas Hainmueller
- Neuroscience Institute and Department of Neurology, NYU Grossman School of Medicine, New York University, New York City, NY, USA
- Department of Psychiatry, New York University Langone Medical Center, New York City, NY, USA
| | - Kirill Kiselev
- Center for Neural Science, New York University, New York City, NY, USA
| | - György Buzsáki
- Neuroscience Institute and Department of Neurology, NYU Grossman School of Medicine, New York University, New York City, NY, USA
- Center for Neural Science, New York University, New York City, NY, USA
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32
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Hoffman C, Cheng J, Morales R, Ji D, Dabaghian Y. Altered patterning of neural activity in a tauopathy mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.23.586417. [PMID: 38585991 PMCID: PMC10996513 DOI: 10.1101/2024.03.23.586417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative condition that manifests at multiple levels and involves a spectrum of abnormalities ranging from the cellular to cognitive. Here, we investigate the impact of AD-related tau-pathology on hippocampal circuits in mice engaged in spatial navigation, and study changes of neuronal firing and dynamics of extracellular fields. While most studies are based on analyzing instantaneous or time-averaged characteristics of neuronal activity, we focus on intermediate timescales-spike trains and waveforms of oscillatory potentials, which we consider as single entities. We find that, in healthy mice, spike arrangements and wave patterns (series of crests or troughs) are coupled to the animal's location, speed, and acceleration. In contrast, in tau-mice, neural activity is structurally disarrayed: brainwave cadence is detached from locomotion, spatial selectivity is lost, the spike flow is scrambled. Importantly, these alterations start early and accumulate with age, which exposes progressive disinvolvement the hippocampus circuit in spatial navigation. These features highlight qualitatively different neurodynamics than the ones provided by conventional analyses, and are more salient, thus revealing a new level of the hippocampal circuit disruptions.
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Affiliation(s)
- C Hoffman
- Department of Neurology, The University of Texas McGovern Medical School, 6431 Fannin St, Houston, TX 77030
| | - J Cheng
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - R Morales
- Department of Neurology, The University of Texas McGovern Medical School, 6431 Fannin St, Houston, TX 77030
| | - D Ji
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - Y Dabaghian
- Department of Neurology, The University of Texas McGovern Medical School, 6431 Fannin St, Houston, TX 77030
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33
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Navas-Olive A, Rubio A, Abbaspoor S, Hoffman KL, de la Prida LM. A machine learning toolbox for the analysis of sharp-wave ripples reveals common waveform features across species. Commun Biol 2024; 7:211. [PMID: 38438533 PMCID: PMC10912113 DOI: 10.1038/s42003-024-05871-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 01/29/2024] [Indexed: 03/06/2024] Open
Abstract
The study of sharp-wave ripples has advanced our understanding of memory function, and their alteration in neurological conditions such as epilepsy is considered a biomarker of dysfunction. Sharp-wave ripples exhibit diverse waveforms and properties that cannot be fully characterized by spectral methods alone. Here, we describe a toolbox of machine-learning models for automatic detection and analysis of these events. The machine-learning architectures, which resulted from a crowdsourced hackathon, are able to capture a wealth of ripple features recorded in the dorsal hippocampus of mice across awake and sleep conditions. When applied to data from the macaque hippocampus, these models are able to generalize detection and reveal shared properties across species. We hereby provide a user-friendly open-source toolbox for model use and extension, which can help to accelerate and standardize analysis of sharp-wave ripples, lowering the threshold for its adoption in biomedical applications.
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Affiliation(s)
| | | | - Saman Abbaspoor
- Psychological Sciences, Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - Kari L Hoffman
- Psychological Sciences, Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
- Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
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34
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Kunz L, Staresina BP, Reinacher PC, Brandt A, Guth TA, Schulze-Bonhage A, Jacobs J. Ripple-locked coactivity of stimulus-specific neurons and human associative memory. Nat Neurosci 2024; 27:587-599. [PMID: 38366143 PMCID: PMC10917673 DOI: 10.1038/s41593-023-01550-x] [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: 12/09/2022] [Accepted: 12/11/2023] [Indexed: 02/18/2024]
Abstract
Associative memory enables the encoding and retrieval of relations between different stimuli. To better understand its neural basis, we investigated whether associative memory involves temporally correlated spiking of medial temporal lobe (MTL) neurons that exhibit stimulus-specific tuning. Using single-neuron recordings from patients with epilepsy performing an associative object-location memory task, we identified the object-specific and place-specific neurons that represented the separate elements of each memory. When patients encoded and retrieved particular memories, the relevant object-specific and place-specific neurons activated together during hippocampal ripples. This ripple-locked coactivity of stimulus-specific neurons emerged over time as the patients' associative learning progressed. Between encoding and retrieval, the ripple-locked timing of coactivity shifted, suggesting flexibility in the interaction between MTL neurons and hippocampal ripples according to behavioral demands. Our results are consistent with a cellular account of associative memory, in which hippocampal ripples coordinate the activity of specialized cellular populations to facilitate links between stimuli.
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Affiliation(s)
- Lukas Kunz
- Department of Epileptology, University Hospital Bonn, Bonn, Germany.
- Epilepsy Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Bernhard P Staresina
- Department of Experimental Psychology, University of Oxford, Oxford, UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, UK
| | - Peter C Reinacher
- Department of Stereotactic and Functional Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Fraunhofer Institute for Laser Technology, Aachen, Germany
| | - Armin Brandt
- Epilepsy Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tim A Guth
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
- Epilepsy Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Schulze-Bonhage
- Epilepsy Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Joshua Jacobs
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
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35
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Sakon JJ, Halpern DJ, Schonhaut DR, Kahana MJ. Human Hippocampal Ripples Signal Encoding of Episodic Memories. J Neurosci 2024; 44:e0111232023. [PMID: 38233218 PMCID: PMC10883616 DOI: 10.1523/jneurosci.0111-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 01/19/2024] Open
Abstract
Direct human brain recordings have confirmed the presence of high-frequency oscillatory events, termed ripples, during awake behavior. While many prior studies have focused on medial temporal lobe (MTL) ripples during memory retrieval, here we investigate ripples during memory encoding. Specifically, we ask whether ripples during encoding predict whether and how memories are subsequently recalled. Detecting ripples from MTL electrodes implanted in 116 neurosurgical participants (n = 61 male) performing a verbal episodic memory task, we find that encoding ripples do not distinguish recalled from not recalled items in any MTL region, even as high-frequency activity during encoding predicts recall in these same regions. Instead, hippocampal ripples increase during encoding of items that subsequently lead to recall of temporally and semantically associated items during retrieval, a phenomenon known as clustering. This subsequent clustering effect arises specifically when hippocampal ripples co-occur during encoding and retrieval, suggesting that ripples mediate both encoding and reinstatement of episodic memories.
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Affiliation(s)
- John J Sakon
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
| | - David J Halpern
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
| | - Daniel R Schonhaut
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
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36
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Mack ML, Love BC, Preston AR. Distinct hippocampal mechanisms support concept formation and updating. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580181. [PMID: 38405893 PMCID: PMC10888746 DOI: 10.1101/2024.02.14.580181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Learning systems must constantly decide whether to create new representations or update existing ones. For example, a child learning that a bat is a mammal and not a bird would be best served by creating a new representation, whereas updating may be best when encountering a second similar bat. Characterizing the neural dynamics that underlie these complementary memory operations requires identifying the exact moments when each operation occurs. We address this challenge by interrogating fMRI brain activation with a computational learning model that predicts trial-by-trial when memories are created versus updated. We found distinct neural engagement in anterior hippocampus and ventral striatum for model-predicted memory create and update events during early learning. Notably, the degree of this effect in hippocampus, but not ventral striatum, significantly related to learning outcome. Hippocampus additionally showed distinct patterns of functional coactivation with ventromedial prefrontal cortex and angular gyrus during memory creation and premotor cortex during memory updating. These findings suggest that complementary memory functions, as formalized in computational learning models, underlie the rapid formation of novel conceptual knowledge, with the hippocampus and its interactions with frontoparietal circuits playing a crucial role in successful learning. Significance statement How do we reconcile new experiences with existing knowledge? Prominent theories suggest that novel information is either captured by creating new memories or leveraged to update existing memories, yet empirical support of how these distinct memory operations unfold during learning is limited. Here, we combine computational modeling of human learning behaviour with functional neuroimaging to identify moments of memory formation and updating and characterize their neural signatures. We find that both hippocampus and ventral striatum are distinctly engaged when memories are created versus updated; however, it is only hippocampus activation that is associated with learning outcomes. Our findings motivate a key theoretical revision that positions hippocampus is a key player in building organized memories from the earliest moments of learning.
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37
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Lara-Vasquez A, Espinosa N, Morales C, Moran C, Billeke P, Gallagher J, Strohl JJ, Huerta PT, Fuentealba P. Dominance hierarchy regulates social behavior during spatial movement. Front Neurosci 2024; 18:1237748. [PMID: 38384483 PMCID: PMC10879816 DOI: 10.3389/fnins.2024.1237748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 01/24/2024] [Indexed: 02/23/2024] Open
Abstract
Rodents establish dominance hierarchy as a social ranking system in which one subject acts as dominant over all the other subordinate individuals. Dominance hierarchy regulates food access and mating opportunities, but little is known about its significance in other social behaviors, for instance during collective navigation for foraging or migration. Here, we implemented a simplified goal-directed spatial task in mice, in which animals navigated individually or collectively with their littermates foraging for food. We compared between conditions and found that the social condition exerts significant influence on individual displacement patterns, even when efficient navigation rules leading to reward had been previously learned. Thus, movement patterns and consequent task performance were strongly dependent on contingent social interactions arising during collective displacement, yet their influence on individual behavior was determined by dominance hierarchy. Dominant animals did not behave as leaders during collective displacement; conversely, they were most sensitive to the social environment adjusting their performance accordingly. Social ranking in turn was associated with specific spontaneous neural activity patterns in the prefrontal cortex and hippocampus, with dominant mice showing higher firing rates, larger ripple oscillations, and stronger neuronal entrainment by ripples than subordinate animals. Moreover, dominant animals selectively increased their cortical spiking activity during collective movement, while subordinate mice did not modify their firing rates, consistent with dominant animals being more sensitive to the social context. These results suggest that dominance hierarchy influences behavioral performance during contingent social interactions, likely supported by the coordinated activity in the hippocampal-prefrontal circuit.
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Affiliation(s)
- Ariel Lara-Vasquez
- Centro Integrativo de Neurociencias y Departamento de Psiquiatría, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nelson Espinosa
- Centro Integrativo de Neurociencias y Departamento de Psiquiatría, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Cristian Morales
- Centro Integrativo de Neurociencias y Departamento de Psiquiatría, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Constanza Moran
- Centro Integrativo de Neurociencias y Departamento de Psiquiatría, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo Billeke
- Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social, Universidad del Desarrollo, Santiago, Chile
| | - Joseph Gallagher
- Laboratory of Immune & Neural Networks, Feinstein Institutes for Medical Research, Manhasset, NY, United States
| | - Joshua J. Strohl
- Laboratory of Immune & Neural Networks, Feinstein Institutes for Medical Research, Manhasset, NY, United States
- Department of Molecular Medicine, Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY, United States
| | - Patricio T. Huerta
- Laboratory of Immune & Neural Networks, Feinstein Institutes for Medical Research, Manhasset, NY, United States
- Department of Molecular Medicine, Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY, United States
| | - Pablo Fuentealba
- Centro Integrativo de Neurociencias y Departamento de Psiquiatría, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Investigación en Nanotecnología y Materiales Avanzados – CIEN-UC, Pontificia Universidad Católica de Chile, Santiago, Chile
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38
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Alemi A, Aksay ERF, Goldman MS. A Lyapunov theory demonstrating a fundamental limit on the speed of systems consolidation. ARXIV 2024:arXiv:2402.01605v1. [PMID: 38351934 PMCID: PMC10862927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
The nervous system reorganizes memories from an early site to a late site, a commonly observed feature of learning and memory systems known as systems consolidation. Previous work has suggested learning rules by which consolidation may occur. Here, we provide conditions under which such rules are guaranteed to lead to stable convergence of learning and consolidation. We use the theory of Lyapunov functions, which enforces stability by requiring learning rules to decrease an energy-like (Lyapunov) function. We present the theory in the context of a simple circuit architecture motivated by classic models of learning in systems consolidation mediated by the cerebellum. Stability is only guaranteed if the learning rate in the late stage is not faster than the learning rate in the early stage. Further, the slower the learning rate at the late stage, the larger the perturbation the system can tolerate with a guarantee of stability. We provide intuition for this result by mapping the consolidation model to a damped driven oscillator system, and showing that the ratio of early-to late-stage learning rates in the consolidation model can be directly identified with the (square of the) oscillator's damping ratio. This work suggests the power of the Lyapunov approach to provide constraints on nervous system function.
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Affiliation(s)
- Alireza Alemi
- Center for Neuroscience, and Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616, USA
| | - Emre R. F. Aksay
- Institute for Computational Biomedicine and Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10021, USA
| | - Mark S. Goldman
- Center for Neuroscience, and Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616, USA
- Department of Ophthalmology and Vision Science, University of California, Davis, Davis, CA 95616, USA
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39
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Koketsu S, Matsubara K, Ueki Y, Shinohara Y, Inoue K, Murakami S, Ueki T. The defects of the hippocampal ripples and theta rhythm in depression, and the effects of physical exercise on their amelioration. Heliyon 2024; 10:e23738. [PMID: 38226277 PMCID: PMC10788462 DOI: 10.1016/j.heliyon.2023.e23738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 10/24/2023] [Accepted: 12/12/2023] [Indexed: 01/17/2024] Open
Abstract
Adverse environmental stress causes depressive symptoms with the impairments of memory formation, cognition, and motivation, however, their underlying neural bases have not been well understood, especially based on the observation of living animals. In the present study, therefore, the mice model of restraint-induced stress was examined electrophysiologically to investigate the alterations of hippocampal sharp wave ripples (SWRs) and theta rhythms. In addition, the therapeutic effects of physical exercise on the amelioration of those hippocampal impairments were examined in combination with a series of behavioral tests. The data demonstrated that chronic restraint stress caused the reductions of occurrence and amplitude of hippocampal SWRs and the decreases of occurrence, duration, and power of theta rhythms, while physical exercise significantly reverted them to the levels of healthy control. Furthermore, hippocampal adult neurogenesis and microglial activation, previously reported to be involved in the etiology of depression, were histologically examined in the mice. The results showed that the impairment of neurogenesis and alleviation of microglial activation were induced in the depressed mice. On the other hand, physical exercise considerably ameliorated those pathological conditions in the affected brain. Consistently, the data of behavioral tests in mice suggested that physical exercise ameliorated the symptomatic defects of motivation, memory formation, and cognition in the depressed mice. The impairments of hippocampal SWRs and theta rhythms in the affected hippocampus are linked with the symptomatic impairments of cognition and motivation, and the defect of memory formation, respectively, in depression. Taken together, this study demonstrated the implications of impairment of the hippocampal SWRs and theta rhythms in the etiology of depression and their usefulness as diagnostic markers of depression.
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Affiliation(s)
- Shinnosuke Koketsu
- Department of Rehabilitation Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
- Department of Integrative Anatomy, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
- Department of Physical Therapy, Nagoya Women's University Faculty of Medical Science, Nagoya, Aichi, 467-8610, Japan
| | - Kohki Matsubara
- Department of Rehabilitation Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Yoshino Ueki
- Department of Rehabilitation Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Yoshiaki Shinohara
- Department of Integrative Anatomy, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
- Department of Anatomy and Cell Biology, Yamanashi University Graduate School of Medical Sciences, Chuo, Yamanashi, 409-3898, Japan
| | - Koichi Inoue
- Department of Integrative Anatomy, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
- Department of Anatomy and Cell Biology, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Satona Murakami
- Department of Rehabilitation Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
| | - Takatoshi Ueki
- Department of Integrative Anatomy, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, 467-8601, Japan
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40
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Zimmerman CA, Pan-Vazquez A, Wu B, Keppler EF, Guthman EM, Fetcho RN, Bolkan SS, McMannon B, Lee J, Hoag AT, Lynch LA, Janarthanan SR, López Luna JF, Bondy AG, Falkner AL, Wang SSH, Witten IB. A neural mechanism for learning from delayed postingestive feedback. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.06.561214. [PMID: 37873112 PMCID: PMC10592633 DOI: 10.1101/2023.10.06.561214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Animals learn the value of foods based on their postingestive effects and thereby develop aversions to foods that are toxic1-6 and preferences to those that are nutritious7-14. However, it remains unclear how the brain is able to assign credit to flavors experienced during a meal with postingestive feedback signals that can arise after a substantial delay. Here, we reveal an unexpected role for postingestive reactivation of neural flavor representations in this temporal credit assignment process. To begin, we leverage the fact that mice learn to associate novel15-18, but not familiar, flavors with delayed gastric malaise signals to investigate how the brain represents flavors that support aversive postingestive learning. Surveying cellular resolution brainwide activation patterns reveals that a network of amygdala regions is unique in being preferentially activated by novel flavors across every stage of the learning process: the initial meal, delayed malaise, and memory retrieval. By combining high-density recordings in the amygdala with optogenetic stimulation of genetically defined hindbrain malaise cells, we find that postingestive malaise signals potently and specifically reactivate amygdalar novel flavor representations from a recent meal. The degree of malaise-driven reactivation of individual neurons predicts strengthening of flavor responses upon memory retrieval, leading to stabilization of the population-level representation of the recently consumed flavor. In contrast, meals without postingestive consequences degrade neural flavor representations as flavors become familiar and safe. Thus, our findings demonstrate that interoceptive reactivation of amygdalar flavor representations provides a neural mechanism to resolve the temporal credit assignment problem inherent to postingestive learning.
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Affiliation(s)
| | | | - Bichan Wu
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Emma F Keppler
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Eartha Mae Guthman
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Robert N Fetcho
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Scott S Bolkan
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Brenna McMannon
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Junuk Lee
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Austin T Hoag
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Laura A Lynch
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | | | - Juan F López Luna
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Adrian G Bondy
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Annegret L Falkner
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Samuel S-H Wang
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Ilana B Witten
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
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41
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Zhang H, Skelin I, Ma S, Paff M, Mnatsakanyan L, Yassa MA, Knight RT, Lin JJ. Awake ripples enhance emotional memory encoding in the human brain. Nat Commun 2024; 15:215. [PMID: 38172140 PMCID: PMC10764865 DOI: 10.1038/s41467-023-44295-8] [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: 11/29/2021] [Accepted: 12/07/2023] [Indexed: 01/05/2024] Open
Abstract
Enhanced memory for emotional experiences is hypothesized to depend on amygdala-hippocampal interactions during memory consolidation. Here we show using intracranial recordings from the human amygdala and the hippocampus during an emotional memory encoding and discrimination task increased awake ripples after encoding of emotional, compared to neutrally-valenced stimuli. Further, post-encoding ripple-locked stimulus similarity is predictive of later memory discrimination. Ripple-locked stimulus similarity appears earlier in the amygdala than in hippocampus and mutual information analysis confirms amygdala influence on hippocampal activity. Finally, the joint ripple-locked stimulus similarity in the amygdala and hippocampus is predictive of correct memory discrimination. These findings provide electrophysiological evidence that post-encoding ripples enhance memory for emotional events.
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Affiliation(s)
- Haoxin Zhang
- Department of Neurology, University of California Irvine, Irvine, 92603, CA, USA.
- Department of Biomedical Engineering, University of California Irvine, Irvine, 92603, CA, USA.
| | - Ivan Skelin
- Krembil Brain Institute, Toronto Western Hospital, Toronto, Ontario, M5T 1M8, Canada
- Department Center for Advancing Neurotechnological Innovation to Application, Toronto, Ontario, M5G 2A2, Canada
| | - Shiting Ma
- Department of Neurology, University of California Irvine, Irvine, 92603, CA, USA
| | - Michelle Paff
- Department of Neurosurgery, University of California Irvine, Irvine, 92603, CA, USA
| | - Lilit Mnatsakanyan
- Department of Neurology, University of California Irvine, Irvine, 92603, CA, USA
| | - Michael A Yassa
- Department of Neurology, University of California Irvine, Irvine, 92603, CA, USA
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, 92697, CA, USA
- Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, 92697, CA, USA
| | - Robert T Knight
- Department of Psychology, University of California Berkeley, Berkeley, 94720, CA, USA
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, 94720, CA, USA
| | - Jack J Lin
- Department of Neurology, School of Medicine, University of California Davis, Sacramento, 95817, CA, USA.
- Center for Mind and Brain, University of California Davis, Davis, 95618, CA, USA.
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42
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Keil J, Kiiski H, Doherty L, Hernandez-Urbina V, Vassiliou C, Dean C, Müschenich M, Bahmani H. Artificial sharp-wave-ripples to support memory and counter neurodegeneration. Brain Res 2024; 1822:148646. [PMID: 37871674 DOI: 10.1016/j.brainres.2023.148646] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/11/2023] [Accepted: 10/20/2023] [Indexed: 10/25/2023]
Abstract
Information processed in our sensory neocortical areas is transported to the hippocampus during memory encoding, and between hippocampus and neocortex during memory consolidation, and retrieval. Short bursts of high-frequency oscillations, so called sharp-wave-ripples, have been proposed as a potential mechanism for this information transfer: They can synchronize neural activity to support the formation of local neural networks to store information, and between distant cortical sites to act as a bridge to transfer information between sensory cortical areas and hippocampus. In neurodegenerative diseases like Alzheimer's Disease, different neuropathological processes impair normal neural functioning and neural synchronization as well as sharp-wave-ripples, which impairs consolidation and retrieval of information, and compromises memory. Here, we formulate a new hypothesis, that artificially inducing sharp-wave-ripples with noninvasive high-frequency visual stimulation could potentially support memory functioning, as well as target the neuropathological processes underlying neurodegenerative diseases. We also outline key challenges for empirical tests of the hypothesis.
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Affiliation(s)
- Julian Keil
- Department of Psychology, Christian-Albrechts-University Kiel, Germany; Ababax Health GmbH, Berlin, Germany; Department of Cognitive Science, University of Potsdam, Germany.
| | - Hanni Kiiski
- Ababax Health GmbH, Berlin, Germany; Department of Cognitive Science, University of Potsdam, Germany
| | | | | | - Chrystalleni Vassiliou
- German Center for Neurodegenerative Diseases, Charité University of Medicine, Berlin, Germany
| | - Camin Dean
- German Center for Neurodegenerative Diseases, Charité University of Medicine, Berlin, Germany
| | | | - Hamed Bahmani
- Ababax Health GmbH, Berlin, Germany; Bernstein Center for Computational Neuroscience, Tuebingen, Germany
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43
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Dorst KE, Ramirez S. Engrams: From Behavior to Brain-Wide Networks. ADVANCES IN NEUROBIOLOGY 2024; 38:13-28. [PMID: 39008008 DOI: 10.1007/978-3-031-62983-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Animals utilize a repertoire of behavioral responses during everyday experiences. During a potentially dangerous encounter, defensive actions such as "fight, flight, or freeze" are selected for survival. The successful use of behavior is determined by a series of real-time computations combining an animal's internal (i.e., body) and external (i.e., environment) state. Brain-wide neural pathways are engaged throughout this process to detect stimuli, integrate information, and command behavioral output. The hippocampus, in particular, plays a role in the encoding and storing of the episodic information surrounding these encounters as putative "engram" or experience-modified cellular ensembles. Recalling a negative experience then reactivates a dedicated engram ensemble and elicits a behavioral response. How hippocampus-based engrams modulate brain-wide states and an animal's internal/external milieu to influence behavior is an exciting area of investigation for contemporary neuroscience. In this chapter, we provide an overview of recent technological advancements that allow researchers to tag, manipulate, and visualize putative engram ensembles, with an overarching goal of casually connecting their brain-wide underpinnings to behavior. We then discuss how hippocampal fear engrams alter behavior in a manner that is contingent on an environment's physical features as well as how they influence brain-wide patterns of cellular activity. Overall, we propose here that studies on memory engrams offer an exciting avenue for contemporary neuroscience to casually link the activity of cells to cognition and behavior while also offering testable theoretical and experimental frameworks for how the brain organizes experience.
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Affiliation(s)
- Kaitlyn E Dorst
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA
| | - Steve Ramirez
- Department of Psychological & Brain Sciences, Boston University, Boston, MA, USA.
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44
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Veselic S, Muller TH, Gutierrez E, Behrens TEJ, Hunt LT, Butler JL, Kennerley SW. A cognitive map for value-guided choice in ventromedial prefrontal cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.15.571895. [PMID: 38168410 PMCID: PMC10760117 DOI: 10.1101/2023.12.15.571895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
The prefrontal cortex is crucial for economic decision-making and representing the value of options. However, how such representations facilitate flexible decisions remains unknown. We reframe economic decision-making in prefrontal cortex in line with representations of structure within the medial temporal lobe because such cognitive map representations are known to facilitate flexible behaviour. Specifically, we framed choice between different options as a navigation process in value space. Here we show that choices in a 2D value space defined by reward magnitude and probability were represented with a grid-like code, analogous to that found in spatial navigation. The grid-like code was present in ventromedial prefrontal cortex (vmPFC) local field potential theta frequency and the result replicated in an independent dataset. Neurons in vmPFC similarly contained a grid-like code, in addition to encoding the linear value of the chosen option. Importantly, both signals were modulated by theta frequency - occurring at theta troughs but on separate theta cycles. Furthermore, we found sharp-wave ripples - a key neural signature of planning and flexible behaviour - in vmPFC, which were modulated by accuracy and reward. These results demonstrate that multiple cognitive map-like computations are deployed in vmPFC during economic decision-making, suggesting a new framework for the implementation of choice in prefrontal cortex.
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Affiliation(s)
- Sebastijan Veselic
- Department of Experimental Psychology, University of Oxford, UK
- Clinical and Movement Neurosciences, Department of Motor Neuroscience, University College London, London, UK
| | - Timothy H Muller
- Department of Experimental Psychology, University of Oxford, UK
- Clinical and Movement Neurosciences, Department of Motor Neuroscience, University College London, London, UK
| | - Elena Gutierrez
- Department of Experimental Psychology, University of Oxford, UK
- Clinical and Movement Neurosciences, Department of Motor Neuroscience, University College London, London, UK
| | - Timothy E J Behrens
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, FMRIB, John Radcliffe Hospital, Oxford, UK
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour College, University College London, London, UK
| | - Laurence T Hunt
- Department of Experimental Psychology, University of Oxford, UK
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - James L Butler
- Department of Experimental Psychology, University of Oxford, UK
| | - Steven W Kennerley
- Department of Experimental Psychology, University of Oxford, UK
- Clinical and Movement Neurosciences, Department of Motor Neuroscience, University College London, London, UK
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45
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Torok Z, Luebbert L, Feldman J, Duffy A, Nevue AA, Wongso S, Mello CV, Fairhall A, Pachter L, Gonzalez WG, Lois C. Recovery of a learned behavior despite partial restoration of neuronal dynamics after chronic inactivation of inhibitory neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.17.541057. [PMID: 37292888 PMCID: PMC10245685 DOI: 10.1101/2023.05.17.541057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Maintaining motor skills is crucial for an animal's survival, enabling it to endure diverse perturbations throughout its lifespan, such as trauma, disease, and aging. What mechanisms orchestrate brain circuit reorganization and recovery to preserve the stability of behavior despite the continued presence of a disturbance? To investigate this question, we chronically silenced a fraction of inhibitory neurons in a brain circuit necessary for singing in zebra finches. Song in zebra finches is a complex, learned motor behavior and central to reproduction. This manipulation altered brain activity and severely perturbed song for around two months, after which time it was precisely restored. Electrophysiology recordings revealed abnormal offline dynamics, resulting from chronic inhibition loss, some aspects of which returned to normal as the song recovered. However, even after the song had fully recovered, the levels of neuronal firing in the premotor and motor areas did not return to a control-like state. Single-cell RNA sequencing revealed that chronic silencing of interneurons led to elevated levels of microglia and MHC I, which were also observed in normal juveniles during song learning. These experiments demonstrate that the adult brain can overcome extended periods of abnormal activity, and precisely restore a complex behavior, without recovering normal neuronal dynamics. These findings suggest that the successful functional recovery of a brain circuit after a perturbation can involve more than mere restoration to its initial configuration. Instead, the circuit seems to adapt and reorganize into a new state capable of producing the original behavior despite the persistence of some abnormal neuronal dynamics.
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Affiliation(s)
- Zsofia Torok
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA, USA
| | - Laura Luebbert
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA, USA
| | - Jordan Feldman
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA, USA
| | | | | | - Shelyn Wongso
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA, USA
| | | | | | - Lior Pachter
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA, USA
- Department of Computing and Mathematical Sciences, California Institute of Technology; Pasadena, CA, USA
| | - Walter G. Gonzalez
- Department of Physiology, University of San Francisco; San Francisco, CA, USA
| | - Carlos Lois
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA, USA
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46
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Shin JD, Jadhav SP. Cortical ripples mediate top-down suppression of hippocampal reactivation during sleep memory consolidation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.571373. [PMID: 38168420 PMCID: PMC10760112 DOI: 10.1101/2023.12.12.571373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Consolidation of initially encoded hippocampal representations in the neocortex through reactivation is crucial for long-term memory formation, and is facilitated by the coordination of hippocampal sharp-wave ripples (SWRs) with cortical oscillations during non-REM sleep. However, the contribution of high-frequency cortical ripples to consolidation is still unclear. We used continuous recordings in the hippocampus and prefrontal cortex (PFC) over the course of spatial learning and show that independent PFC ripples, when dissociated from SWRs, predominantly suppress hippocampal activity in non-REM sleep. PFC ripples paradoxically mediate top-down suppression of hippocampal reactivation, which is inversely related to reactivation strength during coordinated CA1-PFC ripples. Further, we show non-canonical, serial coordination of ripples with cortical slow and spindle oscillations. These results establish a role for cortical ripples in regulating consolidation.
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Affiliation(s)
- Justin D. Shin
- Neuroscience Program, Department of Psychology, and Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02453, USA
| | - Shantanu P. Jadhav
- Neuroscience Program, Department of Psychology, and Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02453, USA
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47
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Vitale P, Librizzi F, Vaiana AC, Capuana E, Pezzoli M, Shi Y, Romani A, Migliore M, Migliore R. Different responses of mice and rats hippocampus CA1 pyramidal neurons to in vitro and in vivo-like inputs. Front Cell Neurosci 2023; 17:1281932. [PMID: 38130870 PMCID: PMC10733970 DOI: 10.3389/fncel.2023.1281932] [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: 08/23/2023] [Accepted: 11/16/2023] [Indexed: 12/23/2023] Open
Abstract
The fundamental role of any neuron within a network is to transform complex spatiotemporal synaptic input patterns into individual output spikes. These spikes, in turn, act as inputs for other neurons in the network. Neurons must execute this function across a diverse range of physiological conditions, often based on species-specific traits. Therefore, it is crucial to determine the extent to which findings can be extrapolated between species and, ultimately, to humans. In this study, we employed a multidisciplinary approach to pinpoint the factors accounting for the observed electrophysiological differences between mice and rats, the two species most used in experimental and computational research. After analyzing the morphological properties of their hippocampal CA1 pyramidal cells, we conducted a statistical comparison of rat and mouse electrophysiological features in response to somatic current injections. This analysis aimed to uncover the parameters underlying these distinctions. Using a well-established computational workflow, we created ten distinct single-cell computational models of mouse CA1 pyramidal neurons, ready to be used in a full-scale hippocampal circuit. By comparing their responses to a variety of somatic and synaptic inputs with those of rat models, we generated experimentally testable hypotheses regarding species-specific differences in ion channel distribution, kinetics, and the electrophysiological mechanisms underlying their distinct responses to synaptic inputs during the behaviorally relevant Gamma and Sharp-Wave rhythms.
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Affiliation(s)
- Paola Vitale
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Fabio Librizzi
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Andrea C. Vaiana
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Elisa Capuana
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Maurizio Pezzoli
- Laboratory of Neural Microcircuitry, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Campus Biotech, Geneva, Switzerland
| | - Ying Shi
- Laboratory of Neural Microcircuitry, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Campus Biotech, Geneva, Switzerland
| | - Armando Romani
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Campus Biotech, Geneva, Switzerland
| | - Michele Migliore
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Rosanna Migliore
- Institute of Biophysics, National Research Council, Palermo, Italy
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48
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Han F, Liu X, Mailman RB, Huang X, Liu X. Resting-state global brain activity affects early β-amyloid accumulation in default mode network. Nat Commun 2023; 14:7788. [PMID: 38012153 PMCID: PMC10682457 DOI: 10.1038/s41467-023-43627-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/14/2023] [Indexed: 11/29/2023] Open
Abstract
It remains unclear why β-amyloid (Aβ) plaque, a hallmark pathology of Alzheimer's disease (AD), first accumulates cortically in the default mode network (DMN), years before AD diagnosis. Resting-state low-frequency ( < 0.1 Hz) global brain activity recently was linked to AD, presumably due to its role in glymphatic clearance. Here we show that the preferential Aβ accumulation in the DMN at the early stage of Aβ pathology was associated with the preferential reduction of global brain activity in the same regions. This can be partly explained by its failure to reach these regions as propagating waves. Together, these findings highlight the important role of resting-state global brain activity in early preferential Aβ deposition in the DMN.
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Affiliation(s)
- Feng Han
- Department of Biomedical Engineering, The Pennsylvania State University, State College, PA, USA
| | - Xufu Liu
- Department of Biomedical Engineering, The Pennsylvania State University, State College, PA, USA
| | - Richard B Mailman
- Departments of Neurology and Pharmacology, Translational Brain Research Center, Pennsylvania State University College of Medicine and Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Xuemei Huang
- Departments of Neurology and Pharmacology, Translational Brain Research Center, Pennsylvania State University College of Medicine and Milton S. Hershey Medical Center, Hershey, PA, USA
- Departments of Radiology, Neurosurgery, and Kinesiology, Translational Brain Research Center, Pennsylvania State University and Milton S. Hershey Medical Center, Hershey, PA, USA
- Institute for Computational and Data Sciences, The Pennsylvania State University, State College, PA, USA
| | - Xiao Liu
- Department of Biomedical Engineering, The Pennsylvania State University, State College, PA, USA.
- Institute for Computational and Data Sciences, The Pennsylvania State University, State College, PA, USA.
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49
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Plitt MH, Kaganovsky K, Südhof TC, Giocomo LM. Hippocampal place code plasticity in CA1 requires postsynaptic membrane fusion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.20.567978. [PMID: 38045362 PMCID: PMC10690209 DOI: 10.1101/2023.11.20.567978] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Rapid delivery of glutamate receptors to the postsynaptic membrane via vesicle fusion is a central component of synaptic plasticity. However, it is unknown how this process supports specific neural computations during behavior. To bridge this gap, we combined conditional genetic deletion of a component of the postsynaptic membrane fusion machinery, Syntaxin3 (Stx3), in hippocampal CA1 neurons of mice with population in vivo calcium imaging. This approach revealed that Stx3 is necessary for forming the neural dynamics that support novelty processing, spatial reward memory and offline memory consolidation. In contrast, CA1 Stx3 was dispensable for maintaining aspects of the neural code that exist presynaptic to CA1 such as representations of context and space. Thus, manipulating postsynaptic membrane fusion identified computations that specifically require synaptic restructuring via membrane trafficking in CA1 and distinguished them from neural representation that could be inherited from upstream brain regions or learned through other mechanisms.
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50
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Yang W, Sun C, Huszár R, Hainmueller T, Buzsáki G. Selection of experience for memory by hippocampal sharp wave ripples. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.565935. [PMID: 37987008 PMCID: PMC10659301 DOI: 10.1101/2023.11.07.565935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
A general wisdom is that experiences need to be tagged during learning for further consolidation. However, brain mechanisms that select experiences for lasting memory are not known. Combining large-scale neural recordings with a novel application of dimensionality reduction techniques, we observed that successive traversals in the maze were tracked by continuously drifting populations of neurons, providing neuronal signatures of both places visited and events encountered (trial number). When the brain state changed during reward consumption, sharp wave ripples (SPW-Rs) occurred on some trials and their unique spike content most often decoded the trial in which they occurred. In turn, during post-experience sleep, SPW-Rs continued to replay those trials that were reactivated most frequently during awake SPW-Rs. These findings suggest that replay content of awake SPW-Rs provides a tagging mechanism to select aspects of experience that are preserved and consolidated for future use.
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Affiliation(s)
- Wannan Yang
- Center for Neural Science, New York University, NY, USA
- Neuroscience Institute, NYU Grossman School of Medicine, New York University, New York, NY, USA
| | - Chen Sun
- Mila - Quebec AI Institute, Montréal, Canada
| | - Roman Huszár
- Neuroscience Institute, NYU Grossman School of Medicine, New York University, New York, NY, USA
| | - Thomas Hainmueller
- Neuroscience Institute, NYU Grossman School of Medicine, New York University, New York, NY, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA
| | - György Buzsáki
- Center for Neural Science, New York University, NY, USA
- Neuroscience Institute, NYU Grossman School of Medicine, New York University, New York, NY, USA
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