1
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Raju RV, Guntupalli JS, Zhou G, Wendelken C, Lázaro-Gredilla M, George D. Space is a latent sequence: A theory of the hippocampus. SCIENCE ADVANCES 2024; 10:eadm8470. [PMID: 39083616 PMCID: PMC11290523 DOI: 10.1126/sciadv.adm8470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 06/26/2024] [Indexed: 08/02/2024]
Abstract
Fascinating phenomena such as landmark vector cells and splitter cells are frequently discovered in the hippocampus. Without a unifying principle, each experiment seemingly uncovers new anomalies or coding types. Here, we provide a unifying principle that the mental representation of space is an emergent property of latent higher-order sequence learning. Treating space as a sequence resolves numerous phenomena and suggests that the place field mapping methodology that interprets sequential neuronal responses in Euclidean terms might itself be a source of anomalies. Our model, clone-structured causal graph (CSCG), employs higher-order graph scaffolding to learn latent representations by mapping aliased egocentric sensory inputs to unique contexts. Learning to compress sequential and episodic experiences using CSCGs yields allocentric cognitive maps that are suitable for planning, introspection, consolidation, and abstraction. By explicating the role of Euclidean place field mapping and demonstrating how latent sequential representations unify myriad observed phenomena, our work positions the hippocampus in a sequence-centric paradigm, challenging the prevailing space-centric view.
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2
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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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3
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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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4
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Wang Y, Wang X, Wang L, Zheng L, Meng S, Zhu N, An X, Wang L, Yang J, Zheng C, Ming D. Dynamic prediction of goal location by coordinated representation of prefrontal-hippocampal theta sequences. Curr Biol 2024; 34:1866-1879.e6. [PMID: 38608677 DOI: 10.1016/j.cub.2024.03.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/20/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024]
Abstract
Prefrontal (PFC) and hippocampal (HPC) sequences of neuronal firing modulated by theta rhythms could represent upcoming choices during spatial memory-guided decision-making. How the PFC-HPC network dynamically coordinates theta sequences to predict specific goal locations and how it is interrupted in memory impairments induced by amyloid beta (Aβ) remain unclear. Here, we detected theta sequences of firing activities of PFC neurons and HPC place cells during goal-directed spatial memory tasks. We found that PFC ensembles exhibited predictive representation of the specific goal location since the starting phase of memory retrieval, earlier than the hippocampus. High predictive accuracy of PFC theta sequences existed during successful memory retrieval and positively correlated with memory performance. Coordinated PFC-HPC sequences showed PFC-dominant prediction of goal locations during successful memory retrieval. Furthermore, we found that theta sequences of both regions still existed under Aβ accumulation, whereas their predictive representation of goal locations was weakened with disrupted spatial representation of HPC place cells and PFC neurons. These findings highlight the essential role of coordinated PFC-HPC sequences in successful memory retrieval of a precise goal location.
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Affiliation(s)
- Yimeng Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Xueling Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Ling Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
| | - Li Zheng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Shuang Meng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Nan Zhu
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Xingwei An
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
| | - Lei Wang
- School of Statistics and Data Science, Nankai University, Tianjin 300071, China.
| | - Jiajia Yang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
| | - Chenguang Zheng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
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5
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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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6
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Muysers H, Chen HL, Hahn J, Folschweiller S, Sigurdsson T, Sauer JF, Bartos M. A persistent prefrontal reference frame across time and task rules. Nat Commun 2024; 15:2115. [PMID: 38459033 PMCID: PMC10923947 DOI: 10.1038/s41467-024-46350-4] [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: 10/11/2023] [Accepted: 02/22/2024] [Indexed: 03/10/2024] Open
Abstract
Behavior can be remarkably consistent, even over extended time periods, yet whether this is reflected in stable or 'drifting' neuronal responses to task features remains controversial. Here, we find a persistently active ensemble of neurons in the medial prefrontal cortex (mPFC) of mice that reliably maintains trajectory-specific tuning over several weeks while performing an olfaction-guided spatial memory task. This task-specific reference frame is stabilized during learning, upon which repeatedly active neurons show little representational drift and maintain their trajectory-specific tuning across long pauses in task exposure and across repeated changes in cue-target location pairings. These data thus suggest a 'core ensemble' of prefrontal neurons forming a reference frame of task-relevant space for the performance of consistent behavior over extended periods of time.
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Affiliation(s)
- Hannah Muysers
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
| | - Hung-Ling Chen
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
| | - Johannes Hahn
- Institute of Neurophysiology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Shani Folschweiller
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
- Sleep-Wake-Epilepsy Center and Center for Experimental Neurology, Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Torfi Sigurdsson
- Institute of Neurophysiology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jonas-Frederic Sauer
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
| | - Marlene Bartos
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
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7
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Sosa M, Plitt MH, Giocomo LM. Hippocampal sequences span experience relative to rewards. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.27.573490. [PMID: 38234842 PMCID: PMC10793396 DOI: 10.1101/2023.12.27.573490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Hippocampal place cells fire in sequences that span spatial environments and non-spatial modalities, suggesting that hippocampal activity can anchor to the most behaviorally salient aspects of experience. As reward is a highly salient event, we hypothesized that sequences of hippocampal activity can anchor to rewards. To test this, we performed two-photon imaging of hippocampal CA1 neurons as mice navigated virtual environments with changing hidden reward locations. When the reward moved, the firing fields of a subpopulation of cells moved to the same relative position with respect to reward, constructing a sequence of reward-relative cells that spanned the entire task structure. The density of these reward-relative sequences increased with task experience as additional neurons were recruited to the reward-relative population. Conversely, a largely separate subpopulation maintained a spatially-based place code. These findings thus reveal separate hippocampal ensembles can flexibly encode multiple behaviorally salient reference frames, reflecting the structure of the experience.
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Affiliation(s)
- Marielena Sosa
- Department of Neurobiology, Stanford University School of Medicine; Stanford, CA, USA
| | - Mark H. Plitt
- Department of Neurobiology, Stanford University School of Medicine; Stanford, CA, USA
- Present address: Department of Molecular and Cell Biology, University of California Berkeley; Berkeley, CA, USA
| | - Lisa M. Giocomo
- Department of Neurobiology, Stanford University School of Medicine; Stanford, CA, USA
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8
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Nakai S, Kitanishi T, Mizuseki K. Distinct manifold encoding of navigational information in the subiculum and hippocampus. SCIENCE ADVANCES 2024; 10:eadi4471. [PMID: 38295173 PMCID: PMC10830115 DOI: 10.1126/sciadv.adi4471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 12/29/2023] [Indexed: 02/02/2024]
Abstract
The subiculum (SUB) plays a crucial role in spatial navigation and encodes navigational information differently from the hippocampal CA1 area. However, the representation of subicular population activity remains unknown. Here, we investigated the neuronal population activity recorded extracellularly from the CA1 and SUB of rats performing T-maze and open-field tasks. The trajectory of population activity in both areas was confined to low-dimensional neural manifolds homoeomorphic to external space. The manifolds conveyed position, speed, and future path information with higher decoding accuracy in the SUB than in the CA1. The manifolds exhibited common geometry across rats and regions for the CA1 and SUB and between tasks in the SUB. During post-task ripples in slow-wave sleep, population activity represented reward locations/events more frequently in the SUB than in CA1. Thus, the CA1 and SUB encode information distinctly into the neural manifolds that underlie navigational information processing during wakefulness and sleep.
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Affiliation(s)
- Shinya Nakai
- Department of Physiology, Graduate School of Medicine, Osaka Metropolitan University, Osaka 545-8585, Japan
- Department of Physiology, Graduate School of Medicine, Osaka City University, Osaka 545-8585, Japan
| | - Takuma Kitanishi
- Department of Physiology, Graduate School of Medicine, Osaka City University, Osaka 545-8585, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
- Komaba Institute for Science, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Kenji Mizuseki
- Department of Physiology, Graduate School of Medicine, Osaka Metropolitan University, Osaka 545-8585, Japan
- Department of Physiology, Graduate School of Medicine, Osaka City University, Osaka 545-8585, Japan
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9
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Guidera JA, Gramling DP, Comrie AE, Joshi A, Denovellis EL, Lee KH, Zhou J, Thompson P, Hernandez J, Yorita A, Haque R, Kirst C, Frank LM. Regional specialization manifests in the reliability of neural population codes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.25.576941. [PMID: 38328245 PMCID: PMC10849741 DOI: 10.1101/2024.01.25.576941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The brain has the remarkable ability to learn and guide the performance of complex tasks. Decades of lesion studies suggest that different brain regions perform specialized functions in support of complex behaviors1-3. Yet recent large-scale studies of neural activity reveal similar patterns of activity and encoding distributed widely throughout the brain4-6. How these distributed patterns of activity and encoding are compatible with regional specialization of brain function remains unclear. Two frontal brain regions, the dorsal medial prefrontal cortex (dmPFC) and orbitofrontal cortex (OFC), are a paradigm of this conundrum. In the setting complex behaviors, the dmPFC is necessary for choosing optimal actions2,7,8, whereas the OFC is necessary for waiting for3,9 and learning from2,7,9-12 the outcomes of those actions. Yet both dmPFC and OFC encode both choice- and outcome-related quantities13-20. Here we show that while ensembles of neurons in the dmPFC and OFC of rats encode similar elements of a cognitive task with similar patterns of activity, the two regions differ in when that coding is consistent across trials ("reliable"). In line with the known critical functions of each region, dmPFC activity is more reliable when animals are making choices and less reliable preceding outcomes, whereas OFC activity shows the opposite pattern. Our findings identify the dynamic reliability of neural population codes as a mechanism whereby different brain regions may support distinct cognitive functions despite exhibiting similar patterns of activity and encoding similar quantities.
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Affiliation(s)
- Jennifer A. Guidera
- UCSF-UC Berkeley Graduate Program in Bioengineering, University of California, San Francisco; San Francisco, 94158, USA and University of California, Berkeley; Berkely, 94720, USA
- Medical Scientist Training Program, University of California, San Francisco; San Francisco, 94158, USA
| | - Daniel P. Gramling
- Departments of Physiology and Psychiatry, University of California, San Francisco; San Francisco, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco; San Francisco, 94158, USA
| | - Alison E. Comrie
- Departments of Physiology and Psychiatry, University of California, San Francisco; San Francisco, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco; San Francisco, 94158, USA
| | - Abhilasha Joshi
- Departments of Physiology and Psychiatry, University of California, San Francisco; San Francisco, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco; San Francisco, 94158, USA
- Howard Hughes Medical Institute, University of California, San Francisco; San Francisco, 94158, USA
| | - Eric L. Denovellis
- Departments of Physiology and Psychiatry, University of California, San Francisco; San Francisco, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco; San Francisco, 94158, USA
- Howard Hughes Medical Institute, University of California, San Francisco; San Francisco, 94158, USA
| | - Kyu Hyun Lee
- Departments of Physiology and Psychiatry, University of California, San Francisco; San Francisco, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco; San Francisco, 94158, USA
- Howard Hughes Medical Institute, University of California, San Francisco; San Francisco, 94158, USA
| | - Jenny Zhou
- Center for Micro- and Nano-Technology, Lawrence Livermore National Laboratory; Livermore, 94158, USA
| | - Paige Thompson
- Center for Micro- and Nano-Technology, Lawrence Livermore National Laboratory; Livermore, 94158, USA
| | - Jose Hernandez
- Center for Micro- and Nano-Technology, Lawrence Livermore National Laboratory; Livermore, 94158, USA
| | - Allison Yorita
- Center for Micro- and Nano-Technology, Lawrence Livermore National Laboratory; Livermore, 94158, USA
| | - Razi Haque
- Center for Micro- and Nano-Technology, Lawrence Livermore National Laboratory; Livermore, 94158, USA
| | - Christoph Kirst
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco; San Francisco, 94158, USA
- Department of Anatomy, University of California, San Francisco; San Francisco, 94158, USA
| | - Loren M. Frank
- UCSF-UC Berkeley Graduate Program in Bioengineering, University of California, San Francisco; San Francisco, 94158, USA and University of California, Berkeley; Berkely, 94720, USA
- Departments of Physiology and Psychiatry, University of California, San Francisco; San Francisco, 94158, USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco; San Francisco, 94158, USA
- Howard Hughes Medical Institute, University of California, San Francisco; San Francisco, 94158, USA
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10
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Sylte OC, Muysers H, Chen HL, Bartos M, Sauer JF. Neuronal tuning to threat exposure remains stable in the mouse prefrontal cortex over multiple days. PLoS Biol 2024; 22:e3002475. [PMID: 38206890 PMCID: PMC10783789 DOI: 10.1371/journal.pbio.3002475] [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: 06/28/2023] [Accepted: 12/19/2023] [Indexed: 01/13/2024] Open
Abstract
Intense threat elicits action in the form of active and passive coping. The medial prefrontal cortex (mPFC) executes top-level control over the selection of threat coping strategies, but the dynamics of mPFC activity upon continuing threat encounters remain unexplored. Here, we used 1-photon calcium imaging in mice to probe the activity of prefrontal pyramidal cells during repeated exposure to intense threat in a tail suspension (TS) paradigm. A subset of prefrontal neurons displayed selective activation during TS, which was stably maintained over days. During threat, neurons showed specific tuning to active or passive coping. These responses were unrelated to general motion tuning and persisted over days. Moreover, the neural manifold traversed by low-dimensional population activity remained stable over subsequent days of TS exposure and was preserved across individuals. These data thus reveal a specific, temporally, and interindividually conserved repertoire of prefrontal tuning to behavioral responses under threat.
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Affiliation(s)
- Ole Christian Sylte
- University of Freiburg, Medical Faculty, Institute of Physiology I, Freiburg, Germany
- University of Freiburg, Faculty of Biology, Freiburg, Germany
| | - Hannah Muysers
- University of Freiburg, Medical Faculty, Institute of Physiology I, Freiburg, Germany
- University of Freiburg, Faculty of Biology, Freiburg, Germany
| | - Hung-Ling Chen
- University of Freiburg, Medical Faculty, Institute of Physiology I, Freiburg, Germany
| | - Marlene Bartos
- University of Freiburg, Medical Faculty, Institute of Physiology I, Freiburg, Germany
| | - Jonas-Frederic Sauer
- University of Freiburg, Medical Faculty, Institute of Physiology I, Freiburg, Germany
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11
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Esparza J, Sebastián ER, de la Prida LM. From cell types to population dynamics: Making hippocampal manifolds physiologically interpretable. Curr Opin Neurobiol 2023; 83:102800. [PMID: 37898015 DOI: 10.1016/j.conb.2023.102800] [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: 05/25/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/30/2023]
Abstract
The study of the hippocampal code is gaining momentum. While the physiological approach targets the contribution of individual cells as determined by genetic, biophysical and circuit factors, the field pushes for a population dynamic approach that considers the representation of behavioural variables by a large number of neurons. In this alternative framework, neuronal activity is projected into low-dimensional manifolds. These manifolds can reveal the structure of population representations, but their physiological interpretation is challenging. Here, we review the recent literature and propose that integrating information regarding behavioral traits, local field potential oscillations and cell-type-specificity into neural manifolds offers strategies to make them interpretable at the physiological level.
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12
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Courellis HS, Mixha J, Cardenas AR, Kimmel D, Reed CM, Valiante TA, Salzman CD, Mamelak AN, Fusi S, Rutishauser U. Abstract representations emerge in human hippocampal neurons during inference behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.10.566490. [PMID: 37986878 PMCID: PMC10659400 DOI: 10.1101/2023.11.10.566490] [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
Humans have the remarkable cognitive capacity to rapidly adapt to changing environments. Central to this capacity is the ability to form high-level, abstract representations that take advantage of regularities in the world to support generalization 1 . However, little is known about how these representations are encoded in populations of neurons, how they emerge through learning, and how they relate to behavior 2,3 . Here we characterized the representational geometry of populations of neurons (single-units) recorded in the hippocampus, amygdala, medial frontal cortex, and ventral temporal cortex of neurosurgical patients who are performing an inferential reasoning task. We find that only the neural representations formed in the hippocampus simultaneously encode multiple task variables in an abstract, or disentangled, format. This representational geometry is uniquely observed after patients learn to perform inference, and consisted of disentangled directly observable and discovered latent task variables. Interestingly, learning to perform inference by trial and error or through verbal instructions led to the formation of hippocampal representations with similar geometric properties. The observed relation between representational format and inference behavior suggests that abstract/disentangled representational geometries are important for complex cognition.
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13
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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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Shin JD, Tang W, Jadhav SP. Protocol for geometric transformation of cognitive maps for generalization across hippocampal-prefrontal circuits. STAR Protoc 2023; 4:102513. [PMID: 37572325 PMCID: PMC10448425 DOI: 10.1016/j.xpro.2023.102513] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/06/2023] [Accepted: 07/25/2023] [Indexed: 08/14/2023] Open
Abstract
Memory generalization is the ability to abstract knowledge from prior experiences and is critical for flexible behavior in novel situations. Here, we describe a protocol for simultaneous recording of hippocampal (area CA1)-prefrontal cortical neural ensembles in Long-Evans rats during task generalization across two distinct environments. We describe steps for building and assembling experimental apparatuses, animal preparation and surgery, and performing experiments. We then detail procedures for histology, data processing, and assessing population geometry using Uniform Manifold Approximation and Projection. For complete details on the use and execution of this protocol, please refer to Tang et al. (2023).1.
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Affiliation(s)
- Justin D Shin
- Neuroscience Program, Department of Psychology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02453, USA.
| | - Wenbo Tang
- Neuroscience Program, Department of Psychology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02453, USA
| | - Shantanu P Jadhav
- Neuroscience Program, Department of Psychology, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 02453, USA.
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