1
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Gandit B, Posani L, Zhang CL, Saha S, Ortiz C, Allegra M, Schmidt-Hieber C. Transformation of spatial representations along hippocampal circuits. iScience 2024; 27:110361. [PMID: 39071886 PMCID: PMC11277690 DOI: 10.1016/j.isci.2024.110361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 03/01/2024] [Accepted: 06/21/2024] [Indexed: 07/30/2024] Open
Abstract
The hippocampus is thought to provide the brain with a cognitive map of the external world by processing various types of spatial information. To understand how essential spatial variables such as direction, position, and distance are transformed along its circuits to construct this global map, we perform single-photon widefield microendoscope calcium imaging in the dentate gyrus and CA3 of mice freely navigating along a narrow corridor. We find that spatial activity maps in the dentate gyrus, but not in CA3, are correlated after aligning them to the running directions, suggesting that they represent the distance traveled along the track in egocentric coordinates. Together with population activity decoding, our data suggest that while spatial representations in the dentate gyrus and CA3 are anchored in both egocentric and allocentric coordinates, egocentric distance coding is more prevalent in the dentate gyrus than in CA3, providing insights into the assembly of the cognitive map.
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Affiliation(s)
- Bérénice Gandit
- Institut Pasteur, Université Paris Cité, Neural Circuits for Spatial Navigation and Memory, Department of Neuroscience, F-75015 Paris, France
- Sorbonne Université, Collège Doctoral, F-75005 Paris, France
| | - Lorenzo Posani
- Center for Theoretical Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Chun-Lei Zhang
- Institut Pasteur, Université Paris Cité, Neural Circuits for Spatial Navigation and Memory, Department of Neuroscience, F-75015 Paris, France
| | - Soham Saha
- Institut Pasteur, Université Paris Cité, Neural Circuits for Spatial Navigation and Memory, Department of Neuroscience, F-75015 Paris, France
| | - Cantin Ortiz
- Institut Pasteur, Université Paris Cité, Neural Circuits for Spatial Navigation and Memory, Department of Neuroscience, F-75015 Paris, France
- Sorbonne Université, Collège Doctoral, F-75005 Paris, France
| | - Manuela Allegra
- Institut Pasteur, Université Paris Cité, Neural Circuits for Spatial Navigation and Memory, Department of Neuroscience, F-75015 Paris, France
| | - Christoph Schmidt-Hieber
- Institut Pasteur, Université Paris Cité, Neural Circuits for Spatial Navigation and Memory, Department of Neuroscience, F-75015 Paris, France
- Institute for Physiology I, Jena University Hospital, 07743 Jena, Germany
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2
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Chen Y, Zhang H, Cameron M, Sejnowski T. Predictive sequence learning in the hippocampal formation. Neuron 2024:S0896-6273(24)00371-4. [PMID: 38917804 DOI: 10.1016/j.neuron.2024.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 01/21/2024] [Accepted: 05/22/2024] [Indexed: 06/27/2024]
Abstract
The hippocampus receives sequences of sensory inputs from the cortex during exploration and encodes the sequences with millisecond precision. We developed a predictive autoencoder model of the hippocampus including the trisynaptic and monosynaptic circuits from the entorhinal cortex (EC). CA3 was trained as a self-supervised recurrent neural network to predict its next input. We confirmed that CA3 is predicting ahead by analyzing the spike coupling between simultaneously recorded neurons in the dentate gyrus, CA3, and CA1 of the mouse hippocampus. In the model, CA1 neurons signal prediction errors by comparing CA3 predictions to the next direct EC input. The model exhibits the rapid appearance and slow fading of CA1 place cells and displays replay and phase precession from CA3. The model could be learned in a biologically plausible way with error-encoding neurons. Similarities between the hippocampal and thalamocortical circuits suggest that such computation motif could also underlie self-supervised sequence learning in the cortex.
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Affiliation(s)
- Yusi Chen
- Computational Neurobiology Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037, USA; Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA; Computational Neuroscience Center, University of Washington, Seattle, WA 98195, USA.
| | - Huanqiu Zhang
- Computational Neurobiology Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037, USA; Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mia Cameron
- Computational Neurobiology Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037, USA; Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Terrence Sejnowski
- Computational Neurobiology Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037, USA; Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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3
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O’Hare JK, Wang J, Shala MD, Polleux F, Losonczy A. Variable recruitment of distal tuft dendrites shapes new hippocampal place fields. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.26.582144. [PMID: 38464058 PMCID: PMC10925200 DOI: 10.1101/2024.02.26.582144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Hippocampal pyramidal neurons support episodic memory by integrating complementary information streams into new 'place fields'. Distal tuft dendrites are widely thought to initiate place field formation by locally generating prolonged, globally-spreading Ca 2+ spikes known as plateau potentials. However, the hitherto experimental inaccessibility of distal tuft dendrites in the hippocampus has rendered their in vivo function entirely unknown. Here we gained direct optical access to this elusive dendritic compartment. We report that distal tuft dendrites do not serve as the point of origin for place field-forming plateau potentials. Instead, the timing and extent of peri-formation distal tuft recruitment is variable and closely predicts multiple properties of resultant place fields. Therefore, distal tuft dendrites play a more powerful role in hippocampal feature selectivity than simply initiating place field formation. Moreover, place field formation is not accompanied by global Ca 2+ influx as previously thought. In addition to shaping new somatic place fields, distal tuft dendrites possess their own local place fields. Tuft place fields are back-shifted relative to that of their soma and appear to maintain somatic place fields via post-formation plateau potentials. Through direct in vivo observation, we provide a revised dendritic basis for hippocampal feature selectivity during navigational learning.
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Affiliation(s)
- Justin K. O’Hare
- Department of Neuroscience, Columbia University; New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, United States
| | - Jamie Wang
- Department of Biomedical Engineering, Duke University; Durham, NC, United States
| | - Margjele D. Shala
- Department of Neuroscience, Columbia University; New York, NY, United States
| | - Franck Polleux
- Department of Neuroscience, Columbia University; New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, United States
| | - Attila Losonczy
- Department of Neuroscience, Columbia University; New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, United States
- Lead contact
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4
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Fenton AA. Remapping revisited: how the hippocampus represents different spaces. Nat Rev Neurosci 2024; 25:428-448. [PMID: 38714834 DOI: 10.1038/s41583-024-00817-x] [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: 04/04/2024] [Indexed: 05/25/2024]
Abstract
The representation of distinct spaces by hippocampal place cells has been linked to changes in their place fields (the locations in the environment where the place cells discharge strongly), a phenomenon that has been termed 'remapping'. Remapping has been assumed to be accompanied by the reorganization of subsecond cofiring relationships among the place cells, potentially maximizing hippocampal information coding capacity. However, several observations challenge this standard view. For example, place cells exhibit mixed selectivity, encode non-positional variables, can have multiple place fields and exhibit unreliable discharge in fixed environments. Furthermore, recent evidence suggests that, when measured at subsecond timescales, the moment-to-moment cofiring of a pair of cells in one environment is remarkably similar in another environment, despite remapping. Here, I propose that remapping is a misnomer for the changes in place fields across environments and suggest instead that internally organized manifold representations of hippocampal activity are actively registered to different environments to enable navigation, promote memory and organize knowledge.
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Affiliation(s)
- André A Fenton
- Center for Neural Science, New York University, New York, NY, USA.
- Neuroscience Institute at the NYU Langone Medical Center, New York, NY, USA.
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5
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Becker S, Modirshanechi A, Gerstner W. Computational models of intrinsic motivation for curiosity and creativity. Behav Brain Sci 2024; 47:e94. [PMID: 38770870 DOI: 10.1017/s0140525x23003424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
We link Ivancovsky et al.'s novelty-seeking model (NSM) to computational models of intrinsically motivated behavior and learning. We argue that dissociating different forms of curiosity, creativity, and memory based on the involvement of distinct intrinsic motivations (e.g., surprise and novelty) is essential to empirically test the conceptual claims of the NSM.
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Affiliation(s)
- Sophia Becker
- Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, ; https://lcnwww.epfl.ch/gerstner/
- School of Computer and Communication Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Alireza Modirshanechi
- Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, ; https://lcnwww.epfl.ch/gerstner/
- School of Computer and Communication Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Wulfram Gerstner
- Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, ; https://lcnwww.epfl.ch/gerstner/
- School of Computer and Communication Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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6
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Zheng Z(S, Huszár R, Hainmueller T, Bartos M, Williams A, Buzsáki G. Perpetual step-like restructuring of hippocampal circuit dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.22.590576. [PMID: 38712105 PMCID: PMC11071370 DOI: 10.1101/2024.04.22.590576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Representation of the environment by hippocampal populations is known to drift even within a familiar environment, which could reflect gradual changes in single cell activity or result from averaging across discrete switches of single neurons. Disambiguating these possibilities is crucial, as they each imply distinct mechanisms. Leveraging change point detection and model comparison, we found that CA1 population vectors decorrelated gradually within a session. In contrast, individual neurons exhibited predominantly step-like emergence and disappearance of place fields or sustained change in within-field firing. The changes were not restricted to particular parts of the maze or trials and did not require apparent behavioral changes. The same place fields emerged, disappeared, and reappeared across days, suggesting that the hippocampus reuses pre-existing assemblies, rather than forming new fields de novo. Our results suggest an internally-driven perpetual step-like reorganization of the neuronal assemblies.
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Affiliation(s)
| | - Roman Huszár
- Center for Neural Science, New York University, New York, NY, USA
- Neuroscience Institute, New York University, New York, NY, USA
| | - Thomas Hainmueller
- Department of Psychiatry, NYU Grossman School of Medicine, New York University, New York, NY, USA
| | - Marlene Bartos
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104 Freiburg, Germany
| | - Alex Williams
- Center for Neural Science, New York University, New York, NY, USA
- Neuroscience Institute, New York University, New York, NY, USA
- Center for Computational Neuroscience, Flatiron Institute
| | - György Buzsáki
- Neuroscience Institute, New York University, New York, NY, USA
- Department of Neurology, and New York University, New York, NY, USA
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7
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Tamboli S, Singh S, Topolnik D, El Amine Barkat M, Radhakrishnan R, Guet-McCreight A, Topolnik L. Mouse hippocampal CA1 VIP interneurons detect novelty in the environment and support recognition memory. Cell Rep 2024; 43:114115. [PMID: 38607918 DOI: 10.1016/j.celrep.2024.114115] [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: 08/08/2023] [Revised: 02/17/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024] Open
Abstract
In the CA1 hippocampus, vasoactive intestinal polypeptide-expressing interneurons (VIP-INs) play a prominent role in disinhibitory circuit motifs. However, the specific behavioral conditions that lead to circuit disinhibition remain uncertain. To investigate the behavioral relevance of VIP-IN activity, we employed wireless technologies allowing us to monitor and manipulate their function in freely behaving mice. Our findings reveal that, during spatial exploration in new environments, VIP-INs in the CA1 hippocampal region become highly active, facilitating the rapid encoding of novel spatial information. Remarkably, both VIP-INs and pyramidal neurons (PNs) exhibit increased activity when encountering novel changes in the environment, including context- and object-related alterations. Concurrently, somatostatin- and parvalbumin-expressing inhibitory populations show an inverse relationship with VIP-IN and PN activity, revealing circuit disinhibition that occurs on a timescale of seconds. Thus, VIP-IN-mediated disinhibition may constitute a crucial element in the rapid encoding of novelty and the acquisition of recognition memory.
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Affiliation(s)
- Suhel Tamboli
- Neuroscience Axis, CRCHUQ-CHUL, Quebec City, PQ, Canada; Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, PQ, Canada
| | - Sanjay Singh
- Neuroscience Axis, CRCHUQ-CHUL, Quebec City, PQ, Canada; Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, PQ, Canada
| | - Dimitry Topolnik
- Neuroscience Axis, CRCHUQ-CHUL, Quebec City, PQ, Canada; Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, PQ, Canada
| | - Mohamed El Amine Barkat
- Neuroscience Axis, CRCHUQ-CHUL, Quebec City, PQ, Canada; Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, PQ, Canada
| | - Risna Radhakrishnan
- Neuroscience Axis, CRCHUQ-CHUL, Quebec City, PQ, Canada; Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, PQ, Canada
| | | | - Lisa Topolnik
- Neuroscience Axis, CRCHUQ-CHUL, Quebec City, PQ, Canada; Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, PQ, Canada.
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8
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Bowler JC, Zakka G, Yong HC, Li W, Rao B, Liao Z, Priestley JB, Losonczy A. behaviorMate: An Intranet of Things Approach for Adaptable Control of Behavioral and Navigation-Based Experiments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.04.569989. [PMID: 38116032 PMCID: PMC10729741 DOI: 10.1101/2023.12.04.569989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Investigators conducting behavioral experiments often need precise control over the timing of the delivery of stimuli to subjects and to collect the precise times of the subsequent behavioral responses. Furthermore, investigators want fine-tuned control over how various multi-modal cues are presented. behaviorMate takes an "Intranet of Things" approach, using a networked system of hardware and software components for achieving these goals. The system outputs a file with integrated timestamp-event pairs that investigators can then format and process using their own analysis pipelines. We present an overview of the electronic components and GUI application that make up behaviorMate as well as mechanical designs for compatible experimental rigs to provide the reader with the ability to set up their own system. A wide variety of paradigms are supported, including goal-oriented learning, random foraging, and context switching. We demonstrate behaviorMate's utility and reliability with a range of use cases from several published studies and benchmark tests. Finally, we present experimental validation demonstrating different modalities of hippocampal place field studies. Both treadmill with burlap belt and virtual reality with running wheel paradigms were performed to confirm the efficacy and flexibility of the approach. Previous solutions rely on proprietary systems that may have large upfront costs or present frameworks that require customized software to be developed. behaviorMate uses open-source software and a flexible configuration system to mitigate both concerns. behaviorMate has a proven record for head-fixed imaging experiments and could be easily adopted for task control in a variety of experimental situations.
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Affiliation(s)
- John C. Bowler
- Department of Neuroscience
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
- Department of Neurobiology University of Utah, Salt Lake City, UT 84112, USA
| | - George Zakka
- Department of Neuroscience
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
| | - Hyun Choong Yong
- Department of Neuroscience
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
| | - Wenke Li
- Aquabyte, San Francisco, CA 94111
| | - Bovey Rao
- Department of Neuroscience
- Doctoral Program in Neurobiology and Behavior
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
| | - Zhenrui Liao
- Department of Neuroscience
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
| | | | - Attila Losonczy
- Department of Neuroscience
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027 USA
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9
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Savelli F. Spontaneous Dynamics of Hippocampal Place Fields in a Model of Combinatorial Competition among Stable Inputs. J Neurosci 2024; 44:e1663232024. [PMID: 38316560 PMCID: PMC10977031 DOI: 10.1523/jneurosci.1663-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 01/16/2024] [Accepted: 01/21/2024] [Indexed: 02/07/2024] Open
Abstract
We present computer simulations illustrating how the plastic integration of spatially stable inputs could contribute to the dynamic character of hippocampal spatial representations. In novel environments of slightly larger size than typical apparatus, the emergence of well-defined place fields in real place cells seems to rely on inputs from normally functioning grid cells. Theoretically, the grid-to-place transformation is possible if a place cell is able to respond selectively to a combination of suitably aligned grids. We previously identified the functional characteristics that allow a synaptic plasticity rule to accomplish this selection by synaptic competition during rat foraging behavior. Here, we show that the synaptic competition can outlast the formation of place fields, contributing to their spatial reorganization over time, when the model is run in larger environments and the topographical/modular organization of grid inputs is taken into account. Co-simulated cells that differ only by their randomly assigned grid inputs display different degrees and kinds of spatial reorganization-ranging from place-field remapping to more subtle in-field changes or lapses in firing. The model predicts a greater number of place fields and propensity for remapping in place cells recorded from more septal regions of the hippocampus and/or in larger environments, motivating future experimental standardization across studies and animal models. In sum, spontaneous remapping could arise from rapid synaptic learning involving inputs that are functionally homogeneous, spatially stable, and minimally stochastic.
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Affiliation(s)
- Francesco Savelli
- Department of Neuroscience, Developmental and Regenerative Biology, The University of Texas at San Antonio, San Antonio, Texas 78249
- Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas 78249
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, Texas 78249
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10
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Shi J, Nutkovich B, Kushinsky D, Rao BY, Herrlinger SA, Mihaila TS, Malina KCK, O’Toole CK, Conde Paredes ME, Yong HC, Varol E, Losonczy A, Spiegel I. 2P-NucTag: on-demand phototagging for molecular analysis of functionally identified cortical neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.21.586118. [PMID: 38585980 PMCID: PMC10996538 DOI: 10.1101/2024.03.21.586118] [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
Neural circuits are characterized by genetically and functionally diverse cell types. A mechanistic understanding of circuit function is predicated on linking the genetic and physiological properties of individual neurons. However, it remains highly challenging to map the functional properties of transcriptionally heterogeneous neuronal subtypes in mammalian cortical circuits in vivo. Here, we introduce a high-throughput two-photon nuclear phototagging (2P-NucTag) approach optimized for on-demand and indelible labeling of single neurons via a photoactivatable red fluorescent protein following in vivo functional characterization in behaving mice. We demonstrate the utility of this function-forward pipeline by selectively labeling and transcriptionally profiling previously inaccessible 'place' and 'silent' cells in the mouse hippocampus. Our results reveal unexpected differences in gene expression between these hippocampal pyramidal neurons with distinct spatial coding properties. Thus, 2P-NucTag opens a new way to uncover the molecular principles that govern the functional organization of neural circuits.
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Affiliation(s)
- Jingcheng Shi
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
- Doctoral Program in Neurobiology and Behavior, Columbia University, New York, NY, United States
| | - Boaz Nutkovich
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Dahlia Kushinsky
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Bovey Y. Rao
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
- Doctoral Program in Neurobiology and Behavior, Columbia University, New York, NY, United States
| | - Stephanie A. Herrlinger
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
| | - Tiberiu S. Mihaila
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
| | - Katayun Cohen-Kashi Malina
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Cliodhna K. O’Toole
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
| | - Margaret E. Conde Paredes
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
- Doctoral Program in Neurobiology and Behavior, Columbia University, New York, NY, United States
- Tandon School of Engineering, New York University, New York, NY, United States
| | - Hyun Choong Yong
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
| | - Erdem Varol
- Tandon School of Engineering, New York University, New York, NY, United States
| | - Attila Losonczy
- Department of Neuroscience, Columbia University, New York, NY, United States
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
| | - Ivo Spiegel
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
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11
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Malone TJ, Tien NW, Ma Y, Cui L, Lyu S, Wang G, Nguyen D, Zhang K, Myroshnychenko MV, Tyan J, Gordon JA, Kupferschmidt DA, Gu Y. A consistent map in the medial entorhinal cortex supports spatial memory. Nat Commun 2024; 15:1457. [PMID: 38368457 PMCID: PMC10874432 DOI: 10.1038/s41467-024-45853-4] [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: 09/20/2023] [Accepted: 02/05/2024] [Indexed: 02/19/2024] Open
Abstract
The medial entorhinal cortex (MEC) is hypothesized to function as a cognitive map for memory-guided navigation. How this map develops during learning and influences memory remains unclear. By imaging MEC calcium dynamics while mice successfully learned a novel virtual environment over ten days, we discovered that the dynamics gradually became more spatially consistent and then stabilized. Additionally, grid cells in the MEC not only exhibited improved spatial tuning consistency, but also maintained stable phase relationships, suggesting a network mechanism involving synaptic plasticity and rigid recurrent connectivity to shape grid cell activity during learning. Increased c-Fos expression in the MEC in novel environments further supports the induction of synaptic plasticity. Unsuccessful learning lacked these activity features, indicating that a consistent map is specific for effective spatial memory. Finally, optogenetically disrupting spatial consistency of the map impaired memory-guided navigation in a well-learned environment. Thus, we demonstrate that the establishment of a spatially consistent MEC map across learning both correlates with, and is necessary for, successful spatial memory.
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Affiliation(s)
- Taylor J Malone
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Nai-Wen Tien
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
- Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Yan Ma
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Lian Cui
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Shangru Lyu
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Garret Wang
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Duc Nguyen
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
- Center of Neural Science, New York University, New York, NY, USA
| | - Kai Zhang
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Maxym V Myroshnychenko
- Integrative Neuroscience Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jean Tyan
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Joshua A Gordon
- Integrative Neuroscience Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA
- Office of the Director, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA
| | - David A Kupferschmidt
- Integrative Neuroscience Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yi Gu
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA.
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12
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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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13
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Hainmueller T, Cazala A, Huang LW, Bartos M. Subfield-specific interneuron circuits govern the hippocampal response to novelty in male mice. Nat Commun 2024; 15:714. [PMID: 38267409 PMCID: PMC10808551 DOI: 10.1038/s41467-024-44882-3] [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: 09/12/2023] [Accepted: 01/04/2024] [Indexed: 01/26/2024] Open
Abstract
The hippocampus is the brain's center for episodic memories. Its subregions, the dentate gyrus and CA1-3, are differentially involved in memory encoding and recall. Hippocampal principal cells represent episodic features like movement, space, and context, but less is known about GABAergic interneurons. Here, we performed two-photon calcium imaging of parvalbumin- and somatostatin-expressing interneurons in the dentate gyrus and CA1-3 of male mice exploring virtual environments. Parvalbumin-interneurons increased activity with running-speed and reduced it in novel environments. Somatostatin-interneurons in CA1-3 behaved similar to parvalbumin-expressing cells, but their dentate gyrus counterparts increased activity during rest and in novel environments. Congruently, chemogenetic silencing of dentate parvalbumin-interneurons had prominent effects in familiar contexts, while silencing somatostatin-expressing cells increased similarity of granule cell representations between novel and familiar environments. Our data indicate unique roles for parvalbumin- and somatostatin-positive interneurons in the dentate gyrus that are distinct from those in CA1-3 and may support routing of novel information.
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Affiliation(s)
- Thomas Hainmueller
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany.
- NYU Neuroscience Institute, 435 East 30th Street, New York, NY, 10016, USA.
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, 10016, USA.
| | - Aurore Cazala
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany
| | - Li-Wen Huang
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany
| | - Marlene Bartos
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany.
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14
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Cone I, Clopath C. Latent representations in hippocampal network model co-evolve with behavioral exploration of task structure. Nat Commun 2024; 15:687. [PMID: 38263408 PMCID: PMC10806076 DOI: 10.1038/s41467-024-44871-6] [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: 05/02/2023] [Accepted: 01/03/2024] [Indexed: 01/25/2024] Open
Abstract
To successfully learn real-life behavioral tasks, animals must pair actions or decisions to the task's complex structure, which can depend on abstract combinations of sensory stimuli and internal logic. The hippocampus is known to develop representations of this complex structure, forming a so-called "cognitive map". However, the precise biophysical mechanisms driving the emergence of task-relevant maps at the population level remain unclear. We propose a model in which plateau-based learning at the single cell level, combined with reinforcement learning in an agent, leads to latent representational structures codependently evolving with behavior in a task-specific manner. In agreement with recent experimental data, we show that the model successfully develops latent structures essential for task-solving (cue-dependent "splitters") while excluding irrelevant ones. Finally, our model makes testable predictions concerning the co-dependent interactions between split representations and split behavioral policy during their evolution.
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Affiliation(s)
- Ian Cone
- Department of Bioengineering, Imperial College London, London, UK.
| | - Claudia Clopath
- Department of Bioengineering, Imperial College London, London, UK
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15
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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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16
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Bowler JC, Losonczy A. Direct cortical inputs to hippocampal area CA1 transmit complementary signals for goal-directed navigation. Neuron 2023; 111:4071-4085.e6. [PMID: 37816349 DOI: 10.1016/j.neuron.2023.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 07/14/2023] [Accepted: 09/13/2023] [Indexed: 10/12/2023]
Abstract
The subregions of the entorhinal cortex (EC) are conventionally thought to compute dichotomous representations for spatial processing, with the medial EC (MEC) providing a global spatial map and the lateral EC (LEC) encoding specific sensory details of experience. Yet, little is known about the specific types of information EC transmits downstream to the hippocampus. Here, we exploit in vivo sub-cellular imaging to record from EC axons in CA1 while mice perform navigational tasks in virtual reality (VR). We uncover distinct yet overlapping representations of task, location, and context in both MEC and LEC axons. MEC transmitted highly location- and context-specific codes; LEC inputs were biased by ongoing navigational goals. However, during tasks with reliable reward locations, the animals' position could be accurately decoded from either subregion. Our results revise the prevailing dogma about EC information processing, revealing novel ways spatial and non-spatial information is routed and combined upstream of the hippocampus.
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Affiliation(s)
- John C Bowler
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Doctoral Program in Neurobiology and Behavior, Columbia University, New York, NY 10027, USA.
| | - Attila Losonczy
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA.
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17
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Ratigan HC, Krishnan S, Smith S, Sheffield MEJ. A thalamic-hippocampal CA1 signal for contextual fear memory suppression, extinction, and discrimination. Nat Commun 2023; 14:6758. [PMID: 37875465 PMCID: PMC10598272 DOI: 10.1038/s41467-023-42429-6] [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: 03/23/2023] [Accepted: 10/10/2023] [Indexed: 10/26/2023] Open
Abstract
The adaptive regulation of fear memories is a crucial neural function that prevents inappropriate fear expression. Fear memories can be acquired through contextual fear conditioning (CFC) which relies on the hippocampus. The thalamic nucleus reuniens (NR) is necessary to extinguish contextual fear and innervates hippocampal CA1. However, the role of the NR-CA1 pathway in contextual fear is unknown. We developed a head-restrained virtual reality CFC paradigm, and demonstrate that mice can acquire and extinguish context-dependent fear responses. We found that inhibiting the NR-CA1 pathway following CFC lengthens the duration of fearful freezing epochs, increases fear generalization, and delays fear extinction. Using in vivo imaging, we recorded NR-axons innervating CA1 and found that NR-axons become tuned to fearful freezing following CFC. We conclude that the NR-CA1 pathway actively suppresses fear by disrupting contextual fear memory retrieval in CA1 during fearful freezing behavior, a process that also reduces fear generalization and accelerates extinction.
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Affiliation(s)
- Heather C Ratigan
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60615, USA
| | - Seetha Krishnan
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60615, USA
| | - Shai Smith
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL, 60615, USA
| | - Mark E J Sheffield
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA.
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL, 60615, USA.
- Neuroscience Institute, University of Chicago, Chicago, IL, 60615, USA.
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL, 60615, USA.
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18
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Madar A, Dong C, Sheffield M. BTSP, not STDP, Drives Shifts in Hippocampal Representations During Familiarization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.562791. [PMID: 37904999 PMCID: PMC10614909 DOI: 10.1101/2023.10.17.562791] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Synaptic plasticity is widely thought to support memory storage in the brain, but the rules determining impactful synaptic changes in-vivo are not known. We considered the trial-by-trial shifting dynamics of hippocampal place fields (PFs) as an indicator of ongoing plasticity during memory formation. By implementing different plasticity rules in computational models of spiking place cells and comparing to experimentally measured PFs from mice navigating familiar and novel environments, we found that Behavioral-Timescale-Synaptic-Plasticity (BTSP), rather than Hebbian Spike-Timing-Dependent-Plasticity, is the principal mechanism governing PF shifting dynamics. BTSP-triggering events are rare, but more frequent during novel experiences. During exploration, their probability is dynamic: it decays after PF onset, but continually drives a population-level representational drift. Finally, our results show that BTSP occurs in CA3 but is less frequent and phenomenologically different than in CA1. Overall, our study provides a new framework to understand how synaptic plasticity shapes neuronal representations during learning.
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Affiliation(s)
- A.D. Madar
- Department of Neurobiology, Neuroscience Institute, University of Chicago
| | - C. Dong
- Department of Neurobiology, Neuroscience Institute, University of Chicago
- current affiliation: Department of Neurobiology, Stanford University School of Medicine
| | - M.E.J. Sheffield
- Department of Neurobiology, Neuroscience Institute, University of Chicago
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19
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Malone TJ, Tien NW, Ma Y, Cui L, Lyu S, Wang G, Nguyen D, Zhang K, Myroshnychenko MV, Tyan J, Gordon JA, Kupferschmidt DA, Gu Y. A consistent map in the medial entorhinal cortex supports spatial memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.30.560254. [PMID: 37986767 PMCID: PMC10659391 DOI: 10.1101/2023.09.30.560254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
The medial entorhinal cortex (MEC) is hypothesized to function as a cognitive map for memory-guided navigation. How this map develops during learning and influences memory remains unclear. By imaging MEC calcium dynamics while mice successfully learned a novel virtual environment over ten days, we discovered that the dynamics gradually became more spatially consistent and then stabilized. Additionally, grid cells in the MEC not only exhibited improved spatial tuning consistency, but also maintained stable phase relationships, suggesting a network mechanism involving synaptic plasticity and rigid recurrent connectivity to shape grid cell activity during learning. Increased c-Fos expression in the MEC in novel environments further supports the induction of synaptic plasticity. Unsuccessful learning lacked these activity features, indicating that a consistent map is specific for effective spatial memory. Finally, optogenetically disrupting spatial consistency of the map impaired memory-guided navigation in a well-learned environment. Thus, we demonstrate that the establishment of a spatially consistent MEC map across learning both correlates with, and is necessary for, successful spatial memory.
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Affiliation(s)
- Taylor J. Malone
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- These authors contributed equally to this work
| | - Nai-Wen Tien
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- Current address: Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- These authors contributed equally to this work
| | - Yan Ma
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- These authors contributed equally to this work
| | - Lian Cui
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shangru Lyu
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Garret Wang
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Duc Nguyen
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- Current address: Center of Neural Science, New York University, New York, NY, USA
| | - Kai Zhang
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Maxym V. Myroshnychenko
- Integrative Neuroscience Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jean Tyan
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joshua A. Gordon
- Integrative Neuroscience Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
- Office of the Director, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - David A. Kupferschmidt
- Integrative Neuroscience Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yi Gu
- Spatial Navigation and Memory Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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20
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O'Donnell C. Nonlinear slow-timescale mechanisms in synaptic plasticity. Curr Opin Neurobiol 2023; 82:102778. [PMID: 37657186 DOI: 10.1016/j.conb.2023.102778] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 09/03/2023]
Abstract
Learning and memory rely on synapses changing their strengths in response to neural activity. However, there is a substantial gap between the timescales of neural electrical dynamics (1-100 ms) and organism behaviour during learning (seconds-minutes). What mechanisms bridge this timescale gap? What are the implications for theories of brain learning? Here I first cover experimental evidence for slow-timescale factors in plasticity induction. Then I review possible underlying cellular and synaptic mechanisms, and insights from recent computational models that incorporate such slow-timescale variables. I conclude that future progress in understanding brain learning across timescales will require both experimental and computational modelling studies that map out the nonlinearities implemented by both fast and slow plasticity mechanisms at synapses, and crucially, their joint interactions.
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Affiliation(s)
- Cian O'Donnell
- School of Computing, Engineering, and Intelligent Systems, Magee Campus, Ulster University, Derry/Londonderry, UK; School of Computer Science, Electrical and Electronic Engineering, and Engineering Maths, University of Bristol, Bristol, UK.
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21
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Nicoll RA, Schulman H. Synaptic memory and CaMKII. Physiol Rev 2023; 103:2877-2925. [PMID: 37290118 PMCID: PMC10642921 DOI: 10.1152/physrev.00034.2022] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 04/26/2023] [Accepted: 04/30/2023] [Indexed: 06/10/2023] Open
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) and long-term potentiation (LTP) were discovered within a decade of each other and have been inextricably intertwined ever since. However, like many marriages, it has had its up and downs. Based on the unique biochemical properties of CaMKII, it was proposed as a memory molecule before any physiological linkage was made to LTP. However, as reviewed here, the convincing linkage of CaMKII to synaptic physiology and behavior took many decades. New technologies were critical in this journey, including in vitro brain slices, mouse genetics, single-cell molecular genetics, pharmacological reagents, protein structure, and two-photon microscopy, as were new investigators attracted by the exciting challenge. This review tracks this journey and assesses the state of this marriage 40 years on. The collective literature impels us to propose a relatively simple model for synaptic memory involving the following steps that drive the process: 1) Ca2+ entry through N-methyl-d-aspartate (NMDA) receptors activates CaMKII. 2) CaMKII undergoes autophosphorylation resulting in constitutive, Ca2+-independent activity and exposure of a binding site for the NMDA receptor subunit GluN2B. 3) Active CaMKII translocates to the postsynaptic density (PSD) and binds to the cytoplasmic C-tail of GluN2B. 4) The CaMKII-GluN2B complex initiates a structural rearrangement of the PSD that may involve liquid-liquid phase separation. 5) This rearrangement involves the PSD-95 scaffolding protein, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs), and their transmembrane AMPAR-regulatory protein (TARP) auxiliary subunits, resulting in an accumulation of AMPARs in the PSD that underlies synaptic potentiation. 6) The stability of the modified PSD is maintained by the stability of the CaMKII-GluN2B complex. 7) By a process of subunit exchange or interholoenzyme phosphorylation CaMKII maintains synaptic potentiation in the face of CaMKII protein turnover. There are many other important proteins that participate in enlargement of the synaptic spine or modulation of the steps that drive and maintain the potentiation. In this review we critically discuss the data underlying each of the steps. As will become clear, some of these steps are more firmly grounded than others, and we provide suggestions as to how the evidence supporting these steps can be strengthened or, based on the new data, be replaced. Although the journey has been a long one, the prospect of having a detailed cellular and molecular understanding of learning and memory is at hand.
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Affiliation(s)
- Roger A Nicoll
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California, United States
| | - Howard Schulman
- Department of Neurobiology, Stanford University School of Medicine, Stanford, California, United States
- Panorama Research Institute, Sunnyvale, California, United States
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22
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Xiao K, Li Y, Chitwood RA, Magee JC. A critical role for CaMKII in behavioral timescale synaptic plasticity in hippocampal CA1 pyramidal neurons. SCIENCE ADVANCES 2023; 9:eadi3088. [PMID: 37672577 PMCID: PMC10482326 DOI: 10.1126/sciadv.adi3088] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/03/2023] [Indexed: 09/08/2023]
Abstract
Behavioral timescale synaptic plasticity (BTSP) is a type of non-Hebbian synaptic plasticity reported to underlie place field formation. Despite this important function, the molecular mechanisms underlying BTSP are poorly understood. The α-calcium-calmodulin-dependent protein kinase II (αCaMKII) is activated by synaptic transmission-mediated calcium influx, and its subsequent phosphorylation is central to synaptic plasticity. Because the activity of αCaMKII is known to outlast the event triggering phosphorylation, we hypothesized that it could mediate the extended timescale of BTSP. To examine the role of αCaMKII in BTSP, we performed whole-cell in vivo and in vitro recordings in CA1 pyramidal neurons from mice engineered with a point mutation at the autophosphorylation site (T286A) causing accelerated signaling kinetics. Here, we demonstrate a profound deficit in synaptic plasticity, strongly suggesting that αCaMKII signaling is required for BTSP. This study elucidates part of the molecular mechanism of BTSP and provides insight into the function of αCaMKII in place cell formation and ultimately learning and memory.
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Affiliation(s)
- Kuo Xiao
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Yiding Li
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
| | - Raymond A. Chitwood
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
| | - Jeffrey C. Magee
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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23
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Savelli F. Spontaneous dynamics of hippocampal place fields in a model of combinatorial competition among stable inputs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.04.556254. [PMID: 37732194 PMCID: PMC10508775 DOI: 10.1101/2023.09.04.556254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
We present computer simulations illustrating how the plastic integration of spatially stable inputs could contribute to the dynamic character of hippocampal spatial representations. In novel environments of slightly larger size than typical apparatus, the emergence of well-defined place fields in real place cells seems to rely on inputs from normally functioning grid cells. Theoretically, the grid-to-place transformation is possible if a place cell is able to respond selectively to a combination of suitably aligned grids. We previously identified the functional characteristics that allow a synaptic plasticity rule to accomplish this selection by synaptic competition during rat foraging behavior. Here, we show that the synaptic competition can outlast the formation of place fields, contributing to their spatial reorganization over time, when the model is run in larger environments and the topographical/modular organization of grid inputs is taken into account. Co-simulated cells that differ only by their randomly assigned grid inputs display different degrees and kinds of spatial reorganization-ranging from place-field remapping to more subtle in-field changes or lapses in firing. The model predicts a greater number of place fields and propensity for remapping in place cells recorded from more septal regions of the hippocampus and/or in larger environments, motivating future experimental standardization across studies and animal models. In sum, spontaneous remapping could arise from rapid synaptic learning involving inputs that are functionally homogeneous, spatially stable, and minimally stochastic. Significance Statement In both AI and theoretical neuroscience, learning systems often rely on the asymptotic convergence of slow-acting learning rules applied to input spaces that are presumed to be sampled repeatedly, for example over developmental timescales. Place cells of the hippocampus testify to a neural system capable of rapidly encoding cognitive variables-such as the animal's position in space-from limited experience. These internal representations undergo "spontaneous" changes over time, spurring much interest in their cognitive significance and underlying mechanisms. We investigate a model suggesting that some of these changes could be a tradeoff of rapid learning.
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24
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McDermott KD, Frechou MA, Jordan JT, Martin SS, Gonçalves JT. Delayed formation of neural representations of space in aged mice. Aging Cell 2023; 22:e13924. [PMID: 37491802 PMCID: PMC10497831 DOI: 10.1111/acel.13924] [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: 03/29/2023] [Revised: 05/31/2023] [Accepted: 06/20/2023] [Indexed: 07/27/2023] Open
Abstract
Aging is associated with cognitive deficits, with spatial memory being very susceptible to decline. The hippocampal dentate gyrus (DG) is important for processing spatial information in the brain and is particularly vulnerable to aging, yet its sparse activity has led to difficulties in assessing changes in this area. Using in vivo two-photon calcium imaging, we compared DG neuronal activity and representations of space in young and aged mice walking on an unfamiliar treadmill. We found that calcium activity was significantly higher and less tuned to location in aged mice, resulting in decreased spatial information encoded in the DG. However, with repeated exposure to the same treadmill, both spatial tuning and information levels in aged mice became similar to young mice, while activity remained elevated. Our results show that spatial representations of novel environments are impaired in the aged hippocampus and gradually improve with increased familiarity. Moreover, while the aged DG is hyperexcitable, this does not disrupt neural representations of familiar environments.
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Affiliation(s)
- Kelsey D. McDermott
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative MedicineAlbert Einstein College of MedicineBronxNew YorkUSA
| | - M. Agustina Frechou
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative MedicineAlbert Einstein College of MedicineBronxNew YorkUSA
| | - Jake T. Jordan
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative MedicineAlbert Einstein College of MedicineBronxNew YorkUSA
| | - Sunaina S. Martin
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative MedicineAlbert Einstein College of MedicineBronxNew YorkUSA
| | - J. Tiago Gonçalves
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative MedicineAlbert Einstein College of MedicineBronxNew YorkUSA
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25
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Li PY, Roxin A. Rapid memory encoding in a recurrent network model with behavioral time scale synaptic plasticity. PLoS Comput Biol 2023; 19:e1011139. [PMID: 37624848 PMCID: PMC10484462 DOI: 10.1371/journal.pcbi.1011139] [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: 04/29/2023] [Revised: 09/07/2023] [Accepted: 07/10/2023] [Indexed: 08/27/2023] Open
Abstract
Episodic memories are formed after a single exposure to novel stimuli. The plasticity mechanisms underlying such fast learning still remain largely unknown. Recently, it was shown that cells in area CA1 of the hippocampus of mice could form or shift their place fields after a single traversal of a virtual linear track. In-vivo intracellular recordings in CA1 cells revealed that previously silent inputs from CA3 could be switched on when they occurred within a few seconds of a dendritic plateau potential (PP) in the post-synaptic cell, a phenomenon dubbed Behavioral Time-scale Plasticity (BTSP). A recently developed computational framework for BTSP in which the dynamics of synaptic traces related to the pre-synaptic activity and post-synaptic PP are explicitly modelled, can account for experimental findings. Here we show that this model of plasticity can be further simplified to a 1D map which describes changes to the synaptic weights after a single trial. We use a temporally symmetric version of this map to study the storage of a large number of spatial memories in a recurrent network, such as CA3. Specifically, the simplicity of the map allows us to calculate the correlation of the synaptic weight matrix with any given past environment analytically. We show that the calculated memory trace can be used to predict the emergence and stability of bump attractors in a high dimensional neural network model endowed with BTSP.
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Affiliation(s)
- Pan Ye Li
- Centre de Recerca Matemàtica, Barcelona, Spain
| | - Alex Roxin
- Centre de Recerca Matemàtica, Barcelona, Spain
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26
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Michon FX, Laplante I, Bosson A, Robitaille R, Lacaille JC. mTORC1-mediated acquisition of reward-related representations by hippocampal somatostatin interneurons. Mol Brain 2023; 16:55. [PMID: 37400913 DOI: 10.1186/s13041-023-01042-w] [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: 02/27/2023] [Accepted: 06/03/2023] [Indexed: 07/05/2023] Open
Abstract
Plasticity of principal cells and inhibitory interneurons underlies hippocampal memory. Bidirectional modulation of somatostatin cell mTORC1 activity, a crucial translational control mechanism in synaptic plasticity, causes parallel changes in hippocampal CA1 somatostatin interneuron (SOM-IN) long-term potentiation and hippocampus-dependent memory, indicating a key role in learning. However, SOM-IN activity changes and behavioral correlates during learning, and the role of mTORC1 in these processes, remain ill-defined. To address these questions, we used two-photon Ca2+ imaging from SOM-INs during a virtual reality goal-directed spatial memory task in head-fixed control mice (SOM-IRES-Cre mice) or in mice with conditional knockout of Rptor (SOM-Rptor-KO mice) to block mTORC1 activity in SOM-INs. We found that control mice learn the task, but SOM-Raptor-KO mice exhibit a deficit. Also, SOM-IN Ca2+ activity became increasingly related to reward during learning in control mice but not in SOM-Rptor-KO mice. Four types of SOM-IN activity patterns related to reward location were observed, "reward off sustained", "reward off transient", "reward on sustained" and "reward on transient", and these responses showed reorganization after reward relocation in control but not SOM-Rptor-KO mice. Thus, SOM-INs develop mTORC1-dependent reward- related activity during learning. This coding may bi-directionally interact with pyramidal cells and other structures to represent and consolidate reward location.
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Affiliation(s)
- François-Xavier Michon
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Isabel Laplante
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Anthony Bosson
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Richard Robitaille
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada
| | - Jean-Claude Lacaille
- Department of Neurosciences, Center for Interdisciplinary Research on Brain and Learning (CIRCA) and Research Group on Neural Signaling and Circuitry (GRSNC), Université de Montréal, Montreal, QC, H3C 3J7, Canada.
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27
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Forro T, Klausberger T. Differential behavior-related activity of distinct hippocampal interneuron types during odor-associated spatial navigation. Neuron 2023:S0896-6273(23)00380-X. [PMID: 37279749 DOI: 10.1016/j.neuron.2023.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 04/02/2023] [Accepted: 05/10/2023] [Indexed: 06/08/2023]
Abstract
Hippocampal pyramidal cells represent an animal's position in space together with specific contexts and events. However, it is largely unknown how distinct types of GABAergic interneurons contribute to such computations. We recorded from the intermediate CA1 hippocampus of head-fixed mice exhibiting odor-to-place memory associations during navigation in a virtual reality (VR). The presence of an odor cue and its prediction of a different reward location induced a remapping of place cell activity in the virtual maze. Based on this, we performed extracellular recording and juxtacellular labeling of identified interneurons during task performance. The activity of parvalbumin (PV)-expressing basket, but not of PV-expressing bistratified cells, reflected the expected contextual change in the working-memory-related sections of the maze. Some interneurons, including identified cholecystokinin-expressing cells, decreased activity during visuospatial navigation and increased activity during reward. Our findings suggest that distinct types of GABAergic interneuron are differentially involved in cognitive processes of the hippocampus.
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Affiliation(s)
- Thomas Forro
- Division of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria.
| | - Thomas Klausberger
- Division of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria.
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28
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Geiller T, Priestley JB, Losonczy A. A local circuit-basis for spatial navigation and memory processes in hippocampal area CA1. Curr Opin Neurobiol 2023; 79:102701. [PMID: 36878147 PMCID: PMC10020891 DOI: 10.1016/j.conb.2023.102701] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/02/2023] [Accepted: 02/06/2023] [Indexed: 03/06/2023]
Abstract
The hippocampus is a multi-stage neural circuit that is critical for memory formation. Its distinct anatomy has long inspired theories that rely on local interactions between neurons within each subregion in order to perform serial operations important for memory encoding and storage. These local computations have received less attention in CA1 area, the primary output node of the hippocampus, where excitatory neurons are thought to be only very sparsely interconnected. However, recent findings have demonstrated the power of local circuitry in CA1, with evidence for strong functional interactions among excitatory neurons, regulation by diverse inhibitory microcircuits, and novel plasticity rules that can profoundly reshape the hippocampal ensemble code. Here we review how these properties expand the dynamical repertoire of CA1 beyond the confines of feedforward processing, and what implications they have for hippocampo-cortical functions in memory formation.
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Affiliation(s)
- Tristan Geiller
- Department of Neuroscience, Columbia University, New York, NY, 10027, USA; Mortimer B Zuckerman Mind Brain Behavior Institute, New York, NY, 10027, USA. https://twitter.com/tgeiller
| | - James B Priestley
- Department of Neuroscience, Columbia University, New York, NY, 10027, USA; Mortimer B Zuckerman Mind Brain Behavior Institute, New York, NY, 10027, USA; Center for Theoretical Neuroscience, Columbia University, New York, NY, 10027, USA. https://twitter.com/jamespriestley4
| | - Attila Losonczy
- Department of Neuroscience, Columbia University, New York, NY, 10027, USA; Mortimer B Zuckerman Mind Brain Behavior Institute, New York, NY, 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY, 10027, USA.
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29
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Ratigan HC, Krishnan S, Smith S, Sheffield MEJ. Direct Thalamic Inputs to Hippocampal CA1 Transmit a Signal That Suppresses Ongoing Contextual Fear Memory Retrieval. RESEARCH SQUARE 2023:rs.3.rs-2729263. [PMID: 37034716 PMCID: PMC10081386 DOI: 10.21203/rs.3.rs-2729263/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Memory retrieval of fearful experiences is essential for survival but can be maladaptive if not appropriately suppressed. Fear memories can be acquired through contextual fear conditioning (CFC) which relies on the hippocampus. The thalamic subregion Nucleus Reuniens (NR) is necessary for contextual fear extinction and strongly projects to hippocampal subregion CA1. However, the NR-CA1 pathway has not been investigated during behavior, leaving unknown its role in contextual fear memory retrieval. We implement a novel head-restrained virtual reality CFC paradigm and show that inactivation of the NR-CA1 pathway prolongs fearful freezing epochs, induces fear generalization, and delays extinction. We use in vivo sub-cellular imaging to specifically record NR-axons innervating CA1 before and after CFC. We find NR-axons become selectively tuned to freezing only after CFC, and this activity is well-predicted by an encoding model. We conclude that the NR-CA1 pathway actively suppresses fear responses by disrupting ongoing hippocampal-dependent contextual fear memory retrieval.
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Affiliation(s)
- Heather C. Ratigan
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
| | - Seetha Krishnan
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
| | - Shai Smith
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL 60615, USA
| | - Mark E. J. Sheffield
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
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30
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Ratigan HC, Krishnan S, Smith S, Sheffield MEJ. Direct Thalamic Inputs to Hippocampal CA1 Transmit a Signal That Suppresses Ongoing Contextual Fear Memory Retrieval. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534420. [PMID: 37034812 PMCID: PMC10081195 DOI: 10.1101/2023.03.27.534420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Memory retrieval of fearful experiences is essential for survival but can be maladaptive if not appropriately suppressed. Fear memories can be acquired through contextual fear conditioning (CFC) which relies on the hippocampus. The thalamic subregion Nucleus Reuniens (NR) is necessary for contextual fear extinction and strongly projects to hippocampal subregion CA1. However, the NR-CA1 pathway has not been investigated during behavior, leaving unknown its role in contextual fear memory retrieval. We implement a novel head-restrained virtual reality CFC paradigm and show that inactivation of the NR-CA1 pathway prolongs fearful freezing epochs, induces fear generalization, and delays extinction. We use in vivo sub-cellular imaging to specifically record NR-axons innervating CA1 before and after CFC. We find NR-axons become selectively tuned to freezing only after CFC, and this activity is well-predicted by an encoding model. We conclude that the NR-CA1 pathway actively suppresses fear responses by disrupting ongoing hippocampal-dependent contextual fear memory retrieval.
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Affiliation(s)
- Heather C. Ratigan
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
| | - Seetha Krishnan
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
| | - Shai Smith
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL 60615, USA
| | - Mark E. J. Sheffield
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
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31
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McDermott KD, Frechou MA, Jordan JT, Martin SS, Gonçalves JT. Delayed formation of neural representations of space in aged mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.03.531021. [PMID: 37034736 PMCID: PMC10081265 DOI: 10.1101/2023.03.03.531021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Aging is associated with cognitive deficits, with spatial memory being very susceptible to decline. The hippocampal dentate gyrus (DG) is important for processing spatial information in the brain and is particularly vulnerable to aging, yet its sparse activity has led to difficulties in assessing changes in this area. Using in vivo two-photon calcium imaging, we compared DG neuronal activity and representations of space in young and aged mice walking on an unfamiliar treadmill. We found that calcium activity was significantly higher and less tuned to location in aged mice, resulting in decreased spatial information encoded in the DG. However, with repeated exposure to the same treadmill, both spatial tuning and information levels in aged mice became similar to young mice, while activity remained elevated. Our results show that spatial representations of novel environments are impaired in the aged hippocampus and gradually improve with increased familiarity. Moreover, while the aged DG is hyperexcitable, this does not disrupt neural representations of familiar environments.
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Affiliation(s)
- Kelsey D. McDermott
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - M. Agustina Frechou
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Jake T. Jordan
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Sunaina S. Martin
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - J. Tiago Gonçalves
- Dominick P. Purpura Department of Neuroscience and Gottesmann Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY
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32
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Aru J, Drüke M, Pikamäe J, Larkum ME. Mental navigation and the neural mechanisms of insight. Trends Neurosci 2023; 46:100-109. [PMID: 36462993 DOI: 10.1016/j.tins.2022.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022]
Abstract
How do new ideas come about? The central hypothesis presented here states that insights might happen during mental navigation and correspond to rapid plasticity at the cellular level. We highlight the differences between neocortical and hippocampal mechanisms of insight. We argue that the suddenness of insight can be related to the sudden emergence of place fields in the hippocampus. According to our hypothesis, insights are supported by a state of mind-wandering that can be tied to the process of combining knowledge pieces during sharp-wave ripples (SWRs). Our framework connects the dots between research on creativity, mental navigation, and specific synaptic plasticity mechanisms in the hippocampus.
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Affiliation(s)
- Jaan Aru
- Institute of Computer Science, University of Tartu, Tartu, Estonia.
| | - Moritz Drüke
- Institute of Biology, Humboldt University Berlin, Berlin, Germany
| | - Juhan Pikamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Matthew E Larkum
- Institute of Biology, Humboldt University Berlin, Berlin, Germany; Neurocure Center for Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
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33
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Shin J, Lee HW, Jin SW, Lee I. Subtle visual change in a virtual environment induces heterogeneous remapping systematically in CA1, but not CA3. Cell Rep 2022; 41:111823. [PMID: 36516763 DOI: 10.1016/j.celrep.2022.111823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 08/10/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Environmental change may lead to new memories or modify old ones, but the underlying neural mechanisms are largely unclear. We recorded hippocampal place cells simultaneously from CA1 and CA3 in a virtual reality environment. Compared with CA1, place cells in CA3 are more tolerant of individual landmark changes but undergo orthogonal changes to code distinctively different environments. As visual noise (virtual fog) is introduced to a visually enriched environment, place cells in CA1 split into two subpopulations: in one, place cells maintain their field locations while changing their firing rates to reflect sensory changes; in the other, place cells exhibit global remapping in response to the contextual change. In contrast, place cells in CA3 exhibit mainly rate remapping under the same conditions. Our results suggest that CA1 may simultaneously represent heterogeneous maps of the same environment when subtle visual noise induces both sensory and contextual changes.
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Affiliation(s)
- Jhoseph Shin
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Hyun-Woo Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Seung-Woo Jin
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea.
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34
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Lee SM, Shin J, Lee I. Significance of visual scene-based learning in the hippocampal systems across mammalian species. Hippocampus 2022; 33:505-521. [PMID: 36458555 DOI: 10.1002/hipo.23483] [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: 09/05/2022] [Revised: 10/26/2022] [Accepted: 11/19/2022] [Indexed: 12/04/2022]
Abstract
The hippocampus and its associated cortical regions in the medial temporal lobe play essential roles when animals form a cognitive map and use it to achieve their goals. As the nature of map-making involves sampling different local views of the environment and putting them together in a spatially cohesive way, visual scenes are essential ingredients in the formative process of cognitive maps. Visual scenes also serve as important cues during information retrieval from the cognitive map. Research in humans has shown that there are regions in the brain that selectively process scenes and that the hippocampus is involved in scene-based memory tasks. The neurophysiological correlates of scene-based information processing in the hippocampus have been reported as "spatial view cells" in nonhuman primates. Like primates, it is widely accepted that rodents also use visual scenes in their background for spatial navigation and other kinds of problems. However, in rodents, it is not until recently that researchers examined the neural correlates of the hippocampus from the perspective of visual scene-based information processing. With the advent of virtual reality (VR) systems, it has been demonstrated that place cells in the hippocampus exhibit remarkably similar firing correlates in the VR environment compared with that of the real-world environment. Despite some limitations, the new trend of studying hippocampal functions in a visually controlled environment has the potential to allow investigation of the input-output relationships of network functions and experimental testing of traditional computational predictions more rigorously by providing well-defined visual stimuli. As scenes are essential for navigation and episodic memory in humans, further investigation of the rodents' hippocampal systems in scene-based tasks will provide a critical functional link across different mammalian species.
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Affiliation(s)
- Su-Min Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Jhoseph Shin
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
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35
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Entorhinal cortex directs learning-related changes in CA1 representations. Nature 2022; 611:554-562. [DOI: 10.1038/s41586-022-05378-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 09/20/2022] [Indexed: 11/16/2022]
Abstract
AbstractLearning-related changes in brain activity are thought to underlie adaptive behaviours1,2. For instance, the learning of a reward site by rodents requires the development of an over-representation of that location in the hippocampus3–6. How this learning-related change occurs remains unknown. Here we recorded hippocampal CA1 population activity as mice learned a reward location on a linear treadmill. Physiological and pharmacological evidence suggests that the adaptive over-representation required behavioural timescale synaptic plasticity (BTSP)7. BTSP is known to be driven by dendritic voltage signals that we proposed were initiated by input from entorhinal cortex layer 3 (EC3). Accordingly, the CA1 over-representation was largely removed by optogenetic inhibition of EC3 activity. Recordings from EC3 neurons revealed an activity pattern that could provide an instructive signal directing BTSP to generate the over-representation. Consistent with this function, our observations show that exposure to a second environment possessing a prominent reward-predictive cue resulted in both EC3 activity and CA1 place field density that were more elevated at the cue than at the reward. These data indicate that learning-related changes in the hippocampus are produced by synaptic plasticity directed by an instructive signal from the EC3 that seems to be specifically adapted to the behaviourally relevant features of the environment.
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