1
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Jellinger AL, Suthard RL, Yuan B, Surets M, Ruesch EA, Caban AJ, Liu S, Shpokayte M, Ramirez S. Chronic activation of a negative engram induces behavioral and cellular abnormalities. eLife 2024; 13:RP96281. [PMID: 38990919 PMCID: PMC11239178 DOI: 10.7554/elife.96281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
Negative memories engage a brain and body-wide stress response in humans that can alter cognition and behavior. Prolonged stress responses induce maladaptive cellular, circuit, and systems-level changes that can lead to pathological brain states and corresponding disorders in which mood and memory are affected. However, it is unclear if repeated activation of cells processing negative memories induces similar phenotypes in mice. In this study, we used an activity-dependent tagging method to access neuronal ensembles and assess their molecular characteristics. Sequencing memory engrams in mice revealed that positive (male-to-female exposure) and negative (foot shock) cells upregulated genes linked to anti- and pro-inflammatory responses, respectively. To investigate the impact of persistent activation of negative engrams, we chemogenetically activated them in the ventral hippocampus over 3 months and conducted anxiety and memory-related tests. Negative engram activation increased anxiety behaviors in both 6- and 14-month-old mice, reduced spatial working memory in older mice, impaired fear extinction in younger mice, and heightened fear generalization in both age groups. Immunohistochemistry revealed changes in microglial and astrocytic structure and number in the hippocampus. In summary, repeated activation of negative memories induces lasting cellular and behavioral abnormalities in mice, offering insights into the negative effects of chronic negative thinking-like behaviors on human health.
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Affiliation(s)
- Alexandra L Jellinger
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston UniversityBostonUnited States
| | - Rebecca L Suthard
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston UniversityBostonUnited States
- Graduate Program for Neuroscience, Boston UniversityBostonUnited States
| | - Bingbing Yuan
- Whitehead Institute for Biomedical Research, MITCambridgeUnited States
| | - Michelle Surets
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston UniversityBostonUnited States
| | - Evan A Ruesch
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston UniversityBostonUnited States
| | - Albit J Caban
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston UniversityBostonUnited States
- Graduate Program for Neuroscience, Boston UniversityBostonUnited States
| | - Shawn Liu
- Department of Physiology and Cellular Biophysics, Columbia University Medical CenterNew YorkUnited States
| | - Monika Shpokayte
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston UniversityBostonUnited States
- Graduate Program for Neuroscience, Boston UniversityBostonUnited States
| | - Steve Ramirez
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston UniversityBostonUnited States
- Neurophotonics Center, and Photonics Center, Boston UniversityBostonUnited States
- Department of Biomedical Engineering, Boston UniversityBostonUnited States
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2
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McNaughton N, Bannerman D. The homogenous hippocampus: How hippocampal cells process available and potential goals. Prog Neurobiol 2024; 240:102653. [PMID: 38960002 DOI: 10.1016/j.pneurobio.2024.102653] [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: 01/04/2024] [Revised: 04/25/2024] [Accepted: 06/24/2024] [Indexed: 07/05/2024]
Abstract
We present here a view of the firing patterns of hippocampal cells that is contrary, both functionally and anatomically, to conventional wisdom. We argue that the hippocampus responds to efference copies of goals encoded elsewhere; and that it uses these to detect and resolve conflict or interference between goals in general. While goals can involve space, hippocampal cells do not encode spatial (or other special types of) memory, as such. We also argue that the transverse circuits of the hippocampus operate in an essentially homogeneous way along its length. The apparently different functions of different parts (e.g. memory retrieval versus anxiety) result from the different (situational/motivational) inputs on which those parts perform the same fundamental computational operations. On this view, the key role of the hippocampus is the iterative adjustment, via Papez-like circuits, of synaptic weights in cell assemblies elsewhere.
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Affiliation(s)
- Neil McNaughton
- Department of Psychology and Brain Health Research Centre, University of Otago, POB56, Dunedin 9054, New Zealand.
| | - David Bannerman
- Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, England, UK
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3
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Valdivia G, Espinosa N, Lara-Vasquez A, Caneo M, Inostroza M, Born J, Fuentealba P. Sleep-dependent decorrelation of hippocampal spatial representations. iScience 2024; 27:110076. [PMID: 38883845 PMCID: PMC11176648 DOI: 10.1016/j.isci.2024.110076] [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: 10/16/2023] [Revised: 02/02/2024] [Accepted: 05/19/2024] [Indexed: 06/18/2024] Open
Abstract
Neuronal ensembles are crucial for episodic memory and spatial mapping. Sleep, particularly non-REM (NREM), is vital for memory consolidation, as it triggers plasticity mechanisms through brain oscillations that reactivate neuronal ensembles. Here, we assessed their role in consolidating hippocampal spatial representations during sleep. We recorded hippocampus activity in rats performing a spatial object-place recognition (OPR) memory task, during encoding and retrieval periods, separated by intervening sleep. Successful OPR retrieval correlated with NREM duration, during which cortical oscillations decreased in power and density as well as neuronal spiking, suggesting global downregulation of network excitability. However, neurons encoding specific spatial locations (i.e., place cells) or objects during OPR showed stronger synchrony with brain oscillations compared to non-encoding neurons, and the stability of spatial representations decreased proportionally with NREM duration. Our findings suggest that NREM sleep may promote flexible remapping in hippocampal ensembles, potentially aiding memory consolidation and adaptation to novel spatial contexts.
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Affiliation(s)
- Gonzalo Valdivia
- Laboratory of Neural Circuits, Departamento de Psiquiatria, Facultad de Medicina, Pontificia Universidad Catolica de Chile. Santiago, Chile
| | - Nelson Espinosa
- Laboratory of Neural Circuits, Departamento de Psiquiatria, Facultad de Medicina, Pontificia Universidad Catolica de Chile. Santiago, Chile
| | - Ariel Lara-Vasquez
- Laboratory of Neural Circuits, Departamento de Psiquiatria, Facultad de Medicina, Pontificia Universidad Catolica de Chile. Santiago, Chile
| | - Mauricio Caneo
- Laboratory of Neural Circuits, Departamento de Psiquiatria, Facultad de Medicina, Pontificia Universidad Catolica de Chile. Santiago, Chile
| | - Marion Inostroza
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Jan Born
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Pablo Fuentealba
- Laboratory of Neural Circuits, Departamento de Psiquiatria, Facultad de Medicina, Pontificia Universidad Catolica de Chile. Santiago, Chile
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4
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Choucry A, Nomoto M, Inokuchi K. Engram mechanisms of memory linking and identity. Nat Rev Neurosci 2024; 25:375-392. [PMID: 38664582 DOI: 10.1038/s41583-024-00814-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2024] [Indexed: 05/25/2024]
Abstract
Memories are thought to be stored in neuronal ensembles referred to as engrams. Studies have suggested that when two memories occur in quick succession, a proportion of their engrams overlap and the memories become linked (in a process known as prospective linking) while maintaining their individual identities. In this Review, we summarize the key principles of memory linking through engram overlap, as revealed by experimental and modelling studies. We describe evidence of the involvement of synaptic memory substrates, spine clustering and non-linear neuronal capacities in prospective linking, and suggest a dynamic somato-synaptic model, in which memories are shared between neurons yet remain separable through distinct dendritic and synaptic allocation patterns. We also bring into focus retrospective linking, in which memories become associated after encoding via offline reactivation, and discuss key temporal and mechanistic differences between prospective and retrospective linking, as well as the potential differences in their cognitive outcomes.
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Affiliation(s)
- Ali Choucry
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Masanori Nomoto
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan
- Japan Agency for Medical Research and Development (AMED), Tokyo, Japan
| | - Kaoru Inokuchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan.
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5
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Mocle AJ, Ramsaran AI, Jacob AD, Rashid AJ, Luchetti A, Tran LM, Richards BA, Frankland PW, Josselyn SA. Excitability mediates allocation of pre-configured ensembles to a hippocampal engram supporting contextual conditioned threat in mice. Neuron 2024; 112:1487-1497.e6. [PMID: 38447576 PMCID: PMC11065628 DOI: 10.1016/j.neuron.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 01/08/2024] [Accepted: 02/05/2024] [Indexed: 03/08/2024]
Abstract
Little is understood about how engrams, sparse groups of neurons that store memories, are formed endogenously. Here, we combined calcium imaging, activity tagging, and optogenetics to examine the role of neuronal excitability and pre-existing functional connectivity on the allocation of mouse cornu ammonis area 1 (CA1) hippocampal neurons to an engram ensemble supporting a contextual threat memory. Engram neurons (high activity during recall or TRAP2-tagged during training) were more active than non-engram neurons 3 h (but not 24 h to 5 days) before training. Consistent with this, optogenetically inhibiting scFLARE2-tagged neurons active in homecage 3 h, but not 24 h, before conditioning disrupted memory retrieval, indicating that neurons with higher pre-training excitability were allocated to the engram. We also observed stable pre-configured functionally connected sub-ensembles of neurons whose activity cycled over days. Sub-ensembles that were more active before training were allocated to the engram, and their functional connectivity increased at training. Therefore, both neuronal excitability and pre-configured functional connectivity mediate allocation to an engram ensemble.
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Affiliation(s)
- Andrew J Mocle
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Adam I Ramsaran
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Alexander D Jacob
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Asim J Rashid
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada
| | - Alessandro Luchetti
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada
| | - Lina M Tran
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada; Vector Institute, Toronto, ON M5G 1M1, Canada
| | | | - Paul W Frankland
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada
| | - Sheena A Josselyn
- Program in Neurosciences & Mental Health, Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Psychology, University of Toronto, Toronto, ON M5G 1X8, Canada.
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6
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Sortman BW, Rakela S, Paprotna S, Cerci B, Warren BL. Nucleus accumbens neuronal ensembles vary with cocaine reinforcement in male and female rats. Addict Biol 2024; 29:e13397. [PMID: 38711205 PMCID: PMC11074382 DOI: 10.1111/adb.13397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 03/08/2024] [Accepted: 04/03/2024] [Indexed: 05/08/2024]
Abstract
Neuronal ensembles in the medial prefrontal cortex mediate cocaine self-administration via projections to the nucleus accumbens. We have recently shown that neuronal ensembles in the prelimbic cortex form rapidly to mediate cocaine self-administration. However, the role of neuronal ensembles within the nucleus accumbens in initial cocaine-seeking behaviour remains unknown. Here, we sought to expand the current literature by testing the necessity of the cocaine self-administration ensemble in the nucleus accumbens core (NAcCore) 1 day after male and female rats acquire cocaine self-administration by using the Daun02 inactivation procedure. We found that disrupting the NAcCore ensembles after a no-cocaine reward-seeking test increased subsequent cocaine seeking, while disrupting NAcCore ensembles following a cocaine self-administration session decreased subsequent cocaine seeking. We then characterized neuronal cell type in the NAcCore using RNAscope in situ hybridization. In the no-cocaine session, we saw reduced dopamine D1 type neuronal activation, while in the cocaine self-administration session, we found preferential dopamine D1 type neuronal activity in the NAcCore.
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Affiliation(s)
- Bo W. Sortman
- Department of PharmacodynamicsUniversity of FloridaGainesvilleFloridaUSA
| | - Samantha Rakela
- Department of PharmacodynamicsUniversity of FloridaGainesvilleFloridaUSA
| | - Sarah Paprotna
- Department of PharmacodynamicsUniversity of FloridaGainesvilleFloridaUSA
| | - Berk Cerci
- Department of PharmacodynamicsUniversity of FloridaGainesvilleFloridaUSA
| | - Brandon L. Warren
- Department of PharmacodynamicsUniversity of FloridaGainesvilleFloridaUSA
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7
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Chettih SN, Mackevicius EL, Hale S, Aronov D. Barcoding of episodic memories in the hippocampus of a food-caching bird. Cell 2024; 187:1922-1935.e20. [PMID: 38554707 PMCID: PMC11015962 DOI: 10.1016/j.cell.2024.02.032] [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: 07/18/2023] [Revised: 11/28/2023] [Accepted: 02/23/2024] [Indexed: 04/02/2024]
Abstract
The hippocampus is critical for episodic memory. Although hippocampal activity represents place and other behaviorally relevant variables, it is unclear how it encodes numerous memories of specific events in life. To study episodic coding, we leveraged the specialized behavior of chickadees-food-caching birds that form memories at well-defined moments in time whenever they cache food for subsequent retrieval. Our recordings during caching revealed very sparse, transient barcode-like patterns of firing across hippocampal neurons. Each "barcode" uniquely represented a caching event and transiently reactivated during the retrieval of that specific cache. Barcodes co-occurred with the conventional activity of place cells but were uncorrelated even for nearby cache locations that had similar place codes. We propose that animals recall episodic memories by reactivating hippocampal barcodes. Similarly to computer hash codes, these patterns assign unique identifiers to different events and could be a mechanism for rapid formation and storage of many non-interfering memories.
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Affiliation(s)
- Selmaan N Chettih
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Emily L Mackevicius
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Basis Research Institute, New York, NY 10027, USA
| | - Stephanie Hale
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Dmitriy Aronov
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA.
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8
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Lopez MR, Wasberg SMH, Gagliardi CM, Normandin ME, Muzzio IA. Mystery of the memory engram: History, current knowledge, and unanswered questions. Neurosci Biobehav Rev 2024; 159:105574. [PMID: 38331127 DOI: 10.1016/j.neubiorev.2024.105574] [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: 09/18/2023] [Revised: 12/22/2023] [Accepted: 02/03/2024] [Indexed: 02/10/2024]
Abstract
The quest to understand the memory engram has intrigued humans for centuries. Recent technological advances, including genetic labelling, imaging, optogenetic and chemogenetic techniques, have propelled the field of memory research forward. These tools have enabled researchers to create and erase memory components. While these innovative techniques have yielded invaluable insights, they often focus on specific elements of the memory trace. Genetic labelling may rely on a particular immediate early gene as a marker of activity, optogenetics may activate or inhibit one specific type of neuron, and imaging may capture activity snapshots in a given brain region at specific times. Yet, memories are multifaceted, involving diverse arrays of neuronal subpopulations, circuits, and regions that work in concert to create, store, and retrieve information. Consideration of contributions of both excitatory and inhibitory neurons, micro and macro circuits across brain regions, the dynamic nature of active ensembles, and representational drift is crucial for a comprehensive understanding of the complex nature of memory.
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Affiliation(s)
- M R Lopez
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - S M H Wasberg
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - C M Gagliardi
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - M E Normandin
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - I A Muzzio
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA.
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9
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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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10
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Yuste R, Cossart R, Yaksi E. Neuronal ensembles: Building blocks of neural circuits. Neuron 2024; 112:875-892. [PMID: 38262413 PMCID: PMC10957317 DOI: 10.1016/j.neuron.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/07/2023] [Accepted: 12/13/2023] [Indexed: 01/25/2024]
Abstract
Neuronal ensembles, defined as groups of neurons displaying recurring patterns of coordinated activity, represent an intermediate functional level between individual neurons and brain areas. Novel methods to measure and optically manipulate the activity of neuronal populations have provided evidence of ensembles in the neocortex and hippocampus. Ensembles can be activated intrinsically or in response to sensory stimuli and play a causal role in perception and behavior. Here we review ensemble phenomenology, developmental origin, biophysical and synaptic mechanisms, and potential functional roles across different brain areas and species, including humans. As modular units of neural circuits, ensembles could provide a mechanistic underpinning of fundamental brain processes, including neural coding, motor planning, decision-making, learning, and adaptability.
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Affiliation(s)
- Rafael Yuste
- NeuroTechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA.
| | - Rosa Cossart
- Inserm, INMED, Turing Center for Living Systems Aix-Marseille University, Marseille, France.
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway; Koç University Research Center for Translational Medicine, Koç University School of Medicine, Istanbul, Turkey.
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11
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Vasudevan K, Hassell JE, Maren S. Hippocampal Engrams and Contextual Memory. ADVANCES IN NEUROBIOLOGY 2024; 38:45-66. [PMID: 39008010 DOI: 10.1007/978-3-031-62983-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Memories are not formed in a vacuum and often include rich details about the time and place in which events occur. Contextual stimuli promote the retrieval of events that have previously occurred in the encoding context and limit the retrieval of context-inappropriate information. Contexts that are associated with traumatic or harmful events both directly elicit fear and serve as reminders of aversive events associated with trauma. It has long been appreciated that the hippocampus is involved in contextual learning and memory and is central to contextual fear conditioning. However, little is known about the underlying neuronal mechanisms underlying the encoding and retrieval of contextual fear memories. Recent advancements in neuronal labeling methods, including activity-dependent tagging of cellular ensembles encoding memory ("engrams"), provide unique insight into the neural substrates of memory in the hippocampus. Moreover, these methods allow for the selective manipulation of memory ensembles. Attenuating or erasing fear memories may have considerable therapeutic value for patients with post-traumatic stress disorder or other trauma- or stressor-related conditions. In this chapter, we review the role of the hippocampus in contextual fear conditioning in rodents and explore recent work implicating hippocampal ensembles in the encoding and retrieval of aversive memories.
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Affiliation(s)
- Krithika Vasudevan
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, TX, USA
| | - James E Hassell
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, TX, USA
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, TX, USA.
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12
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Andreoli L, Tanaka KZ. What Can Hippocampal Engrams Tell Us About Encoding Spatial Navigation? ADVANCES IN NEUROBIOLOGY 2024; 38:195-214. [PMID: 39008017 DOI: 10.1007/978-3-031-62983-9_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
The hippocampus is indispensable for episodic memories, but its particular role in the process is still unclear. This chapter briefly overviews past studies focusing on place cells and memory engrams, highlighting their potential roles in spatial navigation. Future work reconciling these two lines of studies would provide a comprehensive view of the specific contribution of the hippocampus and a better understanding of how memory engrams support memory.
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Affiliation(s)
- Lorena Andreoli
- Okinawa Institute of Science and Technology Graduate University (OIST), Memory Research Unit, Okinawa, Japan
| | - Kazumasa Z Tanaka
- Okinawa Institute of Science and Technology Graduate University (OIST), Memory Research Unit, Okinawa, Japan.
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13
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Yelhekar TD, Meng M, Doupe J, Lin Y. All IEGs Are Not Created Equal-Molecular Sorting Within the Memory Engram. ADVANCES IN NEUROBIOLOGY 2024; 38:81-109. [PMID: 39008012 DOI: 10.1007/978-3-031-62983-9_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
When neurons are recruited to form the memory engram, they are driven to activate the expression of a series of immediate-early genes (IEGs). While these IEGs have been used relatively indiscriminately to identify the so-called engram neurons, recent research has demonstrated that different IEG ensembles can be physically and functionally distinct within the memory engram. This inherent heterogeneity of the memory engram is driven by the diversity in the functions and distributions of different IEGs. This process, which we call molecular sorting, is analogous to sorting the entire population of engram neurons into different sub-engrams molecularly defined by different IEGs. In this chapter, we will describe the molecular sorting process by systematically reviewing published work on engram ensemble cells defined by the following four major IEGs: Fos, Npas4, Arc, and Egr1. By comparing and contrasting these likely different components of the memory engram, we hope to gain a better understanding of the logic and significance behind the molecular sorting process for memory functions.
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Affiliation(s)
- Tushar D Yelhekar
- Department of Psychiatry, O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Meizhen Meng
- Department of Psychiatry, O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Neuroscience Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joslyn Doupe
- Neuroscience Graduate Program, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Yingxi Lin
- Department of Psychiatry, O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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14
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Liang M, Jian T, Tao J, Wang X, Wang R, Jin W, Chen Q, Yao J, Zhao Z, Yang X, Xiao J, Yang Z, Liao X, Chen X, Wang L, Qin H. Hypothalamic supramammillary neurons that project to the medial septum modulate wakefulness in mice. Commun Biol 2023; 6:1255. [PMID: 38087004 PMCID: PMC10716381 DOI: 10.1038/s42003-023-05637-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
The hypothalamic supramammillary nucleus (SuM) plays a crucial role in controlling wakefulness, but the downstream target regions participating in this control process remain unknown. Here, using circuit-specific fiber photometry and single-neuron electrophysiology together with electroencephalogram, electromyogram and behavioral recordings, we find that approximately half of SuM neurons that project to the medial septum (MS) are wake-active. Optogenetic stimulation of axonal terminals of SuM-MS projection induces a rapid and reliable transition to wakefulness from non-rapid-eye movement or rapid-eye movement sleep, and chemogenetic activation of SuMMS projecting neurons significantly increases wakefulness time and prolongs latency to sleep. Consistently, chemogenetically inhibiting these neurons significantly reduces wakefulness time and latency to sleep. Therefore, these results identify the MS as a functional downstream target of SuM and provide evidence for the modulation of wakefulness by this hypothalamic-septal projection.
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Affiliation(s)
- Mengru Liang
- Department of Anatomy, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China
| | - Tingliang Jian
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jie Tao
- Advanced Institute for Brain and Intelligence, School of Medicine, Guangxi University, Nanning, 530004, China
| | - Xia Wang
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Rui Wang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Wenjun Jin
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Qianwei Chen
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Jiwei Yao
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Zhikai Zhao
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Xinyu Yang
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Jingyu Xiao
- Department of Anesthesiology, Chongqing University Cancer Hospital, Chongqing, 400030, China
| | - Zhiqi Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Xiang Liao
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, 400044, China
| | - Xiaowei Chen
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, 400038, China.
- Chongqing Institute for Brain and Intelligence, Guangyang Bay Laboratory, Chongqing, 400064, China.
| | - Liecheng Wang
- Department of Anatomy, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, China.
| | - Han Qin
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, 400044, China.
- Chongqing Institute for Brain and Intelligence, Guangyang Bay Laboratory, Chongqing, 400064, China.
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15
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Friedenberger Z, Harkin E, Tóth K, Naud R. Silences, spikes and bursts: Three-part knot of the neural code. J Physiol 2023; 601:5165-5193. [PMID: 37889516 DOI: 10.1113/jp281510] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 09/28/2023] [Indexed: 10/28/2023] Open
Abstract
When a neuron breaks silence, it can emit action potentials in a number of patterns. Some responses are so sudden and intense that electrophysiologists felt the need to single them out, labelling action potentials emitted at a particularly high frequency with a metonym - bursts. Is there more to bursts than a figure of speech? After all, sudden bouts of high-frequency firing are expected to occur whenever inputs surge. The burst coding hypothesis advances that the neural code has three syllables: silences, spikes and bursts. We review evidence supporting this ternary code in terms of devoted mechanisms for burst generation, synaptic transmission and synaptic plasticity. We also review the learning and attention theories for which such a triad is beneficial.
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Affiliation(s)
- Zachary Friedenberger
- Brain and Mind Institute, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Neural Dynamics and Artifical Intelligence, Department of Physics, University of Ottawa, Ottawa, Ontario, Ottawa
| | - Emerson Harkin
- Brain and Mind Institute, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Katalin Tóth
- Brain and Mind Institute, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Richard Naud
- Brain and Mind Institute, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Neural Dynamics and Artifical Intelligence, Department of Physics, University of Ottawa, Ottawa, Ontario, Ottawa
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16
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Lacagnina AF, Dong TN, Iyer RR, Khan S, Mohamed MK, Clem RL. Ventral hippocampal interneurons govern extinction and relapse of contextual associations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.28.568835. [PMID: 38077077 PMCID: PMC10705382 DOI: 10.1101/2023.11.28.568835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Contextual associations are critical for survival but must be extinguished when new conditions render them nonproductive. By most accounts, extinction forms a new memory that competes with the original association for control over behavior, but the mechanisms underlying this competition remain largely enigmatic. Here we find the retrieval of contextual fear conditioning and extinction yield contrasting patterns of activity in prefrontal cortex and ventral hippocampus. Within ventral CA1, activation of somatostatin-expressing interneurons (SST-INs) occurs preferentially during extinction retrieval and correlates with differences in input synaptic transmission. Optogenetic manipulation of these cells but not parvalbumin interneurons (PV-INs) elicits bidirectional changes in fear expression following extinction, and the ability of SST-INs to gate fear is specific to the context in which extinction was acquired. A similar pattern of results was obtained following reward-based extinction. These data show that ventral hippocampal SST-INs are critical for extinguishing prior associations and thereby gate relapse of both aversive and appetitive responses.
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17
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Berdugo‐Vega G, Dhingra S, Calegari F. Sharpening the blades of the dentate gyrus: how adult-born neurons differentially modulate diverse aspects of hippocampal learning and memory. EMBO J 2023; 42:e113524. [PMID: 37743770 PMCID: PMC11059975 DOI: 10.15252/embj.2023113524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 06/19/2023] [Accepted: 08/18/2023] [Indexed: 09/26/2023] Open
Abstract
For decades, the mammalian hippocampus has been the focus of cellular, anatomical, behavioral, and computational studies aimed at understanding the fundamental mechanisms underlying cognition. Long recognized as the brain's seat for learning and memory, a wealth of knowledge has been accumulated on how the hippocampus processes sensory input, builds complex associations between objects, events, and space, and stores this information in the form of memories to be retrieved later in life. However, despite major efforts, our understanding of hippocampal cognitive function remains fragmentary, and models trying to explain it are continually revisited. Here, we review the literature across all above-mentioned domains and offer a new perspective by bringing attention to the most distinctive, and generally neglected, feature of the mammalian hippocampal formation, namely, the structural separability of the two blades of the dentate gyrus into "supra-pyramidal" and "infra-pyramidal". Next, we discuss recent reports supporting differential effects of adult neurogenesis in the regulation of mature granule cell activity in these two blades. We propose a model for how differences in connectivity and adult neurogenesis in the two blades can potentially provide a substrate for subtly different cognitive functions.
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Affiliation(s)
- Gabriel Berdugo‐Vega
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
- Present address:
Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale Lausanne (EPFL)LausanneSwitzerland
| | - Shonali Dhingra
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Federico Calegari
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
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18
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Power SD, Stewart E, Zielke LG, Byrne EP, Douglas A, Ortega-de San Luis C, Lynch L, Ryan TJ. Immune activation state modulates infant engram expression across development. SCIENCE ADVANCES 2023; 9:eadg9921. [PMID: 37939176 PMCID: PMC10631722 DOI: 10.1126/sciadv.adg9921] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
Infantile amnesia is possibly the most ubiquitous form of memory loss in mammals. We investigated how memories are stored in the brain throughout development by integrating engram labeling technology with mouse models of infantile amnesia. Here, we found a phenomenon in which male offspring in maternal immune activation models of autism spectrum disorder do not experience infantile amnesia. Maternal immune activation altered engram ensemble size and dendritic spine plasticity. We rescued the same apparently forgotten infantile memories in neurotypical mice by optogenetically reactivating dentate gyrus engram cells labeled during complex experiences in infancy. Furthermore, we permanently reinstated lost infantile memories by artificially updating the memory engram, demonstrating that infantile amnesia is a reversible process. Our findings suggest not only that infantile amnesia is due to a reversible retrieval deficit in engram expression but also that immune activation during development modulates innate, and reversible, forgetting switches that determine whether infantile amnesia will occur.
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Affiliation(s)
- Sarah D. Power
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
| | - Erika Stewart
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Louisa G. Zielke
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Eric P. Byrne
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - Aaron Douglas
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Clara Ortega-de San Luis
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Lydia Lynch
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Tomás J. Ryan
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
- Trinity College Institute for Neuroscience, Trinity College Dublin, Dublin, Ireland
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada
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19
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Levy ERJ, Carrillo-Segura S, Park EH, Redman WT, Hurtado JR, Chung S, Fenton AA. A manifold neural population code for space in hippocampal coactivity dynamics independent of place fields. Cell Rep 2023; 42:113142. [PMID: 37742193 PMCID: PMC10842170 DOI: 10.1016/j.celrep.2023.113142] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 06/14/2023] [Accepted: 08/30/2023] [Indexed: 09/26/2023] Open
Abstract
Hippocampus place cell discharge is temporally unreliable across seconds and days, and place fields are multimodal, suggesting an "ensemble cofiring" spatial coding hypothesis with manifold dynamics that does not require reliable spatial tuning, in contrast to hypotheses based on place field (spatial tuning) stability. We imaged mouse CA1 (cornu ammonis 1) ensembles in two environments across three weeks to evaluate these coding hypotheses. While place fields "remap," being more distinct between than within environments, coactivity relationships generally change less. Decoding location and environment from 1-s ensemble location-specific activity is effective and improves with experience. Decoding environment from cell-pair coactivity relationships is also effective and improves with experience, even after removing place tuning. Discriminating environments from 1-s ensemble coactivity relies crucially on the cells with the most anti-coactive cell-pair relationships because activity is internally organized on a low-dimensional manifold of non-linear coactivity relationships that intermittently reregisters to environments according to the anti-cofiring subpopulation activity.
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Affiliation(s)
| | - Simón Carrillo-Segura
- Center for Neural Science, New York University, New York, NY 10003, USA; Graduate Program in Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, USA
| | - Eun Hye Park
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - William Thomas Redman
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | | | - SueYeon Chung
- Center for Neural Science, New York University, New York, NY 10003, USA; Flatiron Institute Center for Computational Neuroscience, New York, NY 10010, USA
| | - André Antonio Fenton
- Center for Neural Science, New York University, New York, NY 10003, USA; Neuroscience Institute at the NYU Langone Medical Center, New York, NY 10016, USA.
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20
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Barth AM, Jelitai M, Vasarhelyi-Nagy MF, Varga V. Aversive stimulus-tuned responses in the CA1 of the dorsal hippocampus. Nat Commun 2023; 14:6841. [PMID: 37891171 PMCID: PMC10611787 DOI: 10.1038/s41467-023-42611-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Throughout life animals inevitably encounter unforeseen threatening events. Activity of principal cells in the hippocampus is tuned for locations and for salient stimuli in the animals' environment thus forming a map known to be pivotal for guiding behavior. Here, we explored if a code of threatening stimuli exists in the CA1 region of the dorsal hippocampus of mice by recording neuronal response to aversive stimuli delivered at changing locations. We have discovered a rapidly emerging, location independent response to innoxious aversive stimuli composed of the coordinated activation of subgroups of pyramidal cells and connected interneurons. Activated pyramidal cells had higher basal firing rate, more probably participated in ripples, targeted more interneurons than place cells and many of them lacked place fields. We also detected aversive stimulus-coupled assemblies dominated by the activated neurons. Notably, these assemblies could be observed even before the delivery of the first aversive event. Finally, we uncovered the systematic shift of the spatial code from the aversive to, surprisingly, the reward location during the fearful stimulus. Our results uncovered components of the dorsal CA1 circuit possibly key for re-sculpting the spatial map in response to abrupt aversive events.
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Affiliation(s)
- Albert M Barth
- Subcortical Modulation Research Group, Institute of Experimental Medicine, Budapest, 1083, Hungary.
- Cerebral Cortex Research Group, Institute of Experimental Medicine, Budapest, 1083, Hungary.
| | - Marta Jelitai
- Subcortical Modulation Research Group, Institute of Experimental Medicine, Budapest, 1083, Hungary
| | | | - Viktor Varga
- Subcortical Modulation Research Group, Institute of Experimental Medicine, Budapest, 1083, Hungary.
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21
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Liu J, Hall AF, Wang DV. Emerging many-to-one weighted mapping in hippocampus-amygdala network underlies memory formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.06.556568. [PMID: 37732176 PMCID: PMC10508749 DOI: 10.1101/2023.09.06.556568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Memories are crucial for our daily lives, yet the network-level organizing principle that governs neural representations of our experiences remains to be determined. Employing dual-site electrophysiology recording in freely behaving mice, we discovered that hippocampal dorsal CA1 (dCA1) and basolateral amygdala (BLA) utilize distinct coding strategies to represent novel experiences. A small assembly of BLA neurons rapidly emerged during memory acquisition and remained active during subsequent consolidation, whereas the majority of dCA1 neurons engaged in the same processes. Machine learning decoding revealed that dCA1 population spikes predicted the BLA assembly firing rate. This suggests that most dCA1 neurons concurrently index an episodic event by rapidly establishing weighted communications with a specific BLA assembly, a process we call "many-to-one weighted mapping." Furthermore, we demonstrated that closed-loop optoinhibition of BLA activity triggered by dCA1 ripples after new learning resulted in impaired memory. These findings highlight a new principle of hippocampus-amygdala communication underlying memory formation and provide new insights into how the brain creates and stores memories.
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Affiliation(s)
- Jun Liu
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Arron F Hall
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Dong V Wang
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
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22
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Ding L, Balsamo G, Diamantaki M, Preston-Ferrer P, Burgalossi A. Opto-juxtacellular interrogation of neural circuits in freely moving mice. Nat Protoc 2023; 18:2415-2440. [PMID: 37420087 DOI: 10.1038/s41596-023-00842-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 04/11/2023] [Indexed: 07/09/2023]
Abstract
Neural circuits are assembled from an enormous variety of neuronal cell types. Although significant advances have been made in classifying neurons on the basis of morphological, molecular and electrophysiological properties, understanding how this diversity contributes to brain function during behavior has remained a major experimental challenge. Here, we present an extension to our previous protocol, in which we describe the technical procedures for performing juxtacellular opto-tagging of single neurons in freely moving mice by using Channelrhodopsin-2-expressing viral vectors. This method allows one to selectively target molecularly defined cell classes for in vivo single-cell recordings. The targeted cells can be labeled via juxtacellular procedures and further characterized via post-hoc morphological and molecular analysis. In its current form, the protocol allows multiple recording and labeling attempts to be performed within individual animals, by means of a mechanical pipette micropositioning system. We provide proof-of-principle validation of this technique by recording from Calbindin-positive pyramidal neurons in the mouse hippocampus during spatial exploration; however, this approach can easily be extended to other behaviors and cortical or subcortical areas. The procedures described here, from the viral injection to the histological processing of brain sections, can be completed in ~4-5 weeks.This protocol is an extension to: Nat. Protoc. 9, 2369-2381 (2014): https://doi.org/10.1038/nprot.2014.161.
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Affiliation(s)
- Lingjun Ding
- Institute of Neurobiology, Eberhard Karls University of Tübingen, Tübingen, Germany
- Werner-Reichardt Centre for Integrative Neuroscience, Tübingen, Germany
- Graduate Training Centre of Neuroscience-International Max-Planck Research School (IMPRS), Tübingen, Germany
| | - Giuseppe Balsamo
- Institute of Neurobiology, Eberhard Karls University of Tübingen, Tübingen, Germany
- Werner-Reichardt Centre for Integrative Neuroscience, Tübingen, Germany
- Graduate Training Centre of Neuroscience-International Max-Planck Research School (IMPRS), Tübingen, Germany
| | - Maria Diamantaki
- Institute of Neurobiology, Eberhard Karls University of Tübingen, Tübingen, Germany
- Werner-Reichardt Centre for Integrative Neuroscience, Tübingen, Germany
- Graduate Training Centre of Neuroscience-International Max-Planck Research School (IMPRS), Tübingen, Germany
- Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology-Hellas, Heraklion, Greece
| | - Patricia Preston-Ferrer
- Institute of Neurobiology, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Werner-Reichardt Centre for Integrative Neuroscience, Tübingen, Germany.
| | - Andrea Burgalossi
- Institute of Neurobiology, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Werner-Reichardt Centre for Integrative Neuroscience, Tübingen, Germany.
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23
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Sierra RO, Pedraza LK, Barcsai L, Pejin A, Li Q, Kozák G, Takeuchi Y, Nagy AJ, Lőrincz ML, Devinsky O, Buzsáki G, Berényi A. Closed-loop brain stimulation augments fear extinction in male rats. Nat Commun 2023; 14:3972. [PMID: 37407557 DOI: 10.1038/s41467-023-39546-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 06/16/2023] [Indexed: 07/07/2023] Open
Abstract
Dysregulated fear reactions can result from maladaptive processing of trauma-related memories. In post-traumatic stress disorder (PTSD) and other psychiatric disorders, dysfunctional extinction learning prevents discretization of trauma-related memory engrams and generalizes fear responses. Although PTSD may be viewed as a memory-based disorder, no approved treatments target pathological fear memory processing. Hippocampal sharp wave-ripples (SWRs) and concurrent neocortical oscillations are scaffolds to consolidate contextual memory, but their role during fear processing remains poorly understood. Here, we show that closed-loop, SWR triggered neuromodulation of the medial forebrain bundle (MFB) can enhance fear extinction consolidation in male rats. The modified fear memories became resistant to induced recall (i.e., 'renewal' and 'reinstatement') and did not reemerge spontaneously. These effects were mediated by D2 receptor signaling-induced synaptic remodeling in the basolateral amygdala. Our results demonstrate that SWR-triggered closed-loop stimulation of the MFB reward system enhances extinction of fearful memories and reducing fear expression across different contexts and preventing excessive and persistent fear responses. These findings highlight the potential of neuromodulation to augment extinction learning and provide a new avenue to develop treatments for anxiety disorders.
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Affiliation(s)
- Rodrigo Ordoñez Sierra
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
| | - Lizeth Katherine Pedraza
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
| | - Lívia Barcsai
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
- HCEMM-SZTE Magnetotherapeutics Research Group, University of Szeged, Szeged, 6720, Hungary
- Neunos Inc, Boston, MA, 02108, USA
| | - Andrea Pejin
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
- HCEMM-SZTE Magnetotherapeutics Research Group, University of Szeged, Szeged, 6720, Hungary
- Neunos Inc, Boston, MA, 02108, USA
| | - Qun Li
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
| | - Gábor Kozák
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
| | - Yuichi Takeuchi
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
- Department of Biopharmaceutical Sciences and Pharmacy, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Anett J Nagy
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
- HCEMM-SZTE Magnetotherapeutics Research Group, University of Szeged, Szeged, 6720, Hungary
- Neunos Inc, Boston, MA, 02108, USA
| | - Magor L Lőrincz
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary
- Department of Physiology, Anatomy and Neuroscience, Faculty of Sciences University of Szeged, Szeged, 6726, Hungary
- Neuroscience Division, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Orrin Devinsky
- Department of Neurology, NYU Langone Comprehensive Epilepsy Center, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - György Buzsáki
- Neuroscience Institute, New York University, New York, NY, 10016, USA
- Center for Neural Science, New York University, New York, NY, 10016, USA
| | - Antal Berényi
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged, 6720, Hungary.
- HCEMM-SZTE Magnetotherapeutics Research Group, University of Szeged, Szeged, 6720, Hungary.
- Neunos Inc, Boston, MA, 02108, USA.
- Neuroscience Institute, New York University, New York, NY, 10016, USA.
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24
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Chettih SN, Mackevicius EL, Hale S, Aronov D. Barcoding of episodic memories in the hippocampus of a food-caching bird. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.27.542597. [PMID: 37461442 PMCID: PMC10349996 DOI: 10.1101/2023.05.27.542597] [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: 07/24/2023]
Abstract
Episodic memory, or memory of experienced events, is a critical function of the hippocampus1-3. It is therefore important to understand how hippocampal activity represents specific events in an animal's life. We addressed this question in chickadees - specialist food-caching birds that hide food at scattered locations and use memory to find their caches later in time4,5. We performed high-density neural recordings in the hippocampus of chickadees as they cached and retrieved seeds in a laboratory arena. We found that each caching event was represented by a burst of firing in a unique set of hippocampal neurons. These 'barcode-like' patterns of activity were sparse (<10% of neurons active), uncorrelated even for immediately adjacent caches, and different even for separate caches at the same location. The barcode representing a specific caching event was transiently reactivated whenever a bird later interacted with the same cache - for example, to retrieve food. Barcodes co-occurred with conventional place cell activity6,7, as well as location-independent responses to cached seeds. We propose that barcodes are signatures of episodic memories evoked during memory recall. These patterns assign a unique identifier to each event and may be a mechanism for rapid formation and storage of many non-interfering memories.
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Affiliation(s)
| | | | - Stephanie Hale
- Zuckerman Mind Brain Behavior Institute, Columbia University
| | - Dmitriy Aronov
- Zuckerman Mind Brain Behavior Institute, Columbia University
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Zichó K, Sos KE, Papp P, Barth AM, Misák E, Orosz Á, Mayer MI, Sebestény RZ, Nyiri G. Fear memory recall involves hippocampal somatostatin interneurons. PLoS Biol 2023; 21:e3002154. [PMID: 37289847 DOI: 10.1371/journal.pbio.3002154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 05/09/2023] [Indexed: 06/10/2023] Open
Abstract
Fear-related memory traces are encoded by sparse populations of hippocampal principal neurons that are recruited based on their inhibitory-excitatory balance during memory formation. Later, the reactivation of the same principal neurons can recall the memory. The details of this mechanism are still unclear. Here, we investigated whether disinhibition could play a major role in this process. Using optogenetic behavioral experiments, we found that when fear was associated with the inhibition of mouse hippocampal somatostatin positive interneurons, the re-inhibition of the same interneurons could recall fear memory. Pontine nucleus incertus neurons selectively inhibit hippocampal somatostatin cells. We also found that when fear was associated with the activity of these incertus neurons or fibers, the reactivation of the same incertus neurons or fibers could also recall fear memory. These incertus neurons showed correlated activity with hippocampal principal neurons during memory recall and were strongly innervated by memory-related neocortical centers, from which the inputs could also control hippocampal disinhibition in vivo. Nonselective inhibition of these mouse hippocampal somatostatin or incertus neurons impaired memory recall. Our data suggest a novel disinhibition-based memory mechanism in the hippocampus that is supported by local somatostatin interneurons and their pontine brainstem inputs.
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Affiliation(s)
- Krisztián Zichó
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Katalin E Sos
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Péter Papp
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Albert M Barth
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Erik Misák
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Áron Orosz
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Márton I Mayer
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Réka Z Sebestény
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Gábor Nyiri
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
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Ramsaran AI, Wang Y, Golbabaei A, Aleshin S, de Snoo ML, Yeung BRA, Rashid AJ, Awasthi A, Lau J, Tran LM, Ko SY, Abegg A, Duan LC, McKenzie C, Gallucci J, Ahmed M, Kaushik R, Dityatev A, Josselyn SA, Frankland PW. A shift in the mechanisms controlling hippocampal engram formation during brain maturation. Science 2023; 380:543-551. [PMID: 37141366 DOI: 10.1126/science.ade6530] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The ability to form precise, episodic memories develops with age, with young children only able to form gist-like memories that lack precision. The cellular and molecular events in the developing hippocampus that underlie the emergence of precise, episodic-like memory are unclear. In mice, the absence of a competitive neuronal engram allocation process in the immature hippocampus precluded the formation of sparse engrams and precise memories until the fourth postnatal week, when inhibitory circuits in the hippocampus mature. This age-dependent shift in precision of episodic-like memories involved the functional maturation of parvalbumin-expressing interneurons in subfield CA1 through assembly of extracellular perineuronal nets, which is necessary and sufficient for the onset of competitive neuronal allocation, sparse engram formation, and memory precision.
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Affiliation(s)
- Adam I Ramsaran
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Ying Wang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Ali Golbabaei
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Stepan Aleshin
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases, Magdeburg, Germany
| | - Mitchell L de Snoo
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Bi-Ru Amy Yeung
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Asim J Rashid
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ankit Awasthi
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jocelyn Lau
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Lina M Tran
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Vector Institute, Toronto, Ontario, Canada
| | - Sangyoon Y Ko
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Andrin Abegg
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Lana Chunan Duan
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Cory McKenzie
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Julia Gallucci
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Moriam Ahmed
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rahul Kaushik
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
- Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Sheena A Josselyn
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Brain, Mind, & Consciousness Program, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | - Paul W Frankland
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
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Leong ATL, Wong EC, Wang X, Wu EX. Hippocampus Modulates Vocalizations Responses at Early Auditory Centers. Neuroimage 2023; 270:119943. [PMID: 36828157 DOI: 10.1016/j.neuroimage.2023.119943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 02/13/2023] [Indexed: 02/24/2023] Open
Abstract
Despite its prominence in learning and memory, hippocampal influence in early auditory processing centers remains unknown. Here, we examined how hippocampal activity modulates sound-evoked responses in the auditory midbrain and thalamus using optogenetics and functional MRI (fMRI) in rodents. Ventral hippocampus (vHP) excitatory neuron stimulation at 5 Hz evoked robust hippocampal activity that propagates to the primary auditory cortex. We then tested 5 Hz vHP stimulation paired with either natural vocalizations or artificial/noise acoustic stimuli. vHP stimulation enhanced auditory responses to vocalizations (with a negative or positive valence) in the inferior colliculus, medial geniculate body, and auditory cortex, but not to their temporally reversed counterparts (artificial sounds) or broadband noise. Meanwhile, pharmacological vHP inactivation diminished response selectivity to vocalizations. These results directly reveal the large-scale hippocampal participation in natural sound processing at early centers of the ascending auditory pathway. They expand our present understanding of hippocampus in global auditory networks.
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Affiliation(s)
- Alex T L Leong
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
| | - Eddie C Wong
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Xunda Wang
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
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28
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Wilmerding LK, Kondratyev I, Ramirez S, Hasselmo ME. Route-dependent spatial engram tagging in mouse dentate gyrus. Neurobiol Learn Mem 2023; 200:107738. [PMID: 36822466 PMCID: PMC10106405 DOI: 10.1016/j.nlm.2023.107738] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 01/30/2023] [Accepted: 02/16/2023] [Indexed: 02/23/2023]
Abstract
The dentate gyrus (DG) of hippocampus is hypothesized to act as a pattern separator that distinguishes between similar input patterns during memory formation and retrieval. Sparse ensembles of DG cells associated with learning and memory, i.e. engrams, have been labeled and manipulated to recall novel context memories. Functional studies of DG cell activity have demonstrated the spatial specificity and stability of DG cells during navigation. To reconcile how the DG contributes to separating global context as well as individual navigational routes, we trained mice to perform a delayed-non-match-to-position (DNMP) T-maze task and labeled DG neurons during performance of this task on a novel T-maze. The following day, mice navigated a second environment: the same T-maze, the same T-maze with one route permanently blocked but still visible, or a novel open field. We found that the degree of engram reactivation across days differed based on the traversal of maze routes, such that mice traversing only one arm had higher ensemble overlap than chance but less overlap than mice running the full two-route task. Mice experiencing the open field had similar ensemble sizes to the other groups but only chance-level ensemble reactivation. Ensemble overlap differences could not be explained by behavioral variability across groups, nor did behavioral metrics correlate to degree of ensemble reactivation. Together, these results support the hypothesis that DG contributes to spatial navigation memory and that partially non-overlapping ensembles encode different routes within the context of an environment.
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Affiliation(s)
- Lucius K Wilmerding
- Center for Systems Neuroscience, Boston University, United States; Graduate Program for Neuroscience, Boston University, United States; Department of Psychological and Brain Sciences, Boston University, United States.
| | - Ivan Kondratyev
- Center for Systems Neuroscience, Boston University, United States
| | - Steve Ramirez
- Center for Systems Neuroscience, Boston University, United States; Graduate Program for Neuroscience, Boston University, United States; Department of Psychological and Brain Sciences, Boston University, United States
| | - Michael E Hasselmo
- Center for Systems Neuroscience, Boston University, United States; Graduate Program for Neuroscience, Boston University, United States; Department of Psychological and Brain Sciences, Boston University, United States
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29
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Chen L, Francisco TR, Baggetta AM, Zaki Y, Ramirez S, Clem RL, Shuman T, Cai DJ. Ensemble-specific deficit in neuronal intrinsic excitability in aged mice. Neurobiol Aging 2023; 123:92-97. [PMID: 36652783 PMCID: PMC9892234 DOI: 10.1016/j.neurobiolaging.2022.12.007] [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: 03/30/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
With the prevalence of age-related cognitive deficits on the rise, it is essential to identify cellular and circuit alterations that contribute to age-related memory impairment. Increased intrinsic neuronal excitability after learning is important for memory consolidation, and changes to this process could underlie memory impairment in old age. Some studies find age-related deficits in hippocampal neuronal excitability that correlate with memory impairment but others do not, possibly due to selective changes only in activated neural ensembles. Thus, we tagged CA1 neurons activated during learning and recorded their intrinsic excitability 5 hours or 7 days post-training. Adult mice exhibited increased neuronal excitability 5 hours after learning, specifically in ensemble (learning-activated) CA1 neurons. As expected, ensemble excitability returned to baseline 7 days post-training. In aged mice, there was no ensemble-specific excitability increase after learning, which was associated with impaired hippocampal memory performance. These results suggest that CA1 may be susceptible to age-related impairments in post-learning ensemble excitability and underscore the need to selectively measure ensemble-specific changes in the brain.
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Affiliation(s)
- Lingxuan Chen
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Taylor R Francisco
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Austin M Baggetta
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yosif Zaki
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Steve Ramirez
- Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | - Roger L Clem
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tristan Shuman
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Denise J Cai
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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30
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Wang CH, McHugh TJ. Putting memories in their place. Cell Res 2023; 33:91-92. [PMID: 36257980 PMCID: PMC9892484 DOI: 10.1038/s41422-022-00737-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Chia-Hsuan Wang
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan.
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31
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Aery Jones EA, Giocomo LM. Neural ensembles in navigation: From single cells to population codes. Curr Opin Neurobiol 2023; 78:102665. [PMID: 36542882 PMCID: PMC9845194 DOI: 10.1016/j.conb.2022.102665] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/27/2022] [Accepted: 11/21/2022] [Indexed: 12/23/2022]
Abstract
The brain can represent behaviorally relevant information through the firing of individual neurons as well as the coordinated firing of ensembles of neurons. Neurons in the hippocampus and associated cortical regions participate in a variety of types of ensembles to support navigation. These ensemble types include single cell codes, population codes, time-compressed sequences, behavioral sequences, and engrams. We present the physiological basis and behavioral relevance of ensemble firing. We discuss how these traditional definitions of ensembles can constrain or expand potential analyses due to the underlying assumptions and abstractions made. We highlight how coding can change at the ensemble level while underlying single cell codes remain intact. Finally, we present how ensemble definitions could be broadened to better understand the full complexity of the brain.
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Affiliation(s)
- Emily A Aery Jones
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Lisa M Giocomo
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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32
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Kobayashi KS, Matsuo N. Persistent representation of the environment in the hippocampus. Cell Rep 2023; 42:111989. [PMID: 36640328 DOI: 10.1016/j.celrep.2022.111989] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 11/23/2022] [Accepted: 12/23/2022] [Indexed: 01/13/2023] Open
Abstract
In the hippocampus, environmental changes elicit rearrangement of active neuronal ensembles or remapping of place cells. However, it remains elusive how the brain ensures a consistent representation of a certain environment itself despite salient events occurring there. Here, we longitudinally tracked calcium dynamics of dorsal hippocampal CA1 neurons in mice subjected to contextual fear conditioning and extinction training. Overall population activities were significantly changed by fear conditioning and were responsive to footshocks and freezing. However, a small subset of neurons, termed environment cells, were consistently active in a specific environment irrespective of experiences. A decoder modeling study showed that these cells, but not place cells, were able to predict the environment to which the mouse was exposed. Environment cells might underlie the constancy of cognition for distinct environments across time and events. Additionally, our study highlights the functional heterogeneity of cells in the hippocampus.
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Affiliation(s)
- Kyogo S Kobayashi
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan.
| | - Naoki Matsuo
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan.
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Ghandour K, Inokuchi K. Memory reactivations during sleep. Neurosci Res 2022; 189:60-65. [PMID: 36581176 DOI: 10.1016/j.neures.2022.12.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/27/2022]
Abstract
Neuronal activities that occur during awake periods are often reactivated again during sleep, to consolidate recently encoded memories, a process known as consolidation. In recent years, advanced tools, specially optical techniques and in-vivo live Ca2+ imaging, have revealed a deeper understanding to the offline periods' neuronal activities and their correspondence to later awake behavioral outputs. Recently, there is a growing consensus that sleep is more of an active process. Sleep has been associated with various functions, memory updating, future imaginations of possible familiar scenarios, decision making and planning by replaying past memories. Also, boosting insightful thoughts, creative thinking and problem solving by forming new associations and connections that were not present in awake states. Sleep activities have been directly associated with many "EUREKA" or "AHA" moments. Here, we describe recent views on memory reactivations during sleep and their implications on learning and memory.
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Affiliation(s)
- Khaled Ghandour
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan; Research Center for Idling Brain Science, University of Toyama, Toyama 930-0194, Japan; Department of Biochemistry, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Kaoru Inokuchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan; Research Center for Idling Brain Science, University of Toyama, Toyama 930-0194, Japan.
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Wan M, Xia R, Lin H, Ye Y, Qiu P, Zheng G. Baduanjin exercise modulates the hippocampal subregion structure in community-dwelling older adults with cognitive frailty. Front Aging Neurosci 2022; 14:956273. [PMID: 36600804 PMCID: PMC9806122 DOI: 10.3389/fnagi.2022.956273] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Background Regular Baduanjin exercise intervention was proven to be beneficial in improving the cognitive ability and physical performance of older adults with different health conditions but was unclear to influence the structural plasticity of the hippocampus. This study aimed to explore the modulation of hippocampal subregions as a mechanism by which Baduanjin exercise improves cognitive frailty in older adults. Methods A total of 102 community-dwelling older adults with cognitive frailty were recruited and randomly allocated to the Baduanjin exercise training group and usual physical activity control group. The participants in the Baduanjin exercise training group participated in a 24-week Baduanjin exercise intervention program with an exercise frequency of 60 min per day, 3 days per week. Cognitive ability and physical frailty were assessed, and MRI scans were performed on all participants at baseline and after 24 weeks of intervention. The structural MRI data were processed with MRIConvert (version 2.0 Rev. 235) and FreeSurfer (version 6.0.0) software. Data analyses were performed using the independent sample t tests/Mann-Whitney U tests with the Bonferroni correction, mixed linear model, correlation, or mediation analysis by the SPSS 24.0 software (IBM Corp, Armonk, NY, United States). Results After 24 weeks of intervention, a statistically significant increase was found for the Montreal Cognitive Assessment (MoCA) scores (p = 0.002) with a large effect size (Cohen's d = 0.94) and the significant interaction effect (P goup × time < 0.05), Memory Quotient (MQ) scores (p = 0.019) with a medium effect size (Cohen's d = 0.688) and the significant interaction effect (P goup × time < 0.05), and other parameters of WMS-RC test including pictures (p = 0.042), recognition (p = 0.017), and association (p = 0.045) test with a medium effect size (Cohens' d = 0.592, 0.703, and 0.581) for the Baduanjin training group, while significant decrease for the Edmonton Frailty Scale (EFS) score (p = 0.022), with a medium effect size (Cohen's d = -0.659) and the significant interaction effect (P goup × time < 0.05) for the Baduanjin training group. The differences in the left parasubiculum, Hippocampal Amygdala Transition Area (HATA), right Cornu Ammonis Subfield 1 (CA1) and presubiculum volumes from baseline to 24 weeks after intervention in the Baduanjin training group were significantly greater than those in the control group (p < 0.05/12). Further analysis showed that the changes in right CA1 volume were positively correlated with the changes in MoCA and MQ scores (r = 0.510, p = 0.015; r = 0.484, p = 0.022;), the changes in right presubiculum and left parasubiculum volumes were positively correlated with the changes in MQ (r = 0.435, p = 0.043) and picture test scores (r = 0.509, p = 0.016), respectively, and the changes in left parasubiculum and HATA volumes were negatively correlated with the changes in EFS scores (r = -0.534, p = 0.011; r = -0.575, p = 0.005) in the Baduanjin training group, even after adjusting for age, sex, years of education and marital status; furthermore, the volume changes in left parasubiculum and left HATA significantly mediated the Baduanjin exercise training-induced decrease in the EFS scores (β = 0.376, 95% CI 0.024 ~ 0.947; β = 0.484, 95% CI 0.091 ~ 0.995); the changes of left parasubiculum and right CA1 significantly mediated the Baduanjin exercise training-induced increase in the picture and MO scores (β = -0.83, 95% CI-1.95 ~ -0.002; β = -2.44, 95% CI-5.99 ~ -0.32). Conclusion A 24-week Baduanjin exercise intervention effectively improved cognitive ability and reduced physical frailty in community-dwelling older adults with cognitive frailty, and the mechanism might be associated with modulating the structural plasticity of the hippocampal subregion.
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Affiliation(s)
- Mingyue Wan
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China,College of Nursing and Health Management, Shanghai University of Medicine and Health Sciences, Shanghai, China,College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Rui Xia
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China,Department of Rehabilitation, Shenzhen Bao ‘an District People’s Hospital, Shenzhen, China
| | - Huiying Lin
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Yu Ye
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Pingting Qiu
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Guohua Zheng
- College of Nursing and Health Management, Shanghai University of Medicine and Health Sciences, Shanghai, China,*Correspondence: Guohua Zheng,
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35
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Ruzicka J, Dalecka M, Safrankova K, Peretti D, Jendelova P, Kwok JCF, Fawcett JW. Perineuronal nets affect memory and learning after synapse withdrawal. Transl Psychiatry 2022; 12:480. [PMID: 36379919 PMCID: PMC9666654 DOI: 10.1038/s41398-022-02226-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/08/2022] [Accepted: 10/19/2022] [Indexed: 11/16/2022] Open
Abstract
Perineuronal nets (PNNs) enwrap mature neurons, playing a role in the control of plasticity and synapse dynamics. PNNs have been shown to have effects on memory formation, retention and extinction in a variety of animal models. It has been proposed that the cavities in PNNs, which contain synapses, can act as a memory store and that they remain stable after events that cause synaptic withdrawal such as anoxia or hibernation. We examine this idea by monitoring place memory before and after synaptic withdrawal caused by acute hibernation-like state (HLS). Animals lacking hippocampal PNNs due to enzymatic digestion by chondroitinase ABC or knockout of the PNN component aggrecan were compared with wild type controls. HLS-induced synapse withdrawal caused a memory deficit, but not to the level of untreated naïve animals and not worsened by PNN attenuation. After HLS, only animals lacking PNNs showed memory restoration or relearning. Absence of PNNs affected the restoration of excitatory synapses on PNN-bearing neurons. The results support a role for hippocampal PNNs in learning, but not in long-term memory storage for correction of deficits.
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Affiliation(s)
- Jiri Ruzicka
- grid.424967.a0000 0004 0404 6946Institute of Experimental Medicine, CAS, Prague, Czech Republic
| | - Marketa Dalecka
- grid.418095.10000 0001 1015 3316Imaging Methods Core Facility, BIOCEV, CAS, Vestec, Czech Republic
| | - Kristyna Safrankova
- grid.424967.a0000 0004 0404 6946Institute of Experimental Medicine, CAS, Prague, Czech Republic
| | - Diego Peretti
- grid.5335.00000000121885934UK Dementia Research Institute and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Pavla Jendelova
- grid.424967.a0000 0004 0404 6946Institute of Experimental Medicine, CAS, Prague, Czech Republic
| | - Jessica C. F. Kwok
- grid.424967.a0000 0004 0404 6946Institute of Experimental Medicine, CAS, Prague, Czech Republic ,grid.9909.90000 0004 1936 8403Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - James W. Fawcett
- grid.424967.a0000 0004 0404 6946Institute of Experimental Medicine, CAS, Prague, Czech Republic ,grid.5335.00000000121885934John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, UK
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36
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Zhu M, Perkins MG, Lennertz R, Abdulzahir A, Pearce RA. Dose-dependent suppression of hippocampal contextual memory formation, place cells, and spatial engrams by the NMDAR antagonist (R)-CPP. Neuropharmacology 2022; 218:109215. [PMID: 35977628 PMCID: PMC9673467 DOI: 10.1016/j.neuropharm.2022.109215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022]
Abstract
We recently reported that the competitive NMDAR antagonist (R,S)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) does not suppress NMDAR-mediated field EPSPs (fEPSPNMDA) or long-term potentiation (LTP) in vitro at concentrations that block contextual conditioning in vivo. Here we tested one possible explanation for the mismatch - that the hippocampus is relatively resistant to CPP compared to other brain structures engaged in contextual fear conditioning. Using the context pre-exposure facilitation effect (CPFE) paradigm to separate the hippocampal and extra-hippocampal components of contextual learning, we found that the active enantiomer (R)-CPP suppressed the hippocampal component with an IC50 of 3.1 mg/kg, a dose that produces brain concentrations below those required to block fEPSPNMDA or LTP. Moreover, using in-vivo calcium imaging of place cells and spatial engrams to directly assess hippocampal spatial coding, we found that (R)-CPP dose-dependently reduced the development of place cells and interfered with the formation of stable spatial engrams when it was administered prior to exposing mice to a novel context. Both effects occurred at doses that interfered with freezing to context in CPFE experiments. We conclude that (R)-CPP blocks memory formation by interfering with hippocampal function, but that it does so by modulating NMDARs at sites that are not engaged in vitro in the same manner that they are in vivo - perhaps through interneuron circuits that do not contribute to fEPSPs and are not required to elicit LTP using standard induction protocols in vitro, but are essential for successful mnemonic function in vivo.
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Affiliation(s)
- Mengwen Zhu
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, 53705, USA.
| | - Mark G Perkins
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, 53705, USA.
| | - Richard Lennertz
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, 53705, USA.
| | - Alifayaz Abdulzahir
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, 53705, USA.
| | - Robert A Pearce
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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Lamothe-Molina PJ, Franzelin A, Beck L, Li D, Auksutat L, Fieblinger T, Laprell L, Alhbeck J, Gee CE, Kneussel M, Engel AK, Hilgetag CC, Morellini F, Oertner TG. ΔFosB accumulation in hippocampal granule cells drives cFos pattern separation during spatial learning. Nat Commun 2022; 13:6376. [PMID: 36289226 PMCID: PMC9606265 DOI: 10.1038/s41467-022-33947-w] [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: 09/09/2020] [Accepted: 10/07/2022] [Indexed: 12/25/2022] Open
Abstract
Mice display signs of fear when neurons that express cFos during fear conditioning are artificially reactivated. This finding gave rise to the notion that cFos marks neurons that encode specific memories. Here we show that cFos expression patterns in the mouse dentate gyrus (DG) change dramatically from day to day in a water maze spatial learning paradigm, regardless of training level. Optogenetic inhibition of neurons that expressed cFos on the first training day affected performance days later, suggesting that these neurons continue to be important for spatial memory recall. The mechanism preventing repeated cFos expression in DG granule cells involves accumulation of ΔFosB, a long-lived splice variant of FosB. CA1 neurons, in contrast, repeatedly expressed cFos. Thus, cFos-expressing granule cells may encode new features being added to the internal representation during the last training session. This form of timestamping is thought to be required for the formation of episodic memories.
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Affiliation(s)
- Paul J. Lamothe-Molina
- grid.13648.380000 0001 2180 3484Institute for Synaptic Physiology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas Franzelin
- grid.13648.380000 0001 2180 3484Institute for Synaptic Physiology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lennart Beck
- grid.13648.380000 0001 2180 3484Institute for Synaptic Physiology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dong Li
- grid.13648.380000 0001 2180 3484Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lea Auksutat
- grid.13648.380000 0001 2180 3484Research Group Behavioral Biology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Fieblinger
- grid.13648.380000 0001 2180 3484Institute for Synaptic Physiology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Laura Laprell
- grid.13648.380000 0001 2180 3484Institute for Synaptic Physiology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Joachim Alhbeck
- grid.13648.380000 0001 2180 3484Department of Neurophysiology and Pathophysiology, Center for Experimental Medicine (ZEM), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christine E. Gee
- grid.13648.380000 0001 2180 3484Institute for Synaptic Physiology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Matthias Kneussel
- grid.13648.380000 0001 2180 3484Institute for Molecular Neurogenetics, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas K. Engel
- grid.13648.380000 0001 2180 3484Department of Neurophysiology and Pathophysiology, Center for Experimental Medicine (ZEM), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Claus C. Hilgetag
- grid.13648.380000 0001 2180 3484Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fabio Morellini
- grid.13648.380000 0001 2180 3484Research Group Behavioral Biology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas G. Oertner
- grid.13648.380000 0001 2180 3484Institute for Synaptic Physiology, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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38
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Jeong N, Singer AC. Learning from inhibition: Functional roles of hippocampal CA1 inhibition in spatial learning and memory. Curr Opin Neurobiol 2022; 76:102604. [PMID: 35810533 DOI: 10.1016/j.conb.2022.102604] [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: 01/14/2022] [Revised: 05/19/2022] [Accepted: 06/07/2022] [Indexed: 11/19/2022]
Abstract
Hippocampal inhibitory interneurons exert a powerful influence on learning and memory. Inhibitory interneurons are known to play a major role in many diseases that affect memory, and to strongly influence brain functions required for memory-related tasks. While previous studies involving genetic, optogenetic, and pharmacological manipulations have shown that hippocampal interneurons play essential roles in spatial and episodic learning and memory, exactly how interneurons affect local circuit computations during spatial navigation is not well understood. Given the significant anatomical, morphological, and functional heterogeneity in hippocampal interneurons, one may suspect cell-type specific roles in circuit computations. Here, we review emerging evidence of CA1 hippocampal interneurons' role in local circuit computations that support spatial learning and memory and discuss open questions about CA1 interneurons in spatial learning.
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Affiliation(s)
- Nuri Jeong
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA; Neuroscience Graduate Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA. https://twitter.com/nuriscientist
| | - Annabelle C Singer
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA.
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39
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Zaki Y, Mau W, Cincotta C, Monasterio A, Odom E, Doucette E, Grella SL, Merfeld E, Shpokayte M, Ramirez S. Hippocampus and amygdala fear memory engrams re-emerge after contextual fear relapse. Neuropsychopharmacology 2022; 47:1992-2001. [PMID: 35941286 PMCID: PMC9485238 DOI: 10.1038/s41386-022-01407-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/17/2022] [Accepted: 07/16/2022] [Indexed: 11/09/2022]
Abstract
The formation and extinction of fear memories represent two forms of learning that each engage the hippocampus and amygdala. How cell populations in these areas contribute to fear relapse, however, remains unclear. Here, we demonstrate that, in male mice, cells active during fear conditioning in the dentate gyrus of hippocampus exhibit decreased activity during extinction and are re-engaged after contextual fear relapse. In vivo calcium imaging reveals that relapse drives population dynamics in the basolateral amygdala to revert to a network state similar to the state present during fear conditioning. Finally, we find that optogenetic inactivation of neuronal ensembles active during fear conditioning in either the hippocampus or amygdala is sufficient to disrupt fear expression after relapse, while optogenetic stimulation of these same ensembles after extinction is insufficient to artificially mimic fear relapse. These results suggest that fear relapse triggers a partial re-emergence of the original fear memory representation, providing new insight into the neural substrates of fear relapse.
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Affiliation(s)
- Yosif Zaki
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - William Mau
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Christine Cincotta
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA
| | - Amy Monasterio
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA
| | - Emma Odom
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA
| | - Emily Doucette
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA
| | - Stephanie L Grella
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA
| | - Emily Merfeld
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA
| | - Monika Shpokayte
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA
| | - Steve Ramirez
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA.
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40
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Hodapp A, Kaiser ME, Thome C, Ding L, Rozov A, Klumpp M, Stevens N, Stingl M, Sackmann T, Lehmann N, Draguhn A, Burgalossi A, Engelhardt M, Both M. Dendritic axon origin enables information gating by perisomatic inhibition in pyramidal neurons. Science 2022; 377:1448-1452. [PMID: 36137045 DOI: 10.1126/science.abj1861] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Information processing in neuronal networks involves the recruitment of selected neurons into coordinated spatiotemporal activity patterns. This sparse activation results from widespread synaptic inhibition in conjunction with neuron-specific synaptic excitation. We report the selective recruitment of hippocampal pyramidal cells into patterned network activity. During ripple oscillations in awake mice, spiking is much more likely in cells in which the axon originates from a basal dendrite rather than from the soma. High-resolution recordings in vitro and computer modeling indicate that these spikes are elicited by synaptic input to the axon-carrying dendrite and thus escape perisomatic inhibition. Pyramidal cells with somatic axon origin can be activated during ripple oscillations by blocking their somatic inhibition. The recruitment of neurons into active ensembles is thus determined by axonal morphological features.
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Affiliation(s)
- Alexander Hodapp
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Martin E Kaiser
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Christian Thome
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany.,Institute of Anatomy and Cell Biology, Medical Faculty, Johannes Kepler University, Linz, Austria.,Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Lingjun Ding
- Institute of Neurobiology, University of Tübingen, Tübingen, Germany.,Werner-Reichardt Centre for Integrative Neuroscience, Tübingen, Germany.,Graduate Training Centre of Neuroscience, IMPRS, Tübingen, Germany
| | - Andrei Rozov
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany.,Federal Center of Brain Research and Neurotechnologies, Moscow, Russian Federation.,OpenLab of Neurobiology, Kazan Federal University, Kazan, Russian Federation
| | - Matthias Klumpp
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Nikolas Stevens
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Moritz Stingl
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Tina Sackmann
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Nadja Lehmann
- Institute of Neuroanatomy, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Andrea Burgalossi
- Institute of Neurobiology, University of Tübingen, Tübingen, Germany.,Werner-Reichardt Centre for Integrative Neuroscience, Tübingen, Germany
| | - Maren Engelhardt
- Institute of Anatomy and Cell Biology, Medical Faculty, Johannes Kepler University, Linz, Austria.,Institute of Neuroanatomy, Mannheim Center for Translational Neuroscience (MCTN), Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Heidelberg, Germany
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Chenani A, Weston G, Ulivi AF, Castello-Waldow TP, Huettl RE, Chen A, Attardo A. Repeated stress exposure leads to structural synaptic instability prior to disorganization of hippocampal coding and impairments in learning. Transl Psychiatry 2022; 12:381. [PMID: 36096987 PMCID: PMC9468341 DOI: 10.1038/s41398-022-02107-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/15/2022] [Accepted: 08/05/2022] [Indexed: 12/30/2022] Open
Abstract
Stress exposure impairs brain structure and function, resulting in cognitive deficits and increased risk for psychiatric disorders such as depression, schizophrenia, anxiety and post-traumatic stress disorder. In particular, stress exposure affects function and structure of hippocampal CA1 leading to impairments in episodic memory. Here, we applied longitudinal deep-brain optical imaging to investigate the link between changes in activity patterns and structural plasticity of dorsal CA1 pyramidal neurons and hippocampal-dependent learning and memory in mice exposed to stress. We found that several days of repeated stress led to a substantial increase in neuronal activity followed by disruption of the temporal structure of this activity and spatial coding. We then tracked dynamics of structural excitatory connectivity as a potential underlying cause of the changes in activity induced by repeated stress. We thus discovered that exposure to repeated stress leads to an immediate decrease in spinogenesis followed by decrease in spine stability. By comparison, acute stress led to stabilization of the spines born in temporal proximity to the stressful event. Importantly, the temporal relationship between changes in activity levels, structural connectivity and activity patterns, suggests that loss of structural connectivity mediates the transition between increased activity and impairment of temporal organization and spatial information content in dorsal CA1 upon repeated stress exposure.
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Affiliation(s)
- Alireza Chenani
- grid.419548.50000 0000 9497 5095Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Ghabiba Weston
- grid.419548.50000 0000 9497 5095Max Planck Institute of Psychiatry, 80804 Munich, Germany ,grid.5252.00000 0004 1936 973XGraduate School of Systemic Neurosciences GSN-LMU, 82152 Munich, Germany
| | - Alessandro F. Ulivi
- grid.419548.50000 0000 9497 5095Max Planck Institute of Psychiatry, 80804 Munich, Germany ,grid.418723.b0000 0001 2109 6265Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Tim P. Castello-Waldow
- grid.419548.50000 0000 9497 5095Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Rosa-Eva Huettl
- grid.419548.50000 0000 9497 5095Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Alon Chen
- grid.419548.50000 0000 9497 5095Max Planck Institute of Psychiatry, 80804 Munich, Germany ,grid.5252.00000 0004 1936 973XGraduate School of Systemic Neurosciences GSN-LMU, 82152 Munich, Germany ,grid.13992.300000 0004 0604 7563Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Alessio Attardo
- Max Planck Institute of Psychiatry, 80804, Munich, Germany. .,Graduate School of Systemic Neurosciences GSN-LMU, 82152, Munich, Germany. .,Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany.
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42
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Pettit NL, Yap EL, Greenberg ME, Harvey CD. Fos ensembles encode and shape stable spatial maps in the hippocampus. Nature 2022; 609:327-334. [PMID: 36002569 PMCID: PMC9452297 DOI: 10.1038/s41586-022-05113-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/14/2022] [Indexed: 12/24/2022]
Abstract
In the hippocampus, spatial maps are formed by place cells while contextual memories are thought to be encoded as engrams1-6. Engrams are typically identified by expression of the immediate early gene Fos, but little is known about the neural activity patterns that drive, and are shaped by, Fos expression in behaving animals7-10. Thus, it is unclear whether Fos-expressing hippocampal neurons also encode spatial maps and whether Fos expression correlates with and affects specific features of the place code11. Here we measured the activity of CA1 neurons with calcium imaging while monitoring Fos induction in mice performing a hippocampus-dependent spatial learning task in virtual reality. We find that neurons with high Fos induction form ensembles of cells with highly correlated activity, exhibit reliable place fields that evenly tile the environment and have more stable tuning across days than nearby non-Fos-induced cells. Comparing neighbouring cells with and without Fos function using a sparse genetic loss-of-function approach, we find that neurons with disrupted Fos function have less reliable activity, decreased spatial selectivity and lower across-day stability. Our results demonstrate that Fos-induced cells contribute to hippocampal place codes by encoding accurate, stable and spatially uniform maps and that Fos itself has a causal role in shaping these place codes. Fos ensembles may therefore link two key aspects of hippocampal function: engrams for contextual memories and place codes that underlie cognitive maps.
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Affiliation(s)
- Noah L Pettit
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Ee-Lynn Yap
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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43
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Abstract
Arc is one of the genes that are rapidly transcribed by neuronal activity and thus used as a marker for memory trace or engram cells. However, the dynamics of engram cell populations is not well-known because of the difficulty in monitoring the rapid and transient gene expression in live animals. Using a mouse model in which endogenous Arc messenger RNA (mRNA) is fluorescently labeled, we demonstrate that Arc-expressing neuronal populations have distinct dynamics in different brain regions and that only a small subpopulation that consistently expresses Arc during both memory encoding and retrieval exhibits context-specific calcium activity. This live-animal RNA-imaging technique will offer a powerful tool for connecting gene expression to neuronal activity patterns and to behavior. Memories are thought to be encoded in populations of neurons called memory trace or engram cells. However, little is known about the dynamics of these cells because of the difficulty in real-time monitoring of them over long periods of time in vivo. To overcome this limitation, we present a genetically encoded RNA indicator (GERI) mouse for intravital chronic imaging of endogenous Arc messenger RNA (mRNA)—a popular marker for memory trace cells. We used our GERI to identify Arc-positive neurons in real time without the delay associated with reporter protein expression in conventional approaches. We found that the Arc-positive neuronal populations rapidly turned over within 2 d in the hippocampal CA1 region, whereas ∼4% of neurons in the retrosplenial cortex consistently expressed Arc following contextual fear conditioning and repeated memory retrievals. Dual imaging of GERI and a calcium indicator in CA1 of mice navigating a virtual reality environment revealed that only the population of neurons expressing Arc during both encoding and retrieval exhibited relatively high calcium activity in a context-specific manner. This in vivo RNA-imaging approach opens the possibility of unraveling the dynamics of the neuronal population underlying various learning and memory processes.
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44
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Synaptic plasticity during systems memory consolidation. Neurosci Res 2022; 183:1-6. [PMID: 35667493 DOI: 10.1016/j.neures.2022.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/29/2022] [Accepted: 05/31/2022] [Indexed: 11/23/2022]
Abstract
After learning, memory is initially encoded in the hippocampus but subsequently stabilized in other brain regions such as the cortex for long-lasting storage. This process is known as systems memory consolidation, and its cellular mechanism has long been a fundamental question. Synaptic plasticity is the major cellular mechanism underlying learning and memory, and is therefore considered a key function in the process of systems memory consolidation. Therefore, many studies have aimed to establish a causal link between synaptic plasticity in the brain and memory-associated behaviors. In this review, I discuss the various lines of research showing the function of synaptic plasticity, mainly in the hippocampus and cortex during memory consolidation.
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45
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Nambu MF, Lin YJ, Reuschenbach J, Tanaka KZ. What does engram encode?: Heterogeneous memory engrams for different aspects of experience. Curr Opin Neurobiol 2022; 75:102568. [PMID: 35660988 DOI: 10.1016/j.conb.2022.102568] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/26/2022] [Accepted: 05/01/2022] [Indexed: 01/03/2023]
Abstract
Long-lasting synaptic changes within the neuronal network mediate memory. Neurons bearing such physical traces of memory (memory engram cells) are often equated with neurons expressing immediate early genes (IEGs) during a specific experience. However, past studies observed the expression of different IEGs in non-overlapping neurons or synaptic plasticity in neurons that do not express a particular IEG. Importantly, recent studies revealed that distinct subsets of neurons expressing different IEGs or even IEG negative-(yet active) neurons support different aspects of memory or computation, suggesting a more complex nature of memory engram cells than previously thought. In this short review, we introduce studies revealing such heterogeneous composition of the memory engram and discuss how the memory system benefits from it.
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Affiliation(s)
- Miyu F Nambu
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan. https://twitter.com/meowmiyu
| | - Yu-Ju Lin
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan. https://twitter.com/linyuru25199808
| | - Josefine Reuschenbach
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan. https://twitter.com/Jausefine
| | - Kazumasa Z Tanaka
- Okinawa Institute of Science and Technology Graduate University (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
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46
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Shen Y, Zhou M, Cai D, Filho DA, Fernandes G, Cai Y, de Sousa AF, Tian M, Kim N, Lee J, Necula D, Zhou C, Li S, Salinas S, Liu A, Kang X, Kamata M, Lavi A, Huang S, Silva T, Heo WD, Silva AJ. CCR5 closes the temporal window for memory linking. Nature 2022; 606:146-152. [PMID: 35614219 PMCID: PMC9197199 DOI: 10.1038/s41586-022-04783-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/20/2022] [Indexed: 11/09/2022]
Abstract
Real-world memories are formed in a particular context and are often not acquired or recalled in isolation1-5. Time is a key variable in the organization of memories, as events that are experienced close in time are more likely to be meaningfully associated, whereas those that are experienced with a longer interval are not1-4. How the brain segregates events that are temporally distinct is unclear. Here we show that a delayed (12-24 h) increase in the expression of C-C chemokine receptor type 5 (CCR5)-an immune receptor that is well known as a co-receptor for HIV infection6,7-after the formation of a contextual memory determines the duration of the temporal window for associating or linking that memory with subsequent memories. This delayed expression of CCR5 in mouse dorsal CA1 neurons results in a decrease in neuronal excitability, which in turn negatively regulates neuronal memory allocation, thus reducing the overlap between dorsal CA1 memory ensembles. Lowering this overlap affects the ability of one memory to trigger the recall of the other, and therefore closes the temporal window for memory linking. Our findings also show that an age-related increase in the neuronal expression of CCR5 and its ligand CCL5 leads to impairments in memory linking in aged mice, which could be reversed with a Ccr5 knockout and a drug approved by the US Food and Drug Administration (FDA) that inhibits this receptor, a result with clinical implications. Altogether, the findings reported here provide insights into the molecular and cellular mechanisms that shape the temporal window for memory linking.
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Affiliation(s)
- Yang Shen
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Miou Zhou
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA.
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA.
| | - Denise Cai
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
- Neuroscience Department, Icahn School of Medicine, New York, NY, USA
| | - Daniel Almeida Filho
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Giselle Fernandes
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Ying Cai
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - André F de Sousa
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Min Tian
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Nury Kim
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, Republic of Korea
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Jinsu Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Deanna Necula
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Chengbin Zhou
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Shuoyi Li
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Shelbi Salinas
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Andy Liu
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Xiaoman Kang
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Masakazu Kamata
- Department of Hematology and Oncology, University of California Los Angeles, Los Angeles, CA, USA
| | - Ayal Lavi
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Shan Huang
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Tawnie Silva
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA
| | - Won Do Heo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Alcino J Silva
- Neurobiology, Psychiatry and Psychology Departments and Integrative Center for Learning and Memory, University of California Los Angeles, Los Angeles, CA, USA.
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47
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The role of inhibitory circuits in hippocampal memory processing. Nat Rev Neurosci 2022; 23:476-492. [DOI: 10.1038/s41583-022-00599-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2022] [Indexed: 11/08/2022]
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48
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Wilmerding LK, Yazdanbakhsh A, Hasselmo ME. Impact of optogenetic pulse design on CA3 learning and replay: A neural model. CELL REPORTS METHODS 2022; 2:100208. [PMID: 35637904 PMCID: PMC9142690 DOI: 10.1016/j.crmeth.2022.100208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 10/22/2021] [Accepted: 04/11/2022] [Indexed: 11/23/2022]
Abstract
Optogenetic manipulation of hippocampal circuitry is an important tool for investigating learning in vivo. Numerous approaches to pulse design have been employed to elicit desirable circuit and behavioral outcomes. Here, we systematically test the outcome of different single-pulse waveforms in a rate-based model of hippocampal memory function at the level of mnemonic replay extension and de novo synaptic weight formation in CA3 and CA1. Lower-power waveforms with long forward or forward and backward ramps yield more natural sequence replay dynamics and induce synaptic plasticity that allows for more natural memory replay timing, in contrast to square or backward ramps. These differences between waveform shape and amplitude are preserved with the addition of noise in membrane potential, light scattering, and protein expression, improving the potential validity of predictions for in vivo work. These results inform future optogenetic experimental design choices in the field of learning and memory.
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Affiliation(s)
- Lucius K. Wilmerding
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Arash Yazdanbakhsh
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Michael E. Hasselmo
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
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49
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Ferreira-Fernandes E, Peça J. The Neural Circuit Architecture of Social Hierarchy in Rodents and Primates. Front Cell Neurosci 2022; 16:874310. [PMID: 35634473 PMCID: PMC9133341 DOI: 10.3389/fncel.2022.874310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Social status is recognized as a major determinant of social behavior and health among animals; however, the neural circuits supporting the formation and navigation of social hierarchies remain under extensive research. Available evidence suggests the prefrontal cortex is a keystone in this circuit, but upstream and downstream candidates are progressively emerging. In this review, we compare and integrate findings from rodent and primate studies to create a model of the neural and cellular networks supporting social hierarchies, both from a macro (i.e., circuits) to a micro-scale perspective (microcircuits and synapses). We start by summarizing the literature on the prefrontal cortex and other relevant brain regions to expand the current “prefrontal-centric” view of social hierarchy behaviors. Based on connectivity data we also discuss candidate regions that might inspire further investigation, as well as the caveats and strategies that have been used to further our understanding of the biological substrates underpinning social hierarchy and dominance.
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Affiliation(s)
- Emanuel Ferreira-Fernandes
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Institute of Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal
| | - João Peça
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal
- *Correspondence: João Peça
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50
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Ortega-de San Luis C, Ryan TJ. Understanding the physical basis of memory: Molecular mechanisms of the engram. J Biol Chem 2022; 298:101866. [PMID: 35346687 PMCID: PMC9065729 DOI: 10.1016/j.jbc.2022.101866] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 12/18/2022] Open
Abstract
Memory, defined as the storage and use of learned information in the brain, is necessary to modulate behavior and critical for animals to adapt to their environments and survive. Despite being a cornerstone of brain function, questions surrounding the molecular and cellular mechanisms of how information is encoded, stored, and recalled remain largely unanswered. One widely held theory is that an engram is formed by a group of neurons that are active during learning, which undergoes biochemical and physical changes to store information in a stable state, and that are later reactivated during recall of the memory. In the past decade, the development of engram labeling methodologies has proven useful to investigate the biology of memory at the molecular and cellular levels. Engram technology allows the study of individual memories associated with particular experiences and their evolution over time, with enough experimental resolution to discriminate between different memory processes: learning (encoding), consolidation (the passage from short-term to long-term memories), and storage (the maintenance of memory in the brain). Here, we review the current understanding of memory formation at a molecular and cellular level by focusing on insights provided using engram technology.
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Affiliation(s)
- Clara Ortega-de San Luis
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
| | - Tomás J Ryan
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Victoria, Australia; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada.
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