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Fenton AA. Remapping revisited: how the hippocampus represents different spaces. Nat Rev Neurosci 2024; 25:428-448. [PMID: 38714834 DOI: 10.1038/s41583-024-00817-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2024] [Indexed: 05/25/2024]
Abstract
The representation of distinct spaces by hippocampal place cells has been linked to changes in their place fields (the locations in the environment where the place cells discharge strongly), a phenomenon that has been termed 'remapping'. Remapping has been assumed to be accompanied by the reorganization of subsecond cofiring relationships among the place cells, potentially maximizing hippocampal information coding capacity. However, several observations challenge this standard view. For example, place cells exhibit mixed selectivity, encode non-positional variables, can have multiple place fields and exhibit unreliable discharge in fixed environments. Furthermore, recent evidence suggests that, when measured at subsecond timescales, the moment-to-moment cofiring of a pair of cells in one environment is remarkably similar in another environment, despite remapping. Here, I propose that remapping is a misnomer for the changes in place fields across environments and suggest instead that internally organized manifold representations of hippocampal activity are actively registered to different environments to enable navigation, promote memory and organize knowledge.
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Affiliation(s)
- André A Fenton
- Center for Neural Science, New York University, New York, NY, USA.
- Neuroscience Institute at the NYU Langone Medical Center, New York, NY, USA.
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2
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Park EH, Kao HY, Jourdi H, van Dijk MT, Carrillo-Segura S, Tunnell KW, Gutierrez J, Wallace EJ, Troy-Regier M, Radwan B, Lesburguères E, Alarcon JM, Fenton AA. Phencyclidine Disrupts Neural Coordination and Cognitive Control by Dysregulating Translation. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2024; 4:252-263. [PMID: 38298788 PMCID: PMC10829677 DOI: 10.1016/j.bpsgos.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 02/02/2024] Open
Abstract
Background Phencyclidine (PCP) causes psychosis, is abused with increasing frequency, and was extensively used in antipsychotic drug discovery. PCP discoordinates hippocampal ensemble action potential discharge and impairs cognitive control in rats, but how this uncompetitive NMDA receptor (NMDAR) antagonist impairs cognition remains unknown. Methods The effects of PCP were investigated on hippocampal CA1 ensemble action potential discharge in vivo in urethane-anesthetized rats and during awake behavior in mice, on synaptic responses in ex vivo mouse hippocampus slices, in mice on a hippocampus-dependent active place avoidance task that requires cognitive control, and on activating the molecular machinery of translation in acute hippocampus slices. Mechanistic causality was assessed by comparing the PCP effects with the effects of inhibitors of protein synthesis, group I metabotropic glutamate receptors (mGluR1/5), and subunit-selective NMDARs. Results Consistent with ionotropic actions, PCP discoordinated CA1 ensemble action potential discharge. PCP caused hyperactivity and impaired active place avoidance, despite the rodents having learned the task before PCP administration. Consistent with metabotropic actions, PCP exaggerated protein synthesis-dependent DHPG-induced mGluR1/5-stimulated long-term synaptic depression. Pretreatment with anisomycin or the mGluR1/5 antagonist MPEP, both of which repress translation, prevented PCP-induced discoordination and the cognitive and sensorimotor impairments. PCP as well as the NR2A-containing NMDAR antagonist NVP-AAM077 unbalanced translation that engages the Akt, mTOR (mechanistic target of rapamycin), and 4EBP1 translation machinery and increased protein synthesis, whereas the NR2B-containing antagonist Ro25-6981 did not. Conclusions PCP dysregulates translation, acting through NR2A-containing NMDAR subtypes, recruiting mGluR1/5 signaling pathways, and leading to neural discoordination that is central to the cognitive and sensorimotor impairments.
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Affiliation(s)
- Eun Hye Park
- Center for Neural Science, New York University, New York, New York
| | - Hsin-Yi Kao
- Center for Neural Science, New York University, New York, New York
| | - Hussam Jourdi
- Center for Neural Science, New York University, New York, New York
| | - Milenna T. van Dijk
- Center for Neural Science, New York University, New York, New York
- Graduate Program in Neuroscience and Physiology, New York University Langone Medical Center, New York, New York
| | - Simón Carrillo-Segura
- Center for Neural Science, New York University, New York, New York
- Graduate Program in Mechanical and Aerospace Engineering, New York University Tandon School of Engineering, New York, New York
| | - Kayla W. Tunnell
- Center for Neural Science, New York University, New York, New York
| | | | - Emma J. Wallace
- Graduate Program in Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - Matthew Troy-Regier
- Graduate Program in Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - Basma Radwan
- Graduate Program in Neural Science, Center for Neural Science, New York University, New York, New York
| | | | - Juan Marcos Alarcon
- Department of Pathology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - André A. Fenton
- Center for Neural Science, New York University, New York, New York
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Neuroscience Institute, NYU Langone Health, New York, New York
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3
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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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4
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Fenton AA, Hurtado JR, Broek JAC, Park E, Mishra B. Do Place Cells Dream of Deceptive Moves in a Signaling Game? Neuroscience 2023; 529:129-147. [PMID: 37591330 PMCID: PMC10592151 DOI: 10.1016/j.neuroscience.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 07/27/2023] [Accepted: 08/06/2023] [Indexed: 08/19/2023]
Abstract
We consider the possibility of applying game theory to analysis and modeling of neurobiological systems. Specifically, the basic properties and features of information asymmetric signaling games are considered and discussed as having potential to explain diverse neurobiological phenomena; we focus on neuronal action potential discharge that can represent cognitive variables in memory and purposeful behavior. We begin by arguing that there is a pressing need for conceptual frameworks that can permit analysis and integration of information and explanations across many scales of biological function including gene regulation, molecular and biochemical signaling, cellular and metabolic function, neuronal population, and systems level organization to generate plausible hypotheses across these scales. Developing such integrative frameworks is crucial if we are to understand cognitive functions like learning, memory, and perception. The present work focuses on systems neuroscience organized around the connected brain regions of the entorhinal cortex and hippocampus. These areas are intensely studied in rodent subjects as model neuronal systems that undergo activity-dependent synaptic plasticity to form neuronal circuits and represent memories and spatial knowledge used for purposeful navigation. Examples of cognition-related spatial information in the observed neuronal discharge of hippocampal place cell populations and medial entorhinal head-direction cell populations are used to illustrate possible challenges to information maximization concepts. It may be natural to explain these observations using the ideas and features of information asymmetric signaling games.
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Affiliation(s)
- André A Fenton
- Neurobiology of Cognition Laboratory, Center for Neural Science, New York University, New York, NY, USA; Neuroscience Institute at the NYU Langone Medical Center, New York, NY, USA.
| | - José R Hurtado
- Neurobiology of Cognition Laboratory, Center for Neural Science, New York University, New York, NY, USA
| | - Jantine A C Broek
- Departments of Computer Science and Mathematics, Courant Institute of Mathematical Sciences, New York University, New York, NY, USA
| | - EunHye Park
- Neurobiology of Cognition Laboratory, Center for Neural Science, New York University, New York, NY, USA
| | - Bud Mishra
- Departments of Computer Science and Mathematics, Courant Institute of Mathematical Sciences, New York University, New York, NY, USA; Department of Cell Biology, NYU Langone Medical Center, New York, NY, USA; Simon Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
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5
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Delgado-Sallent C, Nebot P, Gener T, Fath AB, Timplalexi M, Puig MV. Atypical, but Not Typical, Antipsychotic Drugs Reduce Hypersynchronized Prefrontal-Hippocampal Circuits during Psychosis-Like States in Mice: Contribution of 5-HT2A and 5-HT1A Receptors. Cereb Cortex 2021; 32:3472-3487. [PMID: 34875009 DOI: 10.1093/cercor/bhab427] [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: 07/12/2021] [Revised: 10/30/2021] [Accepted: 11/02/2021] [Indexed: 11/12/2022] Open
Abstract
Neural synchrony and functional connectivity are disrupted in schizophrenia. We investigated changes in prefrontal-hippocampal neural dynamics during psychosis-like states induced by the NMDAR antagonist phencyclidine and subsequent rescue by two atypical antipsychotic drugs (AAPDs), risperidone and clozapine, and the classical APD haloperidol. The psychotomimetic effects of phencyclidine were associated with prefrontal hypersynchronization, hippocampal desynchronization, and disrupted circuit connectivity. Phencyclidine boosted prefrontal oscillatory power at atypical bands within delta, gamma, and high frequency ranges, while irregular cross-frequency and spike-LFP coupling emerged. In the hippocampus, phencyclidine enhanced delta rhythms but suppressed theta oscillations, theta-gamma coupling, and theta-beta spike-LFP coupling. Baseline interregional theta-gamma coupling, theta phase coherence, and hippocampus-to-cortex theta signals were redirected to delta frequencies. Risperidone and clozapine, but not haloperidol, reduced phencyclidine-induced prefrontal and cortical-hippocampal hypersynchrony. None of the substances restored hippocampal and circuit desynchronization. These results suggest that AAPDs, but not typical APDs, target prefrontal-hippocampal pathways to elicit antipsychotic action. We investigated whether the affinity of AAPDs for serotonin receptors could explain their distinct effects. Serotonin 5-HT2AR antagonism by M100907 and 5-HT1AR agonism by 8-OH-DPAT reduced prefrontal hypersynchronization. Our results point to fundamentally different neural mechanisms underlying the action of atypical versus typical APDs with selective contribution of serotonin receptors.
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Affiliation(s)
- Cristina Delgado-Sallent
- Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - Pau Nebot
- Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - Thomas Gener
- Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - Amanda B Fath
- Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, 08003 Barcelona, Spain.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Melina Timplalexi
- Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
| | - M Victoria Puig
- Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, 08003 Barcelona, Spain
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Quirk CR, Zutshi I, Srikanth S, Fu ML, Marciano ND, Wright MK, Parsey DF, Liu S, Siretskiy RE, Huynh TL, Leutgeb JK, Leutgeb S. Precisely timed theta oscillations are selectively required during the encoding phase of memory. Nat Neurosci 2021; 24:1614-1627. [PMID: 34608335 PMCID: PMC8556344 DOI: 10.1038/s41593-021-00919-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 08/02/2021] [Indexed: 11/12/2022]
Abstract
Brain oscillations have been hypothesized to support cognitive function by coordinating spike timing within and across brain regions, yet it is often not known when timing is either critical for neural computations or an epiphenomenon. The entorhinal cortex and hippocampus are necessary for learning and memory and exhibit prominent theta oscillations (6-9 Hz), which are controlled by pacemaker cells in the medial septal area. Here we show that entorhinal and hippocampal neuronal activity patterns were strongly entrained by rhythmic optical stimulation of parvalbumin-positive medial septal area neurons in mice. Despite strong entrainment, memory impairments in a spatial working memory task were not observed with pacing frequencies at or below the endogenous theta frequency and only emerged at frequencies ≥10 Hz, and specifically when pacing was targeted to maze segments where encoding occurs. Neural computations during the encoding phase were therefore selectively disrupted by perturbations of the timing of neuronal firing patterns.
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Affiliation(s)
- Clare R. Quirk
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ipshita Zutshi
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sunandha Srikanth
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Maylin L. Fu
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Naomie Devico Marciano
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Morgan K. Wright
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Darian F. Parsey
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stanley Liu
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rachel E. Siretskiy
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Tiffany L. Huynh
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jill K. Leutgeb
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stefan Leutgeb
- Neurobiology Section and Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA,Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, CA 92093, USA,Correspondence should be addressed to S.L. ()
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7
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Speers LJ, Bilkey DK. Disorganization of Oscillatory Activity in Animal Models of Schizophrenia. Front Neural Circuits 2021; 15:741767. [PMID: 34675780 PMCID: PMC8523827 DOI: 10.3389/fncir.2021.741767] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/16/2021] [Indexed: 01/02/2023] Open
Abstract
Schizophrenia is a chronic, debilitating disorder with diverse symptomatology, including disorganized cognition and behavior. Despite considerable research effort, we have only a limited understanding of the underlying brain dysfunction. In this article, we review the potential role of oscillatory circuits in the disorder with a particular focus on the hippocampus, a region that encodes sequential information across time and space, as well as the frontal cortex. Several mechanistic explanations of schizophrenia propose that a loss of oscillatory synchrony between and within these brain regions may underlie some of the symptoms of the disorder. We describe how these oscillations are affected in several animal models of schizophrenia, including models of genetic risk, maternal immune activation (MIA) models, and models of NMDA receptor hypofunction. We then critically discuss the evidence for disorganized oscillatory activity in these models, with a focus on gamma, sharp wave ripple, and theta activity, including the role of cross-frequency coupling as a synchronizing mechanism. Finally, we focus on phase precession, which is an oscillatory phenomenon whereby individual hippocampal place cells systematically advance their firing phase against the background theta oscillation. Phase precession is important because it allows sequential experience to be compressed into a single 120 ms theta cycle (known as a 'theta sequence'). This time window is appropriate for the induction of synaptic plasticity. We describe how disruption of phase precession could disorganize sequential processing, and thereby disrupt the ordered storage of information. A similar dysfunction in schizophrenia may contribute to cognitive symptoms, including deficits in episodic memory, working memory, and future planning.
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Affiliation(s)
| | - David K. Bilkey
- Department of Psychology, Otago University, Dunedin, New Zealand
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8
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Kubie JL, Levy ERJ, Fenton AA. Is hippocampal remapping the physiological basis for context? Hippocampus 2019; 30:851-864. [PMID: 31571314 DOI: 10.1002/hipo.23160] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022]
Abstract
In 1980, Nadel and Wilner extended Richard Hirsh's notion that the hippocampus creates environmental representations, called "contexts," suggesting that the fundamental structure of context was the spatial representation proposed by O'Keefe and Nadel's landmark book, The Hippocampus as a Cognitive Map (1978). This book, in turn, derives from the discovery that individual hippocampal neurons act as place cells, with the complete set of place cells tiling an enclosure, forming a type of spatial map. It was found that unique environments had unique place cell representations. That is, if one takes the hippocampal map of a specific environment, this representation scrambles, or "remaps" when the animal is placed in a different environment. Several authors have speculated that "maps" and "remapping" form the physiological substrates for context and context shifting. One difficulty with this definition is that it is exclusively spatial; it can only be inferred when an animal locomotes in an enclosure. There are five aims for this article. The first is to give an historical overview of context as a variable that controls behavior. The second aim is to give an historical overview of concepts of place cell maps and remapping. The third aim is to propose an updated definition of a place cell map, based on temporal rather than spatial overlaps, which adds flexibility. The fourth aim is to address the issue of whether the biological phenomenon of hippocampal remapping, is, in fact, the substrate for shifts in the psychological phenomenon of context. The final aim is speculation of how contextual representations may contribute to effective behavior.
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Affiliation(s)
- John L Kubie
- Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn, New York.,Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Medical Center, Brooklyn, New York
| | - Eliott R J Levy
- Center for Neural Science, New York University, New York, New York
| | - André A Fenton
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Medical Center, Brooklyn, New York.,Center for Neural Science, New York University, New York, New York.,Neuroscience Institute at the New York University Langone Medical Center, New York University, New York, New York
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Krajcovic B, Fajnerova I, Horacek J, Kelemen E, Kubik S, Svoboda J, Stuchlik A. Neural and neuronal discoordination in schizophrenia: From ensembles through networks to symptoms. Acta Physiol (Oxf) 2019; 226:e13282. [PMID: 31002202 DOI: 10.1111/apha.13282] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/27/2019] [Accepted: 04/12/2019] [Indexed: 12/22/2022]
Abstract
Despite the substantial knowledge accumulated by past research, the exact mechanisms of the pathogenesis of schizophrenia and causal treatments still remain unclear. Deficits of cognition and information processing in schizophrenia are today often viewed as the primary and core symptoms of this devastating disorder. These deficits likely result from disruptions in the coordination of neuronal and neural activity. The aim of this review is to bring together convergent evidence of discoordinated brain circuits in schizophrenia at multiple levels of resolution, ranging from principal cells and interneurons, neuronal ensembles and local circuits, to large-scale brain networks. We show how these aberrations could underlie deficits in cognitive control and other higher order cognitive-behavioural functions. Converging evidence from both animal models and patients with schizophrenia is presented in an effort to gain insight into common features of deficits in the brain information processing in this disorder, marked by disruption of several neurotransmitter and signalling systems and severe behavioural outcomes.
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Affiliation(s)
- Branislav Krajcovic
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Third Faculty of Medicine Charles University Prague Czech Republic
| | - Iveta Fajnerova
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Jiri Horacek
- Third Faculty of Medicine Charles University Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Eduard Kelemen
- Research Programme 1 - Experimental Neurobiology National Institute of Mental Health Klecany Czech Republic
| | - Stepan Kubik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Jan Svoboda
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Ales Stuchlik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
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10
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O'Reilly KC, Perica MI, Fenton AA. Synaptic plasticity/dysplasticity, process memory and item memory in rodent models of mental dysfunction. Schizophr Res 2019; 207:22-36. [PMID: 30174252 PMCID: PMC6395534 DOI: 10.1016/j.schres.2018.08.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 08/14/2018] [Accepted: 08/14/2018] [Indexed: 12/21/2022]
Abstract
Activity-dependent changes in the effective connection strength of synapses are a fundamental feature of a nervous system. This so-called synaptic plasticity is thought to underlie storage of information in memory and has been hypothesized to be crucial for the effects of cognitive behavioral therapy. Synaptic plasticity stores information in a neural network, creating a trace of neural activity from past experience. The plasticity can also change the behavior of the network so the network can differentially transform/compute information in future activations. We discuss these two related but separable functions of synaptic plasticity; one we call "item memory" as it represents and stores items of information in memory, the other we call "process memory" as it encodes and stores functions such as computations to modify network information processing capabilities. We review evidence of item and process memory operations in behavior and evidence that experience modifies the brain's functional networks. We discuss neurodevelopmental rodent models relevant for understanding mental illness and compare two models in which one model, neonatal ventral hippocampal lesion (NVHL) has beneficial adult outcomes after being exposed to an adolescent cognitive experience that is potentially similar to cognitive behavioral therapy. The other model, gestational day 17 methylazoxymethanol acetate (GD17-MAM), does not benefit from the same adolescent cognitive experience. We propose that process memory is altered by early cognitive experience in NVHL rats but not in GD17-MAM rats, and discuss how dysplasticity factors may contribute to the differential adult outcomes after early cognitive experience in the NVHL and MAM models.
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Affiliation(s)
- Kally C O'Reilly
- Center for Neural Science, New York University, New York, NY 10003, USA.
| | - Maria I Perica
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - André A Fenton
- Center for Neural Science, New York University, New York, NY 10003, USA; Neuroscience Institute at the New York University Langone Medical Center, New York, NY 10016, USA; Department of Physiology & Pharmacology, Robert F. Furchgott Center for Neuroscience, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
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11
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Buzsáki G, Tingley D. Space and Time: The Hippocampus as a Sequence Generator. Trends Cogn Sci 2018; 22:853-869. [PMID: 30266146 PMCID: PMC6166479 DOI: 10.1016/j.tics.2018.07.006] [Citation(s) in RCA: 198] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 01/27/2023]
Abstract
Neural computations are often compared to instrument-measured distance or duration, and such relationships are interpreted by a human observer. However, neural circuits do not depend on human-made instruments but perform computations relative to an internally defined rate-of-change. While neuronal correlations with external measures, such as distance or duration, can be observed in spike rates or other measures of neuronal activity, what matters for the brain is how such activity patterns are utilized by downstream neural observers. We suggest that hippocampal operations can be described by the sequential activity of neuronal assemblies and their internally defined rate of change without resorting to the concept of space or time.
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Affiliation(s)
- György Buzsáki
- Neuroscience Institute, 435 East 30th Street, Langone Medical Center, New York University, New York, NY 10016, USA; Department of Neurology, Langone Medical Center, New York University, New York, NY 10016, USA; Center for Neural Science, New York University, New York, NY 10003, USA.
| | - David Tingley
- Neuroscience Institute, 435 East 30th Street, Langone Medical Center, New York University, New York, NY 10016, USA
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12
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Tingley D, Buzsáki G. Transformation of a Spatial Map across the Hippocampal-Lateral Septal Circuit. Neuron 2018; 98:1229-1242.e5. [PMID: 29779942 PMCID: PMC6605060 DOI: 10.1016/j.neuron.2018.04.028] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/20/2018] [Accepted: 04/19/2018] [Indexed: 01/08/2023]
Abstract
The hippocampus constructs a map of the environment. How this "cognitive map" is utilized by other brain regions to guide behavior remains unexplored. To examine how neuronal firing patterns in the hippocampus are transmitted and transformed, we recorded neurons in its principal subcortical target, the lateral septum (LS). We observed that LS neurons carry reliable spatial information in the phase of action potentials, relative to hippocampal theta oscillations, while the firing rates of LS neurons remained uninformative. Furthermore, this spatial phase code had an anatomical microstructure within the LS and was bound to the hippocampal spatial code by synchronous gamma frequency cell assemblies. Using a data-driven model, we show that rate-independent spatial tuning arises through the dynamic weighting of CA1 and CA3 cell assemblies. Our findings demonstrate that transformation of the hippocampal spatial map depends on higher-order theta-dependent neuronal sequences. VIDEO ABSTRACT.
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Affiliation(s)
- David Tingley
- Neuroscience Institute, New York University, New York, NY 10016, USA
| | - György Buzsáki
- Neuroscience Institute, New York University, New York, NY 10016, USA; Department of Neurology, New York University, New York, NY 10016, USA; Langone Medical Center, New York University, New York, NY 10016, USA; Center for Neural Science, New York University, New York, NY 10003, USA.
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Scharfman HE, Kanner AM, Friedman A, Blümcke I, Crocker CE, Cendes F, Diaz-Arrastia R, Förstl H, Fenton AA, Grace AA, Palop J, Morrison J, Nehlig A, Prasad A, Wilcox KS, Jette N, Pohlmann-Eden B. Epilepsy as a Network Disorder (2): What can we learn from other network disorders such as dementia and schizophrenia, and what are the implications for translational research? Epilepsy Behav 2018; 78:302-312. [PMID: 29097123 PMCID: PMC5756681 DOI: 10.1016/j.yebeh.2017.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 09/18/2017] [Accepted: 09/18/2017] [Indexed: 12/18/2022]
Abstract
There is common agreement that many disorders of the central nervous system are 'complex', that is, there are many potential factors that influence the development of the disease, underlying mechanisms, and successful treatment. Most of these disorders, unfortunately, have no cure at the present time, and therapeutic strategies often have debilitating side effects. Interestingly, some of the 'complexities' of one disorder are found in another, and the similarities are often network defects. It seems likely that more discussions of these commonalities could advance our understanding and, therefore, have clinical implications or translational impact. With this in mind, the Fourth International Halifax Epilepsy Conference and Retreat was held as described in the prior paper, and this companion paper focuses on the second half of the meeting. Leaders in various subspecialties of epilepsy research were asked to address aging and dementia or psychosis in people with epilepsy (PWE). Commonalities between autism, depression, aging and dementia, psychosis, and epilepsy were the focus of the presentations and discussion. In the last session, additional experts commented on new conceptualization of translational epilepsy research efforts. Here, the presentations are reviewed, and salient points are highlighted.
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Affiliation(s)
- Helen E Scharfman
- Departments of Psychiatry, Neurosciences and Physiology, and the Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
| | - Andres M Kanner
- University of Miami, Miller School of Medicine, 1120 NW 14th Street, Room #1324, Miami, FL 33136, USA
| | - Alon Friedman
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada; Department of Pediatrics, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada; Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ingmar Blümcke
- Neuropathological Institute, University Hospitals Erlangen, Germany
| | - Candice E Crocker
- Nova Scotia Early Psychosis Program, Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Fernando Cendes
- Department of Neurology, University of Campinas, 13083-888 Campinas, Sao Paulo, Brazil
| | - Ramon Diaz-Arrastia
- Centre for Neuroscience & Regenerative Medicine, Uniformed Services University of the Health Sciences, 12725 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Hans Förstl
- Department of Psychiatry, University of Munich, Klinikum rechts der Isar, Ismaninger Strabe 22, D-81675 Munich, Germany
| | - André A Fenton
- Centre for Neural Science, New York University, 4 Washington Place, Room 809, New York, NY 10003, USA
| | - Anthony A Grace
- University of Pittsburgh, 456 Langley Hall, 4200 Fifth Avenue, Pittsburgh, PA 15269, USA
| | - Jorge Palop
- Department of Neurology, Gladstone Institute, 1650 Owens Street, San Francisco, CA 94158-2261, USA
| | - Jason Morrison
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Astrid Nehlig
- INSERM U 1129, Hôpital Necker, Paris, Faculty of Medicine, Strasbourg, France
| | - Asuri Prasad
- Department of Pediatrics, Children's Hospital of Western Ontario, London, ON, Canada
| | - Karen S Wilcox
- Department of Pharmacology & Toxicology, Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, USA
| | - Nathalie Jette
- Icahn School of Medicine at Mount Sinai, Department of Neurology, New York, NY, USA; Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Bernd Pohlmann-Eden
- Brain Repair Center, Life Science Research Institute, Dalhousie University, Room 229, PO Box 15000, Halifax, NS B3H4R2, Canada.
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