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Raghuraman R, Aoun A, Herman M, Shetler O, Nahmani E, Hussaini SA. Lateral Entorhinal Cortex Dysfunction in Alzheimer's disease Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589589. [PMID: 38659892 PMCID: PMC11042344 DOI: 10.1101/2024.04.15.589589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
In Alzheimer's disease (AD), the formation of amyloid beta (A β ) and neurofibrillary tangles (NFTs) leads to neuronal loss in entorhinal cortex (EC), a crucial brain region involved in memory and navigation. These pathological changes are concurrent with the onset of memory-related issues in AD patients with symptoms of forgetfulness such as misplacing items, disorientation in familiar environments etc. The lateral EC (LEC) is associated with non-spatial memory processing including object recognition. Since in LEC, neurons fire in response to objects (object cells) and at locations previously occupied by objects (trace cells), pathology in this region could lead to dysfunction in object location coding. In this paper we show that a transgenic mouse model, EC-App/Tau, which expresses both APP and tau primarily in the EC region, have deficits in LEC-specific memory tasks. Using in vivo single-unit electrophysiology recordings we show that the LEC neurons are hyperactive with low information content and high sparsity compared to the controls indicating poor firing fidelity. We finally show that object cells and trace cells fire less precisely in the EC-App/Tau mice compared to controls indicating poor encoding of objects. Overall, we show that AD pathology causes erratic firing of LEC neurons and object coding defects leading to LEC-specific memory impairment.
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Hoang TH, Manahan-Vaughan D. Differentiated somatic gene expression is triggered in the dorsal hippocampus and the anterior retrosplenial cortex by hippocampal synaptic plasticity prompted by spatial content learning. Brain Struct Funct 2024; 229:639-655. [PMID: 37690045 PMCID: PMC10978647 DOI: 10.1007/s00429-023-02694-z] [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: 04/05/2023] [Accepted: 08/07/2023] [Indexed: 09/12/2023]
Abstract
Hippocampal afferent inputs, terminating on proximal and distal subfields of the cornus ammonis (CA), enable the functional discrimination of 'what' (item identity) and 'where' (spatial location) elements of a spatial representation. This kind of information is supported by structures such as the retrosplenial cortex (RSC). Spatial content learning promotes the expression of hippocampal synaptic plasticity, particularly long-term depression (LTD). In the CA1 region, this is specifically facilitated by the learning of item-place features of a spatial environment. Gene-tagging, by means of time-locked fluorescence in situ hybridization (FISH) to detect nuclear expression of immediate early genes, can reveal neuronal populations that engage in experience-dependent information encoding. In the current study, using FISH, we examined if learning-facilitated LTD results in subfield-specific information encoding in the hippocampus and RSC. Rats engaged in novel exploration of small items during stimulation of Schaffer collateral-CA1 synapses. This resulted in LTD (> 24 h). FISH, to detect nuclear expression of Homer1a, revealed that the distal-CA1 and proximal-CA3 subcompartments were particularly activated by this event. By contrast, all elements of the proximodistal cornus ammonis-axis showed equal nuclear Homer1a expression following LTD induction solely by means of afferent stimulation. The RSC exhibited stronger nuclear Homer1a expression in response to learning-facilitated LTD, and to novel item-place experience, compared to LTD induced by sole afferent stimulation in CA1. These results show that both the cornus ammonis and RSC engage in differentiated information encoding of item-place learning that is salient enough, in its own right, to drive the expression of hippocampal LTD. These results also reveal a novel role of the RSC in item-place learning.
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Affiliation(s)
- Thu-Huong Hoang
- Medical Faculty, Department of Neurophysiology, Ruhr University Bochum, Universitätsstr. 150, MA 4/150, 44780, Bochum, Germany
| | - Denise Manahan-Vaughan
- Medical Faculty, Department of Neurophysiology, Ruhr University Bochum, Universitätsstr. 150, MA 4/150, 44780, Bochum, Germany.
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Chmiel J, Malinowska A, Rybakowski F, Leszek J. The Effectiveness of Mindfulness in the Treatment of Methamphetamine Addiction Symptoms: Does Neuroplasticity Play a Role? Brain Sci 2024; 14:320. [PMID: 38671972 PMCID: PMC11047954 DOI: 10.3390/brainsci14040320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 03/23/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
INTRODUCTION Methamphetamine is a highly stimulating psychoactive drug that causes life-threatening addictions and affects millions of people around the world. Its effects on the brain are complex and include disturbances in the neurotransmitter systems and neurotoxicity. There are several known treatment methods, but their effectiveness is moderate. It must be emphasised that no drugs have been approved for treatment. For this reason, there is an urgent need to develop new, effective, and safe treatments for methamphetamine. One of the potential treatments is mindfulness meditation. In recent years, this technique has been researched extensively in the context of many neurological and psychiatric disorders. METHODS This review explores the use of mindfulness in the treatment of methamphetamine addiction. Searches were conducted in the PubMed/Medline, Research Gate, and Cochrane databases. RESULTS Ten studies were identified that used mindfulness-based interventions in the treatment of methamphetamine addiction. The results show that mindfulness is an effective form of reducing hunger, risk of relapses, stress indicators, depression, and aggression, alone or in combination with transcranial direct current stimulation (tDCS). Mindfulness also improved the cognitive function in addicts. The included studies used only behavioural measures. The potential mechanisms of mindfulness in addiction were explained, and it was proposed that it can induce neuroplasticity, alleviating the symptoms of addiction. CONCLUSIONS Evidence from the studies suggest that mindfulness may be an effective treatment option for methamphetamine addiction, used alone or in combination with tDCS. However, further high-quality research is required to establish the role of this treatment option in this field. The use of neuroimaging and neurophysiological measures is fundamental to understand the mechanisms of mindfulness.
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Affiliation(s)
- James Chmiel
- Institute of Neurofeedback and tDCS Poland, 70-393 Szczecin, Poland
| | | | - Filip Rybakowski
- Department and Clinic of Psychiatry, Poznan University of Medical Sciences, 61-701 Poznań, Poland
| | - Jerzy Leszek
- Department and Clinic of Psychiatry, Wrocław Medical University, 54-235 Wrocław, Poland
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Issa JB, Radvansky BA, Xuan F, Dombeck DA. Lateral entorhinal cortex subpopulations represent experiential epochs surrounding reward. Nat Neurosci 2024; 27:536-546. [PMID: 38272968 PMCID: PMC11097142 DOI: 10.1038/s41593-023-01557-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/13/2023] [Indexed: 01/27/2024]
Abstract
During goal-directed navigation, 'what' information, describing the experiences occurring in periods surrounding a reward, can be combined with spatial 'where' information to guide behavior and form episodic memories. This integrative process likely occurs in the hippocampus, which receives spatial information from the medial entorhinal cortex; however, the source of the 'what' information is largely unknown. Here, we show that mouse lateral entorhinal cortex (LEC) represents key experiential epochs during reward-based navigation tasks. We discover separate populations of neurons that signal goal approach and goal departure and a third population signaling reward consumption. When reward location is moved, these populations immediately shift their respective representations of each experiential epoch relative to reward, while optogenetic inhibition of LEC disrupts learning the new reward location. Therefore, the LEC contains a stable code of experiential epochs surrounding and including reward consumption, providing reward-centric information to contextualize the spatial information carried by the medial entorhinal cortex.
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Affiliation(s)
- John B Issa
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Brad A Radvansky
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Feng Xuan
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Daniel A Dombeck
- Department of Neurobiology, Northwestern University, Evanston, IL, USA.
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Hainmueller T, Cazala A, Huang LW, Bartos M. Subfield-specific interneuron circuits govern the hippocampal response to novelty in male mice. Nat Commun 2024; 15:714. [PMID: 38267409 PMCID: PMC10808551 DOI: 10.1038/s41467-024-44882-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/04/2024] [Indexed: 01/26/2024] Open
Abstract
The hippocampus is the brain's center for episodic memories. Its subregions, the dentate gyrus and CA1-3, are differentially involved in memory encoding and recall. Hippocampal principal cells represent episodic features like movement, space, and context, but less is known about GABAergic interneurons. Here, we performed two-photon calcium imaging of parvalbumin- and somatostatin-expressing interneurons in the dentate gyrus and CA1-3 of male mice exploring virtual environments. Parvalbumin-interneurons increased activity with running-speed and reduced it in novel environments. Somatostatin-interneurons in CA1-3 behaved similar to parvalbumin-expressing cells, but their dentate gyrus counterparts increased activity during rest and in novel environments. Congruently, chemogenetic silencing of dentate parvalbumin-interneurons had prominent effects in familiar contexts, while silencing somatostatin-expressing cells increased similarity of granule cell representations between novel and familiar environments. Our data indicate unique roles for parvalbumin- and somatostatin-positive interneurons in the dentate gyrus that are distinct from those in CA1-3 and may support routing of novel information.
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Affiliation(s)
- Thomas Hainmueller
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany.
- NYU Neuroscience Institute, 435 East 30th Street, New York, NY, 10016, USA.
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, 10016, USA.
| | - Aurore Cazala
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany
| | - Li-Wen Huang
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany
| | - Marlene Bartos
- Institute for Physiology I, University of Freiburg, Medical Faculty, 79104, Freiburg, Germany.
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Aoun A, Shetler O, Raghuraman R, Rodriguez GA, Hussaini SA. Beyond Correlation: Optimal Transport Metrics For Characterizing Representational Stability and Remapping in Neurons Encoding Spatial Memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.11.548592. [PMID: 37503011 PMCID: PMC10369988 DOI: 10.1101/2023.07.11.548592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Spatial representations in the entorhinal cortex (EC) and hippocampus (HPC) are fundamental to cognitive functions like navigation and memory. These representations, embodied in spatial field maps, dynamically remap in response to environmental changes. However, current methods, such as Pearson's correlation coefficient, struggle to capture the complexity of these remapping events, especially when fields do not overlap, or transformations are non-linear. This limitation hinders our understanding and quantification of remapping, a key aspect of spatial memory function. To address this, we propose a family of metrics based on the Earth Mover's Distance (EMD) as a versatile framework for characterizing remapping. Applied to both normalized and unnormalized distributions, the EMD provides a granular, noise-resistant, and rate-robust description of remapping. This approach enables the identification of specific cell types and the characterization of remapping in various scenarios, including disease models. Furthermore, the EMD's properties can be manipulated to identify spatially tuned cell types and to explore remapping as it relates to alternate information forms such as spatiotemporal coding. By employing approximations of the EMD, we present a feasible, lightweight approach that complements traditional methods. Our findings underscore the potential of the EMD as a powerful tool for enhancing our understanding of remapping in the brain and its implications for spatial navigation, memory studies and beyond.
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Affiliation(s)
- Andrew Aoun
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
- Co-first author
| | - Oliver Shetler
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
- Co-first author
| | - Radha Raghuraman
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Gustavo A. Rodriguez
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - S. Abid Hussaini
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
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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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Issa JB, Radvansky BA, Xuan F, Dombeck DA. Lateral entorhinal cortex subpopulations represent experiential epochs surrounding reward. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.09.561557. [PMID: 37873482 PMCID: PMC10592707 DOI: 10.1101/2023.10.09.561557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
During goal-directed navigation, "what" information, which describes the experiences occurring in periods surrounding a reward, can be combined with spatial "where" information to guide behavior and form episodic memories1,2. This integrative process is thought to occur in the hippocampus3, which receives spatial information from the medial entorhinal cortex (MEC)4; however, the source of the "what" information and how it is represented is largely unknown. Here, by establishing a novel imaging method, we show that the lateral entorhinal cortex (LEC) of mice represents key experiential epochs during a reward-based navigation task. We discover a population of neurons that signals goal approach and a separate population of neurons that signals goal departure. A third population of neurons signals reward consumption. When reward location is moved, these populations immediately shift their respective representations of each experiential epoch relative to reward, while optogenetic inhibition of LEC disrupts learning of the new reward location. Together, these results indicate the LEC provides a stable code of experiential epochs surrounding and including reward consumption, providing reward-centric information to contextualize the spatial information carried by the MEC. Such parallel representations are well-suited for generating episodic memories of rewarding experiences and guiding flexible and efficient goal-directed navigation5-7.
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Affiliation(s)
- John B. Issa
- Department of Neurobiology, Northwestern University, Evanston, IL 60608, USA
| | - Brad A. Radvansky
- Department of Neurobiology, Northwestern University, Evanston, IL 60608, USA
| | - Feng Xuan
- Department of Neurobiology, Northwestern University, Evanston, IL 60608, USA
| | - Daniel A. Dombeck
- Department of Neurobiology, Northwestern University, Evanston, IL 60608, USA
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Borzello M, Ramirez S, Treves A, Lee I, Scharfman H, Stark C, Knierim JJ, Rangel LM. Assessments of dentate gyrus function: discoveries and debates. Nat Rev Neurosci 2023; 24:502-517. [PMID: 37316588 PMCID: PMC10529488 DOI: 10.1038/s41583-023-00710-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2023] [Indexed: 06/16/2023]
Abstract
There has been considerable speculation regarding the function of the dentate gyrus (DG) - a subregion of the mammalian hippocampus - in learning and memory. In this Perspective article, we compare leading theories of DG function. We note that these theories all critically rely on the generation of distinct patterns of activity in the region to signal differences between experiences and to reduce interference between memories. However, these theories are divided by the roles they attribute to the DG during learning and recall and by the contributions they ascribe to specific inputs or cell types within the DG. These differences influence the information that the DG is thought to impart to downstream structures. We work towards a holistic view of the role of DG in learning and memory by first developing three critical questions to foster a dialogue between the leading theories. We then evaluate the extent to which previous studies address our questions, highlight remaining areas of conflict, and suggest future experiments to bridge these theories.
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Affiliation(s)
- Mia Borzello
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, USA
| | - Steve Ramirez
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | | | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Helen Scharfman
- Departments of Child and Adolescent Psychiatry, Neuroscience and Physiology and Psychiatry and the Neuroscience Institute, New York University Langone Health, New York, NY, USA
- The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Craig Stark
- Department of Neurobiology and Behaviour, University of California, Irvine, Irvine, CA, USA
| | - James J Knierim
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - Lara M Rangel
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, USA.
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10
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Ardanaz CG, Ezkurdia A, Bejarano A, Echarte B, Smerdou C, Martisova E, Martínez-Valbuena I, Luquin MR, Ramírez MJ, Solas M. JNK3 Overexpression in the Entorhinal Cortex Impacts on the Hippocampus and Induces Cognitive Deficiencies and Tau Misfolding. ACS Chem Neurosci 2023. [PMID: 37236204 DOI: 10.1021/acschemneuro.3c00092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
c-Jun N-terminal kinases (JNKs) are a family of protein kinases activated by a myriad of stimuli consequently modulating a vast range of biological processes. In human postmortem brain samples affected with Alzheimer's disease (AD), JNK overactivation has been described; however, its role in AD onset and progression is still under debate. One of the earliest affected areas in the pathology is the entorhinal cortex (EC). Noteworthy, the deterioration of the projection from EC to hippocampus (Hp) point toward the idea that the connection between EC and Hp is lost in AD. Thus, the main objective of the present work is to address if JNK3 overexpression in the EC could impact on the hippocampus, inducing cognitive deficits. Data obtained in the present work suggest that JNK3 overexpression in the EC influences the Hp leading to cognitive impairment. Moreover, proinflammatory cytokine expression and Tau immunoreactivity were increased both in the EC and in the Hp. Therefore, activation of inflammatory signaling and induction of Tau aberrant misfolding caused by JNK3 could be responsible for the observed cognitive impairment. Altogether, JNK3 overexpression in the EC may impact on the Hp inducing cognitive dysfunction and underlie the alterations observed in AD.
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Affiliation(s)
- Carlos G Ardanaz
- Department of Pharmacology and Toxicology, University of Navarra, 31008 Pamplona, Spain
- IdISNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Amaia Ezkurdia
- Department of Pharmacology and Toxicology, University of Navarra, 31008 Pamplona, Spain
- IdISNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Arantza Bejarano
- Department of Pharmacology and Toxicology, University of Navarra, 31008 Pamplona, Spain
| | - Beatriz Echarte
- Department of Pharmacology and Toxicology, University of Navarra, 31008 Pamplona, Spain
| | - Cristian Smerdou
- IdISNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
- Division of Gene Therapy and Regulation of Gene Expression, Cima Universidad de Navarra, 31008 Pamplona, Spain
| | - Eva Martisova
- Division of Gene Therapy and Regulation of Gene Expression, Cima Universidad de Navarra, 31008 Pamplona, Spain
| | - Iván Martínez-Valbuena
- IdISNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
- Neurosciences Division, Cima Universidad de Navarra, 31008 Pamplona, Spain
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, M5S 1A8 Toronto, Canada
| | - María-Rosario Luquin
- IdISNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
- Neurosciences Division, Cima Universidad de Navarra, 31008 Pamplona, Spain
- Neurology Department, Clinica Universidad de Navarra, 31008 Pamplona, Spain
| | - María J Ramírez
- Department of Pharmacology and Toxicology, University of Navarra, 31008 Pamplona, Spain
- IdISNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Maite Solas
- Department of Pharmacology and Toxicology, University of Navarra, 31008 Pamplona, Spain
- IdISNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
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Kozhevnikov M, Puri J. Different Types of Survey-Based Environmental Representations: Egocentric vs. Allocentric Cognitive Maps. Brain Sci 2023; 13:brainsci13050834. [PMID: 37239306 DOI: 10.3390/brainsci13050834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
The goal of the current study was to show the existence of distinct types of survey-based environmental representations, egocentric and allocentric, and provide experimental evidence that they are formed by different types of navigational strategies, path integration and map-based navigation, respectively. After traversing an unfamiliar route, participants were either disoriented and asked to point to non-visible landmarks encountered on the route (Experiment 1) or presented with a secondary spatial working memory task while determining the spatial locations of objects on the route (Experiment 2). The results demonstrate a double dissociation between the navigational strategies underlying the formation of allocentric and egocentric survey-based representation. Specifically, only the individuals who generated egocentric survey-based representations of the route were affected by disorientation, suggesting they relied primarily on a path integration strategy combined with landmark/scene processing at each route segment. In contrast, only allocentric-survey mappers were affected by the secondary spatial working memory task, suggesting their use of map-based navigation. This research is the first to show that path integration, in conjunction with egocentric landmark processing, is a distinct standalone navigational strategy underpinning the formation of a unique type of environmental representation-the egocentric survey-based representation.
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Affiliation(s)
- Maria Kozhevnikov
- Department of Psychology, National University of Singapore, 9 Arts Link, Singapore 117572, Singapore
- Martinos Center for Biomedical Imaging, Harvard Medical School Department of Radiology, 149 Thirteenth Street, Charlestown, MA 02129, USA
| | - Jyotika Puri
- Department of Psychology, National University of Singapore, 9 Arts Link, Singapore 117572, Singapore
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Schmitt O, Eipert P, Wang Y, Kanoke A, Rabiller G, Liu J. Connectome-based prediction of functional impairment in experimental stroke models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.05.539601. [PMID: 37205373 PMCID: PMC10187266 DOI: 10.1101/2023.05.05.539601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Experimental rat models of stroke and hemorrhage are important tools to investigate cerebrovascular disease pathophysiology mechanisms, yet how significant patterns of functional impairment induced in various models of stroke are related to changes in connectivity at the level of neuronal populations and mesoscopic parcellations of rat brains remain unresolved. To address this gap in knowledge, we employed two middle cerebral artery occlusion models and one intracerebral hemorrhage model with variant extent and location of neuronal dysfunction. Motor and spatial memory function was assessed and the level of hippocampal activation via Fos immunohistochemistry. Contribution of connectivity change to functional impairment was analyzed for connection similarities, graph distances and spatial distances as well as the importance of regions in terms of network architecture based on the neuroVIISAS rat connectome. We found that functional impairment correlated with not only the extent but also the locations of the injury among the models. In addition, via coactivation analysis in dynamic rat brain models, we found that lesioned regions led to stronger coactivations with motor function and spatial learning regions than with other unaffected regions of the connectome. Dynamic modeling with the weighted bilateral connectome detected changes in signal propagation in the remote hippocampus in all 3 stroke types, predicting the extent of hippocampal hypoactivation and impairment in spatial learning and memory function. Our study provides a comprehensive analytical framework in predictive identification of remote regions not directly altered by stroke events and their functional implication.
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Affiliation(s)
- Oliver Schmitt
- Medical School Hamburg - University of Applied Sciences, Department of Anatomy; University of Rostock, Institute of Anatomy
- SFVAMC, 1700 Owens Street, San Francisco, CA 94158
| | - Peter Eipert
- Medical School Hamburg - University of Applied Sciences, Department of Anatomy; University of Rostock, Institute of Anatomy
- SFVAMC, 1700 Owens Street, San Francisco, CA 94158
| | - Yonggang Wang
- Department of Neurological Surgery, UCSF
- SFVAMC, 1700 Owens Street, San Francisco, CA 94158
- Department of Neurological Surgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China, 100050
| | - Atsushi Kanoke
- Department of Neurological Surgery, UCSF
- SFVAMC, 1700 Owens Street, San Francisco, CA 94158
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Gratianne Rabiller
- Department of Neurological Surgery, UCSF
- SFVAMC, 1700 Owens Street, San Francisco, CA 94158
| | - Jialing Liu
- Department of Neurological Surgery, UCSF
- SFVAMC, 1700 Owens Street, San Francisco, CA 94158
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Çakır M, Yüksel F, Mustafa Özkut M, Durhan M, Kaymak E, Tekin S, Çiğremiş Y. Neuroprotective effect of transient receptor potential Vanilloid 1 agonist capsaicin in Alzheimer’s disease model induced with okadaic acid. Int Immunopharmacol 2023; 118:109925. [PMID: 37011502 DOI: 10.1016/j.intimp.2023.109925] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/30/2023] [Accepted: 02/18/2023] [Indexed: 04/04/2023]
Abstract
BACKGROUND The presence of Transient Receptor Potential Vanilloid 1 (TRPV1) channels was detected in many regions of the human and rat brain, including the cortex and hippocampus. TRPV1 channels have functions such as the modulation of synaptic transmission and plasticity and the regulation of cognitive functions. Previous studies conducted with TRPV1 agonists and antagonists show that this channel is associated with the neurodegenerative process. In the present study, the purpose was to investigate the effects of capsaicin, which is a TRPV1 agonist, and capsazepine, a TRPV1 antagonist, in the Alzheimer's Disease (AD) model that was induced by intracerebroventricular (ICV) administration of okadaic acid (OKA). METHODS The AD-like experimental model was created with bilateral ICV OKA injection. Intraperitoneal capsaicin and capsazepine injections were administered to the treatment groups for 13 days and histological and immunohistochemical examinations were performed from the cortex and hippocampal CA3 regions of the brain. The Morris Water Maze Test was used for spatial memory measurement. RESULTS ICV OKA administration increased the levels of caspase-3, phosphorylated-tau-(ser396), Aβ, TNF-α, and IL1-β, from the cortex and hippocampal CA3 regions of the brain and decreased the phosphorylated-Glycogen synthase kinase-3 beta-(ser9) levels. In addition, the OKA administration corrupted the spatial memory. The TRPV1 agonist capsaicin reversed the pathological changes induced by ICV OKA administration, but not the TRPV1 antagonist capsazepine. CONCLUSIONS It was found in the study that the administration of the TRPV1 agonist capsaicin reduced neurodegeneration, neuroinflammation, and deterioration in spatial memory in the AD model induced by OKA.
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Layfield D, Sidell N, Blankenberger K, Newman EL. Hippocampal inactivation during rearing on hind legs impairs spatial memory. Sci Rep 2023; 13:6136. [PMID: 37061540 PMCID: PMC10105745 DOI: 10.1038/s41598-023-33209-9] [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: 10/24/2022] [Accepted: 04/09/2023] [Indexed: 04/17/2023] Open
Abstract
Spatial memory requires an intact hippocampus. Hippocampal function during epochs of locomotion and quiet rest (e.g., grooming and reward consumption) has been the target of extensive study. However, during navigation rats frequently rear up onto their hind legs, and the importance of hippocampal activity during these periods of attentive sampling for spatial memory is unknown. To address this, we tested the necessity of dorsal hippocampal activity during rearing epochs in the study phase of a delayed win-shift task for memory performance in the subsequent test phase. Hippocampal activity was manipulated with closed-loop, bilateral, optogenetic inactivation. Spatial memory accuracy was significantly and selectively reduced when the dorsal hippocampus was inactivated during rearing epochs at encoding. These data show that hippocampal activity during periods of rearing can be important for spatial memory, revealing a novel link between hippocampal function during epochs of rearing and spatial memory.
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Affiliation(s)
- Dylan Layfield
- Program in Neuroscience, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA.
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA.
| | - Nathan Sidell
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
| | - Kevin Blankenberger
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
| | - Ehren Lee Newman
- Program in Neuroscience, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, 1101 E 10th St, Bloomington, IN, 47405, USA
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15
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Kurth-Nelson Z, Behrens T, Wayne G, Miller K, Luettgau L, Dolan R, Liu Y, Schwartenbeck P. Replay and compositional computation. Neuron 2023; 111:454-469. [PMID: 36640765 DOI: 10.1016/j.neuron.2022.12.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/11/2022] [Accepted: 12/18/2022] [Indexed: 01/15/2023]
Abstract
Replay in the brain has been viewed as rehearsal or, more recently, as sampling from a transition model. Here, we propose a new hypothesis: that replay is able to implement a form of compositional computation where entities are assembled into relationally bound structures to derive qualitatively new knowledge. This idea builds on recent advances in neuroscience, which indicate that the hippocampus flexibly binds objects to generalizable roles and that replay strings these role-bound objects into compound statements. We suggest experiments to test our hypothesis, and we end by noting the implications for AI systems which lack the human ability to radically generalize past experience to solve new problems.
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Affiliation(s)
- Zeb Kurth-Nelson
- DeepMind, London, UK; Max Planck UCL Centre for Computational Psychiatry and Ageing Research, London, UK.
| | - Timothy Behrens
- Wellcome Centre for Human Neuroimaging, University College London, London, UK; Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | | | - Kevin Miller
- DeepMind, London, UK; Institute of Ophthalmology, University College London, London, UK
| | - Lennart Luettgau
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research, London, UK
| | - Ray Dolan
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research, London, UK; Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Yunzhe Liu
- State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China; Chinese Institute for Brain Research, Beijing, China
| | - Philipp Schwartenbeck
- Max Planck Institute for Biological Cybernetics, Tubingen, Germany; University of Tubingen, Tubingen, Germany
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16
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Network localization of transient global amnesia beyond the hippocampus. Neurol Sci 2023; 44:649-657. [PMID: 36222907 DOI: 10.1007/s10072-022-06439-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 09/29/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND Transient global amnesia is common in the older adult, but the cause and mechanism remain unclear. Focal brain lesions allow for causal links between the lesion location and resulting symptoms, and we based on the reported TGA-causing lesions and used lesion network mapping to explore the causal neuroanatomical substrate of TGA. METHODS Fifty-one cases of transient global amnesias with DWI lesions from the literature were identified, and clinical data were extracted and analyzed. Next, we mapped each lesion volume onto a reference brain and computed the network of regions functionally connected to each lesion location using a large normative connectome dataset. RESULTS Lesions primarily occurred in the hippocampus, and in addition to the hippocampus, there are also other locations of TGA-causing lesions such as the cingulate gyrus, anterior thalamic nucleus (ATN), putamen, caudate nucleus, corpus callosum, fornix. More than 90% of TGA-causing lesions inside the hippocampus were functionally connected with the default mode network (DMN). CONCLUSION Structural abnormality in the hippocampus was the most consistently reported in TGA, and besides the hippocampus, lesions occurring at several other brain locations also could cause TGA. The DMN may also be involved in the pathophysiology of TGA. According to the clinical and neuroimaging characteristics, TGA may be a syndrome with multiple causes and cannot be treated simply as a subtype of TIA.
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Aru J, Drüke M, Pikamäe J, Larkum ME. Mental navigation and the neural mechanisms of insight. Trends Neurosci 2023; 46:100-109. [PMID: 36462993 DOI: 10.1016/j.tins.2022.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022]
Abstract
How do new ideas come about? The central hypothesis presented here states that insights might happen during mental navigation and correspond to rapid plasticity at the cellular level. We highlight the differences between neocortical and hippocampal mechanisms of insight. We argue that the suddenness of insight can be related to the sudden emergence of place fields in the hippocampus. According to our hypothesis, insights are supported by a state of mind-wandering that can be tied to the process of combining knowledge pieces during sharp-wave ripples (SWRs). Our framework connects the dots between research on creativity, mental navigation, and specific synaptic plasticity mechanisms in the hippocampus.
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Affiliation(s)
- Jaan Aru
- Institute of Computer Science, University of Tartu, Tartu, Estonia.
| | - Moritz Drüke
- Institute of Biology, Humboldt University Berlin, Berlin, Germany
| | - Juhan Pikamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Matthew E Larkum
- Institute of Biology, Humboldt University Berlin, Berlin, Germany; Neurocure Center for Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
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18
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Dimsdale-Zucker HR, Montchal ME, Reagh ZM, Wang SF, Libby LA, Ranganath C. Representations of Complex Contexts: A Role for Hippocampus. J Cogn Neurosci 2023; 35:90-110. [PMID: 36166300 PMCID: PMC9832373 DOI: 10.1162/jocn_a_01919] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The hippocampus plays a critical role in supporting episodic memory, in large part by binding together experiences and items with surrounding contextual information. At present, however, little is known about the roles of different hippocampal subfields in supporting this item-context binding. To address this question, we constructed a task in which items were affiliated with differing types of context-cognitive associations that vary at the local, item level and membership in temporally organized lists that linked items together at a global level. Participants made item recognition judgments while undergoing high-resolution fMRI. We performed voxel pattern similarity analyses to answer the question of how human hippocampal subfields represent retrieved information about cognitive states and the time at which a past event took place. As participants recollected previously presented items, activity patterns in the CA23DG subregion carried information about prior cognitive states associated with these items. We found no evidence to suggest reinstatement of information about temporal context at the level of list membership, but exploratory analyses revealed representations of temporal context at a coarse level in conjunction with representations of cognitive contexts. Results are consistent with characterizations of CA23DG as a critical site for binding together items and contexts in the service of memory retrieval.
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Lee SM, Shin J, Lee I. Significance of visual scene-based learning in the hippocampal systems across mammalian species. Hippocampus 2022; 33:505-521. [PMID: 36458555 DOI: 10.1002/hipo.23483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/26/2022] [Accepted: 11/19/2022] [Indexed: 12/04/2022]
Abstract
The hippocampus and its associated cortical regions in the medial temporal lobe play essential roles when animals form a cognitive map and use it to achieve their goals. As the nature of map-making involves sampling different local views of the environment and putting them together in a spatially cohesive way, visual scenes are essential ingredients in the formative process of cognitive maps. Visual scenes also serve as important cues during information retrieval from the cognitive map. Research in humans has shown that there are regions in the brain that selectively process scenes and that the hippocampus is involved in scene-based memory tasks. The neurophysiological correlates of scene-based information processing in the hippocampus have been reported as "spatial view cells" in nonhuman primates. Like primates, it is widely accepted that rodents also use visual scenes in their background for spatial navigation and other kinds of problems. However, in rodents, it is not until recently that researchers examined the neural correlates of the hippocampus from the perspective of visual scene-based information processing. With the advent of virtual reality (VR) systems, it has been demonstrated that place cells in the hippocampus exhibit remarkably similar firing correlates in the VR environment compared with that of the real-world environment. Despite some limitations, the new trend of studying hippocampal functions in a visually controlled environment has the potential to allow investigation of the input-output relationships of network functions and experimental testing of traditional computational predictions more rigorously by providing well-defined visual stimuli. As scenes are essential for navigation and episodic memory in humans, further investigation of the rodents' hippocampal systems in scene-based tasks will provide a critical functional link across different mammalian species.
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Affiliation(s)
- Su-Min Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Jhoseph Shin
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
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20
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Persson BM, Ambrozova V, Duncan S, Wood ER, O’Connor AR, Ainge JA. Lateral entorhinal cortex lesions impair odor-context associative memory in male rats. J Neurosci Res 2022; 100:1030-1046. [PMID: 35187710 PMCID: PMC9302644 DOI: 10.1002/jnr.25027] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 01/14/2023]
Abstract
Lateral entorhinal cortex (LEC) has been hypothesized to process nonspatial, item information that is combined with spatial information from medial entorhinal cortex to form episodic memories within the hippocampus. Recent studies, however, have demonstrated that LEC has a role in integrating features of episodic memory prior to the hippocampus. While the precise role of LEC is still unclear, anatomical studies show that LEC is ideally placed to be a hub integrating multisensory information. The current study tests whether the role of LEC in integrating information extends to long-term multimodal item-context associations. In Experiment 1, male rats were trained on a context-dependent odor discrimination task, where two different contexts served as the cue to the correct odor. Rats were pretrained on the task and then received either bilateral excitotoxic LEC or sham lesions. Following surgery, rats were tested on the previously learned odor-context associations. Control rats showed good memory for the previously learned association but rats with LEC lesions showed significantly impaired performance relative to both their own presurgery performance and to control rats. Experiment 2 went on to test whether impairments in Experiment 1 were the result of LEC lesions impairing either odor or context memory retention alone. Male rats were trained on simple odor and context discrimination tasks that did not require integration of features to solve. Following surgery, both LEC and control rats showed good memory for previously learned odors and contexts. These data show that LEC is critical for long-term odor-context associative memory.
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Affiliation(s)
- Bjorn M. Persson
- School of Psychology & NeuroscienceUniversity of St AndrewsSt AndrewsUK
| | | | - Stephen Duncan
- School of Psychology & NeuroscienceUniversity of St AndrewsSt AndrewsUK
| | - Emma R. Wood
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Akira R. O’Connor
- School of Psychology & NeuroscienceUniversity of St AndrewsSt AndrewsUK
| | - James A. Ainge
- School of Psychology & NeuroscienceUniversity of St AndrewsSt AndrewsUK
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21
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GoodSmith D, Kim SH, Puliyadi V, Ming GL, Song H, Knierim JJ, Christian KM. Flexible encoding of objects and space in single cells of the dentate gyrus. Curr Biol 2022; 32:1088-1101.e5. [PMID: 35108522 PMCID: PMC8930604 DOI: 10.1016/j.cub.2022.01.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/12/2021] [Accepted: 01/10/2022] [Indexed: 01/05/2023]
Abstract
The hippocampus is involved in the formation of memories that require associations among stimuli to construct representations of space and the items and events within that space. Neurons in the dentate gyrus (DG), an initial input region of the hippocampus, have robust spatial tuning, but it is unclear how nonspatial information may be integrated with spatial activity in this region. We recorded from the DG of 21 adult mice as they foraged for food in an environment that contained discrete objects. We found DG cells with multiple firing fields at a fixed distance and direction from objects (landmark vector cells) and cells that exhibited localized changes in spatial firing when objects in the environment were manipulated. By classifying recorded DG cells into putative dentate granule cells and mossy cells, we examined how the addition or displacement of objects affected the spatial firing of these DG cell types. Object-related activity was detected in a significant proportion of mossy cells. Although few granule cells with responses to object manipulations were recorded, likely because of the sparse nature of granule cell firing, there was generally no significant difference in the proportion of granule cells and mossy cells with object responses. When mice explored a second environment with the same objects, DG spatial maps completely reorganized, and a different subset of cells responded to object manipulations. Together, these data reveal the capacity of DG cells to detect small changes in the environment while preserving a stable spatial representation of the overall context.
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Affiliation(s)
- Douglas GoodSmith
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA; Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD 21205, USA; Department of Neurobiology and Neuroscience Institute, University of Chicago, 5801 S Ellis Avenue, Chicago, IL 60637, USA
| | - Sang Hoon Kim
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - Vyash Puliyadi
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA; The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA.
| | - James J Knierim
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD 21205, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD 21205, USA.
| | - Kimberly M Christian
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA.
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22
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Schlecht M, Jayachandran M, Rasch GE, Allen TA. Dual projecting cells linking thalamic and cortical communication routes between the medial prefrontal cortex and hippocampus. Neurobiol Learn Mem 2022; 188:107586. [PMID: 35045320 PMCID: PMC8851867 DOI: 10.1016/j.nlm.2022.107586] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/23/2021] [Accepted: 01/11/2022] [Indexed: 02/06/2023]
Abstract
The interactions between the medial prefrontal cortex (mPFC) and the hippocampus (HC) are critical for memory and decision making and have been specifically implicated in several neurological disorders including schizophrenia, epilepsy, frontotemporal dementia, and Alzheimer's disease. The ventral midline thalamus (vmThal), and lateral entorhinal cortex and perirhinal cortex (LEC/PER) constitute major communication pathways that facilitate mPFC-HC interactions in memory. Although vmThal and LEC/PER circuits have been delineated separately we sought to determine whether these two regions share cell-specific inputs that could influence both routes simultaneously. To do this we used a dual fluorescent retrograde tracing approach using cholera toxin subunit-B (CTB-488 and CTB-594) with injections targeting vmThal and the LEC/PER in rats. Retrograde cell body labeling was examined in key regions of interest within the mPFC-HC system including: (1) mPFC, specifically anterior cingulate cortex (ACC), dorsal and ventral prelimbic cortex (dPL, vPL), and infralimbic cortex (IL); (2) medial and lateral septum (MS, LS); (3) subiculum (Sub) along the dorsal-ventral and proximal-distal axes; and (4) LEC and medial entorhinal cortex (MEC). Results showed that dual vmThal-LEC/PER-projecting cell populations are found in MS, vSub, and the shallow layers II/III of LEC and MEC. We did not find any dual projecting cells in mPFC or in the cornu ammonis (CA) subfields of the HC. Thus, mPFC and HC activity is sent to vmThal and LEC/PER via non-overlapping projection cell populations. Importantly, the dual projecting cell populations in MS, vSub, and EC are in a unique position to simultaneously influence both cortical and thalamic mPFC-HC pathways critical to memory. SIGNIFICANCE STATEMENT: The interactions between mPFC and HC are critical for learning and memory, and dysfunction within this circuit is implicated in various neurodegenerative and psychiatric diseases. mPFC-HC interactions are mediated through multiple communication pathways including a thalamic hub through the vmThal and a cortical hub through lateral entorhinal cortex and perirhinal cortex. Our data highlight newly identified dual projecting cell populations in the septum, Sub, and EC of the rat brain. These dual projecting cells may have the ability to modify the information flow within the mPFC-HC circuit through synchronous activity, and thus offer new cell-specific circuit targets for basic and translational studies in memory.
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Affiliation(s)
- Maximilian Schlecht
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL 33199, USA
| | - Maanasa Jayachandran
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL 33199, USA
| | - Gabriela E Rasch
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL 33199, USA; Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Timothy A Allen
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL 33199, USA.
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23
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Di Castro MA, Volterra A. Astrocyte control of the entorhinal cortex-dentate gyrus circuit: Relevance to cognitive processing and impairment in pathology. Glia 2021; 70:1536-1553. [PMID: 34904753 PMCID: PMC9299993 DOI: 10.1002/glia.24128] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/28/2021] [Accepted: 11/30/2021] [Indexed: 12/20/2022]
Abstract
The entorhinal cortex-dentate gyrus circuit is centrally involved in memory processing conveying to the hippocampus spatial and nonspatial context information via, respectively, medial and lateral perforant path (MPP and LPP) excitatory projections onto dentate granule cells (GCs). Here, we review work of several years from our group showing that astrocytes sense local synaptic transmission and exert in turn a presynaptic control at PP-GC synapses. Modulation of neurotransmitter release probability by astrocytes sets basal synaptic strength and dynamic range for long-term potentiation of PP-GC synapses. Intriguingly, this astrocyte control is circuit-specific, being present only at MPP-GC (not LPP-GC) synapses, which selectively express atypical presynaptic N-methyl-D-aspartate receptors (NMDAR) suitable to activation by astrocyte-released glutamate. Moreover, the astrocytic control is peculiarly dependent on the cytokine TNFα, which at constitutive levels acts as a gating factor for the astrocyte signaling. During inflammation/infection processes, increased levels of TNFα lead to uncontrolled astrocyte glutamate release, altered PP-GC circuit processing and, ultimately, impaired contextual memory performance. The TNFα-dependent pathological switch of the synaptic control from astrocytes and its deleterious consequences are observed in animal models of HIV brain infection and multiple sclerosis, conditions both known to cause cognitive disturbances in up to 50% of patients. The review also discusses open issues related to the identified astrocytic pathway: its role in contextual memory processing, potential damaging role in Alzheimer's disease, the existence of vesicular glutamate release from DG astrocytes, and the possible synaptic-like connectivity between astrocytic output sites and PP receptive sites.
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Affiliation(s)
- Maria Amalia Di Castro
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland.,Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy
| | - Andrea Volterra
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
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24
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Yu XT, Yu J, Choi A, Takehara-Nishiuchi K. Lateral entorhinal cortex supports the development of prefrontal network activity that bridges temporally discontiguous stimuli. Hippocampus 2021; 31:1285-1299. [PMID: 34606152 DOI: 10.1002/hipo.23389] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 09/14/2021] [Accepted: 09/16/2021] [Indexed: 01/16/2023]
Abstract
The lateral entorhinal cortex (LEC) is an essential component of the brain circuitry supporting long-term memory by serving as an interface between the hippocampus and neocortex. Dysfunction of the LEC affects sensory coding in the hippocampus, leading to a view that the LEC provides the hippocampus with highly processed sensory information. It remains unclear, however, how the LEC modulates neural processing in the neocortical regions. To address this point, we pharmacologically inactivated the LEC of male rats during a temporal associative learning task and examined its impact on local network activity in one of the LEC's efferent targets, the prelimbic region of the medial prefrontal cortex (mPFC). Rats were exposed to two neutral stimuli, one of which was paired with an aversive eyelid shock over a short temporal delay. The LEC inhibition reduced the expression of anticipatory blinking responses to the reinforced stimuli without increasing responses to nonreinforced stimuli. In control rats, both the reinforced and nonreinforced stimuli evoked a short-lived, wide-band increase in the prelimbic network activity. With learning, the initial increase of gamma-band activity started to extend into the interval between the reinforced neutral stimulus and the eyelid shock. LEC inhibition attenuated the learning-induced sustained activity, without affecting the initial transient activity. These results suggest that the integrity of LEC is necessary for the formation of temporal stimulus associations and its neural correlates in the mPFC. Given the minimal effects on the innate network responses to sensory stimuli, the LEC appears not to be the main source of sensory inputs to the mPFC; rather it may provide a framework that shapes the mPFC network response to behaviorally relevant cues.
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Affiliation(s)
- Xiaotian Tag Yu
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Jessica Yu
- Human Biology Program, University of Toronto, Toronto, Canada
| | - Allison Choi
- Human Biology Program, University of Toronto, Toronto, Canada
| | - Kaori Takehara-Nishiuchi
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Psychology, University of Toronto, Toronto, Canada.,Collaborative Program in Neuroscience, University of Toronto, Toronto, Canada
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25
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DiFazio LE, Reis DS, Manns JR. Optogenetic stimulation of the basolateral amygdala accelerates acquisition of object-context associations. Behav Neurosci 2021; 135:354-358. [PMID: 34264688 DOI: 10.1037/bne0000428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The basolateral complex of the amygdala (BLA) is capable of modulating memory and is thought to do so via projections to regions such as the hippocampus. The present study used optogenetic stimulation of glutamatergic projection neurons in the BLA as rats learned object-context associations during a well-studied hippocampus-dependent memory task. Relative to a control condition, optogenetic BLA stimulation resulted in the accelerated acquisition of when stimulation was delivered following correct choices but not when it was delivered during the intertrial interval. These results extend prior examples of amygdala-mediated memory enhancement to a canonical example of hippocampus-dependent memory and provide an opportunity for future dissection of amygdalar modulation of object-context associative memory. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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Collitti-Klausnitzer J, Hagena H, Dubovyk V, Manahan-Vaughan D. Preferential frequency-dependent induction of synaptic depression by the lateral perforant path and of synaptic potentiation by the medial perforant path inputs to the dentate gyrus. Hippocampus 2021; 31:957-981. [PMID: 34002905 DOI: 10.1002/hipo.23338] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 04/28/2021] [Accepted: 05/02/2021] [Indexed: 12/19/2022]
Abstract
The encoding of spatial representations is enabled by synaptic plasticity. The entorhinal cortex sends information to the hippocampus via the lateral (LPP) and medial perforant (MPP) paths that transfer egocentric item-related and allocentric spatial information, respectively. To what extent LPP and MPP information-relay results in different homosynaptic synaptic plasticity responses is unclear. We examined the frequency dependency (at 1, 5, 10, 50, 100, 200 Hz) of long-term potentiation (LTP) and long-term depression (LTD) at MPP and LPP synapses in the dentate gyrus (DG) of freely behaving adult rats. We report that whereas the MPP-DG synapses exhibit a predisposition toward the expression of LTP, LPP-DG synapses prefer to express synaptic depression. The divergence of synaptic plasticity responses is most prominent at afferent frequencies of 5, 100, Hz and 200 Hz. Priming with 10 or 50 Hz significantly modified the subsequent plasticity response in a frequency-dependent manner, but failed to change the preferred direction of change in synaptic strength of MPP and LPP synapses. Evaluation of the expression of GluN1, GluN2A, or GluN2B subunits of the NMDA receptor revealed equivalent expression in the outer and middle thirds of the molecular layer where LPP and MPP inputs convene, respectively, thus excluding NMDA receptors as a substrate for the frequency-dependent differences in bidirectional plasticity. These findings demonstrate that the LPP and MPP inputs to the DG enable differentiated and distinct forms of synaptic plasticity in response to the same afferent frequencies. Effects are extremely robust and resilient to metaplastic priming. These properties may support the functional differentiation of allocentric and item information provided to the DG by the MPP and LPP, respectively, that has been proposed by others. We propose that allocentric spatial information, conveyed by the MPP is encoded through hippocampal LTP in a designated synaptic network. This network is refined and optimized to include egocentric contextual information through LTD triggered by LPP inputs.
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Affiliation(s)
| | - Hardy Hagena
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Germany
| | - Valentyna Dubovyk
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Germany
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Vandrey B, Duncan S, Ainge JA. Object and object-memory representations across the proximodistal axis of CA1. Hippocampus 2021; 31:881-896. [PMID: 33942429 DOI: 10.1002/hipo.23331] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 03/11/2021] [Accepted: 03/28/2021] [Indexed: 11/07/2022]
Abstract
Episodic memory requires information about objects to be integrated into a spatial framework. Place cells in the hippocampus encode spatial representations of objects that could be generated through signaling from the entorhinal cortex. Projections from lateral (LEC) and medial entorhinal cortex (MEC) to the hippocampus terminate in distal and proximal CA1, respectively. We recorded place cells in distal and proximal CA1 as rats explored an environment that contained objects. Place cells in distal CA1 demonstrated higher measures of spatial tuning, stability, and closer proximity of place fields to objects. Furthermore, remapping to object displacement was modulated by place field proximity to objects in distal, but not proximal CA1. Finally, representations of previous object locations were closer to those locations in distal CA1 than proximal CA1. Our data suggest that in cue-rich environments, LEC inputs to the hippocampus support spatial representations with higher spatial tuning, closer proximity to objects, and greater stability than those receiving inputs from MEC. This is consistent with functional segregation in the entorhinal-hippocampal circuits underlying object-place memory.
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Affiliation(s)
- Brianna Vandrey
- University of St Andrews, School of Psychology and Neuroscience, St Andrews, Fife, UK
- University of Edinburgh, Centre for Discovery Brain Sciences, Edinburgh, EH8 9XD, UK
| | - Stephen Duncan
- University of St Andrews, School of Psychology and Neuroscience, St Andrews, Fife, UK
| | - James A Ainge
- University of St Andrews, School of Psychology and Neuroscience, St Andrews, Fife, UK
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Koutsoumpa A, Papatheodoropoulos C. Frequency-dependent layer-specific differences in short-term synaptic plasticity in the dorsal and ventral CA1 hippocampal field. Synapse 2021; 75:e22199. [PMID: 33687106 DOI: 10.1002/syn.22199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 12/25/2022]
Abstract
Information from the entorhinal cortex arrives to the hippocampal CA1 microcircuit directly through the temporoammonic path (TA) that terminates in the stratum lacunosum-moleculare (SLM), and indirectly through Schaffer collateral pathway (SC) that terminates in the stratum radiatum (SR). By virtue of this input convergence, CA1 circuitry may act to compare and integrate incoming cortical information. Although a remarkable dorsal-ventral difference in short-term plasticity (STP) has been recently described at SC-CA1 synapses, the corresponding properties at TA-CA1 synapses have not been examined. Here, we report that stimulation of TA in the dorsal hippocampus produces significant facilitation of all conditioned responses evoked by 1-30 Hz, peaking at 20-30 Hz, and significant depression of steady-state responses to 50-100 Hz. Dorsal SC-CA1 synapses display a similar pattern of responses, yet, facilitation peaked at 10 Hz and depression (at 75-100 Hz) is weaker. Strikingly, stimulation of TA in the ventral hippocampus produces facilitation of steady-state responses to 1-30 Hz and highly contrasts with the depression of SC-CA1 synapses. Steady-state responses to 40-100 Hz in the ventral hippocampus depress in both layers similarly. High-frequency TA input (40-100 Hz) to the dorsal hippocampus depresses more in proximal than in distal SLM, while low-frequency (1-3 Hz) TA input to the ventral hippocampus facilitates more in distal than in proximal SLM. The present evidence suggests that direct and indirect entorhinal cortical inputs across the septotemporal extent of hippocampal CA1 field display frequency selectivity both in the radial and transverse axes, and that a rapid information processing may take place through direct ventral hippocampal CA1-EC circuit interactions independently of trisynaptic circuit.
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Affiliation(s)
- Andriana Koutsoumpa
- Laboratory of Neurophysiology, Department of Medicine, University of Patras, Rion, Greece
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Effective connectivity alteration according to recurrence in transient global amnesia. Neuroradiology 2021; 63:1441-1449. [PMID: 33486582 DOI: 10.1007/s00234-021-02645-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/11/2021] [Indexed: 01/26/2023]
Abstract
PURPOSE This study aimed to evaluate alterations in structural covariance network and effective connectivity of the intrahippocampal circuit in patients with transient global amnesia (TGA). We also investigated whether there were differences of them according to recurrence. METHODS We enrolled 88 patients with TGA and 50 healthy controls. We classified patients with TGA into two groups: the single event group (N = 77) and recurrent events group (N = 11). We performed volumetric analysis using the FreeSurfer program and structural covariance network analysis based on the structural volumes using a graph theoretical analysis in patients with TGA and healthy controls. The effective connectivity of the intrahippocampal circuit was also evaluated using structural equation modeling. RESULTS There were no significant differences between patients with all TGA events/a single TGA event and healthy controls with regard to global structural covariance network. However, patients with recurrent events had significant alterations in global structural covariance network with a decrease in the small-worldness index (0.907 vs. 0.970, p = 0.032). In patients with all events/a single, there were alterations in effective connectivity from the entorhinal cortex to CA4, only. However, in patients with recurrent events, there were alterations in effective connectivity from the subiculum to the fimbria as well as from the entorhinal cortex to CA4 in bilateral hemispheres. CONCLUSION Our study revealed significant alterations in structural covariance network and disruption of the intrahippocampal circuit in patients with TGA compared to healthy controls, which is more prominent when amnestic events recurred. It could be related to the pathogenesis of TGA.
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Lee SM, Jin SW, Park SB, Park EH, Lee CH, Lee HW, Lim HY, Yoo SW, Ahn JR, Shin J, Lee SA, Lee I. Goal-directed interaction of stimulus and task demand in the parahippocampal region. Hippocampus 2021; 31:717-736. [PMID: 33394547 PMCID: PMC8359334 DOI: 10.1002/hipo.23295] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/05/2020] [Accepted: 12/12/2020] [Indexed: 11/10/2022]
Abstract
The hippocampus and parahippocampal region are essential for representing episodic memories involving various spatial locations and objects, and for using those memories for future adaptive behavior. The “dual‐stream model” was initially formulated based on anatomical characteristics of the medial temporal lobe, dividing the parahippocampal region into two streams that separately process and relay spatial and nonspatial information to the hippocampus. Despite its significance, the dual‐stream model in its original form cannot explain recent experimental results, and many researchers have recognized the need for a modification of the model. Here, we argue that dividing the parahippocampal region into spatial and nonspatial streams a priori may be too simplistic, particularly in light of ambiguous situations in which a sensory cue alone (e.g., visual scene) may not allow such a definitive categorization. Upon reviewing evidence, including our own, that reveals the importance of goal‐directed behavioral responses in determining the relative involvement of the parahippocampal processing streams, we propose the Goal‐directed Interaction of Stimulus and Task‐demand (GIST) model. In the GIST model, input stimuli such as visual scenes and objects are first processed by both the postrhinal and perirhinal cortices—the postrhinal cortex more heavily involved with visual scenes and perirhinal cortex with objects—with relatively little dependence on behavioral task demand. However, once perceptual ambiguities are resolved and the scenes and objects are identified and recognized, the information is then processed through the medial or lateral entorhinal cortex, depending on whether it is used to fulfill navigational or non‐navigational goals, respectively. As complex sensory stimuli are utilized for both navigational and non‐navigational purposes in an intermixed fashion in naturalistic settings, the hippocampus may be required to then put together these experiences into a coherent map to allow flexible cognitive operations for adaptive behavior to occur.
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Affiliation(s)
- Su-Min Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Seung-Woo Jin
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Seong-Beom Park
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Eun-Hye Park
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Choong-Hee Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Hyun-Woo Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Heung-Yeol Lim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Seung-Woo Yoo
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Brain Institute, Florida Atlantic University, Jupiter, Florida, USA
| | - Jae Rong Ahn
- Department of Biology, Tufts University, Medford, Massachusetts, USA
| | - Jhoseph Shin
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Sang Ah Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
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Lee H, GoodSmith D, Knierim JJ. Parallel processing streams in the hippocampus. Curr Opin Neurobiol 2020; 64:127-134. [PMID: 32502734 PMCID: PMC8136469 DOI: 10.1016/j.conb.2020.03.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 03/12/2020] [Indexed: 01/06/2023]
Abstract
The hippocampus performs two complementary processes, pattern separation and pattern completion, to minimize interference and maximize the storage capacity of memories. Classic computational models have suggested that the dentate gyrus (DG) supports pattern separation and the putative attractor circuitry in CA3 supports pattern completion. However, recent evidence of functional heterogeneity along the CA3 transverse axis of the hippocampus suggests that the DG and proximal CA3 work as a functional unit for pattern separation, while distal CA3 forms an autoassociative network for pattern completion. We propose that the outputs of these functional circuits, combined with direct projections from entorhinal cortex to CA1, form interconnected, parallel processing circuits to support accurate memory storage and retrieval.
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Affiliation(s)
- Heekyung Lee
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Douglas GoodSmith
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - James J Knierim
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA.
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32
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Hippocampal CA2 sharp-wave ripples reactivate and promote social memory. Nature 2020; 587:264-269. [PMID: 32968277 DOI: 10.1038/s41586-020-2758-y] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 06/25/2020] [Indexed: 02/08/2023]
Abstract
The consolidation of spatial memory depends on the reactivation ('replay') of hippocampal place cells that were active during recent behaviour. Such reactivation is observed during sharp-wave ripples (SWRs)-synchronous oscillatory electrical events that occur during non-rapid-eye-movement (non-REM) sleep1-8 and whose disruption impairs spatial memory3,5,6,8. Although the hippocampus also encodes a wide range of non-spatial forms of declarative memory, it is not yet known whether SWRs are necessary for such memories. Moreover, although SWRs can arise from either the CA3 or the CA2 region of the hippocampus7,9, the relative importance of SWRs from these regions for memory consolidation is unknown. Here we examine the role of SWRs during the consolidation of social memory-the ability of an animal to recognize and remember a member of the same species-focusing on CA2 because of its essential role in social memory10-12. We find that ensembles of CA2 pyramidal neurons that are active during social exploration of previously unknown conspecifics are reactivated during SWRs. Notably, disruption or enhancement of CA2 SWRs suppresses or prolongs social memory, respectively. Thus, SWR-mediated reactivation of hippocampal firing related to recent experience appears to be a general mechanism for binding spatial, temporal and sensory information into high-order memory representations, including social memory.
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Abstract
Several types of neurons involved in spatial navigation and memory encode the distance and direction (that is, the vector) between an agent and items in its environment. Such vectorial information provides a powerful basis for spatial cognition by representing the geometric relationships between the self and the external world. Here, we review the explicit encoding of vectorial information by neurons in and around the hippocampal formation, far from the sensory periphery. The parahippocampal, retrosplenial and parietal cortices, as well as the hippocampal formation and striatum, provide a plethora of examples of vector coding at the single neuron level. We provide a functional taxonomy of cells with vectorial receptive fields as reported in experiments and proposed in theoretical work. The responses of these neurons may provide the fundamental neural basis for the (bottom-up) representation of environmental layout and (top-down) memory-guided generation of visuospatial imagery and navigational planning.
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Abstract
Contemporary brain research seeks to understand how cognition is reducible to neural activity. Crucially, much of this effort is guided by a scientific paradigm that views neural activity as essentially driven by external stimuli. In contrast, recent perspectives argue that this paradigm is by itself inadequate and that understanding patterns of activity intrinsic to the brain is needed to explain cognition. Yet, despite this critique, the stimulus-driven paradigm still dominates-possibly because a convincing alternative has not been clear. Here, we review a series of findings suggesting such an alternative. These findings indicate that neural activity in the hippocampus occurs in one of three brain states that have radically different anatomical, physiological, representational, and behavioral correlates, together implying different functional roles in cognition. This three-state framework also indicates that neural representations in the hippocampus follow a surprising pattern of organization at the timescale of ∼1 s or longer. Lastly, beyond the hippocampus, recent breakthroughs indicate three parallel states in the cortex, suggesting shared principles and brain-wide organization of intrinsic neural activity.
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Affiliation(s)
- Kenneth Kay
- Howard Hughes Medical Institute, Kavli Institute for Fundamental Neuroscience, Department of Physiology, University of California San Francisco, San Francisco, California
| | - Loren M Frank
- Howard Hughes Medical Institute, Kavli Institute for Fundamental Neuroscience, Department of Physiology, University of California San Francisco, San Francisco, California
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35
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Parizkova M, Lerch O, Andel R, Kalinova J, Markova H, Vyhnalek M, Hort J, Laczó J. Spatial Pattern Separation in Early Alzheimer's Disease. J Alzheimers Dis 2020; 76:121-138. [PMID: 32444544 DOI: 10.3233/jad-200093] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND The hippocampus, entorhinal cortex, and basal forebrain are among the first brain structures affected by Alzheimer's disease (AD). They play an essential role in spatial pattern separation, a process critical for accurate encoding of similar spatial information. OBJECTIVE Our aim was to examine spatial pattern separation and its association with volumetric changes of the hippocampus, entorhinal cortex, and basal forebrain nuclei projecting to the hippocampus (the medial septal nuclei and vertical limb of the diagonal band of Broca - Ch1-2 nuclei) in the biomarker-defined early clinical stages of AD. METHODS A total of 98 older adults were recruited from the Czech Brain Aging Study cohort. The participants with amnestic mild cognitive impairment (aMCI) due to AD (n = 44), mild AD dementia (n = 31), and cognitively normal older adults (CN; n = 23) underwent spatial pattern separation testing, comprehensive cognitive assessment, and MRI brain volumetry. RESULTS Spatial pattern separation accuracy was lower in the early clinical stages of AD compared to the CN group (p < 0.001) and decreased with disease severity (CN > aMCI due to AD > AD dementia). Controlling for general memory and cognitive performance, demographic characteristics and psychological factors did not change the results. Hippocampal and Ch1-2 volumes were directly associated with spatial pattern separation performance while the entorhinal cortex operated on pattern separation indirectly through the hippocampus. CONCLUSION Smaller volumes of the hippocampus, entorhinal cortex, and basal forebrain Ch1-2 nuclei are linked to spatial pattern separation impairment in biomarker-defined early clinical AD and may contribute to AD-related spatial memory deficits.
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Affiliation(s)
- Martina Parizkova
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Ondrej Lerch
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Ross Andel
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic.,School of Aging Studies, University of South Florida, Tampa, FL, USA
| | - Jana Kalinova
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
| | - Hana Markova
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Martin Vyhnalek
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Jakub Hort
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Jan Laczó
- Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
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The medial prefrontal cortex - hippocampus circuit that integrates information of object, place and time to construct episodic memory in rodents: Behavioral, anatomical and neurochemical properties. Neurosci Biobehav Rev 2020; 113:373-407. [PMID: 32298711 DOI: 10.1016/j.neubiorev.2020.04.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 02/25/2020] [Accepted: 04/06/2020] [Indexed: 12/31/2022]
Abstract
Rats and mice have been demonstrated to show episodic-like memory, a prototype of episodic memory, as defined by an integrated memory of the experience of an object or event, in a particular place and time. Such memory can be assessed via the use of spontaneous object exploration paradigms, variably designed to measure memory for object, place, temporal order and object-location inter-relationships. We review the methodological properties of these tests, the neurobiology about time and discuss the evidence for the involvement of the medial prefrontal cortex (mPFC), entorhinal cortex (EC) and hippocampus, with respect to their anatomy, neurotransmitter systems and functional circuits. The systematic analysis suggests that a specific circuit between the mPFC, lateral EC and hippocampus encodes the information for event, place and time of occurrence into the complex episodic-like memory, as a top-down regulation from the mPFC onto the hippocampus. This circuit can be distinguished from the neuronal component memory systems for processing the individual information of object, time and place.
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37
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Liang L, Zhao L, Wei Y, Mai W, Duan G, Su J, Nong X, Yu B, Li C, Mo X, Wilson G, Deng D, Kong J. Structural and Functional Hippocampal Changes in Subjective Cognitive Decline From the Community. Front Aging Neurosci 2020; 12:64. [PMID: 32256336 PMCID: PMC7090024 DOI: 10.3389/fnagi.2020.00064] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/24/2020] [Indexed: 01/07/2023] Open
Abstract
Background Recently, subjective cognitive decline (SCD) has been described as the earliest at-risk state of Alzheimer’s disease (AD), and drawn attention of investigators. Studies suggested that SCD-community individuals may constitute a more vulnerable population than SCD-clinic patients, therefore, to investigate the early changes of the brain may provide guidance for treatment of the disease. We sought to investigate the changes of structure and functional connectivity alternation of the hippocampus in individuals with SCD recruited from the community using structural and resting-state functional MRI (fMRI). Methods Thirty-five SCD patients and 32 healthy controls were recruited. Resting-state fMRI data and high-resolution T1-weighted images were collected. Whole-brain voxel-based morphometry was used to examine the brain structural changes. We also used the hippocampal tail and the whole hippocampus as seeds to investigate functional connectivity alternation in SCD. Results Individuals with SCD showed significant gray matter volume decreases in the bilateral hippocampal tails and enlargement of the bilateral paracentral lobules. We also found that individuals with SCD showed decreased hippocampal tail resting-state functional connectivity (rsFC) with the right medial prefrontal cortex (mPFC) and the left temporoparietal junction (TPJ), and decreased whole hippocampus rsFC with the bilateral mPFC and TPJ. These brain region and FC showing significant differences also showed significantly correlation with Montreal Cognitive Assessment (MoCA) scores. Conclusion Individuals with SCD recruited from the community is associated with structural and functional changes of the hippocampus, and these changes may serve as potential biomarkers of SCD. Clinical Trial Registration The Declaration of Helsinki, and the study was registered in http://www.chictr.org.cn. The Clinical Trial Registration Number was ChiCTR-IPR-16009144.
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Affiliation(s)
- Lingyan Liang
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Lihua Zhao
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Yichen Wei
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Wei Mai
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Gaoxiong Duan
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Jiahui Su
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Xiucheng Nong
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Bihan Yu
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Chong Li
- Department of Acupuncture, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Xiaping Mo
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Georgia Wilson
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Demao Deng
- Department of Radiology, First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Jian Kong
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
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Cembrowski MS, Spruston N. Heterogeneity within classical cell types is the rule: lessons from hippocampal pyramidal neurons. Nat Rev Neurosci 2019; 20:193-204. [PMID: 30778192 DOI: 10.1038/s41583-019-0125-5] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The mechanistic operation of brain regions is often interpreted by partitioning constituent neurons into 'cell types'. Historically, such cell types were broadly defined by their correspondence to gross features of the nervous system (such as cytoarchitecture). Modern-day neuroscientific techniques, enabling a more nuanced examination of neuronal properties, have illustrated a wealth of heterogeneity within these classical cell types. Here, we review the extent of this within-cell-type heterogeneity in one of the simplest cortical regions of the mammalian brain, the rodent hippocampus. We focus on the mounting evidence that the classical CA3, CA1 and subiculum pyramidal cell types all exhibit prominent and spatially patterned within-cell-type heterogeneity, and suggest these cell types provide a model system for exploring the organization and function of such heterogeneity. Given that the hippocampus is structurally simple and evolutionarily ancient, within-cell-type heterogeneity is likely to be a general and crucial feature of the mammalian brain.
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Affiliation(s)
- Mark S Cembrowski
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| | - Nelson Spruston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
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39
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Dentate Gyrus Mossy Cells Share a Role in Pattern Separation with Dentate Granule Cells and Proximal CA3 Pyramidal Cells. J Neurosci 2019; 39:9570-9584. [PMID: 31641051 DOI: 10.1523/jneurosci.0940-19.2019] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/26/2019] [Accepted: 10/03/2019] [Indexed: 01/04/2023] Open
Abstract
The complementary processes of pattern completion and pattern separation are thought to be essential for successful memory storage and recall. The dentate gyrus (DG) and proximal CA3 (pCA3) regions have been implicated in pattern separation, in part through extracellular recording studies of these areas. However, the DG contains two types of excitatory cells: granule cells of the granule layer and mossy cells of the hilus. Little is known about the firing properties of mossy cells in freely moving animals, and it is unclear how their activity may contribute to the mnemonic functions of the hippocampus. Furthermore, tetrodes in the dentate granule layer and pCA3 pyramidal layer can also record mossy cells, thus introducing ambiguity into the identification of cell types recorded. Using a random forests classifier, we classified cells recorded in DG (Neunuebel and Knierim, 2014) and pCA3 (Lee et al., 2015) of 16 male rats and separately examined the responses of granule cells, mossy cells, and pCA3 pyramidal cells in a local/global cue mismatch task. All three cell types displayed low correlations between the population representations of the rat's position in the standard and cue-mismatch sessions. These results suggest that all three excitatory cell types within the DG/pCA3 circuit may act as a single functional unit to support pattern separation.SIGNIFICANCE STATEMENT Mossy cells in the dentate gyrus (DG) are an integral component of the DG/pCA3 circuit. While the role of granule cells in the circuitry and computations of the hippocampus has been a focus of study for decades, the contributions of mossy cells have been largely overlooked. Recent studies have revealed the spatial firing properties of mossy cells in awake behaving animals, but how the activity of these highly active cells contributes to the mnemonic functions of the DG is uncertain. We separately analyzed mossy cells, granule cells, and pCA3 cells and found that all three cell types respond similarly to a local/global cue mismatch, suggesting that they form a single functional unit supporting pattern separation.
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Lima KR, da Silva de Vargas L, Ramborger B, Roehrs R, Sevenster D, Izquierdo I, D'Hooge R, Mello-Carpes PB. Noradrenergic and dopaminergic involvement in novelty modulation of aversive memory generalization of adult rats. Behav Brain Res 2019; 371:111991. [PMID: 31150747 DOI: 10.1016/j.bbr.2019.111991] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/11/2019] [Accepted: 05/27/2019] [Indexed: 11/17/2022]
Abstract
The generalization of aversive memory can be defined as the phenomenon in which a situation similar to (but distinctive from) a previous aversive event triggers an avoidance response. This phenomenon has been suggested to play a role in several psychological disorders. In this study, we investigate the effects of novelty on the generalization of fear memories, and the involvement of noradrenergic and dopaminergic systems in this process. For this study we used male Wistar rats (3 months old, 300-400 g). The participation of each neurotransmitter system was evaluated separately (two set of experiments). In each experimental set, the animals were divided in groups (8 animals each): (i) control, (ii) novelty, and, (iii) antagonist + novelty group (timolol, a β-adrenergic antagonist, or SCH23390, a D1/D5 dopaminergic antagonist, in the first and in the second set of experiments, respectively). Additionaly, to investigate whether novelty exposure increases the levels of noradrenaline and/or dopamine in the hippocampus fifteen animals were divided in three groups (5 animals each).: (i) naïve, (ii) control; and, (iii) novelty. To examine aversive memory, and generalization of aversive memory, we trained adult male Wistar rats in an inhibitory avoidance (IA) memory task and after in a modified inhibitory avoidance (MIA). Before the MIA training some of the animals were exposed to environmental novelty (open field). Immediately before this novelty exposure, some animals received intrahippocampal infusion of timolol (β-adrenergic antagonist), SCH23390 (D1/D5 antagonist) or vehicle to evaluate the involvement of noradrenergic and dopaminergic systems. Finally, to evaluate aversive memory and generalization of aversive memory respectively, half of the animals in each group were tested on IA and half on MIA. We confirmed that the exposure to novelty blocks the generalization of aversive memory, but moreover, demonstrated that this process involves activation of β-adrenergic and dopaminergic D1/D5 pathways. We additionally observed that exposure to novelty raises hippocampal levels of noradrenaline and dopamine. This suggests that these neurotransmitters not only influence long-term memory (LTM) as such, but also aversive memory generalization.
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Affiliation(s)
- Karine Ramires Lima
- Physiology Research Group, Federal University of Pampa, Uruguaiana, RS, Brazil
| | | | - Bruna Ramborger
- Interdisciplinary Group of Research in Teaching Practice, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Rafael Roehrs
- Interdisciplinary Group of Research in Teaching Practice, Federal University of Pampa, Uruguaiana, RS, Brazil
| | | | - Iván Izquierdo
- National Institute of Translational Neuroscience, National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, University of Leuven, Belgium
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Bloss EB, Hunt DL. Revealing the Synaptic Hodology of Mammalian Neural Circuits With Multiscale Neurocartography. Front Neuroinform 2019; 13:52. [PMID: 31427940 PMCID: PMC6690003 DOI: 10.3389/fninf.2019.00052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 07/02/2019] [Indexed: 11/20/2022] Open
Abstract
The functional features of neural circuits are determined by a combination of properties that range in scale from projections systems across the whole brain to molecular interactions at the synapse. The burgeoning field of neurocartography seeks to map these relevant features of brain structure—spanning a volume ∼20 orders of magnitude—to determine how neural circuits perform computations supporting cognitive function and complex behavior. Recent technological breakthroughs in tissue sample preparation, high-throughput electron microscopy imaging, and automated image analyses have produced the first visualizations of all synaptic connections between neurons of invertebrate model systems. However, the sheer size of the central nervous system in mammals implies that reconstruction of the first full brain maps at synaptic scale may not be feasible for decades. In this review, we outline existing and emerging technologies for neurocartography that complement electron microscopy-based strategies and are beginning to derive some basic organizing principles of circuit hodology at the mesoscale, microscale, and nanoscale. Specifically, we discuss how a host of light microscopy techniques including array tomography have been utilized to determine both long-range and subcellular organizing principles of synaptic connectivity. In addition, we discuss how new techniques, such as two-photon serial tomography of the entire mouse brain, have become attractive approaches to dissect the potential connectivity of defined cell types. Ultimately, principles derived from these techniques promise to facilitate a conceptual understanding of how connectomes, and neurocartography in general, can be effectively utilized toward reaching a mechanistic understanding of circuit function.
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Affiliation(s)
- Erik B Bloss
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, United States
| | - David L Hunt
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, United States
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Jayachandran M, Linley SB, Schlecht M, Mahler SV, Vertes RP, Allen TA. Prefrontal Pathways Provide Top-Down Control of Memory for Sequences of Events. Cell Rep 2019; 28:640-654.e6. [PMID: 31315044 PMCID: PMC6662648 DOI: 10.1016/j.celrep.2019.06.053] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 05/19/2019] [Accepted: 06/14/2019] [Indexed: 11/30/2022] Open
Abstract
We remember our lives as sequences of events, but it is unclear how these memories are controlled during retrieval. In rats, the medial prefrontal cortex (mPFC) is positioned to influence sequence memory through extensive top-down inputs to regions heavily interconnected with the hippocampus, notably the nucleus reuniens of the thalamus (RE) and perirhinal cortex (PER). Here, we used an hM4Di synaptic-silencing approach to test our hypothesis that specific mPFC→RE and mPFC→PER projections regulate sequence memory retrieval. First, we found non-overlapping populations of mPFC cells project to RE and PER. Second, suppressing mPFC activity impaired sequence memory. Third, inhibiting mPFC→RE and mPFC→PER pathways effectively abolished sequence memory. Finally, a sequential lag analysis showed that the mPFC→RE pathway contributes to a working memory retrieval strategy, whereas the mPFC→PER pathway supports a temporal context memory retrieval strategy. These findings demonstrate that mPFC→RE and mPFC→PER pathways serve as top-down mechanisms that control distinct sequence memory retrieval strategies.
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Affiliation(s)
- Maanasa Jayachandran
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL 33199, USA
| | - Stephanie B Linley
- Center for Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Maximilian Schlecht
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL 33199, USA
| | - Stephen V Mahler
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA
| | - Robert P Vertes
- Center for Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Timothy A Allen
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL 33199, USA; Department of Environmental Health Sciences, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, FL 33199, USA.
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Dolleman-van der Weel MJ, Griffin AL, Ito HT, Shapiro ML, Witter MP, Vertes RP, Allen TA. The nucleus reuniens of the thalamus sits at the nexus of a hippocampus and medial prefrontal cortex circuit enabling memory and behavior. Learn Mem 2019; 26:191-205. [PMID: 31209114 PMCID: PMC6581009 DOI: 10.1101/lm.048389.118] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/16/2019] [Indexed: 12/12/2022]
Abstract
The nucleus reuniens of the thalamus (RE) is a key component of an extensive network of hippocampal and cortical structures and is a fundamental substrate for cognition. A common misconception is that RE is a simple relay structure. Instead, a better conceptualization is that RE is a critical component of a canonical higher-order cortico-thalamo-cortical circuit that supports communication between the medial prefrontal cortex (mPFC) and the hippocampus (HC). RE dysfunction is implicated in several clinical disorders including, but not limited to Alzheimer's disease, schizophrenia, and epilepsy. Here, we review key anatomical and physiological features of the RE based primarily on studies in rodents. We present a conceptual model of RE circuitry within the mPFC-RE-HC system and speculate on the computations RE enables. We review the rapidly growing literature demonstrating that RE is critical to, and its neurons represent, aspects of behavioral tasks that place demands on memory focusing on its role in navigation, spatial working memory, the temporal organization of memory, and executive functions.
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Affiliation(s)
- Margriet J Dolleman-van der Weel
- Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam NL-1007MB, The Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam NL-1098XH, The Netherlands
| | - Amy L Griffin
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19716, USA
| | - Hiroshi T Ito
- Max Planck Institute for Brain Research, 60438, Frankfurt am Main, Germany
| | - Matthew L Shapiro
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York 12208, USA
| | - Menno P Witter
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, NTNU Norwegian University of Science and Technology, Trondheim NO-7491, Norway
| | - Robert P Vertes
- Center for Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton, Florida 33431, USA
| | - Timothy A Allen
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, Florida 33199, USA
- Department of Environmental Health Sciences, Florida International University, Miami, Florida 33199, USA
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Matsumoto N, Kitanishi T, Mizuseki K. The subiculum: Unique hippocampal hub and more. Neurosci Res 2019; 143:1-12. [DOI: 10.1016/j.neures.2018.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/10/2018] [Accepted: 08/03/2018] [Indexed: 01/09/2023]
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Cembrowski MS, Wang L, Lemire AL, Copeland M, DiLisio SF, Clements J, Spruston N. The subiculum is a patchwork of discrete subregions. eLife 2018; 7:e37701. [PMID: 30375971 PMCID: PMC6226292 DOI: 10.7554/elife.37701] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 10/27/2018] [Indexed: 11/13/2022] Open
Abstract
In the hippocampus, the classical pyramidal cell type of the subiculum acts as a primary output, conveying hippocampal signals to a diverse suite of downstream regions. Accumulating evidence suggests that the subiculum pyramidal cell population may actually be comprised of discrete subclasses. Here, we investigated the extent and organizational principles governing pyramidal cell heterogeneity throughout the mouse subiculum. Using single-cell RNA-seq, we find that the subiculum pyramidal cell population can be deconstructed into eight separable subclasses. These subclasses were mapped onto abutting spatial domains, ultimately producing a complex laminar and columnar organization with heterogeneity across classical dorsal-ventral, proximal-distal, and superficial-deep axes. We further show that these transcriptomically defined subclasses correspond to differential protein products and can be associated with specific projection targets. This work deconstructs the complex landscape of subiculum pyramidal cells into spatially segregated subclasses that may be observed, controlled, and interpreted in future experiments.
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Affiliation(s)
- Mark S Cembrowski
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Lihua Wang
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Andrew L Lemire
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Monique Copeland
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | | | - Jody Clements
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Nelson Spruston
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
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Libby LA, Reagh ZM, Bouffard NR, Ragland JD, Ranganath C. The Hippocampus Generalizes across Memories that Share Item and Context Information. J Cogn Neurosci 2018; 31:24-35. [PMID: 30240315 DOI: 10.1162/jocn_a_01345] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Episodic memory is known to rely on the hippocampus, but how the hippocampus organizes different episodes to permit their subsequent retrieval remains controversial. One major area of debate hinges on a discrepancy between two hypothesized roles of the hippocampus: differentiating between similar events to reduce interference and assigning similar representations to events that share overlapping items and contextual information. Here, we used multivariate analyses of activity patterns measured with fMRI to characterize how the hippocampus distinguishes between memories based on similarity at the level of items and/or context. Hippocampal activity patterns discriminated between events that shared either item or context information but generalized across events that shared similar item-context associations. The current findings provide evidence that, whereas the hippocampus can reduce mnemonic interference by separating events that generalize along a single attribute dimension, overlapping hippocampal codes may support memory for events with overlapping item-context relations. This lends new insights into the way the hippocampus may balance multiple mnemonic operations in adaptively guiding behavior.
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47
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Ranganath C. Time, memory, and the legacy of Howard Eichenbaum. Hippocampus 2018; 29:146-161. [DOI: 10.1002/hipo.23007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 01/12/2023]
Affiliation(s)
- Charan Ranganath
- Center for Neuroscience and Department of Psychology University of California at Davis Davis California
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48
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Abstract
One of the consequences of chronic methamphetamine (Meth) abuse and Meth addiction is impaired hippocampal function which plays a critical role in enhanced propensity for relapse. This impairment is predicted by alterations in hippocampal neurogenesis, structural- and functional-plasticity of granule cell neurons (GCNs), and expression of plasticity-related proteins in the dentate gyrus. This review will elaborate on the effects of Meth in animal models during different stages of addiction-like behavior on proliferation, differentiation, maturation, and survival of newly born neural progenitor cells. We will then discuss evidence for the contribution of adult neurogenesis in context-driven Meth-seeking behavior in animal models. These findings from interdisciplinary studies suggest that a subset of newly born GCNs contribute to context-driven Meth-seeking in Meth addicted animals.
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Affiliation(s)
- Yoshio Takashima
- Department of Anesthesiology, University of California San Diego, VA San Diego Healthcare System, San Diego, CA, USA
| | - Chitra D. Mandyam
- Department of Anesthesiology, University of California San Diego, VA San Diego Healthcare System, San Diego, CA, USA
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49
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Trimper JB, Galloway CR, Jones AC, Mandi K, Manns JR. Gamma Oscillations in Rat Hippocampal Subregions Dentate Gyrus, CA3, CA1, and Subiculum Underlie Associative Memory Encoding. Cell Rep 2018; 21:2419-2432. [PMID: 29186681 DOI: 10.1016/j.celrep.2017.10.123] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 09/01/2017] [Accepted: 10/29/2017] [Indexed: 01/05/2023] Open
Abstract
Neuronal oscillations in the rat hippocampus relate to both memory and locomotion, raising the question of how these cognitive and behavioral correlates interact to determine the oscillatory network state of this region. Here, rats freely locomoted while performing an object-location task designed to test hippocampus-dependent spatial associative memory. Rhythmic activity in theta, beta, slow gamma, and fast gamma frequency ranges were observed in both action potentials and local field potentials (LFPs) across four main hippocampal subregions. Several patterns of LFP oscillations corresponded to overt behavior (e.g., increased dentate gyrus-CA3 beta coherence during stationary moments and CA1-subiculum theta coherence during locomotion). In comparison, slow gamma (∼40 Hz) oscillations throughout the hippocampus related most specifically to object-location associative memory encoding rather than overt behavior. The results help to untangle how hippocampal oscillations relate to both memory and motion and single out slow gamma oscillations as a distinguishing correlate of spatial associative memory.
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Affiliation(s)
- John B Trimper
- Department of Psychology, Emory University, Atlanta, GA 30322, USA
| | | | - Andrew C Jones
- Neuroscience and Behavioral Biology Program, Emory University, Atlanta, GA 30322, USA
| | - Kaavya Mandi
- Neuroscience and Behavioral Biology Program, Emory University, Atlanta, GA 30322, USA
| | - Joseph R Manns
- Department of Psychology, Emory University, Atlanta, GA 30322, USA.
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50
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Galloway CR, Ravipati K, Singh S, Lebois EP, Cohen RM, Levey AI, Manns JR. Hippocampal place cell dysfunction and the effects of muscarinic M 1 receptor agonism in a rat model of Alzheimer's disease. Hippocampus 2018; 28:568-585. [PMID: 29742799 DOI: 10.1002/hipo.22961] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 04/02/2018] [Accepted: 05/06/2018] [Indexed: 11/09/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that disproportionately impacts memory and the hippocampus. However, it is unclear how AD pathology influences the activity of surviving neurons in the hippocampus to contribute to the memory symptoms in AD. One well-understood connection between spatial memory and neuronal activity in healthy brains is the activity of place cells, neurons in the hippocampus that fire preferentially in a specific location of a given environment (the place field of the place cell). In the present study, place cells were recorded from the hippocampus in a recently-developed rat model of AD (Tg-F344 AD) at an age (12-20 months) at which the AD rats showed marked spatial memory deficits. Place cells in the CA2 and CA3 pyramidal regions of the hippocampus in AD rats showed sharply reduced spatial fidelity relative to wild-type (WT) rats. In contrast, spiking activity of place cells recorded in region CA1 in AD rats showed good spatial fidelity that was similar to CA1 place cells in WT rats. Oral administration of the M1 muscarinic acetylcholine receptor agonist VU0364572 impacted place cell firing rates in CA1 and CA2/3 hippocampal regions, but did not improve the spatial fidelity of CA2/3 hippocampal place cells in AD rats. The results indicated that, to the extent the spatial memory impairment in AD rats was attributable to hippocampal dysfunction, the memory impairment was more attributable to dysfunction in hippocampal regions CA2 and CA3 rather than CA1.
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Affiliation(s)
| | - Kaushik Ravipati
- Neuroscience and Behavioral Biology Program, Emory University, Atlanta, Georgia
| | - Suyashi Singh
- Neuroscience and Behavioral Biology Program, Emory University, Atlanta, Georgia
| | - Evan P Lebois
- Internal Medicine Research Unit, Pfizer Inc, Cambridge, Massachusetts
| | - Robert M Cohen
- Department of Psychiatry, Emory University, Atlanta, Georgia
| | - Allan I Levey
- Department of Neurology, Emory University, Atlanta, Georgia
| | - Joseph R Manns
- Department of Psychology, Emory University, Atlanta, Georgia
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