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Duan YL, Hu SY, Ge XF, Long JL, Deng C, Sun YM, Li CJ, Zhang R, Cai X, Lu L. Object-translocation induces event coding in the rat hippocampus. Commun Biol 2025; 8:797. [PMID: 40413308 PMCID: PMC12103614 DOI: 10.1038/s42003-025-08241-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2025] [Accepted: 05/15/2025] [Indexed: 05/27/2025] Open
Abstract
Episodic memory is the ability to recall personally experienced events that are situated within specific spatial contexts. Within a navigation environment, salient objects can function as landmarks, and interactions with them can be encoded as distinct episodic events. However, the nuanced integration of "where" and "what" aspects of objects during episodic memory formation remains poorly understood. In this study, we conduct a comprehensive analysis of neuronal responses along the rat CA1 proximodistal axis to manipulations of environmental cues and object features. Our results demonstrate that the proximal and distal portions of CA1 preferentially represent landmarks and events, respectively. Following object displacement, we identify an event-like population coding within CA1, distinct from the anticipated pattern of landmark representation. These findings elucidate the specific roles that objects may play in spatial navigation and memory encoding, providing novel insights into the selective processing of object-related information within the entorhinal-hippocampal network under varying conditions.
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Affiliation(s)
- Ya-Li Duan
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Shu-Yi Hu
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xiao-Fan Ge
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Jia-Li Long
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Chu Deng
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yu-Ming Sun
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Cheng-Ji Li
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- National Resource Center for Non-Human Primates, Kunming Primate Research Center, and National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Rong Zhang
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- National Resource Center for Non-Human Primates, Kunming Primate Research Center, and National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xing Cai
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- National Resource Center for Non-Human Primates, Kunming Primate Research Center, and National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Li Lu
- State Key Laboratory of Genetic Evolution & Animal Models, and Key Laboratory of Animal Models & Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.
- National Resource Center for Non-Human Primates, Kunming Primate Research Center, and National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.
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Vania CJ, Padova D, Ratnanather JT, Agrawal Y. The Inner Ear and Aging Brain: A Cross-Sectional Study of Vestibular Function and Morphometric Variations in the Entorhinal and Trans-Entorhinal Cortex. J Assoc Res Otolaryngol 2025; 26:171-184. [PMID: 39994083 PMCID: PMC11996744 DOI: 10.1007/s10162-025-00977-2] [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: 07/25/2024] [Accepted: 01/24/2025] [Indexed: 02/26/2025] Open
Abstract
PURPOSE While the vestibular system is crucial for balance, posture, and stable vision, emerging evidence connects vestibular loss in older adults to spatial cognitive deficits. However, the specific neural pathways remain unclear. This study examines morphometric changes in the entorhinal cortex (ERC) and trans-entorhinal cortex (TEC), key regions in the vestibular spatial cognitive network, with vestibular function. METHODS This cross-sectional study used T1-weighted MRI images and vestibular physiological data from 103 Baltimore Longitudinal Study of Aging participants (74 males and 29 females). Vestibular function was assessed through the cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP (oVEMP), and video head-impulse test (vHIT), examining both categorical presence/absence of responses and continuous measures (cVEMP amplitude, oVEMP amplitude, and VOR gain). Morphometric changes in the ERC and TEC were analyzed by examining surface expansions and contractions relative to average shapes. RESULTS Reduced saccular function correlated with surface expansion in the left ERC's pro-rhinal, right ERC's intermediate caudal and superior regions, and right TEC's sulcal region. The decreased utricular function was associated with surface contraction in the left lateral TEC, left ERC's anterior sulcal and trans-entorhinal regions, and surface expansion in the lateral region of the left ERC. Reduced canal function showed surface contraction in the right ERC's pro-rhinal and lateral regions and the right TEC's posterior sulcal and trans-entorhinal regions. CONCLUSION These findings highlight the intricate link between vestibular function and ERC/TEC morphology, emphasizing their role in spatial and cognitive abilities. Future research will assess if structural changes due to vestibular loss contribute to cognitive deficits in aging and Alzheimer's disease.
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Affiliation(s)
- Claire J Vania
- Department of Biomedical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA.
| | - Dominic Padova
- Center for Imaging Science and Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - J Tilak Ratnanather
- Center for Imaging Science and Institute for Computational Medicine, Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Yuri Agrawal
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Otolaryngology-Head and Neck Surgery, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
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3
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Ananth MR, Gardus JD, Huang C, Palekar N, Slifstein M, Zaborszky L, Parsey RV, Talmage DA, DeLorenzo C, Role LW. A central role for acetylcholine in entorhinal cortex function and dysfunction with age in humans and mice. Cell Rep 2025; 44:115249. [PMID: 39891909 DOI: 10.1016/j.celrep.2025.115249] [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: 05/31/2024] [Revised: 11/15/2024] [Accepted: 01/09/2025] [Indexed: 02/03/2025] Open
Abstract
Structural and functional changes in the entorhinal cortex (EC) are among the earliest signs of cognitive aging. Here, we ask whether a compromised cholinergic system influences early EC impairments and plays a primary role in EC cognition. We evaluated the relationship between loss of integrity of cholinergic inputs to the EC and cognitive deficits in otherwise healthy humans and mice. Using in vivo imaging (PET/MRI) in older humans and high-resolution imaging in wild-type mice and mice with genetic susceptibility to Alzheimer's disease pathology, we establish that loss of cholinergic input to the EC is, in fact, an early feature in cognitive aging. Through mechanistic studies in mice, we find a central role for EC-projecting cholinergic neurons in the expression of EC-related behaviors. Our data demonstrate that alterations to the cholinergic EC are an early, conserved feature of cognitive aging across species and may serve as an early predictor of cognitive status.
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Affiliation(s)
- Mala R Ananth
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA.
| | - John D Gardus
- Department of Psychiatry and Behavioral Health, Stony Brook Medicine, Stony Brook, NY, USA
| | - Chuan Huang
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Nikhil Palekar
- Department of Psychiatry and Behavioral Health, Stony Brook Medicine, Stony Brook, NY, USA
| | - Mark Slifstein
- Department of Psychiatry and Behavioral Health, Stony Brook Medicine, Stony Brook, NY, USA
| | - Laszlo Zaborszky
- Center for Molecular and Behavioral Neuroscience, Rutgers University, New Newark, NJ, USA
| | - Ramin V Parsey
- Department of Psychiatry and Behavioral Health, Stony Brook Medicine, Stony Brook, NY, USA; Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - David A Talmage
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA
| | - Christine DeLorenzo
- Department of Psychiatry and Behavioral Health, Stony Brook Medicine, Stony Brook, NY, USA; Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Lorna W Role
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA.
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Duncan S, Rehman S, Sagen V, Choi I, Lawrence S, Kalani O, Gold L, Goldman L, Ramlo S, Stickel K, Layfield D, Wolbers T, Tiganj Z, Newman EL. rTCT: Rodent Triangle Completion Task to facilitate translational study of path integration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.02.04.636463. [PMID: 39975325 PMCID: PMC11838589 DOI: 10.1101/2025.02.04.636463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/21/2025]
Abstract
Path integration is navigation in the absence of environmental landmarks and is a primary cognitive mechanism underlying spatial memory. Path integration performance is primarily assessed in humans using the Triangle Completion Task (TCT). In humans, TCT has shown promise for the early diagnosis of Alzheimer's disease. In rodents, however, path integration is assessed using a wide variety of tasks but none of which currently provide a homologue for the TCT. As rodents are routinely used as preclinical models, homologous path integration tasks that result in comparable performance metrics between species are important. In the present study we developed and tested a novel rodent version of the triangle completion task to enhance cross species comparability of path integration performance. Rats were able to comprehend and perform the task. A group of Alzheimer's disease model rats (TgF344-AD) exhibited similar path integration performance to their wild-type littermates; however, analysis of behavioural structure suggests use of differing behavioural strategies. This work establishes a novel rodent homologue of the triangle completion task, facilitating enhanced reverse translational study of human path integration.
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Affiliation(s)
- Stephen Duncan
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Sulaiman Rehman
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Vladislava Sagen
- German Center for Neurodegenerative Diseases (DZNE), 39120, Magdeburg, Germany
| | - Irene Choi
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Sami Lawrence
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Om Kalani
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Lisette Gold
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Lillian Goldman
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Sophia Ramlo
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Kylene Stickel
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Dylan Layfield
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Thomas Wolbers
- German Center for Neurodegenerative Diseases (DZNE), 39120, Magdeburg, Germany
| | - Zoran Tiganj
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
| | - Ehren L. Newman
- Department of Psychology & Brain Sciences, Indiana University; 1101 E. 10 Street, Bloomington, IN, 47405, U.S.A
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Maaroufi K, Khadhraoui Y, Moulahi A, Ouarghi A, Poirot K, Save E, Sebai H. Sub-Chronic 30 mg/kg Iron Treatment Induces Spatial Cognition Impairment and Brain Oxidative Stress in Wistar Rats. Biol Trace Elem Res 2025:10.1007/s12011-024-04511-y. [PMID: 39810017 DOI: 10.1007/s12011-024-04511-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Accepted: 12/31/2024] [Indexed: 01/16/2025]
Abstract
Iron overload has been shown to have deleterious effects in the brain through the formation of reactive oxygen species, which ultimately may contribute to neurodegenerative disorders. Accordingly, rodent studies have indicated that systemic administration of iron produces excess iron in the brain and results in behavioral and cognitive deficits. To what extent cognitive abilities are affected and which neurobiological mechanisms underlie those deficits remain to be more fully characterized. In the present study, we looked at the effects of a 30 mg/kg iron sub-chronic treatment on cognitive abilities in two hippocampal-dependent spatial tasks (place navigation, spatial/non-spatial object recognition), in relation with iron content and oxidative stress biomarkers (MDA, SOD, CAT) in the cerebellum, hippocampus, prefrontal cortex and striatum, four brain areas known to be involved in the processing of spatial information. Iron-treated rats were impaired in acquisition and retention of the platform location in the navigation task and in the spatial/non-spatial object recognition task. Iron content and MDA were found to be increased in the four brain regions of interest, but activity of the antioxidant enzymes was not modified. The results indicate that the ability of rats to process spatial information whether in place navigation or spontaneous object spatial/non-spatial recognition is disrupted following a 30 mg/kg sub-chronic treatment. The deficits are hypothesized to result from iron excess-induced oxidative stress in the network of brain areas involved in the processing of spatial information.
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Affiliation(s)
- Karima Maaroufi
- Laboratory Functional Physiology and Bio-Resources Valorisation, Higher Institute of Biotechnology of Beja, University of Jendouba, Avenue Habib Bourguiba BP 382, 9000, Beja, Tunisia
| | - Yassine Khadhraoui
- Laboratory Functional Physiology and Bio-Resources Valorisation, Higher Institute of Biotechnology of Beja, University of Jendouba, Avenue Habib Bourguiba BP 382, 9000, Beja, Tunisia
| | - Afef Moulahi
- Laboratory Functional Physiology and Bio-Resources Valorisation, Higher Institute of Biotechnology of Beja, University of Jendouba, Avenue Habib Bourguiba BP 382, 9000, Beja, Tunisia
| | - Abid Ouarghi
- Laboratory Functional Physiology and Bio-Resources Valorisation, Higher Institute of Biotechnology of Beja, University of Jendouba, Avenue Habib Bourguiba BP 382, 9000, Beja, Tunisia
| | - Kevin Poirot
- Aix Marseille Univ, CNRS, CRPN, Marseille, France
| | - Etienne Save
- Aix Marseille Univ, CNRS, CRPN, Marseille, France.
| | - Hichem Sebai
- Laboratory Functional Physiology and Bio-Resources Valorisation, Higher Institute of Biotechnology of Beja, University of Jendouba, Avenue Habib Bourguiba BP 382, 9000, Beja, Tunisia
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Li K, Qian L, Zhang C, Zhang J, Xue C, Zhang Y, Deng W. The entorhinal cortex and cognitive impairment in schizophrenia: A comprehensive review. Prog Neuropsychopharmacol Biol Psychiatry 2025; 136:111218. [PMID: 39672531 DOI: 10.1016/j.pnpbp.2024.111218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 11/19/2024] [Accepted: 12/09/2024] [Indexed: 12/15/2024]
Abstract
Schizophrenia, a severe mental illness characterized by cognitive impairment and olfactory dysfunction, remains an enigma with its pathological mechanism yet to be fully elucidated. The entorhinal cortex, a pivotal structure involved in numerous neural loop circuits related to olfaction, cognition, and emotion, has garnered significant attention due to its structural and functional abnormalities, which have been implicated in the pathogenesis of schizophrenia. This review focuses on the abnormal structural and functional changes in the entorhinal cortex in schizophrenia patients, as evidenced by neuroimaging, cellular biology, and genetic studies. These changes are posited to play a crucial role in the pathogenesis of cognitive impairment in schizophrenia. Furthermore, this review explores the various intervention strategies targeting the entorhinal cortex in current treatment modalities and proposes potential directions for future research endeavors, thereby providing a novel perspective on unraveling the complexity of neural mechanisms underlying schizophrenia and developing innovative therapeutic approaches for schizophrenia.
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Affiliation(s)
- Kun Li
- Shandong Daizhuang Hospital, Jining, Shandong Province 272075, China; Jining Key Laboratory of Neuromodulation, Jining, Shandong Province 272075, China.
| | - Liju Qian
- Shandong Daizhuang Hospital, Jining, Shandong Province 272075, China
| | - Chenchen Zhang
- Shandong Daizhuang Hospital, Jining, Shandong Province 272075, China
| | - Jiajia Zhang
- Department of Psychology, Xinxiang Medical University, Henan 453003, China
| | - Chuang Xue
- Affiliated Mental Health Center & Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310063, China
| | - Yuebing Zhang
- Shandong Daizhuang Hospital, Jining, Shandong Province 272075, China
| | - Wei Deng
- Affiliated Mental Health Center & Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310063, China; Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-Machine Integration, State Key Laboratory of Brain-Machine Intelligence, Zhejiang University, 1369 West Wenyi Road, Hangzhou 311121, China.
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Redish AD. Mental Time Travel: A Retrospective. Hippocampus 2025; 35:e23661. [PMID: 39676592 DOI: 10.1002/hipo.23661] [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: 07/11/2024] [Revised: 09/16/2024] [Accepted: 11/26/2024] [Indexed: 12/17/2024]
Abstract
Because imagination activates the same neural circuits used in understanding the present, one can access that imagination even in non-linguistic animals through decoding techniques applied to large neural ensembles. This personal retrospective traces the history of the initial discovery that hippocampal theta sequences sweep forward to goals during moments of deliberation and discusses the history that was necessary to put ourselves in the position to recognize this signal. It also discusses how that discovery fits into the larger picture of hippocampal function and the concept of cognition as computation.
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Affiliation(s)
- A David Redish
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
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8
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Arai S, Sypniewski KA, Pavlides C. Differential roles of medial/lateral entorhinal cortex in spatial/object memory and contribution to hippocampal functional neuronal organization. Neurobiol Learn Mem 2025; 217:108015. [PMID: 39689754 DOI: 10.1016/j.nlm.2024.108015] [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: 06/22/2024] [Revised: 12/06/2024] [Accepted: 12/11/2024] [Indexed: 12/19/2024]
Abstract
Episodic memory is subserved by interactions between entorhinal cortex (EC) and hippocampus. Within EC, a functional dissociation has been proposed for medial (MEC) and lateral (LEC) subregions, whereby, MEC processes spatial information while LEC processes information about objects and their location in space. Most of these studies, however, used classical methods which lack both spatial and temporal specificity, thus, the precise role of MEC/LEC in memory could use further clarification. First, we show a possible functional dissociation of MEC/LEC for place/object fear memory, by optogenetic suppression of these areas during memory acquisition. The main output of EC is to the hippocampus. MEC projects mainly towards proximal/superficial CA1 and deep CA3 while LEC towards distal/deep CA1 and superficial CA3. Dentate gyrus (DG), terminations of MEC/LEC are dissociated septotemporally. A functional dissociation has also been proposed for subregions of the hippocampus. Previous studies reported that proximal/distal CA1 process spatial/nonspatial information, respectively. For the second part of the study, we used the immediate-early gene Zif-268 to map neuronal activity in CA1. We first show enhanced Zif-268 expression and cluster-type organization in the proximal CA1 by place exposure and enhanced Zif-268 expression/cluster organization in distal CA1 following object exposure. Second, direct optogenetic stimulation of MEC/LEC, produced a similar enhancement/cluster-type organization in the same areas. Enhanced Zif-268 expression was also observed in CA3 and DG. These results substantiate previous findings and are proof positive that the hippocampus is organized in clusters to encode information generally ascribed to this structure.
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Affiliation(s)
- Shoko Arai
- Department of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8577, Japan
| | - Krzysztof A Sypniewski
- Department of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8577, Japan
| | - Constantine Pavlides
- Department of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8577, Japan.
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9
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Pedroncini O, Federman N, Marin-Burgin A. Lateral entorhinal cortex afferents reconfigure the activity in piriform cortex circuits. Proc Natl Acad Sci U S A 2024; 121:e2414038121. [PMID: 39570314 PMCID: PMC11621770 DOI: 10.1073/pnas.2414038121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Accepted: 10/14/2024] [Indexed: 11/22/2024] Open
Abstract
Odors are key signals for guiding spatial behaviors such as foraging and navigation in rodents. Recent findings reveal that odor representations in the piriform cortex (PCx) also encode spatial context information. However, the brain origins of this information and its integration into PCx microcircuitry remain unclear. This study investigates the lateral entorhinal cortex (LEC) as a potential source of spatial contextual information affecting the PCx microcircuit and its olfactory responses. Using mice brain slices, we performed patch-clamp recordings on superficial (SP) and deep (DP) pyramidal neurons, as well as parvalbumin (PV) and somatostatin (SOM) inhibitory interneurons. Concurrently, we optogenetically stimulated excitatory LEC projections to observe their impact on PCx activity. Results show that LEC inputs are heterogeneously distributed in the PCx microcircuit, evoking larger excitatory currents in SP and PV neurons due to higher monosynaptic connectivity. LEC inputs also differentially affect inhibitory circuits, activating PV while suppressing SOM interneurons. Studying the interaction between LEC inputs and sensory signals from the lateral olfactory tract (LOT) revealed that simultaneous LEC and LOT activation increases spiking in SP and DP neurons, with DP neurons showing a sharpened response due to LEC-induced inhibition that suppresses delayed LOT-evoked spikes. This suggests a regulatory mechanism where LEC inputs inhibit recurrent activity by activating PV interneurons. Our findings demonstrate that LEC afferents reconfigure PCx activity, aiding the understanding of how odor objects form within the PCx by integrating olfactory and nonolfactory information.
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Affiliation(s)
- Olivia Pedroncini
- Instituto de Investigación en Biomedicina de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas-Partner Institute of the Max Planck Society, Buenos AiresC1425FQD, Argentina
| | - Noel Federman
- Instituto de Investigación en Biomedicina de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas-Partner Institute of the Max Planck Society, Buenos AiresC1425FQD, Argentina
| | - Antonia Marin-Burgin
- Instituto de Investigación en Biomedicina de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas-Partner Institute of the Max Planck Society, Buenos AiresC1425FQD, Argentina
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Kuhn HM, Serrano LC, Stys GA, Smith BL, Speckmaier J, Dawson BD, Murray BR, He J, Robison AJ, Eagle AL. Lateral entorhinal cortex neurons that project to nucleus accumbens mediate contextual associative memory. Learn Mem 2024; 31:a054026. [PMID: 39592189 PMCID: PMC11606517 DOI: 10.1101/lm.054026.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Accepted: 10/21/2024] [Indexed: 11/28/2024]
Abstract
The lateral entorhinal cortex (LEC) contains glutamatergic projections that innervate the nucleus accumbens (NAc) and may be involved in the encoding of contextual associations with both positive and negative valences, such as those encountered in drug cues or fear conditioning. To determine whether LEC-NAc neurons are activated by the encoding and recall of contexts associated with cocaine or footshock, we measured c-fos expression in these neurons and found that LEC-NAc neurons are activated in both contexts. Specifically, activation patterns of the LEC-NAc were observed in a novel context and reexposure to the same context, highlighting the specific role for LEC-NAc neurons in encoding rather than the valence of a specific event-related memory. Using a combination of circuit-specific chemogenetic tools and behavioral assays, we selectively inactivated LEC-NAc neurons in mice during the encoding and retrieval of memories of contexts associated with cocaine or footshock. Chemogenetic inactivation of LEC-NAc neurons impaired the formation of both positive and negative context-associated memories without affecting the retrieval of an established memory. This finding suggests a critical role for this circuit in the initial encoding of contextual associations. In summary, LEC-NAc neurons facilitate the encoding of contextual information, guiding motivational behaviors without directly mediating the hedonic or aversive properties of these associations.
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Affiliation(s)
- Hayley M Kuhn
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
| | | | - Grace A Stys
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Brianna L Smith
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | | - Brooklynn R Murray
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Jin He
- Department of Biochemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Alfred J Robison
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Andrew L Eagle
- Department of Neuroscience, The University of Texas at Dallas, Richardson, Texas 75080, USA
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11
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Farmer AL, Febo M, Wilkes BJ, Lewis MH. Environmental enrichment reduces restricted repetitive behavior by altering gray matter microstructure. PLoS One 2024; 19:e0307290. [PMID: 39083450 PMCID: PMC11290697 DOI: 10.1371/journal.pone.0307290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Accepted: 07/02/2024] [Indexed: 08/02/2024] Open
Abstract
Restricted, repetitive behaviors are common symptoms in neurodevelopmental disorders including autism spectrum disorder. Despite being associated with poor developmental outcomes, repetitive behaviors remain poorly understood and have limited treatment options. Environmental enrichment attenuates the development of repetitive behaviors, but the exact mechanisms remain obscure. Using the C58 mouse model of repetitive behavior, we performed diffusion tensor imaging to examine microstructural alterations associated with the development of repetitive behavior and its attenuation by environmental enrichment. The C57BL/6 mouse strain, which displays little or no repetitive behavior, was used as a control group. We observed widespread differences in diffusion metrics between C58 mice and C57BL/6 mice. In juvenile C58 mice, repetitive motor behavior displayed strong negative correlations with fractional anisotropy in multiple gray matter regions, whereas in young adult C58 mice, high repetitive motor behavior was most strongly associated with lower fractional anisotropy and higher radial diffusivity in the striatum. Environmental enrichment increased fractional anisotropy and axial diffusivity throughout gray matter regions in the brains of juvenile C58 mice and overlapped predominantly with cerebellar and sensory regions associated with repetitive behavior. Our results suggest environmental enrichment reduces repetitive behavior development by altering gray matter microstructure in the cerebellum, medial entorhinal cortex, and sensory processing regions in juvenile C58 mice. Under standard laboratory conditions, early pathology in these regions appears to contribute to later striatal and white matter dysfunction in adult C58 mice. Future studies should examine the role these regions play in the development of repetitive behavior and the relationship between sensory processing and cerebellar deficits and repetitive behavior.
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Affiliation(s)
- Anna L. Farmer
- Department of Psychology, University of Florida, Gainesville, Florida, United States of America
| | - Marcelo Febo
- Department of Psychiatry, University of Florida, Gainesville, Florida, United States of America
| | - Bradley J. Wilkes
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, United States of America
| | - Mark H. Lewis
- Department of Psychology, University of Florida, Gainesville, Florida, United States of America
- Department of Psychiatry, University of Florida, Gainesville, Florida, United States of America
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12
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Fu Y, Cao Z, Ye T, Yang H, Chu C, Lei C, Wen Y, Cai Z, Yuan Y, Guo X, Yang L, Sheng H, Cui D, Shao D, Chen M, Lai B, Zheng P. Projection neurons from medial entorhinal cortex to basolateral amygdala are critical for the retrieval of morphine withdrawal memory. iScience 2024; 27:110239. [PMID: 39021787 PMCID: PMC11253517 DOI: 10.1016/j.isci.2024.110239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 04/10/2024] [Accepted: 06/07/2024] [Indexed: 07/20/2024] Open
Abstract
The medial entorhinal cortex (MEC) is crucial for contextual memory, yet its role in context-induced retrieval of morphine withdrawal memory remains unclear. This study investigated the role of the MEC and its projection neurons from MEC layer 5 to the basolateral amygdala (BLA) (MEC-BLA neurons) in context-induced retrieval of morphine withdrawal memory. Results show that context activates the MEC in morphine withdrawal mice, and the inactivation of the MEC inhibits context-induced retrieval of morphine withdrawal memory. At neural circuits, context activates MEC-BLA neurons in morphine withdrawal mice, and the inactivation of MEC-BLA neurons inhibits context-induced retrieval of morphine withdrawal memory. But MEC-BLA neurons are not activated by conditioning of context and morphine withdrawal, and the inhibition of MEC-BLA neurons do not influence the coupling of context and morphine withdrawal memory. These results suggest that MEC-BLA neurons are critical for the retrieval, but not for the formation, of morphine withdrawal memory.
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Affiliation(s)
- Yali Fu
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zixuan Cao
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Ting Ye
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Hao Yang
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Chenshan Chu
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Chao Lei
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Yaxian Wen
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zhangyin Cai
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Yu Yuan
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xinli Guo
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Li Yang
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Huan Sheng
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Dongyang Cui
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Da Shao
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Ming Chen
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Bin Lai
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Ping Zheng
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, MOE Frontier Center for Brain Science, Department of Neurology of Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Medical College of China Three Gorges University, Yichang 443002, China
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13
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Catumbela CSG, Morales R. Elderly mice with history of acetaminophen intoxication display worsened cognitive impairment and persistent elevation of astrocyte and microglia burden. Sci Rep 2024; 14:14205. [PMID: 38902507 PMCID: PMC11190293 DOI: 10.1038/s41598-024-65185-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: 03/16/2024] [Accepted: 06/18/2024] [Indexed: 06/22/2024] Open
Abstract
Acetaminophen (APAP) is a leading cause of acute liver failure. The effect of APAP metabolite's effects in the periphery are well characterized; however, associated consequences in the brain remain poorly understood. Animal studies on this subject are few and reveal that frequent APAP intake can trigger cerebral abnormalities that vary depending on the subject's age. Alarmingly, experimental efforts have yet to examine associated consequences in elderly hosts, who correspond to the highest risk of medication overload, impaired drug clearance, and cognitive deficits. Here, we interrogated the cerebral and peripheral pathology of elderly mice submitted to monthly episodes of APAP intoxication since a young adult age. We found that weeks after the final episode of recurrent APAP exposure, mice exhibited worsened non-spatial memory deficit whereas spatial memory performance was unaltered. Interestingly, one month after the period of APAP intoxication, these mice showed increased glial burden without associated drivers, namely, blood-brain barrier disruption, cholesterol accumulation, and elevation of inflammatory molecules in the brain and/or periphery. Our experimental study reveals how recurrent APAP exposure affects the cognitive performance and cellular events in elderly brains. These data suggest that APAP-containing pharmacological interventions may foreshadow the elevated risk of neuropsychiatric disorders that afflict elderly populations.
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Affiliation(s)
- Celso S G Catumbela
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Rodrigo Morales
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
- Centro Integrativo de Biologia y Quimica Aplicada (CIBQA), Universidad Bernardo O'Higgins, Santiago, Chile.
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14
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Tang Z, Wang X, Yang C, Chen Z, Zeng Z. A Bionic Localization Memristive Circuit Based on Spatial Cognitive Mechanisms of Hippocampus and Entorhinal Cortex. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2024; 18:552-563. [PMID: 38805341 DOI: 10.1109/tbcas.2024.3350135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
In this article, a bionic localization memristive circuit is proposed, which mainly consists of head direction cell module, grid cell module, place cell module and decoding module. This work modifies the two-dimensional Continuous Attractor Network (CAN) model of grid cells into two one-dimensional models in X and Y directions. The head direction cell module utilizes memristors to integrate angular velocity and represents the real orientation of an agent. The grid cell module uses memristors to sense linear velocity and orientation signals, which are both self-motion cues, and encodes the position in space by firing in a periodic mode. The place cell module receives the grid cell module's output and fires in a specific position. The decoding module decodes the angle or place information and transfers the neuron state to a 'one-hot' code. This proposed circuit completes the localizing task in space and realizes in-memory computing due to the use of memristors, which can shorten the execution time. The functions mentioned above are implemented in LTSPICE. The simulation results show that the proposed circuit can realize path integration and localization. Moreover, it is shown that the proposed circuit has good robustness and low area overhead. This work provides a possible application idea in a prospective robot platform to help the robot localize and build maps.
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15
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Karimani F, Asgari Taei A, Abolghasemi-Dehaghani MR, Safari MS, Dargahi L. Impairment of entorhinal cortex network activity in Alzheimer's disease. Front Aging Neurosci 2024; 16:1402573. [PMID: 38882526 PMCID: PMC11176617 DOI: 10.3389/fnagi.2024.1402573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Accepted: 05/20/2024] [Indexed: 06/18/2024] Open
Abstract
The entorhinal cortex (EC) stands out as a critical brain region affected in the early phases of Alzheimer's disease (AD), with some of the disease's pathological processes originating from this area, making it one of the most crucial brain regions in AD. Recent research highlights disruptions in the brain's network activity, characterized by heightened excitability and irregular oscillations, may contribute to cognitive impairment. These disruptions are proposed not only as potential therapeutic targets but also as early biomarkers for AD. In this paper, we will begin with a review of the anatomy and function of EC, highlighting its selective vulnerability in AD. Subsequently, we will discuss the disruption of EC network activity, exploring changes in excitability and neuronal oscillations in this region during AD and hypothesize that, considering the advancements in neuromodulation techniques, addressing the disturbances in the network activity of the EC could offer fresh insights for both the diagnosis and treatment of AD.
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Affiliation(s)
- Farnaz Karimani
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Afsaneh Asgari Taei
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Mir-Shahram Safari
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Leila Dargahi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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16
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Hales JB, Olivas L, Abouchedid D, Blaser RE. Contribution of the medial entorhinal cortex to performance on the Traveling Salesperson Problem in rats. Behav Brain Res 2024; 463:114883. [PMID: 38281708 DOI: 10.1016/j.bbr.2024.114883] [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: 09/15/2023] [Revised: 01/17/2024] [Accepted: 01/25/2024] [Indexed: 01/30/2024]
Abstract
In order to successfully navigate through space, animals must rely on multiple cognitive processes, including orientation in space, memory of object locations, and navigational decisions based on that information. Although highly-controlled behavioral tasks are valuable for isolating and targeting specific processes, they risk producing a narrow understanding of complex behavior in natural contexts. The Traveling Salesperson Problem (TSP) is an optimization problem that can be used to study naturalistic foraging behaviors, in which subjects select routes between multiple baited targets. Foraging is a spontaneous, yet complex, behavior, involving decision-making, attention, course planning, and memory. Previous research found that hippocampal lesions in rats impaired TSP task performance, particularly on measures of spatial memory. Although traditional laboratory tests have shown the medial entorhinal cortex (MEC) to play an important role in spatial memory, if and how the MEC is involved in finding efficient solutions to the TSP remains unknown. In the current study, rats were trained on the TSP, learning to retrieve bait from targets in a variety of spatial configurations. After recovering from either an MEC lesion or control sham surgery, the rats were tested on eight new configurations. Our results showed that, similar to rats with hippocampal lesions, MEC-lesioned rats were impaired on measures of spatial memory, but not spatial decision-making, with greatest impairments on configurations requiring a global navigational strategy for selecting the optimal route. These findings suggest that the MEC is important for effective spatial navigation, especially when global cue processing is required.
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Affiliation(s)
- Jena B Hales
- University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA.
| | - Larissa Olivas
- University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
| | | | - Rachel E Blaser
- University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA.
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17
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Ananth MR, Gardus JD, Huang C, Palekar N, Slifstein M, Zaborszky L, Parsey RV, Talmage DA, DeLorenzo C, Role LW. Loss of cholinergic input to the entorhinal cortex is an early indicator of cognitive impairment in natural aging of humans and mice. RESEARCH SQUARE 2024:rs.3.rs-3851086. [PMID: 38260541 PMCID: PMC10802688 DOI: 10.21203/rs.3.rs-3851086/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
In a series of translational experiments using fully quantitative positron emission tomography (PET) imaging with a new tracer specific for the vesicular acetylcholine transporter ([18F]VAT) in vivo in humans, and genetically targeted cholinergic markers in mice, we evaluated whether changes to the cholinergic system were an early feature of age-related cognitive decline. We found that deficits in cholinergic innervation of the entorhinal cortex (EC) and decline in performance on behavioral tasks engaging the EC are, strikingly, early features of the aging process. In human studies, we recruited older adult volunteers that were physically healthy and without prior clinical diagnosis of cognitive impairment. Using [18F]VAT PET imaging, we demonstrate that there is measurable loss of cholinergic inputs to the EC that can serve as an early signature of decline in EC cognitive performance. These deficits are specific to the cholinergic circuit between the medial septum and vertical limb of the diagonal band (MS/vDB; CH1/2) to the EC. Using diffusion imaging, we further demonstrate impaired structural connectivity in the tracts between the MS/vDB and EC in older adults with mild cognitive impairment. Experiments in mouse, designed to parallel and extend upon the human studies, used high resolution imaging to evaluate cholinergic terminal density and immediate early gene (IEG) activity of EC neurons in healthy aging mice and in mice with genetic susceptibility to accelerated accumulation amyloid beta plaques and hyperphosphorylated mouse tau. Across species and aging conditions, we find that the integrity of cholinergic projections to the EC directly correlates with the extent of EC activation and with performance on EC-related object recognition memory tasks. Silencing EC-projecting cholinergic neurons in young, healthy mice during the object-location memory task impairs object recognition performance, mimicking aging. Taken together we identify a role for acetylcholine in normal EC function and establish loss of cholinergic input to the EC as an early, conserved feature of age-related cognitive decline in both humans and rodents.
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18
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Santiago RMM, Lopes-Dos-Santos V, Aery Jones EA, Huang Y, Dupret D, Tort ABL. Waveform-based classification of dentate spikes. Sci Rep 2024; 14:2989. [PMID: 38316828 PMCID: PMC10844627 DOI: 10.1038/s41598-024-53075-3] [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: 12/10/2023] [Accepted: 01/27/2024] [Indexed: 02/07/2024] Open
Abstract
Synchronous excitatory discharges from the entorhinal cortex (EC) to the dentate gyrus (DG) generate fast and prominent patterns in the hilar local field potential (LFP), called dentate spikes (DSs). As sharp-wave ripples in CA1, DSs are more likely to occur in quiet behavioral states, when memory consolidation is thought to take place. However, their functions in mnemonic processes are yet to be elucidated. The classification of DSs into types 1 or 2 is determined by their origin in the lateral or medial EC, as revealed by current source density (CSD) analysis, which requires recordings from linear probes with multiple electrodes spanning the DG layers. To allow the investigation of the functional role of each DS type in recordings obtained from single electrodes and tetrodes, which are abundant in the field, we developed an unsupervised method using Gaussian mixture models to classify such events based on their waveforms. Our classification approach achieved high accuracies (> 80%) when validated in 8 mice with DG laminar profiles. The average CSDs, waveforms, rates, and widths of the DS types obtained through our method closely resembled those derived from the CSD-based classification. As an example of application, we used the technique to analyze single-electrode LFPs from apolipoprotein (apo) E3 and apoE4 knock-in mice. We observed that the latter group, which is a model for Alzheimer's disease, exhibited wider DSs of both types from a young age, with a larger effect size for DS type 2, likely reflecting early pathophysiological alterations in the EC-DG network, such as hyperactivity. In addition to the applicability of the method in expanding the study of DS types, our results show that their waveforms carry information about their origins, suggesting different underlying network dynamics and roles in memory processing.
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Affiliation(s)
- Rodrigo M M Santiago
- Computational Neurophysiology Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59078-900, Brazil.
| | - Vítor Lopes-Dos-Santos
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Emily A Aery Jones
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA, 94158, USA
| | - David Dupret
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Adriano B L Tort
- Computational Neurophysiology Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59078-900, Brazil
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19
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Santiago RM, Lopes-dos-Santos V, Jones EAA, Huang Y, Dupret D, Tort AB. Waveform-based classification of dentate spikes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563826. [PMID: 37961150 PMCID: PMC10634814 DOI: 10.1101/2023.10.24.563826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Synchronous excitatory discharges from the entorhinal cortex (EC) to the dentate gyrus (DG) generate fast and prominent patterns in the hilar local field potential (LFP), called dentate spikes (DSs). As sharp-wave ripples in CA1, DSs are more likely to occur in quiet behavioral states, when memory consolidation is thought to take place. However, their functions in mnemonic processes are yet to be elucidated. The classification of DSs into types 1 or 2 is determined by their origin in the lateral or medial EC, as revealed by current source density (CSD) analysis, which requires recordings from linear probes with multiple electrodes spanning the DG layers. To allow the investigation of the functional role of each DS type in recordings obtained from single electrodes and tetrodes, which are abundant in the field, we developed an unsupervised method using Gaussian mixture models to classify such events based on their waveforms. Our classification approach achieved high accuracies (> 80%) when validated in 8 mice with DG laminar profiles. The average CSDs, waveforms, rates, and widths of the DS types obtained through our method closely resembled those derived from the CSD-based classification. As an example of application, we used the technique to analyze single-electrode LFPs from apolipoprotein (apo) E3 and apoE4 knock-in mice. We observed that the latter group, which is a model for Alzheimer's disease, exhibited wider DSs of both types from a young age, with a larger effect size for DS type 2, likely reflecting early pathophysiological alterations in the EC-DG network, such as hyperactivity. In addition to the applicability of the method in expanding the study of DS types, our results show that their waveforms carry information about their origins, suggesting different underlying network dynamics and roles in memory processing.
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Affiliation(s)
- Rodrigo M.M. Santiago
- Computational Neurophysiology Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59078-900, Brazil
| | - Vítor Lopes-dos-Santos
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Emily A. Aery Jones
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - David Dupret
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Adriano B.L. Tort
- Computational Neurophysiology Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59078-900, Brazil
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20
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Najafian Jazi M, Tymorek A, Yen TY, Jose Kavarayil F, Stingl M, Chau SR, Baskurt B, García Vilela C, Allen K. Hippocampal firing fields anchored to a moving object predict homing direction during path-integration-based behavior. Nat Commun 2023; 14:7373. [PMID: 37968268 PMCID: PMC10651862 DOI: 10.1038/s41467-023-42642-3] [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: 10/18/2022] [Accepted: 10/17/2023] [Indexed: 11/17/2023] Open
Abstract
Homing based on path integration (H-PI) is a form of navigation in which an animal uses self-motion cues to keep track of its position and return to a starting point. Despite evidence for a role of the hippocampus in homing behavior, the hippocampal spatial representations associated with H-PI are largely unknown. Here we developed a homing task (AutoPI task) that required a mouse to find a randomly placed lever on an arena before returning to its home base. Recordings from the CA1 area in male mice showed that hippocampal neurons remap between random foraging and AutoPI task, between trials in light and dark conditions, and between search and homing behavior. During the AutoPI task, approximately 25% of the firing fields were anchored to the lever position. The activity of 24% of the cells with a lever-anchored field predicted the homing direction of the animal on each trial. Our results demonstrate that the activity of hippocampal neurons with object-anchored firing fields predicts homing behavior.
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Affiliation(s)
- Maryam Najafian Jazi
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Adrian Tymorek
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Ting-Yun Yen
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Felix Jose Kavarayil
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Moritz Stingl
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Sherman Richard Chau
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Benay Baskurt
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Celia García Vilela
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany
| | - Kevin Allen
- Medical Faculty of Heidelberg University and German Cancer Research Center, Heidelberg, Germany.
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21
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Robert V, O'Neil K, Rashid SK, Johnson CD, De La Torre RG, Zemelman BV, Clopath C, Basu J. Entorhinal cortex glutamatergic and GABAergic projections bidirectionally control discrimination and generalization of hippocampal representations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566107. [PMID: 37986793 PMCID: PMC10659280 DOI: 10.1101/2023.11.08.566107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Discrimination and generalization are crucial brain-wide functions for memory and object recognition that utilize pattern separation and completion computations. Circuit mechanisms supporting these operations remain enigmatic. We show lateral entorhinal cortex glutamatergic (LEC GLU ) and GABAergic (LEC GABA ) projections are essential for object recognition memory. Silencing LEC GLU during in vivo two-photon imaging increased the population of active CA3 pyramidal cells but decreased activity rates, suggesting a sparse coding function through local inhibition. Silencing LEC GLU also decreased place cell remapping between different environments validating this circuit drives pattern separation and context discrimination. Optogenetic circuit mapping confirmed that LEC GLU drives dominant feedforward inhibition to prevent CA3 somatic and dendritic spikes. However, conjunctively active LEC GABA suppresses this local inhibition to disinhibit CA3 pyramidal neuron soma and selectively boost integrative output of LEC and CA3 recurrent network. LEC GABA thus promotes pattern completion and context generalization. Indeed, without this disinhibitory input, CA3 place maps show decreased similarity between contexts. Our findings provide circuit mechanisms whereby long-range glutamatergic and GABAergic cortico-hippocampal inputs bidirectionally modulate pattern separation and completion, providing neuronal representations with a dynamic range for context discrimination and generalization.
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22
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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: 0.5] [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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23
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Huang X, Schlesiger MI, Barriuso-Ortega I, Leibold C, MacLaren DAA, Bieber N, Monyer H. Distinct spatial maps and multiple object codes in the lateral entorhinal cortex. Neuron 2023; 111:3068-3083.e7. [PMID: 37478849 DOI: 10.1016/j.neuron.2023.06.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 05/12/2023] [Accepted: 06/23/2023] [Indexed: 07/23/2023]
Abstract
The lateral entorhinal cortex (LEC) is a major cortical input area to the hippocampus, and it is crucial for associative object-place-context memories. An unresolved question is whether these associations are performed exclusively in the hippocampus or also upstream of it. Anatomical evidence suggests that the LEC processes both object and spatial information. We describe here a gradient of spatial selectivity along the antero-posterior axis of the LEC. We demonstrate that the LEC generates distinct spatial maps for different contexts that are independent of object coding and vice versa, thus providing evidence for pure spatial and pure object codes upstream of the hippocampus. While space and object coding occur by and large separately in the LEC, we identified neurons that encode for space and objects conjunctively. Together, these findings point to a scenario in which the LEC sustains both distinct space and object coding and associative space-object coding.
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Affiliation(s)
- Xu Huang
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Magdalene Isabell Schlesiger
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Isabel Barriuso-Ortega
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Christian Leibold
- Institute Biology III & Bernstein Center Freiburg, University of Freiburg, 79104 Freiburg im Breisgau, Germany; BrainLinks-BrainTools, University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Duncan Archibald Allan MacLaren
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Nina Bieber
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Hannah Monyer
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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24
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Danieli K, Guyon A, Bethus I. Episodic Memory formation: A review of complex Hippocampus input pathways. Prog Neuropsychopharmacol Biol Psychiatry 2023; 126:110757. [PMID: 37086812 DOI: 10.1016/j.pnpbp.2023.110757] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/08/2023] [Accepted: 03/22/2023] [Indexed: 04/24/2023]
Abstract
Memories of everyday experiences involve the encoding of a rich and dynamic representation of present objects and their contextual features. Traditionally, the resulting mnemonic trace is referred to as Episodic Memory, i.e. the "what", "where" and "when" of a lived episode. The journey for such memory trace encoding begins with the perceptual data of an experienced episode handled in sensory brain regions. The information is then streamed to cortical areas located in the ventral Medio Temporal Lobe, which produces multi-modal representations concerning either the objects (in the Perirhinal cortex) or the spatial and contextual features (in the parahippocampal region) of the episode. Then, this high-level data is gated through the Entorhinal Cortex and forwarded to the Hippocampal Formation, where all the pieces get bound together. Eventually, the resulting encoded neural pattern is relayed back to the Neocortex for a stable consolidation. This review will detail these different stages and provide a systematic overview of the major cortical streams toward the Hippocampus relevant for Episodic Memory encoding.
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Affiliation(s)
| | - Alice Guyon
- Université Cote d'Azur, Neuromod Institute, France; Université Cote d'Azur, CNRS UMR 7275, IPMC, Valbonne, France
| | - Ingrid Bethus
- Université Cote d'Azur, Neuromod Institute, France; Université Cote d'Azur, CNRS UMR 7275, IPMC, Valbonne, France
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25
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Traub RD, Whittington MA, Cunningham MO. Simulation of oscillatory dynamics induced by an approximation of grid cell output. Rev Neurosci 2023; 34:517-532. [PMID: 36326795 PMCID: PMC10329426 DOI: 10.1515/revneuro-2022-0107] [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: 08/17/2022] [Accepted: 10/06/2022] [Indexed: 07/20/2023]
Abstract
Grid cells, in entorhinal cortex (EC) and related structures, signal animal location relative to hexagonal tilings of 2D space. A number of modeling papers have addressed the question of how grid firing behaviors emerge using (for example) ideas borrowed from dynamical systems (attractors) or from coupled oscillator theory. Here we use a different approach: instead of asking how grid behavior emerges, we take as a given the experimentally observed intracellular potentials of superficial medial EC neurons during grid firing. Employing a detailed neural circuit model modified from a lateral EC model, we then ask how the circuit responds when group of medial EC principal neurons exhibit such potentials, simultaneously with a simulated theta frequency input from the septal nuclei. The model predicts the emergence of robust theta-modulated gamma/beta oscillations, suggestive of oscillations observed in an in vitro medial EC experimental model (Cunningham, M.O., Pervouchine, D.D., Racca, C., Kopell, N.J., Davies, C.H., Jones, R.S.G., Traub, R.D., and Whittington, M.A. (2006). Neuronal metabolism governs cortical network response state. Proc. Natl. Acad. Sci. U S A 103: 5597-5601). Such oscillations result because feedback interneurons tightly synchronize with each other - despite the varying phases of the grid cells - and generate a robust inhibition-based rhythm. The lack of spatial specificity of the model interneurons is consistent with the lack of spatial periodicity in parvalbumin interneurons observed by Buetfering, C., Allen, K., and Monyer, H. (2014). Parvalbumin interneurons provide grid cell-driven recurrent inhibition in the medial entorhinal cortex. Nat. Neurosci. 17: 710-718. If in vivo EC gamma rhythms arise during exploration as our model predicts, there could be implications for interpreting disrupted spatial behavior and gamma oscillations in animal models of Alzheimer's disease and schizophrenia. Noting that experimental intracellular grid cell potentials closely resemble cortical Up states and Down states, during which fast oscillations also occur during Up states, we propose that the co-occurrence of slow principal cell depolarizations and fast network oscillations is a general property of the telencephalon, in both waking and sleep states.
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Affiliation(s)
- Roger D. Traub
- AI Foundations, IBM T.J. Watson Research Center, Yorktown Heights, NY10598, USA
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA19104, USA
| | | | - Mark O. Cunningham
- Discipline of Physiology, School of Medicine, Trinity College Dublin, University of Dublin, 152-160 Pearse St., Dublin 2, Ireland
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26
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Ginosar G, Aljadeff J, Las L, Derdikman D, Ulanovsky N. Are grid cells used for navigation? On local metrics, subjective spaces, and black holes. Neuron 2023; 111:1858-1875. [PMID: 37044087 DOI: 10.1016/j.neuron.2023.03.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 11/18/2022] [Accepted: 03/20/2023] [Indexed: 04/14/2023]
Abstract
The symmetric, lattice-like spatial pattern of grid-cell activity is thought to provide a neuronal global metric for space. This view is compatible with grid cells recorded in empty boxes but inconsistent with data from more naturalistic settings. We review evidence arguing against the global-metric notion, including the distortion and disintegration of the grid pattern in complex and three-dimensional environments. We argue that deviations from lattice symmetry are key for understanding grid-cell function. We propose three possible functions for grid cells, which treat real-world grid distortions as a feature rather than a bug. First, grid cells may constitute a local metric for proximal space rather than a global metric for all space. Second, grid cells could form a metric for subjective action-relevant space rather than physical space. Third, distortions may represent salient locations. Finally, we discuss mechanisms that can underlie these functions. These ideas may transform our thinking about grid cells.
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Affiliation(s)
- Gily Ginosar
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Johnatan Aljadeff
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Liora Las
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Dori Derdikman
- Department of Neuroscience, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 31096, Israel.
| | - Nachum Ulanovsky
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
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27
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El-Demerdash N, Pan T, Choi O, Saraswati M, Koehler RC, Robertson CL, Savonenko A. Importance of Control Groups for Evaluating Long-Term Behavioral and Cognitive Outcomes of Controlled Cortical Impact in Immature Rats. J Neurotrauma 2023; 40:1197-1215. [PMID: 36416234 PMCID: PMC10259614 DOI: 10.1089/neu.2021.0376] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Therapies are limited for pediatric traumatic brain injury (TBI), especially for the very young who can experience long-term consequences to learning, memory, and social behavior. Animal models of pediatric TBI have yielded mechanistic insights, but demonstration of clinically relevant long-term behavioral and/or cognitive deficits has been challenging. We characterized short- and long-term outcomes in a controlled cortical impact (CCI) model of pediatric TBI using a panel of tests between 2 weeks and ∼4 months after injury. Male rats with CCI at postnatal Day (PND) 10 were compared with three control groups: Naïve, Anesthesia, and Craniotomy. Motor testing (PND 25-33), novel object recognition (NOR; PND 40-50), and multiple tasks in water maze (WM; PND 65-100) were followed by social interaction tests (PND 120-140). Anesthesia rats performed the same as Naïve rats in all tasks. TBI rats, when compared with Naïve controls, had functional impairments across most tests studied. The most sensitive cognitive processes affected by TBI included those that required fast one-trial learning (NOR, WM), flexibility of acquired memory traces (reversals in WM), response strategies (WM), or recognition memory in the setting of reciprocal social interactions. Both TBI and Craniotomy groups demonstrated increased rates of decision making across several WM tasks, suggesting disinhibition of motor responses. When the TBI group was compared with the Craniotomy group, however, deficits were detected in a limited number of outcomes. The latter included learning speed (WM), cognitive flexibility (WM), and social recognition memory. Notably, effects of craniotomy, when compared with Naïve controls, spanned across multiple tasks, and in some tasks, could reach the effect sizes observed in TBI. These results highlight the importance of appropriate control groups in pediatric CCI models. In addition, the study demonstrates the high sensitivity of comprehensive cognitive testing to detect long-term effects of early-age craniotomy and TBI and provides a template for future testing of experimental therapies.
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Affiliation(s)
- Nagat El-Demerdash
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Tiffany Pan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Olivia Choi
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Manda Saraswati
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Raymond C. Koehler
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Courtney L. Robertson
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Alena Savonenko
- Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
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28
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Wang C, Lee H, Rao G, Doreswamy Y, Savelli F, Knierim JJ. Superficial-layer versus deep-layer lateral entorhinal cortex: Coding of allocentric space, egocentric space, speed, boundaries, and corners. Hippocampus 2023; 33:448-464. [PMID: 36965194 PMCID: PMC11717144 DOI: 10.1002/hipo.23528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 02/06/2023] [Accepted: 03/08/2023] [Indexed: 03/27/2023]
Abstract
Entorhinal cortex is the major gateway between the neocortex and the hippocampus and thus plays an essential role in subserving episodic memory and spatial navigation. It can be divided into the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC), which are commonly theorized to be critical for spatial (context) and non-spatial (content) inputs, respectively. Consistent with this theory, LEC neurons are found to carry little information about allocentric self-location, even in cue-rich environments, but they exhibit egocentric spatial information about external items in the environment. The superficial and deep layers of LEC are believed to mediate the input to and output from the hippocampus, respectively. As earlier studies mainly examined the spatial firing properties of superficial-layer LEC neurons, here we characterized the deep-layer LEC neurons and made direct comparisons with their superficial counterparts in single unit recordings from behaving rats. Because deep-layer LEC cells received inputs from hippocampal regions, which have strong selectivity for self-location, we hypothesized that deep-layer LEC neurons would be more informative about allocentric position than superficial-layer LEC neurons. We found that deep-layer LEC cells showed only slightly more allocentric spatial information and higher spatial consistency than superficial-layer LEC cells. Egocentric coding properties were comparable between these two subregions. In addition, LEC neurons demonstrated preferential firing at lower speeds, as well as at the boundary or corners of the environment. These results suggest that allocentric spatial outputs from the hippocampus are transformed in deep-layer LEC into the egocentric coding dimensions of LEC, rather than maintaining the allocentric spatial tuning of the CA1 place fields.
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Affiliation(s)
- Cheng Wang
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland, USA
| | - Heekyung Lee
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland, USA
| | - Geeta Rao
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yoganarasimha Doreswamy
- Department of Neurobiology and Anatomy, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Francesco Savelli
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland, USA
| | - James J Knierim
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, Maryland, USA
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29
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El Mahmoudi N, Laurent C, Péricat D, Watabe I, Lapotre A, Jacob PY, Tonetto A, Tighilet B, Sargolini F. Long-lasting spatial memory deficits and impaired hippocampal plasticity following unilateral vestibular loss. Prog Neurobiol 2023; 223:102403. [PMID: 36821981 DOI: 10.1016/j.pneurobio.2023.102403] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/25/2022] [Accepted: 01/04/2023] [Indexed: 02/23/2023]
Abstract
Unilateral vestibular loss (UVL) induces a characteristic vestibular syndrome composed of various posturo-locomotor, oculomotor, vegetative and perceptivo-cognitive symptoms. Functional deficits are progressively recovered over time during vestibular compensation, that is supported by the expression of multiscale plasticity mechanisms. While the dynamic of post-UVL posturo-locomotor and oculomotor deficits is well characterized, the expression over time of the cognitive deficits, and in particular spatial memory deficits, is still debated. In this study we aimed at investigating spatial memory deficits and their recovery in a rat model of unilateral vestibular neurectomy (UVN), using a wide spectrum of behavioral tasks. In parallel, we analyzed markers of hippocampal plasticity involved in learning and memory. Our results indicate the UVN affects all domains of spatial memory, from working memory to reference memory and object-in-place recognition. These deficits are associated with long-lasting impaired plasticity in the ipsilesional hippocampus. These results highlight the crucial role of symmetrical vestibular information in spatial memory and contribute to a better understanding of the cognitive disorders observed in vestibular patients.
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Affiliation(s)
- Nada El Mahmoudi
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France.
| | - Célia Laurent
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - David Péricat
- Université de Toulouse Paul Sabatier -CNRS, Institut de pharmacologie et de biologie structurale, Toulouse, France
| | - Isabelle Watabe
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Agnès Lapotre
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Pierre-Yves Jacob
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Alain Tonetto
- Aix Marseille Université-CNRS, Centrale Marseille, FSCM (FR 1739), PRATIM, F-13397 Marseille, France
| | - Brahim Tighilet
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Francesca Sargolini
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France.
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30
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Joshi S, Williams CL, Kapur J. Limbic progesterone receptors regulate spatial memory. Sci Rep 2023; 13:2164. [PMID: 36750584 PMCID: PMC9905062 DOI: 10.1038/s41598-023-29100-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
Progesterone and its receptors (PRs) participate in mating and reproduction, but their role in spatial declarative memory is not understood. Male mice expressed PRs, predominately in excitatory neurons, in brain regions that support spatial memory, such as the hippocampus and entorhinal cortex (EC). Furthermore, segesterone, a specific PR agonist, activates neurons in both the EC and hippocampus. We assessed the contribution of PRs in promoting spatial and non-spatial cognitive learning in male mice by examining the performance of mice lacking this receptor (PRKO), in novel object recognition, object placement, Y-maze alternation, and Morris-Water Maze (MWM) tasks. In the recognition test, the PRKO mice preferred the familiar object over the novel object. A similar preference for the familiar object was also seen following the EC-specific deletion of PRs. PRKO mice were also unable to recognize the change in object position. We confirmed deficits in spatial memory of PRKO mice by testing them on the Y-maze forced alternation and MWM tasks; PR deletion affected animal's performance in both these tasks. In contrast to spatial tasks, PR removal did not alter the response to fear conditioning. These studies provide novel insights into the role of PRs in facilitating spatial, declarative memory in males, which may help with finding reproductive partners.
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Affiliation(s)
- Suchitra Joshi
- Department of Neurology, University of Virginia, Health Sciences Center, P.O. Box 801330, Charlottesville, VA, 22908, USA.
| | - Cedric L Williams
- Department of Psychology, University of Virginia, Charlottesville, VA, 22908, USA
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Health Sciences Center, P.O. Box 801330, Charlottesville, VA, 22908, USA.,Department of Neuroscience, University of Virginia, Charlottesville, VA, 22908, USA.,UVA Brain Institute, University of Virginia, Charlottesville, VA, 22908, USA
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31
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Lee SH, Bolshakov VY, Shen J. Presenilins regulate synaptic plasticity in the perforant pathways of the hippocampus. Mol Brain 2023; 16:17. [PMID: 36710361 PMCID: PMC9885562 DOI: 10.1186/s13041-023-01009-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/20/2023] [Indexed: 01/31/2023] Open
Abstract
Mutations in the Presenilin genes (PSEN1 and PSEN2) are the major cause of familial Alzheimer's disease (AD), highlighting the importance of Presenilin (PS) in AD pathogenesis. Previous studies of PS function in the hippocampus demonstrated that loss of PS results in the impairment of short- and long-term synaptic plasticity and neurotransmitter release at hippocampal Schaffer collateral (SC) and mossy fiber (MF) synapses. Cortical input to the hippocampus through the lateral perforant pathway (LPP) and the medial perforant pathway (MPP) is critical for normal cognitive functions and is particularly vulnerable during aging and early stages of AD. Whether PS regulates synaptic function in the perforant pathways, however, remained unknown. In the current study, we investigate PS function in the LPP and MPP by performing whole-cell and field-potential electrophysiological recordings using acute hippocampal slices from postnatal forebrain-restricted excitatory neuron-specific PS conditional double knockout (cDKO) mice. We found that paired-pulse ratio (PPR) is reduced in the LPP and MPP of PS cDKO mice. Moreover, synaptic frequency facilitation or depression in the LPP or MPP, respectively, is impaired in PS cDKO mice. Notably, depletion of intracellular Ca2+ stores by inhibition of sarcoendoplasmic reticulum Ca2+ ATPase (SERCA) minics and occludes the effects of PS inactivation, as evidenced by decreases of the evoked excitatory postsynaptic currents (EPSCs) amplitude in the LPP and MPP of control neurons but no effect on the EPSC amplitude in PS cDKO neurons, suggesting that impaired intracellular calcium homeostasis in the absence of PS may contribute to the observed deficits in synaptic transmission. While spontaneous synaptic events, such as both the frequency and the amplitude of spontaneous or miniature EPSCs, are similar between PS cDKO and control neurons, long-term potentiation (LTP) is impaired in the LPP and MPP of PS cDKO mice, accompanied with reduction of evoked NMDA receptor-mediated responses. These findings show the importance of PS in the regulation of synaptic plasticity and intracellular calcium homeostasis in the hippocampal perforant pathways.
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Affiliation(s)
- Sang Hun Lee
- Department of Neurology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
| | - Vadim Y Bolshakov
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, 02478, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA, 02115, USA
| | - Jie Shen
- Department of Neurology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA, 02115, USA
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32
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Protachevicz PR, Bonin CA, Iarosz KC, Caldas IL, Batista AM. Large coefficient of variation of inter-spike intervals induced by noise current in the resonate-and-fire model neuron. Cogn Neurodyn 2022; 16:1461-1470. [PMID: 36408063 PMCID: PMC9666614 DOI: 10.1007/s11571-022-09789-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 02/03/2022] [Accepted: 02/08/2022] [Indexed: 11/26/2022] Open
Abstract
Neuronal spike variability is a statistical property associated with the noise environment. Considering a linearised Hodgkin-Huxley model, we investigate how large spike variability can be induced in a typical stellate cell when submitted to constant and noise current amplitudes. For low noise current, we observe only periodic firing (active) or silence activities. For intermediate noise values, in addition to only active or inactive periods, we also identify a single transition from an initial spike-train (active) to silence dynamics over time, where the spike variability is low. However, for high noise current, we find intermittent active and silence periods with different values. The spike intervals during active and silent states follow the exponential distribution, which is similar to the Poisson process. For non-maximal noise current, we observe the highest values of inter-spike variability. Our results suggest sub-threshold oscillations as a possible mechanism for the appearance of high spike variability in a single neuron due to noise currents.
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Affiliation(s)
| | - C. A. Bonin
- Department of Mathematics and Statistics, State University of Ponta Grossa, Ponta Grossa, Brazil
| | - K. C. Iarosz
- Engineering Department, Faculdade de Telêmaco Borba, Telêmaco Borba, Brazil
| | - I. L. Caldas
- Institute of Physics, University of São Paulo, São Paulo, Brazil
| | - A. M. Batista
- Department of Mathematics and Statistics, State University of Ponta Grossa, Ponta Grossa, Brazil
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33
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Chao OY, Nikolaus S, Yang YM, Huston JP. Neuronal circuitry for recognition memory of object and place in rodent models. Neurosci Biobehav Rev 2022; 141:104855. [PMID: 36089106 PMCID: PMC10542956 DOI: 10.1016/j.neubiorev.2022.104855] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/23/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022]
Abstract
Rats and mice are used for studying neuronal circuits underlying recognition memory due to their ability to spontaneously remember the occurrence of an object, its place and an association of the object and place in a particular environment. A joint employment of lesions, pharmacological interventions, optogenetics and chemogenetics is constantly expanding our knowledge of the neural basis for recognition memory of object, place, and their association. In this review, we summarize current studies on recognition memory in rodents with a focus on the novel object preference, novel location preference and object-in-place paradigms. The evidence suggests that the medial prefrontal cortex- and hippocampus-connected circuits contribute to recognition memory for object and place. Under certain conditions, the striatum, medial septum, amygdala, locus coeruleus and cerebellum are also involved. We propose that the neuronal circuitry for recognition memory of object and place is hierarchically connected and constructed by different cortical (perirhinal, entorhinal and retrosplenial cortices), thalamic (nucleus reuniens, mediodorsal and anterior thalamic nuclei) and primeval (hypothalamus and interpeduncular nucleus) modules interacting with the medial prefrontal cortex and hippocampus.
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Affiliation(s)
- Owen Y Chao
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA
| | - Susanne Nikolaus
- Department of Nuclear Medicine, University Hospital Düsseldorf, Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Yi-Mei Yang
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Joseph P Huston
- Center for Behavioral Neuroscience, Institute of Experimental Psychology, Heinrich-Heine University, 40225 Düsseldorf, Germany.
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Castegnaro A, Howett D, Li A, Harding E, Chan D, Burgess N, King J. Assessing mild cognitive impairment using object-location memory in immersive virtual environments. Hippocampus 2022; 32:660-678. [PMID: 35916343 PMCID: PMC9543035 DOI: 10.1002/hipo.23458] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 06/24/2022] [Accepted: 07/16/2022] [Indexed: 11/12/2022]
Abstract
Pathological changes in the medial temporal lobe (MTL) are found in the early stages of Alzheimer's disease (AD) and aging. The earliest pathological accumulation of tau colocalizes with the areas of the MTL involved in object processing as part of a wider anterolateral network. Here, we sought to assess the diagnostic potential of memory for object locations in iVR environments in individuals at high risk of AD dementia (amnestic mild cognitive impairment [aMCI] n = 23) as compared to age-related cognitive decline. Consistent with our primary hypothesis that early AD would be associated with impaired object location, aMCI patients exhibited impaired spatial feature binding. Compared to both older (n = 24) and younger (n = 53) controls, aMCI patients, recalled object locations with significantly less accuracy (p < .001), with a trend toward an impaired identification of the object's correct context (p = .05). Importantly, these findings were not explained by deficits in object recognition (p = .6). These deficits differentiated aMCI from controls with greater accuracy (AUC = 0.89) than the standard neuropsychological tests. Within the aMCI group, 16 had CSF biomarkers indicative of their likely AD status (MCI+ n = 9 vs. MCI- n = 7). MCI+ showed lower accuracy in the object-context association than MCI- (p = .03) suggesting a selective deficit in object-context binding postulated to be associated with anterior-temporal areas. MRI volumetric analysis across healthy older participants and aMCI revealed that test performance positively correlates with lateral entorhinal cortex volumes (p < .05) and hippocampus volumes (p < .01), consistent with their hypothesized role in binding contextual and spatial information with object identity. Our results indicate that tests relying on the anterolateral object processing stream, and in particular requiring successful binding of an object with spatial information, may aid detection of pre-dementia AD due to the underlying early spread of tau pathology.
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Affiliation(s)
- Andrea Castegnaro
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
| | - David Howett
- School of Psychological ScienceUniversity of BristolBristolUK
| | - Adrienne Li
- Department of PsychologyYork UniversityTorontoOntarioCanada
| | - Elizabeth Harding
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
| | - Dennis Chan
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
| | - Neil Burgess
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
| | - John King
- Department of Clinical, Educational and Health PsychologyUniversity College LondonLondonUK
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Caputi A, Liu X, Fuchs EC, Liu YC, Monyer H. Medial entorhinal cortex commissural input regulates the activity of spatially and object-tuned cells contributing to episodic memory. Neuron 2022; 110:3389-3405.e7. [PMID: 36084654 DOI: 10.1016/j.neuron.2022.08.013] [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: 08/19/2021] [Revised: 07/14/2022] [Accepted: 08/08/2022] [Indexed: 10/14/2022]
Abstract
Extensive interhemispheric projections connect many homotopic brain regions, including the hippocampal formation, but little is known as to how information transfer affects the functions supported by the target area. Here, we studied whether the commissural projections connecting the medial entorhinal cortices contribute to spatial coding, object coding, and memory. We demonstrate that input from the contralateral medial entorhinal cortex targets all major cell types in the superficial medial entorhinal cortex, modulating their firing rate. Notably, a fraction of responsive cells displayed object tuning and exhibited a reduction in their firing rate upon the inhibition of commissural input. In line with this finding are behavioral results that revealed the contribution of commissural input to episodic-like memory retrieval.
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Affiliation(s)
- Antonio Caputi
- Department of Clinical Neurobiology at the Medical Faculty of the Heidelberg University and of the German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Xinghua Liu
- Department of Clinical Neurobiology at the Medical Faculty of the Heidelberg University and of the German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Elke C Fuchs
- Department of Clinical Neurobiology at the Medical Faculty of the Heidelberg University and of the German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Yu-Chao Liu
- Department of Clinical Neurobiology at the Medical Faculty of the Heidelberg University and of the German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Hannah Monyer
- Department of Clinical Neurobiology at the Medical Faculty of the Heidelberg University and of the German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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Stacho M, Manahan-Vaughan D. The Intriguing Contribution of Hippocampal Long-Term Depression to Spatial Learning and Long-Term Memory. Front Behav Neurosci 2022; 16:806356. [PMID: 35548697 PMCID: PMC9084281 DOI: 10.3389/fnbeh.2022.806356] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/10/2022] [Indexed: 01/03/2023] Open
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) comprise the principal cellular mechanisms that fulfill established criteria for the physiological correlates of learning and memory. Traditionally LTP, that increases synaptic weights, has been ascribed a prominent role in learning and memory whereas LTD, that decreases them, has often been relegated to the category of "counterpart to LTP" that serves to prevent saturation of synapses. In contradiction of these assumptions, studies over the last several years have provided functional evidence for distinct roles of LTD in specific aspects of hippocampus-dependent associative learning and information encoding. Furthermore, evidence of the experience-dependent "pruning" of excitatory synapses, the majority of which are located on dendritic spines, by means of LTD has been provided. In addition, reports exist of the temporal and physical restriction of LTP in dendritic compartments by means of LTD. Here, we discuss the role of LTD and LTP in experience-dependent information encoding based on empirical evidence derived from conjoint behavioral and electrophysiological studies conducted in behaving rodents. We pinpoint the close interrelation between structural modifications of dendritic spines and the occurrence of LTP and LTD. We report on findings that support that whereas LTP serves to acquire the general scheme of a spatial representation, LTD enables retention of content details. We argue that LTD contributes to learning by engaging in a functional interplay with LTP, rather than serving as its simple counterpart, or negator. We propose that similar spatial experiences that share elements of neuronal representations can be modified by means of LTD to enable pattern separation. Therewith, LTD plays a crucial role in the disambiguation of similar spatial representations and the prevention of generalization.
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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: 11] [Impact Index Per Article: 3.7] [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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Borcuk C, Héraud C, Herbeaux K, Diringer M, Panzer É, Scuto J, Hashimoto S, Saido TC, Saito T, Goutagny R, Battaglia D, Mathis C. Early memory deficits and extensive brain network disorganization in the AppNL-F/MAPT double knock-in mouse model of familial Alzheimer's disease. AGING BRAIN 2022; 2:100042. [PMID: 36908877 PMCID: PMC9997176 DOI: 10.1016/j.nbas.2022.100042] [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: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 10/18/2022] Open
Abstract
A critical challenge in current research on Alzheimer's disease (AD) is to clarify the relationship between network dysfunction and the emergence of subtle memory deficits in itspreclinical stage. The AppNL-F/MAPT double knock-in (dKI) model with humanized β-amyloid peptide (Aβ) and tau was used to investigate both memory and network dysfunctions at an early stage. Young male dKI mice (2 to 6 months) were tested in three tasks taxing different aspects of recognition memory affected in preclinical AD. An early deficit first appeared in the object-place association task at the age of 4 months, when increased levels of β-CTF and Aβ were detected in both the hippocampus and the medial temporal cortex, and tau pathology was found only in the medial temporal cortex. Object-place task-dependent c-Fos activation was then analyzed in 22 subregions across the medial prefrontal cortex, claustrum, retrosplenial cortex, and medial temporal lobe. Increased c-Fos activation was detected in the entorhinal cortex and the claustrum of dKI mice. During recall, network efficiency was reduced across cingulate regions with a major disruption of information flow through the retrosplenial cortex. Our findings suggest that early perirhinal-entorhinal pathology is associated with abnormal activity which may spread to downstream regions such as the claustrum, the medial prefrontal cortex and ultimately the key retrosplenial hub which relays information from frontal to temporal lobes. The similarity between our findings and those reported in preclinical stages of AD suggests that the AppNL-F/MAPT dKI model has a high potential for providing key insights into preclinical AD.
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Key Words
- AD, Alzheimer’s disease
- ADAD, autosomal dominant Alzheimer’s disease
- Associative memory
- CLA, claustrum
- Claustrum
- DMN, default mode network
- EI, exploration index
- FC, functional connectivity
- Functional connectivity
- MI, Memory index
- MTC, medial temporal cortex
- MTL, medial temporal lobe
- Medial temporal cortex
- NOR, novel object recognition
- OL, Object location
- OP, object-place
- PS, Pattern Separation
- Preclinical Alzheimer disease
- Retrosplenial cortex
- aMCI, amnestic mild cognitive impairment
- amyloid beta, Aβ
- dKI, AppNL-F/MAPT double knock-in
- ptau Thr 181, Thr181phosphorylated tau protein
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Affiliation(s)
- Christopher Borcuk
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
| | - Céline Héraud
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
| | - Karine Herbeaux
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
| | - Margot Diringer
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
| | - Élodie Panzer
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
| | - Jil Scuto
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
| | - Shoko Hashimoto
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-city, Saitama 351-0198, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-city, Saitama 351-0198, Japan
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-city, Saitama 351-0198, Japan
| | - Romain Goutagny
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
| | - Demian Battaglia
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France.,University of Strasbourg Institute for Advanced Studies (USIAS), F-67000 Strasbourg, France.,Université d'Aix-Marseille, Inserm, Institut de Neurosciences des Systèmes (INS) UMR_S 1106, F-13005 Marseille, France
| | - Chantal Mathis
- Université de Strasbourg, CNRS, Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA) UMR 7364, F-67000 Strasbourg, France
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Differential Effects of Lateral and Medial Entorhinal Cortex Lesions on Trace, Delay and Contextual Fear Memories. Brain Sci 2021; 12:brainsci12010034. [PMID: 35053778 PMCID: PMC8773659 DOI: 10.3390/brainsci12010034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 11/20/2022] Open
Abstract
The entorhinal cortex (EC), with connections to the hippocampus, amygdala, and neocortex, is a critical, yet still underexplored, contributor to fear memory. Previous research suggests possible heterogeneity of function among its lateral (LEC) and medial (MEC) subregions. However, it is not well established what unique roles these subregions serve as the literature has shown mixed results depending on target of manipulation and type of conditioning used. Few studies have manipulated both the LEC and MEC within the same experiment. The present experiment systematically manipulated LEC and MEC function to examine their potential roles in fear memory expression. Long-Evans rats were trained using either trace or delay fear conditioning. The following day, rats received an N-methyl-D-aspartate (NMDA)-induced lesion to the LEC or MEC or received a sham surgery. Following recovery, rats were given an 8-min context test in the original context. The next day, rats were tested for tone freezing in a novel context with three discrete tone presentations. Further, rats were tested for hyperactivity in an open field under both dark and bright light gradient conditions. Results: Following either LEC or MEC lesion, freezing to context was significantly reduced in both trace and delay conditioned rats. LEC-lesioned rats consistently showed significantly less freezing following tone-offset (trace interval, or equivalent, and intertrial interval) in both trace and delay fear conditioned rats. Conclusions: These data suggest that the LEC may play a role in the expression of a conjunctive representation between the tone and context that mediates the maintenance of post-tone freezing.
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40
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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: 7] [Impact Index Per Article: 1.8] [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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41
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Ribeiro FF, Ferreira F, Rodrigues RS, Soares R, Pedro DM, Duarte-Samartinho M, Aroeira RI, Ferreiro E, Valero J, Solá S, Mira H, Sebastião AM, Xapelli S. Regulation of hippocampal postnatal and adult neurogenesis by adenosine A 2A receptor: Interaction with brain-derived neurotrophic factor. Stem Cells 2021; 39:1362-1381. [PMID: 34043863 DOI: 10.1002/stem.3421] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/06/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
Adenosine A2A receptor (A2A R) activation modulates several brain processes, ranging from neuronal maturation to synaptic plasticity. Most of these actions occur through the modulation of the actions of the neurotrophin brain-derived neurotrophic factor (BDNF). In this work, we studied the role of A2A Rs in regulating postnatal and adult neurogenesis in the rat hippocampal dentate gyrus (DG). Here, we show that A2A R activation with CGS 21680 promoted neural stem cell self-renewal, protected committed neuronal cells from cell death and contributed to a higher density of immature and mature neuronal cells, particularly glutamatergic neurons. Moreover, A2A R endogenous activation was found to be essential for BDNF-mediated increase in cell proliferation and neuronal differentiation. Our findings contribute to further understand the role of adenosinergic signaling in the brain and may have an impact in the development of strategies for brain repair under pathological conditions.
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Affiliation(s)
- Filipa F Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Filipa Ferreira
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Rui S Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Rita Soares
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa, Lisbon, Portugal
| | - Diogo M Pedro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Marta Duarte-Samartinho
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Rita I Aroeira
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Elisabete Ferreiro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Jorge Valero
- Laboratory of Glial Cell Biology, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Ikerbasque Foundation, Bilbao, Spain
- University of the Basque Country EHU/UPV, Leioa, Spain
| | - Susana Solá
- iMed.ULisboa, Faculdade de Farmácia, Universidade de Lisboa, Lisbon, Portugal
| | - Helena Mira
- Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes (iMM, JLB), Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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42
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Batallán Burrowes AA, Sundarakrishnan A, Bouhour C, Chapman CA. G protein-coupled estrogen receptor-1 enhances excitatory synaptic responses in the entorhinal cortex. Hippocampus 2021; 31:1191-1201. [PMID: 34399010 DOI: 10.1002/hipo.23383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 07/16/2021] [Accepted: 07/24/2021] [Indexed: 12/22/2022]
Abstract
Activation of estrogen receptors is thought to modulate cognitive function in the hippocampus, prefrontal cortex, and striatum by affecting both excitatory and inhibitory synaptic transmission. The entorhinal cortex is a major source of cortical sensory and associational input to the hippocampus, but it is unclear whether either estrogens or progestogens may modulate cognitive function through effects on synaptic transmission in the entorhinal cortex. This study assessed the effects of the brief application of either 17-β estradiol (E2) or progesterone on excitatory glutamatergic synaptic transmission in the female rat entorhinal cortex in vitro. Rats were ovariectomized on postnatal day (PD) 63 and also received subdermal E2 implants to maintain constant low levels of circulating E2 on par with estrus. Electrophysiological recordings from brain slices were obtained between PD70 and PD86, and field excitatory postsynaptic potentials (fEPSPs) reflecting the activation of the superficial layers of the entorhinal cortex were evoked by the stimulation of layer I afferents. The application of E2 (10 nM) for 20 min resulted in a small increase in the amplitude of fEPSPs that reversed during the 30-min washout period. The application of the ERα agonist propylpyrazoletriol (PPT) (100 nM) or the β agonist DPN (1 μM) did not significantly affect synaptic responses. However, the application of the G protein-coupled estrogen receptor-1 (GPER1) agonist G1 (100 nM) induced a reversible increase in fEPSP amplitude similar to that induced by E2. Furthermore, the potentiation of responses induced by G1 was blocked by the GPER1 antagonist G15 (1 μM). Application of progesterone (100 nM) or its metabolite allopregnanolone (1 μM) did not significantly affect synaptic responses. The potentiation of synaptic transmission in the entorhinal cortex induced by the activation of GPER1 receptors may contribute to the modulation of cognitive function in female rats.
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Affiliation(s)
- Ariel A Batallán Burrowes
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada
| | - Adithi Sundarakrishnan
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada
| | - Camille Bouhour
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada
| | - Clifton Andrew Chapman
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada
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43
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Poitreau J, Buttet M, Manrique C, Poucet B, Sargolini F, Save E. Navigation using global or local reference frames in rats with medial and lateral entorhinal cortex lesions. Behav Brain Res 2021; 413:113448. [PMID: 34246711 DOI: 10.1016/j.bbr.2021.113448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/18/2021] [Accepted: 07/06/2021] [Indexed: 11/28/2022]
Abstract
The medial (MEC) and the lateral (LEC) regions of the entorhinal cortex send a major input to the hippocampus and have been proposed to play a foremost role in combining spatial and non-spatial attributes of episodic memory. In addition, it has been recently suggested that the MEC is involved in the processing of information in a global reference frame and the LEC in the processing of information in a local reference frame. Whether these putative functions could be generalized to navigation contexts has not been established yet. To address this hypothesis, rats with MEC or LEC NMDA-induced lesions were trained in two versions of a navigation task in the water maze, a global cue condition in which they had to use distal room cues and a local cue condition in which they had to use 3 objects placed in the pool. In the global cue condition, MEC-lesioned rats exhibited slower acquisition and were not able to precisely locate the submerged platform during the probe trial. In contrast LEC-lesioned rats exhibited control-like performance. In the local cue condition, navigational abilities were spared in both lesion groups. In addition when the 3 different objects were replaced by 3 identical objects, all groups maintained their navigation accuracy suggesting that the identity of objects is not crucial for place navigation. Overall, the results indicate that the MEC is necessary for place navigation using a global reference frame. In contrast, navigation using a local reference frame does not require the LEC nor the MEC.
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Affiliation(s)
| | - Manon Buttet
- Laboratory of Cognitive Neuroscience, Marseille, France
| | | | - Bruno Poucet
- Laboratory of Cognitive Neuroscience, Marseille, France
| | | | - Etienne Save
- Laboratory of Cognitive Neuroscience, Marseille, France.
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Tran T, Tobin KE, Block SH, Puliyadi V, Gallagher M, Bakker A. Effect of aging differs for memory of object identity and object position within a spatial context. Learn Mem 2021; 28:239-247. [PMID: 34131055 PMCID: PMC8212778 DOI: 10.1101/lm.053181.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 05/14/2021] [Indexed: 01/05/2023]
Abstract
There has been considerable focus on investigating age-related memory changes in cognitively healthy older adults, in the absence of neurodegenerative disorders. Previous studies have reported age-related domain-specific changes in older adults, showing increased difficulty encoding and processing object information but minimal to no impairment in processing spatial information compared with younger adults. However, few of these studies have examined age-related changes in the encoding of concurrently presented object and spatial stimuli, specifically the integration of both spatial and nonspatial (object) information. To more closely resemble real-life memory encoding and the integration of both spatial and nonspatial information, the current study developed a new experimental paradigm with novel environments that allowed for the placement of different objects in different positions within the environment. The results show that older adults have decreased performance in recognizing changes of the object position within the spatial context but no significant differences in recognizing changes in the identity of the object within the spatial context compared with younger adults. These findings suggest there may be potential age-related differences in the mechanisms underlying the representations of complex environments and furthermore, the integration of spatial and nonspatial information may be differentially processed relative to independent and isolated representations of object and spatial information.
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Affiliation(s)
- Tammy Tran
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Kaitlyn E. Tobin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA
| | - Sophia H. Block
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Vyash Puliyadi
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Arnold Bakker
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA
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Vyleta NP, Snyder JS. Prolonged development of long-term potentiation at lateral entorhinal cortex synapses onto adult-born neurons. PLoS One 2021; 16:e0253642. [PMID: 34143843 PMCID: PMC8213073 DOI: 10.1371/journal.pone.0253642] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/09/2021] [Indexed: 11/18/2022] Open
Abstract
Critical period plasticity at adult-born neuron synapses is widely believed to contribute to the learning and memory functions of the hippocampus. Experience regulates circuit integration and for a transient interval, until cells are ~6 weeks old, new neurons display enhanced long-term potentiation (LTP) at afferent and efferent synapses. Since neurogenesis declines substantially with age, this raises questions about the extent of lasting plasticity offered by adult-born neurons. Notably, however, the hippocampus receives sensory information from two major cortical pathways. Broadly speaking, the medial entorhinal cortex conveys spatial information to the hippocampus via the medial perforant path (MPP), and the lateral entorhinal cortex, via the lateral perforant path (LPP), codes for the cues and items that make experiences unique. While enhanced critical period plasticity at MPP synapses is relatively well characterized, no studies have examined long-term plasticity at LPP synapses onto adult-born neurons, even though the lateral entorhinal cortex is uniquely vulnerable to aging and Alzheimer's pathology. We therefore investigated LTP at LPP inputs both within (4-6 weeks) and beyond (8+ weeks) the traditional critical period. At immature stages, adult-born neurons did not undergo significant LTP at LPP synapses, and often displayed long-term depression after theta burst stimulation. However, over the course of 3-4 months, adult-born neurons displayed increasingly greater amounts of LTP. Analyses of short-term plasticity point towards a presynaptic mechanism, where transmitter release probability declines as cells mature, providing a greater dynamic range for strengthening synapses. Collectively, our findings identify a novel form of new neuron plasticity that develops over an extended interval, and may therefore be relevant for maintaining cognitive function in aging.
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Affiliation(s)
- Nicholas P. Vyleta
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Jason S. Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
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46
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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: 2.3] [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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47
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Hoang TH, Böge J, Manahan-Vaughan D. Hippocampal subfield-specific Homer1a expression is triggered by learning-facilitated long-term potentiation and long-term depression at medial perforant path synapses. Hippocampus 2021; 31:897-915. [PMID: 33964041 DOI: 10.1002/hipo.23333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 03/22/2021] [Accepted: 04/11/2021] [Indexed: 12/23/2022]
Abstract
Learning about general aspects, or content details, of space results in differentiated neuronal information encoding within the proximodistal axis of the hippocampus. These processes are tightly linked to long-term potentiation (LTP) and long-term depression (LTD). Here, we explored the precise sites of encoding of synaptic plasticity in the hippocampus that are mediated by information throughput from the perforant path. We assessed nuclear Homer1a-expression that was triggered by electrophysiological induction of short and long forms of hippocampal synaptic plasticity, and compared it to Homer1a-expression that was triggered by LTP and LTD enabled by different forms of spatial learning. Plasticity responses were induced by patterned stimulation of the perforant path and were recorded in the dentate gyrus (DG) of freely behaving rats. We used fluorescence in situ hybridization to detect experience-dependent nuclear encoding of Homer1a in proximodistal hippocampal subfields. Induction of neither STP nor STD resulted in immediate early gene (IEG) encoding. Electrophysiological induction of robust LTP, or LTD, resulted in highly significant and widespread induction of nuclear Homer1a in all hippocampal subfields. LTP that was facilitated by novel spatial exploration triggered similar widespread Homer1a-expression. The coupling of synaptic depression with the exploration of a novel configuration of landmarks resulted in localized IEG expression in the proximal CA3 region and the lower (infrapyramidal) blade of the DG. Our findings support that synaptic plasticity induction via perforant path inputs promotes widespread hippocampal information encoding. Furthermore, novel spatial exploration promotes the selection of a hippocampal neuronal network by means of LTP that is distributed in an experience-dependent manner across all hippocampus subfields. This network may be modified during spatial content learning by LTD in specific hippocampal subfields. Thus, long-term plasticity-inducing events result in IEG expression that supports establishment and/or restructuring of neuronal networks that are necessary for long-term information storage.
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Affiliation(s)
- Thu-Huong Hoang
- Medical Faculty, Department of Neurophysiology, Ruhr University Bochum, Bochum, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Juliane Böge
- Medical Faculty, Department of Neurophysiology, Ruhr University Bochum, 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: 16] [Impact Index Per Article: 4.0] [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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Fernández-Ruiz A, Oliva A, Soula M, Rocha-Almeida F, Nagy GA, Martin-Vazquez G, Buzsáki G. Gamma rhythm communication between entorhinal cortex and dentate gyrus neuronal assemblies. Science 2021; 372:eabf3119. [PMID: 33795429 PMCID: PMC8285088 DOI: 10.1126/science.abf3119] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 01/29/2021] [Indexed: 01/02/2023]
Abstract
Gamma oscillations are thought to coordinate the spike timing of functionally specialized neuronal ensembles across brain regions. To test this hypothesis, we optogenetically perturbed gamma spike timing in the rat medial (MEC) and lateral (LEC) entorhinal cortices and found impairments in spatial and object learning tasks, respectively. MEC and LEC were synchronized with the hippocampal dentate gyrus through high- and low-gamma-frequency rhythms, respectively, and engaged either granule cells or mossy cells and CA3 pyramidal cells in a task-dependent manner. Gamma perturbation disrupted the learning-induced assembly organization of target neurons. Our findings imply that pathway-specific gamma oscillations route task-relevant information between distinct neuronal subpopulations in the entorhinal-hippocampal circuit. We hypothesize that interregional gamma-time-scale spike coordination is a mechanism of neuronal communication.
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Affiliation(s)
- Antonio Fernández-Ruiz
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA.
| | - Azahara Oliva
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Marisol Soula
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
| | - Florbela Rocha-Almeida
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
- Division of Neurosciences, University Pablo de Olavide, 41013 Seville, Spain
| | - Gergo A Nagy
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Szigony utca 43, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, H-1085 Budapest, Üllői út 26, Hungary
| | - Gonzalo Martin-Vazquez
- Department of Theoretical Physics, Complutense University, 28040 Madrid, Spain
- School of Experimental Sciences, University Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - György Buzsáki
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA.
- Center for Neural Science, New York University, New York, NY 10016, USA
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50
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Krishna A, Mittal D, Virupaksha SG, Nair AR, Narayanan R, Thakur CS. Biomimetic FPGA-based spatial navigation model with grid cells and place cells. Neural Netw 2021; 139:45-63. [PMID: 33677378 DOI: 10.1016/j.neunet.2021.01.028] [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: 06/21/2020] [Revised: 01/15/2021] [Accepted: 01/25/2021] [Indexed: 12/22/2022]
Abstract
The mammalian spatial navigation system is characterized by an initial divergence of internal representations, with disparate classes of neurons responding to distinct features including location, speed, borders and head direction; an ensuing convergence finally enables navigation and path integration. Here, we report the algorithmic and hardware implementation of biomimetic neural structures encompassing a feed-forward trimodular, multi-layer architecture representing grid-cell, place-cell and decoding modules for navigation. The grid-cell module comprised of neurons that fired in a grid-like pattern, and was built of distinct layers that constituted the dorsoventral span of the medial entorhinal cortex. Each layer was built as an independent continuous attractor network with distinct grid-field spatial scales. The place-cell module comprised of neurons that fired at one or few spatial locations, organized into different clusters based on convergent modular inputs from different grid-cell layers, replicating the gradient in place-field size along the hippocampal dorso-ventral axis. The decoding module, a two-layer neural network that constitutes the convergence of the divergent representations in preceding modules, received inputs from the place-cell module and provided specific coordinates of the navigating object. After vital design optimizations involving all modules, we implemented the tri-modular structure on Zynq Ultrascale+ field-programmable gate array silicon chip, and demonstrated its capacity in precisely estimating the navigational trajectory with minimal overall resource consumption involving a mere 2.92% Look Up Table utilization. Our implementation of a biomimetic, digital spatial navigation system is stable, reliable, reconfigurable, real-time with execution time of about 32 s for 100k input samples (in contrast to 40 minutes on Intel Core i7-7700 CPU with 8 cores clocking at 3.60 GHz) and thus can be deployed for autonomous-robotic navigation without requiring additional sensors.
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Affiliation(s)
- Adithya Krishna
- NeuRonICS Lab, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 560012, India.
| | - Divyansh Mittal
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
| | - Siri Garudanagiri Virupaksha
- NeuRonICS Lab, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 560012, India.
| | - Abhishek Ramdas Nair
- NeuRonICS Lab, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 560012, India.
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
| | - Chetan Singh Thakur
- NeuRonICS Lab, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 560012, India.
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