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Lu T, Chen X, Zhang Q, Shang K, Yang X, Xiang W. Vitamin D Relieves Epilepsy Symptoms and Neuroinflammation in Juvenile Mice by Activating the mTOR Signaling Pathway via RAF1: Insights from Network Pharmacology and Molecular Docking Studies. Neurochem Res 2024:10.1007/s11064-024-04176-y. [PMID: 38837094 DOI: 10.1007/s11064-024-04176-y] [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: 11/10/2023] [Revised: 03/15/2024] [Accepted: 05/22/2024] [Indexed: 06/06/2024]
Abstract
Epilepsy is a common neurological disorder, and the exploration of potential therapeutic drugs for its treatment is still ongoing. Vitamin D has emerged as a promising treatment due to its potential neuroprotective effects and anti-epileptic properties. This study aimed to investigate the effects of vitamin D on epilepsy and neuroinflammation in juvenile mice using network pharmacology and molecular docking, with a focus on the mammalian target of rapamycin (mTOR) signaling pathway. Experimental mouse models of epilepsy were established through intraperitoneal injection of pilocarpine, and in vitro injury models of hippocampal neurons were induced by glutamate (Glu) stimulation. The anti-epileptic effects of vitamin D were evaluated both in vivo and in vitro. Network pharmacology and molecular docking analysis were used to identify potential targets and regulatory pathways of vitamin D in epilepsy. The involvement of the mTOR signaling pathway in the regulation of mouse epilepsy by vitamin D was validated using rapamycin (RAPA). The levels of inflammatory cytokines (TNF-α, IL-1β, and IL-6) were assessed by enzyme-linked immunosorbent assay (ELISA). Gene and protein expressions were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) staining was used to analyze the apoptosis of hippocampal neurons. In in vivo experiments, vitamin D reduced the Racine scores of epileptic mice, prolonged the latency of epilepsy, and inhibited the production of TNF-α, IL-1β, and IL-6 in the hippocampus. Furthermore, network pharmacology analysis identified RAF1 as a potential target of vitamin D in epilepsy, which was further confirmed by molecular docking analysis. Additionally, the mTOR signaling pathway was found to be involved in the regulation of mouse epilepsy by vitamin D. In in vitro experiments, Glu stimulation upregulated the expressions of RAF1 and LC3II/LC3I, inhibited mTOR phosphorylation, and induced neuronal apoptosis. Mechanistically, vitamin D activated the mTOR signaling pathway and alleviated mouse epilepsy via RAF1, while the use of the pathway inhibitor RAPA reversed this effect. Vitamin D alleviated epilepsy symptoms and neuroinflammation in juvenile mice by activating the mTOR signaling pathway via RAF1. These findings provided new insights into the molecular mechanisms underlying the anti-epileptic effects of vitamin D and further supported its use as an adjunctive therapy for existing anti-epileptic drugs.
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Affiliation(s)
- Tiantian Lu
- School of Pediatrics, Hainan Medical University, Haikou, 571199, China
- Department of Neonatology, Haikou Maternal and Child Health Hospital, Haikou, 570203, China
| | - Xiuling Chen
- Department of Pediatric Medicine, Affiliated Haikou Hospital of Xiangya Medical School Central South University, Haikou, 570208, China
| | - Qin Zhang
- Department of Neurosurgery, Hainan Women and Children's Medical Center, Haikou, 570312, China
| | - Kun Shang
- Institute of Deep-sea Science and Engineering, Chinese Academy of Science, Sanya, 572000, China
| | - Xiaogui Yang
- Department of Neonatology, Haikou Maternal and Child Health Hospital, Haikou, 570203, China
| | - Wei Xiang
- School of Pediatrics, Hainan Medical University, Haikou, 571199, China.
- Hainan Women and Children's Medical Center, Hainan Medical University, Haikou, 570312, China.
- National Health Commission (NHC) Key Laboratory of Tropical Disease Control, Hainan Medical University, Haikou, 570216, China.
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B Szabo A, Sayegh F, Gauzin S, Lejards C, Guiard B, Valton L, Verret L, Rampon C, Dahan L. No major effect of dopamine receptor 1/5 antagonist SCH-23390 on epileptic activity in the Tg2576 mouse model of amyloidosis. Eur J Neurosci 2024; 59:1558-1566. [PMID: 38308520 DOI: 10.1111/ejn.16268] [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: 08/01/2023] [Revised: 12/19/2023] [Accepted: 01/14/2024] [Indexed: 02/04/2024]
Abstract
The excitation-inhibition imbalance manifesting as epileptic activities in Alzheimer's disease is gaining more and more attention, and several potentially involved cellular and molecular pathways are currently under investigation. Based on in vitro studies, dopamine D1-type receptors in the anterior cingulate cortex and the hippocampus have been proposed to participate in this peculiar co-morbidity in mouse models of amyloidosis. Here, we tested the implication of dopaminergic transmission in vivo in the Tg2576 mouse model of Alzheimer's disease by monitoring epileptic activities via intracranial EEG before and after treatment with dopamine antagonists. Our results show that neither the D1-like dopamine receptor antagonist SCH23390 nor the D2-like dopamine receptor antagonist haloperidol reduces the frequency of epileptic activities. While requiring further investigation, our results indicate that on a systemic level, dopamine receptors are not significantly contributing to epilepsy observed in vivo in this mouse model of Alzheimer's disease.
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Affiliation(s)
- Anna B Szabo
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
- Centre de recherche Cerveau et Cognition (CerCo), CNRS, UMR 5549, Toulouse Mind and Brain Institute (TMBI), University of Toulouse, University Paul Sabatier (UPS), Toulouse, France
| | - Farès Sayegh
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sèbastien Gauzin
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Camille Lejards
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Bruno Guiard
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Luc Valton
- Centre de recherche Cerveau et Cognition (CerCo), CNRS, UMR 5549, Toulouse Mind and Brain Institute (TMBI), University of Toulouse, University Paul Sabatier (UPS), Toulouse, France
- Department of Neurology, Hôpital Pierre Paul Riquet - Purpan, Toulouse University Hospital, University of Toulouse, Toulouse, France
| | - Laure Verret
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Claire Rampon
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Lionel Dahan
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
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Xiao W, Li P, Kong F, Kong J, Pan A, Long L, Yan X, Xiao B, Gong J, Wan L. Unraveling the Neural Circuits: Techniques, Opportunities and Challenges in Epilepsy Research. Cell Mol Neurobiol 2024; 44:27. [PMID: 38443733 PMCID: PMC10914928 DOI: 10.1007/s10571-024-01458-5] [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: 12/25/2023] [Accepted: 01/24/2024] [Indexed: 03/07/2024]
Abstract
Epilepsy, a prevalent neurological disorder characterized by high morbidity, frequent recurrence, and potential drug resistance, profoundly affects millions of people globally. Understanding the microscopic mechanisms underlying seizures is crucial for effective epilepsy treatment, and a thorough understanding of the intricate neural circuits underlying epilepsy is vital for the development of targeted therapies and the enhancement of clinical outcomes. This review begins with an exploration of the historical evolution of techniques used in studying neural circuits related to epilepsy. It then provides an extensive overview of diverse techniques employed in this domain, discussing their fundamental principles, strengths, limitations, as well as their application. Additionally, the synthesis of multiple techniques to unveil the complexity of neural circuits is summarized. Finally, this review also presents targeted drug therapies associated with epileptic neural circuits. By providing a critical assessment of methodologies used in the study of epileptic neural circuits, this review seeks to enhance the understanding of these techniques, stimulate innovative approaches for unraveling epilepsy's complexities, and ultimately facilitate improved treatment and clinical translation for epilepsy.
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Affiliation(s)
- Wenjie Xiao
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Peile Li
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Fujiao Kong
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Jingyi Kong
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Aihua Pan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Xiaoxin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Jiaoe Gong
- Department of Neurology, Hunan Children's Hospital, Changsha, Hunan Province, China.
| | - Lily Wan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China.
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Basu S, Ro EJ, Liu Z, Kim H, Bennett A, Kang S, Suh H. The Mef2c Gene Dose-Dependently Controls Hippocampal Neurogenesis and the Expression of Autism-Like Behaviors. J Neurosci 2024; 44:e1058232023. [PMID: 38123360 PMCID: PMC10860657 DOI: 10.1523/jneurosci.1058-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 11/30/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023] Open
Abstract
Mutations in the activity-dependent transcription factor MEF2C have been associated with several neuropsychiatric disorders. Among these, autism spectrum disorder (ASD)-related behavioral deficits are manifested. Multiple animal models that harbor mutations in Mef2c have provided compelling evidence that Mef2c is indeed an ASD gene. However, studies in mice with germline or global brain knock-out of Mef2c are limited in their ability to identify the precise neural substrates and cell types that are required for the expression of Mef2c-mediated ASD behaviors. Given the role of hippocampal neurogenesis in cognitive and social behaviors, in this study we aimed to investigate the role of Mef2c in the structure and function of newly generated dentate granule cells (DGCs) in the postnatal hippocampus and to determine whether disrupted Mef2c function is responsible for manifesting ASD behaviors. Overexpression of Mef2c (Mef2cOE ) arrested the transition of neurogenesis at progenitor stages, as indicated by sustained expression of Sox2+ in Mef2cOE DGCs. Conditional knock-out of Mef2c (Mef2ccko ) allowed neuronal commitment of Mef2ccko cells; however, Mef2ccko impaired not only dendritic arborization and spine formation but also synaptic transmission onto Mef2ccko DGCs. Moreover, the abnormal structure and function of Mef2ccko DGCs led to deficits in social interaction and social novelty recognition, which are key characteristics of ASD behaviors. Thus, our study revealed a dose-dependent requirement of Mef2c in the control of distinct steps of neurogenesis, as well as a critical cell-autonomous function of Mef2c in newborn DGCs in the expression of proper social behavior in both sexes.
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Affiliation(s)
- Sreetama Basu
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland 44109, Ohio
| | - Eun Jeoung Ro
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland 44109, Ohio
| | - Zhi Liu
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland 44109, Ohio
| | - Hyunjung Kim
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta 30912, Georgia
| | - Aubrey Bennett
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta 30912, Georgia
| | - Seungwoo Kang
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta 30912, Georgia
| | - Hoonkyo Suh
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland 44109, Ohio
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Zhu F, Shi Q, Jiang YH, Zhang YQ, Zhao H. Impaired synaptic function and hyperexcitability of the pyramidal neurons in the prefrontal cortex of autism-associated Shank3 mutant dogs. Mol Autism 2024; 15:9. [PMID: 38297387 PMCID: PMC10829216 DOI: 10.1186/s13229-024-00587-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 01/22/2024] [Indexed: 02/02/2024] Open
Abstract
BACKGROUND SHANK3 gene is a highly replicated causative gene for autism spectrum disorder and has been well characterized in multiple Shank3 mutant rodent models. When compared to rodents, domestic dogs are excellent animal models in which to study social cognition as they closely interact with humans and exhibit similar social behaviors. Using CRISPR/Cas9 editing, we recently generated a dog model carrying Shank3 mutations, which displayed a spectrum of autism-like behaviors, such as social impairment and heightened anxiety. However, the neural mechanism underlying these abnormal behaviors remains to be identified. METHODS We used Shank3 mutant dog models to examine possible relationships between Shank3 mutations and neuronal dysfunction. We studied electrophysiological properties and the synaptic transmission of pyramidal neurons from acute brain slices of the prefrontal cortex (PFC). We also examined dendrite elaboration and dendritic spine morphology in the PFC using biocytin staining and Golgi staining. We analyzed the postsynaptic density using electron microscopy. RESULTS We established a protocol for the electrophysiological recording of canine brain slices and revealed that excitatory synaptic transmission onto PFC layer 2/3 pyramidal neurons in Shank3 heterozygote dogs was impaired, and this was accompanied by reduced dendrite complexity and spine density when compared to wild-type dogs. Postsynaptic density structures were also impaired in Shank3 mutants; however, pyramidal neurons exhibited hyperexcitability. LIMITATIONS Causal links between impaired PFC pyramidal neuron function and behavioral alterations remain unclear. Further experiments such as manipulating PFC neuronal activity or restoring synaptic transmission in Shank3 mutant dogs are required to assess PFC roles in altered social behaviors. CONCLUSIONS Our study demonstrated the feasibility of using canine brain slices as a model system to study neuronal circuitry and disease. Shank3 haploinsufficiency causes morphological and functional abnormalities in PFC pyramidal neurons, supporting the notion that Shank3 mutant dogs are new and valid animal models for autism research.
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Affiliation(s)
- Feipeng Zhu
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qi Shi
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong-Hui Jiang
- Department of Genetics and Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Yong Q Zhang
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
- School of Life Sciences, Hubei University, Wuhan, 430415, China.
| | - Hui Zhao
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.
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Dvorak NM, Domingo ND, Tapia CM, Wadsworth PA, Marosi M, Avchalumov Y, Fongsaran C, Koff L, Di Re J, Sampson CM, Baumgartner TJ, Wang P, Villarreal PP, Solomon OD, Stutz SJ, Aditi, Porter J, Gbedande K, Prideaux B, Green TA, Seeley EH, Samir P, Dineley KT, Vargas G, Zhou J, Cisneros I, Stephens R, Laezza F. TNFR1 signaling converging on FGF14 controls neuronal hyperactivity and sickness behavior in experimental cerebral malaria. J Neuroinflammation 2023; 20:306. [PMID: 38115011 PMCID: PMC10729485 DOI: 10.1186/s12974-023-02992-7] [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: 08/25/2023] [Accepted: 12/11/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Excess tumor necrosis factor (TNF) is implicated in the pathogenesis of hyperinflammatory experimental cerebral malaria (eCM), including gliosis, increased levels of fibrin(ogen) in the brain, behavioral changes, and mortality. However, the role of TNF in eCM within the brain parenchyma, particularly directly on neurons, remains underdefined. Here, we investigate electrophysiological consequences of eCM on neuronal excitability and cell signaling mechanisms that contribute to observed phenotypes. METHODS The split-luciferase complementation assay (LCA) was used to investigate cell signaling mechanisms downstream of tumor necrosis factor receptor 1 (TNFR1) that could contribute to changes in neuronal excitability in eCM. Whole-cell patch-clamp electrophysiology was performed in brain slices from eCM mice to elucidate consequences of infection on CA1 pyramidal neuron excitability and cell signaling mechanisms that contribute to observed phenotypes. Involvement of identified signaling molecules in mediating behavioral changes and sickness behavior observed in eCM were investigated in vivo using genetic silencing. RESULTS Exploring signaling mechanisms that underlie TNF-induced effects on neuronal excitability, we found that the complex assembly of fibroblast growth factor 14 (FGF14) and the voltage-gated Na+ (Nav) channel 1.6 (Nav1.6) is increased upon tumor necrosis factor receptor 1 (TNFR1) stimulation via Janus Kinase 2 (JAK2). On account of the dependency of hyperinflammatory experimental cerebral malaria (eCM) on TNF, we performed patch-clamp studies in slices from eCM mice and showed that Plasmodium chabaudi infection augments Nav1.6 channel conductance of CA1 pyramidal neurons through the TNFR1-JAK2-FGF14-Nav1.6 signaling network, which leads to hyperexcitability. Hyperexcitability of CA1 pyramidal neurons caused by infection was mitigated via an anti-TNF antibody and genetic silencing of FGF14 in CA1. Furthermore, knockdown of FGF14 in CA1 reduced sickness behavior caused by infection. CONCLUSIONS FGF14 may represent a therapeutic target for mitigating consequences of TNF-mediated neuroinflammation.
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Affiliation(s)
- Nolan M Dvorak
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Nadia D Domingo
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Cynthia M Tapia
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Paul A Wadsworth
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Mate Marosi
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Yosef Avchalumov
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Chanida Fongsaran
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Leandra Koff
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Jessica Di Re
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Catherine M Sampson
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Timothy J Baumgartner
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Pingyuan Wang
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Paula P Villarreal
- Department of Neurobiology, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Clinical Sciences Program, The Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Olivia D Solomon
- Department of Neurobiology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Sonja J Stutz
- Center for Addiction Sciences and Therapeutics, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Aditi
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Jacob Porter
- Department of Chemistry, University of Texas, Austin, TX, 78712, USA
| | - Komi Gbedande
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA
- Center for Immunity and Inflammation and Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07301, USA
| | - Brendan Prideaux
- Department of Neurobiology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Thomas A Green
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Erin H Seeley
- Department of Chemistry, University of Texas, Austin, TX, 78712, USA
| | - Parimal Samir
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Kelley T Dineley
- Center for Addiction Sciences and Therapeutics, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Gracie Vargas
- Department of Neurobiology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Jia Zhou
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Irma Cisneros
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Robin Stephens
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, 77555, USA.
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
- Center for Immunity and Inflammation and Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07301, USA.
| | - Fernanda Laezza
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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Proddutur A, Nguyen S, Yeh CW, Gupta A, Santhakumar V. Reclusive chandeliers: Functional isolation of dentate axo-axonic cells after experimental status epilepticus. Prog Neurobiol 2023; 231:102542. [PMID: 37898313 PMCID: PMC10842856 DOI: 10.1016/j.pneurobio.2023.102542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 10/22/2023] [Accepted: 10/24/2023] [Indexed: 10/30/2023]
Abstract
Axo-axonic cells (AACs) provide specialized inhibition to the axon initial segment (AIS) of excitatory neurons and can regulate network output and synchrony. Although hippocampal dentate AACs are structurally altered in epilepsy, physiological analyses of dentate AACs are lacking. We demonstrate that parvalbumin neurons in the dentate molecular layer express PTHLH, an AAC marker, and exhibit morphology characteristic of AACs. Dentate AACs show high-frequency, non-adapting firing but lack persistent firing in the absence of input and have higher rheobase than basket cells suggesting that AACs can respond reliably to network activity. Early after pilocarpine-induced status epilepticus (SE), dentate AACs receive fewer spontaneous excitatory and inhibitory synaptic inputs and have significantly lower maximum firing frequency. Paired recordings and spatially localized optogenetic stimulation revealed that SE reduced the amplitude of unitary synaptic inputs from AACs to granule cells without altering reliability, short-term plasticity, or AIS GABA reversal potential. These changes compromised AAC-dependent shunting of granule cell firing in a multicompartmental model. These early post-SE changes in AAC physiology would limit their ability to receive and respond to input, undermining a critical brake on the dentate throughput during epileptogenesis.
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Affiliation(s)
- Archana Proddutur
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Susan Nguyen
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Chia-Wei Yeh
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Akshay Gupta
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Vijayalakshmi Santhakumar
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA.
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Wenzel M, Huberfeld G, Grayden DB, de Curtis M, Trevelyan AJ. A debate on the neuronal origin of focal seizures. Epilepsia 2023; 64 Suppl 3:S37-S48. [PMID: 37183507 DOI: 10.1111/epi.17650] [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: 02/09/2023] [Revised: 04/26/2023] [Accepted: 05/12/2023] [Indexed: 05/16/2023]
Abstract
A critical question regarding how focal seizures start is whether we can identify particular cell classes that drive the pathological process. This was the topic for debate at the recent International Conference for Technology and Analysis of Seizures (ICTALS) meeting (July 2022, Bern, CH) that we summarize here. The debate has been fueled in recent times by the introduction of powerful new ways to manipulate subpopulations of cells in relative isolation, mostly using optogenetics. The motivation for resolving the debate is to identify novel targets for therapeutic interventions through a deeper understanding of the etiology of seizures.
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Affiliation(s)
- Michael Wenzel
- Department of Epileptology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Gilles Huberfeld
- Neurology Department, Hopital Fondation Adolphe de Rothschild, Paris, France
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - David B Grayden
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
- Graeme Clark Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Marco de Curtis
- Epilepsy Unit, Fondazione I.R.C.C.S., Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrew J Trevelyan
- Newcastle University Biosciences Institute, Medical School, Framlington Place, Newcastle upon Tyne, UK
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Metcalf CS. Brake Early: RGS14 in CA2 Limits Seizures and Oxidative Stress After SE. Epilepsy Curr 2023; 23:372-374. [PMID: 38269350 PMCID: PMC10805082 DOI: 10.1177/15357597231199343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
RGS14 Limits Seizure-Induced Mitochondrial Oxidative Stress and Pathology in Hippocampus Harbin NH, Lustberg DJ, Hurst C, Pare J, Crotty KM, Waters AL, Yeligar SM, Smith Y, Seyfried NT, Weinschenker D, Hepler JR. Neurobiol Dis. 2023;181:106128. doi:10.1016/j.nbd.2023.106128 . PMID: 37075948 RGS14 is a complex multifunctional scaffolding protein that is highly enriched within pyramidal cells (PCs) of hippocampal area CA2. In these neurons, RGS14 suppresses glutamate-induced calcium influx and related G protein and ERK signaling in dendritic spines to restrain postsynaptic signaling and plasticity. Previous findings show that, unlike PCs of hippocampal areas CA1 and CA3, CA2 PCs are resistant to a number of neurological insults, including degeneration caused by temporal lobe epilepsy (TLE). While RGS14 is protective against peripheral injury, similar roles for RGS14 during pathological injury in hippocampus remain unexplored. Recent studies showed that area CA2 modulates hippocampal excitability, generates epileptiform activity and promotes hippocampal pathology in animal models and patients with TLE. Because RGS14 suppresses CA2 excitability and signaling, we hypothesized that RGS14 would moderate seizure behavior and early hippocampal pathology following seizure activity, possibly affording protection to CA2 PCs. Using kainic acid (KA) to induce status epilepticus (KA-SE) in mice, we show that the loss of RGS14 (RGS14 KO) accelerated onset of limbic motor seizures and mortality compared to wild type (WT) mice, and that KA-SE upregulated RGS14 protein expression in CA2 and CA1 PCs of WT. Our proteomics data show that the loss of RGS14 impacted the expression of a number of proteins at baseline and after KA-SE, many of which associated unexpectedly with mitochondrial function and oxidative stress. RGS14 was shown to localize to the mitochondria in CA2 PCs of mice and reduce mitochondrial respiration in vitro. As a readout of oxidative stress, we found that RGS14 KO dramatically increased 3-nitrotyrosine levels in CA2 PCs, which was greatly exacerbated following KA-SE and correlated with a lack of superoxide dismutase 2 (SOD2) induction. Assessing for hallmarks of seizure pathology in RGS14 KO, we unexpectedly found no differences in neuronal injury in CA2 PCs. However, we observed a striking and surprising lack of microgliosis in CA1 and CA2 of RGS14 KO compared to WT. Together, our data demonstrate a newly appreciated role for RGS14 in limiting intense seizure activity and pathology in hippocampus. Our findings are consistent with a model where RGS14 limits seizure onset and mortality and, after seizure, is upregulated to support mitochondrial function, prevent oxidative stress in CA2 PCs, and promote microglial activation in hippocampus.
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Whitebirch AC, Santoro B, Barnett A, Lisgaras CP, Scharfman HE, Siegelbaum SA. Reduced Cholecystokinin-Expressing Interneuron Input Contributes to Disinhibition of the Hippocampal CA2 Region in a Mouse Model of Temporal Lobe Epilepsy. J Neurosci 2023; 43:6930-6949. [PMID: 37643861 PMCID: PMC10573827 DOI: 10.1523/jneurosci.2091-22.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 08/04/2023] [Accepted: 08/15/2023] [Indexed: 08/31/2023] Open
Abstract
A significant proportion of temporal lobe epilepsy (TLE) patients experience drug-resistant seizures associated with mesial temporal sclerosis, in which there is extensive cell loss in the hippocampal CA1 and CA3 subfields, with a relative sparing of dentate gyrus granule cells and CA2 pyramidal neurons (PNs). A role for CA2 in seizure generation was suggested based on findings of a reduction in CA2 synaptic inhibition (Williamson and Spencer, 1994) and the presence of interictal-like spike activity in CA2 in resected hippocampal tissue from TLE patients (Wittner et al., 2009). We recently found that in the pilocarpine-induced status epilepticus (PILO-SE) mouse model of TLE there was an increase in CA2 intrinsic excitability associated with a loss of CA2 synaptic inhibition. Furthermore, chemogenetic silencing of CA2 significantly reduced seizure frequency, consistent with a role of CA2 in promoting seizure generation and/or propagation (Whitebirch et al., 2022). In the present study, we explored the cellular basis of this inhibitory deficit using immunohistochemical and electrophysiological approaches in PILO-SE male and female mice. We report a widespread decrease in the density of pro-cholecystokinin-immunopositive (CCK+) interneurons and a functional impairment of CCK+ interneuron-mediated inhibition of CA2 PNs. We also found a disruption in the perisomatic perineuronal net in the CA2 stratum pyramidale. Such pathologic alterations may contribute to an enhanced excitation of CA2 PNs and CA2-dependent seizure activity in the PILO-SE mouse model.SIGNIFICANCE STATEMENT Impaired synaptic inhibition in hippocampal circuits has been identified as a key feature that contributes to the emergence and propagation of seizure activity in human patients and animal models of temporal lobe epilepsy (TLE). Among the hippocampal subfields, the CA2 region is particularly resilient to seizure-associated neurodegeneration and has been suggested to play a key role in seizure activity in TLE. Here we report that perisomatic inhibition of CA2 pyramidal neurons mediated by cholecystokinin-expressing interneurons is selectively reduced in acute hippocampal slices from epileptic mice. Parvalbumin-expressing interneurons, in contrast, appear relatively conserved in epileptic mice. These findings advance our understanding of the cellular mechanisms underlying inhibitory disruption in hippocampal circuits in a mouse model of spontaneous recurring seizures.
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Affiliation(s)
- Alexander C Whitebirch
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
| | - Bina Santoro
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
| | - Anastasia Barnett
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
| | - Christos Panagiotis Lisgaras
- Department of Child & Adolescent Psychiatry, New York University Langone Health, New York, New York 10016
- Department of Neuroscience & Physiology, New York University Langone Health, New York, New York 10016
- Department of Psychiatry, New York University Langone Health, New York, New York 10016
- The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962
| | - Helen E Scharfman
- Department of Child & Adolescent Psychiatry, New York University Langone Health, New York, New York 10016
- Department of Neuroscience & Physiology, New York University Langone Health, New York, New York 10016
- Department of Psychiatry, New York University Langone Health, New York, New York 10016
- The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962
| | - Steven A Siegelbaum
- Departments of Neuroscience and Pharmacology, Kavli Institute for Brain Science, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University Irving Medical Center, New York, New York 10027
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11
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Chameh HM, Falby M, Movahed M, Arbabi K, Rich S, Zhang L, Lefebvre J, Tripathy SJ, De Pittà M, Valiante TA. Distinctive biophysical features of human cell-types: insights from studies of neurosurgically resected brain tissue. Front Synaptic Neurosci 2023; 15:1250834. [PMID: 37860223 PMCID: PMC10584155 DOI: 10.3389/fnsyn.2023.1250834] [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: 06/30/2023] [Accepted: 08/21/2023] [Indexed: 10/21/2023] Open
Abstract
Electrophysiological characterization of live human tissue from epilepsy patients has been performed for many decades. Although initially these studies sought to understand the biophysical and synaptic changes associated with human epilepsy, recently, it has become the mainstay for exploring the distinctive biophysical and synaptic features of human cell-types. Both epochs of these human cellular electrophysiological explorations have faced criticism. Early studies revealed that cortical pyramidal neurons obtained from individuals with epilepsy appeared to function "normally" in comparison to neurons from non-epilepsy controls or neurons from other species and thus there was little to gain from the study of human neurons from epilepsy patients. On the other hand, contemporary studies are often questioned for the "normalcy" of the recorded neurons since they are derived from epilepsy patients. In this review, we discuss our current understanding of the distinct biophysical features of human cortical neurons and glia obtained from tissue removed from patients with epilepsy and tumors. We then explore the concept of within cell-type diversity and its loss (i.e., "neural homogenization"). We introduce neural homogenization to help reconcile the epileptogenicity of seemingly "normal" human cortical cells and circuits. We propose that there should be continued efforts to study cortical tissue from epilepsy patients in the quest to understand what makes human cell-types "human".
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Affiliation(s)
- Homeira Moradi Chameh
- Division of Clinical and Computational Neuroscience, Krembil Brain Institute, University Health Network (UHN), Toronto, ON, Canada
| | - Madeleine Falby
- Division of Clinical and Computational Neuroscience, Krembil Brain Institute, University Health Network (UHN), Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Mandana Movahed
- Division of Clinical and Computational Neuroscience, Krembil Brain Institute, University Health Network (UHN), Toronto, ON, Canada
| | - Keon Arbabi
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Scott Rich
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
| | - Liang Zhang
- Division of Clinical and Computational Neuroscience, Krembil Brain Institute, University Health Network (UHN), Toronto, ON, Canada
| | - Jérémie Lefebvre
- Division of Clinical and Computational Neuroscience, Krembil Brain Institute, University Health Network (UHN), Toronto, ON, Canada
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
- Department of Mathematics, University of Toronto, Toronto, ON, Canada
| | - Shreejoy J. Tripathy
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Maurizio De Pittà
- Division of Clinical and Computational Neuroscience, Krembil Brain Institute, University Health Network (UHN), Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Basque Center for Applied Mathematics, Bilbao, Spain
- Faculty of Medicine, University of the Basque Country, Leioa, Spain
| | - Taufik A. Valiante
- Division of Clinical and Computational Neuroscience, Krembil Brain Institute, University Health Network (UHN), Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada
- Center for Advancing Neurotechnological Innovation to Application (CRANIA), Toronto, ON, Canada
- Max Planck-University of Toronto Center for Neural Science and Technology, University of Toronto, Toronto, ON, Canada
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Proddutur A, Nguyen S, Yeh CW, Gupta A, Santhakumar V. RECLUSIVE CHANDELIERS: FUNCTIONAL ISOLATION OF DENTATE AXO-AXONIC CELLS AFTER EXPERIMENTAL STATUS EPILEPTICUS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.01.560378. [PMID: 37873292 PMCID: PMC10592856 DOI: 10.1101/2023.10.01.560378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Axo-axonic cells (AACs) provide specialized inhibition to the axon initial segment (AIS) of excitatory neurons and can regulate network output and synchrony. Although hippocampal dentate AACs are structurally altered in epilepsy, physiological analyses of dentate AACs are lacking. We demonstrate that parvalbumin neurons in the dentate molecular layer express PTHLH, an AAC marker, and exhibit morphology characteristic of AACs. Dentate AACs show high-frequency, non-adapting firing but lack persistent firing in the absence of input and have higher rheobase than basket cells suggesting that AACs can respond reliably to network activity. Early after pilocarpine-induced status epilepticus (SE), dentate AACs receive fewer spontaneous excitatory and inhibitory synaptic inputs and have significantly lower maximum firing frequency. Paired recordings and spatially localized optogenetic stimulation revealed that SE reduced the amplitude of unitary synaptic inputs from AACs to granule cells without altering reliability, short-term plasticity, or AIS GABA reversal potential. These changes compromised AAC-dependent shunting of granule cell firing in a multicompartmental model. These early post-SE changes in AAC physiology would limit their ability to receive and respond to input, undermining a critical brake on the dentate throughput during epileptogenesis.
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Affiliation(s)
- Archana Proddutur
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey 07103
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
| | - Susan Nguyen
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
| | - Chia-Wei Yeh
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
| | - Akshay Gupta
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey 07103
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
| | - Vijayalakshmi Santhakumar
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey 07103
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
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Liu X, Zhao Y, Liang X, Ding Y, Hu J, Deng N, Zhao Y, Huang P, Xie W. In Vivo Evaluation of Self-assembled nano-Saikosaponin-a for Epilepsy Treatment. Mol Biotechnol 2023:10.1007/s12033-023-00851-7. [PMID: 37608078 DOI: 10.1007/s12033-023-00851-7] [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: 04/10/2023] [Accepted: 08/03/2023] [Indexed: 08/24/2023]
Abstract
Saikosaponin-a (SSa) exhibits antiepileptic effects. However, its poor water solubility and inability to pass through the blood-brain barrier greatly limit its clinical development and application. In this study, SSa-loaded Methoxy poly (ethylene glycol)-poly(ε-caprolactone) (MePEG-SSa-PCL) NPs were successfully prepared and characterized. Our objective was to further investigate the effect of this composite on acute seizure in mice. First, we confirmed the particle size and surface potential of the composite (51.00 ± 0.25 nm and - 33.77 ± 2.04 mV, respectively). Further, we compared the effects of various MePEG-SSa-PCL doses (low, medium, and high) with those of free SSa, valproic acid (VPA - positive control), and saline only (model group) on acute seizure using three different acute epilepsy mouse models. We observed that compared with the model group, the three MePEG-SSa-PCL treatments showed significantly lowered seizure frequency in mice belonging to the maximum electroconvulsive model group. In the pentylenetetrazol and kainic acid (KA) acute epilepsy models, MePEG-SSa-PCL increased both clonic and convulsion latency periods and shortened convulsion duration more effectively than equivalent SSa-only doses. Furthermore, hematoxylin-eosin and Nissl staining revealed considerably less neuronal damage in the hippocampal CA3 area of KA mice in the SSa, VPA, and three MePEG-SSa-PCL groups relative to mice in the model group. Hippocampal gamma-aminobutyric acid-A (GABA-A) receptor and cleaved caspase-3 expression levels in KA mice were significantly higher and lower, respectively, in the three MePEG-SSa-PCL treatment groups than in the model group. Thus, MePEG-SSa-PCL exhibited a more potent antiepileptic effect than SSa in acute mouse epilepsy models and could alleviate neuronal damage in the hippocampus following epileptic seizures, possibly via GABA-A receptor expression upregulation.
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Affiliation(s)
- Xueqi Liu
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Yunyan Zhao
- Department of Critical Care Medicine, The Afflliated Traditional Chinese Medicine Hospital of Guangzhou Medical University, Guangzhou, 510130, China
| | - Xiaoshan Liang
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Yuewen Ding
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Jiao Hu
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Ning Deng
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Yiting Zhao
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Ping Huang
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Wei Xie
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China.
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Jain S, LaFrancois JJ, Gerencer K, Botterill JJ, Kennedy M, Criscuolo C, Scharfman HE. Increasing adult neurogenesis protects mice from epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.08.548217. [PMID: 37502909 PMCID: PMC10369878 DOI: 10.1101/2023.07.08.548217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Neurogenesis occurs in the adult brain in the hippocampal dentate gyrus, an area that contains neurons which are vulnerable to insults and injury, such as severe seizures. Previous studies showed that increasing adult neurogenesis reduced neuronal damage after these seizures. Because the damage typically is followed by chronic lifelong seizures (epilepsy), we asked if increasing adult neurogenesis would prevent epilepsy. Adult neurogenesis was selectively increased by deleting the pro-apoptotic gene Bax from Nestin-expressing progenitors. Tamoxifen was administered at 6 weeks of age to conditionally delete Bax in Nestin-CreERT2Baxfl/fl mice. Six weeks after tamoxifen administration, severe seizures (status epilepticus; SE) were induced by injection of the convulsant pilocarpine. Mice with increased adult neurogenesis exhibited fewer chronic seizures. Postictal depression was reduced also. These results were primarily female mice, possibly because they were the more affected by Bax deletion than males, consistent with sex differences in Bax in development. The female mice with enhanced adult neurogenesis also showed less neuronal loss of hilar mossy cells and hilar somatostatin-expressing neurons than wild type females or males, which is notable because these two cell types are implicated in epileptogenesis. The results suggest that increasing adult neurogenesis in the normal adult brain can reduce experimental epilepsy, and the effect shows a striking sex difference. The results are surprising in light of past studies showing that suppressing adult-born neurons can also reduce chronic seizures.
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Affiliation(s)
- Swati Jain
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962
| | - John J. LaFrancois
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962
| | - Kasey Gerencer
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962
- Department of Psychology, The University of Maine, Orono, ME 04469
| | - Justin J. Botterill
- Department of Anatomy, Physiology, & Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5
| | - Meghan Kennedy
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962
| | - Chiara Criscuolo
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962
- Departments of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY 10016
| | - Helen E. Scharfman
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962
- Departments of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY 10016
- Departments of Neuroscience & Physiology, Psychiatry, and the New York University, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016
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15
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Takeuchi Y, Yamashiro K, Noguchi A, Liu J, Mitsui S, Ikegaya Y, Matsumoto N. Machine learning-based segmentation of the rodent hippocampal CA2 area from Nissl-stained sections. Front Neuroanat 2023; 17:1172512. [PMID: 37449243 PMCID: PMC10336234 DOI: 10.3389/fnana.2023.1172512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 06/05/2023] [Indexed: 07/18/2023] Open
Abstract
The hippocampus is a center of learning, memory, and spatial navigation. This region is divided into the CA1, CA2, and CA3 areas, which are anatomically different from each other. Among these divisions, the CA2 area is unique in terms of functional relevance to sociality. The CA2 area is often manually detected based on the size, shape, and density of neurons in the hippocampal pyramidal cell layer, but this manual segmentation relying on cytoarchitecture is impractical to apply to a large number of samples and dependent on experimenters' proficiency. Moreover, the CA2 area has been defined based on expression pattern of molecular marker proteins, but it generally takes days to complete immunostaining for such proteins. Thus, we asked whether the CA2 area can be systematically segmented based on cytoarchitecture alone. Since the expression pattern of regulator of G-protein signaling 14 (RGS14) signifies the CA2 area, we visualized the CA2 area in the mouse hippocampus by RGS14-immunostaining and Nissl-counterstaining and manually delineated the CA2 area. We then established "CAseg," a machine learning-based automated algorithm to segment the CA2 area with the F1-score of approximately 0.8 solely from Nissl-counterstained images that visualized cytoarchitecture. CAseg was extended to the segmentation of the prairie vole CA2 area, which raises the possibility that the use of this algorithm can be expanded to other species. Thus, CAseg will be beneficial for investigating unique properties of the hippocampal CA2 area.
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Affiliation(s)
- Yuki Takeuchi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kotaro Yamashiro
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Asako Noguchi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Jiayan Liu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Shinichi Mitsui
- Department of Rehabilitation Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, Japan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, Japan
| | - Nobuyoshi Matsumoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, Japan
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16
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Stöber TM, Batulin D, Triesch J, Narayanan R, Jedlicka P. Degeneracy in epilepsy: multiple routes to hyperexcitable brain circuits and their repair. Commun Biol 2023; 6:479. [PMID: 37137938 PMCID: PMC10156698 DOI: 10.1038/s42003-023-04823-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 04/06/2023] [Indexed: 05/05/2023] Open
Abstract
Due to its complex and multifaceted nature, developing effective treatments for epilepsy is still a major challenge. To deal with this complexity we introduce the concept of degeneracy to the field of epilepsy research: the ability of disparate elements to cause an analogous function or malfunction. Here, we review examples of epilepsy-related degeneracy at multiple levels of brain organisation, ranging from the cellular to the network and systems level. Based on these insights, we outline new multiscale and population modelling approaches to disentangle the complex web of interactions underlying epilepsy and to design personalised multitarget therapies.
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Affiliation(s)
- Tristan Manfred Stöber
- Frankfurt Institute for Advanced Studies, 60438, Frankfurt am Main, Germany
- Institute for Neural Computation, Faculty of Computer Science, Ruhr University Bochum, 44801, Bochum, Germany
- Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe University, 60590, Frankfurt, Germany
| | - Danylo Batulin
- Frankfurt Institute for Advanced Studies, 60438, Frankfurt am Main, Germany
- CePTER - Center for Personalized Translational Epilepsy Research, Goethe University, 60590, Frankfurt, Germany
- Faculty of Computer Science and Mathematics, Goethe University, 60486, Frankfurt, Germany
| | - Jochen Triesch
- Frankfurt Institute for Advanced Studies, 60438, Frankfurt am Main, Germany
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Peter Jedlicka
- ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University Giessen, 35390, Giessen, Germany.
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, 60590, Frankfurt am Main, Germany.
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17
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Dudek SM, Alexander GM, Farris S. Introduction to the special issue on: A new view of hippocampal area CA2. Hippocampus 2023; 33:127-132. [PMID: 36826426 DOI: 10.1002/hipo.23514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2023] [Indexed: 02/25/2023]
Affiliation(s)
- Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, North Carolina, USA
| | - Georgia M Alexander
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, North Carolina, USA
| | - Shannon Farris
- Center for Neurobiology Research, Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, Virginia, USA
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18
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Chevaleyre V, Piskorowski R. New hues for CA2. Hippocampus 2023; 33:161-165. [PMID: 36585825 DOI: 10.1002/hipo.23496] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 12/10/2022] [Accepted: 12/16/2022] [Indexed: 01/01/2023]
Affiliation(s)
- Vivien Chevaleyre
- INSERM U1266, Institute of Psychiatry and Neuroscience of Paris (IPNP), Université Paris Cité, Paris, France.,GHU Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Paris, France
| | - Rebecca Piskorowski
- INSERM U1266, Institute of Psychiatry and Neuroscience of Paris (IPNP), Université Paris Cité, Paris, France.,GHU Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Paris, France
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19
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Kilias A, Tulke S, Barheier N, Ruther P, Häussler U. Integration of the CA2 region in the hippocampal network during epileptogenesis. Hippocampus 2023; 33:223-240. [PMID: 36421040 DOI: 10.1002/hipo.23479] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/14/2022] [Accepted: 11/02/2022] [Indexed: 11/26/2022]
Abstract
The CA2 pyramidal cells are mostly resistant to cell death in mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis, but they are aberrantly integrated into the epileptic hippocampal network via mossy fiber sprouting. Furthermore, they show increased excitability in vitro in hippocampal slices obtained from human MTLE specimens or animal epilepsy models. Although these changes promote CA2 to contribute to epileptic activity (EA) in vivo, the role of CA2 in the epileptic network within and beyond the sclerotic hippocampus is still unclear. We used the intrahippocampal kainate mouse model for MTLE, which recapitulates most features of the human disease including pharmacoresistant epileptic seizures and hippocampal sclerosis, with preservation of dentate gyrus (DG) granule cells and CA2 pyramidal cells. In vivo recordings with electrodes in CA2 and the DG showed that EA occurs at high coincidence between the ipsilateral DG and CA2 and current source density analysis of silicon probe recordings in dorsal ipsilateral CA2 revealed CA2 as a local source of EA. Cell-specific viral tracing in Amigo2-icreERT2 mice confirmed the preservation of the axonal projection from ipsilateral CA2 pyramidal cells to contralateral CA2 under epileptic conditions and indeed, EA propagated from ipsi- to contralateral CA2 with increasing likelihood with time after KA injection, but always at lower intensity than within the ipsilateral hippocampus. Furthermore, we show that CA2 presents with local theta oscillations and like the DG, shows a pathological reduction of theta frequency already from 2 days after KA onward. The early changes in activity might be facilitated by the loss of glutamic acid decarboxylase 67 (Gad67) mRNA-expressing interneurons directly after the initial status epilepticus in ipsi- but not contralateral CA2. Together, our data highlight CA2 as an active player in the epileptic network and with its contralateral connections as one possible router of aberrant activity.
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Affiliation(s)
- Antje Kilias
- Institute for Physiology I, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Susanne Tulke
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Nicole Barheier
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Patrick Ruther
- Microsystem Materials Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany.,Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
| | - Ute Häussler
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Center BrainLinks-BrainTools, University of Freiburg, Freiburg, Germany
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Harbin NH, Lustberg DJ, Hurst C, Pare JF, Crotty KM, Waters AL, Yeligar SM, Smith Y, Seyfried NT, Weinshenker D, Hepler JR. RGS14 is neuroprotective against seizure-induced mitochondrial oxidative stress and pathology in hippocampus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526349. [PMID: 36778349 PMCID: PMC9915580 DOI: 10.1101/2023.02.01.526349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
RGS14 is a complex multifunctional scaffolding protein that is highly enriched within pyramidal cells (PCs) of hippocampal area CA2. There, RGS14 suppresses glutamate-induced calcium influx and related G protein and ERK signaling in dendritic spines to restrain postsynaptic signaling and plasticity. Previous findings show that, unlike PCs of hippocampal areas CA1 and CA3, CA2 PCs are resistant to a number of neurological insults, including degeneration caused by temporal lobe epilepsy (TLE). While RGS14 is protective against peripheral injury, similar roles for RGS14 during pathological injury in hippocampus remain unexplored. Recent studies show that area CA2 modulates hippocampal excitability, generates epileptiform activity and promotes hippocampal pathology in animal models and patients with TLE. Because RGS14 suppresses CA2 excitability and signaling, we hypothesized that RGS14 would moderate seizure behavior and early hippocampal pathology following seizure activity. Using kainic acid (KA) to induce status epilepticus (KA-SE) in mice, we show loss of RGS14 (RGS14 KO) accelerated onset of limbic motor seizures and mortality compared to wild type (WT) mice, and that KA-SE upregulated RGS14 protein expression in CA2 and CA1 PCs of WT. Utilizing proteomics, we saw loss of RGS14 impacted the expression of a number of proteins at baseline and after KA-SE, many of which associated unexpectedly with mitochondrial function and oxidative stress. RGS14 was shown to localize to the mitochondria in CA2 PCs of mice and reduce mitochondrial respiration in vitro . As a readout of oxidative stress, we found RGS14 KO dramatically increased 3-nitrotyrosine levels in CA2 PCs, which was greatly exacerbated following KA-SE and correlated with a lack of superoxide dismutase 2 (SOD2) induction. Assessing for hallmarks of seizure pathology in RGS14 KO, we observed worse neuronal injury in area CA3 (but none in CA2 or CA1), and a lack of microgliosis in CA1 and CA2 compared to WT. Together, our data demonstrates a newly appreciated neuroprotective role for RGS14 against intense seizure activity in hippocampus. Our findings are consistent with a model where, after seizure, RGS14 is upregulated to support mitochondrial function and prevent oxidative stress in CA2 PCs, limit seizure onset and hippocampal neuronal injury, and promote microglial activation in hippocampus.
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Lisgaras CP, Oliva A, Mckenzie S, LaFrancois J, Siegelbaum SA, Scharman HE. Hippocampal area CA2 controls seizure dynamics, interictal EEG abnormalities and social comorbidity in mouse models of temporal lobe epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.15.524149. [PMID: 36711983 PMCID: PMC9882187 DOI: 10.1101/2023.01.15.524149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Temporal lobe epilepsy (TLE) is characterized by spontaneous recurrent seizures, abnormal activity between seizures, and impaired behavior. CA2 pyramidal neurons (PNs) are potentially important because inhibiting them with a chemogenetic approach reduces seizure frequency in a mouse model of TLE. However, whether seizures could be stopped by timing inhibition just as a seizure begins is unclear. Furthermore, whether inhibition would reduce the cortical and motor manifestations of seizures are not clear. Finally, whether interictal EEG abnormalities and TLE comorbidities would be improved are unknown. Therefore, real-time optogenetic silencing of CA2 PNs during seizures, interictal activity and behavior were studied in 2 mouse models of TLE. CA2 silencing significantly reduced seizure duration and time spent in convulsive behavior. Interictal spikes and high frequency oscillations were significantly reduced, and social behavior was improved. Therefore, brief focal silencing of CA2 PNs reduces seizures, their propagation, and convulsive manifestations, improves interictal EEG, and ameliorates social comorbidities. HIGHLIGHTS Real-time CA2 silencing at the onset of seizures reduces seizure durationWhen CA2 silencing reduces seizure activity in hippocampus it also reduces cortical seizure activity and convulsive manifestations of seizuresInterictal spikes and high frequency oscillations are reduced by real-time CA2 silencingReal-time CA2 silencing of high frequency oscillations (>250Hz) rescues social memory deficits of chronic epileptic mice.
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Shuman T. Et tu, CA2: CA2 Is Hyperexcitable and Controls Seizures in a Mouse Model of Temporal Lobe Epilepsy. Epilepsy Curr 2023; 23:121-123. [PMID: 37122405 PMCID: PMC10131565 DOI: 10.1177/15357597221150068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
[Box: see text]
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Affiliation(s)
- Tristan Shuman
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai
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Piskorowski RA, Chevaleyre V. Hippocampal area CA2: interneuron disfunction during pathological states. Front Neural Circuits 2023; 17:1181032. [PMID: 37180763 PMCID: PMC10174260 DOI: 10.3389/fncir.2023.1181032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/07/2023] [Indexed: 05/16/2023] Open
Abstract
Hippocampal area CA2 plays a critical role in social recognition memory and has unique cellular and molecular properties that distinguish it from areas CA1 and CA3. In addition to having a particularly high density of interneurons, the inhibitory transmission in this region displays two distinct forms of long-term synaptic plasticity. Early studies on human hippocampal tissue have reported unique alteration in area CA2 with several pathologies and psychiatric disorders. In this review, we present recent studies revealing changes in inhibitory transmission and plasticity of area CA2 in mouse models of multiple sclerosis, autism spectrum disorder, Alzheimer's disease, schizophrenia and the 22q11.2 deletion syndrome and propose how these changes could underly deficits in social cognition observed during these pathologies.
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Affiliation(s)
- Rebecca A. Piskorowski
- Université Paris Cité, INSERM UMRS 1266, Institute of Psychiatry and Neuroscience of Paris, GHU Paris Psychiatrie et Neurosciences, Paris, France
- Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR 8246, INSERM U1130, Sorbonne Université, Paris, France
- *Correspondence: Rebecca A. Piskorowski,
| | - Vivien Chevaleyre
- Université Paris Cité, INSERM UMRS 1266, Institute of Psychiatry and Neuroscience of Paris, GHU Paris Psychiatrie et Neurosciences, Paris, France
- Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR 8246, INSERM U1130, Sorbonne Université, Paris, France
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