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Yonan JM, Chen KD, Baram TZ, Steward O. PTEN DELETION IN THE ADULT DENTATE GYRUS INDUCES EPILEPSY. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.07.606938. [PMID: 39149280 PMCID: PMC11326251 DOI: 10.1101/2024.08.07.606938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Embryonic and early postnatal promotor-driven deletion of the phosphatase and tensin homolog (PTEN) gene results in neuronal hypertrophy, hyperexcitable circuitry and development of spontaneous seizures in adulthood. We previously documented that focal, vector-mediated PTEN deletion in mature granule cells of adult dentate gyrus triggers dramatic growth of cell bodies, dendrites, and axons, similar to that seen with early postnatal PTEN deletion. Here, we assess the functional consequences of focal, adult PTEN deletion, focusing on its pro-epileptogenic potential. PTEN deletion was accomplished by injecting AAV-Cre either bilaterally or unilaterally into the dentate gyrus of double transgenic PTEN-floxed, ROSA-reporter mice. Hippocampal recording electrodes were implanted for continuous digital EEG with concurrent video recordings in the home cage. Electrographic seizures and epileptiform spikes were assessed manually by two investigators, and corelated with concurrent videos. Spontaneous electrographic and behavioral seizures appeared after focal PTEN deletion in adult dentate granule cells, commencing around 2 months post-AAV-Cre injection. Seizures occurred in the majority of mice with unilateral or bilateral PTEN deletion and led to death in several cases. PTEN-deletion provoked epilepsy was not associated with apparent hippocampal neuron death; supra-granular mossy fiber sprouting was observed in a few mice. In summary, focal, unilateral deletion of PTEN in the adult dentate gyrus suffices to provoke time-dependent emergence of a hyperexcitable circuit generating hippocampus-origin, generalizing spontaneous seizures, providing a novel model for studies of adult-onset epileptogenesis.
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Affiliation(s)
- Jennifer M Yonan
- Reeve-Irvine Research Center, Departments of Anatomy & Neurobiology, Neurobiology & Behavior, Neurosurgery, Pediatrics and Neurology, Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA 92697
| | - Kevin D Chen
- Reeve-Irvine Research Center, Departments of Anatomy & Neurobiology, Neurobiology & Behavior, Neurosurgery, Pediatrics and Neurology, Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA 92697
| | - Tallie Z Baram
- Reeve-Irvine Research Center, Departments of Anatomy & Neurobiology, Neurobiology & Behavior, Neurosurgery, Pediatrics and Neurology, Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA 92697
| | - Oswald Steward
- Reeve-Irvine Research Center, Departments of Anatomy & Neurobiology, Neurobiology & Behavior, Neurosurgery, Pediatrics and Neurology, Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA 92697
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Liu X, Zhang Y, Zhao Y, Zhang Q, Han F. The Neurovascular Unit Dysfunction in the Molecular Mechanisms of Epileptogenesis and Targeted Therapy. Neurosci Bull 2024; 40:621-634. [PMID: 38564049 PMCID: PMC11127907 DOI: 10.1007/s12264-024-01193-3] [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: 08/04/2023] [Accepted: 12/09/2023] [Indexed: 04/04/2024] Open
Abstract
Epilepsy is a multifaceted neurological syndrome characterized by recurrent, spontaneous, and synchronous seizures. The pathogenesis of epilepsy, known as epileptogenesis, involves intricate changes in neurons, neuroglia, and endothelium, leading to structural and functional disorders within neurovascular units and culminating in the development of spontaneous epilepsy. Although current research on epilepsy treatments primarily centers around anti-seizure drugs, it is imperative to seek effective interventions capable of disrupting epileptogenesis. To this end, a comprehensive exploration of the changes and the molecular mechanisms underlying epileptogenesis holds the promise of identifying vital biomarkers for accurate diagnosis and potential therapeutic targets. Emphasizing early diagnosis and timely intervention is paramount, as it stands to significantly improve patient prognosis and alleviate the socioeconomic burden. In this review, we highlight the changes and molecular mechanisms of the neurovascular unit in epileptogenesis and provide a theoretical basis for identifying biomarkers and drug targets.
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Affiliation(s)
- Xiuxiu Liu
- Medical Basic Research Innovation Center for Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Nanjing, 211166, China.
- International Joint Laboratory for Drug Target of Critical Illnesses, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China.
| | - Ying Zhang
- Medical Basic Research Innovation Center for Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Nanjing, 211166, China
- International Joint Laboratory for Drug Target of Critical Illnesses, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China
| | - Yanming Zhao
- Medical Basic Research Innovation Center for Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Nanjing, 211166, China
- International Joint Laboratory for Drug Target of Critical Illnesses, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China
| | - Qian Zhang
- Medical Basic Research Innovation Center for Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Nanjing, 211166, China
- International Joint Laboratory for Drug Target of Critical Illnesses, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China
| | - Feng Han
- Medical Basic Research Innovation Center for Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Nanjing, 211166, China.
- International Joint Laboratory for Drug Target of Critical Illnesses, School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China.
- Institute of Brain Science, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, 211166, China.
- Gusu School, Nanjing Medical University, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, 210019, China.
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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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Zhang S, Xie S, Zheng Y, Chen Z, Xu C. Current advances in rodent drug-resistant temporal lobe epilepsy models: Hints from laboratory studies. Neurochem Int 2024; 174:105699. [PMID: 38382810 DOI: 10.1016/j.neuint.2024.105699] [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: 12/19/2023] [Revised: 01/23/2024] [Accepted: 02/18/2024] [Indexed: 02/23/2024]
Abstract
Anti-seizure drugs (ASDs) are the first choice for the treatment of epilepsy, but there is still one-third of patients with epilepsy (PWEs) who are resistant to two or more appropriately chosen ASDs, named drug-resistant epilepsy (DRE). Temporal lobe epilepsy (TLE), a common type of epilepsy usually associated with hippocampal sclerosis (HS), shares the highest proportion of drug resistance (approximately 70%). In view of the key role of the temporal lobe in memory, emotion, and other physiological functions, patients with drug-resistant temporal lobe epilepsy (DR-TLE) are often accompanied by serious complications, and surgical procedures also yield extra considerations. The exact mechanisms for the genesis of DR-TLE remain unillustrated, which makes it hard to manage patients with DR-TLE in clinical practice. Animal models of DR-TLE play an irreplaceable role in both understanding the mechanism and searching for new therapeutic strategies or drugs. In this review article, we systematically summarized different types of current DR-TLE models, and then recent advances in mechanism investigations obtained in these models were presented, especially with the development of advanced experimental techniques and tools. We are deeply encouraged that novel strategies show great therapeutic potential in those DR-TLE models. Based on the big steps reached from the bench, a new light has been shed on the precise management of DR-TLE.
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Affiliation(s)
- Shuo Zhang
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Shengyang Xie
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China
| | - Yang Zheng
- Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhong Chen
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cenglin Xu
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
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Kloc ML, Chen Y, Daglian JM, Holmes GL, Baram TZ, Barry JM. Spatial learning impairments and discoordination of entorhinal-hippocampal circuit coding following prolonged febrile seizures. Hippocampus 2023; 33:970-992. [PMID: 37096324 PMCID: PMC10529121 DOI: 10.1002/hipo.23541] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 03/30/2023] [Accepted: 04/08/2023] [Indexed: 04/26/2023]
Abstract
How the development and function of neural circuits governing learning and memory are affected by insults in early life remains poorly understood. The goal of this study was to identify putative changes in cortico-hippocampal signaling mechanisms that could lead to learning and memory deficits in a clinically relevant developmental pathophysiological rodent model, Febrile status epilepticus (FSE). FSE in both pediatric cases and the experimental animal model, is associated with enduring physiological alterations of the hippocampal circuit and cognitive impairment. Here, we deconstruct hippocampal circuit throughput by inducing slow theta oscillations in rats under urethane anesthesia and isolating the dendritic compartments of CA1 and dentate gyrus subfields, their reception of medial and lateral entorhinal cortex inputs, and the efficacy of signal propagation to each somatic cell layer. We identify FSE-induced theta-gamma decoupling at cortical synaptic input pathways and altered signal phase coherence along the CA1 and dentate gyrus somatodendritic axes. Moreover, increased DG synaptic activity levels are predictive of poor cognitive outcomes. We propose that these alterations in cortico-hippocampal coordination interfere with the ability of hippocampal dendrites to receive, decode and propagate neocortical inputs. If this frequency-specific syntax is necessary for cortico-hippocampal coordination and spatial learning and memory, its loss could be a mechanism for FSE cognitive comorbidities.
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Affiliation(s)
- Michelle L. Kloc
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Yuncai Chen
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
- Departments of Anatomy/Neurobiology, University California-Irvine, Irvine, California, USA
| | - Jennifer M. Daglian
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
| | - Gregory L. Holmes
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Tallie Z. Baram
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
- Departments of Anatomy/Neurobiology, University California-Irvine, Irvine, California, USA
- Departments of Neurology, University California-Irvine, Irvine, California, USA
| | - Jeremy M. Barry
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
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Wang Y, Wei P, Yan F, Luo Y, Zhao G. Animal Models of Epilepsy: A Phenotype-oriented Review. Aging Dis 2022; 13:215-231. [PMID: 35111370 PMCID: PMC8782545 DOI: 10.14336/ad.2021.0723] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/23/2021] [Indexed: 12/26/2022] Open
Abstract
Epilepsy is a serious neurological disorder characterized by abnormal, recurrent, and synchronous discharges in the brain. Long-term recurrent seizure attacks can cause serious damage to brain function, which is usually observed in patients with temporal lobe epilepsy. Controlling seizure attacks is vital for the treatment and prognosis of epilepsy. Animal models, such as the kindling model, which was the most widely used model in the past, allow the understanding of the potential epileptogenic mechanisms and selection of antiepileptic drugs. In recent years, various animal models of epilepsy have been established to mimic different seizure types, without clear merits and demerits. Accordingly, this review provides a summary of the views mentioned above, aiming to provide a reference for animal model selection.
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Affiliation(s)
- Yilin Wang
- 2Institute of Cerebrovascular Diseases Research and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Penghu Wei
- 1Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, Beijing, China.,4Clinical Research Center for Epilepsy Capital Medical University, Beijing, China
| | - Feng Yan
- 2Institute of Cerebrovascular Diseases Research and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yumin Luo
- 2Institute of Cerebrovascular Diseases Research and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,3Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,4Clinical Research Center for Epilepsy Capital Medical University, Beijing, China
| | - Guoguang Zhao
- 1Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, Beijing, China.,3Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,4Clinical Research Center for Epilepsy Capital Medical University, Beijing, China
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Buchanan GF. Staving Off the Heat With Microglia. Epilepsy Curr 2021; 21:295-297. [PMID: 34690572 PMCID: PMC8512919 DOI: 10.1177/15357597211017138] [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: 11/16/2022] Open
Abstract
Microglial Displacement of GABAergic Synapses Is a Protective Event During
Complex Febrile Seizures Wan Y, Feng B, You Y, et al. Cell Reports. 2020;33(5):108346.
doi:10.1016/j.celrep.2020.108346 Complex febrile seizures (FSs) lead to a high risk of intractable temporal lobe
epilepsy during adulthood, yet the pathological process of complex FSs is largely
unknown. Here, we demonstrate that activated microglia extensively associated with
glutamatergic neuronal soma displace surrounding GABAergic presynapses in complex FSs.
Patch clamp electrophysiology establishes that the microglial displacement of
GABAergic presynapses abrogates a complex-FS-induced increase in GABAergic
neurotransmission and neuronal excitability, whereas GABA exerts an excitatory action
in this immature stage. Pharmacological inhibition of microglial displacement of
GABAergic presynapses or selective ablation of microglia in CD11bDTR mice
promotes the generation of complex FSs. Blocking or deleting the P2Y12
receptor (P2Y12R) reduces microglial displacement of GABAergic presynapses
and shortens the latency of complex FSs. Together, microglial displacement of
GABAergic presynapses, regulated by P2Y12R, reduces neuronal excitability
to mitigate the generation of complex FSs. Microglial displacement is a protective
event during the pathological process of complex FSs.
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