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Jain S, LaFrancois JJ, Gerencer K, Botterill JJ, Kennedy M, Criscuolo C, Scharfman HE. Increasing adult-born neurons protects mice from epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.08.548217. [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 life-long seizures (epilepsy), we asked if increasing adult-born neurons would prevent epilepsy. Adult-born neurons were 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-CreERT2 Bax fl/fl mice. Six weeks after tamoxifen administration, severe seizures (status epilepticus; SE) were induced by injection of the convulsant pilocarpine. After mice developed epilepsy, seizure frequency was quantified for 3 weeks. Mice with increased adult-born neurons exhibited fewer chronic seizures. Postictal depression was reduced also. These results were primarily in female mice, possibly because they were the more affected by Bax deletion than males, consistent with sex differences in Bax. The female mice with enhanced adult-born neurons 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 hilar cell types are implicated in epileptogenesis. The results suggest that selective Bax deletion to increase adult-born neurons 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
- Current address: Department of Psychology, The University of Maine, Orono, ME 04469
| | - Justin J. Botterill
- Department of Anatomy, Physiology, & Pharmacology, College of Medicine, 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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Huang S, Dong W, Lin X, Xu K, Li K, Xiong S, Wang Z, Nie X, Bian JS. Disruption of the Na +/K +-ATPase-purinergic P2X7 receptor complex in microglia promotes stress-induced anxiety. Immunity 2024; 57:495-512.e11. [PMID: 38395698 DOI: 10.1016/j.immuni.2024.01.018] [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: 03/30/2023] [Revised: 11/15/2023] [Accepted: 01/29/2024] [Indexed: 02/25/2024]
Abstract
Na+/K+-ATPase (NKA) plays an important role in the central nervous system. However, little is known about its function in the microglia. Here, we found that NKAα1 forms a complex with the purinergic P2X7 receptor (P2X7R), an adenosine 5'-triphosphate (ATP)-gated ion channel, under physiological conditions. Chronic stress or treatment with lipopolysaccharide plus ATP decreased the membrane expression of NKAα1 in microglia, facilitated P2X7R function, and promoted microglia inflammatory activation via activation of the NLRP3 inflammasome. Accordingly, global deletion or conditional deletion of NKAα1 in microglia under chronic stress-induced aggravated anxiety-like behavior and neuronal hyperexcitability. DR5-12D, a monoclonal antibody that stabilizes membrane NKAα1, improved stress-induced anxiety-like behavior and ameliorated neuronal hyperexcitability and neurogenesis deficits in the ventral hippocampus of mice. Our results reveal that NKAα1 limits microglia inflammation and may provide a target for the treatment of stress-related neuroinflammation and diseases.
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Affiliation(s)
- Songqiang Huang
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| | - Wanting Dong
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China
| | - Xiaoqian Lin
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| | - Kangtai Xu
- Department of Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| | - Kun Li
- Department of Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| | - Siping Xiong
- Department of Pathology, the Eighth Affiliated Hospital of Sun Yat-Sen University, Shenzhen 518033, Guangdong, China
| | - Zilong Wang
- Department of Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
| | - Xiaowei Nie
- Key Laboratory of Shenzhen Respiratory Disease, Shenzhen Institute of Respiratory Disease, Shenzhen People's Hospital (the First Affiliated Hospital of Southern University of Science and Technology, the Second Clinical Medical College of Jinan University), Shenzhen 518020, Guangdong, China.
| | - Jin-Song Bian
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
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Brigo F, Zelano J, Abraira L, Bentes C, Ekdahl CT, Lattanzi S, Ingvar Lossius M, Redfors P, Rouhl RPW, Russo E, Sander JW, Vogrig A, Wickström R. Proceedings of the "International Congress on Structural Epilepsy & Symptomatic Seizures" (STESS, Gothenburg, Sweden, 29-31 March 2023). Epilepsy Behav 2024; 150:109538. [PMID: 38039602 DOI: 10.1016/j.yebeh.2023.109538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 12/03/2023]
Affiliation(s)
- Francesco Brigo
- Innovation, Research and Teaching Service (SABES-ASDAA), Teaching Hospital of the Paracelsus Medical Private University (PMU), Bolzano, Italy.
| | - Johan Zelano
- Department of Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden; Institute of Neuroscience and Physiology, Department of Clinical Neuroscience, Sahlgrenska Academy, Gothenburg University, Sweden; Wallenberg Center of Molecular and Translational Medicine, Gothenburg University, Sweden
| | - Laura Abraira
- Neurology Department, Epilepsy Unit, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain; Epilepsy Unit, Neurology Department, Vall d'Hebron University Hospital, Barcelona, Spain; Epilepsy Research Group, Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain
| | - Carla Bentes
- Neurophysiological Monitoring Unit - EEG/Sleep Laboratory, Refractory Epilepsy Reference Centre (member of EpiCARE), Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal; Centro de Estudos Egas Moniz, Faculty of Medicine, Lisbon University, Lisbon, Portugal
| | - Christine T Ekdahl
- Division of Clinical Neurophysiology and Department of Clinical Sciences, Lund University, Sweden; Lund Epilepsy Center, Department of Clinical Sciences, Lund University, Sweden
| | - Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Morten Ingvar Lossius
- National Centre for Epilepsy, Division of Clinical Neuroscience, Oslo University Hospital, Member of the ERN EpiCARE, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Petra Redfors
- Department of Neurology, Member of the ERN EpiCARE, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Rob P W Rouhl
- Department of Neurology, Maastricht University Medical Centre+, Maastricht, The Netherlands; Academic Centre for Epileptology Kempenhaeghe/MUMC+ Heeze and Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Emilio Russo
- Science of Health Department, University Magna Grecia of Catanzaro, Italy
| | - Josemir W Sander
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK; Centre for Epilepsy, Chalfont St Peter, Bucks., SL9 0RJ, United Kingdom; Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede 2103 SW, The Netherlands; Neurology Department, West of China Hospital, Sichuan University, Chengdu 610041, China
| | - Alberto Vogrig
- Department of Medicine (DAME), University of Udine, Udine, Italy; Clinical Neurology, Department of Head-Neck and Neuroscience, Azienda Sanitaria Universitaria Friuli Centrale (ASU FC), Udine, Italy
| | - Ronny Wickström
- Neuropediatric Unit, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden
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Tyulmenkova A, Zwick A, Dillon T, Isgor C. Progressive generalized tonic-clonic seizures in a transgenic mouse model of adult-onset epilepsy: Implications for morphological changes in cortico-limbic and brainstem structures. Epilepsy Res 2023; 194:107178. [PMID: 37295319 PMCID: PMC10527249 DOI: 10.1016/j.eplepsyres.2023.107178] [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: 03/17/2023] [Revised: 05/21/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Video/cortical electroencephalography (EEG) is monitored to assess progressive severity of generalized tonic clonic seizures (GTCSs) in a transgenic mouse model of adult-onset epilepsy with increased death risk. The mice overexpress the brain derived neurotrophic factor (BDNF) in the forebrain under the calcium/calmodulin dependent protein kinase 2a (termed TgBDNF) and develop GTCSs in response to tail suspension/cage agitation stimulation at 3-4 months of age. With successive GTCSs (a total of 16 across 10 weeks of assessment), seizures became more severe as evidenced by increased duration of postictal generalized EEG suppression (PGES) associated with loss of posture/consciousness. Mice also developed spike wave discharges with behavioral arrest during the seizure recovery that increased in duration as a function of number of GTCSs. Overall seizure duration (from preictal spike to offset of PGES) and ictal spectral power (full spectra) were also increased. Half of the TgBDNF mice expired following a long period of PGES at the last recorded GTCS. Seizure-evoked general arousal impairment was associated with a striking decrease in total number of gigantocellular neurons of the brainstem nucleus pontis oralis along with increase in volumes of the anterior cingulate cortex and dorsal dentate gyrus in severely convulsive TgBDNF mice compared to litter-matched WT controls and non-convulsive TgBDNF mice. The latter effect was accompanied with an increase in total number of hippocampal granule neurons. These results provide structure-function associations in an animal model of adult-onset GTCSs that progressively increase in severity with clinical relevance for sudden unexpected death following generalized seizures.
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Affiliation(s)
- Anastasia Tyulmenkova
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Amanda Zwick
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Tashi Dillon
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Ceylan Isgor
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
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Chen L, Xu Y, Cheng H, Li Z, Lai N, Li M, Ruan Y, Zheng Y, Fei F, Xu C, Ma J, Wang S, Gu Y, Han F, Chen Z, Wang Y. Adult-born neurons in critical period maintain hippocampal seizures via local aberrant excitatory circuits. Signal Transduct Target Ther 2023; 8:225. [PMID: 37280192 DOI: 10.1038/s41392-023-01433-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 03/15/2023] [Accepted: 04/06/2023] [Indexed: 06/08/2023] Open
Abstract
Temporal lobe epilepsy (TLE), one common type of medically refractory epilepsy, is accompanied with altered adult-born dentate granule cells (abDGCs). However, the causal role of abDGCs in recurrent seizures of TLE is not fully understood. Here, taking advantage of optogenetic and chemogenetic tools to selectively manipulate abDGCs in a reversible manner, combined with Ca2+ fiber photometry, trans-synaptic viral tracing, in vivo/vitro electrophysiology approaches, we aimed to test the role of abDGCs born at different period of epileptogenic insult in later recurrent seizures in mouse TLE models. We found that abDGCs were functionally inhibited during recurrent seizures. Optogenetic activation of abDGCs significantly extended, while inhibition curtailed, the seizure duration. This seizure-modulating effect was attributed to specific abDGCs born at a critical early phase after kindled status, which experienced specific type of circuit re-organization. Further, abDGCs extended seizure duration via local excitatory circuit with early-born granule cells (ebDGCs). Repeated modulation of "abDGC-ebDGC" circuit may easily induce a change of synaptic plasticity, and achieve long-term anti-seizure effects in both kindling and kainic acid-induced TLE models. Together, we demonstrate that abDGCs born at a critical period of epileptogenic insult maintain seizure duration via local aberrant excitatory circuits, and inactivation of these aberrant circuits can long-termly alleviate severity of seizures. This provides a deeper and more comprehensive understanding of the potential pathological changes of abDGCs circuit and may be helpful for the precise treatment in TLE.
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Affiliation(s)
- Liying Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yingwei Xu
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Heming Cheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhongxia Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
- Zhejiang Rehabilitation Medical Center Department, The Third Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China
| | - Nanxi Lai
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Menghan Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yeping Ruan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yang Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Fan Fei
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jiao Ma
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yan Gu
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Feng Han
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China.
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
| | - Yi Wang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China.
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
- Zhejiang Rehabilitation Medical Center Department, The Third Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China.
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6
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Ahmad Hariza AM, Mohd Yunus MH, Murthy JK, Wahab S. Clinical Improvement in Depression and Cognitive Deficit Following Electroconvulsive Therapy. Diagnostics (Basel) 2023; 13:diagnostics13091585. [PMID: 37174977 PMCID: PMC10178332 DOI: 10.3390/diagnostics13091585] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/17/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Electroconvulsive therapy (ECT) is a long-standing treatment choice for disorders such as depression when pharmacological treatments have failed. However, a major drawback of ECT is its cognitive side effects. While numerous studies have investigated the therapeutic effects of ECT and its mechanism, much less research has been conducted regarding the mechanism behind the cognitive side effects of ECT. As both clinical remission and cognitive deficits occur after ECT, it is possible that both may share a common mechanism. This review highlights studies related to ECT as well as those investigating the mechanism of its outcomes. The process underlying these effects may lie within BDNF and NMDA signaling. Edema in the astrocytes may also be responsible for the adverse cognitive effects and is mediated by metabotropic glutamate receptor 5 and the protein Homer1a.
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Affiliation(s)
- Ahmad Mus'ab Ahmad Hariza
- Department of Physiology, Faculty of Medicine, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, Kuala Lumpur 56000, Malaysia
| | - Mohd Heikal Mohd Yunus
- Department of Physiology, Faculty of Medicine, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, Kuala Lumpur 56000, Malaysia
| | - Jaya Kumar Murthy
- Department of Physiology, Faculty of Medicine, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, Kuala Lumpur 56000, Malaysia
| | - Suzaily Wahab
- Department of Psychiatry, Faculty of Medicine, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, Kuala Lumpur 56000, Malaysia
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Li Q, Wang X, Wang ZH, Lin Z, Yang J, Chen J, Wang R, Ye W, Li Y, Wu Y, Xuan A. Changes in dendritic complexity and spine morphology following BCG immunization in APP/PS1 mice. Hum Vaccin Immunother 2022; 18:2121568. [PMID: 36113067 DOI: 10.1080/21645515.2022.2121568] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Bacillus Calmette - Guerin (BCG) is an immune regulator that can enhance hippocampal synaptic plasticity in rats; however, it is unclear whether it can improve synaptic function in a mouse model with Alzheimer's disease (AD). We hypothesized that BCG plays a protective role in AD mice and investigated its effect on dendritic morphology. The results obtained show that BCG immunization significantly increases dendritic complexity, as indicated by the increased number of dendritic intersections and branch points, as well as the increase in the fractal dimension. Furthermore, the number of primary neurites and dendritic length also increased following BCG immunization, which increased the number of spines and promoted maturation. IFN-γ and IL-4 levels increased, while TNF-α levels decreased following BCG immunization; expression levels of p-JAK2, P-STAT3, SYN, and PSD-95 also increased. Therefore, this study demonstrates that BCG immunization in APP/PS1 mice mitigated hippocampal dendritic spine pathology, especially after the third round of immunization. This effect could possibly be attributed to; changes in dendritic arborization and spine morphology or increases in SYN and PSD-95 expression levels. It could also be related to mechanisms of BCG-induced increases in IFN-γ or IL-4/JAK2/STAT3 levels.
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Affiliation(s)
| | | | | | - Zhenzong Lin
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
| | - Jieyi Yang
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
| | - Jichun Chen
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
| | - Rui Wang
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
| | - Wenfeng Ye
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
| | - Ya Li
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
| | - Yingying Wu
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
| | - Aiguo Xuan
- Department of Anatomy and Neurobiology, Guangzhou Medical University, Guangzhou, PR China
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Dohm-Hansen S, Donoso F, Lucassen PJ, Clarke G, Nolan YM. The gut microbiome and adult hippocampal neurogenesis: A new focal point for epilepsy? Neurobiol Dis 2022; 170:105746. [DOI: 10.1016/j.nbd.2022.105746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 04/13/2022] [Accepted: 04/29/2022] [Indexed: 02/07/2023] Open
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Hoogland G, Raijmakers M, Clynen E, Brône B, Rigo JM, Swijsen A. Experimental early-life febrile seizures cause a sustained increase in excitatory neurotransmission in newborn dentate granule cells. Brain Behav 2022; 12:e2505. [PMID: 35191203 PMCID: PMC8933791 DOI: 10.1002/brb3.2505] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/25/2021] [Accepted: 01/02/2022] [Indexed: 11/25/2022] Open
Abstract
Prolonged febrile seizures (FS) are a risk factor for the development of hippocampal-associated temporal lobe epilepsy. The dentate gyrus is the major gateway to the hippocampal network and one of the sites in the brain where neurogenesis continues postnatally. Previously, we found that experimental FS increase the survival rate and structural integration of newborn dentate granule cells (DGCs). In addition, mature post-FS born DGCs express an altered receptor panel. Here, we aimed to study if these molecular and structural changes are accompanied by an altered cellular functioning. Experimental FS were induced by hyperthermia in 10-days-old Sprague-Dawley rats. Proliferating progenitor cells were labeled the next day by injecting green fluorescent protein expressing retroviral particles bilaterally in the dentate gyri. Eight weeks later, spontaneous excitatory and inhibitory postsynaptic events (sEPSCs and sIPSCs, respectively) were recorded from labeled DGCs using the whole-cell patch-clamp technique. Experimental FS resulted in a robust decrease of the inter event interval (p < .0001) and a small decrease of the amplitude of sEPSCs (p < .001). Collectively the spontaneous excitatory charge transfer increased (p < .01). Experimental FS also slightly increased the frequency of sIPSCs (p < .05), while the amplitude of these events decreased strongly (p < .0001). The net inhibitory charge transfer remained unchanged. Experimental, early-life FS have a long-term effect on post-FS born DGCs, as they display an increased spontaneous excitatory input when matured. It remains to be established if this presents a mechanism for FS-induced epileptogenesis.
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Affiliation(s)
- Govert Hoogland
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Marjolein Raijmakers
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Neurophysiology Lab, Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Elke Clynen
- Neurophysiology Lab, Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Bert Brône
- Neurophysiology Lab, Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Jean-Michel Rigo
- Neurophysiology Lab, Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Ann Swijsen
- Neurophysiology Lab, Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
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Myo-Inositol Limits Kainic Acid-Induced Epileptogenesis in Rats. Int J Mol Sci 2022; 23:ijms23031198. [PMID: 35163126 PMCID: PMC8835653 DOI: 10.3390/ijms23031198] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 01/09/2023] Open
Abstract
Epilepsy is a severe neurological disease characterized by spontaneous recurrent seizures (SRS). A complex pathophysiological process referred to as epileptogenesis transforms a normal brain into an epileptic one. Prevention of epileptogenesis is a subject of intensive research. Currently, there are no clinically approved drugs that can act as preventive medication. Our previous studies have revealed highly promising antiepileptogenic properties of a compound-myo-inositol (MI) and the present research broadens previous results and demonstrates the long-term disease-modifying effect of this drug, as well as the amelioration of cognitive comorbidities. For the first time, we show that long-term treatment with MI: (i) decreases the frequency and duration of electrographic SRS in the hippocampus; (ii) has an ameliorating effect on spatial learning and memory deficit associated with epileptogenesis, and (iii) attenuates cell loss in the hippocampus. MI treatment also alters the expression of the glial fibrillary acidic protein, LRRC8A subunit of volume-regulated anion channels, and protein tyrosine phosphatase receptor type R, all expected to counteract the epileptogenesis. All these effects are still present even 4 weeks after MI treatment ceased. This suggests that MI may exert multiple actions on various epileptogenesis-associated changes in the brain and, therefore, could be considered as a candidate target for prevention of epileptogenesis.
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11
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Blankers SA, Galea LA. Androgens and Adult Neurogenesis in the Hippocampus. ANDROGENS: CLINICAL RESEARCH AND THERAPEUTICS 2021; 2:203-215. [PMID: 35024692 PMCID: PMC8744005 DOI: 10.1089/andro.2021.0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/19/2021] [Indexed: 11/12/2022]
Abstract
Adult neurogenesis in the hippocampus is modulated by steroid hormones, including androgens, in male rodents. In this review, we summarize research showing that chronic exposure to androgens, such as testosterone and dihydrotestosterone, enhances the survival of new neurons in the dentate gyrus of male, but not female, rodents, via the androgen receptor. However, the neurogenesis promoting the effect of androgens in the dentate gyrus may be limited to younger adulthood as it is not evident in middle-aged male rodents. Although direct exposure to androgens in adult or middle age does not significantly influence neurogenesis in female rodents, the aromatase inhibitor letrozole enhances neurogenesis in the hippocampus of middle-aged female mice. Unlike other androgens, androgenic anabolic steroids reduce neurogenesis in the hippocampus of male rodents. Collectively, the research indicates that the ability of androgens to enhance hippocampal neurogenesis in adult rodents is dependent on dose, androgen type, sex, duration, and age. We discuss these findings and how androgens may be influencing neuroprotection, via neurogenesis in the hippocampus, in the context of health and disease.
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Affiliation(s)
- Samantha A. Blankers
- Graduate Program in Neuroscience, The University of British Columbia, Vancouver, Canada
- Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, Canada
| | - Liisa A.M. Galea
- Graduate Program in Neuroscience, The University of British Columbia, Vancouver, Canada
- Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, Canada
- Department of Psychology, The University of British Columbia, Vancouver, Canada
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12
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Alshebib YA, Hori T, Kashiwagi T. HOP protein expression in the hippocampal dentate gyrus is acutely downregulated in a status epilepticus mouse model. IBRO Neurosci Rep 2021; 11:183-193. [PMID: 34766103 PMCID: PMC8569711 DOI: 10.1016/j.ibneur.2021.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 10/19/2021] [Indexed: 12/01/2022] Open
Abstract
Status epilepticus (SE) is a neurological emergency, and delayed management can lead to higher morbidity and mortality. It is thought that prolonged seizures stimulate stem cells in the hippocampus and that epileptogenesis may arise from aberrant connections formed by newly born cells, while others have suggested that the acute neuroinflammation and gliosis often seen in epileptic hippocampi contribute to hyperexcitability and epilepsy development. Previous studies have identified the expression of homeodomain-only protein (HOP) in the hippocampal dentate gyrus (HDG) and the heart. HOP was found to be a regulator of cell proliferation and differentiation during heart development, while it maintains the 'heart conduction system' in adulthood. However, little is known about HOP function in the adult HDG, particularly in the SE setting. Here, a HOP immunohistochemical profile in an SE mouse model was established. A total of 24 adult mice were analyzed 3-10 days following the SE episode, the 'acute phase'. Our findings demonstrate a significant downregulation of HOP and BLBP protein expression in the SE group following SE episodes, while HOP/Ki67 coexpression did not remarkably differ. Furthermore, coexpression of HOP/S100β and HOP/Prox1 was not observed, although we noticed insignificant HOP/DCX coexpression level. The findings of this study show no compelling evidence of proliferation, and newly added neurons were not identified during the acute phase following SE, although HOP protein expression was significantly decreased in the HDG. Similar to its counterpart in the adult heart, this suggests that HOP seems to play a key role in regulating signal conduction in adult hippocampus. Moreover, acute changes in HOP expression following SE could be part of an inflammatory response that could subsequently influence epileptogenicity.
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Key Words
- BLBP, Brain lipid-binding protein
- BrdU, 5-Bromo-2′-deoxyuridine
- Ctrl, control tissue
- DCX, Doublecortin
- EGFP, enhanced green fluorescent protein
- Epileptogenicity
- GCL, granule cell layer
- GFAP, Glial fibrillary acidic protein
- GFP, green fluorescent protein
- HDG, Hippocampal Dentate Gyrus
- HF, Hippocampus Formation
- HOP
- HOP, Homeodomain Only Protein
- Hippocampal Formation
- Homeodomain-Only Protein
- IHC, Immunohistochemistry
- NSC, Neural stem cells
- Neurocardiology
- Prox1, Prospero Homeobox 1
- RGL cell, Radial glia-like cell
- S100β, S100 calcium-binding protein B
- SE, Status Epilepticus
- SGZ, subgranular zone
- SVZ, subventricular zone
- Seizure-induced neuroinflammation
- Status Epileptics
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Affiliation(s)
- YA Alshebib
- Department of Histology and Neuroanatomy, Tokyo Medical University, Tokyo 160-8402, Japan
- Department of Neurosurgery, Tokyo Neurological Center Hospital, Tokyo 134-0088, Japan
| | - Tomokatsu Hori
- Department of Neurosurgery, Tokyo Neurological Center Hospital, Tokyo 134-0088, Japan
| | - Taichi Kashiwagi
- Department of Histology and Neuroanatomy, Tokyo Medical University, Tokyo 160-8402, Japan
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13
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Ermine CM, Nithianantharajah J, O'Brien K, Kauhausen JA, Frausin S, Oman A, Parsons MW, Brait VH, Brodtmann A, Thompson LH. Hemispheric cortical atrophy and chronic microglial activation following mild focal ischemic stroke in adult male rats. J Neurosci Res 2021; 99:3222-3237. [PMID: 34651338 DOI: 10.1002/jnr.24939] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 01/05/2023]
Abstract
Animal modeling has played an important role in our understanding of the pathobiology of stroke. The vast majority of this research has focused on the acute phase following severe forms of stroke that result in clear behavioral deficits. Human stroke, however, can vary widely in severity and clinical outcome. There is a rapidly building body of work suggesting that milder ischemic insults can precipitate functional impairment, including cognitive decline, that continues through the chronic phase after injury. Here we show that a small infarction localized to the frontal motor cortex of rats following injection of endothelin-1 results in an essentially asymptomatic state based on motor and cognitive testing, and yet produces significant histopathological change including remote atrophy and inflammation that persists up to 1 year. While there is understandably a major focus in stroke research on mitigating the acute consequences of primary infarction, these results point to progressive atrophy and chronic inflammation as additional targets for intervention in the chronic phase after injury. The present rodent model provides an important platform for further work in this area.
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Affiliation(s)
- Charlotte M Ermine
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Jess Nithianantharajah
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Katrina O'Brien
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Jessica A Kauhausen
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Stefano Frausin
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Alexander Oman
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Mark W Parsons
- Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia.,Department of Neurology, University of New Wales South Western Clinical School, Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
| | - Vanessa H Brait
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Amy Brodtmann
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia.,Department of Neurology, Austin Health, Melbourne, VIC, Australia.,Eastern Cognitive Disorders Clinic, Eastern Health, Monash University, Clayton, VIC, Australia
| | - Lachlan H Thompson
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
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14
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de Curtis M, Rossetti AO, Verde DV, van Vliet EA, Ekdahl CT. Brain pathology in focal status epilepticus: evidence from experimental models. Neurosci Biobehav Rev 2021; 131:834-846. [PMID: 34517036 DOI: 10.1016/j.neubiorev.2021.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 09/02/2021] [Accepted: 09/05/2021] [Indexed: 12/01/2022]
Abstract
Status Epilepticus (SE) is often a neurological emergency characterized by abnormally sustained, longer than habitual seizures. The new ILAE classification reports that SE "…can have long-term consequences including neuronal death, neuronal injury…depending on the type and duration of seizures". While it is accepted that generalized convulsive SE exerts detrimental effects on the brain, it is not clear if other forms of SE, such as focal non-convulsive SE, leads to brain pathology and contributes to long-term deficits in patients. With the available clinical and experimental data, it is hard to discriminate the specific action of the underlying SE etiologies from that exerted by epileptiform activity. This information is highly relevant in the clinic for better treatment stratification, which may include both medical and surgical intervention for seizure control. Here we review experimental studies of focal SE, with an emphasis on focal non-convulsive SE. We present a repertoire of brain pathologies observed in the most commonly used animal models and attempt to establish a link between experimental findings and human condition(s). The extensive literature on focal SE animal models suggest that the current approaches have significant limitations in terms of translatability of the findings to the clinic. We highlight the need for a more stringent description of SE features and brain pathology in experimental studies in animal models, to improve the accuracy in predicting clinical translation.
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Affiliation(s)
- Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto NeurologicoCarlo Besta, Milano, Italy.
| | - Andrea O Rossetti
- Department of Clinical Neuroscience, University Hospital (CHUV) and University of Lausanne, Lausanne, Switzerland
| | - Diogo Vila Verde
- Epilepsy Unit, Fondazione IRCCS Istituto NeurologicoCarlo Besta, Milano, Italy
| | - Erwin A van Vliet
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, P.O. Box 94246, 1090 GE, Amsterdam, the Netherlands; Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, the Netherlands
| | - Christine T Ekdahl
- Division of Clinical Neurophysiology, Lund University, Sweden; Lund Epilepsy Center, Dept Clinical Sciences, Lund University, Sweden
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15
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Fernandez-Muñoz B, Garcia-Delgado AB, Arribas-Arribas B, Sanchez-Pernaute R. Human Neural Stem Cells for Cell-Based Medicinal Products. Cells 2021; 10:2377. [PMID: 34572024 PMCID: PMC8469920 DOI: 10.3390/cells10092377] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 12/15/2022] Open
Abstract
Neural stem cells represent an attractive tool for the development of regenerative therapies and are being tested in clinical trials for several neurological disorders. Human neural stem cells can be isolated from the central nervous system or can be derived in vitro from pluripotent stem cells. Embryonic sources are ethically controversial and other sources are less well characterized and/or inefficient. Recently, isolation of NSC from the cerebrospinal fluid of patients with spina bifida and with intracerebroventricular hemorrhage has been reported. Direct reprogramming may become another alternative if genetic and phenotypic stability of the reprogrammed cells is ensured. Here, we discuss the advantages and disadvantages of available sources of neural stem cells for the production of cell-based therapies for clinical applications. We review available safety and efficacy clinical data and discuss scalability and quality control considerations for manufacturing clinical grade cell products for successful clinical application.
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Affiliation(s)
- Beatriz Fernandez-Muñoz
- Cellular Reprogramming and Production Unit, Andalusian Network for the Design and Translation of Advanced Therapies, 41092 Sevilla, Spain; (A.B.G.-D.); (B.A.-A.)
| | - Ana Belen Garcia-Delgado
- Cellular Reprogramming and Production Unit, Andalusian Network for the Design and Translation of Advanced Therapies, 41092 Sevilla, Spain; (A.B.G.-D.); (B.A.-A.)
| | - Blanca Arribas-Arribas
- Cellular Reprogramming and Production Unit, Andalusian Network for the Design and Translation of Advanced Therapies, 41092 Sevilla, Spain; (A.B.G.-D.); (B.A.-A.)
- Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - Rosario Sanchez-Pernaute
- Cellular Reprogramming and Production Unit, Andalusian Network for the Design and Translation of Advanced Therapies, 41092 Sevilla, Spain; (A.B.G.-D.); (B.A.-A.)
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16
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Chen L, Wang Y, Chen Z. Adult Neurogenesis in Epileptogenesis: An Update for Preclinical Finding and Potential Clinical Translation. Curr Neuropharmacol 2021; 18:464-484. [PMID: 31744451 PMCID: PMC7457402 DOI: 10.2174/1570159x17666191118142314] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 10/31/2019] [Accepted: 11/18/2019] [Indexed: 12/22/2022] Open
Abstract
Epileptogenesis refers to the process in which a normal brain becomes epileptic, and is characterized by hypersynchronous spontaneous recurrent seizures involving a complex epileptogenic network. Current available pharmacological treatment of epilepsy is generally symptomatic in controlling seizures but is not disease-modifying in epileptogenesis. Cumulative evidence suggests that adult neurogenesis, specifically in the subgranular zone of the hippocampal dentate gyrus, is crucial in epileptogenesis. In this review, we describe the pathological changes that occur in adult neurogenesis in the epileptic brain and how adult neurogenesis is involved in epileptogenesis through different interventions. This is followed by a discussion of some of the molecular signaling pathways involved in regulating adult neurogenesis, which could be potential druggable targets for epileptogenesis. Finally, we provide perspectives on some possible research directions for future studies.
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Affiliation(s)
- Liying Chen
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
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17
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Ceanga M, Guenther M, Ingrisch I, Kunze A. Characterization of Hippocampal Adult-borne Granule Cells in a Transient Cerebral Ischemia Model. Bio Protoc 2021; 11:e3890. [PMID: 33732779 DOI: 10.21769/bioprotoc.3890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 11/02/2022] Open
Abstract
Long-term consequences of stroke significantly impair the quality of life in a growing population of stroke survivors. Hippocampal adult neurogenesis has been hypothesized to play a role in the pathophysiology of cognitive and neuropsychiatric long-term sequelae of stroke. Reliable animal models of stroke are paramount to understanding their biomechanisms and to advancing therapeutic strategies. We present a detailed protocol of a transient cerebral ischemia model which does not cause direct ischemic damage in the hippocampus, allowing investigations into the pathophysiology of long-term neurocognitive deficits of stroke. Furthermore, we describe a protocol for obtaining acute hippocampal slices for the purpose of electrophysiological and morphological characterization of adult-borne granule cells. Particularities relating to performing electrophysiological recordings from small cells, such as immature adult-borne granule cells, are also discussed. The present protocol may be complemented by multi-modal investigations (behavioral, morpho-structural, biochemical), to hopefully facilitate research and advances into the long-term sequelae of stroke and the discovery of new therapeutic opportunities.
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Affiliation(s)
- Mihai Ceanga
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum, Jena, Germany
| | - Madlen Guenther
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum, Jena, Germany
| | - Ina Ingrisch
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum, Jena, Germany
| | - Albrecht Kunze
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum, Jena, Germany
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18
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19
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Lourenço DM, Ribeiro-Rodrigues L, Sebastião AM, Diógenes MJ, Xapelli S. Neural Stem Cells and Cannabinoids in the Spotlight as Potential Therapy for Epilepsy. Int J Mol Sci 2020; 21:E7309. [PMID: 33022963 PMCID: PMC7582633 DOI: 10.3390/ijms21197309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/28/2020] [Accepted: 09/30/2020] [Indexed: 01/18/2023] Open
Abstract
Epilepsy is one of the most common brain diseases worldwide, having a huge burden in society. The main hallmark of epilepsy is the occurrence of spontaneous recurrent seizures, having a tremendous impact on the lives of the patients and of their relatives. Currently, the therapeutic strategies are mostly based on the use of antiepileptic drugs, and because several types of epilepsies are of unknown origin, a high percentage of patients are resistant to the available pharmacotherapy, continuing to experience seizures overtime. Therefore, the search for new drugs and therapeutic targets is highly important. One key aspect to be targeted is the aberrant adult hippocampal neurogenesis (AHN) derived from Neural Stem Cells (NSCs). Indeed, targeting seizure-induced AHN may reduce recurrent seizures and shed some light on the mechanisms of disease. The endocannabinoid system is a known modulator of AHN, and due to the known endogenous antiepileptic properties, it is an interesting candidate for the generation of new antiepileptic drugs. However, further studies and clinical trials are required to investigate the putative mechanisms by which cannabinoids can be used to treat epilepsy. In this manuscript, we will review how cannabinoid-induced modulation of NSCs may promote neural plasticity and whether these drugs can be used as putative antiepileptic treatment.
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Affiliation(s)
- Diogo M. Lourenço
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Leonor Ribeiro-Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Ana M. Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Maria J. Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
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20
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Hwang Y, Kim HC, Shin EJ. Enhanced neurogenesis is involved in neuroprotection provided by rottlerin against trimethyltin-induced delayed apoptotic neuronal damage. Life Sci 2020; 262:118494. [PMID: 32991881 DOI: 10.1016/j.lfs.2020.118494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/12/2020] [Accepted: 09/20/2020] [Indexed: 12/26/2022]
Abstract
AIMS We here investigated the effect of late- and post-ictal treatment with rottlerin, a polyphenol compound isolated from Mallotus philippinensis, on delayed apoptotic neuronal death induced by trimethyltin (TMT) in mice. MAIN METHODS Male C57BL/6N mice received a single injection of TMT (2.4 mg/kg, i.p.), and mice were treated with rottlerin after a peak time (i.e., 2 d post-TMT) of convulsive behaviors and apoptotic cell death (5.0 mg/kg, i.p. at 3 and 4 d after TMT injection). Object location test and tail suspension test were performed at 5 d after TMT injection. In addition, changes in the expression of apoptotic and neurogenic markers in the dentate gyrus were examined. KEY FINDINGS Late- and post-ictal treatment with rottlerin suppressed delayed neuronal apoptosis in the dentate gyrus, and attenuated memory impairments (as evaluated by object location test) and depression-like behaviors (as evaluated by tail suspension test) at 5 days after TMT injection in mice. In addition, rottlerin enhanced the expression of Sox2 and DCX, and facilitated p-ERK expression in BrdU-incorporated cells in the dentate gyrus of TMT-treated mice. Rottlerin also increased p-Akt expression, and attenuated the increase in the ratio of pro-apoptotic factors/anti-apoptotic factors, and consequent cytosolic cytochrome c release and caspase-3 cleavage. Rottlerin-mediated action was significantly reversed by SL327, an ERK inhibitor. SIGNIFICANCE Our results suggest that late- and post-ictal treatment with rottlerin attenuates TMT-induced delayed neuronal apoptosis in the dentate gyrus of mice via promotion of neurogenesis and inhibition of an on-going apoptotic process through up-regulation of p-ERK.
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Affiliation(s)
- Yeonggwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea.
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea.
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21
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Abstract
AbstractEpilepsy is a chronic neurological disorder that has an extensive impact on a patient’s life. Accumulating evidence has suggested that inflammation participates in the progression of spontaneous and recurrent seizures. Pro-convulsant incidences can stimulate immune cells, augment the release of pro-inflammatory cytokines, elicit neuronal excitation as well as blood-brain barrier (BBB) dysfunction, and finally trigger the generation or recurrence of seizures. Understanding the pathogenic roles of inflammatory mediators, including inflammatory cytokines, cells, and BBB, in epileptogenesis will be beneficial for the treatment of epilepsy. In this systematic review, we performed a literature search on the PubMed database using the following keywords: “epilepsy” or “seizures” or “epileptogenesis”, and “immunity” or “inflammation” or “neuroinflammation” or “damage-associated molecular patterns” or “cytokines” or “chemokines” or “adhesion molecules” or “microglia” or “astrocyte” or “blood-brain barrier”. We summarized the classic inflammatory mediators and their pathogenic effects in the pathogenesis of epilepsy, based on the most recent findings from both human and animal model studies.
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22
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Abstract
In the adult mammalian hippocampus, new neurons arise from stem and progenitor cell division, in a process known as adult neurogenesis. Adult-generated neurons are sensitive to experience and may participate in hippocampal functions, including learning and memory, anxiety and stress regulation, and social behavior. Increasing evidence emphasizes the importance of new neuron connectivity within hippocampal circuitry for understanding the impact of adult neurogenesis on brain function. In this Review, we discuss how the functional consequences of new neurons arise from the collective interactions of presynaptic and postsynaptic neurons, glial cells, and the extracellular matrix, which together form the "tetrapartite synapse."
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Affiliation(s)
- Elise C Cope
- Princeton Neuroscience Institute and Department of Psychology, Princeton University, Princeton, NJ 08544, USA
| | - Elizabeth Gould
- Princeton Neuroscience Institute and Department of Psychology, Princeton University, Princeton, NJ 08544, USA.
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23
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Hanin A, Lambrecq V, Denis JA, Imbert-Bismut F, Rucheton B, Lamari F, Bonnefont-Rousselot D, Demeret S, Navarro V. Cerebrospinal fluid and blood biomarkers of status epilepticus. Epilepsia 2019; 61:6-18. [PMID: 31828792 DOI: 10.1111/epi.16405] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/12/2019] [Accepted: 11/12/2019] [Indexed: 12/28/2022]
Abstract
Status epilepticus is a condition resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms that lead to abnormally prolonged seizures and require urgent administration of antiepileptic drugs. Refractory status epilepticus requires anesthetics drugs and may lead to brain injury with molecular and cellular alterations (eg, inflammation, and neuronal and astroglial injury) that could induce neurologic sequels and further development of epilepsy. Outcome scores based on demographic, clinical, and electroencephalography (EEG) condition are available, allowing prediction of the risk of mortality, but the severity of brain injury in survivors is poorly evaluated. New biomarkers are needed to predict with higher accuracy the outcome of patients admitted with status in an intensive care unit. Here, we summarize the findings of studies from patients and animal models of status epilepticus. Specific protein markers can be detected in the cerebrospinal fluid and the blood. One of the first described markers of neuronal death is the neuron-specific enolase. Gliosis resulting from inflammatory responses after status can be detected through the increase of S100-beta, or some cytokines, like the High Mobility Group Box 1. Other proteins, like progranulin may reflect the neuroprotective mechanisms resulting from the brain adaptation to excitotoxicity. These new biomarkers aim to prospectively identify the severity and development of disability, and subsequent epilepsy of patients with status. We discuss the advantages and disadvantages of each biomarker, by evaluating their brain specificity, stability in the fluids, and sensitivity to external interferences, such as hemolysis. Finally, we emphasize the need for further development and validation of such biomarkers in order to better assess patients with severe status epilepticus.
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Affiliation(s)
- Aurélie Hanin
- Brain and Spine Institute, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Virginie Lambrecq
- Brain and Spine Institute, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France.,Epilepsy Unit (VL, VN) and Neuro-Intensive care Unit (SD), Neurology Department, AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France.,Sorbonne Université, Paris, France
| | - Jérôme Alexandre Denis
- Sorbonne Université, Paris, France.,Department of Endocrine and Oncological Biochemistry (J.AD), Metabolic Biochemistry (BR, DBR, FI, FL), AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Françoise Imbert-Bismut
- Department of Endocrine and Oncological Biochemistry (J.AD), Metabolic Biochemistry (BR, DBR, FI, FL), AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Benoît Rucheton
- Department of Endocrine and Oncological Biochemistry (J.AD), Metabolic Biochemistry (BR, DBR, FI, FL), AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Foudil Lamari
- Department of Endocrine and Oncological Biochemistry (J.AD), Metabolic Biochemistry (BR, DBR, FI, FL), AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Dominique Bonnefont-Rousselot
- Department of Endocrine and Oncological Biochemistry (J.AD), Metabolic Biochemistry (BR, DBR, FI, FL), AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France.,UTCBS, U 1022 Inserm, UMR 8258 CNRS, Paris University, Paris, France
| | - Sophie Demeret
- Epilepsy Unit (VL, VN) and Neuro-Intensive care Unit (SD), Neurology Department, AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Vincent Navarro
- Brain and Spine Institute, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France.,Epilepsy Unit (VL, VN) and Neuro-Intensive care Unit (SD), Neurology Department, AP-HP, GH Pitié-Salpêtrière-Charles Foix, Paris, France.,Sorbonne Université, Paris, France
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24
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Abstract
Compelling evidence indicates that hippocampal dentate granule cells are generated throughout human life and into old age. While animal studies demonstrate that these new neurons are important for memory function, animal research also implicates these cells in the pathogenesis of temporal lobe epilepsy. Several recent preclinical studies in rodents now suggest that targeting these new neurons can have disease-modifying effects in epilepsy.
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Affiliation(s)
- Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Anesthesia, University of Cincinnati, Cincinnati, OH, USA.,Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Center for Pediatric Neuroscience, Cincinnati Children's Hospital, Cincinnati, OH, USA
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25
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Jain S, LaFrancois JJ, Botterill JJ, Alcantara-Gonzalez D, Scharfman HE. Adult neurogenesis in the mouse dentate gyrus protects the hippocampus from neuronal injury following severe seizures. Hippocampus 2019; 29:683-709. [PMID: 30672046 PMCID: PMC6640126 DOI: 10.1002/hipo.23062] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/29/2018] [Accepted: 11/30/2018] [Indexed: 01/20/2023]
Abstract
Previous studies suggest that reducing the numbers of adult-born neurons in the dentate gyrus (DG) of the mouse increases susceptibility to severe continuous seizures (status epilepticus; SE) evoked by systemic injection of the convulsant kainic acid (KA). However, it was not clear if the results would be the same for other ways to induce seizures, or if SE-induced damage would be affected. Therefore, we used pilocarpine, which induces seizures by a different mechanism than KA. Also, we quantified hippocampal damage after SE. In addition, we used both loss-of-function and gain-of-function methods in adult mice. We hypothesized that after loss-of-function, mice would be more susceptible to pilocarpine-induced SE and SE-associated hippocampal damage, and after gain-of-function, mice would be more protected from SE and hippocampal damage after SE. For loss-of-function, adult neurogenesis was suppressed by pharmacogenetic deletion of dividing radial glial precursors. For gain-of-function, adult neurogenesis was increased by conditional deletion of pro-apoptotic gene Bax in Nestin-expressing progenitors. Fluoro-Jade C (FJ-C) was used to quantify neuronal injury and video-electroencephalography (video-EEG) was used to quantify SE. Pilocarpine-induced SE was longer in mice with reduced adult neurogenesis, SE had more power and neuronal damage was greater. Conversely, mice with increased adult-born neurons had shorter SE, SE had less power, and there was less neuronal damage. The results suggest that adult-born neurons exert protective effects against SE and SE-induced neuronal injury.
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Affiliation(s)
- Swati Jain
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - John J. LaFrancois
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - Justin J. Botterill
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - David Alcantara-Gonzalez
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - Helen E. Scharfman
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
- Departments of Child & Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, New York Langone Medical Center, New York, NY 10016, USA
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26
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Lambert K, Eisch AJ, Galea LAM, Kempermann G, Merzenich M. Optimizing brain performance: Identifying mechanisms of adaptive neurobiological plasticity. Neurosci Biobehav Rev 2019; 105:60-71. [PMID: 31356835 DOI: 10.1016/j.neubiorev.2019.06.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 06/18/2019] [Accepted: 06/24/2019] [Indexed: 01/19/2023]
Abstract
Although neuroscience research has debunked the late 19th century claims suggesting that large portions of the brain are typically unused, recent evidence indicates that an enhanced understanding of neural plasticity may lead to greater insights related to the functional capacity of brains. Continuous and real-time neural modifications in concert with dynamic environmental contexts provide opportunities for targeted interventions for maintaining healthy brain functions throughout the lifespan. Neural design, however, is far from simplistic, requiring close consideration of context-specific and other relevant variables from both species and individual perspectives to determine the functional gains from increased and decreased markers of neuroplasticity. Caution must be taken in the interpretation of any measurable change in neurobiological responses or behavioral outcomes, as definitions of optimal functions are extremely complex. Even so, current behavioral neuroscience approaches offer unique opportunities to evaluate adaptive functions of various neural responses in an attempt to enhance the functional capacity of neural systems.
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Affiliation(s)
- Kelly Lambert
- Dept of Psychology, B326 Gottwald Science Center, University of Richmond, VA, 23173, USA.
| | - Amelia J Eisch
- Dept of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104-4399, USA.
| | - Liisa A M Galea
- Dept of Psychology, University of British Columbia, 2136 West Mall, Vancouver, BC V6T, Canada.
| | - Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) Dresden and CRTD-Center for Regenerative Therapies Dresden at Technische Universität Dresden, 01307 Dresden, Germany.
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27
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Targeting Seizure-Induced Neurogenesis in a Clinically Relevant Time Period Leads to Transient But Not Persistent Seizure Reduction. J Neurosci 2019; 39:7019-7028. [PMID: 31308098 DOI: 10.1523/jneurosci.0920-19.2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 11/21/2022] Open
Abstract
Mesial temporal lobe epilepsy (mTLE), the most common form of medically refractory epilepsy in adults, is usually associated with hippocampal pathophysiology. Using rodent models of mTLE, many studies including work from our laboratory have shown that new neurons born around the onset of severe acute seizures known as status epilepticus (SE) are crucial for the process of epileptogenesis and targeting seizure-induced neurogenesis either genetically or pharmacologically can impact the frequency of chronic seizures. However, these studies are limited in their clinical relevance as none of them determines the potential of blocking new neurons generated after the epileptogenic insult to alleviate the development of chronic seizures. Therefore, using a pilocarpine-induced SE model of mTLE in mice of either sex, we show that >4 weeks of continuous and concurrent ablation of seizure-induced neurogenesis after SE can reduce the formation of spontaneous recurrent seizures by 65%. We also found that blocking post-SE neurogenesis does not lead to long-term seizure reduction as the effect was observed only transiently for 10 d with >4 weeks of continuous and concurrent ablation of seizure-induced neurogenesis. Thus, these findings provide evidence that seizure-induced neurogenesis when adequately reduced in a clinically relevant time period has the potential to transiently suppress recurrent seizures, but additional mechanisms need to be targeted to permanently prevent epilepsy development.SIGNIFICANCE STATEMENT Consistent with morphological and electrophysiological studies suggesting aberrant adult-generated neurons contribute to epilepsy development, ablation of seizure-induced new neurons at the time of the initial insult reduces the frequency of recurrent seizures. In this study, we show that continuous targeting of post-insult new neurons in a therapeutically relevant time period reduces chronic seizures; however, this effect does not persist suggesting possible additional mechanisms.
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28
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Kalinina A, Maletta T, Carr J, Lehmann H, Fournier NM. Spatial exploration induced expression of immediate early genes Fos and Zif268 in adult-born neurons Is reduced after pentylenetetrazole kindling. Brain Res Bull 2019; 152:74-84. [PMID: 31279580 DOI: 10.1016/j.brainresbull.2019.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 07/02/2019] [Accepted: 07/02/2019] [Indexed: 01/05/2023]
Abstract
Seizure activity stimulates adult neurogenesis, the birth of new neurons, in the hippocampus. Many new neurons that develop in the presence of repeatedly induced seizures acquire abnormal morphological and functional characteristics that can promote network hyperexcitability and hippocampal dysfunction. However, the impact of seizure induced neurogenesis on behaviour remains poorly understood. In this study, we investigated whether adult-born neurons generated immediately before and during chronic seizures were capable of integration into behaviorally relevant hippocampal networks. Adult rats underwent pentylenetetrazole (PTZ) kindling for either 1 or 2 weeks. Proliferating cells were labelled with BrdU immediately before kindling commenced. Twenty-four hours after receiving their last kindling treatment, rats were placed in a novel environment and allowed to freely explore for 30 min. The rats were euthanized 90 min later to examine for behaviourally-induced immediate early gene expression (c-fos, Zif268). Using this approach, we found that PTZ kindled rats did not differ from control rats in regards to exploratory behaviour, but there was a marked attenuation in behaviour-induced expression of Fos and Zif268 for rats that received 2 weeks of PTZ kindling. Further examination revealed that PTZ kindled rats showed reduced colocalization of Fos and Zif268 in 2.5 week old BrdU + cells. The proportion of immature granule cells (doublecortin-positive) expressing behaviorally induced Zif268 was also significantly lower for PTZ kindled rats than control rats. These results suggest that chronic seizures can potentially disrupt the ability of adult-born cells to functionally integrate into hippocampal circuits important for the processing of spatial information.
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Affiliation(s)
- Alena Kalinina
- Department of Psychology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Teresa Maletta
- Department of Psychology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Joshua Carr
- Department of Psychology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Hugo Lehmann
- Department of Psychology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - Neil M Fournier
- Department of Psychology, Trent University, Peterborough, ON K9J 7B8, Canada.
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29
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A balanced evaluation of the evidence for adult neurogenesis in humans: implication for neuropsychiatric disorders. Brain Struct Funct 2019; 224:2281-2295. [PMID: 31278571 DOI: 10.1007/s00429-019-01917-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 06/25/2019] [Indexed: 12/17/2022]
Abstract
There is a widespread belief that neurogenesis exists in adult human brain, especially in the dentate gyrus, and it is to be maintained and, if possible, augmented with different stimuli including exercise and certain drugs. Here, we examine the evidence for adult human neurogenesis and note important limitations of the methodologies used to study it. A balanced review of the literature and evaluation of the data indicate that adult neurogenesis in human brain is improbable. In fact, in several high-quality recent studies in adult human brain, unlike in adult brains of other species, neurogenesis was not detectable. These findings suggest that the human brain requires a permanent set of neurons to maintain acquired knowledge for decades, which is essential for complex high cognitive functions unique to humans. Thus, stimulation and/or injection of neural stem cells into human brains may not only disrupt brain homeostatic systems, but also disturb normal neuronal circuits. We propose that the focus of research should be the preservation of brain neurons by prevention of damage, not replacement.
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30
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Altered Synaptic Drive onto Birthdated Dentate Granule Cells in Experimental Temporal Lobe Epilepsy. J Neurosci 2019; 39:7604-7614. [PMID: 31270158 DOI: 10.1523/jneurosci.0654-18.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/24/2019] [Accepted: 06/27/2019] [Indexed: 12/29/2022] Open
Abstract
Dysregulated adult hippocampal neurogenesis occurs in many temporal lobe epilepsy (TLE) models. Most dentate granule cells (DGCs) generated in response to an epileptic insult develop features that promote increased excitability, including ectopic location, persistent hilar basal dendrites (HBDs), and mossy fiber sprouting. However, some appear to integrate normally and even exhibit reduced excitability compared to other DGCs. To examine the relationship between DGC birthdate, morphology, and network integration in a model of TLE, we retrovirally birthdated either early-born [EB; postnatal day (P)7] or adult-born (AB; P60) DGCs. Male rats underwent pilocarpine-induced status epilepticus (SE) or sham treatment at P56. Three to six months after SE or sham treatment, we used whole-cell patch-clamp and fluorescence microscopy to record spontaneous excitatory and inhibitory currents from birthdated DGCs. We found that both AB and EB populations of DGCs recorded from epileptic rats received increased excitatory input compared with age-matched controls. Interestingly, when AB populations were separated into normally integrated (normotopic) and aberrant (ectopic or HBD-containing) subpopulations, only the aberrant populations exhibited a relative increase in excitatory input (amplitude, frequency, and charge transfer). The ratio of excitatory-to-inhibitory input was most dramatically upregulated for ectopically localized DGCs. These data provide definitive physiological evidence that aberrant integration of post-SE, AB DGCs contributes to increased synaptic drive and support the idea that ectopic DGCs serve as putative hub cells to promote seizures.SIGNIFICANCE STATEMENT Adult dentate granule cell (DGC) neurogenesis is altered in rodent models of temporal lobe epilepsy (TLE). Some of the new neurons show abnormal morphology and integration, but whether adult-generated DGCs contribute to the development of epilepsy is controversial. We examined the synaptic inputs of age-defined populations of DGCs using electrophysiological recordings and fluorescent retroviral reporter birthdating. DGCs generated neonatally were compared with those generated in adulthood, and adult-born (AB) neurons with normal versus aberrant morphology or integration were examined. We found that AB, ectopically located DGCs exhibit the most pro-excitatory physiological changes, implicating this population in seizure generation or progression.
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31
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Loss CM, da Rosa NS, Mestriner RG, Xavier LL, Oliveira DL. Blockade of GluN2B-containing NMDA receptors reduces short-term brain damage induced by early-life status epilepticus. Neurotoxicology 2019; 71:138-149. [PMID: 30639357 DOI: 10.1016/j.neuro.2019.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 11/22/2018] [Accepted: 01/09/2019] [Indexed: 12/11/2022]
Abstract
Status epilepticus (SE) during developmental periods can cause short- and long-term consequences to the brain. Brain damage induced by SE is associated to NMDA receptors (NMDAR)-mediated excitotoxicity. This study aimed to investigate whether blockade of GluN2B-containing NMDAR is neuroprotective against SE-induced neurodegeneration and neuroinflammation in young rats. Forty-eight Wistar rats (16 days of life) were injected with pilocarpine (60 mg/kg; i.p.) 12-18 h after LiCl (3 mEq/kg; i.p.). Fifteen minutes after pilocarpine administration, animals received i.p. injections of saline solution (0.9% NaCl; SE + SAL group), ketamine (a non-selective and noncompetitive NMDAR antagonist; 25 mg/kg; SE + KET), CI-1041 (a GluN2B-containing NMDAR antagonist; 10 mg/kg; SE + CI group) or CP-101,606 (a NMDAR antagonist with great selectivity for NMDAR composed by GluN1/GluN2B diheteromers; 10 mg/kg; SE + CP group). Seven days after SE, brains were removed for Fluoro-Jade C staining and Iba1/ED1 immunolabeling. GluN2B-containing NMDAR blockade by CI-1041 or CP-101,606 did not terminate LiCl-pilocarpine-induced seizures. SE + SAL group presented intense neurodegeneration and Iba1+/ED1+ double-labeling in hippocampus (CA1 and dentate gyrus; DG) and amygdala (MePV nucleus). Administration of CP-101,606 did not alter this pattern. However, GluN2B-containing NMDAR blockade by CI-1041 reduced neurodegeneration and Iba1+/ED1+ double-labeling in hippocampus and amygdala similar to the reduction observed for SE + KET group. Our results indicate that GluN2B-containing NMDAR are involved in SE-induced neurodegeneration and microglial recruitment and activation, and suggest that stopping epileptic activity is not a condition required to prevent short-term brain damage in young animals.
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Affiliation(s)
- Cássio Morais Loss
- Cellular Neurochemistry Laboratory, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Cellular Biochemistry Laboratory, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
| | - Natã Sehn da Rosa
- Cellular Neurochemistry Laboratory, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Régis Gemerasca Mestriner
- Neurorehabilitation and Neural Repair Research Group, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Léder Leal Xavier
- Laboratory of Cell and Tissue Biology, School of Sciences, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Diogo Losch Oliveira
- Cellular Neurochemistry Laboratory, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
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32
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Stroke Accelerates and Uncouples Intrinsic and Synaptic Excitability Maturation of Mouse Hippocampal DCX + Adult-Born Granule Cells. J Neurosci 2019; 39:1755-1766. [PMID: 30617211 DOI: 10.1523/jneurosci.3303-17.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 11/05/2018] [Accepted: 11/08/2018] [Indexed: 11/21/2022] Open
Abstract
Stroke robustly stimulates adult neurogenesis in the hippocampal dentate gyrus. It is currently unknown whether this process induces beneficial or maladaptive effects, but morphological and behavioral studies have reported aberrant neurogenesis and impaired hippocampal-dependent memory following stroke. However, the intrinsic function and network incorporation of adult-born granule cells (ABGCs) after ischemia is unclear. Using patch-clamp electrophysiology, we evaluated doublecortin-positive (DCX+) ABGCs as well as DCX- dentate gyrus granule cells 2 weeks after a stroke or sham operation in DCX/DsRed transgenic mice of either sex. The developmental status, intrinsic excitability, and synaptic excitability of ABGCs were accelerated following stroke, while dendritic morphology was not aberrant. Regression analysis revealed uncoupled development of intrinsic and network excitability, resulting in young, intrinsically hyperexcitable ABGCs receiving disproportionately large glutamatergic inputs. This aberrant functional maturation in the subgroup of ABGCs in the hippocampus may contribute to defective hippocampal function and increased seizure susceptibility following stroke.SIGNIFICANCE STATEMENT Stroke increases hippocampal neurogenesis but the functional consequences of the postlesional response is mostly unclear. Our findings provide novel evidence of aberrant functional maturation of newly generated neurons following stroke. We demonstrate that stroke not only causes an accelerated maturation of the intrinsic and synaptic parameters of doublecortin-positive, new granule cells in the hippocampus, but that this accelerated development does not follow physiological dynamics due to uncoupled intrinsic and synaptic maturation. Hyperexcitable immature neurons may contribute to disrupted network integration following stroke.
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33
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Beamer EH, Jurado-Arjona J, Jimenez-Mateos EM, Morgan J, Reschke CR, Kenny A, de Leo G, Olivos-Oré LA, Arribas-Blázquez M, Madden SF, Merchán-Rubira J, Delanty N, Farrell MA, O'Brien DF, Avila J, Diaz-Hernandez M, Miras-Portugal MT, Artalejo AR, Hernandez F, Henshall DC, Engel T. MicroRNA-22 Controls Aberrant Neurogenesis and Changes in Neuronal Morphology After Status Epilepticus. Front Mol Neurosci 2018; 11:442. [PMID: 30618601 PMCID: PMC6298134 DOI: 10.3389/fnmol.2018.00442] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022] Open
Abstract
Prolonged seizures (status epilepticus, SE) may drive hippocampal dysfunction and epileptogenesis, at least partly, through an elevation in neurogenesis, dysregulation of migration and aberrant dendritic arborization of newly-formed neurons. MicroRNA-22 was recently found to protect against the development of epileptic foci, but the mechanisms remain incompletely understood. Here, we investigated the contribution of microRNA-22 to SE-induced aberrant adult neurogenesis. SE was induced by intraamygdala microinjection of kainic acid (KA) to model unilateral hippocampal neuropathology in mice. MicroRNA-22 expression was suppressed using specific oligonucleotide inhibitors (antagomir-22) and newly-formed neurons were visualized using the thymidine analog iodo-deoxyuridine (IdU) and a green fluorescent protein (GFP)-expressing retrovirus to visualize the dendritic tree and synaptic spines. Using this approach, we quantified differences in the rate of neurogenesis and migration, the structure of the apical dendritic tree and density and morphology of dendritic spines in newly-formed neurons.SE resulted in an increased rate of hippocampal neurogenesis, including within the undamaged contralateral dentate gyrus (DG). Newly-formed neurons underwent aberrant migration, both within the granule cell layer and into ectopic sites. Inhibition of microRNA-22 exacerbated these changes. The dendritic diameter and the density and average volume of dendritic spines were unaffected by SE, but these parameters were all elevated in mice in which microRNA-22 was suppressed. MicroRNA-22 inhibition also reduced the length and complexity of the dendritic tree, independently of SE. These data indicate that microRNA-22 is an important regulator of morphogenesis of newly-formed neurons in adults and plays a role in supressing aberrant neurogenesis associated with SE.
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Affiliation(s)
- Edward H Beamer
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Jeronimo Jurado-Arjona
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - Eva M Jimenez-Mateos
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - James Morgan
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Cristina R Reschke
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.,FutureNeuro Research Centre, RCSI, Dublin, Ireland
| | - Aidan Kenny
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gioacchino de Leo
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Luis A Olivos-Oré
- Department of Pharmacology and Toxicology, Veterinary Faculty, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, Madrid, Spain
| | - Marina Arribas-Blázquez
- Department of Pharmacology and Toxicology, Veterinary Faculty, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, Madrid, Spain
| | - Stephen F Madden
- Data Science Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Jesús Merchán-Rubira
- Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - Norman Delanty
- FutureNeuro Research Centre, RCSI, Dublin, Ireland.,Beaumont Hospital, Dublin, Ireland
| | | | | | - Jesus Avila
- Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - Miguel Diaz-Hernandez
- Department of Biochemistry and Molecular Biology, Veterinary Faculty, Universidad Complutense de Madrid, Madrid, Spain
| | - M Teresa Miras-Portugal
- Department of Biochemistry and Molecular Biology, Veterinary Faculty, Universidad Complutense de Madrid, Madrid, Spain
| | - Antonio R Artalejo
- Department of Pharmacology and Toxicology, Veterinary Faculty, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, Madrid, Spain
| | - Felix Hernandez
- Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.,FutureNeuro Research Centre, RCSI, Dublin, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.,FutureNeuro Research Centre, RCSI, Dublin, Ireland
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Kubová H, Folbergrová J, Rejchrtová J, Tsenov G, Pařízková M, Burchfiel J, Mikulecká A, Mareš P. The Free Radical Scavenger N-Tert-Butyl-α-Phenylnitrone (PBN) Administered to Immature Rats During Status Epilepticus Alters Neurogenesis and Has Variable Effects, Both Beneficial and Detrimental, on Long-Term Outcomes. Front Cell Neurosci 2018; 12:266. [PMID: 30210297 PMCID: PMC6121067 DOI: 10.3389/fncel.2018.00266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/02/2018] [Indexed: 12/11/2022] Open
Abstract
Status epilepticus (SE), especially in immature animals, is known to produce recurrent spontaneous seizures and behavioral comorbidities later in life. The cause of these adverse long-term outcomes is unknown, but it has been hypothesized that free radicals produced by SE may play a role. We tested this hypothesis by treating immature (P25) rats with the free radical scavenger N-tert-butyl-α-phenylnitrone (PBN) at the time of lithium chloride (LiCl)/pilocarpine (PILO)-induced SE. Later, long-term outcomes were assessed. Cognitive impairment (spatial memory) was tested in the Morris water maze (MWM). Emotional disturbances were assessed by the capture test (aggressiveness) and elevated plus maze's (EPM) test (anxiety). Next, the presence and severity of spontaneous seizures were assessed by continuous video/EEG monitoring for 5 days. Finally, immunochemistry, stereology and morphology were used to assess the effects of PBN on hippocampal neuropathology and neurogenesis. PBN treatment modified the long-term effects of SE in varying ways, some beneficial and some detrimental. Beneficially, PBN protected against severe anatomical damage in the hippocampus and associated spatial memory impairment. Detrimentally, PBN treated animals had more severe seizures later in life. PBN also made animals more aggressive and more anxious. Correlating with these detrimental long-term outcomes, PBN significantly modified post-natal neurogenesis. Treated animals had significantly increased numbers of mature granule cells (GCs) ectopically located in the dentate hilus (DH). These results raise the possibility that abnormal neurogenesis may significantly contribute to the development of post-SE epilepsy and behavioral comorbidities.
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Affiliation(s)
- Hana Kubová
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Jaroslava Folbergrová
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Jana Rejchrtová
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Grygoriy Tsenov
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Martina Pařízková
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - James Burchfiel
- Strong Epilepsy Center, Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
| | - Anna Mikulecká
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Pavel Mareš
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
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35
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Danzer SC. Contributions of Adult-Generated Granule Cells to Hippocampal Pathology in Temporal Lobe Epilepsy: A Neuronal Bestiary. Brain Plast 2018; 3:169-181. [PMID: 30151341 PMCID: PMC6091048 DOI: 10.3233/bpl-170056] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hippocampal neurogenesis continues throughout life in mammals – including humans. During the development of temporal lobe epilepsy, newly-generated hippocampal granule cells integrate abnormally into the brain. Abnormalities include ectopic localization of newborn cells, de novo formation of abnormal basal dendrites, and disruptions of the apical dendritic tree. Changes in granule cell position and dendritic structure fundamentally alter the types of inputs these cells are able to receive, as well as the relative proportions of remaining inputs. Dendritic abnormalities also create new pathways for recurrent excitation in the hippocampus. These abnormalities are hypothesized to contribute to the development of epilepsy, and may underlie cognitive disorders associated with the disease as well. To test this hypothesis, investigators have used pharmacological and genetic strategies in animal models to alter neurogenesis rates, or ablate the newborn cells outright. While findings are mixed and many unanswered questions remain, numerous studies now demonstrate that ablating newborn granule cells can have disease modifying effects in epilepsy. Taken together, findings provide a strong rationale for continued work to elucidate the role of newborn granule cells in epilepsy: both to understand basic mechanisms underlying the disease, and as a potential novel therapy for epilepsy.
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Affiliation(s)
- Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, OH, USA
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36
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Hiragi T, Ikegaya Y, Koyama R. Microglia after Seizures and in Epilepsy. Cells 2018; 7:cells7040026. [PMID: 29597334 PMCID: PMC5946103 DOI: 10.3390/cells7040026] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/24/2018] [Accepted: 03/26/2018] [Indexed: 01/23/2023] Open
Abstract
Microglia are the resident immune cells in the brain that constitute the brain’s innate immune system. Recent studies have revealed various functions of microglia in the development and maintenance of the central nervous system (CNS) in both health and disease. However, the role of microglia in epilepsy remains largely undiscovered, partly because of the complex phenotypes of activated microglia. Activated microglia likely exert different effects on brain function depending on the phase of epileptogenesis. In this review, we mainly focus on the animal models of temporal lobe epilepsy (TLE) and discuss the proepileptic and antiepileptic roles of activated microglia in the epileptic brain. Specifically, we focus on the roles of microglia in the production of inflammatory cytokines, regulation of neurogenesis, and surveillance of the surrounding environment in epilepsy.
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Affiliation(s)
- Toshimitsu Hiragi
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan.
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan.
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan.
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Matsuda T, Hisatsune T. Cholinergic Modification of Neurogenesis and Gliosis Improves the Memory of AβPPswe/PSEN1dE9 Alzheimer's Disease Model Mice Fed a High-Fat Diet. J Alzheimers Dis 2018; 56:1-23. [PMID: 27911310 DOI: 10.3233/jad-160761] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We previously reported that neuroinflammation contributes to the amnesia of AβPPswe/PSEN1dE9 Alzheimer's disease model mice fed a high-fat diet to induce type-2 diabetes (T2DM-AD mice), but the underlying mechanism for the memory decline remained unclear. Recent studies have suggested that cholinergic modulation is involved in neuroinflammatory cellular reactions including neurogenesis and gliosis, and in memory improvement. In this study, we administered a broad-spectrum cholinesterase inhibitor, rivastigmine (2 mg/kg/day, s.c.), into T2DM-AD mice for 6 weeks, and evaluated their memory performance, neurogenesis, and neuroinflammatory reactions. By two hippocampal-dependent memory tests, the Morris water maze and contextual fear conditioning, rivastigmine improved the memory deterioration of the T2DM-AD mice (n = 8, p < 0.01). The number of newborn neurons in the hippocampal dentate gyrus was 1138±324 (Ave±SEM) in wild-type littermates, 2573±442 in T2DM-AD-Vehicle, and 2165±300 in T2DM-AD-Rivastigmine mice, indicating that neurogenesis was accelerated in the two T2DM-AD groups (n = 5, p < 0.05). The dendritic maturation of new neurons in T2DM-AD-Vehicle mice was severely abrogated, and rivastigmine treatment reversed this retarded maturation. In addition, the hippocampus of T2DM-AD-Vehicle mice showed increased proinflammatory cytokines IL-1β and TNF-α and gliosis, and rivastigmine treatment blocked these inflammatory reactions. Rivastigmine did not change the insulin abnormality or amyloid pathology in these mice. Thus, cholinergic modulation by rivastigmine treatment led to enhanced neurogenesis and the suppression of gliosis, which together ameliorated the memory decline in T2DM-AD model mice.
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38
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Navidhamidi M, Ghasemi M, Mehranfard N. Epilepsy-associated alterations in hippocampal excitability. Rev Neurosci 2018; 28:307-334. [PMID: 28099137 DOI: 10.1515/revneuro-2016-0059] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/03/2016] [Indexed: 11/15/2022]
Abstract
The hippocampus exhibits a wide range of epilepsy-related abnormalities and is situated in the mesial temporal lobe, where limbic seizures begin. These abnormalities could affect membrane excitability and lead to overstimulation of neurons. Multiple overlapping processes refer to neural homeostatic responses develop in neurons that work together to restore neuronal firing rates to control levels. Nevertheless, homeostatic mechanisms are unable to restore normal neuronal excitability, and the epileptic hippocampus becomes hyperexcitable or hypoexcitable. Studies show that there is hyperexcitability even before starting recurrent spontaneous seizures, suggesting although hippocampal hyperexcitability may contribute to epileptogenesis, it alone is insufficient to produce epileptic seizures. This supports the concept that the hippocampus is not the only substrate for limbic seizure onset, and a broader hyperexcitable limbic structure may contribute to temporal lobe epilepsy (TLE) seizures. Nevertheless, seizures also occur in conditions where the hippocampus shows a hypoexcitable phenotype. Since TLE seizures most often originate in the hippocampus, it could therefore be assumed that both hippocampal hypoexcitability and hyperexcitability are undesirable states that make the epileptic hippocampal network less stable and may, under certain conditions, trigger seizures.
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39
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Gheorghe A, Qiu W, Galea LAM. Hormonal Regulation of Hippocampal Neurogenesis: Implications for Depression and Exercise. Curr Top Behav Neurosci 2018; 43:379-421. [PMID: 30414016 DOI: 10.1007/7854_2018_62] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Adult hippocampal neurogenesis exists in all mammalian species, including humans, and although there has been considerable research investigating the function and regulation of neurogenesis, there remain many open questions surrounding the complexity of this phenomenon. This stems partially from the fact that neurogenesis is a multistage process that involves proliferation, differentiation, migration, survival, and eventual integration of new cells into the existing hippocampal circuitry, each of which can be independently influenced. The function of adult neurogenesis in the hippocampus is related to stress regulation, behavioral efficacy of antidepressants, long-term spatial memory, forgetting, and pattern separation. Steroid hormones influence the regulation of hippocampal neurogenesis, stress regulation, and cognition and differently in males and females. In this chapter, we will briefly tap into the complex network of steroid hormone modulation of neurogenesis in the hippocampus with specific emphasis on stress, testosterone, and estrogen. We examine the possible role of neurogenesis in the etiology of depression and influencing treatment by examining the influence of both pharmacological (selective serotonin reuptake inhibitors, tricyclic antidepressants) treatments and non-pharmacological (exercise) remedies.
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Affiliation(s)
- Ana Gheorghe
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada
| | - Wansu Qiu
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada
| | - Liisa A M Galea
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada. .,Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada. .,Department of Psychology, University of British Columbia, Vancouver, BC, Canada.
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40
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41
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Magagna-Poveda A, Moretto JN, Scharfman HE. Increased gyrification and aberrant adult neurogenesis of the dentate gyrus in adult rats. Brain Struct Funct 2017; 222:4219-4237. [PMID: 28656372 PMCID: PMC5909844 DOI: 10.1007/s00429-017-1457-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 06/06/2017] [Indexed: 02/08/2023]
Abstract
A remarkable example of maladaptive plasticity is the development of epilepsy after a brain insult or injury to a normal animal or human. A structure that is considered central to the development of this type of epilepsy is the dentate gyrus (DG), because it is normally a relatively inhibited structure and its quiescence is thought to reduce hippocampal seizure activity. This characteristic of the DG is also considered to be important for normal hippocampal-dependent cognitive functions. It has been suggested that the brain insults which cause epilepsy do so because they cause the DG to be more easily activated. One type of brain insult that is commonly used is induction of severe seizures (status epilepticus; SE) by systemic injection of a convulsant drug. Here we describe an alteration in the DG after this type of experimental SE that may contribute to chronic seizures that has not been described before: large folds or gyri that develop in the DG by 1 month after SE. Large gyri appeared to increase network excitability because epileptiform discharges recorded in hippocampal slices after SE were longer in duration when recorded inside gyri relative to locations outside gyri. Large gyri may also increase excitability because immature adult-born neurons accumulated at the base of gyri with time after SE, and previous studies have suggested that abnormalities in adult-born DG neurons promote seizures after SE. In summary, large gyri after SE are a common finding in adult rats, show increased excitability, and are associated with the development of an abnormal spatial distribution of adult-born neurons. Together these alterations may contribute to chronic seizures and associated cognitive comorbidities after SE.
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Affiliation(s)
- Alejandra Magagna-Poveda
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA
| | - Jillian N Moretto
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA
| | - Helen E Scharfman
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA.
- Department of Child and Adolescent Psychiatry, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
- Department of Physiology and Neuroscience, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
- Department of Psychiatry, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
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42
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Lasoń W, Ślusarczyk J, Regulska M, Leśkiewicz M, Basta-Kaim A. Do minocycline and other suppressors of microglia reactivity have a future in prevention or treatment of epilepsy? JOURNAL OF EPILEPTOLOGY 2017. [DOI: 10.1515/joepi-2017-0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
SummaryIntroduction.An increasing body of evidence points to an important role of neuroinflammatory processes in the pathomechanism of epilepsy. This hypothesis is mainly supported by data showing an increase of pro-inflammatory cytokine levels and glia activation in animal models of epilepsy and in brain tissue of epileptic patients. On the other hand, less emphasis has been put on pharmacological verification of this hypothesis.Aim.The aim of this review is to summarize current knowledge on potential usefulness of microglia regulators and anti-inflammatory agents in designing antiepileptic/antiepileptogenic drugs, with the primary mechanism of action based on the inhibition of neuroinflammation.Methods.We reviewed PubMed and MEDLINE databases to select publications in the topic: epilepsy, neuroinflammation, microglia and microglia regulators with antiepileptic properties. We searched the databases up to April 2017 with no date restrictions.Review and Discussion.In the present paper, we will discuss new concepts of epileptogenesis which focus not only on changes in neurons but also take into consideration the role of activation of glial cells: microglia and astrocytes. Neuroinflammation, mainly through increased production of pro-inflammatory factors such as cytokines or chemokines, may play an important role in the development of epilepsy. Drugs regulating glial cells activation and consequently inflammatory status in the central nervous system have beneficial effects in different animal models of epilepsy as well as in clinical study in patients. The most promising compound seems to be minocycline which in some studies has been shown to possess antiepileptogenetic action. On the other hand, some antiepileptic drugs exhibit marked anti-inflammatory potency.Conclusions.There are much data to suggest that there is significant opportunity for designing new antiepileptic drugs whose primary mechanism of action entails the inhibition of neuroinflammatory processes.
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Castro OW, Upadhya D, Kodali M, Shetty AK. Resveratrol for Easing Status Epilepticus Induced Brain Injury, Inflammation, Epileptogenesis, and Cognitive and Memory Dysfunction-Are We There Yet? Front Neurol 2017; 8:603. [PMID: 29180982 PMCID: PMC5694141 DOI: 10.3389/fneur.2017.00603] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 10/30/2017] [Indexed: 12/29/2022] Open
Abstract
Status epilepticus (SE) is a medical emergency exemplified by self-sustaining, unceasing seizures or swiftly recurring seizure events with no recovery between seizures. The early phase after SE event is associated with neurodegeneration, neuroinflammation, and abnormal neurogenesis in the hippocampus though the extent of these changes depends on the severity and duration of seizures. In many instances, over a period, the initial precipitating injury caused by SE leads to temporal lobe epilepsy (TLE), typified by spontaneous recurrent seizures, cognitive, memory and mood impairments associated with chronic inflammation, reduced neurogenesis, abnormal synaptic reorganization, and multiple molecular changes in the hippocampus. While antiepileptic drugs are efficacious for terminating or greatly reducing seizures in most cases of SE, they have proved ineffective for easing SE-induced epileptogenesis and TLE. Despite considerable advances in elucidating SE-induced multiple cellular, electrophysiological, and molecular changes in the brain, efficient strategies that prevent SE-induced TLE development are yet to be discovered. This review critically confers the efficacy and promise of resveratrol, a phytoalexin found in the skin of red grapes, for easing SE-induced neurodegeneration, neuroinflammation, aberrant neurogenesis, and for restraining the evolution of SE-induced brain injury into a chronic epileptic state typified by spontaneous recurrent seizures, and learning, memory, and mood impairments.
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Affiliation(s)
- Olagide W Castro
- Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas, United States.,Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas, United States.,Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Maceio, Brazil
| | - Dinesh Upadhya
- Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas, United States.,Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas, United States.,Department of Anatomy, Kasturba Medical College, Manipal University, Manipal, India
| | - Maheedhar Kodali
- Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas, United States.,Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas, United States
| | - Ashok K Shetty
- Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas, United States.,Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas, United States
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44
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Bielefeld P, Mooney C, Henshall DC, Fitzsimons CP. miRNA-Mediated Regulation of Adult Hippocampal Neurogenesis; Implications for Epilepsy. Brain Plast 2017; 3:43-59. [PMID: 29765859 PMCID: PMC5928558 DOI: 10.3233/bpl-160036] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hippocampal neural stem/progenitor cells (NSPCs) proliferate and differentiate to generate new neurons across the life span of most mammals, including humans. This process takes place within a characteristic local microenvironment where NSPCs interact with a variety of other cell types and encounter systemic regulatory factors. Within this microenvironment, cell intrinsic gene expression programs are modulated by cell extrinsic signals through complex interactions, in many cases involving short non-coding RNA molecules, such as miRNAs. Here we review the regulation of gene expression in NSPCs by miRNAs and its possible implications for epilepsy, which has been linked to alterations in adult hippocampal neurogenesis.
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Affiliation(s)
- Pascal Bielefeld
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, The Netherlands
| | - Catherine Mooney
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - David C. Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Carlos P. Fitzsimons
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, The Netherlands
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Ablation of Newly Generated Hippocampal Granule Cells Has Disease-Modifying Effects in Epilepsy. J Neurosci 2017; 36:11013-11023. [PMID: 27798182 DOI: 10.1523/jneurosci.1371-16.2016] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/21/2016] [Indexed: 12/30/2022] Open
Abstract
Hippocampal granule cells generated in the weeks before and after an epileptogenic brain injury can integrate abnormally into the dentate gyrus, potentially mediating temporal lobe epileptogenesis. Previous studies have demonstrated that inhibiting granule cell production before an epileptogenic brain insult can mitigate epileptogenesis. Here, we extend upon these findings by ablating newly generated cells after the epileptogenic insult using a conditional, inducible diphtheria-toxin receptor expression strategy in mice. Diphtheria-toxin receptor expression was induced among granule cells born up to 5 weeks before pilocarpine-induced status epilepticus and these cells were then eliminated beginning 3 d after the epileptogenic injury. This treatment produced a 50% reduction in seizure frequency, but also a 20% increase in seizure duration, when the animals were examined 2 months later. These findings provide the first proof-of-concept data demonstrating that granule cell ablation therapy applied at a clinically relevant time point after injury can have disease-modifying effects in epilepsy. SIGNIFICANCE STATEMENT These findings support the long-standing hypothesis that newly generated dentate granule cells are pro-epileptogenic and contribute to the occurrence of seizures. This work also provides the first evidence that ablation of newly generated granule cells can be an effective therapy when begun at a clinically relevant time point after an epileptogenic insult. The present study also demonstrates that granule cell ablation, while reducing seizure frequency, paradoxically increases seizure duration. This paradoxical effect may reflect a disruption of homeostatic mechanisms that normally act to reduce seizure duration, but only when seizures occur frequently.
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46
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Brulet R, Zhu J, Aktar M, Hsieh J, Cho KO. Mice with conditional NeuroD1 knockout display reduced aberrant hippocampal neurogenesis but no change in epileptic seizures. Exp Neurol 2017; 293:190-198. [PMID: 28427858 PMCID: PMC5503142 DOI: 10.1016/j.expneurol.2017.04.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/12/2017] [Accepted: 04/14/2017] [Indexed: 12/19/2022]
Abstract
Adult neurogenesis is significantly increased in the hippocampus of rodent models of temporal lobe epilepsy (TLE). These adult-generated neurons have recently been shown to play a contributing role in the development of spontaneous recurrent seizures (SRS). In order to eventually target pro-epileptic adult neurogenesis in the clinical setting, it will be important to identify molecular players involved in the control of aberrant neurogenesis after seizures. Here, we focused on NeuroD1 (ND1), a member of the bHLH family of transcription factors previously shown to play an essential role in the differentiation and maturation of adult-generated neurons in the hippocampus. Wild-type mice treated with pilocarpine to induce status epilepticus (SE) showed a significant up-regulation of NeuroD1+ immature neuroblasts located in both the granule cell layer (GCL), and ectopically localized to the hilar region of the hippocampus. As expected, conditional knockout (cKO) of NeuroD1 in Nestin-expressing stem/progenitors and their progeny led to a reduction in the number of NeuroD1+ adult-generated neurons after pilocarpine treatment compared to WT littermates. Surprisingly, there was no change in SRS in NeuroD1 cKO mice, suggesting that NeuroD1 cKO fails to reduce aberrant neurogenesis below the threshold needed to impact SRS. Consistent with this conclusion, the total number of adult-generated neurons in the pilocarpine model, especially the total number of Prox1+ hilar ectopic granule cells were unchanged after NeuroD1 cKO, suggesting strategies to reduce SRS will need to achieve a greater removal of aberrant adult-generated neurons.
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Affiliation(s)
- Rebecca Brulet
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jingfei Zhu
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Mahafuza Aktar
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jenny Hsieh
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Kyung-Ok Cho
- Department of Pharmacology, Catholic Neuroscience Institute, School of Medicine, The Catholic University of Korea, Seoul 06591, South Korea.
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Ge T, Yang W, Fan J, Li B. Preclinical evidence of ghrelin as a therapeutic target in epilepsy. Oncotarget 2017; 8:59929-59939. [PMID: 28938694 PMCID: PMC5601790 DOI: 10.18632/oncotarget.18349] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/22/2017] [Indexed: 12/17/2022] Open
Abstract
Ghrelin, an orexigenic peptide synthesized by endocrine cells of the gastric mucosa, plays a major role in inhibiting seizures. However, the underlying mechanism of ghrelin's anticonvulsant action is still unclear. Nowadays, there are considerable evidences showing that ghrelin is implicated in various neurophysiological processes, including learning and memory, neuroprotection, neurogenesis, and inflammatory effects. In this review, we will summarize the effects of ghrelin on epilepsy. It may provide a comprehensive picture of the role of ghrelin in epilepsy.
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Affiliation(s)
- Tongtong Ge
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Wei Yang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Jie Fan
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Bingjin Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
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48
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Zhu K, Hu M, Yuan B, Liu JX, Liu Y. Aspirin attenuates spontaneous recurrent seizures in the chronically epileptic mice. Neurol Res 2017; 39:744-757. [PMID: 28481152 DOI: 10.1080/01616412.2017.1326657] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Neuroinflammatory processes are pathologic hallmarks of both experimental and human epilepsy, and could be implicated in the neuronal hyperexcitability. Aspirin represents one of the non-selective nonsteroidal anti-inflammatory drugs with fewer side effects in long-term application. This study was carried out to assess the anti-epileptic effects of aspirin when administered during the chronic stage of temporal lobe epilepsy [TLE] in mice. The alteration of hippocampal neurogenesis was also examined for raising a possible mechanism underlying the protective effect of anti-inflammatory treatment in the TLE. METHODS Two months after pilocarpine-induced status epilepticus, the chronically epileptic mice were treated with aspirin (20 mg, 60 mg or 80 mg/kg) once a day for 10 weeks. Spontaneous recurrent seizures were monitored by video camera for 2 weeks. To evaluate the profile of hippocampal neurogenesis, the newly generated cells in the dentate gyrus were labeled by the proliferation marker BrdU. The newborn neurons that extended axons to CA3 area were visualized by cholera toxin B subunit retrograde tracing. RESULTS Administration of aspirin with a dosage of 60 mg or 80 mg/kg initiated at 2 months after pilocarpine-induced status epilepticus significantly reduced the frequency and duration of spontaneous recurrent seizures. Aspirin treatment also increased the number of newborn neurons with anatomic integration through improving the survival of the newly generated cells. CONCLUSION Aspirin treatment during the chronic stage of TLE could attenuate the spontaneous recurrent seizures in mice. Promotion of hippocampal neurogenesis and inhibition of COX-PGE2 pathway might partly contribute to this anti-epileptic effect. Highlights • Aspirin attenuates spontaneous recurrent seizures of chronically epileptic mice • Aspirin increases neurogenesis of chronically epileptic hippocampus by improving the survival of newly generated cells • Promotion of hippocampal neurogenesis and inhibition of COX-PGE2 pathway might partly contribute to anti-epileptic effects of aspirin.
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Affiliation(s)
- Kun Zhu
- a Institute of Neurobiology , School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center , Xi'an , China
| | - Ming Hu
- a Institute of Neurobiology , School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center , Xi'an , China.,b Department of Human Anatomy, Histology and Embryology , School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center , Xi'an , China
| | - Bo Yuan
- a Institute of Neurobiology , School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center , Xi'an , China
| | - Jian-Xin Liu
- a Institute of Neurobiology , School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center , Xi'an , China
| | - Yong Liu
- a Institute of Neurobiology , School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center , Xi'an , China
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Active Dentate Granule Cells Encode Experience to Promote the Addition of Adult-Born Hippocampal Neurons. J Neurosci 2017; 37:4661-4678. [PMID: 28373391 DOI: 10.1523/jneurosci.3417-16.2017] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/01/2017] [Accepted: 03/05/2017] [Indexed: 01/09/2023] Open
Abstract
The continuous addition of new dentate granule cells (DGCs), which is regulated exquisitely by brain activity, renders the hippocampus plastic. However, how neural circuits encode experiences to affect the addition of adult-born neurons remains unknown. Here, we used endoscopic Ca2+ imaging to track the real-time activity of individual DGCs in freely behaving mice. For the first time, we found that active DGCs responded to a novel experience by increasing their Ca2+ event frequency preferentially. This elevated activity, which we found to be associated with object exploration, returned to baseline by 1 h in the same environment, but could be dishabituated via introduction to a novel environment. To transition seamlessly between environments, we next established a freely controllable virtual reality system for unrestrained mice. We again observed increased firing of active neurons in a virtual enriched environment. Interestingly, multiple novel virtual experiences increased the number of newborn neurons accumulatively compared with a single experience. Finally, optogenetic silencing of existing DGCs during novel environmental exploration perturbed experience-induced neuronal addition. Our study shows that the adult brain conveys novel, enriched experiences to increase the addition of adult-born hippocampal neurons by increasing the firing of active DGCs.SIGNIFICANCE STATEMENT Adult brains are constantly reshaping themselves from synapses to circuits as we encounter novel experiences from moment to moment. Importantly, this reshaping includes the addition of newborn hippocampal neurons. However, it remains largely unknown how our circuits encode experience-induced brain activity to govern the addition of new hippocampal neurons. By coupling in vivo Ca2+ imaging of dentate granule neurons with a novel, unrestrained virtual reality system for rodents, we discovered that a new experience increased firing of active dentate granule neurons rapidly and robustly. Exploration in multiple novel virtual environments, compared with a single environment, promoted dentate activation and enhanced the addition of new hippocampal neurons accumulatively. Finally, silencing this activation optogenetically during novel experiences perturbed experience-induced neuronal addition.
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Zhou Z, Liu T, Sun X, Mu X, Zhu G, Xiao T, Zhao M, Zhao C. CXCR4 antagonist AMD3100 reverses the neurogenesis promoted by enriched environment and suppresses long-term seizure activity in adult rats of temporal lobe epilepsy. Behav Brain Res 2017; 322:83-91. [DOI: 10.1016/j.bbr.2017.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/02/2017] [Accepted: 01/06/2017] [Indexed: 12/16/2022]
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