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Cao Y, Sun C, Huang J, Sun P, Wang L, He S, Liao J, Lu Z, Lu Y, Zhong C. Dysfunction of the Hippocampal-Lateral Septal Circuit Impairs Risk Assessment in Epileptic Mice. Front Mol Neurosci 2022; 15:828891. [PMID: 35571372 PMCID: PMC9103201 DOI: 10.3389/fnmol.2022.828891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 03/29/2022] [Indexed: 11/16/2022] Open
Abstract
Temporal lobe epilepsy, a chronic disease of the brain characterized by degeneration of the hippocampus, has impaired risk assessment. Risk assessment is vital for survival in complex environments with potential threats. However, the underlying mechanisms remain largely unknown. The intricate balance of gene regulation and expression across different brain regions is related to the structure and function of specific neuron subtypes. In particular, excitation/inhibition imbalance caused by hyperexcitability of glutamatergic neurons and/or dysfunction of GABAergic neurons, have been implicated in epilepsy. First, we estimated the risk assessment (RA) by evaluating the behavior of mice in the center of the elevated plus maze, and found that the kainic acid-induced temporal lobe epilepsy mice were specifically impaired their RA. This experiment evaluated approach-RA, with a forthcoming approach to the open arm, and avoid-RA, with forthcoming avoidance of the open arm. Next, results from free-moving electrophysiological recordings showed that in the hippocampus, ∼7% of putative glutamatergic neurons and ∼15% of putative GABAergic neurons were preferentially responsive to either approach-risk assessment or avoid-risk assessment, respectively. In addition, ∼12% and ∼8% of dorsal lateral septum GABAergic neurons were preferentially responsive to approach-risk assessment and avoid-risk assessment, respectively. Notably, during the impaired approach-risk assessment, the favorably activated dorsal dentate gyrus and CA3 glutamatergic neurons increased (∼9%) and dorsal dentate gyrus and CA3 GABAergic neurons decreased (∼7%) in the temporal lobe epilepsy mice. Then, we used RNA sequencing and immunohistochemical staining to investigate which subtype of GABAergic neuron loss may contribute to excitation/inhibition imbalance. The results show that temporal lobe epilepsy mice exhibit significant neuronal loss and reorganization of neural networks. In particular, the dorsal dentate gyrus and CA3 somatostatin-positive neurons and dorsal lateral septum cholecystokinin-positive neurons are selectively vulnerable to damage after temporal lobe epilepsy. Optogenetic activation of the hippocampal glutamatergic neurons or chemogenetic inhibition of the hippocampal somatostatin neurons directly disrupts RA, suggesting that an excitation/inhibition imbalance in the dHPC dorsal lateral septum circuit results in the impairment of RA behavior. Taken together, this study provides insight into epilepsy and its comorbidity at different levels, including molecular, cell, neural circuit, and behavior, which are expected to decrease injury and premature mortality in patients with epilepsy.
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Affiliation(s)
- Yi Cao
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
- Division of Life Sciences and Medicine, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Chongyang Sun
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Jianyu Huang
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
- Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Peng Sun
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
- College of Electronic and Information Engineering, Hebei University, Baoding, China
| | - Lulu Wang
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Shuyu He
- Shenzhen Children’s Hospital, China Medical University, Shenzhen, China
| | - Jianxiang Liao
- Epilepsy Center, Shenzhen Children’s Hospital, Shenzhen, China
| | - Zhonghua Lu
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Yi Lu
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
- Yi Lu,
| | - Cheng Zhong
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
- *Correspondence: Cheng Zhong,
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Comorbidities of early-onset temporal epilepsy: Cognitive, social, emotional, and morphologic dimensions. Exp Neurol 2019; 320:113005. [PMID: 31278943 DOI: 10.1016/j.expneurol.2019.113005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/16/2019] [Accepted: 07/02/2019] [Indexed: 02/06/2023]
Abstract
Epilepsy, the most common neurologic disorder in childhood, is associated with a subset of psychiatric dysfunctions, including cognitive deficits, and alterations in emotionality (e.g., anxiety and depression) and social functioning. In the present study, we evaluated an integrative set of behavioral responses, including cognitive/socio-cognitive and emotional dimensions, using a number of behavioral paradigms in the LiCl/pilocarpine model of status epilepticus (SE) in rats. The aims of the study were to examine whether SE affects: 1) non-associative learning (habituation of exploratory behavior); 2) investigatory response to an indifferent stimulus object; 3) sociability/social novelty preference; 4) social recognition or discrimination; and 4) short- and long-term memory in the Morris water maze (MWM). Finally, we investigated the morphology of key brain structures involved in the examined behavioral dysfunctions. SE did not affect habituation to an open-field arena in juvenile (P25), adolescent (P32), or adult (P80) rats. SE rats spent less time in the central part of the arena. SE adolescent rats (P32) displayed a higher number of rearings with a shorter duration. SE rats displayed a markedly attenuated investigatory response to an indifferent stimulus object. SE rats in all age groups demonstrated pronounced deficits in sociability and the preference for social novelty. In addition, SE rats spent a reduced amount of time investigating a juvenile rat upon first exposure. After 30 min re-exposure together with an additional, novel juvenile, the SE rats spent equal time investigating both juveniles. In the MWM task, acquisition was unimpaired but there was a deficit in delayed memory retention after 10 days. SE did not affect cognitive flexibility expressed by reversal learning. Together, these findings suggest that early-life SE leads to alterations in emotional/anxiety-related behavior and affects sociability/preference for social novelty and social discrimination. Early-life SE did not alter acquisition of spatial learning, but it impaired delayed retention. Using Fluoro Jade B staining performed 24 h after SE revealed apparent neurodegeneration in the dorsal hippocampus, mediodorsal thalamic nucleus and medial amygdala, brain areas that are critically involved in network underlying emotional behavior and cognitive functions.
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Vega-García A, Santana-Gómez CE, Rocha L, Magdaleno-Madrigal VM, Morales-Otal A, Buzoianu-Anguiano V, Feria-Romero I, Orozco-Suárez S. Magnolia officinalis reduces the long-term effects of the status epilepticus induced by kainic acid in immature rats. Brain Res Bull 2019; 149:156-167. [PMID: 30978383 DOI: 10.1016/j.brainresbull.2019.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 04/05/2019] [Indexed: 02/06/2023]
Abstract
During critical periods of neurodevelopment, the immature brain is susceptible to neuronal hyperexcitability, alterations such as hyperthermia, hypoxia, brain trauma or a preexisting neuroinflammatory condition can trigger, promote and prolong epileptiform activity and facilitate the development of epilepsy. The goal of the present study was to evaluate the long-term neuroprotective effects Magnolia officinalis extract, on a model of recurrent status epilepticus (SE) in immature rats. Sprague-Dawley rats were treated with kainic acid (KA) (3 mg/kg, dissolved in saline solution) beginning at day 10 P N every 24 h for five days (10 P N-14PN). Two experimental groups (KA) received two treatments for 10 days (14-24 P N): one group was treated with 300 mg/kg Magnolia Officinalis (MO) (KA-MO), and another was treated with 20 mg/kg of celecoxib (Clbx) (KA-Clbx) as a control drug. A SHAM control group at day 90 P N was established. Seizure susceptibility was analyzed through an after-discharge threshold (ADT) evaluation, and electroencephalographic activity was recorded. The results obtained from the ADT evaluation and the analysis of the electroencephalographic activity under basal conditions showed that the MO and Clbx treatments protected against epileptiform activity, and decreases long-term excitability. All rats in the KA-MO and KA-Clbx groups presented a phase I seizure on the Racine scale, corresponding to the shaking of a wet dog. In contrast, the KA group showed phase V convulsive activity on the Racine scale. Similarly, MO and Clbx exerted neuroprotective effects on hippocampal neurons and reduced gliosis in the same areas. Based on these results, early intervention with MO and Clbx treatments to prevent the inflammatory activity derived from SE in early phases of neurodevelopment exerts neuroprotective effects on epileptogenesis in adult stages.
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Affiliation(s)
- A Vega-García
- Programa de Doctorado del Departamento de Ciencias Biológicas y de la Salud, UAM-I, Universidad Autónoma Metropolitana Campus Iztapalapa, Ciudad de México, Mexico; Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico
| | - C E Santana-Gómez
- Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados, Tlalpan, Ciudad de México, Mexico
| | - L Rocha
- Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados, Tlalpan, Ciudad de México, Mexico
| | - V M Magdaleno-Madrigal
- División de Investigación en Neurociencias, Instituto Nacional de Psiquiatría "Ramón de la Fuente Muñis", Ciudad de México, Mexico
| | - A Morales-Otal
- Área de Neurociencias. Departamento de Neurohistología y Conducta. Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, Mexico
| | - V Buzoianu-Anguiano
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico
| | - I Feria-Romero
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico
| | - S Orozco-Suárez
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, IMSS, Ciudad de México, Mexico.
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Pisani F, Pavlidis E. What is new: Talk about status epilepticus in the neonatal period. Eur J Paediatr Neurol 2018; 22:757-762. [PMID: 29861333 DOI: 10.1016/j.ejpn.2018.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 04/30/2018] [Accepted: 05/20/2018] [Indexed: 10/16/2022]
Abstract
Nowadays, no general consensus was achieved regarding neonatal status epilepticus and its definition. Indeed, different criteria (mainly based on seizure duration) were used. Whereas a recent proposal has been developed to define status epilepticus in older ages, it seems that the peculiar characteristics of neonatal seizures and of the immature brain make difficult to find a tailored definition for this period of life. Achieving a consensus on this entity would mean to make the first step toward a targeted therapeutic strategy of intervention.
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Affiliation(s)
- Francesco Pisani
- Child Neuropsychiatry Unit, Medicine & Surgery Department, University of Parma, Italy
| | - Elena Pavlidis
- Child Neuropsychiatry Unit, Medicine & Surgery Department, University of Parma, Italy.
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Ruiz-Roso MB, Olivares-Álvaro E, Quintela JC, Ballesteros S, Espinosa-Parrilla JF, Ruiz-Roso B, Lahera V, de Las Heras N, Martín-Fernández B. Effects of Low Phytanic Acid-Concentrated DHA on Activated Microglial Cells: Comparison with a Standard Phytanic Acid-Concentrated DHA. Neuromolecular Med 2018; 20:328-342. [PMID: 29846873 DOI: 10.1007/s12017-018-8496-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 05/24/2018] [Indexed: 02/04/2023]
Abstract
Docosahexaenoic acid (DHA, 22:6 n-3) is an essential omega-3 (ω-3) long chain polyunsaturated fatty acid of neuronal membranes involved in normal growth, development, and function. DHA has been proposed to reduce deleterious effects in neurodegenerative processes. Even though, some inconsistencies in findings from clinical and pre-clinical studies with DHA could be attributed to the presence of phytanic acid (PhA) in standard DHA treatments. Thus, the aim of our study was to analyze and compare the effects of a low PhA-concentrated DHA with a standard PhA-concentrated DHA under different neurotoxic conditions in BV-2 activated microglial cells. To this end, mouse microglial BV-2 cells were stimulated with either lipopolysaccharide (LPS) or hydrogen peroxide (H2O2) and co-incubated with DHA 50 ppm of PhA (DHA (PhA:50)) or DHA 500 ppm of PhA (DHA (PhA:500)). Cell viability, superoxide anion (O2-) production, Interleukin 6 (L-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), glutathione peroxidase (GtPx), glutathione reductase (GtRd), Caspase-3, and the brain-derived neurotrophic factor (BDNF) protein expression were explored. Low PhA-concentrated DHA protected against LPS or H2O2-induced cell viability reduction in BV-2 activated cells and O2- production reduction compared to DHA (PhA:500). Low PhA-concentrated DHA also decreased COX-2, IL-6, iNOS, GtPx, GtRd, and SOD-1 protein expression when compared to DHA (PhA:500). Furthermore, low PhA-concentrated DHA increased BDNF protein expression in comparison to DHA (PhA:500). The study provides data supporting the beneficial effect of low PhA-concentrated DHA in neurotoxic injury when compared to a standard PhA-concentrated DHA in activated microglia.
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Affiliation(s)
- María Belén Ruiz-Roso
- Department of Physiology, Faculty of Medicine, Complutense University, 28040, Madrid, Spain
| | - Elena Olivares-Álvaro
- Department of Physiology, Faculty of Medicine, Complutense University, 28040, Madrid, Spain
| | | | - Sandra Ballesteros
- Department of Physiology, Faculty of Medicine, Complutense University, 28040, Madrid, Spain
| | | | - Baltasar Ruiz-Roso
- Department of Nutrition and Bromatology I (Nutrition), Faculty of Pharmacy, Complutense University, 28040, Madrid, Spain
| | - Vicente Lahera
- Department of Physiology, Faculty of Medicine, Complutense University, 28040, Madrid, Spain
| | - Natalia de Las Heras
- Department of Physiology, Faculty of Medicine, Complutense University, 28040, Madrid, Spain
| | - Beatriz Martín-Fernández
- Department of Physiology, Faculty of Medicine, Complutense University, 28040, Madrid, Spain.
- Natac Biotech S.L., 28923, Alcorcón, Madrid, Spain.
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6
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Chen J, Zheng G, Guo H, Shi ZN, Jiang J, Wang XY, Yang X, Liu XY. The effect of metformin treatment on endoplasmic reticulum (ER) stress induced by status epilepticus (SE) via the PERK-eIF2α-CHOP pathway. Bosn J Basic Med Sci 2018; 18:49-54. [PMID: 28686850 DOI: 10.17305/bjbms.2017.2044] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/26/2017] [Accepted: 05/27/2017] [Indexed: 11/16/2022] Open
Abstract
Status epilepticus (SE) is defined as continuous seizure activity lasting more than 5 minutes. It results in neuronal cell death, mediated by endoplasmic reticulum (ER) stress response. Previously, metformin demonstrated neuroprotective effects in primary cortical neurons. In this study, we analyzed the effect of metformin on ER stress via the pro-apoptotic protein kinase RNA-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2α (eIF2α)-C/EBP homologous protein (CHOP) pathway. SE was induced in rats by pentylenetetrazole. Following SE, the rats were treated with salubrinal, GSK2656157, or metformin. In a control group (normal saline) SE was not induced. CHOP, eIF2α, and PERK expression was determined by Western blot; apoptosis was analyzed by TUNEL assay. CHOP expression was significantly increased at 6 and 24 hours following SE. At both time points, eIF2α and PERK levels were also increased. At 6 hours, CHOP expression was significantly reduced in salubrinal, GSK2656157 and metformin groups versus SE group. eIF2α and PERK levels were decreased in metformin compared to SE group. eIF2α expression was markedly decreased in salubrinal versus SE group, while PERK expression was markedly reduced in GSK2656157 versus SE group. At 6 and 24 hours, the apoptosis rate was significantly increased in SE versus control group, while it was significantly reduced in salubrinal, GSK2656157, and metformin groups compared to SE group. The apoptosis rate also decreased in salubrinal group at 24 hours, although not to the extent observed in metformin group. Overall, CHOP expression and apoptosis induced by SE in rats were reduced with metformin. Further studies are required to evaluate the clinical relevance of metformin for patients with SE.
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Affiliation(s)
- Jing Chen
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China.
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Su W, Foster SC, Xing R, Feistel K, Olsen RHJ, Acevedo SF, Raber J, Sherman LS. CD44 Transmembrane Receptor and Hyaluronan Regulate Adult Hippocampal Neural Stem Cell Quiescence and Differentiation. J Biol Chem 2017; 292:4434-4445. [PMID: 28154169 DOI: 10.1074/jbc.m116.774109] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 01/26/2017] [Indexed: 11/06/2022] Open
Abstract
Adult neurogenesis in the hippocampal subgranular zone (SGZ) is involved in learning and memory throughout life but declines with aging. Mice lacking the CD44 transmembrane receptor for the glycosaminoglycan hyaluronan (HA) demonstrate a number of neurological disturbances including hippocampal memory deficits, implicating CD44 in the processes underlying hippocampal memory encoding, storage, or retrieval. Here, we found that HA and CD44 play important roles in regulating adult neurogenesis, and we provide evidence that HA contributes to age-related reductions in neural stem cell (NSC) expansion and differentiation in the hippocampus. CD44-expressing NSCs isolated from the mouse SGZ are self-renewing and capable of differentiating into neurons, astrocytes, and oligodendrocytes. Mice lacking CD44 demonstrate increases in NSC proliferation in the SGZ. This increased proliferation is also observed in NSCs grown in vitro, suggesting that CD44 functions to regulate NSC proliferation in a cell-autonomous manner. HA is synthesized by NSCs and increases in the SGZ with aging. Treating wild type but not CD44-null NSCs with HA inhibits NSC proliferation. HA digestion in wild type NSC cultures or in the SGZ induces increased NSC proliferation, and CD44-null as well as HA-disrupted wild type NSCs demonstrate delayed neuronal differentiation. HA therefore signals through CD44 to regulate NSC quiescence and differentiation, and HA accumulation in the SGZ may contribute to reductions in neurogenesis that are linked to age-related decline in spatial memory.
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Affiliation(s)
- Weiping Su
- From the Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006
| | - Scott C Foster
- From the Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006
| | - Rubing Xing
- From the Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006
| | - Kerstin Feistel
- From the Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006.,Institute of Zoology, University of Hohenheim, Garbenstrasse 30, 70593 Stuttgart, Germany, and
| | | | | | - Jacob Raber
- From the Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006.,Departments of Behavioral Neuroscience.,Neurology and Radiation Medicine, and
| | - Larry S Sherman
- From the Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006, .,Cell, Developmental and Cancer Biology, School of Medicine, Oregon Health and Science University, Portland, Oregon 97239
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Application of the Co-culture Membrane System Pointed to a Protective Role of Catestatin on Hippocampal Plus Hypothalamic Neurons Exposed to Oxygen and Glucose Deprivation. Mol Neurobiol 2016; 54:7369-7381. [PMID: 27815840 DOI: 10.1007/s12035-016-0240-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 10/17/2016] [Indexed: 12/30/2022]
Abstract
Depletion of oxygen and glucose even for brief periods is sufficient to cause cerebral ischemia, which is a predominant worldwide cause of motor deficits with the reduction of life quality and subsequently death. Hence, more insights regarding protective measures against ischemic events are becoming a major research goal. Among the many neuronal factors, N-methyl-D-aspartate receptors (NMDAR), orexinergic neuroreceptors (ORXR), and sympatho-inhibitory neuropeptide catestatin (CST) are widely involved with ischemic episodes. In this study, it was possible to induce in vitro ischemic conditions of the hamster (Mesocricetus auratus) hippocampal and hypothalamic neuronal cultures, grown on a newly compartmentalized membrane system, via oxygen and glucose deprivation (OGD). These cultures displayed notably differentiated NMDARergic and ORXergic receptor expression activities along with evident brain-derived neurotrophic factor (BDNF) plus orexin A (ORX-A) secretion, especially under co-cultured conditions. Interestingly, addition of CST in OGD-insulted hippocampal cells accounted for upregulated GluN1 and ORX1R transcripts that in the case of the latter neuroreceptor was very strongly (p < 0.001) increased when co-cultured with hypothalamic cells. Similarly, hypothalamic neurons supplied very evident upregulations of GluN1, ORX1R, and above all of GluN2A transcripts along with increased BDNF and ORX-A secretion in the presence of hippocampal cells. Overall, the preferential CST effects on BDNF plus ORX-A production together with altered NMDAR and ORXR levels, especially in co-cultured hypothalamic cells pointed to ORX-containing neurons as major protective constituents against ischemic damages thus opening new scenarios on the cross-talking roles of CST during ischemic disorders.
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Raijmakers M, Clynen E, Smisdom N, Nelissen S, Brône B, Rigo JM, Hoogland G, Swijsen A. Experimental febrile seizures increase dendritic complexity of newborn dentate granule cells. Epilepsia 2016; 57:717-26. [PMID: 27020476 DOI: 10.1111/epi.13357] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2016] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Febrile seizures (FS) are fever-associated convulsions, being the most common seizure disorder in early childhood. A subgroup of these children later develops epilepsy characterized by a hyperexcitable neuronal network in the hippocampus. Hippocampal excitability is regulated by the hippocampal dentate gyrus (DG) where postnatal neurogenesis occurs. Experimental FS increase the survival of newborn hippocampal dentate granule cells (DGCs), yet the significance of this neuronal subpopulation to the hippocampal network remains unclear. In the current study, we characterized the temporal maturation and structural integration of these post-FS born DGCs in the DG. METHODS Experimental FS were induced in 10-day-old rat pups. The next day, retroviral particles coding for enhanced green fluorescent protein (eGFP) were stereotactically injected in the DG to label newborn cells. Histochemical analyses of eGFP expressing DGCs were performed one, 4, and 8 weeks later and consisted of the following: (1) colocalization with neurodevelopmental markers doublecortin, calretinin, and the mature neuronal marker NeuN; (2) quantification of dendritic complexity; and (3) quantification of spine density and morphology. RESULTS At neither time point were neurodevelopmental markers differently expressed between FS animals and normothermia (NT) controls. One week after treatment, DGCs from FS animals showed dendrites that were 66% longer than those from NT controls. At 4 and 8 weeks, Sholl analysis of the outer 83% of the molecular layer showed 20-25% more intersections in FS animals than in NT controls (p < 0.01). Although overall spine density was not affected, an increase in mushroom-type spines was observed after 8 weeks. SIGNIFICANCE Experimental FS increase dendritic complexity and the number of mushroom-type spines in post-FS born DGCs, demonstrating a more mature phenotype and suggesting increased incoming excitatory information. The consequences of this hyperconnectivity to signal processing in the DG and the output of the hippocampus remain to be studied.
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Affiliation(s)
- Marjolein Raijmakers
- Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium.,Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Elke Clynen
- Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Nick Smisdom
- Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium.,Flemish Institute for Technological Research, Environmental Risk and Health Unit, Mol, Belgium
| | - Sofie Nelissen
- Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Bert Brône
- Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Jean-Michel Rigo
- Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
| | - Govert Hoogland
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ann Swijsen
- Biomedical Research Institute BIOMED, Hasselt University, Hasselt, Belgium
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10
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Pavlidis E, Spagnoli C, Pelosi A, Mazzotta S, Pisani F. Neonatal status epilepticus: differences between preterm and term newborns. Eur J Paediatr Neurol 2015; 19:314-9. [PMID: 25613545 DOI: 10.1016/j.ejpn.2015.01.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 12/02/2014] [Accepted: 01/04/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Despite the many studies on neonatal seizures, neonatal status epilepticus (NSE) remains a controversial entity, with no general consensus about its definition. We report the characteristics of newborns with NSE in order to assess whether they showed homogeneous features or displayed clinical and/or instrumental differences depending on gestational age (GA). Preterm and term neonates were compared and risk factors for adverse outcome evaluated. METHODS From 154 newborns with video-EEG confirmed neonatal seizures admitted to the NICU of Parma University Hospital between January 1999 and December 2012, we collected a cohort of 47 newborns (19 preterm, 28 full-term) with NSE. NSE was defined as continuous seizure activity for at least 30 min or recurrent seizures lasting a total of 30 min without definite return to the baseline neurologic condition between seizures. Outcome was assessed at least at one year. We applied the χ(2) test to compare nominal data, and multivariate logistic regression analysis to determine independent risk factors for adverse outcome. RESULTS Only Apgar scores and neurologic examination (p ≤ .02) were different between the groups. None of the preterm newborns had a favourable outcome compared to 25% of the full-term ones (p = .032). Moreover, 52.6% of preterm neonates died compared to 17.8% of the full-term newborns (p = .01; OR = 5.11). The only variable related to outcome was Apgar score at 5 min (p = .02). CONCLUSION Newborns with NSE represented a quite homogeneous group regardless of the GA. Outcome was unfavourable in most of the subjects; however adverse outcome and death were more represented in preterm newborns.
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Affiliation(s)
- Elena Pavlidis
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Italy.
| | - Carlotta Spagnoli
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Italy
| | - Annalisa Pelosi
- Psychometrics, Neuroscience Department, University of Parma, Italy
| | - Silvia Mazzotta
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Italy
| | - Francesco Pisani
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Italy
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Iyengar SS, LaFrancois JJ, Friedman D, Drew LJ, Denny CA, Burghardt NS, Wu MV, Hsieh J, Hen R, Scharfman HE. Suppression of adult neurogenesis increases the acute effects of kainic acid. Exp Neurol 2015; 264:135-49. [PMID: 25476494 PMCID: PMC4800819 DOI: 10.1016/j.expneurol.2014.11.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 11/10/2014] [Accepted: 11/20/2014] [Indexed: 01/17/2023]
Abstract
Adult neurogenesis, the generation of new neurons in the adult brain, occurs in the hippocampal dentate gyrus (DG) and the olfactory bulb (OB) of all mammals, but the functions of these new neurons are not entirely clear. Originally, adult-born neurons were considered to have excitatory effects on the DG network, but recent studies suggest a net inhibitory effect. Therefore, we hypothesized that selective removal of newborn neurons would lead to increased susceptibility to the effects of a convulsant. This hypothesis was tested by evaluating the response to the chemoconvulsant kainic acid (KA) in mice with reduced adult neurogenesis, produced either by focal X-irradiation of the DG, or by pharmacogenetic deletion of dividing radial glial precursors. In the first 4 hrs after KA administration, when mice have the most robust seizures, mice with reduced adult neurogenesis had more severe convulsive seizures, exhibited either as a decreased latency to the first convulsive seizure, greater number of convulsive seizures, or longer convulsive seizures. Nonconvulsive seizures did not appear to change or they decreased. Four-21 hrs after KA injection, mice with reduced adult neurogenesis showed more interictal spikes (IIS) and delayed seizures than controls. Effects were greater when the anticonvulsant ethosuximide was injected 30 min prior to KA administration; ethosuximide allows forebrain seizure activity to be more easily examined in mice by suppressing seizures dominated by the brainstem. These data support the hypothesis that reduction of adult-born neurons increases the susceptibility of the brain to effects of KA.
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Affiliation(s)
- Sloka S Iyengar
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962
| | - John J LaFrancois
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962
| | - Daniel Friedman
- Department of Neurology, New York University Langone Medical Center, New York, NY 10016
| | - Liam J Drew
- WIBR, University College of London, London, UK WC1E 6BT
| | - Christine A Denny
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, NY 10032
| | - Nesha S Burghardt
- Department of Psychology, Hunter College, City University of New York, New York, NY 10065
| | - Melody V Wu
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, NY 10032
| | - Jenny Hsieh
- Department of Molecular Neurobiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - René Hen
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, NY 10032; Department of Molecular Neurobiology, University of Texas Southwestern Medical Center, Dallas, TX 75390; New York State Psychiatric Institute, New York, NY 10032
| | - Helen E Scharfman
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962; Departments of Child & Adolescent Psychiatry, Physiology & Neuroscience, and Psychiatry, New York University Langone Medical Center, New York, NY 10016.
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12
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Chen J, Guo H, Zheng G, Shi ZN. Region-specific vulnerability to endoplasmic reticulum stress-induced neuronal death in rat brain after status epilepticus. J Biosci 2014; 38:877-86. [PMID: 24296890 DOI: 10.1007/s12038-013-9391-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We sought to clarify the involvement and the intra-cerebral distribution variability of C/EBP homologous protein (CHOP), a representative molecule related to endoplasmic reticulum (ER) stress-induced cell death signalling pathways, in neuronal death resulting from status epilepticus in rats. The expression patterns of CHOP and glucose-regulated protein (GRP) 78, a good marker of ER stress, were assessed by Western blotting, real-time PCR, Hoechst and immunohistochemistry in the hippocampus, cortex and striatum on a status epilepticus (SE) model. Double-fluorescent staining of CHOP and the terminal deoxynucleotidyl transferase-mediated DNA nick-end labelling (TUNEL) method were performed to clarify the involvement of CHOP in cell death. SE resulted in a timedependent increase in the expression of GRP78 and CHOP. The expression of GRP78 protein was increased at 3, 6 and 12 h after SE and no brain region variability was found. The expression of CHOP protein was also increased, reached its peak at 24 h and remained high at 48 h. CHOP protein expression, however, showed brain region variability with highest expression noted in the hippocampus followed by the striatum, and lowest in the cortex. The up-regulation of CHOP occurring at the transcriptional level was demonstrated by real-time PCR. Double fluorescence showed that CHOP expression strongly correlated with neurons undergoing apoptosis. The results indicated that SE compromises the function of the ER and that the hippocampus is more vulnerable than the cortex and the striatum.
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Affiliation(s)
- Jing Chen
- Department of Neurology, Nanjing Children's Hospital Affiliated to Nanjing Medical University, No. 72, Guangzhou Road, Gu Lou District, Nanjing 210008, People's Republic of China
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Galanopoulou AS, Moshé SL. Does epilepsy cause a reversion to immature function? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 813:195-209. [PMID: 25012378 DOI: 10.1007/978-94-017-8914-1_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Seizures have variable effects on brain. Numerous studies have examined the consequences of seizures, in light of the way that these may alter the susceptibility of the brain to seizures, promote epileptogenesis, or functionally alter brain leading to seizure-related comorbidities. In many -but not all- situations, seizures shift brain function towards a more immature state, promoting the birth of newborn neurons, altering the dendritic structure and neuronal connectivity, or changing neurotransmitter signaling towards more immature patterns. These effects depend upon many factors, including the seizure type, age of seizure occurrence, sex, and brain region studied. Here we discuss some of these findings proposing that these seizure-induced immature features do not simply represent rejuvenation of the brain but rather a de-synchronization of the homeostatic mechanisms that were in place to maintain normal physiology, which may contribute to epileptogenesis or the cognitive comorbidities.
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Affiliation(s)
- Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, The Laboratory of Developmental Epilepsy, Comprehensive Einstein/Montefiore Epilepsy Center, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Kennedy Center Rm 306, Bronx, NY, 10461, USA,
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