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Kang W. Factor Structure of the GHQ-12 and Their Applicability to Epilepsy Patients for Screening Mental Health Problems. Healthcare (Basel) 2023; 11:2209. [PMID: 37570449 PMCID: PMC10418596 DOI: 10.3390/healthcare11152209] [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: 07/06/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Epilepsy, a severe neurological disorder impacting approximately 50 million individuals worldwide, is associated with a high prevalence of mental health issues. However, existing research has predominantly examined the relationship between epilepsy and depression or anxiety, neglecting other dimensions of mental health as assessed by factor scores from the general health survey (GHQ), such as the GHQ-12. This study aimed to explore how epilepsy affects both general mental health and specific dimensions of mental health. By employing a factor analysis and a predictive normative modeling approach, the study examined 426 epilepsy patients and 39,171 individuals without epilepsy. The findings revealed that epilepsy patients experienced poorer general mental health and specific aspects of mental health. Consequently, this study highlights the validity of GHQ-12 as a measure of mental health problems in epilepsy patients and emphasizes the importance of considering the impact of epilepsy on various dimensions of mental health, rather than focusing solely on depression or anxiety. Clinicians should incorporate these study results into the development of interventions aimed at enhancing mental well-being in epilepsy patients, ultimately leading to improved outcomes.
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Affiliation(s)
- Weixi Kang
- Department of Brain Sciences, Imperial College London, London W12 0BZ, UK
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2
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Farina MG, Sandhu MRS, Parent M, Sanganahalli BG, Derbin M, Dhaher R, Wang H, Zaveri HP, Zhou Y, Danbolt NC, Hyder F, Eid T. Small loci of astroglial glutamine synthetase deficiency in the postnatal brain cause epileptic seizures and impaired functional connectivity. Epilepsia 2021; 62:2858-2870. [PMID: 34536233 DOI: 10.1111/epi.17072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/03/2021] [Accepted: 09/03/2021] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The astroglial enzyme glutamine synthetase (GS) is deficient in small loci in the brain in adult patients with different types of focal epilepsy; however, the role of this deficiency in the pathogenesis of epilepsy has been difficult to assess due to a lack of sufficiently sensitive and specific animal models. The aim of this study was to develop an in vivo approach for precise and specific deletions of the GS gene in the postnatal brain. METHODS We stereotaxically injected various adeno-associated virus (AAV)-Cre recombinase constructs into the hippocampal formation and neocortex in 22-70-week-old GSflox/flox mice to knock out the GS gene in a specific and focal manner. The mice were subjected to seizure threshold determination, continuous video-electroencephalographic recordings, advanced in vivo neuroimaging, and immunocytochemistry for GS. RESULTS The construct AAV8-glial fibrillary acidic protein-green fluorescent protein-Cre eliminated GS in >99% of astrocytes in the injection center with a gradual return to full GS expression toward the periphery. Such focal GS deletion reduced seizure threshold, caused spontaneous recurrent seizures, and diminished functional connectivity. SIGNIFICANCE These results suggest that small loci of GS deficiency in the postnatal brain are sufficient to cause epilepsy and impaired functional connectivity. Additionally, given the high specificity and precise spatial resolution of our GS knockdown approach, we anticipate that this model will be extremely useful for rigorous in vivo and ex vivo studies of astroglial GS function at the brain-region and single-cell levels.
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Affiliation(s)
- Maxwell G Farina
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Mani Ratnesh S Sandhu
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Maxime Parent
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Basavaraju G Sanganahalli
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Matthew Derbin
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Roni Dhaher
- Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Helen Wang
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Hitten P Zaveri
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Yun Zhou
- Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Niels C Danbolt
- Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Fahmeed Hyder
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA
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3
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Sandhu MRS, Gruenbaum BF, Gruenbaum SE, Dhaher R, Deshpande K, Funaro MC, Lee TSW, Zaveri HP, Eid T. Astroglial Glutamine Synthetase and the Pathogenesis of Mesial Temporal Lobe Epilepsy. Front Neurol 2021; 12:665334. [PMID: 33927688 PMCID: PMC8078591 DOI: 10.3389/fneur.2021.665334] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 03/19/2021] [Indexed: 12/21/2022] Open
Abstract
The enzyme glutamine synthetase (GS), also referred to as glutamate ammonia ligase, is abundant in astrocytes and catalyzes the conversion of ammonia and glutamate to glutamine. Deficiency or dysfunction of astrocytic GS in discrete brain regions have been associated with several types of epilepsy, including medically-intractable mesial temporal lobe epilepsy (MTLE), neocortical epilepsies, and glioblastoma-associated epilepsy. Moreover, experimental inhibition or deletion of GS in the entorhinal-hippocampal territory of laboratory animals causes an MTLE-like syndrome characterized by spontaneous, recurrent hippocampal-onset seizures, loss of hippocampal neurons, and in some cases comorbid depressive-like features. The goal of this review is to summarize and discuss the possible roles of astroglial GS in the pathogenesis of epilepsy.
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Affiliation(s)
| | - Benjamin F Gruenbaum
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL, United States
| | - Shaun E Gruenbaum
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL, United States
| | - Roni Dhaher
- Department of Neurosurgery, New Haven, CT, United States
| | | | - Melissa C Funaro
- Harvey Cushing/John Hay Whitney Medical Library, Yale University, New Haven, CT, United States
| | | | - Hitten P Zaveri
- Department of Neurology, Yale School of Medicine, New Haven, CT, United States
| | - Tore Eid
- Department of Laboratory Medicine, New Haven, CT, United States
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4
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Zhou Y, Eid T, Hassel B, Danbolt NC. Novel aspects of glutamine synthetase in ammonia homeostasis. Neurochem Int 2020; 140:104809. [DOI: 10.1016/j.neuint.2020.104809] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/08/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023]
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5
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Yoshino K, Oda Y, Kimura M, Kimura H, Nangaku M, Shirayama Y, Iyo M. The alterations of glutamate transporter 1 and glutamine synthetase in the rat brain of a learned helplessness model of depression. Psychopharmacology (Berl) 2020; 237:2547-2553. [PMID: 32445055 DOI: 10.1007/s00213-020-05555-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 05/11/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND Although glutamate transmission via astrocytes has been proposed to contribute to the pathophysiology of depression, the precise mechanisms are unknown. Herein, we investigated the levels of glutamate transporter-1 (GLT-1) and glutamine synthetase (GS) of astrocytes in learned helplessness (LH) rats (an animal model of depression) and non-LH rats (an animal model of resilience). METHODS We administered inescapable mild electric shock to rats and then discriminated the LH and non-LH rats by a post-shock test. Almost 55% of the rats acquired LH. We then measured the expressions of GLT-1 and GS in several brain regions of LH and non-LH rats by Western blot analysis. RESULTS The levels of GLT-1 and GS in the CA-1, CA-3, dentate gyrus (DG), medial prefrontal cortex (mPF), and nucleus accumbens (NAc) of the LH group were significantly higher than those of the control group. The GS levels in the amygdala of the LH rats were significantly decreased compared to the controls. There were significant differences in GLT-1 and GS levels between the non-LH and LH rats in the CA-1 and CA-3. CONCLUSIONS These results suggest that the LH rats experienced up-regulations of GLT-1 and GS in the CA-1, CA-3, DG, mPF, and NAc and a down-regulation of GS in the amygdala. It is possible that the effects of the GLT-1 and GS levels on astrocytes in the CA-1 and CA-3 are critical for the differentiation of resilience from vulnerability.
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Affiliation(s)
- Kouhei Yoshino
- Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana Chuou-ku, Chiba, Chiba, 260-8670, Japan
| | - Yasunori Oda
- Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana Chuou-ku, Chiba, Chiba, 260-8670, Japan.
| | - Makoto Kimura
- Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana Chuou-ku, Chiba, Chiba, 260-8670, Japan
| | - Hiroshi Kimura
- Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana Chuou-ku, Chiba, Chiba, 260-8670, Japan
| | - Masahito Nangaku
- Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana Chuou-ku, Chiba, Chiba, 260-8670, Japan
| | - Yukihiko Shirayama
- Department of Psychiatry, Teikyo University Chiba Medical Center, 3426-3 Anesaki, Ichihara, Chiba, 290-0111, Japan
| | - Masaomi Iyo
- Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana Chuou-ku, Chiba, Chiba, 260-8670, Japan
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6
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Alese OO, Ngoupaye GT, Rakgantsho C, Mkhize NV, Zulu S, Mabandla MV. Glutamatergic pathway in depressive-like behavior associated with pentylenetetrazole rat model of epilepsy with history of prolonged febrile seizures. Life Sci 2020; 253:117692. [PMID: 32376271 DOI: 10.1016/j.lfs.2020.117692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/03/2020] [Accepted: 04/16/2020] [Indexed: 11/26/2022]
Abstract
BACKGROUND Depression is the most significant cause of suicide among neuropsychiatric illnesses. Major depression further affects the quality of life in an individual with epilepsy. The treatment of depression in an epileptic patient could be very challenging because of drug selection or the fact that some antiepileptic drugs are known to cause depression. It has been shown that in addition to the known involvement of the serotonergic pathway in depression, the glutamatergic system is also involved in the evolution of the disease, but this knowledge is limited. This study assessed if induction of epilepsy in rats will cause depressive-like behavior, alters the concentrations of metabotropic receptor 5 (mGluR5), glutamate transport protein (GLAST), glutamate synthase (GS) and brain derived neurotrophic factor (BDNF). MATERIALS AND METHOD Epilepsy was induced in rats by injecting Pentylenetetrazole at 35 mg/kg every other day. At kindle, rats were subjected to sucrose preference test (SPT) and forced swim test (FST) and decapitated 4 h later. Hippocampal tissue was collected and the BDNF concentration was measured with ELISA; mGluR5 and GS protein expression was measured using western blot while amygdala tissue was used for GLAST expression with flow cytometry. RESULTS Our results showed that epilepsy leads to depressive-like behavior in rats and alters the glutamatergic system. CONCLUSION Therefore, we conclude that targeting the glutamate pathway may be a good strategy to alleviate depressive-like behavior associated with epilepsy.
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Affiliation(s)
- Oluwole Ojo Alese
- Department of Human Physiology, College of Health Sciences, University of Kwazulu-Natal, South Africa.
| | - Gwladys Temkou Ngoupaye
- Department of Human Physiology, College of Health Sciences, University of Kwazulu-Natal, South Africa
| | - Cleopatra Rakgantsho
- Department of Human Physiology, College of Health Sciences, University of Kwazulu-Natal, South Africa
| | - Nombuso V Mkhize
- Department of Human Physiology, College of Health Sciences, University of Kwazulu-Natal, South Africa
| | - Simo Zulu
- Department of Human Physiology, College of Health Sciences, University of Kwazulu-Natal, South Africa
| | - Musa V Mabandla
- Department of Human Physiology, College of Health Sciences, University of Kwazulu-Natal, South Africa
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7
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Eid T, Lee TSW, Patrylo P, Zaveri HP. Astrocytes and Glutamine Synthetase in Epileptogenesis. J Neurosci Res 2019; 97:1345-1362. [PMID: 30022509 PMCID: PMC6338538 DOI: 10.1002/jnr.24267] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 05/15/2018] [Accepted: 05/22/2018] [Indexed: 12/31/2022]
Abstract
The cellular, molecular, and metabolic mechanisms that underlie the development of mesial temporal lobe epilepsy are incompletely understood. Here we review the role of astrocytes in epilepsy development (a.k.a. epileptogenesis), particularly astrocyte pathologies related to: aquaporin 4, the inwardly rectifying potassium channel Kir4.1, monocarboxylate transporters MCT1 and MCT2, excitatory amino acid transporters EAAT1 and EAAT2, and glutamine synthetase. We propose that inhibition, dysfunction or loss of astrocytic glutamine synthetase is an important causative factor for some epilepsies, particularly mesial temporal lobe epilepsy and glioblastoma-associated epilepsy. We postulate that the regulatory mechanisms of glutamine synthetase as well as the downstream effects of glutamine synthetase dysfunction, represent attractive, new targets for antiepileptogenic interventions. Currently, no antiepileptogenic therapies are available for human use. The discovery of such interventions is important as it will fundamentally change the way we approach epilepsy by preventing the disease from ever becoming manifest after an epileptogenic insult to the brain.
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Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine
- Department of Molecular Medicine, University of Oslo
| | | | - Peter Patrylo
- Department of Physiology, Southern Illinois University School of Medicine
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8
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Mundorf A, Knorr A, Mezö C, Klein C, Beyer DK, Fallgatter AJ, Schwarz M, Freund N. Lithium and glutamine synthetase: Protective effects following stress. Psychiatry Res 2019; 281:112544. [PMID: 31499341 DOI: 10.1016/j.psychres.2019.112544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 12/13/2022]
Abstract
Even though lithium is widely used as treatment for mood disorders, the exact mechanisms of lithium in the brain remain unknown. A potential mechanism affects the downstream target of the Wnt/β-catenin signaling pathway, specifically glutamine synthetase (GS). Here, we investigate the effect of lithium on GS-promoter activity in the brain. Over seven days, B6C3H-Glultm(T2A-LacZ) mice that carry LacZ as a reporter gene fused to the GS-promotor received either daily intraperitoneal injections of lithium carbonate (25 mg/kg) or NaCl, or no treatment. Following histochemical staining of β-galactosidase relative GS-promotor activity was measured by analyzing the intensity of the staining. Furthermore cell counts were conducted. GS-promotor activity was significantly decreased in female compared to male mice. Treatment group differences were only found in male hippocampi, with increased activity after NaCl treatment compared to both the lithium treatment and no treatment. Lithium treatment increased the overall number of cells in the CA1 region in males. Daily injections of NaCl might have been sufficient to induce stress-related GS-promotor activity changes in male mice; however, lithium was able to reverse the effect. Taken together, the current study indicates that lithium acts to prevent stress, rather affecting general GS-promoter activity.
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Affiliation(s)
- Annakarina Mundorf
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University Bochum, Bochum, 44780, Germany; Clinic for Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany
| | - Alexandra Knorr
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University Bochum, Bochum, 44780, Germany
| | - Charlotte Mezö
- Clinic for Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany
| | - Christina Klein
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University Bochum, Bochum, 44780, Germany
| | - Dominik Ke Beyer
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University Bochum, Bochum, 44780, Germany; Clinic for Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany
| | - Andreas J Fallgatter
- Clinic for Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany
| | - Michael Schwarz
- Institute of Pharmacology and Toxicology, University of Tuebingen, Tuebingen, Germany
| | - Nadja Freund
- Division of Experimental and Molecular Psychiatry, Department of Psychiatry, Psychotherapy and Preventive Medicine, LWL University Hospital, Ruhr-University Bochum, Bochum, 44780, Germany; Clinic for Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.
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9
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Effects of Branched-Chain Amino Acid Supplementation on Spontaneous Seizures and Neuronal Viability in a Model of Mesial Temporal Lobe Epilepsy. J Neurosurg Anesthesiol 2019; 31:247-256. [PMID: 29620688 DOI: 10.1097/ana.0000000000000499] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The essential branched-chain amino acids (BCAAs) leucine, isoleucine, and valine have recently emerged as a potential novel treatment for medically refractory epilepsy. Blood-derived BCAAs can readily enter the brain, where they contribute to glutamate biosynthesis and may either suppress or trigger acute seizures. However, the effects of BCAAs on chronic (ie, spontaneous recurrent) seizures and epilepsy-associated neuron loss are incompletely understood. MATERIALS AND METHODS Sixteen rats with mesial temporal lobe epilepsy were randomized into 2 groups that could drink, ad libitum, either a 4% solution of BCAAs in water (n=8) or pure water (n=8). The frequency and relative percent of convulsive and nonconvulsive spontaneous seizures were monitored for a period of 21 days, and the brains were then harvested for immunohistochemical analysis. RESULTS Although the frequency of convulsive and nonconvulsive spontaneous recurrent seizures over a 3-week drinking/monitoring period were not different between the groups, there were differences in the relative percent of convulsive seizures in the first and third week of treatment. Moreover, the BCAA-treated rats had over 25% fewer neurons in the dentate hilus of the hippocampus compared with water-treated controls. CONCLUSIONS Acute BCAA supplementation reduces seizure propagation, whereas chronic oral supplementation with BCAAs worsens seizure propagation and causes neuron loss in rodents with mesial temporal lobe epilepsy. These findings raise the question of whether such supplementation has a similar effect in humans.
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10
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Wang H, Huang Y, Coman D, Munbodh R, Dhaher R, Zaveri HP, Hyder F, Eid T. Network evolution in mesial temporal lobe epilepsy revealed by diffusion tensor imaging. Epilepsia 2017; 58:824-834. [PMID: 28378878 DOI: 10.1111/epi.13731] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2017] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The objective of the present study is to identify novel, time-indexed imaging biomarkers of epileptogenesis in mesial temporal lobe epilepsy (MTLE). METHODS We used high-resolution brain diffusion tensor imaging (DTI) of the translationally relevant methionine sulfoximine (MSO) brain infusion model of MTLE. MSO inhibits astroglial glutamine synthetase, which is deficient in the epileptogenic hippocampal formation of patients with MTLE. MSO-infused (epileptogenic) rats were compared with phosphate-buffered saline (PBS)-infused (nonepileptogenic) rats at early (3-4 days) and late (6-9 weeks) time points during epileptogenesis. RESULTS The epileptogenic rats exhibited significant changes in DTI-measured fractional anisotropy (FA) in numerous brain regions versus nonepileptogenic rats. Changes included decreases and increases in FA in regions such as the entorhinal-hippocampal area, amygdala, corpus callosum, thalamus, striatum, accumbens, and neocortex. The FA changes evolved over time as animals transitioned from early to late epileptogenesis. For example, some areas with significant decreases in FA early in epileptogenesis changed to significant increases late in epileptogenesis. Finally, the FA changes significantly correlated with the seizure load. SIGNIFICANCE Our results suggest (1) that high-resolution DTI can be used for early identification and tracking of the epileptogenic process in MTLE, and (2) that the process identified by DTI is present in multiple brain areas, even though infusion of MSO is restricted to the unilateral entorhinal-hippocampal region.
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Affiliation(s)
- Helen Wang
- Department of Laboratory Medicine, Yale University, New Haven, CT, U.S.A
| | - Yuegao Huang
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, U.S.A
| | - Daniel Coman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, U.S.A
| | - Reshma Munbodh
- School of Informatics, Informatics Forum, University of Edinburgh, Edinburgh, United Kingdom
| | - Roni Dhaher
- Department of Laboratory Medicine, Yale University, New Haven, CT, U.S.A
| | - Hitten P Zaveri
- Department of Neurology, Yale University, New Haven, CT, U.S.A
| | - Fahmeed Hyder
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, U.S.A.,Department of Biomedical Engineering, Yale University, New Haven, CT, U.S.A
| | - Tore Eid
- Department of Laboratory Medicine, Yale University, New Haven, CT, U.S.A
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11
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Albright B, Dhaher R, Wang H, Harb R, Lee TSW, Zaveri H, Eid T. Progressive neuronal activation accompanies epileptogenesis caused by hippocampal glutamine synthetase inhibition. Exp Neurol 2016; 288:122-133. [PMID: 27769717 DOI: 10.1016/j.expneurol.2016.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 09/29/2016] [Accepted: 10/13/2016] [Indexed: 01/01/2023]
Abstract
Loss of glutamine synthetase (GS) in hippocampal astrocytes has been implicated in the causation of human mesial temporal lobe epilepsy (MTLE). However, the mechanism by which the deficiency in GS leads to epilepsy is incompletely understood. Here we ask how hippocampal GS inhibition affects seizure phenotype and neuronal activation during epilepsy development (epileptogenesis). Epileptogenesis was induced by infusing the irreversible GS blocker methionine sulfoximine (MSO) unilaterally into the hippocampal formation of rats. We then used continuous video-intracranial electroencephalogram (EEG) monitoring and c-Fos immunohistochemistry to determine the type of seizures and spatial distribution of neuronal activation early (1-5days postinfusion) and late (16-43days postinfusion) in epileptogenesis. Early in epileptogenesis, seizures were preferentially mild (stage 1-2), activating neurons in the entorhinal-hippocampal area, the basolateral amygdala, the piriform cortex, the midline thalamus, and the anterior olfactory area. Late in epileptogenesis, the seizures were generally more severe (stages 4-5) with neuronal activation extending to the neocortex, the bed nucleus of the stria terminalis, the mediodorsal thalamu\s, and the central nucleus of the amygdala. Our findings demonstrate that inhibition of GS focally in the hippocampal formation triggers a process of epileptogenesis characterized by gradual worsening of seizure severity and involvement of progressively larger neuronal populations over a period of several weeks. Knowledge about the underlying mechanism of epileptogenesis is important because such knowledge may result in more specific and efficacious treatments of MTLE by moving away from large and poorly specific surgical resections to highly targeted surgical or pharmacological interventions of the epileptogenic process.
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Affiliation(s)
- Benjamin Albright
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Roni Dhaher
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Helen Wang
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Roa Harb
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Tih-Shih W Lee
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Hitten Zaveri
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Tore Eid
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.
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12
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Tao K, Wang X. The comorbidity of epilepsy and depression: diagnosis and treatment. Expert Rev Neurother 2016; 16:1321-1333. [PMID: 27327645 DOI: 10.1080/14737175.2016.1204233] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Kaiyan Tao
- Chongqing Key Laboratory of Neurology, Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xuefeng Wang
- Chongqing Key Laboratory of Neurology, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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13
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Eid T, Gruenbaum SE, Dhaher R, Lee TSW, Zhou Y, Danbolt NC. The Glutamate-Glutamine Cycle in Epilepsy. ADVANCES IN NEUROBIOLOGY 2016; 13:351-400. [PMID: 27885637 DOI: 10.1007/978-3-319-45096-4_14] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Epilepsy is a complex, multifactorial disease characterized by spontaneous recurrent seizures and an increased incidence of comorbid conditions such as anxiety, depression, cognitive dysfunction, and sudden unexpected death. About 70 million people worldwide are estimated to suffer from epilepsy, and up to one-third of all people with epilepsy are expected to be refractory to current medications. Development of more effective and specific antiepileptic interventions is therefore requisite. Perturbations in the brain's glutamate-glutamine cycle, such as increased extracellular levels of glutamate, loss of astroglial glutamine synthetase, and changes in glutaminase and glutamate dehydrogenase, are frequently encountered in patients with epilepsy. Hence, manipulations of discrete glutamate-glutamine cycle components may represent novel approaches to treat the disease. The goal of his review is to discuss some of the glutamate-glutamine cycle components that are altered in epilepsy, particularly neurotransmitters and metabolites, enzymes, amino acid transporters, and glutamate receptors. We will also review approaches that potentially could be used in humans to target the glutamate-glutamine cycle. Examples of such approaches are treatment with glutamate receptor blockers, glutamate scavenging, dietary intervention, and hypothermia.
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Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine, 330 Cedar Street, 208035, New Haven, CT, 06520-8035, USA.
| | - Shaun E Gruenbaum
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Roni Dhaher
- Department of Laboratory Medicine, Yale School of Medicine, 330 Cedar Street, 208035, New Haven, CT, 06520-8035, USA
| | - Tih-Shih W Lee
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Yun Zhou
- Department of Molecular Medicine, Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Niels Christian Danbolt
- Department of Molecular Medicine, Institute for Basic Medical Sciences, University of Oslo, Oslo, Norway
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