101
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Steullet P, Cabungcal JH, Monin A, Dwir D, O'Donnell P, Cuenod M, Do KQ. Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology? Schizophr Res 2016; 176:41-51. [PMID: 25000913 PMCID: PMC4282982 DOI: 10.1016/j.schres.2014.06.021] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/06/2014] [Accepted: 06/08/2014] [Indexed: 12/18/2022]
Abstract
Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease.
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Affiliation(s)
- P Steullet
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - J H Cabungcal
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - A Monin
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - D Dwir
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - P O'Donnell
- Neuroscience Research Unit, Pfizer, Inc., 700 Main Street, Cambridge, MA 02139, USA
| | - M Cuenod
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - K Q Do
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland.
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102
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Ketamine-dependent neuronal activation in healthy volunteers. Brain Struct Funct 2016; 222:1533-1542. [PMID: 27578365 DOI: 10.1007/s00429-016-1291-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 08/12/2016] [Indexed: 01/03/2023]
Abstract
Over the last years, a number of studies have been conducted to clarify the neurobiological correlates of ketamine application. However, comprehensive information regarding the influence of ketamine on cortical activity is still lacking. Using resting-state functional MRI and integrating pharmacokinetic information, a double-blind, randomized, placebo-controlled, crossover study was performed to determine the effects of ketamine on neuronal activation. During a 55 min resting-state fMRI scan, esketamine (Ketanest S®) was administered intravenously to 35 healthy volunteers. Neural activation as indicated by the BOLD signal using the pharmacokinetic curve of ketamine plasma levels as a regressor was computed. Compared with placebo, ketamine-dependent increases of neural activation were observed in the midcingulate cortex, the dorsal part of the anterior cingulate cortex, the insula bilaterally, and the thalamus (t values ranging between 5.95-9.78, p < 0.05; FWE-corrected). A significant decrease of neural activation in the ketamine condition compared to placebo was found in a cluster within the subgenual/subcallosal part of the anterior cingulate cortex, the orbitofrontal cortex and the gyrus rectus (t = 7.81, p < 0.05, FWE-corrected). Using an approach combining pharmacological and fMRI data, important information about the neurobiological correlates of the clinical antidepressant effects of ketamine could be revealed.
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103
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Beck K, Javitt DC, Howes OD. Targeting glutamate to treat schizophrenia: lessons from recent clinical studies. Psychopharmacology (Berl) 2016; 233:2425-8. [PMID: 27212398 DOI: 10.1007/s00213-016-4318-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 03/03/2016] [Indexed: 12/18/2022]
Affiliation(s)
- Katherine Beck
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
| | - Daniel C Javitt
- Division of Experimental Therapeutics, Departments of Psychiatry and Neuroscience, Columbia University Medical Center, 1051 Riverside Drive, New York, NY, 10032, USA
- Schizophrenia Research Division, Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY, 10962, USA
| | - Oliver D Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
- Psychiatric Imaging Group, Imperial College, MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK.
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104
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Mouchlianitis E, Bloomfield MAP, Law V, Beck K, Selvaraj S, Rasquinha N, Waldman A, Turkheimer FE, Egerton A, Stone J, Howes OD. Treatment-Resistant Schizophrenia Patients Show Elevated Anterior Cingulate Cortex Glutamate Compared to Treatment-Responsive. Schizophr Bull 2016; 42:744-52. [PMID: 26683625 PMCID: PMC4838083 DOI: 10.1093/schbul/sbv151] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Resistance to antipsychotic treatment is a significant clinical problem in patients with schizophrenia with approximately 1 in 3 showing limited or no response to repeated treatments with antipsychotic medication. The neurobiological basis for treatment resistance is unknown but recent evidence implicates glutamatergic function in the anterior cingulate cortex. We examined glutamate levels of chronically ill treatment-resistant patients directly compared to treatment-responsive patients. METHODS We acquired proton magnetic resonance spectroscopy (1H-MRS) at 3 Tesla from 21 treatment-resistant and 20 treatment-responsive patients. All participants had a DSM-IV diagnosis of schizophrenia. Treatment-resistant patients were classified using the modified Kane criteria. The groups were matched for age, sex, smoking status, and illness duration. RESULTS Glutamate to creatine ratio levels were higher in treatment-resistant patients (Mean [SD] = 1.57 [0.24]) than in treatment-responsive patients (Mean[SD] = 1.38 [0.23]), (T[35] = 2.34, P = .025, 2-tailed), with a large effect size of d = 0.76. A model assuming 2 populations showed a 25% improvement in the fit of the Akaike weights (0.55) over a model assuming 1 population (0.44), producing group values almost identical to actual group means. DISCUSSION Increased anterior cingulate glutamate level is associated with treatment-resistant schizophrenia. This appears to be a stable neurobiological trait of treatment-resistant patients. We discuss possible explanations for glutamatergic dysfunction playing a significant role in resistance to conventional antipsychotic treatments, which are all dopamine-2 receptor blockers. Our findings suggest that glutamatergic treatments may be particularly effective in resistant patients and that 1H-MRS glutamate indices can potentially have clinical use.
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Affiliation(s)
- Elias Mouchlianitis
- Medical Research Council Clinical Sciences Centre, Psychiatric Imaging Group, Hammersmith Hospital, London, UK; Institute of Psychiatry Psychology and Neuroscience, Department of Psychosis Studies, King's College London, UK;
| | - Michael A. P. Bloomfield
- Medical Research Council Clinical Sciences Centre, Psychiatric Imaging Group, Hammersmith Hospital, London, UK;,University College London, Division of Psychiatry, London, UK
| | - Vincent Law
- Medical Research Council Clinical Sciences Centre, Psychiatric Imaging Group, Hammersmith Hospital, London, UK
| | - Katherine Beck
- Institute of Psychiatry Psychology and Neuroscience, Department of Psychosis Studies, King’s College London, UK
| | - Sudhakar Selvaraj
- Department of Psychiatry and Behavioral Sciences, University of Texas, Houston, TX
| | | | - Adam Waldman
- Division of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Federico E. Turkheimer
- Institute of Psychiatry Psychology and Neuroscience, Department of Psychosis Studies, King’s College London, UK
| | - Alice Egerton
- Institute of Psychiatry Psychology and Neuroscience, Department of Psychosis Studies, King’s College London, UK
| | - James Stone
- Medical Research Council Clinical Sciences Centre, Psychiatric Imaging Group, Hammersmith Hospital, London, UK;,Institute of Psychiatry Psychology and Neuroscience, Department of Psychosis Studies, King’s College London, UK
| | - Oliver D. Howes
- Medical Research Council Clinical Sciences Centre, Psychiatric Imaging Group, Hammersmith Hospital, London, UK;,Institute of Psychiatry Psychology and Neuroscience, Department of Psychosis Studies, King’s College London, UK
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105
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Jadi MP, Behrens MM, Sejnowski TJ. Abnormal Gamma Oscillations in N-Methyl-D-Aspartate Receptor Hypofunction Models of Schizophrenia. Biol Psychiatry 2016; 79:716-726. [PMID: 26281716 PMCID: PMC4720598 DOI: 10.1016/j.biopsych.2015.07.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 06/03/2015] [Accepted: 07/07/2015] [Indexed: 12/21/2022]
Abstract
N-methyl-D-aspartate receptor (NMDAR) hypofunction in parvalbumin-expressing (PV+) inhibitory neurons (INs) may contribute to symptoms in patients with schizophrenia (SZ). This hypothesis was inspired by studies in humans involving NMDAR antagonists that trigger SZ symptoms. Animal models of SZ using neuropharmacology and genetic knockouts have successfully replicated some of the key observations in human subjects involving alteration of gamma band oscillations (GBO) observed in electroencephalography and magnetoencephalography signals. However, it remains to be seen if NMDAR hypofunction in PV+ neurons is fundamental to the phenotype observed in these models. In this review, we discuss some of the key computational models of GBO and their predictions in the context of NMDAR hypofunction in INs. While PV+ INs have been the main focus of SZ studies in animal models, we also discuss the implications of NMDAR hypofunction in other types of INs using computational models for GBO modulation in the visual cortex.
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Affiliation(s)
- Monika P Jadi
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, California; Division of Biological Sciences, University of California at San Diego, La Jolla, California.
| | - M Margarita Behrens
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, California
| | - Terrence J Sejnowski
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, California; Division of Biological Sciences, University of California at San Diego, La Jolla, California
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106
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Masdeu JC, Dalmau J, Berman KF. NMDA Receptor Internalization by Autoantibodies: A Reversible Mechanism Underlying Psychosis? Trends Neurosci 2016; 39:300-310. [PMID: 27130657 DOI: 10.1016/j.tins.2016.02.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/13/2016] [Accepted: 02/22/2016] [Indexed: 12/31/2022]
Abstract
Since the early 1990s it has been postulated that hypofunction of N-methyl-d-aspartate (NMDA) receptors in brain networks supporting perception and cognition underlies schizophrenic psychosis. Recently, NMDA receptor hypofunction was described in patients with psychotic manifestations who exhibited autoantibodies binding the GluN1 subunit of the receptor, and who improved when the level of these antibodies was lowered by immunomodulation. In this disorder, NMDA receptor antibodies decrease the availability of NMDA receptors by internalizing them. In this opinion article, we review this mechanism as well as data supporting or refuting the possibility that this disorder or similar autoimmune disorders affecting synaptic proteins, which are therefore treatable with immunomodulation, could account for some cases of idiopathic psychosis. We also suggest methodological approaches to clarify this issue.
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Affiliation(s)
- Joseph C Masdeu
- Houston Methodist Neurological Institute and Department of Neurology, Weill Cornell Medical College, Houston, TX 77030, USA.
| | - Josep Dalmau
- ICREA-IDIBAPS, Hospital Clinic, Service of Neurology, University of Barcelona, Barcelona, Spain; Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karen F Berman
- Clinical and Translational Neuroscience Branch, National Institutes of Health, NIMH Intramural Research Program, Bethesda, MD 20892, USA
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107
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Brandt AS, Unschuld PG, Pradhan S, Lim IAL, Churchill G, Harris AD, Hua J, Barker PB, Ross CA, van Zijl PCM, Edden RAE, Margolis RL. Age-related changes in anterior cingulate cortex glutamate in schizophrenia: A (1)H MRS Study at 7 Tesla. Schizophr Res 2016; 172:101-5. [PMID: 26925800 PMCID: PMC4821673 DOI: 10.1016/j.schres.2016.02.017] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 02/08/2016] [Accepted: 02/10/2016] [Indexed: 12/27/2022]
Abstract
The extent of age-related changes in glutamate and other neurometabolites in the anterior cingulate cortex (ACC) in individuals with schizophrenia remain unclear. Magnetic resonance spectroscopy (MRS) at 7 T, which yields precise measurements of various metabolites and can distinguish glutamate from glutamine, was used to determine levels of ACC glutamate and other metabolites in 24 individuals with schizophrenia and 24 matched controls. Multiple regression analysis revealed that ACC glutamate decreased with age in patients but not controls. No changes were detected in levels of glutamine, N-acetylaspartate, N-acetylaspartylglutamic acid, myo-inositol, GABA, glutathione, total creatine, and total choline. These results suggest that age may be an important modifier of ACC glutamate in schizophrenia.
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Affiliation(s)
- Allison S Brandt
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Paul G Unschuld
- Laboratory for Aging Neuroscience and Neuroimaging, Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich, Zurich, Switzerland
| | - Subechhya Pradhan
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Issel Anne L Lim
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Gregory Churchill
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ashley D Harris
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Jun Hua
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Peter B Barker
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Christopher A Ross
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Departments of Pharmacology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter C M van Zijl
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Russell L Margolis
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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108
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Plitman E, de la Fuente-Sandoval C, Reyes-Madrigal F, Chavez S, Gómez-Cruz G, León-Ortiz P, Graff-Guerrero A. Elevated Myo-Inositol, Choline, and Glutamate Levels in the Associative Striatum of Antipsychotic-Naive Patients With First-Episode Psychosis: A Proton Magnetic Resonance Spectroscopy Study With Implications for Glial Dysfunction. Schizophr Bull 2016; 42:415-24. [PMID: 26320195 PMCID: PMC4753594 DOI: 10.1093/schbul/sbv118] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Glial disturbances are highly implicated in the pathophysiology of schizophrenia and may be linked with glutamatergic dysregulation. Myo-inositol (mI), a putative marker of glial cells, and choline (Cho), representative of membrane turnover, are both present in larger concentrations within glial cells than in neurons, and their elevation is often interpreted to reflect glial activation. Proton magnetic resonance spectroscopy ((1)H-MRS) allows for the evaluation of mI, Cho, glutamate, glutamate + glutamine (Glx), and N-acetylaspartate (NAA). A collective investigation of these measures in antipsychotic-naive patients experiencing their first nonaffective episode of psychosis (FEP) can improve the understanding of glial dysfunction and its implications in the early stages of schizophrenia. 3-Tesla (1)H-MRS (echo time = 35 ms) was performed in 60 antipsychotic-naive patients with FEP and 60 age- and sex-matched healthy controls. mI, Cho, glutamate, Glx, and NAA were estimated using LCModel and corrected for cerebrospinal fluid composition within the voxel. mI, Cho, and glutamate were elevated in the FEP group. After correction for multiple comparisons, mI positively correlated with grandiosity. The relationships between mI and glutamate, and Cho and glutamate, were more positive in the FEP group. These findings are suggestive of glial activation in the absence of neuronal loss and may thereby provide support for the presence of a neuroinflammatory process within the early stages of schizophrenia. Dysregulation of glial function might result in the disruption of glutamatergic neurotransmission, which may influence positive symptomatology in patients with FEP.
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Affiliation(s)
- Eric Plitman
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada;,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Camilo de la Fuente-Sandoval
- Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico; Neuropsychiatry Department, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico;
| | - Francisco Reyes-Madrigal
- Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico
| | - Sofia Chavez
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada;,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Gladys Gómez-Cruz
- Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico
| | - Pablo León-Ortiz
- Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico;,Department of Education, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico
| | - Ariel Graff-Guerrero
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada;,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada;,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada;,Geriatric Mental Health Division, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada;,Campbell Institute Research Program, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada
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109
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Kosten L, Verhaeghe J, Verkerk R, Thomae D, De Picker L, Wyffels L, Van Eetveldt A, Dedeurwaerdere S, Stroobants S, Staelens S. Multiprobe molecular imaging of an NMDA receptor hypofunction rat model for glutamatergic dysfunction. Psychiatry Res Neuroimaging 2016; 248:1-11. [PMID: 26803479 DOI: 10.1016/j.pscychresns.2016.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 12/23/2015] [Accepted: 01/07/2016] [Indexed: 12/21/2022]
Abstract
There are many indications of a connection between abnormal glutamate transmission through N-methyl-d-aspartate (NMDA) receptor hypofunction and the occurrence of schizophrenia. The importance of metabotropic glutamate receptor subtype 5 (mGluR5) became generally recognized due to its physical link through anchor proteins with NMDAR. Neuroinflammation as well as the kynurenine (tryptophan catabolite; TRYCAT) pathway are equally considered as major contributors to the pathology. We aimed to investigate this interplay between glutamate release, neuronal activation and inflammatory markers, by using small-animal positron emission tomography (PET) in a rat model known to induce schizophrenia-like symptoms. Daily intraperitoneal injection of MK801 or saline were administered to induce the model together with N-Acetyl-cysteine (NAc) or saline as the treatment in 24 male Sprague Dawley rats for one month. Biweekly in vivo [(11)C]-ABP688 microPET was performed together with mGluR5 immunohistochemistry. Simultaneously, weekly in vivo [(18)F]-FDG microPET imaging data for glucose metabolism was acquired and microglial activation was investigated with biweekly in vivo [(18)F]-PBR111 scans versus OX42 immunohistochemistry. Finally, plasma samples were analyzed for TRYCAT metabolites. We show that chronic MK801 administration (and thus elevated endogenous glutamate) causes significant tissue loss in rat brain, enhances neuroinflammatory pathways and may upregulate mGluR5 expression.
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Affiliation(s)
- Lauren Kosten
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Robert Verkerk
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - David Thomae
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium; Department of Nuclear Medicine, University Hospital Antwerp, Antwerp, Belgium
| | - Livia De Picker
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium; Department of Nuclear Medicine, University Hospital Antwerp, Antwerp, Belgium
| | | | | | - Sigrid Stroobants
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium; Department of Nuclear Medicine, University Hospital Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium.
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110
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Caravaggio F, Nakajima S, Plitman E, Gerretsen P, Chung JK, Iwata Y, Graff-Guerrero A. The effect of striatal dopamine depletion on striatal and cortical glutamate: A mini-review. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:49-53. [PMID: 26334687 PMCID: PMC5323253 DOI: 10.1016/j.pnpbp.2015.08.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 08/19/2015] [Accepted: 08/27/2015] [Indexed: 02/07/2023]
Abstract
Understanding the interplay between the neurotransmitters dopamine and glutamate in the striatum has become the highlight of several theories of neuropsychiatric illnesses, such as schizophrenia. Using in vivo brain imaging in humans, alterations in dopamine and glutamate concentrations have been observed in several neuropsychiatric disorders. However, it is unclear a priori how alterations in striatal dopamine should modulate glutamate concentrations in the basal ganglia. In this selective mini-review, we examine the consequence of reducing striatal dopamine functioning on glutamate concentrations in the striatum and cortex; regions of interest heavily examined in the human brain imaging studies. We examine the predictions of the classical model of the basal ganglia, and contrast it with findings in humans and animals. The review concludes that chronic dopamine depletion (>4months) produces decreases in striatal glutamate levels which are consistent with the classical model of the basal ganglia. However, acute alterations in striatal dopamine functioning, specifically at the D2 receptors, may produce opposite affects. This has important implications for models of the basal ganglia and theorizing about neurochemical alterations in neuropsychiatric diseases. Moreover, these findings may help guide a priori hypotheses for (1)H-MRS studies measuring glutamate changes given alterations in dopaminergic functioning in humans.
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Affiliation(s)
- Fernando Caravaggio
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Shinichiro Nakajima
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada
| | - Eric Plitman
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Philip Gerretsen
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada
| | - Jun Ku Chung
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Yusuke Iwata
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Ariel Graff-Guerrero
- Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8, Canada; Institute of Medical Science, University of Toronto, 2374 Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
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111
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Landek-Salgado MA, Faust TE, Sawa A. Molecular substrates of schizophrenia: homeostatic signaling to connectivity. Mol Psychiatry 2016; 21:10-28. [PMID: 26390828 PMCID: PMC4684728 DOI: 10.1038/mp.2015.141] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 06/24/2015] [Accepted: 06/25/2015] [Indexed: 02/06/2023]
Abstract
Schizophrenia (SZ) is a devastating psychiatric condition affecting numerous brain systems. Recent studies have identified genetic factors that confer an increased risk of SZ and participate in the disease etiopathogenesis. In parallel to such bottom-up approaches, other studies have extensively reported biological changes in patients by brain imaging, neurochemical and pharmacological approaches. This review highlights the molecular substrates identified through studies with SZ patients, namely those using top-down approaches, while also referring to the fruitful outcomes of recent genetic studies. We have subclassified the molecular substrates by system, focusing on elements of neurotransmission, targets in white matter-associated connectivity, immune/inflammatory and oxidative stress-related substrates, and molecules in endocrine and metabolic cascades. We further touch on cross-talk among these systems and comment on the utility of animal models in charting the developmental progression and interaction of these substrates. Based on this comprehensive information, we propose a framework for SZ research based on the hypothesis of an imbalance in homeostatic signaling from immune/inflammatory, oxidative stress, endocrine and metabolic cascades that, at least in part, underlies deficits in neural connectivity relevant to SZ. Thus, this review aims to provide information that is translationally useful and complementary to pathogenic hypotheses that have emerged from genetic studies. Based on such advances in SZ research, it is highly expected that we will discover biomarkers that may help in the early intervention, diagnosis or treatment of SZ.
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Affiliation(s)
- M A Landek-Salgado
- Department of Psychiatry, John Hopkins University School of Medicine, Baltimore, MD, USA
| | - T E Faust
- Department of Psychiatry, John Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Neuroscience, John Hopkins University School of Medicine, Baltimore, MD, USA
| | - A Sawa
- Department of Psychiatry, John Hopkins University School of Medicine, Baltimore, MD, USA
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112
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Astrocytes as Pharmacological Targets in the Treatment of Schizophrenia. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2016. [DOI: 10.1016/b978-0-12-800981-9.00025-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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113
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Monin A, Fournier M, Baumann PS, Cuénod M, Do KQ. Role of Redox Dysregulation in White Matter Anomalies Associated with Schizophrenia. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2016. [DOI: 10.1016/b978-0-12-800981-9.00028-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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114
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Coughlin JM, Tanaka T, Marsman A, Wang H, Bonekamp S, Kim PK, Higgs C, Varvaris M, Edden RAE, Pomper M, Schretlen D, Barker PB, Sawa A. Decoupling of N-acetyl-aspartate and glutamate within the dorsolateral prefrontal cortex in schizophrenia. Curr Mol Med 2015; 15:176-83. [PMID: 25732147 DOI: 10.2174/1566524015666150303104811] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 12/20/2014] [Accepted: 01/18/2015] [Indexed: 11/22/2022]
Abstract
Aberrant function of glutamatergic pathways is likely to underlie the pathology of schizophrenia. Evidence of oxidative stress in the disease pathology has also been reported. N-Acetylaspartate (NAA) is metabolically linked to both cascades and may be a key marker in exploring the interconnection of glutamatergic pathways and oxidative stress. Several studies have reported positive correlation between the levels of NAA and Glx (the sum of glutamate and glutamine) in several brain regions in healthy subjects, by using proton magnetic resonance spectroscopy ([(1)H]MRS). Interestingly, one research group recently reported decoupling of the relationship between NAA and Glx in the hippocampus of patients with schizophrenia. Here we report levels of NAA and Glx measured using [(1)H]MRS, relative to the level of creatine (Cr) as an internal control. The dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) in 25 patients with schizophrenia and 17 matched healthy controls were studied. In DLPFC, NAA/Cr and Glx/Cr were significantly positively correlated in healthy controls after correction for the effect of age and smoking status and after correction for multiple comparisons (r= 0.627, P= 0.017). However, in patients with schizophrenia, the positive correlation between NAA/Cr and Glx/Cr was not observed even after correcting for these two variables (r= -0.330, P= 0.124). Positive correlation between NAA/Cr and Glx/Cr was not observed in the ACC in both groups. Decoupling of NAA and Glx in the DLPFC may reflect the interconnection of glutamatergic pathways and oxidative stress in the pathology of schizophrenia, and may possibly be a biomarker of the disease.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - A Sawa
- Department of Psychiatry and Behavioral Sciences, Hopkins Medical Institutions, 600 N. Wolfe Street, Meyer 3-166A, Baltimore, MD 21287, USA.
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115
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Burhan AM, Marlatt NM, Palaniyappan L, Anazodo UC, Prato FS. Role of Hybrid Brain Imaging in Neuropsychiatric Disorders. Diagnostics (Basel) 2015; 5:577-614. [PMID: 26854172 PMCID: PMC4728476 DOI: 10.3390/diagnostics5040577] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/21/2015] [Accepted: 11/26/2015] [Indexed: 01/09/2023] Open
Abstract
This is a focused review of imaging literature to scope the utility of hybrid brain imaging in neuropsychiatric disorders. The review focuses on brain imaging modalities that utilize hybrid (fusion) techniques to characterize abnormal brain molecular signals in combination with structural and functional changes that have been observed in neuropsychiatric disorders. An overview of clinical hybrid brain imaging technologies for human use is followed by a selective review of the literature that conceptualizes the use of these technologies in understanding basic mechanisms of major neuropsychiatric disorders and their therapeutics. Neuronal network abnormalities are highlighted throughout this review to scope the utility of hybrid imaging as a potential biomarker for each disorder.
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Affiliation(s)
- Amer M Burhan
- St. Joseph's Health Care London, Parkwood Institute, 550 Wellington Road, London, ON N6C 0A7, Canada.
- Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6C 2R6, Canada.
| | - Nicole M Marlatt
- St. Joseph's Health Care London, Parkwood Institute, 550 Wellington Road, London, ON N6C 0A7, Canada.
| | - Lena Palaniyappan
- Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6C 2R6, Canada.
| | | | - Frank S Prato
- Lawson Health Research Institute, London, ON N6C 2R5, Canada.
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116
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Wierońska JM, Zorn SH, Doller D, Pilc A. Metabotropic glutamate receptors as targets for new antipsychotic drugs: Historical perspective and critical comparative assessment. Pharmacol Ther 2015; 157:10-27. [PMID: 26549541 DOI: 10.1016/j.pharmthera.2015.10.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this review, we aim to present, discuss and clarify our current understanding regarding the prediction of possible antipsychotic effects of metabotropic glutamate (mGlu) receptor ligands. The number of preclinical trials clearly indicates, that this group of compounds constitutes an excellent alternative to presently used antipsychotic therapy, being effective not only to positive, but also negative and cognitive symptoms of schizophrenia. Although the results of clinical trials that were performed for the group of mGlu2/3 agonists were not so enthusiastic as in animal studies, they still showed that mGlu ligands do not induced variety of side effects typical for presently used antipsychotics, and were generally well tolerated. The lack of satisfactory effectiveness towards schizophrenia symptoms of mGlu2/3 activators in humans could be a result of variety of uncontrolled factors and unidentified biomarkers different for each schizophrenia patient, that should be taken into consideration in the future set of clinical trials. The subject is still open for further research, and the novel classes of mGlu5 or mGlu2/3 agonists/PAMs were recently introduced, including the large group of compounds from the third group of mGlu receptors, especially of mGlu4 subtype. Finally, more precise treatment based on simultaneous administration of minimal doses of the ligands for two or more receptors, seems to be promising in the context of symptoms-specific schizophrenia treatment.
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Affiliation(s)
- Joanna M Wierońska
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Krakow, Poland
| | | | | | - Andrzej Pilc
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Krakow, Poland.
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117
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Rodríguez-Muñoz M, Cortés-Montero E, Pozo-Rodrigálvarez A, Sánchez-Blázquez P, Garzón-Niño J. The ON:OFF switch, σ1R-HINT1 protein, controls GPCR-NMDA receptor cross-regulation: implications in neurological disorders. Oncotarget 2015; 6:35458-77. [PMID: 26461475 PMCID: PMC4742118 DOI: 10.18632/oncotarget.6064] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/23/2015] [Indexed: 12/11/2022] Open
Abstract
In the brain, the histidine triad nucleotide-binding protein 1 (HINT1) and sigma 1 receptors (σ1Rs) coordinate the activity of certain G-protein coupled receptors (GPCRs) with that of glutamate N-methyl-D-aspartate receptors (NMDARs). To determine the role of HINT1-σ1R in the plasticity of GPCR-NMDAR interactions, substances acting at MOR, cannabinoid CB1 receptor, NMDAR and σ1R were injected into mice, and their effects were evaluated through in vivo, ex vivo, and in vitro assays. It was observed that HINT1 protein binds to GPCRs and NMDAR NR1 subunits in a calcium-independent manner, whereas σ1R binding to these proteins increases in the presence of calcium. In this scenario, σ1R agonists keep HINT1 at the GPCR and stimulate GPCR-NMDAR interaction, whereas σ1R antagonists transfer HINT1 to NR1 subunits and disengage both receptors. This regulation is lost in σ1R-/- mice, where HINT1 proteins mostly associate with NMDARs, and GPCRs are physically and functionally disconnected from NMDARs. In HINT1-/- mice, ischemia produces low NMDAR-mediated brain damage, suggesting that several different GPCRs enhance glutamate excitotoxicity via HINT1-σ1R. Thus, several GPCRs associate with NMDARs by a dynamic process under the physiological control of HINT1 proteins and σ1Rs. The NMDAR-HINT1-σ1R complex deserves attention because it offers new therapeutic opportunities.
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Affiliation(s)
- María Rodríguez-Muñoz
- Department of Molecular, Cellular and Developmental Neurobiology, Laboratory of Neuropharmacology. Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC). Madrid, Spain
| | - Elsa Cortés-Montero
- Department of Molecular, Cellular and Developmental Neurobiology, Laboratory of Neuropharmacology. Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC). Madrid, Spain
| | - Andrea Pozo-Rodrigálvarez
- Department of Molecular, Cellular and Developmental Neurobiology, Laboratory of Neuropharmacology. Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC). Madrid, Spain
| | - Pilar Sánchez-Blázquez
- Department of Molecular, Cellular and Developmental Neurobiology, Laboratory of Neuropharmacology. Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC). Madrid, Spain
| | - Javier Garzón-Niño
- Department of Molecular, Cellular and Developmental Neurobiology, Laboratory of Neuropharmacology. Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC). Madrid, Spain
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118
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McAllister KAL, Mar AC, Theobald DE, Saksida LM, Bussey TJ. Comparing the effects of subchronic phencyclidine and medial prefrontal cortex dysfunction on cognitive tests relevant to schizophrenia. Psychopharmacology (Berl) 2015. [PMID: 26194915 DOI: 10.1007/s00213-015-4018-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
RATIONALE It is becoming increasingly clear that the development of treatments for cognitive symptoms of schizophrenia requires urgent attention, and that valid animal models of relevant impairments are required. With subchronic psychotomimetic agent phencyclidine (scPCP), a putative model of such impairment, the extent to which changes following scPCP do or do not resemble those following dysfunction of the prefrontal cortex is of importance. OBJECTIVES The present study carried out a comparison of the most common scPCP dosing regimen with excitotoxin-induced medial prefrontal cortex (mPFC) dysfunction in rats, across several cognitive tests relevant to schizophrenia. METHODS ScPCP subjects were dosed intraperitoneal with 5 mg/kg PCP or vehicle twice daily for 1 week followed by 1 week washout prior to behavioural testing. mPFC dysfunction was induced via fibre-sparing excitotoxin infused into the pre-limbic and infralimbic cortex. Subjects were tested on spontaneous novel object recognition, touchscreen object-location paired-associates learning and touchscreen reversal learning. RESULTS A double-dissociation was observed between object-location paired-associates learning and object recognition: mPFC dysfunction impaired acquisition of the object-location task but not spontaneous novel object recognition, while scPCP impaired spontaneous novel object recognition but not object-location associative learning. Both scPCP and mPFC dysfunction resulted in a similar facilitation of reversal learning. CONCLUSIONS The pattern of impairment following scPCP raises questions around its efficacy as a model of cognitive impairment in schizophrenia, particularly if importance is placed on faithfully replicating the effects of mPFC dysfunction.
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Affiliation(s)
- K A L McAllister
- University of Cambridge Department of Psychology, Downing Street, Cambridge, CB2 3EB, UK. .,MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK. .,, 20 Manchester Sq., London, W1U 3PZ, UK.
| | - A C Mar
- University of Cambridge Department of Psychology, Downing Street, Cambridge, CB2 3EB, UK.,MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
| | - D E Theobald
- University of Cambridge Department of Psychology, Downing Street, Cambridge, CB2 3EB, UK.,MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
| | - L M Saksida
- University of Cambridge Department of Psychology, Downing Street, Cambridge, CB2 3EB, UK.,MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
| | - T J Bussey
- University of Cambridge Department of Psychology, Downing Street, Cambridge, CB2 3EB, UK.,MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
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119
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Increased glutamate levels observed upon functional activation in the anterior cingulate cortex using the Stroop Task and functional spectroscopy. Neuroreport 2015; 26:107-12. [PMID: 25536234 PMCID: PMC4323558 DOI: 10.1097/wnr.0000000000000309] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It has been shown in recent studies that it is possible to detect changes in the main excitatory neurotransmitter, glutamate, upon functional activation with visual and motor paradigms using a 7 T MRI and functional magnetic resonance spectroscopy. A cognitive task would be desirable for this technique because it could then be used to examine psychiatric disorders that have cognitive deficiencies. The aim of the work presented here was to use functional magnetic resonance spectroscopy with a 7 T MRI to show that increases in glutamate can be observed within the anterior cingulate cortex using the Stroop Task as the activation paradigm in healthy controls. Significant glutamate increases (0.24±0.09 µmol/g, P<0.025), comparable with what has been reported in the studies of the occipital cortex and motor cortex, were observed when the participants (n=7) performed the task, followed by a trend toward returning to baseline in the post-task recovery period (−0.23±0.13 µmol/g). This method would be ideal for the study of neuropsychiatric disorders that have been shown to have abnormal resting glutamate levels and cognitive deficiencies in the anterior cingulate cortex, such as schizophrenia. This exploratory study is the first to demonstrate functional magnetic resonance spectroscopy in the anterior cingulate with a cognitive task using a 7 T MRI.
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120
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Smesny S, Gussew A, Biesel NJ, Schack S, Walther M, Rzanny R, Milleit B, Gaser C, Sobanski T, Schultz CC, Amminger P, Hipler UC, Sauer H, Reichenbach JR. Glutamatergic dysfunction linked to energy and membrane lipid metabolism in frontal and anterior cingulate cortices of never treated first-episode schizophrenia patients. Schizophr Res 2015; 168:322-9. [PMID: 26255566 DOI: 10.1016/j.schres.2015.07.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 06/10/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022]
Abstract
BACKGROUND Glutamatergic dysfunction and altered membrane lipid and energy metabolism have been repeatedly demonstrated in the frontal/prefrontal and anterior cingulate cortex (ACC) in schizophrenia. Though having been already studied in animals, the presumed link between glutamatergic function and structural plasticity has not been investigated directly in the human brain yet. We measured glutamate (Glu), focal energy metabolism, and membrane phospholipid turnover to investigate main pathologies in those key brain regions of schizophrenia. METHODS (1)H- and (31)P-Chemical Shift Imaging (CSI) was combined in a single session to assess Glu and markers of energy (PCr, ATP) and membrane lipid (PME, PDE) metabolism in 31 neuroleptic-naïve first acute onset psychosis patients and 31 matched healthy controls. Multivariate analyses of covariance were used to assess disease effects on Glu and to investigate the impact of Glu alterations on phospholipid and energy metabolites. RESULTS Glu levels of patients were increased in the frontal and prefrontal cortex bilaterally and in the ACC. Higher Glu was associated with increased left frontal/prefrontal PME and right frontal/prefrontal PDE in patients, which was not observed in healthy controls. In contrast, higher Glu levels were associated with lower PCr or ATP values in the frontal/prefrontal cortex bilaterally and in the right ACC of controls. This was not observed in the right ACC and left frontal/prefrontal cortex of patients. CONCLUSION Frontal glutamatergic hyperactivity is disconnected from physiologically regulated energy metabolism and is associated with increased membrane breakdown in right and increased membrane restoration in left frontal and prefrontal cortical regions. As indicated by previous findings, this pathology is likely dynamic during the course of first acute illness and possibly associated with negative symptoms and cognitive impairment. Our findings underline the importance of further research on neuroprotective treatment options during the early acute or even better for the ultra-high risk state of psychotic illness.
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Affiliation(s)
- Stefan Smesny
- Department of Psychiatry, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany.
| | - Alexander Gussew
- Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Philosophenweg 3, D-07740 Jena, Germany
| | - Natalie Joan Biesel
- Department of Psychiatry, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany
| | - Stephan Schack
- Department of Psychiatry, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany
| | - Mario Walther
- Institute of Medical Statistics, Computer Sciences and Documentation (IMSID), Jena University Hospital, Friedrich-Schiller University Jena, Bachstraße 18, D-07743 Jena, Germany
| | - Reinhard Rzanny
- Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Philosophenweg 3, D-07740 Jena, Germany
| | - Berko Milleit
- Department of Psychiatry, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany; Department of Psychiatry, Thüringen-Kliniken "Georgius Agricola" GmbH Rainweg 68, D-07318 Saalfeld/Saale, Germany
| | - Christian Gaser
- Department of Psychiatry, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany
| | - Thomas Sobanski
- Department of Psychiatry, Thüringen-Kliniken "Georgius Agricola" GmbH Rainweg 68, D-07318 Saalfeld/Saale, Germany
| | - Carl Christoph Schultz
- Department of Psychiatry, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany
| | - Paul Amminger
- Department of Child and Adolescent Psychiatry, Medical University Vienna, Währingergürtel 18-20, A-1090 Vienna, Austria; Orygen Youth Health Research Centre, The University of Melbourne, Locked Bag 10, 35 Poplar Road Parkville, Victoria 3052, Melbourne, Australia
| | - Uta-Christina Hipler
- Department of Dermatology, Jena University Hospital, Erfurter Straße 35, D-07743 Jena, Germany
| | - Heinrich Sauer
- Department of Psychiatry, Jena University Hospital, Philosophenweg 3, D-07743 Jena, Germany
| | - Jürgen R Reichenbach
- Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Philosophenweg 3, D-07740 Jena, Germany
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Taylor R, Neufeld RWJ, Schaefer B, Densmore M, Rajakumar N, Osuch EA, Williamson PC, Théberge J. Functional magnetic resonance spectroscopy of glutamate in schizophrenia and major depressive disorder: anterior cingulate activity during a color-word Stroop task. NPJ SCHIZOPHRENIA 2015; 1:15028. [PMID: 27336037 PMCID: PMC4849454 DOI: 10.1038/npjschz.2015.28] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/16/2015] [Accepted: 06/18/2015] [Indexed: 12/29/2022]
Abstract
Background: Glutamate abnormalities have been suggested to be associated with symptoms of schizophrenia. Using functional magnetic resonance spectroscopy (1H-fMRS), it is possible to monitor glutamate dynamically in the activated brain areas, which has yet to be reported in schizophrenia. It was hypothesized that subjects with schizophrenia would have weaker glutamatergic responses in the anterior cingulate to a color-word Stroop Task. AIMS: The aim of this study was to gain insight into the health of GLU neurotransmission and the GLU-GLN cycle in SZ using a 1H-fMRS protocol. Methods: Spectra were acquired from the anterior cingulate of 16 participants with schizophrenia, 16 healthy controls and 16 participants with major depressive disorder (MDD) while performing the Stroop task in a 7T magnetic resonance imaging scanner. 1H-fMRS spectra were acquired for 20 min in which there were three 4-min blocks of cross fixation interleaved with two 4-min blocks of the Stroop paradigm. Results: A repeated-measures analysis of variance revealed a main effect of time for glutamate concentrations of all groups (P<0.001). The healthy control group increased glutamate concentrations in the first run of the Stroop task (P=0.006) followed by a decrease in the recovery period (P=0.007). Neither the schizophrenia (P=0.107) nor MDD (P=0.081) groups had significant glutamate changes in the first run of the task, while the schizophrenia group had a significant increase in glutamine (P=0.005). The MDD group decreased glutamate concentrations in the second run of the task (P=0.003), as did all the groups combined (P=0.003). Conclusions: 1H-fMRS data were successfully acquired from psychiatric subjects with schizophrenia and mood disorder using a cognitive paradigm for the first time. Future study designs should further elucidate the glutamatergic response to functional activation in schizophrenia.
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Affiliation(s)
- Reggie Taylor
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada
| | - Richard W J Neufeld
- Department of Psychiatry, University of Western Ontario, London, ON, Canada; Department of Psychology, University of Western Ontario, London, ON, Canada; Department of Neuroscience, University of Western Ontario, London, ON, Canada
| | - Betsy Schaefer
- Department of Psychiatry, University of Western Ontario , London, ON, Canada
| | - Maria Densmore
- Lawson Health Research Institute, London, ON, Canada; Department of Psychiatry, University of Western Ontario, London, ON, Canada
| | - Nagalingam Rajakumar
- Department of Psychiatry, University of Western Ontario, London, ON, Canada; Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, Canada
| | - Elizabeth A Osuch
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada; Department of Psychiatry, University of Western Ontario, London, ON, Canada
| | - Peter C Williamson
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada; Department of Psychiatry, University of Western Ontario, London, ON, Canada
| | - Jean Théberge
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada; Department of Psychiatry, University of Western Ontario, London, ON, Canada
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122
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Banerjee A, Wang HY, Borgmann-Winter KE, MacDonald ML, Kaprielian H, Stucky A, Kvasic J, Egbujo C, Ray R, Talbot K, Hemby SE, Siegel SJ, Arnold SE, Sleiman P, Chang X, Hakonarson H, Gur RE, Hahn CG. Src kinase as a mediator of convergent molecular abnormalities leading to NMDAR hypoactivity in schizophrenia. Mol Psychiatry 2015; 20:1091-100. [PMID: 25330739 PMCID: PMC5156326 DOI: 10.1038/mp.2014.115] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 08/19/2014] [Accepted: 08/21/2014] [Indexed: 01/28/2023]
Abstract
Numerous investigations support decreased glutamatergic signaling as a pathogenic mechanism of schizophrenia, yet the molecular underpinnings for such dysregulation are largely unknown. In the post-mortem dorsolateral prefrontal cortex (DLPFC), we found striking decreases in tyrosine phosphorylation of N-methyl-D aspartate (NMDA) receptor subunit 2 (GluN2) that is critical for neuroplasticity. The decreased GluN2 activity in schizophrenia may not be because of downregulation of NMDA receptors as MK-801 binding and NMDA receptor complexes in postsynaptic density (PSD) were in fact increased in schizophrenia cases. At the postreceptor level, however, we found striking reductions in the protein kinase C, Pyk 2 and Src kinase activity that in tandem can decrease GluN2 activation. Given that Src serves as a hub of various signaling mechanisms affecting GluN2 phosphorylation, we postulated that Src hypoactivity may result from convergent alterations of various schizophrenia susceptibility pathways and thus mediate their effects on NMDA receptor signaling. Indeed, the DLPFC of schizophrenia cases exhibit increased PSD-95 and erbB4 and decreased receptor-type tyrosine-protein phosphatase-α (RPTPα) and dysbindin-1, each of which reduces Src activity via protein interaction with Src. To test genomic underpinnings for Src hypoactivity, we examined genome-wide association study results, incorporating 13 394 cases and 34 676 controls. We found no significant association of individual variants of Src and its direct regulators with schizophrenia. However, a protein-protein interaction-based network centered on Src showed significant enrichment of gene-level associations with schizophrenia compared with other psychiatric illnesses. Our results together demonstrate striking decreases in NMDA receptor signaling at the postreceptor level and propose Src as a nodal point of convergent dysregulations affecting NMDA receptor pathway via protein-protein associations.
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Affiliation(s)
- Anamika Banerjee
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Hoau-Yan Wang
- Department of Physiology, Pharmacology and Neuroscience, City University of New York Medical School, New York, NY 10031
| | | | - Mathew L. MacDonald
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Hagop Kaprielian
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Andres Stucky
- Department of Physiology, Pharmacology and Neuroscience, City University of New York Medical School, New York, NY 10031
| | - Jessica Kvasic
- Department of Physiology, Pharmacology and Neuroscience, City University of New York Medical School, New York, NY 10031
| | - Chijioke Egbujo
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Rabindranath Ray
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Konrad Talbot
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Scott E Hemby
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27106
| | - Steven J. Siegel
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Steven E. Arnold
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Patrick Sleiman
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, and Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104
| | - Xiao Chang
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, and Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104
| | - Hakon Hakonarson
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, and Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Chang-Gyu Hahn
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
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Batalla A, Bargalló N, Gassó P, Molina O, Pareto D, Mas S, Roca JM, Bernardo M, Lafuente A, Parellada E. Apoptotic markers in cultured fibroblasts correlate with brain metabolites and regional brain volume in antipsychotic-naive first-episode schizophrenia and healthy controls. Transl Psychiatry 2015; 5:e626. [PMID: 26305477 PMCID: PMC4564572 DOI: 10.1038/tp.2015.122] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/03/2015] [Accepted: 07/11/2015] [Indexed: 01/22/2023] Open
Abstract
Cultured fibroblasts from first-episode schizophrenia patients (FES) have shown increased susceptibility to apoptosis, which may be related to glutamate dysfunction and progressive neuroanatomical changes. Here we determine whether apoptotic markers obtained from cultured fibroblasts in FES and controls correlate with changes in brain glutamate and N-acetylaspartate (NAA) and regional brain volumes. Eleven antipsychotic-naive FES and seven age- and gender-matched controls underwent 3-Tesla magnetic resonance imaging scanning. Glutamate plus glutamine (Glx) and NAA levels were measured in the anterior cingulate (AC) and the left thalamus (LT). Hallmarks of apoptotic susceptibility (caspase-3-baseline activity, phosphatidylserine externalization and chromatin condensation) were measured in fibroblast cultures obtained from skin biopsies after inducing apoptosis with staurosporine (STS) at doses of 0.25 and 0.5 μM. Apoptotic biomarkers were correlated to brain metabolites and regional brain volume. FES and controls showed a negative correlation in the AC between Glx levels and percentages of cells with condensed chromatin (CC) after both apoptosis inductions (STS 0.5 μM: r = -0.90; P = 0.001; STS 0.25 μM: r = -0.73; P = 0.003), and between NAA and cells with CC (STS 0.5 μM induction r = -0.76; P = 0.002; STS 0.25 μM r = -0.62; P = 0.01). In addition, we found a negative correlation between percentages of cells with CC and regional brain volume in the right supratemporal cortex and post-central region (STS 0.25 and 0.5 μM; P < 0.05 family-wise error corrected (FWEc)). We reveal for the first time that peripheral markers of apoptotic susceptibility may correlate with brain metabolites, Glx and NAA, and regional brain volume in FES and controls, which is consistent with the neuroprogressive theories around the onset of the schizophrenia illness.
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Affiliation(s)
- A Batalla
- Department of Psychiatry and Psychology, Clinical Institute of Neuroscience, Hospital Clínic de Barcelona, Barcelona, Spain,Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain,Radboud University Medical Centre, Department of Psychiatry, Nijmegen, The Netherlands,Radboud University, Nijmegen Institute for Scientist-Practitioners in Addiction, Nijmegen, The Netherlands,Radboud University Medical Center, Department of Psychiatry, Reinier Postlaan 10, route 966, Nijmegen 6500 HB, The Netherlands.
| | - N Bargalló
- Medical Image Core facility Institut d'Investigacions Biomèdiques August Pi i Sunyer, Centre de diagnòstic per la Imatge Clínic, Hospital Clinic of Barcelona, Barcelona, Spain,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain,Centro de Investigación Biomédica en Red de Salud Mental, Barcelona, Spain
| | - P Gassó
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain,Department of Pathological Anatomy, Pharmacology and Microbiology, University of Barcelona, Barcelona, Spain
| | - O Molina
- Department of Psychiatry, Hospital Universitari Mútua de Terrassa, Barcelona, Spain
| | - D Pareto
- Magnetic Resonance Unit, Vall Hebron University Hospital IDI, Barcelona, Spain
| | - S Mas
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain,Centro de Investigación Biomédica en Red de Salud Mental, Barcelona, Spain,Department of Pathological Anatomy, Pharmacology and Microbiology, University of Barcelona, Barcelona, Spain
| | - J M Roca
- Department of Psychiatry and Psychology, Clinical Institute of Neuroscience, Hospital Clínic de Barcelona, Barcelona, Spain
| | - M Bernardo
- Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain,Centro de Investigación Biomédica en Red de Salud Mental, Barcelona, Spain,Barcelona Clinic Schizophrenia Unit, Neuroscience Institute, Hospital Clinic of Barcelona, Barcelona, Spain
| | - A Lafuente
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain,Centro de Investigación Biomédica en Red de Salud Mental, Barcelona, Spain,Department of Pathological Anatomy, Pharmacology and Microbiology, University of Barcelona, Barcelona, Spain
| | - E Parellada
- Department of Psychiatry and Psychology, Clinical Institute of Neuroscience, Hospital Clínic de Barcelona, Barcelona, Spain,Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain,Centro de Investigación Biomédica en Red de Salud Mental, Barcelona, Spain,Department of Pathological Anatomy, Pharmacology and Microbiology, University of Barcelona, Barcelona, Spain,Barcelona Clinic Schizophrenia Unit, Neuroscience Institute, Hospital Clinic of Barcelona, Barcelona, Spain
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124
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Vaessen T, Hernaus D, Myin-Germeys I, van Amelsvoort T. The dopaminergic response to acute stress in health and psychopathology: A systematic review. Neurosci Biobehav Rev 2015. [PMID: 26196459 DOI: 10.1016/j.neubiorev.2015.07.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Previous work in animals has shown that dopamine (DA) in cortex and striatum plays an essential role in stress processing. For the first time, we systematically reviewed the in vivo evidence for DAergic stress processing in health and psychopathology in humans. All studies included (n studies=25, n observations=324) utilized DA D2/3 positron emission tomography and measured DAergic activity during an acute stress challenge. The evidence in healthy volunteers (HV) suggests that physiological, but not psychological, stress consistently increases striatal DA release. Instead, increased medial prefrontal cortex (mPFC) DAergic activity in HV was observed during psychological stress. Across brain regions, stress-related DAergic activity was correlated with the physiological and psychological intensity of the stressor. The magnitude of stress-induced DA release was dependent on rearing conditions, personality traits and genetic variations in several SNPs. In psychopathology, preliminary evidence was found for stress-related dorsal striatal DAergic hyperactivity in psychosis spectrum and a blunted response in chronic cannabis use and pain-related disorders, but results were inconsistent. Physiological stress-induced DAergic activity in striatum in HV may reflect somatosensory properties of the stressor and readiness for active fight-or-flight behavior. DAergic activity in HV in the ventral striatum and mPFC may be more related to expectations about the stressor and threat evaluation, respectively. Future studies with increased sample size in HV and psychopathology assessing the functional relevance of stress-induced DAergic activity, the association between cortical and subcortical DAergic activity and the direct comparison of different stressors are necessary to conclusively elucidate the role of the DA system in the stress response.
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Affiliation(s)
- Thomas Vaessen
- Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, School for Mental Health and Neuroscience MHeNS, Maastricht University, The Netherlands.
| | - Dennis Hernaus
- Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, School for Mental Health and Neuroscience MHeNS, Maastricht University, The Netherlands
| | - Inez Myin-Germeys
- Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, School for Mental Health and Neuroscience MHeNS, Maastricht University, The Netherlands
| | - Thérèse van Amelsvoort
- Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, School for Mental Health and Neuroscience MHeNS, Maastricht University, The Netherlands
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125
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Lemke C, Hess A, Clare S, Bachtiar V, Stagg C, Jezzard P, Emir U. Two-voxel spectroscopy with dynamic B0 shimming and flip angle adjustment at 7 T in the human motor cortex. NMR IN BIOMEDICINE 2015; 28:852-860. [PMID: 25973740 DOI: 10.1002/nbm.3328] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 04/17/2015] [Accepted: 04/19/2015] [Indexed: 06/04/2023]
Abstract
The aim of this study was to acquire high-quality in vivo (1) H spectra concurrently from two voxels at ultra-high field (7 T) without specialized hardware. To this end, an acquisition scheme was developed in which first-order shims and flip angles are dynamically updated to acquire spectra from both of the brain's motor cortices in an alternating fashion. To validate this acquisition scheme, separate, static, single-voxel acquisitions were also performed for comparison. Six subjects were examined using semi-LASER spectroscopy at 7 T. Barium titanate pads were used to increase the extent of the effective transmit field (B1 (+) ). Spectra were obtained from the hand area of both motor cortices for both acquisition schemes. LCModel was used to determine neurochemical profiles in order to examine variations between acquisition schemes and volumes of interest. The dynamic two-voxel acquisition protocol produced water linewidths (full width at half-maximum between 11.6 and 12.8 Hz) and signal-to-noise ratios similar to those from static single-voxel measurements. The concentrations of 13 individual and 3 combined metabolites with Cramér-Rao lower bounds below 30% were reliably detected for both acquisition schemes, and agreed well with previous postmortem assay and spectroscopy studies. The results show that high spectral quality from two voxels can be acquired concurrently without specialized hardware. This practical technique can be applied to many neuroscience applications.
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Affiliation(s)
- Clark Lemke
- Oxford Centre for Functional MRI of the Brain, University of Oxford, Oxford, Oxfordshire, UK
| | - Aaron Hess
- Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, Oxfordshire, UK
| | - Stuart Clare
- Oxford Centre for Functional MRI of the Brain, University of Oxford, Oxford, Oxfordshire, UK
| | - Velicia Bachtiar
- Oxford Centre for Functional MRI of the Brain, University of Oxford, Oxford, Oxfordshire, UK
| | - Charlotte Stagg
- Oxford Centre for Functional MRI of the Brain, University of Oxford, Oxford, Oxfordshire, UK
| | - Peter Jezzard
- Oxford Centre for Functional MRI of the Brain, University of Oxford, Oxford, Oxfordshire, UK
| | - Uzay Emir
- Oxford Centre for Functional MRI of the Brain, University of Oxford, Oxford, Oxfordshire, UK
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126
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Hugdahl K. Auditory hallucinations: A review of the ERC “VOICE” project. World J Psychiatry 2015; 5:193-209. [PMID: 26110121 PMCID: PMC4473491 DOI: 10.5498/wjp.v5.i2.193] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 12/08/2014] [Accepted: 04/14/2015] [Indexed: 02/05/2023] Open
Abstract
In this invited review I provide a selective overview of recent research on brain mechanisms and cognitive processes involved in auditory hallucinations. The review is focused on research carried out in the “VOICE” ERC Advanced Grant Project, funded by the European Research Council, but I also review and discuss the literature in general. Auditory hallucinations are suggested to be perceptual phenomena, with a neuronal origin in the speech perception areas in the temporal lobe. The phenomenology of auditory hallucinations is conceptualized along three domains, or dimensions; a perceptual dimension, experienced as someone speaking to the patient; a cognitive dimension, experienced as an inability to inhibit, or ignore the voices, and an emotional dimension, experienced as the “voices” having primarily a negative, or sinister, emotional tone. I will review cognitive, imaging, and neurochemistry data related to these dimensions, primarily the first two. The reviewed data are summarized in a model that sees auditory hallucinations as initiated from temporal lobe neuronal hyper-activation that draws attentional focus inward, and which is not inhibited due to frontal lobe hypo-activation. It is further suggested that this is maintained through abnormal glutamate and possibly gamma-amino-butyric-acid transmitter mediation, which could point towards new pathways for pharmacological treatment. A final section discusses new methods of acquiring quantitative data on the phenomenology and subjective experience of auditory hallucination that goes beyond standard interview questionnaires, by suggesting an iPhone/iPod app.
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127
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Dysfunctional prefrontal gamma-band oscillations reflect working memory and other cognitive deficits in schizophrenia. Biol Psychiatry 2015; 77:1010-9. [PMID: 25847179 DOI: 10.1016/j.biopsych.2015.02.034] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 01/22/2015] [Accepted: 02/24/2015] [Indexed: 12/30/2022]
Abstract
Impairments in working memory (WM) and other cognitive functions are cardinal neuropsychological symptoms in schizophrenia (ScZ). The prefrontal cortex (PFC) is important for mediating and executing these functions. Functional neuroimaging and molecular studies have consistently shown PFC abnormalities in ScZ. In addition, recent studies have suggested that impairments in oscillatory activity, especially in the gamma band (approximately 30-80 Hz), reflect disturbed cortical information processing in this patient group. Here we review evidence that dysfunctional gamma-band responses (GBR) in the PFC could be a factor contributing to WM and other cognitive deficits in ScZ. We provide an overview of noninvasive electrophysiological studies reporting frontal GBR abnormalities in ScZ patients during WM and other cognitive tasks. In agreement with the often-reported hypofrontality in functional neuroimaging studies, the majority of reviewed studies revealed reduced amplitudes or reduced phase locking of GBR over frontal areas in this patient group. Clinical implications derived from these findings and possibilities to foster future studies on GBR abnormalities in ScZ patients, are discussed. Since oscillatory activity in the gamma band has previously been linked to a variety of neurotransmitters, such as the gamma-aminobutyric acid-ergic system, the study of prefrontal GBR could also have implications for pharmacologic approaches in the treatment of WM and other cognitive deficits in ScZ.
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128
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Abstract
PURPOSE OF REVIEW The ketamine model has dominated drug discovery in schizophrenia over the past decade, supported by genetic and postmortem evidence implicating glutamatergic transmission. This review assesses recent successes and disappointments of glutamatergic agents and identifies promising new directions. RECENT FINDINGS Strategies focused on enhancing activity of the N-methyl D-aspartate (NMDA) receptor via direct agonists at the glycine site or by inhibition of glycine reuptake have produced modest and often inconsistent evidence of efficacy, as have approaches to reduce excessive glutamate release by lamotrigine or by mGluR2/3 agonists. Strategies targeting α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors have also met with only limited success. Newer approaches include selective allosteric modulation of NMDA receptor subunits and of mGluR5 receptors. In addition, intracellular pathways downstream of NMDA receptors may also provide new treatment targets, as exemplified by phosphodiesterase (PDE) inhibitors. SUMMARY Targeting glutamatergic transmission remains one of the most promising strategies in schizophrenia, particularly early in the course of illness, but therapeutic approaches may require greater specificity for receptor subtype type, illness phase, and individual biology in order to enhance efficacy and overcome problems with reproducibility of clinical results.
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129
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Millan MJ, Goodwin GM, Meyer-Lindenberg A, Ove Ögren S. Learning from the past and looking to the future: Emerging perspectives for improving the treatment of psychiatric disorders. Eur Neuropsychopharmacol 2015; 25:599-656. [PMID: 25836356 DOI: 10.1016/j.euroneuro.2015.01.016] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 01/28/2015] [Indexed: 02/06/2023]
Abstract
Modern neuropsychopharmacology commenced in the 1950s with the serendipitous discovery of first-generation antipsychotics and antidepressants which were therapeutically effective yet had marked adverse effects. Today, a broader palette of safer and better-tolerated agents is available for helping people that suffer from schizophrenia, depression and other psychiatric disorders, while complementary approaches like psychotherapy also have important roles to play in their treatment, both alone and in association with medication. Nonetheless, despite considerable efforts, current management is still only partially effective, and highly-prevalent psychiatric disorders of the brain continue to represent a huge personal and socio-economic burden. The lack of success in discovering more effective pharmacotherapy has contributed, together with many other factors, to a relative disengagement by pharmaceutical firms from neuropsychiatry. Nonetheless, interest remains high, and partnerships are proliferating with academic centres which are increasingly integrating drug discovery and translational research into their traditional activities. This is, then, a time of transition and an opportune moment to thoroughly survey the field. Accordingly, the present paper, first, chronicles the discovery and development of psychotropic agents, focusing in particular on their mechanisms of action and therapeutic utility, and how problems faced were eventually overcome. Second, it discusses the lessons learned from past successes and failures, and how they are being applied to promote future progress. Third, it comprehensively surveys emerging strategies that are (1), improving our understanding of the diagnosis and classification of psychiatric disorders; (2), deepening knowledge of their underlying risk factors and pathophysiological substrates; (3), refining cellular and animal models for discovery and validation of novel therapeutic agents; (4), improving the design and outcome of clinical trials; (5), moving towards reliable biomarkers of patient subpopulations and medication efficacy and (6), promoting collaborative approaches to innovation by uniting key partners from the regulators, industry and academia to patients. Notwithstanding the challenges ahead, the many changes and ideas articulated herein provide new hope and something of a framework for progress towards the improved prevention and relief of psychiatric and other CNS disorders, an urgent mission for our Century.
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Affiliation(s)
- Mark J Millan
- Pole for Innovation in Neurosciences, IDR Servier, 125 chemin de ronde, 78290 Croissy sur Seine, France.
| | - Guy M Goodwin
- University Department of Psychiatry, Oxford University, Warneford Hospital, Oxford OX3 7JX, England, UK
| | - Andreas Meyer-Lindenberg
- Central Institute of Mental Health, University of Heidelberg/Medical Faculty Mannheim, J5, D-68159 Mannheim, Germany
| | - Sven Ove Ögren
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, S-17177 Stockholm, Sweden
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130
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Scarr E, Millan MJ, Bahn S, Bertolino A, Turck CW, Kapur S, Möller HJ, Dean B. Biomarkers for Psychiatry: The Journey from Fantasy to Fact, a Report of the 2013 CINP Think Tank. Int J Neuropsychopharmacol 2015; 18:pyv042. [PMID: 25899066 PMCID: PMC4648162 DOI: 10.1093/ijnp/pyv042] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND A think tank sponsored by the Collegium Internationale Neuropsychopharmacologium (CINP) debated the status and prospects of biological markers for psychiatric disorders, focusing on schizophrenia and major depressive disorder. METHODS Discussions covered markers defining and predicting specific disorders or domains of dysfunction, as well as predicting and monitoring medication efficacy. Deliberations included clinically useful and viable biomarkers, why suitable markers are not available, and the need for tightly-controlled sample collection. RESULTS Different types of biomarkers, appropriate sensitivity, specificity, and broad-based exploitability were discussed. Whilst a number of candidates are in the discovery phases, all will require replication in larger, real-life cohorts. Clinical cost-effectiveness also needs to be established. CONCLUSIONS Since a single measure is unlikely to suffice, multi-modal strategies look more promising, although they bring greater technical and implementation complexities. Identifying reproducible, robust biomarkers will probably require pre-competitive consortia to provide the resources needed to identify, validate, and develop the relevant clinical tests.
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Affiliation(s)
- Elizabeth Scarr
- Department of Psychiatry, University of Melbourne, Victoria, Australia (Drs Scarr and Dean); The Molecular Psychiatry Laboratory, Florey Institute for Neuroscience and Mental Health, Victoria, Australia (Drs Scarr and Dean); Pole d'Innovation Thérapeutique en Neuropsychiatrie, Institut de Recherches Servier, Paris, France (Dr Millan); Cambridge Centre for Neuropsychiatric Research, University of Cambridge, UK (Dr Bahn); Pharma Research & Early Development, NORD, DTA, Hoffman - La Roche, Ltd., Basel, Switzerland (Dr Bertolino); School of Medicine, Basic Medical Sciences, Neuroscience and Sense Organs (DMBNOS), University of Bari, Italy (Dr Bertolino); Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany (Dr Turck); Institute of Psychiatry, Kings College London, London, UK (Dr Kapur); Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany (Dr Möller)
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131
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Wijtenburg SA, Yang S, Fischer BA, Rowland LM. In vivo assessment of neurotransmitters and modulators with magnetic resonance spectroscopy: application to schizophrenia. Neurosci Biobehav Rev 2015; 51:276-95. [PMID: 25614132 PMCID: PMC4427237 DOI: 10.1016/j.neubiorev.2015.01.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 01/02/2015] [Accepted: 01/08/2015] [Indexed: 12/28/2022]
Abstract
In vivo measurement of neurotransmitters and modulators is now feasible with advanced proton magnetic resonance spectroscopy ((1)H MRS) techniques. This review provides a basic tutorial of MRS, describes the methods available to measure brain glutamate, glutamine, γ-aminobutyric acid, glutathione, N-acetylaspartylglutamate, glycine, and serine at magnetic field strengths of 3T or higher, and summarizes the neurochemical findings in schizophrenia. Overall, (1)H MRS holds great promise for producing biomarkers that can serve as treatment targets, prediction of disease onset, or illness exacerbation in schizophrenia and other brain diseases.
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Affiliation(s)
- S Andrea Wijtenburg
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, PO Box 21247, Baltimore, MD 21228, USA.
| | - Shaolin Yang
- Department of Psychiatry, University of Illinois at Chicago, 1601 W. Taylor Street, Suite 512, Chicago, IL 60612, USA; Department of Radiology, University of Illinois at Chicago, 1601 W. Taylor Street, Suite 512, Chicago, IL 60612, USA; Department of Bioengineering, University of Illinois at Chicago, 1601 W. Taylor Street, Suite 512, Chicago, IL 60612, USA
| | - Bernard A Fischer
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, PO Box 21247, Baltimore, MD 21228, USA; Veterans Affairs Capital Network (VISN 5) Mental Illness Research, Education, and Clinical Center (MIRECC), Department of Veterans Affairs, 10 N. Greene Street, Baltimore, MD 21201, USA
| | - Laura M Rowland
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, PO Box 21247, Baltimore, MD 21228, USA; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA; Department of Psychology, University of Maryland, Baltimore County, Baltimore, MD 21228, USA
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132
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No evidence for attenuated stress-induced extrastriatal dopamine signaling in psychotic disorder. Transl Psychiatry 2015; 5:e547. [PMID: 25871972 PMCID: PMC4462602 DOI: 10.1038/tp.2015.37] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 01/30/2015] [Accepted: 02/09/2015] [Indexed: 12/17/2022] Open
Abstract
Stress is an important risk factor in the etiology of psychotic disorder. Preclinical work has shown that stress primarily increases dopamine (DA) transmission in the frontal cortex. Given that DA-mediated hypofrontality is hypothesized to be a cardinal feature of psychotic disorder, stress-related extrastriatal DA release may be altered in psychotic disorder. Here we quantified for the first time stress-induced extrastriatal DA release and the spatial extent of extrastriatal DA release in individuals with non-affective psychotic disorder (NAPD). Twelve healthy volunteers (HV) and 12 matched drug-free NAPD patients underwent a single infusion [(18)F]fallypride positron emission tomography scan during which they completed the control and stress condition of the Montreal Imaging Stress Task. HV and NAPD did not differ in stress-induced [(18)F]fallypride displacement and the spatial extent of stress-induced [(18)F]fallypride displacement in medial prefrontal cortex (mPFC) and temporal cortex (TC). In the whole sample, the spatial extent of stress-induced radioligand displacement in right ventro-mPFC, but not dorso-mPFC or TC, was positively associated with task-induced subjective stress. Psychotic symptoms during the scan or negative, positive and general subscales of the Positive and Negative Syndrome Scale were not associated with stress-induced [(18)F]fallypride displacement nor the spatial extent of stress-induced [(18)F]fallypride displacement in NAPD. Our results do not offer evidence for altered stress-induced extrastriatal DA signaling in NAPD, nor altered functional relevance. The implications of these findings for the role of the DA system in NAPD and stress processing are discussed.
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133
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Basu D, Tian Y, Hui P, Bhandari J, Johnson RL, Mishra RK. Change in expression of vesicular protein synapsin II by chronic treatment with D2 allosteric modulator PAOPA. Peptides 2015; 66:58-62. [PMID: 25703303 DOI: 10.1016/j.peptides.2015.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/20/2015] [Accepted: 01/20/2015] [Indexed: 12/21/2022]
Abstract
The hallmark symptoms of schizophrenia include profound disturbances in thought, perception, cognition etc., which negatively impacts an individual's quality of life. Current antipsychotic drugs are not effective in treating all symptoms of this disorder, and often cause severe movement and metabolic side effects. Consequently, there remains a strong impetus to develop safer and more efficacious therapeutics for patients, as well as elucidating the etiology of schizophrenia. Previous work in our lab has introduced a novel candidate for the treatment of this disease: the dopamine D2 receptor (D2R) allosteric modulator, 3(R)-[(2(S)-pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide (PAOPA). We have previously shown that PAOPA, by selectively modulating D2R, can ameliorate schizophrenia-like symptoms in animal models, although the precise mechanism is presently not understood. Synapsin II is a presynaptic vesicular protein which has been strongly implicated in schizophrenia, as it is reduced in the prefrontal cortex of patients, and knockdown of this protein elicits schizophrenia-like phenotypes in animal models. Given the therapeutic effects of PAOPA and the role of synapsin II in schizophrenia, the objective of this study was to investigate the effect of chronic administration of PAOPA (45 days) on neuronal synapsin II protein expression in rodents. Immunoblot results revealed that the synapsin IIa, but not the IIb isoform, was increased in the dopaminergic regions of the striatum, nucleus accumbens, and medial prefrontal cortex. The results of this study implicate a role for modulation of synapsin II as a possible therapeutic mechanism of action for potential antipsychotic drug PAOPA.
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Affiliation(s)
- Dipannita Basu
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Yuxin Tian
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Patricia Hui
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Jayant Bhandari
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5
| | - Rodney L Johnson
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Ram K Mishra
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1200 Main St. W., Hamilton, ON, Canada L8N 3Z5.
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134
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Investigation of Heschl's gyrus and planum temporale in patients with schizophrenia and bipolar disorder: a proton magnetic resonance spectroscopy study. Schizophr Res 2015; 161:202-9. [PMID: 25480359 PMCID: PMC4308441 DOI: 10.1016/j.schres.2014.11.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 11/03/2014] [Accepted: 11/05/2014] [Indexed: 11/21/2022]
Abstract
BACKGROUND Superior temporal cortices include brain regions dedicated to auditory processing and several lines of evidence suggest structural and functional abnormalities in both schizophrenia and bipolar disorder within this brain region. However, possible glutamatergic dysfunction within this region has not been investigated in adult patients. METHODS Thirty patients with schizophrenia (38.67±12.46years of age), 28 euthymic patients with bipolar I disorder (35.32±9.12years of age), and 30 age-, gender- and education-matched healthy controls were enrolled. Proton magnetic resonance spectroscopy data were acquired using a 3.0T Siemens MAGNETOM TIM Trio MR system and single voxel Point REsolved Spectroscopy Sequence (PRESS) in order to quantify brain metabolites within the left and right Heschl's gyrus and planum temporale of superior temporal cortices. RESULTS There were significant abnormalities in glutamate (Glu) (F(2,78)=8.52, p<0.0001), N-acetyl aspartate (tNAA) (F(2,81)=5.73, p=0.005), creatine (tCr) (F(2,83)=5.91, p=0.004) and inositol (Ins) (F(2,82)=8.49, p<0.0001) concentrations in the left superior temporal cortex. In general, metabolite levels were lower for bipolar disorder patients when compared to healthy participants. Moreover, patients with bipolar disorder exhibited significantly lower tCr and Ins concentrations when compared to schizophrenia patients. In addition, we have found significant correlations between the superior temporal cortex metabolites and clinical measures. CONCLUSION As the left auditory cortices are associated with language and speech, left hemisphere specific abnormalities may have clinical significance. Our findings are suggestive of shared glutamatergic abnormalities in schizophrenia and bipolar disorder.
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135
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Hugdahl K, Craven AR, Nygård M, Løberg EM, Berle JØ, Johnsen E, Kroken R, Specht K, Andreassen OA, Ersland L. Glutamate as a mediating transmitter for auditory hallucinations in schizophrenia: a (1)H MRS study. Schizophr Res 2015; 161:252-60. [PMID: 25542859 DOI: 10.1016/j.schres.2014.11.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 11/07/2014] [Accepted: 11/15/2014] [Indexed: 01/16/2023]
Abstract
This is a (1)H MR spectroscopy (MRS) study of glutamate (Glu), measured as Glx, levels in temporal and frontal lobe regions in patients with schizophrenia compared with a healthy control group with the objective of revealing aspects of the underlying neurochemistry of auditory hallucinations. We further compared and correlated Glu(Glx) levels for the patients-only against frequency and severity of auditory hallucinations and the sum of Positive symptoms, and also for frequency and severity of emotional withdrawal, and sum of Negative symptoms. The sample included 23 patients with an ICD-10 and DSM-IV diagnosis of schizophrenia, and 26 healthy control subjects without any known psychiatric or neurological disorders. Symptom scores were obtained from the Positive and Negative Syndrome Scale (PANSS). (1)H MRS data were acquired on a 3T MR scanner from two temporal and two frontal voxels, using standard sequences and analysis parameters. The results showed that schizophrenia patients as a group had reduced Glu(Glx) levels in the voxels of interest compared to the healthy control subjects, while increased levels were found for patients with frequent and severe auditory hallucinations, relative to patients with less frequent and severe hallucination. We further found significant positive correlations between frequency and severity of auditory hallucinations, and for sum Positive symptoms, and Glu(Glx) levels in all regions, not seen when the analysis was done for negative symptoms. It is concluded that the results show for the first time that glutamate may be a mediating factor in auditory hallucinations in schizophrenia.
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Affiliation(s)
- Kenneth Hugdahl
- Department of Biological and Medical Psychology, University of Bergen, Norway; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway; Department of Radiology, Haukeland University Hospital, Bergen, Norway; NORMENT Center of Excellence, University of Oslo and Oslo University Hospital, Norway.
| | - Alexander R Craven
- Department of Biological and Medical Psychology, University of Bergen, Norway
| | - Merethe Nygård
- Department of Biological and Medical Psychology, University of Bergen, Norway
| | - Else-Marie Løberg
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway; Department of Clinical Psychology, University of Bergen, Norway
| | - Jan Øystein Berle
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Erik Johnsen
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway; Section of Psychiatry, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Rune Kroken
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Karsten Specht
- Department of Biological and Medical Psychology, University of Bergen, Norway; Department of Clinical Engineering, Haukeland University Hospital, Bergen, Norway
| | - Ole A Andreassen
- Division of Mental Health and Addiction, Oslo University Hospital & Institute of Clinical Medicine, University of Oslo, Norway; NORMENT Center of Excellence, University of Oslo and Oslo University Hospital, Norway
| | - Lars Ersland
- Department of Clinical Engineering, Haukeland University Hospital, Bergen, Norway
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136
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de Leeuw M, Kahn RS, Vink M. Fronto-striatal dysfunction during reward processing in unaffected siblings of schizophrenia patients. Schizophr Bull 2015; 41:94-103. [PMID: 25368371 PMCID: PMC4266310 DOI: 10.1093/schbul/sbu153] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Schizophrenia is a psychiatric disorder that is associated with impaired functioning of the fronto-striatal network, in particular during reward processing. However, it is unclear whether this dysfunction is related to the illness itself or whether it reflects a genetic vulnerability to develop schizophrenia. Here, we examined reward processing in unaffected siblings of schizophrenia patients using functional magnetic resonance imaging. Brain activity was measured during reward anticipation and reward outcome in 27 unaffected siblings of schizophrenia patients and 29 healthy volunteers using a modified monetary incentive delay task. Task performance was manipulated online so that all subjects won the same amount of money. Despite equal performance, siblings showed reduced activation in the ventral striatum, insula, and supplementary motor area (SMA) during reward anticipation compared to controls. Decreased ventral striatal activation in siblings was correlated with sub-clinical negative symptoms. During the outcome of reward, siblings showed increased activation in the ventral striatum and orbitofrontal cortex compared to controls. Our finding of decreased activity in the ventral striatum during reward anticipation and increased activity in this region during receiving reward may indicate impaired cue processing in siblings. This is consistent with the notion of dopamine dysfunction typically associated with schizophrenia. Since unaffected siblings share on average 50% of their genes with their ill relatives, these deficits may be related to the genetic vulnerability for schizophrenia.
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Affiliation(s)
- Max de Leeuw
- Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht, the Netherlands
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137
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Salavati B, Rajji TK, Price R, Sun Y, Graff-Guerrero A, Daskalakis ZJ. Imaging-based neurochemistry in schizophrenia: a systematic review and implications for dysfunctional long-term potentiation. Schizophr Bull 2015; 41:44-56. [PMID: 25249654 PMCID: PMC4266301 DOI: 10.1093/schbul/sbu132] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cognitive deficits are commonly observed in patients with schizophrenia. Converging lines of evidence suggest that these deficits are associated with impaired long-term potentiation (LTP). In our systematic review, this hypothesis is evaluated using neuroimaging literature focused on proton magnetic resonance spectroscopy, positron emission tomography, and single-photon emission computed tomography. The review provides evidence for abnormal dopaminergic, GABAergic, and glutamatergic neurotransmission in antipsychotic-naive/free patients with schizophrenia compared with healthy controls. The review concludes with a model illustrating how these abnormalities could lead to impaired LTP in patients with schizophrenia and consequently cognitive deficits.
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Affiliation(s)
- Bahar Salavati
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada;,Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Tarek K. Rajji
- *To whom correspondence should be addressed; 80 Workman Way, Room 6312, Toronto, Ontario M6J 1H4, Canada; tel: +1 416 535 8501 x 33661; fax: +1 416 583 1307; e-mail:
| | - Rae Price
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada;,Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Yinming Sun
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Ariel Graff-Guerrero
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Zafiris J. Daskalakis
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada;,Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, Canada;,Department of Psychiatry, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada;,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
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138
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Schadt EE, Buchanan S, Brennand KJ, Merchant KM. Evolving toward a human-cell based and multiscale approach to drug discovery for CNS disorders. Front Pharmacol 2014; 5:252. [PMID: 25520658 PMCID: PMC4251289 DOI: 10.3389/fphar.2014.00252] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/30/2014] [Indexed: 12/14/2022] Open
Abstract
A disruptive approach to therapeutic discovery and development is required in order to significantly improve the success rate of drug discovery for central nervous system (CNS) disorders. In this review, we first assess the key factors contributing to the frequent clinical failures for novel drugs. Second, we discuss cancer translational research paradigms that addressed key issues in drug discovery and development and have resulted in delivering drugs with significantly improved outcomes for patients. Finally, we discuss two emerging technologies that could improve the success rate of CNS therapies: human induced pluripotent stem cell (hiPSC)-based studies and multiscale biology models. Coincident with advances in cellular technologies that enable the generation of hiPSCs directly from patient blood or skin cells, together with methods to differentiate these hiPSC lines into specific neural cell types relevant to neurological disease, it is also now possible to combine data from large-scale forward genetics and post-mortem global epigenetic and expression studies in order to generate novel predictive models. The application of systems biology approaches to account for the multiscale nature of different data types, from genetic to molecular and cellular to clinical, can lead to new insights into human diseases that are emergent properties of biological networks, not the result of changes to single genes. Such studies have demonstrated the heterogeneity in etiological pathways and the need for studies on model systems that are patient-derived and thereby recapitulate neurological disease pathways with higher fidelity. In the context of two common and presumably representative neurological diseases, the neurodegenerative disease Alzheimer's Disease, and the psychiatric disorder schizophrenia, we propose the need for, and exemplify the impact of, a multiscale biology approach that can integrate panomic, clinical, imaging, and literature data in order to construct predictive disease network models that can (i) elucidate subtypes of syndromic diseases, (ii) provide insights into disease networks and targets and (iii) facilitate a novel drug screening strategy using patient-derived hiPSCs to discover novel therapeutics for CNS disorders.
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Affiliation(s)
- Eric E Schadt
- Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai New York, NY, USA ; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai New York, NY, USA
| | - Sean Buchanan
- Lilly Research Laboratories, Eli Lilly and Company Indianapolis, IN, USA
| | - Kristen J Brennand
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai New York, NY, USA
| | - Kalpana M Merchant
- Lilly Research Laboratories, Eli Lilly and Company Indianapolis, IN, USA
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139
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Park SJ, Lee Y, Oh HK, Lee HE, Lee Y, Ko SY, Kim B, Cheong JH, Shin CY, Ryu JH. Oleanolic acid attenuates MK-801-induced schizophrenia-like behaviors in mice. Neuropharmacology 2014; 86:49-56. [DOI: 10.1016/j.neuropharm.2014.06.025] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/21/2014] [Accepted: 06/24/2014] [Indexed: 12/29/2022]
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140
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Bubser M, Bridges TM, Dencker D, Gould RW, Grannan M, Noetzel MJ, Lamsal A, Niswender CM, Daniels JS, Poslusney MS, Melancon BJ, Tarr JC, Byers FW, Wess J, Duggan ME, Dunlop J, Wood MW, Brandon NJ, Wood MR, Lindsley CW, Conn PJ, Jones CK. Selective activation of M4 muscarinic acetylcholine receptors reverses MK-801-induced behavioral impairments and enhances associative learning in rodents. ACS Chem Neurosci 2014; 5:920-42. [PMID: 25137629 PMCID: PMC4324418 DOI: 10.1021/cn500128b] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Positive allosteric modulators (PAMs) of the M4 muscarinic acetylcholine receptor (mAChR) represent a novel approach for the treatment of psychotic symptoms associated with schizophrenia and other neuropsychiatric disorders. We recently reported that the selective M4 PAM VU0152100 produced an antipsychotic drug-like profile in rodents after amphetamine challenge. Previous studies suggest that enhanced cholinergic activity may also improve cognitive function and reverse deficits observed with reduced signaling through the N-methyl-d-aspartate subtype of the glutamate receptor (NMDAR) in the central nervous system. Prior to this study, the M1 mAChR subtype was viewed as the primary candidate for these actions relative to the other mAChR subtypes. Here we describe the discovery of a novel M4 PAM, VU0467154, with enhanced in vitro potency and improved pharmacokinetic properties relative to other M4 PAMs, enabling a more extensive characterization of M4 actions in rodent models. We used VU0467154 to test the hypothesis that selective potentiation of M4 receptor signaling could ameliorate the behavioral, cognitive, and neurochemical impairments induced by the noncompetitive NMDAR antagonist MK-801. VU0467154 produced a robust dose-dependent reversal of MK-801-induced hyperlocomotion and deficits in preclinical models of associative learning and memory functions, including the touchscreen pairwise visual discrimination task in wild-type mice, but failed to reverse these stimulant-induced deficits in M4 KO mice. VU0467154 also enhanced the acquisition of both contextual and cue-mediated fear conditioning when administered alone in wild-type mice. These novel findings suggest that M4 PAMs may provide a strategy for addressing the more complex affective and cognitive disruptions associated with schizophrenia and other neuropsychiatric disorders.
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Affiliation(s)
- Michael Bubser
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Thomas M. Bridges
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Ditte Dencker
- Laboratory
of Neuropsychiatry, Psychiatric Centre Copenhagen, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark
| | - Robert W. Gould
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Michael Grannan
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Meredith J. Noetzel
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Atin Lamsal
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Colleen M. Niswender
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - J. Scott Daniels
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Michael S. Poslusney
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Bruce J. Melancon
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - James C. Tarr
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Frank W. Byers
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Jürgen Wess
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20814, United States
| | - Mark E. Duggan
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - John Dunlop
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - Michael W. Wood
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - Nicholas J. Brandon
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - Michael R. Wood
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Craig W. Lindsley
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - P. Jeffrey Conn
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Carrie K. Jones
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
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141
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GLT-1 transporter: an effective pharmacological target for various neurological disorders. Pharmacol Biochem Behav 2014; 127:70-81. [PMID: 25312503 DOI: 10.1016/j.pbb.2014.10.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 09/01/2014] [Accepted: 10/03/2014] [Indexed: 11/23/2022]
Abstract
L-Glutamate is the predominant excitatory neurotransmitter in the central nervous system (CNS) and is directly and indirectly involved in a variety of brain functions. Glutamate is released in the synaptic cleft at a particular concentration that further activates the various glutaminergic receptors. This concentration of glutamate in the synapse is maintained by either glutamine synthetase or excitatory amino acid proteins which reuptake the excessive glutamate from the synapse and named as excitatory amino acid transporters (EAATs). Out of all the subtypes GLT-1 (glutamate transporter 1) is abundantly distributed in the CNS. Down-regulation of GLT-1 is reported in various neurological diseases such as, epilepsy, stroke, Alzheimer's disease and movement disorders. Therefore, positive modulators of GLT-1 which up-regulate the GLT-1 expression can serve as a potential target for the treatment of neurological disorders. GLT-1 translational activators such as ceftriaxone are found to have significant protective effects in ALS and epilepsy animal models, suggesting that this translational activation approach works well in rodents and that these compounds are worth further pursuit for various neurological disorders. This drug is currently in human clinical trials for ALS. In addition, a thorough understanding of the mechanisms underlying translational regulation of GLT-1, such as identifying the molecular targets of the compounds, signaling pathways involved in the regulation, and translational activation processes, is very important for this novel drug-development effort. This review mainly emphasizes the role of glutamate and its transporter, GLT-1 subtype in excitotoxicity. Further, recent reports on GLT-1 transporters for the treatment of various neurological diseases, including a summary of the presumed physiologic mechanisms behind the pharmacology of these disorders are also explained.
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142
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Plitman E, Nakajima S, de la Fuente-Sandoval C, Gerretsen P, Chakravarty MM, Kobylianskii J, Chung JK, Caravaggio F, Iwata Y, Remington G, Graff-Guerrero A. Glutamate-mediated excitotoxicity in schizophrenia: a review. Eur Neuropsychopharmacol 2014; 24:1591-605. [PMID: 25159198 PMCID: PMC4470624 DOI: 10.1016/j.euroneuro.2014.07.015] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/22/2014] [Accepted: 07/26/2014] [Indexed: 12/16/2022]
Abstract
Findings from neuroimaging studies in patients with schizophrenia suggest widespread structural changes although the mechanisms through which these changes occur are currently unknown. Glutamatergic activity appears to be increased in the early phases of schizophrenia and may contribute to these structural alterations through an excitotoxic effect. The primary aim of this review was to describe the possible role of glutamate-mediated excitotoxicity in explaining the presence of neuroanatomical changes within schizophrenia. A Medline(®) literature search was conducted, identifying English language studies on the topic of glutamate-mediated excitotoxicity in schizophrenia, using the terms "schizophreni" and "glutam" and (("MRS" or "MRI" or "magnetic resonance") or ("computed tomography" or "CT")). Studies concomitantly investigating glutamatergic activity and brain structure in patients with schizophrenia were included. Results are discussed in the context of findings from preclinical studies. Seven studies were identified that met the inclusion criteria. These studies provide inconclusive support for the role of glutamate-mediated excitotoxicity in the occurrence of structural changes within schizophrenia, with the caveat that there is a paucity of human studies investigating this topic. Preclinical data suggest that an excitotoxic effect may occur as a result of a paradoxical increase in glutamatergic activity following N-methyl-D-aspartate receptor hypofunction. Based on animal literature, glutamate-mediated excitotoxicity may account for certain structural changes present in schizophrenia, but additional human studies are required to substantiate these findings. Future studies should adopt a longitudinal design and employ magnetic resonance imaging techniques to investigate whether an association between glutamatergic activity and structural changes exists in patients with schizophrenia.
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Affiliation(s)
- Eric Plitman
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Shinichiro Nakajima
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan; Geriatric Mental Health Division, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Camilo de la Fuente-Sandoval
- Experimental Psychiatry Laboratory, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico; Neuropsychiatry Department, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico
| | - Philip Gerretsen
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Division, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - M Mallar Chakravarty
- Cerebral Imaging Centre, Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada; Departments of Psychiatry and Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Jane Kobylianskii
- Department of Medicine, Queen׳s University, Kingston, Ontario, Canada
| | - Jun Ku Chung
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Fernando Caravaggio
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Yusuke Iwata
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Gary Remington
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Campbell Institute Research Program, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Schizophrenia Program, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada
| | - Ariel Graff-Guerrero
- Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Division, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Campbell Institute Research Program, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.
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143
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Barkus C, Sanderson DJ, Rawlins JNP, Walton ME, Harrison PJ, Bannerman DM. What causes aberrant salience in schizophrenia? A role for impaired short-term habituation and the GRIA1 (GluA1) AMPA receptor subunit. Mol Psychiatry 2014; 19:1060-70. [PMID: 25224260 PMCID: PMC4189912 DOI: 10.1038/mp.2014.91] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/19/2014] [Accepted: 06/25/2014] [Indexed: 01/13/2023]
Abstract
The GRIA1 locus, encoding the GluA1 (also known as GluRA or GluR1) AMPA glutamate receptor subunit, shows genome-wide association to schizophrenia. As well as extending the evidence that glutamatergic abnormalities have a key role in the disorder, this finding draws attention to the behavioural phenotype of Gria1 knockout mice. These mice show deficits in short-term habituation. Importantly, under some conditions the attention being paid to a recently presented neutral stimulus can actually increase rather than decrease (sensitization). We propose that this mouse phenotype represents a cause of aberrant salience and, in turn, that aberrant salience (and the resulting positive symptoms) in schizophrenia may arise, at least in part, from a glutamatergic genetic predisposition and a deficit in short-term habituation. This proposal links an established risk gene with a psychological process central to psychosis and is supported by findings of comparable deficits in short-term habituation in mice lacking the NMDAR receptor subunit Grin2a (which also shows association to schizophrenia). As aberrant salience is primarily a dopaminergic phenomenon, the model supports the view that the dopaminergic abnormalities can be downstream of a glutamatergic aetiology. Finally, we suggest that, as illustrated here, the real value of genetically modified mice is not as 'models of schizophrenia' but as experimental tools that can link genomic discoveries with psychological processes and help elucidate the underlying neural mechanisms.
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Affiliation(s)
- C Barkus
- Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, OX3 7JX, U.K
| | - DJ Sanderson
- Department of Psychology, Durham University, Durham, DH1 3LE, U.K
| | - JNP Rawlins
- Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford, OX1 3UD, U.K
| | - ME Walton
- Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford, OX1 3UD, U.K
| | - PJ Harrison
- Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, OX3 7JX, U.K
| | - DM Bannerman
- Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford, OX1 3UD, U.K
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144
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LIU D, XU Y, JIANG K. Advances in neuroimaging research of schizophrenia in China. SHANGHAI ARCHIVES OF PSYCHIATRY 2014; 26:181-93. [PMID: 25317005 PMCID: PMC4194001 DOI: 10.3969/j.issn.1002-0829.2014.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 08/20/2014] [Indexed: 11/26/2022]
Abstract
SUMMARY Since Hounsfield's first report about X-ray computed tomography (CT) in 1972, there has been substantial progress in the application of neuroimaging techniques to study the structure, function, and biochemistry of the brain. This review provides a summary of recent research in structural and functional neuroimaging of schizophrenia in China and four tables describing all of the relevant studies from mainland China. The first research report using neuroimaging techniques in China dates back to 1983, a study that reported encephalatrophy in 30% of individuals with schizophrenia. Functional neuroimaging research in China emerged in the 1990s and has undergone rapid development since. Recently, structural and functional brain networks has become a hot topic among China's neuroimaging researchers.
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Affiliation(s)
| | - Yifeng XU
- Division of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kaida JIANG
- Division of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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145
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Hashimoto K. Targeting of NMDA receptors in new treatments for schizophrenia. Expert Opin Ther Targets 2014; 18:1049-63. [PMID: 24965576 DOI: 10.1517/14728222.2014.934225] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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146
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Millan MJ, Fone K, Steckler T, Horan WP. Negative symptoms of schizophrenia: clinical characteristics, pathophysiological substrates, experimental models and prospects for improved treatment. Eur Neuropsychopharmacol 2014; 24:645-92. [PMID: 24820238 DOI: 10.1016/j.euroneuro.2014.03.008] [Citation(s) in RCA: 228] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 03/19/2014] [Indexed: 12/11/2022]
Abstract
Schizophrenia is a complex and multifactorial disorder generally diagnosed in young adults at the time of the first psychotic episode of delusions and hallucinations. These positive symptoms can be controlled in most patients by currently-available antipsychotics. Conversely, they are poorly effective against concomitant neurocognitive dysfunction, deficits in social cognition and negative symptoms (NS), which strongly contribute to poor functional outcome. The precise notion of NS has evolved over the past century, with recent studies - underpinned by novel rating methods - suggesting two major sub-domains: "decreased emotional expression", incorporating blunted affect and poverty of speech, and "avolition", which embraces amotivation, asociality and "anhedonia" (inability to anticipate pleasure). Recent studies implicate a dysfunction of frontocortico-temporal networks in the aetiology of NS, together with a disruption of cortico-striatal circuits, though other structures are also involved, like the insular and parietal cortices, amygdala and thalamus. At the cellular level, a disruption of GABAergic-glutamatergic balance, dopaminergic signalling and, possibly, oxytocinergic and cannibinoidergic transmission may be involved. Several agents are currently under clinical investigation for the potentially improved control of NS, including oxytocin itself, N-Methyl-d-Aspartate receptor modulators and minocycline. Further, magnetic-electrical "stimulation" strategies to recruit cortical circuits and "cognitive-behavioural-psychosocial" therapies likewise hold promise. To acquire novel insights into the causes and treatment of NS, experimental study is crucial, and opportunities are emerging for improved genetic, pharmacological and developmental modelling, together with more refined readouts related to deficits in reward, sociality and "expression". The present article comprises an integrative overview of the above issues as a platform for this Special Issue of European Neuropsychopharmacology in which five clinical and five preclinical articles treat individual themes in greater detail. This Volume provides, then, a framework for progress in the understanding - and ultimately control - of the debilitating NS of schizophrenia.
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Affiliation(s)
- Mark J Millan
- Pole of Innovation in Neuropsychiatry, Institut de Recherche Servier, 125 Chemin de Ronde, 78290 Croissy-sur-Seine, Paris, France.
| | - Kevin Fone
- School of Biomedical Sciences, Medical School, Queen׳s Medical Centre, Nottingham University, Nottingham NG72UH, UK
| | - Thomas Steckler
- Janssen Research and Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - William P Horan
- VA Greater Los Angeles Healthcare System, University of California, Los Angeles, MIRECC 210A, Bldg. 210, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA
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147
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Gruber O, Chadha Santuccione A, Aach H. Magnetic resonance imaging in studying schizophrenia, negative symptoms, and the glutamate system. Front Psychiatry 2014; 5:32. [PMID: 24765078 PMCID: PMC3982059 DOI: 10.3389/fpsyt.2014.00032] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 03/14/2014] [Indexed: 01/27/2023] Open
Abstract
Schizophrenia is characterized by positive, negative, and cognitive symptoms. While positive symptoms occur periodically during psychotic exacerbations, negative and cognitive symptoms often emerge before the first psychotic episode and persist with low functional outcome and poor prognosis. This review article outlines the importance of modern functional magnetic resonance imaging techniques for developing a stratified therapy of schizophrenic disorders. Functional neuroimaging evidence on the neural correlates of positive and particularly negative symptoms and cognitive deficits in schizophrenic disorders is briefly reviewed. Acute dysregulation of dopaminergic neurotransmission is crucially involved in the occurrence of psychotic symptoms. However, increasing evidence also implicates glutamatergic pathomechanisms, in particular N-methyl-d-aspartate (NMDA) receptor dysfunction in the pathogenesis of schizophrenia and in the appearance of negative symptoms and cognitive dysfunctions. In line with this notion, several gene variants affecting the NMDA receptor's pathway have been reported to increase susceptibility for schizophrenia, and have been investigated using the imaging genetics approach. In recent years, several attempts have been made to develop medications modulating the glutamatergic pathway with modest evidences for efficacy. The most successful approaches were those that aimed at influencing this pathway using compounds that enhance NMDA receptor function. More recently, the selective glycine reuptake inhibitor bitopertin has been shown to improve NMDA receptor hypofunction by increasing glycine concentrations in the synaptic cleft. Further research is required to test whether pharmacological agents with effects on the glutamatergic system can help to improve the treatment of negative symptoms in schizophrenic disorders.
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Affiliation(s)
- Oliver Gruber
- Center for Translational Research in Systems Neuroscience and Psychiatry, Clinic for Psychiatry and Psychotherapy, University Medical Center Göttingen , Göttingen , Germany
| | | | - Helmut Aach
- Medical Affairs - Psychiatry, Roche Pharma AG , Grenzach-Wyhlen , Germany
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