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Ceanga M, Rahmati V, Haselmann H, Schmidl L, Hunter D, Brauer AK, Liebscher S, Kreye J, Prüss H, Groc L, Hallermann S, Dalmau J, Ori A, Heckmann M, Geis C. Human NMDAR autoantibodies disrupt excitatory-inhibitory balance, leading to hippocampal network hypersynchrony. Cell Rep 2023; 42:113166. [PMID: 37768823 DOI: 10.1016/j.celrep.2023.113166] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/30/2023] [Accepted: 09/07/2023] [Indexed: 09/30/2023] Open
Abstract
Anti-NMDA receptor autoantibodies (NMDAR-Abs) in patients with NMDAR encephalitis cause severe disease symptoms resembling psychosis and cause cognitive dysfunction. After passive transfer of patients' cerebrospinal fluid or human monoclonal anti-GluN1-autoantibodies in mice, we find a disrupted excitatory-inhibitory balance resulting from CA1 neuronal hypoexcitability, reduced AMPA receptor (AMPAR) signaling, and faster synaptic inhibition in acute hippocampal slices. Functional alterations are also reflected in widespread remodeling of the hippocampal proteome, including changes in glutamatergic and GABAergic neurotransmission. NMDAR-Abs amplify network γ oscillations and disrupt θ-γ coupling. A data-informed network model reveals that lower AMPAR strength and faster GABAA receptor current kinetics chiefly account for these abnormal oscillations. As predicted in silico and evidenced ex vivo, positive allosteric modulation of AMPARs alleviates aberrant γ activity, reinforcing the causative effects of the excitatory-inhibitory imbalance. Collectively, NMDAR-Ab-induced aberrant synaptic, cellular, and network dynamics provide conceptual insights into NMDAR-Ab-mediated pathomechanisms and reveal promising therapeutic targets that merit future in vivo validation.
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Affiliation(s)
- Mihai Ceanga
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Vahid Rahmati
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Holger Haselmann
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Lars Schmidl
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Daniel Hunter
- Université de Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Anna-Katherina Brauer
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Martinsried, Germany; Biomedical Center, Ludwig Maximilians University Munich, Martinsried, Germany
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Martinsried, Germany; Biomedical Center, Ludwig Maximilians University Munich, Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Jakob Kreye
- Department of Neurology and Experimental Neurology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Department of Pediatric Neurology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Harald Prüss
- Department of Neurology and Experimental Neurology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
| | - Laurent Groc
- Université de Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Stefan Hallermann
- Carl Ludwig Institute for Physiology, Faculty of Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Josep Dalmau
- Catalan Institution for Research and Advanced Studies (ICREA) and IDIBAPS-Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Alessandro Ori
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), 07745 Jena, Germany
| | - Manfred Heckmann
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
| | - Christian Geis
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, 07747 Jena, Germany.
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Gaidin SG, Kosenkov AM. mRNA editing of kainate receptor subunits: what do we know so far? Rev Neurosci 2022; 33:641-655. [DOI: 10.1515/revneuro-2021-0144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 01/18/2022] [Indexed: 11/15/2022]
Abstract
Abstract
Kainate receptors (KARs) are considered one of the key modulators of synaptic activity in the mammalian central nervous system. These receptors were discovered more than 30 years ago, but their role in brain functioning remains unclear due to some peculiarities. One such feature of these receptors is the editing of pre-mRNAs encoding GluK1 and GluK2 subunits. Despite the long history of studying this phenomenon, numerous questions remain unanswered. This review summarizes the current data about the mechanism and role of pre-mRNA editing of KAR subunits in the mammalian brain and proposes a perspective of future investigations.
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Affiliation(s)
- Sergei G. Gaidin
- Institute of Cell Biophysics of the Russian Academy of Sciences , 142290 , Pushchino , Russia
| | - Artem M. Kosenkov
- Institute of Cell Biophysics of the Russian Academy of Sciences , 142290 , Pushchino , Russia
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Yavas E, Young AM. Repeated phencyclidine disrupts nicotinic acetylcholine regulation of dopamine release in nucleus accumbens: Implications for models of schizophrenia. Neurochem Int 2020; 140:104836. [DOI: 10.1016/j.neuint.2020.104836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 01/02/2023]
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The allosteric dopamine D1 receptor potentiator, DETQ, ameliorates subchronic phencyclidine-induced object recognition memory deficits and enhances cortical acetylcholine efflux in male humanized D1 receptor knock-in mice. Behav Brain Res 2019; 361:139-150. [DOI: 10.1016/j.bbr.2018.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/30/2018] [Accepted: 12/01/2018] [Indexed: 12/13/2022]
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Filippini A, Bonini D, La Via L, Barbon A. The Good and the Bad of Glutamate Receptor RNA Editing. Mol Neurobiol 2016; 54:6795-6805. [DOI: 10.1007/s12035-016-0201-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/11/2016] [Indexed: 12/15/2022]
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Abdolmaleky HM, Zhou JR, Thiagalingam S. An update on the epigenetics of psychotic diseases and autism. Epigenomics 2015; 7:427-49. [DOI: 10.2217/epi.14.85] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The examination of potential roles of epigenetic alterations in the pathogenesis of psychotic diseases have become an essential alternative in recent years as genetic studies alone are yet to uncover major gene(s) for psychosis. Here, we describe the current state of knowledge from the gene-specific and genome-wide studies of postmortem brain and blood cells indicating that aberrant DNA methylation, histone modifications and dysregulation of micro-RNAs are linked to the pathogenesis of mental diseases. There is also strong evidence supporting that all classes of psychiatric drugs modulate diverse features of the epigenome. While comprehensive environmental and genetic/epigenetic studies are uncovering the origins, and the key genes/pathways affected in psychotic diseases, characterizing the epigenetic effects of psychiatric drugs may help to design novel therapies in psychiatry.
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Affiliation(s)
- Hamid Mostafavi Abdolmaleky
- Departments of Medicine (Biomedical Genetics Section), Genetics & Genomics, Boston University School of Medicine, Boston, MA 02118, USA
- Nutrition/Metabolism Laboratory at Beth Israel Deaconess Medical Center, Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Jin-Rong Zhou
- Nutrition/Metabolism Laboratory at Beth Israel Deaconess Medical Center, Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Sam Thiagalingam
- Departments of Medicine (Biomedical Genetics Section), Genetics & Genomics, Boston University School of Medicine, Boston, MA 02118, USA
- Department of Pathology & Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
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Brand SJ, Moller M, Harvey BH. A Review of Biomarkers in Mood and Psychotic Disorders: A Dissection of Clinical vs. Preclinical Correlates. Curr Neuropharmacol 2015; 13:324-68. [PMID: 26411964 PMCID: PMC4812797 DOI: 10.2174/1570159x13666150307004545] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 02/04/2015] [Accepted: 03/06/2015] [Indexed: 11/23/2022] Open
Abstract
Despite significant research efforts aimed at understanding the neurobiological underpinnings of mood (depression, bipolar disorder) and psychotic disorders, the diagnosis and evaluation of treatment of these disorders are still based solely on relatively subjective assessment of symptoms as well as psychometric evaluations. Therefore, biological markers aimed at improving the current classification of psychotic and mood-related disorders, and that will enable patients to be stratified on a biological basis into more homogeneous clinically distinct subgroups, are urgently needed. The attainment of this goal can be facilitated by identifying biomarkers that accurately reflect pathophysiologic processes in these disorders. This review postulates that the field of psychotic and mood disorder research has advanced sufficiently to develop biochemical hypotheses of the etiopathology of the particular illness and to target the same for more effective disease modifying therapy. This implies that a "one-size fits all" paradigm in the treatment of psychotic and mood disorders is not a viable approach, but that a customized regime based on individual biological abnormalities would pave the way forward to more effective treatment. In reviewing the clinical and preclinical literature, this paper discusses the most highly regarded pathophysiologic processes in mood and psychotic disorders, thereby providing a scaffold for the selection of suitable biomarkers for future studies in this field, to develope biomarker panels, as well as to improve diagnosis and to customize treatment regimens for better therapeutic outcomes.
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Affiliation(s)
| | | | - Brian H Harvey
- Division of Pharmacology and Center of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Potchefstroom, South Africa.
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Enhanced interaction among ErbB4, PSD-95 and NMDAR by chronic MK-801 treatment is associated with behavioral abnormalities. Pharmacol Biochem Behav 2013; 108:44-53. [DOI: 10.1016/j.pbb.2013.04.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 04/04/2013] [Accepted: 04/11/2013] [Indexed: 11/19/2022]
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Drummond JB, Tucholski J, Haroutunian V, Meador-Woodruff JH. Transmembrane AMPA receptor regulatory protein (TARP) dysregulation in anterior cingulate cortex in schizophrenia. Schizophr Res 2013; 147:32-38. [PMID: 23566497 PMCID: PMC3650109 DOI: 10.1016/j.schres.2013.03.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 03/07/2013] [Accepted: 03/11/2013] [Indexed: 02/09/2023]
Abstract
The glutamate hypothesis of schizophrenia proposes that abnormal glutamatergic neurotransmission occurs in this illness, and a major contribution may involve dysregulation of the AMPA subtype of ionotropic glutamate receptor (AMPAR). Transmembrane AMPAR regulatory proteins (TARPs) form direct associations with AMPARs to modulate the trafficking and biophysical functions of these receptors, and their dysregulation may alter the localization and activity of AMPARs, thus having a potential role in the pathophysiology of schizophrenia. We performed comparative quantitative real-time PCR and Western blot analysis to measure transcript (schizophrenia, N=25; comparison subjects, N=25) and protein (schizophrenia, N=36; comparison subjects, N=33) expression of TARPs (γ subunits 1-8) in the anterior cingulate cortex (ACC) in schizophrenia and a comparison group. TARP expression was also measured in frontal cortex of rats chronically treated with haloperidol decanoate (28.5mg/kg every three weeks for nine months) to determine the effect of antipsychotic treatment on the expression of these molecules. We found decreased transcript expression of TARP γ-8 in schizophrenia. At the protein level, γ-3 and γ-5 were increased, while γ-4, γ-7 and γ-8 were decreased in schizophrenia. No changes in any of the molecules were noted in the frontal cortex of haloperidol-treated rats. TARPs are abnormally expressed at transcript and protein levels in ACC in schizophrenia, and these changes are likely due to the illness and not to the antipsychotic treatment. Alterations in the expression of TARPs may contribute to the pathophysiology of schizophrenia, and represent a potential mechanism of glutamatergic dysregulation in this illness.
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Affiliation(s)
- Jana B. Drummond
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, CIRC 589A, 1719 6th Ave South, Birmingham, AI 25294 USA
,Corresponding author. . Tel.: 205.996.6164; fax: 205.975.4879
| | - Janusz Tucholski
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, CIRC 589A, 1719 6th Ave South, Birmingham, AI 25294 USA
| | - Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, James J Peters Veteran Adminis Room 4F-20 130 West Kingsbridge Road Bronx, NY 10468 USA
| | - James H. Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, CIRC 589A, 1719 6th Ave South, Birmingham, AI 25294 USA
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La Via L, Bonini D, Russo I, Orlandi C, Barlati S, Barbon A. Modulation of dendritic AMPA receptor mRNA trafficking by RNA splicing and editing. Nucleic Acids Res 2012; 41:617-31. [PMID: 23166306 PMCID: PMC3592400 DOI: 10.1093/nar/gks1223] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
RNA trafficking to dendrites and local translation are crucial processes for superior neuronal functions. To date, several α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) mRNAs have been detected in dendrites and are subject to local protein synthesis. Here, we report the presence of all AMPAR GluA1-4 mRNAs in hippocampal and cortical rat synaptic spines by synaptoneurosomes analysis. In particular, we showed that dendritic AMPAR mRNAs are present in the Flip versions in the cortex and hippocampus. To further confirm these data, we demonstrate, using in situ hybridization, the dendritic localization of the GluA2 Flip isoform in vitro and in vivo, whereas the Flop variant is restricted mainly to the soma. In addition, we report that dendritic AMPA mRNAs are edited at low levels at their R/G sites; this result was also supported with transfection experiments using chimeric GluA2 DNA vectors, showing that transcripts carrying an unedited nucleotide at the R/G site, in combination with the Flip exon, are more efficiently targeted to dendrites when compared with the edited-Flip versions. Our data show that post-transcriptional regulations such as RNA splicing, editing and trafficking might be mutually coordinated and that the localization of different AMPAR isoforms in dendrites might play a functional role in the regulation of neuronal transmission.
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Affiliation(s)
- Luca La Via
- Department of Biomedical Sciences and Biotechnology, Division of Biology and Genetics, National Institute of Neuroscience, University of Brescia, Viale Europa 11, Brescia 25123, Italy
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Tariq A, Jantsch MF. Transcript diversification in the nervous system: a to I RNA editing in CNS function and disease development. Front Neurosci 2012; 6:99. [PMID: 22787438 PMCID: PMC3391646 DOI: 10.3389/fnins.2012.00099] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 06/14/2012] [Indexed: 12/16/2022] Open
Abstract
RNA editing by adenosine deaminases that act on RNA converts adenosines to inosines in coding and non-coding regions of mRNAs. Inosines are interpreted as guanosines and hence, this type of editing can change codons, alter splice patterns, or influence the fate of an RNA. A to I editing is most abundant in the central nervous system (CNS). Here, targets for this type of nucleotide modification frequently encode receptors and channels. In many cases, the editing-induced amino acid exchanges alter the properties of the receptors and channels. Consistently, changes in editing patterns are frequently found associated with diseases of the CNS. In this review we describe the mechanisms of RNA editing and focus on target mRNAs of editing that are functionally relevant to normal and aberrant CNS activity.
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Affiliation(s)
- Aamira Tariq
- Max F. Perutz Laboratories, Department of Chromosome Biology, University of Vienna Vienna, Austria
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Lyddon R, Navarrett S, Dracheva S. Ionotropic glutamate receptor mRNA editing in the prefrontal cortex: no alterations in schizophrenia or bipolar disorder. J Psychiatry Neurosci 2012; 37:267-72. [PMID: 22469055 PMCID: PMC3380098 DOI: 10.1503/jpn.110107] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Dysfunction of glutamate neurotransmission has been implicated in the pathology of schizophrenia and bipolar disorder, and one mechanism by which glutamate signalling can be altered is through RNA editing of ionotropic glutamate receptors (iGluRs). The objectives of the present study were to evaluate the editing status of iGluRs in the human prefrontal cortex, determine whether iGluR editing is associated with psychiatric disease or suicide and evaluate a potential association between editing and alternative splicing in the α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) iGluR subunits' pre-mRNA. METHODS We studied specimens derived from patients with antemortem diagnoses of bipolar disorder (n = 31) or schizophrenia (n = 34) who died by suicide or other causes, and from psychiatrically healthy controls (n = 34) who died from causes other than suicide. The RNA editing at all 8 editing sites within AMPA (GluA2-4 subunits) and kainate (GluK1-2 subunits) iGluRs was analyzed using a novel real-time quantitative polymerase chain reaction assay. RESULTS No differences in editing were detected among schizophrenia, bipolar or control groups or between suicide completers and patients who died from causes other than suicide. The editing efficiency was significantly higher in the flop than in the flip splicoforms of GluA3-4 AMPA subunits (all p < 0.001). LIMITATIONS The study is limited by the near absence of specimens from medicationnaive psychiatric patients and considerable variation in medication regimens among individuals, both of which introduce considerable uncertainty into the analysis of potential medication effects. CONCLUSION We found that iGluR RNA editing status was not associated with bipolar disorder, schizophrenia or suicide. Differences in editing between flip and flop splicoforms suggest that glutamate sensitivity of receptors containing GluA3 and/or GluA4 flop subunits is moderated as a result of increased editing.
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Affiliation(s)
| | | | - Stella Dracheva
- Correspondence to: S. Dracheva, Psychiatry Research (4F-02), Bronx VA Medical Center, 130 West Kingsbridge Rd., Bronx NY 10468;
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Barbon A, Barlati S. Glutamate receptor RNA editing in health and disease. BIOCHEMISTRY (MOSCOW) 2012; 76:882-9. [PMID: 22022961 DOI: 10.1134/s0006297911080037] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RNA editing is a post-transcriptional process with an important role in gene modification. This editing process involves site-selective deamination of adenosine into inosine in the pre-mRNA, leading to the alteration of translation codons and splicing sites in nuclear transcripts, thereby enabling functionally distinct proteins to arise from a single gene. One important instance is the neuron editing of the ionotropic glutamate receptors (iGluRs). GluRs play a key role in excitatory synaptic transmission and plasticity in the central nervous system (CNS); their channel properties are largely dictated by the subunit composition of the tetrameric receptors. AMPA/kainate channels are assembled from GluA1-4 AMPA or GluK1-5 kainate receptor subunits. In particular, three of the four AMPA and two of the five kainate receptor subunits are subject to RNA editing. The editing positions have been named on the basis of the amino acid substitutions, such as the Q/R site in AMPA GluA2; the Q/R site in GluK1 and GluK2; the R/G site in GluA2, GluA3, and GluA4; and the I/V and Y/C sites in GluK2. These amino acid changes lead to profound alterations of the channel properties. This paper reviews the most relevant data showing the importance of glutamate receptor RNA editing in finely tuning glutamatergic neurotransmission in the normal CNS and following alterations of the editing process in association with disease phenotypes. Overall, these data indicate that a highly regulated process of glutamate receptor editing is of key importance in the proper function of neuronal cells and in their ability to adapt and modulate synaptic function.
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Affiliation(s)
- A Barbon
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, 25123, Italy
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Silberberg G, Lundin D, Navon R, Öhman M. Deregulation of the A-to-I RNA editing mechanism in psychiatric disorders. Hum Mol Genet 2012; 21:311-21. [PMID: 21984433 DOI: 10.1093/hmg/ddr461] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Schizophrenia and bipolar disorder (BPD) are common neurodevelopmental disorders, characterized by various life-crippling symptoms and high suicide rates. Multiple studies support a strong genetic involvement in the etiology of these disorders, although patterns of inheritance are variable and complex. Adenosine-to-inosine RNA editing is a cellular mechanism, which has been implicated in mental disorders and suicide. To examine the involvement of altered RNA editing in these disorders, we: (i) quantified the mRNA levels of the adenosine deaminase acting on RNA (ADAR) editing enzymes by real-time quantitative polymerase chain reaction, and (ii) measured the editing levels in transcripts of several neuroreceptors using 454 high-throughput sequencing, in dorsolateral-prefrontal cortices of schizophrenics, BPD patients and controls. Increased expression of specific ADAR2 variants with diminished catalytic activity was observed in schizophrenia. Our results also indicate that the I/V editing site in the glutamate receptor, ionotropic kainate 2 (GRIK2) transcript is under-edited in BPD (type I) patients (45.8 versus 53.9%, P= 0.023). GRIK2 has been implicated in mood disorders, and editing of its I/V site can modulate Ca(+2) permeability of the channel, consistent with numerous observations of elevated intracellular Ca(+2) levels in BPD patients. Our findings may therefore, at least partly, explain a molecular mechanism underlying the disorder. In addition, an intriguing correlation was found between editing events on separate exons of GRIK2. Finally, multiple novel editing sites were detected near previously known sites, albeit most with very low editing rates. This supports the hypothesis raised previously regarding the existence of wide-spread low-level 'background' editing as a mechanism that enhances adaptation and evolvability.
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Affiliation(s)
- Gilad Silberberg
- Department of Molecular Biology and Functional Genomics, Stockholm University, Stockholm 10691, Sweden.
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Prolonged exposure to NMDAR antagonist induces cell-type specific changes of glutamatergic receptors in rat prefrontal cortex. Neuropharmacology 2011; 62:1808-22. [PMID: 22182778 DOI: 10.1016/j.neuropharm.2011.11.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 11/28/2011] [Accepted: 11/29/2011] [Indexed: 01/01/2023]
Abstract
N-methyl-d-aspartic acid (NMDA) receptors are critical for both normal brain functions and the pathogenesis of schizophrenia. We investigated the functional changes of glutamatergic receptors in the pyramidal cells and fast-spiking (FS) interneurons in the adolescent rat prefrontal cortex in MK-801 model of schizophrenia. We found that although both pyramidal cells and FS interneurons were affected by in vivo subchronic blockade of NMDA receptors, MK-801 induced distinct changes in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and NMDA receptors in the FS interneurons compared with pyramidal cells. Specifically, the amplitude, but not the frequency, of AMPA-mediated miniature excitatory postsynaptic currents (mEPSCs) in FS interneurons was significantly decreased whereas both the frequency and amplitude in pyramidal neurons were increased. In addition, MK-801-induced new presynaptic NMDA receptors were detected in the glutamatergic terminals targeting pyramidal neurons but not FS interneurons. MK-801 also induced distinct alterations in FS interneurons but not in pyramidal neurons, including significantly decreased rectification index and increased calcium permeability. These data suggest a distinct cell-type specific and homeostatic synaptic scaling and redistribution of AMPA and NMDA receptors in response to the subchronic blockade of NMDA receptors and thus provide a direct mechanistic explanation for the NMDA hypofunction hypothesis that have long been proposed for the schizophrenia pathophysiology.
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Chronic antidepressant treatments induce a time-dependent up-regulation of AMPA receptor subunit protein levels. Neurochem Int 2011; 59:896-905. [DOI: 10.1016/j.neuint.2011.07.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/30/2011] [Accepted: 07/28/2011] [Indexed: 12/15/2022]
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Sodhi MS, Simmons M, McCullumsmith R, Haroutunian V, Meador-Woodruff JH. Glutamatergic gene expression is specifically reduced in thalamocortical projecting relay neurons in schizophrenia. Biol Psychiatry 2011; 70:646-54. [PMID: 21549355 PMCID: PMC3176961 DOI: 10.1016/j.biopsych.2011.02.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 01/28/2011] [Accepted: 02/22/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Impairment of glutamate neurons that relay sensory and cognitive information from the medial dorsal thalamus to the dorsolateral prefrontal cortex and other cortical regions may contribute to the pathophysiology of schizophrenia. In this study, we have assessed the cell-specific expression of glutamatergic transcripts in the medial dorsal thalamus. METHODS We used laser capture microdissection to harvest two populations of medial dorsal thalamic cells, one enriched with glutamatergic relay neurons and the other with gamma-aminobutyric acidergic neurons and astroglia, from postmortem brains of subjects with schizophrenia (n = 14) and a comparison group (n = 20). Quantitative polymerase chain reaction of extracted RNA was used to assay gene expression in the different cell populations. RESULTS The transcripts encoding the ionotropic glutamate receptor subunits NR2D, GluR3, GluR6, GluR7, and the intracellular proteins GRIP1 and SynGAP1 were significantly decreased in relay neurons but not in the mixed glial and interneuron population in schizophrenia. CONCLUSIONS Our data suggest that reduced ionotropic glutamatergic expression occurs selectively in neurons, which give rise to the cortical projections of the medial dorsal thalamus in schizophrenia, rather than in thalamic cells that function locally. Our findings indicate that glutamatergic innervation is dysfunctional in the circuitry between the medial dorsal thalamus and cortex.
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Affiliation(s)
- Monsheel S. Sodhi
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA,Dept. Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, 900 S Ashland Ave, Chicago, Illinois 60607-4067, USA,Correspondence should be addressed to: Monsheel Sodhi Ph.D., 900 S. Ashland Ave. Chicago IL 60607-4067, USA, Tel: +1-312-355-5949, Fax: +1-312-413-9303,
| | - Micah Simmons
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA
| | - Robert McCullumsmith
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA
| | - Vahram Haroutunian
- Dept. Psychiatry, The Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, New York 10029-6574, USA
| | - James H. Meador-Woodruff
- Dept. Psychiatry and Behavioral Neurobiology, UAB, 1720 7 Avenue Sth. Birmingham, Alabama 35294-0019, USA
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Caracciolo L, Barbon A, Palumbo S, Mora C, Toscano CD, Bosetti F, Barlati S. Altered mRNA editing and expression of ionotropic glutamate receptors after kainic acid exposure in cyclooxygenase-2 deficient mice. PLoS One 2011; 6:e19398. [PMID: 21589914 PMCID: PMC3093380 DOI: 10.1371/journal.pone.0019398] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 04/04/2011] [Indexed: 12/31/2022] Open
Abstract
Kainic acid (KA) binds to the AMPA/KA receptors and induces seizures that result in inflammation, oxidative damage and neuronal death. We previously showed that cyclooxygenase-2 deficient (COX-2(-/-)) mice are more vulnerable to KA-induced excitotoxicity. Here, we investigated whether the increased susceptibility of COX-2(-/-) mice to KA is associated with altered mRNA expression and editing of glutamate receptors. The expression of AMPA GluR2, GluR3 and KA GluR6 was increased in vehicle-injected COX-2(-/-) mice compared to wild type (WT) mice in hippocampus and cortex, whereas gene expression of NMDA receptors was decreased. KA treatment decreased the expression of AMPA, KA and NMDA receptors in the hippocampus, with a significant effect in COX-2(-/-) mice. Furthermore, we analyzed RNA editing levels and found that the level of GluR3 R/G editing site was selectively increased in the hippocampus and decreased in the cortex in COX-2(-/-) compared with WT mice. After KA, GluR4 R/G editing site, flip form, was increased in the hippocampus of COX-2(-/-) mice. Treatment of WT mice with the COX-2 inhibitor celecoxib for two weeks decreased the expression of AMPA/KA and NMDAR subunits after KA, as observed in COX-2(-/-) mice. After KA exposure, COX-2(-/-) mice showed increased mRNA expression of markers of inflammation and oxidative stress, such as cytokines (TNF-α, IL-1β and IL-6), inducible nitric oxide synthase (iNOS), microglia (CD11b) and astrocyte (GFAP). Thus, COX-2 gene deletion can exacerbate the inflammatory response to KA. We suggest that COX-2 plays a role in attenuating glutamate excitotoxicity by modulating RNA editing of AMPA/KA and mRNA expression of all ionotropic glutamate receptor subunits and, in turn, neuronal excitability. These changes may contribute to the increased vulnerability of COX-2(-/-) mice to KA. The overstimulation of glutamate receptors as a consequence of COX-2 gene deletion suggests a functional coupling between COX-2 and the glutamatergic system.
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Affiliation(s)
- Luca Caracciolo
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
| | - Alessandro Barbon
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
| | - Sara Palumbo
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Cristina Mora
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
| | - Christopher D. Toscano
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Francesca Bosetti
- Molecular Neuroscience Unit, Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Sergio Barlati
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy
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19
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Group II metabotropic glutamate receptor agonist ameliorates MK801-induced dysfunction of NMDA receptors via the Akt/GSK-3β pathway in adult rat prefrontal cortex. Neuropsychopharmacology 2011; 36:1260-74. [PMID: 21326193 PMCID: PMC3079418 DOI: 10.1038/npp.2011.12] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pharmacological intervention targeting mGluRs has emerged as a potential treatment for schizophrenia, whereas the mechanisms involved remain elusive. We explored the antipsychotic effects of an mGluR2/3 agonist in the MK-801 model of schizophrenia in the rat prefrontal cortex. We found that the mGluR2/3 agonist LY379268 effectively recovered the disrupted expression of NMDA receptors induced by MK-801 administration. This effect was attributable to the direct regulatory action of LY379268 on NMDA receptors via activation of the Akt/GSK-3β signaling pathway. As occurs with the antipsychotic drug clozapine, acute treatment with LY379268 significantly increased the expression and phosphorylation of NMDA receptors, as well as Akt and GSK-3β. Physiologically, LY379268 significantly enhanced NMDA-induced current in prefrontal neurons and a GSK-3β inhibitor occluded this effect. In contrast to the widely proposed mechanism of modulating presynaptic glutamate release, our results strongly argue that mGluR2/3 agonists modulate the function of NMDA receptors through postsynaptic actions and reverse the MK-801-induced NMDA dysfunction via the Akt/GSK-3β pathway. This study provides novel evidence for postsynaptic mechanisms of mGluR2/3 in regulation of NMDA receptors and presents useful insights into the mechanistic actions of mGluR2/3 agonists as potential antipsychotic agents for treating schizophrenia.
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20
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Hammond JC, McCullumsmith RE, Funk AJ, Haroutunian V, Meador-Woodruff JH. Evidence for abnormal forward trafficking of AMPA receptors in frontal cortex of elderly patients with schizophrenia. Neuropsychopharmacology 2010; 35:2110-9. [PMID: 20571483 PMCID: PMC2922423 DOI: 10.1038/npp.2010.87] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 05/20/2010] [Accepted: 05/24/2010] [Indexed: 01/01/2023]
Abstract
Several lines of evidence point to alterations of alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor trafficking in schizophrenia. Multiple proteins, including synapse-associated protein 97 (SAP97), glutamate receptor-interacting protein 1 (GRIP1), and N-ethylmaleimide sensitive factor (NSF), facilitate the forward trafficking of AMPA receptors toward the synapse. Once localized to the synapse, AMPA receptors are trafficked in a complex endosomal system. We hypothesized that alterations in the expression of these proteins and alterations in the subcellular localization of AMPA receptors in endosomes may contribute to the pathophysiology of schizophrenia. Accordingly, we measured protein expression of SAP97, GRIP1, and NSF in the dorsolateral prefrontal cortex and found an increase in the expression of SAP97 and GRIP1 in schizophrenia. To determine the subcellular localization of AMPA receptor subunits, we developed a technique to isolate early endosomes from post-mortem tissue. We found increased GluR1 receptor subunit protein in early endosomes in subjects with schizophrenia. Together, these data suggest that there is an alteration of forward trafficking of AMPA receptors as well as changes in the subcellular localization of an AMPA receptor subunit in schizophrenia.
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Affiliation(s)
- John C Hammond
- Department of Neurobiology, University of Alabama Birmingham, 35294-0021, USA.
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21
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Dizocilpine (MK-801) induces distinct changes of N-methyl-D-aspartic acid receptor subunits in parvalbumin-containing interneurons in young adult rat prefrontal cortex. Int J Neuropsychopharmacol 2009; 12:1395-408. [PMID: 19435549 PMCID: PMC2859425 DOI: 10.1017/s146114570900042x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
N-methyl-D-aspartic acid receptor (NMDAR) hypofunction has long been implicated in schizophrenia and NMDARs on gamma-aminobutyric acid (GABA)ergic interneurons are proposed to play an essential role in the pathogenesis. However, controversial results have been reported regarding the regulation of NMDAR expression, and direct evidence of how NMDAR antagonists act on specific subpopulations of prefrontal interneurons is missing. We investigated the effects of the NMDAR antagonist dizocilpine (MK-801) on the expression of NMDAR subtypes in the identified interneurons in young adult rat prefrontal cortex (PFC) by using laser microdissection and real-time polymerase chain reaction, combined with Western blotting and immunofluorescent staining. We found that MK-801 induced distinct changes of NMDAR subunits in the parvalbumin-immunoreactive (PV-ir) interneurons vs. pyramidal neurons in the PFC circuitry. The messenger RNA (mRNA) expression of all NMDAR subtypes, including NR1 and NR2A to 2D, exhibited inverted-U dose-dependent changes in response to MK-801 treatment in the PFC. In contrast, subunit mRNAs of NMDARs in PV-ir interneurons were significantly down-regulated at low doses, unaltered at medium doses, and significantly decreased again at high doses, suggesting a biphasic dose response to MK-801. The differential effects of MK-801 in mRNA expression of NMDAR subunits were consistent with the protein expression of NR2A and NR2B subunits revealed with Western blotting and double immunofluorescent staining. These results suggest that PV-containing interneurons in the PFC exhibit a distinct responsiveness to NMDAR antagonism and that NMDA antagonist can differentially and dose-dependently regulate the functions of pyramidal neurons and GABAergic interneurons in the prefrontal cortical circuitry.
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Bellesi M, Melone M, Gubbini A, Battistacci S, Conti F. GLT-1 upregulation impairs prepulse inhibition of the startle reflex in adult rats. Glia 2009; 57:703-13. [PMID: 18985735 DOI: 10.1002/glia.20798] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We tested the hypothesis that glutamate transporter GLT-1 (also known as EAAT2) plays a role in the regulation of prepulse inhibition (PPI) of the acoustic startle reflex, a simple form of information processing which is reduced in schizophrenia. To do this, we studied PPI in rats treated with ceftriaxone (200 mg/kg/day for 8 days), an antibiotic that selectively enhances GLT-1 expression and activity. We showed that ceftriaxone-induced GLT-1 upregulation is associated with impaired PPI of the startle, that this effect is reversed by dihydrokainate, a GLT-1 antagonist, that GLT-1 expression correlates negatively with PPI, and that PPI normalizes when GLT-1a levels return to baseline. Our data indicate that GLT-1 regulates PPI of the startle reflex.
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Affiliation(s)
- Michele Bellesi
- Dipartimento di Neuroscienze, Università Politecnica delle Marche, Ancona, Italy
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23
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Kainate receptors: Pharmacology, function and therapeutic potential. Neuropharmacology 2009; 56:90-113. [DOI: 10.1016/j.neuropharm.2008.08.023] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 08/04/2008] [Accepted: 08/07/2008] [Indexed: 01/28/2023]
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Fattorini G, Melone M, Bragina L, Candiracci C, Cozzi A, Pellegrini Giampietro DE, Torres-Ramos M, Pérez-Samartín A, Matute C, Conti F. GLT-1 expression and Glu uptake in rat cerebral cortex are increased by phencyclidine. Glia 2008; 56:1320-7. [PMID: 18615569 DOI: 10.1002/glia.20700] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Using western blottings, microdialysis, and functional assays we tested the hypothesis that phencyclidine (PCP) modifies the expression and function of glutamate (Glu) transporters in the rat frontal cortex. Western blotting studies revealed that administration of PCP (10 mg/kg/day; 7 days) increased significantly the expression of the astrocytic Glu transporter GLT-1/EAAT2. Functional studies showed that PCP increased significantly Na+-dependent Glu uptake in slices and in neuron/astrocyte co-cultures, and microdialysis studies evidenced that PCP treatment reduced basal Glu output. In our experimental conditions, PCP did not induce toxicity. These studies show that PCP increases the expression of GLT-1 in the cerebral cortex, thereby increasing Glu uptake and reducing extracellular [Glu].
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Affiliation(s)
- Giorgia Fattorini
- Dipartimento di Neuroscienze, Università Politecnica delle Marche, Ancona, Italy
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25
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Modelling prefrontal cortex deficits in schizophrenia: implications for treatment. Br J Pharmacol 2008; 153 Suppl 1:S465-70. [PMID: 18311160 DOI: 10.1038/bjp.2008.24] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Current treatments of schizophrenia are compromised by their inability to treat all symptoms of the disease and their side-effects. Whilst existing antipsychotic drugs are effective against positive symptoms, they have negligible efficacy against the prefrontal cortex (PFC)-associated cognitive deficits and negative symptoms. New models that reproduce core pathophysiological features of schizophrenia are more likely to have improved predictive validity in identifying new treatments. We have developed a NMDA receptor antagonist model that reproduces core PFC deficits of schizophrenia and discuss this in relation to pathophysiology and treatments. Subchronic and chronic intermittent PCP (2.6 mg/kg i.p.) was administered to rats. PFC activity was assessed by 2-deoxyglucose imaging, parvalbumin and Kv3.1 mRNA expression, and the attentional set-shifting test (ASST) of executive function. Affymetrix gene array technology was employed to examine gene expression profile patterns. PCP treatment reduced glucose utilization in the PFC (hypofrontality). This was accompanied by a reduction in markers of GABAergic interneurones (parvalbumin and Kv3.1 mRNA expression) and deficits in the extradimensional shift dimension of the ASST. Consistent with their clinical profile, the hypofrontality was not reversed by clozapine or haloperidol. Transcriptional analysis revealed patterns of change consistent with current neurobiological theories of schizophrenia. This model mirrors core neurobiological deficits of schizophrenia; hypofrontality, altered markers of GABAergic interneurone activity and deficits in executive function. As such it is likely to be a valuable translational model for understanding the neurobiological mechanisms underlying hypofrontality and for identifying and validating novel drug targets that may restore PFC deficits in schizophrenia.
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