101
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Rahmanzadeh R, Eftekhari S, Shahbazi A, Khodaei Ardakani MR, Rahmanzade R, Mehrabi S, Barati M, Joghataei MT. Effect of bumetanide, a selective NKCC1 inhibitor, on hallucinations of schizophrenic patients; a double-blind randomized clinical trial. Schizophr Res 2017; 184:145-146. [PMID: 27956008 DOI: 10.1016/j.schres.2016.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 11/28/2016] [Accepted: 12/04/2016] [Indexed: 11/20/2022]
Affiliation(s)
- Reza Rahmanzadeh
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sanaz Eftekhari
- Faculty of Advanced Technologies in Medicine, Department of Neuroscience, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Shahbazi
- Faculty of Advanced Technologies in Medicine, Department of Neuroscience, Iran University of Medical Sciences, Tehran, Iran
| | | | - Ramin Rahmanzade
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Soraya Mehrabi
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahmood Barati
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
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102
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Matsumoto M, Walton NM, Yamada H, Kondo Y, Marek GJ, Tajinda K. The impact of genetics on future drug discovery in schizophrenia. Expert Opin Drug Discov 2017; 12:673-686. [PMID: 28521526 DOI: 10.1080/17460441.2017.1324419] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Failures of investigational new drugs (INDs) for schizophrenia have left huge unmet medical needs for patients. Given the recent lackluster results, it is imperative that new drug discovery approaches (and resultant drug candidates) target pathophysiological alterations that are shared in specific, stratified patient populations that are selected based on pre-identified biological signatures. One path to implementing this paradigm is achievable by leveraging recent advances in genetic information and technologies. Genome-wide exome sequencing and meta-analysis of single nucleotide polymorphism (SNP)-based association studies have already revealed rare deleterious variants and SNPs in patient populations. Areas covered: Herein, the authors review the impact that genetics have on the future of schizophrenia drug discovery. The high polygenicity of schizophrenia strongly indicates that this disease is biologically heterogeneous so the identification of unique subgroups (by patient stratification) is becoming increasingly necessary for future investigational new drugs. Expert opinion: The authors propose a pathophysiology-based stratification of genetically-defined subgroups that share deficits in particular biological pathways. Existing tools, including lower-cost genomic sequencing and advanced gene-editing technology render this strategy ever more feasible. Genetically complex psychiatric disorders such as schizophrenia may also benefit from synergistic research with simpler monogenic disorders that share perturbations in similar biological pathways.
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Affiliation(s)
- Mitsuyuki Matsumoto
- a Unit 2, Candidate Discovery Science Labs., Drug Discovery Research , Astellas Pharma Inc. , Tsukuba , Ibaraki , Japan
| | - Noah M Walton
- b La Jolla Laboratory , Astellas Research Institute of America LLC , San Diego , CA , USA
| | - Hiroshi Yamada
- b La Jolla Laboratory , Astellas Research Institute of America LLC , San Diego , CA , USA
| | - Yuji Kondo
- a Unit 2, Candidate Discovery Science Labs., Drug Discovery Research , Astellas Pharma Inc. , Tsukuba , Ibaraki , Japan
| | - Gerard J Marek
- c Development Medical Sciences, Astellas Pharma Global Development , Northbrook , IL , USA
| | - Katsunori Tajinda
- b La Jolla Laboratory , Astellas Research Institute of America LLC , San Diego , CA , USA
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103
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Kanoski SE, Grill HJ. Hippocampus Contributions to Food Intake Control: Mnemonic, Neuroanatomical, and Endocrine Mechanisms. Biol Psychiatry 2017; 81:748-756. [PMID: 26555354 PMCID: PMC4809793 DOI: 10.1016/j.biopsych.2015.09.011] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/22/2015] [Accepted: 09/21/2015] [Indexed: 10/23/2022]
Abstract
Food intake is a complex behavior that can occur or cease to occur for a multitude of reasons. Decisions about where, when, what, and how much to eat are not merely reflexive responses to food-relevant stimuli or to changes in energy status. Rather, feeding behavior is modulated by various contextual factors and by previous experiences. The data reviewed here support the perspective that neurons in multiple hippocampal subregions constitute an important neural substrate linking the external context, the internal context, and mnemonic and cognitive information to control both appetitive and ingestive behavior. Feeding behavior is heavily influenced by hippocampal-dependent mnemonic functions, including episodic meal-related memories and conditional learned associations between food-related stimuli and postingestive consequences. These mnemonic processes are undoubtedly influenced by both external and internal factors relating to food availability, location, and physiological energy status. The afferent and efferent neuroanatomical connectivity of the subregions of the hippocampus is reviewed with regard to the integration of visuospatial and olfactory sensory information (the external context) with endocrine and gastrointestinal interoceptive stimuli (the internal context). Also discussed are recent findings demonstrating that peripherally derived endocrine signals act on receptors in hippocampal neurons to reduce (leptin, glucagon-like peptide-1) or increase (ghrelin) food intake and learned food reward-driven responding, thereby highlighting endocrine and neuropeptidergic signaling in hippocampal neurons as a novel substrate of importance in the higher-order regulation of feeding behavior.
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Affiliation(s)
- Scott E. Kanoski
- Department of Biological Sciences, University of Southern California
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104
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Liu Q, Shi J, Lin R, Wen T. Dopamine and dopamine receptor D1 associated with decreased social interaction. Behav Brain Res 2017; 324:51-57. [DOI: 10.1016/j.bbr.2017.01.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 01/22/2017] [Accepted: 01/27/2017] [Indexed: 12/16/2022]
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105
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Howes OD, McCutcheon R. Inflammation and the neural diathesis-stress hypothesis of schizophrenia: a reconceptualization. Transl Psychiatry 2017; 7:e1024. [PMID: 28170004 PMCID: PMC5438023 DOI: 10.1038/tp.2016.278] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/27/2016] [Indexed: 12/12/2022] Open
Abstract
An interaction between external stressors and intrinsic vulnerability is one of the longest standing pathoaetiological explanations for schizophrenia. However, novel lines of evidence from genetics, preclinical studies, epidemiology and imaging have shed new light on the mechanisms that may underlie this, implicating microglia as a key potential mediator. Microglia are the primary immune cells of the central nervous system. They have a central role in the inflammatory response, and are also involved in synaptic pruning and neuronal remodeling. In addition to immune and traumatic stimuli, microglial activation occurs in response to psychosocial stress. Activation of microglia perinatally may make them vulnerable to subsequent overactivation by stressors experienced in later life. Recent advances in genetics have shown that variations in the complement system are associated with schizophrenia, and this system has been shown to regulate microglial synaptic pruning. This suggests a mechanism via which genetic and environmental influences may act synergistically and lead to pathological microglial activation. Microglial overactivation may lead to excessive synaptic pruning and loss of cortical gray matter. Microglial mediated damage to stress-sensitive regions such as the prefrontal cortex and hippocampus may lead directly to cognitive and negative symptoms, and account for a number of the structural brain changes associated with the disorder. Loss of cortical control may also lead to disinhibition of subcortical dopamine-thereby leading to positive psychotic symptoms. We review the preclinical and in vivo evidence for this model and consider the implications this has for treatment, and future directions.
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Affiliation(s)
- O D Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK,MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK,PET Imaging Group, MRC Clinical Sciences Centre, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK. E-mail:
| | - R McCutcheon
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK,MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
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A novel electrochemical biomimetic sensor based on poly(Cu-AMT) with reduced graphene oxide for ultrasensitive detection of dopamine. Talanta 2017; 162:80-89. [DOI: 10.1016/j.talanta.2016.10.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/19/2016] [Accepted: 10/02/2016] [Indexed: 11/19/2022]
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107
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Grace AA. Dopamine System Dysregulation and the Pathophysiology of Schizophrenia: Insights From the Methylazoxymethanol Acetate Model. Biol Psychiatry 2017; 81:5-8. [PMID: 26705848 PMCID: PMC4870144 DOI: 10.1016/j.biopsych.2015.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 11/04/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Anthony A. Grace
- Department of Neuroscience, A210 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, USA, Tel: +1 412 624 4609, FAX: +1 412 624 9198,
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108
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Rahmanzadeh R, Shahbazi A, Ardakani MRK, Mehrabi S, Rahmanzade R, Joghataei MT. Lack of the effect of bumetanide, a selective NKCC1 inhibitor, in patients with schizophrenia: A double-blind randomized trial. Psychiatry Clin Neurosci 2017; 71:72-73. [PMID: 27800670 DOI: 10.1111/pcn.12475] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 10/15/2016] [Accepted: 10/25/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Reza Rahmanzadeh
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Shahbazi
- Faculty of Advanced Technologies in Medicine, Department of Neuroscience, Iran University of Medical Sciences, Tehran, Iran
| | | | - Soraya Mehrabi
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ramin Rahmanzade
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.,Faculty of Advanced Technologies in Medicine, Department of Neuroscience, Iran University of Medical Sciences, Tehran, Iran
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109
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Walter A, Suenderhauf C, Harrisberger F, Lenz C, Smieskova R, Chung Y, Cannon TD, Bearden CE, Rapp C, Bendfeldt K, Borgwardt S, Vogel T. Hippocampal volume in subjects at clinical high-risk for psychosis: A systematic review and meta-analysis. Neurosci Biobehav Rev 2016; 71:680-690. [DOI: 10.1016/j.neubiorev.2016.10.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/09/2016] [Accepted: 10/11/2016] [Indexed: 01/16/2023]
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Ragland JD, Layher E, Hannula DE, Niendam TA, Lesh TA, Solomon M, Carter CS, Ranganath C. Impact of schizophrenia on anterior and posterior hippocampus during memory for complex scenes. NEUROIMAGE-CLINICAL 2016; 13:82-88. [PMID: 27942450 PMCID: PMC5133646 DOI: 10.1016/j.nicl.2016.11.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 11/15/2016] [Accepted: 11/16/2016] [Indexed: 11/30/2022]
Abstract
Objectives Hippocampal dysfunction has been proposed as a mechanism for memory deficits in schizophrenia. Available evidence suggests that the anterior and posterior hippocampus could be differentially affected. Accordingly, we used fMRI to test the hypothesis that activity in posterior hippocampus is disproportionately reduced in schizophrenia, particularly during spatial memory retrieval. Methods 26 healthy participants and 24 patients with schizophrenia from the UC Davis Early Psychosis Program were studied while fMRI was acquired on a 3 Tesla Siemens scanner. During encoding, participants were oriented to critical items through questions about item features (e.g., “Does the lamp have a square shade?”) or spatial location (e.g., “Is the lamp on the table next to the couch?”). At test, participants determined whether scenes were changed or unchanged. fMRI analyses contrasted activation in a priori regions of interest (ROI) in anterior and posterior hippocampus during correct recognition of item changes and spatial changes. Results As predicted, patients with schizophrenia exhibited reduced activation in the posterior hippocampus during detection of spatial changes but not during detection of item changes. Unexpectedly, patients exhibited increased activation of anterior hippocampus during detection of item changes. Whole brain analyses revealed reduced fronto-parietal and striatal activation in patients for spatial but not for item change trials. Conclusions Results suggest a gradient of hippocampal dysfunction in which posterior hippocampus – which is necessary for processing fine-grained spatial relationships – is underactive, and anterior hippocampus – which may process context more globally - is overactive. Patients with schizophrenia show impaired memory for spatial relationships amongst objects in scenes. Patients have less posterior hippocampal activation during spatial memory and more anterior hippocampal activation during item memory. This gradient of hippocampal dysfunction in schizophrenia, suggests that it should not be examined as a unitary structure in future studies.
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Affiliation(s)
- J D Ragland
- Department of Psychiatry, Imaging Research Center, University of California at Davis, Sacramento, CA, United States
| | - E Layher
- Department of Psychiatry, Imaging Research Center, University of California at Davis, Sacramento, CA, United States
| | - D E Hannula
- Department of Psychology, University of Wisconsin at Milwaukee, Milwaukee, WI, United States
| | - T A Niendam
- Department of Psychiatry, Imaging Research Center, University of California at Davis, Sacramento, CA, United States
| | - T A Lesh
- Department of Psychiatry, Imaging Research Center, University of California at Davis, Sacramento, CA, United States
| | - M Solomon
- Department of Psychiatry, The MIND Institute, Sacramento, CA, United States
| | - C S Carter
- Department of Psychiatry, Imaging Research Center, University of California at Davis, Sacramento, CA, United States; Department of Psychology, Center for Neuroscience, University of California at Davis, Davis, CA, United States
| | - C Ranganath
- Department of Psychology, Center for Neuroscience, University of California at Davis, Davis, CA, United States
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111
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Gomes FV, Rincón-Cortés M, Grace AA. Adolescence as a period of vulnerability and intervention in schizophrenia: Insights from the MAM model. Neurosci Biobehav Rev 2016; 70:260-270. [PMID: 27235082 PMCID: PMC5074867 DOI: 10.1016/j.neubiorev.2016.05.030] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 05/24/2016] [Accepted: 05/24/2016] [Indexed: 11/30/2022]
Abstract
Adolescence is a time of extensive neuroanatomical, functional and chemical reorganization of the brain, which parallels substantial maturational changes in behavior and cognition. Environmental factors that impinge on the timing of these developmental factors, including stress and drug exposure, increase the risk for psychiatric disorders. Indeed, antecedents to affective and psychotic disorders, which have clinical and pathophysiological overlap, are commonly associated with risk factors during adolescence that predispose to these disorders. In the context of schizophrenia, psychosis typically begins in late adolescence/early adulthood, which has been replicated by animal models. Rats exposed during gestational day (GD) 17 to the mitotoxin methylazoxymethanol acetate (MAM) exhibit behavioral, pharmacological, and anatomical characteristics consistent with an animal model of schizophrenia. Here we provide an overview of adolescent changes within the dopamine system and the PFC and review recent findings regarding the effects of stress and cannabis exposure during the peripubertal period as risk factors for the emergence of schizophrenia-like deficits. Finally, we discuss peripubertal interventions appearing to circumvent the emergence of adult schizophrenia-like deficits.
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Affiliation(s)
- Felipe V Gomes
- Departments of Neuroscience, Psychiatry and Psychology, United States
| | | | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, United States.
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112
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Mostaid MS, Lloyd D, Liberg B, Sundram S, Pereira A, Pantelis C, Karl T, Weickert CS, Everall IP, Bousman CA. Neuregulin-1 and schizophrenia in the genome-wide association study era. Neurosci Biobehav Rev 2016; 68:387-409. [DOI: 10.1016/j.neubiorev.2016.06.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 05/30/2016] [Accepted: 06/03/2016] [Indexed: 12/22/2022]
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113
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Grace AA. Dysregulation of the dopamine system in the pathophysiology of schizophrenia and depression. Nat Rev Neurosci 2016; 17:524-32. [PMID: 27256556 PMCID: PMC5166560 DOI: 10.1038/nrn.2016.57] [Citation(s) in RCA: 682] [Impact Index Per Article: 85.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The dopamine system is unique among the brain's modulatory systems in that it has discrete projections to specific brain regions involved in motor behaviour, cognition and emotion. Dopamine neurons exhibit several activity patterns - including tonic and phasic firing - that are determined by a combination of endogenous pacemaker conductances and regulation by multiple afferent systems. Emerging evidence suggests that disruptions in these regulatory systems may underlie the pathophysiology of several psychiatric disorders, including schizophrenia and depression.
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Affiliation(s)
- Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, Department of Neuroscience, A210 Langley Hall, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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114
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Bolkan SS, Carvalho Poyraz F, Kellendonk C. Using human brain imaging studies as a guide toward animal models of schizophrenia. Neuroscience 2016; 321:77-98. [PMID: 26037801 PMCID: PMC4664583 DOI: 10.1016/j.neuroscience.2015.05.055] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/15/2015] [Accepted: 05/21/2015] [Indexed: 12/17/2022]
Abstract
Schizophrenia is a heterogeneous and poorly understood mental disorder that is presently defined solely by its behavioral symptoms. Advances in genetic, epidemiological and brain imaging techniques in the past half century, however, have significantly advanced our understanding of the underlying biology of the disorder. In spite of these advances clinical research remains limited in its power to establish the causal relationships that link etiology with pathophysiology and symptoms. In this context, animal models provide an important tool for causally testing hypotheses about biological processes postulated to be disrupted in the disorder. While animal models can exploit a variety of entry points toward the study of schizophrenia, here we describe an approach that seeks to closely approximate functional alterations observed with brain imaging techniques in patients. By modeling these intermediate pathophysiological alterations in animals, this approach offers an opportunity to (1) tightly link a single functional brain abnormality with its behavioral consequences, and (2) to determine whether a single pathophysiology can causally produce alterations in other brain areas that have been described in patients. In this review we first summarize a selection of well-replicated biological abnormalities described in the schizophrenia literature. We then provide examples of animal models that were studied in the context of patient imaging findings describing enhanced striatal dopamine D2 receptor function, alterations in thalamo-prefrontal circuit function, and metabolic hyperfunction of the hippocampus. Lastly, we discuss the implications of findings from these animal models for our present understanding of schizophrenia, and consider key unanswered questions for future research in animal models and human patients.
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Affiliation(s)
- S S Bolkan
- Department of Pharmacology, Columbia University, New York, NY 10032, USA; Department of Psychiatry, Columbia University, New York, NY 10032, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - F Carvalho Poyraz
- Department of Pharmacology, Columbia University, New York, NY 10032, USA; Department of Psychiatry, Columbia University, New York, NY 10032, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - C Kellendonk
- Department of Pharmacology, Columbia University, New York, NY 10032, USA; Department of Psychiatry, Columbia University, New York, NY 10032, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA.
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115
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Salgado-Pineda P, Landin-Romero R, Portillo F, Bosque C, Pomes A, Spanlang B, Franquelo JC, Teixido C, Sarró S, Salvador R, Slater M, Pomarol-Clotet E, McKenna PJ. Examining hippocampal function in schizophrenia using a virtual reality spatial navigation task. Schizophr Res 2016; 172:86-93. [PMID: 26924620 DOI: 10.1016/j.schres.2016.02.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 02/22/2016] [Accepted: 02/22/2016] [Indexed: 11/28/2022]
Abstract
BACKGROUND Structural pathology in the hippocampus is well-documented in schizophrenia, but brain functional changes have not been consistently found. We used spatial navigation in a virtual reality environment, a task that is known to produce robust hippocampal activation in healthy subjects, to examine task-related activations and de-activations in the disorder. METHODS Twenty-seven DSM IV schizophrenia patients and 32 healthy controls underwent fMRI while they navigated to a goal through a virtual reality town. Activations and de-activations were examined at the whole brain level and also using a region-of-interest (ROI) in the hippocampus. RESULTS Spatial navigation was associated with activation in the posterior hippocampus and parahippocampal gyrus plus widespread neocortical areas. The patients showed reduced activation compared to the controls in the left dorsolateral prefrontal cortex (DLPFC) and the left occipital/temporal cortex. No differences in hippocampal activation were seen either at the whole-brain level or in the ROI analysis. The patients showed failure of de-activation affecting some but not all subregions of the default mode network. CONCLUSIONS Schizophrenia is associated with task-related hypoactivation in the DLPFC during spatial navigation, but not with functional changes in the hippocampus. The failure of de-activation also found adds to evidence for default mode network dysfunction in the disorder.
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Affiliation(s)
- Pilar Salgado-Pineda
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain.
| | - Ramón Landin-Romero
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | | | - Clara Bosque
- Benito Menni Complex Assistencial en Salut Mental, Barcelona, Spain
| | - Ausias Pomes
- Event Lab, Faculty of Psychology, University of Barcelona, Barcelona, Spain
| | - Bernhard Spanlang
- Event Lab, Faculty of Psychology, University of Barcelona, Barcelona, Spain
| | | | - Cristina Teixido
- Hospital Mare de Dèu de la Mercé, Unitat Polivalent Barcelona Nord, Barcelona, Spain
| | - Salvador Sarró
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | - Raymond Salvador
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | - Mel Slater
- Hospital Sagrat Cor, CSMA Sant Feliu, Sant Feliu de Llobregat, Spain
| | - Edith Pomarol-Clotet
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | - Peter J McKenna
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
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de Kloet ER, Molendijk ML. Coping with the Forced Swim Stressor: Towards Understanding an Adaptive Mechanism. Neural Plast 2016; 2016:6503162. [PMID: 27034848 PMCID: PMC4806646 DOI: 10.1155/2016/6503162] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 10/19/2015] [Indexed: 12/20/2022] Open
Abstract
In the forced swim test (FST) rodents progressively show increased episodes of immobility if immersed in a beaker with water from where escape is not possible. In this test, a compound qualifies as a potential antidepressant if it prevents or delays the transition to this passive (energy conserving) behavioural style. In the past decade however the switch from active to passive "coping" was used increasingly to describe the phenotype of an animal that has been exposed to a stressful history and/or genetic modification. A PubMed analysis revealed that in a rapidly increasing number of papers (currently more than 2,000) stress-related immobility in the FST is labeled as a depression-like phenotype. In this contribution we will examine the different phases of information processing during coping with the forced swim stressor. For this purpose we focus on the action of corticosterone that is mediated by the closely related mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) in the limbic brain. The evidence available suggests a model in which we propose that the limbic MR-mediated response selection operates in complementary fashion with dopaminergic accumbens/prefrontal executive functions to regulate the transition between active and passive coping styles. Upon rescue from the beaker the preferred, mostly passive, coping style is stored in the memory via a GR-dependent action in the hippocampal dentate gyrus. It is concluded that the rodent's behavioural response to a forced swim stressor does not reflect depression. Rather the forced swim experience provides a unique paradigm to investigate the mechanistic underpinning of stress coping and adaptation.
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Affiliation(s)
- E. R. de Kloet
- Division of Medical Pharmacology and Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, Netherlands
- Division of Endocrinology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, Netherlands
| | - M. L. Molendijk
- Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333 AK Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, Netherlands
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117
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Rao Vusa CS, Manju V, Aneesh K, Berchmans S, Palaniappan A. Tailored interfacial architecture of chitosan modified glassy carbon electrodes facilitating selective, nanomolar detection of dopamine. RSC Adv 2016. [DOI: 10.1039/c5ra20124a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chitosan was tailored directly on the electrode surface to detect DA selectively in nanomolar level at physiological pH.
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Affiliation(s)
| | - Venkatesan Manju
- Electrodics and Electrocatalysis Division
- CSIR-Central Electrochemical Research Institute
- Karaikudi
- India
| | - K. Aneesh
- Electrodics and Electrocatalysis Division
- CSIR-Central Electrochemical Research Institute
- Karaikudi
- India
| | - Sheela Berchmans
- Electrodics and Electrocatalysis Division
- CSIR-Central Electrochemical Research Institute
- Karaikudi
- India
| | - Arumugam Palaniappan
- Electrodics and Electrocatalysis Division
- CSIR-Central Electrochemical Research Institute
- Karaikudi
- India
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The frequency of spontaneous seizures in rats correlates with alterations in sensorimotor gating, spatial working memory, and parvalbumin expression throughout limbic regions. Neuroscience 2015; 312:86-98. [PMID: 26582750 DOI: 10.1016/j.neuroscience.2015.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 11/02/2015] [Accepted: 11/04/2015] [Indexed: 01/03/2023]
Abstract
Cognitive deficits and psychotic symptoms are highly prevalent in patients with temporal lobe epilepsy (TLE). Imaging studies in humans have suggested that these comorbidities are associated with atrophy in temporal lobe structures and other limbic regions. It remains to be clarified whether TLE comorbidities are due to the frequency of spontaneous seizures or to limbic structural damage per se. Here, we used the pilocarpine model of chronic spontaneous seizures to evaluate the possible association of seizure frequency with sensorimotor gating, spatial working memory, and neuropathology throughout limbic regions. For TLE modeling, we induced a 2-h status epilepticus by the systemic administration of lithium-pilocarpine. Once spontaneous seizures were established, we tested the locomotor activity (open field), spatial working memory (eight-arm radial maze), and sensorimotor gating (prepulse inhibition of acoustic startle). After behavioral testing, the brains were sectioned for hematoxylin-eosin staining (cell density) and parvalbumin immunohistochemistry (GABAergic neuropil) in the prefrontal cortex, nucleus accumbens, thalamus, amygdala, hippocampus, and entorhinal cortex. The animal groups analyzed included chronic epileptic rats, their controls, and rats that received lithium-pilocarpine but eventually failed to express status epilepticus or spontaneous seizures. Epileptic rats showed deficits in sensorimotor gating that negatively correlated with the radial maze performance, and impairments in both behavioral tests correlated with seizure frequency. In addition to neuronal loss at several sites, we found increased parvalbumin immunostaining in the prefrontal cortex (infralimbic area), thalamus (midline and reticular nuclei), amygdala, Ammon's horn, dentate gyrus, and entorhinal cortex. These tissue changes correlated with seizure frequency and impairments in sensorimotor gating. Our work indicates that chronic seizures might impact the inhibitory-excitatory balance in the temporal lobe and its interconnected limbic regions, which could increase the likelihood of cognitive deficits and interictal psychiatric disorders.
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Janhunen SK, Svärd H, Talpos J, Kumar G, Steckler T, Plath N, Lerdrup L, Ruby T, Haman M, Wyler R, Ballard TM. The subchronic phencyclidine rat model: relevance for the assessment of novel therapeutics for cognitive impairment associated with schizophrenia. Psychopharmacology (Berl) 2015; 232:4059-83. [PMID: 26070547 DOI: 10.1007/s00213-015-3954-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/27/2015] [Indexed: 12/26/2022]
Abstract
RATIONALE Current treatments for schizophrenia have modest, if any, efficacy on cognitive dysfunction, creating a need for novel therapies. Their development requires predictive animal models. The N-methyl-D-aspartate (NMDA) hypothesis of schizophrenia indicates the use of NMDA antagonists, like subchronic phencyclidine (scPCP) to model cognitive dysfunction in adult animals. OBJECTIVES The objective of this study was to assess the scPCP model by (1) reviewing published findings of scPCP-induced neurochemical changes and effects on cognitive tasks in adult rats and (2) comparing findings from a multi-site study to determine scPCP effects on standard and touchscreen cognitive tasks. METHODS Across four research sites, the effects of scPCP (typically 5 mg/kg twice daily for 7 days, followed by at least 7-day washout) in adult male Lister Hooded rats were studied on novel object recognition (NOR) with 1-h delay, acquisition and reversal learning in Morris water maze and touchscreen-based visual discrimination. RESULTS Literature findings showed that scPCP impaired attentional set-shifting (ASST) and NOR in several labs and induced a variety of neurochemical changes across different labs. In the multi-site study, scPCP impaired NOR, but not acquisition or reversal learning in touchscreen or water maze. Yet, this treatment regimen induced locomotor hypersensitivity to acute PCP until 13-week post-cessation. CONCLUSIONS The multi-site study confirmed that scPCP impaired NOR and ASST only and demonstrated the reproducibility and usefulness of the touchscreen approach. Our recommendation, prior to testing novel therapeutics in the scPCP model, is to be aware that further work is required to understand the neurochemical changes and specificity of the cognitive deficits.
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Affiliation(s)
- Sanna K Janhunen
- CNS Research, Research and Development, Orion Pharma, Orion Corporation, Tengstrominkatu 8, P.O. Box 425, 20101, Turku, Finland.
| | - Heta Svärd
- CNS Research, Research and Development, Orion Pharma, Orion Corporation, Tengstrominkatu 8, P.O. Box 425, 20101, Turku, Finland
| | - John Talpos
- Janssen Research and Development, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - Gaurav Kumar
- Janssen Research and Development, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - Thomas Steckler
- Janssen Research and Development, Turnhoutseweg 30, 2340, Beerse, Belgium
| | - Niels Plath
- Synaptic Transmission, H. Lundbeck A/S, Ottiliavej 9, 2500, Valby, Denmark
| | - Linda Lerdrup
- Synaptic Transmission, H. Lundbeck A/S, Ottiliavej 9, 2500, Valby, Denmark
| | - Trine Ruby
- Synaptic Transmission, H. Lundbeck A/S, Ottiliavej 9, 2500, Valby, Denmark
| | - Marie Haman
- Neuroscience, Ophthalmology and Rare Diseases, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070, Basel, Switzerland
| | - Roger Wyler
- Neuroscience, Ophthalmology and Rare Diseases, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070, Basel, Switzerland
| | - Theresa M Ballard
- Neuroscience, Ophthalmology and Rare Diseases, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070, Basel, Switzerland
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Aberrant Salience Is Related to Reduced Reinforcement Learning Signals and Elevated Dopamine Synthesis Capacity in Healthy Adults. J Neurosci 2015; 35:10103-11. [PMID: 26180188 DOI: 10.1523/jneurosci.0805-15.2015] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The striatum is known to play a key role in reinforcement learning, specifically in the encoding of teaching signals such as reward prediction errors (RPEs). It has been proposed that aberrant salience attribution is associated with impaired coding of RPE and heightened dopamine turnover in the striatum, and might be linked to the development of psychotic symptoms. However, the relationship of aberrant salience attribution, RPE coding, and dopamine synthesis capacity has not been directly investigated. Here we assessed the association between a behavioral measure of aberrant salience attribution, the salience attribution test, to neural correlates of RPEs measured via functional magnetic resonance imaging while healthy participants (n = 58) performed an instrumental learning task. A subset of participants (n = 27) also underwent positron emission tomography with the radiotracer [(18)F]fluoro-l-DOPA to quantify striatal presynaptic dopamine synthesis capacity. Individual variability in aberrant salience measures related negatively to ventral striatal and prefrontal RPE signals and in an exploratory analysis was found to be positively associated with ventral striatal presynaptic dopamine levels. These data provide the first evidence for a specific link between the constructs of aberrant salience attribution, reduced RPE processing, and potentially increased presynaptic dopamine function.
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Raij TT, Mäntylä T, Kieseppä T, Suvisaari J. Aberrant functioning of the putamen links delusions, antipsychotic drug dose, and compromised connectivity in first episode psychosis--Preliminary fMRI findings. Psychiatry Res 2015; 233:201-11. [PMID: 26184459 DOI: 10.1016/j.pscychresns.2015.06.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/24/2015] [Accepted: 06/25/2015] [Indexed: 01/26/2023]
Abstract
The dopamine theory proposes the relationship of delusions to aberrant signaling in striatal circuitries that can be normalized with dopamine D2 receptor-blocking drugs. Localization of such circuitries, as well as their upstream and downstream signaling, remains poorly known. We collected functional magnetic resonance images from first-episode psychosis patients and controls during an audiovisual movie. Final analyses included 20 patients and 20 controls; another sample of 10 patients and 10 controls was used to calculate a comparison signal-time course. We identified putamen circuitry in which the signal aberrance (poor correlation with the comparison signal time course) was predicted by the dopamine theory, being greater in patients than controls; correlating positively with delusion scores; and correlating negatively with antipsychotic-equivalent dosage. In Granger causality analysis, patients showed a compromised contribution of the cortical salience network to the putamen and compromised contribution of the putamen to the default mode network. Results were corrected for multiple comparisons at the cluster level with primary voxel-wise threshold p < 0.005 for the salience network contribution, but liberal primary threshold p < 0.05 was used in other group comparisons. If replicated in larger studies, these findings may help unify and extend current hypotheses on dopaminergic dysfunction, salience processing and pathogenesis of delusions.
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Affiliation(s)
- Tuukka T Raij
- Department of Psychiatry, Helsinki University and Helsinki University Central Hospital, Välskärinkatu 12, P.O Box 590, 00029 HUS, Finland; Department of Neuroscience and Biomedical engineering and Advanced Magnetic Imaging Centre, Aalto NeuroImaging, Aalto University School of Science, P.O Box 13000, 00076 AALTO, Finland.
| | - Teemu Mäntylä
- Department of Neuroscience and Biomedical engineering and Advanced Magnetic Imaging Centre, Aalto NeuroImaging, Aalto University School of Science, P.O Box 13000, 00076 AALTO, Finland; Department of Health, Mental Health Unit, National Institute for Health and Welfare, Helsinki, P.O. Box 30, 00271 Helsinki, Finland; Institute of Behavioural Sciences, Siltavuorenpenger 1-5, P.O. Box 9, 00014 University of Helsinki, Helsinki, Finland
| | - Tuula Kieseppä
- Department of Psychiatry, Helsinki University and Helsinki University Central Hospital, Välskärinkatu 12, P.O Box 590, 00029 HUS, Finland; Department of Health, Mental Health Unit, National Institute for Health and Welfare, Helsinki, P.O. Box 30, 00271 Helsinki, Finland
| | - Jaana Suvisaari
- Department of Health, Mental Health Unit, National Institute for Health and Welfare, Helsinki, P.O. Box 30, 00271 Helsinki, Finland
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Gilmour G, Gastambide F, Marston HM, Walton ME. Using Intermediate Cognitive Endpoints to Facilitate Translational Research in Psychosis. Curr Opin Behav Sci 2015; 4:128-135. [PMID: 26937447 PMCID: PMC4770458 DOI: 10.1016/j.cobeha.2015.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Recent advances in the understanding of psychosis have uncovered potential for a paradigm shift in related drug discovery efforts. The study of psychosis is evolving from its origins in serendipity and empiricism to more formal, hypothesis driven accounts of the cognitive substrates underlying hallucinations and delusions. Recent evidence suggests that misattribution of salience and abnormal prediction error might underlie some forms of psychosis. If substantiated, such intermediate constructs could significantly facilitate translational research for drug discovery. Aberrant salience and prediction error can be assayed with simple tests of associative learning in both species, and a convincing back translation of effects, when combined with measures of neurotransmitter release and brain activity could for the first time allow robust, causal connections to be made between molecular mechanisms in rodents and symptoms in patients.
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Affiliation(s)
- Gary Gilmour
- In Vivo Pharmacology, Eli Lilly & Co. Ltd., Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, UK
| | - Francois Gastambide
- In Vivo Pharmacology, Eli Lilly & Co. Ltd., Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, UK
| | - Hugh M Marston
- In Vivo Pharmacology, Eli Lilly & Co. Ltd., Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, UK
| | - Mark E Walton
- Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford, OX1 3UD, U.K
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Melka MG, Castellani CA, O'Reilly R, Singh SM. Insights into the origin of DNA methylation differences between monozygotic twins discordant for schizophrenia. J Mol Psychiatry 2015; 3:7. [PMID: 26137221 PMCID: PMC4487197 DOI: 10.1186/s40303-015-0013-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/15/2015] [Indexed: 12/22/2022] Open
Abstract
Background DNA methylation differences between monozygotic twins discordant for schizophrenia have been previously reported. However, the origin of methylation differences between monozygotic twins discordant for schizophrenia is not clear. The findings here argue that all DNA methylation differences may not necessarily represent the cause of the disease; rather some may result from the effect of antipsychotics. Methods Methylation differences in rat brain regions and also in two pairs of unrelated monozygotic twins discordant for schizophrenia have been studied using genome-wide DNA methylation arrays at Arraystar Inc. (Rockville, Maryland, USA). The identified gene promoters showing significant alterations to DNA methylation were then further characterized using ingenuity pathway analysis (Ingenuity System Inc, CA, USA). Results Pathway analysis of the most significant gene promoter hyper/hypomethylation revealed a significant enrichment of DNA methylation changes in biological networks and pathways directly relevant to neural development and psychiatric disorders. These included HIPPO signaling (p = 3.93E-03) and MAPK signaling (p = 4.27E-03) pathways involving hypermethylated genes in schizophrenia-affected patients as compared to their unaffected co-twins. Also, a number of significant pathways and networks involving genes with hypomethylated gene promoters have been identified. These included CREB signaling in neurons (p = 1.53E-02), Dopamine-DARPP32 feedback in cAMP signaling (p = 7.43E-03) and Ephrin receptors (p = 1.13E-02). Further, there was significant enrichment for pathways involved in nervous system development and function (p = 1.71E-03-4.28E-02). Conclusion The findings highlight the significance of antipsychotic drugs on DNA methylation in schizophrenia patients. The unique pathways affected by DNA methylation in the two pairs of monozygotic twins suggest that patient-specific pathways are responsible for the disease; suggesting that patient-specific treatment strategies may be necessary in treating the disorder. The study reflects the need for developing personalized medicine approaches that take into consideration epigenetic variations between patients. Electronic supplementary material The online version of this article (doi:10.1186/s40303-015-0013-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Melkaye G Melka
- Molecular Genetics Unit, Western Science Centre, Department of Biology, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Christina A Castellani
- Molecular Genetics Unit, Western Science Centre, Department of Biology, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Richard O'Reilly
- Department of Psychiatry, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Shiva M Singh
- Molecular Genetics Unit, Western Science Centre, Department of Biology, The University of Western Ontario, London, Ontario N6A 5B7 Canada
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Anvari AA, Friedman LA, Greenstein D, Gochman P, Gogtay N, Rapoport JL. Hippocampal volume change relates to clinical outcome in childhood-onset schizophrenia. Psychol Med 2015; 45:2667-2674. [PMID: 25936396 DOI: 10.1017/s0033291715000677] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Fixed hippocampal volume reductions and shape abnormalities are established findings in schizophrenia, but the relationship between hippocampal volume change and clinical outcome has been relatively unexplored in schizophrenia and other psychotic disorders. In light of recent findings correlating hippocampal volume change and clinical outcome in first-episode psychotic adults, we hypothesized that fewer decreases in hippocampal volume would be associated with better functional outcome and fewer psychotic symptoms in our rare and chronically ill population of childhood-onset schizophrenia (COS) patients. METHOD We prospectively obtained 114 structural brain magnetic resonance images (MRIs) from 27 COS subjects, each with three or more scans between the ages of 10 and 30 years. Change in hippocampal volume, measured by fit slope and percentage change, was regressed against clinical ratings (Children's Global Assessment Scale, Scale for the Assessment of Positive Symptoms, Scale for the Assessment of Negative Symptoms) at last scan (controlling for sex, time between scans and total intracranial volume). RESULTS Fewer negative symptoms were associated with less hippocampal volume decrease (fit slope: p = 0.0003, and percentage change: p = 0.005) while positive symptoms were not related to hippocampal change. There was also a relationship between improved clinical global functioning and maintained hippocampal volumes (fit slope: p = 0.025, and percentage change: p = 0.043). CONCLUSIONS These results suggest that abnormal hippocampal development in schizophrenia can be linked to global functioning and negative symptoms. The hippocampus can be considered a potential treatment target for future therapies.
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Affiliation(s)
- A A Anvari
- Child Psychiatry Branch,National Institute of Mental Health, National Institutes of Health,Bethesda,MD,USA
| | - L A Friedman
- Child Psychiatry Branch,National Institute of Mental Health, National Institutes of Health,Bethesda,MD,USA
| | - D Greenstein
- Child Psychiatry Branch,National Institute of Mental Health, National Institutes of Health,Bethesda,MD,USA
| | - P Gochman
- Child Psychiatry Branch,National Institute of Mental Health, National Institutes of Health,Bethesda,MD,USA
| | - N Gogtay
- Child Psychiatry Branch,National Institute of Mental Health, National Institutes of Health,Bethesda,MD,USA
| | - J L Rapoport
- Child Psychiatry Branch,National Institute of Mental Health, National Institutes of Health,Bethesda,MD,USA
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Wang J, Li G, Xu Y, Zhang WN. Hyperactivity and disruption of prepulse inhibition induced by NMDA infusion of the rat ventral hippocampus: Comparison of uni- and bilateral stimulation. Neurosci Lett 2015; 594:150-4. [DOI: 10.1016/j.neulet.2015.03.066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/20/2015] [Accepted: 03/31/2015] [Indexed: 12/17/2022]
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Silver H, Bilker WB. Similar verbal memory impairments in schizophrenia and healthy aging. Implications for understanding of neural mechanisms. Psychiatry Res 2015; 226:277-83. [PMID: 25639372 DOI: 10.1016/j.psychres.2014.12.062] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/26/2014] [Accepted: 12/20/2014] [Indexed: 12/14/2022]
Abstract
Memory is impaired in schizophrenia patients but it is not clear whether this is specific to the illness and whether different types of memory (verbal and nonverbal) or memories in different cognitive domains (executive, object recognition) are similarly affected. To study relationships between memory impairments and schizophrenia we compared memory functions in 77 schizophrenia patients, 58 elderly healthy individuals and 41 young healthy individuals. Tests included verbal associative and logical memory and memory in executive and object recognition domains. We compared relationships of memory functions to each other and to other cognitive functions including psychomotor speed and verbal and spatial working memory. Compared to the young healthy group, schizophrenia patients and elderly healthy individuals showed similar severe impairment in logical memory and in the ability to learn new associations (NAL), and similar but less severe impairment in spatial working memory and executive and object memory. Verbal working memory was significantly more impaired in schizophrenia patients than in the healthy elderly. Verbal episodic memory impairment in schizophrenia may share common mechanisms with similar impairment in healthy aging. Impairment in verbal working memory in contrast may reflect mechanisms specific to schizophrenia. Study of verbal explicit memory impairment tapped by the NAL index may advance understanding of abnormal hippocampus dependent mechanisms common to schizophrenia and aging.
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Affiliation(s)
- Henry Silver
- Brain Behavior Laboratory, Sha׳ar Menashe Mental Health Center, Mobile Post Hefer 37806, Israel; Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel.
| | - Warren B Bilker
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia 19104-6021, USA.
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Chase HW, Clos M, Dibble S, Fox P, Grace AA, Phillips ML, Eickhoff SB. Evidence for an anterior-posterior differentiation in the human hippocampal formation revealed by meta-analytic parcellation of fMRI coordinate maps: focus on the subiculum. Neuroimage 2015; 113:44-60. [PMID: 25776219 DOI: 10.1016/j.neuroimage.2015.02.069] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 12/17/2014] [Accepted: 02/25/2015] [Indexed: 02/05/2023] Open
Abstract
Previous studies, predominantly in experimental animals, have suggested the presence of a differentiation of function across the hippocampal formation. In rodents, ventral regions are thought to be involved in emotional behavior while dorsal regions mediate cognitive or spatial processes. Using a combination of modeling the co-occurrence of significant activations across thousands of neuroimaging experiments and subsequent data-driven clustering of these data we were able to provide evidence of distinct subregions within a region corresponding to the human subiculum, a critical hub within the hippocampal formation. This connectivity-based model consists of a bilateral anterior region, as well as separate posterior and intermediate regions on each hemisphere. Functional connectivity assessed both by meta-analytic and resting fMRI approaches revealed that more anterior regions were more strongly connected to the default mode network, and more posterior regions were more strongly connected to 'task positive' regions. In addition, our analysis revealed that the anterior subregion was functionally connected to the ventral striatum, midbrain and amygdala, a circuit that is central to models of stress and motivated behavior. Analysis of a behavioral taxonomy provided evidence for a role for each subregion in mnemonic processing, as well as implication of the anterior subregion in emotional and visual processing and the right posterior subregion in reward processing. These findings lend support to models which posit anterior-posterior differentiation of function within the human hippocampal formation and complement other early steps toward a comparative (cross-species) model of the region.
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Affiliation(s)
- Henry W Chase
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Mareike Clos
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Germany; Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Germany
| | - Sofia Dibble
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter Fox
- Research Imaging Center, University of Texas Health Science Center San Antonio, San Antonio, TX, USA; South Texas Veterans Administration Medical Center, San Antonio, TX, USA
| | - Anthony A Grace
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA; Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mary L Phillips
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Simon B Eickhoff
- Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Germany; Institute of Clinical Neuroscience and Medical Psychology, Heinrich-Heine University Düsseldorf, Germany
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Richetto J, Labouesse MA, Poe MM, Cook JM, Grace AA, Riva MA, Meyer U. Behavioral effects of the benzodiazepine-positive allosteric modulator SH-053-2'F-S-CH₃ in an immune-mediated neurodevelopmental disruption model. Int J Neuropsychopharmacol 2015; 18:pyu055. [PMID: 25636893 PMCID: PMC4360215 DOI: 10.1093/ijnp/pyu055] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Impaired γ-aminobutyric acid (GABA) signaling may contribute to the emergence of cognitive deficits and subcortical dopaminergic hyperactivity in patients with schizophrenia and related psychotic disorders. Against this background, it has been proposed that pharmacological interventions targeting GABAergic dysfunctions may prove useful in correcting such cognitive impairments and dopaminergic imbalances. METHODS Here, we explored possible beneficial effects of the benzodiazepine-positive allosteric modulator SH-053-2'F-S-CH₃, with partial selectivity at the α2, α3, and α5 subunits of the GABAA receptor in an immune-mediated neurodevelopmental disruption model. The model is based on prenatal administration of the viral mimetic polyriboinosinic-polyribocytidilic acid [poly(I:C)] in mice, which is known to capture various GABAergic, dopamine-related, and cognitive abnormalities implicated in schizophrenia and related disorders. RESULTS Real-time polymerase chain reaction analyses confirmed the expected alterations in GABAA receptor α subunit gene expression in the medial prefrontal cortices and ventral hippocampi of adult poly(I:C) offspring relative to control offspring. Systemic administration of SH-053-2'F-S-CH₃ failed to normalize the poly(I:C)-induced deficits in working memory and social interaction, but instead impaired performance in these cognitive and behavioral domains both in control and poly(I:C) offspring. In contrast, SH-053-2'F-S-CH₃ was highly effective in mitigating the poly(I:C)-induced amphetamine hypersensitivity phenotype without causing side effects in control offspring. CONCLUSIONS Our preclinical data suggest that benzodiazepine-like positive allosteric modulators with activity at the α2, α3, and α5 subunits of the GABAA receptor may be particularly useful in correcting pathological overactivity of the dopaminergic system, but they may be ineffective in targeting multiple pathological domains that involve the co-existence of psychotic, social, and cognitive dysfunctions.
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Affiliation(s)
| | | | | | | | | | | | - Urs Meyer
- Center of Neuropharmacology, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy (Drs Richetto and Riva); Physiology and Behavior Laboratory, ETH Zurich, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland (Drs Labouesse and Meyer); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI (Drs Poe and Cook); Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA (Dr Grace); Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milan, Italy (Dr Riva).
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DeAngeli NE, Todd TP, Chang SE, Yeh HH, Yeh PW, Bucci DJ. Exposure to Kynurenic Acid during Adolescence Increases Sign-Tracking and Impairs Long-Term Potentiation in Adulthood. Front Behav Neurosci 2015; 8:451. [PMID: 25610382 PMCID: PMC4285091 DOI: 10.3389/fnbeh.2014.00451] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 12/16/2014] [Indexed: 11/21/2022] Open
Abstract
Changes in brain reward systems are thought to contribute significantly to the cognitive and behavioral impairments of schizophrenia, as well as the propensity to develop co-occurring substance abuse disorders. Presently, there are few treatments for persons with a dual diagnosis and little is known about the neural substrates that underlie co-occurring schizophrenia and substance abuse. One goal of the present study was to determine if a change in the concentration of kynurenic acid (KYNA), a tryptophan metabolite that is increased in the brains of people with schizophrenia, affects reward-related behavior. KYNA is an endogenous antagonist of NMDA glutamate receptors and α7 nicotinic acetylcholine receptors, both of which are critically involved in neurodevelopment, plasticity, and behavior. In Experiment 1, rats were treated throughout adolescence with L-kynurenine (L-KYN), the precursor of KYNA. As adults, the rats were tested drug-free in an autoshaping procedure in which a lever was paired with food. Rats treated with L-KYN during adolescence exhibited increased sign-tracking behavior (lever pressing) when they were tested as adults. Sign-tracking is thought to reflect the lever acquiring incentive salience (motivational value) as a result of its pairing with reward. Thus, KYNA exposure may increase the incentive salience of cues associated with reward, perhaps contributing to an increase in sensitivity to drug-related cues in persons with schizophrenia. In Experiment 2, we tested the effects of exposure to KYNA during adolescence on hippocampal long-term potentiation (LTP). Rats treated with L-KYN exhibited no LTP after a burst of high-frequency stimulation that was sufficient to produce robust LTP in vehicle-treated rats. This finding represents the first demonstrated consequence of elevated KYNA concentration during development and provides insight into the basis for cognitive and behavioral deficits that result from exposure to KYNA during adolescence.
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Affiliation(s)
- Nicole E DeAngeli
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
| | - Travis P Todd
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
| | - Stephen E Chang
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
| | - Hermes H Yeh
- Department of Physiology and Neurobiology, Geisel School of Medicine, Dartmouth College , Hanover, NH , USA
| | - Pamela W Yeh
- Department of Physiology and Neurobiology, Geisel School of Medicine, Dartmouth College , Hanover, NH , USA
| | - David J Bucci
- Department of Psychological and Brain Sciences, Dartmouth College , Hanover, NH , USA
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Zhuo C, Zhu J, Qin W, Qu H, Ma X, Tian H, Xu Q, Yu C. Functional connectivity density alterations in schizophrenia. Front Behav Neurosci 2014; 8:404. [PMID: 25477799 PMCID: PMC4237131 DOI: 10.3389/fnbeh.2014.00404] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/05/2014] [Indexed: 11/30/2022] Open
Abstract
Background: Schizophrenia is characterized by altered resting-state functional connectivity. Most previous studies have focused on changes in connectivity strengths; however, the alterations in connectivity density in schizophrenia remain largely unknown. Here, we aimed to investigate changes in resting-state functional connectivity density (rsFCD) in schizophrenia. Methods: A total of 95 schizophrenia patients and 93 sex- and age-matched healthy controls (HCs) underwent resting-state functional MRI examinations. The rsFCD, which reflects the total number of functional connections between a given brain voxel and all other voxels in the entire brain, was calculated for each voxel of each subject. Voxel-based comparisons were performed to identify brain regions with significant rsFCD differences between patients and controls (P < 0.05, corrected). Results: Compared with HCs, patients with schizophrenia showed significantly increased rsFCD in the bilateral striatum and hippocampus and significantly decreased rsFCD in the bilateral sensorimotor cortices and right occipital cortex. However, the rsFCD values of these brain regions were not correlated with antipsychotic dosage, illness duration, or clinical symptom severity. Conclusions: The striatal and hippocampal regions and parietal-occipital regions exhibited completely different changes in rsFCD in schizophrenia, which roughly correspond to dopamine activity in these regions in schizophrenia. These findings support the connectivity disorder hypothesis of schizophrenia and increase our understanding of the neural mechanisms of schizophrenia.
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Affiliation(s)
- Chuanjun Zhuo
- Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital Tianjin, China ; Functional Neuroimaging Laboratory, Department of Psychiatry, Tianjin Mental Health Center, Tianjin Anding Hospital Tianjin, China ; Tianjin Anning Hospital Tianjin, China
| | - Jiajia Zhu
- Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital Tianjin, China
| | - Wen Qin
- Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital Tianjin, China
| | - Hongru Qu
- Tianjin Anning Hospital Tianjin, China
| | | | - Hongjun Tian
- Functional Neuroimaging Laboratory, Department of Psychiatry, Tianjin Mental Health Center, Tianjin Anding Hospital Tianjin, China
| | | | - Chunshui Yu
- Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital Tianjin, China
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Allen JL, Liu X, Pelkowski S, Palmer B, Conrad K, Oberdörster G, Weston D, Mayer-Pröschel M, Cory-Slechta DA. Early postnatal exposure to ultrafine particulate matter air pollution: persistent ventriculomegaly, neurochemical disruption, and glial activation preferentially in male mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:939-45. [PMID: 24901756 PMCID: PMC4154219 DOI: 10.1289/ehp.1307984] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 05/22/2014] [Indexed: 05/17/2023]
Abstract
BACKGROUND Air pollution has been associated with adverse neurological and behavioral health effects in children and adults. Recent studies link air pollutant exposure to adverse neurodevelopmental outcomes, including increased risk for autism, cognitive decline, ischemic stroke, schizophrenia, and depression. OBJECTIVES We sought to investigate the mechanism(s) by which exposure to ultrafine concentrated ambient particles (CAPs) adversely influences central nervous system (CNS) development. METHODS We exposed C57BL6/J mice to ultrafine (< 100 nm) CAPs using the Harvard University Concentrated Ambient Particle System or to filtered air on postnatal days (PNDs) 4-7 and 10-13, and the animals were euthanized either 24 hr or 40 days after cessation of exposure. Another group of males was exposed at PND270, and lateral ventricle area, glial activation, CNS cytokines, and monoamine and amino acid neurotransmitters were quantified. RESULTS We observed ventriculomegaly (i.e., lateral ventricle dilation) preferentially in male mice exposed to CAPs, and it persisted through young adulthood. In addition, CAPs-exposed males generally showed decreases in developmentally important CNS cytokines, whereas in CAPs-exposed females, we observed a neuroinflammatory response as indicated by increases in CNS cytokines. We also saw changes in CNS neurotransmitters and glial activation across multiple brain regions in a sex-dependent manner and increased hippocampal glutamate in CAPs-exposed males. CONCLUSIONS We observed brain region- and sex-dependent alterations in cytokines and neurotransmitters in both male and female CAPs-exposed mice. Lateral ventricle dilation (i.e., ventriculomegaly) was observed only in CAPs-exposed male mice. Ventriculomegaly is a neuropathology that has been associated with poor neurodevelopmental outcome, autism, and schizophrenia. Our findings suggest alteration of developmentally important neurochemicals and lateral ventricle dilation may be mechanistically related to observations linking ambient air pollutant exposure and adverse neurological/neurodevelopmental outcomes in humans.
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Affiliation(s)
- Joshua L Allen
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, New York, USA
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132
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Manghera M, Ferguson J, Douville R. Endogenous Retrovirus-K and Nervous System Diseases. Curr Neurol Neurosci Rep 2014; 14:488. [DOI: 10.1007/s11910-014-0488-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Huang Y, Miao YE, Ji S, Tjiu WW, Liu T. Electrospun carbon nanofibers decorated with Ag-Pt bimetallic nanoparticles for selective detection of dopamine. ACS APPLIED MATERIALS & INTERFACES 2014; 6:12449-12456. [PMID: 25029608 DOI: 10.1021/am502344p] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Electrospun nanoporous carbon nanofibers (pCNFs) decorated with Ag-Pt bimetallic nanoparticles have been successfully synthesized by combining template carbonization and seed-growth reduction approach. Porous-structured polyacrylonitrile (PAN) nanofibers (pPAN) were first prepared by electrospinning PAN/polyvinylpyrrolidone (PVP) blend solution, followed by subsequent water extraction and heat treatment to obtain pCNFs. Ag-Pt/pCNFs were then obtained by using pCNFs as support for bimetallic nanoparticle loading. Thus, the obtained Ag-Pt/pCNFs were used to modify glassy carbon electrode (GCE) for selective detection of dopamine (DA) in the presence of uric acid (UA) and ascorbic acid (AA). This novel sensor exhibits fast amperometric response and high sensitivity toward DA with a wide linear concentration range of 10-500 μM and a low detection limit of 0.11 μM (S/N = 3), wherein the interference of UA and AA can be eliminated effectively.
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Affiliation(s)
- Yunpeng Huang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University , Shanghai 200433, P. R. China
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Single and combined effects of prenatal immune activation and peripubertal stress on parvalbumin and reelin expression in the hippocampal formation. Brain Behav Immun 2014; 40:48-54. [PMID: 24859043 DOI: 10.1016/j.bbi.2014.04.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 04/03/2014] [Accepted: 04/15/2014] [Indexed: 11/21/2022] Open
Abstract
Exposure to prenatal infection and traumatizing experiences in peripubertal life are two environmental risk factors for developmental neuropsychiatric disorders. Modeling the cumulative neuronal impact of these factors in a translational animal model has led to the recent identification of pathological interactions between these environmental adversities in the development of adult brain dysfunctions. The present study explored the consequences of combined prenatal immune challenge and peripubertal stress on discrete cellular abnormalities in the γ-aminobutyric acid (GABA) system of the hippocampus. Pregnant mice were treated with the viral mimetic poly(I:C) (=polyriboinosinic-polyribocytidilic acid) or control solution, and offspring born to poly(I:C)-exposed or control mothers were then left undisturbed or subjected to unpredictable sub-chronic stress during peripubertal development. Stereological estimations of parvalbumin-expressing cells revealed a significant reduction of these GABAergic interneurons in the ventral dentate gyrus of adult offspring exposed to combined immune activation and stress. Single exposure to either environmental factor was insufficient to cause similar neuropathology. We further found that peripubertal stress exerted opposite effects on reelin-immunoreactive cells in the dorsal cornu ammonis (CA) region of the hippocampus, with stress increasing and decreasing reelin expression in control offspring and prenatally immune challenged animals, respectively. The present data suggest that the combination of two environmental risk factors, which have each been implicated in the etiology of major neuropsychiatric disease, induces significant but restricted neuropathological effects on hippocampal GABAergic cell populations known to be affected in brain disorders with neurodevelopmental components.
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135
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Goldman MB. Brain circuit dysfunction in a distinct subset of chronic psychotic patients. Schizophr Res 2014; 157:204-13. [PMID: 24994556 PMCID: PMC6195810 DOI: 10.1016/j.schres.2014.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/30/2014] [Accepted: 06/02/2014] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To identify the mechanism of unexplained hyponatremia and primary polydipsia in schizophrenia and its relationship to the underlying psychiatric illness. METHODS Briefly review previous studies that led to the conclusion the hyponatremia reflects altered hippocampal inhibition of peripheral neuroendocrine secretion. In greater detail, present the evidence supporting the hypothesis that circuit dysfunction associated with the hyponatremia and the polydipsia contributes to the underlying mental disorder. RESULTS Polydipsic patients with and without hyponatremia exhibit enhanced neuroendocrine responses to psychological stress in proportion to structural deformations on their anterior hippocampus, amygdala and anterior hypothalamus. Nonpolydipsic patients exhibit blunted responses and deformations on other hippocampal and amygdala surfaces. The deformations in polydipsic patients are also proportional to diminished peripheral oxytocin levels and impaired facial affect recognition that is reversed by intranasal oxytocin. The anterior hippocampus is at the hub of a circuit that modulates neuroendocrine and other responses to psychological stress and is implicated in schizophrenia. Preliminary data indicate that other measures of stress reactivity are also enhanced in polydipsics and that the functional connectivity of the hippocampus with the other structures in this circuitry differs in schizophrenia patients with and without polydipsia. CONCLUSION Polydipsia may identify a subset of schizophrenia patients whose enhanced stress reactivity contributes to their mental illness. Stress reactivity may be a symptom dimension of chronic psychosis that arises from circuit dysfunction that can be modeled in animals. Hence polydipsia could be a biomarker that helps to clarify the pathophysiology and heterogeneity of psychosis as well as identify novel therapies. Clinical investigators should consider obtaining indices of water balance, as these may help them unravel and more concisely interpret their findings. Basic researchers should assess if the polydipsic subset is a patient group particularly suitable to test hypotheses arising from their translational studies.
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Affiliation(s)
- Morris B. Goldman
- Northwestern University, Department of Psychiatry, 446 East Ontario, Suite 7-100, Chicago, Illinois 60611, USA, phone:1 312 695 2089, fax: 1 708 383 6344
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Gutierrez F, Comba FN, Gasnier A, Gutierrez A, Galicia L, Parrado C, Rubianes MD, Rivas GA. Graphene Paste Electrode: Analytical Applications for the Quantification of Dopamine, Phenolic Compounds and Ethanol. ELECTROANAL 2014. [DOI: 10.1002/elan.201400247] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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137
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Belujon P, Patton MH, Grace AA. Role of the prefrontal cortex in altered hippocampal-accumbens synaptic plasticity in a developmental animal model of schizophrenia. Cereb Cortex 2014; 24:968-77. [PMID: 23236209 PMCID: PMC4047286 DOI: 10.1093/cercor/bhs380] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Schizophrenia is characterized by alterations in cortico-limbic processes believed to involve modifications in activity within the prefrontal cortex (PFC) and the hippocampus. The nucleus accumbens (NAc) integrates information from these 2 brain regions and is involved in cognitive and psychomotor functions that are disrupted in schizophrenia, indicating an important role for this structure in the pathophysiology of this disorder. In this study, we used in vivo electrophysiological recordings from the NAc and the PFC of adult rats and the MAM developmental disruption rodent model of schizophrenia to explore the influence of the medial PFC on the hippocampal-accumbens pathway. We found that, in MAM-treated rats, tetanization of hippocampal inputs to the NAc produce opposite synaptic plasticity compared with controls, which is a consequence of alterations in the hippocampal-mPFC pathway. Moreover, we show that administration of the D2-receptor-blocking antipsychotic drug sulpiride either systemically or directly into the mPFC reverses the alterations in the MAM rat. Therefore, specific disruptions in cortical and hippocampal inputs in the MAM-treated rat abnormally alter plasticity in subcortical structures. Moreover, our results suggest that, in the presence of antipsychotic drugs, the disrupted plasticities are normalized, supporting a role for this mechanism in antipsychotic drug action in schizophrenia.
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Affiliation(s)
- Pauline Belujon
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Mary H. Patton
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Voon V, Rizos A, Chakravartty R, Mulholland N, Robinson S, Howell NA, Harrison N, Vivian G, Ray Chaudhuri K. Impulse control disorders in Parkinson's disease: decreased striatal dopamine transporter levels. J Neurol Neurosurg Psychiatry 2014; 85:148-52. [PMID: 23899625 PMCID: PMC4031642 DOI: 10.1136/jnnp-2013-305395] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/13/2013] [Accepted: 06/18/2013] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Impulse control disorders are commonly associated with dopaminergic therapy in Parkinson's disease (PD). PD patients with impulse control disorders demonstrate enhanced dopamine release to conditioned cues and a gambling task on [(11)C]raclopride positron emission tomography (PET) imaging and enhanced ventral striatal activity to reward on functional MRI. We compared PD patients with impulse control disorders and age-matched and gender-matched controls without impulse control disorders using [(123)I]FP-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane) single photon emission computed tomography (SPECT), to assess striatal dopamine transporter (DAT) density. METHODS The [(123)I]FP-CIT binding data in the striatum were compared between 15 PD patients with and 15 without impulse control disorders using independent t tests. RESULTS Those with impulse control disorders showed significantly lower DAT binding in the right striatum with a trend in the left (right: F(1,24)=5.93, p=0.02; left: F(1,24)=3.75, p=0.07) compared to controls. CONCLUSIONS Our findings suggest that greater dopaminergic striatal activity in PD patients with impulse control disorders may be partly related to decreased uptake and clearance of dopamine from the synaptic cleft. Whether these findings are related to state or trait effects is not known. These findings dovetail with reports of lower DAT levels secondary to the effects of methamphetamine and alcohol. Although any regulation of DAT by antiparkinsonian medication appears to be modest, PD patients with impulse control disorders may be differentially sensitive to regulatory mechanisms of DAT expression by dopaminergic medications.
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Affiliation(s)
- Valerie Voon
- Department of Psychiatry, University of Cambridge, Cambridge, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK
| | - Alexandra Rizos
- National Parkinson Foundation Centre of Excellence, Kings College Hospital, and Kings College, London, UK
| | - Riddhika Chakravartty
- National Parkinson Foundation Centre of Excellence, Kings College Hospital, and Kings College, London, UK
- Department of Nuclear Imaging, Kings College Hospital, London, UK
| | - Nicola Mulholland
- National Parkinson Foundation Centre of Excellence, Kings College Hospital, and Kings College, London, UK
- Department of Nuclear Imaging, Kings College Hospital, London, UK
| | - Stephanie Robinson
- National Parkinson Foundation Centre of Excellence, Kings College Hospital, and Kings College, London, UK
| | - Nicholas A Howell
- Department of Psychiatry, University of Cambridge, Cambridge, UK
- University of Toronto, Toronto, Canada
| | | | - Gill Vivian
- Department of Nuclear Imaging, Kings College Hospital, London, UK
| | - K Ray Chaudhuri
- National Parkinson Foundation Centre of Excellence, Kings College Hospital, and Kings College, London, UK
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139
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Yin B, Meck WH. Comparison of interval timing behaviour in mice following dorsal or ventral hippocampal lesions with mice having δ-opioid receptor gene deletion. Philos Trans R Soc Lond B Biol Sci 2014; 369:20120466. [PMID: 24446500 DOI: 10.1098/rstb.2012.0466] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mice with cytotoxic lesions of the dorsal hippocampus (DH) underestimated 15 s and 45 s target durations in a bi-peak procedure as evidenced by proportional leftward shifts of the peak functions that emerged during training as a result of decreases in both 'start' and 'stop' times. In contrast, mice with lesions of the ventral hippocampus (VH) displayed rightward shifts that were immediately present and were largely limited to increases in the 'stop' time for the 45 s target duration. Moreover, the effects of the DH lesions were congruent with the scalar property of interval timing in that the 15 s and 45 s functions superimposed when plotted on a relative timescale, whereas the effects of the VH lesions violated the scalar property. Mice with DH lesions also showed enhanced reversal learning in comparison to control and VH lesioned mice. These results are compared with the timing distortions observed in mice lacking δ-opioid receptors (Oprd1(-/-)) which were similar to mice with DH lesions. Taken together, these results suggest a balance between hippocampal-striatal interactions for interval timing and demonstrate possible functional dissociations along the septotemporal axis of the hippocampus in terms of motivation, timed response thresholds and encoding in temporal memory.
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Affiliation(s)
- Bin Yin
- Department of Psychology and Neuroscience, Duke University, , Durham, NC 27708, USA
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140
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Melka MG, Laufer BI, McDonald P, Castellani CA, Rajakumar N, O'Reilly R, Singh SM. The effects of olanzapine on genome-wide DNA methylation in the hippocampus and cerebellum. Clin Epigenetics 2014; 6:1. [PMID: 24382160 PMCID: PMC3895844 DOI: 10.1186/1868-7083-6-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 12/04/2013] [Indexed: 12/23/2022] Open
Abstract
Background The mechanism of action of olanzapine in treating schizophrenia is not clear. This research reports the effects of a therapeutic equivalent treatment of olanzapine on DNA methylation in a rat model in vivo. Genome-wide DNA methylation was assessed using a MeDIP-chip analysis. All methylated DNA immunoprecipitation (MeDIP), sample labelling, hybridization and processing were performed by Arraystar Inc (Rockville, MD, USA). The identified gene promoters showing significant alterations to DNA methylation were then subjected to Ingenuity Pathway Analysis (Ingenuity System Inc, CA, USA). Results The results show that olanzapine causes an increase in methylation in 1,140, 1,294 and 1,313 genes and a decrease in methylation in 633, 565 and 532 genes in the hippocampus, cerebellum and liver, respectively. Most genes affected are tissue specific. Only 41 affected genes (approximately 3%) showed an increase and no gene showed a decrease in methylation in all three tissues. Further, the two brain regions shared 123 affected genes (approximately 10%). The affected genes are enriched in pathways affecting dopamine signalling, molecular transport, nervous system development and functions in the hippocampus; ephrin receptor signalling and synaptic long-term potentiation in the cerebellum; and tissue morphology, cellular assembly and organization in the liver. Also, the affected genes included those previously implicated in psychosis. Conclusions The known functions of affected genes suggest that the observed epigenetic changes may underlie the amelioration of symptoms as well as accounting for certain adverse effects including the metabolic syndrome. The results give insights into the mechanism of action of olanzapine, therapeutic effects and the side effects of antipsychotics.
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Affiliation(s)
| | | | | | | | | | | | - Shiva M Singh
- Molecular Genetics Unit, Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada.
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Brisch R, Saniotis A, Wolf R, Bielau H, Bernstein HG, Steiner J, Bogerts B, Braun K, Jankowski Z, Kumaratilake J, Henneberg M, Gos T, Henneberg M, Gos T. The role of dopamine in schizophrenia from a neurobiological and evolutionary perspective: old fashioned, but still in vogue. Front Psychiatry 2014; 5:47. [PMID: 24904434 PMCID: PMC4032934 DOI: 10.3389/fpsyt.2014.00047] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/23/2014] [Indexed: 12/12/2022] Open
Abstract
Dopamine is an inhibitory neurotransmitter involved in the pathology of schizophrenia. The revised dopamine hypothesis states that dopamine abnormalities in the mesolimbic and prefrontal brain regions exist in schizophrenia. However, recent research has indicated that glutamate, GABA, acetylcholine, and serotonin alterations are also involved in the pathology of schizophrenia. This review provides an in-depth analysis of dopamine in animal models of schizophrenia and also focuses on dopamine and cognition. Furthermore, this review provides not only an overview of dopamine receptors and the antipsychotic effects of treatments targeting them but also an outline of dopamine and its interaction with other neurochemical models of schizophrenia. The roles of dopamine in the evolution of the human brain and human mental abilities, which are affected in schizophrenia patients, are also discussed.
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Affiliation(s)
- Ralf Brisch
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
| | - Arthur Saniotis
- School of Medical Sciences, The University of Adelaide , Adelaide, SA , Australia ; Centre for Evolutionary Medicine, University of Zurich , Zurich , Switzerland
| | - Rainer Wolf
- Department of Psychiatry and Psychotherapy, Ruhr University Bochum , Bochum , Germany
| | - Hendrik Bielau
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Hans-Gert Bernstein
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Johann Steiner
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Bernhard Bogerts
- Department of Psychiatry, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Katharina Braun
- Department of Zoology, Institute of Biology, Otto-von-Guericke-University of Magdeburg , Magdeburg , Germany
| | - Zbigniew Jankowski
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
| | - Jaliya Kumaratilake
- Biological Anthropology and Comparative Anatomy Research Unit, School of Biomedical Sciences, The University of Adelaide , Adelaide, SA , Australia
| | - Maciej Henneberg
- Biological Anthropology and Comparative Anatomy Research Unit, School of Biomedical Sciences, The University of Adelaide , Adelaide, SA , Australia
| | - Tomasz Gos
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
| | - Maciej Henneberg
- Biological Anthropology and Comparative Anatomy Research Unit, School of Biomedical Sciences, The University of Adelaide , Adelaide, SA , Australia
| | - Tomasz Gos
- Department of Forensic Medicine, Medical University of Gdańsk , Gdańsk , Poland
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142
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Cazé RD, van der Meer MAA. Adaptive properties of differential learning rates for positive and negative outcomes. BIOLOGICAL CYBERNETICS 2013; 107:711-719. [PMID: 24085507 DOI: 10.1007/s00422-013-0571-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 09/14/2013] [Indexed: 06/02/2023]
Abstract
The concept of the reward prediction error-the difference between reward obtained and reward predicted-continues to be a focal point for much theoretical and experimental work in psychology, cognitive science, and neuroscience. Models that rely on reward prediction errors typically assume a single learning rate for positive and negative prediction errors. However, behavioral data indicate that better-than-expected and worse-than-expected outcomes often do not have symmetric impacts on learning and decision-making. Furthermore, distinct circuits within cortico-striatal loops appear to support learning from positive and negative prediction errors, respectively. Such differential learning rates would be expected to lead to biased reward predictions and therefore suboptimal choice performance. Contrary to this intuition, we show that on static "bandit" choice tasks, differential learning rates can be adaptive. This occurs because asymmetric learning enables a better separation of learned reward probabilities. We show analytically how the optimal learning rate asymmetry depends on the reward distribution and implement a biologically plausible algorithm that adapts the balance of positive and negative learning rates from experience. These results suggest specific adaptive advantages for separate, differential learning rates in simple reinforcement learning settings and provide a novel, normative perspective on the interpretation of associated neural data.
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Affiliation(s)
- Romain D Cazé
- Department of Bioengineering, Imperial College, London, UK,
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143
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Melka MG, Castellani CA, Laufer BI, Rajakumar RN, O'Reilly R, Singh SM. Olanzapine induced DNA methylation changes support the dopamine hypothesis of psychosis. J Mol Psychiatry 2013; 1:19. [PMID: 25408910 PMCID: PMC4223857 DOI: 10.1186/2049-9256-1-19] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 10/16/2013] [Indexed: 01/06/2023] Open
Abstract
Background The dopamine (DA) hypothesis of schizophrenia proposes the mental illness is caused by excessive transmission of dopamine in selected brain regions. Multiple lines of evidence, including blockage of dopamine receptors by antipsychotic drugs that are used to treat schizophrenia, support the hypothesis. However, the dopamine D2 receptor (DRD2) blockade cannot explain some important aspects of the therapeutic effect of antipsychotic drugs. In this study, we hypothesized that antipsychotic drugs could affect the transcription of genes in the DA pathway by altering their epigenetic profile. Methods To test this hypothesis, we examined the effect of olanzapine, a commonly used atypical antipsychotic drug, on the DNA methylation status of genes from DA neurotransmission in the brain and liver of rats. Genomic DNA isolated from hippocampus, cerebellum, and liver of olanzapine treated (n = 2) and control (n = 2) rats were analyzed using rat specific methylation arrays. Results Our results show that olanzapine causes methylation changes in genes encoding for DA receptors (dopamine D1 receptor, dopamine D2 receptor and dopamine D5 receptor), a DA transporter (solute carrier family 18 member 2), a DA synthesis (differential display clone 8), and a DA metabolism (catechol-O-methyltransferase). We assessed a total of 40 genes in the DA pathway and found 19 to be differentially methylated between olanzapine treated and control rats. Most (17/19) genes showed an increase in methylation, in their promoter regions with in silico analysis strongly indicating a functional potential to suppress transcription in the brain. Conclusion Our results suggest that chronic olanzapine may reduce DA activity by altering gene methylation. It may also explain the delayed therapeutic effect of antipsychotics, which occurs despite rapid dopamine blockade. Furthermore, given the common nature of epigenetic variation, this lends insight into the differential therapeutic response of psychotic patients who display adequate blockage of dopamine receptors.
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Affiliation(s)
- Melkaye G Melka
- Department of Biology, Molecular Genetics Unit, Western Science Centre, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Christina A Castellani
- Department of Biology, Molecular Genetics Unit, Western Science Centre, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Benjamin I Laufer
- Department of Biology, Molecular Genetics Unit, Western Science Centre, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Raj N Rajakumar
- Department of Psychiatry, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Richard O'Reilly
- Department of Psychiatry, The University of Western Ontario, London, Ontario N6A 5B7 Canada
| | - Shiva M Singh
- Department of Biology, Molecular Genetics Unit, Western Science Centre, The University of Western Ontario, London, Ontario N6A 5B7 Canada
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Patton MH, Bizup BT, Grace AA. The infralimbic cortex bidirectionally modulates mesolimbic dopamine neuron activity via distinct neural pathways. J Neurosci 2013; 33:16865-73. [PMID: 24155293 PMCID: PMC3807020 DOI: 10.1523/jneurosci.2449-13.2013] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/07/2013] [Accepted: 09/12/2013] [Indexed: 12/21/2022] Open
Abstract
The ventral tegmental area (VTA) has been implicated in a number of psychiatric disorders, including schizophrenia, depression, and bipolar disorder. One major regulator of the mesolimbic dopaminergic system is the medial prefrontal cortex (mPFC), which makes direct and indirect connections to the hippocampus and amygdala, as well as directly to the VTA. The mPFC is comprised of two subregions: the infralimbic and prelimbic cortices (ilPFC and plPFC). However, the specific roles of these subregions in regulating VTA dopamine activity have remained unclear. In this study, we aim to clarify this role and to examine the divergent neuranatomical circuits by which the mPFC regulates VTA activity. Using in vivo extracellular recordings in rats, we tested the effects of pharmacological activation (with NMDA) and inactivation (with TTX) of the ilPFC and plPFC on dopamine neuron activity, and tested the roles of the ventral subiculum (vSub) and basolateral amygdala in this process. We found that the ilPFC exerts a bidirectional control of VTA dopamine neurons, which are differentially modulated through the vSub and the basolateral amygdala. Specifically, activation or inactivation of the ilPFC attenuated or activated dopamine neuron population activity, respectively. Furthermore, dopamine activation depended on the ventral hippocampus and inactivation on the amygdala. In contrast, only inactivation of the plPFC altered dopamine neuron activity. These data indicate that the mPFC has the ability to uniquely fine-tune dopaminergic activity in the VTA. Furthermore, the data presented here suggest that the ilPFC may have a role in the pathophysiology of psychiatric disorders.
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Affiliation(s)
- Mary H. Patton
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Brandon T. Bizup
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
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145
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Xue C, Han Q, Wang Y, Wu J, Wen T, Wang R, Hong J, Zhou X, Jiang H. Amperometric detection of dopamine in human serum by electrochemical sensor based on gold nanoparticles doped molecularly imprinted polymers. Biosens Bioelectron 2013; 49:199-203. [PMID: 23747995 DOI: 10.1016/j.bios.2013.04.022] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 04/04/2013] [Accepted: 04/18/2013] [Indexed: 11/30/2022]
Abstract
In this work, a highly sensitive and selective biomimetic electrochemical sensor for the amperometric detection of trace dopamine (DA) in human serums was achieved by gold nanoparticles (AuNPs) doped molecularly imprinted polymers (MIPs). Functionalized AuNPs (F-AuNPs), a novel functional monomer bearing aniline moieties on the surface of the AuNPs, were prepared via a direct synthesis method and then used to fabricate the conductive MIPs film on the modified electrode by electropolymerization method in the presence of DA and p-aminobenzenethiol (p-ATP). The obtained electrochemical sensor based on the conductive film of AuNPs doped MIPs (AuNPs@MIPs) could effectively minimize the interferences caused by ascorbic acid (AA) and uric acid (UA). The linear range for amperometric detection of DA was from 0.02 μmol L(-1) to 0.54 μmol L(-1) with the detection limit of 7.8 nmol L(-1) (S/N=3). Furthermore, the AuNPs@MIPs modified electrode (AuNPs@MIES) was successfully employed to detect trace DA in different human serums.
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Affiliation(s)
- Cheng Xue
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
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146
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Jiang G, Cao Q, Li J, Zhang Y, Liu X, Wang Z, Guo F, Chen Y, Chen Y, Chen G, Wang X. Altered expression of vesicular monoamine transporter 2 in epileptic patients and experimental rats. Synapse 2013; 67:415-26. [PMID: 23504951 DOI: 10.1002/syn.21663] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 03/11/2013] [Indexed: 12/17/2022]
Abstract
In the central nervous system (CNS), vesicular monoamine transporter 2 (VMAT2) transports cytoplasmic monoamines such as dopamine into synaptic vesicles for storage and subsequent exocytotic release. Recent studies have provided direct evidence for VMAT2-regulated monoamine neurotransmitter involvement in the neurophysiological activities of neurological disease. This study investigated the expression pattern of VMAT2 in patients with temporal lobe epilepsy (TLE) and in a rat model of epilepsy. We assessed the expression of VMAT2 in the temporal neocortex in 24 TLE patients using western blotting and quantitative real time PCR (qRT-PCR) analyses. These results showed that VMAT2 expression dynamically decreased in TLE patients when compared with the control subjects (n = 12). And that VMAT2 protein transiently increased in acute stages (1 day and 3 days) after epileptic seizures in pilocarpine-treated rats; however, it clearly decreased after spontaneous recurrent seizures (7 days, 21 days, and 60 days after seizures). In addition, double immunofluorescence and immunohistochemical labeling studies performed in patient and experimental animal tissue revealed that VMAT2 protein was mainly expressed in the cytoplasm and in the axons of neurons but not glial cells in the hippocampus and temporal lobe cortex. These data suggested that the abnormal expression of VMAT2 mRNA and protein in epileptic brain tissue may contribute to vulnerability toward epilepsy-related psychiatric disorders and cognitive impairment.
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Affiliation(s)
- Guohui Jiang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, 400016, China
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147
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Belujon P, Patton MH, Grace AA. Disruption of prefrontal cortical-hippocampal balance in a developmental model of schizophrenia: reversal by sulpiride. Int J Neuropsychopharmacol 2013; 16:507-12. [PMID: 23067577 PMCID: PMC3687537 DOI: 10.1017/s146114571200106x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The nucleus accumbens (NAc) receives converging inputs from the medial prefrontal cortex (mPFC) and the hippocampus which have competitive interactions in the NAc to influence motivational drive. We have previously shown altered synaptic plasticity in the hippocampal-NAc pathway in the methylazoxymethanol acetate (MAM) developmental model of schizophrenia in rodents that is dependent on cortical inputs. Thus, because mPFC-hippocampal balance is known to be partially altered in this model, we investigated potential pathological changes in the hippocampal influence over cortex-driven NAc spike activity. Here we show that the reciprocal interaction between the hippocampus and mPFC is absent in MAM animals but is able to be reinstated with administration of the antipsychotic drug, sulpiride. The lack of interaction between these structures in this model could explain the attentional deficits in schizophrenia patients and shed light onto their inability to focus on a single task.
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Affiliation(s)
- Pauline Belujon
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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148
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Snyder MA, Gao WJ. NMDA hypofunction as a convergence point for progression and symptoms of schizophrenia. Front Cell Neurosci 2013; 7:31. [PMID: 23543703 PMCID: PMC3608949 DOI: 10.3389/fncel.2013.00031] [Citation(s) in RCA: 163] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/11/2013] [Indexed: 01/05/2023] Open
Abstract
Schizophrenia is a disabling mental illness that is now recognized as a neurodevelopmental disorder. It is likely that genetic risk factors interact with environmental perturbations to affect normal brain development and that this altered trajectory results in a combination of positive, negative, and cognitive symptoms. Although the exact pathophysiology of schizophrenia is unknown, the N-methyl-D-aspartate receptor (NMDAR), a major glutamate receptor subtype, has received great attention. Proper expression and regulation of NMDARs in the brain is critical for learning and memory processes as well as cortical plasticity and maturation. Evidence from both animal models and human studies implicates a dysfunction of NMDARs both in disease progression and symptoms of schizophrenia. Furthermore, mutations in many of the known genetic risk factors for schizophrenia suggest that NMDAR hypofunction is a convergence point for schizophrenia. In this review, we discuss how disrupted NMDAR function leads to altered neurodevelopment that may contribute to the progression and development of symptoms for schizophrenia, particularly cognitive deficits. We review the shared signaling pathways among the schizophrenia susceptibility genes DISC1, neuregulin1, and dysbindin, focusing on the AKT/GSK3β pathway, and how their mutations and interactions can lead to NMDAR dysfunction during development. Additionally, we explore what open questions remain and suggest where schizophrenia research needs to move in order to provide mechanistic insight into the cause of NMDAR dysfunction, as well as generate possible new avenues for therapeutic intervention.
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Affiliation(s)
- Melissa A Snyder
- Department of Neurobiology and Anatomy, Drexel University College of Medicine Philadelphia, PA, USA
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149
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DeVylder J, Ben-David S, Schobel S, Kimhy D, Malaspina D, Corcoran C. Temporal association of stress sensitivity and symptoms in individuals at clinical high risk for psychosis. Psychol Med 2013; 43:259-268. [PMID: 22651857 PMCID: PMC3716006 DOI: 10.1017/s0033291712001262] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Increased sensitivity and exposure to stress are associated with psychotic symptoms in schizophrenia and its risk states, but little is known about the co-evolution of stress sensitivity and exposure with positive and other symptoms in a clinical high-risk (CHR) cohort. METHOD A combined cross-sectional and longitudinal design was used to examine the associations over time of stress sensitivity and exposure (i.e. life events) with 'prodromal' symptoms in a cohort of 65 CHR patients assessed quarterly for up to 4 years, and at baseline in 24 healthy controls similar in age and gender. RESULTS Impaired stress tolerance was greater in patients, in whom it was associated over time with positive and negative symptoms, in addition to depression, anxiety and poor function. By contrast, life events were comparable in patients and controls, and bore no association with symptoms. In this treated cohort, there was a trajectory of improvement in stress tolerance, symptoms and function over time. CONCLUSIONS Impaired stress tolerance was associated with a wide range of 'prodromal' symptoms, consistent with it being a core feature of the psychosis risk state. Self-reported life events were not relevant as a correlate of clinical status. As in other treated CHR cohorts, most patients improved over time across symptom domains.
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Affiliation(s)
- J.E. DeVylder
- Columbia University School of Social Work, New York, NY, USA
| | - S. Ben-David
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - S.A. Schobel
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - D. Kimhy
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - D. Malaspina
- Department of Psychiatry, New York University, New York, NY, USA
| | - C.M. Corcoran
- Department of Psychiatry, Columbia University, New York, NY, USA
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150
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Ewing SG, Grace AA. Deep brain stimulation of the ventral hippocampus restores deficits in processing of auditory evoked potentials in a rodent developmental disruption model of schizophrenia. Schizophr Res 2013; 143:377-83. [PMID: 23269227 PMCID: PMC3547127 DOI: 10.1016/j.schres.2012.11.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 11/18/2012] [Accepted: 11/20/2012] [Indexed: 12/30/2022]
Abstract
Existing antipsychotic drugs are most effective at treating the positive symptoms of schizophrenia but their relative efficacy is low and they are associated with considerable side effects. In this study deep brain stimulation of the ventral hippocampus was performed in a rodent model of schizophrenia (MAM-E17) in an attempt to alleviate one set of neurophysiological alterations observed in this disorder. Bipolar stimulating electrodes were fabricated and implanted, bilaterally, into the ventral hippocampus of rats. High frequency stimulation was delivered bilaterally via a custom-made stimulation device and both spectral analysis (power and coherence) of resting state local field potentials and amplitude of auditory evoked potential components during a standard inhibitory gating paradigm were examined. MAM rats exhibited alterations in specific components of the auditory evoked potential in the infralimbic cortex, the core of the nucleus accumbens, mediodorsal thalamic nucleus, and ventral hippocampus in the left hemisphere only. DBS was effective in reversing these evoked deficits in the infralimbic cortex and the mediodorsal thalamic nucleus of MAM-treated rats to levels similar to those observed in control animals. In contrast stimulation did not alter evoked potentials in control rats. No deficits or stimulation-induced alterations were observed in the prelimbic and orbitofrontal cortices, the shell of the nucleus accumbens or ventral tegmental area. These data indicate a normalization of deficits in generating auditory evoked potentials induced by a developmental disruption by acute high frequency, electrical stimulation of the ventral hippocampus.
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Affiliation(s)
- Samuel G. Ewing
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA,Corresponding author (Samuel G. Ewing)
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA
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