51
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Gao F, Yin X, Edden RAE, Evans AC, Xu J, Cao G, Li H, Li M, Zhao B, Wang J, Wang G. Altered hippocampal GABA and glutamate levels and uncoupling from functional connectivity in multiple sclerosis. Hippocampus 2019; 28:813-823. [PMID: 30069963 DOI: 10.1002/hipo.23001] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 05/01/2018] [Accepted: 06/11/2018] [Indexed: 12/16/2022]
Abstract
There is growing evidence for dysfunctional glutamatergic excitation and/or gamma-aminobutyric acid (GABA)ergic inhibition in patients with multiple sclerosis (MS). Cognitive impairment may occur during the early stages of MS and hippocampal abnormalities have been suggested as biomarkers. However, researchers have not clearly determined whether changes in hippocampal GABA and glutamate (Glu) levels are associated with cognitive impairment and aberrant neural activity in patients with MS. We used magnetic resonance spectroscopy to measure GABA+ and Glu levels in the left hippocampal region of 29 patients with relapsing-remitting MS and 29 healthy controls (HCs). Resting-state functional connectivity (FC) with the hippocampus was also examined. Compared to HCs, patients exhibited significantly lower GABA+ and Glu levels, which were associated with verbal and visuospatial memory deficits, respectively. Patients also showed decreased FC strengths between the hippocampus and several cortical regions, which are located within the default mode network. Moreover, hippocampal GABA+ levels and Glu/GABA+ ratios correlated with the FC strengths in HCs but not in patients with MS. This study describes a novel method for investigating the complex relationships among excitatory/inhibitory neurotransmitters, brain connectivity and cognition in health and disease. Strategies that modulate Glu and GABA neurotransmission may represent new therapeutic treatments for patients with MS.
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Affiliation(s)
- Fei Gao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Xuntao Yin
- Department of Radiology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Alan C Evans
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Quebec, Canada
| | - Junhai Xu
- Tianjin Key Laboratory of Cognitive Computing and Application, School of Computer Science and Technology, Tianjin University, Tianjin, China
| | - Guanmei Cao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Honghao Li
- Department of Neurology, Shandong Provincial Hospital, Shandong University, Jinan, China
| | - Muwei Li
- Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA
| | - Bin Zhao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
| | - Jian Wang
- Department of Radiology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Guangbin Wang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, China
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Krajcovic B, Fajnerova I, Horacek J, Kelemen E, Kubik S, Svoboda J, Stuchlik A. Neural and neuronal discoordination in schizophrenia: From ensembles through networks to symptoms. Acta Physiol (Oxf) 2019; 226:e13282. [PMID: 31002202 DOI: 10.1111/apha.13282] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/27/2019] [Accepted: 04/12/2019] [Indexed: 12/22/2022]
Abstract
Despite the substantial knowledge accumulated by past research, the exact mechanisms of the pathogenesis of schizophrenia and causal treatments still remain unclear. Deficits of cognition and information processing in schizophrenia are today often viewed as the primary and core symptoms of this devastating disorder. These deficits likely result from disruptions in the coordination of neuronal and neural activity. The aim of this review is to bring together convergent evidence of discoordinated brain circuits in schizophrenia at multiple levels of resolution, ranging from principal cells and interneurons, neuronal ensembles and local circuits, to large-scale brain networks. We show how these aberrations could underlie deficits in cognitive control and other higher order cognitive-behavioural functions. Converging evidence from both animal models and patients with schizophrenia is presented in an effort to gain insight into common features of deficits in the brain information processing in this disorder, marked by disruption of several neurotransmitter and signalling systems and severe behavioural outcomes.
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Affiliation(s)
- Branislav Krajcovic
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Third Faculty of Medicine Charles University Prague Czech Republic
| | - Iveta Fajnerova
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Jiri Horacek
- Third Faculty of Medicine Charles University Prague Czech Republic
- Research Programme 3 - Applied Neurosciences and Brain Imaging National Institute of Mental Health Klecany Czech Republic
| | - Eduard Kelemen
- Research Programme 1 - Experimental Neurobiology National Institute of Mental Health Klecany Czech Republic
| | - Stepan Kubik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Jan Svoboda
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Ales Stuchlik
- Department of Neurophysiology of Memory Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
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Davies C, Paloyelis Y, Rutigliano G, Cappucciati M, De Micheli A, Ramella-Cravaro V, Provenzani U, Antoniades M, Modinos G, Oliver D, Stahl D, Murguia S, Zelaya F, Allen P, Shergill S, Morrison P, Williams S, Taylor D, McGuire P, Fusar-Poli P. Oxytocin modulates hippocampal perfusion in people at clinical high risk for psychosis. Neuropsychopharmacology 2019; 44:1300-1309. [PMID: 30626906 PMCID: PMC6784972 DOI: 10.1038/s41386-018-0311-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 11/27/2018] [Accepted: 12/18/2018] [Indexed: 12/15/2022]
Abstract
Preclinical and human studies suggest that hippocampal dysfunction is a key factor in the onset of psychosis. People at Clinical High Risk for psychosis (CHR-P) present with a clinical syndrome that can include social withdrawal and have a 20-35% risk of developing psychosis in the next 2 years. Recent research shows that resting hippocampal blood flow is altered in CHR-P individuals and predicts adverse clinical outcomes, such as non-remission/transition to frank psychosis. Previous work in healthy males indicates that a single dose of intranasal oxytocin has positive effects on social function and marked effects on resting hippocampal blood flow. The present study examined the effects of intranasal oxytocin on hippocampal blood flow in CHR-P individuals. In a double-blind, placebo-controlled, crossover design, 30 CHR-P males were studied using pseudo-continuous Arterial Spin Labelling on 2 occasions, once after 40IU intranasal oxytocin and once after placebo. The effects of oxytocin on left hippocampal blood flow were examined in a region-of-interest analysis of data acquired at 22-28 and at 30-36 minutes post-intranasal administration. Relative to placebo, administration of oxytocin was associated with increased hippocampal blood flow at both time points (p = .0056; p = .034), although the effect at the second did not survive adjustment for the effect of global blood flow. These data indicate that oxytocin can modulate hippocampal function in CHR-P individuals and therefore merits further investigation as a candidate novel treatment for this group.
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Grants
- G0901868 Medical Research Council
- 22593 Brain and Behavior Research Foundation (Brain & Behavior Research Foundation)
- Dominic Oliver is supported by the UK Medical Research Council (MR/N013700/1) and is a King’s College London member of the MRC Doctoral Training Partnership in Biomedical Sciences.
- National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) at South London and Maudsley NHS Foundation Trust and King’s College London, London, UK
- DH | National Institute for Health Research (NIHR)
- This work was supported by the National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) at South London and Maudsley NHS Foundation Trust and King’s College London (PFP, PM, DS); by a Brain & Behaviour Research Foundation NARSAD Award (grant number 22593 to PFP); and by the Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care. The funders had no influence on the design, collection, analysis and interpretation of the data, writing of the report and decision to submit this article for publication.
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Affiliation(s)
- Cathy Davies
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Yannis Paloyelis
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Grazia Rutigliano
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Marco Cappucciati
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Andrea De Micheli
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- National Institute for Health Research (NIHR) Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust, London, UK
| | - Valentina Ramella-Cravaro
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Umberto Provenzani
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Mathilde Antoniades
- National Institute for Health Research (NIHR) Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Gemma Modinos
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Dominic Oliver
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Daniel Stahl
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Silvia Murguia
- Tower Hamlets Early Detection Service (THEDS), East London NHS Foundation Trust, London, UK
| | - Fernando Zelaya
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Paul Allen
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Department of Psychology, University of Roehampton, London, UK
| | - Sukhi Shergill
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Paul Morrison
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Steve Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - David Taylor
- Institute of Pharmaceutical Science, King's College London, London, UK
| | - Philip McGuire
- National Institute for Health Research (NIHR) Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Outreach And Support in South London (OASIS) Service, South London and Maudsley NHS Foundation Trust, London, UK
| | - Paolo Fusar-Poli
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
- National Institute for Health Research (NIHR) Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust, London, UK.
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
- Outreach And Support in South London (OASIS) Service, South London and Maudsley NHS Foundation Trust, London, UK.
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54
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Ota M, Noda T, Sato N, Hidese S, Teraishi T, Setoyama S, Matsuda H, Kunugi H. The use of diffusional kurtosis imaging and neurite orientation dispersion and density imaging of the brain in bipolar disorder. J Affect Disord 2019; 251:231-234. [PMID: 30928862 DOI: 10.1016/j.jad.2019.03.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/14/2019] [Accepted: 03/21/2019] [Indexed: 02/01/2023]
Abstract
BACKGROUND Diffusional kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) are new diffusional magnetic resonance imaging (dMRI) techniques to clarify the characterization of neural tissues in the human brain. In this study, we evaluated the structural changes of the cerebrum in patients with bipolar disorder (BD) by these dMRI techniques. METHODS Thirty-one Japanese patients with BD (male/female: 14/17; 29 out of 31 patients were right-handed; mean age: 39.5 ± 9.3) and 28 healthy, right-handed Japanese subjects underwent 3-Tesla dMRI. We compared the dMRI metrics between the 2 groups and examined the relationships among the metrics. LIMITATION The majority of the participants in this study were medicated with antidepressants and antipsychotics. Further studies with drug-free participants will be needed before any conclusions can be drawn regarding microstructural changes in BD. RESULTS The BD patients showed significantly reduced mean kurtosis in right inferior front-occipital fasciculus and right posterior cingulate cortex (PCC), and neurite density indices in the right -PCC, compared with the controls. As for the orientation dispersion index, we detected significant decrease in the left hippocampal region of BD patients. CONCLUSIONS Using the new dMRI techniques, we observed disease-related alterations in the inferior front-occipital fasciculus, PCC, and hippocampal regions which play important roles in BD. These results may indicate that NODDI and DKI are useful to detect changes in the microstructural tissue organization in BD. It is anticipated that these techniques will be adopted as the mainstream methods for neuroimaging study.
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Affiliation(s)
- Miho Ota
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan; Department of Neuropsychiatry, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8576, Japan.
| | - Takamasa Noda
- Department of Psychiatry, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8551, Japan; Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8551, Japan
| | - Noriko Sato
- Department of Radiology, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8551, Japan
| | - Shinsuke Hidese
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Toshiya Teraishi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Shiori Setoyama
- Department of Psychiatry, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8551, Japan
| | - Hiroshi Matsuda
- Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8551, Japan
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
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55
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Popiolek M, Mandelblat-Cerf Y, Young D, Garst-Orozco J, Lotarski SM, Stark E, Kramer M, Butler CR, Kozak R. In Vivo Modulation of Hippocampal Excitability by M4 Muscarinic Acetylcholine Receptor Activator: Implications for Treatment of Alzheimer's Disease and Schizophrenic Patients. ACS Chem Neurosci 2019; 10:1091-1098. [PMID: 30335349 DOI: 10.1021/acschemneuro.8b00496] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Abnormal hippocampal activity has been linked to impaired cognitive performance in Alzheimer's disease and schizophrenia, leading to a hypothesis that normalization of this activity may be therapeutically beneficial. Our work suggests that one approach for hippocampal normalization may be through activation of the M4 muscarinic acetylcholine receptor. We used a brain penetrant M4 muscarinic acetylcholine receptor selective activator, PT-3763, to show dose-dependent attenuation of field potentials in Schaffer collateral (CA3-CA1) and recurrent associational connections (CA3-CA3) ex vivo in hippocampal slices. In vivo, systemic administration of PT-3763 led to attenuation of glutamate release in CA3 as measured by amperometry and to a dose-dependent decrease in population CA1 pyramidal activity as measured by fiber photometry. This decrease in population activity was also evident with a localized administration of the compound to the recorded site. Finally, PT-3763 reversed scopolamine-induced deficit in Morris water maze. Our results suggest that M4 muscarinic acetylcholine receptor activation may be a suitable therapeutic treatment in diseases associated with hyperactive hippocampal activity.
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56
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Ano Y, Ohya R, Kondo K, Nakayama H. Iso-α-acids, Hop-Derived Bitter Components of Beer, Attenuate Age-Related Inflammation and Cognitive Decline. Front Aging Neurosci 2019; 11:16. [PMID: 30778295 PMCID: PMC6369178 DOI: 10.3389/fnagi.2019.00016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 01/17/2019] [Indexed: 01/18/2023] Open
Abstract
With the aging population rapidly increasing worldwide, preventive measures and treatments for age-related cognitive decline and dementia are of utmost importance. We have previously demonstrated that the consumption of iso-α-acids (IAA), which are hop-derived bitter compounds in beer, prevents the formation of disease pathology in a transgenic mouse model of Alzheimer’s disease (AD). However, the effect of IAA consumption on age-related cognitive decline is unknown. In the present study, we examined the effect of long-term and short-term dietary consumption of IAA, on age-related memory impairments and inflammation in the hippocampus of aged mice. When compared with young mice, aged mice showed impairment in spatial working memory during the Y-maze spontaneous alternation test, impairment in object recognition memory during the novel object recognition test (NORT), a pro-inflammatory hippocampal microglial phenotype with increased CD86 expression and inflammatory cytokine production, increased levels of glutamate and amyloid β1–42, and decreased levels of dopamine (DA). In aged mice fed IAA for 3 months, the age-related alterations in memory, microglial inflammation, and glutamate, amyloid β1–42, and DA levels were all significantly attenuated. Additionally, the oral administration of IAA for 7 days in aged mice with memory impairment, also improved spatial and object recognition memory. These results suggest that IAA consumption prevents inflammation in the hippocampus and ameliorates age-related cognitive decline.
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Affiliation(s)
- Yasuhisa Ano
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Research Laboratories for Health Science & Food Technologies, Kirin Company Ltd, Yokohama, Japan
| | - Rena Ohya
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Research Laboratories for Health Science & Food Technologies, Kirin Company Ltd, Yokohama, Japan
| | - Keiji Kondo
- Research Laboratories for Health Science & Food Technologies, Kirin Company Ltd, Yokohama, Japan
| | - Hiroyuki Nakayama
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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57
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Abstract
Hippocampal abnormalities have been heavily implicated in the pathophysiology of schizophrenia. The dentate gyrus of the hippocampus was shown to manifest an immature molecular profile in schizophrenia subjects, as well as in various animal models of the disorder. In this position paper, we advance a hypothesis that this immature molecular profile is accompanied by an identifiable immature morphology of the dentate gyrus granule cell layer. We adduce evidence for arrested maturation of the dentate gyrus in the human schizophrenia-affected brain, as well as multiple rodent models of the disease. Implications of this neurohistopathological signature for current theory regarding the development of schizophrenia are discussed.
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Affiliation(s)
- Ayda Tavitian
- Department of Neurology & Neurosurgery, Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Wei Song
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Hyman M. Schipper
- Department of Neurology & Neurosurgery, Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
- Department of Medicine, McGill University, Montreal, Quebec, Canada
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58
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Pocivavsek A, Elmer GI, Schwarcz R. Inhibition of kynurenine aminotransferase II attenuates hippocampus-dependent memory deficit in adult rats treated prenatally with kynurenine. Hippocampus 2018; 29:73-77. [PMID: 30311334 DOI: 10.1002/hipo.23040] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/01/2018] [Accepted: 10/07/2018] [Indexed: 11/11/2022]
Abstract
A combination of genetic and environmental factors contributes to schizophrenia (SZ), a catastrophic psychiatric disorder with a hypothesized neurodevelopmental origin. Increases in the brain levels of the tryptophan metabolite kynurenic acid (KYNA), an endogenous antagonist of α7 nicotinic acetylcholine and NMDA receptors, have been implicated specifically in the cognitive deficits seen in persons with SZ. Here we evaluated this role of KYNA by adding the KYNA precursor kynurenine (100 mg/day) to chow fed to pregnant rat dams from embryonic day (ED) 15 to ED 22 (control: ECon; kynurenine treated: EKyn). Upon termination of the treatment, all rats received normal rodent chow until the animals were evaluated in adulthood (postnatal days 56-85). EKyn treatment resulted in increased extracellular KYNA and reduced extracellular glutamate in the hippocampus, measured by in vivo microdialysis, and caused impairments in hippocampus-dependent learning in adult rats. Acute administration of BFF816, a systemically active inhibitor of kynurenine aminotransferase II (KAT II), the major KYNA-synthesizing enzyme in the brain, normalized neurochemistry and prevented contextual memory deficits in adult EKyn animals. Collectively, these results demonstrate that acute inhibition of KYNA neosynthesis can overcome cognitive impairments that arise as a consequence of elevated brain KYNA in early brain development.
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Affiliation(s)
- Ana Pocivavsek
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland
| | - Greg I Elmer
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland
| | - Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland
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59
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Neuroimaging hippocampal subfields in schizophrenia and bipolar disorder: A systematic review and meta-analysis. J Psychiatr Res 2018; 104:217-226. [PMID: 30107268 DOI: 10.1016/j.jpsychires.2018.08.012] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/27/2018] [Accepted: 08/06/2018] [Indexed: 01/15/2023]
Abstract
The hippocampus is a complex structure consisting of subregions with specialized cytoarchitecture and functions. Magnetic resonance imaging (MRI) studies in psychotic disorders show hippocampal subfield abnormalities, but affected regions differ between studies. We here present an overview of hippocampal anatomy and function relevant to psychosis, and the first systematic review and meta-analysis of MRI studies of hippocampal subfield morphology in schizophrenia and bipolar disorder. Twenty-one MRI studies assessing hippocampal subfield volumes or shape in schizophrenia or bipolar disorder were included (n 15-887 subjects). Nine volumetric group comparison studies (total n = 2593) were included in random effects meta-analyses of group differences. The review showed mixed results, with volume reductions reported in most subfields in schizophrenia and bipolar disorder. Volumetric studies using ex-vivo based image analysis templates corresponded best with the shape studies, with CA1 as the most affected region. The meta-analyses showed volume reductions in all subfields in schizophrenia and bipolar disorder compared to healthy controls (all p < .005; schizophrenia: d = 0.28-0.49, bipolar disorder: d = 0.20-0.35), and smaller left CA2/3 and right subiculum in schizophrenia than bipolar disorder. In conclusion, the hippocampal subfields appear to be differently affected in psychotic disorders. However, due to the lack of control for putative confounders such as medication, alcohol and illicit substance use, and illness stage, the results from the meta-analysis should be interpreted with caution. Methodological subfield segmentation weaknesses should be addressed in future studies.
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60
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Leung LS, Ma J. Medial septum modulates hippocampal gamma activity and prepulse inhibition in an N-methyl-d-aspartate receptor antagonist model of schizophrenia. Schizophr Res 2018; 198:36-44. [PMID: 28801194 DOI: 10.1016/j.schres.2017.07.053] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 07/25/2017] [Accepted: 07/28/2017] [Indexed: 01/07/2023]
Abstract
We reviewed the participation of the septohippocampal system in an animal model of schizophrenia that was acutely induced by systemic injection of an N-methyl-d-aspartate (NMDA) receptor antagonist such as phencyclidine, MK-801 and ketamine. The NMDA receptor antagonist-induced model of schizophrenia is characterized by behavioral and electrophysiological disruptions, including a decrease in prepulse inhibition of the acoustic startle response (PPI), hyperlocomotion, decrease in gating of hippocampal auditory evoked potentials and robust increase in hippocampal gamma (30-100Hz) oscillations. Similar disruptions were also induced by a single electrographic seizure in the hippocampus. The behavioral and electrophysiological disruptions induced by an NMDA receptor antagonist can be reduced by inactivation or lesion of GABAergic neurons in the medial septum, deep brain stimulation of the medial septum or nucleus accumbens, or positive modulation of GABAB receptors. Our results suggest a close association between high-amplitude hippocampal gamma oscillations and psychosis-relevant behaviors including PPI loss, behavioral hyperactivity and loss in auditory gating. Abnormal electrophysiology suggests a disruption of somatic and apical dendritic inhibition in the hippocampus, resulting in distorted sensory integration, and impaired cognitive and memory processing. The hippocampus is suggested to be a hub in a brain network that participates in psychosis-relevant behaviors, through its direct projection to the nucleus accumbens, or through indirect connections via the entorhinal, cingulate and prefrontal cortices.
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Affiliation(s)
- L Stan Leung
- Department of Physiology and Pharmacology, The University of Western Ontario, London N6A 5C1, Canada.
| | - Jingyi Ma
- Department of Physiology and Pharmacology, The University of Western Ontario, London N6A 5C1, Canada
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Hua J, Liu P, Kim T, Donahue M, Rane S, Chen JJ, Qin Q, Kim SG. MRI techniques to measure arterial and venous cerebral blood volume. Neuroimage 2018; 187:17-31. [PMID: 29458187 DOI: 10.1016/j.neuroimage.2018.02.027] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/12/2018] [Accepted: 02/14/2018] [Indexed: 12/14/2022] Open
Abstract
The measurement of cerebral blood volume (CBV) has been the topic of numerous neuroimaging studies. To date, however, most in vivo imaging approaches can only measure CBV summed over all types of blood vessels, including arterial, capillary and venous vessels in the microvasculature (i.e. total CBV or CBVtot). As different types of blood vessels have intrinsically different anatomy, function and physiology, the ability to quantify CBV in different segments of the microvascular tree may furnish information that is not obtainable from CBVtot, and may provide a more sensitive and specific measure for the underlying physiology. This review attempts to summarize major efforts in the development of MRI techniques to measure arterial (CBVa) and venous CBV (CBVv) separately. Advantages and disadvantages of each type of method are discussed. Applications of some of the methods in the investigation of flow-volume coupling in healthy brains, and in the detection of pathophysiological abnormalities in brain diseases such as arterial steno-occlusive disease, brain tumors, schizophrenia, Huntington's disease, Alzheimer's disease, and hypertension are demonstrated. We believe that the continual development of MRI approaches for the measurement of compartment-specific CBV will likely provide essential imaging tools for the advancement and refinement of our knowledge on the exquisite details of the microvasculature in healthy and diseased brains.
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Affiliation(s)
- Jun Hua
- Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
| | - Peiying Liu
- Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Tae Kim
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Manus Donahue
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Swati Rane
- Radiology, University of Washington Medical Center, Seattle, WA, USA
| | - J Jean Chen
- Rotman Research Institute, Baycrest Centre, Canada; Department of Medical Biophysics, University of Toronto, Canada
| | - Qin Qin
- Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, South Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
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Hippocampal Pathophysiology: Commonality Shared by Temporal Lobe Epilepsy and Psychiatric Disorders. NEUROSCIENCE JOURNAL 2018; 2018:4852359. [PMID: 29610762 PMCID: PMC5828345 DOI: 10.1155/2018/4852359] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/02/2017] [Accepted: 12/20/2017] [Indexed: 11/18/2022]
Abstract
Accumulating evidence points to the association of epilepsy, particularly, temporal lobe epilepsy (TLE), with psychiatric disorders, such as schizophrenia. Among these illnesses, the hippocampus is considered the regional focal point of the brain, playing an important role in cognition, psychosis, and seizure activity and potentially suggesting common etiologies and pathophysiology of TLE and schizophrenia. In the present review, we overview abnormal network connectivity between the dentate gyrus (DG) and the Cornus Ammonis area 3 (CA3) subregions of the hippocampus relative to the induction of epilepsy and schizophrenia. In light of our recent finding on the misguidance of hippocampal mossy fiber projection in the rodent model of schizophrenia, we discuss whether ectopic mossy fiber projection is a commonality in order to evoke TLE as well as symptoms related to schizophrenia.
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63
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Busquets-Garcia A, Soria-Gómez E, Redon B, Mackenbach Y, Chaouloff F, Varilh M, Ferreira G, Piazza PV, Marsicano G, Marsicano G. Pregnenolone blocks cannabinoid-induced acute psychotic-like states in mice. Mol Psychiatry 2017; 22:1594-1603. [PMID: 28220044 PMCID: PMC5447368 DOI: 10.1038/mp.2017.4] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 11/04/2016] [Accepted: 12/21/2016] [Indexed: 01/08/2023]
Abstract
Cannabis-induced acute psychotic-like states (CIAPS) represent a growing health issue, but their underlying neurobiological mechanisms are poorly understood. The use of antipsychotics and benzodiazepines against CIAPS is limited by side effects and/or by their ability to tackle only certain aspects of psychosis. Thus, safer wide-spectrum treatments are currently needed. Although the blockade of cannabinoid type-1 receptor (CB1) had been suggested as a therapeutical means against CIAPS, the use of orthosteric CB1 receptor full antagonists is strongly limited by undesired side effects and low efficacy. The neurosteroid pregnenolone has been recently shown to act as a potent endogenous allosteric signal-specific inhibitor of CB1 receptors. Thus, we tested in mice the potential therapeutic use of pregnenolone against acute psychotic-like effects of Δ9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis. We found that pregnenolone blocks a wide spectrum of THC-induced endophenotypes typically associated with psychotic-like states, including impairments in cognitive functions, somatosensory gating and social interaction. In order to capture THC-induced positive psychotic-like symptoms (e.g. perceptual delusions), we adapted a behavioral paradigm based on associations between different sensory modalities and selective devaluation, allowing the measurement of mental sensory representations in mice. Acting at hippocampal CB1 receptors, THC impaired the correct processing of mental sensory representations (reality testing) in an antipsychotic- and pregnenolone-sensitive manner. Overall, this work reveals that signal-specific inhibitors mimicking pregnenolone effects can be considered as promising new therapeutic tools to treat CIAPS.
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Affiliation(s)
- Arnau Busquets-Garcia
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France
| | - Edgar Soria-Gómez
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France
| | - Bastien Redon
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France
| | - Yarmo Mackenbach
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France
| | - Francis Chaouloff
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France
| | - Marjorie Varilh
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France
| | - Guillaume Ferreira
- University of Bordeaux, France,INRA, Nutrition et Neurobiologie Intégrée, UMR 1286, Bordeaux, France
| | - Pier-Vincenzo Piazza
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France
| | - Giovanni Marsicano
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France,University of Bordeaux, France,Correspondence to Giovanni Marsicano: Giovanni Marsicano DVM, PhD, NeuroCentre Magendie, U1215 INSERM Université Bordeaux 2, Group “Endocannabinoids and Neuroadaptation”, 146, rue Léo Saignat, 33077 Bordeaux, France, Tel. Office ++33 5 5757 3756, Tel mobile ++33 6 7523 3536, Tel. home ++33 9 5019 5703, Fax ++33 5 5757 3751,
| | - G Marsicano
- INSERM, U1215 NeuroCentre Magendie, Bordeaux, France.,University of Bordeaux, Bordeaux, France
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Batten SR, Matveeva EA, Whiteheart SW, Vanaman TC, Gerhardt GA, Slevin JT. Linking kindling to increased glutamate release in the dentate gyrus of the hippocampus through the STXBP5/tomosyn-1 gene. Brain Behav 2017; 7:e00795. [PMID: 28948088 PMCID: PMC5607557 DOI: 10.1002/brb3.795] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 06/29/2017] [Accepted: 07/02/2017] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION In kindling, repeated electrical stimulation of certain brain areas causes progressive and permanent intensification of epileptiform activity resulting in generalized seizures. We focused on the role(s) of glutamate and a negative regulator of glutamate release, STXBP5/tomosyn-1, in kindling. METHODS Stimulating electrodes were implanted in the amygdala and progression to two successive Racine stage 5 seizures was measured in wild-type and STXBP5/tomosyn-1-/- (Tom-/-) animals. Glutamate release measurements were performed in distinct brain regions using a glutamate-selective microelectrode array (MEA). RESULTS Naïve Tom-/- mice had significant increases in KCl-evoked glutamate release compared to naïve wild type as measured by MEA of presynaptic release in the hippocampal dentate gyrus (DG). Kindling progression was considerably accelerated in Tom-/- mice, requiring fewer stimuli to reach a fully kindled state. Following full kindling, MEA measurements of both kindled Tom+/+ and Tom-/- mice showed significant increases in KCl-evoked and spontaneous glutamate release in the DG, indicating a correlation with the fully kindled state independent of genotype. Resting glutamate levels in all hippocampal subregions were significantly lower in the kindled Tom-/- mice, suggesting possible changes in basal control of glutamate circuitry in the kindled Tom-/- mice. CONCLUSIONS Our studies demonstrate that increased glutamate release in the hippocampal DG correlates with acceleration of the kindling process. Although STXBP5/tomosyn-1 loss increased evoked glutamate release in naïve animals contributing to their prokindling phenotype, the kindling process can override any attenuating effect of STXBP5/tomosyn-1. Loss of this "braking" effect of STXBP5/tomosyn-1 on kindling progression may set in motion an alternative but ultimately equally ineffective compensatory response, detected here as reduced basal glutamate release.
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Affiliation(s)
- Seth R. Batten
- Department of PsychologyUniversity of KentuckyCollege of Arts and SciencesLexingtonKYUSA
| | - Elena A. Matveeva
- Department of Molecular & Cellular BiochemistryUniversity of Kentucky Medical CenterLexingtonKYUSA
| | - Sidney W. Whiteheart
- Department of Molecular & Cellular BiochemistryUniversity of Kentucky Medical CenterLexingtonKYUSA
| | - Thomas C. Vanaman
- Department of Molecular & Cellular BiochemistryUniversity of Kentucky Medical CenterLexingtonKYUSA
| | - Greg A. Gerhardt
- Department of NeuroscienceUniversity of Kentucky Medical CenterLexingtonKYUSA
- Department of NeurologyUniversity of Kentucky Medical CenterLexingtonKYUSA
| | - John T. Slevin
- Neurology ServiceVeterans Affairs Medical CenterLexingtonKYUSA
- Department of NeurologyUniversity of Kentucky Medical CenterLexingtonKYUSA
- Department of Pharmacology and Nutritional SciencesUniversity of Kentucky Medical CenterLexingtonKYUSA
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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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Hua J, Brandt AS, Lee S, Blair NIS, Wu Y, Lui S, Patel J, Faria AV, Lim IAL, Unschuld PG, Pekar JJ, van Zijl PCM, Ross CA, Margolis RL. Abnormal Grey Matter Arteriolar Cerebral Blood Volume in Schizophrenia Measured With 3D Inflow-Based Vascular-Space-Occupancy MRI at 7T. Schizophr Bull 2017; 43:620-632. [PMID: 27539951 PMCID: PMC5464028 DOI: 10.1093/schbul/sbw109] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Metabolic dysfunction and microvascular abnormality may contribute to the pathogenesis of schizophrenia. Most previous studies of cerebral perfusion in schizophrenia measured total cerebral blood volume (CBV) and cerebral blood flow (CBF) in the brain, which reflect the ensemble signal from the arteriolar, capillary, and venular compartments of the microvasculature. As the arterioles are the most actively regulated blood vessels among these compartments, they may be the most sensitive component of the microvasculature to metabolic disturbances. In this study, we adopted the inflow-based vascular-space-occupancy (iVASO) MRI approach to investigate alterations in the volume of small arterial (pial) and arteriolar vessels (arteriolar cerebral blood volume [CBVa]) in the brain of schizophrenia patients. The iVASO approach was extended to 3-dimensional (3D) whole brain coverage, and CBVa was measured in the brains of 12 schizophrenia patients and 12 matched controls at ultra-high magnetic field (7T). Significant reduction in grey matter (GM) CBVa was found in multiple areas across the whole brain in patients (relative changes of 14%-51% and effect sizes of 0.7-2.3). GM CBVa values in several regions in the temporal cortex showed significant negative correlations with disease duration in patients. GM CBVa increase was also found in a few brain regions. Our results imply that microvascular abnormality may play a role in schizophrenia, and suggest GM CBVa as a potential marker for the disease. Further investigation is needed to elucidate whether such effects are due to primary vascular impairment or secondary to other causes, such as metabolic dysfunction.
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Affiliation(s)
- Jun Hua
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD;,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD
| | - Allison S. Brandt
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD
| | - SeungWook Lee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | | | - Yuankui Wu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD;,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD;,Department of Medical Imaging, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Su Lui
- Department of Radiology, Huaxi MR Research Center (HMRRC), West China Hospital of Sichuan University, Chengdu, China;,Department of Radiology, the Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jaymin Patel
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD
| | - Andreia V. Faria
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Issel Anne L. Lim
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD;,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD
| | - Paul G. Unschuld
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - James J. Pekar
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD;,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD
| | - Peter C. M. van Zijl
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD;,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD
| | - Christopher A. Ross
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD;,Department of Neurology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD;,Departments of Neuroscience and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Russell L. Margolis
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD;,Department of Neurology and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
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Watmuff B, Liu B, Karmacharya R. Stem cell-derived neurons in the development of targeted treatment for schizophrenia and bipolar disorder. Pharmacogenomics 2017; 18:471-479. [PMID: 28346060 DOI: 10.2217/pgs-2016-0187] [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: 12/23/2022] Open
Abstract
The recent advent of induced pluripotent stem cells has enabled the study of patient-specific and disease-related neurons in vitro and has facilitated new directions of inquiry into disease mechanisms. With these approaches, we now have the possibility of correlating ex vivo cellular phenotypes with individual patient response to treatment and/or side effects, which makes targeted treatments for schizophrenia and bipolar disorder a distinct prospect in the coming years. Here, we briefly review the current state of stem cell-based models and explore studies that are providing new insights into the disease biology of schizophrenia and bipolar disorder, which are laying the foundations for the development of novel targeted therapies.
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Affiliation(s)
- Bradley Watmuff
- Center for Experimental Drugs & Diagnostics, Psychiatric & Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School & Massachusetts General Hospital, Boston, MA 02114, USA.,Chemical Biology Program, Broad Institute of Harvard & MIT, Cambridge, MA 02142, USA
| | - Bangyan Liu
- Center for Experimental Drugs & Diagnostics, Psychiatric & Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School & Massachusetts General Hospital, Boston, MA 02114, USA
| | - Rakesh Karmacharya
- Center for Experimental Drugs & Diagnostics, Psychiatric & Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Harvard Medical School & Massachusetts General Hospital, Boston, MA 02114, USA.,Chemical Biology Program, Broad Institute of Harvard & MIT, Cambridge, MA 02142, USA.,Schizophrenia & Bipolar Disorder Program, McLean Hospital, Belmont, MA 02478, USA
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Transmembrane protein 108 is required for glutamatergic transmission in dentate gyrus. Proc Natl Acad Sci U S A 2017; 114:1177-1182. [PMID: 28096412 DOI: 10.1073/pnas.1618213114] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neurotransmission in dentate gyrus (DG) is critical for spatial coding, learning memory, and emotion processing. Although DG dysfunction is implicated in psychiatric disorders, including schizophrenia, underlying pathological mechanisms remain unclear. Here we report that transmembrane protein 108 (Tmem108), a novel schizophrenia susceptibility gene, is highly enriched in DG granule neurons and its expression increased at the postnatal period critical for DG development. Tmem108 is specifically expressed in the nervous system and enriched in the postsynaptic density fraction. Tmem108-deficient neurons form fewer and smaller spines, suggesting that Tmem108 is required for spine formation and maturation. In agreement, excitatory postsynaptic currents of DG granule neurons were decreased in Tmem108 mutant mice, indicating a hypofunction of glutamatergic activity. Further cell biological studies indicate that Tmem108 is necessary for surface expression of AMPA receptors. Tmem108-deficient mice display compromised sensorimotor gating and cognitive function. Together, these observations indicate that Tmem108 plays a critical role in regulating spine development and excitatory transmission in DG granule neurons. When Tmem108 is mutated, mice displayed excitatory/inhibitory imbalance and behavioral deficits relevant to schizophrenia, revealing potential pathophysiological mechanisms of schizophrenia.
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69
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Donegan JJ, Lodge DJ. Cell-based therapies for the treatment of schizophrenia. Brain Res 2017; 1655:262-269. [PMID: 27544423 PMCID: PMC5474910 DOI: 10.1016/j.brainres.2016.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 08/04/2016] [Accepted: 08/08/2016] [Indexed: 02/08/2023]
Abstract
Schizophrenia is a devastating psychiatric disorder characterized by positive, negative and cognitive symptoms. While aberrant dopamine system function is typically associated with the positive symptoms of the disease, it is thought that this is secondary to pathology in afferent regions. Indeed, schizophrenia patients show dysregulated activity in the hippocampus and prefrontal cortex, two regions known to regulate dopamine neuron activity. These deficits in hippocampal and prefrontal cortical function are thought to result, in part, from reductions in inhibitory interneuron function in these brain regions. Therefore, it has been hypothesized that restoring interneuron function in the hippocampus and/or prefrontal cortex may be an effective treatment strategy for schizophrenia. In this article, we will discuss the evidence for interneuron pathology in schizophrenia and review recent advances in our understanding of interneuron development. Finally, we will explore how these advances have allowed us to test the therapeutic value of interneuron transplants in multiple preclinical models of schizophrenia. This article is part of a Special Issue entitled SI:StemsCellsinPsychiatry.
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Affiliation(s)
- Jennifer J Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX 78229, USA.
| | - Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX 78229, USA
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Uranova NA, Kolomeets NS, Vikhreva OV, Zimina IS, Rakhmanova VI, Orlovskaya DD. Ultrastructural changes of myelinated fibers in the brain in continuous and attack-like paranoid schizophrenia. Zh Nevrol Psikhiatr Im S S Korsakova 2017; 117:104-109. [DOI: 10.17116/jnevro201711721104-109] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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71
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Behrendt RP. Hallucinatory experience as aberrant event memory formation: Implications for the pathophysiology of schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2016; 71:203-9. [PMID: 27492675 DOI: 10.1016/j.pnpbp.2016.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/15/2016] [Accepted: 07/26/2016] [Indexed: 11/29/2022]
Abstract
If hallucinations are not fundamentally different from normal wakeful experiences, then the neural basis of hallucinations has to be essentially that of consciousness in general. The additional insight that consciousness reflects the formation (as opposed to consolidation) of event (episodic) memories links the pathophysiology of hallucinations to the hippocampus. Perceptions and misperceptions, insofar as they are consciously experienced, constitute contextualized and unitary phenomena (which are embedded as discrete events in the stream of consciousness); they are experiential manifestations of activity patters that recurrently emerge in the CA3 network of the hippocampus (and that are secondarily consolidated into retrievable and declarable memories). The hippocampus, forming allocentric representations of objects in their world context (event memories), is a point of convergence of neocortical sensory processing streams. Moreover, being extensively modulated by the organism's physiological state, the hippocampus embeds such representations in an emotional context and, through its output to the medial prefrontal cortex, guides decision-making and goal-selection processes. Although sensory and associative processing in the neocortex makes an important contribution to the formation of behaviourally adaptive representations in the hippocampus, it is becoming clearer that pattern formation in the hippocampus is in itself the neural correlate of consciousness and that disruptions in relational memory processing in the hippocampus can give rise to hallucinations. Neurobiological and neuroimaging findings in schizophrenia research can be integrated within the proposed conceptual framework.
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Affiliation(s)
- Ralf-Peter Behrendt
- Elderly Mental Health Service, Oberlands Centre, Princess Elizabeth Hospital, St Martin's GY4 6UU, Guernsey.
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Hollins SL, Zavitsanou K, Walker FR, Cairns MJ. Alteration of transcriptional networks in the entorhinal cortex after maternal immune activation and adolescent cannabinoid exposure. Brain Behav Immun 2016; 56:187-96. [PMID: 26923065 DOI: 10.1016/j.bbi.2016.02.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 02/16/2016] [Accepted: 02/24/2016] [Indexed: 02/04/2023] Open
Abstract
Maternal immune activation (MIA) and adolescent cannabinoid exposure (ACE) have both been identified as major environmental risk factors for schizophrenia. We examined the effects of these two risk factors alone, and in combination, on gene expression during late adolescence. Pregnant rats were exposed to the viral infection mimic polyriboinosinic-polyribocytidylic acid (poly I:C) on gestational day (GD) 15. Adolescent offspring received daily injections of the cannabinoid HU210 for 14days starting on postnatal day (PND) 35. Gene expression was examined in the left entorhinal cortex (EC) using mRNA microarrays. We found prenatal treatment with poly I:C alone, or HU210 alone, produced relatively minor changes in gene expression. However, following combined treatments, offspring displayed significant changes in transcription. This dramatic and persistent alteration of transcriptional networks enriched with genes involved in neurotransmission, cellular signalling and schizophrenia, was associated with a corresponding perturbation in the expression of small non-coding microRNA (miRNA). These results suggest that a combination of environmental exposures during development leads to significant genomic remodeling that disrupts maturation of the EC and its associated circuitry with important implications as the potential antecedents of memory and learning deficits in schizophrenia and other neuropsychiatric disorders.
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Affiliation(s)
- Sharon L Hollins
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia; Schizophrenia Research Institute, Sydney, NSW, Australia; Centre for Brain and Mental Health Research, Hunter Medical Research Institute, Newcastle, NSW 2305, Australia
| | - Katerina Zavitsanou
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - Frederick Rohan Walker
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia; Centre for Brain and Mental Health Research, Hunter Medical Research Institute, Newcastle, NSW 2305, Australia
| | - Murray J Cairns
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia; Schizophrenia Research Institute, Sydney, NSW, Australia; Centre for Brain and Mental Health Research, Hunter Medical Research Institute, Newcastle, NSW 2305, Australia.
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Falkai P, Malchow B, Wetzestein K, Nowastowski V, Bernstein HG, Steiner J, Schneider-Axmann T, Kraus T, Hasan A, Bogerts B, Schmitz C, Schmitt A. Decreased Oligodendrocyte and Neuron Number in Anterior Hippocampal Areas and the Entire Hippocampus in Schizophrenia: A Stereological Postmortem Study. Schizophr Bull 2016; 42 Suppl 1:S4-S12. [PMID: 27460617 PMCID: PMC4960426 DOI: 10.1093/schbul/sbv157] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The hippocampus is involved in cognition as well as emotion, with deficits in both domains consistently described in schizophrenia. Moreover, the whole volumes of both the anterior and posterior region have been reported to be decreased in schizophrenia patients. While fewer oligodendrocyte numbers in the left and right cornu ammonis CA4 subregion of the posterior part of the hippocampus have been reported, the aim of this stereological study was to investigate cell numbers in either the dentate gyrus (DG) or subregions of the anterior hippocampus. In this design-based stereological study of the anterior part of the hippocampus comparing 10 patients with schizophrenia to 10 age- and gender-matched healthy controls were examined. Patients showed a decreased number of oligodendrocytes in the left CA4, fewer neurons in the left DG and smaller volumes in both the left CA4 and DG, which correlated with oligodendrocyte and neuron numbers, respectively. When exploring the total hippocampus, keeping previously published own results from the posterior part of the same brains in mind, both decreased oligodendrocyte numbers in the left CA4 and reduced volume remained significant. The decreased oligodendrocyte number speaks for a deficit in myelination and connectivity in schizophrenia which may originate from disturbed maturational processes. The reduced neuron number of the DG in the anterior hippocampus may well point to a reduced capacity of this region to produce new neurons up to adulthood. Both mechanisms may be involved in cognitive dysfunction in schizophrenia patients.
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Affiliation(s)
- Peter Falkai
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany; These authors contributed equally to the article
| | - Berend Malchow
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany; These authors contributed equally to the article
| | - Katharina Wetzestein
- Department of Psychiatry and Psychotherapy, University of Göttingen, Göttingen, Germany
| | - Verena Nowastowski
- Department of Psychiatry and Psychotherapy, University of Göttingen, Göttingen, Germany
| | - Hans-Gert Bernstein
- Department of Psychiatry and Psychotherapy, University of Magdeburg, Magdeburg, Germany
| | - Johann Steiner
- Department of Psychiatry and Psychotherapy, University of Magdeburg, Magdeburg, Germany
| | - Thomas Schneider-Axmann
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Theo Kraus
- Center for Neuropathology and Prion Research (ZNP), Ludwig-Maximilians-University Munich, Munich, Germany
| | - Alkomiet Hasan
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Bernhard Bogerts
- Department of Psychiatry and Psychotherapy, University of Magdeburg, Magdeburg, Germany
| | - Christoph Schmitz
- Department of Neuroanatomy, Ludwig Maximilian University, Munich, Germany
| | - Andrea Schmitt
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany; Laboratory of Neuroscience (LIM27), Institute of Psychiatry, University of Sao Paulo, São Paulo, Brazil
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74
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de Beaurepaire R. Imagerie cérébrale et déconstruction de l’esprit. EVOLUTION PSYCHIATRIQUE 2016. [DOI: 10.1016/j.evopsy.2016.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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75
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Disease signatures for schizophrenia and bipolar disorder using patient-derived induced pluripotent stem cells. Mol Cell Neurosci 2016; 73:96-103. [PMID: 26777134 DOI: 10.1016/j.mcn.2016.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/05/2016] [Accepted: 01/11/2016] [Indexed: 12/12/2022] Open
Abstract
Schizophrenia and bipolar disorder are complex psychiatric disorders that present unique challenges in the study of disease biology. There are no objective biological phenotypes for these disorders, which are characterized by complex genetics and prominent roles for gene-environment interactions. The study of the neurobiology underlying these severe psychiatric disorders has been hindered by the lack of access to the tissue of interest - neurons from patients. The advent of reprogramming methods that enable generation of induced pluripotent stem cells (iPSCs) from patient fibroblasts and peripheral blood mononuclear cells has opened possibilities for new approaches to study relevant disease biology using iPSC-derived neurons. While early studies with patient iPSCs have led to promising and intriguing leads, significant hurdles remain in our attempts to capture the complexity of these disorders in vitro. We present here an overview of studies to date of schizophrenia and bipolar disorder using iPSC-derived neuronal cells and discuss potential future directions that can result in the identification of robust and valid cellular phenotypes that in turn can lay the groundwork for meaningful clinical advances.
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76
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Tregellas JR, Smucny J, Legget KT, Stevens KE. Effects of a ketogenic diet on auditory gating in DBA/2 mice: A proof-of-concept study. Schizophr Res 2015; 169:351-354. [PMID: 26453015 PMCID: PMC4827327 DOI: 10.1016/j.schres.2015.09.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 11/20/2022]
Abstract
Although the ketogenic diet has shown promise in a pilot study and case report in schizophrenia, its effects in animal models of hypothesized disease mechanisms are unknown. This study examined effects of treatment with the ketogenic diet on hippocampal P20/N40 gating in DBA/2 mice, a translational endophenotype that mirrors inhibitory deficits in P50 sensory gating in schizophrenia patients. As expected, the diet increased blood ketone levels. Animals with the highest ketone levels showed the lowest P20/N40 gating ratios. These preliminary results suggest that the ketogenic diet may effectively target sensory gating deficits and is a promising area for additional research in schizophrenia.
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Affiliation(s)
- Jason R Tregellas
- Research Service, Denver VA Medical Center, Denver, CO, USA; Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Jason Smucny
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kristina T Legget
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Karen E Stevens
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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77
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Smucny J, Olincy A, Rojas DC, Tregellas JR. Neuronal effects of nicotine during auditory selective attention in schizophrenia. Hum Brain Mapp 2015; 37:410-21. [PMID: 26518728 DOI: 10.1002/hbm.23040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 09/29/2015] [Accepted: 10/18/2015] [Indexed: 12/11/2022] Open
Abstract
Although nicotine has been shown to improve attention deficits in schizophrenia, the neurobiological mechanisms underlying this effect are poorly understood. We hypothesized that nicotine would modulate attention-associated neuronal response in schizophrenia patients in the ventral parietal cortex (VPC), hippocampus, and anterior cingulate based on previous findings in control subjects. To test this hypothesis, the present study examined response in these regions in a cohort of nonsmoking patients and healthy control subjects using an auditory selective attention task with environmental noise distractors during placebo and nicotine administration. In agreement with our hypothesis, significant diagnosis (Control vs. Patient) X drug (Placebo vs. Nicotine) interactions were observed in the VPC and hippocampus. The interaction was driven by task-associated hyperactivity in patients (relative to healthy controls) during placebo administration, and decreased hyperactivity in patients after nicotine administration (relative to placebo). No significant interaction was observed in the anterior cingulate. Task-associated hyperactivity of the VPC predicted poor task performance in patients during placebo. Poor task performance also predicted symptoms in patients as measured by the Brief Psychiatric Rating Scale. These results are the first to suggest that nicotine may modulate brain activity in a selective attention-dependent manner in schizophrenia.
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Affiliation(s)
- Jason Smucny
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Ann Olincy
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Research Service, Denver VA Medical Center, Denver, Colorado
| | - Donald C Rojas
- Department of Psychology, Colorado State University, Fort Collins, Colorado
| | - Jason R Tregellas
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Research Service, Denver VA Medical Center, Denver, Colorado
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78
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Associations of hippocampal metabolism and regional brain grey matter in neuroleptic-naïve ultra-high-risk subjects and first-episode schizophrenia. Eur Neuropsychopharmacol 2015; 25:1661-8. [PMID: 26088723 DOI: 10.1016/j.euroneuro.2015.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/06/2015] [Accepted: 05/13/2015] [Indexed: 01/21/2023]
Abstract
Hippocampal pathology has been shown to be central to the pathophysiology of schizophrenia and a putative risk marker for developing psychosis. We applied both (1)H MRS (proton magnetic resonance spectroscopy) at 3Tesla and voxel-based morphometry (VBM) of high-resolution brain structural images in order to study the association of the metabolites glutamate (Glu) and N-acetyl-aspartate (NAA) in the hippocampus with whole-brain morphometry in 31 persons at ultra-high-risk for psychosis (UHR), 18 first-episode schizophrenia patients (Sz), and 42 healthy controls (all subjects being neuroleptic-naïve). Significantly diverging associations emerged for UHR subjects hippocampal glutamate showed positive correlation with the left superior frontal cortex, not seen in Sz or controls, while in first-episode schizophrenia patients a negative correlation was significant between glutamate and a left prefrontal area. For NAA, we observed different associations for left prefrontal and caudate clusters bilaterally for both high-risk and first-episode schizophrenia subjects, diverging from the pattern seen in healthy subjects. Our results suggest that associations of hippocampal metabolites in key areas of schizophrenia might vary due to liability to or onset of the disorder.
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79
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Tamminga CA, Zukin RS. Schizophrenia: Evidence implicating hippocampal GluN2B protein and REST epigenetics in psychosis pathophysiology. Neuroscience 2015. [PMID: 26211447 DOI: 10.1016/j.neuroscience.2015.07.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The hippocampus is strongly implicated in the psychotic symptoms of schizophrenia. Functionally, basal hippocampal activity (perfusion) is elevated in schizophrenic psychosis, as measured with positron emission tomography (PET) and with magnetic resonance (MR) perfusion techniques, while hippocampal activation to memory tasks is reduced. Subfield-specific hippocampal molecular pathology exists in human psychosis tissue which could underlie this neuronal hyperactivity, including increased GluN2B-containing NMDA receptors in hippocampal CA3, along with increased postsynaptic density protein-95 (PSD-95) along with augmented dendritic spines on the pyramidal neuron apical dendrites. We interpret these observations to implicate a reduction in the influence of a ubiquitous gene repressor, repressor element-1 silencing transcription factor (REST) in psychosis; REST is involved in the age-related maturation of the NMDA receptor from GluN2B- to GluN2A-containing NMDA receptors through epigenetic remodeling. These CA3 changes in psychosis leave the hippocampus liable to pathological increases in neuronal activity, feedforward excitation and false memory formation, sometimes with psychotic content.
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Affiliation(s)
- C A Tamminga
- UT Southwestern Medical School, Dallas, TX, United States.
| | - R S Zukin
- Albert Einstein School of Medicine, New York, NY, United States
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80
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Li W, Ghose S, Gleason K, Begovic’ A, Perez J, Bartko J, Russo S, Wagner AD, Selemon L, Tamminga CA. Synaptic proteins in the hippocampus indicative of increased neuronal activity in CA3 in schizophrenia. Am J Psychiatry 2015; 172:373-82. [PMID: 25585032 PMCID: PMC4457341 DOI: 10.1176/appi.ajp.2014.14010123] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE In schizophrenia, hippocampal perfusion is increased and declarative memory function is degraded. Based on an a priori model of hippocampal dysfunction in schizophrenic psychosis, the authors postulated molecular and cellular changes in CA3 consistent with increased NMDA receptor signaling. METHOD Postmortem hippocampal subfield tissue (CA3, CA1) from subjects with schizophrenia and nonpsychiatric comparison subjects was analyzed using Western blotting and Golgi histochemistry to examine the hypothesized outcomes. RESULTS The GluN2B-containing NMDA receptors (GluN2B/GluN1) and their associated postsynaptic membrane protein PSD95 were both increased in schizophrenia in CA3 tissue, but not in CA1 tissue. Quantitative analyses of Golgi-stained hippocampal neurons showed an increase in spine density on CA3 pyramidal cell apical dendrites (stratum radiatum) and an increase in the number of thorny excrescences. CONCLUSIONS The hippocampal data are consistent with increased excitatory signaling in CA3 and/or with an elevation in silent synapses in CA3, a state that may contribute to an increase in long-term potentiation in CA3 with subsequent stimulation and "unsilencing." These changes are plausibly associated with increased associational activity in CA3, with degraded declarative memory function, and with formation of false memories with psychotic content. The influence of these hyperactive hippocampal projections on targets in the limbic neocortex could contribute to components of schizophrenia manifestations in other cerebral regions.
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Affiliation(s)
- Wei Li
- Division of Translational Neuroscience in Schizophrenia, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Subroto Ghose
- Division of Translational Neuroscience in Schizophrenia, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Kelly Gleason
- Division of Translational Neuroscience in Schizophrenia, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Anita Begovic’
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510
| | - Jessica Perez
- Division of Translational Neuroscience in Schizophrenia, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - John Bartko
- Division of Translational Neuroscience in Schizophrenia, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Scott Russo
- Neuroscience Department, Mount Sinai Medical School, NY NY 10029
| | - Anthony D. Wagner
- Department of Psychology and Neuroscience Program, Stanford University, Palo Alto, CA 94305
| | - Lynn Selemon
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510
| | - Carol A. Tamminga
- Division of Translational Neuroscience in Schizophrenia, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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81
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Haukvik UK, Westlye LT, Mørch-Johnsen L, Jørgensen KN, Lange EH, Dale AM, Melle I, Andreassen OA, Agartz I. In vivo hippocampal subfield volumes in schizophrenia and bipolar disorder. Biol Psychiatry 2015; 77:581-8. [PMID: 25127742 DOI: 10.1016/j.biopsych.2014.06.020] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 05/30/2014] [Accepted: 06/22/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Hippocampal dysfunction and volume reductions have been reported in patients with schizophrenia and bipolar disorder. The hippocampus consists of anatomically distinct subfields. We investigated to determine whether in vivo volumes of hippocampal subfields differ between clinical groups and healthy control subjects. METHODS Clinical examination and magnetic resonance imaging were performed in 702 subjects (patients with schizophrenia spectrum [n = 210; mean age, 32.0 ± 9.3 (SD) years; 59% male], patients with bipolar spectrum [n = 192; mean age, 35.5 ± 11.5 years; 40% male] and healthy control subjects [n = 300; mean age, 35.3 ± 9.9 years; 53% male]). Hippocampal subfield volumes were estimated with FreeSurfer. General linear models were used to explore diagnostic differences in hippocampal subfield volumes, covarying for age, intracranial volume, and medication. Post hoc analyses of associations to psychosis symptoms (Positive and Negative Syndrome Scale) and cognitive function (verbal memory [California Verbal Learning Test, second edition] and IQ [Wechsler Abbreviated Scale of Intelligence]) were performed. RESULTS Patient groups had smaller cornu ammonis (CA) subfields CA2/3 (left, p = 7.2 × 10(-6); right, p = 2.3 × 10(-6)), CA4/dentate gyrus (left, p = 1.4 × 10(-5); right, p = 2.3 × 10(-6)), subiculum (left, p = 3.7 × 10(-6); right, p = 2.8 × 10(-8)), and right CA1 (p = .006) volumes than healthy control subjects, but smaller presubiculum volumes were found only in patients with schizophrenia (left, p = 6.7 × 10(-5); right, p = 1.6 × 10(-7)). Patients with schizophrenia had smaller subiculum (left, p = .035; right, p = .031) and right presubiculum (p = .002) volumes than patients with bipolar disorder. Smaller subiculum volumes were related to poorer verbal memory in patients with bipolar disorder and healthy control subjects and to negative symptoms in patients with schizophrenia. CONCLUSIONS Hippocampal subfield volume reductions are found in patients with schizophrenia and bipolar disorder. The magnitude of reduction is greater in patients with schizophrenia, particularly in the hippocampal outflow regions presubiculum and subiculum.
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Affiliation(s)
- Unn K Haukvik
- Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.
| | - Lars T Westlye
- Department of Psychology, University of, Oslo, Norway; Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Lynn Mørch-Johnsen
- Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway
| | - Kjetil N Jørgensen
- Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway
| | - Elisabeth H Lange
- Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway
| | - Anders M Dale
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, California; Department of Radiology, University of California, San Diego, School of Medicine, La Jolla, California
| | - Ingrid Melle
- Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Ole A Andreassen
- Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Ingrid Agartz
- Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway
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82
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Enhanced dopamine-dependent hippocampal plasticity after single MK-801 application. Neuropsychopharmacology 2015; 40:987-95. [PMID: 25315194 PMCID: PMC4330513 DOI: 10.1038/npp.2014.276] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 09/17/2014] [Accepted: 09/25/2014] [Indexed: 11/09/2022]
Abstract
Dopaminergic hyperfunction and N-methyl-D-aspartate receptor (NMDAR) hypofunction have both been implicated in psychosis. Dopamine-releasing drugs and NMDAR antagonists replicate symptoms associated with psychosis in healthy humans and exacerbate symptoms in patients with schizophrenia. Though hippocampal dysfunction contributes to psychosis, the impact of NMDAR hypofunction on hippocampal plasticity remains poorly understood. Here, we used an NMDAR antagonist rodent model of psychosis to investigate hippocampal long-term potentiation (LTP). We found that single systemic NMDAR antagonism results in a region-specific, presynaptic LTP at hippocampal CA1-subiculum synapses that is induced by activation of D1/D5 dopamine receptors and modulated by L-type voltage-gated Ca(2+) channels. Thereby, our findings may provide a cellular mechanism how NMDAR antagonism can lead to an enhanced hippocampal output causing activation of the hippocampus-ventral tegmental area-loop and overdrive of the dopamine system.
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83
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Kawano M, Sawada K, Shimodera S, Ogawa Y, Kariya S, Lang DJ, Inoue S, Honer WG. Hippocampal subfield volumes in first episode and chronic schizophrenia. PLoS One 2015; 10:e0117785. [PMID: 25658118 PMCID: PMC4319836 DOI: 10.1371/journal.pone.0117785] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/30/2014] [Indexed: 02/07/2023] Open
Abstract
Background Reduced hippocampal volume in schizophrenia is a well-replicated finding. New imaging techniques allow delineation of hippocampal subfield volumes. Studies including predominantly chronic patients demonstrate differences between subfields in sensitivity to illness, and in associations with clinical features. We carried out a cross-sectional and longitudinal study of first episode, sub-chronic, and chronic patients, using an imaging strategy that allows for the assessment of multiple hippocampal subfields. Methods Hippocampal subfield volumes were measured in 34 patients with schizophrenia (19 first episode, 6 sub-chronic, 9 chronic) and 15 healthy comparison participants. A subset of 10 first episode and 12 healthy participants were rescanned after six months. Results Total left hippocampal volume was smaller in sub-chronic (p = 0.04, effect size 1.12) and chronic (p = 0.009, effect size 1.42) patients compared with healthy volunteers. The CA2-3 subfield volume of chronic patients was significantly decreased (p = 0.009, effect size 1.42) compared to healthy volunteers. The CA4-DG volume was significantly reduced in all three patient groups compared to healthy group (all p < 0.005). The two affected subfield volumes were inversely correlated with severity of negative symptoms (p < 0.05). There was a small, but statistically significant decline in left CA4-DG volume over the first six months of illness (p = 0.01). Conclusions Imaging strategies defining the subfields of the hippocampus may be informative in linking symptoms and structural abnormalities, and in understanding more about progression during the early phases of illness in schizophrenia.
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Affiliation(s)
- Mitsuhiko Kawano
- Department of Neuropsychiatry, Kochi Medical School, Kochi, Japan
| | - Ken Sawada
- Department of Neuropsychiatry, Kochi Medical School, Kochi, Japan
- Department of Psychiatry, Aki General Hospital, Kochi, Japan
- * E-mail:
| | - Shinji Shimodera
- Department of Neuropsychiatry, Kochi Medical School, Kochi, Japan
| | - Yasuhiro Ogawa
- Department of Radiology, Hyogo Prefectural Kakogawa Hospital, Hyogo, Japan
| | - Shinji Kariya
- Departments of Diagnostic Radiology and Radiation Oncology, Kochi Medical School, Kochi, Japan
| | - Donna J. Lang
- Department of Radiology, University of British Columbia, Vancouver, Canada
| | - Shimpei Inoue
- Department of Neuropsychiatry, Aizu Medical Center, Fukushima Medical University, Fukushima, Japan
| | - William G. Honer
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
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84
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Arnold SJM, Ivleva EI, Gopal TA, Reddy AP, Jeon-Slaughter H, Sacco CB, Francis AN, Tandon N, Bidesi AS, Witte B, Poudyal G, Pearlson GD, Sweeney JA, Clementz BA, Keshavan MS, Tamminga CA. Hippocampal volume is reduced in schizophrenia and schizoaffective disorder but not in psychotic bipolar I disorder demonstrated by both manual tracing and automated parcellation (FreeSurfer). Schizophr Bull 2015; 41:233-49. [PMID: 24557771 PMCID: PMC4266285 DOI: 10.1093/schbul/sbu009] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study examined hippocampal volume as a putative biomarker for psychotic illness in the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) psychosis sample, contrasting manual tracing and semiautomated (FreeSurfer) region-of-interest outcomes. The study sample (n = 596) included probands with schizophrenia (SZ, n = 71), schizoaffective disorder (SAD, n = 70), and psychotic bipolar I disorder (BDP, n = 86); their first-degree relatives (SZ-Rel, n = 74; SAD-Rel, n = 62; BDP-Rel, n = 88); and healthy controls (HC, n = 145). Hippocampal volumes were derived from 3Tesla T1-weighted MPRAGE images using manual tracing/3DSlicer3.6.3 and semiautomated parcellation/FreeSurfer5.1,64bit. Volumetric outcomes from both methodologies were contrasted in HC and probands and relatives across the 3 diagnoses, using mixed-effect regression models (SAS9.3 Proc MIXED); Pearson correlations between manual tracing and FreeSurfer outcomes were computed. SZ (P = .0007-.02) and SAD (P = .003-.14) had lower hippocampal volumes compared with HC, whereas BDP showed normal volumes bilaterally (P = .18-.55). All relative groups had hippocampal volumes not different from controls (P = .12-.97) and higher than those observed in probands (P = .003-.09), except for FreeSurfer measures in bipolar probands vs relatives (P = .64-.99). Outcomes from manual tracing and FreeSurfer showed direct, moderate to strong, correlations (r = .51-.73, P < .05). These findings from a large psychosis sample support decreased hippocampal volume as a putative biomarker for schizophrenia and schizoaffective disorder, but not for psychotic bipolar I disorder, and may reflect a cumulative effect of divergent primary disease processes and/or lifetime medication use. Manual tracing and semiautomated parcellation regional volumetric approaches may provide useful outcomes for defining measurable biomarkers underlying severe mental illness.
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Affiliation(s)
- Sara J. M. Arnold
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Elena I. Ivleva
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235;,*To whom correspondence should be addressed; tel: 214-645-8942, fax: 214-648-5321, e-mail:
| | - Tejas A. Gopal
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Anil P. Reddy
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Haekyung Jeon-Slaughter
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Carolyn B. Sacco
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Alan N. Francis
- Department of Psychiatry, Beth Israel Deaconess Hospital, Harvard Medical School, Boston, MA
| | - Neeraj Tandon
- Department of Psychiatry, Beth Israel Deaconess Hospital, Harvard Medical School, Boston, MA
| | - Anup S. Bidesi
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Bradley Witte
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Gaurav Poudyal
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | - Godfrey D. Pearlson
- Department of Psychiatry, Institute of Living/Hartford Hospital, Yale School of Medicine, New Haven, CT
| | - John A. Sweeney
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
| | | | - Matcheri S. Keshavan
- Department of Psychiatry, Beth Israel Deaconess Hospital, Harvard Medical School, Boston, MA
| | - Carol A. Tamminga
- Department of Psychiatry, UT Southwestern Medical Center, 5352 Harry Hines Boulevard, NE5.110H, Dallas, TX 75235
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Hazan L, Gaisler-Salomon I. Glutaminase1 heterozygous mice show enhanced trace fear conditioning and Arc/Arg3.1 expression in hippocampus and cingulate cortex. Eur Neuropsychopharmacol 2014; 24:1916-24. [PMID: 25453483 DOI: 10.1016/j.euroneuro.2014.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 07/22/2014] [Accepted: 10/11/2014] [Indexed: 01/27/2023]
Abstract
Mice heterozygous for a mutation in the glutaminase (GLS1) gene (GLS1 HZ mice), with reduced glutamate recycling and release, display reduced hippocampal function as well as memory of contextual cues in a delay fear conditioning (FC) paradigm. Here, we asked whether this deficit reflects an inability to process contextual information or a selective alteration in salience attribution. In addition, we asked whether baseline and activity-induced hippocampal activity were diminished in GLS1 HZ mice. For this purpose, we manipulated the relative salience of the conditioned stimulus (CS) and contextual cues in FC tasks, and examined gene expression of the immediate early gene Arc (Arc/Arg3.1) in hippocampus and anterior cingulate cortex (ACC) following trace FC (tFC). The results indicate that GLS1 HZ mice succeed in processing contextual information when the salient CS is absent or less predictive. In addition, in the hippocampus-dependent tFC paradigm GLS1 HZ mice display enhanced CS learning. Furthermore, while baseline arc activation was reduced in GLS1 HZ mice in the hippocampus, in line with previous fMRI findings, it was enhanced in the hippocampus and anterior cingulate cortex following tFC. These findings suggest that GLS1 HZ mice have a pro-cognitive profile in the tFC paradigm, and this phenotype involves activation of both hippocampus and ACC. Taken together with previous work on the GLS1 HZ mouse, this study sheds light on the importance of glutamate transmission to memory processes that require the allocation of attentional resources, and extends our understanding of the underpinnings of attention deficits in SZ.
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Affiliation(s)
- Liran Hazan
- Department of Psychology, University of Haifa, Haifa 3498838, Israel
| | - Inna Gaisler-Salomon
- Department of Psychology, University of Haifa, Haifa 3498838, Israel; Department of Psychiatry, Columbia University, New York, NY 10032, USA.
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Marty VN, Vlkolinsky R, Minassian N, Cohen T, Nelson GA, Spigelman I. Radiation-Induced Alterations in Synaptic Neurotransmission of Dentate Granule Cells Depend on the Dose and Species of Charged Particles. Radiat Res 2014; 182:653-65. [DOI: 10.1667/rr13647.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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87
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Kraguljac NV, White DM, Hadley J, Reid MA, Lahti AC. Hippocampal-parietal dysconnectivity and glutamate abnormalities in unmedicated patients with schizophrenia. Hippocampus 2014; 24:1524-32. [PMID: 25045047 DOI: 10.1002/hipo.22332] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2014] [Indexed: 01/09/2023]
Abstract
Abnormalities in resting state connectivity in schizophrenia (SZ) are now well established, but the biological substrates of these functional alterations remain to be elucidated. We performed a combined functional magnetic resonance imaging and magnetic resonance spectroscopy study in 22 unmedicated patients with SZ and 22 matched healthy controls (HCs) to evaluate resting state functional connectivity of the hippocampus and Glx/Cr (a combined glutamate + glutamine peak normalized to creatine) in the hippocampus and investigate functional and neurometabolic abnormalities and examine the relationship between these. Functional connectivity between the left hippocampus and bilateral precuneus was significantly decreased in unmedicated patients with SZ when compared to HCs [t(4.22), cluster extent (kE) = 751, PFDRcorr = 0.001, Montreal Neurological Institute coordinates: x = -4, y = -56, z = 44]. Glx/Cr in the hippocampus was significantly elevated in SZ (HC: mean = 0.60+/-0.10 SZ: 0.67+/-0.10; F = 5.742; P = 0.02), but was not correlated with functional connectivity deficits (P > 0.05). In this study, we found hippocampal resting state functional connectivity deficits to the precuneus in unmedicated patients with SZ and an increase of Glx/Cr in the hippocampus, but did not observe a direct relationship between these abnormalities. However, our findings do not exclude the possibility of a shared underlying pathology, which warrants further investigation.
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Affiliation(s)
- Nina Vanessa Kraguljac
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham
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Talati P, Rane S, Kose S, Blackford JU, Gore J, Donahue MJ, Heckers S. Increased hippocampal CA1 cerebral blood volume in schizophrenia. NEUROIMAGE-CLINICAL 2014; 5:359-64. [PMID: 25161901 PMCID: PMC4141978 DOI: 10.1016/j.nicl.2014.07.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hippocampal hyperactivity has been proposed as a biomarker in schizophrenia. However, there is a debate whether the CA1 or the CA2/3 subfield is selectively affected. We studied 15 schizophrenia patients and 15 matched healthy control subjects with 3T steady state, gadolinium-enhanced, absolute cerebral blood volume (CBV) maps, perpendicular to the long axis of the hippocampus. The subfields of the hippocampal formation (subiculum, CA1, CA2/3, and hilus/dentate gyrus) were manually segmented to establish CBV values. Comparing anterior CA1 and CA2/3 CBV between patients and controls revealed a significant subfield-by-diagnosis interaction. This interaction was due to the combined effect of a trend of increased CA1 CBV (p = .06) and non-significantly decreased CA2/3 CBV (p = 0.14) in patients relative to healthy controls. These results support the emerging hypothesis of increased hippocampal activity as a biomarker of schizophrenia and highlight the importance of subfield-level investigations. Hippocampal hyperactivity has been proposed as a biomarker in schizophrenia Subfield-specificity hyperactivity (anterior CA1 versus CA2/3) is currently debated We used contrast-enhanced MRI to test hyperactivity in these two subfields We find a significant diagnosis by group interaction due to the combined effect of a trend of increased CA1 CBV and non-significantly decreased CA2/3 CBV in patients compared to healthy controls No significant group differences in the anterior subiculum and dentate gyrus CBV
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Affiliation(s)
- Pratik Talati
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37235, USA ; Department of Psychiatry, Vanderbilt University, Nashville, TN 37235, USA
| | - Swati Rane
- Department of Radiology and Radiological Sciences, Institute of Imaging Science, Vanderbilt University, Nashville, TN 37235, USA
| | - Samet Kose
- Department of Psychiatry, Vanderbilt University, Nashville, TN 37235, USA
| | | | - John Gore
- Department of Radiology and Radiological Sciences, Institute of Imaging Science, Vanderbilt University, Nashville, TN 37235, USA
| | - Manus J Donahue
- Department of Psychiatry, Vanderbilt University, Nashville, TN 37235, USA ; Department of Radiology and Radiological Sciences, Institute of Imaging Science, Vanderbilt University, Nashville, TN 37235, USA
| | - Stephan Heckers
- Department of Psychiatry, Vanderbilt University, Nashville, TN 37235, USA
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Tregellas JR. Neuroimaging biomarkers for early drug development in schizophrenia. Biol Psychiatry 2014; 76:111-9. [PMID: 24094513 PMCID: PMC4026337 DOI: 10.1016/j.biopsych.2013.08.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 11/18/2022]
Abstract
Given the relative inability of currently available antipsychotic treatments to adequately provide sustained recovery and improve quality of life for patients with schizophrenia, new treatment strategies are urgently needed. One way to improve the therapeutic development process may be an increased use of biomarkers in early clinical trials. Reliable biomarkers that reflect aspects of disease pathophysiology can be used to determine if potential treatment strategies are engaging their desired biological targets. This review evaluates three potential neuroimaging biomarkers: hippocampal hyperactivity, gamma-band deficits, and default network abnormalities. These deficits have been widely replicated in the illness, correlate with measures of positive symptoms, are consistent with models of disease pathology, and have shown initial promise as biomarkers of biological response in early studies of potential treatment strategies. Two key features of these deficits, and a guiding rationale for the focus of this review, are that the deficits are not dependent upon patients' performance of specific cognitive tasks and they have analogues in animal models of schizophrenia, greatly increasing their appeal for use as biomarkers. Using neuroimaging biomarkers such as those proposed here to establish early in the therapeutic development process if treatment strategies are having their intended biological effect in humans may facilitate development of new treatments for schizophrenia.
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Affiliation(s)
- Jason R Tregellas
- Research Service, Denver Veterans Affairs Medical Center, and Department of Psychiatry, University of Colorado Medical School, Aurora, Colorado.
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90
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Overrepresentation of glutamate signaling in Alzheimer's disease: network-based pathway enrichment using meta-analysis of genome-wide association studies. PLoS One 2014; 9:e95413. [PMID: 24755620 PMCID: PMC3995778 DOI: 10.1371/journal.pone.0095413] [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: 04/02/2013] [Accepted: 03/26/2014] [Indexed: 02/07/2023] Open
Abstract
Genome-wide association studies (GWAS) have successfully identified several risk loci for Alzheimer's disease (AD). Nonetheless, these loci do not explain the entire susceptibility of the disease, suggesting that other genetic contributions remain to be identified. Here, we performed a meta-analysis combining data of 4,569 individuals (2,540 cases and 2,029 healthy controls) derived from three publicly available GWAS in AD and replicated a broad genomic region (>248,000 bp) associated with the disease near the APOE/TOMM40 locus in chromosome 19. To detect minor effect size contributions that could help to explain the remaining genetic risk, we conducted network-based pathway analyses either by extracting gene-wise p-values (GW), defined as the single strongest association signal within a gene, or calculated a more stringent gene-based association p-value using the extended Simes (GATES) procedure. Comparison of these strategies revealed that ontological sub-networks (SNs) involved in glutamate signaling were significantly overrepresented in AD (p<2.7×10−11, p<1.9×10−11; GW and GATES, respectively). Notably, glutamate signaling SNs were also found to be significantly overrepresented (p<5.1×10−8) in the Alzheimer's disease Neuroimaging Initiative (ADNI) study, which was used as a targeted replication sample. Interestingly, components of the glutamate signaling SNs are coordinately expressed in disease-related tissues, which are tightly related to known pathological hallmarks of AD. Our findings suggest that genetic variation within glutamate signaling contributes to the remaining genetic risk of AD and support the notion that functional biological networks should be targeted in future therapies aimed to prevent or treat this devastating neurological disorder.
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91
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Kubík Š, Buchtová H, Valeš K, Stuchlík A. MK-801 Impairs Cognitive Coordination on a Rotating Arena (Carousel) and Contextual Specificity of Hippocampal Immediate-Early Gene Expression in a Rat Model of Psychosis. Front Behav Neurosci 2014; 8:75. [PMID: 24659959 PMCID: PMC3950493 DOI: 10.3389/fnbeh.2014.00075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 02/21/2014] [Indexed: 01/05/2023] Open
Abstract
Flexible behavior in dynamic, real-world environments requires more than static spatial learning and memory. Discordant and unstable cues must be organized in coherent subsets to give rise to meaningful spatial representations. We model this form of cognitive coordination on a rotating arena - Carousel where arena- and room-bound spatial cues are dissociated. Hippocampal neuronal ensemble activity can repeatedly switch between multiple representations of such an environment. Injection of tetrodotoxin into one hippocampus prevents cognitive coordination during avoidance of a stationary room-defined place on the Carousel and increases coactivity of previously unrelated neurons in the uninjected hippocampus. Place avoidance on the Carousel is impaired after systemic administration of non-competitive NMDAr blockers (MK-801) used to model schizophrenia in animals and people. We tested if this effect is due to cognitive disorganization or other effect of NMDAr antagonism such as hyperlocomotion, spatial memory impairment, or general learning deficit. We also examined if the same dose of MK-801 alters patterns of immediate-early gene (IEG) expression in the hippocampus. IEG expression is triggered in neuronal nuclei in a context-specific manner after behavioral exploration and it is used to map activity in neuronal populations. IEG expression is critical for maintenance of synaptic plasticity and memory consolidation. We show that the same dose of MK-801 that impairs spatial coordination of rats on the Carousel also eliminates contextual specificity of IEG expression in hippocampal CA1 ensembles. This effect is due to increased similarity between ensembles activated in different environments, consistent with the idea that it is caused by increased coactivity between neurons, which did not previously fire together. Our data support the proposition of the Hypersynchrony theory that cognitive disorganization in psychosis is due to increased coactivity between unrelated neurons.
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Affiliation(s)
- Štěpán Kubík
- Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Helena Buchtová
- Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Karel Valeš
- Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Aleš Stuchlík
- Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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92
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Kraguljac NV, White DM, Reid MA, Lahti AC. Increased hippocampal glutamate and volumetric deficits in unmedicated patients with schizophrenia. JAMA Psychiatry 2013; 70:1294-302. [PMID: 24108440 PMCID: PMC7891898 DOI: 10.1001/jamapsychiatry.2013.2437] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Alterations in glutamatergic neurotransmission have been postulated to be a key pathophysiologic mechanism in schizophrenia. OBJECTIVE To evaluate hippocampal volumetric measures and neurometabolites in unmedicated patients with schizophrenia and the correlations between these markers. Our a priori hypothesis was that glutamate levels would negatively correlate with hippocampal volume in schizophrenia. DESIGN, SETTING, AND PARTICIPANTS Combined 3-T structural magnetic resonance imaging and single-voxel proton magnetic resonance spectroscopy study at the Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, of 27 unmedicated patients with schizophrenia and 27 healthy controls. MAIN OUTCOMES AND MEASURES Hippocampal volumetric measures and neurometabolites, and the correlations between volumetric measurements and neurometabolites. RESULTS Hippocampal volumetric deficits, increased ratios of hippocampal glutamate and glutamine to creatine (Glx/Cr), and a loss of correlation between hippocampal N-acetylaspartate (NAA)/Cr and Glx/Cr in patients with schizophrenia were found. Significant correlations between hippocampal volumetric measures and Glx/Cr were also found in patients with schizophrenia but not healthy controls. CONCLUSIONS AND RELEVANCE Our findings support the theory that alterations in hippocampal glutamate levels potentially account for structural deficits in the hippocampus observed in schizophrenia neuroimaging studies.
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Affiliation(s)
- Nina V Kraguljac
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham
| | - David M White
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham
| | - Meredith A Reid
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham,Department of Biomedical Engineering, University of Alabama at Birmingham
| | - Adrienne C Lahti
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham
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93
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Williams LE, Blackford JU, Luksik A, Gauthier I, Heckers S. Reduced habituation in patients with schizophrenia. Schizophr Res 2013; 151:124-32. [PMID: 24200419 PMCID: PMC3908315 DOI: 10.1016/j.schres.2013.10.017] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 10/11/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Neural habituation, the decrease in brain response to repeated stimulation, is a basic form of learning. There is strong evidence for behavioral and physiological habituation deficits in schizophrenia, and one previous study found reduced neural habituation within the hippocampus. However, it is unknown whether neural habituation deficits are specific to faces and limited to the hippocampus. Here we studied habituation of several brain regions in schizophrenia, using both face and object stimuli. Post-scan memory measures were administered to test for a link between hippocampal habituation and memory performance. METHODS During an fMRI scan, 23 patients with schizophrenia and 21 control subjects viewed blocks of a repeated neutral face or neutral object, and blocks of different neutral faces and neutral objects. Habituation in the hippocampus, primary visual cortex and fusiform face area (FFA) was compared between groups. Memory for faces, words, and word pairs was assessed after the scan. RESULTS Patients showed reduced habituation to faces in the hippocampus and primary visual cortex, but not the FFA. Healthy control subjects exhibited a pattern of hippocampal discrimination that distinguished between repeated and different images for both faces and objects, and schizophrenia patients did not. Hippocampal discrimination was positively correlated with memory for word pairs. CONCLUSION Patients with schizophrenia showed reduced habituation of the hippocampus and visual cortex, and a lack of neural discrimination between old and new images in the hippocampus. Hippocampal discrimination correlated with memory performance, suggesting reduced habituation may contribute to the memory deficits commonly observed in schizophrenia.
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Affiliation(s)
- Lisa E. Williams
- Department of Psychiatry, Vanderbilt University, 1601 23rd Ave S., Nashville, TN, 37212, USA
| | | | - Andrew Luksik
- Department of Psychiatry, Vanderbilt University, 1601 23rd Ave S., Nashville, TN, 37212, USA
| | - Isabel Gauthier
- Department of Psychology, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN, 37240, USA
| | - Stephan Heckers
- Department of Psychiatry, Vanderbilt University, 1601 23rd Ave S., Nashville, TN, 37212, USA
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94
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Daulatzai MA. Neurotoxic Saboteurs: Straws that Break the Hippo’s (Hippocampus) Back Drive Cognitive Impairment and Alzheimer’s Disease. Neurotox Res 2013; 24:407-59. [DOI: 10.1007/s12640-013-9407-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/06/2013] [Accepted: 06/17/2013] [Indexed: 12/29/2022]
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Hagihara H, Takao K, Walton NM, Matsumoto M, Miyakawa T. Immature dentate gyrus: an endophenotype of neuropsychiatric disorders. Neural Plast 2013; 2013:318596. [PMID: 23840971 PMCID: PMC3694492 DOI: 10.1155/2013/318596] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/17/2013] [Accepted: 04/19/2013] [Indexed: 12/13/2022] Open
Abstract
Adequate maturation of neurons and their integration into the hippocampal circuit is crucial for normal cognitive function and emotional behavior, and disruption of this process could cause disturbances in mental health. Previous reports have shown that mice heterozygous for a null mutation in α -CaMKII, which encodes a key synaptic plasticity molecule, display abnormal behaviors related to schizophrenia and other psychiatric disorders. In these mutants, almost all neurons in the dentate gyrus are arrested at a pseudoimmature state at the molecular and electrophysiological levels, a phenomenon defined as "immature dentate gyrus (iDG)." To date, the iDG phenotype and shared behavioral abnormalities (including working memory deficit and hyperlocomotor activity) have been discovered in Schnurri-2 knockout, mutant SNAP-25 knock-in, and forebrain-specific calcineurin knockout mice. In addition, both chronic fluoxetine treatment and pilocarpine-induced seizures reverse the neuronal maturation, resulting in the iDG phenotype in wild-type mice. Importantly, an iDG-like phenomenon was observed in post-mortem analysis of brains from patients with schizophrenia/bipolar disorder. Based on these observations, we proposed that the iDG is a potential endophenotype shared by certain types of neuropsychiatric disorders. This review summarizes recent data describing this phenotype and discusses the data's potential implication in elucidating the pathophysiology of neuropsychiatric disorders.
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Affiliation(s)
- Hideo Hagihara
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Keizo Takao
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
- Section of Behavior Patterns, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 5-1 Aza-Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan
| | - Noah M. Walton
- CNS, Astellas Research Institute of America LLC, 8045 Lamon Avenue, Skokie, IL 60077, USA
| | - Mitsuyuki Matsumoto
- CNS, Astellas Research Institute of America LLC, 8045 Lamon Avenue, Skokie, IL 60077, USA
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
- Section of Behavior Patterns, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 5-1 Aza-Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan
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Ohira K, Kobayashi K, Toyama K, Nakamura HK, Shoji H, Takao K, Takeuchi R, Yamaguchi S, Kataoka M, Otsuka S, Takahashi M, Miyakawa T. Synaptosomal-associated protein 25 mutation induces immaturity of the dentate granule cells of adult mice. Mol Brain 2013; 6:12. [PMID: 23497716 PMCID: PMC3605216 DOI: 10.1186/1756-6606-6-12] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 02/21/2013] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Synaptosomal-associated protein, 25 kDa (SNAP-25) regulates the exocytosis of neurotransmitters. Growing evidence suggests that SNAP-25 is involved in neuropsychiatric disorders, such as schizophrenia, attention-deficit/hyperactivity disorder, and epilepsy. Recently, increases in anxiety-related behaviors and epilepsy have been observed in SNAP-25 knock-in (KI) mice, which have a single amino acid substitution of Ala for Ser187. However, the molecular and cellular mechanisms underlying the abnormalities in this mutant remain unknown. RESULTS In this study, we found that a significant number of dentate gyrus (DG) granule cells was histologically and electrophysiologically similar to immature DG neurons in the dentate gyrus of the adult mutants, a phenomenon termed the "immature DG" (iDG). SNAP-25 KI mice and other mice possessing the iDG phenotype, i.e., alpha-calcium/calmodulin-dependent protein kinase II heterozygous mice, Schnurri-2 knockout mice, and mice treated with the antidepressant fluoxetine, showed similar molecular expression patterns, with over 100 genes similarly altered. A working memory deficit was also identified in mutant mice during a spontaneous forced alternation task using a modified T-maze, a behavioral task known to be dependent on hippocampal function. Chronic treatments with the antiepileptic drug valproate abolished the iDG phenotype and the working memory deficit in mutants. CONCLUSIONS These findings suggest that the substitution of Ala for Ser187 in SNAP-25 induces the iDG phenotype, which can also be caused by epilepsy, and led to a severe working memory deficit. In addition, the iDG phenotype in adulthood is likely an endophenotype for at least a part of some common psychiatric disorders.
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Affiliation(s)
- Koji Ohira
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, 470-1192, Japan
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
| | - Katsunori Kobayashi
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
- Department of Pharmacology, Graduate School of Medicine, Nippon Medical School, Tokyo, 113-8602, Japan
| | - Keiko Toyama
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, 470-1192, Japan
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
| | - Hironori K Nakamura
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, 470-1192, Japan
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
| | - Hirotaka Shoji
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, 470-1192, Japan
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
| | - Keizo Takao
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, 444-8585, Japan
| | - Rika Takeuchi
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, 470-1192, Japan
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
| | - Shun Yamaguchi
- Division of Morphological Neuroscience, Gifu University Graduate School of Medicine, Gifu, 501-1194, Japan
- JST, PRESTO, Kawaguchi, 332-0012, Japan
| | - Masakazu Kataoka
- Department of Environmental Science and Technology, Faculty of Engineering, Shinshu University, Nagano, 380-8553, Japan
| | - Shintaro Otsuka
- Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, 228-8555, Japan
| | - Masami Takahashi
- Department of Biochemistry, Kitasato University School of Medicine, Sagamihara, 228-8555, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, 470-1192, Japan
- Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Kawaguchi, 332-0012, Japan
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, 444-8585, Japan
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Hunsaker MR, Kesner RP. The operation of pattern separation and pattern completion processes associated with different attributes or domains of memory. Neurosci Biobehav Rev 2012; 37:36-58. [PMID: 23043857 DOI: 10.1016/j.neubiorev.2012.09.014] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 09/19/2012] [Accepted: 09/26/2012] [Indexed: 12/21/2022]
Abstract
Pattern separation and pattern completion processes are central to how the brain processes information in an efficient manner. Research into these processes is escalating and deficient pattern separation is being implicated in a wide array of genetic disorders as well as in neurocognitive aging. Despite the quantity of research, there remains a controversy as to precisely which behavioral paradigms should be used to best tap into pattern separation and pattern completion processes, as well as to what constitute legitimate outcome measures reflecting impairments in pattern separation and pattern completion. This review will discuss a theory based on multiple memory systems that provides a framework upon which behavioral tasks can be designed and their results interpreted. Furthermore, this review will discuss the nature of pattern separation and pattern completion and extend these processes outside the hippocampus and across all domains of information processing. After these discussions, an optimal strategy for designing behavioral paradigms to evaluate pattern separation and pattern completion processes will be provided.
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Affiliation(s)
- Michael R Hunsaker
- Department of Psychiatry and Behavioral Sciences, MIND Institute, University of California, Davis Medical Center, 2805 50th Street, Room 1415, Sacramento, CA 95817, USA.
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Developmental regulation of expression of schizophrenia susceptibility genes in the primate hippocampal formation. Transl Psychiatry 2012; 2:e173. [PMID: 23092977 PMCID: PMC3565813 DOI: 10.1038/tp.2012.105] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The hippocampal formation is essential for normal memory function and is implicated in many neurodevelopmental, neurodegenerative and neuropsychiatric disorders. In particular, abnormalities in hippocampal structure and function have been identified in schizophrenic subjects. Schizophrenia has a strong polygenic component, but the role of numerous susceptibility genes in normal brain development and function has yet to be investigated. Here we described the expression of schizophrenia susceptibility genes in distinct regions of the monkey hippocampal formation during early postnatal development. We found that, as compared with other genes, schizophrenia susceptibility genes exhibit a differential regulation of expression in the dentate gyrus, CA3 and CA1, over the course of postnatal development. A number of these genes involved in synaptic transmission and dendritic morphology exhibit a developmental decrease of expression in CA3. Abnormal CA3 synaptic organization observed in schizophrenics might be related to some specific symptoms, such as loosening of association. Interestingly, changes in gene expression in CA3 might occur at a time possibly corresponding to the late appearance of the first clinical symptoms. We also found earlier changes in expression of schizophrenia susceptibility genes in CA1, which might be linked to prodromal psychotic symptoms. A number of schizophrenia susceptibility genes including APOE, BDNF, MTHFR and SLC6A4 are involved in other disorders, and thus likely contribute to nonspecific changes in hippocampal structure and function that must be combined with the dysregulation of other genes in order to lead to schizophrenia pathogenesis.
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Abstract
At present, all medications for schizophrenia function primarily by blocking dopamine D2 receptors. Over 50 years ago, the first observations were made that subsequently led to development of alternative, glutamatergic conceptualizations. This special issue traces the historic development of the phencyclidine (PCP) model of schizophrenia from the initial description of the psychotomimetic effects of PCP in the early 1960s, through discovery of the link to N-methyl-D-aspartate-type glutamate receptors (NMDAR) in the 1980s, and finally to the development of NMDA-based treatment strategies starting in the 1990s. NMDAR antagonists uniquely reproduce both positive and negative symptoms of schizophrenia, and induce schizophrenia-like cognitive deficits and neurophysiological dysfunction. At present, there remain several hypotheses concerning mechanisms by which NMDAR dysfunction leads to symptoms/deficits, and several theories regarding ideal NMDAR-based treatment approaches as outlined in the issue. Several classes of agent, including metabotropic glutamate agonists, glycine transport inhibitors, and D-serine-based compounds are currently in late-stage clinical development and may provide long-sought treatments for persistent positive and negative symptoms and cognitive dysfunction in schizophrenia.
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Affiliation(s)
- Daniel C. Javitt
- To whom correspondence should be addressed; tel: 845-398-6534, fax: 845-398-6546, e-mail:
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