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Roberts D, Rösler L, Wijnen JP, Thakkar KN. Associations between N-Acetylaspartate and white matter integrity in individuals with schizophrenia and unaffected relatives. Psychiatry Res Neuroimaging 2023; 330:111612. [PMID: 36805928 PMCID: PMC10023491 DOI: 10.1016/j.pscychresns.2023.111612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/27/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Abstract
Compromised white matter has been reported in schizophrenia; however, few studies have investigated neurochemical abnormalities underlying microstructural differences. N-acetylaspartate (NAA) is used to synthesize myelin and is often reduced in persons with schizophrenia (PSZ) and their unaffected first-degree relatives (REL). Low levels of NAA could affect white matter by preventing the synthesis or repair of myelin. We used magnetic resonance spectroscopy and diffusion tensor imaging to investigate the relationship between NAA and white matter integrity in PSZ. REL were included to examine whether putative relationships are associated with symptom expression or illness liability. 52 controls, 23 REL and 25 PSZ underwent 7T proton magnetic resonance spectroscopy and/or 3T diffusion tensor imaging. NAA in the visual cortex and basal ganglia were measured and compared across groups. Diffusivity measures were compared across groups using tract-based spatial statistics and related to NAA concentrations. Visual cortex NAA was significantly reduced in PSZ compared to controls. White matter integrity did not differ between groups. Reduced cortical and subcortical NAA were associated with diffusivity measures of poor white matter microstructure. These data suggest that levels of neural NAA may be related to white matter integrity similarly across individuals with schizophrenia, those at genetic risk, and controls.
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Affiliation(s)
- Dominic Roberts
- Department of Psychology, Michigan State University, East Lansing, MI, United States
| | - Lara Rösler
- Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Jannie P Wijnen
- Department of Radiology, High Field MR Research, Centre for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Katharine N Thakkar
- Department of Psychology, Michigan State University, East Lansing, MI, United States; Department of Psychiatry and Behavioral Medicine, Michigan State University, East Lansing, Michigan, United States.
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Proton Magnetic Resonance Spectroscopy of N-acetyl Aspartate in Chronic Schizophrenia, First Episode of Psychosis and High-Risk of Psychosis: A Systematic Review and Meta-Analysis. Neurosci Biobehav Rev 2020; 119:255-267. [PMID: 33068555 DOI: 10.1016/j.neubiorev.2020.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/01/2020] [Accepted: 10/07/2020] [Indexed: 02/06/2023]
Abstract
N-acetyl-aspartate (NAA) is a readily measured marker of neuronal metabolism. Previous analyses in schizophrenia have shown NAA levels are low in frontal, temporal and thalamic regions, but may be underpowered to detect effects in other regions, in high-risk states and in first episode psychosis. We searched for magnetic resonance spectroscopy studies comparing NAA in chronic schizophrenia, first episode psychosis and high risk of psychosis to controls. 182 studies were included and meta-analysed using a random-effects model for each region and illness stage. NAA levels were significantly lower than controls in the frontal lobe [Hedge's g = -0.36, p < 0.001], hippocampus [-0.52, p < 0.001], temporal lobe [-0.35, p = 0.031], thalamus [-0.32, p = 0.012] and parietal lobe [-0.25, p = 0.028] in chronic schizophrenia, and lower than controls in the frontal lobe [-0.26, p = 0.002], anterior cingulate cortex [-0.24, p = 0.016] and thalamus [-0.28, p = 0.028] in first episode psychosis. NAA was lower in high-risk of psychosis in the hippocampus [-0.20, p = 0.049]. In schizophrenia, NAA alterations appear to begin in hippocampus, frontal cortex and thalamus, and extend later to many other regions.
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3
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Affiliation(s)
- S Yeap
- Neuroscience Center, St. Vincent's Hospital, Richmond Road, Dublin 3, Ireland
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Collado-Torres L, Burke EE, Peterson A, Shin J, Straub RE, Rajpurohit A, Semick SA, Ulrich WS, Price AJ, Valencia C, Tao R, Deep-Soboslay A, Hyde TM, Kleinman JE, Weinberger DR, Jaffe AE. Regional Heterogeneity in Gene Expression, Regulation, and Coherence in the Frontal Cortex and Hippocampus across Development and Schizophrenia. Neuron 2019; 103:203-216.e8. [PMID: 31174959 DOI: 10.1016/j.neuron.2019.05.013] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 04/08/2019] [Accepted: 05/06/2019] [Indexed: 02/06/2023]
Abstract
The hippocampus formation, although prominently implicated in schizophrenia pathogenesis, has been overlooked in large-scale genomics efforts in the schizophrenic brain. We performed RNA-seq in hippocampi and dorsolateral prefrontal cortices (DLPFCs) from 551 individuals (286 with schizophrenia). We identified substantial regional differences in gene expression and found widespread developmental differences that were independent of cellular composition. We identified 48 and 245 differentially expressed genes (DEGs) associated with schizophrenia within the hippocampus and DLPFC, with little overlap between the brain regions. 124 of 163 (76.6%) of schizophrenia GWAS risk loci contained eQTLs in any region. Transcriptome-wide association studies in each region identified many novel schizophrenia risk features that were brain region-specific. Last, we identified potential molecular correlates of in vivo evidence of altered prefrontal-hippocampal functional coherence in schizophrenia. These results underscore the complexity and regional heterogeneity of the transcriptional correlates of schizophrenia and offer new insights into potentially causative biology.
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Affiliation(s)
- Leonardo Collado-Torres
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; Center for Computational Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Emily E Burke
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | - Amy Peterson
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - JooHeon Shin
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | - Richard E Straub
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | - Anandita Rajpurohit
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | - Stephen A Semick
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | - William S Ulrich
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | | | - Amanda J Price
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Cristian Valencia
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Ran Tao
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | - Amy Deep-Soboslay
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA
| | - Thomas M Hyde
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Joel E Kleinman
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Daniel R Weinberger
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
| | - Andrew E Jaffe
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD 21205, USA; Center for Computational Biology, Johns Hopkins University, Baltimore, MD 21205, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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Bustillo JR, Jones T, Chen H, Lemke N, Abbott C, Qualls C, Stromberg S, Canive J, Gasparovic C. Glutamatergic and Neuronal Dysfunction in Gray and White Matter: A Spectroscopic Imaging Study in a Large Schizophrenia Sample. Schizophr Bull 2017; 43:611-619. [PMID: 27550776 PMCID: PMC5473520 DOI: 10.1093/schbul/sbw122] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Glutamine plus glutamate (Glx), as well as N-acetylaspartate compounds (NAAc, N-acetylaspartate plus N-acetyl-aspartyl-glutamate), a marker of neuronal viability, can be quantified with proton magnetic resonance spectroscopy (1H-MRS). We used 1H-MRS imaging to assess Glx and NAAc, as well as total-choline (glycerophospho-choline plus phospho-choline), myo-inositol and total-creatine (creatine plus phosphocreatine) from an axial supraventricular slab of gray matter (GM, medial-frontal and medial-parietal) and white matter (WM, bilateral-frontal and bilateral-parietal) voxels. Schizophrenia subjects (N = 104) and healthy controls (N = 97) with a broad age range (16 to 65) were studied. In schizophrenia, Glx was increased in GM (P < .001) and WM (P = .01), regardless of age. However, with greater age, NAAc increased in GM (P < .001) but decreased in WM (P < .001) in schizophrenia. In patients, total creatine decreased with age in WM (P < .001). Finally, overall cognitive score correlated positively with WM neurometabolites in controls but negatively in the schizophrenia group (NAAc, P < .001; and creatine [only younger], P < .001). We speculate the results support an ongoing process of increased glutamate metabolism in schizophrenia. Later in the illness, disease progression is suggested by increased cortical compaction without neuronal loss (elevated NAAc) and reduced axonal integrity (lower NAAc). Furthermore, this process is associated with fundamentally altered relationships between neurometabolite concentrations and cognitive function in schizophrenia.
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Affiliation(s)
- Juan R Bustillo
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
- Department of Neurosciences, University of New Mexico, Albuquerque, NM, USA
| | - Thomas Jones
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
| | - Hongji Chen
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
| | - Nicholas Lemke
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
| | - Christopher Abbott
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
| | - Clifford Qualls
- Department of Mathematics & Statistics, University of New Mexico, Albuquerque, NM, USA
| | - Shannon Stromberg
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
| | - Jose Canive
- Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA
- Department of Neurosciences, University of New Mexico, Albuquerque, NM, USA
- Department of Psychiatry, VA Health Care System, Albuquerque, NM, USA
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Strzelecki D, Podgórski M, Kałużyńska O, Gawlik-Kotelnicka O, Stefańczyk L, Kotlicka-Antczak M, Gmitrowicz A, Grzelak P. Supplementation of antipsychotic treatment with sarcosine – GlyT1 inhibitor – causes changes of glutamatergic (1)NMR spectroscopy parameters in the left hippocampus in patients with stable schizophrenia. Neurosci Lett 2015; 606:7-12. [PMID: 26306650 DOI: 10.1016/j.neulet.2015.08.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 07/30/2015] [Accepted: 08/20/2015] [Indexed: 02/01/2023]
Abstract
Glutamatergic system, the main stimulating system of the brain, plays an important role in the pathogenesis of schizophrenia. Hippocampus, a structure crucial for memory and cognitive functions and rich in glutamatergic neurons, is a natural object of interest in studies on psychoses. Sarcosine, a glycine transporter (GlyT-1) inhibitor influences the function of NMDA receptor and glutamate-dependent transmission. The aim of the study was to assess the effects of sarcosine on metabolism parameters in the left hippocampus in patients with schizophrenia. Assessments were performed using proton nuclear magnetic resonance ((1)H NMR) spectroscopy (1.5T). Fifty patients diagnosed with schizophrenia (DSM-IV-TR), with dominant negative symptoms, in stable clinical condition and stable antipsychotics doses were treated either with sarcosine (n=25) or placebo (n=25). Spectroscopic parameters were evaluated within groups and between two groups before and after 6-month intervention. All patients were also assessed with the Positive and Negative Syndrome Scale (PANSS). In the sarcosine group, after 6-month treatment, we found significant decrease in hippocampal Glx/Cr (Glx-complex of glutamate, glutamine and GABA, Cr-creatine) and Glx/Cho (Cho-choline), while N-acetylaspartate (NAA), myo-inositol (mI), Cr and Cho parameters remained stable along the study and also did not differ significantly between both groups. This is the first study showing that a pharmacological intervention in schizophrenia, particularly augmentation of the antypsychotic treatment with sarcosine, may reverse the pathological increase in glutamatergic transmission in the hippocampus. The results confirm involvement of glutamatergic system in the pathogenesis of schizophrenia and demonstrate beneficial effects of GlyT-1 inhibitor on the metabolism in the hippocampus and symptoms of schizophrenia.
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Affiliation(s)
- Dominik Strzelecki
- Department of Affective and Psychotic Disorders, Medical University of Łódź, Central Clinical Hospital, ul. Pomorska 251, 92-213 Łódź, Poland.
| | - Michał Podgórski
- Department of Radiology and Diagnostic Imaging, Medical University of Łódź, Poland
| | - Olga Kałużyńska
- Department of Affective and Psychotic Disorders, Medical University of Łódź, Central Clinical Hospital, ul. Pomorska 251, 92-213 Łódź, Poland
| | - Oliwia Gawlik-Kotelnicka
- Department of Affective and Psychotic Disorders, Medical University of Łódź, Central Clinical Hospital, ul. Pomorska 251, 92-213 Łódź, Poland
| | - Ludomir Stefańczyk
- Department of Radiology and Diagnostic Imaging, Medical University of Łódź, Poland
| | - Magdalena Kotlicka-Antczak
- Department of Affective and Psychotic Disorders, Medical University of Łódź, Central Clinical Hospital, ul. Pomorska 251, 92-213 Łódź, Poland
| | | | - Piotr Grzelak
- Department of Radiology and Diagnostic Imaging, Medical University of Łódź, Poland
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Schwerk A, Alves FDS, Pouwels PJW, van Amelsvoort T. Metabolic alterations associated with schizophrenia: a critical evaluation of proton magnetic resonance spectroscopy studies. J Neurochem 2013; 128:1-87. [DOI: 10.1111/jnc.12398] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 07/31/2013] [Accepted: 08/03/2013] [Indexed: 12/19/2022]
Affiliation(s)
- Anne Schwerk
- Department of Neurology; Charité - University Medicine; Berlin Germany
| | - Fabiana D. S. Alves
- Department of Psychiatry; Academic Medical Centre; Amsterdam The Netherlands
| | - Petra J. W. Pouwels
- Department of Physics& Medical Technology; VU University Medical Centre; Amsterdam The Netherlands
| | - Therese van Amelsvoort
- Department of Psychiatry and Psychology; Maastricht University; Maastricht The Netherlands
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8
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T2 relaxation effects on apparent N-acetylaspartate concentration in proton magnetic resonance studies of schizophrenia. Psychiatry Res 2013; 213:142-53. [PMID: 23769421 PMCID: PMC3748739 DOI: 10.1016/j.pscychresns.2013.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 03/18/2013] [Accepted: 03/20/2013] [Indexed: 11/24/2022]
Abstract
Over the past two decades, many magnetic resonance spectroscopy (MRS) studies reported lower N-acetylaspartate (NAA) in key brain regions of patients with schizophrenia (SZ) compared to healthy subjects. A smaller number of studies report no difference in NAA. Many sources of variance may contribute to these discordant results including heterogeneity of the SZ subject populations and methodological differences such as MRS acquisition parameters, and post-acquisition analytic methods. The current study reviewed proton MRS literature reporting measurements of NAA in SZ with a focus on methodology. Studies which reported lower NAA were significantly more likely to have used longer echo times (TEs), while studies with shorter TEs reported no concentration difference. This suggests that NAA quantitation using MRS was affected by the choice of TE, and that published MRS literature reporting NAA in SZ using a long TE is confounded by apparent differential T2 relaxation effects between SZ and healthy control groups. Future MRS studies should measure T2 relaxation times. This would allow for spectral concentration measurements to be appropriately corrected for these relaxation effects. In addition, as metabolite concentration and T2 relaxation times are completely independent variables, this could offer distinct information about the metabolite of interest.
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Di Giorgio A, Gelao B, Caforio G, Romano R, Andriola I, D'Ambrosio E, Papazacharias A, Elifani F, Bianco LL, Taurisano P, Fazio L, Popolizio T, Blasi G, Bertolino A. Evidence that hippocampal-parahippocampal dysfunction is related to genetic risk for schizophrenia. Psychol Med 2013; 43:1661-1671. [PMID: 23111173 DOI: 10.1017/s0033291712002413] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Abnormalities in hippocampal-parahippocampal (H-PH) function are prominent features of schizophrenia and have been associated with deficits in episodic memory. However, it remains unclear whether these abnormalities represent a phenotype related to genetic risk for schizophrenia or whether they are related to disease state. METHOD We investigated H-PH-mediated behavior and physiology, using blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI), during episodic memory in a sample of patients with schizophrenia, clinically unaffected siblings and healthy subjects. RESULTS Patients with schizophrenia and unaffected siblings displayed abnormalities in episodic memory performance. During an fMRI memory encoding task, both patients and siblings demonstrated a similar pattern of reduced H-PH engagement compared with healthy subjects. CONCLUSIONS Our findings suggest that the pathophysiological mechanism underlying the inability of patients with schizophrenia to properly engage the H-PH during episodic memory is related to genetic risk for the disorder. Therefore, H-PH dysfunction can be assumed as a schizophrenia susceptibility-related phenotype.
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Affiliation(s)
- A Di Giorgio
- IRCCS 'Casa Sollievo della Sofferenza', San Giovanni Rotondo, Foggia, Italy
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Mondino M, Brunelin J, Saoud M. N-Acetyl-Aspartate Level is Decreased in the Prefrontal Cortex in Subjects At-Risk for Schizophrenia. Front Psychiatry 2013; 4:99. [PMID: 24046751 PMCID: PMC3763479 DOI: 10.3389/fpsyt.2013.00099] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 08/21/2013] [Indexed: 11/13/2022] Open
Abstract
Reduced N-acetyl-aspartate (NAA) levels have been reported in the prefrontal cortex (PFC) in patients with schizophrenia using proton magnetic resonance spectroscopy. However, it is unclear whether this NAA reduction predates the illness onset and is reported in subjects at-risk for developing schizophrenia (HRS). The aim of this study was to assess NAA levels in the PFC in HRS. We hypothesized that HRS display lower NAA levels than healthy controls in the PFC. Studies assessing levels of NAA/Creatine (NAA/Cr) in the PFC in HRS were extracted from literature. Meta-analysis tools were used to compute effect sizes of nine selected studies meeting our inclusion criteria (clinical and/or genetic HRS, groups of HRS, and healthy controls matched for age and gender, spectral acquisition in the PFC). We reported that HRS exhibited a significant lower NAA/Cr level (2.15 ± 0.29; n = 208) than healthy controls (2.21 ± 0.32; n = 234) in the PFC with a medium pooled effect size [Hedges's g = -0.42; 95% confidence interval: (-0.61; -0.23); p < 0.0001] corresponding to an average 5.7% of NAA/Cr decrease. Secondary analysis revealed that this reduction was observed in young HRS (<40 years old) who have not reached the peak age of risk for schizophrenia (-11%, g = -0.82, p < 0.00001) but not in old HRS (>40 years old) who have already passed the peak age (g = 0.11, p = 0.56), when they are compared with their matched healthy controls. Our findings suggest that the NAA/Cr reduction in the PFC reported in patients with schizophrenia is observable only in HRS who have not passed the peak age of risk for schizophrenia. NAA/Cr level in the PFC could therefore be considered as a biological vulnerability marker of schizophrenia.
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Affiliation(s)
- Marine Mondino
- EA4615, CH le Vinatier, Université Claude Bernard Lyon 1 , Lyon , France
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Neurometabolites in schizophrenia and bipolar disorder - a systematic review and meta-analysis. Psychiatry Res 2012; 203:111-25. [PMID: 22981426 PMCID: PMC3466386 DOI: 10.1016/j.pscychresns.2012.02.003] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/02/2012] [Accepted: 02/08/2012] [Indexed: 01/10/2023]
Abstract
This meta-analysis evaluates alterations of neurometabolites in schizophrenia and bipolar disorder. PubMed was searched to find controlled studies evaluating N-acetylaspartate (NAA), Choline (Cho) and Creatine (Cr) assessed with ((1))H-MRS (proton magnetic resonance spectroscopy) in patients with schizophrenia and bipolar disorder up to September 2010. Random effects meta-analyses were conducted to estimate pooled standardized mean differences. The statistic was used to quantify inconsistencies. Subgroup analyses were conducted to explore potential explanations for inconsistencies. The systematic review included 146 studies with 5643 participants. NAA levels were affected in schizophrenia and bipolar disorder. Decreased levels in the basal ganglia and frontal lobe were the most consistent findings in schizophrenia; decreased levels in the basal ganglia were the most consistent findings in bipolar disorder. Cho and Cr levels were not altered in either disorder. Findings for Cr were most consistent in the thalamus, frontal lobe and dorsolateral prefrontal cortex in schizophrenia and the basal ganglia and frontal lobe in bipolar disorder. Findings for Cho were most consistent in the thalamus, frontal lobe and anterior cingulate cortex in schizophrenia and basal ganglia in bipolar disorder. Large, carefully designed studies are needed to better estimate the extent of alterations in neurometabolites.
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Owens SF, Picchioni MM, Ettinger U, McDonald C, Walshe M, Schmechtig A, Murray RM, Rijsdijk F, Toulopoulou T. Prefrontal deviations in function but not volume are putative endophenotypes for schizophrenia. ACTA ACUST UNITED AC 2012; 135:2231-44. [PMID: 22693145 DOI: 10.1093/brain/aws138] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study sought to systematically investigate whether prefrontal cortex grey matter volume reductions are valid endophenotypes for schizophrenia, specifically investigating their presence in unaffected relatives, heritability, genetic overlap with the disorder itself and finally to contrast their performance on these criteria with putative neuropsychological indices of prefrontal functioning. We used a combined twin and family design and examined four prefrontal cortical regions of interest. Superior and inferior regions were significantly smaller in patients. However, the volumes of these same regions were normal in unaffected relatives and therefore, we could confirm that such deficits were not due to familial effects. Volumes of the prefrontal and orbital cortices were, however, moderately heritable, but neither shared a genetic overlap with schizophrenia. Total prefrontal cortical volume reductions shared a significant unique environmental overlap with the disorder, suggesting that the reductions were not familial. In contrast, prefrontal (executive) functioning deficits were present in the unaffected relatives, were moderately heritable and shared a substantial genetic overlap with liability to schizophrenia. These results suggest that the well recognized prefrontal volume reductions are not related to the same familial influences that increase schizophrenia liability and instead may be attributable to illness related biological changes or indeed confounded by illness trajectory, chronicity, medication or substance abuse, or in fact a combination of some or all of them.
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Affiliation(s)
- Sheena F Owens
- Department of Psychosis Studies, Institute of Psychiatry, Kings College, London, UK.
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14
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Batouli SAH, Sachdev PS, Wen W, Wright MJ, Suo C, Ames D, Trollor JN. The heritability of brain metabolites on proton magnetic resonance spectroscopy in older individuals. Neuroimage 2012; 62:281-9. [PMID: 22561359 DOI: 10.1016/j.neuroimage.2012.04.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 04/18/2012] [Accepted: 04/22/2012] [Indexed: 11/16/2022] Open
Abstract
Twin studies have shown that many aspects of brain structure are heritable, suggesting a strong genetic contribution to brain structure. Less is known about functional aspects of the brain, in particular biologically relevant metabolites in the brain such as those measured by proton magnetic resonance spectroscopy (((1))H MRS), N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho) and myoinositol (ml), which have been suggested as possible markers of brain aging and early dementia. We examined 296 (56 male/108 female monozygotic and 43 male/89 female dizygotic) older twins (mean age 72.2 ± 5.5 years, range 65-88), for the levels of these metabolites relative to the H(2)O signal in the posterior cingulate cortex using ((1))H MRS. All metabolites showed substantial heritability, which was greatest for the neuronal integrity marker NAA (72%), and less so for the others - Cr (51%), Cho (33%) and ml (55%). The heritability of these markers did not change significantly with age or sex. The genetic determination of NAA, along with the evidence that NAA levels change in aging and neurodegenerative diseases suggest that it is a potential endophenotype of brain aging and dementia.
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Affiliation(s)
- Seyed Amir Hossein Batouli
- School of Psychiatry, University of New South Wales, 22-32 King Street, Building R1F, Randwick Campus, UNSW, Randwick, 2052, Sydney, Australia.
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15
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Watson DR, Anderson JM, Bai F, Barrett SL, McGinnity TM, Mulholland CC, Rushe TM, Cooper SJ. A voxel based morphometry study investigating brain structural changes in first episode psychosis. Behav Brain Res 2012; 227:91-9. [DOI: 10.1016/j.bbr.2011.10.034] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 10/19/2011] [Accepted: 10/21/2011] [Indexed: 01/04/2023]
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Abstract
The results of imaging studies have played an important role in the formulation of hypotheses regarding the etiology of psychosis and schizophrenia, as well as in our understanding of the mechanisms of action of antipsychotics. Since this volume is primarily directed to molecular aspects of psychosis and antipsychotics, only the results of molecular imaging techniques addressing these topics will be discussed here.One of the most consistent findings of molecular imaging studies in schizophrenia is an increased uptake of DOPA in the striatum, which may be interpreted as an increased synthesis of L-DOPA. Also, several studies reported an increased release of dopamine induced by amphetamine in schizophrenia patients. These findings played an important role in reformulating the dopamine hypothesis of schizophrenia. To study the roles of the neurotransmitters γ-aminobutyric acid (GABA) and glutamate in schizophrenia, SPECT as well as MR spectroscopy have been used. The results of preliminary SPECT studies are consistent with the hypothesis of NMDA receptor dysfunction in schizophrenia. Regarding the GABA deficit hypothesis of schizophrenia, imaging results are inconsistent. No changes in serotonin transporters were demonstrated in imaging studies in schizophrenia, but studies of several serotonin receptors showed conflicting results. The lack of selective radiotracers for muscarinic receptors may have hampered examination of this system in schizophrenia as well as its role in the induction of side effects of antipsychotics. Interestingly, preliminary molecular imaging studies on the cannabinoid-1 receptor and on neuroinflammatory processes in schizophrenia have recently been published. Finally, a substantial number of PET/SPECT studies have examined the occupancy of receptors by antipsychotics and an increasing number of studies is now focusing on the effects of these drugs using techniques like spectroscopy and pharmacological MRI.
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Wood SJ, Yücel M, Yung AR, Berger GE, Velakoulis D, Pantelis C. The transition to psychosis: risk factors and brain changes. ACTA ACUST UNITED AC 2011; 13:137-40. [PMID: 15529818 DOI: 10.1017/s1121189x00003390] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Capizzano AA, Toscano JLN, Ho BC. Magnetic resonance spectroscopy of limbic structures displays metabolite differences in young unaffected relatives of schizophrenia probands. Schizophr Res 2011; 131:4-10. [PMID: 21705196 PMCID: PMC3485075 DOI: 10.1016/j.schres.2011.05.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 05/19/2011] [Accepted: 05/23/2011] [Indexed: 01/25/2023]
Abstract
Imaging studies of schizophrenia patients showed fronto-temporal brain volume deficits, while magnetic resonance spectroscopy (MRS) studies of patients and unaffected biological relatives have found a decrement of the neuronal marker N-acetyl-aspartate (NAA) in the hippocampus and frontal lobes, and increased choline-containing phospholipids. Using a 3T MR scanner, we determined the metabolite profile within limbic regions (anterior cingulate cortex (ACC) and left hippocampus) of 36 unaffected, adolescent/young adult relatives of schizophrenia probands (first-degree=16, second-degree=20) and 25 healthy controls with no family history of schizophrenia. Significant main effects of group were found on NAA/Cho ratios for both the left hippocampus (F = 6.11, p ≤ 0.02) and ACC (F = 4.89, p ≤ 0.03) as well as for the left hippocampus Cho/Cr ratio (F = 5.55, p ≤ 0.02). Compared to age and sex matched healthy controls without a family history of schizophrenia, first-degree relatives of probands had greater MRS metabolite deviations than second-degree relatives. Greater familial proximity to the schizophrenia proband (or higher schizophrenia susceptibility) among biological relatives was associated with stepwise lowering of NAA/Cho and elevations in Cho/Cr ratios. The observed limbic metabolite changes among young, nonpsychotic biological relatives are likely related to shared genetic vulnerability factors, and may assist in the early identification of schizophrenia for primary and secondary prevention.
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Affiliation(s)
- Aristides A. Capizzano
- Department of Radiology, Division of Neuroradiology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA
,Corresponding author. Tel.: +1 319 384 8795; fax: +1 319 353 6275. (A.A. Capizzano), (J.L. Nicoll Toscano), (B.-C. Ho)
| | - Juana L. Nicoll Toscano
- Department of Family Medicine, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA
| | - Beng-Choon Ho
- Department of Psychiatry, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA
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Keshavan MS, DeLisi LE, Seidman LJ. Early and broadly defined psychosis risk mental states. Schizophr Res 2011; 126:1-10. [PMID: 21123033 PMCID: PMC3388534 DOI: 10.1016/j.schres.2010.10.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 09/29/2010] [Accepted: 10/04/2010] [Indexed: 11/28/2022]
Abstract
Current definitions of the prodromal (or at-risk mental state) phase of schizophrenia include attenuated and/or transient psychotic symptoms as well as a combination of different risk indicators and a recent significant deterioration in global functioning. Data accumulated to date suggest rates of conversion to frank psychosis within two years in 25 to 40% of cases supporting the validity of these criteria. However, at this late phase of illness, functional deterioration is often already pronounced, highlighting the need for earlier identification. Moreover, negative symptoms and social impairments, cognitive deficits, other non-psychotic psychopathology and/or functional decline and non-specific biological indicators, often can be detected well before the at-risk mental state as currently defined; indicating that a broad characterization of an earlier stage may be possible. Identifying specific criteria to define this group of individuals, starting from the framework of familial high-risk, can help define a broader group of people, including earlier at-risk mental states, for future research. The hope is that this research will help facilitate intervention at earlier stages that may in turn minimize functional deterioration, and delay, attenuate or even prevent transition to psychosis. The disadvantages as well as the potential benefits of this approach are discussed.
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Affiliation(s)
- Matcheri S. Keshavan
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center; Harvard Medical School, Boston, MA, USA,Correspondence: Matcheri S. Keshavan, MD, Beth Israel Deaconess Medical Center, Department of Psychiatry, Massachusetts Mental Health Center 401 Park Drive, Room 2P12 The Landmark Center Boston, MA 02215 USA
| | - Lynn E. DeLisi
- Department of Psychiatry, VA Boston Healthcare System, Brockton, Mass; Visiting Professor, Harvard Medical School, Boston, MA, USA
| | - Larry J. Seidman
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Massachusetts Mental Health Center; Harvard Medical School, Boston, MA, USA
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Brugger S, Davis JM, Leucht S, Stone JM. Proton magnetic resonance spectroscopy and illness stage in schizophrenia--a systematic review and meta-analysis. Biol Psychiatry 2011; 69:495-503. [PMID: 21145039 DOI: 10.1016/j.biopsych.2010.10.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 09/14/2010] [Accepted: 10/05/2010] [Indexed: 01/12/2023]
Abstract
BACKGROUND It is not known whether regional brain N-acetyl aspartate (NAA) changes in the progression from prodrome to chronic schizophrenia. We used effect size meta-analysis to determine which brain regions show the most robust reductions in NAA first episode and chronic schizophrenia as measured by proton magnetic resonance spectroscopy and to determine whether these changes are present in individuals at high risk of developing schizophrenia. METHODS We identified 131 articles, of which 97 met inclusion criteria. Data were separated by stage of illness (at risk, first episode schizophrenia, chronic schizophrenia) and by brain region. For each region, mean and SD of the NAA measure was extracted. RESULTS Significant reductions in NAA levels were found in frontal lobe, temporal lobe, and thalamus in both patient groups (effect size > .3; p < .01). In individuals at high risk of schizophrenia (of whom approximately 20% would be expected to undergo transition to psychosis), significant NAA reductions were present in thalamus (effect size = .78; p < .05), with reductions at trend level only in temporal lobe (effect size = .32; p < .1), and no reductions in frontal lobe (effect size = .05; p = .5). CONCLUSIONS These data suggest that schizophrenia is associated with loss of neuronal integrity in frontal and temporal cortices and in the thalamus and suggest that these changes in the frontal and temporal lobe might occur in the transition between the at-risk phase and the first episode.
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Affiliation(s)
- Stefan Brugger
- Institute of Psychiatry, King's College London, London, United Kingdom
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Rimol LM, Hartberg CB, Nesvåg R, Fennema-Notestine C, Hagler DJ, Pung CJ, Jennings RG, Haukvik UK, Lange E, Nakstad PH, Melle I, Andreassen OA, Dale AM, Agartz I. Cortical thickness and subcortical volumes in schizophrenia and bipolar disorder. Biol Psychiatry 2010; 68:41-50. [PMID: 20609836 DOI: 10.1016/j.biopsych.2010.03.036] [Citation(s) in RCA: 353] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 03/05/2010] [Accepted: 03/25/2010] [Indexed: 01/12/2023]
Abstract
BACKGROUND Schizophrenia and bipolar disorder are severe psychiatric diseases with overlapping symptomatology. Widespread brain morphologic abnormalities, including cortical thinning and subcortical volume reductions, have been demonstrated in schizophrenia but it is unclear whether similar abnormalities are present in bipolar disorder. The purpose of this study was to compare cortical thickness and subcortical volumes in schizophrenia and bipolar disorder, to assess differences and similarities in cortical and subcortical brain structure. METHODS We analyzed magnetic resonance images from a sample of 173 patients with schizophrenia spectrum disorder, 139 patients with bipolar disorder, and 207 healthy control subjects. Cortical thickness was compared between the groups in multiple locations across the continuous cortical surface. Subcortical volumes were compared on a structure-by-structure basis. RESULTS There was widespread cortical thinning in schizophrenia compared with control subjects, in frontal, temporal, occipital, and smaller parietal regions. There was no cortical thinning in bipolar disorder compared with control subjects or in schizophrenia compared with bipolar disorder. However, the subgroup of patients with bipolar disorder Type 1 showed cortical thinning, primarily in the frontal lobes and superior temporal and temporoparietal regions. Both patient groups showed substantial subcortical volume reductions bilaterally in the hippocampus, the left thalamus, the right nucleus accumbens, the left cerebellar cortex, and the brainstem, along with substantial ventricular enlargements. CONCLUSIONS We found substantial overlap in the underlying brain morphologic abnormalities in schizophrenia and bipolar disorder in subcortical structures, and between schizophrenia and bipolar disorder Type 1 in the cerebral cortex.
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Affiliation(s)
- Lars M Rimol
- Department of Psychiatry, Section Vinderen, University of Oslo, Oslo, Norway.
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Lutkenhoff ES, van Erp TG, Thomas MA, Therman S, Manninen M, Huttunen MO, Kaprio J, Lönnqvist J, O'Neill J, Cannon TD. Proton MRS in twin pairs discordant for schizophrenia. Mol Psychiatry 2010; 15:308-18. [PMID: 18645571 DOI: 10.1038/mp.2008.87] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Proton magnetic resonance spectroscopy ((1)H MRS) neurometabolite abnormalities have been detected widely in subjects with and at risk for schizophrenia. We hypothesized that such abnormalities would be present both in patients with schizophrenia and in their unaffected twin siblings. We acquired magnetic resonance spectra (TR/TE=3000/30 ms) at voxels in the mesial prefrontal gray matter, left prefrontal white matter and left hippocampus in 14 twin pairs discordant for schizophrenia (2 monozygotic, 12 dizygotic), 13 healthy twin pairs (4 monozygotic, 9 dizygotic) and 1 additional unaffected co-twin of a schizophrenia proband. In the mesial prefrontal gray matter voxel, N-acetylaspartate (NAA), creatine+phosphocreatine (Cr), glycerophosphocholine+phosphocholine (Cho) and myo-inositol (mI) did not differ significantly between patients with schizophrenia, their unaffected co-twins or healthy controls. However, glutamate (Glu) was significantly lower in patients with schizophrenia (31%, percent difference) and unaffected co-twins (21%) than in healthy controls (collapsed across twin pairs). In the left hippocampus voxel, levels of NAA (23%), Cr (22%) and Cho (36%) were higher in schizophrenia patients compared with controls. Hippocampal NAA (25%), Cr (22%) and Cho (37%) were also significantly higher in patients than in their unaffected co-twins. Region-to-region differences in metabolite levels were also notable within all three diagnosis groups. These findings suggest that (1)H MRS neurometabolite abnormalities are present not only in patients with schizophrenia, but also in their unaffected co-twins. Thus, reduced mesial prefrontal cortical Glu and elevated hippocampal NAA, Cr and Cho may represent trait markers of schizophrenia risk and, when exacerbated, state markers of schizophrenia itself.
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Affiliation(s)
- E S Lutkenhoff
- Department of Neuroscience IDP, UCLA, Los Angeles, CA, USA.
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Marenco S, Radulescu E. Imaging genetics of structural brain connectivity and neural integrity markers. Neuroimage 2009; 53:848-56. [PMID: 19932755 DOI: 10.1016/j.neuroimage.2009.11.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/12/2009] [Accepted: 11/13/2009] [Indexed: 01/15/2023] Open
Abstract
We review studies that have used diffusion imaging (DI) and magnetic resonance spectroscopy (MRS) to investigate genetic associations. A brief description of the measures obtainable with these methods and of some methodological and interpretability limitations is given. The usefulness of DI and MRS in defining intermediate phenotypes and in demonstrating the effects of common genetic variants known to increase risk for psychiatric manifestations on anatomical and metabolic phenotypes is reviewed. The main focus is on schizophrenia where the greatest amount of data has been collected. Moreover, we present an example coming from a different approach, where the genetic alteration is known (the deletion that causes Williams syndrome) and the DI phenotype can shed new light on the function of genes affected by the mutation. We conclude that, although these are still early days of this type of research and many findings remain controversial, both techniques can significantly contribute to the understanding of genetic effects in the brain and the pathophysiology of psychiatric disorders.
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Affiliation(s)
- Stefano Marenco
- Unit for Multimodal Imaging Genetics, Clinical Brain Disorders Branch, GCAP, IRP, NIMH, 10 Center Drive, Building 10, Room 3C103, Bethesda, MD 20892, USA.
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Rutter L, Carver FW, Holroyd T, Nadar SR, Mitchell‐Francis J, Apud J, Weinberger DR, Coppola R. Magnetoencephalographic gamma power reduction in patients with schizophrenia during resting condition. Hum Brain Mapp 2009; 30:3254-64. [PMID: 19288463 PMCID: PMC2748144 DOI: 10.1002/hbm.20746] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE The "default network" represents a baseline condition of brain function and is of interest in schizophrenia research because its component brain regions are believed to be aberrant in the disorder. We hypothesized that magnetoencephalographic (MEG) source localization analysis would reveal abnormal resting activity within particular frequency bands in schizophrenia. EXPERIMENTAL DESIGN Eyes-closed resting state MEG signals were collected for two comparison groups. Patients with schizophrenia (N = 38) were age-gender matched with healthy control subjects (N = 38), and with a group of unmedicated unaffected siblings of patients with schizophrenia (N = 38). To localize 3D-brain regional differences, synthetic aperture magnetometry was calculated across established frequency bands as follows: delta (0.9-4 Hz), theta (4-8 Hz), alpha (8-14 Hz), beta (14-30 Hz), gamma (30-80 Hz), and super-gamma (80-150 Hz). PRINCIPLE OBSERVATIONS: Patients with schizophrenia showed significantly reduced activation in the gamma frequency band in the posterior region of the medial parietal cortex. As a group, unaffected siblings of schizophrenia patients also showed significantly reduced activation in the gamma bandwidth across similar brain regions. Moreover, using the significant region for the patients and examining the gamma band power gave an odds ratio of 6:1 for reductions of two standard deviations from the mean. This suggests that the measure might be the basis of an intermediate phenotype. CONCLUSIONS MEG resting state analysis adds to the evidence that schizophrenic patients experience this condition very differently than healthy controls. Whether this baseline difference relates to network abnormalities remains to be seen.
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Affiliation(s)
- Lindsay Rutter
- MEG Core Facility, National Institute of Mental Health, Bethesda, Maryland
| | | | - Tom Holroyd
- MEG Core Facility, National Institute of Mental Health, Bethesda, Maryland
| | | | | | - Jose Apud
- Clinical Brain Disorders Branch, NIMH, Bethesda, Maryland
| | | | - Richard Coppola
- MEG Core Facility, National Institute of Mental Health, Bethesda, Maryland
- Clinical Brain Disorders Branch, NIMH, Bethesda, Maryland
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Yoo SY, Yeon S, Choi CH, Kang DH, Lee JM, Shin NY, Jung WH, Choi JS, Jang DP, Kwon JS. Proton magnetic resonance spectroscopy in subjects with high genetic risk of schizophrenia: investigation of anterior cingulate, dorsolateral prefrontal cortex and thalamus. Schizophr Res 2009; 111:86-93. [PMID: 19406622 DOI: 10.1016/j.schres.2009.03.036] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2008] [Revised: 03/21/2009] [Accepted: 03/21/2009] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Reduced N-acetylaspartate levels in regions of the frontal cortex, including the anterior cingulate cortex, dorsolateral prefrontal cortex, and thalamus, involved in the pathophysiology of schizophrenia suggest that brain metabolite abnormalities may be a marker of genetic vulnerability to schizophrenia. We used proton magnetic resonance spectroscopy (H-MRS) to acquire absolute concentrations of brain metabolites in subjects with a high genetic risk of schizophrenia to investigate the potential relationship between unexpressed genetic liability to schizophrenia and neuronal dysfunction. METHOD Included in the study were 22 subjects who had at least two relatives with schizophrenia (high genetic risk group) and 22 controls with no second-degree relatives with schizophrenia. Absolute concentrations of N-acetylaspartate, creatine, choline, glutamate/glutamine, and myo-inositol and the ratios of metabolites in the anterior cingulate cortex, left dorsolateral prefrontal cortex, and left thalamus were measured using H-MRS at 1.5 Tesla. RESULTS Relative to the controls, the high genetic risk group showed significant differences in absolute metabolite levels in the spectra of the regions of the left thalamus, including significant decreases in N-acetylaspartate, creatine, and choline concentrations. CONCLUSIONS The study points to neuronal dysfunction, and in particular thalamic dysfunction, as a key region of the vulnerability marker of schizophrenia. Further studies should examine the nature of the thalamus more intensively to further our understanding of thalamic dysfunction as a vulnerability marker.
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Affiliation(s)
- So Young Yoo
- Department of Psychiatry, Seoul National University College of Medicine, Seoul, Republic of Korea
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26
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Goldman AL, Pezawas L, Mattay VS, Fischl B, Verchinski BA, Chen Q, Weinberger DR, Meyer-Lindenberg A. Widespread reductions of cortical thickness in schizophrenia and spectrum disorders and evidence of heritability. ACTA ACUST UNITED AC 2009; 66:467-77. [PMID: 19414706 DOI: 10.1001/archgenpsychiatry.2009.24] [Citation(s) in RCA: 214] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CONTEXT Schizophrenia is a brain disorder with predominantly genetic risk factors, and previous research has identified heritable cortical and subcortical reductions in local brain volume. To our knowledge, cortical thickness, a measure of particular interest in schizophrenia, has not previously been evaluated in terms of its heritability in relationship to risk for schizophrenia. OBJECTIVE To quantify the distribution and heritability of cortical thickness changes in schizophrenia. DESIGN We analyzed a large sample of normal controls, affected patients, and unaffected siblings using a surface-based approach. Cortical thickness was compared between diagnosis groups on a surfacewide node-by-node basis. Heritability related to disease risk was assessed in regions derived from an automated cortical parcellation algorithm by calculating the Risch lambda. SETTING Research hospital. PARTICIPANTS One hundred ninety-six normal controls, 115 affected patients with schizophrenia, and 192 unaffected siblings. MAIN OUTCOME MEASURE Regional cortical thickness. RESULTS Node-by-node mapping statistics revealed widespread thickness reductions in the patient group, most pronouncedly in the frontal lobe and temporal cortex. Unaffected siblings did not significantly differ from normal controls at the chosen conservative threshold. Risch lambda analysis revealed widespread evidence for heritability for cortical thickness reductions throughout the brain. CONCLUSIONS To our knowledge, the present study provides the first evidence of broadly distributed and heritable reductions of cortical thickness alterations in schizophrenia. However, since only trend-level reductions of thickness were observed in siblings, cortical thickness per se (at least as measured by this approach) is not a strong intermediate phenotype for schizophrenia.
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Affiliation(s)
- Aaron L Goldman
- Neuroimaging Core Facility, Genes, Cognition, and Psychosis Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
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27
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Sanches R, Crippa J, Hallak J, de Sousa J, Araújo D, Santos A, Zuardi A. Proton magnetic resonance spectroscopy of the frontal, cingulate and perirolandic cortices and its relationship to skin conductance in patients with schizophrenia. Braz J Med Biol Res 2008; 41:1132-41. [DOI: 10.1590/s0100-879x2008001200015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Accepted: 12/04/2008] [Indexed: 11/21/2022] Open
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Impact of the brain-derived neurotrophic factor Val66Met polymorphism on levels of hippocampal N-acetyl-aspartate assessed by magnetic resonance spectroscopic imaging at 3 Tesla. Biol Psychiatry 2008; 64:856-62. [PMID: 18707679 PMCID: PMC2586327 DOI: 10.1016/j.biopsych.2008.07.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 06/19/2008] [Accepted: 07/07/2008] [Indexed: 02/08/2023]
Abstract
BACKGROUND This study was conducted to corroborate prior evidence of an effect of the brain-derived neurotrophic factor (BDNF) valine (val) to methionine (met) amino acid substitution at codon 66 (val66met) polymorphism on measures of N-acetyl-aspartate (NAA) containing compounds in healthy subjects. METHODS The NAA to creatine (Cre) ratio (NAA/Cre), NAA to choline (Cho) ratio (NAA/Cho), and Cho to Cre ratio (Cho/Cre) were measured in the left and right hippocampi, left and right dorsolateral prefrontal cortices, occipital lobe, anterior cingulate, and white matter of the centrum semiovale of 69 carefully screened healthy volunteers utilizing proton magnetic resonance spectroscopic imaging (MRSI) at 3 Tesla (T). RESULTS Val/met subjects exhibited significantly reduced levels of left hippocampal NAA/Cre and NAA/Cho compared with val/val subjects. This effect was independent of age, IQ, number of voxels, hippocampal volume, or gray matter content in the voxels of interest. Analysis of other brain regions showed no effect of BDNF genotype on NAA measures. CONCLUSIONS We confirmed the association between the met-BDNF variant and reduced levels of hippocampal NAA found with a similar technique at 1.5T. The consonance of our results with prior findings adds to the evidence that the BDNF val/met genotype affects hippocampal biology with implications for a variety of neuropsychiatric disorders.
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Goldman AL, Pezawas L, Mattay VS, Fischl B, Verchinski BA, Zoltick B, Weinberger DR, Meyer-Lindenberg A. Heritability of brain morphology related to schizophrenia: a large-scale automated magnetic resonance imaging segmentation study. Biol Psychiatry 2008; 63:475-83. [PMID: 17727823 DOI: 10.1016/j.biopsych.2007.06.006] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 05/08/2007] [Accepted: 06/06/2007] [Indexed: 11/17/2022]
Abstract
BACKGROUND Schizophrenia is a devastating psychiatric disorder with a strong genetic component that has been related to a number of structural brain alterations. Currently available data on the heritability of these structural changes are inconsistent. METHODS To examine heritability of morphological alterations in a large sample, we used a novel and validated fully-automated whole brain segmentation technique to study disease-related variability and heritability in anatomically defined regions of interest in 221 healthy control subjects, 169 patients with schizophrenia, and 183 unaffected siblings. RESULTS Compared with healthy control subjects, patients showed a bilateral decrease in hippocampal and cortical gray matter volume and increases in bilateral dorsal striatum and right lateral ventricle. No significant volumetric differences were found in unaffected siblings compared with normal control subjects in any structure. Post hoc analysis of the dorsal striatum showed the volumetric increase to be widespread, including caudate, putamen, and globus pallidus. With Risch's lambda (lambda(s)), we found strong evidence for heritability of reduced cortical volume and moderate evidence for hippocampal volume, whereas abnormal striatal and ventricle volumes showed no sign of heritability. Additional exploratory analyses were performed on amygdala, thalamus, nucleus accumbens, ventral diencephalon, and cerebral and cerebellar cortex and white matter. Of these regions, patients showed increased volume in ventral diencephalon and cerebellum. CONCLUSIONS These findings support evidence of genetic control of brain volume even in adults, particularly of hippocampal and neocortical volume and of cortical volumetric reductions being familial, but do not support measures of subcortical volumes per se as representing intermediate biologic phenotypes.
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Affiliation(s)
- Aaron L Goldman
- Neuroimaging Core Facility, Genes, Cognition and Psychosis Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
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30
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Honea RA, Meyer-Lindenberg A, Hobbs KB, Pezawas L, Mattay VS, Egan MF, Verchinski B, Passingham RE, Weinberger DR, Callicott JH. Is gray matter volume an intermediate phenotype for schizophrenia? A voxel-based morphometry study of patients with schizophrenia and their healthy siblings. Biol Psychiatry 2008; 63:465-74. [PMID: 17689500 PMCID: PMC2390785 DOI: 10.1016/j.biopsych.2007.05.027] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 04/30/2007] [Accepted: 05/22/2007] [Indexed: 02/06/2023]
Abstract
BACKGROUND Shared neuropathological characteristics of patients with schizophrenia and their siblings might represent intermediate phenotypes that could be used to investigate genetic susceptibility to the illness. We sought to discover previously unidentified gray matter volume differences in patients with schizophrenia and their siblings with optimized voxel-based morphometry. METHODS We studied 169 patients with schizophrenia, 213 of their unaffected siblings, and 212 healthy volunteers from the Clinical Brain Disorders Branch/National Institute of Mental Health Genetic Study of Schizophrenia with magnetic resonance imaging. RESULTS Patients with schizophrenia had significant regional gray matter decreases in the frontal, temporal, and parietal cortices compared with healthy volunteers. Their unaffected siblings tended to share gray matter decreases in the medial frontal, superior temporal, and insular cortices, but these decreases were not significant after correction for multiple comparisons, even when we looked at a subgroup of siblings with a past history of mood disorder. As an exploratory analysis, we estimated heritability with regions of interest from the VBM analysis as well as from the hippocampus. Hippocampal volume was significantly correlated within sibling-pairs. CONCLUSIONS Our findings confirm and extend previous voxel-based morphometry analyses in ill subjects with schizophrenia. Furthermore, these data argue that although siblings might share some regional gray matter decreases with their affected siblings, the pattern of regional differences might be a weak intermediate phenotype for schizophrenia.
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Affiliation(s)
- Robyn A Honea
- Genes, Cognition and Psychosis Program, National Institute of Mental Health, Division of Intramural Research, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892-1364, USA
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31
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Purdon SE, Valiakalayil A, Hanstock CC, Seres P, Tibbo P. Elevated 3T proton MRS glutamate levels associated with poor Continuous Performance Test (CPT-0X) scores and genetic risk for schizophrenia. Schizophr Res 2008; 99:218-24. [PMID: 18248960 DOI: 10.1016/j.schres.2007.11.028] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 11/05/2007] [Accepted: 11/13/2007] [Indexed: 11/15/2022]
Abstract
Glutamate was quantified by proton magnetic resonance spectroscopy ((1)H-MRS) in the medial frontal lobes of 15 adult siblings of individuals with schizophrenia (HR) and 14 healthy volunteers (HV), all of whom also completed a Continuous Performance Test (CPT). Subjects were free of psychopathology but the HR group showed greater variability in glutamate levels. After median stratification, the high glutamate group contained a larger proportion of HR than HV subjects and scored lower on the CPT. Elevated glutamate may relate to poor sustained attention and elevated risk of schizophrenia, suggesting a potential role for glutamate in an endophenotype for schizophrenia.
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Affiliation(s)
- Scot E Purdon
- Bebensee Schizophrenia Research Unit, Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada.
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Hong CJ, Liou YJ, Liao DL, Hou SJ, Yen FC, Tsai SJ. Association study of polymorphisms in the mitochondrial aspartate/glutamate carrier SLC25A12 (aralar) gene with schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2007; 31:1510-3. [PMID: 17693006 DOI: 10.1016/j.pnpbp.2007.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 06/18/2007] [Accepted: 07/09/2007] [Indexed: 11/16/2022]
Abstract
Aralar is a mitochondrial calcium-regulated aspartate-glutamate carrier mainly distributed in brain and skeletal muscle, and involved in the transport of aspartate from mitochondria to the cytosol of a cell. Studies have shown that the brain N-acetyl aspartate (NAA) levels are greatly decreased in aralar-deficient mice, suggesting that aralar plays an important role in the synthesis of NAA in neuronal cells. Since magnetic resonance spectroscopy studies have revealed consistently reduced NAA levels in various brain regions of schizophrenic patients and their unaffected relatives, genes that affect aralar levels or NAA metabolism in the brain may be implicated in the pathogenesis of schizophrenia. Aralar is encoded by the SLC25A12 gene. In the past this gene has been found to be associated with susceptibility to autism; in this study we tested the hypothesis that SLC25A12 genetic variants confer susceptibility to schizophrenia. Six SLC25A12 polymorphisms were studied in a sample population of 253 people with schizophrenia and 216 normal controls. Significant linkage disequilibrium was obtained among the six polymorphisms. However, neither single marker nor haplotype analysis revealed an association between variants at the SLC25A12 locus and schizophrenia, suggesting that it is unlikely that the SLC25A12 polymorphisms investigated play a substantial role in conferring susceptibility to schizophrenia in the Chinese population. Further studies with SLC25A12 variants relating to brain NAA levels in patients with schizophrenia are suggested.
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Affiliation(s)
- Chen-Jee Hong
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan
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Abstract
Individuals with schizophrenia experience a range of cognitive deficits and associated dysfunctions in the neural systems that support cognitive processes. This chapter reviews the literature on disturbances in working memory, executive control, and episodic memory in schizophrenia. Advances in basic cognitive neuroscience are described to help explain the cognitive neuroscience of schizophrenia. For working memory in schizophrenia, evidence is reviewed regarding deficits in the verbal (phonological loop) and nonverbal (visual-spatial scratch pad) buffer systems as well as in the central executive function. In the domain of episodic memory, evidence is reviewed for deficits in recollection versus familiarity processes in episodic memory. Also discussed are conceptual issues and potential confounds relevant to understanding the cognitive neuroscience of schizophrenia, including the role that cognitive deficits play in the developmental course of schizophrenia, relationships to specific symptom domains, behavioral performance confounds, and medication influences on behavioral performance and brain function.
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Affiliation(s)
- Deanna M Barch
- Department of Psychology, Washington University, St. Louis, Missouri 63130, USA.
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Abstract
This review synthesizes our current knowledge on the neurobiology of psychosis from an array of in vivo brain-imaging studies. The evidence base consists of hundreds of studies of patients with schizophrenia and fewer on bipolar disorder but rarely providing direct comparisons between the disorders or integration across methods. Replicated findings in schizophrenia include reduced whole-brain and hippocampal volume as potential vulnerability markers, with further progression at onset; reduced N-acetyl aspartate concentrations in hippocampus and prefrontal cortex; striatal dopamine D(2) receptors upregulation; and alteration in the relation between frontal and temporal activation. These findings are not attributable to medication effects but are of unclear specificity and may apply across the psychosis spectrum. There are consistently replicated associations of psychotic symptoms and cognitive impairment in both structural and functional imaging in schizophrenia but not, as yet, in bipolar disorder. Therefore, it would be premature to dispense with current diagnostic categories because direct comparisons among them are rare, insufficient studies have examined longitudinal changes, and long-term imaging outcome studies in first-episode psychosis have not yet been done. To address these issues and make neuroimaging "clinically relevant," investigators will need to standardize their approaches to data acquisition and analysis, and construct the necessary range of "human brain maps," to implement studies that are sufficiently powered to provide reliable data pertinent to deconstructing psychosis.
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Affiliation(s)
- Raquel E Gur
- Department of Psychiatry, University of Pennsylvania 10 Gates, 3400 Spruce Philadelphia, PA 19104, USA.
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35
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Reimold M, Smolka MN, Schumann G, Zimmer A, Wrase J, Mann K, Hu XZ, Goldman D, Reischl G, Solbach C, Machulla HJ, Bares R, Heinz A. Midbrain serotonin transporter binding potential measured with [11C]DASB is affected by serotonin transporter genotype. J Neural Transm (Vienna) 2007; 114:635-9. [PMID: 17225932 DOI: 10.1007/s00702-006-0609-0] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2006] [Accepted: 11/02/2006] [Indexed: 12/16/2022]
Abstract
BACKGROUND Homozygote carriers of two long (L) alleles of the serotonin transporter (5-HTT) regulatory region displayed in vitro a twofold increase in 5-HTT expression compared with carriers of one or two short (S) alleles. However, in vivo imaging studies yielded contradictory results. Recently, an A > G exchange leading to differential transcriptional activation of 5-HTT mRNA in lymphobalstoid cell lines was discovered in the 5-HTT regulatory region. In vitro and in vivo evidence suggests that [(11)C]DASB, a new 5-HTT ligand offers some advantages over the ligands used in previous studies in measuring 5-HTT density independent of synaptic levels of serotonin. METHOD We assessed 5-HTT binding potential (BP (2)) in the midbrain of 19 healthy subjects with positron emission tomography and [(11)C]DASB. Accounting for the hypothesized functional similarity of L (G) and S in driving 5-HTT transcription, we assessed whether L (A) L (A) homozygotes display increased midbrain BP (2) compared with carriers of at least one S allele. RESULTS BP (2) in the midbrain was significantly increased in L (A) L (A) homozygotes compared with carriers of at least one S allele. Interestingly, the genotype effect on the midbrain was significantly different from that on the thalamus and the amygdala where no group differences were detected. CONCLUSIONS This in vivo study provides further evidence that subjects homozygous for the L (A) allele display increased expression of 5-HTT in the midbrain, the origin of central serotonergic projections.
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Affiliation(s)
- M Reimold
- Department of Nuclear Medicine and PET Center, University of Tübingen, Tübingen, Germany
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36
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Fusar-Poli P, Perez J, Broome M, Borgwardt S, Placentino A, Caverzasi E, Cortesi M, Veggiotti P, Politi P, Barale F, McGuire P. Neurofunctional correlates of vulnerability to psychosis: a systematic review and meta-analysis. Neurosci Biobehav Rev 2007; 31:465-84. [PMID: 17223194 DOI: 10.1016/j.neubiorev.2006.11.006] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 11/16/2006] [Accepted: 11/17/2006] [Indexed: 11/19/2022]
Abstract
An understanding of the neurobiological correlates of vulnerability to psychosis is fundamental to research on schizophrenia. We systematically reviewed data from studies published from 1992 to 2006 on the neurocognitive correlates (as measured by fMRI) of increased vulnerability to psychosis. We also conducted a meta-analysis of abnormalities of activation in the prefrontal cortex (PFC) in high-risk and first episode subjects, and reviewed neuroimaging studies of high-risk subjects that used PET, SPECT and MRS. Twenty-four original fMRI papers were identified, most of which involved tasks that engaged the PFC. In fMRI studies, vulnerability to psychosis was associated with medium to large effect sizes when prefrontal activation was contrasted with that in controls. Relatives of patients affected with psychosis, the co-twins of patients and subjects with an At Risk Mental State (ARMS) appear to share similar neurocognitive abnormalities. Furthermore, these are qualitatively similar but less severe than those observed in the first episode of illness. These abnormalities have mainly been described in the prefrontal and anterior cingulated cortex, the basal ganglia, hippocampus and cerebellum.
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Affiliation(s)
- Paolo Fusar-Poli
- Department of Applied and Psychobehavioural Health Sciences, University of Pavia, Italy.
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37
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Jessen F, Scherk H, Träber F, Theyson S, Berning J, Tepest R, Falkai P, Schild HH, Maier W, Wagner M, Block W. Proton magnetic resonance spectroscopy in subjects at risk for schizophrenia. Schizophr Res 2006; 87:81-8. [PMID: 16842971 DOI: 10.1016/j.schres.2006.06.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 06/07/2006] [Accepted: 06/08/2006] [Indexed: 12/01/2022]
Abstract
We used proton magnetic resonance spectroscopy (1H MRS) to examine biochemical characteristics of the brain tissue in subjects at risk for schizophrenia. Nineteen participants fulfilling research criteria for an early (n=10) or a late (n=9) at-risk syndrome, 21 patients with full disease according to DSM IV and 31 healthy control subjects were included in the study. Single-voxel 1H MRS was performed in the left frontal lobe, the anterior cingulate gyrus and the left superior temporal lobe. Subjects were followed longitudinally to detect conversion to schizophrenia. We observed a significant reduction of the metabolic ratios NAA/Cr and NAA/Cho in the left frontal lobe and of NAA/Cr in the anterior cingulate gyrus in both at-risk groups and in the schizophrenic patients compared with healthy controls. Those at-risk subjects, who converted to schizophrenia within the observation period, had a higher Cho/Cr and a lower NAA/Cho ratio in the anterior cingulate gyrus compared with non-converters. NAA/Cr did not differ between converters and non-converters. Six at-risk subjects were taking antidepressants, two were taking antipsychotics. There was no difference in any metabolic ratio in any region between at-risk subjects with and without medication. We conclude that the reduction of the neuronal marker NAA in the left prefrontal lobe and the anterior cingulate gyrus may represent a vulnerability indicator for schizophrenia in at-risk subjects, while elevated Cho in the anterior cingulate gyrus may be a predictor for conversion from the prodromal state to the full disease.
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Affiliation(s)
- Frank Jessen
- Department of Psychiatry, University of Bonn Sigmund-Freud-Str. 25 53105 Bonn, Germany.
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38
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Brahmbhatt SB, Haut K, Csernansky JG, Barch DM. Neural correlates of verbal and nonverbal working memory deficits in individuals with schizophrenia and their high-risk siblings. Schizophr Res 2006; 87:191-204. [PMID: 16842976 DOI: 10.1016/j.schres.2006.05.019] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 05/12/2006] [Accepted: 05/17/2006] [Indexed: 11/21/2022]
Abstract
Impaired working memory and functional brain activation deficits within prefrontal cortex (PFC) may be associated with vulnerability to schizophrenia. This study compared working memory and PFC activation in individuals with schizophrenia, their unaffected siblings and healthy comparison participants. We administered a "2back" version of the "nback" task. Functional MRI (fMRI) was used to measure brain activity. Nineteen individuals with DSM-IV schizophrenia, 18 of their siblings, and 72 healthy comparison participants underwent fMRI scans while performing word and face "nback" working memory tasks. Repeated trials (items whose prior presentation was not in the correct nback position) allowed us to assess group differences in the ability to code the temporal order of items. Individuals with schizophrenia and their siblings performed worse than controls on repeated lure trials, suggesting an association between schizophrenia and impairments in the coding of temporal order within working memory. Both individuals with schizophrenia and their siblings also demonstrated abnormal brain activation in PFC, such that both groups had hyperactivation in response to word stimuli and hypoactivation in response to face stimuli. These results provide further evidence that individuals with schizophrenia and their siblings are impaired in their ability to encode the temporal order of items within working memory and that disturbances in working memory and PFC activation may be genetic markers of the vulnerability to schizophrenia.
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Affiliation(s)
- Shefali B Brahmbhatt
- Washington University, Department of Psychology, One Brookings Drive, Box 1125, St. Louis, MO 63130, USA.
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39
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Marenco S, Bertolino A, Weinberger DR. In vivo NMR measures of NAA and the neurobiology of schizophrenia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 576:227-40; discussion 361-3. [PMID: 16802716 DOI: 10.1007/0-387-30172-0_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Affiliation(s)
- Stefano Marenco
- Genes, Cognition and Psychosis Program, Division of Intramural Research, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
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40
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Numata S, Ueno S, Iga J, Yamauchi K, Hongwei S, Kinouchi S, Shibuya-Tayoshi S, Tayoshi S, Aki H, Sumitani S, Itakura M, Ohmori T. Interaction between catechol-O-methyltransferase (COMT) Val108/158Met and brain-derived neurotrophic factor (BDNF) Val66Met polymorphisms in age at onset and clinical symptoms in schizophrenia. J Neural Transm (Vienna) 2006; 114:255-9. [PMID: 16897602 DOI: 10.1007/s00702-006-0543-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 06/04/2006] [Indexed: 12/29/2022]
Abstract
Catechol-O-methyltransferase (COMT) gene is one of the candidate genes for schizophrenia because it codes an enzyme that participates in the metabolic inactivation of dopamine and noradrenaline and a limiting factor of dopamine metabolism in the prefrontal cortex. COMT gene lies on chromosome 22q11.2, which has been associated with schizophrenia susceptibility. A single-nucleotide polymorphism of COMT gene at position 108/158 results in an amino acid substitution from valine (val) to methionine (met), which modifies its enzymatic activity and may change the brain morphology and expressional behaviors. On the other hand, brain-derived neurotrophic factor (BDNF) plays a critical role in the development of mesolimbic dopaminergic- related systems. BDNF also contains a functional single-nucleotide polymorphism at codon 66 (Val66Met) of its prodomain and this polymorphism is responsible for schizophrenia susceptibility. In this study, we first investigated the relationship between COMT Val108/158Met polymorphism and age at onset as well as levels of clinical symptoms in 158 of chronic schizophrenia inpatients and then we investigated the gene-by-gene interaction between COMT Val108/158Met polymorphism and BDNF Val66Met polymorphism with age- and sex-matched control subjects (n = 318). We concluded that the COMT Val108/158Met polymorphism was not related to either the onset at age or the levels of clinical symptoms after long-term antipsychotic treatment in schizophrenia.
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Affiliation(s)
- S Numata
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
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41
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Abstract
Recent important advancements in genomic research have opened the way to new strategies for public health management. One of these questions pertains to how individual genetic variation may be associated with individual variability in response to drug treatment. The field of pharmacogenetics may have a profound impact on treatment of complex psychiatric disorders like schizophrenia. However, pharmacogenetic studies in schizophrenia have produced conflicting results. The first studies examined potential associations between clinical response and drug receptor genes. Subsequent studies have tried to use more objective phenotypes still in association with drug receptor genes. More recently, other studies have sought the association between putative causative or modifier genes and intermediate phenotypes. Thus, conflicting results may be at least in part explained by variability and choice of the phenotype, by choice of candidate genes, or by the relatively little knowledge about the neurobiology of this disorder. We propose that choosing intermediate phenotypes that allow in vivo measurement of specific neuronal functions may be of great help in reducing several of the potential confounds intrinsic to clinical measurements. Functional neuroimaging is ideally suited to address several of these potential confounds, and it may represent a powerful strategy to investigate the relationship between behavior, brain function, genes, and individual variability in the response to treatment with antipsychotic drugs in schizophrenia. Preliminary evidence with potential susceptilibity genes such as COMT, DISC1, and GRM3 support these assumptions.
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Affiliation(s)
- Giuseppe Blasi
- />Psychiatric Neuroscience Group, Department of Neurological and Psychiatric Sciences, University of Bari, 70125 Bari, Italy
- />Clinical Brain Disorders Branch, Gene, Cognition and Psychosis Program, National Institute of Mental Health, National Institutes of Health, 20892 Bethesda, MD
| | - Alessandro Bertolino
- />Psychiatric Neuroscience Group, Department of Neurological and Psychiatric Sciences, University of Bari, 70125 Bari, Italy
- />Clinical Brain Disorders Branch, Gene, Cognition and Psychosis Program, National Institute of Mental Health, National Institutes of Health, 20892 Bethesda, MD
- />Department of Neuroradiology, IRCCSS “Casa Sollievo della Sofferenza,”, 71013 San Giovanni Rotondo, Italy
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42
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Preston GA, Weinberger DR. Intermediate phenotypes in schizophrenia: a selective review. DIALOGUES IN CLINICAL NEUROSCIENCE 2005. [PMID: 16262211 PMCID: PMC3181731 DOI: 10.31887/dcns.2005.7.2/gpreston] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Studies aiming to identify susceptibility genes for schizophrenia and other complex psychiatric disorders are faced with the confounds of subjective clinical criteria, commonly occurring phenocopies, significant between-subject variability of candidate traits, and the likelihood of allelic and locus heterogeneity that has been shown to define the genetics of other complex human brain and somatic disorders. Additionally, research aimed at identification of the molecular origins of schizophrenia must also deal with the confounding nature of the human brain. Unlike organs with a few common cellular phenotypes, transcriptomes, and proteomes, individual neurons are often distinct from one another in all of these respects. In this review, we present recent work testing the assumption that studies of genetic susceptibility in complex polygenic disorders such as schizophrenia might be enhanced by the identification of intermediate phenotypes related to more fundamental aspects of brain development and function. Progress in the identification of meaningful intermediate phenotypes in schizophrenia has been made possible by the advent of newer methods in cognitive neuroscience and neuroimaging, and the use of combined multimodal techniques.
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Affiliation(s)
- Gilbert A Preston
- Genes, Cognition and Psychosis Program, Clinical Brain Disorders Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Room 4s235, MSC 1379, 9000 Rockville Pike, Bethesda, MD 20892-1379, USA.
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Steen RG, Hamer RM, Lieberman JA. Measurement of brain metabolites by 1H magnetic resonance spectroscopy in patients with schizophrenia: a systematic review and meta-analysis. Neuropsychopharmacology 2005; 30:1949-62. [PMID: 16123764 DOI: 10.1038/sj.npp.1300850] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A systematic review of the literature identified 64 published English-language papers that used proton (1H) magnetic resonance spectroscopy to measure N-acetylaspartate (NAA) concurrently in healthy controls and in patients with a diagnosis of schizophrenia (SZ). A total of 1209 controls and 1256 patients have been evaluated, with 88% of studies carried out at 1.5 T field strength, and 77% of studies focused on patients with chronic SZ. There is consistent evidence that NAA is reduced in a broad range of tissues in the SZ brain. Broad consensus (> or =10 studies) is emerging that NAA levels are reduced > or =5% in hippocampus and in both cortical gray matter (GM) and white matter (WM) of the frontal lobe. There is no evidence to support a hypothesis that relative NAA levels are reduced to a different degree in frontal lobe GM and WM, nor is there robust evidence of a difference in NAA levels between patients with first-episode and chronic SZ. Study reliability may be a problem, as most studies appear to be underpowered. With simple assumptions about the inherent difference in NAA levels between patients and controls, it can be calculated that a minimum sample size of approximately 39 patients and 39 controls is required for acceptable statistical power. Only three of 64 studies included enough subjects to have 80% power to detect a 10% NAA reduction in patients, and no studies were adequately powered to detect a 5% NAA reduction with 80% power.
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Affiliation(s)
- R Grant Steen
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7160, USA.
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44
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Keshavan MS, Diwadkar VA, Montrose DM, Rajarethinam R, Sweeney JA. Premorbid indicators and risk for schizophrenia: a selective review and update. Schizophr Res 2005; 79:45-57. [PMID: 16139479 DOI: 10.1016/j.schres.2005.07.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Prospective studies of young relatives at risk for schizophrenia (high-risk studies, HR) can shed light on premorbid precursors of schizophrenia. Early HR studies pointed to a wide prevalence of schizophrenia spectrum psychopathology among young relatives at increased genetic risk. Recent studies suggest that young HR relatives have neurobehavioral deficits and structural, physiological, and neurochemical brain abnormalities that may date back to childhood or earlier. In this paper, we provide a selected overview of the lessons and limitations of early "first generation" studies and the beginning insights from recent "second generation" studies. We also provide an interim summary of data from the ongoing studies of young relatives at risk for schizophrenia in Pittsburgh. Collectively, such data may help us to predict the eventual emergence of schizophrenia, and schizophrenia spectrum or non-spectrum psychopathology.
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Affiliation(s)
- Matcheri S Keshavan
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, 4201 St Antoine, Suite 9B, Detroit, MI 48201, USA.
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45
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Abstract
Magnetic resonance spectroscopy is a noninvasive investigative technique for in vivo detection of biochemical changes in neuropsychiatric disorders for which especially proton (1H-MRS) and phosphorus (31P-MRS) magnetic resonance spectroscopy have been used. In this review we explain the principles of MRS and summarize the studies in schizophrenia. A systematic literature review was carried out for 1H-MRS studies investigating schizophrenic patients compared to controls. The inconsistent results in the cited studies may be due to different study population, specific neuroimaging technique, and selected brain regions. Frequent findings are decreased PME and increased PDE concentrations (31P-MRS) linked to altered metabolism of membrane phospholipids and decreased N-acetylaspartate (NAA) or NAA/choline ratio (1H-MRS) linked to neuronal damage in frontal (DLPFC) or temporal regions in patients with schizophrenia. These results contribute to the disturbed frontotemporal-thalamic network assumed in schizophrenia and are supported by additional functional neuroimaging, MRI morphometry, and neuropsychological evaluation. The combination of the described investigative techniques with MRS in follow-up studies may provide more specific clues for understanding the pathogenesis and disease course in schizophrenia.
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Affiliation(s)
- T Wobrock
- Klinik für Psychiatrie und Psychotherapie, Universitätsklinikum des Saarlandes, Homburg/Saar.
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46
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Geuze E, Vermetten E, Bremner JD. MR-based in vivo hippocampal volumetrics: 2. Findings in neuropsychiatric disorders. Mol Psychiatry 2005; 10:160-84. [PMID: 15356639 DOI: 10.1038/sj.mp.4001579] [Citation(s) in RCA: 272] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Magnetic resonance imaging (MRI) has opened a new window to the brain. Measuring hippocampal volume with MRI has provided important information about several neuropsychiatric disorders. We reviewed the literature and selected all English-language, human subject, data-driven papers on hippocampal volumetry, yielding a database of 423 records. Smaller hippocampal volumes have been reported in epilepsy, Alzheimer's disease, dementia, mild cognitive impairment, the aged, traumatic brain injury, cardiac arrest, Parkinson's disease, Huntington's disease, Cushing's disease, herpes simplex encephalitis, Turner's syndrome, Down's syndrome, survivors of low birth weight, schizophrenia, major depression, posttraumatic stress disorder, chronic alcoholism, borderline personality disorder, obsessive-compulsive disorder, and antisocial personality disorder. Significantly larger hippocampal volumes have been correlated with autism and children with fragile X syndrome. Preservation of hippocampal volume has been reported in congenital hyperplasia, children with fetal alcohol syndrome, anorexia nervosa, attention-deficit and hyperactivity disorder, bipolar disorder, and panic disorder. Possible mechanisms of hippocampal volume loss in neuropsychiatric disorders are discussed.
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Affiliation(s)
- E Geuze
- Department of Military Psychiatry, Central Military Hospital, Utrecht, Rudolf Magnus Institute of Neuroscience, Mailbox B.01.2.06, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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47
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Egan MF, Straub RE, Goldberg TE, Yakub I, Callicott JH, Hariri AR, Mattay VS, Bertolino A, Hyde TM, Shannon-Weickert C, Akil M, Crook J, Vakkalanka RK, Balkissoon R, Gibbs RA, Kleinman JE, Weinberger DR. Variation in GRM3 affects cognition, prefrontal glutamate, and risk for schizophrenia. Proc Natl Acad Sci U S A 2004; 101:12604-9. [PMID: 15310849 PMCID: PMC515104 DOI: 10.1073/pnas.0405077101] [Citation(s) in RCA: 304] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
GRM3, a metabotropic glutamate receptor-modulating synaptic glutamate, is a promising schizophrenia candidate gene. In a family-based association study, a common GRM3 haplotype was strongly associated with schizophrenia (P = 0.0001). Within this haplotype, the A allele of single-nucleotide polymorphism (SNP) 4 (hCV11245618) in intron 2 was slightly overtransmitted to probands (P = 0.02). We studied the effects of this SNP on neurobiological traits related to risk for schizophrenia and glutamate neurotransmission. The SNP4 A allele was associated with poorer performance on several cognitive tests of prefrontal and hippocampal function. The physiological basis of this effect was assessed with functional MRI, which showed relatively deleterious activation patterns in both cortical regions in control subjects homozygous for the SNP4 A allele. We next looked at SNP4's effects on two indirect measures of prefrontal glutamate neurotransmission. Prefrontal N-acetylaspartate, an in vivo MRI measure related to synaptic activity and closely correlated with tissue glutamate, was lower in SNP4 AA homozygotes. In postmortem human prefrontal cortex, AA homozygotes had lower mRNA levels of the glial glutamate transporter EAAT2, a protein regulated by GRM3 that critically modulates synaptic glutamate. Effects of SNP4 on prefrontal GRM3 mRNA and protein levels were marginal. Resequencing revealed no missense or splice-site SNPs, suggesting that the intronic SNP4 or related haplotypes may exert subtle regulatory effects on GRM3 transcription. These convergent data point to a specific molecular pathway by which GRM3 genotype alters glutamate neurotransmission, prefrontal and hippocampal physiology and cognition, and thereby increased risk for schizophrenia.
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Affiliation(s)
- Michael F Egan
- Clinical Brain Disorders Branch, Intramural Research Program, National Institute of Mental Health/NIH/DHHS, Building 10, Center Drive, Bethesda, MD 20892, USA
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48
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Diwadkar VA, Prasad KM, Keshavan MS. Approaches for adolescents with an affected family member with schizophrenia. Curr Psychiatry Rep 2004; 6:296-302. [PMID: 15260946 PMCID: PMC3408040 DOI: 10.1007/s11920-004-0080-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Prospective studies of adolescents at risk for schizophrenia (high-risk studies) can shed light on the possible premorbid precursors of schizophrenia. Recent studies have provided evidence of neurobehavioral, brain structural, physiologic, and neurochemical deficits in adolescent nonpsychotic high-risk relatives that may date back to childhood or earlier. These results are collectively providing a critical window into the inter-relationships between genetic predisposition, neurodevelopment, and premorbid indicators of risk in schizophrenia. Convergent approaches are inherently powerful in mutually informing each other in enriching the knowledge of the risk factors that predict the eventual onset of schizophrenia. Defining such reliable predictors of the onset of schizophrenia may provide us with the tools to better understand the etiology and pathophysiology of the illness, and may pave the way for innovative methods of treatment and possibly prevention. The authors review the relevant literature in this promising field of inquiry and summarize recent findings from high-risk studies.
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49
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Blasi G, Bertolino A, Brudaglio F, Sciota D, Altamura M, Antonucci N, Scarabino T, Weinberger DR, Nardini M. Hippocampal neurochemical pathology in patients at first episode of affective psychosis: a proton magnetic resonance spectroscopic imaging study. Psychiatry Res 2004; 131:95-105. [PMID: 15313516 DOI: 10.1016/j.pscychresns.2003.11.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2003] [Revised: 01/19/2004] [Accepted: 03/30/2004] [Indexed: 10/26/2022]
Abstract
While several studies have suggested a relationship between the hippocampus and psychosis in schizophrenia, fewer studies have specifically investigated the presence of psychosis in mood disorders from a neurobiological perspective. Moreover, a limitation of these earlier studies is that the majority of them were performed in chronic patients. The present proton magnetic resonance spectroscopic imaging (1H-MRSI) study assessed neuronal integrity (as assessed with N-acetylaspartate, NAA) in the hippocampus of patients with a first episode of mood disorders with psychotic symptoms. We studied 17 patients and 17 healthy subjects matched for age and sex. Subjects underwent 1H-MRSI, and measures of NAA, choline-containing compounds (CHO), and creatine+phosphocreatine (CRE) in 11 brain regions were obtained, i.e. hippocampus (HIPPO), dorsolateral prefrontal cortex, superior temporal gyrus, inferior frontal gyrus, occipital cortex, anterior and posterior cingulate, centrum semiovale, prefrontal white matter, thalamus and putamen. NAA/CRE ratios in HIPPO of patients were significantly lower than in controls. Sporadic and non-hypothesis-driven results were found in occipital cortex and prefrontal white matter as a main effect of diagnosis, and in superior temporal gyrus as a hemisphere by diagnosis interaction. These results would not survive a Bonferroni correction for the number of ROIs. No correlations were found with the available demographic and clinical data. Therefore, hippocampal neuronal abnormalities are present at the onset of mood disorders with psychotic symptoms. These data suggest that neuronal abnormalities in HIPPO may be associated with psychosis in mood disorders. Since these data were obtained in patients at first episode, they cannot be explained by chronicity of illness or pharmacological treatment.
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Affiliation(s)
- Giuseppe Blasi
- Psychiatric Neuroscience Group, Department of Psychiatric and Neurological Sciences, University of Bari, Piazza Giulio Cesare, 9, 70124, Bari, Italy
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Narr KL, Thompson PM, Szeszko P, Robinson D, Jang S, Woods RP, Kim S, Hayashi KM, Asunction D, Toga AW, Bilder RM. Regional specificity of hippocampal volume reductions in first-episode schizophrenia. Neuroimage 2004; 21:1563-75. [PMID: 15050580 DOI: 10.1016/j.neuroimage.2003.11.011] [Citation(s) in RCA: 208] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Revised: 11/06/2003] [Accepted: 11/07/2003] [Indexed: 11/27/2022] Open
Abstract
Hippocampal volume reductions are widely observed in schizophrenia. Some studies suggest anterior hippocampal regions are more susceptible and associated with frontal lobe dysfunctions, while others implicate posterior regions. Using high-resolution MR images and novel computational image analysis methods, we identified the hippocampal subregions most vulnerable to disease processes in 62 (45 m/17 f) first-episode schizophrenia patients compared to 60 (30 m/30 f) healthy controls, similar in age. The hippocampi were traced on coronal brain slices and hemispheric volumes were compared between diagnostic groups. Regional structural abnormalities were identified by comparing distances, measured from homologous hippocampal surface points to the central core of each individual's hippocampal surface model, between groups in 3D. CSF concentrations were also compared statistically at homologous hippocampal surface points to localize corresponding gray matter reductions. Significant bilateral hippocampal volume reductions were observed in schizophrenia irrespective of brain size corrections. Statistical mapping results, confirmed by permutation testing, showed pronounced left hemisphere shape differences in anterior and midbody CA1 and CA2 regions in patients. Significant CSF increases surrounding the hippocampus were observed in a similar spatial pattern in schizophrenia. Results confirm that hippocampal volume reductions are a robust neuroanatomical correlate of schizophrenia and are present by first episode. Mid- to antero-lateral hippocampal regions show pronounced volume changes and complementary increases in peri-hippocampal CSF, suggesting that these hippocampal regions are more susceptible to disease processes in schizophrenia. Targeting regional hippocampal abnormalities may help dissociate schizophrenia patients from other groups exhibiting global hippocampal volume changes, and better focus systems-level pathophysiological hypotheses.
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Affiliation(s)
- Katherine L Narr
- Laboratory of Neuro Imaging, Department of Neurology, Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1769, USA
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