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Executive functioning in schizophrenia: Unique and shared variance with measures of fluid intelligence. Brain Cogn 2015; 99:57-67. [DOI: 10.1016/j.bandc.2015.07.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/26/2015] [Accepted: 07/30/2015] [Indexed: 01/10/2023]
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Fujihara K, Miwa H, Kakizaki T, Kaneko R, Mikuni M, Tanahira C, Tamamaki N, Yanagawa Y. Glutamate Decarboxylase 67 Deficiency in a Subset of GABAergic Neurons Induces Schizophrenia-Related Phenotypes. Neuropsychopharmacology 2015; 40:2475-86. [PMID: 25904362 PMCID: PMC4538341 DOI: 10.1038/npp.2015.117] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 04/05/2015] [Accepted: 04/07/2015] [Indexed: 02/08/2023]
Abstract
Decreased expression of the GABA synthetic enzyme glutamate decarboxylase 67 (GAD67) in a subset of GABAergic neurons, including parvalbumin (PV)-expressing neurons, has been observed in postmortem brain studies of schizophrenics and in animal models of schizophrenia. However, it is unclear whether and how the perturbations of GAD67-mediated GABA synthesis and signaling contribute to the pathogenesis of schizophrenia. To address this issue, we generated the mice lacking GAD67 primarily in PV neurons and characterized them with focus on schizophrenia-related parameters. We found that heterozygous mutant mice exhibited schizophrenia-related behavioral abnormalities such as deficits in prepulse inhibition, MK-801 sensitivity, and social memory. Furthermore, we observed reduced inhibitory synaptic transmission, altered properties of NMDA receptor-mediated synaptic responses in pyramidal neurons, and increased spine density in hippocampal CA1 apical dendrites, suggesting a possible link between GAD67 deficiency and disturbed glutamatergic excitatory synaptic functions in schizophrenia. Thus, our results indicate that the mice heterozygous for GAD67 deficiency primarily in PV neurons share several neurochemical and behavioral abnormalities with schizophrenia, offering a novel tool for addressing the underlying pathophysiology of schizophrenia.
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Affiliation(s)
- Kazuyuki Fujihara
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan,Department of Psychiatry and Human Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hideki Miwa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan,Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan, Tel: +81 27 220 8044, Fax: +81 27 220 8046, E-mail:
| | - Toshikazu Kakizaki
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan
| | - Ryosuke Kaneko
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan,Institute of Experimental Animal Research, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masahiko Mikuni
- Department of Psychiatry and Human Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Chiyoko Tanahira
- Department of Morphological Neural Science, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Nobuaki Tamamaki
- Department of Morphological Neural Science, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan
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Wang HN, Liu GH, Zhang RG, Xue F, Wu D, Chen YC, Peng Y, Peng ZW, Tan QR. Quetiapine Ameliorates Schizophrenia-Like Behaviors and Protects Myelin Integrity in Cuprizone Intoxicated Mice: The Involvement of Notch Signaling Pathway. Int J Neuropsychopharmacol 2015; 19:pyv088. [PMID: 26232790 PMCID: PMC4772821 DOI: 10.1093/ijnp/pyv088] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 07/28/2015] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND White matter disturbances and myelin impairment are key features of schizophrenia. The antipsychotic drug quetiapine can promote the maturation of oligodendrocytes, but the molecular mechanisms remain largely unknown. METHODS The schizophrenia-like behaviors, degrees of demyelination, and levels of Notch signaling molecules in forebrains of adult male C57BL/6 mice were examined after fed with cuprizone (0.2% wt/wt) in the presence or absence of 10mg/kg/d quetiapine for 6 weeks. These parameters were also observed after the transcranial injection of Notch signaling inhibitor MW167 (1mM) daily during the last week of the treatment period. RESULTS Quetiapine ameliorated the schizophrenia-like behaviors and decreased expression of myelin basic protein and inhibition of Notch signaling molecules, such as Notch1, Hes1, and Hes5, in the forebrain that induced by cuprizone. These beneficial effects of quetiapine were abolished by MW167. CONCLUSIONS The antipsychotic and myelin protective effects of quetiapine are mediated by Notch signaling in a mouse model of cuprizone-induced demyelination associated with schizophrenia-like behaviors. The Notch pathway might therefore be a novel target for the development of antipsychotic drugs.
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Affiliation(s)
| | | | | | | | | | | | | | - Zheng-wu Peng
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, China (Drs Wang, Liu, Zhang, Xue, Wu, Chen, Y. Peng, Z.-w. Peng, and Tan); Air Force General Hospital of PLA, Beijing, China (Dr Y. Peng); Department of Toxicology, Shaanxi Key Lab of Free Radical Biology and Medicine, School of Public Health, Fourth Military Medical University, Xi'an, China (Dr Z-w. Peng).
| | - Qing-rong Tan
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, China (Drs Wang, Liu, Zhang, Xue, Wu, Chen, Y. Peng, Z.-w. Peng, and Tan); Air Force General Hospital of PLA, Beijing, China (Dr Y. Peng); Department of Toxicology, Shaanxi Key Lab of Free Radical Biology and Medicine, School of Public Health, Fourth Military Medical University, Xi'an, China (Dr Z-w. Peng).
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A Potential Contributory Role for Ciliary Dysfunction in the 16p11.2 600 kb BP4-BP5 Pathology. Am J Hum Genet 2015; 96:784-96. [PMID: 25937446 DOI: 10.1016/j.ajhg.2015.04.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 04/02/2015] [Indexed: 12/21/2022] Open
Abstract
The 16p11.2 600 kb copy-number variants (CNVs) are associated with mirror phenotypes on BMI, head circumference, and brain volume and represent frequent genetic lesions in autism spectrum disorders (ASDs) and schizophrenia. Here we interrogated the transcriptome of individuals carrying reciprocal 16p11.2 CNVs. Transcript perturbations correlated with clinical endophenotypes and were enriched for genes associated with ASDs, abnormalities of head size, and ciliopathies. Ciliary gene expression was also perturbed in orthologous mouse models, raising the possibility that ciliary dysfunction contributes to 16p11.2 pathologies. In support of this hypothesis, we found structural ciliary defects in the CA1 hippocampal region of 16p11.2 duplication mice. Moreover, by using an established zebrafish model, we show genetic interaction between KCTD13, a key driver of the mirrored neuroanatomical phenotypes of the 16p11.2 CNV, and ciliopathy-associated genes. Overexpression of BBS7 rescues head size and neuroanatomical defects of kctd13 morphants, whereas suppression or overexpression of CEP290 rescues phenotypes induced by KCTD13 under- or overexpression, respectively. Our data suggest that dysregulation of ciliopathy genes contributes to the clinical phenotypes of these CNVs.
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Abstract
Long-range synchrony between distant brain regions accompanies multiple forms of behavior. This review compares and contrasts the methods by which long-range synchrony is evaluated in both humans and model animals. Three examples of behaviorally relevant long-range synchrony are discussed in detail: gamma-frequency synchrony during visual perception, hippocampal-prefrontal synchrony during working memory, and prefrontal-amygdala synchrony during anxiety. Implications for circuit mechanism, translation, and clinical relevance are discussed.
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Affiliation(s)
- Alexander Z Harris
- Department of Psychiatry, Columbia University, New York, New York 10032; ,
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Snyder HR, Miyake A, Hankin BL. Advancing understanding of executive function impairments and psychopathology: bridging the gap between clinical and cognitive approaches. Front Psychol 2015; 6:328. [PMID: 25859234 PMCID: PMC4374537 DOI: 10.3389/fpsyg.2015.00328] [Citation(s) in RCA: 514] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 03/07/2015] [Indexed: 12/11/2022] Open
Abstract
Executive function (EF) is essential for successfully navigating nearly all of our daily activities. Of critical importance for clinical psychological science, EF impairments are associated with most forms of psychopathology. However, despite the proliferation of research on EF in clinical populations, with notable exceptions clinical and cognitive approaches to EF have remained largely independent, leading to failures to apply theoretical and methodological advances in one field to the other field and hindering progress. First, we review the current state of knowledge of EF impairments associated with psychopathology and limitations to the previous research in light of recent advances in understanding and measuring EF. Next, we offer concrete suggestions for improving EF assessment. Last, we suggest future directions, including integrating modern models of EF with state of the art, hierarchical models of dimensional psychopathology as well as translational implications of EF-informed research on clinical science.
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Affiliation(s)
- Hannah R Snyder
- Department of Psychology, University of Denver, Denver CO, USA
| | - Akira Miyake
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder CO, USA
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The Protective Effects of Areca catechu Extract on Cognition and Social Interaction Deficits in a Cuprizone-Induced Demyelination Model. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:426092. [PMID: 25815032 PMCID: PMC4357051 DOI: 10.1155/2015/426092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/09/2015] [Accepted: 02/10/2015] [Indexed: 01/05/2023]
Abstract
Schizophrenia is a serious psychiatric illness with an unclear cause. One theory is that demyelination of white matter is one of the main pathological factors involved in the development of schizophrenia. The current study evaluated the protective effects of Areca catechu nut extract (ANE) on a cuprizone-induced demyelination mouse model. Two doses of ANE (1% and 2%) were administered orally in the diet for 8 weeks. Animals subjected to demyelination showed impaired spatial memory and less social activity. In addition, mice subjected to demyelination displayed significant myelin damage in cortex and demonstrated a higher expression of NG2 and PDGFRα and AMPK activation. ANE treatment not only significantly enhanced cognitive ability and social activity, but also protected myelin against cuprizone toxicity by promoting oligodendrocyte precursor cell (OPC) differentiation. In addition, ANE treatment demonstrated significant dephosphorylation of AMPKα, indicating a regulatory role for ANE in schizophrenia. This study showed that ANE treatment may enhance cognitive ability and social activity by facilitating OPC differentiation and protecting against myelin damage in cortex. Results also suggest the AMPK signaling pathway may be involved in this process.
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58
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Zhou FC, Hou WM, Wang CY, Ungvari GS, Chiu HFK, Correll CU, Shum DHK, Man D, Liu DT, Xiang YT. Prospective memory performance in non-psychotic first-degree relatives of patients with schizophrenia: a controlled study. PLoS One 2014; 9:e111562. [PMID: 25365028 PMCID: PMC4218767 DOI: 10.1371/journal.pone.0111562] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 10/03/2014] [Indexed: 11/24/2022] Open
Abstract
Objective We aimed at investigating prospective memory and its socio-demographic and neurocognitive correlates in non-psychotic, first-degree relatives (FDRs) of patients with schizophrenia compared to patients with first episode schizophrenia (FES), and healthy controls (HCs). Methods Forty-seven FES patients, 50 non-psychotic FDRs (23 offspring and 27 siblings) of patients with chronic schizophrenia (unrelated to the FES group) and 51 HCs were studied. The Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) was used to measure time-based prospective memory (TBPM) and event-based prospective memory (EBPM) performance. Other cognitive functions (involving respective memory and executive functions) were evaluated with standardized tests. Results After controlling for basic demographic characteristics including age, gender and educational level, there was a significant difference between FDRs, FES and HCs with respect to both TBPM (F(2,142) = 10.4, p<0.001) and EBPM (F(2,142) = 10.8, p<0.001). Multiple linear regression analyses revealed that lower scores of the Hopkins Verbal Learning Test-Revised (HVLT-R) and the STROOP Word-Color Test (SWCT) contributed to TBPM impairment, while lower educational level and higher scores of the Color Trails Test-2 (CTT-2) contributed to EBPM deficit in FDRs. Conclusions FDRs share similar but attenuated prospective memory impairments with schizophrenia patients, suggesting that prospective memory deficits may represent an endophenotype of schizophrenia.
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Affiliation(s)
- Fu-Chun Zhou
- Beijing Key Laboratory of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Wei-Min Hou
- Beijing Daxing Mental Health Center, Beijing, China
| | - Chuan-Yue Wang
- Beijing Key Laboratory of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China
- * E-mail: (C-YW); (Y-TX)
| | - Gabor S. Ungvari
- School of Psychiatry & Clinical Neurosciences, University of Western Australia, Perth, Australia
| | - Helen F. K. Chiu
- Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR, China
| | - Christoph U. Correll
- Division of Psychiatry Research, The Zucker Hillside Hospital, North Shore-Long Island Jewish Health System, Glen Oaks, New York, United States of America
| | - David H. K. Shum
- School of Psychology and Griffith Health Institute, Griffith University, Brisbane, Queensland, Australia
| | - David Man
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Deng-Tang Liu
- Department of Psychiatry, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu-Tao Xiang
- Faculty of Health Sciences, University of Macau, Macao SAR, China
- * E-mail: (C-YW); (Y-TX)
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Luck SJ, McClenon C, Beck VM, Hollingworth A, Leonard CJ, Hahn B, Robinson BM, Gold JM. Hyperfocusing in schizophrenia: Evidence from interactions between working memory and eye movements. JOURNAL OF ABNORMAL PSYCHOLOGY 2014; 123:783-95. [PMID: 25089655 PMCID: PMC4227934 DOI: 10.1037/abn0000003] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent research suggests that processing resources are focused more narrowly but more intensely in people with schizophrenia (PSZ) than in healthy control subjects (HCS), possibly reflecting local cortical circuit abnormalities. This hyperfocusing hypothesis leads to the counterintuitive prediction that, although PSZ cannot store as much information in working memory as HCS, the working memory representations that are present in PSZ may be more intense than those in HCS. To test this hypothesis, we used a task in which participants make a saccadic eye movement to a peripheral target and avoid a parafoveal nontarget while they are holding a color in working memory. Previous research with this task has shown that the parafoveal nontarget is more distracting when it matches the color being held in working memory. This effect should be enhanced in PSZ if their working memory representations are more intense. Consistent with this prediction, we found that the effect of a match between the distractor color and the memory color was larger in PSZ than in HCS. We also observed evidence that PSZ hyperfocused spatially on the region surrounding the fixation point. These results provide further evidence that some aspects of cognitive dysfunction in schizophrenia may be a result of a narrower and more intense focusing of processing resources.
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Affiliation(s)
- Steven J. Luck
- University of California, Davis, Center for Mind & Brain and Department of Psychology, 267 Cousteau Place, Davis, CA 95618, USA
| | - Clara McClenon
- University of California, Davis, Center for Mind & Brain and Department of Psychology, 267 Cousteau Place, Davis, CA 95618, USA
| | - Valerie M. Beck
- University of Iowa, Department of Psychology, 11 Seashore Hall E, Iowa City, IA 52242, USA
- University of California, Davis, Center for Mind & Brain and Department of Psychology, 267 Cousteau Place, Davis, CA 95618, USA
| | - Andrew Hollingworth
- University of Iowa, Department of Psychology, 11 Seashore Hall E, Iowa City, IA 52242, USA
| | - Carly J. Leonard
- University of California, Davis, Center for Mind & Brain and Department of Psychology, 267 Cousteau Place, Davis, CA 95618, USA
| | - Britta Hahn
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228, USA
| | - Benjamin M. Robinson
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228, USA
| | - James M. Gold
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228, USA
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60
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Jiang T, Zhou Y. Brainnetome of schizophrenia: focus on impaired cognitive function. SHANGHAI ARCHIVES OF PSYCHIATRY 2014; 24:3-10. [PMID: 25324595 PMCID: PMC4198886 DOI: 10.3969/j.issn.1002-0829.2012.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Impaired cognitive function, along with positive and negative symptoms, is a core clinical feature of schizophrenia. Earlier studies suggest that impaired cognitive functioning should be assessed from the perspective of brain networks. The recently developed brainnetome approach to evaluating brain networks—an approach that was initially developed by Chinese scientists—provides a new methodology for studying this issue. In this paper we first introduce the concept of brainnetome. We then review recent progress in developing a brainnetome of impaired cognitive function in people with schizophrenia. The models of the relevant brain networks considered were created using data obtained from functional and anatomical brain imaging technologies at different levels of analysis: networks centered on regions of interest, networks related to specific cognitive functions, whole brain networks, and the attributes of brain networks. Finally, we discuss the current challenges and potential new directions for research about brainnetome.
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Affiliation(s)
- Tianzi Jiang
- LIAMA Center for Computational Medicine, National Laboratory of Pattern Recognition, Institute of Automation, The Chinese Academy of Sciences, Beijing, China
| | - Yuan Zhou
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
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Zhou Y, Wang Z, Zuo XN, Zhang H, Wang Y, Jiang T, Liu Z. Hyper-coupling between working memory task-evoked activations and amplitude of spontaneous fluctuations in first-episode schizophrenia. Schizophr Res 2014; 159:80-9. [PMID: 25132644 DOI: 10.1016/j.schres.2014.07.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 04/16/2014] [Accepted: 07/20/2014] [Indexed: 12/15/2022]
Abstract
Working memory (WM) deficit is an important component of impaired cognition in schizophrenia. However, between-studies inconsistencies as to the specific functional substrate imply that inter-individual variability (IIV) in the WM performance is associated with IIV in brain activity in schizophrenia. To examine the neural substrate of this WM IIV, we studied whether the neural mechanisms that underlie individual differences in WM capacity are the same in schizophrenia patients and healthy people. We correlated the IIV of the task-evoked brain activity and task performance during an n-back WM task with the IIV of the moment-to-moment variability in intrinsic resting-state activity, as measured by the amplitude of low-frequency fluctuations (ALFFs) and further compared this relationship between 17 patients with first-episode schizophrenia (FES) and 18 healthy controls. Between-group comparisons of the correlation patterns indicated aberrant ALFF-WM activation correlations and ALFF-WM performance correlations in the FES patients, but no significant changes were detected in any single measurement of these three characteristics. Specifically, we found increased positive ALFF-WM activation correlations in the bilateral lateral prefrontal cortices, posterior parietal cortices and fusiform gyri in the FES patients. We also observed significant increases in positive ALFF-WM performance correlations in the bilateral ventromedial prefrontal cortices in the FES patients. This hyper-coupling between the ALFF and fMRI measures during a WM task may indicate that it was difficult for the patients to detach themselves from one state to transition to another and suggests that the inefficient cortical function in schizophrenia stems from the intrinsic functional architecture of the brain.
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Affiliation(s)
- Yuan Zhou
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zheng Wang
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Xi-Nian Zuo
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huiran Zhang
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Yun Wang
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tianzi Jiang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China; National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhening Liu
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China.
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Fajnerová I, Rodriguez M, Levčík D, Konrádová L, Mikoláš P, Brom C, Stuchlík A, Vlček K, Horáček J. A virtual reality task based on animal research - spatial learning and memory in patients after the first episode of schizophrenia. Front Behav Neurosci 2014; 8:157. [PMID: 24904329 PMCID: PMC4034703 DOI: 10.3389/fnbeh.2014.00157] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 04/16/2014] [Indexed: 11/23/2022] Open
Abstract
Objectives: Cognitive deficit is considered to be a characteristic feature of schizophrenia disorder. A similar cognitive dysfunction was demonstrated in animal models of schizophrenia. However, the poor comparability of methods used to assess cognition in animals and humans could be responsible for low predictive validity of current animal models. In order to assess spatial abilities in schizophrenia and compare our results with the data obtained in animal models, we designed a virtual analog of the Morris water maze (MWM), the virtual Four Goals Navigation (vFGN) task. Methods: Twenty-nine patients after the first psychotic episode with schizophrenia symptoms and a matched group of healthy volunteers performed the vFGN task. They were required to find and remember four hidden goal positions in an enclosed virtual arena. The task consisted of two parts. The Reference memory (RM) session with a stable goal position was designed to test spatial learning. The Delayed-matching-to-place (DMP) session presented a modified working memory protocol designed to test the ability to remember a sequence of three hidden goal positions. Results: Data obtained in the RM session show impaired spatial learning in schizophrenia patients compared to the healthy controls in pointing and navigation accuracy. The DMP session showed impaired spatial memory in schizophrenia during the recall of spatial sequence and a similar deficit in spatial bias in the probe trials. The pointing accuracy and the quadrant preference showed higher sensitivity toward the cognitive deficit than the navigation accuracy. Direct navigation to the goal was affected by sex and age of the tested subjects. The age affected spatial performance only in healthy controls. Conclusions: Despite some limitations of the study, our results correspond well with the previous studies in animal models of schizophrenia and support the decline of spatial cognition in schizophrenia, indicating the usefulness of the vFGN task in comparative research.
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Affiliation(s)
- Iveta Fajnerová
- Prague Psychiatric Center Prague, Czech Republic ; Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic v.v.i. Prague, Czech Republic ; Department of Psychiatry and Medical Psychology, 3rd Faculty of Medicine, Charles University in Prague Prague, Czech Republic
| | | | - David Levčík
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic v.v.i. Prague, Czech Republic
| | | | - Pavol Mikoláš
- Prague Psychiatric Center Prague, Czech Republic ; Department of Psychiatry and Medical Psychology, 3rd Faculty of Medicine, Charles University in Prague Prague, Czech Republic
| | - Cyril Brom
- Department of Software and Computer Science Education, Faculty of Mathematics and Physics, Charles University in Prague Prague, Czech Republic
| | - Aleš Stuchlík
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic v.v.i. Prague, Czech Republic
| | - Kamil Vlček
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic v.v.i. Prague, Czech Republic
| | - Jiří Horáček
- Prague Psychiatric Center Prague, Czech Republic ; Department of Psychiatry and Medical Psychology, 3rd Faculty of Medicine, Charles University in Prague Prague, Czech Republic
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63
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Bates RC, Stith BJ, Stevens KE, Adams CE. Reduced CHRNA7 expression in C3H mice is associated with increases in hippocampal parvalbumin and glutamate decarboxylase-67 (GAD67) as well as altered levels of GABA(A) receptor subunits. Neuroscience 2014; 273:52-64. [PMID: 24836856 DOI: 10.1016/j.neuroscience.2014.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/23/2014] [Accepted: 05/02/2014] [Indexed: 12/14/2022]
Abstract
Decreased expression of CHRNA7, the gene encoding the α7(∗) subtype of nicotinic receptor, may contribute to the cognitive dysfunction observed in schizophrenia by disrupting the inhibitory/excitatory balance in the hippocampus. C3H mice with reduced Chrna7 expression have significant reductions in hippocampal α7(∗) receptor density, deficits in hippocampal auditory gating, increased hippocampal activity as well as significant decreases in hippocampal glutamate decarboxylase-65 (GAD65) and γ-aminobutyric acid-A (GABAA) receptor levels. The current study investigated whether altered Chrna7 expression is associated with changes in the levels of parvalbumin, GAD67 and/or GABAA receptor subunits in the hippocampus from male and female C3H Chrna7 wildtype, C3H Chrna7 heterozygous and C3H Chrna7 knockout (KO) mice using quantitative Western immunoblotting. Reduced Chrna7 expression was associated with significant increases in hippocampal parvalbumin and GAD67 and with complex alterations in GABAA receptor subunits. A decrease in α3 subunit protein was seen in both female C3H Chrna7 Het and KO mice while a decrease in α4 subunit protein was also detected in C3H Chrna7 KO mice with no sex difference. In contrast, an increase in δ subunit protein was observed in C3H Chrna7 Het mice while a decrease in this subunit was observed in C3H Chrna7 KO mice, with δ subunit protein levels being greater in males than in females. Finally, an increase in γ2 subunit protein was found in C3H Chrna7 KO mice with the levels of this subunit again being greater in males than in females. The increases in hippocampal parvalbumin and GAD67 observed in C3H Chrna7 mice are contrary to reports of reductions in these proteins in the postmortem hippocampus from schizophrenic individuals. We hypothesize that the disparate results may occur because of the influence of factors other than CHRNA7 that have been found to be abnormal in schizophrenia.
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Affiliation(s)
- R C Bates
- Medical Research, Veterans Affairs Medical Center, Denver, CO 80220, United States; Department of Psychiatry, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, United States; Department of Integrative Biology, University of Colorado Denver Downtown Denver Campus, Denver, CO 80217, United States
| | - B J Stith
- Department of Integrative Biology, University of Colorado Denver Downtown Denver Campus, Denver, CO 80217, United States
| | - K E Stevens
- Medical Research, Veterans Affairs Medical Center, Denver, CO 80220, United States; Department of Psychiatry, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, United States
| | - C E Adams
- Medical Research, Veterans Affairs Medical Center, Denver, CO 80220, United States; Department of Psychiatry, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, United States.
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Mayer JS, Kim J, Park S. Failure to benefit from target novelty during encoding contributes to working memory deficits in schizophrenia. Cogn Neuropsychiatry 2014; 19:268-79. [PMID: 24215367 PMCID: PMC3945723 DOI: 10.1080/13546805.2013.854199] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
INTRODUCTION Although working memory (WM) impairments are well documented in schizophrenic patients (PSZ), the underlying mechanisms are poorly understood. The aim of this study was to investigate the role of target salience during encoding to determine whether impaired visual attention in PSZ leads to poor WM. METHODS Thirty-one PSZ and 28 demographically matched healthy controls (HC) performed a spatial delayed-response task. Attentional demands were manipulated during WM encoding by presenting high salient (novel) or low salient (familiar) targets. Participants also rated their level of response confidence at the end of each trial, allowing us to analyse different response types. RESULTS WM was impaired in PSZ. Increasing target salience by increasing novelty improved WM performance in HC but not in PSZ. Poor WM performance in PSZ was largely due to an increase in the proportion of incorrect but high confident responses most likely reflecting a failure to encode the correct target. CONCLUSIONS Our findings suggest that dysfunctions of non-mnemonic attentional processes during encoding contribute to WM impairments in schizophrenia and may represent an important target for cognitive remediation strategies.
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Affiliation(s)
- Jutta S. Mayer
- Department of Psychology, Vanderbilt University, Nashville, USA,Department of Psychology, Goethe University, Frankfurt, Germany
| | - Jejoong Kim
- Department of Psychology, Duksung Women's University, Seoul, Korea
| | - Sohee Park
- Department of Psychology, Vanderbilt University, Nashville, USA
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Faget-Agius C, Boyer L, Lançon C, Richieri R, Fassio E, Soulier E, Chanoine V, Auquier P, Ranjeva JP, Guye M. Structural and functional reorganization of working memory system during the first decade in schizophrenia. A cross-sectional study. Schizophr Res 2013; 151:48-60. [PMID: 24230490 DOI: 10.1016/j.schres.2013.10.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 09/19/2013] [Accepted: 10/13/2013] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Progressive atrophy occurs in brain regions involved in the working memory network along the schizophrenia's course, but without parallel evolution of working memory impairment. We investigated the functional organization inside this network at different stages of the disease. METHODS Twenty-eight patients with schizophrenia (16 with long disease duration (>60 months) and 12 with short disease duration (<60 months)) and eleven healthy controls underwent structural and functional MRI during an n-back task to determine atrophy and activation patterns. RESULTS At similar n-back performances and relative to short disease duration patients, long disease duration patients activated more frontal temporal parietal and frontal network during 0-back and 1-back tasks respectively. n-back scores were correlated to atrophy in the frontal-temporal areas. DISCUSSION Functional reorganization in the working memory network may play a compensatory role during the first ten years of schizophrenia.
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Affiliation(s)
- C Faget-Agius
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM) UMR AMU-CNRS 7339, Medical School of Marseille, France; Centre d'exploration Métabolique par Résonance Magnétique (CEMEREM) UMR AMU-CNRS 7339, Timone University Hospital, AP-HM, Marseille, France; Department of Psychiatry, Sainte-Marguerite University Hospital, 13009 Marseille, France; Department of Public Health, Timone University Hospital, Assistance Publique-Hôpitaux de Marseille, 13005 Marseille, France.
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Johnson MK, McMahon RP, Robinson BM, Harvey AN, Hahn B, Leonard CJ, Luck SJ, Gold JM. The relationship between working memory capacity and broad measures of cognitive ability in healthy adults and people with schizophrenia. Neuropsychology 2013; 27:220-9. [PMID: 23527650 DOI: 10.1037/a0032060] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Working memory (WM) capacity, typically measured with cognitively complex span tasks, is correlated with higher order cognitive abilities in healthy adults. The goals of this study were to determine whether a more focused measure of visual WM storage capacity would show similar higher order ability correlations in healthy adults and in people with schizophrenia (PSZ), thereby demonstrating the importance of simple storage capacity; determine whether the illness alters the pattern of correlations across cognitive domains; and evaluate whether between-groups differences in WM capacity could account for the generalized cognitive impairment in PSZ. METHOD Ninety-nine PSZ and 77 healthy controls (HCs) completed a visual WM change-localization task, the Wechsler Abbreviated Scale of Intelligence (WASI), and the MATRICS Consensus Cognitive Battery (MCCB). RESULTS PSZ performed more poorly than HCs on all cognitive measures. The between-groups effect size for WM capacity was large (d = 1.11). WM robustly correlated with WASI and MCCB performance, with no significant differences in the magnitude or pattern of correlations across groups. When the groups were pooled, WM capacity correlated at r = .68 with MCCB composite score and at r = .56 with WASI estimated Full Scale IQ. WM capacity accounted for approximately 40% of the between-groups variance across the WASI and MCCB. CONCLUSIONS A simple measure of WM storage capacity is robustly associated with the higher order cognitive abilities assessed by the WASI and MCCB in HCs and PSZ. WM capacity reduction may be a critical determinant of the general cognitive impairment in PSZ.
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Affiliation(s)
- Melissa K Johnson
- Baltimore VA Mental Health Care System, Mental Illness Research, Education & Clinical Center (VA Capital Health Care Network), Baltimore, Maryland, USA
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Mano QR, Brown GG. Cognition–emotion interactions in schizophrenia: Emerging evidence on working memory load and implicit facial-affective processing. Cogn Emot 2013; 27:875-99. [DOI: 10.1080/02699931.2012.751360] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Landgraf S, Osterheider M. "To see or not to see: that is the question." The "Protection-Against-Schizophrenia" (PaSZ) model: evidence from congenital blindness and visuo-cognitive aberrations. Front Psychol 2013; 4:352. [PMID: 23847557 PMCID: PMC3696841 DOI: 10.3389/fpsyg.2013.00352] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 05/30/2013] [Indexed: 12/12/2022] Open
Abstract
The causes of schizophrenia are still unknown. For the last 100 years, though, both “absent” and “perfect” vision have been associated with a lower risk for schizophrenia. Hence, vision itself and aberrations in visual functioning may be fundamental to the development and etiological explanations of the disorder. In this paper, we present the “Protection-Against-Schizophrenia” (PaSZ) model, which grades the risk for developing schizophrenia as a function of an individual's visual capacity. We review two vision perspectives: (1) “Absent” vision or how congenital blindness contributes to PaSZ and (2) “perfect” vision or how aberrations in visual functioning are associated with psychosis. First, we illustrate that, although congenitally blind and sighted individuals acquire similar world representations, blind individuals compensate for behavioral shortcomings through neurofunctional and multisensory reorganization. These reorganizations may indicate etiological explanations for their PaSZ. Second, we demonstrate that visuo-cognitive impairments are fundamental for the development of schizophrenia. Deteriorated visual information acquisition and processing contribute to higher-order cognitive dysfunctions and subsequently to schizophrenic symptoms. Finally, we provide different specific therapeutic recommendations for individuals who suffer from visual impairments (who never developed “normal” vision) and individuals who suffer from visual deterioration (who previously had “normal” visual skills). Rather than categorizing individuals as “normal” and “mentally disordered,” the PaSZ model uses a continuous scale to represent psychiatrically relevant human behavior. This not only provides a scientific basis for more fine-grained diagnostic assessments, earlier detection, and more appropriate therapeutic assignments, but it also outlines a trajectory for unraveling the causes of abnormal psychotic human self- and world-perception.
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Affiliation(s)
- Steffen Landgraf
- Department for Forensic Psychiatry and Psychotherapy, District Hospital, University Regensburg Regensburg, Germany ; Berlin School of Mind and Brain, Humboldt Universität zu Berlin Berlin, Germany
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Grayton HM, Missler M, Collier DA, Fernandes C. Altered social behaviours in neurexin 1α knockout mice resemble core symptoms in neurodevelopmental disorders. PLoS One 2013; 8:e67114. [PMID: 23840597 PMCID: PMC3696036 DOI: 10.1371/journal.pone.0067114] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/16/2013] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Copy number variants have emerged as an important genomic cause of common, complex neurodevelopmental disorders. These usually change copy number of multiple genes, but deletions at 2p16.3, which have been associated with autism, schizophrenia and mental retardation, affect only the neurexin 1 gene, usually the alpha isoform. Previous analyses of neurexin 1α (Nrxn1α) knockout (KO) mouse as a model of these disorders have revealed impairments in synaptic transmission but failed to reveal defects in social behaviour, one of the core symptoms of autism. METHODS We performed a detailed investigation of the behavioural effects of Nrxn1α deletion in mice bred onto a pure genetic background (C57BL/6J) to gain a better understanding of its role in neurodevelopmental disorders. Wildtype, heterozygote and homozygote Nrxn1α KO male and female mice were tested in a battery of behavioural tests (n = 9-16 per genotype, per sex). RESULTS In homozygous Nrxn1α KO mice, we observed altered social approach, reduced social investigation, and reduced locomotor activity in novel environments. In addition, male Nrxn1α KO mice demonstrated an increase in aggressive behaviours. CONCLUSIONS These are the first experimental data that associate a deletion of Nrxn1α with alterations of social behaviour in mice. Since this represents one of the core symptom domains affected in autism spectrum disorders and schizophrenia in humans, our findings suggest that deletions within NRXN1 found in patients may be responsible for the impairments seen in social behaviours, and that the Nrxn1α KO mice are a useful model of human neurodevelopmental disorder.
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Affiliation(s)
- Hannah Mary Grayton
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, United Kingdom
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Münster, Germany
| | - David Andrew Collier
- Discovery Neuroscience Research, Eli Lilly and Company Ltd, Erl Wood, Windlesham, Surrey, United Kingdom
| | - Cathy Fernandes
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, United Kingdom
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Ding WN, Sun JH, Sun YW, Zhou Y, Li L, Xu JR, Du YS. Altered default network resting-state functional connectivity in adolescents with Internet gaming addiction. PLoS One 2013; 8:e59902. [PMID: 23555827 PMCID: PMC3608539 DOI: 10.1371/journal.pone.0059902] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Accepted: 02/19/2013] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Excessive use of the Internet has been linked to a variety of negative psychosocial consequences. This study used resting-state functional magnetic resonance imaging (fMRI) to investigate whether functional connectivity is altered in adolescents with Internet gaming addiction (IGA). METHODS Seventeen adolescents with IGA and 24 normal control adolescents underwent a 7.3 minute resting-state fMRI scan. Posterior cingulate cortex (PCC) connectivity was determined in all subjects by investigating synchronized low-frequency fMRI signal fluctuations using a temporal correlation method. To assess the relationship between IGA symptom severity and PCC connectivity, contrast images representing areas correlated with PCC connectivity were correlated with the scores of the 17 subjects with IGA on the Chen Internet Addiction Scale (CIAS) and Barratt Impulsiveness Scale-11 (BIS-11) and their hours of Internet use per week. RESULTS There were no significant differences in the distributions of the age, gender, and years of education between the two groups. The subjects with IGA showed longer Internet use per week (hours) (p<0.0001) and higher CIAS (p<0.0001) and BIS-11 (p = 0.01) scores than the controls. Compared with the control group, subjects with IGA exhibited increased functional connectivity in the bilateral cerebellum posterior lobe and middle temporal gyrus. The bilateral inferior parietal lobule and right inferior temporal gyrus exhibited decreased connectivity. Connectivity with the PCC was positively correlated with CIAS scores in the right precuneus, posterior cingulate gyrus, thalamus, caudate, nucleus accumbens, supplementary motor area, and lingual gyrus. It was negatively correlated with the right cerebellum anterior lobe and left superior parietal lobule. CONCLUSION Our results suggest that adolescents with IGA exhibit different resting-state patterns of brain activity. As these alterations are partially consistent with those in patients with substance addiction, they support the hypothesis that IGA as a behavioral addiction that may share similar neurobiological abnormalities with other addictive disorders.
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Affiliation(s)
- Wei-na Ding
- Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Jin-hua Sun
- Department of Child & Adolescent Psychiatry, Shanghai Mental Health Center, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Ya-wen Sun
- Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Yan Zhou
- Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P. R. China
- * E-mail: (YZ); (Y-sD)
| | - Lei Li
- Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Jian-rong Xu
- Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Ya-song Du
- Department of Child & Adolescent Psychiatry, Shanghai Mental Health Center, Shanghai Jiao Tong University, Shanghai, P. R. China
- * E-mail: (YZ); (Y-sD)
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Mayer JS, Park S. Working memory encoding and false memory in schizophrenia and bipolar disorder in a spatial delayed response task. JOURNAL OF ABNORMAL PSYCHOLOGY 2012; 121:784-794. [PMID: 22708888 PMCID: PMC4161120 DOI: 10.1037/a0028836] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Working memory (WM) impairment is a core feature of schizophrenia, but the contributions of different WM components are not yet specified. Here, we investigated the potential role of inefficient encoding in reduced WM performance in patients with schizophrenia (PSZ). Twenty-eight PSZ, 16 patients with bipolar disorder (PBP), 16 unaffected and unmedicated relatives of PSZ (REL), and 29 demographically matched healthy controls (HC) performed a spatial delayed response task with either low or high WM demands. The demands on attentional selection were also manipulated by presenting distractor stimuli during encoding in some of the trials. After each trial, participants rated their level of response confidence. This allowed us to analyze different types of WM responses. WM was severely impaired in PSZ compared to HC; this reduction was mainly due to an increase in the amount of false memory responses (incorrect responses that were given with high confidence) rather than an increase in the amount of incorrect and not-confident responses. Although PBP showed WM impairments, they did not have increased false memory errors. In contrast, reduced WM in REL was also accompanied by an increase in false memory errors. The presentation of distractors led to a decline in WM performance, which was comparable across groups indicating that attentional selection was intact in PSZ. These findings suggest that inefficient WM encoding is responsible for impaired WM in schizophrenia and point to differential mechanisms underlying WM impairments in PSZ and PBP.
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Affiliation(s)
| | - Sohee Park
- Department of Psychology, Vanderbilt University
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72
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Zhang Y, Zhang H, Wang L, Jiang W, Xu H, Xiao L, Bi X, Wang J, Zhu S, Zhang R, He J, Tan Q, Zhang D, Kong J, Li XM. Quetiapine enhances oligodendrocyte regeneration and myelin repair after cuprizone-induced demyelination. Schizophr Res 2012; 138:8-17. [PMID: 22555017 DOI: 10.1016/j.schres.2012.04.006] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 03/26/2012] [Accepted: 04/03/2012] [Indexed: 10/28/2022]
Abstract
Myelin and oligodendrocyte dysfunctions have been consistently found in patients with schizophrenia. The effect of antipsychotics on myelin disturbances is unknown. The present study examined the effects of quetiapine on oligodendrocyte regeneration and myelin repair in a demyelination animal model. C57BL/6 mice were fed with cuprizone (0.2% w/w) for 12 weeks to induce chronic demyelination and oligodendrocyte degeneration, after which cuprizone was withdrawn to allow recovery. Quetiapine (10mg/kg/day) or vehicle (water) was administrated orally to mice for 0, 2, 3, or 4 weeks after cuprizone withdrawal. Locomotor activity and Y-maze tests were used to evaluate behavioral changes in the mice. Immunohistochemical staining was used to detect morphological and biological changes in the brains. Cuprizone administration for 12 weeks resulted in severe demyelination, locomotor hyperactivity, and working memory impairment in mice. Remyelination occurred when cuprizone was withdrawn. Quetiapine treatment during the recovery period significantly improved the spatial working memory and increased myelin restoration. Quetiapine treatment also enhanced the repopulation of mature oligodendrocytes in the demyelinated lesions, which was associated with down-regulation of transcription factor olig2 in the process of cell maturation. The results of this study demonstrated that quetiapine treatment during the recovery period improves spatial working memory and promotes oligodendrocyte development and remyelination. This study supports the role of oligodendrocyte dysfunction in memory deficits in a schizophrenia mouse model and suggests that quetiapine may target oligodendrocytes and improve cognitive function.
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Affiliation(s)
- Yanbo Zhang
- Department of Psychiatry, University of Saskatchewan, Saskatoon, SK, Canada
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Glausier JR, Lewis DA. Dendritic spine pathology in schizophrenia. Neuroscience 2012; 251:90-107. [PMID: 22546337 DOI: 10.1016/j.neuroscience.2012.04.044] [Citation(s) in RCA: 377] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 03/22/2012] [Accepted: 04/05/2012] [Indexed: 01/22/2023]
Abstract
Schizophrenia is a neurodevelopmental disorder whose clinical features include impairments in perception, cognition and motivation. These impairments reflect alterations in neuronal circuitry within and across multiple brain regions that are due, at least in part, to deficits in dendritic spines, the site of most excitatory synaptic connections. Dendritic spine alterations have been identified in multiple brain regions in schizophrenia, but are best characterized in layer 3 of the neocortex, where pyramidal cell spine density is lower. These spine deficits appear to arise during development, and thus are likely the result of disturbances in the molecular mechanisms that underlie spine formation, pruning, and/or maintenance. Each of these mechanisms may provide insight into novel therapeutic targets for preventing or repairing the alterations in neural circuitry that mediate the debilitating symptoms of schizophrenia.
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Affiliation(s)
- J R Glausier
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
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Spieker EA, Astur RS, West JT, Griego JA, Rowland LM. Spatial memory deficits in a virtual reality eight-arm radial maze in schizophrenia. Schizophr Res 2012; 135:84-9. [PMID: 22154760 PMCID: PMC3288352 DOI: 10.1016/j.schres.2011.11.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/23/2011] [Accepted: 11/13/2011] [Indexed: 11/25/2022]
Abstract
Learning and memory impairments are present in schizophrenia (SZ) throughout the illness course and predict psychosocial function. Abnormalities in prefrontal and hippocampal function are thought to contribute to SZ deficits. The radial arm maze (RAM) is a test of spatial learning and memory in rodents that relies on intact prefrontal and hippocampal function. The goal of the present study was to investigate spatial learning in SZ using a virtual RAM. Thirty-three subjects with SZ and thirty-nine healthy controls (HC) performed ten trials of a virtual RAM task. Subjects attempted to learn to retrieve four rewards each located in separate arms. As expected, subjects with SZ used more time and traveled more distance to retrieve rewards, made more reference (RM) and working memory (WM) errors, and retrieved fewer rewards than HC. It is important to note that the SZ group did learn but did not reach the level of HC. Whereas RM errors decreased across trials in the SZ group, WM errors did not. There were no significant relationships between psychiatric symptom severity and maze performance. To our knowledge, use of a virtual 8-arm radial maze task in SZ to assess spatial learning is novel. Impaired virtual RAM performance in SZ is consistent with studies that examined RAM performance in animal models of SZ. Results provide further support for compromised prefrontal and hippocampal function underlying WM and RM deficits in SZ. The virtual RAM task could help bridge preclinical and clinical research for testing novel drug treatments of SZ.
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Affiliation(s)
- Elena A. Spieker
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228
| | - Robert S. Astur
- Department of Psychiatry, Yale University, New Haven, CT 06511
| | - Jeffrey T. West
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228
| | - Jacqueline A. Griego
- Institute of Cognitive Science, University of Osnabrück, 49076 Osnabruck, Germany
| | - Laura M. Rowland
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228
,Corresponding Author: Laura M. Rowland, Maryland Psychiatric Research Center, P.O. Box 21247, Baltimore, MD 21228, , Phone: 410-402-6803, Fax: 410-402-6077
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Thuaire F, Izaute M, Bacon E. Evidence of some strategic preservation of episodic learning in patients with schizophrenia. Psychiatry Res 2012; 195:27-31. [PMID: 21851990 DOI: 10.1016/j.psychres.2011.07.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2011] [Revised: 07/22/2011] [Accepted: 07/25/2011] [Indexed: 01/03/2023]
Abstract
The aim of this study was to gain a better understanding of schizophrenia patients' strategic use of learning time allocation during encoding, and determine whether they are able to use their monitoring and previous performances to adapt their learning behavior efficiently. Schizophrenia is considered to be a pathology of consciousness as well as being associated with impaired awareness of cognitive processes. In this study, after a learning session, individuals may express a Judgment of Learning (JOL), which reflects their sense of being able to retrieve the information later and which forms the basis for their decision whether or not to carry on learning. The introspective abilities of schizophrenia patients and subsequent strategic control of study time during the encoding of easy or difficult word pairs were investigated in 23 patients and 23 healthy comparison subjects. In spite of their memory impairment, patients were able to judge the difficulty of the word pairs with accuracy and adapt their learning time accordingly. Schizophrenia patients are sensitive to difficulty when rating JOLs and afterwards controlling study time. Monitoring their knowledge at the start helped patients to adapt their learning efficiently. These findings may be of value for cognitive remediation.
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Affiliation(s)
- Flavien Thuaire
- Clermont University, Blaise Pascal University, LAPSCO, BP 10448, F-63000 Clermont-Ferrand, France
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Landgraf S, Steingen J, Eppert Y, Niedermeyer U, van der Meer E, Krueger F. Temporal information processing in short- and long-term memory of patients with schizophrenia. PLoS One 2011; 6:e26140. [PMID: 22053182 PMCID: PMC3203868 DOI: 10.1371/journal.pone.0026140] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 09/20/2011] [Indexed: 11/19/2022] Open
Abstract
Cognitive deficits of patients with schizophrenia have been largely recognized as core symptoms of the disorder. One neglected factor that contributes to these deficits is the comprehension of time. In the present study, we assessed temporal information processing and manipulation from short- and long-term memory in 34 patients with chronic schizophrenia and 34 matched healthy controls. On the short-term memory temporal-order reconstruction task, an incidental or intentional learning strategy was deployed. Patients showed worse overall performance than healthy controls. The intentional learning strategy led to dissociable performance improvement in both groups. Whereas healthy controls improved on a performance measure (serial organization), patients improved on an error measure (inappropriate semantic clustering) when using the intentional instead of the incidental learning strategy. On the long-term memory script-generation task, routine and non-routine events of everyday activities (e.g., buying groceries) had to be generated in either chronological or inverted temporal order. Patients were slower than controls at generating events in the chronological routine condition only. They also committed more sequencing and boundary errors in the inverted conditions. The number of irrelevant events was higher in patients in the chronological, non-routine condition. These results suggest that patients with schizophrenia imprecisely access temporal information from short- and long-term memory. In short-term memory, processing of temporal information led to a reduction in errors rather than, as was the case in healthy controls, to an improvement in temporal-order recall. When accessing temporal information from long-term memory, patients were slower and committed more sequencing, boundary, and intrusion errors. Together, these results suggest that time information can be accessed and processed only imprecisely by patients who provide evidence for impaired time comprehension. This could contribute to symptomatic cognitive deficits and strategic inefficiency in schizophrenia.
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Affiliation(s)
- Steffen Landgraf
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
- Inserm-Laboratory of Psychopathology and Mental Diseases, Center for Psychiatry and Neuroscience, U984, Sainte Anne Hospital, Service-Hospitalo Universitaire, Paris, France
| | - Joerg Steingen
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Yvonne Eppert
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - Elke van der Meer
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Frank Krueger
- Department of Molecular Neuroscience, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, United States of America
- Department of Psychology, George Mason University, Fairfax, Virginia, United States of America
- * E-mail:
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Deakin IH, Nissen W, Law AJ, Lane T, Kanso R, Schwab MH, Nave KA, Lamsa KP, Paulsen O, Bannerman DM, Harrison PJ. Transgenic overexpression of the type I isoform of neuregulin 1 affects working memory and hippocampal oscillations but not long-term potentiation. ACTA ACUST UNITED AC 2011; 22:1520-9. [PMID: 21878485 PMCID: PMC3377963 DOI: 10.1093/cercor/bhr223] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Neuregulin 1 (NRG1) is a growth factor involved in neurodevelopment and plasticity. It is a schizophrenia candidate gene, and hippocampal expression of the NRG1 type I isoform is increased in the disorder. We have studied transgenic mice overexpressing NRG1 type I (NRG1tg-type I) and their wild-type littermates and measured hippocampal electrophysiological and behavioral phenotypes. Young NRG1tg-type I mice showed normal memory performance, but in older NRG1tg-type I mice, hippocampus-dependent spatial working memory was selectively impaired. Hippocampal slice preparations from NRG1tg-type I mice exhibited a reduced frequency of carbachol-induced gamma oscillations and an increased tendency to epileptiform activity. Long-term potentiation in NRG1tg-type I mice was normal. The results provide evidence that NRG1 type I impacts on hippocampal function and circuitry. The effects are likely mediated via inhibitory interneurons and may be relevant to the involvement of NRG1 in schizophrenia. However, the findings, in concert with those from other genetic and pharmacological manipulations of NRG1, emphasize the complex and pleiotropic nature of the gene, even with regard to a single isoform.
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Affiliation(s)
- Inga H Deakin
- Department of Psychiatry, University of Oxford, Oxford, UK
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Fukuda T, Hashimoto H, Okayasu N, Kameyama A, Onogi H, Nakagawasai O, Nakazawa T, Kurosawa T, Hao Y, Isaji T, Tadano T, Narimatsu H, Taniguchi N, Gu J. Alpha1,6-fucosyltransferase-deficient mice exhibit multiple behavioral abnormalities associated with a schizophrenia-like phenotype: importance of the balance between the dopamine and serotonin systems. J Biol Chem 2011; 286:18434-43. [PMID: 21471224 DOI: 10.1074/jbc.m110.172536] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previously, we reported that α1,6-fucosyltransferase (Fut8)-deficient (Fut8(-/-)) mice exhibit emphysema-like changes in the lung and severe growth retardation due to dysregulation of TGF-β1 and EGF receptors and to abnormal integrin activation, respectively. To study the role of α1,6-fucosylation in brain tissue where Fut8 is highly expressed, we examined Fut8(-/-) mice using a combination of neurological and behavioral tests. Fut8(-/-) mice exhibited multiple behavioral abnormalities consistent with a schizophrenia-like phenotype. Fut8(-/-) mice displayed increased locomotion compared with wild-type (Fut8(+/+)) and heterozygous (Fut8(+/-)) mice. In particular, Fut8(-/-) mice showed strenuous hopping behavior in a novel environment. Working memory performance was impaired in Fut8(-/-) mice as evidenced by the Y-maze tests. Furthermore, Fut8(-/-) mice showed prepulse inhibition (PPI) deficiency. Intriguingly, although there was no significant difference between Fut8(+/+) and Fut8(+/-) mice in the PPI test under normal conditions, Fut8(+/-) mice showed impaired PPI after exposure to a restraint stress. This result suggests that reduced expression of Fut8 is a plausible cause of schizophrenia and related disorders. The levels of serotonin metabolites were significantly decreased in both the striatum and nucleus accumbens of the Fut8(-/-) mice. Likewise, treatment with haloperidol, which is an antipsychotic drug that antagonizes dopaminergic and serotonergic receptors, significantly reduced hopping behaviors. The present study is the first to clearly demonstrate that α1,6-fucosylation plays an important role in the brain, and that it might be related to schizophrenia-like behaviors. Thus, the results of the present study provide new insights into the underlying mechanisms responsible for schizophrenia and related disorders.
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Affiliation(s)
- Tomohiko Fukuda
- Division of Regulatory Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Komatsusima, Aobaku, Sendai, Miyagi 981-8558, Japan
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79
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Schultz CC, Koch K, Wagner G, Roebel M, Nenadic I, Gaser C, Schachtzabel C, Reichenbach JR, Sauer H, Schlösser RGM. Increased parahippocampal and lingual gyrification in first-episode schizophrenia. Schizophr Res 2010; 123:137-44. [PMID: 20850277 DOI: 10.1016/j.schres.2010.08.033] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 08/17/2010] [Accepted: 08/22/2010] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Cerebral gyrification is attributed to a large extent to genetic and intrauterine/perinatal factors. Hence, investigating gyrification might offer important evidence for disturbed neurodevelopmental mechanisms in schizophrenia. As an extension of recent ROI analyses of gyrification in schizophrenia the present study is the first to compare on a node-by-node basis mean curvature as a sensitive parameter for the identification of local gyrification changes of the whole cortex in first-episode schizophrenia. METHODS A group of 54 patients with first-episode schizophrenia according to DSM-IV and 54 age and gender matched healthy control subjects were included. All participants underwent high-resolution T1-weighted MRI scans on a 1.5 T scanner. Mean curvature was calculated dividing the sum of the principal curvatures by two at each point of the curved surface as implemented in the Freesurfer Software package. Statistical cortical maps were created to estimate gyrification differences between groups based on a clustering approach. RESULTS A significantly increased gyrification was observed in first-episode schizophrenia patients relative to controls in a right parahippocampal-lingual cortex area. The cluster encompassed a surface area of 750 mm². A further analysis of cortical thickness of this cluster demonstrated concurrent significant reduced cortical thickness of this area. CONCLUSIONS This is the first study to reveal an aberrant gyrification of the medial surface in first-episode schizophrenia. This finding is in line with substantial evidence showing medial temporal lobe abnormalities in schizophrenia. The present morphometric data provide further support for an early disruption of cortical maturation in schizophrenia.
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Affiliation(s)
- C Christoph Schultz
- Department of Psychiatry and Psychotherapy, Friedrich-Schiller-University Jena, Philosophenweg 3, 07740 Jena, Germany.
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Prospective memory in non-psychotic first-degree relatives of patients with schizophrenia. Psychiatry Res 2010; 179:285-90. [PMID: 20493547 DOI: 10.1016/j.psychres.2009.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 06/16/2009] [Accepted: 07/15/2009] [Indexed: 11/23/2022]
Abstract
Although a number of studies have found prospective memory (PM) impairment in patients with schizophrenia, very little is known about the PM performance in non-psychotic relatives of these patients. The current study aimed to explore the PM performance in non-psychotic first-degree relatives of these patients. Two groups of participants (26 non-psychotic first-degree relatives of schizophrenia patients and 26 healthy comparison participants) were administered three PM tasks (time-, event-, and activity-based) and a set of neurocognitive tests. Results showed that the relatives performed significantly worse than the comparisons on most indices of the PM tasks, with a similar pattern of impairment found in other neurocognitive measures. Together with findings from previous studies, results of the current study suggest that PM may be a potential endophenotype for schizophrenia.
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81
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Impaired spatial working memory maintenance in schizophrenia involves both spatial coordinates and spatial reference frames. Psychiatry Res 2010; 179:253-8. [PMID: 20493553 DOI: 10.1016/j.psychres.2009.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 09/10/2009] [Accepted: 09/11/2009] [Indexed: 11/20/2022]
Abstract
Spatial working memory (SWM) dysfunction is a central finding in schizophrenia; however, more evidence of impaired maintenance over time is required. Consequently, the present study examined SWM maintenance over short unfilled delays, and with encoding equated. The influence of a vertical reference frame to support maintenance was also investigated. The performance of 58 patients with schizophrenia and 50 healthy controls was assessed using the Visuo-Spatial Working Memory (VSWM) Test across three unfilled delays (0, 2, and 4s). Inaccuracy of direction and distance responses was examined at each delay duration. The results showed that performance was significantly less accurate for both distance and direction responses at 2 and 4s delays in schizophrenia, but was not significantly different from controls at the 0s delay. Patients showed a particularly marked loss of accuracy between the time interval of 0-2s. Furthermore, schizophrenia participants exhibited significantly greater response variability at the vertical axis of symmetry than controls at the 2 and 4s delays, but not at the 0s delay. These data clearly show both impaired maintenance over time and difficulty using a vertical frame of reference in schizophrenia. The latter findings may reflect, in part, dysfunctional reference-related inhibition.
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82
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Hahn B, Robinson BM, Kaiser ST, Harvey AN, Beck VM, Leonard CJ, Kappenman ES, Luck SJ, Gold JM. Failure of schizophrenia patients to overcome salient distractors during working memory encoding. Biol Psychiatry 2010; 68:603-9. [PMID: 20570242 PMCID: PMC2942999 DOI: 10.1016/j.biopsych.2010.04.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 04/07/2010] [Accepted: 04/16/2010] [Indexed: 11/26/2022]
Abstract
BACKGROUND Prior demonstrations of impaired attentional control in schizophrenia focused on conditions in which top-down control is needed to overcome prepotent response tendencies. Attentional control over stimulus processing has received little investigation. Here, we test whether attentional control is impaired during working memory encoding when salient distractors compete with less salient task-relevant stimuli. METHODS Patients with schizophrenia (n = 28) and healthy control subjects (n = 25) performed a visuospatial working memory paradigm in which half of the to-be-encoded stimuli flickered to increase their salience. After a 2-second delay, stimuli reappeared and participants had to decide whether or not a probed item had shifted location. RESULTS In the unbiased condition where flickering and nonflickering stimuli were equally likely to be probed, both groups displayed a trend toward better memory for the flickering items. In the flicker-bias condition in which the flickering stimuli were likely to be probed, both groups displayed a robust selection advantage for the flickering items. However, in the nonflicker-bias condition in which the nonflickering stimuli were likely to be probed, only healthy control subjects showed selection of the nonflickering items. Patients displayed a trend toward preferential memory for the flickering items, as in the unbiased condition. CONCLUSIONS Both groups were able to select salient over nonsalient stimuli, but patients with schizophrenia were unable to select nonsalient over salient stimuli, consistent with impairment in the effortful control of attention. These findings demonstrate the generality of top-down control failure in schizophrenia in the face of bottom-up competition from salient stimuli as with prepotent response tendencies.
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Affiliation(s)
- Britta Hahn
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228,Corresponding author: , Tel: 410-402-6112, Fax: 410-402-7198
| | - Benjamin M. Robinson
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228
| | - Samuel T. Kaiser
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228
| | - Alexander N. Harvey
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228
| | - Valerie M. Beck
- University of California, Davis, Center for Mind & Brain and Department of Psychology, Davis, CA 95618
| | - Carly J. Leonard
- University of California, Davis, Center for Mind & Brain and Department of Psychology, Davis, CA 95618
| | - Emily S. Kappenman
- University of California, Davis, Center for Mind & Brain and Department of Psychology, Davis, CA 95618
| | - Steven J. Luck
- University of California, Davis, Center for Mind & Brain and Department of Psychology, Davis, CA 95618
| | - James M. Gold
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. box 21247, Baltimore, MD 21228
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83
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Lecardeur L, Mendrek A, Stip E. Sexual dimorphism of spatial working memory profiles in schizophrenia. Cogn Neuropsychiatry 2010; 15:397-405. [PMID: 20094930 DOI: 10.1080/13546800903399183] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION The aim of the present study was to compare spatial working memory performance of females and males schizophrenia patients to verify whether the sexual dimorphism of spatial abilities present in the general population is found also in schizophrenia. METHODS We analysed different types of errors committed by each gender on the spatial working memory test of the Cambridge Neuropsychological Test Automated Battery to determine potential differences between them. RESULTS Despite the lack of difference in the number of errors between men and women, different profiles of errors were associated with the strategy used according to gender. The men's strategy was better compared to women. Specifically, for women strategy score correlated positively with searches in previously visited boxes, whereas for men it correlated with both previously visited boxes and never visited ones. However, men's strategy is more impaired by the number of revisits in boxes in which tokens have previously been found than female's one. CONCLUSIONS These results suggested impaired either central executive and/or visuospatial sketchpad of working memory in patients with schizophrenia. We demonstrated also that the worsening of strategy in men is principally due to central executive deficits compared to women with schizophrenia. The study of sex differences in cognitive performances could help in delineating partially different endophenotypes of schizophrenia in men and women.
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Affiliation(s)
- Laurent Lecardeur
- Department of Psychiatry, Centre de Recherche Fernand-Seguin, Hôpital Louis-H Lafontaine, Université de Montreal, Montreal, Quebec, Canada.
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84
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A genetic variation in the dysbindin gene(DTNBP1)is associated with memory performance in healthy controls. World J Biol Psychiatry 2010. [DOI: 10.3109/15622970902736503] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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85
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Cocchi L, Walterfang M, Testa R, Wood SJ, Seal ML, Suckling J, Takahashi T, Proffitt TM, Brewer WJ, Adamson C, Soulsby B, Velakoulis D, McGorry PD, Pantelis C. Grey and white matter abnormalities are associated with impaired spatial working memory ability in first-episode schizophrenia. Schizophr Res 2009; 115:163-72. [PMID: 19837566 DOI: 10.1016/j.schres.2009.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 08/03/2009] [Accepted: 09/07/2009] [Indexed: 11/16/2022]
Abstract
Spatial working memory (SWM) dysfunction has been suggested as a trait marker of schizophrenia and implicates a diffuse network involving prefrontal, temporal and parietal cortices. However, structural abnormalities in both grey and white matter in relation to SWM deficits are largely unexplored. The current magnetic resonance imaging (MRI) study examined this relationship in a sample of young first-episode schizophrenia (FES) patients using a whole-brain voxel-based method. SWM ability of 21 FES patients and 41 comparable controls was assessed by the CANTAB SWM task. Using an automated morphometric analysis of brain MRI scans, we assessed the relationship between SWM abilities and both grey matter volume and white matter density in both groups. Our findings demonstrated the different directionality of the association between SWM errors and grey matter volume in left frontal regions and white matter tracts connecting these regions with temporal and occipital areas between FES patients and controls. This suggests that the substrate underpinning the normal variability in SWM function in healthy individuals may be abnormal in FES, and that the normal neurodevelopmental processes that drive the development of SWM networks are disrupted in schizophrenia.
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Affiliation(s)
- Luca Cocchi
- Department of Psychiatry, Melbourne Neuropsychiatry Centre, The University of Melbourne & Melbourne Health, Melbourne, Australia.
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86
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Bachman P, Kim J, Yee CM, Therman S, Manninen M, Lönnqvist J, Kaprio J, Huttunen MO, Näätänen R, Cannon TD. Efficiency of working memory encoding in twins discordant for schizophrenia. Psychiatry Res 2009; 174:97-104. [PMID: 19853415 PMCID: PMC2792637 DOI: 10.1016/j.pscychresns.2009.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 04/24/2009] [Accepted: 04/24/2009] [Indexed: 10/20/2022]
Abstract
It has been proposed that patients with schizophrenia and some of their relatives suffer from reduced neurocognitive efficiency, increasing their sensitivity to experimental task demands. The present study evaluated such a possibility during performance of a working memory task by schizophrenia patients and their co-twins along with a healthy control sample. Electrophysiological data were obtained from sets of nine twin pairs (monozygotic and dizygotic pairs collapsed) discordant for a diagnosis of schizophrenia and from nine matched healthy control twin pairs, during administration of a variable-load spatial working memory task. Event-related potentials (ERPs) were measured immediately after memory set onset and during a delay period. For correctly performed trials, slow-wave ERP activity measured during the late stimulus encoding and delay periods exhibited a significant Diagnostic Group-by-Memory Load interaction, with schizophrenia patients showing a differentially strong load effect. Patients' co-twins displayed an intermediate level of load sensitivity while healthy controls showed no significant load effect. These results support an inefficiency model of neurocognitive dysfunction in schizophrenia, a pattern that appears to be related to the pathogenesis and inheritance of the disorder. Furthermore, this inefficiency appeared during the late stimulus encoding stage of working memory functioning, possibly reflecting disruptions in stimulus representation consolidation.
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Affiliation(s)
- Peter Bachman
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA 90095-1563, United States.
| | - Junghoon Kim
- Moss Rehabilitation Research Institute, Philadelphia, Pennsylvania, Korman Suite 218, 1200 W. Tabor Rd., Philadelphia, PA 19141,
| | - Cindy M. Yee
- Department of Psychology, and Department of Psychiatry & Biobehavioral Sciences, UCLA, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095-1563, ,
| | - Sebastian Therman
- Department of Mental Health & Alcohol Research, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland, , , ,
| | - Marko Manninen
- Department of Mental Health & Alcohol Research, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland, , , ,
| | - Jouko Lönnqvist
- Department of Mental Health & Alcohol Research, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland, , , ,
| | - Jaakko Kaprio
- Department of Mental Health & Alcohol Research, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland, , , , ,Department of Public Health, University of Helsinki, Finland, Faculty of Medicine, P.O. Box 41 (Mannerheimintie 172), FIN-00014 University of Helsinki,
| | - Matti O. Huttunen
- Department of Mental Health & Alcohol Research, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland, , , ,
| | - Risto Näätänen
- Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, Finland, P.O. Box 9 (Siltavuorenpenger 20 C), FIN-00014 University of Helsinki, ,Helsinki Brain Research Centre, Helsinki, Finland, P.O. Box 9 (Siltavuorenpenger 20 C), FIN-00014 University of Helsinki
| | - Tyrone D. Cannon
- Department of Psychology, and Department of Psychiatry & Biobehavioral Sciences, UCLA, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095-1563, ,
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87
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Belforte JE, Zsiros V, Sklar ER, Jiang Z, Yu G, Li Y, Quinlan EM, Nakazawa K. Postnatal NMDA receptor ablation in corticolimbic interneurons confers schizophrenia-like phenotypes. Nat Neurosci 2009; 13:76-83. [PMID: 19915563 DOI: 10.1038/nn.2447] [Citation(s) in RCA: 599] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 10/07/2009] [Indexed: 12/13/2022]
Abstract
Cortical GABAergic dysfunction may underlie the pathophysiology of psychiatric disorders, including schizophrenia. Here, we characterized a mouse strain in which the essential NR1 subunit of the NMDA receptor (NMDAR) was selectively eliminated in 40-50% of cortical and hippocampal interneurons in early postnatal development. Consistent with the NMDAR hypofunction theory of schizophrenia, distinct schizophrenia-related symptoms emerged after adolescence, including novelty-induced hyperlocomotion, mating and nest-building deficits, as well as anhedonia-like and anxiety-like behaviors. Many of these behaviors were exacerbated by social isolation stress. Social memory, spatial working memory and prepulse inhibition were also impaired. Reduced expression of glutamic acid decarboxylase 67 and parvalbumin was accompanied by disinhibition of cortical excitatory neurons and reduced neuronal synchrony. Postadolescent deletion of NR1 did not result in such abnormalities. These findings suggest that early postnatal inhibition of NMDAR activity in corticolimbic GABAergic interneurons contributes to the pathophysiology of schizophrenia-related disorders.
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Affiliation(s)
- Juan E Belforte
- Unit on Genetics of Cognition and Behavior, Mood and Anxiety Disorders Program, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
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88
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Wang Y, Cui J, Chan RCK, Deng Y, Shi H, Hong X, Li Z, Yu X, Gong QY, Shum D. Meta-analysis of prospective memory in schizophrenia: nature, extent, and correlates. Schizophr Res 2009; 114:64-70. [PMID: 19713081 DOI: 10.1016/j.schres.2009.07.009] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 06/30/2009] [Accepted: 07/09/2009] [Indexed: 11/30/2022]
Abstract
Prospective memory (PM) is the ability to remember to carry out an intended action in the future and it is an important function for everyday living. Studies have found that the neural basis of PM is located mainly in the prefrontal lobes (particularly in Brodmann Area 10) and patients with schizophrenia have functional deficits in this area. The present study provided a meta-analytic review of PM performances in patients with schizophrenia in 11 studies. A total of 485 patients with schizophrenia and 409 controls were included. Results showed that patients with schizophrenia exhibited impairments in all time- (d=-1.33), event- (d=-0.827), and activity-based (d=-0.729) PM, with time-based PM more impaired than event-based PM. In addition, PM was found to be significantly correlated with negative symptoms (r=-0.18), general psychopathology (r=-0.168), medication dosage (r=-0.119), duration of illness (r=-0.131), age (r=-0.23), education (r=0.249), IQ (r=0.439) and premorbid IQ (r=0.356). It has theoretical and clinical implications. Theoretically, the results indicate time-based PM involves more initiation than event-based PM. Clinically, the results indicate patients on high dose of antipsychotic medication and with long duration of illness need special attention from care givers for PM problems.
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Affiliation(s)
- Ya Wang
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
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89
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Kirby BP, Waddington JL, O'Tuathaigh CMP. Advancing a functional genomics for schizophrenia: psychopathological and cognitive phenotypes in mutants with gene disruption. Brain Res Bull 2009; 83:162-76. [PMID: 19800398 DOI: 10.1016/j.brainresbull.2009.09.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2009] [Revised: 08/18/2009] [Accepted: 09/21/2009] [Indexed: 12/19/2022]
Abstract
Schizophrenia is a complex, heritable psychotic disorder in which numerous genes and environmental adversities appear to interact in determining disease phenotype. In addition to genes regulating putative pathophysiological mechanisms, a new generation of molecular studies has indicated numerous candidate genes to be associated with risk for schizophrenia. The present review focuses on studies in mice mutant for genes associated with putative pathophysiological mechanisms and candidate risk genes for the disorder. It seeks to evaluate the extent to which each mutation of a schizophrenia-related gene accurately models multiple aspects of the schizophrenia phenotype or more circumscribed, distinct endophenotypes in terms of psychopathology and pathobiology; in doing so, it places particular emphasis on positive symptoms, negative symptoms and cognitive dysfunction. To further this goal, it juxtaposes continually evolving mutant genomics with emergent clinical genomic studies. Opportunities and challenges associated with the use of such mutants, including diagnostic specificity and the translational barrier associated with modelling schizophrenia, are discussed. The potential value of genetic models for exploring gene-gene and gene-environment interactions relating to schizophrenia is highlighted. Elucidation of the contribution of genetic variation to specific symptom clusters and underlying aspects of pathobiology will have important implications for identifying treatments that target distinct domains of psychopathology and dysfunction on an individual patient basis.
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Affiliation(s)
- Brian P Kirby
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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90
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Halberstadt AL, Geyer MA. Habituation and sensitization of acoustic startle: opposite influences of dopamine D1 and D2-family receptors. Neurobiol Learn Mem 2009; 92:243-8. [PMID: 18644244 PMCID: PMC2745310 DOI: 10.1016/j.nlm.2008.05.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 05/27/2008] [Indexed: 12/01/2022]
Abstract
The startle response evoked by repeated presentation of a loud acoustic stimulus is regulated by the independent processes of sensitization and habituation. While schizophrenia is associated with information processing impairments, there is conflicting evidence regarding the existence of habituation deficits in schizophrenic patients. Recent clinical evidence, however, indicates that patients with schizophrenia display exaggerated startle sensitization and diminished habituation. Given the linkage between dopaminergic abnormalities and schizophrenia, the goal of the present investigation was to examine the effect of deleting D1 and D2-like dopamine receptors on sensitization and habituation of the acoustic startle reflex in mice. For these experiments, the acoustic startle reflex was assessed in dopamine D1, D2, and D3 receptor wild-type (WT) and knockout (KO) mice on a C57BL/6J background, using a methodology that can measure both sensitization and habituation. Mice lacking the D1 receptor gene displayed enhanced sensitization, along with a decrease in the amount of habituation that occurs in response to repetitive presentations of a startling stimulus. Conversely, the loss of the dopamine D2 or D3 receptor gene produced a sensitization deficit and a significant increase in habituation. The behavioral phenotype exhibited by D1 receptor KO mice is clearly distinct from that of the D2 and D3 receptor KO mice. The findings in D1 receptor KO mice are reminiscent of the abnormalities observed in schizophrenic patients tested in comparable startle paradigms, and indicate that D1 agonists may possess therapeutic efficacy against the information processing deficits associated with schizophrenia.
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MESH Headings
- Acoustic Stimulation
- Animals
- Disease Models, Animal
- Habituation, Psychophysiologic/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, Dopamine D1/genetics
- Receptors, Dopamine D1/metabolism
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/metabolism
- Receptors, Dopamine D3/genetics
- Receptors, Dopamine D3/metabolism
- Reflex, Startle/physiology
- Schizophrenia/physiopathology
- Schizophrenic Psychology
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0804, USA
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91
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Piskulić D, Olver JS, Maruff P, Norman TR. Treatment of cognitive dysfunction in chronic schizophrenia by augmentation of atypical antipsychotics with buspirone, a partial 5-HT(1A) receptor agonist. Hum Psychopharmacol 2009; 24:437-46. [PMID: 19637398 DOI: 10.1002/hup.1046] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVES To assess effects of a semi-acute administration of buspirone in comparison to a placebo on cognitive function and negative symptoms in patients with schizophrenia and schizoaffective disorder. METHODS In a 6-week, double-blind, placebo-controlled, independent groups study 18 subjects (14 males, four females) received in random order either placebo or buspirone (15-30 mg/day). A neuropsychological assessment using the Hopkins verbal learning test (HVLT) simple reaction time (SRT), choice reaction time (CRT), n-back spatial working memory task and the stroop colour and word test was performed at baseline and final visit. Symptom rating scales were administered at testing weeks 0, 2, 4 and 6. RESULTS Repeated measures ANOVA was used to examine changes in performance on tests over time. There were no statistically significant differences between placebo and buspirone treatments on either cognitive function measures or symptom ratings. CONCLUSION Semi-acute adjunct treatment with buspirone may be too short to be clinically efficacious in patients with schizophrenia. Intrinsic activation of 5-HT(1A) receptors by atypical antipsychotics may hinder the ability of buspirone to further improve cognitive functions. Buspirone did not affect clinical outcomes for this chronically ill group of patients being treated with atypical antipsychotic drugs.
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92
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Asp L, Beraki S, Kristensson K, Ogren SO, Karlsson H. Neonatal infection with neurotropic influenza A virus affects working memory and expression of type III Nrg1 in adult mice. Brain Behav Immun 2009; 23:733-41. [PMID: 19362585 DOI: 10.1016/j.bbi.2009.04.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 04/05/2009] [Indexed: 12/28/2022] Open
Abstract
Epidemiological studies suggest that early life infections may contribute to the development of psychiatric disorders characterized by cognitive deficits. Here, we studied the effects of a neonatal influenza A/WSN/33 virus infection on locomotor activity, working memory and emotional behavior in adult mice. In addition to wild type mice, immunodeficient (Tap1(-/-)) mice lacking functional CD8(+) T cells, were included in the study to model the potential influence of a genetic deficit relating to virus clearance. Three to four months after the infection, infected Tap1(-/-) mice, but not wild type mice, exhibited deficits in working memory as well as increased rearing activity and anxiety. In the medial prefrontal cortices of these infected Tap1(-/-) mice reduced levels of type III Nrg1 transcripts were observed supporting a role for neuregulin 1 signaling in neuronal circuits involved in working memory. Virus replication, distribution or clearance did not differ between the two genotypes. The lack of CD8(+) T cells, however, appeared to contribute to a more pronounced glia response in Tap1(-/-) than in wild type mice. Thus, the present study suggest that the risk of developing deficits in cognitive and emotional behavior following a CNS infection during brain development is influenced by genetic variation in genes involved in the immune response.
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Affiliation(s)
- Linnéa Asp
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, Stockholm, Sweden
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93
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Mechelli A, Viding E, Kumar A, Pettersson-Yeo W, Fusar-Poli P, Tognin S, O'Donovan MC, McGuire P. Dysbindin modulates brain function during visual processing in children. Neuroimage 2009; 49:817-22. [PMID: 19631276 DOI: 10.1016/j.neuroimage.2009.07.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 07/10/2009] [Accepted: 07/14/2009] [Indexed: 11/29/2022] Open
Abstract
Schizophrenia is a neurodevelopmental disorder, and risk genes are thought to act through disruption of brain development. Several genetic studies have identified dystrobrevin binding protein 1 (DTNBP1, also known as dysbindin) as a potential susceptibility gene for schizophrenia, but its impact on brain function is poorly understood. It has been proposed that DTNBP1 may be associated with differences in visual processing. To test this, we examined the impact on visual processing in 61 healthy children aged 10-12 years of a genetic variant in DTNBP1 (rs2619538) that was common to all schizophrenia associated haplotypes in an earlier UK-Irish study. We tested the hypothesis that carriers of the risk allele would show altered occipital cortical function relative to noncarriers. Functional Magnetic Resonance Imaging (fMRI) was used to measure brain responses during a visual matching task. The data were analysed using statistical parametric mapping and statistical inferences were made at p<0.05 (corrected for multiple comparisons). Relative to noncarriers, carriers of the risk allele had greater activation in the lingual, fusiform gyrus and inferior occipital gyri. In these regions DTNBP1 genotype accounted for 19%, 20% and 14% of the inter-individual variance, respectively. Our results suggest that that genetic variation in DTNBP1 is associated with differences in the function of brain areas that mediate visual processing, and that these effects are evident in young children. These findings are consistent with the notion that the DTNBP1 gene influences brain development and can thereby modulate vulnerability to schizophrenia.
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Affiliation(s)
- A Mechelli
- Department of Psychology, Institute of Psychiatry, King's College London, 103 Denmark Hill, London, UK.
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94
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Zanello A, Curtis L, Badan Bâ M, Merlo MCG. Working memory impairments in first-episode psychosis and chronic schizophrenia. Psychiatry Res 2009; 165:10-8. [PMID: 19046607 DOI: 10.1016/j.psychres.2007.10.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Accepted: 10/03/2007] [Indexed: 12/22/2022]
Abstract
Working memory (WM) impairments are core cognitive deficits in patients with schizophrenia linked to prefrontal cortical dysfunctions. Determining the differences between early phases of illness allows a better understanding of its course and constitutes an important guide for treatment. The present cross-sectional study examined differences of working memory functions between 33 first-episode and 29 chronic schizophrenic patients, as well as 64 healthy controls. On the basis of a two-back visual-verbal computerized working memory task, reaction time was slower and accuracy was worse in both patient groups than in controls. Test variables, however, were not significantly different between the patient groups, suggesting stability of the deficits over time. Effect size accuracy variables nevertheless showed larger deficits in chronic patients.
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Affiliation(s)
- Adriano Zanello
- University Hospitals of Geneva, Department of Psychiatry, Division of Adult Psychiatry, Geneva, Switzerland
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95
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Glutathione depletion in the brain disrupts short-term spatial memory in the Y-maze in rats and mice. Behav Brain Res 2008; 198:258-62. [PMID: 19061918 DOI: 10.1016/j.bbr.2008.11.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 10/29/2008] [Accepted: 11/10/2008] [Indexed: 11/19/2022]
Abstract
Oxidative stress and reduced brain glutathione (GSH) levels have been reported in psychiatric illnesses including schizophrenia and bipolar disorder. However the role of GSH in cognitive impairment in the illness remains unclear. Treatment of Sprague-Dawley rats and C57Bl/6 mice with 2-cyclohexene-1-one (CHX) dose-dependently reduced striatal and frontal cortical GSH levels similar to those in schizophrenia. In both species, GSH depletion resulted in disruption of short-term spatial recognition memory in a Y-maze test. In conclusion, GSH depletion induces cognitive impairment, which may be relevant to the role of GSH in psychiatric illnesses.
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96
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Abdi A, Tahoori MB, Emamian ES. Fault Diagnosis Engineering of Digital Circuits Can Identify Vulnerable Molecules in Complex Cellular Pathways. Sci Signal 2008; 1:ra10. [DOI: 10.1126/scisignal.2000008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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97
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Wang Y, Chan RCK, Hong X, Ma Z, Yang T, Guo L, Yu X, Li Z, Yuan Y, Gong QY, Shum D. Prospective memory in schizophrenia: further clarification of nature of impairment. Schizophr Res 2008; 105:114-24. [PMID: 18707848 DOI: 10.1016/j.schres.2008.07.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 06/16/2008] [Accepted: 07/01/2008] [Indexed: 10/21/2022]
Abstract
Prospective memory (PM) refers to the ability to execute a delayed intention and is different from retrospective memory (RM) in its nature and underlying mechanism (e.g., intention formation, maintenance, detection of PM cue and intention execution). Although preliminary studies have found PM impairment in patients with schizophrenia, the nature and magnitude of this problem in this clinical group is not yet fully known. The current study aimed to further clarify the nature of this impairment in schizophrenia. Fifty-four patients with schizophrenia and fifty-four healthy volunteers matched on demographic variables, IQ and executive functions took part in the study. Time-, event-, and activity-based PM tasks and a set of neurocognitive tests were administered to the participants. Results showed that patients with schizophrenia performed significantly worse on all sub-types of PM tasks, even after controlling for neurocognitive functions such as working memory, verbal memory, visual memory, and executive function. These findings suggest PM deficit is a primary deficit rather than a secondary consequence of neurocognitive impairments in schizophrenia. Analysis found that PM deficits may be mainly due to the impairment of the cue detection and intention retrieval stage.
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Affiliation(s)
- Ya Wang
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Department of Psychology, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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98
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Snyder PJ, Jackson CE, Piskulic D, Olver J, Norman T, Maruff P. Spatial working memory and problem solving in schizophrenia: the effect of symptom stabilization with atypical antipsychotic medication. Psychiatry Res 2008; 160:316-26. [PMID: 18579217 DOI: 10.1016/j.psychres.2007.07.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 04/10/2007] [Accepted: 07/14/2007] [Indexed: 11/19/2022]
Abstract
Reasoning and problem solving in the spatial domain are important aspects of executive function that are reliably impaired in schizophrenia, and the Groton Maze Learning Test(c) (GMLT) provides a valid measure of spatial working memory. In the current study, 34 patients with first-episode schizophrenia and 20 matched controls were assessed for baseline spatial working memory abilities using this hidden maze learning test. Approximately one month after baseline assessment, allowing for symptoms to stabilize in response to treatment with therapeutic doses of atypical antipsychotic medications for individuals with schizophrenia, all participants were again assessed with the GMLT. Prior to pharmacologic intervention, patients with schizophrenia showed significant impairments in performance of all aspects of the GMLT, including measures of learning efficiency and error monitoring. One month of treatment was associated with a reliable improvement in these domains, although impairments in accuracy and error monitoring on this spatial working memory test persisted despite symptomatic improvement. These results indicate that impairments in spatial working memory are present at the earliest stages of the illness, and that such deficits in performance remain present, albeit ameliorated, after treatment with atypical antipsychotic medication.
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Affiliation(s)
- Peter J Snyder
- Department of Psychology, University of Connecticut, Storrs, CT, USA
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99
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Babovic D, O'Tuathaigh CM, O'Connor AM, O'Sullivan GJ, Tighe O, Croke DT, Karayiorgou M, Gogos JA, Cotter D, Waddington JL. Phenotypic characterization of cognition and social behavior in mice with heterozygous versus homozygous deletion of catechol-O-methyltransferase. Neuroscience 2008; 155:1021-9. [PMID: 18674597 DOI: 10.1016/j.neuroscience.2008.07.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 07/01/2008] [Accepted: 07/03/2008] [Indexed: 02/06/2023]
Abstract
Catechol-O-methyltransferase is an important enzyme in the metabolism of dopamine and an important regulator of aspects of dopamine-dependent working memory in prefrontal cortex that are disturbed in schizophrenia. This study investigated the phenotype of mice with heterozygous deletion vs. homozygous knockout of the catechol-O-methyltransferase gene across paradigms that access processes relevant for psychotic illness. Homozygotes evidenced improved performance in spontaneous alternation, an index of immediate spatial working memory; this effect appeared more substantive in males and was reflected in performance in aspects of the Barnes maze, an index of spatial learning/memory. Heterozygotes evidenced impaired performance in object recognition, an index of recognition memory; this effect was evident for both sexes at a retention interval of 5 min but appeared more enduring in males. There were no material effects for either genotype in relation to sociability or social novelty preference. While homozygous catechol-O-methyltransferase deletion results in improvement in spatial learning/working memory with little effect on social behavior, heterozygous deletion results in impairment of recognition memory. We have reported recently, using similar methods, that mice with deletion of the schizophrenia risk gene neuregulin-1 evidence disruption to social behavior, with little effect on spatial learning/working memory. The data suggest that catechol-O-methyltransferase and neuregulin-1 may influence, respectively, primarily cognitive and social endophenotypes of the overall schizophrenia syndrome.
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Affiliation(s)
- D Babovic
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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100
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Bergemann N, Parzer P, Kaiser D, Maier-Braunleder S, Mundt C, Klier C. Testosterone and gonadotropins but not estrogen associated with spatial ability in women suffering from schizophrenia: a double-blind, placebo-controlled study. Psychoneuroendocrinology 2008; 33:507-16. [PMID: 18343039 DOI: 10.1016/j.psyneuen.2008.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 12/20/2007] [Accepted: 01/21/2008] [Indexed: 01/16/2023]
Abstract
The aim of this study was to investigate the association between estrogen and spatial ability tasks in women suffering from schizophrenia. For this purpose, a placebo-controlled, double-blind, three-time cross-over study using 17beta-estradiol combined with norethisterone acetate for replacement therapy and as an adjunct to a naturalistic maintenance antipsychotic treatment was carried out over a period of 8 months. Nineteen women (mean age=38.0 years, SD=9.9 years) with schizophrenia hospitalized for the first time or repeatedly were included in the study. Sex hormones - 17beta-estradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, testosterone, and dehydroepiandrosterone sulfate - were measured and the patients completed a neuropsychological test in the last two active drug and/or placebo phases. Three different spatial ability tasks - spatial orientation, spatial visualization, and flexibility of closure - were measured by a paper-and-pencil test. No association between estrogen and spatial ability was found; however, in an additional exploratory data analysis, high levels of testosterone, LH, and FSH correlated significantly with performance in the flexibility of closure task. This is the very first study, based on estrogen intervention instead of physiological hormone changes, to examine the association between estrogen and spatial ability in women with schizophrenia.
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Affiliation(s)
- Niels Bergemann
- Department of General Psychiatry, University of Heidelberg, Voss-Str. 4, D-69115 Heidelberg, Germany.
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