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Danyeli LV, Sen ZD, Colic L, Opel N, Refisch A, Blekic N, Macharadze T, Kretzschmar M, Munk MJ, Gaser C, Speck O, Walter M, Li M. Cortical thickness of the posterior cingulate cortex is associated with the ketamine-induced altered sense of self: An ultra-high field MRI study. J Psychiatr Res 2024; 172:136-143. [PMID: 38382237 DOI: 10.1016/j.jpsychires.2024.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 01/31/2024] [Accepted: 02/07/2024] [Indexed: 02/23/2024]
Abstract
Subanesthetic doses of ketamine induce an antidepressant effect within hours in individuals with treatment-resistant depression while it furthermore induces immediate but transient psychotomimetic effects. Among these psychotomimetic effects, an altered sense of self has specifically been associated with the antidepressant response to ketamine as well as psychedelics. However, there is plenty of variation in the extent of the drug-induced altered sense of self experience that might be explained by differences in basal morphological characteristics, such as cortical thickness. Regions that have been previously associated with a psychedelics-induced sense of self and with ketamine's mechanism of action, are the posterior cingulate cortex (PCC) and the pregenual anterior cingulate cortex (pgACC). In this randomized, placebo-controlled, double-blind cross-over magnetic resonance imaging study, thirty-five healthy male participants (mean age ± standard deviation (SD) = 25.1 ± 4.2 years) were scanned at 7 T. We investigated whether the cortical thickness of two DMN regions, the PCC and the pgACC, are associated with disembodiment and experience of unity scores, which were used to index the ketamine-induced altered sense of self. We observed a negative correlation between the PCC cortical thickness and the disembodiment scores (R = -0.54, p < 0.001). In contrast, no significant association was found between the pgACC cortical thickness and the ketamine-induced altered sense of self. In the context of the existing literature, our findings highlight the importance of the PCC as a structure involved in the mechanism of ketamine-induced altered sense of self that seems to be shared with different antidepressant agents with psychotomimetic effects operating on different classes of transmitter systems.
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Affiliation(s)
- Lena Vera Danyeli
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Clinical Affective Neuroimaging Laboratory (CANLAB), Magdeburg, Germany; Department of Psychiatry and Psychotherapy, University Tübingen, Tübingen, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany
| | - Zümrüt Duygu Sen
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Clinical Affective Neuroimaging Laboratory (CANLAB), Magdeburg, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany
| | - Lejla Colic
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany; German Center for Mental Health (DZPG), partner site Halle-Jena-Magdeburg, Germany
| | - Nils Opel
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany; German Center for Mental Health (DZPG), partner site Halle-Jena-Magdeburg, Germany
| | - Alexander Refisch
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany
| | - Nikolai Blekic
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Clinical Affective Neuroimaging Laboratory (CANLAB), Magdeburg, Germany
| | - Tamar Macharadze
- Department of Anesthesiology and Intensive Care Medicine, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany; Department Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Moritz Kretzschmar
- Department of Anesthesiology and Intensive Care Medicine, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - MatthiasH J Munk
- Department of Psychiatry and Psychotherapy, University Tübingen, Tübingen, Germany; Systems Neurophysiology, Department of Biology, Darmstadt University of Technology, Darmstadt, Germany
| | - Christian Gaser
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany; German Center for Mental Health (DZPG), partner site Halle-Jena-Magdeburg, Germany; Department of Neurology, Jena University Hospital, Jena, Germany
| | - Oliver Speck
- Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany; German Center for Mental Health (DZPG), partner site Halle-Jena-Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany; Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Martin Walter
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Clinical Affective Neuroimaging Laboratory (CANLAB), Magdeburg, Germany; Department of Psychiatry and Psychotherapy, University Tübingen, Tübingen, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany; German Center for Mental Health (DZPG), partner site Halle-Jena-Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany.
| | - Meng Li
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Clinical Affective Neuroimaging Laboratory (CANLAB), Magdeburg, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Halle-Jena-Magdeburg, Germany.
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Fivel L, Mondino M, Brunelin J, Haesebaert F. Basic auditory processing and its relationship with symptoms in patients with schizophrenia: A systematic review. Psychiatry Res 2023; 323:115144. [PMID: 36940586 DOI: 10.1016/j.psychres.2023.115144] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/09/2023] [Accepted: 03/01/2023] [Indexed: 03/23/2023]
Abstract
Processing of basic auditory features, one of the earliest stages of auditory perception, has been the focus of considerable investigations in schizophrenia. Although numerous studies have shown abnormalities in pitch perception in schizophrenia, other basic auditory features such as intensity, duration, and sound localization have been less explored. Additionally, the relationship between basic auditory features and symptom severity shows inconsistent results, preventing concrete conclusions. Our aim was to present a comprehensive overview of basic auditory processing in schizophrenia and its relationship with symptoms. We conducted a systematic review according to the PRISMA guidelines. PubMed, Embase, and PsycINFO databases were searched for studies exploring auditory perception in schizophrenia compared to controls, with at least one behavioral task investigating basic auditory processing using pure tones. Forty-one studies were included. The majority investigated pitch processing while the others investigated intensity, duration and sound localization. The results revealed that patients have a significant deficit in the processing of all basic auditory features. Although the search for a relationship with symptoms was limited, auditory hallucinations experience appears to have an impact on basic auditory processing. Further research may examine correlations with clinical symptoms to explore the performance of patient subgroups and possibly implement remediation strategies.
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Affiliation(s)
- Laure Fivel
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, Bron F-69500, France
| | - Marine Mondino
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, Bron F-69500, France; Centre Hospitalier Le Vinatier, 95 Boulevard Pinel, Bron F-69500, France.
| | - Jerome Brunelin
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, Bron F-69500, France; Centre Hospitalier Le Vinatier, 95 Boulevard Pinel, Bron F-69500, France
| | - Frédéric Haesebaert
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, Bron F-69500, France; Centre Hospitalier Le Vinatier, 95 Boulevard Pinel, Bron F-69500, France
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Pratt JA, Morris B, Dawson N. Deconstructing Schizophrenia: Advances in Preclinical Models for Biomarker Identification. Curr Top Behav Neurosci 2018; 40:295-323. [PMID: 29721851 DOI: 10.1007/7854_2018_48] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Schizophrenia is considered to develop as a consequence of genetic and environmental factors impacting on brain neural systems and circuits during vulnerable neurodevelopmental periods, thereby resulting in symptoms in early adulthood. Understanding of the impact of schizophrenia risk factors on brain biology and behaviour can help in identifying biologically relevant pathways that are attractive for informing clinical studies and biomarker development. In this chapter, we emphasize the importance of adopting a reciprocal forward and reverse translation approach that is iteratively updated when additional new information is gained, either preclinically or clinically, for offering the greatest opportunity for discovering panels of biomarkers for the diagnosis, prognosis and treatment of schizophrenia. Importantly, biomarkers for identifying those at risk may inform early intervention strategies prior to the development of schizophrenia.Given the emerging nature of this approach in the field, this review will highlight recent research of preclinical biomarkers in schizophrenia that show the most promise for informing clinical needs with an emphasis on relevant imaging, electrophysiological, cognitive behavioural and biochemical modalities. The implementation of this reciprocal translational approach is exemplified firstly by the production and characterization of preclinical models based on the glutamate hypofunction hypothesis, genetic and environmental risk factors for schizophrenia (reverse translation), and then the recent clinical recognition of the thalamic reticular thalamus (TRN) as an important locus of brain dysfunction in schizophrenia as informed by preclinical findings (forward translation).
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Affiliation(s)
- Judith A Pratt
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.
| | - Brian Morris
- Institute of Neuroscience and Psychology, College of Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Neil Dawson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
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Haigh SM, Gupta A, Barb SM, Glass SAF, Minshew NJ, Dinstein I, Heeger DJ, Eack SM, Behrmann M. Differential sensory fMRI signatures in autism and schizophrenia: Analysis of amplitude and trial-to-trial variability. Schizophr Res 2016; 175:12-19. [PMID: 27083780 PMCID: PMC4958557 DOI: 10.1016/j.schres.2016.03.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 03/24/2016] [Accepted: 03/30/2016] [Indexed: 01/06/2023]
Abstract
Autism and schizophrenia share multiple phenotypic and genotypic markers, and there is ongoing debate regarding the relationship of these two disorders. To examine whether cortical dynamics are similar across these disorders, we directly compared fMRI responses to visual, somatosensory and auditory stimuli in adults with autism (N=15), with schizophrenia (N=15), and matched controls (N=15). All participants completed a one-back letter detection task presented at fixation (to control attention) while task-irrelevant sensory stimulation was delivered to the different modalities. We focused specifically on the response amplitudes and the variability in sensory fMRI responses of the two groups, given the evidence of greater trial-to-trial variability in adults with autism. Both autism and schizophrenia individuals showed weaker signal-to-noise ratios (SNR) in sensory-evoked responses compared to controls (d>0.42), but for different reasons. For the autism group, the fMRI response amplitudes were indistinguishable from controls but were more variable trial-to-trial (d=0.47). For the schizophrenia group, response amplitudes were smaller compared to autism (d=0.44) and control groups (d=0.74), but were not significantly more variable (d<0.29). These differential group profiles suggest (1) that greater trial-to-trial variability in cortical responses may be specific to autism and is not a defining characteristic of schizophrenia, and (2) that blunted response amplitudes may be characteristic of schizophrenia. The relationship between the amplitude and the variability of cortical activity might serve as a specific signature differentiating these neurodevelopmental disorders. Identifying the neural basis of these responses and their relationship to the underlying genetic bases may substantially enlighten the understanding of both disorders.
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Affiliation(s)
- Sarah M. Haigh
- Department of Psychology, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Akshat Gupta
- Department of Psychology, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Scott M. Barb
- School of Social Work, University of Pittsburgh, 2117 Cathedral of Learning, Pittsburgh, PA 15260, USA
| | - Summer A. F. Glass
- School of Social Work, University of Pittsburgh, 2117 Cathedral of Learning, Pittsburgh, PA 15260, USA
| | - Nancy J. Minshew
- Departments of Psychiatry & Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ilan Dinstein
- Psychology Department, Ben-Gurion University of the Negev, 653, Beer-Sheva, 84105, Israel
| | - David J. Heeger
- Department of Psychology and Center for Neural Science, New York University, 6 Washington Place, New York, NY 10003, USA
| | - Shaun M. Eack
- School of Social Work, University of Pittsburgh, 2117 Cathedral of Learning, Pittsburgh, PA 15260, USA.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Marlene Behrmann
- Department of Psychology, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
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Roberts RC, Barksdale KA, Roche JK, Lahti AC. Decreased synaptic and mitochondrial density in the postmortem anterior cingulate cortex in schizophrenia. Schizophr Res 2015; 168:543-53. [PMID: 26210550 PMCID: PMC4591176 DOI: 10.1016/j.schres.2015.07.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/07/2015] [Accepted: 07/10/2015] [Indexed: 12/24/2022]
Abstract
Schizophrenia (SZ) is a mental illness characterized by psychosis, negative symptoms, and cognitive deficits. The anterior cingulate cortex (ACC), a structurally and functionally diverse region, is one of several brain regions that is abnormal in SZ. The present study compared synaptic organization and mitochondrial number and morphology in postmortem ACC in SZ versus normal control (NC). Total synaptic density in the combined ACC was decreased in SZ, to 72% of normal controls (NCs), due to selective decreases in axospinous synapses, both asymmetric (excitatory) and symmetric (inhibitory). These changes were present in layers 3 and 5/6. The density of mitochondria in all axon terminals combined in SZ was decreased to 64% of NC. In layer 3, mitochondrial density was decreased only in terminals forming asymmetric synapses with spines, while in layers 5/6 mitochondrial density was decreased in terminals forming symmetric synapses with spines and dendrites. The proportion of terminals making symmetric synapses that contained mitochondria was significantly lower in SZ than in NCs, especially for symmetric axospinous synapses. The number of mitochondria per neuronal somata was decreased in the ACC in SZ compared to NCs; this finding was present in layers 5-6. The size of mitochondria in neuronal somata and throughout the neuropil was similar in SZ and NCs. Our results, though preliminary, are well supported by the literature, and support an anatomical substrate for some of the altered executive functions found in SZ.
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Affiliation(s)
- R C Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States.
| | - K A Barksdale
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States
| | - J K Roche
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States
| | - A C Lahti
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States
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Silver H, Bilker WB. Pathways to similar executive impairment: comparison of schizophrenia patients and healthy aging individuals. Psychiatry Res 2013; 210:694-701. [PMID: 23972766 DOI: 10.1016/j.psychres.2013.07.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 07/17/2013] [Accepted: 07/20/2013] [Indexed: 12/14/2022]
Abstract
Executive impairment is prominent in schizophrenia, in conditions such as Parkinson's disease and dementia and in healthy aging. Identifying processes that critically constrain executive function can advance investigation of their biological basis and treatment planning. Recent findings that elderly healthy individuals showed similar impairment on conditional exclusion task as schizophrenia patients raised the question whether similar processes are impaired. To test this we compared 56 schizophrenia patients, 57 elderly and 77 young healthy individuals on three executive tests: conditional exclusion, abstraction and inhibition and tests of working memory and psychomotor speed. Schizophrenia patients performed worse than elderly healthy on abstraction, inhibition and verbal working memory. They were similarly impaired on Penn Conditional Exclusion Test (PCET) outcome measures but differed in performance characteristics. Schizophrenia patients needed relatively more trials to learn the first PCET category than the second or the third. This correlated with other cognitive impairments, particularly in working memory. Elderly healthy individuals found it most difficult to learn the last category. The two groups showed different error patterns. We propose that schizophrenia patients have particular difficulty in early (probabilistic) learning ("what to do") while aging individuals have selective impairment in executive integration. These constitute distinct targets for customized treatment in the two conditions.
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Affiliation(s)
- Henry Silver
- Brain Behavior Laboratory, Sha'ar Menashe Mental Health Center, Mobile Post Hefer 38814, Israel; Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel.
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Pauli A, Prata DP, Mechelli A, Picchioni M, Fu CHY, Chaddock CA, Kane F, Kalidindi S, McDonald C, Kravariti E, Toulopoulou T, Bramon E, Walshe M, Ehlert N, Georgiades A, Murray R, Collier DA, McGuire P. Interaction between effects of genes coding for dopamine and glutamate transmission on striatal and parahippocampal function. Hum Brain Mapp 2013; 34:2244-58. [PMID: 22438288 PMCID: PMC6869864 DOI: 10.1002/hbm.22061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 01/08/2012] [Accepted: 01/25/2012] [Indexed: 12/17/2022] Open
Abstract
The genes for the dopamine transporter (DAT) and the D-Amino acid oxidase activator (DAOA or G72) have been independently implicated in the risk for schizophrenia and in bipolar disorder and/or their related intermediate phenotypes. DAT and G72 respectively modulate central dopamine and glutamate transmission, the two systems most robustly implicated in these disorders. Contemporary studies have demonstrated that elevated dopamine function is associated with glutamatergic dysfunction in psychotic disorders. Using functional magnetic resonance imaging we examined whether there was an interaction between the effects of genes that influence dopamine and glutamate transmission (DAT and G72) on regional brain activation during verbal fluency, which is known to be abnormal in psychosis, in 80 healthy volunteers. Significant interactions between the effects of G72 and DAT polymorphisms on activation were evident in the striatum, parahippocampal gyrus, and supramarginal/angular gyri bilaterally, the right insula, in the right pre-/postcentral and the left posterior cingulate/retrosplenial gyri (P < 0.05, FDR-corrected across the whole brain). This provides evidence that interactions between the dopamine and the glutamate system, thought to be altered in psychosis, have an impact in executive processing which can be modulated by common genetic variation.
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Affiliation(s)
- Andreina Pauli
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, United Kingdom.
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Abstract
Schizophrenia is an illness where the clinical signs and symptoms, course, and cognitive characteristics are well described. Successful pharmacological treatments do exist, even though they are likely palliative. However, this broad knowledge base has not yet led to the identification of its pathophysiology or etiology The risk factors for schizophrenia are most prominently genetic and scientists anticipate that contributions from the new genetic information in the human genome will help progress towards discovering a disease mechanism. Brain-imaging techniques have opened up the schizophrenic brain for direct inquiries, in terms of structure, neurochemisiry, and function. New proposals for diagnosis include grouping schizophrenia together with schizophrenia-related personality disorders into the same disease entity, and calling this schizophrenia spectrum disorder. New hypotheses of pathophysiology do not overlook dopamine as playing a major role, but do emphasize the participation of integrative neural systems in the expression of the illness and of the limbic system in generating symptoms. Critical observations for future discovery are likely to arise from molecular genetics, combined with hypothesis-generating experiments using brain imaging and human postmortem tissue.
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Affiliation(s)
- C A Tamminga
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Md, USA
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Abstract
Studies on the pathophysiology of schizophrenia have implicated the limbic cortex, using postmortem, structural, and functional data, especially in the hippocampus (HC) and the anterior cingulate cortex (ACC). We have made contributions to the literature consistent with this idea: first, we describe a positive significant correlation between psychotic symptoms in schizophrenia and neuronal activity in the ACC and HC, suggesting the involvement of limbic cortex in the mediation of symptoms in schizophrenia. Second, in the ACC and the anterior HC (but not in the posterior HC), regional cerebral blood flow (rCBF) is abnormal (ie, reduced in the ACC and elevated in the HC) in schizophrenia. Third, the relationship of rCBF to task difficulty in the ACC is altered in schizophrenia, suggesting a failure of participation of the ACC in effortful tasks. Lastly, connectivity between the ACC and HC during the performance of an auditory discrimination task is also lacking, suggesting that cognitive performance in schizophrenia lacks a functional limbic contribution. On the basis of these changes, we studied the effects of antipsychotic drugs in these abnormal areas in persons with schizophrenia. Both first- and second-generation antipsychotics produce functional alterations in these limbic cortical areas, in the direction of normals, putatively acting through the brain's own cortical-subcortical circuits.
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Affiliation(s)
- Carol A Tamminga
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Md, USA
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Silver H, Goodman C, Bilker WB. Impairment in associative memory in healthy aging is distinct from that in other types of episodic memory. Psychiatry Res 2012; 197:135-9. [PMID: 22429482 DOI: 10.1016/j.psychres.2012.01.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 01/22/2012] [Accepted: 01/25/2012] [Indexed: 12/13/2022]
Abstract
There is evidence that age related changes in episodic memory are heterogeneous and result from diverse pathologies. To test this, we examined performance of healthy high-functioning younger (N=41, ages 18-60 y) and older (N=58, ages 61-83 y) individuals in tests of associative memory, logical memory and memory in executive and object-recognition domains. We compared their relationships to each other and to other cognitive functions, including, psychomotor speed and verbal and spatial working memory. Older individuals showed significantly greater reduction in an index of the ability to learn new associations (NAL) than for memory in executive and object-recognition domains. Age-related reduction in NAL and in logical memory was of similar severity, but the two measures showed only moderate correlation when age and other cognitive functions were controlled for. NAL shows an age-related pattern of change distinct from memory in executive and object-recognition domains and from logical (item) memory. We propose that in healthy well-functioning individuals, NAL taps processes which support binding of newly learned association in context of accumulating information, a key function of the hippocampus. NAL may thus serve as a selective marker of complex, hippocampus-based, cognitive functions in studies of normal cognitive aging and of its possible relationship to early dementia.
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Affiliation(s)
- Henry Silver
- Sha'ar Menashe Mental Health Center, Mobile Post Hefer, Israel.
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Prata DP, Papagni SA, Mechelli A, Fu CHY, Kambeitz J, Picchioni M, Kane F, Kalidindi S, McDonald C, Kravariti E, Toulopoulou T, Bramon E, Walshe M, Murray R, Collier DA, McGuire PK. Effect of D-amino acid oxidase activator (DAOA; G72) on brain function during verbal fluency. Hum Brain Mapp 2012; 33:143-53. [PMID: 21391259 PMCID: PMC6870192 DOI: 10.1002/hbm.21198] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 10/17/2010] [Accepted: 10/18/2010] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The D-Amino acid oxidase activator (G72 or DAOA) is believed to play a key role in the regulation of central glutamatergic transmission which is seen to be altered in psychosis. It is thought to regulate D-amino acid oxidase (DAO), which metabolizes D-serine, a co-agonist of NMDA-type glutamate receptors and to be involved in dendritic arborization. Linkage, genetic association and expression studies have implicated the G72 gene in both schizophrenia and bipolar disorder. AIMS To examine the influence of G72 variation on brain function in the healthy population. METHOD Fifty healthy volunteers were assessed using functional magnetic resonance imaging while performing a verbal fluency task. Regional brain activation and task-dependent functional connectivity during word generation was compared between different rs746187 genotypes. RESULTS G72 rs746187 genotype had a significant effect on activation in the left postcentral and supramarginal gyri (FWE P < 0.05), and on the task-dependent functional coupling of this region with the retrosplenial cingulate gyrus (FWE P < 0.05). CONCLUSIONS Our results may reflect an effect of G72 on glutamatergic transmission, mediated by an influence on D-amino acid oxidase activity, on brain areas particularly relevant to the hypoglutamatergic model of psychosis.
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Affiliation(s)
- Diana P Prata
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK.
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Bolding MS, White DM, Hadley JA, Weiler M, Holcomb HH, Lahti AC. Antipsychotic Drugs Alter Functional Connectivity between the Medial Frontal Cortex, Hippocampus, and Nucleus Accumbens as Measured by H215O PET. Front Psychiatry 2012; 3:105. [PMID: 23230425 PMCID: PMC3515723 DOI: 10.3389/fpsyt.2012.00105] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 11/19/2012] [Indexed: 11/23/2022] Open
Abstract
To evaluate changes in functional connectivity as a result of treatment with antipsychotic drugs (APDs) in subjects with schizophrenia (SZ), we identified a limited number of regions that have been implicated in the mechanism of action of APDs and that are part of a neuronal network known to be modulated by dopamine (DA). These regions consisted of the nucleus accumbens (NAcc), the hippocampus (Hip), and the medial frontal cortex (MFC). SZ participants were blindly randomized into a haloperidol treatment group (n = 12) and an olanzapine treatment group (n = 17). Using PET with 15O, we evaluated changes in functional connectivity between these regions during rest and task performance at three treatment time points: (1) at baseline, after withdrawal of all psychotropic medication (2 weeks), (2) after 1 week on medication, and (3) after 6 weeks on medication. Results from the two treatment groups were combined during analysis to investigate the common effects of APDs on functional connectivity. We found that the functional connectivity between MFC and NAcc significantly increased at week one, and then significantly decreased from week one to week 6. The functional connectivity between MFC and Hip significantly decreased at week one and week 6 relative to baseline. Critically, the strength of the functional connectivity between the MFC and Hip after 1 week of treatment was predictive of treatment response. This pattern of changes may represent an important biomarker for indexing treatment response. The regulation by APDs of the balance between prefrontal and limbic inputs to the striatum may be crucial to restoring adaptive behavior.
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Affiliation(s)
- Mark S Bolding
- Department of Psychiatry and Behavioral Neurobiology, The University of Alabama at Birmingham Birmingham, AL, USA ; Department of Vision Sciences, The University of Alabama at Birmingham Birmingham, AL, USA
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Avsar KB, Stoeckel LE, Bolding MS, White DM, Tagamets MA, Holcomb HH, Lahti AC. Aberrant visual circuitry associated with normal spatial match-to-sample accuracy in schizophrenia. Psychiatry Res 2011; 193:138-43. [PMID: 21782395 DOI: 10.1016/j.pscychresns.2011.03.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 12/20/2010] [Accepted: 03/15/2011] [Indexed: 11/16/2022]
Abstract
A goal of this study was to evaluate the function of the anterior cingulate cortex (ACC) and of the dorsolateral prefrontal cortex (DLPFC) in medicated patients with schizophrenia (SZ), a small group of first-degree relatives, and healthy controls using a visual delayed match-to-sample task in conjunction with functional magnetic resonance imaging (fMRI). To mitigate performance differences between SZ and healthy controls, we used a novel task that allows for individualized adjustment of task difficulty to match ability level. We also trained participants on the task prior to scanning. Using an event-related design, we modeled three components of the match-to-sample trial: visual encoding, delay, and discrimination. We did not find significant differences in ACC/medial frontal cortex activation between the groups. However, compared to healthy controls, SZ showed decreased activation in visual processing areas during the encoding and discrimination phases of the task and in the ventrolateral prefrontal cortex during the delay. These findings emphasize the tendency of schizophrenia subjects to solve perceptual memory problems by engaging diverse regions.
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Affiliation(s)
- Kathy Burton Avsar
- Department of Psychiatry and Behavioral Neurobiology, The University of Alabama at Birmingham, Birmingham, AL 35294-0017, USA
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14
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Horga G, Parellada E, Lomeña F, Fernández-Egea E, Mané A, Font M, Falcón C, Konova AB, Pavia J, Ros D, Bernardo M. Differential brain glucose metabolic patterns in antipsychotic-naïve first-episode schizophrenia with and without auditory verbal hallucinations. J Psychiatry Neurosci 2011; 36:312-21. [PMID: 21266125 PMCID: PMC3163647 DOI: 10.1503/jpn.100085] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Auditory verbal hallucinations (AVHs) are a core symptom of schizophrenia. Previous reports on neural activity patterns associated with AVHs are inconsistent, arguably owing to the lack of an adequate control group (i.e., patients with similar characteristics but without AVHs) and neglect of the potential confounding effects of medication. METHODS The current study was conducted in a homogeneous group of patients with schizophrenia to assess whether the presence or absence of AVHs was associated with differential regional cerebral glucose metabolic patterns. We investigated differences between patients with commenting AVHs and patients without AVHs among a group of dextral antipsychotic-naive inpatients with acute first-episode schizophrenia examined with [(18)F]fluoro-deoxyglucose positron emission tomography (FDG-PET) at rest. Univariate and multivariate approaches were used to establish between-group differences. RESULTS We included 9 patients with AVHs and 7 patients without AVHs in this study. Patients experiencing AVHs during FDG uptake had significantly higher metabolic rates in the left superior and middle temporal cortices, bilateral superior medial frontal cortex and left caudate nucleus (cluster level p < 0.005, family wise error-corrected, and bootstrap ratio > 3.3, respectively). Additionally, the multivariate method identified hippocampal-parahippocampal, cerebellar and parietal relative hypoactivity during AVHs in both hemispheres (bootstrap ratio < -3.3). LIMITATIONS The FDG-PET imaging technique does not provide information regarding the temporal course of neural activity. The limited sample size may have increased the risk of false-negative findings. CONCLUSION Our results indicate that AVHs in patients with schizophrenia may be mediated by an alteration of neural pathways responsible for normal language function. Our findings also point to the potential role of the dominant caudate nucleus and the parahippocampal gyri in the pathophysiology of AVHs. We discuss the relevance of phenomenology-based grouping in the study of AVHs.
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Affiliation(s)
- Guillermo Horga
- Clinic Schizophrenia Program, Psychiatry Department, Hospital Clinic of Barcelona, Barcelona, Spain.
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15
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Gur RC, Richard J, Hughett P, Calkins ME, Macy L, Bilker WB, Brensinger C, Gur RE. A cognitive neuroscience-based computerized battery for efficient measurement of individual differences: standardization and initial construct validation. J Neurosci Methods 2009; 187:254-62. [PMID: 19945485 DOI: 10.1016/j.jneumeth.2009.11.017] [Citation(s) in RCA: 355] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 11/17/2009] [Accepted: 11/23/2009] [Indexed: 11/15/2022]
Abstract
There is increased need for efficient computerized methods to collect reliable data on a range of cognitive domains that can be linked to specific brain systems. Such need arises in functional neuroimaging studies, where individual differences in cognitive performance are variables of interest or serve as confounds. In genetic studies of complex behavior, which require particularly large samples, such trait measures can serve as endophenotypes. Traditional neuropsychological tests, based on clinical pathological correlations, are protracted, require extensive training in administration and scoring, and leave lengthy paper trails (double-entry for analysis). We present a computerized battery that takes an average of 1h and provides measures of accuracy and speed on 9 neurocognitive domains. They are cognitive neuroscience-based in that they have been linked experimentally to specific brain systems with functional neuroimaging studies. We describe the process of translating tasks used in functional neuroimaging to tests for assessing individual differences. Data are presented on each test with samples ranging from 139 (81 female) to 536 (311 female) of carefully screened healthy individuals ranging in age from 18 to 84. Item consistency was established with acceptable to high Cronbach alpha coefficients. Inter-item correlations were moderate to high within domain and low to nil across domains, indicating construct validity. Initial criterion validity was demonstrated by sensitivity to sex differences and the effects of age, education and parental education. These results encourage the use of this battery in studies needing an efficient assessment of major neurocognitive domains such as multi-site genetic studies and clinical trials.
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Affiliation(s)
- Ruben C Gur
- Brain Behavior Laboratory, Section of Neuropsychiatry, Department of Psychiatry, Philadelphia, PA 19104-4283, United States.
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16
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Impaired recognition of happy, sad and neutral expressions in schizophrenia is emotion, but not valence, specific and context dependent. Psychiatry Res 2009; 169:101-6. [PMID: 19692127 DOI: 10.1016/j.psychres.2008.11.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2008] [Revised: 11/10/2008] [Accepted: 11/18/2008] [Indexed: 11/27/2022]
Abstract
It is not clear whether the deficits in emotion perception in schizophrenia are distinct from cognitive impairments or affect some emotions more than others. We tested the hypothesis that the emotion perception deficit in schizophrenia is valence specific. Participants comprised 75 chronic schizophrenia patients and 77 healthy controls who were asked to identify happy, sad and neutral facial emotional expressions. A test of facial identity recognition was also performed. Processing of happy, sad and neutral expressions differed in accuracy, processing strategy and efficiency. Patients were impaired on all parameters, but the valence-related pattern of performance did not differ in the two groups. Compared with healthy individuals, schizophrenia patients were more impaired in the processing of facial emotions than identity. Processing of neutral expressions was context dependent. Emotion impairment in schizophrenia appears to be selective for the emotion domain but not specific emotions. Test context influences how neutral facial expressions are processed.
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17
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Mathalon DH, Jorgensen KW, Roach BJ, Ford JM. Error detection failures in schizophrenia: ERPs and FMRI. Int J Psychophysiol 2009; 73:109-17. [PMID: 19414043 PMCID: PMC4005823 DOI: 10.1016/j.ijpsycho.2009.02.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 02/01/2009] [Accepted: 02/25/2009] [Indexed: 01/23/2023]
Abstract
Self-monitoring of actions, critical for guiding goal-directed behavior, is deficient in schizophrenia. Defective error-monitoring may reflect more general self-monitoring deficiencies. Prior studies have shown that the error-related negativity (ERN) component of the event-related potential (ERP) is smaller in patients with schizophrenia. Other studies using functional magnetic resonance imaging (FMRI) have shown the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC), both critical for error detection, to be less responsive to errors in patients with schizophrenia. In the present study, both ERP and FMRI data were collected while 11 patients with schizophrenia and 10 healthy controls performed a Go-NoGo task requiring a button press to Xs (p=.88) while withholding responses to Ks (p=.12). We measured the ERN and ACC and DLPFC activations to false alarms. The task elicited a robust ERN and modest activations in ACC and DLPFC to false alarms. As expected, ERN was larger in controls than patients. However, ACC and DLPFC activations were not greater in controls than patients. Surprisingly, DLPFC was more activated by errors in patients than controls. ERPs may be superior to fMRI for assessing error processing abnormalities in schizophrenia because (1) ERNs can be measured precisely without needing to control for the multiple comparisons of FMRI, and (2) ERPs have the temporal precision to detect transient activity necessary for error detection and on-the-fly behavioral adjustments.
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Affiliation(s)
- Daniel H Mathalon
- Psychiatry Service, San Francisco VA Medical Center, and Department of Psychiatry, University of California-San Francisco, 4150 Clement Street, San Francisco, CA 94121, USA.
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18
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Schirmer TN, Dorflinger JM, Marlow-O'Connor M, Pendergrass JC, Hartzell A, All SD, Charles D. FMRI indices of auditory attention in schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:25-32. [PMID: 18957312 DOI: 10.1016/j.pnpbp.2008.09.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 09/24/2008] [Accepted: 09/30/2008] [Indexed: 12/21/2022]
Abstract
The present study sought to identify abnormalities in activation in several brain regions in response to an auditory attention task in patients with schizophrenia. Ten patients and twenty healthy control participants were examined using Functional Magnetic Resonance Imaging (FMRI) measures acquired during an auditory attention task. Region of interest analyses of activation of targeted regions implicated in attention included: anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), hippocampus, parahippocampal gyrus (PHG), and superior temporal gyrus (STG). The results indicated over-activation in patients with schizophrenia. While the control group showed notable coherence in activation within and across hemispheres the schizophrenia group showed relatively less coherence overall that was only present in the right hemisphere. These findings suggest that patients with schizophrenia show both an over-engagement of brain regions during attention task as well as a lack of communication among neural regions involved.
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Affiliation(s)
- Todd N Schirmer
- Department of Psychology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, Illinois 60064, USA.
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19
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Silver H, Goodman C, Bilker WB, Knoll G, Gur R, Povar G. Suboptimal processing strategy and working-memory impairments predict abstraction deficit in schizophrenia. J Clin Exp Neuropsychol 2008; 29:823-30. [PMID: 18030633 DOI: 10.1080/13803390601125963] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
We studied the relationship between abstraction and other, more basic, cognitive functions in 78 schizophrenia patients and 57 healthy controls. Patients' performance was impaired compared to that of healthy individuals. Regression analysis showed significant contributions of task latency, spatial working memory, and verbal working memory to abstraction performance. The model explained 56.9% of the variance. The latency contribution included linear and quadratic components indicating optimal strategies for normal abstraction performance. Abnormal (suboptimal) processing strategies and working-memory dysfunctions predict impaired abstraction in schizophrenia. The model presented may enable differentiation between impaired and compensating components in schizophrenia patients with an abstraction deficit.
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Affiliation(s)
- Henry Silver
- Brain Behavior Laboratory, Sha'ar Menashe Mental Health Center, Hadera, Israel.
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20
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Ragland JD, Yoon J, Minzenberg MJ, Carter CS. Neuroimaging of cognitive disability in schizophrenia: search for a pathophysiological mechanism. Int Rev Psychiatry 2007; 19:417-27. [PMID: 17671874 PMCID: PMC4332575 DOI: 10.1080/09540260701486365] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This article reviews how functional neuroimaging research of cognitive dysfunction in schizophrenia has resulted in a progression of influential pathophysiological models of the disorder. The review begins with discussion of the 'hypofrontality' model, moving from resting studies examining anterior to posterior gradients of cerebral blood flow (CBF), to cognitive activation studies employing the Wisconsin Card Sorting Test, and current functional magnetic resonance imaging (fMRI) studies of working memory and cognitive control utilizing parametric task designs and event-related procedures. A similar progression is described for development of the temporal lobe model of schizophrenia, moving from research on the temporal cortex and language processing to the hippocampal formation and long-term memory (LTM). These LTM studies found that hippocampal dysfunction was often accompanied by disrupted prefrontal function, supporting a hybrid model of impaired fronto-temporal connectivity. Developments in image analysis procedures are described that allow assessment of these distributed network models. However, given limitations in temporal and spatial resolution, current methods do not provide 'real-time' imaging of network activity, making arrival at a definitive pathophysiologic mechanism difficult. Dorsolateral prefrontal cortex (DLPFC) dysfunction and disrupted fronto-temporal integration appear to be equally viable current models. The article concludes with a discussion of how fMRI can help facilitate development of novel psychosocial and pharmacological interventions designed to improve cognition and functional outcome in patients with schizophrenia.
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Affiliation(s)
- J D Ragland
- Department of Psychiatry and Behavioral Sciences, Imaging Research Center, University of California at Davis, 47-1 X Street, Sacramento, CA 95817, USA.
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21
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Silver H, Goodman C. Impairment in error monitoring predicts poor executive function in schizophrenia patients. Schizophr Res 2007; 94:156-63. [PMID: 17561375 DOI: 10.1016/j.schres.2007.04.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 04/22/2007] [Accepted: 04/24/2007] [Indexed: 11/24/2022]
Abstract
BACKGROUND Impaired ability to detect and correct errors may contribute to poor cognitive and social function in schizophrenia. OBJECTIVE To test the hypothesis that impairment in error monitoring contributes to impaired executive function in schizophrenia. METHODS 56 schizophrenia patients and 77 healthy individuals were tested with the Penn Conditional Exclusion test (PCET), a computerised test of executive function which allowed collection of accuracy and latency performance parameters. Error monitoring was assessed by analyzing reaction times for correct (RTC) and incorrect (RTI) responses. Tests of face recognition, working memory (WM) and processing speed were also administered. RESULTS Executive error-monitoring effort (EXER), calculated by dividing the difference between RTI and RTC by the sum of RTC and RTI, was significantly smaller in patients than controls. A regression model with the executive function (PCET total errors) as dependent variable showed independent contributions of EXER, verbal WM and spatial WM to test performance and explained 35% of the variance. EXER showed significant association with error-monitoring effort for face recognition in patients but not controls. CONCLUSION Impaired error-monitoring contributes to poor executive function in schizophrenia. Independent contributions of error-monitoring effort and verbal WM to executive functions may reflect distinct contributions of prefrontal and medial frontal cortical dysfunctions. Error-monitoring mechanisms in different cognitive domains may share more neural resources in schizophrenia than in healthy individuals, reflecting inefficient processing.
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Affiliation(s)
- Henry Silver
- Brain Behavior Laboratory, Sha'ar Menashe Mental Health Center, Mobile Post Hefer, Israel.
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22
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Lahti AC, Weiler MA, Holcomb HH, Tamminga CA, Carpenter WT, McMahon R. Correlations between rCBF and symptoms in two independent cohorts of drug-free patients with schizophrenia. Neuropsychopharmacology 2006; 31:221-30. [PMID: 16123774 DOI: 10.1038/sj.npp.1300837] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We report on the correlations between whole brain rCBF and the positive and negative symptoms of schizophrenia in two cohorts of patients who were scanned while free of antipsychotic medication. We hypothesized that positive symptoms would correlate with rCBF in limbic and paralimbic regions, and that negative symptoms would correlate with rCBF in frontal and parietal regions. Both cohorts of patients with schizophrenia (Cohort 1: n=32; Cohort 2: n=23) were scanned using PET with H(2)(15)O while free of antipsychotic medication for an average of 21 and 15 days, respectively. Both groups were scanned during a resting state. Using SPM99, we conducted pixel by pixel linear regression analyses between BPRS scores and whole brain rCBF. As hypothesized, positive symptoms correlated with rCBF in the anterior cingulate cortex (ACC) in a positive direction and with the hippocampus/parahippocampus in a negative direction in both patient groups. When the positive symptoms were further divided into disorganization and hallucination/delusion scores, similar positive correlations with ACC and negative correlations with hippocampus rCBF were found. In both cohorts, the disorganization scores correlated positively with rCBF in Broca's area. As expected, negative symptoms correlated inversely with rCBF in frontal and parietal regions. This study provides evidence that limbic dysfunction may underlie the production of positive symptoms. It suggests that abnormal function of Broca's area may add a specific language-related dimension to positive symptoms. This study also provides further support for an independent neurobiological substrate of negative symptoms distinct from positive symptoms. The involvement of both frontal and parietal regions is implicated in the pathophysiology of negative symptoms.
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Affiliation(s)
- Adrienne C Lahti
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD 21228, USA.
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23
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Marquardt RK, Levitt JG, Blanton RE, Caplan R, Asarnow R, Siddarth P, Fadale D, McCracken JT, Toga AW. Abnormal development of the anterior cingulate in childhood-onset schizophrenia: a preliminary quantitative MRI study. Psychiatry Res 2005; 138:221-33. [PMID: 15854790 DOI: 10.1016/j.pscychresns.2005.01.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 12/28/2004] [Accepted: 01/11/2005] [Indexed: 11/23/2022]
Abstract
The anterior cingulate is a key component of neural networks subserving attention and emotion regulation, functions often impaired in patients with psychosis. The study aimed to examine anterior cingulate volumes and sulcal morphology in a group of patients with childhood-onset schizophrenia (COS) compared with controls. Brain magnetic resonance imaging (MRI) scans were obtained in 13 COS and 18 matched control children, ages 6-17 years. Volume measures for the anterior cingulate gyrus (ACG) were obtained through manual labeling. A determination of cingulate sulcal pattern (single or double) was made for each hemisphere. The COS group had a reduced leftward skew of the double cingulate sulcal pattern, and absence of the normal left>right ACG volume asymmetry. The right ACG was larger in the COS than in controls. The schizophrenic children showed decreases in all ACG volumes with age, while the controls showed increases or no change. The data suggest that significant cingulate abnormalities may result from deviations in progressive neurodevelopmental processes, beginning before birth and continuing through childhood and adolescence, in persons who develop schizophrenia. These structural differences may relate to the well-described cognitive deficits these children display, and to the cardinal symptoms of schizophrenia.
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Affiliation(s)
- Renée K Marquardt
- Department of Psychiatry, UCLA Neuropsychiatric Institute, Los Angeles, CA 90024, USA.
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24
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Hong LE, Tagamets M, Avila M, Wonodi I, Holcomb H, Thaker GK. Specific motion processing pathway deficit during eye tracking in schizophrenia: a performance-matched functional magnetic resonance imaging study. Biol Psychiatry 2005; 57:726-32. [PMID: 15820229 DOI: 10.1016/j.biopsych.2004.12.015] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Revised: 11/30/2004] [Accepted: 12/09/2004] [Indexed: 11/27/2022]
Abstract
BACKGROUND The neural mechanisms underlying smooth pursuit eye movement (SPEM) abnormalities in schizophrenia are not well understood. Previous evidence suggests that a deficit in the processing of internal representations of object motion (extraretinal motion) contributes to SPEM deficits in patients. Functional magnetic resonance imaging (fMRI) activation was compared between patients and control subjects to determine whether schizophrenia patients exhibit abnormal cerebral activation in regions associated with extraretinal motion processing during SPEM. METHODS Patients and control subjects were selected based on matched performance in the closed-loop gain. Despite similar performance on closed-loop pursuit gain, patients showed consistent deficits in extraretinal motion based on predictive pursuit. In the magnet, subjects were tested using a traditional smooth-pursuit task that elicits closed-loop response. RESULTS Patients had reduced pursuit-related activation in several known extraretinal motion processing areas including frontal and supplemental eye fields, medial superior temporal cortex, and anterior cingulate. Patients also showed increased activation in medial occipitotemporal cortex. CONCLUSIONS These results provide functional anatomic evidence supporting reduced function in the extraretinal motion processing pathway in schizophrenia. Increased activation in medial occipitotemporal cortex suggests an increased dependence on immediate retinal motion information, which may be used to compensate for reduced extraretinal signaling during sustained visual tracking.
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Affiliation(s)
- L Elliot Hong
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore 21228, USA.
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25
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Northoff G, Richter A, Bermpohl F, Grimm S, Martin E, Marcar VL, Wahl C, Hell D, Boeker H. NMDA hypofunction in the posterior cingulate as a model for schizophrenia: an exploratory ketamine administration study in fMRI. Schizophr Res 2005; 72:235-48. [PMID: 15560968 DOI: 10.1016/j.schres.2004.04.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2003] [Revised: 04/05/2004] [Accepted: 04/06/2004] [Indexed: 11/16/2022]
Abstract
BACKGROUND Based on animal data, NMDA receptor hypofunction has been suggested as a model for positive symptoms in schizophrenia. NMDA receptor hypofunction affects several corticolimbic brain regions, of which the posterior cingulate seems to be the most sensitive. However, empirical support for a crucial role of posterior cingulate NMDA hypofunction in the pathophysiology of positive symptoms is still missing in humans. We therefore conducted an fMRI study using the NMDA antagonist ketamine in healthy human subjects during episodic memory retrieval, which is supposed to activate the posterior cingulate. METHODS We investigated 16 healthy subjects which were assigned to either placebo (n = 7; saline) or ketamine (n = 9; 0.6 mg/kg/h) group in a double-blind study design. All subjects received their infusion while performing an episodic memory retrieval task in the scanner. Immediately after the fMRI session, psychopathological effects of ketamine were measured using the Altered States of Consciousness Questionnaire. RESULTS The placebo group showed BOLD signal increases in the posterior and anterior cingulate during retrieval. Signal increases were significantly lower in the ketamine group. Lower signal increases in the posterior cingulate correlated significantly with positive (i.e. psychosis-like) symptoms induced by ketamine. CONCLUSION The present study for the first time demonstrates a relationship between NMDA receptors, posterior cingulate and positive (i.e. psychosis-like) symptoms in humans. Confirming findings from animal studies, it supports the hypothesis of a pathophysiological role of NMDA receptor hypofunction in the posterior cingulate in schizophrenia.
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Affiliation(s)
- Georg Northoff
- Department of Neurology, Division of Behavioral Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
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Abstract
The discovery of the pathophysiology(ies) for schizophrenia is necessary to direct rational treatment directions for this brain disorder. Firm knowledge about this illness is limited to areas of phenomenology, clinical electrophysiology, and genetic risk; some aspects of dopamine pharmacology, cognitive symptoms, and risk genes are known. Basic questions remain about diagnostic heterogeneity, tissue neurochemistry, and in vivo brain function. It is an illness ripe for molecular characterization using a rational approach with a confirmatory strategy; drug discovery based on knowledge is the only way to advance fully effective treatments. This paper reviews the status of general knowledge in this area and proposes an approach to discovery, including identifying brain regions of dysfunction and subsequent localized, hypothesis-driven molecular screening.
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Affiliation(s)
- C A Tamminga
- Department of Psychiatry, UT Southwestern Medical School, Dallas, TX 75390, USA.
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27
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Mendrek A, Laurens KR, Kiehl KA, Ngan ETC, Stip E, Liddle PF. Changes in distributed neural circuitry function in patients with first-episode schizophrenia. Br J Psychiatry 2004; 185:205-14. [PMID: 15339824 DOI: 10.1192/bjp.185.3.205] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND A number of functional brain abnormalities have been reported in schizophrenia, but it remains to be determined which of them represent trait and state markers of the illness. AIMS To delineate regional brain dysfunctions that remain stable and those that fluctuate during the course of schizophrenia. METHOD A cohort of patients with first-episode schizophrenia and a matched group of control participants underwent functional magnetic resonance imaging on two occasions 6-8 weeks apart during performance of a working memory task. The patients' disease was in partial remission at the second scan. RESULTS Relative to control participants, the function of the left dorsolateral prefrontal cortex, left thalamus and right cerebellum remained disturbed in the people with schizophrenia, whereas the dysfunction of the right dorsolateral prefrontal cortex, right thalamus, left cerebellum and cingulate gyrus normalised, with significant reduction in symptoms. CONCLUSIONS These results suggest that dysfunction of the left fronto-thalamo-cerebellar circuitry is a relatively stable characteristic of schizophrenia, whereas disturbance of the right circuitry and cingulate gyrusis predominantly a state-related phenomenon.
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Affiliation(s)
- A Mendrek
- Department of Psychiatry, University of Montreal, Centre de recherche Fernand-Seguin, 7331 Hochelaga, Montreal, Québec H1N 3V2, Canada.
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28
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Frost DO, Tamminga CA, Medoff DR, Caviness V, Innocenti G, Carpenter WT. Neuroplasticity and schizophrenia. Biol Psychiatry 2004; 56:540-3. [PMID: 15476682 DOI: 10.1016/j.biopsych.2004.01.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2003] [Revised: 01/08/2004] [Accepted: 01/14/2004] [Indexed: 11/18/2022]
Abstract
This article's title is also the name of a workshop sponsored by the International Congress on Schizophrenia Research that was focused on an appraisal of the potential role of neuroplastic processes in the etiology or course of schizophrenia. The workshop brought together clinical investigators of schizophrenia and basic scientists who study various aspects of neuroplasticity, including central nervous system (CNS) development, learning and memory, and drug action. The goal was to identify special opportunities to advance knowledge and understanding of schizophrenia pathology, treatment, or prevention by applying neuroplasticity concepts as a framework to theories of the illness. Although the focus of this workshop was schizophrenia, the phenomena considered are pertinent to other disorders, such as depression and drug abuse.
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Affiliation(s)
- Douglas O Frost
- Department of Pharmacology and Experimental Therapeutics, Baltimore, Maryland, USA
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Gallinat J, Winterer G, Herrmann CS, Senkowski D. Reduced oscillatory gamma-band responses in unmedicated schizophrenic patients indicate impaired frontal network processing. Clin Neurophysiol 2004; 115:1863-74. [PMID: 15261865 DOI: 10.1016/j.clinph.2004.03.013] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2004] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Integration of sensory information by cortical network binding appears to be crucially involved in target detection. Studies in schizophrenia using functional and diffusion tensor neuroimaging, event-related potentials and EEG coherence indicate an impairment of cortical network coupling in this disorder. Previous electrophysiological investigations in animals and humans suggested that gamma activity (oscillations at around 40 Hz) is essential for cortical network binding. Studies in medicated schizophrenia provide evidence for a reduced gamma activity in the context of auditory stimulus processing. This is the first investigation of oscillatory activations in the gamma-band in an auditory oddball paradigm in unmedicated schizophrenic patients. METHODS EEG gamma-band responses (GBRs) of 15 drug-free schizophrenic patients and 15 age- and gender-matched healthy controls were compared. A wavelet transform based on Morlet wavelets was employed for the calculation of oscillatory GBRs. RESULTS In response to standard stimuli, early evoked GBRs (20-100 ms), which are supposed to reflect auditory cortex activation, did not show significant group differences. However, schizophrenic patients showed reduced evoked GBRs in a late latency range (220-350 ms), particularly after target stimuli. This deficit occurred over right frontal scalp regions. Furthermore, significant correlations were observed between oscillatory GBRs and clinical parameters in schizophrenic patients. CONCLUSIONS The results are consistent with a relative preserved stimulus processing in the auditory cortex as reflected by the early GBR. The reduced late GBR is compatible with an abnormal interaction within a frontal lobe network, as was postulated by previous neuroimaging studies. SIGNIFICANCE The present study provides evidence for disturbed processing within frontal cortical regions in unmedicated schizophrenic patients as indicated by reduced evoked EEG GBRs.
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Affiliation(s)
- Jürgen Gallinat
- Clinic for Psychiatry and Psychotherapy, Humboldt University, Berlin, Germany
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Holcomb HH, Parwani A, McMahon RP, Medoff DR, Frey K, Lahti AC, Tamminga CA. Parametric study of accuracy and response time in schizophrenic persons making visual or auditory discriminations. Psychiatry Res 2004; 127:207-16. [PMID: 15296820 DOI: 10.1016/j.psychres.2004.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2003] [Revised: 04/09/2004] [Accepted: 04/17/2004] [Indexed: 10/26/2022]
Abstract
The inability to modulate processing time in conjunction with varying difficulty levels may be a core component of schizophrenia's cognitive deficit. In this study we used a parametric design to demonstrate this group's inability to increase and decrease response times in association with varying levels of task demand during auditory and visual recognition tasks. Unlike participants with schizophrenia, healthy volunteers responded to increasing levels of difficulty and high error by robustly increasing their average response times. In the group with schizophrenia, the greater the correlation between a subject's Response-Time and error rate the better was the subject in his/her overall discrimination accuracy. The higher their correlations the better they performed across all levels of difficulty in both modalities. The schizophrenia group's tendency to process high and low error conditions with similar behavioral resources may reflect a relatively static, non-dynamic cognitive repertoire.
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Affiliation(s)
- Henry H Holcomb
- Maryland Psychiatric Research Center, P.O. Box 21247, Baltimore, MD 21228, USA.
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Lahti AC, Holcomb HH, Weiler MA, Medoff DR, Frey KN, Hardin M, Tamminga CA. Clozapine but not haloperidol Re-establishes normal task-activated rCBF patterns in schizophrenia within the anterior cingulate cortex. Neuropsychopharmacology 2004; 29:171-8. [PMID: 14520337 DOI: 10.1038/sj.npp.1300312] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Our previous work has identified that unmedicated volunteers with schizophrenia have regional cerebral blood flow (rCBF) activation patterns inappropriately related to the cognitive demand of a task in anterior cingulate cortex (ACC). Using positron emission tomography (PET) with (15)O water, we compared task-induced rCBF patterns induced by haloperidol or clozapine in individuals with schizophrenia. We hypothesized that clozapine, given its superior clinical action, would tend to normalize the abnormal task-activated response in ACC more than haloperidol. Schizophrenia volunteers (SVs) (n=6) and normal volunteers (NVs) (n=12) were trained to perform a tone discrimination task with 70-80% accuracy. They were then scanned during three task conditions: (1). Rest, (2). sensory motor control (SMC) task, and (3). decision task (DEC). SVs were initially scanned after withdrawal of all psychotropic medication and again after treatment with therapeutic doses of haloperidol (n=5) and/or clozapine (n=5). rCBF values, sampled in the grown maxima of the task-activated ACC cluster, were analyzed between groups and task conditions. Task performance was similar across the unmedicated, haloperidol- and clozapine-medicated SV groups. There was a reduction in accuracy in the haloperidol SV group compared to the NVs. Group and task conditions affected rCBF in the ACC. Clozapine, but not haloperidol, reversed the abnormal ACC rCBF pattern in unmedicated SV to normal. The clozapine-treated SV group showed a rCBF pattern similar to the NV group in that ACC activation was not observed during the control task but occurred during the decision condition. The pattern seen in the haloperidol-treated SV group was similar to the unmedicated SV group in that ACC activation was seen during the control task and no further activation was seen during the DEC. We report that clozapine, but not haloperidol, normalizes anterior cingulate rCBF patterns in schizophrenia during a cognitive task. Based on these preliminary data, we propose that this pattern may account for the superior therapeutic effect of clozapine and represents a surrogate marker of this action.
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Affiliation(s)
- Adrienne C Lahti
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD 21228, USA.
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Jay TM, Rocher C, Hotte M, Naudon L, Gurden H, Spedding M. Plasticity at hippocampal to prefrontal cortex synapses is impaired by loss of dopamine and stress: importance for psychiatric diseases. Neurotox Res 2004; 6:233-44. [PMID: 15325962 DOI: 10.1007/bf03033225] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The direct hippocampal to prefrontal cortex pathway and its changes in synaptic plasticity is a useful framework for investigating the functional operations of hippocampal-prefrontal cortex communication in cognitive functions. Synapses on this pathway are modifiable and synaptic strength can be turned up or down depending on specific patterns of activity in the pathway. The objective of this review will be to summarize the different studies carried out on this topic including very recent data and to underline the importance of animal models for the development of new and effective medications in psychiatric diseases. We have shown that long-term potentiation (LTP) of hippocampal-prefrontal synapses is driven by the level of mesocortical dopaminergic (DA) activity and more recently that stress is also an environmental determinant of LTP at these cortical synapses. Stimulation of the ventral tegmental area at a frequency known to evoke DA overflow in the prefrontal cortex produces a long-lasting enhancement of the magnitude of hippocampal-prefrontal cortex LTP whereas a depletion of cortical DA levels generates a dramatic decrease in this LTP. Moreover, hippocampal stimulation induces a transient but significant increase in DA release in the prefrontal cortex and an optimal level of D1 receptor activation is essential for LTP expression. We recently investigated the impact of stress on hippocampal-prefrontal LTP and demonstrated that exposure to an acute stress causes a remarkable and long-lasting inhibition of LTP. Furthermore, we demonstrated that tianeptine, an antidepressant which has a unique mode of action, and clozapine an atypical antipsychotic when administered at doses normally used in human testing are able to reverse the impairment in LTP. Stressful life events have a substantial causal association with psychiatric disorders like schizophrenia and depression and recent imaging studies have shown an important role of the limbic-cortical circuit in the pathophysiology of these illnesses. Therefore, we proposed that agents capable of reversing the impairment of plasticity at hippocampal to prefrontal cortex synapses have the potential of becoming new therapeutic classes of antidepressant or antipsychotic drugs.
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Affiliation(s)
- Thérèse M Jay
- INSERM E 0117, Physiopathologie des Maladies Psychiatriques, Centre Paul Broca, 2ter rue d'Alésia, 75014 Paris, France.
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Peinado A, Calderon DP. Hyperactivation of developing cortical circuits by acetylcholine and the ontogeny of abnormal cognition and emotion: findings and hypothesis. PROGRESS IN BRAIN RESEARCH 2003; 145:131-42. [PMID: 14650912 DOI: 10.1016/s0079-6123(03)45009-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Affiliation(s)
- Alejandro Peinado
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA.
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Abstract
With the introduction of conventional antipsychotics in the 1950s, clinicians began to expect effective treatment of positive symptoms of schizophrenia. However, these drugs do not resolve negative and cognitive symptoms of schizophrenia and are also associated with serious side effects, including extrapyramidal side effects (EPS) and tardive dyskinesia. In 1989, clozapine was introduced and labeled the first new antipsychotic owing to its improved efficacy and side-effect profile. Clozapine proved effective in alleviating many of the positive, negative, and cognitive symptoms of schizophrenia, without causing inevitable EPS or tardive dyskinesia. Over the past decade, a number of different new antipsychotics have been developed. These drugs have an affinity for multiple dopamine-receptor subtypes as well as serotonin, norepinephrine, and glutamate receptors, allowing for better treatment outcomes. The antagonism of the 5-HT2A receptor may be responsible for improvement in negative symptoms and decrease in EPS. In addition to providing enhanced efficacy, the affinity of the new drugs for multiple receptors introduces new side effects not seen with the conventional agents, including weight gain. Each new antipsychotic has a unique receptor-binding profile that corresponds to its pharmacologic and side-effect profile. Understanding the differences in mechanisms of action of new antipsychotics will allow physicians to better choose treatment that meets the needs of each individual patient.
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Affiliation(s)
- Carol A Tamminga
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Abstract
Schizophrenia is a common and debilitating illness, characterized by chronic psychotic symptoms and psychosocial impairment that exact considerable human and economic costs. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, treatment, genetics and neurobiology of schizophrenia. Although studied extensively from a clinical, psychological, biological and genetic perspective, our expanding knowledge of schizophrenia provides only an incomplete understanding of this complex disorder. Recent advances in neuroscience have allowed the confirmation or refutation of earlier findings in schizophrenia, and permit useful comparisons between the different levels of organization from which the illness has been studied. Schizophrenia is defined as a clinical syndrome that may include a collection of diseases that share a common presentation. Genetic factors are the most important in the etiology of the disease, with unknown environmental factors potentially modulating the expression of symptoms. Schizophrenia is a complex genetic disorder in which many genes may be implicated, with the possibility of gene-gene interactions and a diversity of genetic causes in different families or populations. A neurodevelopmental rather than degenerative process has received more empirical support as a general explanation of the pathophysiology, although simple dichotomies are not particularly helpful in such a complicated disease. Structural brain changes are present in vivo and post-mortem, with both histopathological and imaging studies in overall agreement that the temporal and frontal lobes of the cerebral cortex are the most affected. Functional imaging, neuropsychological testing and clinical observation are also generally consistent in demonstrating deficits in cognitive ability that correlate with abnormalities in the areas of the brain with structural abnormalities. The dopamine and other neurotransmitter systems are certainly involved in the treatment or modulation of psychotic symptoms. These broad findings represent the distillation of a large body of disparate data, but firm and specific findings are sparse, and much about schizophrenia remains unknown.
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Affiliation(s)
- Albert Hung Choy Wong
- Centre for Addiction and Mental Health, 250 College Street, M5T 1R8, Toronto, Ont., Canada.
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Lahti AC, Holcomb HH, Weiler MA, Medoff DR, Tamminga CA. Functional effects of antipsychotic drugs: comparing clozapine with haloperidol. Biol Psychiatry 2003; 53:601-8. [PMID: 12679238 DOI: 10.1016/s0006-3223(02)01602-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Using positron emission tomography (PET) with (15)O water, we compared regional cerebral blood flow (rCBF) patterns induced by clozapine or haloperidol in individuals with schizophrenia. Based on the known clinical characteristics of each drug, we hypothesized that brain regions where the drugs show similar rCBF patterns are among those mediating their antipsychotic actions; whereas, regions where the drugs produce different rCBF patterns are among those mediating their different drug actions, namely, haloperidol's motor side effects or clozapine's unique therapeutic action. METHODS Persons with schizophrenia were scanned using PET with (15)O water, first after withdrawal of all psychotropic medication (n = 6), then again after treatment with therapeutic doses of haloperidol (n = 5) or clozapine (n = 5). RESULTS Both drugs increased rCBF in the ventral striatum and decreased rCBF in hippocampus and ventrolateral frontal cortex. The rCBF increase associated with haloperidol was greater than that with clozapine in the dorsal and ventral striatum; the rCBF increase with clozapine was greater than that with haloperidol in cortical regions, including anterior cingulate and dorsolateral frontal cortex. CONCLUSIONS These data suggest that the rCBF increase in ventral striatum and/or the decrease in hippocampus and/or ventrolateral frontal cortex mediate a common component of antipsychotic action of these drugs. The increased rCBF in dorsal striatum by haloperidol could well be associated with its prominent motor side effects, whereas the increased rCBF in the anterior cingulate or dorsolateral frontal cortex may mediate the superior antipsychotic action of clozapine. The proposals based on these preliminary observations require further study.
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Affiliation(s)
- Adrienne C Lahti
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland 21228, USA
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Davidson LL, Heinrichs RW. Quantification of frontal and temporal lobe brain-imaging findings in schizophrenia: a meta-analysis. Psychiatry Res 2003; 122:69-87. [PMID: 12714172 DOI: 10.1016/s0925-4927(02)00118-x] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Magnetic resonance imaging (MRI) and positron emission tomography (PET) studies of the frontal and temporal lobes in schizophrenia patients and healthy controls have proliferated over the past 2 decades, but there have been relatively few attempts to quantify the evidence. In this meta-analytic review, 155 studies on frontal and temporal lobe neurobiology were synthesized, reflecting results from 4043 schizophrenia patients and 3977 normal controls. Cohen's d was used to quantify case-control differences, and moderator variable analysis indexed the relation of sample and imaging characteristics to the magnitude of these differences. Frontal metabolic and blood flow deficiencies in conjunction with cognitive activation tasks ("hypofrontality") emerged as the strongest body of evidence, demonstrating abnormalities that distinguish approximately half of schizophrenia patients from healthy people. Most case-control comparisons with structural and functional imaging yield small and in many cases unstable findings. Technical scanning parameters like slice thickness and magnet strength did not vary with case-control differences consistently across the meta-analyses. However, patient sample characteristics including sample size, handedness and gender composition emerged frequently as moderators of brain-imaging effect sizes.
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Affiliation(s)
- Lara L Davidson
- Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.
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SHEWOKIS PATRICIAA. MEMORY CONSOLIDATION AND CONTEXTUAL INTERFERENCE EFFECTS WITH COMPUTER GAMES. Percept Mot Skills 2003. [DOI: 10.2466/pms.97.6.581-589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abnormalities of the cingulate gyrus in bipolar disorder and other severe psychiatric illnesss: postmortem findings from the Stanley Foundation Neuropathology Consortium and literature review. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1566-2772(02)00042-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ojeda N, Ortuño F, Arbizu J, López P, Martí‐Climent JM, Peñuelas I, Cervera‐Enguix S. Functional neuroanatomy of sustained attention in schizophrenia: contribution of parietal cortices. Hum Brain Mapp 2002; 17:116-30. [PMID: 12353245 PMCID: PMC6871970 DOI: 10.1002/hbm.10055] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Deficits in sustained attention have been frequently described in schizophrenia. The neuroanatomical basis reported previously have included altered levels of activation in cingulate and prefrontal cortex, but the contribution of further regions remains unclear. We explored the full neuroanatomy underlying the sustained attentional deficits observed in naïve schizophrenics compared with controls. Participants included 10 controls and 11 patients. The experimental design included rest, auditory stimulation using clicks, and two counting tasks. Subjects were instructed to mentally count the clicks, and then to count forward at the same frequency they heard previously when listening to the clicks. Relative cerebral blood flow (relCBF) was measured by means of PET (15)O-water. Differences were observed between both groups at superior temporal cortex, superior parietal gyrus, and cerebellum during tasks requiring listening. During all counting conditions, additionally to supplementary motor area (SMA), dorsolateral prefrontal cortex (DLPCF), precentral gyrus, cingulate, cerebellum, and inferior parietal (IP) gyrus, patients engaged other frontal structures including inferior, medial, and superior frontal areas. When counting with no auditory stimulation (C; requires components of working memory and time estimation), significant differences were observed in the level of activation of frontal and IP regions. Our naïve patients presented abnormal activation of auditory associative pathways. They failed to activate prefrontal and parietal regions at a similar level during tasks requiring increased cognitive effort, and they required a higher activation of inferior frontal regions to properly respond to cognitive demands.
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Affiliation(s)
- Natalia Ojeda
- Department of Psychiatry and Medical Psychology, University Hospital School of Medicine, University of Navarra, Navarra, Spain
| | - Felipe Ortuño
- Department of Psychiatry and Medical Psychology, University Hospital School of Medicine, University of Navarra, Navarra, Spain
| | - Javier Arbizu
- Department of Nuclear Medicine, University Hospital, School of Medicine, University of Navarra, Navarra, Spain
| | - Pilar López
- Department of Psychiatry and Medical Psychology, University Hospital School of Medicine, University of Navarra, Navarra, Spain
| | - Josep Maria Martí‐Climent
- Department of Nuclear Medicine, University Hospital, School of Medicine, University of Navarra, Navarra, Spain
| | - Ivan Peñuelas
- Department of Nuclear Medicine, University Hospital, School of Medicine, University of Navarra, Navarra, Spain
| | - Salvador Cervera‐Enguix
- Department of Psychiatry and Medical Psychology, University Hospital School of Medicine, University of Navarra, Navarra, Spain
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Medoff DR, Holcomb HH, Lahti AC, Tamminga CA. Probing the human hippocampus using rCBF: contrasts in schizophrenia. Hippocampus 2002; 11:543-50. [PMID: 11732707 DOI: 10.1002/hipo.1070] [Citation(s) in RCA: 210] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Regional cerebral blood flow (rCBF) data from two PET-15O water schizophrenia studies were analyzed using individually placed, magnetic resonance (MR)-guided hippocampal volumes of interest (VOI). In one study, normal (N = 10) and schizophrenic (N = 18) volunteers performed an overlearned auditory discrimination task in rest, control, and decision conditions. In the other study, schizophrenic and normal volunteers received the noncompetitive NMDA receptor antagonist ketamine and placebo and had sequential rCBF evaluations. Moreover, the schizophrenic volunteers were off drug in one study and on antipsychotic drug in the second study, allowing an additional comparison of medication status. VOIs were placed on anterior, middle, and posterior hippocampal areas in each PET image from both studies, redirected from an MR scan, and individually adjusted. While no hippocampal activation was apparent in either the normal or schizophrenic group in the task vs. condition comparison, rCBF was higher in the schizophrenic than in the normal hippocampus in both task and control conditions, independently. In addition, at rest rCBF was significantly higher in the unmedicated group of schizophrenics than in the group of medicated patient volunteers and higher than in the normal comparison group. This suggests that schizophrenia is associated with elevated rCBF in the hippocampus, which "normalizes" with antipsychotic drug treatment. Ketamine, the noncompetitive NMDA receptor antagonist, was more potent in reducing rCBF in the schizophrenic group compared to the normal volunteer group. These data are consistent with a previous report from our laboratory of reduced NMDA receptor NR1 subunit expression and possible abnormal NMDA receptor composition in schizophrenia. These data show an abnormality of hippocampal function in schizophrenia and suggest that this abnormality may be associated with the pathophysiology of the illness.
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Affiliation(s)
- D R Medoff
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore 21228, USA
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Holcomb HH. Perceptual skill and brain physiology in subgroups of persons with schizophrenia. DIALOGUES IN CLINICAL NEUROSCIENCE 2002. [PMID: 22033645 PMCID: PMC3181664 DOI: 10.31887/dcns.2001.3.4/hholcomb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
This paper focuses on treatments for schizophrenia (SZ)--treatments we have now and those we hope to have in the future. The treatments we have are based on serendipity, but are effective nonetheless. Pharmacologic characteristics of the most-prescribed drugs are reviewed. It is apparent that a spectrum of effective drugs exist to support individualized therapy. With a view to future discovery, a strategy is proposed for rational antipsychotic drug development. A few concrete examples from the author's own laboratory illustrate an application of the proposal. These data would support the existence of a drug target in the anterior cingulate and/or hippocampal cortex. The studies suggest a focus on the limbic cortex for SZ pathophysiology. It would depend on future discovery to test whether this proposal will be productive. For sure, the rapid advance of basic neuroscience provides untold promise for the future
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Affiliation(s)
- C A Tamminga
- Department of Psychiatry, University of Michigan Medical Center, Ann Arbor, MI, USA
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