1
|
Dashtban S, Haj-Nasrolah-Fard F, Kosari Z, Ghamari R, Forouzesh F, Alizadeh F. ANK3 and ZNF804A intronic variants increase risk of schizophrenia in Iranian population: An association study. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
2
|
Application of Mass Multivariate Analysis on Neuroimaging Data Sets for Precision Diagnostics of Depression. Diagnostics (Basel) 2022; 12:diagnostics12020469. [PMID: 35204560 PMCID: PMC8871050 DOI: 10.3390/diagnostics12020469] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/18/2022] [Accepted: 02/08/2022] [Indexed: 01/29/2023] Open
Abstract
We used the Mass Multivariate Method on structural, resting-state, and task-related fMRI data from two groups of patients with schizophrenia and depression in order to define several regions of significant relevance to the differential diagnosis of those conditions. The regions included the left planum polare (PP), the left opercular part of the inferior frontal gyrus (OpIFG), the medial orbital gyrus (MOrG), the posterior insula (PIns), and the parahippocampal gyrus (PHG). This study delivered evidence that a multimodal neuroimaging approach can potentially enhance the validity of psychiatric diagnoses. Structural, resting-state, or task-related functional MRI modalities cannot provide independent biomarkers. Further studies need to consider and implement a model of incremental validity combining clinical measures with different neuroimaging modalities to discriminate depressive disorders from schizophrenia. Biological signatures of disease on the level of neuroimaging are more likely to underpin broader nosological entities in psychiatry.
Collapse
|
3
|
Kolla NJ, Harenski CL, Harenski KA, Dupuis M, Crawford JJ, Kiehl KA. Brain gray matter differences among forensic psychiatric patients with psychosis and incarcerated individuals without psychosis: A source-based morphometry study. NEUROIMAGE-CLINICAL 2021; 30:102673. [PMID: 34215145 PMCID: PMC8111335 DOI: 10.1016/j.nicl.2021.102673] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/14/2021] [Accepted: 04/10/2021] [Indexed: 12/03/2022]
Abstract
We employed source-based morphometry to examine grey matter differences in forensic psychiatric patients with psychosis versus incarcerated controls without psychosis. Compared to the psychotic group, the non-psychotic group demonstrated greater loading weights in the superior, transverse, and middle temporal gyrus and the anterior cingulate. Compared to the non-psychotic group, the psychotic group exhibited greater loading weights in the frontal pole, precuneus, basal ganglia, thalamus, parahippocampal gyrus, and visual cortex. Neuroimaging investigations of offenders with psychosis ought to control for the level of psychopathic traits present.
Background While psychosis is a risk factor for violence, the majority of individuals who perpetrate aggression do not present psychotic symptoms. Pathological aggressive behavior is associated with brain gray matter differences, which, in turn, has shown a relationship with increased psychopathic traits. However, no study, to our knowledge, has ever investigated gray matter differences in forensic psychiatric patients with psychosis compared with incarcerated individuals without psychosis matched on levels of psychopathic traits. Here, we employed source-based morphometry (SBM) to investigate gray matter differences in these two populations. Methods We scanned 137 participants comprising two offender subgroups: 69, non-psychotic incarcerated offenders and 68, psychotic, forensic psychiatric patients. Groups showed no difference in age, race, ethnicity, handedness, and Hare Psychopathy Checklist-Revised scores. Source-based morphometry was utilized to identify spatially distinct sets of brain regions where gray matter volumes covaried between groups. SBM is a data-driven, multivariate technique that uses independent components analysis to categorize groups of voxels that display similar variance patterns (e.g., components) that are compared across groups. Results SBM identified four components that differed between groups. These findings indicated greater loading weights in the superior, transverse, and middle temporal gyrus and anterior cingulate in the non-psychotic versus psychotic group; greater loading weights in the basal ganglia in the psychotic versus non-psychotic group; greater loading weights in the frontal pole, precuneus, and visual cortex among psychotic versus non-psychotic offenders; and greater loading weights in the thalamus and parahippocampal gyrus in psychotic versus non-psychotic groups. Conclusions Two different offender groups that perpetrate violence and show comparable levels of psychopathic traits evidenced different gray matter volumes. We suggest that future studies of violent offenders with psychosis take psychopathic traits into account to refine neural phenotypes.
Collapse
Affiliation(s)
- Nathan J Kolla
- Waypoint Centre for Mental Health Care, Penetanguishene, ON, Canada; Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada; Violence Prevention Neurobiological Research Unit, CAMH, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
| | | | | | - Melanie Dupuis
- Waypoint Centre for Mental Health Care, Penetanguishene, ON, Canada
| | | | - Kent A Kiehl
- The Mind Research Network, Albuquerque, NM, USA; University of New Mexico, Albuquerque, NM, USA
| |
Collapse
|
4
|
Kuo SS, Pogue-Geile MF. Variation in fourteen brain structure volumes in schizophrenia: A comprehensive meta-analysis of 246 studies. Neurosci Biobehav Rev 2019; 98:85-94. [PMID: 30615934 PMCID: PMC6401304 DOI: 10.1016/j.neubiorev.2018.12.030] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 11/21/2018] [Accepted: 12/31/2018] [Indexed: 12/24/2022]
Abstract
Despite hundreds of structural MRI studies documenting smaller brain volumes on average in schizophrenia compared to controls, little attention has been paid to group differences in the variability of brain volumes. Examination of variability may help interpret mean group differences in brain volumes and aid in better understanding the heterogeneity of schizophrenia. Variability in 246 MRI studies was meta-analyzed for 13 structures that have shown medium to large mean effect sizes (Cohen's d≥0.4): intracranial volume, total brain volume, lateral ventricles, third ventricle, total gray matter, frontal gray matter, prefrontal gray matter, temporal gray matter, superior temporal gyrus gray matter, planum temporale, hippocampus, fusiform gyrus, insula; and a control structure, caudate nucleus. No significant differences in variability in cortical/subcortical volumes were detected in schizophrenia relative to controls. In contrast, increased variability was found in schizophrenia compared to controls for intracranial and especially lateral and third ventricle volumes. These findings highlight the need for more attention to ventricles and detailed analyses of brain volume distributions to better elucidate the pathophysiology of schizophrenia.
Collapse
Affiliation(s)
- Susan S Kuo
- Department of Psychology, University of Pittsburgh, 4209 Sennott Square, 210 South Bouquet St., Pittsburgh PA 15260, USA.
| | - Michael F Pogue-Geile
- Department of Psychology, University of Pittsburgh, 4209 Sennott Square, 210 South Bouquet St., Pittsburgh PA 15260, USA; Department of Psychology and Department of Psychiatry, University of Pittsburgh, 4207 Sennott Square, 210 South Bouquet St., Pittsburgh PA 15260, USA.
| |
Collapse
|
5
|
Abstract
Objectives:Schizophrenia is a predominant product of pathological alterations distributed throughout interconnected neural systems. Functional connections (FCs) methodology is an effective lever to investigate macroscopic neural activity patterns underlying critical aspects of cognition and behaviour. However, region properties of brain architecture have been less investigated by special markers of dynamical graph in general mental disorders. Methods:Embracing the eigenvector centrality in holism significance, our important process is to uncover noticeable edges and regions with antagonistic stance between morbid and normal FCs of 67 healthy controls (HCs) and 53 chronic schizophrenia patients (SZs). Results: Results suggest that, there are 12 abnormal edges with significant p value of FCs weight, such as lingual gyrus L versus cuneus L, thalamus L versus middle frontal gyrus R, superior temporal gyrus R versus thalamus R. Importantly, SZs' superior temporal gyrus R, parahippocampal gyrus L and parahippocampal gyrus R are endowed with different eigenvector centrality scores. Conclusion: Consistent with SZs' positive symptoms of hallucinations, and negative symptoms of thinking impairment, it can be infer that the functional separation and integration are destroyed in schizophrenia. Thought the strict contrastive study, it is worth stressing that eigenvector centrality is a meaningful biological marker to excavating schizophrenic psychopathology.
Collapse
Affiliation(s)
- Bo Chen
- a School of Science , Hangzhou Dianzi University , Hangzhou , PR China
| |
Collapse
|
6
|
Chen B. Abnormal cortical region and subsystem complexity in dynamical functional connectivity of chronic schizophrenia: A new graph index for fMRI analysis. J Neurosci Methods 2018; 311:28-37. [PMID: 30316890 DOI: 10.1016/j.jneumeth.2018.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/10/2018] [Accepted: 10/10/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Schizophrenia is a predominant product of pathological alterations distributed throughout interconnected neural systems. Designing new objectively diagnostic methods are burning questions. Dynamical functional connectivity (DFCs) methodology based on fMRI data is an effective lever to investigate changeability evolution in macroscopic neural activity patterns underlying critical aspects of cognition and behavior. However, region properties of brain architecture have been less investigated by special indexes of dynamical graph in general mental disorders. METHODS Embracing the network dynamics concept, we introduce topology entropy index (TE-scores) which is focused on time-varying aspects of FCs, hence develop a new framework for researching the dysfunctional roots of schizophrenia in holism significance. In this work, the important process is to uncover noticeable regions endowed with antagonistic stance in TE-scores of between morbid and normal DFCs of 63 healthy controls (HCs) and 57 chronic schizophrenia patients (SZs). RESULTS For the whole brain region levels, right olfactory, right hippocampus, left parahippocampal gyrus, right parahippocampal gyrus, left amygdala, and left cuneus in SZs are endowed with significantly different TE-scores. At brain subsystems level, TE-scores in DMN are abnormal in the SZs. Comparison with existing method(s): Topology entropy in DFCs is introduced to explore the dynamical information organization of diverse regions and their abnormal changes in mental illness. Several classical graph indexes (such as degree strength, betweenness, centrality) in the static brain network measure the region importance of FCs under senses of information integration and separation process. Although highly related to degree strength by comparing the corresponding values, topology entropy further explores the regions' aberrant adaptability of functional contact and function switching. CONCLUSION TE-scores of abnormal regions in SZs are associated to the passive apathetic social withdrawal, unusual thought content, disturbance of volition, preoccupation, active social avoidance and hallucinatory symptoms. Thought the strict contrastive study, it is worth stressing that topology entropy is a meaningful biological marker to excavating schizophrenic psychopathology.
Collapse
Affiliation(s)
- Bo Chen
- School of Science, Hangzhou Dianzi University, Hangzhou, Zhejiang, 310018, PR China.
| |
Collapse
|
7
|
Ma Q, Zhang T, Zanetti MV, Shen H, Satterthwaite TD, Wolf DH, Gur RE, Fan Y, Hu D, Busatto GF, Davatzikos C. Classification of multi-site MR images in the presence of heterogeneity using multi-task learning. Neuroimage Clin 2018; 19:476-486. [PMID: 29984156 PMCID: PMC6029565 DOI: 10.1016/j.nicl.2018.04.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/09/2018] [Accepted: 04/28/2018] [Indexed: 12/21/2022]
Abstract
With the advent of Big Data Imaging Analytics applied to neuroimaging, datasets from multiple sites need to be pooled into larger samples. However, heterogeneity across different scanners, protocols and populations, renders the task of finding underlying disease signatures challenging. The current work investigates the value of multi-task learning in finding disease signatures that generalize across studies and populations. Herein, we present a multi-task learning type of formulation, in which different tasks are from different studies and populations being pooled together. We test this approach in an MRI study of the neuroanatomy of schizophrenia (SCZ) by pooling data from 3 different sites and populations: Philadelphia, Sao Paulo and Tianjin (50 controls and 50 patients from each site), which posed integration challenges due to variability in disease chronicity, treatment exposure, and data collection. Some existing methods are also tested for comparison purposes. Experiments show that classification accuracy of multi-site data outperformed that of single-site data and pooled data using multi-task feature learning, and also outperformed other comparison methods. Several anatomical regions were identified to be common discriminant features across sites. These included prefrontal, superior temporal, insular, anterior cingulate cortex, temporo-limbic and striatal regions consistently implicated in the pathophysiology of schizophrenia, as well as the cerebellum, precuneus, and fusiform, middle temporal, inferior parietal, postcentral, angular, lingual and middle occipital gyri. These results indicate that the proposed multi-task learning method is robust in finding consistent and reliable structural brain abnormalities associated with SCZ across different sites, in the presence of multiple sources of heterogeneity.
Collapse
Affiliation(s)
- Qiongmin Ma
- College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan 410073, China; Center for Biomedical Image Computing and Analytics, and Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, United States; Beijing Institute of System Engineering, China.
| | - Tianhao Zhang
- Center for Biomedical Image Computing and Analytics, and Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Marcus V Zanetti
- Laboratory of Psychiatric Neuroimaging (LIM-21), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Hui Shen
- College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan 410073, China
| | | | - Daniel H Wolf
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Raquel E Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Yong Fan
- Center for Biomedical Image Computing and Analytics, and Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Dewen Hu
- College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan 410073, China
| | - Geraldo F Busatto
- Laboratory of Psychiatric Neuroimaging (LIM-21), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Christos Davatzikos
- Center for Biomedical Image Computing and Analytics, and Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, United States
| |
Collapse
|
8
|
McLachlan E, Bousfield J, Howard R, Reeves S. Reduced parahippocampal volume and psychosis symptoms in Alzheimer's disease. Int J Geriatr Psychiatry 2018; 33:389-395. [PMID: 28741694 DOI: 10.1002/gps.4757] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 05/31/2017] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Establishing structural imaging correlates of psychosis symptoms in Alzheimer's disease (AD) could localise pathology and target symptomatic treatment. This study investigated whether psychosis symptoms are associated with visuoperceptual or frontal networks, and whether regional brain volume differences could be linked with the paranoid (persecutory delusions) or misidentification (misidentification phenomena and/or hallucinations) subtypes. METHODS A total of 104 patients with probable AD (AddNeuroMed; 47 psychotic, 57 non-psychotic), followed up for at least one year with structural MRI at baseline. Presence and subtype of psychosis symptoms were established using the Neuropsychiatric Inventory. Volume and cortical thickness measures in visuoperceptual and frontal networks were explored using multivariate analyses to compare with both a global (psychotic versus not) and subtype-specific approach, adjusting for potential confounding factors. RESULTS There was a significant main effect of psychosis subtypes on the ventral visual stream region of interest (F30,264 = 1.65, p = 0.021, np2 = 0.16). This was explained by reduced left parahippocampal gyrus volume (F1,97 = 11.1, p = 0.001, np2 = 0.10). When comparisons were made across psychosis subtypes, left parahippocampal volume reduction remained significant (F7,95 = 3.94, p = 0.011, np2 = 0.11) and was greatest for the misidentification and mixed subtypes compared to paranoid and non-psychotic groups. CONCLUSIONS These findings implicate the ventral visual stream in psychosis in AD, consistent with integrative theories regarding origins of psychosis, and provide further evidence for a role in the misidentification subtype. Specifically, reduced volume in the parahippocampal gyrus is implicated in misidentification delusion formation, which we hypothesise is due to its role in context attribution. Copyright © 2017 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Emma McLachlan
- Department of Old Age Psychiatry, King's College London, UK.,Division of Psychiatry, University College London, UK
| | | | - Robert Howard
- Department of Old Age Psychiatry, King's College London, UK.,Division of Psychiatry, University College London, UK
| | - Suzanne Reeves
- Department of Old Age Psychiatry, King's College London, UK.,Division of Psychiatry, University College London, UK
| |
Collapse
|
9
|
Liu H, Li L, Shen L, Wang X, Hou Y, Zhao Z, Gu L, Mao J. Cavum septum pellucidum and first-episode psychosis: A meta-analysis. PLoS One 2017; 12:e0177715. [PMID: 28545119 PMCID: PMC5435239 DOI: 10.1371/journal.pone.0177715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 05/02/2017] [Indexed: 02/05/2023] Open
Abstract
Objectives To investigate the prevalence and changes of cavum septum pellucidum (CSP) in first-episode psychosis (FEP) patients. Methods Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify eligible studies comparing FEP patients and healthy controls from inception to Feb 29, 2016. Results Ten cross-sectional studies and three longitudinal studies reported in ten articles met our criteria. Our meta-analysis found no significant differences in the prevalence of either “any CSP” (OR = 1.41; 95% CI 0.90–2.20; p = 0.13; I2 = 52.7%) or “large CSP” (OR = 1.10; 95% CI 0.77–1.58; p = 0.59; I2 = 24.1%) between FEP patients and healthy controls. However, the heterogeneity analysis of the prevalence of “any CSP” suggested bias in outcome reporting. Conclusions The results based on current evidence suggest it is unclear whether “any CSP” is a risk factor for FEP due to the heterogeneity of the studies. There is insufficient evidence to support that “large CSP” is a possible risk factor for FEP.
Collapse
Affiliation(s)
- Hanwen Liu
- Tianjin University of Traditional Chinese Medicine, Tianjin, China
- Internal Medicine Unit, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Ling Li
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Li Shen
- Department of Psychosomatic Medicine, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Xianliang Wang
- Cardiovascular Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yazhu Hou
- Cardiovascular Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Zhiqiang Zhao
- Cardiovascular Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Lili Gu
- Department of Medical Administration, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Jingyuan Mao
- Internal Medicine Unit, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- * E-mail:
| |
Collapse
|
10
|
Tan A, Ma W, Vira A, Marwha D, Eliot L. The human hippocampus is not sexually-dimorphic: Meta-analysis of structural MRI volumes. Neuroimage 2016; 124:350-366. [DOI: 10.1016/j.neuroimage.2015.08.050] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/20/2015] [Accepted: 08/22/2015] [Indexed: 12/31/2022] Open
|
11
|
Luck D, Joober R, Malla A, Lepage M. Altered emotional modulation of associative memory in first episode schizophrenia: An fMRI study. Schizophr Res Cogn 2015; 3:26-32. [PMID: 28740805 PMCID: PMC5506707 DOI: 10.1016/j.scog.2015.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/12/2015] [Accepted: 11/14/2015] [Indexed: 11/30/2022]
Abstract
Alterations of associative memory, resulting from perturbations within the medial temporal lobe, are well established in schizophrenia. So far, all the studies having examined associative memory in schizophrenia have limited ecological validity, as people experience various emotional stimuli in their life. As such, emotion must be taken into account in order to fully understand memory. Thus, we designed an fMRI study aimed at investigating neural correlates of the effects of emotions on associative memory in schizophrenia. Twenty-four first episode schizophrenia (FES) patients and 20 matched controls were instructed to memorize 90 pairs of standardized pictures during a scanned encoding phase. Each of the 90 pairs was composed of a scene and an unrelated object. Furthermore, trials were either neutral or emotional as a function of the emotional valence of the scene comprising each pair. FES patients exhibited lower performance for both conditions than controls, with greater deficits in regard to emotional versus neutral associations. fMRI analyses revealed that these deficits were related to lower activations in mnemonic and limbic regions. This study provides evidence of altered associative memory and emotional modulation in schizophrenia, resulting from dysfunctions in the cerebral networks underlying memory, emotion, and encoding strategies. Together, our results suggest that all these dysfunctions may be targets for new therapeutic interventions known to improve cognitive deficits in schizophrenia.
Collapse
Affiliation(s)
- David Luck
- Institut Universitaire en Santé Mentale de Montréal, QC, Canada.,Département de Psychiatrie, University of Montreal, Pavillon Roger-Gaudry, 2900, boul. Édouard-Montpetit, Montréal, QC H3T 1J4, Canada.,Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Ridha Joober
- Douglas Mental Health University Institute, 6875 Boul. LaSalle, Verdun, H4H 1R3, Canada.,Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Ashok Malla
- Douglas Mental Health University Institute, 6875 Boul. LaSalle, Verdun, H4H 1R3, Canada.,Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Martin Lepage
- Douglas Mental Health University Institute, 6875 Boul. LaSalle, Verdun, H4H 1R3, Canada.,Department of Psychiatry, McGill University, Montreal, QC, Canada
| |
Collapse
|
12
|
Silver H, Bilker WB. Similar verbal memory impairments in schizophrenia and healthy aging. Implications for understanding of neural mechanisms. Psychiatry Res 2015; 226:277-83. [PMID: 25639372 DOI: 10.1016/j.psychres.2014.12.062] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/26/2014] [Accepted: 12/20/2014] [Indexed: 12/14/2022]
Abstract
Memory is impaired in schizophrenia patients but it is not clear whether this is specific to the illness and whether different types of memory (verbal and nonverbal) or memories in different cognitive domains (executive, object recognition) are similarly affected. To study relationships between memory impairments and schizophrenia we compared memory functions in 77 schizophrenia patients, 58 elderly healthy individuals and 41 young healthy individuals. Tests included verbal associative and logical memory and memory in executive and object recognition domains. We compared relationships of memory functions to each other and to other cognitive functions including psychomotor speed and verbal and spatial working memory. Compared to the young healthy group, schizophrenia patients and elderly healthy individuals showed similar severe impairment in logical memory and in the ability to learn new associations (NAL), and similar but less severe impairment in spatial working memory and executive and object memory. Verbal working memory was significantly more impaired in schizophrenia patients than in the healthy elderly. Verbal episodic memory impairment in schizophrenia may share common mechanisms with similar impairment in healthy aging. Impairment in verbal working memory in contrast may reflect mechanisms specific to schizophrenia. Study of verbal explicit memory impairment tapped by the NAL index may advance understanding of abnormal hippocampus dependent mechanisms common to schizophrenia and aging.
Collapse
Affiliation(s)
- Henry Silver
- Brain Behavior Laboratory, Sha׳ar Menashe Mental Health Center, Mobile Post Hefer 37806, Israel; Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel.
| | - Warren B Bilker
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia 19104-6021, USA.
| |
Collapse
|
13
|
Hýža M, Huttlová J, Keřkovský M, Kašpárek T. Psychosis effect on hippocampal reduction in schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2014; 48:186-92. [PMID: 24140928 DOI: 10.1016/j.pnpbp.2013.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 09/23/2013] [Accepted: 10/07/2013] [Indexed: 01/05/2023]
Abstract
INTRODUCTION In schizophrenia, disruption of the neurodevelopmental processes may lead to brain changes and subsequent clinical manifestations of the illness. Reports of the progressive nature of these morphological brain changes raise questions about their causes. The possible toxic effects of repeated stressful psychotic episodes may contribute to the disease progression. OBJECTIVES To analyze the influence of illness duration and previous psychotic episodes on hippocampal gray matter volume (GMV) in schizophrenia. METHODS We performed an analysis of hippocampal GMV correlations with illness duration, number of previous psychotic episodes, and age in 24 schizophrenia patients and 24 matched healthy controls. RESULTS We found a cluster of GMV voxels in the left hippocampal tail that negatively correlated with the number of previous psychotic episodes, independent from the effect of age. On the other hand we found no effect of illness duration independent of age on the hippocampal GMV. Finally, we found a cluster of significant group-by-age interaction in the left hippocampal head. CONCLUSIONS We found an additive adverse effect of psychotic episodes on hippocampal morphology in schizophrenia. Our findings support toxicity of psychosis concept, together with etiological heterogeneity of brain changes in schizophrenia.
Collapse
Affiliation(s)
- Martin Hýža
- Department of Psychiatry, University Hospital Brno and Faculty of Medicine, Masaryk University, Czech Republic
| | | | | | | |
Collapse
|
14
|
Mukherjee P, Whalley HC, McKirdy JW, Sprengelmeyer R, Young AW, McIntosh AM, Lawrie SM, Hall J. Altered amygdala connectivity within the social brain in schizophrenia. Schizophr Bull 2014; 40:152-60. [PMID: 23851067 PMCID: PMC3885300 DOI: 10.1093/schbul/sbt086] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Impairments in social cognition have been described in schizophrenia and relate to core symptoms of the disorder. Social cognition is subserved by a network of brain regions, many of which have been implicated in schizophrenia. We hypothesized that deficits in connectivity between components of this social brain network may underlie the social cognition impairments seen in the disorder. METHODS We investigated brain activation and connectivity in a group of individuals with schizophrenia making social judgments of approachability from faces (n = 20), compared with a group of matched healthy volunteers (n = 24), using functional magnetic resonance imaging. Effective connectivity from the amygdala was estimated using the psychophysiological interaction approach. RESULTS While making approachability judgments, healthy participants recruited a network of social brain regions including amygdala, fusiform gyrus, cerebellum, and inferior frontal gyrus bilaterally and left medial prefrontal cortex. During the approachability task, healthy participants showed increased connectivity from the amygdala to the fusiform gyri, cerebellum, and left superior frontal cortex. In comparison to controls, individuals with schizophrenia overactivated the right middle frontal gyrus, superior frontal gyrus, and precuneus and had reduced connectivity between the amygdala and the insula cortex. DISCUSSION We report increased activation of frontal and medial parietal regions during social judgment in patients with schizophrenia, accompanied by decreased connectivity between the amygdala and insula. We suggest that the increased activation of frontal control systems and association cortex may reflect a compensatory mechanism for impaired connectivity of the amygdala with other parts of the social brain networks in schizophrenia.
Collapse
Affiliation(s)
- Prerona Mukherjee
- *To whom correspondence should be addressed; Department of Psychology, Stony Brook University, Stony Brook, NY 11794-2500, US; tel: 773-916-7662, fax: 631-632-7876, e-mail:
| | | | | | | | - Andrew W. Young
- Department of Psychology and York Neuroimaging Centre, University of York, York, UK
| | | | | | - Jeremy Hall
- Division of Psychiatry, University of Edinburgh, Edinburgh, UK;,Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK
| |
Collapse
|
15
|
Rizos EN, Papathanasiou M, Michalopoulou PG, Mazioti A, Douzenis A, Kastania A, Nikolaidou P, Laskos E, Vasilopoulou K, Lykouras L. Association of serum BDNF levels with hippocampal volumes in first psychotic episode drug-naive schizophrenic patients. Schizophr Res 2011; 129:201-4. [PMID: 21470828 DOI: 10.1016/j.schres.2011.03.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 02/22/2011] [Accepted: 03/01/2011] [Indexed: 12/22/2022]
Abstract
Evidence suggests that hippocampal volumetric abnormalities are present in first-episode schizophrenia. The hippocampus contains the highest brain levels of neurotrophic factors, which are major determinants of neuronal plasticity. Brain-derived neurotrophic factor (BDNF) influences neuronal survival, differentiation, synaptogenesis, and maintenance and is also correlated with neuronal activation in the hippocampus. BDNF is also involved in the development and modulation of dopaminergic-related systems. Alterations of serum BDNF levels have been shown in a number of studies with first episode patients with schizophrenia, probably reflecting an association between BDNF and the pathogenesis of the disorder. In the present study we investigated the correlation between serum BDNF levels and hippocampal volumes in a sample of first episode drug-naïve patients with schizophrenia (FEP) and healthy control subjects. We found that hippocampal volume (HV) was decreased in FEP patients. Corrected right HV of FEP patients were significantly smaller compared to corrected right HVs of healthy subjects. The serum BDNF levels in the sample of FEP patients was significantly reduced compared to the healthy subjects. A significant positive association was found between serum BDNF and the corrected right HV in the group of patients such that the smaller the HV, the more reduced the serum BDNF levels. (Pearson r=0.452, p=0.045). Our findings indicate that low serum BDNF levels are associated with reduction in HV at the onset of schizophrenia and may further support the theory of a neuroprogressive-neurotoxic reaction associated with the onset of psychosis.
Collapse
Affiliation(s)
- E N Rizos
- National and Kapodistrian University of Athens, Medical School, 2nd Department of Psychiatry, ATTIKON" General Hospital, Athens, Greece.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Adriano F, Caltagirone C, Spalletta G. Hippocampal volume reduction in first-episode and chronic schizophrenia: a review and meta-analysis. Neuroscientist 2011; 18:180-200. [PMID: 21531988 DOI: 10.1177/1073858410395147] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Several magnetic resonance imaging studies have reported hippocampal volume reduction in patients with schizophrenia, but other studies have reported contrasting results. In this review and meta-analysis, the authors aim to clarify whether a reduction in hippocampal volume characterizes patients with schizophrenia by considering illness phase (chronic and first episode) and hippocampus side separately. They made a detailed literature search for studies reporting physical volumetric hippocampal measures of patients with schizophrenia and healthy control (HC) participants and found 44 studies that were eligible for meta-analysis. Individual meta-analyses were also performed on 13 studies of first-episode patients and on 22 studies of chronic patients. The authors also detected any different findings when only males or both males and females were considered. Finally, additional meta-analyses and analyses of variance investigated the role of the factors "illness phase" and "side" on hippocampal volume reduction. Overall, the patient group showed significant bilateral hippocampal volume reduction compared with HC. Interestingly, first-episode and chronic patients showed same-size hippocampal volume reduction. Moreover, the left hippocampus was smaller than the right hippocampus in patients and HC. This review and meta-analysis raises the question about whether hippocampal volume reduction in schizophrenia is of neurodevelopmental origin. Future studies should specifically investigate this issue.
Collapse
Affiliation(s)
- Fulvia Adriano
- Laboratory of Clinical and Behavioural Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
| | | | | |
Collapse
|
17
|
van der Staay FJ, Arndt SS, Nordquist RE. Evaluation of animal models of neurobehavioral disorders. BEHAVIORAL AND BRAIN FUNCTIONS : BBF 2009; 5:11. [PMID: 19243583 PMCID: PMC2669803 DOI: 10.1186/1744-9081-5-11] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 02/25/2009] [Indexed: 02/01/2023]
Abstract
Animal models play a central role in all areas of biomedical research. The process of animal model building, development and evaluation has rarely been addressed systematically, despite the long history of using animal models in the investigation of neuropsychiatric disorders and behavioral dysfunctions. An iterative, multi-stage trajectory for developing animal models and assessing their quality is proposed. The process starts with defining the purpose(s) of the model, preferentially based on hypotheses about brain-behavior relationships. Then, the model is developed and tested. The evaluation of the model takes scientific and ethical criteria into consideration.Model development requires a multidisciplinary approach. Preclinical and clinical experts should establish a set of scientific criteria, which a model must meet. The scientific evaluation consists of assessing the replicability/reliability, predictive, construct and external validity/generalizability, and relevance of the model. We emphasize the role of (systematic and extended) replications in the course of the validation process. One may apply a multiple-tiered 'replication battery' to estimate the reliability/replicability, validity, and generalizability of result.Compromised welfare is inherent in many deficiency models in animals. Unfortunately, 'animal welfare' is a vaguely defined concept, making it difficult to establish exact evaluation criteria. Weighing the animal's welfare and considerations as to whether action is indicated to reduce the discomfort must accompany the scientific evaluation at any stage of the model building and evaluation process. Animal model building should be discontinued if the model does not meet the preset scientific criteria, or when animal welfare is severely compromised. The application of the evaluation procedure is exemplified using the rat with neonatal hippocampal lesion as a proposed model of schizophrenia.In a manner congruent to that for improving animal models, guided by the procedure expounded upon in this paper, the developmental and evaluation procedure itself may be improved by careful definition of the purpose(s) of a model and by defining better evaluation criteria, based on the proposed use of the model.
Collapse
Affiliation(s)
- F Josef van der Staay
- Program 'Emotion and Cognition', Department of Farm Animal Health, Veterinary Faculty, Utrecht University, PO Box 80166, 3508 TD Utrecht, the Netherlands
| | - Saskia S Arndt
- Division of Laboratory Animal Science, Department of Animals, Science and Society, Veterinary Faculty, Utrecht University, the Netherlands
| | - Rebecca E Nordquist
- Program 'Emotion and Cognition', Department of Farm Animal Health, Veterinary Faculty, Utrecht University, PO Box 80166, 3508 TD Utrecht, the Netherlands
| |
Collapse
|
18
|
DeLisi LE. The concept of progressive brain change in schizophrenia: implications for understanding schizophrenia. Schizophr Bull 2008; 34:312-21. [PMID: 18263882 PMCID: PMC2632405 DOI: 10.1093/schbul/sbm164] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Kraepelin originally defined dementia praecox as a progressive brain disease, although this concept has received various degrees of acceptance and rejection over the years since his famous published textbooks appeared. This article places an historical perspective on the current renewal of Kraepelin's concept in brain imaging literature that supports progressive brain change in schizophrenia from its earliest stages through its chronic course. It is concluded that a great deal of future research is needed focusing on the longitudinal course of change, the extent to the regions of change within each individual and the underlying mechanism and implications of brain change through functional and neurochemical imaging, combined with structural studies in the same individuals.
Collapse
Affiliation(s)
- Lynn E DeLisi
- New York University School of Medicine, 650 First Avenue, New York, NY 1006, USA.
| |
Collapse
|
19
|
Devrim-Uçok M, Keskin-Ergen HY, Uçok A. Novelty P3 and P3b in first-episode schizophrenia and chronic schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2006; 30:1426-34. [PMID: 16828218 DOI: 10.1016/j.pnpbp.2006.05.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 05/28/2006] [Accepted: 05/29/2006] [Indexed: 10/24/2022]
Abstract
The objective of this study was to evaluate P3b and novelty P3 responses in patients with first-episode schizophrenia (FES) and chronic schizophrenia (CS). P3b is consistently reported to be reduced in CS. However, novelty P3 results in CS are controversial. Novelty P3 is not studied, and there are only a few P3b studies in patients with FES. Subject groups comprised 31 patients with FES and 36 younger control subjects, and 26 patients with CS and 35 older control subjects. Automatically elicited auditory novelty P3 and effortfully elicited auditory P3b potentials were assessed. P3b amplitudes were reduced in both patients with FES and CS relative to their controls. CS and FES patients did not differ in P3b amplitude. Novelty P3 amplitude was reduced in patients with CS. Novelty P3 amplitude in patients with FES did not differ from their controls. P3b amplitude reduction may be a trait marker of schizophrenia and may not progress over the course of illness, although this can only be definitively determined by longitudinal studies. Novelty P3 amplitude reduction present in patients with CS, is not found at the onset of illness. Novelty P3 seems unaffected early in the disease process.
Collapse
Affiliation(s)
- Müge Devrim-Uçok
- Department of Physiology, University of Istanbul, Istanbul Medical Faculty, 34093 Capa-Istanbul, Turkey.
| | | | | |
Collapse
|
20
|
Steen RG, Mull C, McClure R, Hamer RM, Lieberman JA. Brain volume in first-episode schizophrenia: systematic review and meta-analysis of magnetic resonance imaging studies. Br J Psychiatry 2006; 188:510-8. [PMID: 16738340 DOI: 10.1192/bjp.188.6.510] [Citation(s) in RCA: 544] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Studies of people with schizophrenia assessed using magnetic resonance imaging (MRI) usually include patients with first-episode and chronic disease, yet brain abnormalities may be limited to those with chronic schizophrenia. AIMS To determine whether patients with a first episode of schizophrenia have characteristic brain abnormalities. METHOD Systematic review and meta-analysis of 66 papers comparing brain volume in patients with a first psychotic episode with volume in healthy controls. RESULTS A total of 52 cross-sectional studies included 1424 patients with a first psychotic episode; 16 longitudinal studies included 465 such patients. Meta-analysis suggests that whole brain and hippocampal volume are reduced (both P<0.0001) and that ventricular volume is increased (P<0.0001) in these patients relative to healthy controls. CONCLUSIONS Average volumetric changes are close to the limit of detection by MRI methods. It remains to be determined whether schizophrenia is a neurodegenerative process that begins at about the time of symptom onset, or whether it is better characterised as a neurodevelopmental process that produces abnormal brain volumes at an early age.
Collapse
Affiliation(s)
- R Grant Steen
- Department of Psychiatry, University of North Carolina at Chapel Hill, Campus Box 7160, Chapel Hill, North Carolina 27599-7160, USA.
| | | | | | | | | |
Collapse
|
21
|
Sim K, DeWitt I, Ditman T, Zalesak M, Greenhouse I, Goff D, Weiss AP, Heckers S. Hippocampal and parahippocampal volumes in schizophrenia: a structural MRI study. Schizophr Bull 2006; 32:332-40. [PMID: 16319377 PMCID: PMC2632210 DOI: 10.1093/schbul/sbj030] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Smaller medial temporal lobe volume is a frequent finding in studies of patients with schizophrenia, but the relative contributions of the hippocampus and three surrounding cortical regions (entorhinal cortex, perirhinal cortex, and parahippocampal cortex) are poorly understood. We tested the hypothesis that the volumes of medial temporal lobe regions are selectively changed in schizophrenia. We studied 19 male patients with schizophrenia and 19 age-matched male control subjects. Hippocampal and cortical volumes were estimated using a three-dimensional morphometric protocol for the analysis of high-resolution structural magnetic resonance images, and repeated measures ANOVA was used to test for region-specific differences. Patients had smaller overall medial temporal lobe volumes compared to controls. The volume difference was not specific for either region or hemisphere. The finding of smaller medial temporal lobe volumes in the absence of regional specificity has important implications for studying the functional role of the hippocampus and surrounding cortical regions in schizophrenia.
Collapse
Affiliation(s)
- Kang Sim
- Schizophrenia and Bipolar Disorders Program, McLean Hospital/Harvard Medical School, Mill Street, Belmont, MA, 02478, USA.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Vita A, De Peri L, Silenzi C, Dieci M. Brain morphology in first-episode schizophrenia: a meta-analysis of quantitative magnetic resonance imaging studies. Schizophr Res 2006; 82:75-88. [PMID: 16377156 DOI: 10.1016/j.schres.2005.11.004] [Citation(s) in RCA: 278] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Revised: 11/01/2005] [Accepted: 11/05/2005] [Indexed: 11/28/2022]
Abstract
BACKGROUND A number of meta-analytic reviews of structural brain imaging studies have shown that multiple subtle brain abnormalities are consistently found in schizophrenia. However, quantitative reviews till now published have included mainly studies performed on chronic schizophrenic patients but have failed to provide clear information on specific, possibly different, findings in first-episode schizophrenia. METHODS We performed a systematic search for MRI studies that reported quantitative measurements of volumes of brain regions in first-episode schizophrenic patients and in healthy controls. Twelve meta-analyses were performed for 6 cerebral regions. RESULTS Twenty-one studies were identified as suitable for analysis. Significant overall effect sizes were demonstrated for lateral and third ventricular volume increase, and for volume reduction of whole brain and hippocampus, but not for temporal lobe, amygdala and total intracranial volumes. CONCLUSIONS The available literature data strongly indicate that some brain abnormalities are already present in first-episode schizophrenic patients. However, unlike the results of published meta-analyses conducted primarily on samples of chronic schizophrenic patients, the present study did not confirm a significant reduction of temporal lobe or amygdala volumes in first-episode schizophrenia. These findings support the hypothesis of different patterns of involvement of various cerebral areas over the time course of schizophrenia.
Collapse
Affiliation(s)
- A Vita
- Department of Mental Health, University of Brescia, Italy.
| | | | | | | |
Collapse
|
23
|
SHOEMAKER JM, SAINT MARIE RL, BONGIOVANNI MJ, NEARY AC, TOCHEN LS, SWERDLOW NR. Prefrontal D1 and ventral hippocampal N-methyl-D-aspartate regulation of startle gating in rats. Neuroscience 2006; 135:385-94. [PMID: 16125865 PMCID: PMC1364454 DOI: 10.1016/j.neuroscience.2005.06.054] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 06/08/2005] [Accepted: 06/16/2005] [Indexed: 11/16/2022]
Abstract
BACKGROUND Sensorimotor gating, as measured by prepulse inhibition of the startle reflex, is deficient in schizophrenia patients, and in rats after specific manipulations of limbic cortico-striato-pallido-thalamic circuitry. For example, prepulse inhibition in rats is disrupted after D1 blockade in the medial prefrontal cortex, and after N-methyl-D-aspartate infusion into the ventral hippocampus. In the present study, we examined whether these two substrates form part of an integrated circuit regulating sensorimotor gating, which might contribute to the loss of prepulse inhibition in patient populations. METHODS Prepulse inhibition was assessed in male Sprague-Dawley rats after systemic or intra-medial prefrontal cortex administration of the D1 antagonist, SCH 23390. Separate rats received intra-medial prefrontal cortex infusion of the retrograde transported label Fluoro-Gold. In rats with sham or electrolytic lesions of the medial prefrontal cortex, prepulse inhibition was tested after infusion of N-methyl-D-aspartate or vehicle into ventral hippocampus regions that were determined to send projections to the medial prefrontal cortex. RESULTS Prepulse inhibition was disrupted after systemic SCH 23390 treatment and after infusion of SCH 23390 into medial prefrontal cortex sites within the prelimbic and cingulate cortices. Fluoro-Gold infusion into these medial prefrontal cortex sites labeled cells in the ventral hippocampus complex, including regions CA1 and entorhinal cortex. N-methyl-D-aspartate infusions into these ventral hippocampus regions disrupted prepulse inhibition in rats after sham but not electrolytic lesions of the medial prefrontal cortex. CONCLUSIONS Prepulse inhibition appears to be regulated by interacting substrates within the ventral hippocampus and MPFC. Specifically, NMDA activation of the ventral hippocampus appears to disrupt prepulse inhibition in a manner that is dependent on the integrity of infralimbic or cingulate cortical regions that also support a D1-mediated regulation of prepulse inhibition. Conceivably, dysfunction within these hippocampal-frontal circuits may contribute to sensorimotor gating deficits in schizophrenia.
Collapse
Affiliation(s)
| | | | | | | | | | - N. R. SWERDLOW
- *Corresponding author. Tel: +1-619-543-2923; fax: +1-619-543-2493., E-mail address: (N. R. Swerdlow)
| |
Collapse
|
24
|
Moreno D, Burdalo M, Reig S, Parellada M, Zabala A, Desco M, Baca-Baldomero E, Arango C. Structural neuroimaging in adolescents with a first psychotic episode. J Am Acad Child Adolesc Psychiatry 2005; 44:1151-7. [PMID: 16239864 DOI: 10.1097/01.chi.0000179055.46795.3f] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective of the present study is to replicate findings in first-episode psychosis reporting a smaller volume in brain structures in a population with adolescent onset. METHOD Magnetic resonance imaging studies were performed on 23 psychotic adolescents (12-18 years old, 17 males, 6 females) consecutively admitted to an adolescent inpatient unit and on 37 normal controls (13-18 years, 23 males, 14 females) matched for age, sex, and years of education. Diagnosis was made at baseline on the basis of the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version and confirmed after 12 months of follow-up. Total brain volume and gray matter, white matter, and cerebrospinal fluid (CSF) volumes of the frontal, parietal, temporal, and occipital lobes were measured bilaterally using a segmentation method based on the Talairach grid system. RESULTS Male patients showed significantly larger volumes than did male controls in overall CSF and left frontal and right parietal sulci CSF. Male patients also showed significantly lower volumes of gray matter in the right and left frontal lobes. No significant volumetric differences were found in females. There were no differences between individuals with a diagnosis of schizophrenia at follow-up and the rest of the patients. CONCLUSIONS This study suggests that larger CSF and lower gray matter volumes in the frontal lobes may be a nonspecific vulnerability marker for psychosis in male adolescents.
Collapse
Affiliation(s)
- Dolores Moreno
- Unidad de Adolescentes, IPP, Hospital General Universitario Gregorio Marañón, Servicio de Psiquiatría, Madrid, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Thermenos HW, Goldstein JM, Buka SL, Poldrack RA, Koch JK, Tsuang MT, Seidman LJ. The effect of working memory performance on functional MRI in schizophrenia. Schizophr Res 2005; 74:179-94. [PMID: 15721998 DOI: 10.1016/j.schres.2004.07.021] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Revised: 07/16/2004] [Accepted: 07/23/2004] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Studies of prefrontal cortical (PFC) function in schizophrenia have been inconsistent, with studies showing both increased and decreased PFC activation compared to healthy controls. Discrepant findings may be due to task performance effects or demographic differences between samples. We report functional magnetic resonance imaging (fMRI) data comparing subjects with schizophrenia and healthy controls performing a 2-back working memory (WM) task, addressing the effects of task performance. METHODS Twenty-two controls and 14 patients with DSM-IV schizophrenia, scanned on a Siemens 1.5 T scanner, performed a visual letter 2-back task and control task (CPT-X) during fMRI. Data were analyzed using Statistical Parametric Mapping (SPM)-99. RESULTS After statistical adjustment for performance differences, persons with schizophrenia showed significantly greater activation than controls in the right medial frontal gyrus and left inferior parietal lobule/medial temporal gyrus region (BA 39/40), and a trend toward greater activation in the left ventrolateral PFC. This pattern was also observed in demographically matched subgroups of participants. CONCLUSIONS Data are consistent with findings reported in recent studies showing increased PFC and parietal activation in schizophrenia when the effects of reduced WM task performance in patients with schizophrenia are addressed. Further studies are needed to clarify the pathophysiological basis of WM load sensitivity in schizophrenia and its relationship to genes.
Collapse
Affiliation(s)
- Heidi W Thermenos
- Harvard Medical School, Department of Psychiatry, Massachusetts Mental Health Center, Boston, MA 02115, USA.
| | | | | | | | | | | | | |
Collapse
|
26
|
Prasad KMR, Rohm BR, Keshavan MS. Parahippocampal gyrus in first episode psychotic disorders: a structural magnetic resonance imaging study. Prog Neuropsychopharmacol Biol Psychiatry 2004; 28:651-8. [PMID: 15276690 DOI: 10.1016/j.pnpbp.2004.01.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/30/2004] [Indexed: 11/16/2022]
Abstract
Neuropathological abnormalities in schizophrenia have been demonstrated in the parahippocampal gyrus (PHG). Only a few studies on first-episode neuroleptic-naive schizophrenia patients have been done using in vivo neuroimaging techniques. The authors examined the PHG morphology using structural MRI in neuroleptic-naive subjects with first episode psychoses. Volumetric measurements of PHG and intracranial volume (ICV) were obtained on subjects with schizophrenia and schizoaffective disorders (SCZ; n = 33), nonschizophrenia psychotic disorders (NSCZ; n = 11) and matched healthy subjects (HS; n = 43). The subjects were rated on the Brief Psychiatric Rating Scale (BPRS). Group differences and clinical correlations of ICV-adjusted PHG volumes were examined. Left PHG was significantly different across the groups consisting of SCZ, NSCZ and HS. PHG was larger in NSCZ compared to SCZ but not relative to HS. Bilaterally, PHG was no different between SCZ and HS. In pooled psychotic patients, the PHG volume negatively correlated with total positive symptom, delusion and conceptual disorganization scores on BPRS. Patients with delusions had relatively smaller PHG compared to nondelusional subjects. Observed differences in PHG volume in first-episode neuroleptic-naive patients suggest that these observations are not confounded by illness chronicity or medication effects. Significant association of PHG volume with psychotic symptoms suggests that PHG pathology plays an important role in the etiopathology of psychosis and its symptoms.
Collapse
Affiliation(s)
- Konasale M R Prasad
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, PA 15213, USA
| | | | | |
Collapse
|
27
|
Swerdlow NR, Shoemaker JM, Noh HR, Ma L, Gaudet I, Munson M, Crain S, Auerbach PP. The ventral hippocampal regulation of prepulse inhibition and its disruption by apomorphine in rats are not mediated via the fornix. Neuroscience 2004; 123:675-85. [PMID: 14706779 DOI: 10.1016/j.neuroscience.2003.08.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Prepulse inhibition (PPI) of startle is a measure of sensorimotor gating that is impaired in schizophrenia. We have reported that PPI is regulated by the ventral hippocampus (VH) and that the PPI disruptive effects of the dopamine agonist apomorphine are enhanced 4 weeks after excitotoxic lesions of the VH. The mechanisms responsible for the VH influence on PPI are not understood, but have been ascribed to interactions between the VH and nucleus accumbens. In the present study, we examined whether the VH influence on PPI and its dopaminergic regulation is dependent on the integrity of the VH-accumbens projection via the fornix. First, the PPI-disruptive effects of intra-VH NMDA infusion were assessed after sham or electrolytic transection of the fornix. Second, the PPI-disruptive effects of apomorphine were assessed 1 month after excitotoxic or electrolytic lesions of the VH, or after fornix transection. Intra-VH N-methyl-D-aspartate infusion significantly disrupted PPI; this effect was unaffected by fornix lesions. The PPI-disruptive effects of apomorphine were significantly enhanced by excitotoxic or electrolytic lesions of the VH, but not by fornix transection. The influence of the VH on PPI and its dopaminergic regulation does not appear to be mediated via the fornix. The enhanced sensitivity to the PPI-disruptive effects of apomorphine after VH lesions is not dependent on excitotoxin-induced changes in the VH or its downstream projections.
Collapse
Affiliation(s)
- N R Swerdlow
- UCSD Department of Psychiatry, 9500 Gilman Drive, 92037-0804, La Jolla, CA, USA.
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Highley JR, DeLisi LE, Roberts N, Webb JA, Relja M, Razi K, Crow TJ. Sex-dependent effects of schizophrenia: an MRI study of gyral folding, and cortical and white matter volume. Psychiatry Res 2003; 124:11-23. [PMID: 14511792 DOI: 10.1016/s0925-4927(03)00076-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Alterations, sometimes sex-dependent, in volumes and gyral structure of areas of cerebral cortex have been reported in schizophrenia. Such changes imply an anomaly of connectivity. The gyrification, percentage of tissue volume attributed to white matter, cortical volume and white matter volume were measured from magnetic resonance images in males and females with (n = 61) and without (n = 42) schizophrenia. The frontal, temporal and an amalgam of occipital and parietal lobes were examined in both hemispheres. There was no effect of schizophrenia on the gyrification of the brain. For the volume of occipito-parietal white matter, females with schizophrenia had bilaterally lower volumes, while males with schizophrenia had greater volumes than controls. It is concluded that the changes in connectivity underlying the pathogenesis of schizophrenia are sex-specific and expressed in occipito-parietal white matter.
Collapse
Affiliation(s)
- J Robin Highley
- The Schizophrenia Research Group, Department of Clinical Neurology (Neuropathology), Radcliffe Infirmary, OX2 6HE, Oxford, UK
| | | | | | | | | | | | | |
Collapse
|
29
|
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.
Collapse
Affiliation(s)
- Lara L Davidson
- Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.
| | | |
Collapse
|
30
|
Abstract
BACKGROUND Schizophrenia is a common mental illness with an incidence of 15 new cases per 100,000 population per year. AIM To review evidence for current neurodevelopmental models of the aetiology of schizophrenia. METHODS We performed a literature search using Medline and PsychINFO. We evaluated the relevance of each article and tracked other relevant articles through references. RESULTS There is considerable evidence to support neurodevelopmental models of the aetiology of schizophrenia. One or more aetiological events occur between conception and birth that disturb central nervous system (CNS) development, leading to persisting alterations in brain structure and function. These early events, acting in concert with genetic loading and later influences or insults, predispose to the development of schizophrenia in early adulthood. CONCLUSIONS There have been considerable advances in schizophrenia research over the past 20 years. Future study of Indices of neural development will help advance our understanding of this common, disabling mental illness.
Collapse
Affiliation(s)
- B D Kelly
- Stanley Research Unit, Department of Adult Psychiatry, Hospitaller Order of St John of God, Blackrock, Dublin, Ireland.
| | | | | | | |
Collapse
|
31
|
Heiser P, Hausmann C, Frey J, Geller F, Becker R, Wesemann W, Krieg JC, Remschmidt H, Vedder H. Serotonergic effects of clozapine and its metabolites in hippocampal HT22 cells. Psychiatry Res 2002; 112:221-9. [PMID: 12450631 DOI: 10.1016/s0165-1781(02)00239-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the hippocampal neuronal in vitro system of HT22 cells, we studied the effects of clozapine (Cloz) and its metabolites clozapine-N-oxide (Cloz-N-oxide) and norclozapine (Norcloz) on 5-HT transporter affinity (K(M)) and uptake (V(max)), MAO-B affinity (K(M)) and maximal velocity (V(max)), as well as on 5-HT(2) receptor affinity and density. Clinically relevant concentrations of Cloz (200 and 400 ng/ml) and its metabolites (100 and 200 ng/ml) were used for the examination of the effects after short-term (4 h) and long-term (24 h) incubation. Statistical evaluation revealed that a significantly lowered 5-HT transporter affinity (higher K(M)) was related to higher concentrations of Cloz and its metabolites. A significantly higher 5-HT transporter uptake was dependent on both high concentrations of drugs and an increased time of incubation. No significant influence of the investigated independent variables on MAO-B affinity could be demonstrated, whereas a significant drug-related increase of MAO-B velocity was detectable. Additionally, low and high concentrations of Cloz and its metabolites induced a higher 5-HT(2) receptor affinity (lower K(D)). No significant influences of the investigated independent variables on 5-HT(2) receptor density were detectable. The results of the present study show that Cloz and its metabolites induce significant alterations in serotoninergic parameters of hippocampal HT22 cells, validating the system of hippocampal HT22 cells for further examinations of the mechanisms of action of atypical neuroleptics.
Collapse
Affiliation(s)
- Philip Heiser
- Department of Child and Adolescent Psychiatry and Psychotherapy, Hans-Sachs-Str. 6, Philipps-University of Marburg, Marburg, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Joyal CC, Laakso MP, Tiihonen J, Syvälahti E, Vilkman H, Laakso A, Alakare B, Räkköläinen V, Salokangas RKR, Hietala J. A volumetric MRI study of the entorhinal cortex in first episode neuroleptic-naive schizophrenia. Biol Psychiatry 2002; 51:1005-7. [PMID: 12062885 DOI: 10.1016/s0006-3223(01)01368-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Imaging studies have frequently reported volume loss of limbic structures in schizophrenia, yet there appears to be no quantitative data on entorhinal cortex volumes in patients with neuroleptic naive first-episode schizophrenia. METHODS The volume of the entorhinal cortices of 22 control subjects and 18 patients with neuroleptic-naïve first-episode schizophrenia were measured from magnetic resonance images (MRI) scans using recently designed anatomic criteria for MRI anatomy of the entorhinal cortex. RESULTS Smaller entorhinal volumes were found bilaterally in the schizophrenic patients. This volume loss did not correlate with items on the Positive and Negative Syndrome Scale. CONCLUSIONS These data suggest early involvement of the entorhinal cortex in schizophrenia.
Collapse
|
33
|
Abstract
Although not necessarily primary to the disease, hippocampal dysfunction in schizophrenia is suggested by morphological changes in the hippocampal formation reported in schizophrenic patients. This notion receives additional support from studies showing that 1) similar behavioral deficits are exhibited by both schizophrenics and animals with hippocampal lesions, and 2) some of these behavioral deficits are reversed by neuroleptics in both schizophrenics and lesioned animals. A brain-mapped neural network model is used to explain how some impairments in attention can be caused by hippocampal dysfunction and ameliorated by dopaminergic blockers.
Collapse
Affiliation(s)
- N A Schmajuk
- Department of Psychology, Duke University, Durham, North Carolina 27706, USA.
| |
Collapse
|
34
|
Abstract
Velo-cardio-facial syndrome (VCFS), the most frequent known interstitial deletion identified in man, is associated with chromosomal microdeletions in the q11 band of chromosome 22. The VCFS phenotype is complex, with multiple congenital abnormalities affecting several tissues and organs, many of which are derived from neural crest cells. Although phenotypic variability occurs, individuals with VCFS have high rates of psychiatric disorder, especially schizophrenia. Additionally, an increased prevalence of chromosome 22q11 deletions has been reported in populations of people with schizophrenia. Furthermore, results of molecular genetic studies suggest that a schizophrenia susceptibility locus maps to chromosome 22q. These data indicate that aside from being the child of two parents with schizophrenia or the monozygotic co-twin of an affected individual, VCFS and deletion 22q11 represents the highest known risk factor for the development of schizophrenia. Since the entire sequence of chromosome 22 has now been identified, the study of VCFS offers a timely and uniquely powerful opportunity to identify susceptibility genes for schizophrenia in the general population. Furthermore, the strength of the association between schizophrenia and VCFS has important implications for the clinical management of these disorders.
Collapse
Affiliation(s)
- Kieran C Murphy
- Division of Psychological Medicine, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK.
| |
Collapse
|
35
|
Keshavan MS, Jayakumar PN, Diwadkar VA, Singh A. Cavum septi pellucidi in first-episode patients and young relatives at risk for schizophrenia. CNS Spectr 2002; 7:155-8. [PMID: 15220858 DOI: 10.1017/s1092852900017478] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Studies on schizophrenia (SZ) have documented an increased presence of cavum septi pellucidi (CSP) in individuals suffering from the illness. Moreover, the presence of CSP has been cited in support of the early neurodevelopmental hypothesis in SZ. Our objective was to assess the magnetic resonance imaging (MRI) scans of first-episode patients and healthy controls to evaluate the frequency of CSP. The presence and the size of CSP were visually assessed on the MRI scans of 40 first-episode SZ patients, 19 nonpsychotic child and high-risk adolescent offspring of patients with SZ or schizoaffective disorder, and 59 controls. Our analysis revealed an absence of statistically significant differences in the occurrence of CSP between SZ patients, high-risk subjects, and controls. Even when the analysis was restricted to large CSP, no differences were found. Furthermore, no association between CSP and sex or handedness was observed. The absence of CSP abnormalities in first-episode SZ subjects might indicate that SZ is not characterized by developmentally mediated alterations in CSP. Also, family history of SZ might not increase likelihood for CSP.
Collapse
Affiliation(s)
- Matcheri S Keshavan
- Department of Psychiatry, the University of Pittsburgh, Western Psychiatric Institute and Clinic, Pittsburgh, Pennsylvania, USA.
| | | | | | | |
Collapse
|
36
|
Laakso MP, Tiihonen J, Syvälahti E, Vilkman H, Laakso A, Alakare B, Räkköläinen V, Salokangas RK, Koivisto E, Hietala J. A morphometric MRI study of the hippocampus in first-episode, neuroleptic-naïve schizophrenia. Schizophr Res 2001; 50:3-7. [PMID: 11378309 DOI: 10.1016/s0920-9964(00)00155-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Magnetic resonance imaging (MRI) studies have frequently, although not unambiguously, reported hippocampal volume deficit in schizophrenia. Data on the hippocampal volumes in first-episode schizophrenia, however, are sparse. In addition, a recent topographic MRI study proposed a regionally specific volume loss in the hippocampus of chronic schizophrenics, but to date no reports have replicated this finding. In this study two-dimensional MRI-based topographic brain mapping was used to study the possibility of regional changes in the hippocampus of 22 controls and 18 patients with first-episode, neuroleptic-naïve schizophrenia. Compared to controls, there were no significant differences between hippocampal volumes, regional volumes, or length of the hippocampus in the patients with schizophrenia. These data are at odds with the previous reports on hippocampal volume loss in first-episode schizophrenia, and with the hypothesis of regionally specific hippocampal volume deficit in schizophrenia.
Collapse
Affiliation(s)
- M P Laakso
- Department of Neurology, Bldg. 5, Kuopio University Hospital, P.O. Box 1777, Kuopio, Finland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
To provide the most effective care for this difficult patient population, it is helpful to remember that patients with schizophrenia have disease-intrinsic limitations that limit their ability to participate in their care. These limitations are symptoms of a disease and not volitional. For the physician to substitute for these deficits, a certain degree of flexibility as well as the willingness to use unorthodox interventions is necessary. Good medical care is as important for the patient with schizophrenia as for any other patient.
Collapse
Affiliation(s)
- D C Goff
- Schizophrenia Program, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
| | | | | |
Collapse
|
38
|
Swerdlow NR, Hanlon FM, Henning L, Kim YK, Gaudet I, Halim ND. Regulation of sensorimotor gating in rats by hippocampal NMDA: anatomical localization. Brain Res 2001; 898:195-203. [PMID: 11306005 DOI: 10.1016/s0006-8993(01)02143-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Prepulse inhibition (PPI) of the startle reflex is a measure of sensorimotor gating that is reduced in humans with certain neuropsychiatric disorders, including schizophrenia, and in rats after manipulations of limbic cortico-striato-pallido-pontine circuitry. We have reported that PPI is reduced after specific manipulations of the hippocampal complex (HPC) in rats, but the mechanisms for these effects remain poorly understood. For example, dopaminergic substrates clearly regulate PPI, but the PPI-disruptive effects of intra-HPC carbachol or NMDA are not reversed by D2 receptor antagonists. This study examined the anatomical specificity within the hippocampal complex of the PPI-disruptive effects of NMDA infusion. Startle magnitude and PPI were assessed after acute bilateral infusion of NMDA (0, 0.4 or 0.8 microg) into the dorsal subiculum (DS), region CA1, the ventral subiculum (VS), the rostral entorhinal cortex (ECr) and the caudal entorhinal cortex (ECc). A dorsal-ventral gradient for NMDA effects was observed, with a dose-dependent disruption of PPI after NMDA infusion into the VS or EC, but not the DS, and with intermediate level effects observed after NMDA infusion into CA1. A second set of studies confirmed that the failure of NMDA effects in the DS did not reflect site-related differences in startle magnitude or baseline levels of PPI. These findings demonstrate the importance of the ventral, but not the dorsal HPC, in the glutamatergic regulation of PPI.
Collapse
Affiliation(s)
- N R Swerdlow
- Department of Psychiatry, UCSD School of Medicine, 9500 Gilman Dr., La Jolla, CA 92093-0804, USA.
| | | | | | | | | | | |
Collapse
|
39
|
Abstract
After more than 100 years of research, the neuropathology of schizophrenia remains unknown and this is despite the fact that both Kraepelin (1919/1971: Kraepelin, E., 1919/1971. Dementia praecox. Churchill Livingston Inc., New York) and Bleuler (1911/1950: Bleuler, E., 1911/1950. Dementia praecox or the group of schizophrenias. International Universities Press, New York), who first described 'dementia praecox' and the 'schizophrenias', were convinced that schizophrenia would ultimately be linked to an organic brain disorder. Alzheimer (1897: Alzheimer, A., 1897. Beitrage zur pathologischen anatomie der hirnrinde und zur anatomischen grundlage einiger psychosen. Monatsschrift fur Psychiarie und Neurologie. 2, 82-120) was the first to investigate the neuropathology of schizophrenia, though he went on to study more tractable brain diseases. The results of subsequent neuropathological studies were disappointing because of conflicting findings. Research interest thus waned and did not flourish again until 1976, following the pivotal computer assisted tomography (CT) finding of lateral ventricular enlargement in schizophrenia by Johnstone and colleagues. Since that time significant progress has been made in brain imaging, particularly with the advent of magnetic resonance imaging (MRI), beginning with the first MRI study of schizophrenia by Smith and coworkers in 1984 (Smith, R.C., Calderon, M., Ravichandran, G.K., et al. (1984). Nuclear magnetic resonance in schizophrenia: A preliminary study. Psychiatry Res. 12, 137-147). MR in vivo imaging of the brain now confirms brain abnormalities in schizophrenia. The 193 peer reviewed MRI studies reported in the current review span the period from 1988 to August, 2000. This 12 year period has witnessed a burgeoning of MRI studies and has led to more definitive findings of brain abnormalities in schizophrenia than any other time period in the history of schizophrenia research. Such progress in defining the neuropathology of schizophrenia is largely due to advances in in vivo MRI techniques. These advances have now led to the identification of a number of brain abnormalities in schizophrenia. Some of these abnormalities confirm earlier post-mortem findings, and most are small and subtle, rather than large, thus necessitating more advanced and accurate measurement tools. These findings include ventricular enlargement (80% of studies reviewed) and third ventricle enlargement (73% of studies reviewed). There is also preferential involvement of medial temporal lobe structures (74% of studies reviewed), which include the amygdala, hippocampus, and parahippocampal gyrus, and neocortical temporal lobe regions (superior temporal gyrus) (100% of studies reviewed). When gray and white matter of superior temporal gyrus was combined, 67% of studies reported abnormalities. There was also moderate evidence for frontal lobe abnormalities (59% of studies reviewed), particularly prefrontal gray matter and orbitofrontal regions. Similarly, there was moderate evidence for parietal lobe abnormalities (60% of studies reviewed), particularly of the inferior parietal lobule which includes both supramarginal and angular gyri. Additionally, there was strong to moderate evidence for subcortical abnormalities (i.e. cavum septi pellucidi-92% of studies reviewed, basal ganglia-68% of studies reviewed, corpus callosum-63% of studies reviewed, and thalamus-42% of studies reviewed), but more equivocal evidence for cerebellar abnormalities (31% of studies reviewed). The timing of such abnormalities has not yet been determined, although many are evident when a patient first becomes symptomatic. There is, however, also evidence that a subset of brain abnormalities may change over the course of the illness. The most parsimonious explanation is that some brain abnormalities are neurodevelopmental in origin but unfold later in development, thus setting the stage for the development of the symptoms of schizophrenia. Or there may be additional factors, such as stress or neurotoxicity, that occur during adolescence or early adulthood and are necessary for the development of schizophrenia, and may be associated with neurodegenerative changes. Importantly, as several different brain regions are involved in the neuropathology of schizophrenia, new models need to be developed and tested that explain neural circuitry abnormalities effecting brain regions not necessarily structurally proximal to each other but nonetheless functionally interrelated. (ABSTRACT TRUNCATED)
Collapse
Affiliation(s)
- M E Shenton
- Clinical Neuroscience Division, Laboratory of Neuroscience, Department of Psychiatry, Harvard Medical School, Brockton, MA 02301, USA.
| | | | | | | |
Collapse
|
40
|
Aso M, Suzuki M, Kawasaki Y, Matsui M, Hagino H, Kurokawa K, Seto H, Kurachi M. Sylvian fissure and medial temporal lobe structures in patients with schizophrenia: a magnetic resonance imaging study. Psychiatry Clin Neurosci 2001; 55:49-56. [PMID: 11235858 DOI: 10.1046/j.1440-1819.2001.00784.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Volumes of the medial temporal lobe structures (i.e. the amygdala, hippocampus, and parahippocampal gyrus), Sylvian fissure, and inferior horn of the lateral ventricle relative to the cerebral hemisphere were measured in 24 patients with schizophrenia and 23 normal controls using magnetic resonance imaging. The patients had significantly larger Sylvian fissures and inferior horns bilaterally than the controls. In the patients the right Sylvian fissure size showed a significant positive correlation with the duration of illness. Moreover, earlier onset of illness was significantly correlated with decreased volume of the left medial temporal lobe structures. These results replicate previous finding of inferior horn enlargement and suggest the significance of the Sylvian fissure and the medial temporal lobe structures in pathophysiology of schizophrenia.
Collapse
Affiliation(s)
- M Aso
- Department of Neuropsychiatry, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
Hallucinations and delusions - two diagnostic features of psychosis shared across the spectrum of heterogeneous schizophrenia constructs - can be described in terms of the pathophysiology of sensory information processing: hallucination is the impaired ability to classify representations as internally or externally generated, while delusion is the immutable linking of representations with each other in the absence of external dependency. The key anatomical systems in higher-order information processing are the cortex, thalamus, basal ganglia, and medial temporal lobe, each of which is modulated by neurotransmitter projection systems. Preliminary evidence, concentrating to date on the dorsolateral prefontal cortex, thalamus, and hippocampal region of the medial temporal lobe, points to neural circuitry dysfunction within and between each system in psychosis. This may account for specific symptoms and associated cognitive deficits such as memory impairment, attention deficit, and language disturbance.
Collapse
|
42
|
|