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Wang B, Irizar H, Thygesen JH, Zartaloudi E, Austin-Zimmerman I, Bhat A, Harju-Seppänen J, Pain O, Bass N, Gkofa V, Alizadeh BZ, van Amelsvoort T, Arranz MJ, Bender S, Cahn W, Stella Calafato M, Crespo-Facorro B, Di Forti M, Giegling I, de Haan L, Hall J, Hall MH, van Haren N, Iyegbe C, Kahn RS, Kravariti E, Lawrie SM, Lin K, Luykx JJ, Mata I, McDonald C, McIntosh AM, Murray RM, Picchioni M, Powell J, Prata DP, Rujescu D, Rutten BPF, Shaikh M, Simons CJP, Toulopoulou T, Weisbrod M, van Winkel R, Kuchenbaecker K, McQuillin A, Bramon E. Psychosis Endophenotypes: A Gene-Set-Specific Polygenic Risk Score Analysis. Schizophr Bull 2023; 49:1625-1636. [PMID: 37582581 PMCID: PMC10686343 DOI: 10.1093/schbul/sbad088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
BACKGROUND AND HYPOTHESIS Endophenotypes can help to bridge the gap between psychosis and its genetic predispositions, but their underlying mechanisms remain largely unknown. This study aims to identify biological mechanisms that are relevant to the endophenotypes for psychosis, by partitioning polygenic risk scores into specific gene sets and testing their associations with endophenotypes. STUDY DESIGN We computed polygenic risk scores for schizophrenia and bipolar disorder restricted to brain-related gene sets retrieved from public databases and previous publications. Three hundred and seventy-eight gene-set-specific polygenic risk scores were generated for 4506 participants. Seven endophenotypes were also measured in the sample. Linear mixed-effects models were fitted to test associations between each endophenotype and each gene-set-specific polygenic risk score. STUDY RESULTS After correction for multiple testing, we found that a reduced P300 amplitude was associated with a higher schizophrenia polygenic risk score of the forebrain regionalization gene set (mean difference per SD increase in the polygenic risk score: -1.15 µV; 95% CI: -1.70 to -0.59 µV; P = 6 × 10-5). The schizophrenia polygenic risk score of forebrain regionalization also explained more variance of the P300 amplitude (R2 = 0.032) than other polygenic risk scores, including the genome-wide polygenic risk scores. CONCLUSIONS Our finding on reduced P300 amplitudes suggests that certain genetic variants alter early brain development thereby increasing schizophrenia risk years later. Gene-set-specific polygenic risk scores are a useful tool to elucidate biological mechanisms of psychosis and endophenotypes, offering leads for experimental validation in cellular and animal models.
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Affiliation(s)
- Baihan Wang
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Haritz Irizar
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Johan H Thygesen
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Institute of Health Informatics, University College London, London, UK
| | - Eirini Zartaloudi
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Isabelle Austin-Zimmerman
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Anjali Bhat
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Jasmine Harju-Seppänen
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Oliver Pain
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Nick Bass
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Vasiliki Gkofa
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Behrooz Z Alizadeh
- University of Groningen, University Medical Center Groningen, University Center for Psychiatry, Rob Giel Research Center, Groningen, The Netherlands
- Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Therese van Amelsvoort
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Maria J Arranz
- Fundació Docència i Recerca Mutua Terrassa, Terrassa, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Institut de Recerca Biomédica Sant Pau (IIB-Sant Pau), Barcelona, Spain
| | - Stephan Bender
- Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Wiepke Cahn
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Altrecht, General Mental Health Care, Utrecht, The Netherlands
| | - Maria Stella Calafato
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Benedicto Crespo-Facorro
- CIBERSAM, Centro Investigación Biomédica en Red Salud Mental, Sevilla, Spain
- Department of Psychiatry, University Hospital Virgen del Rocio, School of Medicine, University of Sevilla–IBiS, Sevilla, Spain
| | - Marta Di Forti
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | | | - Ina Giegling
- Comprehensive Centers for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Lieuwe de Haan
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Arkin, Institute for Mental Health, Amsterdam, The Netherlands
| | - Jeremy Hall
- Neuroscience and Mental Health Innovation Institute, School of Medicine, Cardiff University, Hadyn Ellis Building, Mandy Road, Cardiff, UK
| | - Mei-Hua Hall
- Psychosis Neurobiology Laboratory, Harvard Medical School, McLean Hospital, Belmont, MA, USA
| | - Neeltje van Haren
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Center, Sophia’s Children Hospital, Rotterdam, The Netherlands
| | - Conrad Iyegbe
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - René S Kahn
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eugenia Kravariti
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Stephen M Lawrie
- Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK
| | - Kuang Lin
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Jurjen J Luykx
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ignacio Mata
- Fundacion Argibide, Pamplona, Spain
- CIBERSAM, Centro Investigación Biomédica en Red Salud Mental, Madrid, Spain
| | - Colm McDonald
- The Centre for Neuroimaging & Cognitive Genomics (NICOG) and NCBES Galway Neuroscience Centre, University of Galway, Galway, Ireland
| | - Andrew M McIntosh
- Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Robin M Murray
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | | | - Marco Picchioni
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- St Magnus Hospital, Surrey, UK
| | - John Powell
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Diana P Prata
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciencias da Universidade de Lisboa, Portugal
| | - Dan Rujescu
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Division of General Psychiatry, Medical University of Vienna, Austria
| | - Bart P F Rutten
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Madiha Shaikh
- North East London Foundation Trust, London, UK
- Research Department of Clinical, Educational and Health Psychology, University College London, London, UK
| | - Claudia J P Simons
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- GGzE Institute for Mental Health Care, Eindhoven, The Netherlands
| | - Timothea Toulopoulou
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Türkiye
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Türkiye
- Department of Psychology, Bilkent University, Ankara, Türkiye
- School of Medicine, Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece
- Department of Psychiatry and Behavioral Health System, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Matthias Weisbrod
- Department of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Germany
- SRH Klinikum, Karlsbad-Langensteinbach, Germany
| | - Ruud van Winkel
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- KU Leuven, Department of Neuroscience, Research Group Psychiatry, Leuven, Belgium
| | - Karoline Kuchenbaecker
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- UCL Genetics Institute, Division of Biosciences, University College London, London, UK
| | - Andrew McQuillin
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Elvira Bramon
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Institute of Cognitive Neuroscience, University College London, London, UK
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Atagun MI, Drukker M, Hall MH, Altun IK, Tatli SZ, Guloksuz S, van Os J, van Amelsvoort T. Meta-analysis of auditory P50 sensory gating in schizophrenia and bipolar disorder. Psychiatry Res Neuroimaging 2020; 300:111078. [PMID: 32361172 DOI: 10.1016/j.pscychresns.2020.111078] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 11/15/2022]
Abstract
The ability of the brain to reduce the amount of trivial or redundant sensory inputs is called gating function. Dysfunction of sensory gating may lead to cognitive fragmentation and poor real-world functioning. The auditory dual-click paradigm is a pertinent neurophysiological measure of sensory gating function. This meta-analysis aimed to examine the subcomponents of abnormal P50 waveforms in bipolar disorder and schizophrenia to assess P50 sensory gating deficits and examine effects of diagnoses, illness states (first-episode psychosis vs. schizophrenia, remission vs. episodes in bipolar disorder), and treatment status (medication-free vs. medicated). Literature search of PubMed between Jan 1st 1980 and March 31st 2019 identified 2091 records for schizophrenia, 362 for bipolar disorder. 115 studies in schizophrenia (4932 patients), 16 in bipolar disorder (975 patients) and 10 in first-degree relatives (848 subjects) met the inclusion criteria. P50 sensory gating ratio (S2/S1) and S1-S2 difference were significantly altered in schizophrenia, bipolar disorder and their first-degree relatives. First-episode psychosis did not differ from schizophrenia, however episodes altered P50 sensory gating in bipolar disorder. Medications improve P50 sensory gating alterations in schizophrenia significantly and at trend level in bipolar disorder. Future studies should examine longitudinal course of P50 sensory gating in schizophrenia and bipolar disorder.
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Affiliation(s)
- Murat Ilhan Atagun
- Department of Psychiatry, Ankara Yildirim Beyazit University Medical School, Universities Region, Ihsan Dogramaci Boulevard. No: 6, Bilkent, Cankaya, Ankara Turkey.
| | - Marjan Drukker
- Department of Psychiatry and Neuropsychology, Maastricht University School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht, the Netherlands
| | - Mei Hua Hall
- Psychosis Neurobiology Laboratory, Harvard Medical School, McLean Hospital, Belmont, Massachusetts, USA
| | - Ilkay Keles Altun
- Department of Psychiatry, Bursa Higher Education Training and Education Hospital, Bursa, Turkey
| | | | - Sinan Guloksuz
- Department of Psychiatry and Neuropsychology, Maastricht University School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht, the Netherlands; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Jim van Os
- Department of Psychiatry and Neuropsychology, Maastricht University School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht, the Netherlands; King's Health Partners Department of Psychosis Studies, King's College London, Institute of Psychiatry, London, United Kingdom; Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Thérèse van Amelsvoort
- Department of Psychiatry and Neuropsychology, Maastricht University School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht, the Netherlands
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Thakkar KN, Rolfs M. Disrupted Corollary Discharge in Schizophrenia: Evidence From the Oculomotor System. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 4:773-781. [PMID: 31105039 PMCID: PMC6733648 DOI: 10.1016/j.bpsc.2019.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 03/04/2019] [Accepted: 03/22/2019] [Indexed: 01/18/2023]
Abstract
Corollary discharge (CD) signals are motor-related signals that exert an influence on sensory processing. They allow mobile organisms to predict the sensory consequences of their imminent actions. Among the many functions of CD is to provide a means by which we can distinguish sensory experiences caused by our own actions from those with external causes. In this way, they contribute to a subjective sense of agency. A disruption in the sense of agency is central to many of the clinical symptoms of schizophrenia, and abnormalities in CD signaling have been theorized to underpin particularly those agency-related psychotic symptoms of the illness. Characterizing abnormal CD associated with eye movements in schizophrenia and their resulting influence on visual processing and subsequent action plans may have advantages over other sensory and motor systems. That is because the most robust psychophysiological and neurophysiological data regarding the dynamics and influence of CD as well as the neural circuitry implicated in CD generation and transmission comes from the study of eye movements in humans and nonhuman primates. We review studies of oculomotor CD signaling in the schizophrenia spectrum and possible neurobiological correlates of CD disturbances. We conclude by speculating on the ways in which oculomotor CD dysfunction, specifically, may invoke specific experiences, clinical symptoms, and cognitive impairments. These speculations lay the groundwork for empirical study, and we conclude by outlining potentially fruitful research directions.
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Affiliation(s)
- Katharine N Thakkar
- Department of Psychology, Michigan State University, East Lansing, Michigan; Division of Psychiatry and Behavioral Medicine, Michigan State University, East Lansing, Michigan.
| | - Martin Rolfs
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany; Bernstein Center for Computational Neuroscience, Berlin, Germany
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4
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Blakey R, Ranlund S, Zartaloudi E, Cahn W, Calafato S, Colizzi M, Crespo-Facorro B, Daniel C, Díez-Revuelta Á, Di Forti M, Iyegbe C, Jablensky A, Jones R, Hall MH, Kahn R, Kalaydjieva L, Kravariti E, Lin K, McDonald C, McIntosh AM, Picchioni M, Powell J, Presman A, Rujescu D, Schulze K, Shaikh M, Thygesen JH, Toulopoulou T, Van Haren N, Van Os J, Walshe M, Murray RM, Bramon E. Associations between psychosis endophenotypes across brain functional, structural, and cognitive domains. Psychol Med 2018; 48:1325-1340. [PMID: 29094675 PMCID: PMC6516747 DOI: 10.1017/s0033291717002860] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND A range of endophenotypes characterise psychosis, however there has been limited work understanding if and how they are inter-related. METHODS This multi-centre study includes 8754 participants: 2212 people with a psychotic disorder, 1487 unaffected relatives of probands, and 5055 healthy controls. We investigated cognition [digit span (N = 3127), block design (N = 5491), and the Rey Auditory Verbal Learning Test (N = 3543)], electrophysiology [P300 amplitude and latency (N = 1102)], and neuroanatomy [lateral ventricular volume (N = 1721)]. We used linear regression to assess the interrelationships between endophenotypes. RESULTS The P300 amplitude and latency were not associated (regression coef. -0.06, 95% CI -0.12 to 0.01, p = 0.060), and P300 amplitude was positively associated with block design (coef. 0.19, 95% CI 0.10-0.28, p 0.38). All the cognitive endophenotypes were associated with each other in the expected directions (all p < 0.001). Lastly, the relationships between pairs of endophenotypes were consistent in all three participant groups, differing for some of the cognitive pairings only in the strengths of the relationships. CONCLUSIONS The P300 amplitude and latency are independent endophenotypes; the former indexing spatial visualisation and working memory, and the latter is hypothesised to index basic processing speed. Individuals with psychotic illnesses, their unaffected relatives, and healthy controls all show similar patterns of associations between endophenotypes, endorsing the theory of a continuum of psychosis liability across the population.
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Affiliation(s)
- R. Blakey
- Division of Psychiatry, University College London, London, UK
| | - S. Ranlund
- Division of Psychiatry, University College London, London, UK
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - E. Zartaloudi
- Division of Psychiatry, University College London, London, UK
| | - W. Cahn
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - S. Calafato
- Division of Psychiatry, University College London, London, UK
| | - M. Colizzi
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - B. Crespo-Facorro
- CIBERSAM, Centro Investigación Biomédica en Red Salud Mental, Madrid, Spain
- Department of Psychiatry, University Hospital Marqués de Valdecilla, School of Medicine, University of Cantabria–IDIVAL, Santander, Spain
| | - C. Daniel
- Division of Psychiatry, University College London, London, UK
| | - Á. Díez-Revuelta
- Division of Psychiatry, University College London, London, UK
- Laboratory of Cognitive and Computational Neuroscience – Centre for Biomedical Technology (CTB), Complutense University and Technical University of Madrid, Madrid, Spain
| | - M. Di Forti
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | | | - C. Iyegbe
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - A. Jablensky
- Centre for Clinical Research in Neuropsychiatry, The University of Western Australia, Perth, Western Australia, Australia
| | - R. Jones
- Division of Psychiatry, University College London, London, UK
| | - M.-H. Hall
- Psychology Research Laboratory, Harvard Medical School, McLean Hospital, Belmont, MA, USA
| | - R. Kahn
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - L. Kalaydjieva
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - E. Kravariti
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - K. Lin
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - C. McDonald
- Department of Psychiatry, Clinical Science Institute, National University of Ireland Galway, Ireland
| | - A. M. McIntosh
- Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, UK
| | | | - M. Picchioni
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - J. Powell
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - A. Presman
- Division of Psychiatry, University College London, London, UK
| | - D. Rujescu
- Department of Psychiatry, Ludwig-Maximilians University of Munich, Munich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, University of Halle Wittenberg, Halle, Germany
| | - K. Schulze
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - M. Shaikh
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- North East London Foundation Trust, London, UK
| | - J. H. Thygesen
- Division of Psychiatry, University College London, London, UK
| | - T. Toulopoulou
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Department of Psychology, Bilkent University, Main Campus, Bilkent, Ankara, Turkey
- Department of Psychology, the University of Hong Kong, Pokfulam Rd, Hong Kong SAR, China
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, The Hong Kong Jockey Club Building for Interdisciplinary Research, Hong Kong SAR, China
| | - N. Van Haren
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - J. Van Os
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Department of Psychiatry and Psychology, Maastricht University Medical Centre, EURON, Maastricht, The Netherlands
| | - M. Walshe
- Division of Psychiatry, University College London, London, UK
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | | | - R. M. Murray
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - E. Bramon
- Division of Psychiatry, University College London, London, UK
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Institute of Cognitive Neuroscience, University College London, London, UK
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Ranlund S, Calafato S, Thygesen JH, Lin K, Cahn W, Crespo‐Facorro B, de Zwarte SM, Díez Á, Di Forti M, Iyegbe C, Jablensky A, Jones R, Hall M, Kahn R, Kalaydjieva L, Kravariti E, McDonald C, McIntosh AM, McQuillin A, Picchioni M, Prata DP, Rujescu D, Schulze K, Shaikh M, Toulopoulou T, van Haren N, van Os J, Vassos E, Walshe M, Lewis C, Murray RM, Powell J, Bramon E. A polygenic risk score analysis of psychosis endophenotypes across brain functional, structural, and cognitive domains. Am J Med Genet B Neuropsychiatr Genet 2018; 177:21-34. [PMID: 28851104 PMCID: PMC5763362 DOI: 10.1002/ajmg.b.32581] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 07/24/2017] [Indexed: 12/26/2022]
Abstract
This large multi-center study investigates the relationships between genetic risk for schizophrenia and bipolar disorder, and multi-modal endophenotypes for psychosis. The sample included 4,242 individuals; 1,087 patients with psychosis, 822 unaffected first-degree relatives of patients, and 2,333 controls. Endophenotypes included the P300 event-related potential (N = 515), lateral ventricular volume (N = 798), and the cognitive measures block design (N = 3,089), digit span (N = 1,437), and the Ray Auditory Verbal Learning Task (N = 2,406). Data were collected across 11 sites in Europe and Australia; all genotyping and genetic analyses were done at the same laboratory in the United Kingdom. We calculated polygenic risk scores for schizophrenia and bipolar disorder separately, and used linear regression to test whether polygenic scores influenced the endophenotypes. Results showed that higher polygenic scores for schizophrenia were associated with poorer performance on the block design task and explained 0.2% (p = 0.009) of the variance. Associations in the same direction were found for bipolar disorder scores, but this was not statistically significant at the 1% level (p = 0.02). The schizophrenia score explained 0.4% of variance in lateral ventricular volumes, the largest across all phenotypes examined, although this was not significant (p = 0.063). None of the remaining associations reached significance after correction for multiple testing (with alpha at 1%). These results indicate that common genetic variants associated with schizophrenia predict performance in spatial visualization, providing additional evidence that this measure is an endophenotype for the disorder with shared genetic risk variants. The use of endophenotypes such as this will help to characterize the effects of common genetic variation in psychosis.
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Affiliation(s)
- Siri Ranlund
- Division of PsychiatryUniversity College LondonLondonUK
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | | | | | - Kuang Lin
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Nuffield Department of Population HealthUniversity of OxfordOxfordUK
| | - Wiepke Cahn
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Benedicto Crespo‐Facorro
- CIBERSAMCentro Investigación Biomédica en Red Salud MentalMadridSpain
- Department of Psychiatry, University Hospital Marqués de Valdecilla, School of MedicineUniversity of Cantabria–IDIVALSantanderSpain
| | - Sonja M.C. de Zwarte
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Álvaro Díez
- Division of PsychiatryUniversity College LondonLondonUK
- Laboratory of Cognitive and Computational Neuroscience—Centre for Biomedical Technology (CTB)Complutense University and Technical University of MadridMadridSpain
| | - Marta Di Forti
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | | | - Conrad Iyegbe
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Assen Jablensky
- Centre for Clinical Research in NeuropsychiatryThe University of Western AustraliaPerth, Western AustraliaAustralia
| | - Rebecca Jones
- Division of PsychiatryUniversity College LondonLondonUK
| | - Mei‐Hua Hall
- Psychosis Neurobiology Laboratory, Harvard Medical SchoolMcLean HospitalBelmontMassachusetts
| | - Rene Kahn
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Luba Kalaydjieva
- Harry Perkins Institute of Medical Research and Centre for Medical ResearchThe University of Western AustraliaPerthAustralia
| | - Eugenia Kravariti
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Colm McDonald
- The Centre for Neuroimaging & Cognitive Genomics (NICOG) and NCBES Galway Neuroscience CentreNational University of Ireland GalwayGalwayIreland
| | - Andrew M. McIntosh
- Division of Psychiatry, University of EdinburghRoyal Edinburgh HospitalEdinburghUK
- Centre for Cognitive Ageing and Cognitive EpidemiologyUniversity of EdinburghEdinburghUK
| | | | | | - Marco Picchioni
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Diana P. Prata
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Faculdade de Medicina, Instituto de Medicina MolecularUniversidade de LisboaPortugal
| | - Dan Rujescu
- Department of PsychiatryLudwig‐Maximilians University of MunichMunichGermany
- Department of Psychiatry, Psychotherapy and PsychosomaticsUniversity of Halle WittenbergHalleGermany
| | - Katja Schulze
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Madiha Shaikh
- North East London Foundation TrustLondonUK
- Research Department of Clinical, Educational and Health PsychologyUniversity College LondonLondonUK
| | - Timothea Toulopoulou
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Department of Psychology, Bilkent UniversityMain CampusBilkent, AnkaraTurkey
- Department of PsychologyThe University of Hong Kong, Pokfulam RdHong Kong SARChina
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong KongThe Hong Kong Jockey Club Building for Interdisciplinary ResearchHong Kong SARChina
| | - Neeltje van Haren
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Jim van Os
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Department of Psychiatry and Psychology, Maastricht University Medical CentreEURONMaastrichtThe Netherlands
| | - Evangelos Vassos
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Muriel Walshe
- Division of PsychiatryUniversity College LondonLondonUK
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | | | - Cathryn Lewis
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Robin M. Murray
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - John Powell
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Elvira Bramon
- Division of PsychiatryUniversity College LondonLondonUK
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
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6
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Clinical correlates of saccadic eye movement in antipsychotic-naïve schizophrenia. Psychiatry Res 2018; 259:154-159. [PMID: 29049907 DOI: 10.1016/j.psychres.2017.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/16/2017] [Accepted: 10/02/2017] [Indexed: 11/21/2022]
Abstract
Some aspects of saccadic performance have been found to be abnormal in chronic schizophrenia. The majority of this research has, however, been performed on patients treated with long-term antipsychotic medication. Very few studies have examined saccadic performance in antipsychotic-naïve/free patients. There are also very few studies describing the relationship between saccadic performance and clinical symptoms, particularly in antipsychotic free patients. In this study, we compared pro and antisaccade performance in a large sample of antipsychotic-naïve/free schizophrenia patients (N = 45) with healthy controls (N = 57). Clinical symptoms were assessed using Scale for Assessment of Positive Symptoms (SAPS) and Negative Symptoms (SANS). In the antisaccade task, patients made significantly more errors, and their correct antisaccades had smaller amplitudes in comparison to healthy controls. Higher error rates were associated with increased severity of hallucinations. In the prosaccade task, patients had less accurate final eye positions, and made saccades with slower latency and reduced amplitude compared to the healthy controls. These observations in schizophrenia patients without the potential confounds of antipsychotic treatment suggest intrinsic link between saccadic deficits and schizophrenia pathogenesis. The relationship between antisaccade errors and hallucination severity supports the potential link between hallucinations and deficits in inhibitory control.
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Thakkar KN, Diwadkar VA, Rolfs M. Oculomotor Prediction: A Window into the Psychotic Mind. Trends Cogn Sci 2017; 21:344-356. [PMID: 28292639 PMCID: PMC5401650 DOI: 10.1016/j.tics.2017.02.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 01/29/2017] [Accepted: 02/01/2017] [Indexed: 12/27/2022]
Abstract
Psychosis - an impaired contact with reality - is a hallmark of schizophrenia. Many psychotic symptoms are associated with disruptions in agency - the sense that 'I' cause my actions. A failure to predict sensory consequences of one's own actions may underlie agency disturbances. Such predictions rely on corollary discharge (CD) signals, 'copies' of movement commands sent to sensory regions prior to action execution. Here, we make a case that the oculomotor system is a promising model for understanding CD in psychosis, building on advances in our understanding of the behavioral and neurophysiological correlates of CD associated with eye movements. In this opinion article, we provide an overview of recent evidence for disturbed oculomotor CD in schizophrenia, potentially linking bizarre and disturbing psychotic experiences with basic physiological processes.
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Affiliation(s)
| | - Vaibhav A Diwadkar
- Department of Psychiatry and Behavioral Neurosciences, Brain Imaging Research Division, Wayne State University, Detroit, MI, USA
| | - Martin Rolfs
- Bernstein Center for Computational Neuroscience and Department of Psychology, Humboldt Universität, 10099 Berlin, Germany
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8
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Abstract
UNLABELLED Disruptions in corollary discharge (CD), motor signals that send information to sensory areas and allow for prediction of sensory states, are argued to underlie the perceived loss of agency in schizophrenia. Behavioral and neurophysiological evidence for CD in primates comes largely from the saccadic double-step task, which requires participants to make two visually triggered saccadic eye movements in brief succession. Healthy individuals use CD to anticipate the change in eye position resulting from the first saccade when preparing the second saccade. In the current study with human participants, schizophrenia patients and healthy controls of both sexes performed a modified double-step task. Most trials required a saccade to a single visual target (T1). On a subset of trials, a second target (T2) was flashed shortly following T1. Subjects were instructed to look directly at T2. Healthy individuals also use CD to make rapid, corrective responses following erroneous saccades to T1. To assess CD in schizophrenia, we examined the following on error trials: (1) frequency and latency of corrective saccades, and (2) mislocalization of the corrective (second) saccade in the direction predicted by a failure to use CD to account for the first eye movement. Consistent with disrupted CD, patients made fewer and slower error corrections. Importantly, the corrective saccade vector angle was biased in a manner consistent with disrupted CD. These results provide novel and clear evidence for dysfunctional CD in the oculomotor system in patients with schizophrenia. Based on neurophysiology work, these disturbances might have their basis in medial thalamus dysfunction. SIGNIFICANCE STATEMENT According to the World Health Organization, acute schizophrenia carries more disability weight than any other disease, but its etiology remains unknown. One promising theory of schizophrenia highlights alterations in a sense of self, in which self-generated thoughts or actions are attributed externally. Disruptions in corollary discharge (CD), motor signals sent to sensory areas that allow for the prediction of impending sensations, are proposed to underlie these symptoms. Direct physiological evidence, however, is limited. In nonhuman primates, inactivation of mediodorsal thalamic neurons disrupts CD associated with eye movements. Using the same task, we show similar impairments in schizophrenia patients, consistent with disrupted CD. These findings allow us to link clinical phenomenology to primate neurophysiology and interpret findings within a biological framework.
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Lang UE, Ackermann TF, Wolfer D, Schubert F, Sohr R, Hörtnagl H, Lang F, Gallinat J. Phosphoinositide-Dependent Protein Kinase 1 (PDK1). ZEITSCHRIFT FUR PSYCHOLOGIE-JOURNAL OF PSYCHOLOGY 2015. [DOI: 10.1027/2151-2604/a000217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Abstract. Phosphatidylinositol-3-kinase (PI3K) signaling influences susceptibility to virus infections, anoxia, obstetric complications, and cancer; which are changed in patients with schizophrenia and their first degree relatives. Therefore PI3K signaling might have impact on the pathophysiology of schizophrenia. PI3K signaling crucially involves phosphoinositide-dependent protein kinase (PDK1). Increased anxiety behavior is observed in PDK1 hypomorphic mice. Here we show enhanced prevalence of schizophrenia in carriers of the PDK1 CC genotype in human beings. Moreover, decreased parietal P300 amplitude, which is a well-studied schizophrenic endophenotype, was observed in PDK1 CC carriers. Glutamate and glutamine concentrations are increased in the frontal lobe of PDK1 dysmorphic mice and human CC individuals. Our results demonstrate that the PDK1 CC genotype is associated with increased risk to develop schizophrenia, a typical endophenotype profile observed in the disease and modified neurotransmitter concentrations in brain regions associated with the disease.
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Affiliation(s)
- Undine E. Lang
- Department of Psychiatry and Psychotherapy, University of Basel, Switzerland
| | | | - David Wolfer
- Institute of Anatomy, University of Zurich and Department of Biology, ETH Zurich, Switzerland
| | | | - Reinhard Sohr
- Department of Pharmacology, Charité University Medicine Berlin, Germany
| | - Heide Hörtnagl
- Department of Pharmacology, University of Innsbruck, Austria
| | - Florian Lang
- Department of Physiology I, University of Tuebingen, Germany
| | - Juergen Gallinat
- Department of Psychiatry and Psychotherapy, University Hospital Hamburg, Germany
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10
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Hirjak D, Breyer T, Thomann PA, Fuchs T. Disturbance of intentionality: a phenomenological study of body-affecting first-rank symptoms in schizophrenia. PLoS One 2013; 8:e73662. [PMID: 24019932 PMCID: PMC3760919 DOI: 10.1371/journal.pone.0073662] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 07/19/2013] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVES In 1950, Kurt Schneider proposed that a considerable number of schizophrenia patients develop first-rank symptoms (FRS). In such cases, patients report made experiences, replaced control of will, thought insertion, broadcast or withdrawal and delusional perception, respectively. Although a number of recent studies tend to explain FRS in terms of neurobiological and neuropsychological processes, the origin of these symptoms still remains unknown. In this paper, we explore the subjective experience of patients with the following two FRS: (1) "made" impulses and (2) "made" volitional acts. METHOD The method applied for the study of two FRS consists first in the overview of psychiatric and philosophical literature and second in the further investigation of subjective experience in patients with FRS. Psychopathological and phenomenological aspects of FRS are discussed by means of patient cases. RESULTS We discovered a profound transformation of intentionality and agency in schizophrenia patients with body-affecting FRS. This concept offers an insight into the interrelatedness between particular FRS. CONCLUSION We propose that the subjective experience of schizophrenia patients with body-affecting FRS is rooted in the disturbance of intentionality and diminished sense of agency. This theoretical account of body-affecting FRS will open up new directions in both phenomenological and neurobiological psychiatric research.
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Affiliation(s)
- Dusan Hirjak
- Section Phenomenological Psychopathology and Psychotherapy, Department of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
- Structural Neuroimaging Group, Department of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
| | - Thiemo Breyer
- Section Phenomenological Psychopathology and Psychotherapy, Department of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
| | - Philipp Arthur Thomann
- Structural Neuroimaging Group, Department of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
| | - Thomas Fuchs
- Section Phenomenological Psychopathology and Psychotherapy, Department of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
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Chhabra S, Badcock JC, Maybery MT. Memory binding in clinical and non-clinical psychotic experiences: how does the continuum model fare? Cogn Neuropsychiatry 2013; 18:304-25. [PMID: 23066885 DOI: 10.1080/13546805.2012.709183] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Both clinical and non-clinical auditory hallucinations (AH) have been associated with source memory deficits, supporting a continuum of underlying cognitive mechanisms, though few studies have employed the same task in patient and nonpatient samples. Recent commentators have called for more debate on the continuum model of psychosis. Consequently, the current study investigated the continuity model of AH with reference to memory binding. METHODS We used an identical voice and word recognition memory task to assess binding in two separate studies of: (1) healthy hallucination-prone individuals and controls (30 high and 30 low scorers on the Launay-Slade Hallucination Scale-Revised) and (2) schizophrenia patient samples (32 with AH, 32 without AH) and 32 healthy controls. RESULTS There was no evidence of impaired binding in high hallucination-prone, compared to low hallucination-prone individuals. In contrast, individuals with schizophrenia (both with and without AH) had difficulties binding (remembering "who said what"), alongside difficulties remembering individual words and voices. Binding ability and memory for voices were also negatively linked to the loudness of hallucinated voices reported by patients with AH. CONCLUSIONS These findings suggest that different mechanisms may exist in clinical and non-clinical hallucinators, adding to the growing debate on the continuum model of psychotic symptoms.
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Affiliation(s)
- S Chhabra
- School of Psychology, University of Western Australia, Crawley, WA, Australia.
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Voice identity discrimination in schizophrenia. Neuropsychologia 2012; 50:2730-2735. [PMID: 22910275 DOI: 10.1016/j.neuropsychologia.2012.08.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 07/08/2012] [Accepted: 08/06/2012] [Indexed: 11/22/2022]
Abstract
Voices provide a wealth of socially-relevant information, including cues to a speaker's identity and emotion. Deficits recognising emotion from voice have been extensively described in schizophrenia, and linked specifically to auditory hallucinations (AH), but relatively little attention has been given to examining the ability to analyse speaker identity. Hence, the current study assessed the ability to discriminate between different speakers in people with schizophrenia (including 33 with and 32 without AH) compared to 32 healthy controls. Participants rated the degree of perceived identity similarity of pairs of unfamiliar voices pronouncing three-syllable words. Multidimensional scaling of the dissimilarity matrices was performed and the resulting dimensions were interpreted, a posteriori, via correlations with acoustic measures relevant to voice identity. A two-dimensional perceptual space was found to be appropriate for both schizophrenia patients and controls, with axes corresponding to the average fundamental frequency (F0) and formant dispersion (D(f)). Patients with schizophrenia did not differ from healthy controls in their reliance on F0 in differentiating voices, suggesting that the ability to use pitch-based cues for discriminating voice identity may be relatively preserved in schizophrenia. On the other hand, patients (both with and without AH) made less use of D(f) in discriminating voices compared to healthy controls. This distorted pattern of responses suggests some potentially important differences in voice identity processing in schizophrenia. Formant dispersion has been linked to perceptions of dominance, masculinity, size and age in healthy individuals. These findings open some interesting new directions for future research.
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Albrecht MA, Martin-Iverson MT, Price G, Lee J, Iyyalol R. Dexamphetamine-induced reduction of P3a and P3b in healthy participants. J Psychopharmacol 2011; 25:1623-31. [PMID: 20699352 DOI: 10.1177/0269881110376686] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The reduced P3 is one of the most robust deficits involved in schizophrenia. Previous research with catecholaminergic agonists or releasers such as amphetamines have used doses too small to adequately demonstrate an effect on P3. In this study, we gave 0.45 mg/kg dexamphetamine to healthy volunteers (final n = 18) using both auditory and visual three-stimulus P3 procedures. Dexamphetamine significantly reduced P3 amplitudes to auditory target, rare non-target and standard stimulus amplitudes. The reduction in auditory P3 induced by dexamphetamine was proportional across stimulus types to placebo P3 values. There were no effects of dexamphetamine on visual P3. We demonstrate a reduced auditory P3 similar to that seen in schizophrenia and other psychotic illnesses. This possibly reflects a common pathology which is hypothesized within the P3 literature to be related to attention and working memory. Differences between auditory and visual P3 modulation may be related to regional variations in catecholamine or specifically dopamine receptor densities. One specific auditory P3 generator is the superior temporal cortex, an area with dopamine D(2) receptor enriched bands. This is contrasted with visual specific generators, such as the inferior temporal cortex and superior parietal cortex, which do not have these enriched bands.
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Affiliation(s)
- Matthew A Albrecht
- School of Medicine and Pharmacology, University of Western Australia, Perth, Australia.
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