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Hird EJ, Diederen K, Leucht S, Jensen KB, McGuire P. The Placebo Effect in Psychosis: Why It Matters and How to Measure It. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2023; 3:605-613. [PMID: 37881581 PMCID: PMC10593894 DOI: 10.1016/j.bpsgos.2023.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 12/04/2022] [Accepted: 02/20/2023] [Indexed: 03/07/2023] Open
Abstract
Psychosis is characterized by unusual percepts and beliefs in the form of hallucinations and delusions. Antipsychotic medication, the primary treatment for psychosis, is often ineffective and accompanied by severe side effects, but research has not identified an effective alternative in several decades. One reason that clinical trials fail is that patients with psychosis tend to show a significant therapeutic response to inert control treatments, known as the placebo effect, which makes it difficult to distinguish drug effects from placebo effects. Conversely, in clinical practice, a strong placebo effect may be useful because it could enhance the overall treatment response. Identifying factors that predict large placebo effects could improve the future outlook of psychosis treatment. Biomarkers of the placebo effect have already been suggested in pain and depression, but not in psychosis. Quantifying markers of the placebo effect would have the potential to predict placebo effects in psychosis clinical trials. Furthermore, the placebo effect and psychosis may represent a shared neurocognitive mechanism in which prior beliefs are weighted against new sensory information to make inferences about reality. Examining this overlap could reveal new insights into the mechanisms underlying psychosis and indicate novel treatment targets. We provide a narrative review of the importance of the placebo effect in psychosis and propose a novel method to assess it.
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Affiliation(s)
- Emily J. Hird
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, England
| | - Kelly Diederen
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, England
| | - Stefan Leucht
- Department of Psychiatry and Psychotherapy, Technical University of Munich, Munich, Germany
| | - Karin B. Jensen
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Philip McGuire
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, England
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Hanewald B, Lockhofen DEL, Sammer G, Stingl M, Gallhofer B, Mulert C, Iffland JR. Functional connectivity in a monetary and social incentive delay task in medicated patients with schizophrenia. Front Psychiatry 2023; 14:1200860. [PMID: 37711426 PMCID: PMC10498543 DOI: 10.3389/fpsyt.2023.1200860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/02/2023] [Indexed: 09/16/2023] Open
Abstract
Introduction Numerous studies indicate impaired reward-related learning in individuals with schizophrenia, with various factors such as illness duration, medication, disease severity, and level of analysis (behavioral or neurophysiological data) potentially confounding the results. Patients with schizophrenia who are treated with second-generation antipsychotics have been found to have a less affected reward system. However, this finding does not explain the neural dysfunctions observed in previous studies. This study aimed to address the open question of whether the less impaired reward-related behavior is associated with unimpaired task-related functional connectivity or altered task-related functional connectivity. Methods The study included 23 participants diagnosed within the schizophrenia spectrum and 23 control participants matched in terms of age, sex, and education. Participants underwent an MRI while performing a monetary incentive delay task and a social incentive delay task. The collected data were analyzed in terms of behavior and functional connectivity. Results Both groups exhibited a main effect of reward type on behavioral performance, indicating faster reaction times in the social incentive delay task, but no main effect of reward level. Altered functional connectivity was observed in predictable brain regions within the patient group, depending on the chosen paradigm, but not when compared to healthy individuals. Discussion In addition to expected slower response times, patients with schizophrenia demonstrated similar response patterns to control participants at the behavioral level. The similarities in behavioral data may underlie different connectivity patterns. Our findings suggest that perturbations in reward processing do not necessarily imply disturbances in underlying connectivities. Consequently, we were able to demonstrate that patients with schizophrenia are indeed capable of exhibiting goal-directed, reward-responsive behavior, although there are differences depending on the type of reward.
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Affiliation(s)
- Bernd Hanewald
- Center for Psychiatry, Justus Liebig University Giessen, Giessen, Germany
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Frydecka D, Piotrowski P, Bielawski T, Pawlak E, Kłosińska E, Krefft M, Al Noaimy K, Rymaszewska J, Moustafa AA, Drapała J, Misiak B. Confirmation Bias in the Course of Instructed Reinforcement Learning in Schizophrenia-Spectrum Disorders. Brain Sci 2022; 12:brainsci12010090. [PMID: 35053833 PMCID: PMC8773670 DOI: 10.3390/brainsci12010090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 11/16/2022] Open
Abstract
A large body of research attributes learning deficits in schizophrenia (SZ) to the systems involved in value representation (prefrontal cortex, PFC) and reinforcement learning (basal ganglia, BG) as well as to the compromised connectivity of these regions. In this study, we employed learning tasks hypothesized to probe the function and interaction of the PFC and BG in patients with SZ-spectrum disorders in comparison to healthy control (HC) subjects. In the Instructed Probabilistic Selection task (IPST), participants received false instruction about one of the stimuli used in the course of probabilistic learning which creates confirmation bias, whereby the instructed stimulus is overvalued in comparison to its real experienced value. The IPST was administered to 102 patients with SZ and 120 HC subjects. We have shown that SZ patients and HC subjects were equally influenced by false instruction in reinforcement learning (RL) probabilistic task (IPST) (p-value = 0.441); however, HC subjects had significantly higher learning rates associated with the process of overcoming cognitive bias in comparison to SZ patients (p-value = 0.018). The behavioral results of our study could be hypothesized to provide further evidence for impairments in the SZ-BG circuitry; however, this should be verified by neurofunctional imaging studies.
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Affiliation(s)
- Dorota Frydecka
- Department of Psychiatry, Wroclaw Medical University, Pasteur Street 10, 50-367 Wroclaw, Poland; (T.B.); (M.K.); (K.A.N.); (J.R.)
- Correspondence:
| | - Patryk Piotrowski
- Department of Psychiatry, Division of Consultation Psychiatry and Neuroscience, Wroclaw Medical University, Pasteur Street 10, 50-367 Wroclaw, Poland; (P.P.); (B.M.)
| | - Tomasz Bielawski
- Department of Psychiatry, Wroclaw Medical University, Pasteur Street 10, 50-367 Wroclaw, Poland; (T.B.); (M.K.); (K.A.N.); (J.R.)
| | - Edyta Pawlak
- Department of Experimental Therapy, Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigel Street 12, 53-114 Wroclaw, Poland;
| | - Ewa Kłosińska
- Day-Care Psychiatric Unit, University Clinical Hospital, Pasteur Street 10, 50-367 Wroclaw, Poland;
| | - Maja Krefft
- Department of Psychiatry, Wroclaw Medical University, Pasteur Street 10, 50-367 Wroclaw, Poland; (T.B.); (M.K.); (K.A.N.); (J.R.)
| | - Kamila Al Noaimy
- Department of Psychiatry, Wroclaw Medical University, Pasteur Street 10, 50-367 Wroclaw, Poland; (T.B.); (M.K.); (K.A.N.); (J.R.)
| | - Joanna Rymaszewska
- Department of Psychiatry, Wroclaw Medical University, Pasteur Street 10, 50-367 Wroclaw, Poland; (T.B.); (M.K.); (K.A.N.); (J.R.)
| | - Ahmed A. Moustafa
- School of Psychology, Marcs Institute for Brain and Behaviour, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia;
- Department of Human Anatomy and Physiology, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2006, South Africa
| | - Jarosław Drapała
- Department of Computer Science and Systems Engineering, Faculty of Information and Communication Technology, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego Street 27, 50-370 Wroclaw, Poland;
| | - Błażej Misiak
- Department of Psychiatry, Division of Consultation Psychiatry and Neuroscience, Wroclaw Medical University, Pasteur Street 10, 50-367 Wroclaw, Poland; (P.P.); (B.M.)
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Savchenko A, Müller C, Lubec J, Leo D, Korz V, Afjehi-Sadat L, Malikovic J, Sialana FJ, Lubec G, Sukhanov I. The Lack of Dopamine Transporter Is Associated With Conditional Associative Learning Impairments and Striatal Proteomic Changes. Front Psychiatry 2022; 13:799433. [PMID: 35370807 PMCID: PMC8971526 DOI: 10.3389/fpsyt.2022.799433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/04/2022] [Indexed: 11/14/2022] Open
Abstract
Dopamine (DA) is critically involved in different functions of the central nervous system (CNS) including control of voluntary movement, affect, reward, sleep, and cognition. One of the key components of DA neurotransmission is DA reuptake by the DA transporter (DAT), ensuring rapid clearance of DA from the synaptic cleft. Thus, lack of DAT leads to persistent high extracellular DA levels. While there is strong evidence for a role of striatal dopaminergic activity in learning and memory processes, little is known about the contribution of DAT deficiency to conditional learning impairments and underlying molecular processes. DAT-knockout (DAT-KO) rats were tested in a set of behavioral experiments evaluating conditional associative learning, which requires unaltered striatal function. In parallel, a large-scale proteomic analysis of the striatum was performed to identify molecular factors probably underlying behavioral patterns. DAT-KO rats were incapable to acquire a new operant skill in Pavlovian/instrumental autoshaping, although the conditional stimulus-unconditional stimulus (CS-US) association seems to be unaffected. These findings suggest that DAT directly or indirectly contributes to the reduction of transference of incentive salience from the reward to the CS. We propose that specific impairment of conditional learning might be caused by molecular adaptations to the hyperdopaminergic state, presumably by dopamine receptor 1 (DRD1) hypofunction, as proposed by proteomic analysis. Whether DRD1 downregulation can cause cognitive deficits in the hyperdopaminergic state is the subject of discussion, and further studies are needed to answer this question. This study may be useful for the interpretation of previous and the design of future studies in the dopamine field.
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Affiliation(s)
- Artem Savchenko
- Institute of Pharmacology, Pavlov First Saint Petersburg State Medical University, St. Petersburg, Russia
| | - Carina Müller
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Jana Lubec
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
| | - Damiana Leo
- Department of Neurosciences, University of Mons, Mons, Belgium
| | - Volker Korz
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
| | - Leila Afjehi-Sadat
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
| | - Jovana Malikovic
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
| | - Fernando J Sialana
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Gert Lubec
- Programme for Proteomics, Paracelsus Medical University, Salzburg, Austria
| | - Ilya Sukhanov
- Institute of Pharmacology, Pavlov First Saint Petersburg State Medical University, St. Petersburg, Russia
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Howes OD, Hird EJ, Adams RA, Corlett PR, McGuire P. Aberrant Salience, Information Processing, and Dopaminergic Signaling in People at Clinical High Risk for Psychosis. Biol Psychiatry 2020; 88:304-314. [PMID: 32430200 DOI: 10.1016/j.biopsych.2020.03.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 03/10/2020] [Accepted: 03/10/2020] [Indexed: 01/24/2023]
Abstract
The aberrant salience hypothesis proposes that striatal dopamine dysregulation causes misattribution of salience to irrelevant stimuli leading to psychosis. Recently, new lines of preclinical evidence on information coding by subcortical dopamine coupled with computational models of the brain's ability to predict and make inferences about the world (predictive processing) provide a new perspective on this hypothesis. We review these and summarize the evidence for dopamine dysfunction, reward processing, and salience abnormalities in people at clinical high risk of psychosis (CHR) relative to findings in patients with psychosis. This review identifies consistent evidence for dysregulated subcortical dopamine function in people at CHR, but also indicates a number of areas where neurobiological processes are different in CHR subjects relative to patients with psychosis, particularly in reward processing. We then consider how predictive processing models may explain psychotic symptoms in terms of alterations in prediction error and precision signaling using Bayesian approaches. We also review the potential role of environmental risk factors, particularly early adverse life experiences, in influencing the prior expectations that individuals have about their world in terms of computational models of the progression from being at CHR to frank psychosis. We identify a number of key outstanding questions, including the relative roles of prediction error or precision signaling in the development of symptoms and the mechanism underlying dopamine dysfunction. Finally, we discuss how the integration of computational psychiatry with biological investigation may inform the treatment for people at CHR of psychosis.
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Affiliation(s)
- Oliver D Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom; National Institute of Health Research Biomedical Research Centre at South London and Maudsley National Health Service Foundation Trust, London, United Kingdom; Medical Research Council London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom.
| | - Emily J Hird
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom; National Institute of Health Research Biomedical Research Centre at South London and Maudsley National Health Service Foundation Trust, London, United Kingdom
| | - Rick A Adams
- Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom; Max Planck University College London Centre for Computational Psychiatry and Ageing Research, London, United Kingdom
| | - Philip R Corlett
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut
| | - Philip McGuire
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom; National Institute of Health Research Biomedical Research Centre at South London and Maudsley National Health Service Foundation Trust, London, United Kingdom
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Strauss GP, Pelletier-Baldelli A, Visser KF, Walker EF, Mittal VA. A review of negative symptom assessment strategies in youth at clinical high-risk for psychosis. Schizophr Res 2020; 222:104-112. [PMID: 32522469 PMCID: PMC7572550 DOI: 10.1016/j.schres.2020.04.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 12/16/2022]
Abstract
Studies attempting to deconstruct the heterogeneity of schizophrenia and the attenuated psychosis syndrome consistently find that negative symptoms are a core dimension that is distinct from other aspects of the illness (e.g., positive and disorganized symptoms). Negative symptoms are also highly predictive of poor community-based functional outcomes, suggesting they are a critical treatment target. Unfortunately, pharmacological and psychosocial treatments for negative symptoms have demonstrated limited effectiveness. To address this critical unmet therapeutic need, the NIMH sponsored a consensus development conference to delineate research priorities for the field and stimulate treatment development. A primary conclusion of this meeting was that next-generation negative symptom rating scales should be developed to address methodological and conceptual limitations of existing instruments. Although second-generation rating scales were developed for adults with schizophrenia, progress in this area has lagged behind for youth at clinical-high risk (CHR) for developing psychosis (i.e. those meeting criteria for a prodromal syndrome). Given that negative symptoms are highly predictive of the transition to diagnosable psychotic illness, enhancing our ability to detect negative symptoms in CHR youth is paramount. The current paper discusses conceptual and methodological limitations inherent to existing scales that assess negative symptoms in CHR youth. The theoretical and clinical implications of these limitations are evaluated. It is concluded that new scales specifically designed to assess negative symptoms in CHR youth are needed to accurately chart mental illness trajectories and determine when, where, and how to intervene. Recent efforts to develop next-generation measures designed specifically for CHR youth to meet this urgent need in the field are discussed. These new approaches offer significant progress for addressing issues inherent to earlier scales.
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Affiliation(s)
- Gregory P. Strauss
- Department of Psychology, University of Georgia, Athens, GA, USA,Correspondence concerning this article should be addressed to Gregory P. Strauss, Ph.D., . Phone: +1-706-542-0307. Fax: +1-706-542-3275. University of Georgia, Department of Psychology, 125 Baldwin St., Athens, GA 30602
| | | | | | | | - Vijay A. Mittal
- Department of Psychology, Northwestern University, Evanston, IL, USA
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Modinos G, Allen P, Zugman A, Dima D, Azis M, Samson C, Bonoldi I, Quinn B, Gifford GWG, Smart SE, Antoniades M, Bossong MG, Broome MR, Perez J, Howes OD, Stone JM, Grace AA, McGuire P. Neural Circuitry of Novelty Salience Processing in Psychosis Risk: Association With Clinical Outcome. Schizophr Bull 2020; 46:670-679. [PMID: 32227226 PMCID: PMC7147595 DOI: 10.1093/schbul/sbz089] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Psychosis has been proposed to develop from dysfunction in a hippocampal-striatal-midbrain circuit, leading to aberrant salience processing. Here, we used functional magnetic resonance imaging (fMRI) during novelty salience processing to investigate this model in people at clinical high risk (CHR) for psychosis according to their subsequent clinical outcomes. Seventy-six CHR participants as defined using the Comprehensive Assessment of At-Risk Mental States (CAARMS) and 31 healthy controls (HC) were studied while performing a novelty salience fMRI task that engaged an a priori hippocampal-striatal-midbrain circuit of interest. The CHR sample was then followed clinically for a mean of 59.7 months (~5 y), when clinical outcomes were assessed in terms of transition (CHR-T) or non-transition (CHR-NT) to psychosis (CAARMS criteria): during this period, 13 individuals (17%) developed a psychotic disorder (CHR-T) and 63 did not. Functional activation and effective connectivity within a hippocampal-striatal-midbrain circuit were compared between groups. In CHR individuals compared to HC, hippocampal response to novel stimuli was significantly attenuated (P = .041 family-wise error corrected). Dynamic Causal Modelling revealed that stimulus novelty modulated effective connectivity from the hippocampus to the striatum, and from the midbrain to the hippocampus, significantly more in CHR participants than in HC. Conversely, stimulus novelty modulated connectivity from the midbrain to the striatum significantly less in CHR participants than in HC, and less in CHR participants who subsequently developed psychosis than in CHR individuals who did not become psychotic. Our findings are consistent with preclinical evidence implicating hippocampal-striatal-midbrain circuit dysfunction in altered salience processing and the onset of psychosis.
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Affiliation(s)
- Gemma Modinos
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK,Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK,To whom correspondence should be addressed; Institute of Psychiatry, Psychology and Neuroscience, King’s College London, 16 De Crespigny Park, SE5 8AF London, UK; tel: +44(0)2078480927, fax: +44(0)2078480976, e-mail:
| | - Paul Allen
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK,Department of Psychology, University of Roehampton, London, UK
| | - Andre Zugman
- Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Danai Dima
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK,Department of Psychology, School of Arts and Social Sciences, City, University of London, London, UK
| | - Matilda Azis
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Carly Samson
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Ilaria Bonoldi
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Beverly Quinn
- CAMEO Early Intervention in Psychosis Service, Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK
| | - George W G Gifford
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Sophie E Smart
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Mathilde Antoniades
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Matthijs G Bossong
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands
| | | | - Jesus Perez
- CAMEO Early Intervention in Psychosis Service, Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK,Department of Psychiatry, University of Cambridge, Cambridge, UK,Department of Neuroscience, Instituto de Investigacion Biomedica de Salamanca (IBSAL), University of Salamanca, Salamanca, Spain
| | - Oliver D Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - James M Stone
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA
| | - Philip McGuire
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
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Cole DM, Diaconescu AO, Pfeiffer UJ, Brodersen KH, Mathys CD, Julkowski D, Ruhrmann S, Schilbach L, Tittgemeyer M, Vogeley K, Stephan KE. Atypical processing of uncertainty in individuals at risk for psychosis. NEUROIMAGE-CLINICAL 2020; 26:102239. [PMID: 32182575 PMCID: PMC7076146 DOI: 10.1016/j.nicl.2020.102239] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/24/2020] [Accepted: 03/06/2020] [Indexed: 12/28/2022]
Abstract
Humans at psychosis clinical high risk (CHR) over-estimate environmental volatility. Low-level prediction error (PE) signals evoke increased frontal activity in CHR. Volatility-related PEs are associated with reduced frontal activity in CHR. Frontal cortical activation to low-level PEs reflects impaired clinical functioning. Atypical PE learning signal representations may promote delusion formation in CHR.
Current theories of psychosis highlight the role of abnormal learning signals, i.e., prediction errors (PEs) and uncertainty, in the formation of delusional beliefs. We employed computational analyses of behaviour and functional magnetic resonance imaging (fMRI) to examine whether such abnormalities are evident in clinical high risk (CHR) individuals. Non-medicated CHR individuals (n = 13) and control participants (n = 13) performed a probabilistic learning paradigm during fMRI data acquisition. We used a hierarchical Bayesian model to infer subject-specific computations from behaviour – with a focus on PEs and uncertainty (or its inverse, precision) at different levels, including environmental ‘volatility’ – and used these computational quantities for analyses of fMRI data. Computational modelling of CHR individuals’ behaviour indicated volatility estimates converged to significantly higher levels than in controls. Model-based fMRI demonstrated increased activity in prefrontal and insular regions of CHR individuals in response to precision-weighted low-level outcome PEs, while activations of prefrontal, orbitofrontal and anterior insula cortex by higher-level PEs (that serve to update volatility estimates) were reduced. Additionally, prefrontal cortical activity in response to outcome PEs in CHR was negatively associated with clinical measures of global functioning. Our results suggest a multi-faceted learning abnormality in CHR individuals under conditions of environmental uncertainty, comprising higher levels of volatility estimates combined with reduced cortical activation, and abnormally high activations in prefrontal and insular areas by precision-weighted outcome PEs. This atypical representation of high- and low-level learning signals might reflect a predisposition to delusion formation.
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Affiliation(s)
- David M Cole
- Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland; Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zurich, Psychiatric Hospital of the University of Zurich, Zurich, Switzerland.
| | - Andreea O Diaconescu
- Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland; Department of Psychiatry (UPK), University of Basel, Basel, Switzerland; Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Canada
| | - Ulrich J Pfeiffer
- Department of Psychiatry and Psychotherapy, Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany
| | - Kay H Brodersen
- Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Christoph D Mathys
- Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland; Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy; Interacting Minds Centre, Aarhus University, Aarhus, Denmark
| | - Dominika Julkowski
- Department of Psychiatry and Psychotherapy, Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany
| | - Stephan Ruhrmann
- Department of Psychiatry and Psychotherapy, Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany
| | - Leonhard Schilbach
- Independent Max Planck Research Group for Social Neuroscience, Max Planck Institute of Psychiatry, Munich, Germany; Graduate School for Systemic Neuroscience, Munich, Germany; International Max Planck Research School for Translational Psychiatry, Munich, Germany; Ludwig-Maximilians-Universität München, Munich, Germany; Kliniken der Heinrich-Heine-Universität/LVR-Klinik Düsseldorf, Düsseldorf, Germany
| | - Marc Tittgemeyer
- Max Planck Institute for Metabolism Research, Cologne, Germany; Cologne Cluster of Excellence in Cellular Stress and Aging associated Disease (CECAD), Germany
| | - Kai Vogeley
- Department of Psychiatry and Psychotherapy, Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany; Institute for Neuroscience and Medicine - Cognitive Neuroscience (INM3), Research Center Juelich, Juelich, Germany
| | - Klaas E Stephan
- Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland; Max Planck Institute for Metabolism Research, Cologne, Germany; Wellcome Centre for Human Neuroimaging, University College London, London, United Kingdom
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Katthagen T, Mathys C, Deserno L, Walter H, Kathmann N, Heinz A, Schlagenhauf F. Modeling subjective relevance in schizophrenia and its relation to aberrant salience. PLoS Comput Biol 2018; 14:e1006319. [PMID: 30096179 PMCID: PMC6105009 DOI: 10.1371/journal.pcbi.1006319] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 08/22/2018] [Accepted: 06/20/2018] [Indexed: 01/09/2023] Open
Abstract
In schizophrenia, increased aberrant salience to irrelevant events and reduced learning of relevant information may relate to an underlying deficit in relevance detection. So far, subjective estimates of relevance have not been probed in schizophrenia patients. The mechanisms underlying belief formation about relevance and their translation into decisions are unclear. Using novel computational methods, we investigated relevance detection during implicit learning in 42 schizophrenia patients and 42 healthy individuals. Participants underwent functional magnetic resonance imaging while detecting the outcomes in a learning task. These were preceded by cues differing in color and shape, which were either relevant or irrelevant for outcome prediction. We provided a novel definition of relevance based on Bayesian precision and modeled reaction times as a function of relevance weighted unsigned prediction errors (UPE). For aberrant salience, we assessed responses to subjectively irrelevant cue manifestations. Participants learned the contingencies and slowed down their responses following unexpected events. Model selection revealed that individuals inferred the relevance of cue features and used it for behavioral adaption to the relevant cue feature. Relevance weighted UPEs correlated with dorsal anterior cingulate cortex activation and hippocampus deactivation. In patients, the aberrant salience bias to subjectively task-irrelevant information was increased and correlated with decreased striatal UPE activation and increased negative symptoms. This study shows that relevance estimates based on Bayesian precision can be inferred from observed behavior. This underscores the importance of relevance detection as an underlying mechanism for behavioral adaptation in complex environments and enhances the understanding of aberrant salience in schizophrenia. Schizophrenia patients display deficits in the appropriate attribution of meaningfulness to stimuli; such as aberrantly increased processing of irrelevant and insufficient processing of relevant information. We aimed to investigate the subjective nature of relevance detection and its deficit in schizophrenia and developed an implicit learning paradigm that allowed for parallel learning from relevant and irrelevant information. Based on the idea that subjective relevance might be captured by Bayesian precision we set up different computational models of how subjective relevance guides learning and behavioral adaptation. We found that subjects use Bayesian precision to estimate stimulus relevance in order to integrate multidimensional information and adapt more to the subjectively relevant stimuli. This relevance weighted adaptation correlated with brain activation within the salience network. Further, schizophrenia patients displayed an increased aberrant tendency to irrelevant events which related to decreased striatal coding of the relevant learning signal. To conclude, our findings demonstrate how individual beliefs about relevance can be inferred from computational models. Furthermore, we suggest that aberrant salience observed in patients with schizophrenia reflects an idiosyncratic bias in states of high subjective uncertainty.
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Affiliation(s)
- Teresa Katthagen
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Psychiatry and Psychotherapy CCM, Berlin, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
- * E-mail:
| | - Christoph Mathys
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research, London, United Kingdom
- Wellcome Trust Centre for Neuroimaging at UCL, London, United Kingdom
| | - Lorenz Deserno
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Psychiatry and Psychotherapy CCM, Berlin, Germany
- Department of Child and Adolescent Psychiatry, Psychotherapy and Psychosomatics, University of Leipzig, Leipzig, Germany
- Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Henrik Walter
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Psychiatry and Psychotherapy CCM, Berlin, Germany
| | - Norbert Kathmann
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Heinz
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Psychiatry and Psychotherapy CCM, Berlin, Germany
| | - Florian Schlagenhauf
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Psychiatry and Psychotherapy CCM, Berlin, Germany
- Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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10
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Dauvermann MR, Lee G, Dawson N. Glutamatergic regulation of cognition and functional brain connectivity: insights from pharmacological, genetic and translational schizophrenia research. Br J Pharmacol 2017. [PMID: 28626937 DOI: 10.1111/bph.13919] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The pharmacological modulation of glutamatergic neurotransmission to improve cognitive function has been a focus of intensive research, particularly in relation to the cognitive deficits seen in schizophrenia. Despite this effort, there has been little success in the clinical use of glutamatergic compounds as procognitive drugs. Here, we review a selection of the drugs used to modulate glutamatergic signalling and how they impact on cognitive function in rodents and humans. We highlight how glutamatergic dysfunction, and NMDA receptor hypofunction in particular, is a key mechanism contributing to the cognitive deficits observed in schizophrenia and outline some of the glutamatergic targets that have been tested as putative procognitive targets for this disorder. Using translational research in this area as a leading exemplar, namely, models of NMDA receptor hypofunction, we discuss how the study of functional brain network connectivity can provide new insight into how the glutamatergic system impacts on cognitive function. Future studies characterizing functional brain network connectivity will increase our understanding of how glutamatergic compounds regulate cognition and could contribute to the future success of glutamatergic drug validation. Linked Articles This article is part of a themed section on Pharmacology of Cognition: a Panacea for Neuropsychiatric Disease? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.19/issuetoc.
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Affiliation(s)
- Maria R Dauvermann
- School of Psychology, National University of Ireland, Galway, Ireland.,McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Graham Lee
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Neil Dawson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
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11
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Maia TV, Frank MJ. An Integrative Perspective on the Role of Dopamine in Schizophrenia. Biol Psychiatry 2017; 81:52-66. [PMID: 27452791 PMCID: PMC5486232 DOI: 10.1016/j.biopsych.2016.05.021] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/19/2016] [Accepted: 05/19/2016] [Indexed: 12/14/2022]
Abstract
We propose that schizophrenia involves a combination of decreased phasic dopamine responses for relevant stimuli and increased spontaneous phasic dopamine release. Using insights from computational reinforcement-learning models and basic-science studies of the dopamine system, we show that each of these two disturbances contributes to a specific symptom domain and explains a large set of experimental findings associated with that domain. Reduced phasic responses for relevant stimuli help to explain negative symptoms and provide a unified explanation for the following experimental findings in schizophrenia, most of which have been shown to correlate with negative symptoms: reduced learning from rewards; blunted activation of the ventral striatum, midbrain, and other limbic regions for rewards and positive prediction errors; blunted activation of the ventral striatum during reward anticipation; blunted autonomic responding for relevant stimuli; blunted neural activation for aversive outcomes and aversive prediction errors; reduced willingness to expend effort for rewards; and psychomotor slowing. Increased spontaneous phasic dopamine release helps to explain positive symptoms and provides a unified explanation for the following experimental findings in schizophrenia, most of which have been shown to correlate with positive symptoms: aberrant learning for neutral cues (assessed with behavioral and autonomic responses), and aberrant, increased activation of the ventral striatum, midbrain, and other limbic regions for neutral cues, neutral outcomes, and neutral prediction errors. Taken together, then, these two disturbances explain many findings in schizophrenia. We review evidence supporting their co-occurrence and consider their differential implications for the treatment of positive and negative symptoms.
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Affiliation(s)
- Tiago V Maia
- Institute for Molecular Medicine, School of Medicine, University of Lisbon, Lisbon, Portugal.
| | - Michael J Frank
- Department of Cognitive, Linguistic and Psychological Sciences, the Department of Psychiatry and Human Behavior, and the Brown Institute for Brain Science, Brown University, Providence, Rhode Island
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12
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Rademacher L, Schulte-Rüther M, Hanewald B, Lammertz S. Reward: From Basic Reinforcers to Anticipation of Social Cues. Curr Top Behav Neurosci 2017; 30:207-221. [PMID: 26728170 DOI: 10.1007/7854_2015_429] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Reward processing plays a major role in goal-directed behavior and motivation. On the neural level, it is mediated by a complex network of brain structures called the dopaminergic reward system. In the last decade, neuroscientific researchers have become increasingly interested in aspects of social interaction that are experienced as rewarding. Recent neuroimaging studies have provided evidence that the reward system mediates the processing of social stimuli in a manner analogous to nonsocial rewards and thus motivates social behavior. In this context, the neuropeptide oxytocin is assumed to play a key role by activating dopaminergic reward pathways in response to social cues, inducing the rewarding quality of social interactions. Alterations in the dopaminergic reward system have been found in several psychiatric disorders that are accompanied by social interaction and motivation problems, for example autism, attention deficit/hyperactivity disorder, addiction disorders, and schizophrenia.
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Affiliation(s)
- Lena Rademacher
- Department of Psychiatry and Psychotherapy, Social Neuroscience Lab, University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
| | - Martin Schulte-Rüther
- Department of Child and Adolescent Psychiatry and Psychotherapy, RWTH Aachen University, Neuenhofer Weg 21, 52074, Aachen, Germany
| | - Bernd Hanewald
- Department of Psychiatry and Psychotherapy, Justus Liebig University Gießen, Am Steg 22, 35385, Gießen, Germany
| | - Sarah Lammertz
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
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13
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Walter A, Suenderhauf C, Smieskova R, Lenz C, Harrisberger F, Schmidt A, Vogel T, Lang UE, Riecher-Rössler A, Eckert A, Borgwardt S. Altered Insular Function during Aberrant Salience Processing in Relation to the Severity of Psychotic Symptoms. Front Psychiatry 2016; 7:189. [PMID: 27933003 PMCID: PMC5120113 DOI: 10.3389/fpsyt.2016.00189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/09/2016] [Indexed: 12/31/2022] Open
Abstract
There is strong evidence for abnormal salience processing in patients with psychotic experiences. In particular, there are indications that the degree of aberrant salience processing increases with the severity of positive symptoms. The aim of the present study was to elucidate this relationship by means of brain imaging. Functional magnetic resonance imaging was acquired to assess hemodynamic responses during the Salience Attribution Test, a paradigm for reaction time that measures aberrant salience to irrelevant stimulus features. We included 42 patients who were diagnosed as having a psychotic disorder and divided them into two groups according to the severity of their positive symptoms. Whole brain analysis was performed using Statistical Parametric Mapping. We found no significant behavioral differences with respect to task performance. Patients with more positive symptoms showed increased hemodynamic responses in the left insula corresponding to aberrant salience than in patients with less positive symptoms. In addition, left insula activation correlated negatively with cumulative antipsychotic medication. Aberrant salience processing in the insula may be increased in psychosis, depending on the severity of positive symptoms. This study indicates that clinically similar psychosis manifestations share the same functional characteristics. In addition, our results suggest that antipsychotic medication can modulate insular function.
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Affiliation(s)
- Anna Walter
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | | | - Renata Smieskova
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | - Claudia Lenz
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | | | - André Schmidt
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | - Tobias Vogel
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | - Undine E. Lang
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | | | - Anne Eckert
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | - Stefan Borgwardt
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
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14
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Abstract
PURPOSE OF REVIEW Anhedonia, traditionally defined as a diminished capacity to experience pleasure, has long been considered a core symptom of schizophrenia. However, recent research calls into question whether individuals with schizophrenia are truly anhedonic, suggesting intact subjective and neurophysiological response to rewarding stimuli in-the-moment. Despite a presumably intact capacity to experience pleasure, people with schizophrenia still engage in fewer reward-seeking behaviors. This discrepancy has been explained as a dissociation between "liking" and "wanting", with dopaminergic and prefrontal influences on incentive salience leading hedonic responses to not effectively translate into motivated behavior. In the current review, the literature on a key aspect of the wanting deficit is reviewed, anticipatory pleasure. RECENT FINDINGS Results provide consistent evidence for impairment in some aspects of anticipatory pleasure (e.g., prospection, associative learning between reward predictive cues and outcomes), and inconsistent evidence for others (e.g., anticipatory affect and affective forecasting). SUMMARY Mechanisms underlying anticipatory pleasure abnormalities in schizophrenia are discussed and a new model of anticipatory pleasure deficits is proposed. Findings suggest that anticipatory pleasure may be a critical component of impairments in wanting that impact motivated behavior in schizophrenia.
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Affiliation(s)
- Katherine H Frost
- Department of Psychology, State University of New York at Binghamton
| | - Gregory P Strauss
- Department of Psychology, State University of New York at Binghamton
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15
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White TP, Wigton R, Joyce DW, Collier T, Fornito A, Shergill SS. Dysfunctional Striatal Systems in Treatment-Resistant Schizophrenia. Neuropsychopharmacology 2016; 41:1274-85. [PMID: 26346637 PMCID: PMC4793111 DOI: 10.1038/npp.2015.277] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/07/2015] [Accepted: 08/09/2015] [Indexed: 01/29/2023]
Abstract
The prevalence of treatment-resistant schizophrenia points to a discrete illness subtype, but to date its pathophysiologic characteristics are undetermined. Information transfer from ventral to dorsal striatum depends on both striato-cortico-striatal and striato-nigro-striatal subcircuits, yet although the functional integrity of the former appears to track improvement of positive symptoms of schizophrenia, the latter have received little experimental attention in relation to the illness. Here, in a sample of individuals with schizophrenia stratified by treatment resistance and matched controls, functional pathways involving four foci along the striatal axis were assessed to test the hypothesis that treatment-resistant and non-refractory patients would exhibit contrasting patterns of resting striatal connectivity. Compared with non-refractory patients, treatment-resistant individuals exhibited reduced connectivity between ventral striatum and substantia nigra. Furthermore, disturbance to corticostriatal connectivity was more pervasive in treatment-resistant individuals. The occurrence of a more distributed pattern of abnormality may contribute to the failure of medication to treat symptoms in these individuals. This work strongly supports the notion of pathophysiologic divergence between individuals with schizophrenia classified by treatment-resistance criteria.
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Affiliation(s)
- Thomas P White
- Cognition, Schizophrenia and Imaging Laboratory, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, London, UK,School of Psychology, University of Birmingham, Birmingham, UK
| | - Rebekah Wigton
- Cognition, Schizophrenia and Imaging Laboratory, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, London, UK,Beth Israel Deaconess Medical Center, EEG Lab, Neurology, Boston, MA, USA,Harvard Medical School, Department of Neurology, Boston, MA, USA
| | - Dan W Joyce
- Cognition, Schizophrenia and Imaging Laboratory, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, London, UK
| | - Tracy Collier
- Cognition, Schizophrenia and Imaging Laboratory, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, London, UK
| | - Alex Fornito
- School of Psychological Sciences and Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia
| | - Sukhwinder S Shergill
- Cognition, Schizophrenia and Imaging Laboratory, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, London, UK,Cognition, Schizophrenia and Imaging Laboratory, Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London SE5 8AF, UK, Tel: +44 (0)207 848 0350, Fax: +44 207 848 0287, E-mail:
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16
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Pankow A, Katthagen T, Diner S, Deserno L, Boehme R, Kathmann N, Gleich T, Gaebler M, Walter H, Heinz A, Schlagenhauf F. Aberrant Salience Is Related to Dysfunctional Self-Referential Processing in Psychosis. Schizophr Bull 2016; 42. [PMID: 26194892 PMCID: PMC4681553 DOI: 10.1093/schbul/sbv098] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND A dysfunctional differentiation between self-relevant and irrelevant information may affect the perception of environmental stimuli as abnormally salient. The aberrant salience hypothesis assumes that positive symptoms arise from an attribution of salience to irrelevant stimuli accompanied by the feeling of self-relevance. Self-referential processing relies on the activation of cortical midline structures which was demonstrated to be impaired in psychosis. We investigated the neural correlates of self-referential processing, aberrant salience attribution, and the relationship between these 2 measures across the psychosis continuum. METHODS Twenty-nine schizophrenia patients, 24 healthy individuals with subclinical delusional ideation, and 50 healthy individuals participated in this study. Aberrant salience was assessed behaviorally in terms of reaction times to task irrelevant cues. Participants performed a self-reference task during fMRI in which they had to apply neutral trait words to them or to a public figure. The correlation between self-referential processing and aberrant salience attribution was tested. RESULTS Schizophrenia patients displayed increased aberrant salience attribution compared with healthy controls and individuals with subclinical delusional ideation, while the latter exhibited intermediate aberrant salience scores. In the self-reference task, schizophrenia patients showed reduced activation in the ventromedial prefrontal cortex (vmPFC), but individuals with subclinical delusional ideation did not differ from healthy controls. In schizophrenia patients, vmPFC activation correlated negatively with implicit aberrant salience attribution. CONCLUSIONS Higher aberrant salience attribution in schizophrenia patients is related to reduced vmPFC activation during self-referential judgments suggesting that aberrant relevance coding is reflected in decreased neural self-referential processing as well as in aberrant salience attribution.
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Affiliation(s)
- Anne Pankow
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany;
| | - Teresa Katthagen
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Sarah Diner
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Rebecca Boehme
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Nobert Kathmann
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Tobias Gleich
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Gaebler
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany; Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Faculty of Medicine, Universität Leipzig, Leipzig, Germany
| | - Henrik Walter
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Andreas Heinz
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Florian Schlagenhauf
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany; Max Planck Fellow Group 'Cognitive and Affective Control of Behavioral Adaption', Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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17
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Cicchese JJ, Berry SD. Hippocampal Non-Theta-Contingent Eyeblink Classical Conditioning: A Model System for Neurobiological Dysfunction. Front Psychiatry 2016; 7:1. [PMID: 26903886 PMCID: PMC4751249 DOI: 10.3389/fpsyt.2016.00001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 01/01/2016] [Indexed: 11/30/2022] Open
Abstract
Typical information processing is thought to depend on the integrity of neurobiological oscillations that may underlie coordination and timing of cells and assemblies within and between structures. The 3-7 Hz bandwidth of hippocampal theta rhythm is associated with cognitive processes essential to learning and depends on the integrity of cholinergic, GABAergic, and glutamatergic forebrain systems. Since several significant psychiatric disorders appear to result from dysfunction of medial temporal lobe (MTL) neurochemical systems, preclinical studies on animal models may be an important step in defining and treating such syndromes. Many studies have shown that the amount of hippocampal theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning and attainment of asymptotic performance. Our lab has developed a brain-computer interface that makes eyeblink training trials contingent upon the explicit presence or absence of hippocampal theta. The behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to fourfold increase in learning speed over non-theta states. The non-theta behavioral impairment is accompanied by disruption of the amplitude and synchrony of hippocampal local field potentials, multiple-unit excitation, and single-unit response patterns dependent on theta state. Our findings indicate a significant electrophysiological and behavioral impact of the pretrial state of the hippocampus that suggests an important role for this MTL system in associative learning and a significant deleterious impact in the absence of theta. Here, we focus on the impairments in the non-theta state, integrate them into current models of psychiatric disorders, and suggest how improvement in our understanding of neurobiological oscillations is critical for theories and treatment of psychiatric pathology.
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Affiliation(s)
- Joseph J Cicchese
- Department of Psychology, Center for Neuroscience, Miami University , Oxford, OH , USA
| | - Stephen D Berry
- Department of Psychology, Center for Neuroscience, Miami University , Oxford, OH , USA
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18
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Chen JE, Glover GH. Functional Magnetic Resonance Imaging Methods. Neuropsychol Rev 2015; 25:289-313. [PMID: 26248581 PMCID: PMC4565730 DOI: 10.1007/s11065-015-9294-9] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 07/28/2015] [Indexed: 12/11/2022]
Abstract
Since its inception in 1992, Functional Magnetic Resonance Imaging (fMRI) has become an indispensible tool for studying cognition in both the healthy and dysfunctional brain. FMRI monitors changes in the oxygenation of brain tissue resulting from altered metabolism consequent to a task-based evoked neural response or from spontaneous fluctuations in neural activity in the absence of conscious mentation (the "resting state"). Task-based studies have revealed neural correlates of a large number of important cognitive processes, while fMRI studies performed in the resting state have demonstrated brain-wide networks that result from brain regions with synchronized, apparently spontaneous activity. In this article, we review the methods used to acquire and analyze fMRI signals.
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Affiliation(s)
- Jingyuan E Chen
- Department of Radiology, Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA,
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19
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Smieskova R, Roiser JP, Chaddock CA, Schmidt A, Harrisberger F, Bendfeldt K, Simon A, Walter A, Fusar-Poli P, McGuire PK, Lang UE, Riecher-Rössler A, Borgwardt S. Modulation of motivational salience processing during the early stages of psychosis. Schizophr Res 2015; 166:17-23. [PMID: 25999039 DOI: 10.1016/j.schres.2015.04.036] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 04/15/2015] [Accepted: 04/27/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Deficits in motivational salience processing have been related to psychotic symptoms and disturbances in dopaminergic neurotransmission. We aimed at exploring changes in salience processing and brain activity during different stages of psychosis and antipsychotic medication effect. METHODS We used fMRI during the Salience Attribution Task to investigate hemodynamic differences between 19 healthy controls (HCs), 34 at-risk mental state (ARMS) individuals and 29 individuals with first-episode psychosis (FEP), including a subgroup of 17 FEP without antipsychotic medication (FEP-UM) and 12 FEP with antipsychotic medication (FEP-M). Motivational salience processing was operationalized by brain activity in response to high-probability rewarding cues (adaptive salience) and in response to low-probability rewarding cues (aberrant salience). RESULTS Behaviorally, adaptive salience response was not accelerated in FEP, although they correctly distinguished between trials with low and high reward probability. In comparison to HC, ARMS exhibited a lower hemodynamic response during adaptive salience in the right inferior parietal lobule and FEP-UM in the left dorsal cingulate gyrus. The FEP-M group exhibited a lower adaptive salience response than HC in the right insula and than ARMS in the anterior cingulate gyrus. In unmedicated individuals, the severity of hallucinations and delusions correlated negatively with the insular- and anterior cingulate hemodynamic response during adaptive salience. We found no differences in aberrant salience processing associated with behavior or medication. CONCLUSION The changes in adaptive motivational salience processing during psychosis development reveal neurofunctional abnormalities in the somatosensory and premotor cortex. Antipsychotic medication seems to modify hemodynamic responses in the anterior cingulate and insula.
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Affiliation(s)
- Renata Smieskova
- Psychiatric University Clinics (UPK) Basel, Wilhelm Klein-Strasse 27, Basel, Switzerland; Medical Image Analysis Center, University Hospital Basel, Switzerland
| | | | | | - André Schmidt
- Psychiatric University Clinics (UPK) Basel, Wilhelm Klein-Strasse 27, Basel, Switzerland; Medical Image Analysis Center, University Hospital Basel, Switzerland
| | - Fabienne Harrisberger
- Psychiatric University Clinics (UPK) Basel, Wilhelm Klein-Strasse 27, Basel, Switzerland; Medical Image Analysis Center, University Hospital Basel, Switzerland
| | - Kerstin Bendfeldt
- Medical Image Analysis Center, University Hospital Basel, Switzerland
| | - Andor Simon
- Specialized Early Psychosis Outpatient Service for Adolescents and Young Adults, Department of Psychiatry, Bruderholz, Switzerland
| | - Anna Walter
- Psychiatric University Clinics (UPK) Basel, Wilhelm Klein-Strasse 27, Basel, Switzerland
| | - Paolo Fusar-Poli
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, UK
| | - Philip K McGuire
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, UK
| | - Undine E Lang
- Psychiatric University Clinics (UPK) Basel, Wilhelm Klein-Strasse 27, Basel, Switzerland
| | - Anita Riecher-Rössler
- Psychiatric University Clinics (UPK) Basel, Wilhelm Klein-Strasse 27, Basel, Switzerland
| | - Stefan Borgwardt
- Psychiatric University Clinics (UPK) Basel, Wilhelm Klein-Strasse 27, Basel, Switzerland; Medical Image Analysis Center, University Hospital Basel, Switzerland; Department of Psychosis Studies, Institute of Psychiatry, King's College London, UK
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20
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Reckless GE, Andreassen OA, Server A, Østefjells T, Jensen J. Negative symptoms in schizophrenia are associated with aberrant striato-cortical connectivity in a rewarded perceptual decision-making task. Neuroimage Clin 2015. [PMID: 26106553 DOI: 10.1016/j.nicl.2015.04.025.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Negative symptoms in schizophrenia have been associated with structural and functional changes in the prefrontal cortex. They often persist after treatment with antipsychotic medication which targets, in particular, the ventral striatum (VS). As schizophrenia has been suggested to arise from dysfunctional connectivity between neural networks, it is possible that residual aberrant striato-cortical connectivity in medicated patients plays a role in enduring negative symptomology. The present study examined the relationship between striato-cortical connectivity and negative symptoms in medicated schizophrenia patients. METHODS We manipulated motivation in a perceptual decision-making task during functional magnetic resonance imaging. Comparing healthy controls (n = 21) and medicated patients with schizophrenia (n = 18) we investigated how motivation-mediated changes in VS activation affected functional connectivity with the frontal cortex, and how changes in connectivity strength from the neutral to motivated condition related to negative symptom severity. RESULTS A pattern of aberrant striato-cortical connectivity was observed in the presence of intact VS, but altered left inferior frontal gyrus (IFG) motivation-mediated activation in patients. The more severe the patient's negative symptoms, the less the connectivity strength between the right VS and left IFG changed from the neutral to the motivated condition. Despite aberrant striato-cortical connectivity and altered recruitment of the left IFG among patients, both patients and healthy controls adopted a more liberal response strategy in the motivated compared to the neutral condition. CONCLUSIONS The present findings suggest that there is a link between dysfunctional striato-cortical connectivity and negative symptom severity, and offer a possible explanation as to why negative symptoms persist after treatment with antipsychotics.
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Affiliation(s)
- Greg E Reckless
- NORMENT - KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway ; Department of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Ole A Andreassen
- NORMENT - KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway ; Department of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Andres Server
- Department of Neuroradiology, Oslo University Hospital, Oslo, Norway
| | - Tiril Østefjells
- NORMENT - KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Jimmy Jensen
- NORMENT - KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway ; Department of Clinical Medicine, University of Oslo, Oslo, Norway ; Centre for Psychology, Kristianstad University, Kristianstad, Sweden
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Negative symptoms in schizophrenia are associated with aberrant striato-cortical connectivity in a rewarded perceptual decision-making task. NEUROIMAGE-CLINICAL 2015; 8:290-7. [PMID: 26106553 PMCID: PMC4474284 DOI: 10.1016/j.nicl.2015.04.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/20/2015] [Accepted: 04/29/2015] [Indexed: 11/24/2022]
Abstract
Background Negative symptoms in schizophrenia have been associated with structural and functional changes in the prefrontal cortex. They often persist after treatment with antipsychotic medication which targets, in particular, the ventral striatum (VS). As schizophrenia has been suggested to arise from dysfunctional connectivity between neural networks, it is possible that residual aberrant striato-cortical connectivity in medicated patients plays a role in enduring negative symptomology. The present study examined the relationship between striato-cortical connectivity and negative symptoms in medicated schizophrenia patients. Methods We manipulated motivation in a perceptual decision-making task during functional magnetic resonance imaging. Comparing healthy controls (n = 21) and medicated patients with schizophrenia (n = 18) we investigated how motivation-mediated changes in VS activation affected functional connectivity with the frontal cortex, and how changes in connectivity strength from the neutral to motivated condition related to negative symptom severity. Results A pattern of aberrant striato-cortical connectivity was observed in the presence of intact VS, but altered left inferior frontal gyrus (IFG) motivation-mediated activation in patients. The more severe the patient's negative symptoms, the less the connectivity strength between the right VS and left IFG changed from the neutral to the motivated condition. Despite aberrant striato-cortical connectivity and altered recruitment of the left IFG among patients, both patients and healthy controls adopted a more liberal response strategy in the motivated compared to the neutral condition. Conclusions The present findings suggest that there is a link between dysfunctional striato-cortical connectivity and negative symptom severity, and offer a possible explanation as to why negative symptoms persist after treatment with antipsychotics. Examined the relationship between striato-cortical connectivity and negative symptoms in medicated schizophrenia patients Patients had normal ventral striatal (VS), but altered left inferior frontal gyrus (IFG) activation. The more severe the negative symptoms, the less the connectivity strength between these regions changed when motivated. Altered striato-cortical connectivity may explain the persistence of negative symptoms after treatment with antipsychotics.
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Abstract
Patients with schizophrenia not only suffer from prototypical psychotic symptoms such as delusions and hallucinations and from cognitive deficits, but also from tremendous deficits in social functioning. However, little is known about the interplay between the cognitive and the social-cognitive deficits in schizophrenia. Our chapter gives an overview on behavioral, as well as functional imaging studies on social cognition in schizophrenia. Main findings on cognitive and motivational deficits in schizophrenia are reviewed and introduced within the context of the dopamine hypothesis of schizophrenia. The reviewed findings suggest that disturbed "social brain" functioning in schizophrenia, depending on the specific context, can either lead to a neglect of the emotions and intentions of others or to the false attribution of these emotions and intentions in an emotionally neutral social content. We integrate these findings with the current knowledge about aberrant dopaminergic firing in schizophrenia by presenting a comprehensive model explaining core symptoms of the disorder. The main implication of the presented model is that neither cognitive-motivational, nor social-cognitive deficits alone cause schizophrenia symptoms, but that symptoms only emerge by the interplay of disturbed social brain functioning with aberrant dopaminergic firing.
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de la Iglesia-Vaya M, Escartí MJ, Molina-Mateo J, Martí-Bonmatí L, Gadea M, Castellanos FX, Aguilar García-Iturrospe EJ, Robles M, Biswal BB, Sanjuan J. Abnormal synchrony and effective connectivity in patients with schizophrenia and auditory hallucinations. Neuroimage Clin 2014; 6:171-9. [PMID: 25379429 PMCID: PMC4215518 DOI: 10.1016/j.nicl.2014.08.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 08/27/2014] [Accepted: 08/31/2014] [Indexed: 11/25/2022]
Abstract
Auditory hallucinations (AH) are the most frequent positive symptoms in patients with schizophrenia. Hallucinations have been related to emotional processing disturbances, altered functional connectivity and effective connectivity deficits. Previously, we observed that, compared to healthy controls, the limbic network responses of patients with auditory hallucinations differed when the subjects were listening to emotionally charged words. We aimed to compare the synchrony patterns and effective connectivity of task-related networks between schizophrenia patients with and without AH and healthy controls. Schizophrenia patients with AH (n = 27) and without AH (n = 14) were compared with healthy participants (n = 31). We examined functional connectivity by analyzing correlations and cross-correlations among previously detected independent component analysis time courses. Granger causality was used to infer the information flow direction in the brain regions. The results demonstrate that the patterns of cortico-cortical functional synchrony differentiated the patients with AH from the patients without AH and from the healthy participants. Additionally, Granger-causal relationships between the networks clearly differentiated the groups. In the patients with AH, the principal causal source was an occipital-cerebellar component, versus a temporal component in the patients without AH and the healthy controls. These data indicate that an anomalous process of neural connectivity exists when patients with AH process emotional auditory stimuli. Additionally, a central role is suggested for the cerebellum in processing emotional stimuli in patients with persistent AH.
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Key Words
- AH, auditory hallucinations
- Auditory hallucinations
- BOLD, blood oxygenation level dependent
- BPRS, Brief Psychiatric Rating Scale
- CCTC, cortico-cerebellar–thalamic–cortical
- Cerebellum
- CoI, component of interest
- Effective connectivity
- Functional connectivity
- GCCA, Granger causal connectivity analysis
- ICA, independent component analysis
- ICA-TC, ICA-time course
- MRI, functional magnetic resonance imaging
- MVAR, multivariate autoregression
- PANSS, Positive and Negative Syndrome Scale
- PSYRATS, Psychotic Symptom Rating Scale
- SPM, statistical parametric maps
- Schizophrenia
- Synchrony
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Affiliation(s)
- Maria de la Iglesia-Vaya
- Centre of Excellence in Biomedical Image (CEIB), Regional Ministry of Health in the Valencia Region (CS), C./Micer Masco nº 31-33, Valencia 46010, Spain
- Brain Connectivity Lab, Prince Felipe Research Centre (CIPF), C./Eduardo Primo Yúfera (Científic), nº 3, Valencia 46012, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISC III. Avda. Blasco Ibáñez 15, Valencia 46010, Spain
- GIBI230 (Grupo de Investigación Biomédica en Imagen, CIBER-BBN), Instituto de Investigación Sanitaria (IIS), Spain
| | - Maria José Escartí
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISC III. Avda. Blasco Ibáñez 15, Valencia 46010, Spain
- Department of Psychiatry, Clinic Hospital, Avda. Blasco Ibáñez, 17, Valencia 46010, Spain
| | - Jose Molina-Mateo
- Centre for Biomaterials and Tissue Engineering, Universidad Politécnica de Valencia, Valencia, Spain
| | - Luis Martí-Bonmatí
- Department of Radiology, Faculty of Medicine of Valencia, Avda. Blasco Ibáñez, 15, Valencia 46010, Spain
- GIBI230 (Grupo de Investigación Biomédica en Imagen, CIBER-BBN), Instituto de Investigación Sanitaria (IIS), Spain
| | - Marien Gadea
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISC III. Avda. Blasco Ibáñez 15, Valencia 46010, Spain
- Department of Psychobiology, Faculty of Psychology. University of Valencia, Avda. Blasco Ibáñez, 21, Valencia 46010, Spain
| | - Francisco Xavier Castellanos
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
- NYU Langone Medical Center, New York, NY, USA
| | - Eduardo J. Aguilar García-Iturrospe
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISC III. Avda. Blasco Ibáñez 15, Valencia 46010, Spain
- Department of Psychiatry, Clinic Hospital, Avda. Blasco Ibáñez, 17, Valencia 46010, Spain
| | - Montserrat Robles
- Instituto de Aplicaciones de las Tecnologías de la Información y de las Comunicaciones Avanzadas (ITACA), Universidad Politécnica de Valencia, Camino de Vera, s/n 46022, Valencia, Spain
| | - Bharat B. Biswal
- Department of Radiology, University of Medicine and Dentistry of New Jersey, Newark, NJ, USA
| | - Julio Sanjuan
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISC III. Avda. Blasco Ibáñez 15, Valencia 46010, Spain
- Department of Psychiatry, Clinic Hospital, Avda. Blasco Ibáñez, 17, Valencia 46010, Spain
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Prefrontal cortical GABA transmission modulates discrimination and latent inhibition of conditioned fear: relevance for schizophrenia. Neuropsychopharmacology 2014; 39:2473-84. [PMID: 24784549 PMCID: PMC4138759 DOI: 10.1038/npp.2014.99] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/11/2014] [Accepted: 04/28/2014] [Indexed: 02/07/2023]
Abstract
Inhibitory gamma-aminobutyric acid (GABA) transmission within the prefrontal cortex (PFC) regulates numerous functions, and perturbations in GABAergic transmission within this region have been proposed to contribute to some of the cognitive and behavioral abnormalities associated with disorders such as schizophrenia. These abnormalities include deficits in emotional regulation and aberrant attributions of affective salience. Yet, how PFC GABA regulates these types of emotional processes are unclear. To address this issue, we investigated the contribution of PFC GABA transmission to different aspects of Pavlovian emotional learning in rats using translational discriminative fear conditioning and latent inhibition (LI) assays. Reducing prelimbic PFC GABAA transmission via infusions of the antagonist bicuculline before the acquisition or expression of fear conditioning eliminated the ability to discriminate between an aversive conditioned stimulus (CS+) paired with footshock vs a neutral CS-, resembling similar deficits observed in schizophrenic patients. In a separate experiment, blockade of PFC GABAA receptors before CS preexposure (PE) and conditioning did not affect subsequent expression of LI, but did enhance fear in rats that were not preexposed to the CS. In contrast, PFC GABA-blockade before a fear expression test disrupted the recall of learned irrelevance and abolished LI. These data suggest that normal PFC GABA transmission is critical for regulating and mitigating multiple aspects of aversive learning, including discrimination between fear vs safety signals and recall of information about the irrelevance of stimuli. Furthermore, they suggest that similar deficits in emotional regulation observed in schizophrenia may be driven in part by deficient PFC GABA activity.
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25
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Khadem A, Hossein-Zadeh GA. Estimation of direct nonlinear effective connectivity using information theory and multilayer perceptron. J Neurosci Methods 2014; 229:53-67. [DOI: 10.1016/j.jneumeth.2014.04.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 03/17/2014] [Accepted: 04/07/2014] [Indexed: 11/24/2022]
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Çetin MS, Christensen F, Abbott CC, Stephen JM, Mayer AR, Cañive JM, Bustillo JR, Pearlson GD, Calhoun VD. Thalamus and posterior temporal lobe show greater inter-network connectivity at rest and across sensory paradigms in schizophrenia. Neuroimage 2014; 97:117-26. [PMID: 24736181 DOI: 10.1016/j.neuroimage.2014.04.009] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 03/15/2014] [Accepted: 04/04/2014] [Indexed: 11/25/2022] Open
Abstract
Although a number of recent studies have examined functional connectivity at rest, few have assessed differences between connectivity both during rest and across active task paradigms. Therefore, the question of whether cortical connectivity patterns remain stable or change with task engagement continues to be unaddressed. We collected multi-scan fMRI data on healthy controls (N=53) and schizophrenia patients (N=42) during rest and across paradigms arranged hierarchically by sensory load. We measured functional network connectivity among 45 non-artifactual distinct brain networks. Then, we applied a novel analysis to assess cross paradigm connectivity patterns applied to healthy controls and patients with schizophrenia. To detect these patterns, we fit a group by task full factorial ANOVA model to the group average functional network connectivity values. Our approach identified both stable (static effects) and state-based differences (dynamic effects) in brain connectivity providing a better understanding of how individuals' reactions to simple sensory stimuli are conditioned by the context within which they are presented. Our findings suggest that not all group differences observed during rest are detectable in other cognitive states. In addition, the stable differences of heightened connectivity between multiple brain areas with thalamus across tasks underscore the importance of the thalamus as a gateway to sensory input and provide new insight into schizophrenia.
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Affiliation(s)
- Mustafa S Çetin
- Computer Science Department, University of New Mexico, Albuquerque, NM 87131, United States.
| | - Fletcher Christensen
- Mathematics Department, University of New Mexico, Albuquerque, NM 87131, United States
| | - Christopher C Abbott
- Psychiatry Department, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
| | - Julia M Stephen
- The Mind Research Network, Albuquerque, NM 87106, United States
| | - Andrew R Mayer
- The Mind Research Network, Albuquerque, NM 87106, United States; Psychology Department, University of New Mexico, Albuquerque, NM 87131, United States; Neurology Department, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
| | - José M Cañive
- Psychiatry Department, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States; Psychiatry Research Program, New Mexico VA Health Care System, Albuquerque, NM 87108, United States; Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
| | - Juan R Bustillo
- Psychiatry Department, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States; Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
| | - Godfrey D Pearlson
- Departments of Psychiatry & Neurobiology, Yale University, New Haven, CT 06511, United States
| | - Vince D Calhoun
- Psychiatry Department, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States; The Mind Research Network, Albuquerque, NM 87106, United States; Electrical and Computer Engineering Department, University of New Mexico, Albuquerque, NM 87131, United States
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Winton-Brown TT, Fusar-Poli P, Ungless MA, Howes OD. Dopaminergic basis of salience dysregulation in psychosis. Trends Neurosci 2014; 37:85-94. [PMID: 24388426 DOI: 10.1016/j.tins.2013.11.003] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/18/2013] [Accepted: 11/20/2013] [Indexed: 12/30/2022]
Abstract
Disrupted salience processing is proposed as central in linking dysregulated dopamine function with psychotic symptoms. Several strands of evidence are now converging in support of this model. Animal studies show that midbrain dopamine neurons are activated by unexpected salient events. In psychotic patients, neurochemical studies have confirmed subcortical striatal dysregulation of dopaminergic neurotransmission, whereas functional magnetic resonance imaging (fMRI) studies of salience tasks have located alterations in prefrontal and striatal dopaminergic projection fields. At the clinical level, this may account for the altered sense of meaning and significance that predates the onset of psychosis. This review draws these different strands of evidence together in support of an emerging understanding of how dopamine dysregulation may lead to aberrant salience and psychotic symptoms.
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Affiliation(s)
- Toby T Winton-Brown
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, SE58AF London, UK.
| | - Paolo Fusar-Poli
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, SE58AF London, UK; OASIS Prodromal Service, South London and Maudsley (SLaM) National Health Service (NHS) Foundation Trust, London, UK
| | - Mark A Ungless
- Medical Research Council Clinical Sciences Centre, Imperial College London, London, UK
| | - Oliver D Howes
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, De Crespigny Park, SE58AF London, UK; Medical Research Council Clinical Sciences Centre, Imperial College London, London, UK
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Deserno L, Boehme R, Heinz A, Schlagenhauf F. Reinforcement learning and dopamine in schizophrenia: dimensions of symptoms or specific features of a disease group? Front Psychiatry 2013; 4:172. [PMID: 24391603 PMCID: PMC3870301 DOI: 10.3389/fpsyt.2013.00172] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/07/2013] [Indexed: 01/26/2023] Open
Abstract
Abnormalities in reinforcement learning are a key finding in schizophrenia and have been proposed to be linked to elevated levels of dopamine neurotransmission. Behavioral deficits in reinforcement learning and their neural correlates may contribute to the formation of clinical characteristics of schizophrenia. The ability to form predictions about future outcomes is fundamental for environmental interactions and depends on neuronal teaching signals, like reward prediction errors. While aberrant prediction errors, that encode non-salient events as surprising, have been proposed to contribute to the formation of positive symptoms, a failure to build neural representations of decision values may result in negative symptoms. Here, we review behavioral and neuroimaging research in schizophrenia and focus on studies that implemented reinforcement learning models. In addition, we discuss studies that combined reinforcement learning with measures of dopamine. Thereby, we suggest how reinforcement learning abnormalities in schizophrenia may contribute to the formation of psychotic symptoms and may interact with cognitive deficits. These ideas point toward an interplay of more rigid versus flexible control over reinforcement learning. Pronounced deficits in the flexible or model-based domain may allow for a detailed characterization of well-established cognitive deficits in schizophrenia patients based on computational models of learning. Finally, we propose a framework based on the potentially crucial contribution of dopamine to dysfunctional reinforcement learning on the level of neural networks. Future research may strongly benefit from computational modeling but also requires further methodological improvement for clinical group studies. These research tools may help to improve our understanding of disease-specific mechanisms and may help to identify clinically relevant subgroups of the heterogeneous entity schizophrenia.
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Affiliation(s)
- Lorenz Deserno
- Max Planck Institute for Human Cognitive and Brain Sciences , Leipzig , Germany ; Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Rebecca Boehme
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Andreas Heinz
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Florian Schlagenhauf
- Max Planck Institute for Human Cognitive and Brain Sciences , Leipzig , Germany ; Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin , Berlin , Germany
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Ventral striatal activation during attribution of stimulus saliency and reward anticipation is correlated in unmedicated first episode schizophrenia patients. Schizophr Res 2012; 140:114-21. [PMID: 22784688 DOI: 10.1016/j.schres.2012.06.025] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/31/2012] [Accepted: 06/18/2012] [Indexed: 11/23/2022]
Abstract
Patients with schizophrenia show deficits in motivation, reward anticipation and salience attribution. Several functional magnetic resonance imaging (fMRI) investigations revealed neurobiological correlates of these deficits, raising the hypothesis of a common basis in midbrain dopaminergic signaling. However, investigations of drug-naïve first-episode patients with comprehensive fMRI tasks are still missing. We recruited unmedicated schizophrenia spectrum patients (N=27) and healthy control subjects (N=27) matched for sex, age and educational levels. An established monetary reward anticipation task in combination with a novel task aiming at implicit salience attribution without the confound of monetary incentive was applied. Patients showed reduced right ventral striatal activation during reward anticipation. Furthermore, patients with a more pronounced hypoactivation attributed more salience to neutral stimuli, had more positive symptoms and better executive functioning. In the patient group, a more differentially active striatum during reward anticipation was correlated positively to differential ventral striatal activation in the implicit salience attribution task. In conclusion, a deficit in ventral striatal activation during reward anticipation can already be seen in drug-naïve, first episode schizophrenia patients. The data suggest that rather a deficit in differential ventral striatal activation than a generally reduced activation underlies motivational deficits in schizophrenia and that this deficit is related to the aberrant salience attribution.
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Repovš G, Barch DM. Working memory related brain network connectivity in individuals with schizophrenia and their siblings. Front Hum Neurosci 2012; 6:137. [PMID: 22654746 PMCID: PMC3358772 DOI: 10.3389/fnhum.2012.00137] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 04/29/2012] [Indexed: 01/16/2023] Open
Abstract
A growing number of studies have reported altered functional connectivity in schizophrenia during putatively “task-free” states and during the performance of cognitive tasks. However, there have been few systematic examinations of functional connectivity in schizophrenia across rest and different task states to assess the degree to which altered functional connectivity reflects a stable characteristic or whether connectivity changes vary as a function of task demands. We assessed functional connectivity during rest and during three working memory loads of an N-back task (0-back, 1-back, 2-back) among: (1) individuals with schizophrenia (N = 19); (2) the siblings of individuals with schizophrenia (N = 28); (3) healthy controls (N = 10); and (4) the siblings of healthy controls (N = 17). We examined connectivity within and between four brain networks: (1) frontal–parietal (FP); (2) cingulo-opercular (CO); (3) cerebellar (CER); and (4) default mode (DMN). In terms of within-network connectivity, we found that connectivity within the DMN and FP increased significantly between resting state and 0-back, while connectivity within the CO and CER decreased significantly between resting state and 0-back. Additionally, we found that connectivity within both the DMN and FP was further modulated by memory load. In terms of between network connectivity, we found that the DMN became significantly more “anti-correlated” with the FP, CO, and CER networks during 0-back as compared to rest, and that connectivity between the FP and both CO and CER networks increased with memory load. Individuals with schizophrenia and their siblings showed consistent reductions in connectivity between both the FP and CO networks with the CER network, a finding that was similar in magnitude across rest and all levels of working memory load. These findings are consistent with the hypothesis that altered functional connectivity in schizophrenia reflects a stable characteristic that is present across cognitive states.
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Affiliation(s)
- Grega Repovš
- Department of Psychology, University of Ljubljana Ljubljana, Slovenia
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31
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Abstract
This review summarizes the current state of knowledge regarding the proposed mechanisms by which antipsychotic agents reduce the symptoms of schizophrenia while giving rise to adverse side effects. The first part summarizes the contribution of neuroimaging studies to our understanding of the neurochemical substrates of schizophrenia, putting emphasis on direct evidence suggestive of a presynaptic rather than a postsynaptic dysregulation of dopaminergic neurotransmission in this disorder. The second part addresses the role of D(2) and non-D(2) receptor blockade in the treatment of schizophrenia and highlights a preponderant role of D(2) receptors in the mechanism of antipsychotic action. Neuroimaging studies have defined a narrow, but optimal, therapeutic window of 65-78 % D(2) receptor blockade within which most antipsychotics achieve optimal clinical efficacy with minimal side effects. Some antipsychotics though do not conform to that therapeutic window, notably clozapine. The reasons for its unexcelled clinical efficacy despite subthreshold levels of D(2) blockade are unclear and current theories on clozapine's mechanisms of action are discussed, including transiency of its D(2) receptor blocking effects or preferential blockade of limbic D(2) receptors. Evidence is also highlighted to consider the use of extended antipsychotic dosing to achieve transiency of D(2) blockade as a way to optimize functional outcomes in patients. We also present some critical clinical considerations regarding the mechanisms linking dopamine disturbance to the expression of psychosis and its blockade to the progressive resolution of psychosis, keeping in perspective the speed and onset of antipsychotic action. Finally, we discuss potential novel therapeutic strategies for schizophrenia.
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Affiliation(s)
- Nathalie Ginovart
- Department of Psychiatry, University of Geneva, Geneva, Switzerland.
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32
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Fervaha G, Remington G. Interpreting a multivariate analysis of functional neuroimaging data. Front Psychiatry 2012; 3:52. [PMID: 22661958 PMCID: PMC3361683 DOI: 10.3389/fpsyt.2012.00052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 05/10/2012] [Indexed: 11/23/2022] Open
Affiliation(s)
- Gagan Fervaha
- Institute of Medical Science, University of Toronto Toronto, ON, Canada
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33
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Richard JM, Berridge KC. Nucleus accumbens dopamine/glutamate interaction switches modes to generate desire versus dread: D(1) alone for appetitive eating but D(1) and D(2) together for fear. J Neurosci 2011; 31:12866-79. [PMID: 21900565 PMCID: PMC3174486 DOI: 10.1523/jneurosci.1339-11.2011] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 07/22/2011] [Accepted: 07/22/2011] [Indexed: 12/31/2022] Open
Abstract
The medial shell of nucleus accumbens (NAc) and its mesolimbic dopamine inputs mediate forms of fearful as well as of incentive motivation. For example, either appetitive and/or actively fearful behaviors are generated in a keyboard pattern by localized glutamate disruptions in NAc (via microinjection of the AMPA receptor antagonist DNQX) at different anatomical locations along a rostrocaudal gradient within the medial shell of rats. Rostral glutamate disruptions produce intense increases in eating, but more caudally placed disruptions produce increasingly fearful behaviors: distress vocalizations and escape attempts to human touch, and a spontaneous and directed antipredator response called defensive treading/burying. Local endogenous dopamine is required for either intense motivation to be generated by AMPA disruptions. Here we report that only endogenous local signaling at D(1) dopamine receptors is needed for rostral generation of excessive eating, potentially implicating a direct output pathway contribution. In contrast, fear generation at caudal sites requires both D(1) and D(2) signaling simultaneously, potentially implicating an indirect output pathway contribution. Finally, when motivation valence generated by AMPA disruptions at intermediate sites was flipped by manipulating environmental ambience, from mostly appetitive in a comfortable home environment to mostly fearful in a stressful environment, the roles of local D(1) and D(2) signaling in dopamine/glutamate interaction at microinjection sites also switched dynamically to match the motivation valence generated at the moment. Thus, NAc D(1) and D(2) receptors, and their associated neuronal circuits, play different and dynamic roles in enabling desire and dread to be generated by localized NAc glutamate disruptions in medial shell.
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Affiliation(s)
- Jocelyn M Richard
- Department of Psychology, University of Michigan, Ann Arbor, Michigan 48109-1043, USA.
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