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Li S, Sakurai K, Ohgidani M, Kato TA, Hikida T. Ameliorative effects of Fingolimod (FTY720) on microglial activation and psychosis-related behavior in short term cuprizone exposed mice. Mol Brain 2023; 16:59. [PMID: 37438826 DOI: 10.1186/s13041-023-01047-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 06/21/2023] [Indexed: 07/14/2023] Open
Abstract
Schizophrenia is a psychiatric disorder that affects around 1% of the population in widespread populations, with severe cases leading to long-term hospitalization and necessitation of lifelong treatment. Recent studies on schizophrenia have highlighted the involvement of inflammatory and immunoregulatory mechanisms with the onset of symptoms, and the usage of anti-inflammatory treatments are being tested against periods of rapid psychosis. In the central nervous system, microglia are the innate immune population which are activated in response to a wide range of physical and psychological stress factors and produce proinflammatory mediators such as cytokines. Microglial activation and neuroinflammation has been associated to numerous psychiatric disorders including schizophrenia, especially during psychotic episodes. Thus, novel treatments which dampen microglial activation may be of great relevance in the treatment of psychiatric disorders. Fingolimod (FTY720) is a drug used as an immunosuppressive treatment to multiple sclerosis. Recent clinical trials have focused on FTY720 as a treatment for the behavioral symptoms in schizophrenia. However, the mechanisms of Fingolimod in treating the symptoms of schizophrenia are not clear. In this study we use a recently developed neuroinflammatory psychosis model in mice: cuprizone short-term exposure, to investigate the effects of FTY720 administration. FTY720 administration was able to completely alleviate methamphetamine hypersensitivity caused by cuprizone exposure. Moreover, administration of FTY720 improved multiple measures of neuroinflammation (microglial activation, cytokine production, and leucocyte infiltration). In conclusion, our results highlight the future use of FTY720 as a direct anti-inflammatory treatment against microglial activation and psychosis.
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Affiliation(s)
- Siyao Li
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, Suita, Osaka, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Koki Sakurai
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
- Laboratory of Protein Profiling and Functional Proteomics, Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
| | - Masahiro Ohgidani
- Department of Functional Anatomy and Neuroscience, Asahikawa Medical University, Hokkaido, Japan
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takahiro A Kato
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Takatoshi Hikida
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
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2
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Social interaction, psychotic disorders and inflammation: A triangle of interest. Prog Neuropsychopharmacol Biol Psychiatry 2023; 122:110697. [PMID: 36521587 DOI: 10.1016/j.pnpbp.2022.110697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022]
Abstract
Social interaction difficulties are a hallmark of psychotic disorders, which in some cases can be definitely traced back to autoimmunological causes. Interestingly, systemic and intrathecal inflammation have been shown to significantly influence social processing by increasing sensitivity to threatening social stimuli, which bears some resemblance to psychosis. In this article, we review evidence for the involvement of systemic and intrathecal inflammatory processes in psychotic disorders and how this might help to explain some of the social impairments associated with this group of disorders. Vice versa, we also discuss evidence for the immunomodulatory function of social interactions and their potential role for therapeutic interventions in psychotic disorders.
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Sex Differences in the Behavioural Aspects of the Cuprizone-Induced Demyelination Model in Mice. Brain Sci 2022; 12:brainsci12121687. [PMID: 36552147 PMCID: PMC9775311 DOI: 10.3390/brainsci12121687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/28/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Multiple sclerosis is an autoimmune disease characterised by demyelination in the central nervous system. The cuprizone-induced demyelination model is often used in mice to test novel treatments for multiple sclerosis. However, despite significant demyelination, behavioural deficits may be subtle or have mixed results depending on the paradigm used. Furthermore, the sex differences within the model are not well understood. In the current study, we have sought to understand the behavioural deficits associated with the cuprizone-induced demyelination model in both male and female C57BL/6J mice. Using Black gold II stain, we found that cuprizone administration over 6 weeks caused significant demyelination in the corpus callosum that was consistent across both sexes. Cuprizone administration caused increased mechanical sensitivity when measured using an electronic von Frey aesthesiometer, with no sex differences observed. However, cuprizone administration decreased motor coordination, with more severe deficits seen in males in the horizontal bar and passive wire hang tests. In contrast, female mice showed more severe deficits in the motor skill sequence test. Cuprizone administration caused more anxiety-like behaviours in males compared to females in the elevated zero maze. Therefore, this study provides a better understanding of the sex differences involved in the behavioural aspects of cuprizone-induced demyelination, which could allow for a better translation of results from the laboratory to the clinic.
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Motor Behavioral Deficits in the Cuprizone Model: Validity of the Rotarod Test Paradigm. Int J Mol Sci 2022; 23:ijms231911342. [PMID: 36232643 PMCID: PMC9570024 DOI: 10.3390/ijms231911342] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/19/2022] [Accepted: 09/22/2022] [Indexed: 11/17/2022] Open
Abstract
Multiple Sclerosis (MS) is a neuroinflammatory disorder, which is histopathologically characterized by multifocal inflammatory demyelinating lesions affecting both the central nervous system’s white and grey matter. Especially during the progressive phases of the disease, immunomodulatory treatment strategies lose their effectiveness. To develop novel progressive MS treatment options, pre-clinical animal models are indispensable. Among the various different models, the cuprizone de- and remyelination model is frequently used. While most studies determine tissue damage and repair at the histological and ultrastructural level, functional readouts are less commonly applied. Among the various overt functional deficits, gait and coordination abnormalities are commonly observed in MS patients. Motor behavior is mediated by a complex neural network that originates in the cortex and terminates in the skeletal muscles. Several methods exist to determine gait abnormalities in small rodents, including the rotarod testing paradigm. In this review article, we provide an overview of the validity and characteristics of the rotarod test in cuprizone-intoxicated mice.
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Biochanin A Improves Memory Decline and Brain Pathology in Cuprizone-Induced Mouse Model of Multiple Sclerosis. Behav Sci (Basel) 2022; 12:bs12030070. [PMID: 35323389 PMCID: PMC8945046 DOI: 10.3390/bs12030070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/30/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system characterized by the demyelination of nerves, neural degeneration, and axonal loss. Cognitive impairment, including memory decline, is a significant feature in MS affecting up to 70% of patients. Thereby, it substantially impacts patients’ quality of life. Biochanin A (BCA) is an o-methylated isoflavone with a wide variety of pharmacological activities, including antioxidant, anti-inflammatory, and neuroprotective activities. Thus, this study aimed to investigate the possible protective effects of BCA on memory decline in the cuprizone (CPZ) model of MS. Thirty Swiss albino male mice (SWR/J) were randomly divided into three groups (n = 10): control (normal chow + i.p. 1:9 mixture of DMSO and PBS), CPZ (0.2% w/w of CPZ mixed into chow + i.p. 1:9 mixture of DMSO and PBS), and CPZ + BCA (0.2% w/w of CPZ mixed into chow + i.p. 40 mg/kg of BCA). At the last week of the study (week 5), a series of behavioral tasks were performed. A grip strength test was performed to assess muscle weakness while Y-maze, novel object recognition task (NORT), and novel arm discrimination task (NADT) were performed to assess memory. Additionally, histological examination of the hippocampus and the prefrontal cortex (PFC) were conducted. BCA administration caused a significant increase in the grip strength compared with the CPZ group. Additionally, BCA significantly improved the mice’s spatial memory in the Y-maze and recognition memory in the NORT and the NADT compared with the CPZ group. Moreover, BCA mitigated neuronal damage in the PFC and the hippocampus after five weeks of administration. In conclusion, our data demonstrates the possible protective effect of BCA against memory deterioration in mice fed with CPZ for five weeks.
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Ohgomori T, Jinno S. Signal Transducer and Activator of Transcription 3 Activation in Hippocampal Neural Stem Cells and Cognitive Deficits in Mice Following Short-term Cuprizone Exposure. Neuroscience 2021; 472:90-102. [PMID: 34358632 DOI: 10.1016/j.neuroscience.2021.07.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/18/2021] [Accepted: 07/27/2021] [Indexed: 12/13/2022]
Abstract
Recent studies have emphasized that adult hippocampal neurogenesis impairment may be associated with cognitive problems. Because cuprizone (CPZ), a copper-chelating reagent, was shown to decrease the production of new neurons, we aimed to further understand the involvement of adult hippocampal neurogenesis impairment in cognitive function by using a short-term (2-week) CPZ exposure paradigm. The CPZ-fed mice showed cognitive deficits, i.e., impaired sensorimotor gating and reduced social novelty preference, compared to normal-fed mice. Although a long-term (e.g., 5-week) CPZ exposure paradigm was found to cause demyelination, we encountered that the labeling for myelin in the hippocampus was unaffected by 2-week CPZ exposure. The densities of neuronal progenitor cells (NPCs) and newborn granule cells (NGCs) were lower in CPZ-fed mice than in normal-fed mice, while those of neural stem cells (NSCs) were comparable between groups. We then examined whether short-term CPZ exposure might induce activation of signal transducer and activator of transcription 3 (STAT3), which plays a major role in cytokine receptor signaling. The densities of phosphorylated STAT3-positive (pSTAT3+) NSCs were higher in CPZ-fed mice than in normal-fed mice, while those of pSTAT3+ NPCs/NGCs were very low in both groups. Interestingly, the densities of bromodeoxyuridine-positive (BrdU+) NSCs were higher in CPZ-fed mice than in normal-fed mice 2 weeks after BrdU injection, while those of BrdU+ NPCs/NGCs were lower in CPZ-fed mice than in normal-fed mice. These findings suggest that short-term CPZ exposure inhibits differentiation of NSCs into NPCs via activation of STAT3, which may in part underlie cognitive deficits.
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Affiliation(s)
- Tomohiro Ohgomori
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Department of Rehabilitation, Osaka Kawasaki Rehabilitation University, Kaizuka 597-0104, Japan
| | - Shozo Jinno
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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Khalilian B, Madadi S, Fattahi N, Abouhamzeh B. Coenzyme Q10 enhances remyelination and regulate inflammation effects of cuprizone in corpus callosum of chronic model of multiple sclerosis. J Mol Histol 2021; 52:125-134. [PMID: 33245472 DOI: 10.1007/s10735-020-09929-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 11/17/2020] [Indexed: 12/30/2022]
Abstract
Multiple Sclerosis (MS) is a chronic, progressive demyelinating disease of the central nervous system that causes the most disability in young people, besides trauma. Coenzyme Q10 (CoQ10)-also known as ubiquinone-is an endogenous lipid-soluble antioxidant in the mitochondrial oxidative respiratory chain which can reduce oxidative stress and inflammation, the processes associated with demyelination in MS. Cuprizone (CPZ) intoxication is a well-established model of inducing MS, best for studying demyelination-remyelination. In this study, we examined for the first time the role of CoQ10 in preventing demyelination and induction of remyelination in the chronic CPZ model of MS. 40 male mice were divided into four groups. 3 group chewed CPZ-containing food for 12 weeks to induce MS. After 4 weeks, one group were treated with CoQ10 (150 mg/kg/day) by daily gavage until the end of the experiment, while CPZ poisoning continued. At the end of 12 weeks, tail suspension test (TST) and open field test (OFT) was taken and animals were sacrificed to assess myelin basic protein (MBP), oligodendrocyte transcription factor-1 (Olig1), tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) by real-time polymerase chain reaction (real-time PCR) and total antioxidant capacity (TAC) and superoxide dismutase (SOD) by Elisa test. Luxol fast blue (LFB) staining was used to evaluate histological changes. CoQ10 administration promoted remyelination in histological findings. MBP and Olig-1 expression were increased significantly in CoQ10 treated group compare to the CPZ-intoxicated group. CoQ10 treatment alleviated stress oxidative status induced by CPZ and dramatically suppress inflammatory biomarkers. CPZ ingestion made no significant difference between normal control group and the CPZ-intoxicated group in TST and OFT. CoQ10 can enhance remyelination in the CPZ model and potentially might have same effects in MS patients.
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Affiliation(s)
- Behnam Khalilian
- Department of Anatomical Sciences, Faculty of Medicine, AJA University of Medical Sciences, 1411718541, Tehran, Iran
| | - Soheila Madadi
- Department of Anatomy, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran
| | - Nima Fattahi
- Non-communicable Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Beheshteh Abouhamzeh
- Department of Anatomical Sciences, Faculty of Medicine, AJA University of Medical Sciences, 1411718541, Tehran, Iran.
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Kopanitsa MV, Lehtimäki KK, Forsman M, Suhonen A, Koponen J, Piiponniemi TO, Kärkkäinen AM, Pavlidi P, Shatillo A, Sweeney PJ, Merenlender-Wagner A, Kaye J, Orbach A, Nurmi A. Cognitive disturbances in the cuprizone model of multiple sclerosis. GENES BRAIN AND BEHAVIOR 2020; 20:e12663. [PMID: 32372528 DOI: 10.1111/gbb.12663] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 04/29/2020] [Accepted: 04/29/2020] [Indexed: 12/19/2022]
Abstract
Cognitive problems frequently accompany neurological manifestations of multiple sclerosis (MS). However, during screening of preclinical candidates, assessments of behaviour in mouse models of MS typically focus on locomotor activity. In the present study, we analysed cognitive behaviour of 9 to 10-week-old female C57Bl/6J mice orally administered with the toxin cuprizone that induces demyelination, a characteristic feature of MS. Animals received 400 mg/kg cuprizone daily for 2 or 4 weeks, and their performance was compared with that of vehicle-treated mice. Cuprizone-treated animals showed multiple deficits in short touchscreen-based operant tasks: they responded more slowly to visual stimuli, rewards and made more errors in a simple rule-learning task. In contextual/cued fear conditioning experiments, cuprizone-treated mice showed significantly lower levels of contextual freezing than vehicle-treated mice. Diffusion tensor imaging showed treatment-dependent changes in fractional anisotropy as well as in axial and mean diffusivities in different white matter areas. Lower values of fractional anisotropy and axial diffusivity in cuprizone-treated mice indicated developing demyelination and/or axonal damage. Several diffusion tensor imaging measurements correlated with learning parameters. Our results show that translational touchscreen operant tests and fear conditioning paradigms can reliably detect cognitive consequences of cuprizone treatment. The suggested experimental approach enables screening novel MS drug candidates in longitudinal experiments for their ability to improve pathological changes in brain structure and reverse cognitive deficits.
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Affiliation(s)
- Maksym V Kopanitsa
- Charles River Discovery Services, Kuopio, Finland.,UK Dementia Research Institute, Department of Brain Sciences, Imperial College, London, UK
| | | | | | - Ari Suhonen
- Charles River Discovery Services, Kuopio, Finland
| | - Juho Koponen
- Charles River Discovery Services, Kuopio, Finland
| | | | | | - Pavlina Pavlidi
- MSc Programme in Translational Neuroscience, Imperial College, London, UK
| | | | | | | | - Joel Kaye
- Teva Pharmaceutical Industries Ltd, Netanya, Israel
| | - Aric Orbach
- Teva Pharmaceutical Industries Ltd, Netanya, Israel
| | - Antti Nurmi
- Charles River Discovery Services, Kuopio, Finland
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9
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Sen MK, Mahns DA, Coorssen JR, Shortland PJ. Behavioural phenotypes in the cuprizone model of central nervous system demyelination. Neurosci Biobehav Rev 2019; 107:23-46. [PMID: 31442519 DOI: 10.1016/j.neubiorev.2019.08.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/01/2019] [Accepted: 08/12/2019] [Indexed: 12/14/2022]
Abstract
The feeding of cuprizone (CPZ) to animals has been extensively used to model the processes of demyelination and remyelination, with many papers adopting a narrative linked to demyelinating conditions like multiple sclerosis (MS), the aetiology of which is unknown. However, no current animal model faithfully replicates the myriad of symptoms seen in the clinical condition of MS. CPZ ingestion causes mitochondrial and endoplasmic reticulum stress and subsequent apoptosis of oligodendrocytes leads to central nervous system demyelination and glial cell activation. Although there are a wide variety of behavioural tests available for characterizing the functional deficits in animal models of disease, including that of CPZ-induced deficits, they have focused on a narrow subset of outcomes such as motor performance, cognition, and anxiety. The literature has not been systematically reviewed in relation to these or other symptoms associated with clinical MS. This paper reviews these tests and makes recommendations as to which are the most important in order to better understand the role of this model in examining aspects of demyelinating diseases like MS.
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Affiliation(s)
- Monokesh K Sen
- School of Medicine, Western Sydney University, New South Wales, Australia
| | - David A Mahns
- School of Medicine, Western Sydney University, New South Wales, Australia
| | - Jens R Coorssen
- Departments of Health Sciences and Biological Sciences, Faculties of Applied Health Sciences and Mathematics & Science, Brock University, Ontario, Canada.
| | - Peter J Shortland
- Science and Health, Western Sydney University, New South Wales, Australia.
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Fukudome D, Hayes LN, Faust TE, Foss CA, Kondo MA, Lee BJ, Saito A, Kano SI, Coughlin JM, Kamiya A, Pomper MG, Sawa A, Niwa M. Translocator protein (TSPO) and stress cascades in mouse models of psychosis with inflammatory disturbances. Schizophr Res 2018; 197:492-497. [PMID: 29398205 PMCID: PMC6470041 DOI: 10.1016/j.schres.2018.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 12/12/2017] [Accepted: 01/17/2018] [Indexed: 11/28/2022]
Abstract
Changes in inflammatory cascades have been implicated in the underlying pathophysiology of psychosis. Translocator protein 18 kDa (TSPO) has been used to assess neuroinflammatory processes in psychotic disorders. Nonetheless, it is unclear whether TSPO, a mitochondrial protein, can be interpreted as a general marker for inflammation in diseases involving psychosis. To address this question, we investigated TSPO signaling in representative mouse models for psychosis with inflammatory disturbances. The maternal immune activation and cuprizone short-term exposure models show different TSPO signaling. Furthermore, we observed similarities and differences in their respective stress pathways including stress hormone signaling and oxidative stress that are functionally interconnected with the inflammatory responses. We propose that more careful studies of TSPO distribution in neuroinflammation and other stress cascades associated with psychotic symptoms will allow us to understand the biological mechanisms underlying psychosis-related behaviors.
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Affiliation(s)
- Daisuke Fukudome
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Lindsay N. Hayes
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Travis E. Faust
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Catherine A. Foss
- Russell H Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, 1550 Orleans Street, Baltimore, MD 21231, USA
| | - Mari A. Kondo
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Brian J. Lee
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Atsushi Saito
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Shin-ichi Kano
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Jennifer M. Coughlin
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Atsushi Kamiya
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Martin G. Pomper
- Russell H Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, 1550 Orleans Street, Baltimore, MD 21231, USA
| | - Akira Sawa
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA.
| | - Minae Niwa
- Department of Psychiatry, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287, USA.
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Palaniyappan L, Das T, Dempster K. The neurobiology of transition to psychosis: clearing the cache. J Psychiatry Neurosci 2017; 42:294-299. [PMID: 28834527 PMCID: PMC5573571 DOI: 10.1503/jpn.170137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The prepsychotic phase of schizophrenia is not only important for indicated prevention strategies, but also crucial for developing mechanistic models of the emergence of frank psychosis (transition). This commentary highlights the work of Dukart and colleagues, published in this issue of the Journal of Psychiatry and Neurosicence, who sought to identify MRI-based anatomic endophenotypes of psychosis in a well-characterized sample of patients with at-risk mental state (ARMS) and first-episode psychosis (FEP). Conceptual and translational challenges in clarifying the neurobiology of transitional prepsychotic states are discussed. A role of intracortical myelin in the neurobiology of transition is proposed. Transition may not be an outcome of "progressive structural deficits"; it may occur due to inadequate compensatory responses in the predisposed. The need to revise our current "deficit-oriented" models of neurobiology of psychosis in the wake of burgeoning evidence indicating a dynamic process of cortical reorganization is emphasized.
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Affiliation(s)
- Lena Palaniyappan
- Correspondence to: L. Palaniyappan, Prevention & Early Intervention Program for Psychoses (PEPP), A2-636, LHSC-VH, 800 Commissioners Road, London, Ont., Canada N6A 5W9;
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Carcone D, Ruocco AC. Six Years of Research on the National Institute of Mental Health's Research Domain Criteria (RDoC) Initiative: A Systematic Review. Front Cell Neurosci 2017; 11:46. [PMID: 28316565 PMCID: PMC5334510 DOI: 10.3389/fncel.2017.00046] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/13/2017] [Indexed: 01/01/2023] Open
Abstract
Six years have passed since the National Institute of Mental Health (NIMH) in the United States launched the Research Domain Criteria (RDoC) initiative. The RDoC introduces a framework for research on the biology of mental illness that integrates research findings across multiple levels of information. The framework outlines constructs that represent specific quantifiable dimensions of behavior (e.g., responses to acute threat, cognitive control) and corresponding units of analysis that can be used to study the constructs, beginning at the levels of genes, molecules, cells, circuits and physiology, and moving up to behaviors and self-reports. In this systematic review, a literature search was conducted to synthesize empirical research published since the proposal of the framework that incorporated the RDoC. Forty-eight peer-reviewed scholarly articles met eligibility criteria for the review. Studies differed according to whether they analyzed RDoC constructs and units of analysis within vs. between clinically-diagnosed and non-psychiatric samples. The most commonly studied constructs were subsumed within the domains of Negative Valence Systems, Positive Valence Systems and Cognitive Systems, providing initial results which primarily connected genetics, brain circuits and physiology research findings with behavior and self-reports. Prospects for future research adopting the RDoC matrix and utilizing a dimensional approach to studying the biology of mental illness are discussed.
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Affiliation(s)
- Dean Carcone
- Departments of Psychology and Psychological Clinical Science, University of Toronto Toronto, ON, Canada
| | - Anthony C Ruocco
- Departments of Psychology and Psychological Clinical Science, University of Toronto Toronto, ON, Canada
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