1
|
Rocchetti J, Fasano C, Dal-Bo G, Guma E, El Mestikawy S, Wong TP, Fakhfouri G, Giros B. Persistent extrasynaptic hyperdopaminergia in the mouse hippocampus induces plasticity and recognition memory deficits reversed by the atypical antipsychotic sulpiride. PLoS One 2023; 18:e0289770. [PMID: 37624765 PMCID: PMC10456148 DOI: 10.1371/journal.pone.0289770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/25/2023] [Indexed: 08/27/2023] Open
Abstract
Evidence suggests that subcortical hyperdopaminergia alters cognitive function in schizophrenia and antipsychotic drugs (APD) fail at rescuing cognitive deficits in patients. In a previous study, we showed that blocking D2 dopamine receptors (D2R), a core action of APD, led to profound reshaping of mesohippocampal fibers, deficits in synaptic transmission and impairments in learning and memory in the mouse hippocampus (HP). However, it is currently unknown how excessive dopamine affects HP-related cognitive functions, and how APD would impact HP functions in such a state. After verifying the presence of DAT-positive neuronal projections in the ventral (temporal), but not in the dorsal (septal), part of the HP, GBR12935, a blocker of dopamine transporter (DAT), was infused in the CA1 of adult C57Bl/6 mice to produce local hyperdopaminergia. Chronic GBR12935 infusion in temporal CA1 induced a mild learning impairment in the Morris Water Maze and abolished long-term recognition memory in novel-object (NORT) and object-place recognition tasks (OPRT). Deficits were accompanied by a significant decrease in DAT+ mesohippocampal fibers. Intrahippocampal or systemic treatment with sulpiride during GBR infusions improved the NORT deficit but not that of OPRT. In vitro application of GBR on hippocampal slices abolished long-term depression (LTD) of fEPSP in temporal CA1. LTD was rescued by co-application with sulpiride. In conclusion, chronic DAT blockade in temporal CA1 profoundly altered mesohippocampal modulation of hippocampal functions. Contrary to previous observations in normodopaminergic mice, antagonising D2Rs was beneficial for cognitive functions in the context of hippocampal hyperdopaminergia.
Collapse
Affiliation(s)
- Jill Rocchetti
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
| | - Caroline Fasano
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
| | - Gregory Dal-Bo
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
| | - Elisa Guma
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
| | - Salah El Mestikawy
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
- Sorbonne Université, INSERM, CNRS, NPS – IBPS, Paris, France
| | - Tak-Pan Wong
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
| | - Gohar Fakhfouri
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
| | - Bruno Giros
- Department of Psychiatry, Douglas Hospital, Mc Gill University, Montreal, Québec, Canada
- Université Paris-Cité, INCC UMR 8002, CNRS, Paris, France
| |
Collapse
|
2
|
Interference of commissural connections through the genu of the corpus callosum specifically impairs sensorimotor gating. Behav Brain Res 2021; 411:113383. [PMID: 34048871 DOI: 10.1016/j.bbr.2021.113383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/19/2021] [Accepted: 05/22/2021] [Indexed: 11/20/2022]
Abstract
White matter abnormalities in schizophrenic patients are characterized as regional tract-specific. Myelin loss at the genu of the corpus callosum (GCC) is one of the most consistent findings in schizophrenic patients across the different populations. We characterized the axons that pass through the GCC by stereotactically injecting an anterograde axonal tracing viral vector into the forceps minor of the corpus callosum in one hemisphere, and identified the homotopic brain structures that have commissural connections in the two hemispheres of the prefrontal cortex, including the anterior cingulate area, the prelimbic area, the secondary motor area, and the dorsal part of the agranular insular area, along with commissural connections with the primary motor area, caudoputamen, and claustrum. To investigate whether dysmyelination in these commissural connections is critical for the development of schizophrenia symptoms, we generated a mouse model with focal demyelination at the GCC by stereotactically injecting demyelinating agent lysolecithin into this site, and tested these mice in a battery of behavioral tasks that are used to model the schizophrenia-like symptom domains. We found that demyelination at the GCC influenced neither the social interest or mood state, nor the locomotive activity or motor coordination. Nevertheless, it specifically reduced the prepulse inhibition of acoustic startle that is a well-known measure of sensorimotor gating. This study advances our understanding of the pathophysiological contributions of the GCC-specific white matter lesion to the related disease, and demonstrates an indispensable role of interhemispheric communication between the frontal cortices for the top-down regulation of the sensorimotor gating.
Collapse
|
3
|
Ang MJ, Lee S, Kim JC, Kim SH, Moon C. Behavioral Tasks Evaluating Schizophrenia-like Symptoms in Animal Models: A Recent Update. Curr Neuropharmacol 2021; 19:641-664. [PMID: 32798374 PMCID: PMC8573744 DOI: 10.2174/1570159x18666200814175114] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/23/2020] [Accepted: 07/31/2020] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Schizophrenia is a serious mental illness that affects more than 21 million people worldwide. Both genetics and the environment play a role in its etiology and pathogenesis. Symptoms of schizophrenia are mainly categorized into positive, negative, and cognitive. One major approach to identify and understand these diverse symptoms in humans has been to study behavioral phenotypes in a range of animal models of schizophrenia. OBJECTIVE We aimed to provide a comprehensive review of the behavioral tasks commonly used for measuring schizophrenia-like behaviors in rodents together with an update of the recent study findings. METHODS Articles describing phenotypes of schizophrenia-like behaviors in various animal models were collected through a literature search in Google Scholar, PubMed, Web of Science, and Scopus, with a focus on advances over the last 10 years. RESULTS Numerous studies have used a range of animal models and behavioral paradigms of schizophrenia to develop antipsychotic drugs for improved therapeutics. In establishing animal models of schizophrenia, the candidate models were evaluated for schizophrenia-like behaviors using several behavioral tasks for positive, negative, and cognitive symptoms designed to verify human symptoms of schizophrenia. Such validated animal models were provided as rapid preclinical avenues for drug testing and mechanistic studies. CONCLUSION Based on the most recent advances in the field, it is apparent that a myriad of behavior tests are needed to confirm and evaluate the congruency of animal models with the numerous behaviors and clinical signs exhibited by patients with schizophrenia.
Collapse
Affiliation(s)
| | | | | | | | - Changjong Moon
- Address correspondence to this author at the Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, South Korea, Tel: +82-62-530-2838; E-mail:
| |
Collapse
|
4
|
Ximenes NC, Dos Santos Júnior MA, Vasconcelos GS, Dias KCF, Jucá MM, Silva AH, Leal LKAM, Viana GSB, de Sousa FCF, Vasconcelos SMM. Ethanolic extract of Erythrina velutina Willd ameliorate schizophrenia-like behavior induced by ketamine in mice. JOURNAL OF COMPLEMENTARY & INTEGRATIVE MEDICINE 2018; 16:/j/jcim.ahead-of-print/jcim-2018-0038/jcim-2018-0038.xml. [PMID: 30315736 DOI: 10.1515/jcim-2018-0038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 09/12/2018] [Indexed: 06/08/2023]
Abstract
Background Schizophrenia is a chronic mental disorder, characterized by positive, negative and cognitive symptoms. In general, several plants have shown activity in diseases related to the central nervous system (e.g., Erythrina velutina (EEEV), also known as "mulungu"). For this reason, we aimed to investigate the effects of standardized ethanol extract obtained from the stem bark of EEEV on the schizophrenia-like behaviors induced by ketamine (KET) administration. Methods Swiss mice were treated with KET (20 mg/kg, i.p.) or saline for 14 days. In addition, from 8th to 14th days, saline, EEEV (200 or 400 mg/kg, p.o.) or olanzapine (OLAN 2 mg/kg, p.o.) were associated to the protocol. On the 14th day of treatment, schizophrenia-like symptoms were evaluated by the prepulse inhibition of the startle reflex (PPI), locomotor activity evaluated by the open field test (OFT), spatial recognition memory evaluated by the Y-maze task and social interaction test (SIT). Results KET has caused deficits in PPI, and it has also has caused hyperlocomotion in OFT and deficits in SIT as compared to control. EEEV in both doses used, reversed behavioral changes induced by KET, likewise results obtained with the administration of OLAN. Conclusions Taken together, the results demonstrate that the standard extract of EEEV was able to revert schizophrenia-like symptoms, due to the administration in repeated doses of ketamine. Thus, our findings lead to a new perspective for the use of EEEV an interesting alternative for drug discovery in schizophrenia.
Collapse
Affiliation(s)
- Naiara Coelho Ximenes
- Department of Physiology and Pharmacology, Federal University of Ceara, Cel. Nunes de Melo 1127, CEP 60431-270, Fortaleza, Brazil
| | - Manuel Alves Dos Santos Júnior
- Department of Physiology and Pharmacology, Federal University of Ceara, Cel. Nunes de Melo 1127, CEP 60431-270, Fortaleza, Brazil
| | - Germana Silva Vasconcelos
- Department of Physiology and Pharmacology, Federal University of Ceara, Cel. Nunes de Melo 1127, CEP 60431-270, Fortaleza, Brazil
| | - Kátia Cilene Ferreira Dias
- Department of Physiology and Pharmacology, Federal University of Ceara, Cel. Nunes de Melo 1127, CEP 60431-270, Fortaleza, Brazil
| | - Mércia Marques Jucá
- Department of Physiology and Pharmacology, Federal University of Ceara, Cel. Nunes de Melo 1127, CEP 60431-270, Fortaleza, Brazil
| | - Aline Holanda Silva
- Department of Pharmacy, Federal University of Ceará, Capitão Francisco Pedro Street 1210, Fortaleza, CE CEP: 60430-170, Brazil
| | | | - Glauce Socorro Barros Viana
- Department of Physiology and Pharmacology, Federal University of Ceara, Cel. Nunes de Melo 1127, CEP 60431-270, Fortaleza, Brazil
| | - Francisca Cléa Florenço de Sousa
- Department of Physiology and Pharmacology, Federal University of Ceara, Cel. Nunes de Melo 1127, CEP 60431-270, Fortaleza, Brazil
| | | |
Collapse
|
5
|
O'Tuathaigh CMP, Desbonnet L, Moran PM, Kirby BP, Waddington JL. Molecular genetic models related to schizophrenia and psychotic illness: heuristics and challenges. Curr Top Behav Neurosci 2016; 7:87-119. [PMID: 21298380 DOI: 10.1007/7854_2010_111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Schizophrenia is a heritable disorder that may involve several common genes of small effect and/or rare copy number variation, with phenotypic heterogeneity across patients. Furthermore, any boundaries vis-à-vis other psychotic disorders are far from clear. Consequently, identification of informative animal models for this disorder, which typically relate to pharmacological and putative pathophysiological processes of uncertain validity, faces considerable challenges. In juxtaposition, the majority of mutant models for schizophrenia relate to the functional roles of a diverse set of genes associated with risk for the disorder or with such putative pathophysiological processes. This chapter seeks to outline the evidence from phenotypic studies in mutant models related to schizophrenia. These have commonly assessed the degree to which mutation of a schizophrenia-related gene is associated with the expression of several aspects of the schizophrenia phenotype or more circumscribed, schizophrenia-related endophenotypes; typically, they place specific emphasis on positive and negative symptoms and cognitive deficits, and extend to structural and other pathological features. We first consider the primary technological approaches to the generation of such mutants, to include their relative merits and demerits, and then highlight the diverse phenotypic approaches that have been developed for their assessment. The chapter then considers the application of mutant phenotypes to study pathobiological and pharmacological mechanisms thought to be relevant for schizophrenia, particularly in terms of dopaminergic and glutamatergic dysfunction, and to an increasing range of candidate susceptibility genes and copy number variants. Finally, we discuss several pertinent issues and challenges within the field which relate to both phenotypic evaluation and a growing appreciation of the functional genomics of schizophrenia and the involvement of gene × environment interactions.
Collapse
Affiliation(s)
- Colm M P O'Tuathaigh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland,
| | | | | | | | | |
Collapse
|
6
|
Transcranial direct current stimulation and neuroplasticity genes: implications for psychiatric disorders. Acta Neuropsychiatr 2016; 28:1-10. [PMID: 25877668 DOI: 10.1017/neu.2015.20] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIM Transcranial direct current stimulation (tDCS) is a non-invasive and well-tolerated brain stimulation technique with promising efficacy as an add-on treatment for schizophrenia and for several other psychiatric disorders. tDCS modulates neuroplasticity; psychiatric disorders are established to be associated with neuroplasticity abnormalities. This review presents the summary of research on potential genetic basis of neuroplasticity-modulation mechanism underlying tDCS and its implications for treating various psychiatric disorders. METHOD A systematic review highlighting the genes involved in neuroplasticity and their role in psychiatric disorders was carried out. The focus was on the established genetic findings of tDCS response relationship with BDNF and COMT gene polymorphisms. RESULT Synthesis of these preliminary observations suggests the potential influence of neuroplastic genes on tDCS treatment response. These include several animal models, pharmacological studies, mentally ill and healthy human subject trials. CONCLUSION Taking into account the rapidly unfolding understanding of tDCS and the role of synaptic plasticity disturbances in neuropsychiatric disorders, in-depth evaluation of the mechanism of action pertinent to neuroplasticity modulation with tDCS needs further systematic research. Genes such as NRG1, DISC1, as well as those linked with the glutamatergic receptor in the context of their direct role in the modulation of neuronal signalling related to neuroplasticity aberrations, are leading candidates for future research in this area. Such research studies might potentially unravel observations that might have potential translational implications in psychiatry.
Collapse
|
7
|
Koppel J, Jimenez H, Azose M, D'Abramo C, Acker C, Buthorn J, Greenwald BS, Lewis J, Lesser M, Liu Z, Davies P. Pathogenic tau species drive a psychosis-like phenotype in a mouse model of Alzheimer's disease. Behav Brain Res 2014; 275:27-33. [PMID: 25151619 DOI: 10.1016/j.bbr.2014.08.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 08/11/2014] [Accepted: 08/13/2014] [Indexed: 01/30/2023]
Abstract
Psychotic Alzheimer's disease (AD+P) is a rapidly progressive variant of AD associated with an increased burden of frontal tau pathology that affects up to 50% of those with AD, and is observed more commonly in females. To date, there are no safe and effective medication interventions with an indication for treatment in this condition, and there has been only very limited exploration of potential animal models for pre-clinical drug development. Pathogenic tau is over represented in the frontal cortex in AD+P, especially in females. In order to develop a candidate animal model of AD+P, we employed a tau mouse model with a heavy burden of frontal tau pathology, the rTg(tauP301L)4510 mouse, hereafter termed rTg4510. We explored deficits of prepulse inhibition of acoustic startle (PPI), a model of psychosis in rodents, and the correlation between pathogenic phospho-tau species associated with AD+P and PPI deficits in female mice. We found that female rTg4510 mice exhibit increasing PPI deficits relative to littermate controls from 4.5 to 5.5 months of age, and that these deficits are driven by insoluble fractions of the phospho-tau species pSer396/404, pSer202, and pThr231 found to be associated with human AD+P. This preliminary data suggests the utility of the rTg4510 mouse as a candidate disease model of human female AD+P. Further work expanded to include both genders and other behavioral outcome measures relevant to AD+P is necessary.
Collapse
Affiliation(s)
- J Koppel
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA.
| | - H Jimenez
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| | - M Azose
- Touro College, Brooklyn, NY, USA
| | - C D'Abramo
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| | - C Acker
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| | - J Buthorn
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| | - B S Greenwald
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| | - J Lewis
- Center for Translational Research in Neurodegenerative Disease, University of Florida College of Medicine, Gainesville, FL, USA
| | - M Lesser
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| | - Z Liu
- Hofstra University, Hempstead, LI, USA
| | - P Davies
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| |
Collapse
|
8
|
Koppel J, Greenwald BS. Optimal treatment of Alzheimer's disease psychosis: challenges and solutions. Neuropsychiatr Dis Treat 2014; 10:2253-62. [PMID: 25473289 PMCID: PMC4247130 DOI: 10.2147/ndt.s60837] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Psychotic symptoms emerging in the context of neurodegeneration as a consequence of Alzheimer's disease was recognized and documented by Alois Alzheimer himself in his description of the first reported case of the disease. Over a quarter of a century ago, in the context of attempting to develop prognostic markers of disease progression, psychosis was identified as an independent predictor of a more-rapid cognitive decline. This finding has been subsequently well replicated, rendering psychotic symptoms an important area of exploration in clinical history taking - above and beyond treatment necessity - as their presence has prognostic significance. Further, there is now a rapidly accreting body of research that suggests that psychosis in Alzheimer's disease (AD+P) is a heritable disease subtype that enjoys neuropathological specificity and localization. There is now hope that the elucidation of the neurobiology of the syndrome will pave the way to translational research eventuating in new treatments. To date, however, the primary treatments employed in alleviating the suffering caused by AD+P are the atypical antipsychotics. These agents are approved by the US Food and Drug Administration for the treatment of schizophrenia, but they have only marginal efficacy in treating AD+P and are associated with troubling levels of morbidity and mortality. For clinical approaches to AD+P to be optimized, this syndrome must be disentangled from other primary psychotic disorders, and recent scientific advances must be translated into disease-specific therapeutic interventions. Here we provide a review of atypical antipsychotic efficacy in AD+P, followed by an overview of critical neurobiological observations that point towards a frontal, tau-mediated model of disease, and we suggest a new preclinical animal model for future translational research.
Collapse
Affiliation(s)
- Jeremy Koppel
- The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY, USA ; Zucker Hillside Hospital, Hofstra North Shore-Long Island Jewish School of Medicine, Glen Oaks, NY, USA
| | - Blaine S Greenwald
- Zucker Hillside Hospital, Hofstra North Shore-Long Island Jewish School of Medicine, Glen Oaks, NY, USA
| |
Collapse
|
9
|
McCullumsmith RE, Hammond JH, Shan D, Meador-Woodruff JH. Postmortem brain: an underutilized substrate for studying severe mental illness. Neuropsychopharmacology 2014; 39:65-87. [PMID: 24091486 PMCID: PMC3857666 DOI: 10.1038/npp.2013.239] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 02/08/2023]
Abstract
We propose that postmortem tissue is an underutilized substrate that may be used to translate genetic and/or preclinical studies, particularly for neuropsychiatric illnesses with complex etiologies. Postmortem brain tissues from subjects with schizophrenia have been extensively studied, and thus serve as a useful vehicle for illustrating the challenges associated with this biological substrate. Schizophrenia is likely caused by a combination of genetic risk and environmental factors that combine to create a disease phenotype that is typically not apparent until late adolescence. The complexity of this illness creates challenges for hypothesis testing aimed at understanding the pathophysiology of the illness, as postmortem brain tissues collected from individuals with schizophrenia reflect neuroplastic changes from a lifetime of severe mental illness, as well as treatment with antipsychotic medications. While there are significant challenges with studying postmortem brain, such as the postmortem interval, it confers a translational element that is difficult to recapitulate in animal models. On the other hand, data derived from animal models typically provide specific mechanistic and behavioral measures that cannot be generated using human subjects. Convergence of these two approaches has led to important insights for understanding molecular deficits and their causes in this illness. In this review, we discuss the problem of schizophrenia, review the common challenges related to postmortem studies, discuss the application of biochemical approaches to this substrate, and present examples of postmortem schizophrenia studies that illustrate the role of the postmortem approach for generating important new leads for understanding the pathophysiology of severe mental illness.
Collapse
Affiliation(s)
| | - John H Hammond
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - Dan Shan
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| | - James H Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama-Birmingham, Birmingham, AL, USA
| |
Collapse
|
10
|
Carter CJ. Susceptibility genes are enriched in those of the herpes simplex virus 1/host interactome in psychiatric and neurological disorders. Pathog Dis 2013; 69:240-61. [PMID: 23913659 DOI: 10.1111/2049-632x.12077] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 07/11/2013] [Accepted: 07/24/2013] [Indexed: 12/22/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) can promote beta-amyloid deposition and tau phosphorylation, demyelination or cognitive deficits relevant to Alzheimer's disease or multiple sclerosis and to many neuropsychiatric disorders with which it has been implicated. A seroprevalence much higher than disease incidence has called into question any primary causal role. However, as also the case with risk-promoting polymorphisms (also present in control populations), any causal effects are likely to be conditional. During its life cycle, the virus binds to many proteins and modifies the expression of multiple genes creating a host/pathogen interactome involving 1347 host genes. This data set is heavily enriched in the susceptibility genes for multiple sclerosis (P = 1.3E-99) > Alzheimer's disease > schizophrenia > Parkinsonism > depression > bipolar disorder > childhood obesity > chronic fatigue > autism > and anorexia (P = 0.047) but not attention deficit hyperactivity disorder, a relationship maintained for genome-wide association study data sets in multiple sclerosis and Alzheimer's disease. Overlapping susceptibility gene/interactome data sets disrupt signalling networks relevant to each disease, suggesting that disease susceptibility genes may filter the attentions of the pathogen towards particular pathways and pathologies. In this way, the same pathogen could contribute to multiple diseases in a gene-dependent manner and condition the risk-promoting effects of the genes whose function it disrupts.
Collapse
|
11
|
Yee BK, Singer P. A conceptual and practical guide to the behavioural evaluation of animal models of the symptomatology and therapy of schizophrenia. Cell Tissue Res 2013; 354:221-46. [PMID: 23579553 DOI: 10.1007/s00441-013-1611-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 03/07/2013] [Indexed: 02/08/2023]
Abstract
Schizophrenia is a chronic debilitating brain disorder characterized by a complex set of perceptual and behavioural symptoms that severely disrupt and undermine the patient's psychological well-being and quality of life. Since the exact disease mechanisms remain essentially unknown, holistic animal models are indispensable tools for any serious investigation into the neurobiology of schizophrenia, including the search for remedies, prevention of the disease and possible biological markers. This review provides some practical advice to those confronted with the task of evaluating their animal models for relevance to schizophrenia, a task that inevitably involves behavioural tests with animals. To a novice, this challenge not only is a technical one but also entails attention to interpretative issues concerning validity and translational power. Here, we attempt to offer some guidance to help overcome these obstacles by drawing on our experience of diverse animal models of schizophrenia based on genetics, strain difference, brain lesions, pharmacological induction and early life developmental manipulations. The review pays equal emphasis to the general (theoretical) considerations of experimental design and the illustration of the problems related to critical test parameters and the data analysis of selected exemplar behavioural tests. Finally, the individual differences of behavioural expression in relevant tests observed in wild-type animals might offer an alternative approach in order to explore the mechanism of schizophrenia-related behavioural dysfunction at the molecular, cellular and structural levels, all of which are of more immediate relevance to cell and tissue research.
Collapse
Affiliation(s)
- Benjamin K Yee
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute, 1225 NE Second Avenue, Portland, OR 97232, USA,
| | | |
Collapse
|
12
|
Razafsha M, Behforuzi H, Harati H, Wafai RA, Khaku A, Mondello S, Gold MS, Kobeissy FH. An updated overview of animal models in neuropsychiatry. Neuroscience 2013; 240:204-18. [PMID: 23473749 DOI: 10.1016/j.neuroscience.2013.02.045] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 01/28/2013] [Accepted: 02/20/2013] [Indexed: 12/20/2022]
Abstract
Animal models are vital tools to study the genetic, molecular, cellular, and environmental parameters involved in several neuropsychiatric disorders. Over the years, these models have expanded our understanding of the pathogenesis of many neuropsychiatric disorders and neurodegenerative diseases. Although animal models have been widely used in psychiatry, and despite several years of extensive research with these models, their validity is still being investigated and presents a challenge to both investigators and clinicians as well. In this concise review, we will describe the most common animal models utilized in neuropsychiatry, including animal models of depression, anxiety, and psychosis. In addition, we will also discuss the validity and reliability of these models and current challenges in this domain. Furthermore, this work will discuss the role of gene-environment interaction as an additional contributing factor that modulates neuropsychological outcome and its implication on animal models. This overview will give a succinct summary of animal models in psychiatry which will be useful both to the seasoned researcher, as well as novices in the field.
Collapse
Affiliation(s)
- M Razafsha
- Residency Program, Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Carter CJ. Toxoplasmosis and Polygenic Disease Susceptibility Genes: Extensive Toxoplasma gondii Host/Pathogen Interactome Enrichment in Nine Psychiatric or Neurological Disorders. J Pathog 2013; 2013:965046. [PMID: 23533776 PMCID: PMC3603208 DOI: 10.1155/2013/965046] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 08/18/2012] [Accepted: 09/10/2012] [Indexed: 01/04/2023] Open
Abstract
Toxoplasma gondii is not only implicated in schizophrenia and related disorders, but also in Alzheimer's or Parkinson's disease, cancer, cardiac myopathies, and autoimmune disorders. During its life cycle, the pathogen interacts with ~3000 host genes or proteins. Susceptibility genes for multiple sclerosis, Alzheimer's disease, schizophrenia, bipolar disorder, depression, childhood obesity, Parkinson's disease, attention deficit hyperactivity disorder (P from 8.01E - 05 (ADHD) to 1.22E - 71) (multiple sclerosis), and autism (P = 0.013), but not anorexia or chronic fatigue are highly enriched in the human arm of this interactome and 18 (ADHD) to 33% (MS) of the susceptibility genes relate to it. The signalling pathways involved in the susceptibility gene/interactome overlaps are relatively specific and relevant to each disease suggesting a means whereby susceptibility genes could orient the attentions of a single pathogen towards disruption of the specific pathways that together contribute (positively or negatively) to the endophenotypes of different diseases. Conditional protein knockdown, orchestrated by T. gondii proteins or antibodies binding to those of the host (pathogen derived autoimmunity) and metabolite exchange, may contribute to this disruption. Susceptibility genes may thus be related to the causes and influencers of disease, rather than (and as well as) to the disease itself.
Collapse
Affiliation(s)
- C. J. Carter
- Polygenic Pathways, Flat 2, 40 Baldslow Road, Hastings, East Sussex TN34 2EY, UK
| |
Collapse
|
14
|
Deng C, Pan B, Engel M, Huang XF. Neuregulin-1 signalling and antipsychotic treatment: potential therapeutic targets in a schizophrenia candidate signalling pathway. Psychopharmacology (Berl) 2013; 226:201-15. [PMID: 23389757 DOI: 10.1007/s00213-013-3003-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Accepted: 01/22/2013] [Indexed: 02/08/2023]
Abstract
Identifying the signalling pathways underlying the pathophysiology of schizophrenia is an essential step in the rational development of new antipsychotic drugs for this devastating disease. Evidence from genetic, transgenic and post-mortem studies have strongly supported neuregulin-1 (NRG1)-ErbB4 signalling as a schizophrenia susceptibility pathway. NRG1-ErbB4 signalling plays crucial roles in regulating neurodevelopment and neurotransmission, with implications for the pathophysiology of schizophrenia. Post-mortem studies have demonstrated altered NRG1-ErbB4 signalling in the brain of schizophrenia patients. Antipsychotic drugs have different effects on NRG1-ErbB4 signalling depending on treatment duration. Abnormal behaviours relevant to certain features of schizophrenia are displayed in NRG1/ErbB4 knockout mice or those with NRG1/ErbB4 over-expression, some of these abnormalities can be improved by antipsychotic treatment. NRG1-ErbB4 signalling has extensive interactions with the GABAergic, glutamatergic and dopaminergic neurotransmission systems that are involved in the pathophysiology of schizophrenia. These interactions provide a number of targets for the development of new antipsychotic drugs. Furthermore, the key interaction points between NRG1-ErbB4 signalling and other schizophrenia susceptibility genes may also potentially provide specific targets for new antipsychotic drugs. In general, identification of these targets in NRG1-ErbB4 signalling and interacting pathways will provide unique opportunities for the development of new generation antipsychotics with specific efficacy and fewer side effects.
Collapse
Affiliation(s)
- Chao Deng
- Antipsychotic Research Laboratory, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong 2522 NSW, Australia.
| | | | | | | |
Collapse
|
15
|
Karl T, Arnold JC. What does a mouse tell us about neuregulin 1-cannabis interactions? Front Cell Neurosci 2013; 7:18. [PMID: 23447438 PMCID: PMC3581817 DOI: 10.3389/fncel.2013.00018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/10/2013] [Indexed: 12/23/2022] Open
Abstract
The link between cannabis and psychosis has been debated although there is substantial epidemiological evidence showing that cannabis increases the risk of psychosis. It has been hypothesized that schizophrenia patients carrying particular risk genes might be more sensitive to the psychosis-inducing effects of cannabis than other patients and healthy test subjects. Here we review the effects of cannabinoids on a mutant mouse model for the schizophrenia candidate gene neuregulin 1 (Nrg1). The studies suggest a complex interaction between cannabis and Nrg1: the neuro-behavioral effects of cannabinoids were different in Nrg1 mutant and control mice and depended on exposure time, sex, and age of test animals. This research provides the first evidence of complex cannabis-Nrg1 interactions suggesting Nrg1 as a prime target for future clinical investigations. Furthermore, it highlights that animal model research can broaden our understanding of the complex multi-factorial etiology of schizophrenia. Finally, the findings are important to preventive psychiatry: if the genes that confer genetic vulnerability to cannabis-induced psychosis were identified patients at-high risk could be forewarned of the potential dangers of cannabis abuse.
Collapse
Affiliation(s)
- Tim Karl
- Neuroscience Research Australia Randwick, NSW, Australia ; Schizophrenia Research Institute Darlinghurst, NSW, Australia ; School of Medical Sciences, University of New South Wales NSW, Australia
| | | |
Collapse
|
16
|
Effects of antipsychotics on dentate gyrus stem cell proliferation and survival in animal models: a critical update. Neural Plast 2012; 2012:832757. [PMID: 23150836 PMCID: PMC3488410 DOI: 10.1155/2012/832757] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 09/19/2012] [Accepted: 09/20/2012] [Indexed: 12/15/2022] Open
Abstract
Schizophrenia is a complex psychiatric disorder. Although a number of different hypotheses have been developed to explain its aetiopathogenesis, we are far from understanding it. There is clinical and experimental evidence indicating that neurodevelopmental factors play a major role. Disturbances in neurodevelopment might result in alterations of neuroanatomy and neurochemistry, leading to the typical symptoms observed in schizophrenia. The present paper will critically address the neurodevelopmental models underlying schizophrenia by discussing the effects of typical and atypical antipsychotics in animal models. We will specifically discuss the vitamin D deficiency model, the poly I:C model, the ketamine model, and the postnatal ventral hippocampal lesion model, all of which reflect core neurodevelopmental issues underlying schizophrenia onset.
Collapse
|
17
|
Tarantino LM, Eisener-Dorman AF. Forward genetic approaches to understanding complex behaviors. Curr Top Behav Neurosci 2012; 12:25-58. [PMID: 22297575 PMCID: PMC6989028 DOI: 10.1007/7854_2011_189] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Assigning function to genes has long been a focus of biomedical research.Even with complete knowledge of the genomic sequences of humans, mice and other experimental organisms, there is still much to be learned about gene function and control. Ablation or overexpression of single genes using knockout or transgenic technologies has provided functional annotation for many genes, but these technologies do not capture the extensive genetic variation present in existing experimental mouse populations. Researchers have only recently begun to truly appreciate naturally occurring genetic variation resulting from single nucleotide substitutions,insertions, deletions, copy number variation, epigenetic changes (DNA methylation,histone modifications, etc.) and gene expression differences and how this variation contributes to complex phenotypes. In this chapter, we will discuss the benefits and limitations of different forward genetic approaches that capture the genetic variation present in inbred mouse strains and present the utility of these approaches for mapping QTL that influence complex behavioral phenotypes.
Collapse
|
18
|
Abstract
Basic research in animals represents a fruitful approach to study the neurobiological basis of brain and behavioral disturbances relevant to neuropsychiatric disease and to establish and evaluate novel pharmacological therapies for their treatment. In the context of schizophrenia, there are models employing specific experimental manipulations developed according to specific pathophysiological or etiological hypotheses. The use of selective lesions in adult animals and the acute administration of psychotomimetic agents are indispensable tools in the elucidation of the contribution of specific brain regions or neurotransmitters to the genesis of a specific symptom or collection of symptoms and enjoy some degrees of predictive validity. However, they may be inaccurate, if not inadequate, in capturing the etiological mechanisms or ontology of the disease needed for a complete understanding of the disease and may be limited in the discovery of novel compounds for the treatment of negative and cognitive symptoms of schizophrenia. Under the prevailing consensus of schizophrenia as a disease of neurodevelopmental origin, we have seen the establishment of neurodevelopmental animal models which aim to identify the etiological processes whereby the brain, following specific triggering events, develops into a "schizophrenia-like brain" over time. Many neurodevelopmental models such as the neonatal ventral hippocampus (vHPC) lesion, methylazoxymethanol (MAM), and prenatal immune activation models can mimic a broad spectrum of behavioral, cognitive, and pharmacological abnormalities directly implicated in schizophrenic disease. These models allow pharmacological screens against multiple and coexisting schizophrenia-related dysfunctions while incorporating the disease-relevant concept of abnormal brain development. The multiplicity of existing models is testimonial to the multifactorial nature of schizophrenia, and there are ample opportunities for their integration. Indeed, one ultimate goal must be to incorporate the successes of distinct models into one unitary account of the complex disorder of schizophrenia and to use such unitary approaches in the further development and evaluation of novel antipsychotic treatment strategies.
Collapse
|
19
|
Beaulieu JM, Del'guidice T, Sotnikova TD, Lemasson M, Gainetdinov RR. Beyond cAMP: The Regulation of Akt and GSK3 by Dopamine Receptors. Front Mol Neurosci 2011; 4:38. [PMID: 22065948 PMCID: PMC3206544 DOI: 10.3389/fnmol.2011.00038] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 10/13/2011] [Indexed: 01/11/2023] Open
Abstract
Brain dopamine receptors have been preferred targets for numerous pharmacological compounds developed for the treatment of various neuropsychiatric disorders. Recent discovery that D2 dopamine receptors, in addition to cAMP pathways, can engage also in Akt/GSK3 signaling cascade provided a new framework to understand intracellular signaling mechanisms involved in dopamine-related behaviors and pathologies. Here we review a recent progress in understanding the role of Akt, GSK3, and related signaling molecules in dopamine receptor signaling and functions. Particularly, we focus on the molecular mechanisms involved, interacting partners, role of these signaling events in the action of antipsychotics, psychostimulants, and antidepressants as well as involvement in pathophysiology of schizophrenia, bipolar disorder, and Parkinson’s disease. Further understanding of the role of Akt/GSK3 signaling in dopamine receptor functions could provide novel targets for pharmacological interventions in dopamine-related disorders.
Collapse
Affiliation(s)
- Jean-Martin Beaulieu
- Department of Psychiatry and Neuroscience, Université Laval-CRULRG Québec, QC, Canada
| | | | | | | | | |
Collapse
|
20
|
Jones CA, Watson DJG, Fone KCF. Animal models of schizophrenia. Br J Pharmacol 2011; 164:1162-94. [PMID: 21449915 PMCID: PMC3229756 DOI: 10.1111/j.1476-5381.2011.01386.x] [Citation(s) in RCA: 532] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 03/09/2011] [Accepted: 03/12/2011] [Indexed: 12/27/2022] Open
Abstract
Developing reliable, predictive animal models for complex psychiatric disorders, such as schizophrenia, is essential to increase our understanding of the neurobiological basis of the disorder and for the development of novel drugs with improved therapeutic efficacy. All available animal models of schizophrenia fit into four different induction categories: developmental, drug-induced, lesion or genetic manipulation, and the best characterized examples of each type are reviewed herein. Most rodent models have behavioural phenotype changes that resemble 'positive-like' symptoms of schizophrenia, probably reflecting altered mesolimbic dopamine function, but fewer models also show altered social interaction, and learning and memory impairment, analogous to negative and cognitive symptoms of schizophrenia respectively. The negative and cognitive impairments in schizophrenia are resistant to treatment with current antipsychotics, even after remission of the psychosis, which limits their therapeutic efficacy. The MATRICS initiative developed a consensus on the core cognitive deficits of schizophrenic patients, and recommended a standardized test battery to evaluate them. More recently, work has begun to identify specific rodent behavioural tasks with translational relevance to specific cognitive domains affected in schizophrenia, and where available this review focuses on reporting the effect of current and potential antipsychotics on these tasks. The review also highlights the need to develop more comprehensive animal models that more adequately replicate deficits in negative and cognitive symptoms. Increasing information on the neurochemical and structural CNS changes accompanying each model will also help assess treatments that prevent the development of schizophrenia rather than treating the symptoms, another pivotal change required to enable new more effective therapeutic strategies to be developed.
Collapse
Affiliation(s)
- C A Jones
- School of Biomedical Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, UK
| | | | | |
Collapse
|
21
|
Iritani S, Sekiguchi H, Habuchi C, Hikita T, Taya S, Kaibuchi K, Ozaki N. Immunohistochemical study of vesicle monoamine transporter 2 in the hippocampal region of genetic animal model of schizophrenia. Synapse 2011; 64:948-53. [PMID: 20815037 DOI: 10.1002/syn.20846] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent research in the etiology of schizophrenia revealed that there may be some neurodevelopmental failures such as neuronal network incompetence in the brain of this disease, and neurotransmitters cannot function accurately or adequately. But, it is unknown precisely what kinds of deficit in neurotransmission may be existed histopathologically. We investigated the expression of vesicle monoamine transporter 2 (VMAT2), which has a significant role in neurotransmission, in the hippocampal formation of the animal model of schizophrenia, 14-3-3 epsilon hetero knockout (KO) mouse, using an immunohistochemical staining technique to clarify the neuronal abnormalities in the model animal. As a result, the expression of VMAT2 was increased significantly in the hippocampal formation of 14-3-3 epsilon hetero KO mice compared to that of the wild-type littermates. In conclusion, these findings might be related the pathophysiology of this disease includes a monoaminergic transmission abnormality, based on the investigation in a genetically-modified mouse as schizophrenic model.
Collapse
Affiliation(s)
- Shuji Iritani
- Department of Psychiatry, Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa-ku, Nagoya, Aichi 466-8550, Japan.
| | | | | | | | | | | | | |
Collapse
|
22
|
Schijndel JEV, Martens GJM. Gene expression profiling in rodent models for schizophrenia. Curr Neuropharmacol 2011; 8:382-93. [PMID: 21629445 PMCID: PMC3080594 DOI: 10.2174/157015910793358132] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Revised: 04/15/2010] [Accepted: 04/30/2010] [Indexed: 12/12/2022] Open
Abstract
The complex neurodevelopmental disorder schizophrenia is thought to be induced by an interaction between predisposing genes and environmental stressors. In order to get a better insight into the aetiology of this complex disorder, animal models have been developed. In this review, we summarize mRNA expression profiling studies on neurodevelopmental, pharmacological and genetic animal models for schizophrenia. We discuss parallels and contradictions among these studies, and propose strategies for future research.
Collapse
Affiliation(s)
- Jessica E Van Schijndel
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Centre for Neuroscience & Nijmegen Centre for Molecular Life Sciences (NCMLS), Faculty of Science, Radboud University Nijmegen, 6525 GA, Nijmegen, The Netherlands
| | | |
Collapse
|
23
|
Abstract
The possible role of the CB(2) receptor (CB(2)r) in psychiatric disorders has been considered. Several animal models use knockout (KO) mice that display schizophrenia-like behaviors and this study evaluated the role of CB(2)r in the regulation of such behaviors. Mice lacking the CB(2)r (CB(2)KO) were challenged in open field, light-dark box, elevated plus-maze, tail suspension, step down inhibitory avoidance, and pre-pulse inhibition tests (PPI). Furthermore, the effects of treatment with cocaine and risperidone were evaluated using the OF and the PPI test. Gene expression of dopamine D(2) (D(2)r), adrenergic-α(2C) (α(2C)r), serotonergic 5-HT(2A) and 5-HT(2C) receptors (5-HT(2A)r and 5-HT(2C)r) were studied by RT-PCR in brain regions related to schizophrenia. Deletion of CB(2)r decreased motor activity in the OF test, but enhanced response to acute cocaine and produced mood-related alterations, PPI deficit, and cognitive impairment. Chronic treatment with risperidone tended to impair PPI in WT mice, whereas it 'normalized' the PPI deficit in CB(2)KO mice. CB(2)KO mice presented increased D(2)r and α(2C)r gene expressions in the prefrontal cortex (PFC) and locus coeruleus (LC), decreased 5-HT(2C)r gene expression in the dorsal raphe (DR), and 5-HT(2A)r gene expression in the PFC. Chronic risperidone treatment in WT mice left α(2C)r gene expression unchanged, decreased D(2)r gene expression (15 μg/kg), and decreased 5-HT(2C)r and 5-HT(2A)r in PFC and DR. In CB(2)KO, the gene expression of D(2)r in the PFC, of α(2C)r in the LC, and of 5-HT(2C)r and 5-HT(2A)r in PFC was reduced; 5-HT(2C)r and 5-HT(2A)r gene expressions in DR were increased after treatment with risperidone. These results suggest that deletion of CB(2)r has a relation with schizophrenia-like behaviors. Pharmacological manipulation of CB(2)r may merit further study as a potential therapeutic target for the treatment of schizophrenia-related disorders.
Collapse
|
24
|
Carter CJ. Schizophrenia: a pathogenetic autoimmune disease caused by viruses and pathogens and dependent on genes. J Pathog 2011; 2011:128318. [PMID: 22567321 PMCID: PMC3335463 DOI: 10.4061/2011/128318] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 02/25/2011] [Indexed: 12/20/2022] Open
Abstract
Many genes have been implicated in schizophrenia as have viral prenatal or adult infections and toxoplasmosis or Lyme disease. Several autoantigens also target key pathology-related proteins. These factors are interrelated. Susceptibility genes encode for proteins homologous to those of the pathogens while the autoantigens are homologous to pathogens' proteins, suggesting that the risk-promoting effects of genes and risk factors are conditional upon each other, and dependent upon protein matching between pathogen and susceptibility gene products. Pathogens' proteins may act as dummy ligands, decoy receptors, or via interactome interference. Many such proteins are immunogenic suggesting that antibody mediated knockdown of multiple schizophrenia gene products could contribute to the disease, explaining the immune activation in the brain and lymphocytes in schizophrenia, and the preponderance of immune-related gene variants in the schizophrenia genome. Schizophrenia may thus be a “pathogenetic” autoimmune disorder, caused by pathogens, genes, and the immune system acting together, and perhaps preventable by pathogen elimination, or curable by the removal of culpable antibodies and antigens.
Collapse
Affiliation(s)
- C J Carter
- Polygenic Pathways, 20 Upper Maze Hill, St Leonards-on-Sea, East Sussex, TN38 OLG, UK
| |
Collapse
|
25
|
Nullmeier S, Panther P, Dobrowolny H, Frotscher M, Zhao S, Schwegler H, Wolf R. Region-specific alteration of GABAergic markers in the brain of heterozygous reeler mice. Eur J Neurosci 2011; 33:689-98. [PMID: 21226776 DOI: 10.1111/j.1460-9568.2010.07563.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Heterozygous reeler mice (HRM), haploinsufficient for reelin, have been proposed to be a genetic mouse model of schizophrenia. Beside behavioural similarities, HRM also demonstrate several neuroanatomical traits similar to patients suffering from schizophrenia. In the present study using immunocytochemical procedures, we investigated HRM and wild-type mice (WT) for differences in the numbers and densities of glutamic acid decarboxylase (GAD)67 and parvalbumin (PARV)-immunoreactive (IR) neurons in the hippocampus, tyrosine hydroxylase (TH)-IR neurons in the ventral tegmental area (VTA) and substantia nigra (SN), and serotonin transporter (5-HT-T)-IR neurons of the raphe nuclei. We found that HRM, compared with WT, show a significant decrease of GAD67-IR neurons in hippocampal subregion CA1 [stratum pyramidale (SP)], CA2 [stratum oriens (SO), stratum pyramidale (SP) and stratum radiatum (SR)] and dentate gyrus [granule cell layer (GL)], and also a significant decrease of PARV-containing neurons in CA1 (SO, SP) and CA2 (SP). No morphological differences were found in the SN/VTA or raphe nuclei. In conclusion, these results support a hippocampal γ-aminobutyric acid (GABA)ergic dysfunction in HRM as previously described by other authors, and may be based on a downregulation of GAD67 and PARV expressions. In summary, the reelin haploinsufficient mouse may provide a useful model for studying the interaction between reelin and hippocampal GABAergic system, its effect on dendritic spine maturation and plasticity related to schizophrenia.
Collapse
Affiliation(s)
- S Nullmeier
- Institute of Anatomy, University of Magdeburg, Magdeburg, Germany.
| | | | | | | | | | | | | |
Collapse
|
26
|
Pestka EL, Derscheid DJ, Ellenbecker SM, Schmid PJ, O'Neil ML, Ray-Mihm RJ, Cox DL. Use of genomic assessments and interventions in psychiatric nursing practice. Issues Ment Health Nurs 2010; 31:623-30. [PMID: 20854035 DOI: 10.3109/01612840.2010.493266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The purpose of this study was to determine the impact of a genomic educational session by measuring participants' application of the class content to their nursing care. A sample of 65 psychiatric nurses participated in a staff development activity and completed a survey. Every respondent reported use of a genomic assessment or intervention with a patient from their clinical practice. The mean use of genomic assessment and intervention items was 5.5 out of the possible 10 which were identified and described in the educational session, providing evidence that nurses are able to include genomic assessments and interventions when caring for a patient with a psychiatric disorder.
Collapse
|
27
|
Iritani S, Sekiguchi H, Habuchi C, Torii Y, Yamada S, Waki Y, Noda Y, Furukawa H, Nabeshima T, Ozaki N. Immunohistochemical study of vesicle monoamine transporter 2 in the hippocampal formation of PCP-treated mice. Neurosci Res 2010; 68:125-30. [DOI: 10.1016/j.neures.2010.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 06/08/2010] [Accepted: 06/09/2010] [Indexed: 02/08/2023]
|
28
|
Wilson C, Terry AV. Neurodevelopmental animal models of schizophrenia: role in novel drug discovery and development. ACTA ACUST UNITED AC 2010; 4:124-37. [PMID: 20643635 DOI: 10.3371/csrp.4.2.4] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Schizophrenia is a devastating mental illness that is associated with a lifetime of disability. For patients to successfully function in society, the amelioration of disease symptoms is imperative. The recently published results of two large antipsychotic clinical trials (e.g., CATIE, CUtLASS) clearly exemplified the limitations of currently available treatment options for schizophrenia, and further highlighted the critical need for novel drug discovery and development in this field. One of the biggest challenges in schizophrenia-related drug discovery is to find an appropriate animal model of the illness so that novel hypotheses can be tested at the basic science level. A number of pharmacological, genetic, and neurodevelopmental models have been introduced; however, none of these models has been rigorously evaluated for translational relevance or to satisfy requirements of "face," "construct" and "predictive" validity. Given the apparent polygenic nature of schizophrenia and the limited translational significance of pharmacological models, neurodevelopmental models may offer the best chance of success. The purpose of this review is to provide a general overview of the various neurodevelopmental models of schizophrenia that have been introduced to date, and to summarize their behavioral and neurochemical phenotypes that may be useful from a drug discovery and development standpoint. While it may be that, in the final analysis, no single animal model will satisfy all the requirements necessary for drug discovery purposes, several of the models may be useful for modeling various phenomenological and pathophysiological components of schizophrenia that could be targeted independently with separate molecules or multi-target drugs.
Collapse
Affiliation(s)
- Christina Wilson
- Department of Pharmacology and Toxicology, School of Graduate Studies, Medical College of Georgia, Augusta, GA 30912-2300, USA
| | | |
Collapse
|
29
|
Chaible LM, Corat MA, Abdelhay E, Dagli MLZ. Genetically modified animals for use in research and biotechnology. GENETICS AND MOLECULAR RESEARCH 2010; 9:1469-82. [PMID: 20677136 DOI: 10.4238/vol9-3gmr867] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Transgenic animals are used extensively in the study of in vivo gene function, as models for human diseases and in the production of biopharmaceuticals. The technology behind obtaining these animals involves molecular biology techniques, cell culture and embryo manipulation; the mouse is the species most widely used as an experimental model. In scientific research, diverse models are available as tools for the elucidation of gene function, such as transgenic animals, knockout and conditional knockout animals, knock-in animals, humanized animals, and knockdown animals. We examined the evolution of the science for the development of these animals, as well as the techniques currently used in obtaining these animal models. We review the phenotypic techniques used for elucidation of alterations caused by genetic modification. We also investigated the role of genetically modified animals in the biotechnology industry, where they promise a revolution in obtaining heterologous proteins through natural secretions, such as milk, increasing the scale of production and facilitating purification, thereby lowering the cost of production of hormones, growth factors and enzymes.
Collapse
Affiliation(s)
- L M Chaible
- Laboratório de Oncologia Experimental, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, SP, Brasil
| | | | | | | |
Collapse
|
30
|
Karam CS, Ballon JS, Bivens NM, Freyberg Z, Girgis RR, Lizardi-Ortiz JE, Markx S, Lieberman JA, Javitch JA. Signaling pathways in schizophrenia: emerging targets and therapeutic strategies. Trends Pharmacol Sci 2010; 31:381-90. [PMID: 20579747 DOI: 10.1016/j.tips.2010.05.004] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 05/17/2010] [Accepted: 05/20/2010] [Indexed: 02/07/2023]
Abstract
Dopamine D(2) receptor antagonism is a unifying property of all antipsychotic drugs in use for schizophrenia. While often effective at ameliorating psychosis, these drugs are largely ineffective at treating negative and cognitive symptoms. Increasing attention is being focused on the complex genetics of the illness and the signaling pathways implicated in its pathophysiology. We review targeted approaches for pharmacotherapy involving the glutamatergic, GABAergic and cholinergic pathways. We also describe several of the major genetic findings that identify signaling pathways representing potential targets for novel pharmacological intervention. These include genes in the 22q11 locus, DISC1, Neuregulin 1/ErbB4, and components of the Akt/GSK-3 pathway.
Collapse
Affiliation(s)
- Caline S Karam
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
O'Tuathaigh CMP, Kirby BP, Moran PM, Waddington JL. Mutant mouse models: genotype-phenotype relationships to negative symptoms in schizophrenia. Schizophr Bull 2010; 36:271-88. [PMID: 19934211 PMCID: PMC2833123 DOI: 10.1093/schbul/sbp125] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Negative symptoms encompass diminution in emotional expression and motivation, some of which relate to human attributes that may not be accessible readily in animals. Additionally, their refractoriness to treatment precludes therapeutic validation of putative models. This review considers critically the application of mutant mouse models to the study of the pathobiology of negative symptoms. It focuses on 4 main approaches: genes related to the pathobiology of schizophrenia, genes associated with risk for schizophrenia, neurodevelopmental-synaptic genes, and variant approaches from other areas of neurobiology. Despite rapid advances over the past several years, it is clear that we continue to face substantive challenges in applying mutant models to better understand the pathobiology of negative symptoms: the majority of evidence relates to impairments in social behavior, with only limited data relating to anhedonia and negligible data concerning avolition and other features; even for the most widely examined feature, social behavior, studies have used diverse assessments thereof; modelling must proceed in cognizance of increasing evidence that genes and pathobiologies implicated in schizophrenia overlap with other psychotic disorders, particularly bipolar disorder. Despite the caveats and challenges, several mutant lines evidence a phenotype for at least one index of social behavior. Though this may suggest superficially some shared relationship to negative symptoms, it is not yet possible to specify either the scope or the pathobiology of that relationship for any given gene. The breadth and depth of ongoing studies in mutants hold the prospect of addressing these shortcomings.
Collapse
Affiliation(s)
- Colm M. P. O'Tuathaigh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin 2, Ireland,To whom correspondence should be addressed; tel: +353-1-402-2377, fax: +353-1-402-2453, e-mail:
| | - Brian P. Kirby
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Paula M. Moran
- School of Psychology, University of Nottingham, Nottingham, UK
| | - John L. Waddington
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin 2, Ireland
| |
Collapse
|
32
|
van den Buuse M. Modeling the positive symptoms of schizophrenia in genetically modified mice: pharmacology and methodology aspects. Schizophr Bull 2010; 36:246-70. [PMID: 19900963 PMCID: PMC2833124 DOI: 10.1093/schbul/sbp132] [Citation(s) in RCA: 278] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In recent years, there have been huge advances in the use of genetically modified mice to study pathophysiological mechanisms involved in schizophrenia. This has allowed rapid progress in our understanding of the role of several proposed gene mechanisms in schizophrenia, and yet this research has also revealed how much still remains unresolved. Behavioral studies in genetically modified mice are reviewed with special emphasis on modeling psychotic-like behavior. I will particularly focus on observations on locomotor hyperactivity and disruptions of prepulse inhibition (PPI). Recommendations are included to address pharmacological and methodological aspects in future studies. Mouse models of dopaminergic and glutamatergic dysfunction are then discussed, reflecting the most important and widely studied neurotransmitter systems in schizophrenia. Subsequently, psychosis-like behavior in mice with modifications in the most widely studied schizophrenia susceptibility genes is reviewed. Taken together, the available studies reveal a wealth of available data which have already provided crucial new insight and mechanistic clues which could lead to new treatments or even prevention strategies for schizophrenia.
Collapse
Affiliation(s)
- Maarten van den Buuse
- Mental Health Research Institute of Victoria, Parkville, Melbourne, Victoria 3052, Australia.
| |
Collapse
|
33
|
O'Tuathaigh CMP, Harte M, O'Leary C, O'Sullivan GJ, Blau C, Lai D, Harvey RP, Tighe O, Fagan AJ, Kerskens C, Reynolds GP, Waddington JL. Schizophrenia-related endophenotypes in heterozygous neuregulin-1 'knockout' mice. Eur J Neurosci 2010; 31:349-58. [PMID: 20074216 DOI: 10.1111/j.1460-9568.2009.07069.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neuregulin-1 (NRG1) has been shown to play a role in glutamatergic neurotransmission and is a risk gene for schizophrenia, in which there is evidence for hypoglutamatergic function. Sensitivity to the behavioural effects of the psychotomimetic N-methyl-D-aspartate receptor antagonists MK-801 and phencyclidine (PCP) was examined in mutant mice with heterozygous deletion of NRG1. Social behaviour (sociability, social novelty preference and dyadic interaction), together with exploratory activity, was assessed following acute or subchronic administration of MK-801 (0.1 and 0.2 mg/kg) or PCP (5 mg/kg). In untreated NRG1 mutants, levels of glutamate, N-acetylaspartate and GABA were determined using high-performance liquid chromatography and regional brain volumes were assessed using magnetic resonance imaging at 7T. NRG1 mutants, particularly males, displayed decreased responsivity to the locomotor-activating effects of acute PCP. Subchronic MK-801 and PCP disrupted sociability and social novelty preference in mutants and wildtypes and reversed the increase in both exploratory activity and social dominance-related behaviours observed in vehicle-treated mutants. No phenotypic differences were demonstrated in N-acetylaspartate, glutamate or GABA levels. The total ventricular and olfactory bulb volume was decreased in mutants. These data indicate a subtle role for NRG1 in modulating several schizophrenia-relevant processes including the effects of psychotomimetic N-methyl-D-aspartate receptor antagonists.
Collapse
Affiliation(s)
- C M P O'Tuathaigh
- Molecular & Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Kirby BP, Waddington JL, O'Tuathaigh CMP. Advancing a functional genomics for schizophrenia: psychopathological and cognitive phenotypes in mutants with gene disruption. Brain Res Bull 2009; 83:162-76. [PMID: 19800398 DOI: 10.1016/j.brainresbull.2009.09.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2009] [Revised: 08/18/2009] [Accepted: 09/21/2009] [Indexed: 12/19/2022]
Abstract
Schizophrenia is a complex, heritable psychotic disorder in which numerous genes and environmental adversities appear to interact in determining disease phenotype. In addition to genes regulating putative pathophysiological mechanisms, a new generation of molecular studies has indicated numerous candidate genes to be associated with risk for schizophrenia. The present review focuses on studies in mice mutant for genes associated with putative pathophysiological mechanisms and candidate risk genes for the disorder. It seeks to evaluate the extent to which each mutation of a schizophrenia-related gene accurately models multiple aspects of the schizophrenia phenotype or more circumscribed, distinct endophenotypes in terms of psychopathology and pathobiology; in doing so, it places particular emphasis on positive symptoms, negative symptoms and cognitive dysfunction. To further this goal, it juxtaposes continually evolving mutant genomics with emergent clinical genomic studies. Opportunities and challenges associated with the use of such mutants, including diagnostic specificity and the translational barrier associated with modelling schizophrenia, are discussed. The potential value of genetic models for exploring gene-gene and gene-environment interactions relating to schizophrenia is highlighted. Elucidation of the contribution of genetic variation to specific symptom clusters and underlying aspects of pathobiology will have important implications for identifying treatments that target distinct domains of psychopathology and dysfunction on an individual patient basis.
Collapse
Affiliation(s)
- Brian P Kirby
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | | | | |
Collapse
|
35
|
Oliver PL, Davies KE. Interaction between environmental and genetic factors modulates schizophrenic endophenotypes in the Snap-25 mouse mutant blind-drunk. Hum Mol Genet 2009; 18:4576-89. [PMID: 19729413 PMCID: PMC2773274 DOI: 10.1093/hmg/ddp425] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
To understand the pathophysiology of neuropsychiatric disorders such as schizophrenia requires consideration of multiple genetic and non-genetic factors. However, very little is known about the consequences of combining models of synaptic dysfunction with controlled environmental manipulations. Therefore, to generate new insights into gene–environment interactions and complex behaviour, we examined the influence of variable prenatal stress (PNS) on two mouse lines with mutations in synaptosomal-associated protein of 25 kDa (Snap-25): the blind-drunk (Bdr) point mutant and heterozygous Snap-25 knockout mice. Neonatal development was analysed in addition to an assessment of adult behavioural phenotypes relevant to the psychotic, cognitive and negative aspects of schizophrenia. These data show that PNS influenced specific anxiety-related behaviour in all animals. In addition, sensorimotor gating deficits previously noted in Bdr mutants were markedly enhanced by PNS; significantly, these effects could be reversed with the application of anti-psychotic drugs. Moreover, social interaction abnormalities were observed only in Bdr animals from stressed dams but not in wild-type littermates or mutants from non-stressed mothers. These results show for the first time that combining a synaptic mouse point mutant with a controlled prenatal stressor paradigm produces both modified and previously unseen phenotypes, generating new insights into the interactions between genetics and the environment relevant to the study of psychiatric disease.
Collapse
Affiliation(s)
- Peter L Oliver
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK.
| | | |
Collapse
|
36
|
Schwarzer C. 30 years of dynorphins--new insights on their functions in neuropsychiatric diseases. Pharmacol Ther 2009; 123:353-70. [PMID: 19481570 DOI: 10.1016/j.pharmthera.2009.05.006] [Citation(s) in RCA: 200] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Accepted: 05/13/2009] [Indexed: 11/28/2022]
Abstract
Since the first description of their opioid properties three decades ago, dynorphins have increasingly been thought to play a regulatory role in numerous functional pathways of the brain. Dynorphins are members of the opioid peptide family and preferentially bind to kappa opioid receptors. In line with their localization in the hippocampus, amygdala, hypothalamus, striatum and spinal cord, their functions are related to learning and memory, emotional control, stress response and pain. Pathophysiological mechanisms that may involve dynorphins/kappa opioid receptors include epilepsy, addiction, depression and schizophrenia. Most of these functions were proposed in the 1980s and 1990s following histochemical, pharmacological and electrophysiological experiments using kappa receptor-specific or general opioid receptor agonists and antagonists in animal models. However, at that time, we had little information on the functional relevance of endogenous dynorphins. This was mainly due to the complexity of the opioid system. Besides actions of peptides from all three classical opioid precursors (proenkephalin, prodynorphin, proopiomelanocortin) on the three classical opioid receptors (delta, mu and kappa), dynorphins were also shown to exert non-opioid effects mainly through direct effects on NMDA receptors. Moreover, discrepancies between the distribution of opioid receptor binding sites and dynorphin immunoreactivity contributed to the difficulties in interpretation. In recent years, the generation of prodynorphin- and opioid receptor-deficient mice has provided the tools to investigate open questions on network effects of endogenous dynorphins. This article examines the physiological, pathophysiological and pharmacological implications of dynorphins in the light of new insights in part obtained from genetically modified animals.
Collapse
Affiliation(s)
- Christoph Schwarzer
- Department of Pharmacology, Innsbruck Medical University, Peter-Mayr-Str. 1a, A-6020 Innsbruck, Austria.
| |
Collapse
|
37
|
Considerations and recent advances in neuroscience. Biochem Soc Trans 2009; 37:299-302. [PMID: 19143651 DOI: 10.1042/bst0370299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Neuroscience is a rapidly developing area of science which has benefitted from the blurring of interdisciplinary boundaries. This was apparent in the range of papers presented at this year's Neuroscience Ireland Conference, held in Galway during August 2008. The event was attended by academics, postdoctoral and postgraduate researchers, scientists from industry and clinicians. The themes of this year's conference, neurodegeneration, neuroregeneration, pain, glial cell biology and psychopharmacology, were chosen for their reflection of areas of strength in neuroscience within Ireland. In addition to basic science, translational research also featured strongly.
Collapse
|