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Fertan E, Wong AA, Montbrun TSGD, Purdon MK, Roddick KM, Yamamoto T, Brown RE. Early postnatal development of the MDGA2 +/- mouse model of synaptic dysfunction. Behav Brain Res 2023; 452:114590. [PMID: 37499910 DOI: 10.1016/j.bbr.2023.114590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/13/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
Synaptic dysfunction underlies many neurodevelopmental disorders (NDDs). The membrane-associated mucin domain-containing glycosylphosphatidylinositol anchor proteins (MDGAs) regulate synaptic development by modulating neurexin-neuroligin complex formation. Since understanding the neurodevelopmental profile and the sex-based differences in the manifestation of the symptoms of NDDs is important for their early diagnosis, we tested a mouse model haploinsufficient for MDGA2 (MDGA2+/-) on a neurodevelopmental test battery, containing sensory, motor, and cognitive measures, as well as ultrasonic vocalizations. When male and female MDGA2+/- and wildtype (WT) C57BL/6 J mice were examined from 2 to 23 days of age using this test battery, genotype and sex differences in body weight, sensory-motor processes, and ultrasonic vocalizations were observed. The auditory startle reflex appeared earlier in the MDGA2+/- than in WT mice and the MDGA2+/- mice produced fewer ultrasonic vocalizations. The MDGA2+/- mice showed reduced locomotion and rearing than WT mice in the open field after 17 days of age and spent less time investigating a novel object than WT mice at 21 days of age. Female MDGA2+/- mice weighed less than WT females and showed lower grip strength, indicating a delay in sensory-motor development in MDGA2+/- mice, which appears to be more pronounced in females than males. The behavioural phenotypes resulting from MDGA2 haploinsufficiency suggests that it shows delayed development of motor behaviour, grip strength and exploratory behaviour, non-social phenotypes of NDDs.
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Affiliation(s)
- Emre Fertan
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Aimée A Wong
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | | | - Michaela K Purdon
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Kyle M Roddick
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Tohru Yamamoto
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kagawa 761-0793, Japan
| | - Richard E Brown
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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2
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Dougnon G, Matsui H. Modelling Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) Using Mice and Zebrafish. Int J Mol Sci 2022; 23:ijms23147550. [PMID: 35886894 PMCID: PMC9319972 DOI: 10.3390/ijms23147550] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 02/06/2023] Open
Abstract
Autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD) are two debilitating neurodevelopmental disorders. The former is associated with social impairments whereas the latter is associated with inattentiveness, hyperactivity, and impulsivity. There is recent evidence that both disorders are somehow related and that genes may play a large role in these disorders. Despite mounting human and animal research, the neurological pathways underlying ASD and ADHD are still not well understood. Scientists investigate neurodevelopmental disorders by using animal models that have high similarities in genetics and behaviours with humans. Mice have been utilized in neuroscience research as an excellent animal model for a long time; however, the zebrafish has attracted much attention recently, with an increasingly large number of studies using this model. In this review, we first discuss ASD and ADHD aetiology from a general point of view to their characteristics and treatments. We also compare mice and zebrafish for their similarities and discuss their advantages and limitations in neuroscience. Finally, we summarize the most recent and existing research on zebrafish and mouse models of ASD and ADHD. We believe that this review will serve as a unique document providing interesting information to date about these models, thus facilitating research on ASD and ADHD.
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Van Der Heijden ME, Gill JS, Rey Hipolito AG, Salazar Leon LE, Sillitoe RV. Quantification of Behavioral Deficits in Developing Mice With Dystonic Behaviors. DYSTONIA 2022; 1:10494. [PMID: 36960404 PMCID: PMC10032351 DOI: 10.3389/dyst.2022.10494] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Converging evidence from structural imaging studies in patients, the function of dystonia-causing genes, and the comorbidity of neuronal and behavioral defects all suggest that pediatric-onset dystonia is a neurodevelopmental disorder. However, to fully appreciate the contribution of altered development to dystonia, a mechanistic understanding of how networks become dysfunctional is required for early-onset dystonia. One current hurdle is that many dystonia animal models are ideally suited for studying adult phenotypes, as the neurodevelopmental features can be subtle or are complicated by broad developmental deficits. Furthermore, most assays that are used to measure dystonia are not suited for developing postnatal mice. Here, we characterize the early-onset dystonia in Ptf1a Cre ;Vglut2 fl/fl mice, which is caused by the absence of neurotransmission from inferior olive neurons onto cerebellar Purkinje cells. We investigate motor control with two paradigms that examine how altered neural function impacts key neurodevelopmental milestones seen in postnatal pups (postnatal day 7-11). We find that Ptf1a Cre ;Vglut2 fl/fl mice have poor performance on the negative geotaxis assay and the surface righting reflex. Interestingly, we also find that Ptf1a Cre ;Vglut2 fl/fl mice make fewer ultrasonic calls when socially isolated from their nests. Ultrasonic calls are often impaired in rodent models of autism spectrum disorders, a condition that can be comorbid with dystonia. Together, we show that these assays can serve as useful quantitative tools for investigating how neural dysfunction during development influences neonatal behaviors in a dystonia mouse model. Our data implicate a shared cerebellar circuit mechanism underlying dystonia-related motor signs and social impairments in mice.
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Affiliation(s)
- Meike E. Van Der Heijden
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, United States
| | - Jason S. Gill
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, United States
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Alejandro G. Rey Hipolito
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Luis E. Salazar Leon
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Roy V. Sillitoe
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, United States
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
- Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, United States
- Correspondence: Roy V. Sillitoe,
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Regan SL, Williams MT, Vorhees CV. Review of rodent models of attention deficit hyperactivity disorder. Neurosci Biobehav Rev 2022; 132:621-637. [PMID: 34848247 PMCID: PMC8816876 DOI: 10.1016/j.neubiorev.2021.11.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023]
Abstract
Attention deficit hyperactivity disorder (ADHD) is a polygenic neurodevelopmental disorder that affects 8-12 % of children and >4 % of adults. Environmental factors are believed to interact with genetic predispositions to increase susceptibility to ADHD. No existing rodent model captures all aspects of ADHD, but several show promise. The main genetic models are the spontaneous hypertensive rat, dopamine transporter knock-out (KO) mice, dopamine receptor subtype KO mice, Snap-25 KO mice, guanylyl cyclase-c KO mice, and latrophilin-3 KO mice and rats. Environmental factors thought to contribute to ADHD include ethanol, nicotine, PCBs, lead (Pb), ionizing irradiation, 6-hydroxydopamine, neonatal hypoxia, some pesticides, and organic pollutants. Model validation criteria are outlined, and current genetic models evaluated against these criteria. Future research should explore induced multiple gene KOs given that ADHD is polygenic and epigenetic contributions. Furthermore, genetic models should be combined with environmental agents to test for interactions.
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Affiliation(s)
- Samantha L. Regan
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45229
| | - Michael T. Williams
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Charles V. Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine, and Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229,Corresponding author: Charles V. Vorhees, Ph.D., Div. of Neurology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, USA:
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5
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Armstrong EC, Caruso A, Servadio M, Andreae LC, Trezza V, Scattoni ML, Fernandes C. Assessing the developmental trajectory of mouse models of neurodevelopmental disorders: Social and communication deficits in mice with Neurexin 1α deletion. GENES BRAIN AND BEHAVIOR 2020; 19:e12630. [DOI: 10.1111/gbb.12630] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/06/2019] [Accepted: 12/07/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Emily C. Armstrong
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & NeuroscienceKing's College London London UK
- MRC Centre for Neurodevelopmental DisordersKing's College London London UK
| | - Angela Caruso
- Research Coordination and Support ServiceIstituto Superiore di Sanità Rome Italy
| | - Michela Servadio
- Department of ScienceSection of Biomedical Sciences and Technologies, University “Roma Tre” Rome Italy
| | - Laura C. Andreae
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & NeuroscienceKing's College London London UK
- MRC Centre for Neurodevelopmental DisordersKing's College London London UK
| | - Viviana Trezza
- Department of ScienceSection of Biomedical Sciences and Technologies, University “Roma Tre” Rome Italy
| | - Maria L. Scattoni
- Research Coordination and Support ServiceIstituto Superiore di Sanità Rome Italy
| | - Cathy Fernandes
- MRC Centre for Neurodevelopmental DisordersKing's College London London UK
- Social, Genetic & Developmental Psychiatry Centre, PO82, Institute of Psychiatry, Psychology & NeuroscienceKing's College London London UK
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6
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Ramos-Miguel A, Gicas K, Alamri J, Beasley CL, Dwork AJ, Mann JJ, Rosoklija G, Cai F, Song W, Barr AM, Honer WG. Reduced SNAP25 Protein Fragmentation Contributes to SNARE Complex Dysregulation in Schizophrenia Postmortem Brain. Neuroscience 2018; 420:112-128. [PMID: 30579835 DOI: 10.1016/j.neuroscience.2018.12.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 12/10/2018] [Accepted: 12/12/2018] [Indexed: 12/15/2022]
Abstract
Recent studies associated schizophrenia with enhanced functionality of the presynaptic SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex. Altered degradation pathways of the three core SNARE proteins: synaptosomal-associated protein 25 (SNAP25), syntaxin-1 and vesicle-associated membrane protein (VAMP) could contribute to enhanced complex function. To investigate these pathways, we first identified a 15-kDa SNAP25 fragment (f-S25) in human and rat brains, highly enriched in synaptosomal extractions, and mainly attached to cytosolic membranes with low hydrophobicity. The presence of f-S25 is consistent with reports of calpain-mediated SNAP25 cleavage. Co-immunoprecipitation assays showed that f-S25 retains the ability to bind syntaxin-1, which might prevent VAMP and/or Munc18-1 assembly into the complex. Quantitative analyses in postmortem human orbitofrontal cortex (OFC) revealed that schizophrenia (n = 35), but not major depression (n = 15), is associated with lower amounts of f-S25 (-37%, P = 0.027), and greater SNARE protein-protein interactions (35%, P < 0.001), compared with healthy matched controls (n = 28). Enhanced SNARE complex formation was strongly correlated with lower SNAP25 fragmentation rates (R = 0.563, P < 0.001). Statistical mediation analyses supported the hypothesis that reduced f-S25 density could upregulate SNARE fusion events in schizophrenia. Cortical calpain activity in schizophrenia did not differ from controls. f-S25 levels did not correlate with total calpain activity, indicating that if present, schizophrenia-related calpain dysfunction might occur locally at the presynaptic terminals. Overall, the present findings suggest the existence of an endogenous SNARE complex inhibitor related to SNAP25 proteolysis, associated with enhanced SNARE activity in schizophrenia.
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Affiliation(s)
- Alfredo Ramos-Miguel
- BC Mental Health and Addictions Research Institute, 938 West 28th Ave, Vancouver, BC V5Z 4H4, Canada; Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 2A1, Canada; Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Biscay, Spain
| | - Kristina Gicas
- BC Mental Health and Addictions Research Institute, 938 West 28th Ave, Vancouver, BC V5Z 4H4, Canada; Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 2A1, Canada
| | - Jehan Alamri
- BC Mental Health and Addictions Research Institute, 938 West 28th Ave, Vancouver, BC V5Z 4H4, Canada; Department of Anesthesiology, Pharmacology, & Therapeutics, University of British Columbia, 2176 Health Sciences Mall Vancouver, BC V6T 1Z3, Canada
| | - Clare L Beasley
- BC Mental Health and Addictions Research Institute, 938 West 28th Ave, Vancouver, BC V5Z 4H4, Canada; Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 2A1, Canada
| | - Andrew J Dwork
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, New York, NY 10032, USA
| | - J John Mann
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, New York, NY 10032, USA
| | - Gorazd Rosoklija
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, New York, NY 10032, USA
| | - Fang Cai
- Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 2A1, Canada
| | - Weihong Song
- Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 2A1, Canada
| | - Alasdair M Barr
- BC Mental Health and Addictions Research Institute, 938 West 28th Ave, Vancouver, BC V5Z 4H4, Canada; Department of Anesthesiology, Pharmacology, & Therapeutics, University of British Columbia, 2176 Health Sciences Mall Vancouver, BC V6T 1Z3, Canada
| | - William G Honer
- BC Mental Health and Addictions Research Institute, 938 West 28th Ave, Vancouver, BC V5Z 4H4, Canada; Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 2A1, Canada.
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7
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Luo J, Norris RH, Gordon SL, Nithianantharajah J. Neurodevelopmental synaptopathies: Insights from behaviour in rodent models of synapse gene mutations. Prog Neuropsychopharmacol Biol Psychiatry 2018; 84:424-439. [PMID: 29217145 DOI: 10.1016/j.pnpbp.2017.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 11/28/2017] [Accepted: 12/03/2017] [Indexed: 11/15/2022]
Abstract
The genomic revolution has begun to unveil the enormous complexity and heterogeneity of the genetic basis of neurodevelopmental disorders such as such epilepsy, intellectual disability, autism spectrum disorder and schizophrenia. Increasingly, human mutations in synapse genes are being identified across these disorders. These neurodevelopmental synaptopathies highlight synaptic homeostasis pathways as a convergence point underlying disease mechanisms. Here, we review some of the key pre- and postsynaptic genes in which penetrant human mutations have been identified in neurodevelopmental disorders for which genetic rodent models have been generated. Specifically, we focus on the main behavioural phenotypes that have been documented in these animal models, to consolidate our current understanding of how synapse genes regulate key behavioural and cognitive domains. These studies provide insights into better understanding the basis of the overlapping genetic and cognitive heterogeneity observed in neurodevelopmental disorders.
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Affiliation(s)
- J Luo
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - R H Norris
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - S L Gordon
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - J Nithianantharajah
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia.
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8
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Dark C, Homman-Ludiye J, Bryson-Richardson RJ. The role of ADHD associated genes in neurodevelopment. Dev Biol 2018; 438:69-83. [DOI: 10.1016/j.ydbio.2018.03.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/04/2018] [Accepted: 03/27/2018] [Indexed: 12/19/2022]
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9
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Bruchhage MMK, Bucci MP, Becker EBE. Cerebellar involvement in autism and ADHD. HANDBOOK OF CLINICAL NEUROLOGY 2018; 155:61-72. [PMID: 29891077 DOI: 10.1016/b978-0-444-64189-2.00004-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The cerebellum has long been known for its importance in motor learning and coordination. However, increasing evidence supports a role for the cerebellum in cognition and emotion. Consistent with a role in cognitive functions, the cerebellum has emerged as one of the key brain regions affected in nonmotor disorders, including autism spectrum disorder and attention deficit-hyperactivity disorder. Here, we discuss behavioral, postmortem, genetic, and neuroimaging studies in humans in order to understand the cerebellar contributions to the pathogenesis of both disorders. We also review relevant animal model findings.
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Affiliation(s)
- Muriel M K Bruchhage
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Maria-Pia Bucci
- Child and Adolescent Psychiatry Department, Robert Debré Hospital, Paris, France
| | - Esther B E Becker
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
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Klein M, Onnink M, van Donkelaar M, Wolfers T, Harich B, Shi Y, Dammers J, Arias-Vásquez A, Hoogman M, Franke B. Brain imaging genetics in ADHD and beyond - Mapping pathways from gene to disorder at different levels of complexity. Neurosci Biobehav Rev 2017; 80:115-155. [PMID: 28159610 PMCID: PMC6947924 DOI: 10.1016/j.neubiorev.2017.01.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 12/08/2016] [Accepted: 01/09/2017] [Indexed: 01/03/2023]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common and often persistent neurodevelopmental disorder. Beyond gene-finding, neurobiological parameters, such as brain structure, connectivity, and function, have been used to link genetic variation to ADHD symptomatology. We performed a systematic review of brain imaging genetics studies involving 62 ADHD candidate genes in childhood and adult ADHD cohorts. Fifty-one eligible research articles described studies of 13 ADHD candidate genes. Almost exclusively, single genetic variants were studied, mostly focussing on dopamine-related genes. While promising results have been reported, imaging genetics studies are thus far hampered by methodological differences in study design and analysis methodology, as well as limited sample sizes. Beyond reviewing imaging genetics studies, we also discuss the need for complementary approaches at multiple levels of biological complexity and emphasize the importance of combining and integrating findings across levels for a better understanding of biological pathways from gene to disease. These may include multi-modal imaging genetics studies, bioinformatic analyses, and functional analyses of cell and animal models.
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Affiliation(s)
- Marieke Klein
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Marten Onnink
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Marjolein van Donkelaar
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Thomas Wolfers
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Benjamin Harich
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Yan Shi
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Janneke Dammers
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Psychiatry, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Alejandro Arias-Vásquez
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Psychiatry, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Cognitive Neuroscience, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Martine Hoogman
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Barbara Franke
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Psychiatry, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
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11
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Kim E, Song DH, Kim NW, Sohn IJ, Cheon KA. The Relationship between the SNAP-25 Polymorphism and Omission Errors in Korean Children with Attention Deficit Hyperactivity Disorder. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2017; 15:222-228. [PMID: 28783930 PMCID: PMC5565073 DOI: 10.9758/cpn.2017.15.3.222] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/07/2016] [Accepted: 11/09/2016] [Indexed: 01/13/2023]
Abstract
Objective This study aimed to investigate the association between the synaptosomal-associated protein 25 kDa (SNAP-25) genotype and performance on the continuous performance test (CPT) in Korean children with attention-deficit/hyperactivity disorder (ADHD). Methods Eighty-seven children with ADHD (mean age, 9.23±1.99 years) participated in this study. Omission errors, commission errors, reaction time, and reaction time variability on the CPT were analyzed. The single-nucleotide polymorphism (SNP) rs3746544 (1065 T>G) of SNAP-25 was genotyped to examine the association with CPT performance. Results We found significantly more omission errors on the CPT among children with the TT genotype of SNAP-25 (t=2.56, p=0.012) after correcting for multiple testing. Conclusion Our results suggest the possible involvement of the SNAP-25 1065 T>G polymorphism in the inattention phenotype in children with ADHD. Further studies with more refined neuropsychological measures and much larger sample sizes are needed to confirm our findings.
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Affiliation(s)
- Eunjoo Kim
- Department of Psychiatry and Institute of Behavioral Science in Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Dong-Ho Song
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Nam-Wook Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - In-Jung Sohn
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Keun-Ah Cheon
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, Korea
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12
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de la Peña JB, Dela Peña IJ, Custodio RJ, Botanas CJ, Kim HJ, Cheong JH. Exploring the Validity of Proposed Transgenic Animal Models of Attention-Deficit Hyperactivity Disorder (ADHD). Mol Neurobiol 2017; 55:3739-3754. [PMID: 28534274 DOI: 10.1007/s12035-017-0608-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 05/09/2017] [Indexed: 12/31/2022]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common, behavioral, and heterogeneous neurodevelopmental condition characterized by hyperactivity, impulsivity, and inattention. Symptoms of this disorder are managed by treatment with methylphenidate, amphetamine, and/or atomoxetine. The cause of ADHD is unknown, but substantial evidence indicates that this disorder has a significant genetic component. Transgenic animals have become an essential tool in uncovering the genetic factors underlying ADHD. Although they cannot accurately reflect the human condition, they can provide insights into the disorder that cannot be obtained from human studies due to various limitations. An ideal animal model of ADHD must have face (similarity in symptoms), predictive (similarity in response to treatment or medications), and construct (similarity in etiology or underlying pathophysiological mechanism) validity. As the exact etiology of ADHD remains unclear, the construct validity of animal models of ADHD would always be limited. The proposed transgenic animal models of ADHD have substantially increased and diversified over the years. In this paper, we compiled and explored the validity of proposed transgenic animal models of ADHD. Each of the reviewed transgenic animal models has strengths and limitations. Some fulfill most of the validity criteria of an animal model of ADHD and have been extensively used, while there are others that require further validation. Nevertheless, these transgenic animal models of ADHD have provided and will continue to provide valuable insights into the genetic underpinnings of this complex disorder.
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Affiliation(s)
- June Bryan de la Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Irene Joy Dela Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Raly James Custodio
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Chrislean Jun Botanas
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Hee Jin Kim
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Jae Hoon Cheong
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea.
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Cupertino RB, Schuch JB, Bandeira CE, da Silva BS, Rovaris DL, Kappel DB, Contini V, Salatino-Oliveira A, Vitola ES, Karam RG, Hutz MH, Rohde LA, Grevet EH, Bau CHD, Mota NR. Replicated association of Synaptotagmin (SYT1) with ADHD and its broader influence in externalizing behaviors. Eur Neuropsychopharmacol 2017; 27:239-247. [PMID: 28130000 DOI: 10.1016/j.euroneuro.2017.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/30/2016] [Accepted: 01/05/2017] [Indexed: 12/20/2022]
Abstract
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common psychiatric disorder, affecting both children and adults. The Soluble N-ethylmaleimide sensitive factor Attachment REceptors (SNARE) complex has been implicated in ADHD pathophysiology since it is a key component of neurotransmitter release events and neurodevelopment processes, and SNPs in this complex have been associated with ADHD. Here we aim to analyze the effects of SNARE complex variants on ADHD susceptibility and its clinical heterogeneity in affected adults. We tested the association between ADHD and polymorphisms on the SNARE genes STX1A (rs2228607), SYT1 (rs1880867 and rs2251214), VAMP2 (26bp Ins/Del) and SNAP25 (rs6108461 and rs8636) on a sample comprised of 548 adults with ADHD and 644 non-affected controls. Regarding clinical heterogeneity, we further investigated the effects of associated SNPs on age at onset of impairment due to ADHD and on relevant externalizing behaviors (i.e. school suspensions/expulsions and problems with law/authority) and comorbidities (i.e. Substance Use Disorder, Oppositional Defiant Disorder, Conduct Disorder and Antisocial Personality Disorder). We replicated a previously reported association between SYT1-rs2251214 and ADHD in adulthood. This SNP was also associated with age at onset of impairment due to ADHD symptoms and with a range of externalizing phenotypes. These findings involving SYT1 suggest that variation in neurotransmitter exocytosis mechanisms may represent an underlying genetic factor shared by a spectrum of externalizing behaviors and disorders, including - but not restricted to - ADHD.
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Affiliation(s)
- Renata Basso Cupertino
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Jaqueline Bohrer Schuch
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Cibele Edom Bandeira
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Bruna Santos da Silva
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Diego Luiz Rovaris
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Djenifer B Kappel
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Verônica Contini
- PPGBIOTEC - Postgraduate Program in Biotechnology, Centro Universitário Univates, Lajeado, Brazil
| | - Angélica Salatino-Oliveira
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Eduardo Schneider Vitola
- Department of Psychiatry, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Rafael Gomes Karam
- ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Mara Helena Hutz
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Luis Augusto Rohde
- Department of Psychiatry, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; National Institute of Developmental Psychiatry for Children and Adolescents, Brazil
| | - Eugenio Horacio Grevet
- Department of Psychiatry, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Claiton Henrique Dotto Bau
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
| | - Nina Roth Mota
- Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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14
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Halm ST, Bottomley MA, Almutairi MM, Di Fulvio M, Halm DR. Survival and growth of C57BL/6J mice lacking the BK channel, Kcnma1: lower adult body weight occurs together with higher body fat. Physiol Rep 2017; 5:5/4/e13137. [PMID: 28242822 PMCID: PMC5328773 DOI: 10.14814/phy2.13137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/23/2016] [Accepted: 01/02/2017] [Indexed: 11/29/2022] Open
Abstract
Big conductance potassium (BK) channels contribute to K+ flow and electrical behavior in many cell types. Mice made null for the gene (Kcnma1) producing the BK channel (BKKO) exhibit numerous deficits in physiological functions. Breeding mice lacking a single allele of Kcnma1 (C57BL/6J background) had litter sizes of approximately eight pups. For the period of maternal care (P0–P21), pup deaths peaked at P1 with a second less severe interval of death peaking near P13. Early deaths were twice as likely during a 20‐month period of building construction compared with the quiescent period after cessation of construction. Births during construction were not consistent with Mendelian predictions indicating the likelihood of a specific disadvantage induced by this environmental stressor. Later BKKO pup deaths (~P13) also were more numerous than Mendelian expectations. After weaning, weight gain was slower for BKKO mice compared with wild‐type littermates: 5 g less for male BKKO mice and 4 g less for female BKKO mice. Body composition determined by quantitative magnetic resonance indicated a higher fat proportion for wild‐type female mice compared with males, as well as a higher hydration ratio. Both male and female BKKO mice showed higher fat proportions than wild‐type, with female BKKO mice exhibiting greater variation. Together, these results indicate that BKKO mice suffered disadvantages that lead to prenatal and perinatal death. A metabolic difference likely related to glucose handling led to the smaller body size and distinct composition for BKKO mice, suggesting a diversion of energy supplies from growth to fat storage.
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Affiliation(s)
- Susan T Halm
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Michael A Bottomley
- Department of Mathematics and Statistics, Statistical Consulting Center, Wright State University, Dayton, Ohio
| | - Mohammed M Almutairi
- Department of Pharmacology and Toxicology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Maurico Di Fulvio
- Department of Pharmacology and Toxicology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Dan R Halm
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
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15
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Whittaker DE, Riegman KL, Kasah S, Mohan C, Yu T, Sala BP, Hebaishi H, Caruso A, Marques AC, Michetti C, Smachetti MES, Shah A, Sabbioni M, Kulhanci O, Tee WW, Reinberg D, Scattoni ML, Volk H, McGonnell I, Wardle FC, Fernandes C, Basson MA. The chromatin remodeling factor CHD7 controls cerebellar development by regulating reelin expression. J Clin Invest 2017; 127:874-887. [PMID: 28165338 PMCID: PMC5330721 DOI: 10.1172/jci83408] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/12/2016] [Indexed: 12/21/2022] Open
Abstract
The mechanisms underlying the neurodevelopmental deficits associated with CHARGE syndrome, which include cerebellar hypoplasia, developmental delay, coordination problems, and autistic features, have not been identified. CHARGE syndrome has been associated with mutations in the gene encoding the ATP-dependent chromatin remodeler CHD7. CHD7 is expressed in neural stem and progenitor cells, but its role in neurogenesis during brain development remains unknown. Here we have shown that deletion of Chd7 from cerebellar granule cell progenitors (GCps) results in reduced GCp proliferation, cerebellar hypoplasia, developmental delay, and motor deficits in mice. Genome-wide expression profiling revealed downregulated expression of the gene encoding the glycoprotein reelin (Reln) in Chd7-deficient GCps. Recessive RELN mutations have been associated with severe cerebellar hypoplasia in humans. We found molecular and genetic evidence that reductions in Reln expression contribute to GCp proliferative defects and cerebellar hypoplasia in GCp-specific Chd7 mouse mutants. Finally, we showed that CHD7 is necessary for maintaining an open, accessible chromatin state at the Reln locus. Taken together, this study shows that Reln gene expression is regulated by chromatin remodeling, identifies CHD7 as a previously unrecognized upstream regulator of Reln, and provides direct in vivo evidence that a mammalian CHD protein can control brain development by modulating chromatin accessibility in neuronal progenitors.
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Affiliation(s)
- Danielle E. Whittaker
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
- Department of Comparative Biomedical Sciences, Royal Veterinary College, and
| | - Kimberley L.H. Riegman
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Sahrunizam Kasah
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Conor Mohan
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Tian Yu
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Blanca Pijuan Sala
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Husam Hebaishi
- King’s College London, Randall Division, New Hunt’s House, London, United Kingdom
| | - Angela Caruso
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
- School of Behavioural Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Ana Claudia Marques
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Caterina Michetti
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
- Department of Physiology and Pharmacology “V. Erspamer,” Sapienza University of Rome, Rome, Italy
| | | | - Apar Shah
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Mara Sabbioni
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
| | - Omer Kulhanci
- MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Wee-Wei Tee
- Howard Hughes Medical Institute, Department of Molecular Pharmacology and Biochemistry, New York University School of Medicine, New York, New York, USA
| | - Danny Reinberg
- Howard Hughes Medical Institute, Department of Molecular Pharmacology and Biochemistry, New York University School of Medicine, New York, New York, USA
| | - Maria Luisa Scattoni
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
| | - Holger Volk
- Department of Comparative Biomedical Sciences, Royal Veterinary College, and
| | - Imelda McGonnell
- Department of Comparative Biomedical Sciences, Royal Veterinary College, and
| | - Fiona C. Wardle
- King’s College London, Randall Division, New Hunt’s House, London, United Kingdom
| | - Cathy Fernandes
- MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
- King’s College London, MRC Centre for Neurodevelopmental Disorders, New Hunt’s House, London, United Kingdom
| | - M. Albert Basson
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
- King’s College London, MRC Centre for Neurodevelopmental Disorders, New Hunt’s House, London, United Kingdom
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16
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Cupertino RB, Kappel DB, Bandeira CE, Schuch JB, da Silva BS, Müller D, Bau CHD, Mota NR. SNARE complex in developmental psychiatry: neurotransmitter exocytosis and beyond. J Neural Transm (Vienna) 2016; 123:867-83. [DOI: 10.1007/s00702-016-1514-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/20/2016] [Indexed: 12/31/2022]
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Sarkar K, Bhaduri N, Ghosh P, Sinha S, Ray A, Chatterjee A, Mukhopadhyay K. Role of SNAP25 explored in eastern Indian attention deficit hyperactivity disorder probands. Neurochem Res 2011; 37:349-57. [PMID: 21996783 DOI: 10.1007/s11064-011-0618-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 09/12/2011] [Accepted: 09/22/2011] [Indexed: 12/01/2022]
Abstract
Synaptosomal-associated protein 25 (SNAP25) is an essential component for synaptic vesicle mediated release of neurotransmitters. Deficiencies or abnormal structure or function of SNAP25 protein, possibly arising through genetic variations in the relevant DNA code, has been suggested to play role in the pathology of several neurobehavioural disorders including Attention deficit Hyperactivity Disorder (ADHD) and a number of polymorphisms in the SNAP25 gene has been studied for association with the disorder. In the present investigation, for the first time association between ADHD and six SNAP25 polymorphisms, rs1889189, rs362569, rs362988, rs3746544, rs1051312, and rs8636 was explored in eastern Indian population. Subjects were recruited following the Diagnostic and Statistical Manual for Mental Disorders-IV. Genomic DNA isolated from peripheral blood leukocytes of ADHD probands (n = 150), their parents (n = 272) and ethnically matched controls (n = 100) was used for amplifying target sites. Data obtained were subjected to population- as well as family-based analyses. While case-control analysis revealed lack of any significant difference for alleles, family-based studies revealed a mild over transmission rs3746544 'T' and rs8636 'C' alleles (P = 0.05 and 0.03 respectively). Haplotypes formed between rs362569 "T", 362988 "G", rs3746544 "T", rs1051312 "T" and rs8636 "C" in different combinations showed statistically significant transmission to ADHD probands. Excepting rs3746544 and rs8636, all the tested sites showed very low linkage disequilibrium between them. Data obtained in this preliminary study indicates that rs3746544 'T' allele may have some role in the disease etiology in the studied Indian population.
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Affiliation(s)
- Kanyakumarika Sarkar
- Manovikas Biomedical Research and Diagnostic Centre, 482, Madudah, Plot I-24, Sec.-J, E.M. Bypass, Kolkata, 700107, India
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18
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Gunn RK, Keenan ME, Brown RE. Analysis of sensory, motor and cognitive functions of the coloboma (C3Sn.Cg-Cm/J) mutant mouse. GENES BRAIN AND BEHAVIOR 2011; 10:579-88. [PMID: 21507201 DOI: 10.1111/j.1601-183x.2011.00697.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The coloboma mutant mouse (C3Sn.Cg-Cm/J) has been proposed as an animal model of attention-deficit hyperactivity disorder (ADHD) because of excessive locomotion in the open field, yet few studies have looked at other behavioral measures in these mice. We analyzed activity levels of male and female Cm mice and their littermate controls (C3H) in two different types of open field, as well as their hearing (acoustic startle) and sensorimotor gating (prepulse inhibition), pain responsiveness (tail flick and hot plate), motor control (balance beam), motor learning (Rotarod), hippocampal working memory (spontaneous alternation in a Y-maze) and olfactory learning and memory (conditioned odor preference). We found hyperactivity and a lack of habituation in the small and large open fields and a deficit in prepulse inhibition in these mice, as well as a learning deficit in male Cm mice in conditioned odor preference but no deficits in pain perception or spontaneous alternation. Results from the rotarod and balance beam tasks indicate that Cm mice have severe motor co-ordination and balance problems compared to their C3H littermates, suggesting that Cm mice may be a more suitable model of ataxia than ADHD.
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Affiliation(s)
- R K Gunn
- Department of Psychology, Dalhousie University, 1459 Oxford Street, Halifax, Nova Scotia, Canada
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19
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Purper-Ouakil D, Ramoz N, Lepagnol-Bestel AM, Gorwood P, Simonneau M. Neurobiology of attention deficit/hyperactivity disorder. Pediatr Res 2011; 69:69R-76R. [PMID: 21289544 DOI: 10.1203/pdr.0b013e318212b40f] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Attention deficit/hyperactivity disorder (ADHD), a prevalent neurodevelopmental disorder, has been associated with various structural and functional CNS abnormalities but findings about neurobiological mechanisms linking genes to brain phenotypes are just beginning to emerge. Despite the high heritability of the disorder and its main symptom dimensions, common individual genetic variants are likely to account for a small proportion of the phenotype's variance. Recent findings have drawn attention to the involvement of rare genetic variants in the pathophysiology of ADHD, some being shared with other neurodevelopmental disorders. Traditionally, neurobiological research on ADHD has focused on catecholaminergic pathways, the main target of pharmacological treatments. However, more distal and basic neuronal processes in relation with cell architecture and function might also play a role, possibly accounting for the coexistence of both diffuse and specific alterations of brain structure and activation patterns. This article aims to provide an overview of recent findings in the rapidly evolving field of ADHD neurobiology with a focus on novel strategies regarding pathophysiological analyses.
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20
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Robertson HR, Feng G. Annual Research Review: Transgenic mouse models of childhood-onset psychiatric disorders. J Child Psychol Psychiatry 2011; 52:442-75. [PMID: 21309772 PMCID: PMC3075087 DOI: 10.1111/j.1469-7610.2011.02380.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Childhood-onset psychiatric disorders, such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), mood disorders, obsessive compulsive spectrum disorders (OCSD), and schizophrenia (SZ), affect many school-age children, leading to a lower quality of life, including difficulties in school and personal relationships that persist into adulthood. Currently, the causes of these psychiatric disorders are poorly understood, resulting in difficulty diagnosing affected children, and insufficient treatment options. Family and twin studies implicate a genetic contribution for ADHD, ASD, mood disorders, OCSD, and SZ. Identification of candidate genes and chromosomal regions associated with a particular disorder provide targets for directed research, and understanding how these genes influence the disease state will provide valuable insights for improving the diagnosis and treatment of children with psychiatric disorders. Transgenic mouse models are one important approach in the study of human diseases, allowing for the use of a variety of experimental approaches to dissect the contribution of a specific chromosomal or genetic abnormality in human disorders. While it is impossible to model an entire psychiatric disorder in a single mouse model, these models can be extremely valuable in dissecting out the specific role of a gene, pathway, neuron subtype, or brain region in a particular abnormal behavior. In this review we discuss existing transgenic mouse models for childhood-onset psychiatric disorders. We compare the strength and weakness of various transgenic mouse models proposed for each of the common childhood-onset psychiatric disorders, and discuss future directions for the study of these disorders using cutting-edge genetic tools.
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Affiliation(s)
- Holly R. Robertson
- Duke University, Neurobiology Department Durham, N.C.,Massachusetts Institute of Technology, Brain and Cognitive Sciences Department Cambridge, M.A
| | - Guoping Feng
- Duke University, Neurobiology Department Durham, N.C.,Massachusetts Institute of Technology, Brain and Cognitive Sciences Department Cambridge, M.A
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21
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Purper-Ouakil D, Lepagnol-Bestel AM, Grosbellet E, Gorwood P, Simonneau M. [Neurobiology of attention deficit/hyperactivity disorder]. Med Sci (Paris) 2010; 26:487-96. [PMID: 20510147 DOI: 10.1051/medsci/2010265487] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Attention deficit/hyperactivity disorder (ADHD) is a frequent and disabling condition in school children, with cognitive and behavioral symptoms persisting into adulthood in a majority of patients. Etiology of ADHD is considered multifactorial and heterogenous, with an important contribution of genetic factors. Apart from genetic risk factors, emphasis has been put on the early environment, and prenatal exposure to nicotine, alcohol, prematurity and low birth weight have been associated with subsequent ADHD symptoms. This article reviews recent findings in neurobiology, genetics and neuroimaging of ADHD. Despite their clinical heterogeneity and frequent comorbidities, key symptoms of ADHD, such as impulsivity, hyperactivity and inattention are regularly improved by dopaminergic agonists, leading to consider dopaminergic dysfunction a possibly contributing factor in ADHD. Norepinephrine agonists also have clinical efficacy on ADHD symptoms and several other neurotransmission systems are likely involved in the etiology of ADHD. Dysfunction of neurotransmitter systems have been related to impairments of sustained attention, inhibitory control and working memory. Cognitive tasks focusing on reaction time and verbal working memory fit certain criteria for ADHD endophenotypes, offering a pathway to bridge the gap between observed traits and genetic vulnerability. Despite ADHD being a highly heritable disorder, most candidate genes with replicated findings across association studies only account for a small proportion of genetic variance. Neuroimaging studies using treatment effect or cognitive tasks show differential activation patterns in ADHD patients, with trends towards normalization under treatment. Further insight into neurobiological mechanisms involved in ADHD will arise from collaborative networks and combination of imaging, genetic and neurobiological techniques with consideration of the developmental aspects of ADHD.
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Affiliation(s)
- Diane Purper-Ouakil
- Inserm U894, Centre de psychiatrie et neurosciences, Equipe 1, Analyse génétique et clinique des comportements addictifs et psychiatriques, 2 ter, rue d'Alesia, Paris, France.
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22
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Barakauskas VE, Beasley CL, Barr AM, Ypsilanti AR, Li HY, Thornton AE, Wong H, Rosokilja G, Mann JJ, Mancevski B, Jakovski Z, Davceva N, Ilievski B, Dwork AJ, Falkai P, Honer WG. A novel mechanism and treatment target for presynaptic abnormalities in specific striatal regions in schizophrenia. Neuropsychopharmacology 2010; 35:1226-38. [PMID: 20072114 PMCID: PMC3055413 DOI: 10.1038/npp.2009.228] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/06/2009] [Accepted: 11/20/2009] [Indexed: 02/01/2023]
Abstract
Abnormalities of amount and function of presynaptic terminals may have an important role in the mechanism of illness in schizophrenia. The SNARE proteins (SNAP-25, syntaxin, and VAMP) are enriched in presynaptic terminals, where they interact to form a functional complex to facilitate vesicle fusion. SNARE protein amounts are altered in the cortical regions in schizophrenia, but studies of protein-protein interactions are limited. We extended these investigations to the striatal regions (such as the nucleus accumbens, ventromedial caudate (VMC), and dorsal caudate) relevant to disease symptoms. In addition to measuring SNARE protein levels, we studied SNARE protein-protein interactions using a novel ELISA method. The possible effect of antipsychotic treatment was investigated in parallel in the striatum of rodents that were administered haloperidol and clozapine. In schizophrenia samples, compared with controls, SNAP-25 was 32% lower (P=0.015) and syntaxin was 26% lower (P=0.006) in the VMC. In contrast, in the same region, SNARE protein-protein interactions were higher in schizophrenia (P=0.008). Confocal microscopy of schizophrenia and control VMC showed qualitatively similar SNARE protein immunostaining. Haloperidol treatment of rats increased levels of SNAP-25 (mean 24%, P=0.003), syntaxin (mean 18%, P=0.010), and VAMP (mean 16%, P=0.001), whereas clozapine increased only the VAMP level (mean 13%, P=0.004). Neither drug altered SNARE protein-protein interactions. These results indicate abnormalities of amount and interactions of proteins directly related to presynaptic function in the VMC in schizophrenia. SNARE proteins and their interactions may be a novel target for the development of therapeutics.
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Affiliation(s)
- Vilte E Barakauskas
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Clare L Beasley
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Alasdair M Barr
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Athena R Ypsilanti
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Hong-Ying Li
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Allen E Thornton
- Department of Psychology, Simon Fraser University, Burnaby, BC, Canada
| | - Hubert Wong
- Department of Health Care and Epidemiology, University of British Columbia, Vancouver, BC, Canada
| | - Gorazd Rosokilja
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Surgeons of Columbia University, New York, NY, USA
- Macedonian Academy of Sciences and Arts, University ‘SS. Cyril and Methodius' Skopje, Macedonia
| | - J John Mann
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Surgeons of Columbia University, New York, NY, USA
| | - Branislav Mancevski
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Surgeons of Columbia University, New York, NY, USA
| | - Zlatko Jakovski
- Institute for Forensic Medicine, University ‘SS. Cyril and Methodius,' Skopje, Macedonia
| | - Natasha Davceva
- Institute for Forensic Medicine, University ‘SS. Cyril and Methodius,' Skopje, Macedonia
| | - Boro Ilievski
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Institute for Pathology, University ‘SS. Cyril and Methodius,', Skopje, Macedonia
| | - Andrew J Dwork
- Department of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Surgeons of Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, College of Physicians, Surgeons of Columbia University, New York, NY, USA
| | - Peter Falkai
- Department of Psychiatry, Göttingen University, Göttingen, Germany
| | - William G Honer
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
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23
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Sontag TA, Tucha O, Walitza S, Lange KW. Animal models of attention deficit/hyperactivity disorder (ADHD): a critical review. ACTA ACUST UNITED AC 2010; 2:1-20. [DOI: 10.1007/s12402-010-0019-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 01/02/2010] [Indexed: 01/04/2023]
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Corradini I, Verderio C, Sala M, Wilson MC, Matteoli M. SNAP-25 in neuropsychiatric disorders. Ann N Y Acad Sci 2009; 1152:93-9. [PMID: 19161380 DOI: 10.1111/j.1749-6632.2008.03995.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
SNAP-25 (synaptosomal-associated protein of 25 kDa) is a plasma membrane protein that, together with syntaxin and the synaptic vesicle protein VAMP/synaptobrevin, forms the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) docking complex for regulated exocytosis. SNAP-25 also modulates different voltage-gated calcium channels, representing therefore a multifunctional protein that plays essential roles in neurotransmitter release at different steps. Recent genetic studies of human populations and of some mouse models implicate alterations in SNAP-25 gene structure, expression, and/or function in contributing directly to these distinct neuropsychiatric and neurological disorders.
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Affiliation(s)
- Irene Corradini
- Department of Medical Pharmacology, University of Milan, Milano, Italy
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Abstract
The search for genes influencing the development of attention-deficit/hyperactivity disorder (ADHD) has identified a number of associated genes within, or influencing, the dopamine neurotransmitter system. The focus on this system as the site of genetic susceptibility was prompted by information from animal models, particularly transgenics, as well as the mechanism of action of the psychostimulants, the primary pharmacological treatment for ADHD. Thus far, genes in the dopamine system reported as associated with ADHD, by at least one study, include the dopamine transporter, the dopamine receptors D1, D4 and D5, as well as genes encoding proteins that control the synthesis, degradation and release of dopamine. For some of these genes, replication across studies provides evidence supporting the relationship; however, for others, the data is far from conclusive and further work is needed. The quick progress in the genetic findings was initially surprising given the complexity of the phenotype and the relatively small sample sizes used in the initial studies. However, the high heritability of ADHD, as indicated by twin studies, may have contributed to the success. The genes studied so far are estimated to contribute only weakly or moderately to the risk for the development of ADHD. This may be because these genes, in fact, make only a small contribution. However, few studies have comprehensively examined the genetic information across the gene. This will lead to underestimates of risk if the polymorphism(s) tested is/are not the functional change(s) actually contributing to the genetic susceptibility and if linkage disequilibrium between tested marker(s) and causal variant(s) is weak, or if there is substantial allelic heterogeneity. While the studies thus far are very promising, virtually nothing is known on precisely how genetic variation in these genes actually contributes to risk; thus, functional studies are now required.
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Affiliation(s)
- Cathy L Barr
- Room MP14-302, Genetics & Development Division, The Toronto Western Hospital, 399 Bathurst St, Toronto, ON, Canada M5T 2S8
| | - Virginia L Misener
- Genetics and Development Division, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
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Associations of SNAP-25 polymorphisms with cognitive dysfunctions in Caucasian patients with schizophrenia during a brief trail of treatment with atypical antipsychotics. Eur Arch Psychiatry Clin Neurosci 2008; 258:335-44. [PMID: 18347838 DOI: 10.1007/s00406-007-0800-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Accepted: 12/04/2007] [Indexed: 10/22/2022]
Abstract
The synaptosomal-associated protein of 25 kDa (SNAP-25) is part of the soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment receptor (SNARE), which mediates synaptic neurotransmission. In earlier studies a possible involvement of this protein in schizophrenia has been shown. As neurocognitive impairment is a core feature in the pathology of schizophrenia and considered to be a putative endophenotype according to genetic studies we investigated the influences of different SNAP-25 polymorphisms on neuropsychological test results before and during treatment with atypical antipsychotics. A total of 104 schizophrenic patients treated with atypical antipsychotics were genotyped for three different polymorphisms of the SNAP-25 gene (MnlI, TaiI and DdeI in the 3'-UTR). Cognitive function was assessed at baseline, week 4 or 6 and week 8 or 12. Results of individual neuropsychological tests were assigned to six cognitive domains (reaction time and quality; executive function; working, verbal and visual memory) and a general cognitive index. The MnlI and TaiI polymorphisms showed no associations to deficits on neuropsychological test results. In contrast, we observed a significant relation between the DdeI polymorphism of the SNAP-25 gene and cognitive dysfunctions. Homozygote T/T allele carriers of the DdeI polymorphism showed significant better neuropsychological test results in cognitive domains verbal memory and executive functions than those with the combined T/C and C/C genotypes (P < 0.01) at all three time points, but no differences in response to treatment with atypical antipsychotics. Additionally, TT carriers exhibited significantly better results in a general cognitive index (P < 0.05). As we observed an association between the DdeI polymorphism of the SNAP-25 gene and cognitive dysfunctions of schizophrenic patients our finding suggests that the SNAP-25 gene could play a role in the pathophysiology of neurocognitive dysfunctions in schizophrenia but is not predictive for treatment response with atypical antipsychotics.
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van der Kooij MA, Glennon JC. Animal models concerning the role of dopamine in attention-deficit hyperactivity disorder. Neurosci Biobehav Rev 2007; 31:597-618. [PMID: 17316796 DOI: 10.1016/j.neubiorev.2006.12.002] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 10/22/2006] [Accepted: 12/30/2006] [Indexed: 11/29/2022]
Abstract
Several models of attention-deficit hyperactivity disorder (ADHD) have been proposed, ranging from administration of neurotoxins to genetically manipulated models. These models are used to gain insight into ADHD as a disorder and assist in the discovery of new therapeutic strategies. However, the information gained from these models differs, depending to a large extent on the validity (or otherwise) of the model. Thus the insights gained from these models with respect to the pathophysiology and aetiology of ADHD remains inconclusive. No animal model resembles the clinical situation of ADHD perfectly but good animal models of ADHD should mimic its characteristics, confirm to an underlying theory of ADHD and ultimately make predictions of future therapies. While the involvement of dopamine (DA) in ADHD has been established, the evaluation of rodent models of ADHD particularly with respect to dopaminergic systems is attempted here. It is concluded that the neonatal 6-hydroxy-dopamine lesioned rat and DA transporter knockout/knockdown mice have the highest degree of validity for ADHD.
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Affiliation(s)
- Michael A van der Kooij
- Laboratory for Psychoneuroimmunology & Department of Neonatology, University Medical Center Utrecht, Lundlaan 6, 3584EA Utrecht, The Netherlands.
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Fan X, Hess EJ. D2-like dopamine receptors mediate the response to amphetamine in a mouse model of ADHD. Neurobiol Dis 2006; 26:201-11. [PMID: 17291774 PMCID: PMC1876677 DOI: 10.1016/j.nbd.2006.12.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 12/05/2006] [Accepted: 12/20/2006] [Indexed: 11/16/2022] Open
Abstract
The mechanisms underlying the effects of psychostimulants in attention deficit hyperactivity disorder (ADHD) are not well understood, but indirect evidence implicates D2 dopamine receptors. Here we dissect the components of dopaminergic neurotransmission in the hyperactive mouse mutant coloboma to identify pre- and postsynaptic elements essential for the effects of amphetamine in these mice. Amphetamine treatment reduced locomotor activity in coloboma mice, but induced a robust increase in dopamine overflow suggesting that abnormal regulation of dopamine efflux does not account for the behavioral effect. However, the D2-like dopamine receptor antagonists haloperidol and raclopride, but not the D1-like dopamine receptor antagonist SCH23390, blocked the amphetamine-induced reduction in locomotor activity in coloboma mice, providing direct evidence that D2-like dopamine receptors mediate the effect of amphetamine in these mice. With the precedent established that it is possible to directly antagonize this response, this strategy should prove useful for identifying novel therapeutics in ADHD.
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Affiliation(s)
- Xueliang Fan
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287
| | - Ellen J. Hess
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287
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29
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Gosso MF, de Geus EJC, van Belzen MJ, Polderman TJC, Heutink P, Boomsma DI, Posthuma D. The SNAP-25 gene is associated with cognitive ability: evidence from a family-based study in two independent Dutch cohorts. Mol Psychiatry 2006; 11:878-86. [PMID: 16801949 DOI: 10.1038/sj.mp.4001868] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The synaptosomal-associated protein of 25 kDa (SNAP-25) gene plays an integral role in synaptic transmission, and is differentially expressed in the mammalian brain in the neocortex, hippocampus, anterior thalamic nuclei, substantia nigra and cerebellar granular cells. Recent studies have suggested a possible involvement of SNAP-25 in learning and memory, both of which are key components of human intelligence. In addition, the SNAP-25 gene lies in a linkage area implicated previously in human intelligence. In two independent family-based Dutch samples of 391 (mean age 12.4 years) and 276 (mean age 37.3 years) subjects, respectively, we genotyped 12 single-nucleotide polymorphisms (SNPs) in the SNAP-25 gene on 20p12-20p11.2. From all individuals, standardized intelligence measures were available. Using a family-based association test, a strong association was found between three SNPs in the SNAP-25 gene and intelligence, two of which showed association in both independent samples. The strongest, replicated association was found between SNP rs363050 and performance IQ (PIQ), where the A allele was associated with an increase of 2.84 PIQ points (P=0.0002). Variance in this SNP accounts for 3.4% of the phenotypic variance in PIQ.
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Affiliation(s)
- M F Gosso
- Department of Biological Psychology, Vrije Universiteit, Amsterdam, The Netherlands.
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Bruno KJ, Hess EJ. The alpha(2C)-adrenergic receptor mediates hyperactivity of coloboma mice, a model of attention deficit hyperactivity disorder. Neurobiol Dis 2006; 23:679-88. [PMID: 16839770 DOI: 10.1016/j.nbd.2006.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 05/19/2006] [Accepted: 05/26/2006] [Indexed: 10/24/2022] Open
Abstract
Drugs that modify noradrenergic transmission such as atomoxetine and clonidine are increasingly prescribed for the treatment of attention deficit hyperactivity disorder (ADHD). However, the therapeutic targets of these compounds are unknown. Norepinephrine is also implicated in the hyperactivity exhibited by coloboma mice. To identify the receptor subtypes that regulate the hyperactivity, coloboma mice were systematically challenged with adrenergic drugs. The beta-adrenergic receptor antagonist propranolol and the alpha(1)-adrenergic receptor antagonist prazosin each had little effect on the hyperactivity. Conversely, the alpha(2)-adrenergic receptor antagonist yohimbine reduced the activity of coloboma mice but not control mice. Subtype-selective blockade of alpha(2C)-, but not alpha(2A)- or alpha(2B)-adrenergic receptors, ameliorated hyperactivity of coloboma mice without affecting activity of control mice, suggesting that alpha(2C)-adrenergic receptors mediate the hyperactivity. Localized in the basal ganglia, alpha(2C)-adrenergic receptors are in a prime position to impact locomotor activity and are, therefore, potential targets of pharmacotherapy for ADHD.
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Affiliation(s)
- Kristy J Bruno
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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31
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Abstract
The study of human behavioural and psychiatric disorders benefits from the development of genetic models in mice and other organisms. Mouse mutants allow one to investigate the molecular basis of disease progression and to develop novel therapies. The number of potential mouse models is increasing dramatically through the implementation of mutagenesis screens for aberrant behavioural phenotypes. The alkylating agent N-ethyl-N-nitrosourea ENU is the mutagen of choice in these screens as it induces mutations at a very high rate. Progeny of chemically-mutagenised animals are screened either in systematic high-throughput test batteries or in specific low-throughput tests. Both approaches have been highly successful with large numbers of novel loci being identified and characterised. Many mutant lines are available for general research with phenotypes and genetic map positions on public websites. Of the mutant genes characterised, the majority have contributed to our knowledge of gene function in physiology and disease. The 'mutagenesis screening' approach continues to evolve through the design of new phenotyping strategies. The development of modifier screens in mice shows promise in the elucidation of complex phenotypes whereas the use of mutagenesis in combination with pharmacological agents targets specific neurochemical systems. Finally, the systematic screening approach has demonstrated that mutations are likely to affect more than one biological process.
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Affiliation(s)
- Sofia I H Godinho
- MRC Mammalian Genetics Unit, Harwell, Didcot, Oxfordshire OX11 0RD, UK
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32
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Abstract
Molecular genetic studies of personality began with two high impact papers in 1996 that showed provisional associations between the dopamine DRD4 exon III repeat region and Novelty Seeking/Extraversion. These first two reports were shortly followed by an investigation linking Neuroticism/Harm Avoidance with the serotonin transporter (SLC6A4) promoter region polymorphism (5-HTTLPR). In the ensuing decade, thousands of subjects have been studied for association between these genes and personality, assessed by using self-report questionnaires, with erratic success in replication of the first findings for Novelty Seeking (DRD4) and Harm Avoidance (5-HTTLPR). Small effect sizes characteristic of non-Mendelian traits, polygenic patterns of inheritance and true heterogeneity between studies confound attempts to reach a consensus regarding the role of common polymorphisms in contributing to personality domains. Nevertheless, the current state of personality genetics is far from being bleak. Several new paradigms especially functional neuroimaging or 'imaging genomics' have strengthened the connection between 5-HTTLPR and anxiety-related personality traits. The demonstrations that early environmental information can considerably strengthen and even uncover associations between genes and behavior (Caspi's seminal studies and more recently the demonstration that early environment impacts on DRD4 and Novelty Seeking) are notable and herald a new era of personality genetics. Finally, consideration of the broader phenotypic expression of common polymorphisms (e.g. the 'social brain', altruism, etc.) and the use of new experimental paradigms including neurophysiological, neuropsychological and computer games that go beyond the narrow self-report questionnaire design will enable a deeper understanding of how common genetic polymorphisms modulate human behavior. Human personality, defined by Webster as the quality or state of being a person or the complex of characteristics that distinguishes an individual, surely requires a more encompassing view towards understanding its complex molecular genetic architecture.
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Affiliation(s)
- R P Ebstein
- Department of Psychology and Scheinfeld Center for Genetic Studies in the Social Sciences, Mount Scopus, Hebrew University, Jerusalem, Israel.
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Feng Y, Crosbie J, Wigg K, Pathare T, Ickowicz A, Schachar R, Tannock R, Roberts W, Malone M, Swanson J, Kennedy JL, Barr CL. The SNAP25 gene as a susceptibility gene contributing to attention-deficit hyperactivity disorder. Mol Psychiatry 2005; 10:998-1005, 973. [PMID: 16088329 DOI: 10.1038/sj.mp.4001722] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The synaptosomal-associated protein of 25 kDa gene (SNAP25) has been suggested as a genetic susceptibility factor in attention-deficit hyperactivity disorder (ADHD) based on the mouse strain coloboma. This strain is hemizygous for the SNAP25 gene and displays hyperactivity that responds to dextroamphetamine, but not to methylphenidate. Previously, we reported association of SNAP25 and ADHD using two polymorphisms. To further investigate this gene, we screened the exons for DNA variation and genotyped ten additional polymorphisms in an expanded sample of families from Toronto and a second sample of families collected in Irvine, CA. Significant results were observed in the Toronto sample for four markers, although not in the Irvine sample. The paper discusses the possible influence of the selection criteria on these differential results. The Irvine sample selected subjects that met the DSM-IV combined subtype diagnosis, whereas the Toronto sample included all subtypes. Analysis of the DSM-IV subtypes in the Toronto sample indicated that the differential results were not attributable to ADHD subtype. Differences in ethnicity, differential medication response, and other clinical characteristics of the samples cannot be ruled out at this time. Quantitative analysis of the dimensions of hyperactivity/impulsivity and inattention in the Toronto sample found that both behavioral traits were associated with SNAP25. Our findings continue to support SNAP25 in the susceptibility to ADHD.
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Affiliation(s)
- Y Feng
- Department of Psychiatry, Cellular and Molecular Division, The Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
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Sagvolden T, Russell VA, Aase H, Johansen EB, Farshbaf M. Rodent models of attention-deficit/hyperactivity disorder. Biol Psychiatry 2005; 57:1239-47. [PMID: 15949994 DOI: 10.1016/j.biopsych.2005.02.002] [Citation(s) in RCA: 329] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Revised: 12/15/2004] [Accepted: 02/01/2005] [Indexed: 10/25/2022]
Abstract
An ideal animal model should be similar to the disorder it models in terms of etiology, biochemistry, symptomatology, and treatment. Animal models provide several advantages over clinical research: simpler nervous systems, easily interpreted behaviors, genetic homogeneity, easily controlled environment, and a greater variety of interventions. Attention-deficit/hyperactivity disorder (ADHD) is a neurobehavioral disorder of childhood onset that is characterized by inattentiveness, hyperactivity, and impulsiveness. Its diagnosis is behaviorally based; therefore, the validation of an ADHD model must be based in behavior. An ADHD model must mimic the fundamental behavioral characteristics of ADHD (face validity), conform to a theoretical rationale for ADHD (construct validity), and predict aspects of ADHD behavior, genetics, and neurobiology previously uncharted in clinical settings (predictive validity). Spontaneously hypertensive rats (SHR) fulfill many of the validation criteria and compare well with clinical cases of ADHD. Poor performers in the five-choice serial reaction time task and Naples high-excitability rats (NHE) are useful models for attention-deficit disorder. Other animal models either focus on the less important symptom of hyperactivity and might be of limited value in ADHD research or are produced in ways that would not lead to a clinical diagnosis of ADHD in humans, even if ADHD-like behavior is displayed.
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Affiliation(s)
- Terje Sagvolden
- Center for Advanced Study at the Norwegian Academy of Science and Letters, Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
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Müller DJ, Klempan TA, De Luca V, Sicard T, Volavka J, Czobor P, Sheitman BB, Lindenmayer JP, Citrome L, McEvoy JP, Lieberman JA, Honer WG, Kennedy JL. The SNAP-25 gene may be associated with clinical response and weight gain in antipsychotic treatment of schizophrenia. Neurosci Lett 2005; 379:81-9. [PMID: 15823421 DOI: 10.1016/j.neulet.2004.12.037] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Revised: 12/13/2004] [Accepted: 12/16/2004] [Indexed: 10/25/2022]
Abstract
The synaptosomal-associated protein of 25 kDa (SNAP-25) is an essential component of the core complex that mediates presynaptic vesicle trafficking. Thus, SNAP-25 is directly involved in the release of neurotransmitters. Quantitative alterations of SNAP-25 expression have been reported in brain regions and cerebrospinal fluid (CSF) of schizophrenics and in haloperidol treated rats. This observed altered expression may be influenced by genetic variants of SNAP-25. We hypothesized that polymorphisms of the SNAP-25 gene (sites DdeI, MnlI and TaiI in the 3'UTR) are associated with antipsychotic drug response and induced weight gain. A sample of 59 patients with prior suboptimal response to antipsychotic treatment and diagnosed with DSM-IV schizophrenia or schizoaffective disorder was examined. Patients were administered clozapine, haloperidol, olanzapine or risperidone for up to 14 weeks. Clinical response was defined as the difference between the baseline and the endpoint total scores on the Positive and Negative Syndrome Scale (PANSS). Weight was assessed at baseline and at study endpoint. ANOVA revealed that the MnlI and TaiI polymorphisms were associated with response (F[2,53] = 4.57, p = 0.01 and F[2,52] = 3.53, p = 0.03) and with weight gain (F[2,52] = 4.28, p = 0.01 and F[2,51] = 3.38, p = 0.04). When covariates were included, the MnlI polymorphism remained significantly associated with changes of PANSS scores, but not with weight gain. The DdeI polymorphism was not associated with response or weight gain. These findings suggest that SNAP-25 gene variants affect clinical response in patients with prior poor response to antipsychotics. Weight changes do not seem to be associated with polymorphism of the SNAP-25 gene, however, replication in independent samples is warranted.
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Affiliation(s)
- Daniel J Müller
- Neurogenetics Section, Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, 250 College Street R30, Toronto, Ont. M5T 1R8, Canada.
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36
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Keays DA, Nolan PM. N-ethyl-N-nitrosourea mouse mutants in the dissection of behavioural and psychiatric disorders. Eur J Pharmacol 2004; 480:205-17. [PMID: 14623363 DOI: 10.1016/j.ejphar.2003.08.107] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Twin and adoption studies have consistently implicated genetics in the aetiology of psychiatric and behavioural disorders. The identification of the genes and molecular pathways that are associated with these traits using linkage studies has been difficult because psychiatric disorders are almost always non-mendelian, heterogeneous, involve multiple genetic loci and are influenced significantly by environmental factors. Mouse models that are based on intermediate signatures of psychiatric disease and pharmacological responsiveness hold promise as a complementary approach to dissecting the molecular basis of neurobehavioural disorders. This has been made possible by the development and refinement of gene targeting technologies and the use of super-efficient chemical mutagens. N-ethyl-N-nitrosourea (ENU) mutagenesis in the mouse, when coupled to a battery of sensitive behavioural screens, is an effective way of creating and identifying novel mouse behavioural mutants. Here, the concept of screening for ENU mutants is introduced while progress with two behavioural screens, an "anxiety" screen and a circadian screen, are presented. It is hoped that the study of mouse mutants that have arisen from these screens will provide new insights into the genetic basis of abnormal behaviour and that they might lead to the development of novel therapeutic compounds for human psychiatric disease.
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Affiliation(s)
- David A Keays
- MRC Mammalian Genetics Unit, Harwell, Didcot, OX11 0RD, Oxfordshire, UK
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38
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Abstract
Schizophrenia is a common and debilitating illness, characterized by chronic psychotic symptoms and psychosocial impairment that exact considerable human and economic costs. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, treatment, genetics and neurobiology of schizophrenia. Although studied extensively from a clinical, psychological, biological and genetic perspective, our expanding knowledge of schizophrenia provides only an incomplete understanding of this complex disorder. Recent advances in neuroscience have allowed the confirmation or refutation of earlier findings in schizophrenia, and permit useful comparisons between the different levels of organization from which the illness has been studied. Schizophrenia is defined as a clinical syndrome that may include a collection of diseases that share a common presentation. Genetic factors are the most important in the etiology of the disease, with unknown environmental factors potentially modulating the expression of symptoms. Schizophrenia is a complex genetic disorder in which many genes may be implicated, with the possibility of gene-gene interactions and a diversity of genetic causes in different families or populations. A neurodevelopmental rather than degenerative process has received more empirical support as a general explanation of the pathophysiology, although simple dichotomies are not particularly helpful in such a complicated disease. Structural brain changes are present in vivo and post-mortem, with both histopathological and imaging studies in overall agreement that the temporal and frontal lobes of the cerebral cortex are the most affected. Functional imaging, neuropsychological testing and clinical observation are also generally consistent in demonstrating deficits in cognitive ability that correlate with abnormalities in the areas of the brain with structural abnormalities. The dopamine and other neurotransmitter systems are certainly involved in the treatment or modulation of psychotic symptoms. These broad findings represent the distillation of a large body of disparate data, but firm and specific findings are sparse, and much about schizophrenia remains unknown.
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Affiliation(s)
- Albert Hung Choy Wong
- Centre for Addiction and Mental Health, 250 College Street, M5T 1R8, Toronto, Ont., Canada.
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Davids E, Zhang K, Tarazi FI, Baldessarini RJ. Animal models of attention-deficit hyperactivity disorder. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2003; 42:1-21. [PMID: 12668288 DOI: 10.1016/s0165-0173(02)00274-6] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Attention-deficit hyperactivity disorder (ADHD) involves clinically heterogeneous dysfunctions of sustained attention, with behavioral overactivity and impulsivity, of juvenile onset. Experimental models, in addition to mimicking syndromal features, should resemble the clinical condition in pathophysiology, and predict potential new treatments. One of the most extensively evaluated animal models of ADHD is the spontaneously hypertensive rat. Other models include additional genetic variants (dopamine transporter gene knock-out mouse, coloboma mouse, Naples hyperexcitable rat, acallosal mouse, hyposexual rat, and population-extreme rodents), neonatal lesioning of dopamine neurons with 6-hydroxydopamine, and exposure to other neurotoxins or hippocampal irradiation. None is fully comparable to clinical ADHD. The pathophysiology involved varies, including both deficient and excessive dopaminergic functioning, and probable involvement of other monoamine neurotransmitters. Improved models as well as further testing of their ability to predict treatment responses are required.
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Affiliation(s)
- Eugen Davids
- Department of Psychiatry and Neuroscience Program, Harvard Medical School, and Mailman Research Center, McLean Division of Massachusetts General Hospital, 115 Mill Street, Belmont, MA 02478-9106, USA
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Adler M, Sheridan RE, Deshpande SS, Oyler GA. Neuromuscular transmission and muscle contractility in SNAP-25-deficient coloboma mice. Neurotoxicology 2001; 22:775-86. [PMID: 11829411 DOI: 10.1016/s0161-813x(01)00066-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Synaptosomal associated protein of 25 kDa (SNAP-25) is a cytoplasmic protein that participates in the docking and fusion of synaptic vesicles with the nerve terminal in preparation for neurotransmitter release. SNAP-25 is also a substrate for three of the seven serotypes of botulinum neurotoxin (BoNT). Intoxication by BoNT/A, /C1 or /E results in weakness and paralysis of skeletal muscle due to cleavage of SNAP-25 (and syntaxin la in the case /C1) at discrete serotype-specific sites. To elucidate the role of SNAP-25 in muscle function in more detail, contractility and neuromuscular transmission were studied in a mutant mouse model termed coloboma. The coloboma mutation results from a contiguous deletion of 1-2 centiMorgans on chromosome 2, which includes the entire SNAP-25 locus and three other identified genes. Homozygotes do not survive beyond gestation day 6; heterozygotes (Cm/+) have a normal life-span but express reduced levels of SNAP-25 mRNA and protein in the brain. The consequences of the Cm/+ mutation on twitch and tetanic tension, quantal release of neurotransmitter and spinal motoneuron expression of SNAP-25 were examined in the present study. Contrary to expectations, Cm/+ mice exhibited no alteration in twitch tension and generated normal tetanic tension even at the highest frequency examined (800 Hz). Microelectrode recordings revealed that MEPP amplitude and frequency were both within control limits. The ventral spinal cord of Cm/+ mice showed no deficiency in SNAP-25 content and immunohistochemical examination of nerve terminals in Cm/+ mice disclosed that SNAP-25 levels and distribution were similar to those of control mice. It is concluded that spinal motor neurons up-regulate SNAP-25 to preserve vital neuromuscular function.
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Affiliation(s)
- M Adler
- Pharmacology Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA.
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41
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Hatcher JP, Jones DN, Rogers DC, Hatcher PD, Reavill C, Hagan JJ, Hunter AJ. Development of SHIRPA to characterise the phenotype of gene-targeted mice. Behav Brain Res 2001; 125:43-7. [PMID: 11682092 DOI: 10.1016/s0166-4328(01)00275-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- J P Hatcher
- Neurology CEDD, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW, UK.
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Paule MG, Rowland AS, Ferguson SA, Chelonis JJ, Tannock R, Swanson JM, Castellanos FX. Attention deficit/hyperactivity disorder: characteristics, interventions and models. Neurotoxicol Teratol 2000; 22:631-51. [PMID: 11106857 DOI: 10.1016/s0892-0362(00)00095-7] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An epidemiological study of Attention Deficit/Hyperactivity Disorder (ADHD) suggests that the prevalence may be two to three times higher than the figure of 3-5% often cited. In addition, the data suggest that both underdiagnosis and overdiagnosis occur frequently. Rodent animal models of ADHD, like the Spontaneously Hypertensive Rat (SHR) and other rat models such as those with chemical and radiation-induced brain lesions and cerebellar stunting, and the Coloboma mouse model exhibit clear similarities with several aspects of the human disorder and should prove useful in studying specific traits. Operant behavioral tasks that model learning, short-term memory and simple discriminations are sensitive to ADHD and methylphenidate has been shown to normalize ADHD performance in a short-term memory task. Recent findings challenge not only the current postulate that response inhibition is a unique deficit in ADHD, but also the concepts of ADHD and its treatment, which presume intact perceptual abilities. Time perception deficits may account, in part, for the excessive variability in motor response times on speeded reaction time tasks, motor control problems and motor clumsiness associated with ADHD. The Multimodality Treatment Study of ADHD (MTA) provided data suggesting that pharmacological interventions that included systematic and frequent follow-up with parents and teachers, with or without psychosocial interventions, are superior to psychosocial interventions or standard community care alone. Additionally, the MTA was one of the first studies to demonstrate benefits of multimodal and pharmacological interventions lasting longer than 1 year. Imaging studies have demonstrated differences in brain areas in children with ADHD: anterior corpus callosum, right anterior white matter, and cerebellar volumes are all decreased in children with ADHD and there is less brain asymmetry in ADHD subjects. Additionally, functional imaging studies, coupled with pharmacological manipulations, suggest decreased blood flow and energy utilization in prefrontal cortex and striatum and the dysregulation of catecholamine systems in persons with ADHD.
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Affiliation(s)
- M G Paule
- Behavioral Toxicology Laboratory, Division of Neurotoxicology, HFT-132, National Center for Toxicological Research, 3900 NCTR Road, Jefferson, AR 72079-9502, USA.
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Barr CL, Feng Y, Wigg K, Bloom S, Roberts W, Malone M, Schachar R, Tannock R, Kennedy JL. Identification of DNA variants in the SNAP-25 gene and linkage study of these polymorphisms and attention-deficit hyperactivity disorder. Mol Psychiatry 2000; 5:405-9. [PMID: 10889551 DOI: 10.1038/sj.mp.4000733] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The gene for the synaptic vesicle docking fusion protein, synaptosomal-associated protein of 25 kDa (SNAP-25), has been implicated in the etiology of attention-deficit hyperactivity disorder (ADHD) based on the mouse mutant strain coloboma. This neutron-irradiation induced mouse strain is hemizygous for the deletion of the SNAP-25 gene and displays spontaneous hyperactivity that is responsive to dextroamphetamine. Because of these characteristics, this strain has been suggested to be a mouse model for ADHD. We identified using single stranded conformational polymorphism analysis (SSCP) four DNA sequence variants in the 3' untranslated region of the human SNAP-25 gene. We searched for polymorphisms in the 3' untranslated region because the intron/exon structure of this gene has not yet been determined. We tested for linkage of this gene and ADHD using two of the identified polymorphisms that change a restriction enzyme recognition site. We examined the transmission of the alleles of each of these polymorphisms and the haplotypes of both polymorphisms using the transmission disequilibrium test in a sample of 97 small nuclear families consisting of a proband with ADHD, their parents, and affected siblings. We observed biased transmission of the haplotypes of the alleles of these two polymorphisms. Our findings are suggestive of a role of this gene in ADHD.
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Affiliation(s)
- C L Barr
- Department of Psychiatry, The Toronto Hospital, Western Division, Canada.
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Wilson MC. Coloboma mouse mutant as an animal model of hyperkinesis and attention deficit hyperactivity disorder. Neurosci Biobehav Rev 2000; 24:51-7. [PMID: 10654661 DOI: 10.1016/s0149-7634(99)00064-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hyperkinesis and developmental behavioral deficiencies are cardinal signs of attention-deficit hyperactivity disorder. In mice, the mutation coloboma (Cm) corresponds to a contiguous gene defect that results in phenotypic abnormalities including spontaneous hyperactivity, head-bobbing, and ocular dysmorphology. In addition, coloboma mutant mice exhibit delays in achieving complex neonatal motor abilities and deficits in hippocampal physiology, which may contribute to learning deficiencies. The hyperkinesis is ameliorated by low doses of the psychostimulant D-amphetamine and can be rescued genetically by a transgene encoding SNAP-25, located within the Cm deletion. Together with syntaxin and synaptobrevin/VAMP, SNAP-25 constitutes a core protein complex integral to synaptic vesicle fusion and neurotransmitter release. Despite the ubiquitous role of SNAP-25 in synaptic transmission, and uniformly decreased expression in the mutants, coloboma mice show marked deficits in Ca2+-dependent dopamine release selectively in dorsal but not ventral striatum. This suggests that haploinsufficiency of SNAP-25 reveals a specific vulnerability of the nigrostriatal pathway which regulates motor activity and may provide a model for impaired striatal input into executive functions encoded by the prefrontal cortex associated with ADHD.
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Affiliation(s)
- M C Wilson
- Department of Neurosciences, University of New Mexico, Health Sciences Center, Albuquerque 87131-5223, USA.
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Matsuura A, Ohno T, Matsushima T, Namikawa T, Ishikawa A. Delayed development of reflexes and hyperactive locomotion in the spontaneous mutant "waltzing" of the musk shrew, Suncus murinus. Exp Anim 1999; 48:191-7. [PMID: 10480024 DOI: 10.1538/expanim.48.191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The autosomal recessive mutation waltzing (wz), displaying abnormal circling and head-shaking behavior, has previously been reported in the musk shrew (Suncus murinus). Postnatal development of reflexes and locomotor patterns in an open arena were examined in wz/wz mutant shrews. The wz/wz shrews showed extreme developmental delays in surface-righting reflex and negative geotaxis until 10-16 days after birth, but both reflexes eventually recovered to the levels of +/wz normal. Nevertheless, the wz/wz adults exhibited bi-directional circling behavior 59 times, head-tossing behavior 22 times and horizontal head-shaking behavior 6 times more frequent than in the +/wz controls. Although the wz/wz adult shrews were extremely hyperactive with daily spontaneous locomotor activity exceeding 4-7 times control shrew activity, they appeared to have a normal circadian rhythm. This shrew mutant may therefore be useful as a model for hyperactivity syndromes in humans.
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Affiliation(s)
- A Matsuura
- Laboratory of Animal Genetics, Graduate School of Bioagricultural Sciences, Nagoya University, Japan
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