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Godar SC, Mosher LJ, Di Giovanni G, Bortolato M. Animal models of tic disorders: a translational perspective. J Neurosci Methods 2014; 238:54-69. [PMID: 25244952 DOI: 10.1016/j.jneumeth.2014.09.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 12/30/2022]
Abstract
Tics are repetitive, sudden movements and/or vocalizations, typically enacted as maladaptive responses to intrusive premonitory urges. The most severe tic disorder, Tourette syndrome (TS), is a childhood-onset condition featuring multiple motor and at least one phonic tic for a duration longer than 1 year. The pharmacological treatment of TS is mainly based on antipsychotic agents; while these drugs are often effective in reducing tic severity and frequency, their therapeutic compliance is limited by serious motor and cognitive side effects. The identification of novel therapeutic targets and development of better treatments for tic disorders is conditional on the development of animal models with high translational validity. In addition, these experimental tools can prove extremely useful to test hypotheses on the etiology and neurobiological bases of TS and related conditions. In recent years, the translational value of these animal models has been enhanced, thanks to a significant re-organization of our conceptual framework of neuropsychiatric disorders, with a greater focus on endophenotypes and quantitative indices, rather than qualitative descriptors. Given the complex and multifactorial nature of TS and other tic disorders, the selection of animal models that can appropriately capture specific symptomatic aspects of these conditions can pose significant theoretical and methodological challenges. In this article, we will review the state of the art on the available animal models of tic disorders, based on genetic mutations, environmental interventions as well as pharmacological manipulations. Furthermore, we will outline emerging lines of translational research showing how some of these experimental preparations have led to significant progress in the identification of novel therapeutic targets for tic disorders.
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Affiliation(s)
- Sean C Godar
- Department of Pharmacology and Toxicology, School of Pharmacy; University of Kansas, Lawrence, KS, USA
| | - Laura J Mosher
- Department of Pharmacology and Toxicology, School of Pharmacy; University of Kansas, Lawrence, KS, USA
| | - Giuseppe Di Giovanni
- Department of Physiology and Biochemistry, University of Malta, Msida, Malta; School of Biosciences, Cardiff University, Cardiff, UK
| | - Marco Bortolato
- Department of Pharmacology and Toxicology, School of Pharmacy; University of Kansas, Lawrence, KS, USA; Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas, Lawrence, KS, USA.
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Jasinska AJ, Lin MK, Service S, Choi OW, DeYoung J, Grujic O, Kong SY, Jung Y, Jorgensen MJ, Fairbanks LA, Turner T, Cantor RM, Wasserscheid J, Dewar K, Warren W, Wilson RK, Weinstock G, Jentsch JD, Freimer NB. A non-human primate system for large-scale genetic studies of complex traits. Hum Mol Genet 2012; 21:3307-16. [PMID: 22556363 PMCID: PMC3392106 DOI: 10.1093/hmg/dds160] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 04/04/2012] [Accepted: 04/18/2012] [Indexed: 12/14/2022] Open
Abstract
Non-human primates provide genetic model systems biologically intermediate between humans and other mammalian model organisms. Populations of Caribbean vervet monkeys (Chlorocebus aethiops sabaeus) are genetically homogeneous and large enough to permit well-powered genetic mapping studies of quantitative traits relevant to human health, including expression quantitative trait loci (eQTL). Previous transcriptome-wide investigation in an extended vervet pedigree identified 29 heritable transcripts for which levels of expression in peripheral blood correlate strongly with expression levels in the brain. Quantitative trait linkage analysis using 261 microsatellite markers identified significant (n = 8) and suggestive (n = 4) linkages for 12 of these transcripts, including both cis- and trans-eQTL. Seven transcripts, located on different chromosomes, showed maximum linkage to markers in a single region of vervet chromosome 9; this observation suggests the possibility of a master trans-regulator locus in this region. For one cis-eQTL (at B3GALTL, beta-1,3-glucosyltransferase), we conducted follow-up single nucleotide polymorphism genotyping and fine-scale association analysis in a sample of unrelated Caribbean vervets, localizing this eQTL to a region of <200 kb. These results suggest the value of pedigree and population samples of the Caribbean vervet for linkage and association mapping studies of quantitative traits. The imminent whole genome sequencing of many of these vervet samples will enhance the power of such investigations by providing a comprehensive catalog of genetic variation.
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Affiliation(s)
- Anna J. Jasinska
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Michelle K. Lin
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
- Department of Neurobehavioral Genetics, Institute of Psychobiology, University of Trier, Johanniterufer 15, D-54290 Trier, Germany
| | - Susan Service
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Oi-Wa Choi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Joseph DeYoung
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Olivera Grujic
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Sit-Yee Kong
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Yoon Jung
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Mathew J. Jorgensen
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Lynn A. Fairbanks
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Trudy Turner
- University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Rita M. Cantor
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Jessica Wasserscheid
- Research Institute of the McGill University Health Centre, McGill University and Génome Québec Innovation Centre
- Department of Human Genetics and
- Department of Experimental Medicine, McGill University, Montreal, PQ, CanadaH3A 1A1
| | - Ken Dewar
- Research Institute of the McGill University Health Centre, McGill University and Génome Québec Innovation Centre
- Department of Human Genetics and
- Department of Experimental Medicine, McGill University, Montreal, PQ, CanadaH3A 1A1
| | - Wesley Warren
- The Genome Institute at Washington University, St Louis, MO 63108, USA and
| | - Richard K. Wilson
- The Genome Institute at Washington University, St Louis, MO 63108, USA and
| | - George Weinstock
- The Genome Institute at Washington University, St Louis, MO 63108, USA and
| | - J. David Jentsch
- Department of Psychology and Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
| | - Nelson B. Freimer
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, CA 90095, USA
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López-Moreno JA, Echeverry-Alzate V, Bühler KM. The genetic basis of the endocannabinoid system and drug addiction in humans. J Psychopharmacol 2012; 26:133-43. [PMID: 21937688 DOI: 10.1177/0269881111416689] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The cannabinoid receptor (CNR1) and the fatty acid amide hydrolase (FAAH) genes are located on chromosomes 6 and 1 in the 6q15 and 1p33 cytogenetic bands, respectively. CNR1 encodes a seven-transmembrane domain protein of 472 amino acids, whereas FAAH encodes one transmembrane domain of 579 amino acids. Several mutations found in these genes lead to altered mRNA stability and transcription rate or a reduction of the activity of the encoded protein. Increasing evidence shows that these functional mutations are related to dependence upon cocaine, alcohol, marijuana, heroin, nicotine and other drugs. One of the most compelling associations is with the C385A single nucleotide polymorphism (SNP), which is found in the FAAH gene. For all of the genetic polymorphisms reviewed here, it is difficult to form overall conclusions due to the high diversity of population samples being studied, ethnicity, the use of volunteers, heterogeneity of the recruitment criteria and the drug addiction phenotype studied. Care should be taken when generalizing the results from different studies. However, many works have repeatedly associated polymorphisms in the CNR1 and FAAH genes with drug-related behaviours; this suggests that these genes should be examined in further genetic studies focusing on drug addiction and other psychiatric disorders.
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Abstract
Animal models are useful in research that examines physiological mechanisms and, as such, are invaluable in developing therapies to alleviate illness and promote health. Ethical considerations are essential for proper animal use and include replacement by nonanimal models where possible, reduction in the numbers of animals used, and refinement of experimental protocols to reduce animal suffering. Choosing the optimum model depends on the long- and short-term goals of the project, and the choice of a model goes hand in hand with appropriate study design. Five key features to think about when choosing a model are as follows: model asymmetry, necessary differences, specificity to the study, model validity, and model improvement. Appropriate use of both male and female animals has also become an important issue in recent times. These considerations will assist in understanding animal model use.
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Understanding the neuropsychological consequences of deployment stress: a public health framework. J Int Neuropsychol Soc 2011; 17:1-6. [PMID: 21083962 DOI: 10.1017/s1355617710001116] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Complaints of neuropsychological dysfunction have emerged among subsets of military personnel after almost every major deployment involving western nations in recent history. Although deployments have been characterized by a range of neural risk factors, psychological stress is common to most prolonged deployments. This review uses a public health framework to address associations between deployment-related stress and neuropsychological performance. Specifically, the review covers mechanisms by which deployment-related psychological stress may affect neuropsychological functioning, considers the advantages and disadvantages of approaching the question from a public health perspective, and discusses how epidemiological research may sort out questions regarding course, cause, and effect.
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Congdon E, Poldrack RA, Freimer NB. Neurocognitive phenotypes and genetic dissection of disorders of brain and behavior. Neuron 2010; 68:218-30. [PMID: 20955930 DOI: 10.1016/j.neuron.2010.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2010] [Indexed: 01/10/2023]
Abstract
Elucidating the molecular mechanisms underlying quantitative neurocognitive phenotypes will further our understanding of the brain's structural and functional architecture and advance the diagnosis and treatment of the psychiatric disorders that these traits underlie. Although many neurocognitive traits are highly heritable, little progress has been made in identifying genetic variants unequivocally associated with these phenotypes. A major obstacle to such progress is the difficulty in identifying heritable neurocognitive measures that are precisely defined and systematically assessed and represent unambiguous mental constructs, yet are also amenable to the high-throughput phenotyping necessary to obtain adequate power for genetic association studies. In this perspective we compare the current status of genetic investigations of neurocognitive phenotypes to that of other categories of biomedically relevant traits and suggest strategies for genetically dissecting traits that may underlie disorders of brain and behavior.
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Affiliation(s)
- Eliza Congdon
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90095, USA
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Animal models of virus-induced neurobehavioral sequelae: recent advances, methodological issues, and future prospects. Interdiscip Perspect Infect Dis 2010; 2010:380456. [PMID: 20490350 PMCID: PMC2872755 DOI: 10.1155/2010/380456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2009] [Revised: 11/14/2009] [Accepted: 03/09/2010] [Indexed: 01/18/2023] Open
Abstract
Converging lines of clinical and epidemiological evidence suggest that viral infections in early developmental stages may be a causal factor in neuropsychiatric disorders such as schizophrenia, bipolar disorder, and autism-spectrum disorders. This etiological link, however, remains controversial in view of the lack of consistent and reproducible associations between viruses and mental illness. Animal models of virus-induced neurobehavioral disturbances afford powerful tools to test etiological hypotheses and explore pathophysiological mechanisms. Prenatal or neonatal inoculations of neurotropic agents (such as herpes-, influenza-, and retroviruses) in rodents result in a broad spectrum of long-term alterations reminiscent of psychiatric abnormalities. Nevertheless, the complexity of these sequelae often poses methodological and interpretational challenges and thwarts their characterization. The recent conceptual advancements in psychiatric nosology and behavioral science may help determine new heuristic criteria to enhance the translational value of these models. A particularly critical issue is the identification of intermediate phenotypes, defined as quantifiable factors representing single neurochemical, neuropsychological, or neuroanatomical aspects of a diagnostic category. In this paper, we examine how the employment of these novel concepts may lead to new methodological refinements in the study of virus-induced neurobehavioral sequelae through animal models.
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