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Ramos A, Granzotto N, Kremer R, Boeder AM, de Araújo JFP, Pereira AG, Izídio GS. Hunting for Genes Underlying Emotionality in the Laboratory Rat: Maps, Tools and Traps. Curr Neuropharmacol 2023; 21:1840-1863. [PMID: 36056863 PMCID: PMC10514530 DOI: 10.2174/1570159x20666220901154034] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/13/2022] [Accepted: 07/28/2022] [Indexed: 11/22/2022] Open
Abstract
Scientists have systematically investigated the hereditary bases of behaviors since the 19th century, moved by either evolutionary questions or clinically-motivated purposes. The pioneer studies on the genetic selection of laboratory animals had already indicated, one hundred years ago, the immense complexity of analyzing behaviors that were influenced by a large number of small-effect genes and an incalculable amount of environmental factors. Merging Mendelian, quantitative and molecular approaches in the 1990s made it possible to map specific rodent behaviors to known chromosome regions. From that point on, Quantitative Trait Locus (QTL) analyses coupled with behavioral and molecular techniques, which involved in vivo isolation of relevant blocks of genes, opened new avenues for gene mapping and characterization. This review examines the QTL strategy applied to the behavioral study of emotionality, with a focus on the laboratory rat. We discuss the challenges, advances and limitations of the search for Quantitative Trait Genes (QTG) playing a role in regulating emotionality. For the past 25 years, we have marched the long journey from emotionality-related behaviors to genes. In this context, our experiences are used to illustrate why and how one should move forward in the molecular understanding of complex psychiatric illnesses. The promise of exploring genetic links between immunological and emotional responses are also discussed. New strategies based on humans, rodents and other animals (such as zebrafish) are also acknowledged, as they are likely to allow substantial progress to be made in the near future.
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Affiliation(s)
- André Ramos
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Natalli Granzotto
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Rafael Kremer
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Ariela Maína Boeder
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Julia Fernandez Puñal de Araújo
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Aline Guimarães Pereira
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Geison Souza Izídio
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
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Penke L, Denissen JJA, Miller GF. Evolution, genes, and inter‐disciplinary personality research. EUROPEAN JOURNAL OF PERSONALITY 2020. [DOI: 10.1002/per.657] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Most commentaries welcomed an evolutionary genetic approach to personality, but several raised concerns about our integrative model. In response, we clarify the scientific status of evolutionary genetic theory and explain the plausibility and value of our evolutionary genetic model of personality, despite some shortcomings with the currently available theories and data. We also have a closer look at mate choice for personality traits, point to promising ways to assess evolutionarily relevant environmental factors and defend higher‐order personality domains and the g‐factor as the best units for evolutionary genetic analyses. Finally, we discuss which extensions of and alternatives to our model appear most fruitful, and end with a call for more inter‐disciplinary personality research grounded in evolutionary theory. Copyright © 2007 John Wiley & Sons, Ltd.
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Affiliation(s)
- Lars Penke
- Humboldt University, Berlin, Germany
- International Max Planck Research School LIFE, Berlin, Germany
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Zhao M, Harris BN, Nguyen CTY, Saltzman W. Effects of single parenthood on mothers' behavior, morphology, and endocrine function in the biparental California mouse. Horm Behav 2019; 114:104536. [PMID: 31153926 DOI: 10.1016/j.yhbeh.2019.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/31/2019] [Accepted: 05/24/2019] [Indexed: 12/29/2022]
Abstract
Motherhood is energetically costly for mammals and is associated with pronounced changes in mothers' physiology, morphology and behavior. In ~5% of mammals, fathers assist their mates with rearing offspring and can enhance offspring survival and development. Although these beneficial consequences of paternal care can be mediated by direct effects on offspring, they might also be mediated indirectly, through beneficial effects on mothers. We tested the hypothesis that fathers in the monogamous, biparental California mouse (Peromyscus californicus) reduce the burden of parental care on their mates, and therefore, that females rearing offspring with and without assistance from their mates will show differences in endocrinology, morphology and behavior, as well as in the survival and development of their pups. We found that pups' survival and development in the lab did not differ between those raised by a single mother and those reared by both mother and father. Single mothers spent more time in feeding behaviors than paired mothers. Both single and paired mothers had higher lean mass and/or lower fat mass and showed more anxiety-like behavior in open-field tests and tail-suspension tests, compared to non-breeding females. Single mothers had higher body-mass-corrected liver and heart masses, but lower ovarian and uterine masses, than paired mothers and/or non-breeding females. Mass of the gastrointestinal tract did not differ between single and paired mothers, but single mothers had heavier gastrointestinal tract compared to non-breeding females. Single motherhood also induced a flattened diel corticosterone rhythm and a blunted corticosterone response to stress, compared to non-breeding conditions. These findings suggest that the absence of a mate induces morphological and endocrine changes in mothers, which might result from increased energetic demands of pup care and could potentially help maintain normal survival and development of pups.
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Affiliation(s)
- Meng Zhao
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, United States of America
| | - Breanna N Harris
- Department of Biological Sciences, Texas Tech University, United States of America
| | - Catherine T Y Nguyen
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, United States of America
| | - Wendy Saltzman
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, United States of America.
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Bendesky A, Bargmann CI. Genetic contributions to behavioural diversity at the gene-environment interface. Nat Rev Genet 2011; 12:809-20. [PMID: 22064512 DOI: 10.1038/nrg3065] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent work on behavioural variation within and between species has furthered our understanding of the genetic architecture of behavioural traits, the identities of relevant genes and the ways in which genetic variants affect neuronal circuits to modify behaviour. Here we review our understanding of the genetics of natural behavioural variation in non-human animals and highlight the implications of these findings for human genetics. We suggest that gene-environment interactions are central to natural genetic variation in behaviour and that genes affecting neuromodulatory pathways and sensory processing are preferred sites of naturally occurring mutations.
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Affiliation(s)
- Andres Bendesky
- Howard Hughes Medical Institute, Laboratory for Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA
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van Oers K, Mueller JC. Evolutionary genomics of animal personality. Philos Trans R Soc Lond B Biol Sci 2011; 365:3991-4000. [PMID: 21078651 DOI: 10.1098/rstb.2010.0178] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Research on animal personality can be approached from both a phenotypic and a genetic perspective. While using a phenotypic approach one can measure present selection on personality traits and their combinations. However, this approach cannot reconstruct the historical trajectory that was taken by evolution. Therefore, it is essential for our understanding of the causes and consequences of personality diversity to link phenotypic variation in personality traits with polymorphisms in genomic regions that code for this trait variation. Identifying genes or genome regions that underlie personality traits will open exciting possibilities to study natural selection at the molecular level, gene-gene and gene-environment interactions, pleiotropic effects and how gene expression shapes personality phenotypes. In this paper, we will discuss how genome information revealed by already established approaches and some more recent techniques such as high-throughput sequencing of genomic regions in a large number of individuals can be used to infer micro-evolutionary processes, historical selection and finally the maintenance of personality trait variation. We will do this by reviewing recent advances in molecular genetics of animal personality, but will also use advanced human personality studies as case studies of how molecular information may be used in animal personality research in the near future.
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Affiliation(s)
- Kees van Oers
- Netherlands Institute of Ecology (NIOO-KNAW), Heteren, The Netherlands.
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Abstract
Individual animals differ in their propensity to engage in dangerous situations, or in their risk-taking behavior. There is a heritable basis to some of this variation, but the environment plays an important role in shaping individuals' risk-taking propensity as well. This chapter describes some of the challenges in studying the genetic basis of individual differences in risk-taking behavior, arguing new insights will emerge from studies which take a whole-genome approach and which simultaneously consider both genetic and environmental influences on the behavior. The availability of genomic tools for three-spined stickleback, a small fish renowned for its variable behavior, opens up new possibilities for studying the genetic basis of natural, adaptive variation in risk-taking behavior. After introducing the general biology of sticklebacks, the chapter summarizes the existing literature on the genetic and environmental influences on risk-taking behavior, and describes the overall strategy that our group is taking to identify inherited and environmentally responsive genes related to risk-taking behavior in this species. Insights gleaned from such studies will be relevant to our understanding of similar behaviors in other organisms, including ourselves.
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Gale GD, Yazdi RD, Khan AH, Lusis AJ, Davis RC, Smith DJ. A genome-wide panel of congenic mice reveals widespread epistasis of behavior quantitative trait loci. Mol Psychiatry 2009; 14:631-45. [PMID: 18379576 PMCID: PMC3014058 DOI: 10.1038/mp.2008.4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Understanding the genetics of behavioral variation remains a fascinating but difficult problem with considerable theoretical and practical implications. We used the genome-tagged mice (GTM) and an extensive test battery of well-validated behavioral assays to scan the genome for behavioral quantitative trait loci (QTLs). The GTM are a panel of 'speed congenic' mice consisting of over 60 strains spanning the entire autosomal genome. Each strain harbors a small (approximately 23 cM) DBA/2J donor segment on a uniform C57BL/6J background. The panel allows for mapping to regions as small as 5 cM and provides a powerful new tool for increasing mapping power and replicability in the analysis of QTLs. A total of 97 loci were mapped for a variety of complex behavioral traits including hyperactivity, anxiety, prepulse inhibition, avoidance and conditional fear. A larger number of loci were recovered than generally attained from standard mapping crosses. In addition, a surprisingly high proportion of loci, 63%, showed phenotypes unlike either of the parental strains. These data suggest that epistasis decreases sensitivity of locus detection in traditional crosses and demonstrate the utility of the GTM for mapping complex behavioral traits with high sensitivity and precision.
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Affiliation(s)
- GD Gale
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - RD Yazdi
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - AH Khan
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - AJ Lusis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - RC Davis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - DJ Smith
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
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Morphological correlates of emotional and cognitive behaviour: insights from studies on inbred and outbred rodent strains and their crosses. Behav Pharmacol 2008; 19:403-34. [PMID: 18690101 DOI: 10.1097/fbp.0b013e32830dc0de] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Every study in rodents is also a behavioural genetic study even if only a single strain is used. Outbred strains are genetically heterogeneous populations with a high intrastrain variation, whereas inbred strains are based on the multiplication of a unique individual. The aim of the present review is to summarize findings on brain regions involved in three major components of rodent behaviour, locomotion, anxiety-related behaviour and cognition, by paying particular attention to the genetic context, genetic models used and interstrain comparisons. Recent trends correlating gene expression in inbred strains with behavioural data in databases, morpho-behavioural-haplotype analyses and problems arising from large-scale multivariate analyses are discussed. Morpho-behavioural correlations in multiple strains are presented, including correlations with projection neurons, interneurons and fibre systems in the striatum, midbrain, amygdala, medial septum and hippocampus, by relating them to relevant transmitter systems. In addition, brain areas differentially activated in different strains are described (hippocampus, prefrontal cortex, nucleus accumbens, locus ceruleus). Direct interstrain comparisons indicate that strain differences in behavioural variables and neuronal markers are much more common than usually thought. The choice of the appropriate genetic model can therefore contribute to an interpretation of positive results in a wider context, and help to avoid misleading interpretations of negative results.
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Hameister TM, Izídio GS, Valiati VH, Ramos A. Association of a locus on rat chromosome 4 with anxiety-related behaviors in two selectively bred rat lines. Genet Mol Biol 2008. [DOI: 10.1590/s1415-47572008000500008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
| | | | | | - André Ramos
- Universidade Federal de Santa Catarina, Brazil
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Lu L, Wei L, Peirce JL, Wang X, Zhou J, Homayouni R, Williams RW, Airey DC. Using gene expression databases for classical trait QTL candidate gene discovery in the BXD recombinant inbred genetic reference population: mouse forebrain weight. BMC Genomics 2008; 9:444. [PMID: 18817551 PMCID: PMC2570693 DOI: 10.1186/1471-2164-9-444] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Accepted: 09/25/2008] [Indexed: 12/28/2022] Open
Abstract
Background Successful strategies for QTL gene identification benefit from combined experimental and bioinformatic approaches. Unique design aspects of the BXD recombinant inbred line mapping panel allow use of archived gene microarray expression data to filter likely from unlikely candidates. This prompted us to propose a simple five-filter protocol for candidate nomination. To filter more likely from less likely candidates, we required candidate genes near to the QTL to have mRNA abundance that correlated with the phenotype among the BXD lines as well as differed between the parental lines C57BL/6J and DBA/2J. We also required verification of mRNA abundance by an independent method, and finally we required either differences in protein levels or confirmed DNA sequence differences. Results QTL mapping of mouse forebrain weight in 34 BXD RI lines found significant association on chromosomes 1 and 11, with each C57BL/6J allele increasing weight by more than half a standard deviation. The intersection of gene lists that were within ± 10 Mb of the strongest associated location, that had forebrain mRNA abundance correlated with forebrain weight among the BXD, and that had forebrain mRNA abundance differing between C57BL/6J and DBA/2J, produced two candidates, Tnni1 (troponin 1) and Asb3 (ankyrin repeat and SOCS box-containing protein 3). Quantitative RT-PCR confirmed the direction of an increased expression in C57BL/6J genotype over the DBA/2J genotype for both genes, a difference that translated to a 2-fold difference in Asb3 protein. Although Tnni1 protein differences could not be confirmed, a 273 bp indel polymorphism was discovered 1 Kb upstream of the transcription start site. Conclusion Delivery of well supported candidate genes following a single quantitative trait locus mapping experiment is difficult. However, by combining available gene expression data with QTL mapping, we illustrated a five-filter protocol that nominated Asb3 and Tnni1 as candidates affecting increased mouse forebrain weight. We recommend our approach when (1) investigators are working with phenotypic differences between C57BL/6J and DBA/2J, and (2) gene expression data are available on that relate to the phenotype of interest. Under these circumstances, measurement of the phenotype in the BXD lines will likely also deliver excellent candidate genes.
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Affiliation(s)
- Lu Lu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, PR China.
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McKinney BC, Chow CY, Meisler MH, Murphy GG. Exaggerated emotional behavior in mice heterozygous null for the sodium channel Scn8a (Nav1.6). GENES BRAIN AND BEHAVIOR 2008; 7:629-38. [PMID: 18363861 DOI: 10.1111/j.1601-183x.2008.00399.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Scn8a gene encodes the alpha-subunit of Na(v)1.6, a neuronal voltage-gated sodium channel. Mice homozygous for mutations in the Scn8a gene exhibit motor impairments. Recently, we described a human family with a heterozygous protein truncation mutation in SCN8A. Rather than motor impairment, neuropsychological abnormalities were more common, suggesting a role for Scn8a in a more diverse range of behaviors. Here, we characterize mice heterozygous for a null mutation of Scn8a (Scn8a(+/-)mice) in a number of behavioral paradigms. We show that Scn8a(+/-)mice exhibit greater conditioned freezing in the Pavlovian fear conditioning paradigm but no apparent abnormalities in other learning and memory paradigms including the Morris water maze and conditioned taste avoidance paradigm. Furthermore, we find that Scn8a(+/-)mice exhibit more pronounced avoidance of well-lit, open environments as well as more stress-induced coping behavior. Together, these data suggest that Scn8a plays a critical role in emotional behavior in mice. Although the behavioral phenotype observed in the Scn8a(+/-)mice only partially models the abnormalities in the human family, we anticipate that the Scn8a(+/-)mice will serve as a valuable tool for understanding the biological basis of emotion and the human diseases in which abnormal emotional behavior is a primary component.
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Affiliation(s)
- B C McKinney
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI 48109-2200, USA
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The regular and light-dark Suok tests of anxiety and sensorimotor integration: utility for behavioral characterization in laboratory rodents. Nat Protoc 2008; 3:129-36. [PMID: 18193029 DOI: 10.1038/nprot.2007.516] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Animal behavioral models are crucial for neurobiological research, allowing for the thorough investigation of brain pathogenesis to be performed. In both animals and humans, anxiety has long been linked to vestibular disorders. However, although there are many tests of anxiety and vestibular deficits, there are few protocols that address the interplay between these two domains. The Suok test and its light-dark modification presented here appear to be suitable for testing this pathogenetic link in laboratory rodents. This protocol adds a new dimension to previously used tests by assessing animal anxiety and balancing simultaneously, resulting in efficient, high-throughput screens for testing psychotropic drugs, phenotyping genetically modified animals, and modeling clusters of human disorders related to stress/anxiety and balancing.
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Phillips TJ, Kamens HM, Wheeler JM. Behavioral genetic contributions to the study of addiction-related amphetamine effects. Neurosci Biobehav Rev 2007; 32:707-59. [PMID: 18207241 PMCID: PMC2360482 DOI: 10.1016/j.neubiorev.2007.10.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Revised: 09/28/2007] [Accepted: 10/28/2007] [Indexed: 11/24/2022]
Abstract
Amphetamines, including methamphetamine, pose a significant cost to society due to significant numbers of amphetamine-abusing individuals who suffer major health-related consequences. In addition, methamphetamine use is associated with heightened rates of violent and property-related crimes. The current paper reviews the existing literature addressing genetic differences in mice that impact behavioral responses thought to be relevant to the abuse of amphetamine and amphetamine-like drugs. Summarized are studies that used inbred strains, selected lines, single-gene knockouts and transgenics, and quantitative trait locus (QTL) mapping populations. Acute sensitivity, neuroadaptive responses, rewarding and conditioned effects are among those reviewed. Some gene mapping work has been accomplished, and although no amphetamine-related complex trait genes have been definitively identified, translational work leading from results in the mouse to studies performed in humans is beginning to emerge. The majority of genetic investigations have utilized single-gene knockout mice and have concentrated on dopamine- and glutamate-related genes. Genes that code for cell support and signaling molecules are also well-represented. There is a large behavioral genetic literature on responsiveness to amphetamines, but a considerably smaller literature focused on genes that influence the development and acceleration of amphetamine use, withdrawal, relapse, and behavioral toxicity. Also missing are genetic investigations into the effects of amphetamines on social behaviors. This information might help to identify at-risk individuals and in the future to develop treatments that take advantage of individualized genetic information.
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