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Dunham KE, Venton BJ. Electrochemical and biosensor techniques to monitor neurotransmitter changes with depression. Anal Bioanal Chem 2024; 416:2301-2318. [PMID: 38289354 PMCID: PMC10950978 DOI: 10.1007/s00216-024-05136-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/29/2023] [Accepted: 01/09/2024] [Indexed: 03/21/2024]
Abstract
Depression is a common mental illness. However, its current treatments, like selective serotonin reuptake inhibitors (SSRIs) and micro-dosing ketamine, are extremely variable between patients and not well understood. Three neurotransmitters: serotonin, histamine, and glutamate, have been proposed to be key mediators of depression. This review focuses on analytical methods to quantify these neurotransmitters to better understand neurological mechanisms of depression and how they are altered during treatment. To quantitatively measure serotonin and histamine, electrochemical techniques such as chronoamperometry and fast-scan cyclic voltammetry (FSCV) have been improved to study how specific molecular targets, like transporters and receptors, change with antidepressants and inflammation. Specifically, these studies show that different SSRIs have unique effects on serotonin reuptake and release. Histamine is normally elevated during stress, and a new inflammation hypothesis of depression links histamine and cytokine release. Electrochemical measurements revealed that stress increases histamine, decreases serotonin, and leads to changes in cytokines, like interleukin-6. Biosensors can also measure non-electroactive neurotransmitters, including glutamate and cytokines. In particular, new genetic sensors have shown how glutamate changes with chronic stress, as well as with ketamine treatment. These techniques have been used to characterize how ketamine changes glutamate and serotonin, and to understand how it is different from SSRIs. This review briefly outlines how these electrochemical techniques work, but primarily highlights how they have been used to understand the mechanisms of depression. Future studies should explore multiplexing techniques and personalized medicine using biomarkers in order to investigate multi-analyte changes to antidepressants.
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Affiliation(s)
- Kelly E Dunham
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - B Jill Venton
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA.
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2
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Early life adversity shapes neural circuit function during sensitive postnatal developmental periods. Transl Psychiatry 2022; 12:306. [PMID: 35915071 PMCID: PMC9343623 DOI: 10.1038/s41398-022-02092-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 07/18/2022] [Accepted: 07/21/2022] [Indexed: 11/24/2022] Open
Abstract
Early life adversity (ELA) is a major risk factor for mental illness, but the neurobiological mechanisms by which ELA increases the risk for future psychopathology are still poorly understood. Brain development is particularly malleable during prenatal and early postnatal life, when complex neural circuits are being formed and refined through an interplay of excitatory and inhibitory neural input, synaptogenesis, synaptic pruning, myelination, and neurogenesis. Adversity that influences these processes during sensitive periods of development can thus have long-lasting and pervasive effects on neural circuit maturation. In this review, we will discuss clinical and preclinical evidence for the impact of ELA on neural circuit formation with a focus on the early postnatal period, and how long-lasting impairments in these circuits can affect future behavior. We provide converging evidence from human and animal studies on how ELA alters the functional development of brain regions, neural circuits, and neurotransmitter systems that are crucial for cognition and affective behavior, including the hippocampus, the hypothalamus-pituitary-adrenal (HPA) axis, neural networks of fear responses and cognition, and the serotonin (5-HT) system. We also discuss how gene-by-environment (GxE) interactions can determine individual differences in susceptibility and resilience to ELA, as well as molecular pathways by which ELA regulates neural circuit development, for which we emphasize epigenetic mechanisms. Understanding the molecular and neurobiological mechanisms underlying ELA effects on brain function and psychopathology during early postnatal sensitive periods may have great potential to advance strategies to better treat or prevent psychiatric disorders that have their origin early in life.
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3
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Wang X, Wang K, Wu X, Huang W, Yang L. Role of the cAMP-PKA-CREB-BDNF pathway in abnormal behaviours of serotonin transporter knockout mice. Behav Brain Res 2022; 419:113681. [PMID: 34838579 DOI: 10.1016/j.bbr.2021.113681] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 11/02/2022]
Abstract
Serotonin transporter gene-linked polymorphic region polymorphisms are associated with anxiety, neuroticism, affective disorders and vulnerability to stressful life events; however, the relevant physiological mechanisms are not well understood. Serotonin transporter knockout mice have been widely used as a model of allelic variation of serotonin transporter function in humans; herein, wild-type mice and heterozygous and homozygous knockout mice models were established to explore the behavioural changes related to different genotypes and the possible physiological mechanisms. Behavioural changes were assessed using behavioural tests, namely, elevated plus maze, open field, Morris water maze and rotarod tests. Serum indicators were detected using the enzyme-linked immunosorbent assay. Compared with wild-type mice, homozygous mice showed significant anxiety-like behaviours in the plus maze and open field tests; conversely, anxiety-like behaviours in heterozygous mice were less pronounced. Homozygous mice also showed cognitive impairment and motor inhibition in the Morris water maze and rotarod tests. Serotonin levels decreased in both heterozygous and homozygous mice, and 5-hydroxytryptophan, protein kinase A, adenylyl cyclase, cyclic adenosine monophosphate response element-binding protein and brain-derived neurotrophic factor levels were lower in homozygous mice than in wild-type and heterozygous mice, whereas no statistical differences were found between wild-type and heterozygous mice. Additionally, there was a correlation between serological and behavioural indicators. This study provided experimental evidence that the cyclic adenosine monophosphate-protein kinase A-cyclic adenosine monophosphate response element-binding protein-brain-derived neurotrophic factor pathway may be involved in the regulation of polymorphism to stress and enriched the behavioural and physiological characteristics of serotonin transporter knockout mice.
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Affiliation(s)
- Xiaomin Wang
- Department of Epidemiology and Health Statistics, School of Public Health, Guangxi Medical University, Nanning, PR China
| | - Ke Wang
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, PR China
| | - Xiangmin Wu
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, PR China
| | - Wenxiu Huang
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, PR China
| | - Li Yang
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, PR China.
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4
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Abdelghany AK, El-Kashlan AM, Emeash HH, Khalil F. Long-term scopolamine treatment altered locomotor, exploratory and anxiety-like behaviours of albino rats. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2022. [DOI: 10.1186/s43088-021-00187-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Animal models are used to provide an adequate investigation of brain-behaviour, physiological and path physiological relationships to give insight into human behaviour and the underlying processes of drugs affecting the nervous system. Scopolamine; SCO (alkaloid l-(2)-scopolamine [l-(2)-hyoscine]) has a competitive inhibitory effect on muscarinic receptors for acetylcholine. Thus, this study was designated to investigate the effect of long-term SCO treatment on locomotor, exploratory and anxiety-like behaviours of rats using open field test.
Results
The long-term SCO treatment induced a prominent increase in locomotion (hyperactivity) and exploratory behaviour of rats. In addition, anxiety-like behavioural patterns showed a non-significant difference in SCO treated compared to control. Serotonin level was significantly decreased in the scopolamine treated group in comparison with the control group.
Conclusions
Data suggested that long-term SCO treatment resulted in marked neurobehavioural alterations in a rat as an animal model.
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5
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María-Ríos CE, Morrow JD. Mechanisms of Shared Vulnerability to Post-traumatic Stress Disorder and Substance Use Disorders. Front Behav Neurosci 2020; 14:6. [PMID: 32082127 PMCID: PMC7006033 DOI: 10.3389/fnbeh.2020.00006] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022] Open
Abstract
Psychoactive substance use is a nearly universal human behavior, but a significant minority of people who use addictive substances will go on to develop an addictive disorder. Similarly, though ~90% of people experience traumatic events in their lifetime, only ~10% ever develop post-traumatic stress disorder (PTSD). Substance use disorders (SUD) and PTSD are highly comorbid, occurring in the same individual far more often than would be predicted by chance given the respective prevalence of each disorder. Some possible reasons that have been proposed for the relationship between PTSD and SUD are self-medication of anxiety with drugs or alcohol, increased exposure to traumatic events due to activities involved in acquiring illegal substances, or addictive substances altering the brain's stress response systems to make users more vulnerable to PTSD. Yet another possibility is that some people have an intrinsic vulnerability that predisposes them to both PTSD and SUD. In this review, we integrate clinical and animal data to explore these possible etiological links between SUD and PTSD, with an emphasis on interactions between dopaminergic, adrenocorticotropic, GABAergic, and glutamatergic neurobehavioral mechanisms that underlie different emotional learning styles.
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Affiliation(s)
| | - Jonathan D. Morrow
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, United States
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6
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Krakenberg V, von Kortzfleisch VT, Kaiser S, Sachser N, Richter SH. Differential Effects of Serotonin Transporter Genotype on Anxiety-Like Behavior and Cognitive Judgment Bias in Mice. Front Behav Neurosci 2019; 13:263. [PMID: 31849623 PMCID: PMC6902087 DOI: 10.3389/fnbeh.2019.00263] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/19/2019] [Indexed: 02/01/2023] Open
Abstract
In humans, the short allele of a common polymorphism in the serotonin transporter (5-HTT) gene is associated with a higher risk to develop depression and anxiety disorders. Furthermore, individuals carrying this allele are characterized by negative judgment biases, as they tend to interpret ambiguous information in a more pessimistic way. 5-HTT knockout mice, lacking the 5-HTT gene either homo- or heterozygously, provide a widely used model organism for the study of symptoms related to human anxiety disorders. In the present study, we aimed to prove the anxiety-like phenotype of the 5-HTT mouse model, and to investigate whether 5-HTT genotype also causes differences in judgment bias. While our results confirm that homozygous 5-HTT knockout mice display highest levels of anxiety-like behavior, it was decreased in heterozygous mice. Against our expectations, we did not detect differences in the animals’ judgment bias. These results indicate that at least in mice the association between 5-HTT genotype and judgment bias is not straightforward and that other factors, including multiple genes as well as environmental influences, are implicated in the modulation of judgment biases. More research is needed to gain further insights into their function as potential endophenotypes for psychopathology.
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Affiliation(s)
- Viktoria Krakenberg
- Department of Behavioural Biology, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - Vanessa Tabea von Kortzfleisch
- Department of Behavioural Biology, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - Sylvia Kaiser
- Department of Behavioural Biology, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - Norbert Sachser
- Department of Behavioural Biology, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - S Helene Richter
- Department of Behavioural Biology, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
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7
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Demartini C, Greco R, Zanaboni AM, Sances G, De Icco R, Borsook D, Tassorelli C. Nitroglycerin as a comparative experimental model of migraine pain: From animal to human and back. Prog Neurobiol 2019; 177:15-32. [DOI: 10.1016/j.pneurobio.2019.02.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 01/19/2019] [Accepted: 02/10/2019] [Indexed: 12/13/2022]
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8
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Lu Q, Komenoi S, Usuki T, Takahashi D, Sakane F. Abnormalities of the serotonergic system in diacylglycerol kinase δ-deficient mouse brain. Biochem Biophys Res Commun 2018; 497:1031-1037. [DOI: 10.1016/j.bbrc.2018.02.165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 02/20/2018] [Indexed: 10/17/2022]
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9
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Nitroglycerin increases serotonin transporter expression in rat spinal cord but anandamide modulated this effect. J Chem Neuroanat 2017. [DOI: 10.1016/j.jchemneu.2017.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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10
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Sjaarda CP, Hecht P, McNaughton AJM, Zhou A, Hudson ML, Will MJ, Smith G, Ayub M, Liang P, Chen N, Beversdorf D, Liu X. Interplay between maternal Slc6a4 mutation and prenatal stress: a possible mechanism for autistic behavior development. Sci Rep 2017; 7:8735. [PMID: 28821725 PMCID: PMC5562880 DOI: 10.1038/s41598-017-07405-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/23/2017] [Indexed: 02/05/2023] Open
Abstract
The low activity allele of the maternal polymorphism, 5HTTLPR, in the serotonin transporter, SLC6A4, coupled with prenatal stress is reported to increase the risk for children to develop autism spectrum disorder (ASD). Similarly, maternal Slc6a4 knock-out and prenatal stress in rodents results in offspring demonstrating ASD-like characteristics. The present study uses an integrative genomics approach to explore mechanistic changes in early brain development in mouse embryos exposed to this maternal gene-environment phenomenon. Restraint stress was applied to pregnant Slc6a4 +/+ and Slc6a4 +/- mice and post-stress embryonic brains were assessed for whole genome level profiling of methylome, transcriptome and miRNA using Next Generation Sequencing. Embryos of stressed Slc6a4 +/+ dams exhibited significantly altered methylation profiles and differential expression of 157 miRNAs and 1009 genes affecting neuron development and cellular adhesion pathways, which may function as a coping mechanism to prenatal stress. In striking contrast, the response of embryos of stressed Slc6a4 +/- dams was found to be attenuated, shown by significantly reduced numbers of differentially expressed genes (458) and miRNA (0) and genome hypermethylation. This attenuated response may pose increased risks on typical brain development resulting in development of ASD-like characteristics in offspring of mothers with deficits in serotonin related pathways during stressful pregnancies.
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Affiliation(s)
- Calvin P Sjaarda
- Department of Psychiatry, Queen's University, Kingston, Ontario, Canada.,Queen's Genomics Lab at Ongwanada (QGLO), Ongwanada Resource Center, Kingston, Ontario, Canada
| | - Patrick Hecht
- Interdisciplinary Neuroscience Program, University of Missouri, Columbia, Missouri, USA
| | - Amy J M McNaughton
- Department of Psychiatry, Queen's University, Kingston, Ontario, Canada.,Queen's Genomics Lab at Ongwanada (QGLO), Ongwanada Resource Center, Kingston, Ontario, Canada
| | - Audrina Zhou
- Department of Psychiatry, Queen's University, Kingston, Ontario, Canada.,Queen's Genomics Lab at Ongwanada (QGLO), Ongwanada Resource Center, Kingston, Ontario, Canada
| | - Melissa L Hudson
- Department of Psychiatry, Queen's University, Kingston, Ontario, Canada.,Queen's Genomics Lab at Ongwanada (QGLO), Ongwanada Resource Center, Kingston, Ontario, Canada
| | - Matt J Will
- Psychological Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri, USA
| | - Garth Smith
- Department of Pediatrics, Queen's University, Kingston, Ontario, Canada.,Child Development Centre, Hotel Dieu Hospital, Kingston, Ontario, Canada
| | - Muhammad Ayub
- Department of Psychiatry, Queen's University, Kingston, Ontario, Canada
| | - Ping Liang
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Nansheng Chen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - David Beversdorf
- Interdisciplinary Neuroscience Program, University of Missouri, Columbia, Missouri, USA.,Departments of Radiology, Neurology, and Psychological Sciences, and the Thompson Center for Autism and Neurodevelopmental Disorders, and William and Nancy Thompson Endowed Chair in Radiology, University of Missouri, Columbia, Missouri, USA
| | - Xudong Liu
- Department of Psychiatry, Queen's University, Kingston, Ontario, Canada. .,Queen's Genomics Lab at Ongwanada (QGLO), Ongwanada Resource Center, Kingston, Ontario, Canada.
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11
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Behavioral and pharmacological phenotypes of brain-specific diacylglycerol kinase δ-knockout mice. Brain Res 2016; 1648:193-201. [DOI: 10.1016/j.brainres.2016.07.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/06/2016] [Accepted: 07/12/2016] [Indexed: 12/31/2022]
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12
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Genetic Variations in the Serotonergic System Mediate a Combined, Weakened Response to SSRI Treatment: A Proposed Model. eNeuro 2015; 2:eN-TNC-0032-14. [PMID: 26464988 PMCID: PMC4586934 DOI: 10.1523/eneuro.0032-14.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 05/01/2015] [Accepted: 05/06/2015] [Indexed: 12/16/2022] Open
Abstract
Individuals with the short (S) allele in the promoter region of the serotonin transporter gene (5-HTTLPR) show a less favorable response to selective serotonin reuptake inhibitor (SSRI) treatment than individuals with the long (L) allele. Similarly, individuals with the C(-1019)G allele for the mutation found in the promoter region of the serotonin 1A receptor gene (5-HTR1A) have shown blunted responses to SSRI treatment when compared with individuals lacking this polymorphism. While these findings have been replicated across multiple studies, only two studies to date have reported data for a gene-gene interaction associated with response to SSRI treatment. Both of these studies reported a combined effect for these genotypes, with individuals homozygous for the L allele and the C allele (5-HTT(L/L)-1A(C/C)) reporting the most favorable response to SSRI treatment, and individuals homozygous for the S allele and the G allele (5-HTT(S/S)-1A(G/G)) reporting the least favorable response to SSRI treatment. Additionally, no neural mechanisms have been proposed to explain why this gene-gene interaction has been observed. To that end, this article provides a review of the relevant literature associated with these polymorphisms and proposes a feasible model that describes a genotype-dependent modulation of postsynaptic serotonin signaling associated with the 5-HTT and 5-HTR1A genes.
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13
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Watson KK, Li D, Brent LJN, Horvath JE, Gonzalez-Martinez J, Lambides RA, Robinson AG, Skene JHP, Platt ML. Genetic influences on social attention in free-ranging rhesus macaques. Anim Behav 2015; 103:267-275. [PMID: 26034313 PMCID: PMC4448754 DOI: 10.1016/j.anbehav.2015.02.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
An ethological approach to attention predicts that organisms orient preferentially to valuable sources of information in the environment. For many gregarious species, orienting to other individuals provides valuable social information but competes with food acquisition, water consumption and predator avoidance. Individual variation in vigilance behaviour in humans spans a continuum from inattentive to pathological levels of interest in others. To assess the comparative biology of this behavioural variation, we probed vigilance rates in free-ranging macaques during water drinking, a behaviour incompatible with the gaze and postural demands of vigilance. Males were significantly more vigilant than females. Moreover, vigilance showed a clear genetic component, with an estimated heritability of 12%. Monkeys carrying a relatively infrequent 'long' allele of TPH2, a regulatory gene that influences serotonin production in the brain, were significantly less vigilant compared to monkeys that did not carry the allele. These findings resonate with the hypothesis that the serotonin pathway regulates vigilance in primates and by extension provoke the idea that individual variation in vigilance and its underlying biology may be adaptive rather than pathological.
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Affiliation(s)
- K. K. Watson
- Institute for Cognitive Science, University of Colorado at Boulder, Boulder, CO, U.S.A
| | - D. Li
- Center for Cognitive Neuroscience, Duke University, Durham, NC, U.S.A
- Duke Institute for Brain Sciences, Duke University, Durham, NC, U.S.A
| | - L. J. N. Brent
- Center for Cognitive Neuroscience, Duke University, Durham, NC, U.S.A
- Duke Institute for Brain Sciences, Duke University, Durham, NC, U.S.A
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, U.K
| | - J. E. Horvath
- Nature Research Center, Museum of Natural Sciences, Raleigh, NC, U.S.A
- Department of Biology, North Carolina Central University, Durham, NC, U.S.A
- Department of Evolutionary Anthropology, Duke University, Durham, NC, U.S.A
| | - J. Gonzalez-Martinez
- Caribbean Primate Research Center, University of Puerto Rico, Punta Santiago, PR, U.S.A
| | - Ruiz- A. Lambides
- Caribbean Primate Research Center, University of Puerto Rico, Punta Santiago, PR, U.S.A
| | - A. G. Robinson
- Department of Neurobiology, Duke University, Research Drive, Durham, NC, U.S.A
| | - J. H. P Skene
- Department of Neurobiology, Duke University, Research Drive, Durham, NC, U.S.A
| | - M. L. Platt
- Center for Cognitive Neuroscience, Duke University, Durham, NC, U.S.A
- Duke Institute for Brain Sciences, Duke University, Durham, NC, U.S.A
- Department of Evolutionary Anthropology, Duke University, Durham, NC, U.S.A
- Department of Neurobiology, Duke University, Research Drive, Durham, NC, U.S.A
- Department of Psychology & Neuroscience, Duke University, Durham, NC, U.S.A
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14
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Goltseker K, Yankelevitch-Yahav R, Albelda NS, Joel D. Signal attenuation as a rat model of obsessive compulsive disorder. J Vis Exp 2015:52287. [PMID: 25650700 PMCID: PMC4354519 DOI: 10.3791/52287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
In the signal attenuation rat model of obsessive-compulsive disorder (OCD), lever-pressing for food is followed by the presentation of a compound stimulus which serves as a feedback cue. This feedback is later attenuated by repeated presentations of the stimulus without food (without the rat emitting the lever-press response). In the next stage, lever-pressing is assessed under extinction conditions (i.e., no food is delivered). At this stage rats display two types of lever-presses, those that are followed by an attempt to collect a reward, and those that are not. The latter are the measure of compulsive-like behavior in the model. A control procedure in which rats do not experience the attenuation of the feedback cue serves to distinguish between the effects of signal attenuation and of extinction. The signal attenuation model is a highly validated model of OCD and differentiates between compulsive-like behaviors and behaviors that are repetitive but not compulsive. In addition the measures collected during the procedure eliminate alternative explanations for differences between the groups being tested, and are quantitative, unbiased and unaffected by inter-experimenter variability. The major disadvantages of this model are the costly equipment, the fact that it requires some technical know-how and the fact that it is time-consuming compared to other models of OCD (11 days). The model may be used for detecting the anti- or pro-compulsive effects of pharmacological and non-pharmacological manipulations and for studying the neural substrate of compulsive behavior.
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Affiliation(s)
| | | | - Noa S Albelda
- School of Psychological Sciences, Tel-Aviv University
| | - Daphna Joel
- School of Psychological Sciences, Tel-Aviv University; Sagol School of Neuroscience, Tel-Aviv University;
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15
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Qin D, Rizak J, Feng X, Yang S, Yang L, Fan X, Lü L, Chen L, Hu X. Cortisol responses to chronic stress in adult macaques: moderation by a polymorphism in the serotonin transporter gene. Behav Brain Res 2014; 278:280-5. [PMID: 25311283 DOI: 10.1016/j.bbr.2014.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/30/2014] [Accepted: 10/04/2014] [Indexed: 02/05/2023]
Abstract
Accumulating evidence has shown that a polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) moderates the association between stress and depressive symptoms. However, the exact etiologies underlying this moderation are not well understood. Here it is reported that among adult female rhesus macaques, an orthologous polymorphism (rh5-HTTLPR) exerted an influence on cortisol responses to chronic stress. It was found that females with two copies of the short allele were associated with increased cortisol responses to chronic stress in comparison to their counterparts who have one or two copies of the long allele. In the absence of stress, no differences related to genotype were observed in these females. This genetic moderation was found without a genetic influence on exposure to stressful situations. Rather it was found to be a genetic modulation of cortisol responses to chronic stress. These findings indicate that the rh5-HTTLPR polymorphism is closely related to hypothalamus-pituitary-adrenal (HPA) axis reactivity, which may increase susceptibility to depression in females with low serotonin transporter efficiency and a history of stress.
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Affiliation(s)
- Dongdong Qin
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China; State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Joshua Rizak
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoli Feng
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China
| | - Shangchuan Yang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China
| | - Lichuan Yang
- School of Pharmaceutical Science and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, Yunnan, China
| | - Xiaona Fan
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China
| | - Longbao Lü
- Kunming Primate Research Center of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China
| | - Lin Chen
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xintian Hu
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China; Kunming Primate Research Center of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China.
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Belsky DW, Suppli NP, Israel S. Gene-environment interaction research in psychiatric epidemiology: a framework and implications for study design. Soc Psychiatry Psychiatr Epidemiol 2014; 49:1525-9. [PMID: 25216778 PMCID: PMC4174337 DOI: 10.1007/s00127-014-0954-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 08/28/2014] [Indexed: 02/08/2023]
Affiliation(s)
- Daniel W Belsky
- Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, NC, USA,
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17
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Liu H, Li Y, Guo G. Gene by Social-Environment Interaction for Youth Delinquency and Violence: Thirty-Nine Aggression-related Genes. ACTA ACUST UNITED AC 2014; 93:881-903. [PMID: 25755300 DOI: 10.1093/sf/sou086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Complex human traits are likely to be affected by many environmental and genetic factors, and the interactions among them. However, previous gene-environment interaction (G×E) studies have typically focused on one or only a few genetic variants at a time. To provide a broader view of G×E, this study examines the relationship between 403 genetic variants from 39 genes and youth delinquency and violence. We find evidence that low social control is associated with greater genetic risk for delinquency and violence and high/moderate social control with smaller genetic risk for delinquency and violence. Our findings are consistent with prior G×E studies based on a small number of genetic variants, and, more importantly, we show that these findings still hold when a large number of genetic variants are considered simultaneously. A key implication of these findings is that the expression of multiple genes related to delinquency depends on the social environment: gene expression is likely to be amplified in low-social-control environments but, tends to be suppressed in high/moderate-social-control environments. This study not only deepens our understanding of how the social environment shapes individual behavior, but also provides important conceptual and methodological insights for future G×E research on complex human traits.
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Affiliation(s)
- Hexuan Liu
- Department of Sociology, the University of North Carolina at Chapel Hill ; Carolina Population Center, the University of North Carolina at Chapel Hill
| | - Yi Li
- Department of Sociology, the University of North Carolina at Chapel Hill
| | - Guang Guo
- Department of Sociology, the University of North Carolina at Chapel Hill ; Carolina Center for Genome Sciences, the University of North Carolina at Chapel Hill ; Carolina Population Center, the University of North Carolina at Chapel Hill
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18
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Epigenetic and epistatic interactions between serotonin transporter and brain-derived neurotrophic factor genetic polymorphism: insights in depression. Neuroscience 2014; 275:455-68. [PMID: 24972302 DOI: 10.1016/j.neuroscience.2014.06.036] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 06/13/2014] [Accepted: 06/17/2014] [Indexed: 01/19/2023]
Abstract
Epidemiological studies have shown significant results in the interaction between the functions of brain-derived neurotrophic factor (BDNF) and 5-HT in mood disorders, such as major depressive disorder (MDD). The latest research has provided convincing evidence that gene transcription of these molecules is a target for epigenetic changes, triggered by stressful stimuli that starts in early childhood and continues throughout life, which are subsequently translated into structural and functional phenotypes culminating in depressive disorders. The short variants of 5-HTTLPR and BDNF-Met are seen as forms which are predisposed to epigenetic aberrations, which leads individuals to a susceptibility to environmental adversities, especially when subjected to stress in early life. Moreover, the polymorphic variants also feature epistatic interactions in directing the functional mechanisms elicited by stress and underlying the onset of depressive disorders. Also emphasized are works which show some mediators between stress and epigenetic changes of the 5-HTT and BDNF genes, such as the hypothalamic-pituitary-adrenal (HPA) axis and the cAMP response element-binding protein (CREB), which is a cellular transcription factor. Both the HPA axis and CREB are also involved in epistatic interactions between polymorphic variants of 5-HTTLPR and Val66Met. This review highlights some research studying changes in the epigenetic patterns intrinsic to genes of 5-HTT and BDNF, which are related to lifelong environmental adversities, which in turn increases the risks of developing MDD.
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Armario A, Nadal R. Individual differences and the characterization of animal models of psychopathology: a strong challenge and a good opportunity. Front Pharmacol 2013; 4:137. [PMID: 24265618 PMCID: PMC3821037 DOI: 10.3389/fphar.2013.00137] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 10/16/2013] [Indexed: 02/06/2023] Open
Abstract
Despite the development of valuable new techniques (i.e., genetics, neuroimage) for the study of the neurobiological substrate of psychiatric diseases, there are strong limitations in the information that can be gathered from human studies. It is thus critical to develop appropriate animal models of psychiatric diseases to characterize their putative biological bases and the development of new therapeutic strategies. The present review tries to offer a general perspective and several examples of how individual differences in animals can contribute to explain differential susceptibility to develop behavioral alterations, but also emphasizes methodological problems that can lead to inappropriate or over-simplistic interpretations. A critical analysis of the approaches currently used could contribute to obtain more reliable data and allow taking full advantage of new and sophisticated technologies. The discussion is mainly focused on anxiety-like and to a lower extent on depression-like behavior in rodents.
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Affiliation(s)
- Antonio Armario
- Institut de Neurociències, Universitat Autònoma de Barcelona Bellaterra, Barcelona, Spain ; Unitat de Fisiologia Animal, Facultat de Biociències, Universitat Autònoma de Barcelona Bellaterra, Barcelona, Spain
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20
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Hymel KA, Salmeto AL, Loria MJ, White SW, Sufka KJ. Strain vulnerability and resiliency in the chick anxiety-depression model. Physiol Behav 2013; 120:124-9. [PMID: 23911807 DOI: 10.1016/j.physbeh.2013.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 07/23/2013] [Accepted: 07/25/2013] [Indexed: 11/18/2022]
Abstract
Increasing research is focused on genetic contributions to variability in stress-related endophenotypes in humans and animal model simulations. The current study sought to identify strain vulnerabilities and resiliencies to an isolation-stressor in the chick anxiety-depression model. Nine different strains of socially raised chicks were tested in isolated or non-isolated conditions for 90 min in which distress vocalization (DVoc) rates were collected and then transformed to depression-like phase threshold (@ 25, 50, 75 and 95%) latencies. In general, chicks in the non-isolated condition displayed relatively low DVoc rates throughout the test session, despite some variability in initial rates. Chicks in the isolated condition displayed relatively high DVoc rates in the first 3 min, indicative of an anxiety-like state, which declined by approximately 50% within 10-25 min in all strains and remained stable thereafter, indicative of a depression-like state. Contrast effects revealed that, relative to all other strains, the Black Australorp strain displayed shorter and the Producrain displayed longer depression threshold latencies, respectively. Of the remaining strains, the Silver Laced Wyandotte displayed depression thresholds that best represent an intermediate stress response. These findings identify vulnerable and resilient strains for examining depression-related endophenotypes in the chick anxiety-depression model.
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Affiliation(s)
- Kristen A Hymel
- Department of Psychology, University of Mississippi, Oxford, MS 38677, USA.
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21
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Xu K, Wang F. Influence of 5-HTTLPR genotypes on structural and functional connectivity within amygdala-prefrontal cortex circuitry. Neurosci Bull 2013; 29:1-2. [PMID: 23322004 DOI: 10.1007/s12264-013-1302-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Ke Xu
- Department of Radiology, The First Affiliated Hospital, China Medical University, Shenyang, 110001, China.
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22
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Heiming RS, Mönning A, Jansen F, Kloke V, Lesch KP, Sachser N. To attack, or not to attack? The role of serotonin transporter genotype in the display of maternal aggression. Behav Brain Res 2013; 242:135-41. [PMID: 23291155 DOI: 10.1016/j.bbr.2012.12.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 12/20/2012] [Accepted: 12/24/2012] [Indexed: 11/26/2022]
Abstract
Aggressive behavior in males has been intensively investigated regarding the influence of the brain serotonergic system. Despite some inconsistencies, a general conclusion is that low levels of serotonin (5-HT) are associated with high levels of male aggression. The role of the serotonergic system for female aggression is less well researched. Female mice rarely show intraspecific aggressive behavior, except during lactation, when they may exhibit intense aggression towards intruders to protect their pups. The aim of the present study was to investigate the impact of 5-HT transporter (5-HTT) inactivation on maternal aggression in mice. Therefore, lactating homozygous and heterozygous 5-HTT knockout as well as wildtype mice were confronted with male intruders in their home cages. Homozygous 5-HTT knockout dams, which exhibit highest levels of extracellular 5-HT in the brain, were significantly less prone to initiate offensive aggression than wildtype controls. Moreover, they showed longer latencies to attack the intruder, attacked less often and displayed an overall lower frequency of offensive aggressive behavior patterns than wildtype dams. Heterozygous 5-HTT knockout mothers generally showed intermediate levels of aggressive behavior. Thus, our data indicate that higher extracellular including synaptic levels of 5-HT are associated with lower intensity of aggressive behavior in lactating mice, adding support to the inhibitory role of 5-HT in aggression also in females.
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Affiliation(s)
- Rebecca S Heiming
- Department of Behavioural Biology, University of Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Germany.
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Abstract
Over the past century, much of genetics was deterministic, and feminist researchers framed justified criticisms of genetics research. However, over the past two decades, genetics research has evolved remarkably and has moved far from earlier deterministic approaches. Our article provides a brief primer on modern genetics, emphasizing contemporary evidence for the complex interplay between genes and environment. We focus particularly on the role of gene–environment interactions for gender-imbalanced disorders such as depression. We review research on epigenetics, which is one mechanism by which environment influences gene expression. Modern genetics is not based on a model of genetic determinism; instead, it recognizes the complexity of genetic influences and the nuanced interplay between genes and environment across life span development. Even with the modern genetics approaches, of course, there is still room for criticism and input from gender researchers. We outline methodological and conceptual issues more generally and from a gender researcher’s perspective. We argue that, with interdisciplinary collaborations, modern genetics can be integrated into gender research and vice versa in ways that will create progress in both fields.
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Affiliation(s)
- Rachel H. Salk
- Department of Psychology, University of Wisconsin-Madison, Madison, WI, USA
| | - Janet S. Hyde
- Department of Psychology, University of Wisconsin-Madison, Madison, WI, USA
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24
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Abstract
There is much evidence for the involvement of central monoaminergic systems, the key targets of stress, in the regulation of mood. Animal and human findings indicate that genetics play a role in the etiology of mood disorders, and so we selected divergent inbred rat strains according to their anxiety-related behaviors on exposure to novel environments. We compared these strains for psychoneuroendocrine response to stressors and/or antidepressants. Molecular genetic studies were also performed to localize the genomic regions associated with these strain-dependent anxiety profiles. We then examined human results indicating that allelic variations in the serotonin transporter (5-HTT) may play a role in the etiology of neuroticism and depression. Thus, we compared inbred rat strains for the 5-HTT, with regard to central and peripheral (platelet) protein expression and function, and the consequences of local application of a selective serotonin reuptake inhibitor (SSRI) on extracellular serotonin (5-HT) levels. Our results indicate that spontaneously hypertensive rats and Lewis rats (LEW) selectively diverge in terms of anxiety-related behaviors and that this divergence is located on chromosome 4. The use of social defeat in LEW and the analysis of its psychoneuroendocrine consequences strongly suggest that such a paradigm, which is sensitive to repeated SSRI treatment, models posttraumatic stress disorder. The Wistar-Kyoto rat may be an adequate model to study the consequences of a genetically driven hypersensitivity to stress and noradrenergic antidepressants. Our most recent findings show that the Fischer 344 and LEW strains differ in protein expression and function of hippocampal and platelet 5-HTT; the divergence in protein expression is not due to allelic variations in the gene-coding sequences and leads to marked differences in extracellular 5-HT levels under basal conditions or SSRI. These examples illustrate how the use of inbred rat strains may complement our knowledge on the genetics of behavior, in the same way as the use of transgenic mice.
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Affiliation(s)
- Francis Chaouloff
- Neurogénétique et Stress, INSERM U471-INRA, Institut F. Magendie, Bordeaux, France
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25
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Abstract
Anxiety is a psychological, physiological, and behavioral state induced in animals and humans by a threat to well-being or survival, either actual or potential. It is characterized by increased arousal, expectancy, autonomic and neuroendocrine activation, and specific behavior patterns. The function of these changes is to facilitate coping with an adverse or unexpected situation. Pathological anxiety interferes with the ability to cope successfully with life challenges. Vulnerability to psychopathology appears to be a consequence of predisposing factors (or traits), which result from numerous gene-environment interactions during development (particularly during the perinatal period) and experience (life events), in this review, the biology of fear and anxiety will be examined from systemic (brain-behavior relationships, neuronal circuitry, and functional neuroanatomy) and cellular/molecular (neurotransmitters, hormones, and other biochemical factors) points of view, with particular reference to animal models. These models have been instrumental in establishing the biological correlates of fear and anxiety, although the recent development of noninvasive investigation methods in humans, such as the various neuroimaging techniques, certainly opens new avenues of research in this field. Our current knowledge of the biological bases of fear and anxiety is already impressive, and further progress toward models or theories integrating contributions from the medical, biological, and psychological sciences can be expected.
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Affiliation(s)
- Thierry Steimer
- Clinical Psychopharmacology Unit, Geneva University Hospital, Chêne-Bourg, Switzerland
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26
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Kyzar EJ, Pham M, Roth A, Cachat J, Green J, Gaikwad S, Kalueff AV. Alterations in grooming activity and syntax in heterozygous SERT and BDNF knockout mice: the utility of behavior-recognition tools to characterize mutant mouse phenotypes. Brain Res Bull 2012; 89:168-76. [PMID: 22951260 DOI: 10.1016/j.brainresbull.2012.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 08/03/2012] [Accepted: 08/08/2012] [Indexed: 12/31/2022]
Abstract
Serotonin transporter (SERT) and brain-derived neurotrophic factor (BDNF) are key modulators of molecular signaling, cognition and behavior. Although SERT and BDNF mutant mouse phenotypes have been extensively characterized, little is known about their self-grooming behavior. Grooming represents an important behavioral domain sensitive to environmental stimuli and is increasingly used as a model for repetitive behavioral syndromes, such as autism and attention deficit/hyperactivity disorder. The present study used heterozygous ((+/-)) SERT and BDNF male mutant mice on a C57BL/6J background and assessed their spontaneous self-grooming behavior applying both manual and automated techniques. Overall, SERT(+/-) mice displayed a general increase in grooming behavior, as indicated by more grooming bouts and more transitions between specific grooming stages. SERT(+/-) mice also aborted more grooming bouts, but showed generally unaltered activity levels in the observation chamber. In contrast, BDNF(+/-) mice displayed a global reduction in grooming activity, with fewer bouts and transitions between specific grooming stages, altered grooming syntax, as well as hypolocomotion and increased turning behavior. Finally, grooming data collected by manual and automated methods (HomeCageScan) significantly correlated in our experiments, confirming the utility of automated high-throughput quantification of grooming behaviors in various genetic mouse models with increased or decreased grooming phenotypes. Taken together, these findings indicate that mouse self-grooming behavior is a reliable behavioral biomarker of genetic deficits in SERT and BDNF pathways, and can be reliably measured using automated behavior-recognition technology.
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Affiliation(s)
- Evan J Kyzar
- Department of Pharmacology and Neuroscience Program, Tulane University Medical School, New Orleans, LA 70112, USA
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27
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Mohamed Saini S, Muhamad Radzi A, Abdul Rahman AH. Polymorphism of the serotonin transporter gene (5-HTTLPR) in major depressive disorder patients in Malaysia. Asia Pac Psychiatry 2012; 4:126-30. [PMID: 26767356 DOI: 10.1111/j.1758-5872.2012.00190.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 12/14/2011] [Indexed: 12/20/2022]
Abstract
INTRODUCTION The serotonin transporter promoter (5-HTTLPR) is a potential susceptibility locus in the pathogenesis of major depressive disorder. However, data from Malaysia is lacking. The present study aimed to determine the association between the homozygous short variant of the serotonin transporter promoter gene (5-HTTLPR) with major depressive disorder. METHODS This is a candidate gene case-control association study. The sample consists of 55 major depressive disorder probands and 66 controls. They were Malaysian descents and were unrelated. The Axis I diagnosis was determined using Mini International Neuropsychiatric Interview (M.I.N.I.). The control group comprised healthy volunteers without personal psychiatric history and family history of mood disorders. Participants' blood was sent to the Institute Medical Research for genotyping. RESULTS The present study failed to detect an association between 5-HTTLPR ss genotype with major depressive disorder (χ(2) = 3.67, d.f. = 1, P = 0.055, odds ratio 0.25, 95% confidence interval = 0.07-1.94). Sub-analysis revealed that the frequency of l allele in healthy controls was higher (78.0%) than that of Caucasian and East Asian population. However, in view of the small sample size this study may be prone to type II error (and type I error). DISCUSSION This preliminary study suggests that the homozygous short variant of the 5-HTTLPR did not appear to be a risk factor for increasing susceptibility to major depressive disorder.
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Affiliation(s)
- Suriati Mohamed Saini
- Department of Psychiatry, National University of Malaysia Medical Center, Kuala Lumpur, Malaysia
| | - Azizah Muhamad Radzi
- Department of Biotechnology, Institute of Medical Research, Kuala Lumpur, Malaysia
| | - Abdul Hamid Abdul Rahman
- Department of Psychiatry, National University of Malaysia Medical Center, Kuala Lumpur, Malaysia
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28
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Albelda N, Joel D. Current animal models of obsessive compulsive disorder: an update. Neuroscience 2012; 211:83-106. [PMID: 21925243 DOI: 10.1016/j.neuroscience.2011.08.070] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 08/29/2011] [Accepted: 08/31/2011] [Indexed: 12/30/2022]
Affiliation(s)
- N Albelda
- Department of Psychology, Tel Aviv University, Ramat-Aviv, Tel Aviv 69978, Israel
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29
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Haddley K, Bubb VJ, Breen G, Parades-Esquivel UM, Quinn JP. Behavioural genetics of the serotonin transporter. Curr Top Behav Neurosci 2012; 12:503-535. [PMID: 22261701 DOI: 10.1007/7854_2011_186] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The serotonin transporter is a key regulator of the bioavailability of serotonin and therefore any modulation in the expression or action of the transporter would be expected to have consequences on behaviour. The transporter has therefore become a target for pharmaceutical intervention in behavioural and mood disorders. The search for polymorphic variants in the transporter that would associate with neurological disorders has been extensive but has become focused on two domains which are both termed variable number tandem repeat (VNTR)polymorphisms. Both of these VNTRs are in non-coding DNA and therefore proposed to be mechanistically involved in a disorder through their ability to modulate transcriptional or post-transcriptional regulation of the transporter. The most extensively studied is in the promoter and is a bi-allelic insertion/deletion found in the 50 promoter region of the gene 1.2 kb upstream of the transcriptional start site. This VNTR, termed, 5-HTTLPR was initially identified as two variants containing either, 14 (short/deletion) or 16 (long/insertion) copies of a 22 bp repeat. A second widely studied VNTR found in the non-coding region of the transporter is located within intron 2 and comprises 9, 10 or 12 copies of a16–17 bp repeat termed, STin2.9, STin2.10 and STin2.12, respectively. These VNTR polymorphisms have been associated with a range of behavioural and psychiatric disorders including depression, OCD, anxiety and schizophrenia, however often the lack of reproducibility in different cohorts has led to debate on the actual association of the polymorphisms with this extensive range of neurological conditions. Here we review these two polymorphic VNTRs in depth and relate that to pharmaceutical response, their ability to regulate differential transporter expression, their core involvement in gene-environment interaction and their genetic association with specific disorders.
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Douthit KZ. The Convergence of Counseling and Psychiatric Genetics: An Essential Role for Counselors. JOURNAL OF COUNSELING AND DEVELOPMENT 2011. [DOI: 10.1002/j.1556-6678.2006.tb00376.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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31
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Narayanan V, Heiming RS, Jansen F, Lesting J, Sachser N, Pape HC, Seidenbecher T. Social defeat: impact on fear extinction and amygdala-prefrontal cortical theta synchrony in 5-HTT deficient mice. PLoS One 2011; 6:e22600. [PMID: 21818344 PMCID: PMC3144906 DOI: 10.1371/journal.pone.0022600] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 06/25/2011] [Indexed: 11/21/2022] Open
Abstract
Emotions, such as fear and anxiety, can be modulated by both environmental and genetic factors. One genetic factor is for example the genetically encoded variation of the serotonin transporter (5-HTT) expression. In this context, the 5-HTT plays a key role in the regulation of central 5-HT neurotransmission, which is critically involved in the physiological regulation of emotions including fear and anxiety. However, a systematic study which examines the combined influence of environmental and genetic factors on fear-related behavior and the underlying neurophysiological basis is missing. Therefore, in this study we used the 5-HTT-deficient mouse model for studying emotional dysregulation to evaluate consequences of genotype specific disruption of 5-HTT function and repeated social defeat for fear-related behaviors and corresponding neurophysiological activities in the lateral amygdala (LA) and infralimbic region of the medial prefrontal cortex (mPFC) in male 5-HTT wild-type (+/+), homo- (−/−) and heterozygous (+/−) mice. Naive males and experienced losers (generated in a resident-intruder paradigm) of all three genotypes, unilaterally equipped with recording electrodes in LA and mPFC, underwent a Pavlovian fear conditioning. Fear memory and extinction of conditioned fear was examined while recording neuronal activity simultaneously with fear-related behavior. Compared to naive 5-HTT+/+ and +/− mice, 5-HTT−/− mice showed impaired recall of extinction. In addition, 5-HTT−/− and +/− experienced losers showed delayed extinction learning and impaired recall of extinction. Impaired behavioral responses were accompanied by increased theta synchronization between the LA and mPFC during extinction learning in 5-HTT-/− and +/− losers. Furthermore, impaired extinction recall was accompanied with increased theta synchronization in 5-HTT−/− naive and in 5-HTT−/− and +/− loser mice. In conclusion, extinction learning and memory of conditioned fear can be modulated by both the 5-HTT gene activity and social experiences in adulthood, accompanied by corresponding alterations of the theta activity in the amygdala-prefrontal cortex network.
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Affiliation(s)
- Venu Narayanan
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Rebecca S. Heiming
- Department of Behavioural Biology, Westfälische Wilhelms-University, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, Westfälische Wilhelms-University, Münster, Germany
| | - Friederike Jansen
- Department of Behavioural Biology, Westfälische Wilhelms-University, Münster, Germany
| | - Jörg Lesting
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Norbert Sachser
- Department of Behavioural Biology, Westfälische Wilhelms-University, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, Westfälische Wilhelms-University, Münster, Germany
| | - Hans-Christian Pape
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Thomas Seidenbecher
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
- * E-mail:
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32
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Albelda N, Joel D. Animal models of obsessive-compulsive disorder: exploring pharmacology and neural substrates. Neurosci Biobehav Rev 2011; 36:47-63. [PMID: 21527287 DOI: 10.1016/j.neubiorev.2011.04.006] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 04/05/2011] [Accepted: 04/08/2011] [Indexed: 01/07/2023]
Abstract
During the last 30 years there have been many attempts to develop animal models of obsessive-compulsive disorder (OCD). Most models have not been studied further following the original publication, and in the past few years, most papers present studies employing a few established animal models, exploring the neural basis of compulsive behavior and developing new treatment strategies. Here we summarize findings from the five most studied animal models of OCD: 8-OHDPAT (8-hydroxy-2-(di-n-propylamino)-tetralin hydrobromide) induced decreased alternation, quinpirole-induced compulsive checking, marble burying, signal attenuation and spontaneous stereotypy in deer mice. We evaluate each model's face validity, derived from similarity between the behavior in the model and the specific symptoms of the human condition, predictive validity, derived from similarity in response to treatment (pharmacological or other), and construct validity, derived from similarity in the mechanism (physiological or psychological) that induces behavioral symptoms and in the neural systems involved. We present ideas regarding future clinical research based on each model's findings, and on this basis, also emphasize possible new approaches for the treatment of OCD.
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Affiliation(s)
- Noa Albelda
- Department of Psychology, Tel Aviv University, Ramat-Aviv, Tel Aviv 69978, Israel
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33
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Haenisch B, Bönisch H. Depression and antidepressants: Insights from knockout of dopamine, serotonin or noradrenaline re-uptake transporters. Pharmacol Ther 2011; 129:352-68. [DOI: 10.1016/j.pharmthera.2010.12.002] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 11/29/2010] [Indexed: 12/15/2022]
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34
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Heiming RS, Sachser N. Consequences of serotonin transporter genotype and early adversity on behavioral profile - pathology or adaptation? Front Neurosci 2010; 4:187. [PMID: 21151780 PMCID: PMC2999984 DOI: 10.3389/fnins.2010.00187] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 10/17/2010] [Indexed: 11/13/2022] Open
Abstract
This review focuses on how behavioral profile is shaped by early adversity in individuals with varying serotonin transporter (5-HTT) genotype. In a recent study on 5-HTT knockout mice Heiming et al. (2009) simulated a 'dangerous environment' by confronting pregnant and lactating females with odor cues of unfamiliar males, indicating the risk of infant killing. Growing up in a dangerous environment induced increased anxiety-related behavior and decreased exploratory locomotion in the offspring, the effects being most pronounced in mice lacking 5-HTT expression. We argue that these alterations in behavioral profile represent adaptive maternal effects that help the individuals to cope with adversity. In principle, such effects of adversity on behavioral profile should not automatically be regarded as pathological. Rather and in accordance with modern evolutionary theory they may represent adaptations, although individuals with 5-HTT genotype induced susceptibility to adversity may be at risk of developing pathologies.
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Affiliation(s)
- Rebecca S Heiming
- Department of Behavioural Biology, University of Muenster Muenster, Germany
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Hagan CE, Neumaier JF, Schenk JO. Rotating disk electrode voltammetric measurements of serotonin transporter kinetics in synaptosomes. J Neurosci Methods 2010; 193:29-38. [PMID: 20713085 PMCID: PMC2952731 DOI: 10.1016/j.jneumeth.2010.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 08/06/2010] [Accepted: 08/06/2010] [Indexed: 12/13/2022]
Abstract
Altered serotonin (5-HT) signaling is implicated in several neuropsychiatric disorders, including depression, anxiety, obsessive-compulsive disorder, and autism. The 5-HT transporter (SERT) modulates 5-HT neurotransmission strength and duration. This is the first study using rotating disk electrode voltammetry (RDEV) to measure 5-HT clearance. SERT kinetics were measured in whole brain synaptosomes. Uptake kinetics of exogenous 5-HT were measured using glassy carbon electrodes rotated in 500 μL glass chambers containing synaptosomes from SERT-knockout (-/-), heterozygous (+/-), or wild-type (+/+) mice. RDEV detected 5-HT concentrations of 5nM and higher. Initial velocities were kinetically resolved with K(m) and V(max) values of 99±35 standard error of regression (SER) nM and 181±11 SER fmol/(s×mg protein), respectively in wild-type synaptosomes. The method enables control over drug and chemical concentrations, facilitating interpretation of results. Results are compared in detail to other techniques used to measure SERT kinetics, including tritium labeled assays, chronoamperometry, and fast scan cyclic voltammetry. RDEV exhibits decreased 5-HT detection limits, decreased vulnerability to 5-HT oxidation products that reduce electrode sensitivity, and also overcomes diffusion limitations via forced convection by providing a continuous, kinetically resolved signal. Finally, RDEV distinguishes functional differences between genotypes, notably, between wild-type and heterozygous mice, an experimental problem with other experimental approaches.
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Affiliation(s)
- Catherine E Hagan
- Department of Comparative Medicine, University of Washington, Seattle, WA 98195, USA.
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36
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The serotonin transporter gene and startle response during nicotine deprivation. Biol Psychol 2010; 86:1-8. [PMID: 20888887 DOI: 10.1016/j.biopsycho.2010.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 08/18/2010] [Accepted: 09/24/2010] [Indexed: 11/21/2022]
Abstract
Affective startle probe methodology was used to examine the effects of nicotine administration and deprivation on emotional processes among individuals carrying at least one s allele versus those with the l/l genotype of the 5-Hydroxytryptamine (Serotonin) Transporter Linked Polymorphic Region, 5-HTTLPR in the promoter region of the serotonin transporter gene [solute ligand carrier family 6 member A4 (SLC6A4) or SERT]. Smokers (n=84) completed four laboratory sessions crossing deprivation (12-h deprived vs. non-deprived) with nicotine spray (nicotine vs. placebo). Participants viewed affective pictures (positive, negative, neutral) while acoustic startle probes were administered. We found that smokers with the l/l genotype showed significantly greater suppression of the startle response when provided with nicotine vs. placebo than those with the s/s or s/l genotypes. The results suggest that l/l smokers, who may have higher levels of the serotonin transporter and more rapid synaptic serotonin clearance, experience substantial reduction in activation of the defensive system when exposed to nicotine.
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Sachser N, Hennessy MB, Kaiser S. Adaptive modulation of behavioural profiles by social stress during early phases of life and adolescence. Neurosci Biobehav Rev 2010; 35:1518-33. [PMID: 20854842 DOI: 10.1016/j.neubiorev.2010.09.002] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 08/12/2010] [Accepted: 09/10/2010] [Indexed: 01/19/2023]
Abstract
The development of individual behavioural profiles can be powerfully influenced by stressful social experiences. Using a comparative approach, we focus on the role of social stressors for the modulation of behavioural profile during early phases of life and adolescence. For gregarious species, the stability of the social environment in which the pregnant and lactating female lives is of major importance for foetal brain development and the behavioural profile of the offspring in later life. Social instability during these critical periods of development generally brings about a behavioural and neuroendocrine masculinisation in daughters and a less pronounced expression of male-typical traits in sons. Moreover, when mothers live in a socially threatening world during this time, anxiety-like behaviour of their offspring often is elevated in adulthood. These effects of the social environment are likely to be mediated by maternal hormones and/or maternal behaviour. In addition, they can be modulated significantly by offspring genotype. We favour the hypothesis that the behavioural effects of social stress during this phase of life are not necessarily "pathological" (nonadaptive) consequences or constraints of adverse social conditions. Rather, mothers could be adjusting the offspring to their environment in an adaptive way. Adolescence is another period in which behavioural development is particularly susceptible to social influences. There is some evidence that stressful social events experienced at this time alter and canalize behaviour in an adaptive fashion, so that earlier influences on behavioural profile development can be complemented and readjusted, if necessary, to meet current environmental conditions. In terms of underlying neuroendocrine mechanism, a central role for the interaction of testosterone and stress hormones is suggested. In summary, the modulation of behavioural profiles by social stress from the prenatal phase through adolescence appears to represent an effective mechanism for repeated and rapid adaptation.
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Affiliation(s)
- Norbert Sachser
- Department of Behavioural Biology, University of Muenster, Badestrasse 9, 48149 Muenster, Germany.
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38
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Cousijn H, Rijpkema M, Qin S, van Marle HJF, Franke B, Hermans EJ, van Wingen G, Fernández G. Acute stress modulates genotype effects on amygdala processing in humans. Proc Natl Acad Sci U S A 2010; 107:9867-72. [PMID: 20457919 PMCID: PMC2906860 DOI: 10.1073/pnas.1003514107] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Probing gene-environment interactions that affect neural processing is crucial for understanding individual differences in behavior and disease vulnerability. Here, we tested whether the current environmental context, which affects the acute brain state, modulates genotype effects on brain function in humans. We manipulated the context by inducing acute psychological stress, which increases noradrenergic activity, and probed its effect on tonic activity and phasic responses in the amygdala using two MRI techniques: conventional blood oxygen level-dependent functional MRI and arterial spin labeling. We showed that only carriers of a common functional deletion in ADRA2B, the gene coding for the alpha2b-adrenoreceptor, displayed increased phasic amygdala responses under stress. Tonic activity, reflecting the perfusion of the amygdala, increased independently of genotype after stress induction. Thus, when tonic activity was heightened by stress, only deletion carriers showed increased amygdala responses. Our results demonstrate that genetic effects on brain operations can be state dependent, such that they only become apparent under specific, often environmentally controlled, conditions.
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Affiliation(s)
- Helena Cousijn
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
| | - Mark Rijpkema
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
| | - Shaozheng Qin
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
- Department of Neurology, Radboud University Nijmegen Medical Center, 6525 GC, Nijmegen, The Netherlands
| | - Hein J. F. van Marle
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
- Department of Neurology, Radboud University Nijmegen Medical Center, 6525 GC, Nijmegen, The Netherlands
- Department of Psychiatry, Radboud University Nijmegen Medical Center, 6525 EZ, Nijmegen, The Netherlands; and
| | - Barbara Franke
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
- Department of Psychiatry, Radboud University Nijmegen Medical Center, 6525 EZ, Nijmegen, The Netherlands; and
- Department of Human Genetics, Radboud University Nijmegen Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Erno J. Hermans
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
- Department of Neurology, Radboud University Nijmegen Medical Center, 6525 GC, Nijmegen, The Netherlands
| | - Guido van Wingen
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
- Department of Neurology, Radboud University Nijmegen Medical Center, 6525 GC, Nijmegen, The Netherlands
| | - Guillén Fernández
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, The Netherlands
- Department of Neurology, Radboud University Nijmegen Medical Center, 6525 GC, Nijmegen, The Netherlands
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39
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Caspi A, Hariri AR, Holmes A, Uher R, Moffitt TE. Genetic sensitivity to the environment: the case of the serotonin transporter gene and its implications for studying complex diseases and traits. Am J Psychiatry 2010; 167:509-27. [PMID: 20231323 PMCID: PMC2943341 DOI: 10.1176/appi.ajp.2010.09101452] [Citation(s) in RCA: 866] [Impact Index Per Article: 61.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Evidence of marked variability in response among people exposed to the same environmental risk implies that individual differences in genetic susceptibility might be at work. The study of such Gene-by-Environment (GxE) interactions has gained momentum. In this article, the authors review research about one of the most extensive areas of inquiry: variation in the promoter region of the serotonin transporter gene (SLC6A4; also known as 5-HTT) and its contribution to stress sensitivity. Research in this area has both advanced basic science and generated broader lessons for studying complex diseases and traits. The authors evaluate four lines of evidence about the 5-HTT stress-sensitivity hypothesis: 1) observational studies about the serotonin transporter linked polymorphic region (5-HTTLPR), stress sensitivity, and depression in humans; 2) experimental neuroscience studies about the 5-HTTLPR and biological phenotypes relevant to the human stress response; 3) studies of 5-HTT variation and stress sensitivity in nonhuman primates; and 4) studies of stress sensitivity and genetically engineered 5-HTT mutations in rodents. The authors then dispel some misconceptions and offer recommendations for GxE research. The authors discuss how GxE interaction hypotheses can be tested with large and small samples, how GxE research can be carried out before as well as after replicated gene discovery, the uses of GxE research as a tool for gene discovery, the importance of construct validation in evaluating GxE research, and the contribution of GxE research to the public understanding of genetic science.
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Affiliation(s)
- Avshalom Caspi
- Department of Psychology, and Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA.
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40
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Bayerer B, Engelbergs J, Savidou I, Boes T, Küper M, Schorn CF, Wissmann A, Knop D, Diener HC, Limmroth V. Single Nucleotide Polymorphisms of the Serotonin Transporter Gene in Migraine - An Association Study. Headache 2010; 50:319-22. [DOI: 10.1111/j.1526-4610.2009.01553.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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41
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Ali FR, Vasiliou SA, Haddley K, Paredes UM, Roberts JC, Miyajima F, Klenova E, Bubb VJ, Quinn JP. Combinatorial interaction between two human serotonin transporter gene variable number tandem repeats and their regulation by CTCF. J Neurochem 2009; 112:296-306. [PMID: 19860858 PMCID: PMC2848977 DOI: 10.1111/j.1471-4159.2009.06453.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two distinct variable number tandem repeats (VNTRs) within the human serotonin transporter gene (SLC6A4) have been implicated as predisposing factors for CNS disorders. The linked polymorphic region in the 5′-promoter exists as short (s) and long (l) alleles of a 22 or 23 bp elements. The second within intron 2 (Stin2) exists as three variants containing 9, 10 or 12 copies of a 16 or 17 bp element. These VNTRs, individually or in combination, supported differential reporter gene expression in rat neonate prefrontal cortical cultures. The level of reporter gene activity from the dual VNTR constructs indicated combinatorial action between the two domains. Chromatin immunoprecipitation demonstrated that both these VNTR domains can bind the CCCTC-binding factor and this correlated with the ability of exogenously supplied CCCTC-binding factor to modulate the expression supported by these reporter gene constructs. We suggest that the potential for interaction between multiple polymorphic domains should be incorporated into genetic association studies. J. Neurochem. (2010) 112, 296–306.
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Affiliation(s)
- Fahad R Ali
- School of Biomedical Sciences, University of Liverpool, Liverpool, UK
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42
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Heiming RS, Jansen F, Lewejohann L, Kaiser S, Schmitt A, Lesch KP, Sachser N. Living in a dangerous world: the shaping of behavioral profile by early environment and 5-HTT genotype. Front Behav Neurosci 2009; 3:26. [PMID: 19826611 PMCID: PMC2759357 DOI: 10.3389/neuro.08.026.2009] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 08/19/2009] [Indexed: 11/20/2022] Open
Abstract
Anxiety and anxiety disorders are influenced by both, environmental and genetic factors. One genetic factor under scrutiny for anxiety disorders is the genetically encoded variation of the serotonin transporter (5-HTT). The aim of this study was to elucidate the effects of a threatening environment during early phases of life on anxiety-like (ANX) and exploratory behavior (EXP) in adult mice, varying in serotonin transporter (5-HTT) genotype. For this purpose, pregnant and lactating 5-HTT +/− dams were repeatedly exposed to olfactory cues of unfamiliar adult males by introducing small amounts of soiled bedding to their home cage. These stimuli signal the danger of infanticide and simulate a threatening environment. Control females were treated with neutral bedding. The offspring (5-HTT +/+, +/−, −/−) were examined for their ANX and EXP. The main results were: (1) a main effect of genotype existed, with 5-HTT −/− showing higher levels of ANX and lower levels of EXP than 5-HTT +/− and wildtypes. (2) When mothers had lived in a threatening environment, their offspring showed increased ANX and reduced EXP compared to controls. (3) These effects were most pronounced in 5-HTT −/− mice. By applying a new ecologically relevant paradigm we conclude: If 5-HTT +/− mothers live in a threatening environment during pregnancy and lactation, their offspring behavioral profile will, in principle, be shaped in an adaptive way preparing the young for an adverse environment. This process is, however, modulated by 5-HTT genotype, bearing the risk that individuals with impaired serotonergic neurotransmission (5-HTT −/−) will develop an exaggerated, potentially pathological level of anxiety from gene × environment interactions.
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Affiliation(s)
- Rebecca S Heiming
- Department of Behavioural Biology, University of Muenster Muenster, Germany
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43
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Kalueff AV, Olivier JDA, Nonkes LJP, Homberg JR. Conserved role for the serotonin transporter gene in rat and mouse neurobehavioral endophenotypes. Neurosci Biobehav Rev 2009; 34:373-86. [PMID: 19698744 DOI: 10.1016/j.neubiorev.2009.08.003] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2009] [Revised: 08/12/2009] [Accepted: 08/13/2009] [Indexed: 10/20/2022]
Abstract
The serotonin transporter knockout (SERT(-/-)) mouse, generated in 1998, was followed by the SERT(-/-) rat, developed in 2006. The availability of SERT(-/-) rodents creates the unique possibility to study the conservation of gene function across species. Here we summarize SERT(-/-) mouse and rat data, and discuss species (dis)similarities in neurobehavioral endophenotypes. Both SERT(-/-) rodent models show a disturbed serotonergic system, altered nociception, higher anxiety, decreased social behavior, as well as increased negative emotionality, behavioral inhibition and decision making. Used to model a wide range of psychiatric disorders, SERT(-/-) rodents may be particularly valuable in research on neurodevelopmental disorders such as depression, anxiety, and possibly autism. We conclude that SERT function is conserved across mice and rats and that their behavioral profile arises from common neurodevelopmental alterations. Because mice and rats have species-specific characteristics that confer differential research advantages, a comparison of the two models has heuristic value in understanding the mechanisms and behavioral outcome of SERT genetic variation in humans.
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Affiliation(s)
- A V Kalueff
- Department of Pharmacology, Tulane University Medical School, New Orleans, LA 70112, USA
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44
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Retz W, Rösler M. The relation of ADHD and violent aggression: What can we learn from epidemiological and genetic studies? INTERNATIONAL JOURNAL OF LAW AND PSYCHIATRY 2009; 32:235-43. [PMID: 19411109 DOI: 10.1016/j.ijlp.2009.04.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Disruptive behavior includes psychopathological and behavioral constructs like aggression, impulsivity, violence, antisociality and psychopathy and is often closely related with diagnostic categories like conduct disorder (CD), attention deficit disorder (ADHD) and antisocial personality disorder (ASP). There is now clear evidence that neurobiological and environmental factors contribute to these phenotypes. A mounting body of evidence also suggests interactive effects of genetic and environmental risks. In this selective review we give an overview over epidemiological aspects of the relation between ADHD and antisocial behavior, including violent aggression and psychopathy. Moreover, we summarize recent findings from molecular genetic studies and particularly discuss pleiotropic effects of a functional polymorphism of the serotonin transporter promoter gene (5HTTLPR) and childhood adversity on ADHD and violent behavior. The reported gene-environment interactions are not only informative for understanding the neurobiological underpinnings of disruptive behavior, but also throw some light on the relation between ADHD and violent behavior from a genetic perspective. The impact of genetic research on forensic psychiatry and future directions of neurobiological research are discussed.
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Affiliation(s)
- Wolfgang Retz
- Institute for Forensic Psychology and Psychiatry, Neurocenter - Saarland University Hospital, Homburg/Saar, Germany.
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45
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Vimpani G. Getting the mix right: family, community and social policy interventions to improve outcomes for young people at risk of substance misuse. Drug Alcohol Rev 2009; 24:111-25. [PMID: 16076581 DOI: 10.1080/09595230500102210] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Societal responses to the existence of substance misuse fluctuate between harm minimisation and prohibition. Both approaches are predominantly downstream reactions to substance misuse that focus on the supply of harmful substances and the containment of misuse through treatment, rehabilitation or punishment. Until recently, little attention has been paid to the upstream individual, family, relationship, community or societal antecedents of substance misuse (which often overlap with those for other adverse life outcomes, such as unemployment, antisocial personality disorder and mental health problems) that have operated during earlier life. A growing body of evidence highlights the overlapping biological and experiential antecedents for substance abuse and other poor outcomes as well as the trajectory-changing protective factors that can prevent risks being translated into destiny. Risk minimisation and protection enhancement embedded in family and social systems are the essential building blocks of a set of early intervention strategies that begin antenatally and continue through the developing years of childhood, adolescence and young adult life, that have been shown to be effective in improving many outcomes in development, health and well-being. Much remains to be done to enable the promise of effective universal and targeted early intervention to be translated into policies, programs and practices that could be life-changing for citizens bogged in the mire of substance misuse and their children. Realistic, timely investment, influenced by the best scientific evidence indicating what works, for whom, under what circumstances, an increased degree of collaboration within and between governments and their agencies to enable "whole of government" responses in partnership with community-based initiatives are essential along with investments in multidisciplinary program evaluation research that will enable evidence-informed policy decisions to be tailored to the needs of individual countries.
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Affiliation(s)
- Graham Vimpani
- Disipline of Paediatrics and Child Health, University of Newcastle, New South Wales, Australia.
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46
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Wersinger C, Sidhu A. Partial regulation of serotonin transporter function by gamma-synuclein. Neurosci Lett 2009; 453:157-61. [PMID: 19429025 PMCID: PMC2825691 DOI: 10.1016/j.neulet.2009.02.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 02/14/2009] [Accepted: 02/18/2009] [Indexed: 12/27/2022]
Abstract
Human alpha-synuclein (alpha-Syn) is instrumental in maintaining homeostasis of monoamine neurotransmitters in brain, through its trafficking, and regulation of the cell surface expression and, thereby, activity of dopamine, serotonin and norepinephrine transporters. Here we have investigated whether other members of the synuclein family of proteins, gamma-synuclein (gamma-Syn) and beta-synuclein (beta-Syn) can similarly modulate the serotonin transporter (SERT). In Ltk(-) cells co-transfected with SERT and gamma-Syn, gamma-Syn reduced [(3)H]5-HT uptake, in a manner dependent on its expression levels. The decrease in SERT activity was via decreased V(max) of the transporter, without change in K(m), compared to cells expressing only SERT. By contrast, beta-Syn co-expression failed to alter SERT uptake activity, and neither the V(max) nor the K(m) was changed in the presence of beta-Syn. gamma-Syn modulation of SERT was only partial, with a maximal approximately 27% decrease in SERT activity seen even at high expression levels of gamma-Syn. By contrast, alpha-Syn attenuated SERT activity by approximately 65% at identical expression levels as gamma-Syn. Co-immunoprecipitation studies showed the presence of heteromeric protein:protein complexes between gamma-Syn or alpha-Syn and SERT, while beta-Syn failed to physically interact with SERT. Both alpha-Syn and gamma-Syn colocalized with SERT in rat primary raphae nuclei neurons. These studies document a novel physiological role for gamma-Syn in regulating 5-HT synaptic availability and homeostasis, and may be of relevance in depression and mood disorders, where SERT function is dysregulated.
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Affiliation(s)
| | - Anita Sidhu
- Department of Biochemistry, Georgetown University, Washington D.C. 20007, USA
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47
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Bearer EL, Zhang X, Janvelyan D, Boulat B, Jacobs RE. Reward circuitry is perturbed in the absence of the serotonin transporter. Neuroimage 2009; 46:1091-104. [PMID: 19306930 DOI: 10.1016/j.neuroimage.2009.03.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 03/10/2009] [Accepted: 03/11/2009] [Indexed: 10/21/2022] Open
Abstract
The serotonin transporter (SERT) modulates the entire serotonergic system in the brain and influences both the dopaminergic and norepinephrinergic systems. These three systems are intimately involved in normal physiological functioning of the brain and implicated in numerous pathological conditions. Here we use high-resolution magnetic resonance imaging (MRI) and spectroscopy to elucidate the effects of disruption of the serotonin transporter in an animal model system: the SERT knock-out mouse. Employing manganese-enhanced MRI, we injected Mn(2+) into the prefrontal cortex and obtained 3D MR images at specific time points in cohorts of SERT and normal mice. Statistical analysis of co-registered datasets demonstrated that active circuitry originating in the prefrontal cortex in the SERT knock-out is dramatically altered, with a bias towards more posterior areas (substantia nigra, ventral tegmental area, and Raphé nuclei) directly involved in the reward circuit. Injection site and tracing were confirmed with traditional track tracers by optical microscopy. In contrast, metabolite levels were essentially normal in the SERT knock-out by in vivo magnetic resonance spectroscopy and little or no anatomical differences between SERT knock-out and normal mice were detected by MRI. These findings point to modulation of the limbic cortical-ventral striatopallidal by disruption of SERT function. Thus, molecular disruptions of SERT that produce behavioral changes also alter the functional anatomy of the reward circuitry in which all the monoamine systems are involved.
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Affiliation(s)
- Elaine L Bearer
- Biological Imaging Center, Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA
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48
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Gerretsen P, Pollock BG. Pharmacogenetics and the serotonin transporter in late-life depression. Expert Opin Drug Metab Toxicol 2009; 4:1465-78. [PMID: 19040324 DOI: 10.1517/17425250802560279] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The etiologies of variable antidepressant response remain elusive. Aging and age-related illness add to the complexity and heterogeneity of late-life depression. The serotonin transporter (5-HTT) is the principal site of initial action for several antidepressants, including serotonin re-uptake inhibitors (SSRIs). The serotonin transporter-linked polymorphic region (5-HTTLPR) is the most widely studied polymorphism of the 5-HTT gene, SLC6A4, and is suspected of conferring vulnerability to elderly depression and resistance to treatment. OBJECTIVE To present an up-to-date account of the influence of 5-HTT polymorphisms on elderly depression, antidepressant response and susceptibility to medication side effects. METHOD A Medline search (1993 - 2008) of 5-HTT gene variation studies and analyses that included elderly depressed subjects was performed using the terms: 'serotonin transporter'; '5-HTT'; 'SERT'; '5-HTTLPR'; 'late-life depression'; 'elderly depression'; 'geriatric depression'; 'antidepressants' and 'SSRIs'. Reference sections were gleaned for relevant articles that may have been overlooked by the search strategy. CONCLUSION 5-HTTLPR may influence treatment response variability in late-life depression in a number of ways. Indirectly, 5-HTTLPR seems to influence the likelihood of adverse effects and non-adherence. Directly, the promoter region may contribute to response variability during the initial stages of treatment, which is explained, in part, by a gene-concentration interaction for paroxetine. Subjects with the S allele may be at an increased risk of adverse drug reactions and may require higher initial SSRI plasma concentrations to maximize response. Conversely, patients with the L/L genotype may respond even at lower concentrations.
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Affiliation(s)
- Philip Gerretsen
- Faculty of Medicine University of Toronto, Centre for Addiction and Mental Health, Division of Psychiatry, Toronto, Ontario, M5S 2S1, Canada
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49
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Karpova NN, Lindholm J, Pruunsild P, Timmusk T, Castrén E. Long-lasting behavioural and molecular alterations induced by early postnatal fluoxetine exposure are restored by chronic fluoxetine treatment in adult mice. Eur Neuropsychopharmacol 2009; 19:97-108. [PMID: 18973993 DOI: 10.1016/j.euroneuro.2008.09.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 08/22/2008] [Accepted: 09/09/2008] [Indexed: 01/17/2023]
Abstract
There is evidence that antidepressant drug treatment during a critical period of postnatal development renders mice susceptible to depression- and anxiety-related behaviour in adulthood. The mechanism of how early antidepressant treatment brings about long-term effects in emotional behaviour is not yet understood, but neurotrophins, particularly brain-derived neurotrophic factor (BDNF), have been implicated in this context. We examined the long-term effects of a transient early postnatal fluoxetine treatment on depression- and anxiety-related behaviours as well as gene expression of BDNF and its receptor TrkB in C57BL/6J mice. Treatment with fluoxetine between postnatal days P4 and P21 resulted in a significant loss of body weight and long-lasting behavioural inhibition in adult mice in response to stressful events such as the light-dark or open field tests. Postnatal fluoxetine exposure also decreased behavioural despair in the forced swim test. Both body weight and behavioural alterations were restored by chronic fluoxetine treatment in adulthood. The behavioral alterations were accompanied by changes in hippocampal BDNF mRNA. Specifically, we show that early-life fluoxetine exposure resulted in the long-term upregulation of BDNF expression in adult mice. However, chromatin immunoprecipitation studies did not reveal any changes in the acetylation or trimethylation of histone H3 at the BDNF promoters. Our experiments show that behavioural and molecular changes induced by early postnatal fluoxetine administration are reversed by chronic fluoxetine treatment of adult mice to control levels.
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Affiliation(s)
- Nina N Karpova
- Neuroscience Centre, University of Helsinki, 00014 Helsinki, Finland
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50
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Conley D. The promise and challenges of incorporating genetic data into longitudinal social science surveys and research. BIODEMOGRAPHY AND SOCIAL BIOLOGY 2009; 55:238-51. [PMID: 20183907 DOI: 10.1080/19485560903415807] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In this paper, I argue that social science and genomics can be integrated; however, the way this marriage is currently occurring rests on spurious methods and assumptions and, as a result, will yield few lasting insights. However, recent advances in both econometrics and in developmental genomics provide scientists with a novel opportunity to understand how genes and environment interact to produce social outcomes. Key to any causal inference about the interplay between genes and social environment is that either genotype be exogenously manipulated (i.e. through sibling fixed effects) while environmental conditions are held constant, and/or that environmental variation is exogenous in nature, i.e. experimental or arising from a natural experiment of sorts. Further, initial allele selection should be motivated by findings from genetic experiments in model animal studies linked to orthologous human genes. Likewise, genetic associations found in human population studies should then be tested through knock-out and over-expression studies in model organisms.
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