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Meyers JL, Brislin SJ, Kamarajan C, Plawecki MH, Chorlian D, Anohkin A, Kuperman S, Merikangas A, Pandey G, Kinreich S, Pandey A, Edenberg HJ, Bucholz KK, Almasy L, Porjesz B. The collaborative study on the genetics of alcoholism: Brain function. GENES, BRAIN, AND BEHAVIOR 2023; 22:e12862. [PMID: 37587903 PMCID: PMC10550791 DOI: 10.1111/gbb.12862] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/19/2023] [Accepted: 07/22/2023] [Indexed: 08/18/2023]
Abstract
Alcohol use disorder (AUD) and related health conditions result from a complex interaction of genetic, neural and environmental factors, with differential impacts across the lifespan. From its inception, the Collaborative Study on the Genetics of Alcoholism (COGA) has focused on the importance of brain function as it relates to the risk and consequences of alcohol use and AUD, through the examination of noninvasively recorded brain electrical activity and neuropsychological tests. COGA's sophisticated neurophysiological and neuropsychological measures, together with rich longitudinal, multi-modal family data, have allowed us to disentangle brain-related risk and resilience factors from the consequences of prolonged and heavy alcohol use in the context of genomic and social-environmental influences over the lifespan. COGA has led the field in identifying genetic variation associated with brain functioning, which has advanced the understanding of how genomic risk affects AUD and related disorders. To date, the COGA study has amassed brain function data on over 9871 participants, 7837 with data at more than one time point, and with notable diversity in terms of age (from 7 to 97), gender (52% female), and self-reported race and ethnicity (28% Black, 9% Hispanic). These data are available to the research community through several mechanisms, including directly through the NIAAA, through dbGAP, and in collaboration with COGA investigators. In this review, we provide an overview of COGA's data collection methods and specific brain function measures assessed, and showcase the utility, significance, and contributions these data have made to our understanding of AUD and related disorders, highlighting COGA research findings.
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Affiliation(s)
- Jacquelyn L. Meyers
- Department of Psychiatry and Behavioral SciencesState University of New York Downstate Medical CenterBrooklynNew YorkUSA
| | - Sarah J. Brislin
- Department of Psychiatry, Robert Wood Johnson Medical SchoolRutgers UniversityNew BrunswickNew JerseyUSA
| | - Chella Kamarajan
- Department of Psychiatry and Behavioral SciencesState University of New York Downstate Medical CenterBrooklynNew YorkUSA
| | | | - David Chorlian
- Department of Psychiatry and Behavioral SciencesState University of New York Downstate Medical CenterBrooklynNew YorkUSA
| | - Andrey Anohkin
- Department of PsychiatryWashington University in St. LouisSt. LouisMissouriUSA
| | - Samuel Kuperman
- Department of PsychiatryUniversity of IowaIowa CityIndianaUSA
| | - Alison Merikangas
- Department of Biomedical and Health InformaticsChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
- Penn‐CHOP Lifespan Brain InstituteUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Department of Genetics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Gayathri Pandey
- Department of Psychiatry and Behavioral SciencesState University of New York Downstate Medical CenterBrooklynNew YorkUSA
| | - Sivan Kinreich
- Department of Psychiatry and Behavioral SciencesState University of New York Downstate Medical CenterBrooklynNew YorkUSA
| | - Ashwini Pandey
- Department of Psychiatry and Behavioral SciencesState University of New York Downstate Medical CenterBrooklynNew YorkUSA
| | - Howard J. Edenberg
- Department of Biochemistry and Molecular BiologyIndiana UniversityBloomingtonIndianaUSA
| | - Kathleen K. Bucholz
- Department of PsychiatryWashington University in St. LouisSt. LouisMissouriUSA
| | | | - Laura Almasy
- Department of Biomedical and Health InformaticsChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
- Penn‐CHOP Lifespan Brain InstituteUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Department of Genetics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Bernice Porjesz
- Department of Psychiatry and Behavioral SciencesState University of New York Downstate Medical CenterBrooklynNew YorkUSA
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2
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Antón-Toro LF, Bruña R, Suárez-Méndez I, Correas Á, García-Moreno LM, Maestú F. Abnormal organization of inhibitory control functional networks in future binge drinkers. Drug Alcohol Depend 2021; 218:108401. [PMID: 33246710 DOI: 10.1016/j.drugalcdep.2020.108401] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIMS Adolescent Binge drinking has become an increasing health and social concern, which cause several detrimental consequences for brain integrity. However, research on neurophysiological traits of vulnerability for binge drinking predisposition is limited at this time. In this work, we conducted a two-year longitudinal study with magnetoencephalography (MEG) over a cohort of initially alcohol-naive adolescents with the purpose of characterize inhibitory cortical networks' anomalies prior to alcohol consumption onset in those youths who will transit into binge drinkers years later. METHODS Sixty-seven participant's inhibitory functional networks, and dysexecutive/impulsivity traits were measured by means of inhibitory task (go/no-go) and questionnaires battery. After a follow-up period of two years, we evaluated their alcohol consumption habits, sub-dividing them in two groups according to their alcohol intake patterns: future binge drinkers (fBD): n = 22; future Light/non-drinkers (fLD): n = 17. We evaluated whole-brain and seed-based functional connectivity profiles, as well as its correlation with impulsive and dysexecutive behaviours, searching for early abnormalities before consumption onset. RESULTS For the first time, abnormalities in MEG functional networks and higher dysexecutive and impulsivity profiles were detected in alcohol-naïve adolescents who two years later became binge drinkers. Concretely, fBD exhibit a distinctive pattern of beta band hyperconnectivity among crucial regions of inhibitory control networks, positively correlated with behavioral traits and future alcohol intake rate. CONCLUSIONS These findings strongly support the idea of early neurobiological vulnerabilities for substances consumption initiation, with inhibitory functional networks' abnormalities as a relevant neurophysiological marker of subjects at risk- we hypothesize this profile is due to neurodevelopmental and neurobiological differences involving cognitive control networks and neurotransmission pathways.
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Affiliation(s)
- Luis F Antón-Toro
- Department of Experimental Psychology, Complutense University of Madrid (UCM), 28223, Madrid, Spain; Laboratory for Cognitive and Computational Neuroscience (UCM - UPM), Center for Biomedical Technology (CBT), 28223, Madrid, Spain.
| | - Ricardo Bruña
- Department of Experimental Psychology, Complutense University of Madrid (UCM), 28223, Madrid, Spain; Laboratory for Cognitive and Computational Neuroscience (UCM - UPM), Center for Biomedical Technology (CBT), 28223, Madrid, Spain; Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
| | - Isabel Suárez-Méndez
- Department of Experimental Psychology, Complutense University of Madrid (UCM), 28223, Madrid, Spain; Laboratory for Cognitive and Computational Neuroscience (UCM - UPM), Center for Biomedical Technology (CBT), 28223, Madrid, Spain; Department of Structure of Matter, Thermal Physics and Electronics, Complutense University of Madrid (UCM), 28223, Madrid, Spain
| | - Ángeles Correas
- Laboratory for Cognitive and Computational Neuroscience (UCM - UPM), Center for Biomedical Technology (CBT), 28223, Madrid, Spain; Department of Psychology, San Diego State University, 5500 Campanile Drive San Diego, CA, 92182-4611, USA
| | - Luis M García-Moreno
- Department of Psychobiology and Methodology in Behavioral Sciences, Complutense University of Madrid (UCM), 28040, Madrid, Spain
| | - Fernando Maestú
- Department of Experimental Psychology, Complutense University of Madrid (UCM), 28223, Madrid, Spain; Laboratory for Cognitive and Computational Neuroscience (UCM - UPM), Center for Biomedical Technology (CBT), 28223, Madrid, Spain; Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain
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3
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Mulligan MK, Abreo T, Neuner SM, Parks C, Watkins CE, Houseal MT, Shapaker TM, Hook M, Tan H, Wang X, Ingels J, Peng J, Lu L, Kaczorowski CC, Bryant CD, Homanics GE, Williams RW. Identification of a Functional Non-coding Variant in the GABA A Receptor α2 Subunit of the C57BL/6J Mouse Reference Genome: Major Implications for Neuroscience Research. Front Genet 2019; 10:188. [PMID: 30984232 PMCID: PMC6449455 DOI: 10.3389/fgene.2019.00188] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 02/21/2019] [Indexed: 12/16/2022] Open
Abstract
GABA type-A (GABA-A) receptors containing the α2 subunit (GABRA2) are expressed in most brain regions and are critical in modulating inhibitory synaptic function. Genetic variation at the GABRA2 locus has been implicated in epilepsy, affective and psychiatric disorders, alcoholism and drug abuse. Gabra2 expression varies as a function of genotype and is modulated by sequence variants in several brain structures and populations, including F2 crosses originating from C57BL/6J (B6J) and the BXD recombinant inbred family derived from B6J and DBA/2J. Here we demonstrate a global reduction of GABRA2 brain protein and mRNA in the B6J strain relative to other inbred strains, and identify and validate the causal mutation in B6J. The mutation is a single base pair deletion located in an intron adjacent to a splice acceptor site that only occurs in the B6J reference genome. The deletion became fixed in B6J between 1976 and 1991 and is now pervasive in many engineered lines, BXD strains generated after 1991, the Collaborative Cross, and the majority of consomic lines. Repair of the deletion using CRISPR-Cas9-mediated gene editing on a B6J genetic background completely restored brain levels of GABRA2 protein and mRNA. Comparison of transcript expression in hippocampus, cortex, and striatum between B6J and repaired genotypes revealed alterations in GABA-A receptor subunit expression, especially in striatum. These results suggest that naturally occurring variation in GABRA2 levels between B6J and other substrains or inbred strains may also explain strain differences in anxiety-like or alcohol and drug response traits related to striatal function. Characterization of the B6J private mutation in the Gabra2 gene is of critical importance to molecular genetic studies in neurobiological research because this strain is widely used to generate genetically engineered mice and murine genetic populations, and is the most widely utilized strain for evaluation of anxiety-like, depression-like, pain, epilepsy, and drug response traits that may be partly modulated by GABRA2 function.
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Affiliation(s)
- Megan K Mulligan
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Timothy Abreo
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Sarah M Neuner
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,The Jackson Laboratory, Bar Harbor, ME, United States
| | - Cory Parks
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Christine E Watkins
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - M Trevor Houseal
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Thomas M Shapaker
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Michael Hook
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Haiyan Tan
- Departments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Xusheng Wang
- Departments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Jesse Ingels
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Junmin Peng
- Departments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Lu Lu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | | | - Camron D Bryant
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry, Boston University School of Medicine, Boston, MA, United States
| | - Gregg E Homanics
- Departments of Anesthesiology and Perioperative Medicine, Neurobiology, and Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Robert W Williams
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
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4
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Cortical networks are disturbed in people with cirrhosis even in the absence of neuropsychometric impairment. Clin Neurophysiol 2018; 130:419-427. [PMID: 30552046 DOI: 10.1016/j.clinph.2018.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/08/2018] [Accepted: 11/22/2018] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Hepatic encephalopathy is a common complication of cirrhosis; it is characterised by neuropsychometric/neurophysiological abnormalities. Its pathophysiology is complex but glial neuronal communication is likely to be disrupted and to impact on oscillatory networks and cortical connectivity. The aim of this study was to use multichannel electroencephalography (EEG) to investigate functional connectivity, as a surrogate for cortical networks, in patients with cirrhosis. METHODS Resting EEGs were recorded in 98 healthy controls and in 264 patients with cirrhosis characterised psychometrically using the Psychometric Hepatic Encephalopathy Score (PHES). Functional connectivity was calculated using the phase-lag index with stratification into standard EEG frequency bands. The findings were validated in a further cohort of 39 healthy controls and 106 patients with cirrhosis. RESULTS Widespread disruption in functional connectivity was observed in the patients compared with the controls; connectivity was increased in the theta (4-8 Hz) band and decreased in the delta (1-3.5 Hz), alpha (8.5-13 Hz) and beta (13.5-26.5 Hz) bands. Changes were apparent even in patients who were psychometrically unimpaired compared with healthy controls viz mean ± SEM theta 0.107 ± 0.001 vs. 0.103 ± 0.002 (p < 0.05) and alpha 0.139 ± 0.003 vs. 0.154 ± 0.003 (p < 0.01); more pronounced changes were observed with increasing neuropsychometric impairment. The findings were replicated in the second cohort. CONCLUSIONS Cortical networks are disturbed in patients with cirrhosis even in the absence of psychometric impairment. SIGNIFICANCE These findings will facilitate further exploration of the pathophysiology of this condition and provide a robust means for assessing treatment effects in research settings.
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5
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Smit DJA, Wright MJ, Meyers JL, Martin NG, Ho YYW, Malone SM, Zhang J, Burwell SJ, Chorlian DB, de Geus EJC, Denys D, Hansell NK, Hottenga JJ, McGue M, van Beijsterveldt CEM, Jahanshad N, Thompson PM, Whelan CD, Medland SE, Porjesz B, Lacono WG, Boomsma DI. Genome-wide association analysis links multiple psychiatric liability genes to oscillatory brain activity. Hum Brain Mapp 2018; 39:4183-4195. [PMID: 29947131 PMCID: PMC6179948 DOI: 10.1002/hbm.24238] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/26/2018] [Accepted: 05/21/2018] [Indexed: 02/02/2023] Open
Abstract
Oscillatory activity is crucial for information processing in the brain, and has a long history as a biomarker for psychopathology. Variation in oscillatory activity is highly heritable, but current understanding of specific genetic influences remains limited. We performed the largest genome‐wide association study to date of oscillatory power during eyes‐closed resting electroencephalogram (EEG) across a range of frequencies (delta 1–3.75 Hz, theta 4–7.75 Hz, alpha 8–12.75 Hz, and beta 13–30 Hz) in 8,425 subjects. Additionally, we performed KGG positional gene‐based analysis and brain‐expression analyses. GABRA2—a known genetic marker for alcohol use disorder and epilepsy—significantly affected beta power, consistent with the known relation between GABAA interneuron activity and beta oscillations. Tissue‐specific SNP‐based imputation of gene‐expression levels based on the GTEx database revealed that hippocampal GABRA2 expression may mediate this effect. Twenty‐four genes at 3p21.1 were significant for alpha power (FDR q < .05). SNPs in this region were linked to expression of GLYCTK in hippocampal tissue, and GNL3 and ITIH4 in the frontal cortex–genes that were previously implicated in schizophrenia and bipolar disorder. In sum, we identified several novel genetic variants associated with oscillatory brain activity; furthermore, we replicated and advanced understanding of previously known genes associated with psychopathology (i.e., schizophrenia and alcohol use disorders). Importantly, these psychopathological liability genes affect brain functioning, linking the genes' expression to specific cortical/subcortical brain regions.
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Affiliation(s)
- Dirk J A Smit
- Psychiatry department, Amsterdam Neuroscience, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Margaret J Wright
- Queensland Brain Institute, University of Queensland, Brisbane, Australia.,Centre of Advanced Imaging, University Queensland, Brisbane, Australia
| | - Jacquelyn L Meyers
- Henri Begleiter Neurodynamics Lab., Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, New York
| | | | - Yvonne Y W Ho
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Stephen M Malone
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota
| | - Jian Zhang
- Henri Begleiter Neurodynamics Lab., Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, New York
| | - Scott J Burwell
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota
| | - David B Chorlian
- Henri Begleiter Neurodynamics Lab., Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, New York
| | - Eco J C de Geus
- Biological Psychology, Amsterdam Public Health research institute, Vrije Universiteit Amsterdam, The Netherlands
| | - Damiaan Denys
- Psychiatry department, Amsterdam Neuroscience, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Narelle K Hansell
- Queensland Brain Institute, University of Queensland, Brisbane, Australia
| | - Jouke-Jan Hottenga
- Biological Psychology, Amsterdam Public Health research institute, Vrije Universiteit Amsterdam, The Netherlands
| | - Matt McGue
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota
| | | | - Neda Jahanshad
- Imaging Genetics Center, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Marina del Rey, California
| | - Paul M Thompson
- Imaging Genetics Center, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Marina del Rey, California
| | - Christopher D Whelan
- Imaging Genetics Center, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Marina del Rey, California
| | - Sarah E Medland
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Bernice Porjesz
- Henri Begleiter Neurodynamics Lab., Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, New York
| | - William G Lacono
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota
| | - Dorret I Boomsma
- Biological Psychology, Amsterdam Public Health research institute, Vrije Universiteit Amsterdam, The Netherlands
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Koulentaki M, Kouroumalis E. GABA A receptor polymorphisms in alcohol use disorder in the GWAS era. Psychopharmacology (Berl) 2018; 235:1845-1865. [PMID: 29721579 DOI: 10.1007/s00213-018-4918-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/18/2018] [Indexed: 12/11/2022]
Abstract
Alcohol use disorder (AUD) is a chronic, relapsing, neuro-psychiatric illness of high prevalence and with a serious public health impact worldwide. It is complex and polygenic, with a heritability of about 50%, and influenced by environmental causal heterogeneity. Risk factors associated with its etiology have a genetic component. GABA (γ-aminobutyric acid) is a major inhibitory neurotransmitter in mammalian brain. GABAA receptors are believed to mediate some of the physiological and behavioral actions of alcohol. In this critical review, relevant genetic terms and type and methodology of the genetic studies are briefly explained. Postulated candidate genes that encode subunits of GABAA receptors, with all the reported SNPs, are presented. Genetic studies and meta-analyses examining polymorphisms of the GABAA receptor and their association with AUD predisposition are presented. The data are critically examined with reference to recent GWAS studies that failed to show relations between GABAA receptors and AUD. Restrictions and perspectives of the different findings are discussed.
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Affiliation(s)
- Mairi Koulentaki
- Alcohology Research Laboratory, Medical School, University of Crete, 71500, Heraklion, Crete, Greece.,Department of Gastroenterology, University Hospital Heraklion, 71500, Heraklion, Crete, Greece
| | - Elias Kouroumalis
- Department of Gastroenterology, University Hospital Heraklion, 71500, Heraklion, Crete, Greece.
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7
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Meyers JL, Zhang J, Wang JC, Su J, Kuo SI, Kapoor M, Wetherill L, Bertelsen S, Lai D, Salvatore JE, Kamarajan C, Chorlian D, Agrawal A, Almasy L, Bauer L, Bucholz KK, Chan G, Hesselbrock V, Koganti L, Kramer J, Kuperman S, Manz N, Pandey A, Seay M, Scott D, Taylor RE, Dick DM, Edenberg HJ, Goate A, Foroud T, Porjesz B. An endophenotype approach to the genetics of alcohol dependence: a genome wide association study of fast beta EEG in families of African ancestry. Mol Psychiatry 2017; 22:1767-1775. [PMID: 28070124 PMCID: PMC5503794 DOI: 10.1038/mp.2016.239] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/24/2016] [Accepted: 10/27/2016] [Indexed: 01/16/2023]
Abstract
Fast beta (20-28 Hz) electroencephalogram (EEG) oscillatory activity may be a useful endophenotype for studying the genetics of disorders characterized by neural hyperexcitability, including substance use disorders (SUDs). However, the genetic underpinnings of fast beta EEG have not previously been studied in a population of African-American ancestry (AA). In a sample of 2382 AA individuals from 482 families drawn from the Collaborative Study on the Genetics of Alcoholism (COGA), we performed a genome-wide association study (GWAS) on resting-state fast beta EEG power. To further characterize our genetic findings, we examined the functional and clinical/behavioral significance of GWAS variants. Ten correlated single-nucleotide polymorphisms (SNPs) (r2>0.9) located in an intergenic region on chromosome 3q26 were associated with fast beta EEG power at P<5 × 10-8. The most significantly associated SNP, rs11720469 (β: -0.124; P<4.5 × 10-9), is also an expression quantitative trait locus for BCHE (butyrylcholinesterase), expressed in thalamus tissue. Four of the genome-wide SNPs were also associated with Diagnostic and Statistical Manual of Mental Disorders Alcohol Dependence in COGA AA families, and two (rs13093097, rs7428372) were replicated in an independent AA sample (Gelernter et al.). Analyses in the AA adolescent/young adult (offspring from COGA families) subsample indicated association of rs11720469 with heavy episodic drinking (frequency of consuming 5+ drinks within 24 h). Converging findings presented in this study provide support for the role of genetic variants within 3q26 in neural and behavioral disinhibition. These novel genetic findings highlight the importance of including AA populations in genetics research on SUDs and the utility of the endophenotype approach in enhancing our understanding of mechanisms underlying addiction susceptibility.
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Affiliation(s)
- JL Meyers
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - J Zhang
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - JC Wang
- Department of Neuroscience, Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - J Su
- Department of Psychology, Virginia Commonwealth University, Richmond, VA, USA
| | - SI Kuo
- Department of Psychology, Virginia Commonwealth University, Richmond, VA, USA
| | - M Kapoor
- Department of Neuroscience, Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - L Wetherill
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - S Bertelsen
- Department of Neuroscience, Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - D Lai
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - JE Salvatore
- Department of Psychology, Virginia Commonwealth University, Richmond, VA, USA,Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - C Kamarajan
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - D Chorlian
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - A Agrawal
- Department of Psychiatry, Washington University School of Medicine in St Louis, St Louis, MO, USA
| | - L Almasy
- Department of Biomedical and Health Informatics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - L Bauer
- Department of Psychiatry, University of Connecticut School of Medicine, Farmington, CT, USA
| | - KK Bucholz
- Department of Psychiatry, Washington University School of Medicine in St Louis, St Louis, MO, USA
| | - G Chan
- Department of Psychiatry, University of Connecticut School of Medicine, Farmington, CT, USA
| | - V Hesselbrock
- Department of Psychiatry, University of Connecticut School of Medicine, Farmington, CT, USA
| | - L Koganti
- Department of Neuroscience, Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - J Kramer
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - S Kuperman
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - N Manz
- Department of Physics, The College of Wooster, Wooster, OH, USA
| | - A Pandey
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - M Seay
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - D Scott
- Collaborative Alcohol Research Center, Howard University College of Medicine, Washington, DC, USA
| | - RE Taylor
- Collaborative Alcohol Research Center, Howard University College of Medicine, Washington, DC, USA
| | - DM Dick
- Department of Psychology, Virginia Commonwealth University, Richmond, VA, USA,Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - HJ Edenberg
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - A Goate
- Department of Neuroscience, Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - T Foroud
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - B Porjesz
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, USA
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9
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Colville AM, Iancu OD, Oberbeck DL, Darakjian P, Zheng CL, Walter NAR, Harrington CA, Searles RP, McWeeney S, Hitzemann RJ. Effects of selection for ethanol preference on gene expression in the nucleus accumbens of HS-CC mice. GENES BRAIN AND BEHAVIOR 2017; 16:462-471. [PMID: 28058793 DOI: 10.1111/gbb.12367] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/16/2016] [Accepted: 01/03/2017] [Indexed: 12/15/2022]
Abstract
Previous studies on changes in murine brain gene expression associated with the selection for ethanol preference have used F2 intercross or heterogeneous stock (HS) founders, derived from standard laboratory strains. However, these populations represent only a small proportion of the genetic variance available in Mus musculus. To investigate a wider range of genetic diversity, we selected mice for ethanol preference using an HS derived from the eight strains of the collaborative cross. These HS mice were selectively bred (four generations) for high and low ethanol preference. The nucleus accumbens shell of naive S4 mice was interrogated using RNA sequencing (RNA-Seq). Gene networks were constructed using the weighted gene coexpression network analysis assessing both coexpression and cosplicing. Selection targeted one of the network coexpression modules (greenyellow) that was significantly enriched in genes associated with receptor signaling activity including Chrna7, Grin2a, Htr2a and Oprd1. Connectivity in the module as measured by changes in the hub nodes was significantly reduced in the low preference line. Of particular interest was the observation that selection had marked effects on a large number of cell adhesion molecules, including cadherins and protocadherins. In addition, the coexpression data showed that selection had marked effects on long non-coding RNA hub nodes. Analysis of the cosplicing network data showed a significant effect of selection on a large cluster of Ras GTPase-binding genes including Cdkl5, Cyfip1, Ndrg1, Sod1 and Stxbp5. These data in part support the earlier observation that preference is linked to Ras/Mapk pathways.
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Affiliation(s)
- A M Colville
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - O D Iancu
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - D L Oberbeck
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - P Darakjian
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - C L Zheng
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - N A R Walter
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - C A Harrington
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - R P Searles
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - S McWeeney
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - R J Hitzemann
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA.,Research Service, Portland Veterans Affairs Medical Center, Portland, OR, USA
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10
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Meyers JL, Zhang J, Manz N, Rangaswamy M, Kamarajan C, Wetherill L, Chorlian DB, Kang SJ, Bauer L, Hesselbrock V, Kramer J, Kuperman S, Nurnberger JI, Tischfield J, Wang JC, Edenberg HJ, Goate A, Foroud T, Porjesz B. A genome wide association study of fast beta EEG in families of European ancestry. Int J Psychophysiol 2016; 115:74-85. [PMID: 28040410 DOI: 10.1016/j.ijpsycho.2016.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 12/08/2016] [Accepted: 12/15/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND Differences in fast beta (20-28Hz) electroencephalogram (EEG) oscillatory activity distinguish some individuals with psychiatric and substance use disorders, suggesting that it may be a useful endophenotype for studying the genetics of disorders characterized by neural hyper-excitability. Despite the high heritability estimates provided by twin and family studies, there have been relatively few genetic studies of beta EEG, and to date only one genetic association finding has replicated (i.e., GABRA2). METHOD In a sample of 1564 individuals from 117 families of European Ancestry (EA) drawn from the Collaborative Study on the Genetics of Alcoholism (COGA), we performed a Genome-Wide Association Study (GWAS) on resting-state fronto-central fast beta EEG power, adjusting regression models for family relatedness, age, sex, and ancestry. To further characterize genetic findings, we examined the functional and behavioral significance of GWAS findings. RESULTS Three intronic variants located within DSE (dermatan sulfate epimerase) on 6q22 were associated with fast beta EEG at a genome wide significant level (p<5×10-8). The most significant SNP was rs2252790 (p<2.6×10-8; MAF=0.36; β=0.135). rs2252790 is an eQTL for ROS1 expressed most robustly in the temporal cortex (p=1.2×10-6) and for DSE/TSPYL4 expressed most robustly in the hippocampus (p=7.3×10-4; β=0.29). Previous studies have indicated that DSE is involved in a network of genes integral to membrane organization; gene-based tests indicated that several variants within this network (i.e., DSE, ZEB2, RND3, MCTP1, and CTBP2) were also associated with beta EEG (empirical p<0.05), and of these genes, ZEB2 and CTBP2 were associated with DSM-V Alcohol Use Disorder (AUD; empirical p<0.05).' DISCUSSION In this sample of EA families enriched for AUDs, fast beta EEG is associated with variants within DSE on 6q22; the most significant SNP influences the mRNA expression of DSE and ROS1 in hippocampus and temporal cortex, brain regions important for beta EEG activity. Gene-based tests suggest evidence of association with related genes, ZEB2, RND3, MCTP1, CTBP2, and beta EEG. Converging data from GWAS, gene expression, and gene-networks presented in this study provide support for the role of genetic variants within DSE and related genes in neural hyperexcitability, and has highlighted two potential candidate genes for AUD and/or related neurological conditions: ZEB2 and CTBP2. However, results must be replicated in large, independent samples.
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Affiliation(s)
- Jacquelyn L Meyers
- Henri Begleiter Neurodynamics Laboratory, Department of Psychiatry and Behavioral Sciences, SUNY Downstate Medical Center, Brooklyn, NY, USA.
| | - Jian Zhang
- Henri Begleiter Neurodynamics Laboratory, Department of Psychiatry and Behavioral Sciences, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Niklas Manz
- Henri Begleiter Neurodynamics Laboratory, Department of Psychiatry and Behavioral Sciences, SUNY Downstate Medical Center, Brooklyn, NY, USA; Department of Physics, College of Wooster, Wooster, OH, USA
| | | | - Chella Kamarajan
- Henri Begleiter Neurodynamics Laboratory, Department of Psychiatry and Behavioral Sciences, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Leah Wetherill
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - David B Chorlian
- Henri Begleiter Neurodynamics Laboratory, Department of Psychiatry and Behavioral Sciences, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Sun J Kang
- Albany Stratton VA Medical Center, Albany, NY, USA
| | - Lance Bauer
- University of Connecticut School of Medicine, Farmington, CT, USA
| | | | - John Kramer
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
| | - Samuel Kuperman
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
| | - John I Nurnberger
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | | | - Howard J Edenberg
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Alison Goate
- Icahn School of Medicine at Mt. Sinai, New York, NY, USA
| | - Tatiana Foroud
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Bernice Porjesz
- Henri Begleiter Neurodynamics Laboratory, Department of Psychiatry and Behavioral Sciences, SUNY Downstate Medical Center, Brooklyn, NY, USA
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11
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Stephens DN, King SL, Lambert JJ, Belelli D, Duka T. GABAAreceptor subtype involvement in addictive behaviour. GENES BRAIN AND BEHAVIOR 2016; 16:149-184. [DOI: 10.1111/gbb.12321] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/19/2016] [Accepted: 08/15/2016] [Indexed: 12/17/2022]
Affiliation(s)
| | - S. L. King
- School of Psychology; University of Sussex; Brighton UK
| | - J. J. Lambert
- Division of Neuroscience; University of Dundee; Dundee UK
| | - D. Belelli
- Division of Neuroscience; University of Dundee; Dundee UK
| | - T. Duka
- School of Psychology; University of Sussex; Brighton UK
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12
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Olesen SS, Gram M, Jackson CD, Halliday E, Sandberg TH, Drewes AM, Morgan MY. Electroencephalogram variability in patients with cirrhosis associates with the presence and severity of hepatic encephalopathy. J Hepatol 2016; 65:517-23. [PMID: 27184531 DOI: 10.1016/j.jhep.2016.05.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/19/2016] [Accepted: 05/07/2016] [Indexed: 01/24/2023]
Abstract
BACKGROUND & AIMS The outputs of physiological systems fluctuate in a complex manner even under resting conditions. Decreased variability or increased regularity of these outputs is documented in several disease states. Changes are observed in the spatial and temporal configuration of the electroencephalogram (EEG) in patients with hepatic encephalopathy (HE), but there is no information on the variability of the EEG signal in this condition. The aim of this study was to measure and characterize EEG variability in patients with cirrhosis and to determine its relationship to neuropsychiatric status. METHODS Eyes-closed, awake EEGs were obtained from 226 patients with cirrhosis, classified, using clinical and psychometric criteria, as neuropsychiatrically unimpaired (n=127) or as having minimal (n=21) or overt (n=78) HE, and from a reference population of 137 healthy controls. Analysis of EEG signal variability was undertaken using continuous wavelet transform and sample entropy. RESULTS EEG variability was reduced in the patients with cirrhosis compared with the reference population (coefficient of variation: 21.2% [19.3-23.4] vs. 22.4% [20.8-24.5]; p<0.001). A significant association was observed between EEG variability and neuropsychiatric status; thus, variability was increased in the patients with minimal HE compared with their neuropsychiatrically unimpaired counterparts (sample entropy: 0.98 [0.87-1.14] vs. 0.83 [0.75-0.95]; p=0.02), and compared with the patients with overt HE (sample entropy: 0.98 [0.87-1.14] vs. 0.82 [0.71-1.01]; p=0.01). CONCLUSIONS Variability of the EEG is associated with both the presence and severity of HE. This novel finding may provide new insights into the pathophysiology of HE and provide a means for monitoring patients over time. LAY SUMMARY Decreased variability or increased regularity of physiological systems is documented in several disease states. Variability of the electroencephalogram was found to be associated with both the presence and severity of brain dysfunction in patients with chronic liver disease.
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Affiliation(s)
- Søren Schou Olesen
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Denmark.
| | - Mikkel Gram
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Denmark
| | - Clive Douglas Jackson
- Department of Neurophysiology, Royal Free Hospital, Royal Free London NHS Foundation Trust, Hampstead, London, UK
| | - Edwin Halliday
- UCL Institute for Liver and Digestive Health, Division of Medicine, Royal Free Campus, University College London, Hampstead, London, UK
| | - Thomas Holm Sandberg
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Denmark
| | - Asbjørn Mohr Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Denmark; Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Marsha Yvonne Morgan
- UCL Institute for Liver and Digestive Health, Division of Medicine, Royal Free Campus, University College London, Hampstead, London, UK
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13
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Abstract
Multiple lines of evidence strongly indicate that genetic factors contribute to the risk for alcohol use disorders (AUD). There is substantial heterogeneity in AUD, which complicates studies seeking to identify specific genetic factors. To identify these genetic effects, several different alcohol-related phenotypes have been analyzed, including diagnosis and quantitative measures related to AUDs. Study designs have used candidate gene analyses, genetic linkage studies, genomewide association studies (GWAS), and analyses of rare variants. Two genes that encode enzymes of alcohol metabolism have the strongest effect on AUD: aldehyde dehydrogenase 2 and alcohol dehydrogenase 1B each has strongly protective variants that reduce risk, with odds ratios approximately 0.2-0.4. A number of other genes important in AUD have been identified and replicated, including GABRA2 and alcohol dehydrogenases 1B and 4. GWAS have identified additional candidates. Rare variants are likely also to play a role; studies of these are just beginning. A multifaceted approach to gene identification, targeting both rare and common variations and assembling much larger datasets for meta-analyses, is critical for identifying the key genes and pathways important in AUD.
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Affiliation(s)
- Howard J Edenberg
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Tatiana Foroud
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
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14
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Malone SM, Burwell SJ, Vaidyanathan U, Miller MB, McGue M, Iacono WG. Heritability and molecular-genetic basis of resting EEG activity: a genome-wide association study. Psychophysiology 2015; 51:1225-45. [PMID: 25387704 DOI: 10.1111/psyp.12344] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Several EEG parameters are potential endophenotypes for different psychiatric disorders. The present study consists of a comprehensive behavioral- and molecular-genetic analysis of such parameters in a large community sample (N = 4,026) of adolescent twins and their parents, genotyped for 527,829 single nucleotide polymorphisms (SNPs). Biometric heritability estimates ranged from .49 to .85, with a median of .78. The additive effect of all SNPs (SNP heritability) varied across electrodes. Although individual SNPs were not significantly associated with EEG parameters, several genes were associated with delta power. We also obtained an association between the GABRA2 gene and beta power (p < .014), consistent with findings reported by others, although this did not survive Bonferroni correction. If EEG parameters conform to a largely polygenic model of inheritance, larger sample sizes will be required to detect individual variants reliably.
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Affiliation(s)
- Stephen M Malone
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota, USA
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15
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Lieberman R, Kranzler HR, Joshi P, Shin DG, Covault J. GABRA2 Alcohol Dependence Risk Allele is Associated with Reduced Expression of Chromosome 4p12 GABAA Subunit Genes in Human Neural Cultures. Alcohol Clin Exp Res 2015; 39:1654-64. [PMID: 26250693 DOI: 10.1111/acer.12807] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 06/05/2015] [Indexed: 01/28/2023]
Abstract
BACKGROUND Genetic variation in a region of chromosome 4p12 that includes the GABAA subunit gene GABRA2 has been reproducibly associated with alcohol dependence (AD). However, the molecular mechanisms underlying the association are unknown. This study examined correlates of in vitro gene expression of the AD-associated GABRA2 rs279858*C-allele in human neural cells using an induced pluripotent stem cell (iPSC) model system. METHODS We examined mRNA expression of chromosome 4p12 GABAA subunit genes (GABRG1, GABRA2, GABRA4, and GABRB1) in 36 human neural cell lines differentiated from iPSCs using quantitative polymerase chain reaction and next-generation RNA sequencing. mRNA expression in adult human brain was examined using the BrainCloud and BRAINEAC data sets. RESULTS We found significantly lower levels of GABRA2 mRNA in neural cell cultures derived from rs279858*C-allele carriers. Levels of GABRA2 RNA were correlated with those of the other 3 chromosome 4p12 GABAA genes, but not other neural genes. Cluster analysis based on the relative RNA levels of the 4 chromosome 4p12 GABAA genes identified 2 distinct clusters of cell lines, a low-expression cluster associated with rs279858*C-allele carriers and a high-expression cluster enriched for the rs279858*T/T genotype. In contrast, there was no association of genotype with chromosome 4p12 GABAA gene expression in postmortem adult cortex in either the BrainCloud or BRAINEAC data sets. CONCLUSIONS AD-associated variation in GABRA2 is associated with differential expression of the entire cluster of GABAA subunit genes on chromosome 4p12 in human iPSC-derived neural cell cultures. The absence of a parallel effect in postmortem human adult brain samples suggests that AD-associated genotype effects on GABAA expression, although not present in mature cortex, could have effects on regulation of the chromosome 4p12 GABAA cluster during neural development.
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Affiliation(s)
- Richard Lieberman
- Alcohol Research Center, Department of Psychiatry, University of Connecticut School of Medicine, Farmington, Connecticut.,Department of Neuroscience, University of Connecticut Health Center, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Henry R Kranzler
- Center for Studies of Addiction, Department of Psychiatry, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania.,VISN4 MIRECC, Philadelphia VAMC, Philadelphia, Pennsylvania
| | - Pujan Joshi
- Department of Computer Science and Engineering, University of Connecticut, Storrs, Connecticut
| | - Dong-Guk Shin
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut.,Department of Computer Science and Engineering, University of Connecticut, Storrs, Connecticut
| | - Jonathan Covault
- Alcohol Research Center, Department of Psychiatry, University of Connecticut School of Medicine, Farmington, Connecticut.,Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut
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16
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Yuan H, Low CM, Moody OA, Jenkins A, Traynelis SF. Ionotropic GABA and Glutamate Receptor Mutations and Human Neurologic Diseases. Mol Pharmacol 2015; 88:203-17. [PMID: 25904555 PMCID: PMC4468639 DOI: 10.1124/mol.115.097998] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/22/2015] [Indexed: 01/03/2023] Open
Abstract
The advent of whole exome/genome sequencing and the technology-driven reduction in the cost of next-generation sequencing as well as the introduction of diagnostic-targeted sequencing chips have resulted in an unprecedented volume of data directly linking patient genomic variability to disorders of the brain. This information has the potential to transform our understanding of neurologic disorders by improving diagnoses, illuminating the molecular heterogeneity underlying diseases, and identifying new targets for therapeutic treatment. There is a strong history of mutations in GABA receptor genes being involved in neurologic diseases, particularly the epilepsies. In addition, a substantial number of variants and mutations have been found in GABA receptor genes in patients with autism, schizophrenia, and addiction, suggesting potential links between the GABA receptors and these conditions. A new and unexpected outcome from sequencing efforts has been the surprising number of mutations found in glutamate receptor subunits, with the GRIN2A gene encoding the GluN2A N-methyl-d-aspartate receptor subunit being most often affected. These mutations are associated with multiple neurologic conditions, for which seizure disorders comprise the largest group. The GluN2A subunit appears to be a locus for epilepsy, which holds important therapeutic implications. Virtually all α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor mutations, most of which occur within GRIA3, are from patients with intellectual disabilities, suggesting a link to this condition. Similarly, the most common phenotype for kainate receptor variants is intellectual disability. Herein, we summarize the current understanding of disease-associated mutations in ionotropic GABA and glutamate receptor families, and discuss implications regarding the identification of human mutations and treatment of neurologic diseases.
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Affiliation(s)
- Hongjie Yuan
- Departments of Pharmacology (H.Y., A.J., S.F.T.) and Anesthesiology (O.A.M., A.J.), Emory University School of Medicine, Rollins Research Center, Atlanta, Georgia; and Departments of Pharmacology and Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore Graduate School for Integrative Sciences and Engineering, and Neurobiology/Ageing Programme, National University of Singapore, Singapore (C.-M.L.)
| | - Chian-Ming Low
- Departments of Pharmacology (H.Y., A.J., S.F.T.) and Anesthesiology (O.A.M., A.J.), Emory University School of Medicine, Rollins Research Center, Atlanta, Georgia; and Departments of Pharmacology and Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore Graduate School for Integrative Sciences and Engineering, and Neurobiology/Ageing Programme, National University of Singapore, Singapore (C.-M.L.)
| | - Olivia A Moody
- Departments of Pharmacology (H.Y., A.J., S.F.T.) and Anesthesiology (O.A.M., A.J.), Emory University School of Medicine, Rollins Research Center, Atlanta, Georgia; and Departments of Pharmacology and Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore Graduate School for Integrative Sciences and Engineering, and Neurobiology/Ageing Programme, National University of Singapore, Singapore (C.-M.L.)
| | - Andrew Jenkins
- Departments of Pharmacology (H.Y., A.J., S.F.T.) and Anesthesiology (O.A.M., A.J.), Emory University School of Medicine, Rollins Research Center, Atlanta, Georgia; and Departments of Pharmacology and Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore Graduate School for Integrative Sciences and Engineering, and Neurobiology/Ageing Programme, National University of Singapore, Singapore (C.-M.L.)
| | - Stephen F Traynelis
- Departments of Pharmacology (H.Y., A.J., S.F.T.) and Anesthesiology (O.A.M., A.J.), Emory University School of Medicine, Rollins Research Center, Atlanta, Georgia; and Departments of Pharmacology and Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore Graduate School for Integrative Sciences and Engineering, and Neurobiology/Ageing Programme, National University of Singapore, Singapore (C.-M.L.)
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17
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The functional GRM3 Kozak sequence variant rs148754219 affects the risk of schizophrenia and alcohol dependence as well as bipolar disorder. Psychiatr Genet 2015; 24:277-8. [PMID: 25046171 PMCID: PMC4272221 DOI: 10.1097/ypg.0000000000000050] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Way M, McQuillin A, Saini J, Ruparelia K, Lydall GJ, Guerrini I, Ball D, Smith I, Quadri G, Thomson AD, Kasiakogia-Worlley K, Cherian R, Gunwardena P, Rao H, Kottalgi G, Patel S, Hillman A, Douglas E, Qureshi SY, Reynolds G, Jauhar S, O'Kane A, Dedman A, Sharp S, Kandaswamy R, Dar K, Curtis D, Morgan MY, Gurling HMD. Genetic variants in or near ADH1B and ADH1C affect susceptibility to alcohol dependence in a British and Irish population. Addict Biol 2015; 20:594-604. [PMID: 24735490 DOI: 10.1111/adb.12141] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Certain single nucleotide polymorphisms (SNPs) in genes encoding alcohol dehydrogenase (ADH) enzymes confer a significant protective effect against alcohol dependence syndrome (ADS) in East Asian populations. Recently, attention has focused on the role of these SNPs in determining ADS risk in European populations. To further elucidate these associations, SNPs of interest in ADH1B, ADH1C and the ADH1B/1C intergenic region were genotyped in a British and Irish population (ADS cases n = 1076: controls n = 1027) to assess their relative contribution to ADS risk. A highly significant, protective association was observed between the minor allele of rs1229984 in ADH1B and ADS risk [allelic P = 8.4 × 10(-6) , odds ratio (OR) = 0.26, 95 percent confidence interval, 0.14, 0.49]. Significant associations were also observed between ADS risk and the ADH1B/1C intergenic variant, rs1789891 [allelic P = 7.2 × 10(-5) , OR = 1.4 (1.2, 1.6)] and three non-synonymous SNPs rs698, rs1693482 and rs283413 in ADH1C. However, these associations were not completely independent; thus, while the ADH1B rs1229984 minor allele association was independent of those of the intergenic variant rs1789891 and the three ADH1C variants, the three ADH1C variants were not individually independent. In conclusion, the rare ADH1B rs1229984 mutation provides significant protection against ADS in this British and Irish population; other variants in the ADH gene cluster also alter ADS risk, although the strong linkage disequilibrium between SNPs at this location precluded clear identification of the variant(s) driving the associations.
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Affiliation(s)
- Michael Way
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Andrew McQuillin
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Jit Saini
- UCL Institute for Liver & Digestive Health; Royal Free Campus; University College London Medical School; UK
| | - Kush Ruparelia
- UCL Institute for Liver & Digestive Health; Royal Free Campus; University College London Medical School; UK
| | - Gregory J. Lydall
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Irene Guerrini
- National Addiction Centre and Social Genetic and Developmental Psychiatry Centre; Institute of Psychiatry; UK
- Bexley Substance Misuse Services; South London & Maudsley NHS Trust; UK
| | - David Ball
- National Addiction Centre and Social Genetic and Developmental Psychiatry Centre; Institute of Psychiatry; UK
| | - Iain Smith
- Kershaw Unit; Gartnavel Royal Hospital; UK
| | - Giorgia Quadri
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Allan D. Thomson
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Katherine Kasiakogia-Worlley
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
- Kershaw Unit; Gartnavel Royal Hospital; UK
| | - Raquin Cherian
- Gatehouse Alcohol Clinic and Max Glatt Unit; Central and North West London NHS Foundation Trust; St Bernard's Hospital; UK
| | - Priyanthi Gunwardena
- Gatehouse Alcohol Clinic and Max Glatt Unit; Central and North West London NHS Foundation Trust; St Bernard's Hospital; UK
| | - Harish Rao
- City and Hackney Centre for Mental Health; East London NHS Foundation Trust; UK
| | - Girija Kottalgi
- Gatehouse Alcohol Clinic and Max Glatt Unit; Central and North West London NHS Foundation Trust; St Bernard's Hospital; UK
| | - Shamir Patel
- Gatehouse Alcohol Clinic and Max Glatt Unit; Central and North West London NHS Foundation Trust; St Bernard's Hospital; UK
| | | | | | | | - Gerry Reynolds
- Homeless Addictions Team; NHS Greater Glasgow and Clyde; UK
| | | | | | - Alex Dedman
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Sally Sharp
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Radhika Kandaswamy
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
| | - Karim Dar
- Gatehouse Alcohol Clinic and Max Glatt Unit; Central and North West London NHS Foundation Trust; St Bernard's Hospital; UK
| | - David Curtis
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
- City and Hackney Centre for Mental Health; East London NHS Foundation Trust; UK
| | - Marsha Y. Morgan
- UCL Institute for Liver & Digestive Health; Royal Free Campus; University College London Medical School; UK
| | - Hugh M. D. Gurling
- Molecular Psychiatry Laboratory; Mental Health Sciences Unit; Faculty of Brain Sciences; University College London; UK
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19
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Melroy WE, Stephens SH, Sakai JT, Kamens HM, McQueen MB, Corley RP, Stallings MC, Hopfer CJ, Krauter KS, Brown SA, Hewitt JK, Ehringer MA. Examination of genetic variation in GABRA2 with conduct disorder and alcohol abuse and dependence in a longitudinal study. Behav Genet 2014; 44:356-67. [PMID: 24687270 DOI: 10.1007/s10519-014-9653-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 03/15/2014] [Indexed: 02/06/2023]
Abstract
Previous studies have shown associations between single nucleotide polymorphisms (SNPs) in gamma aminobutyric acid receptor alpha 2 (GABRA2) and adolescent conduct disorder (CD) and alcohol dependence in adulthood, but not adolescent alcohol dependence. The present study was intended as a replication and extension of this work, focusing on adolescent CD, adolescent alcohol abuse and dependence (AAD), and adult AAD. Family based association tests were run using Hispanics and non-Hispanic European American subjects from two independent longitudinal samples. Although the analysis provided nominal support for an association with rs9291283 and AAD in adulthood and CD in adolescence, the current study failed to replicate previous associations between two well replicated GABRA2 SNPs and CD and alcohol dependence. Overall, these results emphasize the utility of including an independent replication sample in the study design, so that the results from an individual sample can be weighted in the context of its reproducibility.
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Affiliation(s)
- Whitney E Melroy
- Institute for Behavioral Genetics, University of Colorado, Boulder, CO, USA
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20
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Li D, Sulovari A, Cheng C, Zhao H, Kranzler HR, Gelernter J. Association of gamma-aminobutyric acid A receptor α2 gene (GABRA2) with alcohol use disorder. Neuropsychopharmacology 2014; 39:907-18. [PMID: 24136292 PMCID: PMC3924525 DOI: 10.1038/npp.2013.291] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 12/26/2022]
Abstract
Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in mammalian brain. GABA receptor are involved in a number of complex disorders, including substance abuse. No variants of the commonly studied GABA receptor genes that have been associated with substance dependence have been determined to be functional or pathogenic. To reconcile the conflicting associations with substance dependence traits, we performed a meta-analysis of variants in the GABAA receptor genes (GABRB2, GABRA6, GABRA1, and GABRG2 on chromosome 5q and GABRA2 on chromosome 4p12) using genotype data from 4739 cases of alcohol, opioid, or methamphetamine dependence and 4924 controls. Then, we combined the data from candidate gene association studies in the literature with two alcohol dependence (AD) samples, including 1691 cases and 1712 controls from the Study of Addiction: Genetics and Environment (SAGE), and 2644 cases and 494 controls from our own study. Using a Bonferroni-corrected threshold of 0.007, we found strong associations between GABRA2 and AD (P=9 × 10(-6) and odds ratio (OR) 95% confidence interval (CI)=1.27 (1.15, 1.4) for rs567926, P=4 × 10(-5) and OR=1.21 (1.1, 1.32) for rs279858), and between GABRG2 and both dependence on alcohol and dependence on heroin (P=0.0005 and OR=1.22 (1.09, 1.37) for rs211014). Significant association was also observed between GABRA6 rs3219151 and AD. The GABRA2 rs279858 association was observed in the SAGE data sets with a combined P of 9 × 10(-6) (OR=1.17 (1.09, 1.26)). When all of these data sets, including our samples, were meta-analyzed, associations of both GABRA2 single-nucleotide polymorphisms remained (for rs567926, P=7 × 10(-5) (OR=1.18 (1.09, 1.29)) in all the studies, and P=8 × 10(-6) (OR=1.25 (1.13, 1.38)) in subjects of European ancestry and for rs279858, P=5 × 10(-6) (OR=1.18 (1.1, 1.26)) in subjects of European ancestry. Findings from this extensive meta-analysis of five GABAA receptor genes and substance abuse support their involvement (with the best evidence for GABRA2) in the pathogenesis of AD. Further replications with larger samples are warranted.
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Affiliation(s)
- Dawei Li
- Department of Psychiatry, School of Medicine, Yale University, New Haven, CT, USA,Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA,Department of Computer Science, University of Vermont, Burlington, VT, USA,Neuroscience, Behavior, and Health Initiative, University of Vermont, Burlington, VT, USA,Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont 05405, USA, Tel: 802-656-9838; E-mail:
| | - Arvis Sulovari
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - Chao Cheng
- Department of Genetics, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Hongyu Zhao
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA,Department of Genetics, School of Medicine, Yale University, New Haven, CT, USA
| | - Henry R Kranzler
- Department of Psychiatry, Perelman School of Medicine of the University of Pennsylvania and Philadelphia VAMC, Philadelphia, PA, USA
| | - Joel Gelernter
- Department of Psychiatry, School of Medicine, Yale University, New Haven, CT, USA,Department of Genetics, School of Medicine, Yale University, New Haven, CT, USA,VA Connecticut Healthcare Center, West Haven, CT, USA
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21
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Abstract
Alcohol is widely consumed; however, excessive use creates serious physical, psychological and social problems and contributes to the pathogenesis of many diseases. Alcohol use disorders (that is, alcohol dependence and alcohol abuse) are maladaptive patterns of excessive drinking that lead to serious problems. Abundant evidence indicates that alcohol dependence (alcoholism) is a complex genetic disease, with variations in a large number of genes affecting a person's risk of alcoholism. Some of these genes have been identified, including two genes involved in the metabolism of alcohol (ADH1B and ALDH2) that have the strongest known affects on the risk of alcoholism. Studies continue to reveal other genes in which variants affect the risk of alcoholism or related traits, including GABRA2, CHRM2, KCNJ6 and AUTS2. As more variants are analysed and studies are combined for meta-analysis to achieve increased sample sizes, an improved picture of the many genes and pathways that affect the risk of alcoholism will be possible.
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Affiliation(s)
- Howard J Edenberg
- Department of Biochemistry, Indiana University School of Medicine, 635 Barnhill Drive, MS4063, Indianapolis, IN 46202-5122, USA.
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22
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Kaminski BJ, Van Linn ML, Cook JM, Yin W, Weerts EM. Effects of the benzodiazepine GABAA α1-preferring ligand, 3-propoxy-β-carboline hydrochloride (3-PBC), on alcohol seeking and self-administration in baboons. Psychopharmacology (Berl) 2013; 227:127-36. [PMID: 23271191 PMCID: PMC3624026 DOI: 10.1007/s00213-012-2946-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 12/01/2012] [Indexed: 12/18/2022]
Abstract
RATIONALE The various α subtypes of GABAA receptors have been strongly implicated in alcohol reinforcement and consumption. OBJECTIVES The effects of the GABAA α1-preferring ligand, 3-propoxy-β-carboline hydrochloride (3-PBC), on seeking and self-administration responses were evaluated in two groups of baboons trained under a 3-component chained schedule of reinforcement (CSR). METHODS Alcohol (4 % w/v; n = 5; alcohol group) or a preferred nonalcoholic beverage (n = 4; control group) was available for self-administration only in component 3 of the CSR. Responses in component 2 provided indices of motivation to drink (seeking). 3-PBC (1.0-30.0 mg/kg) and saline were administered before drinking sessions under both acute and 5-day dosing conditions. RESULTS Repeated, and not acute, doses of 3-PBC significantly decreased total self-administration responses (p < 0.05), volume consumed (p < 0.05), and gram per kilogram of alcohol (p < 0.05) in the alcohol group. In the control group, 5-day administration of 3-PBC significantly decreased total self-administration responses (p < 0.05) but produced nonsignificant decreases in volume consumed. Within-session pattern of drinking was characterized by a high level of drinking in the first 20 min of the session for both groups, which was significantly (p < 0.05) decreased by all doses of 3-PBC (1.0-18.0 mg/kg) only in the alcohol group. In contrast, the first drinking bout in the control group was only reduced at the highest doses of 3-PBC (10.0 and 18.0 mg/kg). CONCLUSIONS The results support the involvement of the GABAA α1 subtype receptor in alcohol reinforcement and consumption.
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Affiliation(s)
- Barbara J. Kaminski
- Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224
| | - Michael L. Van Linn
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - James M. Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - Wenyuan Yin
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - Elise M. Weerts
- Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224
- Corresponding Author: Elise M. Weerts, Ph.D., Johns Hopkins Bayview Campus, Behavioral Biology Research Center, 5510 Nathan Shock Drive, Suite 3000, Baltimore, MD 21224, USA Tel.: 410-550-2781; Fax: 410-550-2780;
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23
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Dixon CI, Walker SE, King SL, Stephens DN. Deletion of the gabra2 gene results in hypersensitivity to the acute effects of ethanol but does not alter ethanol self administration. PLoS One 2012; 7:e47135. [PMID: 23115637 PMCID: PMC3480382 DOI: 10.1371/journal.pone.0047135] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 09/10/2012] [Indexed: 12/04/2022] Open
Abstract
Human genetic studies have suggested that polymorphisms of the GABRA2 gene encoding the GABAA α2-subunit are associated with ethanol dependence. Variations in this gene also convey sensitivity to the subjective effects of ethanol, indicating a role in mediating ethanol-related behaviours. We therefore investigated the consequences of deleting the α2-subunit on the ataxic and rewarding properties of ethanol in mice. Ataxic and sedative effects of ethanol were explored in GABAA α2-subunit wildtype (WT) and knockout (KO) mice using a Rotarod apparatus, wire hang and the duration of loss of righting reflex. Following training, KO mice showed shorter latencies to fall than WT littermates under ethanol (2 g/kg i.p.) in both Rotarod and wire hang tests. After administration of ethanol (3.5 g/kg i.p.), KO mice took longer to regain the righting reflex than WT mice. To ensure the acute effects are not due to the gabra2 deletion affecting pharmacokinetics, blood ethanol concentrations were measured at 20 minute intervals after acute administration (2 g/kg i.p.), and did not differ between genotypes. To investigate ethanol’s rewarding properties, WT and KO mice were trained to lever press to receive increasing concentrations of ethanol on an FR4 schedule of reinforcement. Both WT and KO mice self-administered ethanol at similar rates, with no differences in the numbers of reinforcers earned. These data indicate a protective role for α2-subunits, against the acute sedative and ataxic effects of ethanol. However, no change was observed in ethanol self administration, suggesting the rewarding effects of ethanol remain unchanged.
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Affiliation(s)
- Claire I. Dixon
- School of Psychology, University of Sussex, Brighton, United Kingdom
| | - Sophie E. Walker
- School of Psychology, University of Sussex, Brighton, United Kingdom
| | - Sarah L. King
- School of Psychology, University of Sussex, Brighton, United Kingdom
| | - David N. Stephens
- School of Psychology, University of Sussex, Brighton, United Kingdom
- * E-mail:
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24
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Palmer RHC, McGeary JE, Francazio S, Raphael BJ, Lander AD, Heath AC, Knopik VS. The genetics of alcohol dependence: advancing towards systems-based approaches. Drug Alcohol Depend 2012; 125:179-91. [PMID: 22854292 PMCID: PMC3470479 DOI: 10.1016/j.drugalcdep.2012.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 07/09/2012] [Accepted: 07/10/2012] [Indexed: 01/02/2023]
Abstract
BACKGROUND Personalized treatment for psychopathologies, in particular alcoholism, is highly dependent upon our ability to identify patterns of genetic and environmental effects that influence a person's risk. Unfortunately, array-based whole genome investigations into heritable factors that explain why one person becomes dependent upon alcohol and another does not, have indicated that alcohol's genetic architecture is highly complex. That said, uncovering and interpreting the missing heritability in alcohol genetics research has become all the more important, especially since the problem may extend to our inability to model the cumulative and combinatorial relationships between common and rare genetic variants. As numerous studies begin to illustrate the dependency of alcohol pharmacotherapies on an individual's genotype, the field is further challenged to identify new ways to transcend agnostic genomewide association approaches. We discuss insights from genetic studies of alcohol related diseases, as well as issues surrounding alcohol's genetic complexity and etiological heterogeneity. Finally, we describe the need for innovative systems-based approaches (systems genetics) that can provide additional statistical power that can enhance future gene-finding strategies and help to identify heretofore-unrealized mechanisms that may provide new targets for prevention/treatments efforts. Emerging evidence from early studies suggest that systems genetics has the potential to organize our neurological, pharmacological, and genetic understanding of alcohol dependence into a biologically plausible framework that represents how perturbations across evolutionarily robust biological systems determine susceptibility to alcohol dependence.
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Affiliation(s)
- R H C Palmer
- Division of Behavioral Genetics, Department of Psychiatry at Rhode Island Hospital, USA.
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25
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Plawecki MH, Wetherill L, Vitvitskiy V, Kosobud A, Zimmermann US, Edenberg HJ, O'Connor S. Voluntary intravenous self-administration of alcohol detects an interaction between GABAergic manipulation and GABRG1 polymorphism genotype: a pilot study. Alcohol Clin Exp Res 2012; 37 Suppl 1:E152-60. [PMID: 22817768 DOI: 10.1111/j.1530-0277.2012.01885.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 05/02/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND Operant responding paradigms quantify a subject's motivation for reward, but such studies employing ingested alcohol cannot assure the same incremental increase in brain exposure to alcohol across subjects because of substantial variability in absorption kinetics. We developed a human progressive ratio (PR) paradigm using the computer-assisted self-infusion of ethanol (CASE) system that overcomes such variability and conducted a pilot study to assess its utility for detecting an interaction of subjects' GABRA2 or GABRG1 genotype and pretreatment with 1 mg of lorazepam (LZ) vs. placebo on their willingness to work for alcohol rewards. METHODS Twenty healthy, nondependent drinkers, aged 21 to 27, were balanced on rs279871 and rs2350439 single nucleotide polymorphisms in the GABRA2 and GABRG1 genes, respectively. Subjects worked for alcohol, with water as an alternative reinforcer (AR), using a progressive schedule of a task that required constant attention and adapted to both fatigue and drug effects. Testing began 1 hour after pretreatment with 1 mg LZ or placebo in a crossover design. RESULTS The CASE system performed well, and the constant attention task was perceived as work by all subjects. GABRA2 homozygosity did not significantly predict either breakpoint or cumulative work, whereas a significant GABRG1 genotype by LZ pretreatment interaction for cumulative work was detected (p = 0.04). Breakpoint revealed a weak trend toward pretreatment drug effects (p = 0.11), and a somewhat stronger interaction of LZ pretreatment with GABRG1 genotype (p = 0.06). GABRG1 status revealed a more complex relationship with respect to motivation for alcohol with and without LZ pretreatment; AG and GG individuals worked more for alcohol under both pretreatment conditions, while AA individuals worked more for the AR. CONCLUSIONS The CASE PR paradigm shows promise as a laboratory method for use in drug development and phenotyping studies.
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Affiliation(s)
- Martin H Plawecki
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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26
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Cui WY, Seneviratne C, Gu J, Li MD. Genetics of GABAergic signaling in nicotine and alcohol dependence. Hum Genet 2012; 131:843-55. [PMID: 22048727 PMCID: PMC3746562 DOI: 10.1007/s00439-011-1108-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 10/23/2011] [Indexed: 12/19/2022]
Abstract
Both nicotine and alcohol addictions are common chronic brain disorders that are of great concern to individuals and society. Although genetics contributes significantly to these disorders, the susceptibility genes and variants underlying them remain largely unknown. Many years of genome-wide linkage and association studies have implicated a number of genes and pathways in the etiology of nicotine and alcohol addictions. In this communication, we focus on current evidence, primarily from human genetic studies, supporting the involvement of genes and variants in the GABAergic signaling system in the etiology of nicotine dependence and alcoholism based on linkage, association, and gene-by-gene interaction studies. Current efforts aim not only to replicate these findings in independent samples, but also to identify which variant contributes to the detected associations and through what molecular mechanisms.
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Affiliation(s)
- Wen-Yan Cui
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- National Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Chamindi Seneviratne
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, 1670 Discovery Drive, Suite 110, Charlottesville, VA 22911, USA
| | - Jun Gu
- National Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Ming D. Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, 1670 Discovery Drive, Suite 110, Charlottesville, VA 22911, USA
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