This is a renewal of ongoing R01 funding to define molecular sites of alcohol action in brain and to link alcohol effects on these receptors with specific behaviors such as consumption, reward/aversion, intoxication and physical dependence. During the current period of funding we were successful in providing molecular and even atomic level of analysis of alcohol sites on pentameric ligand-gated (pLGIC) ion channels, including the first crystallographic structure of alcohols bound within a channel protein. We also succeeded in constructing mutant mice with GABAa receptor subunits which are resistant to alcohol modulation allowing us to link specific GABAa receptors with discrete behavioral actions of alcohol. We are in the middle of the fourth year of this project period and to date have 30 publications with 7 more submitted or in preparation. Although we and others have made considerable progress, the molecular sites of alcohol action in the brain are not completely defined. Emerging evidence from human and rodent genetics, as well as recombinant receptors, indicates that several targets which have received only limited attention may be important sites of alcohol action in brain. We propose to define the role of two groups of ligand-gated ion channels, the glycine-activated chloride channels (GlyR) and GABAaRs formed from ? subunits (? GABAaRs) in actions of alcohol at the molecular, electrophysiological and behavioral levels. A strength of this proposal is the combined use of knock-out (KO) and knock-in (KI) mice allowing us to define the importance of the presence of a subunit (KO) and the importance of direct alcohol action on the protein (KI) for behavioral actions of alcohol. An innovative aspect is use of a new technology (transcription activator- like effector nuclease;TALEN) to be employed by our collaborator, Dr. Gregg Homanics, that markedly reduces the time and cost required for construction of mutant mice. In addition to our behavioral studies, mutant mice will be used by our collaborator, Dr. Neil Harrison for electrophysiological studies of glycinergic function in accumbal regions. Several GlyRs and ? GABAaRs are genetically linked with human alcohol dependence and understanding their role in alcohol actions may provide new targets for pharmacotherapies of alcohol abuse and alcoholism.

Public Health Relevance

Even though alcohol (ethanol) has been consumed for thousands of years, we know remarkably little about the way it produces its effects on the brain. An important advance was the identification of specific proteins (neurotransmitter receptors and ion channels) involved in communication between neurons as a target for ethanol. We will define how ethanol acts on these proteins using novel techniques, ranging from the molecular to the behavioral level, combining mutations in mice with electrophysiological and behavioral studies. The final objective is to define key protein sites that can serve as pharmacological or genetic targets for new therapies to alleviate alcohol addiction.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
2R01AA006399-32
Application #
8631877
Study Section
Special Emphasis Panel (ZRG1-IFCN-C (02))
Program Officer
Liu, Qi-Ying
Project Start
1983-09-29
Project End
2019-05-31
Budget Start
2014-06-10
Budget End
2015-05-31
Support Year
32
Fiscal Year
2014
Total Cost
$471,030
Indirect Cost
$151,843
Name
University of Texas Austin
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
170230239
City
Austin
State
TX
Country
United States
Zip Code
78712
Erickson, Emma K; Farris, Sean P; Blednov, Yuri A et al. (2018) Astrocyte-specific transcriptome responses to chronic ethanol consumption. Pharmacogenomics J 18:578-589
McCarthy, Gizelle M; Warden, Anna S; Bridges, Courtney R et al. (2018) Chronic ethanol consumption: role of TLR3/TRIF-dependent signaling. Addict Biol 23:889-903
Blednov, Yuri A; Da Costa, Adriana J; Harris, R Adron et al. (2018) Apremilast Alters Behavioral Responses to Ethanol in Mice: II. Increased Sedation, Intoxication, and Reduced Acute Functional Tolerance. Alcohol Clin Exp Res 42:939-951
Blednov, Yuri A; Da Costa, Adriana J; Tarbox, Tamara et al. (2018) Apremilast Alters Behavioral Responses to Ethanol in Mice: I. Reduced Consumption and Preference. Alcohol Clin Exp Res 42:926-938
Borghese, Cecilia M; Herman, Melissa; Snell, Lawrence D et al. (2017) Novel Molecule Exhibiting Selective Affinity for GABAA Receptor Subtypes. Sci Rep 7:6230
Blednov, Yuri A; Black, Mendy; Chernis, Julia et al. (2017) Ethanol Consumption in Mice Lacking CD14, TLR2, TLR4, or MyD88. Alcohol Clin Exp Res 41:516-530
McCracken, Lindsay M; Lowes, Daniel C; Salling, Michael C et al. (2017) Glycine receptor ?3 and ?2 subunits mediate tonic and exogenous agonist-induced currents in forebrain. Proc Natl Acad Sci U S A 114:E7179-E7186
Tarvin, Rebecca D; Borghese, Cecilia M; Sachs, Wiebke et al. (2017) Interacting amino acid replacements allow poison frogs to evolve epibatidine resistance. Science 357:1261-1266
Blednov, Yuri A; Borghese, Cecilia M; Ruiz, Carlos I et al. (2017) Mutation of the inhibitory ethanol site in GABAA ?1 receptors promotes tolerance to ethanol-induced motor incoordination. Neuropharmacology 123:201-209
Blednov, Yuri A; Black, Mendy; Benavidez, Jillian M et al. (2017) Sedative and Motor Incoordination Effects of Ethanol in Mice Lacking CD14, TLR2, TLR4, or MyD88. Alcohol Clin Exp Res 41:531-540

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