Acute behavioral responses to ethanol have predictive value for determining an individual's risk of long-term drinking behavior. Although the neurobiology of alcohol abuse is complex, prior studies from our laboratory demonstrated differential myelin-associated gene expression (MAGE) in medial prefrontal cortex (PFC) as one potential mechanism influencing acute ethanol behaviors between C57BL/6J (B6) and DBA/2J (D2) mice. Our laboratory and others have also shown MAGE is reduced in PFC of alcoholics. Herein, I have extended these findings through expression profiling of PFC into chronic models of ethanol self-administration from non-human primates and mice. Together, these results suggest that regulation of MAGE may be relevant to behavioral phenotypes witnessed in alcoholism. The pathogenesis of alcoholism progresses through multiple stages of drug exposure and withdrawal, however, genetic predisposition is also a major contributing factor for this disease. Therefore, I tested the hypothesis that not only does ethanol have direct effects on MAGE, but also variation in basal MAGE within the PFC is a molecular endophenotype underlying ethanol behavioral sensitivity. Bioinformatics of basal MAGE across the BXD recombinant inbred panel (n=29), derived from B6 and D2 mice, revealed a densely correlated myelin gene network associated with several ethanol behavioral phenotypes. Literature association tools identified Fyn kinase as potential regulator of MAGE. Fyn knockout mice are known to be more sensitive to the sedative-hypnotic properties of ethanol in the loss of righting reflex (LORR) paradigm. Microarray analysis ofFyn knockout mice revealed a significant decrease in MAGE, suggesting MAGE may be an underlying factor for LORR. In support of this premise, microarray analysis of genetic variance in LORR across Inbred Long Sleep and Inbred Short Sleep mice, as well as congenics for the Lore5 quantitative trait locus, also demonstrated an inverse relationship between MAGE and duration of LORR. The hypothesis was further investigated using cuprizone to model demyelination in B6 mice and test them in a battery of acute ethanol behaviors. Cuprizone-treated mice had a significantly greater duration in LORR (p < 0.01), demonstrating that myelin is an important contributor to the genetic variance in LORR. Thus, through genetic, genomic, and pharmacological tools I have `molecularly triangulated' a myelin gene network as a contributing factor influencing acute ethanol behavioral sensitivity. The ability of myelin to alter acute ethanol sensitivity may warrant a prospective study of myelin in humans as a predictive molecular phenotype for an individual's risk of developing alcohol dependence. Additionally, further genomic dissection of MAGE architecture and associated networks may aid in developing novel pharmacotherapies for an alcohol use disorder. Supported by NIAAA grants F31 AA018615 to SPF.
|Advisor:||Miles, Michael F.|
|Commitee:||Bigbee, John W., Davies, Andrew G., Hauser, Kurt F., Riley, Brien P.|
|School:||Virginia Commonwealth University|
|Department:||Pharmacology & Toxicology|
|School Location:||United States -- Virginia|
|Source:||DAI-B 73/09(E), Dissertation Abstracts International|
|Keywords:||Alcohol abuse, Alcohol dependence, Gene expression, Myelin|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be