Physical activity (PA) is important to human health, and the genetic and biological regulating factors of physical activity are only beginning to be understood. The dopamine (DA) system has been shown to regulate motivation, and locomotor behavior in animals, and this research was designed to understand the dopaminergic factors important in regulating voluntary physical activity in mice. First, the repeatability of measuring exercise endurance vs. wheel running (WR) in different inbred strains of mice was investigated. It was found that WR behavior is a highly repeatable measurement, while exercise capacity measurements showed low repeatability in Balb/cJ mice. Next, expression levels of the five DA receptors, Tyrosine hydroxylase (TH), and the dopamine transporter (DAT) in the nucleus accumbens and striatum were studied in mice with or without wheel access in differentially active inbred strains of mice. No differences in expression levels of any DA receptors were found within strain between group, suggesting level of PA did not affect DA receptor expression. High active C57L/J mice had significantly decreased expression of Drd1 and TH compared to low active C3H/HeJ mice indicating DA receptor, and enzyme expression/function may act independently to control level of PA. Pharmacological studies showed C57L/J mice significantly decrease WR in response to a D1 agonist, and C3H/HeJ mice significantly increase WR in response to a DAT inhibitor. These results suggest genetic differences in the DA system may mediate differences in PA behavior between inbred strains of mice.
|Commitee:||Flood, Meredith, Huet, Yvette, Schrum, Laura, Turner, Michael|
|School:||The University of North Carolina at Charlotte|
|School Location:||United States -- North Carolina|
|Source:||DAI-B 70/05, Dissertation Abstracts International|
|Subjects:||Molecular biology, Genetics, Physiology|
|Keywords:||Dopamine, Genetic regulation, Physical activity, Receptor, Running wheel|
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