Award Date

5-1-2014

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Psychology

Department

Psychology

First Committee Member

Laurel M. Pritchard

Second Committee Member

Merrill Landers

Third Committee Member

Jefferson Kinney

Fourth Committee Member

Daniel Allen

Number of Pages

97

Abstract

Methamphetamine (METH) abuse impacts the global economy through costs associated with drug enforcement, emergency room visits, and treatment. Hyperthermia is a leading cause of METH induced emergency room visits and may lead to neural damage. Previous research has demonstrated early life stress, such as childhood abuse, increases the likelihood of developing a substance abuse disorder. However, the effects of early life stress on neuronal damage induced by chronic METH administration are unknown. We aimed to elucidate the effects of early life stress on METH induced dopamine damage in the striatum. Animals were separated three hours per day during the first two weeks of development or 15 minutes for control. In adulthood, rats received either a subcutaneous 0.9% saline or 5.0 mg/kg METH injection every two hours for a total of four injections. Rectal temperatures were taken before the first injection and one hour after each subsequent injection. Seven days after testing, rats were euthanized and striatum was collected for quantification of tyrosine hydroxylase (TH) and dopamine transporter (DAT) content by Western blot. METH significantly elevated core body temperature in males and decreased striatal DAT and TH content and this effect was potentiated by early life stress. Females did not exhibit an effect of METH except in the elevated heat condition in the preliminary study, which significantly decreased DAT levels. We further ran a preliminary study looking at early life stress, METH dosing in adulthood during ambient (22-23°C) or elevated (27-30°C) temperature .Preliminary results indicated a replication of experiment one with no effect of elevated temperatures. These studies indicate maternal separation increases METH induced damage in males, and females are less susceptible to METH induced damage.

Keywords

Brain damage; Corpus striatum; Methamphetamine; Methamphetamine abuse; Stress (Physiology)

Disciplines

Biological Psychology

Language

English


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