Interaction of stress and stimulants in female rats : role of dopamine in the stress-induced reactivity to methamphetamine
M.A. (Master of Arts)
Department of Psychology
Methamphetamine--Physiological effect; Dopamine; Stress (Physiology); Physiological psychology
Previous research in humans and animals suggests that exposure to stress alters the susceptibility and behavioral responses to drugs of abuse, including methamphetamine. Female rats have been shown to be more sensitive to the effects of stimulants and stress than males, but few studies have investigated the interaction between stress and stimulants in female rats. Therefore, the current study investigated whether stress potentiated the behavioral and dopaminergic responses to a methamphetamine injection in female rats. Adult female rats were either exposed to 10 days of stressors that varied by day and time or were left undisturbed except for daily weighing (con-trol rats). Fourteen days after the last stressor, all rats received an injection of 7.5 mg/kg meth-amphetamine and distance traveled and stereotypy was measured in an open field box (Experi-ment 1) or dopamine increases were measured in the dorsal striatum (Experiment 2). Female rats exposed to chronic unpredictable stress (CUS) had significantly higher locomotion in the open field immediately following an injection of methamphetamine, with no significant differences at any other time points. In Experiment 2, female rats exposed to CUS had significantly higher levels of dopamine in the dorsal striatum at all time points following an acute injection of meth-amphetamine compared to control rats. Estrous cycle was not found to be a significant predictor of distance traveled following a methamphetamine injection. This is the first study investigating the interaction between stress and methamphetamine in female rats. Interestingly, these findings parallel previous findings from our lab with male rats exposed to CUS showing both an increase in locomotion and dopamine in the dorsal striatum following an injection of methamphetamine compared to control rats. The current findings characterize the interaction of females to stress and stimulants, which may provide insight into potential drug addiction treatments for women.
Anderson, Eden Marie, "Interaction of stress and stimulants in female rats : role of dopamine in the stress-induced reactivity to methamphetamine" (2014). Graduate Research Theses & Dissertations. 3610.
Northern Illinois University
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Advisors: Leslie Matuszewich.||Committee members: Angela Grippo; Doug Wallace.