Date of Award


Degree Type


Degree Name

Master of Science


Psychological Science


Psychological Science (MS)

First Advisor/Chairperson

Dr. Adam Prus


Amphetamine (AMPH) is one of the most common psychotropic drugs abused in the United States. Its major pharmacological effect is to increase synaptic dopamine levels in the mesolimbic reward pathway, which in turn causes behavioral effects in animals, and subjective effects in humans. These reinforcing properties of AMPH trigger very strong levels of craving the drug, and eventually result in patterns of compulsive use of AMPH. Regarding psychostimulant action, female rats have been reported to be more vulnerable to the reinforcing effects of psychostimulants. In the current study, schedule-induced polydipsia (SIP), an animal model of compulsive behavior, was applied for the further study of sex differences in the behavioral effects of AMPH. SIP is a phenomenon whereby food-restricted rats exhibit exaggerated polydipsic behavior when presented with food pellets under an intermittent schedule of reinforcement. This behavior appears to be mediated by the neurotransmitter dopamine in the brain’s limbic system, and this neurotransmitter and system is also affected by psychostimulant drugs. During the SIP training sessions, it was found that female rats needed more sessions to develop stable schedule-induced polydipsic behavior. In line with previous studies, AMPH dose-dependently decreased total water intake and licks during a SIP task. Significant differences were found on their total number of lever presses and reinforcers earned.

Access Type

Open Access