Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Lisa Baker

Second Advisor

Dr. Scott H. Kollins

Third Advisor

Danielle Larson

Access Setting

Masters Thesis-Open Access


The current study examined the effects of methylphenidate (MP) pre-exposure on the acquisition of cocaine discrimination in rats. Sixteen male Sprague-Dawley rats were administered either 10 mg/kg MP or saline for five consecutive days. Following this pre-treatment phase, animals were trained to discriminate 10 mg/kg cocaine-hydrochloride from saline using a two-lever fixed-ratio 20 (FR20) schedule of food reinforcement. Acquisition of cocaine discrimination, as indicated by the number of sessions to criterion, did not differ significantly between the two-pre-treatment groups (MP = 35.5 ± 2.4; SAL = 31.6 ± 2.3). Stimulus generalization tests were conducted with cocaine and methylphenidate using cumulative dosing procedures. The dose response curves for both methylphenidate and cocaine were not significantly different between the two pretreatment groups. Methylphenidate completely substituted for cocaine at doses of 4.0 mg/kg and 8.0 mg/kg in both treatment groups.

Included in

Psychology Commons