Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Lisa Baker

Access Setting

Masters Thesis-Open Access


This study employed a three-choice drug discrimination procedure in order to further delineate the discriminative stimulus properties of the stereoisomers of 3,4- methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA). Eight male Sprague-Dawley rats were trained to discriminate amphetamine (1.0 mg/kg) and LSD (.08 mg/kg) from saline in a three-lever, food reinforced (sweetened condensed milk) drug discrimination procedure. A fixed-ratio (FR) 20 schedule with a reset condition for incorrect responses was employed. When criteria (85% over 10 consecutive sessions) were met, (+)-MDA, (-)-MDA, (+)-MDMA (.31, .63, 1.25 mg/kg) and (-)-MDMA (.88, 1.75, 3.5 mg/kg) were tested for substitution. All of these compounds produced a greater percentage of responding on the LSD lever than on the amphetamine lever. These results suggest that the discriminative stimulus properties of both MDMA and MDA isomers resemble those of LSD more closely than those of amphetamine. It is suggested that the use of a three-lever discrimination procedure affords a greater degree of precision than the traditional two-level assay in the assessment of the complex stimulus properties of these designer drugs.

Included in

Psychology Commons