Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Lisa Baker

Second Advisor

Dr. Alan Poling

Access Setting

Masters Thesis-Open Access


Two groups of male Sprague-Dawley rats (n= 16) were used in a drug discrimination assay to assess the stimulus properties of PNU-99194A, currently the most selective D3 dopamine antagonist. Eight rats were trained to discriminate cocaine-HCL (10 mg/kg) from saline and remaining eight rats were trained to discriminate PNU-99194A-HCL (10 mg/kg) from saline. PNU-99194A was tested for substitution (0-40 mg/kg, i.p and s.c.),. antagonism (5-20 mg/kg), and potentiation (5-20 mg/kg) in the animals trained with cocaine. PNU-99194A did not substitute for cocaine at any dose tested. PNU-99194A did not alter cocaine discrimination when administered in combination with the training dose or with a lower dose of cocaine. d-Amphetamine (0- 2.0 mg/kg, i.p.), cocaine (0-10 mg/kg, i.p. and s.c.), and caffeine (8.0-64.0 mg/kg, i.p.) were tested for substitution in the rats trained to discriminate PNU-99194 A. Cocaine, d-amphetamine, and caffeine produced virtually no responding on the PNU-99194A-lever, although caffeine (64 mg/kg) produced a mean of 32% drug appropriate responding. The present results suggest that PNU-99194A produces discriminative stimulus effects that are uniquely different from known psychomotor stimulants.

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Psychology Commons