Triadimefon, a triazole fungicide, has been observed to increase locomotion and induce stereotyped behavior in rodents. The present experiments characterized the stereotyped behavior induced by triadimefon using a computer-supported observational method, and tested the hypothesis that these effects involved central dopaminergic systems. Adult male and female Sprague-Dawley rats were injected with triadimefon (0, 50, 100, 200 mg/kg) in corn oil (2 mL/kg ip) four hours prior to behavioral assessment. The two lowest doses of triadimefon increased the frequency of locomotion and rearing, while the highest dose induced highly stereotyped behaviors including backward locomotion, circling, and head weaving. Immediately after behavioral testing, the rats were sacrificed, and the striata (STR) and olfactory tubercles (OT), terminal fields of the nigrostriatal and mesolimbic dopamine systems, respectively, were dissected. Steady-state concentrations of dopamine (DA), serotonin (5-HT), and their metabolites were determined by HPLC-EC. (Copyright (c) 1990 Academic Press Inc.)