Bitertanol, a triazole fungicide, increases operant responding but not motor activity

Several recent reports indicate that triadimefon, a triazole fungicide, has effects on behavior that are similar to those of psychomotor stimulants. For example, triadimefon increases overall fixed-interval (FI) response rate, disrupts FI response patterning, increases motor activity, and produces stereotypies at high doses. The present study was designed to determine whether similar behavioral effects on FI performance and motor activity could be produced by another triazole fungicide, bitertanol. The effects of bitertanol (10-300 mg/kg, IP) were determined in rats on performance maintained under a multiple FI 1-min FI 5-min schedule of reinforcement. Intermediate doses of bitertanol increased response rates and disrupted response patterning in both FI components. A second experiment determined the effects of the same doses of bitertanol on motor activity. In contrast to its effects on operant responding, bitertanol did not increase motor activity at any of the doses tested. These findings indicate that the behavioral similarities between bitertanol and triadimefon are limited and that a dissociation exists between biteranol's effects on operant performance and motor activity.