Effects of triadimefon on a multiple schedule of fixed-interval performance: comparison with methylphenidate, d-amphetamine and chlorpromazine.
Triadimefon is a fungicide that has recently been shown to increase motor activity and rates of schedule-controlled responding. These findings indicate that triadimefon resembles psychomotor stimulants and in this respect is a unique pesticide. The present experiment was designed to evaluate triadimefon's effects on performance maintained by a multiple schedule of reinforcement and to compare triadimefon to known psychomotor stimulants. Four rats were trained to perform under a mult FI 1-min FI 5-min schedule of milk reinforcement. They then received a series of dosages of triadimefon (10-170 mg/kg, IP) and of methylphenidate (1-17.3 mg/kg, IP) in a counterbalanced order. Triadimefon increased response rates in both the FI 1-min and FI 5-min components. Methylphenidate did not consistently alter response rates in either component. Temporal patterns of responding were disrupted much more in the FI 5-min component than in the FI 1-min component by both triadimefon and methylphenidate. Performances were then evaluated following a series of dosages of d-amphetamine (0.3-3.0 mg/kg, IP) and chlorpromazine (0.5-2.0 mg/kg, IP). Response rates were increased by d-amphetamine in the FI 1-min component but not in the FI 5-min component. Like triadimefon and methylphenidate, d-amphetamine produced a greater disruption of response patterning in FI 5-min than in FI 1-min. Only chlorpromazine decreased response rates in both components. Chlorpromazine also disrupted FI 5-min response patterning, but left FI 1-min patterning intact.(ABSTRACT TRUNCATED AT 250 WORDS)
Allen
A R
AR
Department of Psychology, University of North Carolina, Chapel Hill 27514.
MacPhail
R C
RC
D000818:Animals; D002746:Chlorpromazine / Q000494:pharmacology; D003913:Dextroamphetamine / Q000494:pharmacology; D004193:Discrimination Learning; D005659:Fungicides, Industrial / Q000633:toxicity; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects*; D051381:Rats; D012055:Reinforcement Schedule; D013268:Stimulation, Chemical; D014230:Triazoles / Q000633:toxicity*
D005659:Fungicides, Industrial; D014230:Triazoles; C032910:triadimefon; D008774:Methylphenidate; D003913:Dextroamphetamine; D002746:Chlorpromazine