The effects of d-amphetamine, chlordiazepoxide and alpha-flupenthixol on food-reinforced tracking of a visual stimulus by rats.
Rats were trained to respond to one of two levers under a random ratio schedule of food reinforcement. Which of the levers was correct was redetermined before each response and signalled by a light. The effects of d-amphetamine (0.2-3.2 mg/kg), chlordiazepoxide (1-8 mg/kg), and the neuroleptic alpha-flupenthixol (0.03-0.33 mg/kg) on the efficiency of rats tracking this visual cue were examined. d-Amphetamine increased the proportion of responses made on the correct lever at low and intermediate doses, but reduced the proportion at 3.2 mg/kg. At the highest dose, chlordiazepoxide produced a small increase in this measure, together with a reduction in response rate, but alpha-flupenthixol had no effect, even at a dose reducing response rate. Low doses of amphetamine also increased switching between the levers, producing a proportionately greater increase in switching from the correct lever to the incorrect lever than vice versa. The results are interpreted as showing that d-amphetamine facilitates tracking performance as a result of its action of enhancing response switching, and supporting the hypothesis that facilitation of performance by amphetamine-like drugs depends on the effect of the drug on response output coinciding with task requirements.
D000818:Animals; D002707:Chlordiazepoxide / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology*; D005475:Flupenthixol / Q000494:pharmacology*; D005502:Food; D008297:Male; D010775:Photic Stimulation; D051381:Rats; D011919:Rats, Inbred Strains; D012054:Reinforcement, Psychology; D013892:Thioxanthenes / Q000494:pharmacology*
D013892:Thioxanthenes; D002707:Chlordiazepoxide; D005475:Flupenthixol; D003913:Dextroamphetamine