Effects of dopamine antagonists on the timing of two intervals.
Rats were trained on a two-interval (12 and 36 s) temporal production task (the peak procedure). Test sessions were conducted in which either the D(1) antagonist SCH-23390 (SCH; 0.02, 0.04, 0.06 mg/kg) or the D(2) antagonist haloperidol (HAL; 0.05, 0.1, 0.2 mg/kg) were injected prior to testing. Both drugs affected the amount of responding, but only HAL affected timing. Under HAL, both intervals were overestimated, consistent with a HAL-induced decrease in clock speed. Drug-induced decreases in response output were more profound for the long interval than the short. In addition, there was evidence of HAL- and SCH-induced delays in response initiation that were more severe for the long interval, perhaps owing to its status as a weaker conditioned stimulus.
Drew
Michael R
MR
Department of Psychology, Columbia University, New York, NY 10027, USA. drew@psych.columbia.edu
Fairhurst
Stephen
S
Malapani
Chara
C
Horvitz
Jon C
JC
Balsam
Peter D
PD
D000161:Acoustic Stimulation; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003216:Conditioning, Operant / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors; D013998:Time Perception / Q000187:drug effects*
D001552:Benzazepines; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D017447:Receptors, Dopamine D1; D006220:Haloperidol