The effects of apomorphine on the acquisition of schedule-induced polydipsia in rats.
Injections of the dopamine agent, apomorphine, at the doses of 0.05, 0.50 and 1.0 mg/kg were given to three different groups of rats while a fourth group received an injection of the drug vehicle. The injections preceded each of 15 schedule-induced polydipsia (SIP) acquisition sessions in which the subjects bar-pressed for food pellets on a fixed interval 60-sec schedule of reinforcement. The vehicle-injected group developed SIP over sessions while each dose of apomorphine suppressed the acquisition of SIP. Bar-press rates were also depressed at the higher doses, while response patterning was affected at the lower dose. The results support the contention that a normally functioning dopamine system is necessary for the acquisition of SIP, but they do not support the view that this neurotransmitter system is specifically involved in the generation of SIP.
Snodgrass
S H
SH
Department of Psychology, University of Georgia, Athens 30602.
Allen
J D
JD
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D004298:Dopamine / Q000502:physiology; D004327:Drinking Behavior / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051381:Rats; D012055:Reinforcement Schedule
D001058:Apomorphine; D004298:Dopamine