Effects of training dose on amphetamine drug discrimination: dose-response functions and generalization to cocaine.
Rats were trained to discriminate one of three doses of amphetamine (AM), 0.5, 1, or 2 mg/kg, from vehicle (VEH) in a two-lever, food-reinforced, drug-discrimination task. The purpose of the study was to investigate the nature of the shift of the dose-response curve and generalization to cocaine (COC) as a function of training dose. In order to preclude potential differences among the groups in stimulus control, the three training-dose groups were required to perform the discrimination at high and equivalent levels of accuracy. The shift of the dose-response functions to the right as a function of increasing training dose was not parallel. The slope decreased as training dose increased. There was a dose-dependent increase in AM lever responding to test doses of COC that tended to be affected by training dose. The results suggest that proper evaluation of training-dose effects requires that groups be trained to equivalent levels of stimulus control.
Stadler
J R
JR
Department of Psychology, Vanderbilt University, 301 Wilson Hall, Nashville, TN 37203, USA. jonathan.r.stadler@vanderbilt.edu
Caul
W F
WF
Barrett
R J
RJ
D000661:Amphetamine / Q000008:administration & dosage*; D000818:Animals; D002755:Choice Behavior / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage*; D004193:Discrimination Learning / Q000187:drug effects* / Q000502:physiology; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D018765:Dopamine Uptake Inhibitors; D000661:Amphetamine; D003042:Cocaine