Discriminative stimulus properties of substituted amphetamine derivatives.
Animals were trained to discriminate amphetamine (1 mg/kg) from saline in a fixed-ratio (FR 10), food-reinforced paradigm. Amphetamine-appropriate responding was engendered by the training dose, and by 3 mg/kg, while at lower doses there was a progressive decrease in the extent of responding on the drug-appropriate lever. The following three novel amphetamine derivatives were tested for their ability to produce amphetamine-appropriate responding: 2,5-dimethoxy-4-ethoxy-amphetamine (DMEA); 2,5-dimethoxy-4-methylthio-amphetamine (DMMTA), and 2,4,5-trimethoxy-amphetamine (TMA). DMEA produced only minimal (< 20%) amphetamine-appropriate responding over a dose range of 0.1-10 mg/kg. Substantial decreases in response rate limited testing of the other amphetamines to a dose maximum of 3 mg/kg, but over the range of 0.1-3.0 mg/kg there was little evidence for generalization. At 3 mg/kg of either DMMTA or TMA, only 2 of 10 animals completed at least one uninterrupted FR 10 on either lever, and with either compound only 1 of these 2 animals responded more than 50% on the drug-appropriate lever. Of the three compounds tested, DMMTA had the greatest response rate-decreasing effect.
Corrigall
W A
WA
Neurobiology Section, Addiction Research Foundation, Toronto, Ontario, Canada.
Coen
K M
KM
Saouda
F M
FM
Robertson
J M
JM
Lodge
B A
BA
D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D004193:Discrimination Learning / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D012055:Reinforcement Schedule
D000662:Amphetamines