Effect of fenfluramine and nicotine upon a stimulant-depressant continuum.
Rats were rapidly trained to discriminate between 0.8 mg/kg d-amphetamine and 6 mg/kg pentobarbital in a two-lever food-motivated operant task by imposing the drug states from the earliest stage of training. Once trained, rats were administered lower doses of each of the training drugs and both d-amphetamine and pentobarbital were observed to produce dose-responsive effects upon discriminative performance. When graphically represented, the dose-response curves were shown to be parallel suggesting a common site and/or mechanism of action. Administration of fenfluramine (1.5 and 2.25 mg/kg) produced pentobarbital-appropriate responding, whereas the injection of three doses of nicotine (0.1-0.4 mg/kg) resulted in amphetamine-like discriminative responding. Inspection of dose-response curves suggested that fenfluramine produces its pentobarbital-like effects by acting differently than does pentobarbital and, although nicotine produces amphetamine-like effects, it acts by a different mechanism than does amphetamine.
D000818:Animals; D003216:Conditioning, Operant; D003913:Dextroamphetamine; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005277:Fenfluramine; D008297:Male; D010424:Pentobarbital; D051381:Rats; D011919:Rats, Inbred Strains
D005277:Fenfluramine; D010424:Pentobarbital; D003913:Dextroamphetamine