THE INFLUENCE OF dl‐, d‐, AND l‐AMPHETAMINE AND d‐METHAMPHETAMINE ON A FIXED‐RATIO SCHEDULE

In 1910, a systematic pharmacological investigation of a series of aliphatic and aromatic amines (Barger & Dale, 1910) revealed a number of compounds that had prop- erties similar to those of epinephrine.These compounds elicited physiological responses of varying degree similar to functional stimulation of the sympathetic nervous system.From this work the term sympathomimetic amine was coined.Prior to this (in the 1880's), ephedrine, the active principle of the Chinese herb Ma Huang, had been studied and was discarded as being too toxic.Upon reinvestigation by Chen and Schmidt (1924), the pharmacological importance of ephedrine as a sympathomimetic was recognized.Publica- tion of this work stimulated new interest in these amine compounds, especially the phenylethylamines and the phenylisopropylamines, the chemical nucleus structures of epinephrine and ephedrine, respectively. CH2-CHCNH CH-CHCH3phenylethylamine phenylisopropylamine (amphetamine)'Normal rate, hereafter in this report, refers to base-line performance determined as the mean response rate of 10 randomly selected daily sessions excluding immediate postdrug-day sessions.