SYMPOSIUM: BEHAVIOR MODIFICATION BY DRUGS

Abstract

The pharmacology of the amphetamines has been studied for several decades. There is now a great deal of information about their tissue distribution and catabolism, largely by enzymatic oxidative processes. The most clearly characterized actions of the amphetamines occur at catecholamineconaining nerve terminals and tend to enhance the availability of the transmitter to post-synaptic receptors. The actions of the drugs in the CNS include stimulation of the ascending reticular formation of the brainstem, and probably enhancement of the activity of a behavior reinforcement system mediated by the median forebrain bundle. Toxic effects of amphetamine include apparent interactions at the basal ganglia to produce stereotyped behaviors in animals and man. All of these actions might involve catecholaminergic synaptic transmission systems. Under careful, controlled medical supervision the amphetamines are remarkably safe, although in excessive doses they can produce severe toxic, sympathomimetic and psychotic effects and can be lethal. They are subject to gross abuses, and to habituation. Tolerance develops to some of their actions, but usually not to their legitimate and rational uses in narcolepsy and hyperkinesis. Withdrawal symptoms are relatively minor.