| The phenomenon of self-stimulation has been used to map the neural circuitry of reinforcement and determine its neurophysiological and neurochemical characteristics. More recently, it has been proposed that drugs of abuse control behavior by their effects on the same neural systems. However, drug effects rise and fall over minutes or hours while conventional brain stimulation trains have abrupt onset and offset and last less than one second. Possibly because of this, the pattern of responding produced by drug reinforcers is different from the pattern produced by conventional brain stimulation. Furthermore, pharmacological antagonists of drug reinforcement increase the rate of drug self-administration while antagonists of brain stimulation reinforcement depress self-stimulation. To test the hypothesis that the differences in the characteristics of brain stimulation and drugs as reinforcers are due to differences in the kinetics of drugs and brain stimulation, we have modelled drug kinetics with frequency modulated brain stimulation trains. It is reported that animals will self-administer such brain stimulation and that, under these conditions, dopamine antagonists can induce an increase in the rate of self-administration. |
