Behavioral studies of the reinforcing properties of cocaine.

In this chapter, the behavioral characteristics of cocaine self-administration were described. Cocaine is a powerful positive reinforcer, and its reinforcing properties have been demonstrated in every species tested, across an enormous range of conditions in experimental studies with animals. To compare the reinforcing efficacy of cocaine with that of other drugs, to determine how these effects might change under different environmental conditions, and, in the present context, to determine their underlying molecular mechanisms require that its reinforcing properties be assessed using indices that are not influenced by the multitude of other pharmacological effects that are produced by cocaine. Many procedures rely on rate of responding or levels of cocaine self-administration as a measure of reinforcing properties, but these may not be adequate. The use of more sophisticated approaches that utilize nonrate measures or an assessment of the resistance of drug-maintained responding to perturbations may enable neuroscientists to design more definitive studies.