Catecholamine release within the striatum of the freely moving rat.

The push-pull method was used in conscious rats in two different types of experiments. In the first, intranigral application of GABAergic agonists was shown to produce both contralateral circling and [3H]dopamine efflux from the ipsilateral striatum. In the second experiment, MK-801, a novel experimental compound, was found to be dissimilar from amphetamine insofar as it does not produce the release of [3H]dopamine from the striatum during its local application. This novel agent presents an intriguing profile of activity whose mechanism of action remains to be fully elucidated. The usefulness of the push-pull method in helping to resolve a complicated behavioral-neurochemical question as well as a tool for studying neuropharmacological effects of novel agents is clear. The development of new and more sensitive HPLC assay techniques should soon alleviate the need for radiolabeling endogenous catecholamine stores and should greatly further advance the usefulness of this technique.