IN-VIVO RELEASE OF DOPAMINE AND ITS METABOLITES FROM RAT STRIATUM IN RESPONSE TO DOMOIC ACID

The microdialysis technique was used to examine the effect of the neur otoxin domoate, an analog of glutamic acid, on striatal dopamine activ ity. Our results show that the intracerebral administration of differe nt concentrations of domoate (100 and 500 mu M) produced increases in the extracellular levels of dopamine associated to decreases in the ex tracellular levels of its metabolites dihydroxyphenylacetate and homov anillate from rat striatum. These changes seem to be related according to a time sequence, indicating a possible effect on the metabolism of dopamine. Changes were also observed in locomotor activity (cycling b ehavior, sniffing around and chewing) in rats during the domoate infus ion. The physiological mechanism by which domoate increased dopamine r elease remains to be worked out.