DOPAMINE REGULATION OF EXTRACELLULAR GLUTAMATE IN THE NUCLEUS-ACCUMBENS

The capacity of dopamine to alter extracellular glutamate in the nucle us accumbens was examined by passing 1, 10 and 100 mu M Of amphetamine , the D-2/3 agonist, quinpirole, or the D-1 agonist, SKF-82958 through a microdialysis probe. It was found that amphetamine and quinpirole p roduced a dose-dependent reduction in the basal levels of extracellula r glutamate, while SKF-82958 was without significant effect. The capac ity of the D-1 antagonist, SCH-23390 (1.0 mg/kg, i.p.) or the D-2 anta gonist, sulpiride (10 mg/kg, i.p.) to block the reduction in extracell ular glutamate by amphetamine (100 mu M) was examined. Both SCH-23390 and sulpiride prevented the reduction in extracellular glutamate by am phetamine. The data indicate that, similar to the striatum, glutamate release in the nucleus accumbens is modulated by presynaptic dopamine receptors. (C) 1997 Elsevier Science B.V.