PT - JOURNAL ARTICLE AU - Karima Chergui AU - Alexandre Bouron AU - Elisabeth Normand AU - Christophe Mulle TI - Functional GluR6 Kainate Receptors in the Striatum: Indirect Downregulation of Synaptic Transmission AID - 10.1523/JNEUROSCI.20-06-02175.2000 DP - 2000 Mar 15 TA - The Journal of Neuroscience PG - 2175--2182 VI - 20 IP - 6 4099 - http://www.jneurosci.org/content/20/6/2175.short 4100 - http://www.jneurosci.org/content/20/6/2175.full SO - J. Neurosci.2000 Mar 15; 20 AB - Kainate receptors (KARs) are abundantly expressed in the basal ganglia, but their function in synaptic transmission has not been established. In the present study, we show that the GluR6 subunit of KARs is expressed in both substance P- and enkephalin-containing GABAergic projection neurons of the mouse striatum. Using whole-cell voltage-clamp recordings in brain slices, we demonstrate the presence of functional KARs in the dorsal striatum activated by low concentrations of the AMPA/KAR agonist domoate in wild-type but not GluR6-deficient mice. Despite the abundance of KARs, we found no evidence for synaptic activation of these receptors after single or repetitive stimulation of glutamatergic afferents. Domoate induces a transient increase in the frequency of spontaneous IPSCs of small amplitude and a sustained depression of large IPSCs evoked by minimal electrical stimulation within the striatum in wild-type mice but not in GluR6-deficient mice. This depressant effect is inhibited in presence of adenosine A2A receptor antagonists, ZM-241385 and SCH-58261. These data strongly suggest that, in striatal neurons, KARs depress GABAergic synaptic transmission indirectly via release of adenosine acting on A2A receptors.