Glutamate receptor-mediated inhibition of l-glutamate efflux from cerebral cortex in vitro

We tested whether glutamate receptor ligands affect oxygen–glucose deprivation-evoked l-glutamate efflux from adult rat cerebrocortical prisms. The uncompetitive NMDA antagonist AR-R15896AR inhibited efflux (IC50 34 μM, 87% maximal inhibition). AMPA/kainate receptor blockade (NBQX, 100 μM) or Group II metabotropic glutamate receptor activation (DCG-IV, 10 μM) inhibited efflux (41%, 67% respectively) but Group I mGluR blockade (CPCCOEt/MPEP, 10 μM) was without effect. These data support a modulatory effect of glutamate receptors on l-glutamate efflux.