Figure 3. Tonic activation of AMPARs upon blockade of glutamate transporters.

A, effects on the holding current of TBOA (100 μm), NBQX (20 μm) and MK801 (40 μm). Note that NBQX slightly reduced the amplitude of the tonic current induced by TBOA. B, in another pyramidal cell the effect of NBQX was more pronounced in the presence of cyclothiazide (CTZ, 100 μm). Note that in A and B the holding current in MK801 reached a lower level than before TBOA indicating the presence of a basal tonic current. C, percent of the TBOA-induced current blocked by NBQX in the absence (CTR) and in the presence of cyclothiazide (CTZ).