Figure 2. Kainate-evoked currents in granule cells not pre-exposed to ConA are blocked by the AMPA-receptor antagonist GYKI 53655.

A, whole-cell currents evoked by 200 μM kainate in a granule cell held at −80 mV in the presence of increasing concentrations of GYKI 53655. The cell was not pretreated with ConA. Portions of the continuous record are displayed so that the onsets of the applications (bar above the traces) are aligned. Kainate and GYKI 53655 were applied simultaneously; the time-dependent fade of the currents reflects the slow kinetics of the GYKI 53655 inhibition. Concentrations of GYKI 53655 are shown to the right of each trace. B, concentration-response curve for GYKI 53655 inhibition of steady-state currents evoked by 200 μM kainate (same cell as in A). The fit to the results (smooth curve) gave an IC₅₀ of 8.2 μM.