Figure 6. Pretreatment of granule cells with ConA reveals activation by SYM 2081 of high-affinity kainate-type currents.
A, whole-cell currents evoked at −80 mV by increasing concentrations of SYM 2081 in 2 granule cells that either were (a) or were not (b) pretreated with ConA. B, concentration-response data from the complete set of results obtained for the cells in Aa and Ab: •, data from a cell exposed to ConA; ^, results from a granule cell not pretreated with ConA. Continuous lines are one-component Hill-type fits to each set of data. The fit to the results obtained from the cell pretreated with ConA gave an EC50 value of 0.95 μM, whereas the corresponding value obtained from the cell not exposed to ConA was 216 μM. The dashed line indicates the Hill-type fit that was obtained for the results from the ConA-treated granule cell when the data for SYM 2081 concentrations of 10 μM and above were excluded (EC50= 0.51 μM).