Figure 1. Pretreatment of cerebellar granule cells with ConA reveals high-affinity kainate-type currents.

Aa, whole-cell currents evoked at −80 mV by increasing concentrations of kainate in a cerebellar granule cell not exposed to ConA. Note the lack of a response to 5 μM kainate. Breaks in the record are indicated by the diagonal bars. Ab, concentration-response curve for steady-state currents evoked by kainate from the same granule cell as in Aa. The Hill-type fit to the data gave an EC₅₀ of 46 μM. B, whole-cell currents evoked at −80 mV by 1 and 10 μM kainate in a granule cell pre-exposed to ConA. Kainate applications are denoted by the bar above the traces. C, concentration-response curve for kainate in a granule cell that was pretreated with ConA (different cell from that in B). The smooth line shows the two-component Hill-type fit to the results which gave EC₅₀ values of 5 and 56 μM for the high- and low-affinity components, respectively.