Fig. 3.

Concentration–response curves for the potassium channel blockers TEA and 4-AP obtained using outside-out patches pulled off from basket cell and Purkinje cell soma regions.Closed circles show block of peak current, andopen circles show block of steady-state current throughout. A, B, TEA reduced basket cell somatic currents in a dose-dependent fashion; peak and steady-state current exhibited similar sensitivity. C, D, Purkinje cell soma currents were reduced by TEA at concentrations >0.01 mm, again peak and steady-state values were similar, and virtually all of the current was blocked by 10 mm TEA. E, F, 4-AP blocks Purkinje cell somatic currents; peak and steady-state current show similar sensitivity to this agent. IC₅₀ values quoted in Results were obtained from the fits illustrated here.