Figure 3.

Blockade of the whole-cell time-dependent inward K⁺ currents by extracellular Al³⁺. A, Currents were recorded in a 36-μm-diameter cell and bathed in 10 mm K⁺ (pH 4), which was then perfused with the same solution containing different levels of Al³⁺ as described at the top of each set of traces. The pipette contained K⁺-based solution. B, The I/V relationship (left) for the currents shown in A recorded in solutions lacking (●) or containing 50 μm (○) or 400 μm (▿) Al³⁺. Current inhibition (right) as a function of extracellular Al³⁺. The percentage of current inhibition was calculated from the ratio of the current magnitude in the presence and absence of Al³⁺ at potentials of −118 (●), −108 (▴), −98 (▾), and −88 (♦) mV. Data points are from one representative experiment. Similar observations were recorded in a total of four cells.