Fig. 4.
La3+ block and recovery occurred in a stepwise manner. A large conductance event with very long open times was blocked completely by 1 mmLaCl3. This block occurred in a stepwise manner (B). After several minutes of continuous wash, the activity began to reappear, occurring again in small stepwise events that were quite variable in amplitude (C, D). After many such small steps open, the events appear to become concerted, opening and closing as a single unit (E). The dashed line at thebottom of each trace represents the closed level. Two stretches of the data have been removed for clarity (at slash marks) because of the long periods of inactivity after the application of the blocker and while it remained open near the end of the top trace. The current trace begins slightly before the application of LaCl3 (bar). Subsequent wash of the patch with bath solution continued for the duration of the trace. Vhold = −40 mV.