Figure 4.

Depolarization does not produce membrane displacement or activate MS channels when the tip of a borosilicate pipette is coated with soft glass. The simultaneous video images in a and current recordings in b indicate that a 60-s depolarizing step from −80 to +80 mV does not displace the membrane patch (arrows) in the pipette or activate MS channels. There is also a lack of movement and activation when the potential is stepped back to −80 mV. The numbers 1–3 in a and b indicate the times of the records. (Bar = 2 μm.) (c) MS channels were present in the same patch, as indicated by their activation by negative pressure (−6 kPa) applied to the patch pipette (downward current steps at the −80 mV potential).