Fig. 10.

A: synoviocyte in current clamp with a resting membrane potential between −50 and −40 mV. When 50 nM κ-dendrotoxin was added, the cell depolarized by >20 mV, suggesting a role for Kv1.1 channels in the maintenance of resting membrane potential. B: montage of a fluo-4-loaded synoviocyte to which 50 nM κ-dendrotoxin was added after 4 s. Intracellular calcium levels rose to a peak between 8 and 10 s, and this was well maintained until the toxin was removed, whereupon it fell to control levels as shown by the F/F₀ plot below.