Figure 4. Staurosporine pre-treatment abolishes evoked endocytosis.

A, a protocol identical to that introduced in Fig. 1 was repeated on cells pre-treated with 40 nm staurosporine for 10 min prior to recording. The averaged capacitance shifts are plotted for the control (black) and Ca²⁺-block (grey) conditions. B, amperometric currents measured from the same cell as in A show evoked catecholamine release in normal BBS but none in the Ca²⁺-block condition again indicating isolation of Ca²⁺-dependent from Ca²⁺-independent capacitance signals. C, the Ca²⁺-dependent secretory component of the evoked capacitance jump in panel A is plotted and reveals no post-pulse decay, indicating no membrane internalisation took place.