Fig. 7. Time course of activation of the swelling-induced membrane current. (A) Dependence of the swelling-activated membrane current on E_m at different times after reducing the extracellular osmolality (–40 mmol l^–1 NaCl). Retzius neurons were clamped from a holding potential of –50 mV to –100, –80, –60 or –40 mV for 1 s with an interstimulus interval of 2 s (see Fig. 6A). This protocol was applied in SLS as well as 50, 100... 300 s after changing the extracellular osmolality to obtain the presented I–V relationships. Data are means ± s.d. of N=5 experiments. (B) Time course of the activation and deactivation of the swelling-induced membrane current, as derived from the data shown in A, as well as from current recordings after return to SLS. Activation and deactivation of the swelling-induced current occurred with a similar time course to the changes in cell volume (compare Fig. 2C, Fig. 5A, Fig. 10A,B).