Figure 5.

NT-induced irreversible channel activity in GTP[γS]. Standard external solution was used. Internal solutions contained either GTP (100 μM) for control, or GTP[γS] (100 μM) for experiments. For each individual patch, after NT was applied, the time course of Np_o was calculated at 4-sec interval. Np_o was then normalized referring to the peak as 100%. In control (GTP-loaded patches), the average Np_o reached a maximum and decreased to almost 0% at ≈80 sec (n = 6). In contrast, the average Np_o of the patch with GTP[γS] reached a peak, then decreased to about 40% of peak and remained steady (n = 6). NT was applied during the time indicated.