Figure 1.
NT (10 nM)-induced channel activity. (A) In whole-cell recording, NT elicited an inward current. Holding potential was −79 mV. Depolarizing (20 mV) and hyperpolarizing (−30 mV) command voltages were applied to monitor the conductance. (B1) NT-induced single-channel activity from an outside–out patch held at −80 mV. On an expanded time base, there was no channel activity before NT application (B2), while single-channel openings appeared after NT was applied (B3). (B4) Npo of the NT response in B1 was calculated at 4-sec intervals. The Npo reached a peak (=0.097) then decreased to zero. (C1) Similar channel activity occasionally could be induced in the cell-attached configuration. Potential was held at 30 mV intracellular side more negative than resting potential. NT was applied outside the patch region, and the patch pipette solution contained standard external solution. On an expanded time base, there was no channel activity before NT application (C2), while single-channel openings appeared after NT was applied (C3). The frequency response was 2 kHz (B2, B3, C2, and C3) and 250 Hz (B1 and C1) for display purposes.