Figure 3. Effects of internal spermine on outward currents with a reduced external K⁺ concentration.

A, outward currents recorded at −15 mV in the absence and presence of spermine. Spermine decreased the open time dependent on the concentration and induced a blocked state of 250–600 ms duration. B, currents in the presence of 100 nm spermine. The numbers to the left of each trace refer to the holding potential. Inward currents were not affected.