Figure 4. Isolation of A-current from total outward current.

A and B were obtained from the superior salivatory neurones labelled from the chorda-lingual nerve. Depolarizing voltage commands (1.5 s) in steps of +10 mV were followed by a 1 s hyperpolarizing prepulse to −120 mV either immediately (a) or with the interposition of a 200 ms delay at a holding potential of −60 mV between the prepulse and command pulses (b). c, the digital subtraction of currents in b from currents in a revealed isolated transient outward currents.