Figure 2. Spontaneous and evoked bursts are superimposed on depolarizing afterpotentials (DAPs).

A, current-clamp recording of a phasically firing SFO neurone showing spontaneous (1) and current-evoked (2) bursts. Spontaneous bursts were triggered by a slow depolarization to action potential threshold, near which the membrane potential remained until the rapid cessation and return to resting potential. B, small current pulses (20 pA, 20 ms) can trigger a burst event consisting of a rapid DAP with superimposed action potentials.