Fig. 2.

Spontaneous EPSCs in afferent fibers. (A) The spontaneous EPSCs recorded from two terminals vary in amplitude and timing but display predominantly monophasic waveforms. (B) A subset of EPSCs display complex waveforms suggestive of multivesicular release slightly dispersed in time. (C) The amplitude distribution of spontaneous EPSCs (black) recorded in a particular afferent fiber extends over more than one order of magnitude. Analysis of these 1,216 events showed a mean amplitude of 100 ± 39 pA and an occurrence rate of 24 s⁻¹. The scaled distribution of noise amplitudes is shown in gray. (D) The 10–90% rise times (Left) and time constants of decay (Right) for EPSCs from the same fiber display tight distributions, suggesting that multiple release events are highly synchronized.