Figure 4.

Timing of synaptic responses in single pulses at different potentials. A1, Synaptic responses at three different potentials, −40 (green), −30 (red), and −20 (black) mV, with no predepolarization. Presynaptic voltage protocol on top, IHC Ca²⁺ currents are in the middle, and postsynaptic currents are in the bottom panels. A2, Same as A1 but using predepolarization to −50 mV for 50 ms. B, Average amplitude of postsynaptic responses as a function of depolarizing potential (with or without predepolarization). C, First synaptic latency for responses elicited with the protocol shown in A1 and A2. D, Jitter in synaptic latency. E1, IHC Ca²⁺ charge, as the integral of the 10 ms current. E2, Activation τ of IHC Ca²⁺ currents (*p < 0.05, **p < 0.01, ***p < 0.001).