Fig. 2.

Cumulative distribution of inter-release intervals (IRIs) for the same curves shown in Fig. 1, verifying the remarkable agreement of the approximation used in Fig. 1b with the simulated data. a1–a2 Static synapses, $p_0=0.5$. b1–b2 Facilitating synapses, $p_0=0.1$, $f_F=0.5$, ${\tau }_F=500\text{ ms}$. c1–c2 depressing synapses, $p_0=0.5$, ${\tau }_D=250\text{ ms}$. a1, b1, c1 Presynaptic Poisson spike train of 2 Hz. a2, b2, c2 Presynaptic Poisson spike train of 50 Hz