Figure 2.

Synaptic efficacy is correlated with the number of release sites, but not with the probability of release or quantal size. The synaptic parameters were plotted vs. the EPSP amplitude of the connections’ response to the first stimulus of the input spike train. (A) The number of release sites, N, was significantly correlated to the EPSP amplitude (t-test, p < 0.00001). (B) The quantal size, q (t-test, p > 0.34), the probability of release, U (t-test, p > 0.38), and the recovery time constant, τ_rec (t-test, p > 0.4), were not correlated to the EPSP amplitude.