Figure 7. Recovery from postsynaptic depression by spike decorrelation and reservoir enlargement.

A spike train at a single synaptic connection can lead to strong postsynaptic depression. The normalized distributions of the maximal number of open AMPARs (for the MN scheme) per pulse at a single participating synapse are shown for different stimulation intensities. Insets: averaged spike-to-spike time course of AMPAR openings. During a single simulated Poissonian spike train, one vesicle was released per pulse where the release sites were 1) clustered at the AZ center (red), 2) uniformly distributed over PSD (blue), 3) uniformly distributed over the cleft (green). Enlarging the AMPAR reservoir from intra-cleft only (A–C) to an additional extra-cleft one of fourfold size (D–F) increases the averaged synaptic response.