Fig. 5.

Distribution of measurements derived from the 19 of the 48 axo-somatic terminals that were apposed by an excitatory terminal. (A) Comparative distribution of the shortest distances between the PSDs of asymmetric synapses and the membrane of the adjacent axo-somatic terminal (circles), and of the distances between the PSDs of asymmetric synapses and of the symmetric axo-somatic synapses (triangles). (B) Cumulative distribution of the minimum distances between the PSDs of axo-dendritic synapses and the membrane of the neighbouring axo-somatic terminals. All distances are smaller than 0.2 μm and while 72% are smaller than 0.1 μm, 56% are less than 0.05 μm. (C) Cumulative distribution of the minimum distances between the PSDs of adjacent axo-dendritic asymmetric and axo-somatic symmetric synapses. Note that the distances in (C) are 10 times that in (B).