Figure 2.

Three-dimensional reconstructions of an adult MFB and its postsynaptic target dendrite. (A) Volume reconstructions of an en passant MFB (depicted in yellow) and its postsynaptic target dendrite (blue). Note, that the spiny excrescences were almost entirely covered by the nerve terminal. (B) Distribution of the two membrane specializations, AZs (in red) and PAs (in orange) on the postsynaptic target dendrite (blue). Note, that AZs were mainly located on the spiny excrescences, whereas PAs were exclusively found at the dendritic shaft. (C) Organization of the pool of synaptic vesicles (green dots) at an individual MFB. Here, the pool was distributed throughout the entire nerve terminal. Mitochondria (in white) formed either cluster-like arrangements or bands associated with the pool of synaptic vesicles (green dots).