Table 1.

Ultrastructural parameters of synapses examined by electron microscopy.

Parameter	Wild-type mice	SNAP-25 KI mice
Synapse density (per 100 μm2)	48.8 ± 2.2	32.6 ± 4.7**
Perforated synapses (% of all synapses)	5.85 ± 2.15	5.28 ± 1.99
Presynaptic terminal area (μm2)	0.17 ± 0.01	0.31 ± 0.06*
Synaptic vesicle density in terminals (per μm2)	151.2 ± 13.1	161.5 ± 37.7
Size of active zone (nm)	203.4 ± 27.9	212.9 ± 11.3
Docked synaptic vesicles (per μm active zone)	7.49 ± 1.54	7.79 ± 0.62

All data are from the distal striatum radiatum of the hippocampal CA1 region in WT and KI mice. Data are presented as the mean ± SD. *P < 0.05, **P < 0.01 (Student’s t-test).