Table 4.

Area (nm²), perimeter (nm) and curvature (ratio) of the SAS. All data are corrected for shrinkage factor

Group	Type of synapse	Area of SAS (nm2; mean ± sem)	Perimeter of SAS (nm; mean ± sem)	Curvature of SAS (mean ± sem)
Control	AS	117,800 ± 1957	1653 ± 18.94	0.049 ± 0.001
	SS	76,190 ± 4082	1423 ± 49.14	0.050 ± 0.004
Alzheimer	AS	123,200 ± 2327	1697 ± 22.96	0.049 ± 0.001
	SS	67,750 ± 3611	1284 ± 41.00	0.049 ± 0.003

AS asymmetric synapses, sem standard error of the mean, SAS synaptic apposition surface, SS symmetric synapses

The data for individual cases are shown in Additional file 1: Table S3