Table 2.

Mean SAS perimeter (nm ± SEM), number of synapses analyzed (n), and the location (µ), and scale (σ) of the log-normal distributions of SAS perimeters in the six cortical layers

	AS				SS
	Mean SAS perimeter ± SEM (nm)	n	μ	σ	Mean SAS perimeter ± SEM (nm)	n	μ	σ
Layer I	1,538.03 ± 42.13	594	7.16	0.60	2,405.01 ± 142.87	77	7.65	0.55
Layer II	1,365.80 ± 29.46	992	7.06	0.55	2,141.62 ± 130.11	64	7.55	0.52
Layer III	1,638.51 ± 19.64	2212	7.27	0.59	2,838.22 ± 118.19	185	7.81	0.54
Layer IV	1,221.79 ± 18.70	1200	6.99	0.47	1,704.83 ± 77.28	172	7.29	0.54
Layer V	1,602.44 ± 38.50	684	7.22	0.56	2,736.41 ± 186.46	62	7.77	0.50
Layer VI	1,191.59 ± 25.83	577	6.97	0.45	1,697.00 ± 112.65	72	7.29	0.55
Layers I–VI	1,460.71 ± 11.29	6259	7.14	0.54	2,266.44 ± 54.61	632	7.56	0.59

Unweighted means for Layers I–VI are also shown.