Table 6.

Summary of the data from the studies of the pattern of synaptic distribution

	Human TEC	Striate cortex (area 17) of the monkey1		Visual cortex of the adult cat2		Somatosensory cortex of the adult rat (P60)3
	Layer II	Layer II−III	All layers	Layer II	All layers	All layers
AS on spines	55.2%	54.9%	53.0%	71.2%	66.4%	73.0%
AS on dendritic shafts	37.4%	27.7%	30.0%	13.3%	17.6%	12.9%
SS on dendritic shafts	6.7%	11.4%	11.9%	10.8%	10.6%	9.3%
SS on spines	0.61%	6.0%	5.1%	4.7%	5.3%	4.8%

Data are given as percentages. Data were taken from: ¹Beaulieu et al., 1992; ²Beaulieu and Colonnier (1985); ³Micheva and Beaulieu (1996).