Table 1.

Means and SD of characteristic angles (degrees) and flatness measures of 3D bifurcations in a data set of random bifurcations (obtained by simulating 1000000 bifurcations), in rat cortical pyramidal cell basal dendrites (no. of bifurcations 1242), and in apical main stems (no. of bifurcations 372).

Angles and flatness measures of 3D bifurcations	Random bifurcations			3D bifurcations in rat cortical pyramidal dendrites
	N = 1000000			Basal dendrites, N = 1242				Apical dendrites, N = 372
	Mean	SD	Median	Mean	SD	Median	SEM	Mean	SD	Median	SEM
Bifurcation angle ρ	90	39.2	90	53.4	27.7	49.3	0.79	64.9	26.6	60.7	1.38
Bifurcation angle σ	90	39.2	90	138	38.7	152.4	1.1	168.8	7.7	170.7	0.4
Bifurcation angle τ	90	39.2	90	122.5	39.2	131.5	1.1	119.4	26.2	123.2	1.4
Angle sum	270	67.8	281	313.9	68	346.6	1.9	353.2	9	357.5	0.5
Cone angle α	133.7	32.8	139.4	159.4	28.2	170.2	0.8	174.4	4.4	175.2	0.2
Solid angle cone ΩC	225	87.7	235	299.4	75.3	329.3	2.1	342.5	13.6	344.9	0.7
Solid angle pyramid ΩP	90	90	56.4	161.2	119	170.4	3.4	222.5	104.2	262.9	5.4
Parent stretch angle η	90	39.2	90	137	39.3	151.6	1.1	150.9	14.2	153.2	0.7
Parent azimuth angle φ	180	103	180	166	56.9	166.6	1.6	152.3	15.4	153.7	0.8
Parent elevation angle θ	32.7	21.6	30	13.1	12.8	9	0.4	5.5	4.7	4.7	0.24
Parent fold angle κ	90	61.2	90	146.7	53.5	170	1.5	174.5	4.7	175.4	0.24
Dihedral angle λ	90	52	90	83.4	56.5	89.9	1.6	101.6	55.9	127.8	2.9
Dihedral angle β	90	52	90	146.3	49.6	168.8	1.4	173.4	6.6	174.7	0.34
Volume pyramid	0.065	0.043	0.06	0.026	0.025	0.018	0.001	0.013	0.01	0.011	0.001

The angles are expressed in degrees.