Table 2

Summary of ultrastructural measures

P30P13
SSWEWCSRSEW4EW15Rec
Total N of dendrites3832313157515436
Total N of measured spines with synapse13671347116790510669121398842
ASI (μm2, mean ± std)
Range (μm2)		0.26 ± 0.29
0.01–2.04		0.30 ± 0.34
0.01–4.02		0.29 ± 0.32
0.01–3.54		0.31 ± 0.37
0.02–4.61		0.25 ± 0.26
0.01–2.17		0.30 ± 0.34
0.01–2.60		0.20 ± 0.23
0.01–2.33		0.19 ± 0.23
0.01–2.01
Spine density
(all protrusions)
(#/μm2, mean ± std)		0.85 ± 0.240.77 ± 0.210.82 ± 0.250.88 ± 0.230.40 ± 0.160.35 ± 0.130.49 ± 0.160.46 ± 0.24
Spine density
(spines with synapse; #/μm2, mean ± std)		0.70 ± 0.200.67 ± 0.190.73 ± 0.240.73 ± 0.220.31 ± 0.130.25 ± 0.100.38 ± 0.150.36 ± 0.21
Spine density
(spines without synapse; #/μm2, mean ± std)		0.15 ± 0.090.10 ± 0.060.10 ± 0.040.15 ± 0.080.09 ± 0.050.10 ± 0.060.10 ± 0.040.10 ± 0.06
Spines without synapse
(%, mean ± std)		16.0 ± 2.812.7 ± 3.311.9 ± 3.217.4 ± 3.522.0 ± 5.426.3 ± 4.421.8 ± 4.122.6 ± 5.2
Dendrite diameter
(μm, mean ± std)		0.87 ± 0.230.92 ± 0.240.84 ± 0.220.78 ± 0.180.92 ± 0.330.94 ± 0.350.90 ± 0.241.00 ± 0.30
Dendrite length
(μm, mean ± std)		21.9 ± 7.026.2 ± 4.722.8 ± 5.919.3 ± 5.123.4 ± 8.526.3 ± 7.126.7 ± 8.725.0 ± 5.7
Spines with spine apparatus (%, mean ± std)26.1 ± 4.330.5 ± 4.527.1 ± 3.130.2 ± 3.57.4 ± 2.57.2 ± 1.95.4 ± 2.39.4 ± 3.2
Spines with non-SER elements (tubules/
vesicles; %, mean ± std)		49.7 ± 7.056.3 ± 13.061.2 ± 6.854.4 ± 6.270.1 ± 4.274.6 ± 7.172.6 ± 3.966.0 ± 8.3

  • All protrusions are defined as spines. In oblique spines, the ASI could not be measured because the synapse was oriented obliquely or orthogonally to the cutting plane. std, standard deviation.