Table 1.
Morphological properties of layer 3 and 5 pyramidal neurons at 1, 2, and 4 weeks. Ages are given as mean ± sd in days postnatal.
| Variable | Week 1 p 6.9 ± 1.0 n = 8/5 | Week 2 p 14.0 ± 0.0 n = 7/5 | Week 4 p 28.4 ± 0.8 n = 7/5 | Omnibus test result |
|---|---|---|---|---|
| Layer 3 | ||||
| Total dendritic length (µm) | 2120.1 ± 313.3*** | 4090.6 ± 275.1 | 4098.3 ± 293.5 | F(2,19) = 15.34 p < 0.001 |
| # dendritic segments | 64.6 ± 4.6 | 72.1 ± 1.9 | 63.4 ± 4.0 | χ 2(2) = 4.75 p = 0.093 |
| Total basal dendritic length (µm) | 967.4 ± 221.8** | 2311.8 ± 319.9 | 2082.6 ± 163.3 | F(2,19) = 9.16 p = 0.002 |
| # basal dendrites | 6.8 ± 0.6 | 8.9 ± 0.6 | 8.1 ± 0.8 | χ 2(2) = 2.20 p = 0.333 |
| # basal branch points | 12.0 ± 2.2 | 16.1 ± 1.8 | 12.7 ± 0.8 | χ 2(2) = 5.22 p = 0.074 |
| Total apical dendritic length (µm) | 1152.7 ± 114.6* | 1777.6 ± 143.8 | 2015.7 ± 210.7 | F(2,19) = 8.26 p = 0.003 |
| # oblique dendrites | 5.0 ± 0.8 | 3.4 ± 0.8 | 3.3 ± 0.6 | χ 2(2) = 3.45 p = 0.179 |
| Total oblique dendrite length (µm) | 332.74 ± 40.75* | 496.75 ± 73.35 | 616.74 ± 99.02 | F(2,18) = 4.13 p = 0.034 |
| # oblique branch points | 2.4 ± 0.5 | 1.9 ± 0.5 | 2.7 ± 0.7 | χ 2(2) = 1.12 p = 0.572 |
| Total apical tuft dendritic length(µm) | 735.7 ± 117.2* | 1,252.1 ± 113.8 | 1,290.6 ± 116.4 | F(2,19) = 7.40 p = 0.004 |
| # apical tuft segments | 18.5 ± 1.0 | 19.6 ± 3.1 | 17.3 ± 2.2 | χ 2(2) = 0.99 p = 0.609 |
| Layer 5 | ||||
| Variable | Week 1 p 6.9 ± 0.9 n = 9/5 | Week 2 p 14.0 ± 0.0 n = 10/5 | Week 4 p 28.9 ± 0.9 n = 10/5 | Omnibus test result |
| Total dendritic length (µm) | 3142.3 ± 233.5*** | 7383.3 ± 245.9 | 7838.0 ± 250.9 | F(2,24) = 93.65 p < 0.001 |
| # dendritic segments | 120.7 ± 5.8 | 113.6 ± 3.5 | 120.0 ± 5.2 | χ 2(2) = 2.52 p = 0.284 |
| Total basal dendritic length (µm) | 1288.8 ± 304.4*** | 2862.7 ± 207.6 | 3164.3 ± 130.3 | F(2,26) = 20.36 p < 0.001 |
| # basal dendrites | 10.1 ± 1.0 | 10.6 ± 0.5 | 9.7 ± 0.7 | χ 2(2) = 0.40 p = 0.819 |
| # basal branch points | 14.7 ± 1.4** | 17.4 ± 1.3 | 20.6 ± 1.4 | χ 2(2) = 8.36 p = 0.015 |
| Total apical dendritic length (µm) | 2756.1 ± 338.3* | 4519.0 140.9 | 4673.7 203.3 | H(2) = 11.66 p = 0.003 |
| # oblique dendrites | 16.3 ± 1.2 | 13.2 ± 0.6 | 12.7 ± 0.7 | χ 2(2) = 5.14 p = 0.077 |
| Total oblique dendrite length (µm) | 1001.5 ± 203.2* | 2143.1 ± 110.8 | 2316.2 ± 95.0 | H(2) = 15.12 p = 0.001 |
| # oblique branch points | 5.3 ± 0.6* | 7.7 ± 0.8 | 8.8 ± 1.0 | χ 2(2) = 8.36 p = 0.015 |
| Total apical tuft dendritic length(µm) | 1487.8 ± 166.7** | 2106.5 ± 70.5 | 2049.9 ± 146.5 | F(2,26) = 6.47 p = 0.005 |
| # apical tuft segments | 33.9 ± 3.8** | 25.5 ± 1.2 | 25.6 ± 2.0 | χ 2(2) = 14.09 p < 0.001 |
N given as number of cells/number of mice. Values are given as mean ± SEM. Asterisks denote post-hoc significance: *p < 0.05, **p < 0.01, ***p < 0.001. Bold values denote statistically significant differences compared to week 2 (in week 1), italics denote statistically significant differences compared to week 4 (in week 1 and 2).