Table 3.
Morphometric dendritic and dendritic spine parameters of LII-IIIPNs within the motor cortex. All data presented as mean ± SEM
| Region | P8-15 (n) Neonatal | P28-35 (n) Pre-symptomatic | P65-75 (n) Onset | P120 (n) Mid-disease |
|---|---|---|---|---|
| Soma volume (μm3) | WT: 587.5 ± 98.1 (7) | WT: 1338.5 ± 119.3 (5) | WT: 1297.5 ± 194.5 (5) | WT: 998.3 ± 112.4 (8) |
| SOD1: 997.0 ± 266.0 (5) | SOD1: 1063.1 ± 271.3 (5) | SOD1: 1218.4 ± 356.2 (5) | SOD1: 701.9 ± 101.4 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Total arbor length (μm) | WT: 2005 ± 414 (7) | WT: 2626 ± 101 (5) | WT: 2468 ± 208 (5) | WT: 2747 ± 288 (8) |
| SOD1: 1709 ± 244 (5) | SOD1: 2116 ± 241 (5) | SOD1: 1831 ± 338 (5) | SOD1: 1883 ± 196 (12) | |
| Adj. P > 0.99 | Adj. P > 0.99 | Adj. P = 0.67 | Adj. P < 0.047* | |
| Apical arbor length (μm) | WT: 762 ± 159 (7) | WT: 1452 ± 165 (5) | WT: 1052 ± 141 (5) | WT: 1602 ± 176 (8) |
| SOD1: 922 ± 47 (5) | SOD1: 899 ± 77 (5) | SOD1: 785 ± 176 (5) | SOD1: 947 ± 107 (12) | |
| Adj. P > 0.99 | Adj. P = 0.09 | Adj. P > 0.99 | Adj. P < 0.001** | |
| Basal arbor length (μm) | WT: 1242 ± 268 (7) | WT: 1174 ± 167 (5) | WT: 1415 ± 77 (5) | WT: 1094 ± 174 (8) |
| SOD1: 787 ± 219 (5) | SOD1: 1208 ± 202 (5) | SOD1: 1046 ± 164 (5) | SOD1: 963 ± 104 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Mean basal tree length (μm) | WT: 300 ± 57 (7) | WT: 290 ± 43 (5) | WT: 314 ± 24 (5) | WT: 320 ± 47 (8) |
| SOD1: 225 ± 58 (5) | SOD1: 317 ± 44 (5) | SOD1: 283 ± 27 (5) | SOD1: 257 ± 27 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Apical reach (μm) | WT: 303 ± 28 (7) | WT: 599 ± 48 (5) | WT: 482 ± 65 (5) | WT: 450 ± 48 (8) |
| SOD1: 424 ± 74 (5) | SOD1: 443 ± 29 (5) | SOD1: 398 ± 64 (5) | SOD1: 321 ± 37 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Basal reach (μm) | WT: 199 ± 22 (7) | WT: 209 ± 21 (5) | WT: 249 ± 18 (5) | WT: 205 ± 18 (8) |
| SOD1: 178 ± 34 (5) | SOD1: 229 ± 29 (5) | SOD1: 193 ± 26 (5) | SOD1: 188 ± 26 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Apical ramifications | WT: 5.2 ± 0.7 (7) | WT: 5.7 ± 0.6 (5) | WT: 5.9 ± 0.3 (5) | WT: 7.9 ± 0.7 (8) |
| SOD1: 8.5 ± 0.8 (5) | SOD1: 5.3 ± 0.3 (5) | SOD1: 5.7 ± 1 (5) | SOD1: 6.3 ± 0.4 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Basal ramifications | WT: 3.9 ± 0.5 (7) | WT: 3.7 ± 0.2 (5) | WT: 3.9 ± 0.2 (5) | WT: 4.3 ± 0.3 (8) |
| SOD1: 3.5 ± 0.3 (5) | SOD1: 4.8 ± 0.4 (5) | SOD1: 3.4 ± 0.3 (5) | SOD1: 3.9 ± 0.2 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Apical spine density per 100 μm | WT: 29.8 ± 1.6 (7) | WT: 34.2 ± 4.4 (5) | WT: 36.3 ± 2 (5) | WT: 22.9 ± 2.3 (8) |
| SOD1: 19.8 ± 3 (5) | SOD1: 19.7 ± 2.2 (5) | SOD1: 25.7 ± 3.1 (5) | SOD1: 22.6 ± 2 (12) | |
| Adj. P = 0.0277* | Adj. P = 0.0039** | Adj. P = 0.0494* | Adj. P > 0.9999 | |
| Basal spine density per 100 μm | WT: 17.4 ± 1.8 (7) | WT: 26.7 ± 3.2 (5) | WT: 27.5 ± 3.5 (5) | WT: 17.2 ± 2.5 (8) |
| SOD1: 20.9 ± 4.3 (5) | SOD1: 16.5 ± 2.1 (5) | SOD1: 19.6 ± 1.7 (5) | SOD1: 18.3 ± 1.9 (12) | |
| Not significant | Not significant | Not significant | Not significant |
All analyses were unpaired two-way ANOVAs for age and genotype of LII-IIIPNs from the motor cortex comparing soma volume (Age: P = 0.0272*; Genotype: P = 0.6421), total dendritic arbor length (Age: P = 0.3006; Genotype: P = 0.0082**), apical dendritic arbor length (Age: P = 0.0185*; Genotype: P = 0.0038**), basal dendritic arbor length (Age: P = 0.5556; Genotype: P = 0.0889), mean basal dendritic tree length (Age: P = 0.8449; Genotype: P = 0.2142), apical dendritic reach (Age: P = 0.0218*; Genotype: P = 0.0963), basal dendritic reach (Age: P = 0.5799; Genotype: P = 0.3441), apical branch ramifications (Age: P = 0.0311*; Genotype: P = 0.1325), basal branch ramifications (Age: P = 0.2204; Genotype: P = 0.8882), apical dendritic spine density per 100 μm (Age: P = 0.0155*; Genotype: P < 0.0001****) and basal dendritic spine density per 100 μm (Age: P = 0.1380; Genotype: P = 0.0877). Bonferroni post-tests were used to compare the effect of genotype at each age group, with the adjusted P-value (adj. P) reported in the table for parameters that had significant genotype effects. Each animal used (n) contains mean values from a minimum of 2 individual neurons, specifically P8-15 (WT: 20 neurons; SOD1: 10 neurons), P28-35 (WT: 11 neurons; SOD1: 11 neurons), P65-75 (WT: 11 neurons; SOD1: 13 neurons) and P120 (WT: 21 neurons; SOD1: 25 neurons)