Table 2.
Morphometric dendritic and dendritic spine parameters of LVPNs 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: 1374.4 ± 210.3 (7) | WT: 1672.7 ± 68.7 (5) | WT: 1709.9 ± 114.5 (5) | WT: 1492.5 ± 178.0 (8) |
| SOD1: 1372.8 ± 252.9 (5) | SOD1: 2221.1 ± 333.7 (5) | SOD1: 2242.7 ± 215.8 (5) | SOD1: 955.3 ± 115.6 (12) | |
| Not significant | Not significant | Not significant | Not significant | |
| Total arbor length (μm) | WT: 2808 ± 442 (7) | WT: 5001 ± 220 (5) | WT: 5046 ± 162 (5) | WT: 1487 ± 324 (8) |
| SOD1: 2943 ± 474 (5) | SOD1: 3485 ± 179 (5) | SOD1: 3181 ± 336 (5) | SOD1: 1136 ± 181 (12) | |
| Adj. P > 0.99 | Adj. P = 0.02* | Adj. P = 0.002** | Adj. P < 0.0001**** | |
| Apical arbor length (μm) | WT: 1701 ± 282 (7) | WT: 2991 ± 163 (5) | WT: 2715 ± 166 (5) | WT: 2781 ± 133 (8) |
| SOD1: 1880 ± 327 (5) | SOD1: 2142 ± 97 (5) | SOD1: 1631 ± 157 (5) | SOD1: 1132 ± 119 (12) | |
| Adj. P > 0.99 | Adj. P = 0.03* | Adj. P = 0.003** | Adj. P < 0.0001**** | |
| Basal arbor length (μm) | WT: 1113 ± 174 (7) | WT: 2010 ± 128 (5) | WT: 2131 ± 246 (5) | WT: 1872 ± 216 (8) |
| SOD1: 1003 ± 163 (5) | SOD1: 1341 ± 103 (5) | SOD1: 1550 ± 189 (5) | SOD1: 946 ± 102 (12) | |
| Adj. P > 0.99 | Adj. P = 0.07 | Adj. P = 0.16 | Adj. P = 0.0001*** | |
| Mean basal tree length (μm) | WT: 275 ± 22 (7) | WT: 452 ± 27 (5) | WT: 527 ± 69 (5) | WT: 380 ± 29 (8) |
| SOD1: 328 ± 163 (5) | SOD1: 332 ± 19 (5) | SOD1: 330 ± 36 (5) | SOD1: 217 ± 29 (12) | |
| Adj. P > 0.99 | Adj. P = 0.15 | Adj. P = 0.004** | Adj. P = 0.0008*** | |
| Apical reach (μm) | WT: 584 ± 37 (7) | WT: 1059 ± 84 (5) | WT: 921 ± 47 (5) | WT: 884 ± 54 (8) |
| SOD1: 656 ± 51 (5) | SOD1: 863 ± 51 (5) | SOD1: 580 ± 98 (5) | SOD1: 465 ± 32 (12) | |
| Adj. P > 0.99 | Adj. P = 0.12 | Adj. P = 0.0012** | Adj. P < 0.0001**** | |
| Basal reach (μm) | WT: 192 ± 19 (7) | WT: 321 ± 20 (5) | WT: 290 ± 22 (5) | WT: 282 ± 28 (8) |
| SOD1: 202 ± 29 (5) | SOD1: 257 ± 13 (5) | SOD1: 254 ± 20 (5) | SOD1: 187 ± 28 (12) | |
| Adj. P > 0.99 | Adj. P = 0.69 | Adj. P > 0.99 | Adj. P < 0.01* | |
| Apical ramifications | WT: 9.7 ± 1.1 (7) | WT: 10.6 ± 1.1 (5) | WT: 11.5 ± 1.7 (5) | WT: 12.7 ± 1 (8) |
| SOD1: 10.7 ± 1.6 (5) | SOD1: 10.6 ± 1 (5) | SOD1: 8.0 ± 0.5 (5) | SOD1: 7.5 ± 0.9 (12) | |
| Adj. P > 0.99 | Adj. P > 0.99 | Adj. P = 0.25 | Adj. P = 0.0005*** | |
| Basal ramifications | WT: 3.8 ± 0.3 (7) | WT: 4.2 ± 0.2 (5) | WT: 4.6 ± 0.3 (5) | WT: 4.4 ± 0.2 (8) |
| SOD1: 4.4 ± 0.4 (5) | SOD1: 3.4 ± 0.2 (5) | SOD1: 3.9 ± 0.2 (5) | SOD1: 3.4 ± 0.2 (12) | |
| Adj. P = 0.64 | Adj. P = 0.31 | Adj. P = 0.33 | Adj. P = 0.008** | |
| Apical spine density per 100 μm | WT: 27.7 ± 2.7 (7) | WT: 31.7 ± 3.1 (5) | WT: 33.4 ± 3 (5) | WT: 23.7 ± 1 (8) |
| SOD1: 23.8 ± 4.4 (5) | SOD1: 17.2 ± 1.3 (5) | SOD1: 18.4 ± 0.8 (5) | SOD1: 16.4 ± 1.9 (12) | |
| Adj. P > 0.99 | Adj. P = 0.002** | Adj. P = 0.002** | Adj. P = 0.049* | |
| Basal spine density per 100 μm | WT: 21.2 ± 1.7 (7) | WT: 27.2 ± 3 (5) | WT: 29.9 ± 2.9 (5) | WT: 19.5 ± 0.8 (8) |
| SOD1: 13.7 ± 5.7 (5) | SOD1: 13.8 ± 1.2 (5) | SOD1: 15.9 ± 2 (5) | SOD1: 13.7 ± 0.8 (12) | |
| Adj. P = 0.10 | Adj. P = 0.002** | Adj. P = 0.001** | Adj. P = 0.11 |
All analyses were unpaired two-way ANOVAs for age and genotype of LVPNs from the motor cortex comparing soma volume (Age: P = 0.0002***; Genotype: P = 0.3378), total dendritic arbor length (Age: P = 0.0004***; Genotype: P < 0.0001****), apical dendritic arbor length (Age: P = 0.0029**; Genotype: P < 0.0001****), basal dendritic arbor length (Age: P = 0.0002***; Genotype: P < 0.0001****), mean basal dendritic tree length (Age: P = 0.0009***; Genotype: P = 0.0001***), apical dendritic reach (Age: P < 0.0001****; Genotype: P < 0.0001****), basal dendritic reach (Age: P = 0.0142*; Genotype: P = 0.0251*), apical branch ramifications (Age: P = 0.9265; Genotype: P = 0.0270*), basal branch ramifications (Age: P = 0.3522; Genotype: P = 0.0153*), apical dendritic spine density per 100 μm (Age: P = 0.0350*; Genotype: P < 0.0001****) and basal dendritic spine density per 100 μm (Age: P = 0.0287*; Genotype: P < 0.0001****). 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 3 individual neurons, specifically P8-15 (WT: 21 neurons; SOD1: 15 neurons), P28-35 (WT: 22 neurons; SOD1: 21 neurons), P65-75 (WT: 16 neurons; SOD1: 16 neurons) and P120 (WT: 29 neurons; SOD1: 38 neurons)