Table 3.
Morphometric dendritic and dendritic spine parameters of XII MNs within the brainstem.
| Region | P8-15 (n) Neonatal | P28-35 (n) Pre-symptomatic | P65-75 (n) Symptom Onset | P120 (n) Mid-disease |
|---|---|---|---|---|
| Soma volume (μm3) | WT: 22920 ± 4672 (7) SOD1: 35226 ± 5774 (5) Not significant |
WT: 40267 ± 5000 (5) SOD1: 39171 ± 4447 (5) Not significant |
WT: 34463 ± 3246 (5) SOD1: 52278 ± 4821 (5) Not significant |
WT: 37516 ± 6432 (8) SOD1: 16578 ± 1934 (12) Not significant |
| Total arbor length (μm) | WT: 2369 ± 284 (7) SOD1: 3537 ± 332 (5) Adj. P = 0.0208* |
WT: 2437 ± 141 (5) SOD1: 4327 ± 409 (5) Adj. P = 0.0003*** |
WT: 3343 ± 226 (5) SOD1: 4023 ± 295 (5) Adj. P = 0.4814 |
WT: 3269 ± 338 (8) SOD1: 1519 ± 115 (12) Adj. P < 0.0001**** |
| Mean tree length (μm) | WT: 567 ± 41 (7) SOD1: 854 ± 80 (5) Adj. P = 0.0094** |
WT: 673 ± 93 (5) SOD1: 1079 ± 93 (5) Adj. P = 0.0005*** |
WT: 864 ± 86 (5) SOD1: 900 ± 53 (5) Adj. P > 0.9999 |
WT: 719 ± 56 (8) SOD1: 385 ± 28 (12) Adj. P < 0.0001**** |
| Dendritic reach (μm) | WT: 339 ± 19 (7) SOD1: 491 ± 51 (5) Not significant |
WT: 436 ± 40 (5) SOD1: 605 ± 6 (5) Not significant |
WT: 575 ± 35 (5) SOD1: 658 ± 42 (5) Not significant |
WT: 540 ± 53 (8) SOD1: 338 ± 17 (12) Not significant |
| Dendritic ramifications | WT: 4.7 ± 0.5 (7) SOD1: 5.3 ± 0.1 (5) Not significant |
WT: 3.9 ± 0.3 (5) SOD1: 5.5 ± 0.2 (5) Not significant |
WT: 4.7 ± 0.3 (5) SOD1: 5.2 ± 0.4 (5) Not significant |
WT: 5.6 ± 0.2 (8) SOD1: 4.2 ± 0.4 (12) Not significant |
| Dendritic spine density per 100 μm | WT: 12.1 ± 2.1 (7) SOD1: 24.3 ± 4.3 (5) Adj. P = 0.0099** |
WT: 12.5 ± 1.1 (5) SOD1: 27.7 ± 4 (5) Adj. P = 0.0023** |
WT: 12.8 ± 1 (5) SOD1: 23.7 ± 3.3 (5) Adj. P = 0.0419* |
WT: 10.8 ± 1.4 (8) SOD1: 20.8 ± 2.1 (12) Adj. P = 0.0051** |
All data presented as mean ± SEM. All analyses were unpaired two-way ANOVAs for age and genotype, comparing soma volume (Age: P = 0.0019**; Genotype: P = 0.5533), total dendritic arbor length (Age: P < 0.0001****; Genotype: P = 0.0154*), mean dendritic tree length (Age: P < 0.0001****; Genotype: P = 0.0313*), dendritic reach (Age: P < 0.0001****; Genotype: P = 0.0758), dendritic ramifications (Age: P = 0.8886; Genotype: P = 0.2070), and dendritic spine density per 100 μm (Age: P = 0.3741; 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 2 individual neurons, specifically P8-15 (WT: 21 neurons; SOD1: 22 neurons), P28-35 (WT: 12 neurons; SOD1: 18 neurons), P65-75 (WT: 12 neurons; SOD1: 11 neurons), and P120 (WT: 18 neurons; SOD1: 27 neurons).