Table 5. Evolution of the neuromuscular transmission from pre-symptomatic to symptomatic phases of the disease.
| Pre-symptomatic | Symptomatic |
||
|---|---|---|---|
| SOD1(G93A) | SOD1a | SOD1b | |
| n (fiber, mice) | 40, 18 | 19, 8 | 20, 10 |
| Males | 17, 7 | 11, 4 | 10, 5 |
| Females | 23, 11 | 8, 4 | 10,5 |
| Age range (days) | 89-108 | 94-107 | 94-102 |
| RMP (mV) | -67.6 ± 1.80 | -64.4 ± 2.05 | -67.1 ± 2.67 |
| EPPs amplitude (mV) | 24.3 ± 1.61 | 11.4 ± 2.00# | 24.9 ± 2.33 |
| EPPs amplitude NOR (mV) | 26.8 ± 1.54 | 12.8 ± 2.06# | 28.1 ± 2.41 |
| Quantal content NOR | 38.1 ± 2.42 | 32.7 ± 4.40 | 38.8 ± 3.30 |
| MEPPs amplitude (mV) | 0.63 ± 0.02 | 0.32 ± 0.02# | 0.64 ± 0.02 |
| MEPPs rise-time (ms) | 1.11 ± 0.08 | 1.39 ± 0.12# | 0.93 ± 0.06 |
| MEPPs decay-time (ms) | 3.67 ± 0.14 | 3.12 ± 0.17* | 3.28 ± 0.20 |
| MEPPs frequency (s-1) | 0.59 ± 0.06 | 0.61 ± 0.11 | 1.26 ± 0.33 |
| N° of NMJs with GMEPPs | 33 | 3 | 17 |
| GMEPPs frequency (s-1) | 0.44 ± 0.08 | 0.07 ± 0.03+ | 0.38 ± 0.12 |
| Fr(GMEPPs)/Fr(MEPPs) | 1.86 ± 0.45 | 0.11 ± 0.07+ | 1.40 ± 0.80 |
The values are mean±SEM. Results from symptomatic SOD1a and SOD1b NMJs were both compared with pre-symptomatic SOD1(G93A) NMJs (*p<0.05, Student test; #p<0.05, Mann-Whitney test and +p<0.05, Student test with Welsh correction). EPP, endplate potential; EPP amplitude NOR, endplate potential normalized to a resting membrane potential (RPM) of - 75mV; MEPP, miniature endplate potential; Quantalcontent NOR, normalized quantal content of EPPs(meanEPPNOR/meanMEPPNOR); Fr(MEPPs), MEPPs frequency; Fr(GMEPPs), GMEPPs frequency; NMJ, neuromuscular junction.