Table 1.
Motoneurone passive and action potential properties
| Control | G93A | |||||
|---|---|---|---|---|---|---|
| All (n = 27) | Low Gn (n = 15) | High Gn (n = 12) | All (n = 33) | Low Gn (n = 16) | High Gn (n = 17) | |
| Input conductance (nS) | 3.8 ± 2.0 | 2.1 ± 0.6 | 5.1 ± 1.6 | 3.7 ± 1.9 | 2.2 ± 0.7 | 5.0 ± 1.5 |
| Resting Vm (mV) | −70 ± 6 | −68 ± 6 | −73 ± 5 | −69 ± 6 | −71 ± 4 | −67 ± 7* |
| AP threshold (mV) | −49 ± 5 | −49 ± 5 | −50 ± 5 | −48 ± 4 | −46 ± 4 | −50 ± 3 |
| AP amplitude (mV) | 76 ± 8 | 74 ± 8 | 78 ± 8 | 72 ± 10 | 70 ± 11 | 74 ± 9 |
| AP half-width duration (ms) | 2.0 ± 0.7 | 2.0 ± 0.6 | 1.9 ± 1.0 | 1.8 ± 0.6 | 2.2 ± 0.4 | 1.5 ± 0.5 |
| Rate of rise (mV ms−1) | 66 ± 20 | 58 ± 13 | 77 ± 22 | 59 ± 18 | 54 ± 18 | 63 ± 19 |
| AHP (mV) | 20 ± 5 | 22 ± 4 | 17 ± 4 | 21 ± 5 | 25 ± 4 | 17 ± 3 |
| (n = 26) | — | (n = 14) | (n = 32) | (n = 15) | — | |
Both control and G93A samples were separated using a threshold of 3.25 nS (see Results) to measure the properties of all cells in the sample, low-input conductance (Gn), and high-input conductance cells in the respective cell types. No passive or action potential (AP) parameters were significantly different between the control and G93A motoneurones, with the exception of the high-input conductance G93A resting Vm (P < 0.05). This, though, was likely to be due to a larger number of cells in this sample exhibiting spontaneous firing and by excluding all tonically firing cells, the resting Vm was not significantly different. All values are mean ±s.d.