TABLE 1.
Voltage dependence and inactivation kinetics parameters of Nav1.2, Nav1.3, and chimeric channels
Values presented are means ± S.D.
| Channel | Voltage dependence of fast inactivation |
Voltage dependence of activation |
Kinetics of fast inactivation (at −10 mV) |
Entry into inactivation |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| V½ | a | n | V½ | Z | n | τSlow | ASlow | τFast | AFast | n | τSlow | ASlow | τFast | AFast | n | |
| mV | mV | mV | e0 | ms | % | ms | % | ms | % | ms | % | |||||
| Nav1.2 | −36.0 ± 3.2 | 8.0 ± 0.6 | 8 | −13.1 ± 1.4 | 5.0 ± 0.3 | 6 | 17.6 ± 3.0 | 38 ± 4 | 4.2 ± 0.9 | 62 ± 4 | 8 | 4.9 ± 0.5 | 97.2 ± 2.8 | NAa | NA | 7 |
| Nav1.3 | −16.2 ± 0.8 | 4.7 ± 0.5 | 8 | −14.6 ± 2.4 | 6.9 ± 0.6 | 8 | 28.4 ± 4.0b | 100 | NA | NA | 14 | 14.8 ± 1.4b | 100 | NA | NA | 6 |
| Nav1.2 + β1 | −44.9 ± 5.0 | 8.5 ± 1.6 | 8 | −13.6 ± 1.4 | 4.4 ± 0.1 | 6 | 9.3 ± 3.0 | 20 ± 7 | 0.9 ± 0.2 | 80 ± 7 | 5 | 3.4 ± 1.5 | 31.2 ± 2.8 | 0.7 ± 0.4 | 63.2 ± 3.2 | 5 |
| Nav1.3 + β1 | −27.8 ± 2.5c | 8.5 ± 0.7 | 12 | −16.2 ± 0.8 | 5.8 ± 0.6 | 5 | 27.5 ± 3.7c | 43 ± 9c | 2.2 ± 0.5c | 57 ± 9c | 9 | 10.6 ± 3.0c | 88.8 ± 8.0 | NA | NA | 8 |
| 2233-3C | −22.3 ± 2.0 | 5.1 ± 0.8 | 12 | −16.3 ± 2.3 | 6.1 ± 0.4 | 6 | 24.1 ± 2.9 | 100 | NA | NA | 7 | 12.2 ± 0.9 | 100 | NA | NA | 5 |
| 2232-2C | −37.6 ± 2.6 | 9.0 ± 0.5 | 8 | −15.2 ± 1.9 | 5.2 ± 0.4 | 7 | 21.6 ± 4.2 | 26 ± 4 | 5.8 ± 0.9 | 74 ± 4 | 8 | 5.4 ± 0.7 | 98.8 ± 2.2 | NA | NA | 9 |
| 2223-3C | −20.6 ± 2.0 | 4.6 ± 0.4 | 10 | −17.2 ± 2.5 | 6.6 ± 0.6 | 9 | 23.0 ± 2.6 | 100 | NA | NA | 6 | 10.8 ± 3.0 | 100 | NA | NA | 5 |
| 2223-2C | −31.5 ± 0.8 | 7.2 ± 0.4 | 8 | −12.5 ± 2.0 | 5.9 ± 0.8 | 8 | 22.8 ± 2.4 | 38 ± 6 | 6.5 ± 1.2 | 62 ± 6 | 8 | 5.4 ± 0.4 | 100 | NA | NA | 8 |
| 2222-3C | −22.3 ± 1.0 | 5.4 ± 0.4 | 11 | −16.4 ± 1.6 | 5.8 ± 0.4 | 8 | 27.4 ± 4.5 | 100 | NA | NA | 5 | 9.9 ± 1.5 | 100 | NA | NA | 11 |
| 3322-2C | −34.2 ± 1.1 | 7.8 ± 0.8 | 5 | −11.8 ± 1.5 | 5.4 ± 0.4 | 8 | 21.5 ± 1.6 | 42 ± 7 | 5.7 ± 0.7 | 58 ± 7 | 5 | 6.3 ± 0.8 | 100 | NA | NA | 6 |
| 3332-2C | −34.6 ± 2.6 | 9.4 ± 0.5 | 8 | −14.4 ± 2.0 | 5.4 ± 0.4 | 8 | 27.4 ± 4.9 | 24 ± 4 | 6.5 ± 1.9 | 76 ± 4 | 5 | 6.8 ± 0.8 | 100 | NA | NA | 8 |
| 3333-2C | −37.4 ± 2.6 | 9.9 ± 1.7 | 7 | −16.2 ± 2.7 | 5.6 ± 0.6 | 5 | 27.6 ± 5.8 | 18 ± 13 | 7.5 ± 1.8 | 82 ± 13 | 5 | 8.2 ± 0.5 | 100 | NA | NA | 8 |
| 3332-3C | −22.6 ± 1.4 | 7.4 ± 0.8 | 11 | −14.3 ± 1.2 | 5.4 ± 0.3 | 9 | 37.7 ± 11.0 | 100 | NA | NA | 6 | 5.2 ± 0.2 | 100 | NA | NA | 5 |
a NA, not applicable because current trace was efficiently fitted with a single exponential equation.
b Significantly different from Nav1.2, p < 0.0001.
c Significantly different from Nav1.2 + β1, p < 0.001.