Table 2.
Ca2+/Ba2+ current amplitudes, membrane capacitances, and activation and inactivation parameters of ICa and IBa in mature IHCs of du/du mice
| Parameters | Apical coil, Ca2+ currents |
Apical coil, Ba2+ currents |
Medial coil, Ba2+ currents |
|||
|---|---|---|---|---|---|---|
| wt (n = 20) | du/du (n = 12) | wt (n = 12) | du/du (n = 11) | wt (n = 13) | du/du (n = 9) | |
| |Imax| (pA) | 103.8 ± 18.2 | 65.1 ± 14.0*** | 201.6 ± 38.3 | 142.9 ± 29.6** | 235.3 ± 32.1 | 123.9 ± 17.3*** |
| Cm (pF) | 10.2 ± 1.4 | 9.2 ± 1.1* | 9.5 ± 1.2 | 9.6 ± 0.7 | 11.2 ± 1.0 | 9.7 ± 1.8* |
| |ID| (pA/pF) | 10.3 ± 1.5 | 7.3 ± 2.1*** | 21.3 ± 3.6 | 15.1 ± 3.8** | 21.3 ± 4.8 | 13.0 ± 2.2*** |
| Vh (mV) | −26.5 ± 2.3 | −21.3 ± 2.9*** | −33.3 ± 1.5 | −26.1 ± 3.4*** | −29.7 ± 1.3 | −21.9 ± 1.5*** |
| k (mV) | 11.4 ± 1.0 | 12.3 ± 0.9* | 9.1 ± 0.5 | 9.8 ± 0.8* | 10.0 ± 0.7 | 10.4 ± 0.5 |
| Inactivation | wt (n = 13) | du/du (n = 12) | wt (n = 10) | du/du (n = 9) |
|---|---|---|---|---|
| Inactivation after 300 ms (%) | 32.3 ± 10.4 | 27.4 ± 7.9 | 10.0 ± 5.6 | 5.6 ± 2.4 |
| τ (ms) | 158.4 ± 75.0 | 125.1 ± 70.8 | 380.4 ± 142.7 | 501.6 ± 190.9 |
Membrane capacitances and voltage-dependent activation parameters of ICa and IBa in mature IHCs of wt and du/du mice. |Imax|, Absolute value of maximum current; Cm, membrane capacitance; |ID|, absolute value of maximum current density. Vh values and the slope factor k were obtained from fitting I–V curves (see Materials and Methods, Eq. 1). All values are given as the mean ± SD.
*p < 0.05,
**p < 0.01,
***p < 0.001.