Table 1.
Variation of some biophysical parameters characteristic of T-type Ca2+ current during prenatal myogenesis
| E14 | E15 | E16 | E17 | E18 | |
|---|---|---|---|---|---|
| Gmax (pS pF−1) | 70.7 ± 7.9 | 88.4 ± 9.2 | 96.4 ± 10.1 | 62.5 ± 9.9 | 51.2 ± 4.1 |
| Imax (pA pF−1) | −2.45 ± 0.31 | −3.26 ± 0.38 | −3.58 ± 0.43 | −2.39 ± 0.38 | −1.85 ± 0.19 |
| Vrev (mV) | 24.4 ± 1.3 | 27.7 ± 1.0 | 28.9 ± 2.1 | 29.5 ± 1.8 | 29.4 ± 2.7 |
| V½,ac (mV) | −25.8 ± 0.9 | −24.8 ± 1.1 | −24.3 ± 0.9 | −26.5 ± 1.4 | −22.9 ± 1.6 |
| kac (mV) | 6.33 ± 0.18 | 5.97 ± 0.18 | 6.41 ± 0.15 | 6.12 ± 0.12 | 6.74 ± 0.45 |
| V½,inac (mV) | −41.4 ± 0.8 | −39.4 ± 0.8 | −41.1 ± 0.9 | −41.1 ± 1.1 | −40.6 ± 0.7 |
| kinac (mV) | −4.31 ± 0.16 | −4.20 ± 0.11 | −4.69 ± 0.15 | −4.58 ± 0.15 | −4.13 ± 0.25 |
| tpeak (ms) | 13.0 ± 0.5 | 12.8 ± 1.0 | 11.5 ± 0.4 | 12.0 ± 0.5 | 12.1 ± 0.5 |
| No. of cells | 13 | 10 | 15 | 8 | 8 |
Gmax, Vrev, V½,ac, kac, V½,inac and kinac are calculated as described in Methods. Imax is the maximum density of T-type current determined from the fit of the I–V curve. tpeak is the duration between the beginning of the pulse and the peak amplitude of the T-type current for a depolarization reaching −10 mV. The mean values (± s.e.m.) given here are calculated by averaging the parameters determined by the fits to each cell data. The values of the different parameters obtained by fitting the average data (as done for the smooth curves shown in Figs 2 and 3) are always included within the error bars given here.