Figure 5.

Transgenic mice exhibit normal voltage dependence of T-type calcium currents. A, B, Representative T-type current traces for SSI from TC cells of the LDN (A) and VB (B) in WT control (n = 6), α1G-Tg1 (n = 6), and α1G-Tg2 (n = 5) mice. A standard double-pulse protocol for SSI was given from the holding potential of −70 mV, in which a 4 s prepulse delivered at various membrane potentials (ranging from −120 to −40 mV) preceded the test stimulus via a voltage step to −50 mV for 200 ms (the interpulse interval was 10 s). C, Normalized current–voltage curves for SSI of T-type currents was plotted as a function of prepulse membrane potentials and best-fitted with a Boltzmann function (see Materials and Methods). No significant changes in either pooled half-maximal voltages or slopes for SSI within the LDN and VB were observed in the α1G-Tg1 (circle, thick dashed line) or α1G-Tg2 (triangle, solid line) lines compared with WT controls (square, thin dashed line). Quantitative data represent mean ± SEM; p > 0.05 versus WT controls.