Fig. 2. Steady-state inactivation of spermatogenic cell T-type currents is not affected by NA.

A) Family of currents recorded with the voltage protocol depicted at the top. Channels were inactivated with 350-ms prepulses to potentials between −110 and −40 mV in 5 mV steps, from a HP = −90 mV. Then, channel availability was tested at −20 mV. B) Family of currents recorded as in A, but in presence of 100 µM NA. C) Steady-state inactivation curves in the absence and the presence of NA. Data points show the normalized peak amplitude of currents elicited under control (filled circles) and NA (open circles) by the testing pulse at −20 mV, and plotted against the prepulse potentials. Continuous lines are the best fits with a Boltzmann function. Values of V₅₀ and k obtained from this curves are summarized in Table 1.