Figure 1. Elementary properties of single Bay K-modified L-channels.

A, unitary L-currents were recorded from -20 to +30 mV with 5 μm Bay K 8644 and 10 μmω-CTX-MVIIC in the pipette control solution; holding potential (V_h) was -40 mV. B, mean unitary current amplitudes plotted versus potential. The linear regression through data points has a mean slope conductance of 20.0 ± 0.6 pS (n = 5-29 patches). C, distribution of single L-current amplitudes at +10 mV best fitted by a Gaussian function with mean -1.24 ± 0.14 pA. D, mean open probability plotted versus potential obtained from 5 to 29 patches. Data points were fitted to a Boltzmann function P_o= P_max/(1 + exp (V_1/2 - V)/k), where P_max= 0.43, V_1/2=+13.7 mV and k = 10.1 mV. E, mean t_o (•, < t_o >, right scale) and mean t_c (○, < t_c >, left scale) plotted between -20 and +20 mV derived from 5-29 patches. The two parameters were estimated by averaging the arithmetic mean of the open and closed times of each patch.