Figure 2.

Current-voltage (I-V) relationships of N-terminal-spliced Ca_V1.2 isoforms determined by electrophysiological recordings in 5-mM Ba²⁺. (A) Representative current traces recorded at a holding potential (HP) of −100 mV and stepped to various depolarizing test potentials (TPs) of −60, −30, −10, 0, and 30 mV are shown. (B) An ensemble of normalized I-V relationships of N-terminal-spliced isoforms is shown. The I-V relationships were fitted with a modified Boltzmann-Ohm function. Currents were elicited over various TPs for 900 ms. (C) The current densities were normalized to the cell capacitance (pA/pF). The number of recorded cells and kinetic constants are tabulated in Table 1.