Fig. 5.

Inhibition of CDI by the E1613P mutation in Ca_V1.2. (A) representative Ca_V1.2 current inactivation of wild-type (Left) and E1613P (Right) Ca_V1.2 channels elicited by a 500-ms depolarization to +20 mV in either 10 mM Ca²⁺ (black traces) or 10 mM Ba²⁺ (gray traces). Ca²⁺ current traces were normalized to the peak of the corresponding Ba²⁺ current trace. The vertical scale bar represents 230 pA and 200 pA for the wild-type Ca²⁺ and Ba²⁺ currents, respectively and 470 pA and 260 pA for the E1613P Ca²⁺ and Ba²⁺ currents, respectively. (B) average (± SE) ratio of current remaining 100 ms after depolarization (r₁₀₀) to the corresponding peak Ca²⁺ (filled symbols) and Ba²⁺ (open symbols) current plotted as a function of test potential for wild-type (Left) and E1613P (Right) Ca_V1.2. (Inset) (f) the difference between r₁₀₀ in Ca²⁺ and Ba²⁺ and measure of CDI strength, is shown for the test potential of +20 mV (P < 0.01).