Fig. 7.

In-depth consideration of strength–current analysis. A, Theoretical curvesillustrating the anticipated shift (arrow) that would result from increased intrinsic Ca²⁺ sensitivity of a regulatory process for global Ca²⁺. The curvature of relationships reflects saturation of Ca²⁺responsiveness, the metric quantifying regulatory strength, or both.B, Underlying transformations connecting peak Ca²⁺ current amplitude (I) and regulatory strength. Increased intrinsic Ca²⁺ sensitivity would affect the second transformation, whereas cell-geometric factors such as channel clustering would affect the first. Changes in either transformation could impact the overall strength–current relationship.C, Diagram illustrating how increased channel clustering could enhance the transformation between I and the global Ca²⁺ signal relevant to channel regulation.