Figure 4.

Enhanced Ca²⁺ Sparks in DM Mice

(A) Representative line-scan images of Ca²⁺ sparks. (B) Increased frequency of Ca²⁺ sparks in DM. (C) Representative trace of caffeine-induced Ca²⁺ transients. (D) Sarcoplasmic reticulum Ca²⁺ content is unchanged (p = 0.407). (E) Transient outward peak potassium current (I_to-peak), (F) total potassium current (I_K^+-peak), and (G) steady-state current (I_K⁺_-SS), revealed similar current densities between Ctrl (n = 5) and DM (n = 10) mice. Values are mean ± SEM. (B, D) The n value within the bars indicates the total number of cells tested from >3 different mice. ∗∗∗p < 0.001. Abbreviations as in Figures 1 and 2.