Assessment of Calcium Sparks in Intact Skeletal Muscle Fibers

Described here is a method to directly measure calcium sparks, the elementary units of Ca²⁺ release from sarcoplasmic reticulum in intact skeletal muscle fibers. This method utilizes osmotic-stress-mediated triggering of Ca²⁺ release from ryanodine receptor in isolated muscle fibers. The dynamics and homeostatic capacity of intracellular Ca²⁺ signaling can be employed to assess muscle function in health and disease.