Action potential properties affect excitation-contraction coupling in skeletal muscle

• Post by: Steve Burke
• February 23, 2022
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We recently coauthored a paper that was published in eLife with collaborators Mark Rich of Wright State University and Roger Bannister of the University of Maryland. The paper investigates the relationships between resting membrane potential and action potential waveform on excitation-contraction coupling and action potential propagation. We show that the width of an action potential affects excitation-contraction coupling and myoplasmic Ca²⁺, whereas the action potential peak has a greater influence on action potential propagation along the length of a muscle fibers. Our lab is now finalizing more mechanistic studies of the influence of the action potential waveform on excitation-contraction coupling (Ca_V1.1 function and Ca²⁺ release from the sarcoplasmic reticulum).  This work has implications for our previous work in Huntington’s disease where we discovered that action potentials were prolonged in Huntington’s disease muscle (Waters et al., PNAS 2013 and Miranda et al., AJP-Cell Physiology 2020) and for normal muscle function.