The mechanism underlying transient weakness in myotonia congenita.

ABSTRACT: In addition to the hallmark muscle stiffness, patients with recessive myotonia congenita (Becker disease) experience debilitating bouts of transient weakness that remain poorly understood despite years of study. We performed intracellular recordings from muscle of both genetic and pharmacologic mouse models of Becker disease to identify the mechanism underlying transient weakness. Our recordings reveal transient depolarizations (plateau potentials) of the membrane potential to -25 to -35 mV in the genetic and pharmacologic models of Becker disease. Both Na⁺ and Ca²⁺ currents contribute to plateau potentials. Na⁺ persistent inward current (NaPIC) through Na_V1.4 channels is the key trigger of plateau potentials and current through Ca_V1.1

SUBMITTER: Myers JH 

PROVIDER: S-EPMC8079152 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature