Charge Movement and Contraction Threshold in Skeletal Muscle Fibres

Abstract

Currents due to the movement of charged particles in the membrane thickness have been shown to exist in skeletal muscle fibers by many authors (Schneider & Chandler, 1973; Chandler, Rakowski & Schneider, 1976a; Adrian & Aimers, 1976a). The voltage range in which this charge movement appears suggests that it may have important physiological role. In fact in excitable cells the membrane potential controls many physiological functions. In particular, in skeletal muscle fibres not only the conductances of K⁺ and Na⁺ ions but also the activation of mechanical contraction is under the control of the electric field existing across the cell membrane (Hodgkin & Horowicz, I960).