A proposed physical explanation of the activation of sodium channels

摘要: Abstract A physical mechanism for activation of excitable Na channels is proposed, based on an electrodiffusion model with the assumption constant dielectric permittivity replaced a equation state descriptive ferroelectric behavior. The postulates channel unit within glycoprotein to be in membrane at resting potential as result field-induced elevation transition temperature. threshold depolarization initiates first-order paraelectric state. screening layer permeant cations drawn across by negative bound charge phase boundary. This hypothesis consistent experimental observations current-voltage hysteresis, voltage-dependent birefringence, single-channel currents, “gating” heat and cold block excitability, electromechanical thermoelectric responses, nonlinear ion conduction, quantitative agreement estimated ma...