Leuchtag H R
Texas Southern University, Houston 77004.
J Theor Biol. 1987 Aug 7;127(3):321-40. doi: 10.1016/s0022-5193(87)80110-8.
Previous work in excitability has focused primarily on the mathematical description of the phenomena, while mechanisms postulated to explain these were simple mechanical interpretations of the terms of this description. The problem considered here is that of the physical mechanism underlying excitation. The experimental facts to be explained must be not only the electrical behavior of the membrane, but also its electromechanical, electro-optic and thermoelectric behavior. Previous work on the physically grounded electrodiffusion theory foundered not because of the incorrectness of the electrodiffusion approach, but because the assumed description of the dielectric properties of the membrane was too simple. Extension of the dielectric equation of state to a nonlinear polynomial form converts the classical electrodiffusion system of equations into a nonlinear polynomial form converts the classical electrodiffusion system of equations into a ferroelectric electrodiffusion system. The consideration of ferroelectric behavior in excitable channels makes possible straight-forward physical explanation of the phenomena of membrane swelling during action potential, currents induced by temperature changes, transition temperatures, current-voltage hysteresis, nonlinear electrical behavior, voltage-dependent birefringence and rectangular pulses from single channels. The hypothesis is therefore proposed that excitable channels contain ferroelectric transmembrane units. These may be crystals or liquid crystals.
先前关于兴奋性的研究主要集中在对这些现象的数学描述上，而用于解释这些现象的假设机制只是对该描述术语的简单机械解释。这里要考虑的问题是兴奋背后的物理机制。有待解释的实验事实不仅包括膜的电行为，还包括其机电、电光和热电行为。先前基于物理的电扩散理论研究失败，并非因为电扩散方法不正确，而是因为对膜介电特性的假设描述过于简单。将介电状态方程扩展为非线性多项式形式，可将经典的电扩散方程组转换为铁电电扩散方程组。考虑可兴奋通道中的铁电行为，使得对动作电位期间膜肿胀、温度变化引起的电流、转变温度、电流-电压滞后、非线性电行为、电压依赖性双折射以及单通道矩形脉冲等现象进行直接的物理解释成为可能。因此提出假设，即可兴奋通道包含铁电跨膜单元。这些单元可能是晶体或液晶。
