Related Experiment Video
Updated: Aug 24, 2026

Introduction to Solid Supported Membrane Based Electrophysiology
Published on: May 11, 2013
The enduring legacy of the "constant-field equation" in membrane ion transport
Osvaldo Alvarez1, Ramon Latorre2
1Departamento de Biología, Facultad de Ciencias, Santiago, Chile.
Abstract:
In 1943, David Goldman published a seminal paper in The Journal of General Physiology that reported a concise expression for the membrane current as a function of ion concentrations and voltage. This body of work was, and still is, the theoretical pillar used to interpret the relationship between a cell's membrane potential and its external and/or internal ionic composition. Here, we describe from an historical perspective the theory underlying the constant-field equation and its application to membrane ion transport.
More Related Videos
Related Concept Videos
The Significance of Membrane Transport
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Resting Potential Decay
At rest, the K+ is the main ion that moves across the membrane through...
Electrostatic Boundary Conditions
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
Continuity Equation
Carrier Transport
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Continuity Equation
The mass flow rate is expressed as:

