Genesis of Horizontal Membrane Electric Field by Bilayer-Embedded Electrodes

Abstract: For over a century, the electric field of biological membranes has been treated as a one-dimensional entity, defined exclusively by the voltage across its thickness (V_VERT). Here, we challenge this conventional view by developing a device that can apply a horizontal membrane voltage (V_HORZ) across a synthetic lipid bilayer. The device consists of electrodes embedded between bilayer leaflets, allowing the steady application of V_HORZ. Applied V_HORZ selectively and reversibly accelerated the slow inactivation of a voltage-gated potassium channel. Physical considerations revealed that V_HORZ is generated from spatially inhomogeneous V_VERT in cell membranes, thus occurring ubiquitously in membrane physiological functions, such as at the action-potential wave front. Our V_HORZ system enables the generation of three-dimensional membrane electric fields, mimicking hitherto overlooked physiological membrane electric activities.