Active matter as the underpinning agency for extraordinary sensitivity of biological membranes to electric fields

TL;DR

This paper proposes a non-equilibrium model of active biological membranes that explains how cells can detect electric fields far weaker than thermal noise limits, highlighting the role of activity in sensory sensitivity.

Contribution

It introduces a novel non-equilibrium statistical mechanics model for active membranes, demonstrating how activity enhances electric field detection beyond equilibrium predictions.

Findings

Model reproduces experimental data by varying activity levels

Active membranes can sense weaker electric fields than equilibrium limits

Activity modulates membrane sensitivity to electric signals

Abstract

Interaction of electric fields with biological cells is indispensable for many physiological processes. Thermal electrical noise in the cellular environment has long been considered as the minimum threshold for detection of electrical signals by cells. However, there is compelling experimental evidence that the minimum electric field sensed by certain cells and organisms is many orders of magnitude weaker than the thermal electrical noise limit estimated purely under equilibrium considerations. We resolve this discrepancy by proposing a non-equilibrium statistical mechanics model for active electromechanical membranes and hypothesize the role of activity in modulating the minimum electrical field that can be detected by a biological membrane. Active membranes contain proteins that use external energy sources to carry out specific functions and drive the membrane away from equilibrium. The central idea behind our model is that active mechanisms, attributed to different sources, endow the membrane with the ability to sense and respond to electric fields that are deemed undetectable based on equilibrium statistical mechanics. Our model for active membranes is capable of reproducing different experimental data available in the literature by varying the activity. Elucidating how active matter can modulate the sensitivity of cells to electric signals can open avenues for a deeper understanding of physiological and pathological processes.