Active Cell Membranes as Intrinsic Sources of Bioelectricity

Recent theoretical research suggests that the cell membrane itself may act as a miniature electricity generator, driven not just by ion pumps and channels but by the inherent motion of molecules within the membrane. Traditionally seen as a passive barrier, the lipid bilayer surrounding cells is now understood to experience continuous tiny shape changes because of active biological processes inside the cell.

Inside living cells, proteins constantly change shape and interact with other molecules by consuming energy from ATP. These interactions cause microscopic bending and rippling of the membrane, creating nonrandom fluctuations that can be harnessed to produce electrical potential differences. This mechanism relies on a phenomenon known as flexoelectricity—where mechanical deformation in a material induces an electrical response. In this context, the bending of the cell membrane can generate electrical voltages across it.

According to the new model, the voltages produced through these membrane motions can reach levels similar to those seen in neurons during signaling (on the order of tens of millivolts). The rapid timescale of these membrane-driven electrical changes closely matches the millisecond dynamics of neural action potentials, suggesting that this effect could contribute to cellular electrical activity.

Beyond simply producing voltage, the membrane’s active motion may also help move ions against their usual concentration gradients, acting like a pump. This provides a physical explanation for how cells might regulate ion transport and electrical signaling without relying solely on traditional molecular machines.

Overall, this work shifts the view of the membrane from a static boundary to a dynamic, energetically active structure that harvests energy from internal molecular motion to generate bioelectric signals. If similar processes coordinate across many cells, they could influence electrical patterns in tissues and help inspire bio-inspired materials that mimic living electrical systems.

Source: PNAS Nexus
ImageCredits: Freepik