Developmental bioelectricity
Developmental bioelectricity is the regulation of cell, tissue, and organ-level patterning and behavior by electrical signals during the development of embryonic animals and plants. The charge carrier in developmental bioelectricity is the ion rather than the electron, and an electric current and field is generated whenever a net ion flux occurs. Cells and tissues of all types use flows of ions to communicate electrically. Endogenous electric currents and fields, ion fluxes, and differences in resting potential across tissues comprise a signalling system. It functions along with biochemical factors, transcriptional networks, and other physical forces to regulate cell behaviour and large-scale patterning in processes such as embryogenesis, regeneration, and cancer suppression.
Overview
Developmental bioelectricity is a sub-discipline of biology, related to, but distinct from, neurophysiology and bioelectromagnetics. Developmental bioelectricity refers to the endogenous ion fluxes, transmembrane and transepithelial voltage gradients, and electric currents and fields produced and sustained in living cells and tissues. This electrical activity is often used during embryogenesis, regeneration, and cancer suppression—it is one layer of the complex field of signals that impinge upon all cells in vivo and regulate their interactions during pattern formation and maintenance. This is distinct from neural bioelectricity, which refers to the rapid and transient spiking in well-recognized excitable cells like neurons and myocytes ; and from bioelectromagnetics, which refers to the effects of applied electromagnetic radiation, and endogenous electromagnetics such as biophoton emission and magnetite.The inside/outside discontinuity at the cell surface enabled by a lipid bilayer membrane is at the core of bioelectricity. The plasma membrane was an indispensable structure for the origin and evolution of life itself. It provided compartmentalization permitting the setting of a differential voltage/potential gradient across the membrane, probably allowing early and rudimentary bioenergetics that fueled cell mechanisms. During evolution, the initially purely passive diffusion of ions, become gradually controlled by the acquisition of ion channels, pumps, exchangers, and transporters. These energetically free or expensive translocators set and fine tune voltage gradients – resting potentials – that are ubiquitous and essential to life's physiology, ranging from bioenergetics, motion, sensing, nutrient transport, toxins clearance, and signaling in homeostatic and disease/injury conditions. Upon stimuli or barrier breaking of the membrane, ions powered by the voltage gradient diffuse or leak, respectively, through the cytoplasm and interstitial fluids, generating measurable electric currents – net ion fluxes – and fields. Some ions and molecules modulate targeted translocators to produce a current or to enhance, mitigate or even reverse an initial current, being switchers.
Endogenous bioelectric signals are produced in cells by the cumulative action of ion channels, pumps, and transporters. In non-excitable cells, the resting potential across the plasma membrane of individual cells propagate across distances via electrical synapses known as gap junctions, which allow cells to share their resting potential with neighbors. Aligned and stacked cells generate transepithelial potentials and electric fields, which likewise propagate across tissues. Tight junctions efficiently mitigate the paracellular ion diffusion and leakage, precluding the voltage short circuit. Together, these voltages and electric fields form rich and dynamic and patterns inside living bodies that demarcate anatomical features, thus acting like blueprints for gene expression and morphogenesis in some instances. More than correlations, these bioelectrical distributions are dynamic, evolving with time and with the microenvironment and even long-distant conditions to serve as instructive influences over cell behavior and large-scale patterning during embryogenesis, regeneration, and cancer suppression. Bioelectric control mechanisms are an important emerging target for advances in regenerative medicine, birth defects, cancer, and synthetic bioengineering.
History
18th century
Developmental bioelectricity began in the 18th century. Several seminal works stimulating muscle contractions using Leyden jars culminated with the publication of classical studies by Luigi Galvani in 1791 and 1794. In these, Galvani thought to have uncovered intrinsic electric-producing ability in living tissues or "animal electricity". Alessandro Volta showed that the frog's leg muscle twitching was due to a static electricity generator and from dissimilar metals undergoing or catalyzing electrochemical reactions. Galvani showed, in a 1794 study, twitching without metal electricity by touching the leg muscle with a deviating cut sciatic nerve, definitively demonstrating "animal electricity". Unknowingly, Galvani with this and related experiments discovered the injury current and injury potential. The injury potential was, in fact, the electrical source behind the leg contraction, as realized in the next century. Subsequent work ultimately extended this field broadly beyond nerve and muscle to all cells, from bacteria to non-excitable mammalian cells.19th century
Building on earlier studies, further glimpses of developmental bioelectricity occurred with the discovery of wound-related electric currents and fields in the 1840s, when the electrophysiologist Emil du Bois-Reymond reported macroscopic level electrical activities in frog, fish and human bodies. He recorded minute electric currents in live tissues and organisms with a then state-of-the-art galvanometer made of insulated copper wire coils. He unveiled the fast-changing electricity associated with muscle contraction and nerve excitation – the action potentials. Du Bois-Reymond also reported in detail less fluctuating electricity at wounds – injury current and potential – he made to himself.Early 20th century
Developmental bioelectricity work began in earnest at the beginning of the 20th century. Ida H. Hyde studied the role of electricity in the development of eggs.T. H. Morgan and others studied the electrophysiology of the earthworm.
Oren E. Frazee studied the effects of electricity on limb regeneration in amphibians.
E. J. Lund explored morphogenesis in flowering plants.
Libbie Hyman studied vertebrate and invertebrate animals.
In the 1920s and 1930s, Elmer J. Lund and Harold Saxton Burr wrote multiple papers about the role of electricity in embryonic development. Lund measured currents in a large number of living model systems, correlating them to changes in patterning. In contrast, Burr used a voltmeter to measure voltage gradients, examining developing embryonic tissues and tumors, in a range of animals and plants. Applied electric fields were demonstrated to alter the regeneration of planarian by Marsh and Beams in the 1940s and 1950s, inducing the formation of heads or tails at cut sites, reversing the primary body polarity.
Late 20th century
In the 1970s, Lionel Jaffe and Richard Nuccittelli's introduction and development of the vibrating probe, the first device for quantitative non-invasive characterization of the extracellular minute ion currents, revitalized the field.Researchers such as Joseph Vanable, Richard Borgens, Ken Robinson, and Colin McCaig explored the roles of endogenous bioelectric signaling in limb development and regeneration, embryogenesis, organ polarity, and wound healing.
C.D. Cone studied the role of resting potential in regulating cell differentiation and proliferation.
Subsequent work has identified specific regions of the resting potential spectrum that correspond to distinct cell states such as quiescent, stem, cancer, and terminally differentiated.
Although this body of work generated a significant amount of high-quality physiological data, this large-scale biophysics approach has historically come second to the study of biochemical gradients and genetic networks in biology education, funding, and overall popularity among biologists. A key factor that contributed to this field lagging behind molecular genetics and biochemistry is that bioelectricity is inherently a living phenomenon – it cannot be studied in fixed specimens. Working with bioelectricity is more complex than traditional approaches to developmental biology, both methodologically and conceptually, as it typically requires a highly interdisciplinary approach.
Biological battery
A “biological battery” was demonstrated in late 2025 at Belmonte Arboretum, part of Wageningen University & Research as part of its program provides educational scientific experiences to young people. In this case a path was marked by small Light-emitting diodes that provide a diffuse night-time glow sufficient to mark the path without disturbing nature.The electricity used to power the LEDs is essentially sunlight that fell on green photosynthesising living plant material. That process takes water from the ground and carbon dioxide in the air to rearrange the hydrogen and oxygen into carbohydrate molecules, releasing unwanted oxygen to the air. Carbohydrates are the basic building blocks of plants.
Only some of the solar energy collected by the green material is used for photosynthesis, some is discharged through the roots int the soil, where bacteria use it to synthesize other essential molecules and elements such as nitrogen that support plant life.
To extract electricity from sunlight conductive carbon electrodes were introduced near the roots of bushes to capture the “free” electrons produced by bacteria. These serve as the negative cell terminals, other carbon electrodes placed in the air provided the corresponding positive connections. Although the energy captured from a single bush is very small many can be connected in series to provide enough to drive the LEDs without conventional electrochemical cells or regular solar cells.