Electrotaxis, also known as galvanotaxis, is the directed motion of biological cells or organisms guided by an electric field or

current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (stre ...

. The directed motion of electrotaxis can take many forms, such as; growth, development, active swimming, and passive migration. A wide variety of biological cells can naturally sense and follow DC electric fields. Such electric fields arise naturally in biological tissues during development and

healing With physical trauma or disease suffered by an organism, healing involves the repairing of damaged tissue(s), organs and the biological system as a whole and resumption of (normal) functioning. Medicine includes the process by which the cells ...

. These and other observations have led to research into how applied electric fields can impact wound healing. An increase in wound healing rate is regularly observed and this is thought to be due to the cell migration and other

signaling pathways Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellula ...

that are activated by the electric field. Additional research has been conducted into how applied electric fields impact cancer

metastasis Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then ...

morphogenesis Morphogenesis (from the Greek ''morphê'' shape and ''genesis'' creation, literally "the generation of form") is the biological process that causes a cell, tissue or organism to develop its shape. It is one of three fundamental aspects of deve ...

neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. ...

guidance,

motility Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...

of pathogenic bacteria,

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

formation, and many other biological phenomena.

History

In 1889, German physiologist Max Verworn applied a low-level

direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or eve ...

to a mixture of bacterial species and observed that some moved toward the anode and others moved to the cathode. Just two years later, in 1891, Belgian microscopist E. Dineur made the first known report of vertebrate cells migrating directionally in a direct current, a phenomenon which he coined galvanotaxis. Dineur used a zinc–copper cell to apply a constant current to the abdominal cavity of a frog via a pair of platinum electrodes. He found that inflammatory leukocytes aggregated at the negative electrode. Since these pioneering studies, a variety of different cell types and organisms have been shown to respond to electric fields.

Mechanism

Understanding of the underlying mechanisms that cause electrotaxis to occur is limited. The diversity of biological cells and environmental conditions make it likely that there are many different mechanisms that allow for cells to migrate due to electric fields. Some researchers have indicated that cells move passively without any specific sensing mechanisms applied to alter active motility.

Bacteria

In a sufficiently strong electric field, small cells may move as uniformly

charged particle In physics, a charged particle is a particle with an electric charge. It may be an ion, such as a molecule or atom with a surplus or deficit of electrons relative to protons. It can also be an electron or a proton, or another elementary pa ...

s or

dipole In physics, a dipole () is an electromagnetic phenomenon which occurs in two ways: *An electric dipole deals with the separation of the positive and negative electric charges found in any electromagnetic system. A simple example of this system ...

s. Other research reports suggest that bacteria cells might perceive local electric fields via chemotaxis. This is done by sensing

redox Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

molecules that have formed a gradient relative to the poised electrical surface in the local environment.

Mammalian Cells

The method of detection of a field in mammalian cells is under active investigation and might involve several mechanisms. For now, it is thought that redistribution of membrane-bound sensors dragged by Coulombic forces and electro-osmosis at the membrane would cause the cell to polarize, then migrate.

References

External links