Bioelectromagnetism

Editor-in-Chief: Robert G. Schwartz, M.D. [1], Piedmont Physical Medicine and Rehabilitation, P.A.;

Associate Editor-In-Chief: [2]Austin Schwartz, Department of Biophysics, Florida State University, Tallahassee, Florida

Bioelectromagnetism (sometimes equated with bioelectricity) refers to the electrical, magnetic or electromagnetic fields produced by living cells, tissues or organisms. Examples include the cell potential of cell membranes and the electric currents that flow in nerves and muscles, as a result of action potentials. It is not to be confused with bioelectromagnetics, which deals with the effect on life from external electromagnetism.

Description

Biological cells use bioelectricity to store metabolic energy, to do work or trigger internal changes, and to signal one another. Bioelectromagnetism is the electric current produced by action potentials along with the magnetic fields they generate through the phenomenon of electromagnetism. These action potentials are generated through activation of ion channels, which in turn cause a change in membrane potential of the cells in which they are located. Ion channels and the ions that flow through them are the most basic units that lead to bioelectromagnetism.

Bioelectromagnetism is studied primarily through the technique of electrophysiology. In the late eighteenth century, the Italian physician and physicist Luigi Galvani first recorded the phenomenon while dissecting a frog at a table where he had been conducting experiments with static electricity. Galvani coined the term animal electricity to describe the phenomenon, while contemporaries labeled it galvanism. Galvani and contemporaries regarded muscle activation as resulting from an electrical fluid or substance in the nerves. Electrophysiology can be used to measure currents and action potentials in single cells from cell culture containing ion channels of interest and tissue culture from central or peripheral nervous systems of interest. Measurements can be made in vivo and in vitro.

Bioelectromagnetism is an aspect of all living things, including all plants and animals. Several kinds of bioelectromagnetism exist. Photo-electromagnetism refers to the special relationship between photons and its biological responses (for example: photosynthesis and cytochrome oxidase dependent electron transport. Bioenergetics is the study of energy relationships of living organisms. Biodynamics deals with the energy utilization and the activities of organisms. Some animals have acute bioelectric sensors, and others, such as migratory birds, are believed to navigate in part by orienting with respect to the Earth's magnetic field. Also, sharks are more sensitive to local interaction in electromagnetic fields than most humans. Other animals, such as the electric eel, are able to generate large electric fields outside their bodies.

In the life sciences, biomedical engineering uses concepts of circuit theory, molecular biology, pharmacology, and bioelectricity. Bioelectromagnetism is associated with biorhythms and chronobiology. Biofeedback is used in physiology and psychology to monitor rhythmic cycles of physical, mental, and emotional characteristics and as a technique for teaching the control of bioelectric functions.

Bioelectromagnetism involves the interaction of ions. Bioelectromagnetism is sometimes difficult to understand because of the differing types of bioelectricity, such as brainwaves, myoelectricity (e.g., heart-muscle phenomena), and other related subdivisions of the same general bioelectromagnetic phenomena. One such phenomenon is a brainwave, which neurophysiology studies, where bioelectromagnetic fluctuations of voltage between parts of the cerebral cortex are detectable with an electroencephalograph. This is primarily studied in the brain by way of the electroencephalogram or "EEG."

See also

• Signals (biology)
• Electrophysiology
• Magnetobiology
• Electroencephalography
  • Brain waves
• Membrane potential
  • Resting potential
  • Action potential
• Biorhythm
• Electrochemical potential
• Electrochemistry
• Electric fish
• Electromyography

External links, resources, and references

Information

• A short history of Bioelectromagnetism [3]
• Malmivuo, Jaakko, and Robert Plonsey, "Bioelectromagnetism, Principles and Applications of Bioelectric and Biomagnetic Fields". Oxford University Press, New York - Oxford. 1995.
• International Journal of Bioelectromagnetism
• International Society for Bioelectromagnetism
• Direct and Inverse Bioelectric Field Problems
• Bioelectricity. Biophysics lectures.

Groups

• Bioelectromagnetism Research Group
• Living State Physics Group
• Physikalisch-Technische Bundesanstalt. Laboratory for Bioelectricity/Biomagnetism, Berlin.
• PSI - Bak - Human Bio-magnetism.
• Ragnar Granit Institute.