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Bioelectricity History |
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Biomagnetism
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Waves
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Infrasonic Waves
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Since the time of its first observations, electromagnetic energy- neither particle-like nor wave-like but both simultaneously, propagating through space at 300,000 km/s (approximately 186,000 miles per second)- was believed to be the "life force" and so it remained a controversy through science. The following is a timeline of the work pursued in order to understand the electromagnetic phenomena and its place in biology. [all dates from (Becker) and (Halsey3)]
* 5000 BC - 332 BC: Ancient Egyptians acknowledge and employ the use of the electricity found in the electric catfish, painting the fish on tombs and in hieroglyphs. * 4000 BC - 146 BC: Ancient Greeks believe all functions of living organisms result from the humors, liquids bearing mystical properties which flow within the body, four of which are distinguished by philosopher and physician Hippocrates (whose medical philosophies are not with merit, as they are not based on reality): blood, black bile, phlegm, and yellow bile, all of which could be observed under varying conditions. The anima, or soul, brought the body to life and sustained it as living. * 146 BC - AD 476: Ancient Romans conceive that function and form are in need of more realistic relations than Hippocrates had claimed: Galen, founder of anatomy and physiology, dissects organisms other than homo sapiens (a prohibited practice on humans) and produces a complete, complex biophilosophical system based on anatomical observation, expanding the original Hippocrates concept of humors. * AD 800 - 1100: Arabs employ use of catfish for medicinal purpose, giving it an arabic name: Ra’ad, meaning "the shaker" . AD 1543: Andreas Vasalius, professor of anatomy at Padua publishes, "De humanis corporus fabricus", based on actual dissection and honest observation- a first for anatomy- after questioning Galen’s work and working with homo sapiens to find the Roman had been wrong. AD 1563: William Gilbert, a young English physician, initiates his London medical practice and continues for twenty-five years to combine medicine with carefully devised and executed experiments, which lay modern physics foundations. Ad 1600: Gilbert publishes "De magnete", establishing distinctions between electricity and magnetism, being first to use the term, "electricity", and to introduce the concept of a magnetic field. He describes the earth as a bar magnet, also inventing the electroscope. * AD 1602 - 1700: Galileo Galilei invents compound microscope and destroys the Geocentric (Ptolemaic) conceptions of cosmology as well as finding himself in trouble with the Church and society in general after pushing his opinions too far. The compound microscope was reversed to see within organisms by Marcello Malphighi, Italian physician and naturalist, discovering detail and complexity in living organisms. Francis Bacon proposes scientific method of experimentation, observation, and verification, however he may have utilized Gilbert’s work, claiming it as his own while simultaneously denying Gilbert’s findings. William Harvey publishes first true series of physiological experiments, describing blood circulation as a closed circuit with the heart as a pumping agent. French mathematician, Rene Descartes, attempts to unify biological concepts mathematically, believing all life mechanical with all functions being directed by the brain and nerves (neural system). However, he still believes in the anima as a necessity to give the body life, as all others believed, and modernizes the Galen humors, claiming a subtle flame or wind located in the nervous system as the only animating spirit. 1660: Otto von Guericke pursues Gilbert’s studies and invents first electrical generating machine- a spinning globe of sulfur which generates static electrical charge.Sir Issac Newton proposes Descartes’ view of vital principle flowing through nerves and producing complex life functions may be the aether of the universe and material bodies. * AD 1700-1800: Anatomy becomes based upon dissection and observations, moving away from the humors, however, it is still believed "vital forces" distinguish the living from the non-living. Englishman, Stephen Gray, demonstrates electrical static charges can be conducted by various material for long varying distances, discovering conductors and insulators. He published "Experiment concerning electricity" after electrifying a human subject with static charge and observing the results. English clergyman, Stephen Hales, suggests nerves function as conductors, where the "vital force" was electricity. Jan Swammerdam of Holland and Sir Francis Glisson of Cambridge find muscles are stationary in volume when contracted, proving Hales correct, as nerve-muscle activity in dealing with humors requires volume increase in muscles as the humor passes through nerve to muscle. Electricity proposed to be vital force, however, there remained no evidence for its role iin living organisms. AD 1746: Leyden jar invented, with a realization of its relation to the torpedo ray by Dutchman, Laurens Storm can’s Gravesande, and French naturalist, Michel Adanson. AD 1775 - 1796: Luigi Galvani, a shy, retiring physician and professor of anatomy in Bologna, dissects muscles of a frog leg when his assistant accidentally touches the nerve to muscles with scalpel as electrical machine operated close by. As the machine produces a spark, the muscle contracts, meaning the electrical force had transferred from air to metal to nerve to muscle in order to generate the contraction. Galvani feels electricity plays role in nerve function and experiments further, avoiding the use of electrical machines to produce muscle contraction through contact of nerve and metal, only to find that is a continuous circuit was completed between nerve, two dissimilar metals in series, and another portion of the body of the specimen, muscle contractions occurred. He concludes electricity is generated by the zoological body where wires merely closed the circuit- he names it "animal electricity" and thus, the "vital force". Alessandro Volta repeats Galvani’s experiments and, though agreeing with the conclusions are first, becomes convinced electricity was generated by two dissimilar metals in the circuit and not the nerve. Volta creates the Voltaic pile (battery) with several metals separated by cardboard disks soaked with acid and salt solutions and concludes there is no electricity in living organisms. Galvani replies to Volta, anonymously publishing reports of additional experiments of muscle contractions produced with no metal present in the circuit and electricity generated by wounded tissue. It was possible for muscle contractions to occur when in presence of two metals or thunderstorms, however, contractions also occurred on clear days without two metals. Volta claims the experiments to be theoretical and Galvani does not respond, however, his nephew, physicist Giovanni Aldini, believes Galvani to be correct and joins the debate, where Galvani is soon forgotten. (It is to be noted that apparently, Galvani and Volta were gentlemen and friends with high scientific principles. Although their supporters fought about the issue, Volta is credited with inventing the term, "galvanism", and wrote of Galvani’s work that it contained "one of the most beautiful and most surprising discoveries". AD 1796: Napoleon Bonaparte defeats Bologna and Galvani is exiled from position, home, and fortune, only to seek refuge with his brother. AD 1797: Baron Friedrich Heinrich Alexander von Humboldt, a mining engineer for the Prussian government and naturalist with equipment to conduct experiments with animal electricity, publishes his conclusion that Galvani and Volta were both wrong and correct: both bimetallic and animal electricity existed. He is also granted permission to visit South America by the Spanish, discovering large fish with electrical apparatus, however, millions of years afore scientists. He gives the first scientific accounts of the behaviour of the electric eel, having stood on one and experienced a painful numbness, spending the day suffering through violent pains in the knees and joints. Predicts it would be found in most zoological specimens that every contraction of muscle is preceded by discharge from nerves into muscles. AD 1798: December 4, Galvani dies in the home of his brother, where he lacks connections to science and scientists: he does not know of von Humboldt’s work. AD 1800: Volta presents his work to Napoleon, receives an award and special honours- including entitlement of Count of Lombardy- then disappears from science. * AD 1800: Aldini continues with animal electricity, experimenting grotesquely with corpses and electrical currents ironically generated by Voltaic piles, having no medical background. However, Volta’s bimetallic electricity was chosen over Galvani’s animal electricity, where electricity was becoming a tool for the material world. AD 1818: Mary Shelley’s, Frankenstein, is published, inspired by Galvani AD 1820: Hans Christian Oersted discovers electromagnetism during a lecture of voltaic electricity, when a compass on the same table moved each time an electrical circuit was completed. He observes electrical currents generate magnetic fields around conductors. Where Gilbert had shown the distinction between magnetism and electricity, Oersted displayed the connection. AD 1830: Carlo Matteucci, a physics professor at Pisa, experiments with animal electricity and not-metal contact, proving by use of Nobeli’s galvanometer that electrical current is generated by wounded tissue. Stacking of each tissue would multiply the current like the metal in the Voltaic pile, however electricity was not necessarily located within the central neural system and seemingly play little role in the debate of the "vital force". AD 1834: Giovanni Aldini dies. AD 1847: Johnannes Müller, one of the most foremost physiologists in the world and professor in Berlin, believed electricity could stimulate nerve, through not involved in regular function. Gives one top student, Emil Du Bois-Reymond, Matteucci’s book, suggesting he duplicate the experiments: Du Bois-Reymond duplicates and expands the experiments, discovering that as nerve was stimulated, an electrically-measurable impulse is generated at site of stimulation, traveling at high speed down nerve to produce muscle contraction. He discovered nerve impulse and knew of its importance, however, he attacked Matteucci’s worked unprofessionally and tarnished his merit. Du Bois-Reymond then begins to dispute with a student, Henry Xavier Hermann, who believes resting potentials (steady voltage observed on unstimulated nerve and muscle) are due to wounded tissue currents of Matteucci and there would be no potential without injury. Du Bois-Reymond believes wound potentials a minor matter, only adding a small part to resting potential. Hermann was the most correct of the debate. Hermann Ludwig Ferdinand von Helmholtz, a colleague in Berlin, measures velocity of nerve impulse and obtains value of 30 m/s, reasoning longer reaction times of stimulation and reaction is due to the length of the pathway taken to reach the brain. Student, Julis Berstein, duplicates and confirms Helmholtz’s velocity and makes precise measurement of nerve impulse. AD 1859: Charles Darwin publishes Origin of Species, with comments on an area of bioelectricity: electric organs............ "The electric organs of fishes offer another case of special difficulty; for it is impossible to conceive by what steps these wondrous organs have been produced. But this is not surprising, for we do not even know of what use they are. In the Gymnotus and Torpedo they no doubt serve as powerful means of defense, and perhaps for securing prey; yet in the Ray, as observed by Matteucci, an analogous organ in the tail manifests but little electricity, even when the animal is greatly irritated; so little, that it can hardly be of nay use for the above purposes. Moreover, in the Ray, besides the organ just referred to, there is, as Dr. R. M’Donnell has shown, another organ near the head, not known to be electrical, but which appears to be the real homologue of the electric battery in the Torpedo. It is generally admitted that there exists between these organs and ordinary muscle a close analogy, in intimate structure, in the distribution of the nerves, and in the manner in which they are acted on by various reagents. It should, also, be especially observed that muscular contraction is accompanied by an electrical discharge; and, as Dr. Radcliffe insists, "in the electrical apparatus of the torpedo during rest, there would seem to be a charge in every respect like that which is met with in muscle and nerve during rest, and the discharge of the torpedo, instead of being peculiar, may be only another form of the discharge which depends upon the action of muscle and motor nerve." Beyond this we cannot at present go in the way of explanation; but as we know so little about the uses of these organs, and as we know nothing about the habits and structure of the progenitors of the existing electric fishes, it would be extremely bold to maintain that no serviceable transitions are possible by which these organs might have been gradually developed. "These organs appear at first to offer another and far more serious difficulty; for they occur in about a dozen kinds of fish, of which several are widely remote in their affinities. When the same organ is found in several members of the same class, especially if in members having very different habits of life, we may generally attribute its presence to inheritance from a common ancestor; and its absence in some of the members to loss through disuse or natural selection. So that, is the electric organs had been inherited from some one ancient progenitor, we might have expected that all electric fishes would have been specially related to each other; but this is far from the case. Nor does geology at all lead to the belief that most fishes formerly possessed electric organs, which their modified descendants have now lost. But when we look a the subject more closely, we find in the several fishes provided with electric organs, that these are situated in different parts of the body, — that they differ in construction as in the arrangement of the plates, and, according to Pacini, in the process or means by which the electricity is excited— and lastly, in being supplied with nerves proceeding from different sources, and this is perhaps the most important of all the differences. Hence in the several fishes furnished with electric organs, these cannot be considered as homologous, but only as analogous in function. Consequently there is no reason to suppose that they have been inherited from a common progenitor; for had this been the case they would have closely resembled each other in all respects. Thus the difficulty of an organ, apparently the same, arising in several remotely allied species, disappears, leaving only the lesser yet still great difficulty; namely, by what graduated steps these organs have been developed in each separate group of fishes." AD 1868: Julius Berstein formulates the Berstein hypothesis: proposes that the nerve cell membrane is capable of selectively passing particular ions, where a mechanism exists within the membrane to separate negative from positive ions, permitting passage into the cell to the positive, leaving negative ions in the fluid surrounding the cell. When equilibrium is reached, an electrical potential exists across membrane as the "transmembrane potential". Nerve impulse is simply a localized region of loss of transmembrane potential which travels down the nerve fiber with membrane potential immediately restored behind it. All cells possess such potential, similarly the product of ion separation. Matteucci’s current is concluded as being due to damaged cell membranes which leaked their transmembrane potential. * AD 1850-1900: Living organisms beginning to be observed as complex, physical-chemical machines, which may be segregated into component parts and studied in isolation, forgoing the concept of "vital force". The age of electrical technology begins and society observes morse code, electric light, James Clerk Maxwell’s electromagnetic radiation, and the first central electrical generating station in New York (1882). AD 1900: Homo sapiens deviate from nature by creating an electromagnetic world, where there is believed to be great social and economical advantage, rising questions regarding possible effects upon the human health. In reply, scientists claim no issues, as electricity plays absolutely no role in living organisms. Thomas Edison experiments with a dog in a strong magnetic field for five hours and five humans in a strong, consistent magnetic field, both experiments yielding "no apparent discomfort" and "no sensations". However, in the following years, such experiments were executed, yielding the opposite of Edison’s results, making the first set of experiments questionable: why were no such affects reported though under conditions known to produce them? D’Arsoncal reports changing fields applied to homo sapiens head produces subjective sensation of light. Science and society deny affects of electromagnetic fields on living organisms. AD 1902: Leduc claims to be able to produce state of narcosis in organisms by transmitting alternating current of 100 Hz at 35 V through the head- becomes used as a therapy. ** AD 1906: Camillo Golgi of Italy and Santiago Ramon Y Cajal receives Nobel Prize in Physiology for structure of neural system. ** AD 1924: Dutch scientist, Willem Einthoven, receives Novel Prize for discovery of the mechanism of the electrocardiogram and also develops the string galvanometer for bioelectrical measurement. AD 1930: "Anyone who aspired to a career in med or biological sciences was well advised to hesitate before publicly proposing that electromagnetic forces had any effect on living things, other than to produce shock or heating of tissues, or that such forces played any sort of functional role in living things." ** AD 1932: Sir Charles Scott Sherrington and Edgar D. Adrian receive Nobel Prize for discoveries of functions of neuron. (Sherrington experimented with electricity in the neural system, studying that which occurred when information was transmitted from one cell to another, acquiring the term, "synapse" to define the gap between neurons. He established four principles: electrical impulses pass through synapse in one direction; there exists a constant delay of approximately one-half millisecond between arrival and departure of electrical impulse at synapse; a bombardment of impulses arriving at a synapse is not kept constant when reproduced on the other side; and arrival of an impulse at a synapse may result in excitation or inhibition of activity in the cell across the synapse). *AD 1930-1940: Burr experiments with measurable DC potentials on surface of organisms, relating changes in potentials to number of physiological functions such a growth, development, and sleep. He formulates the concept of the "bioelectric field", generated by the sum total of electrical activity of all cells in the organisms and controlled by such activity. Lund of Texas and Barth of Columbia University in New York postulate a physiological role for DC current in growth and development. Leao demonstrates depression of activity in brain is always accompanied by a specific DC potential. Gerard and Libet expand the concept, concluding DC potentials direct and control basic brain functions, including excitation, depression, and integration. However, the DC potentials are not Bernstein potentials nor single, short duration impulses produced by breakdowns in transmembrane potential in nerve and muscle. Science rejects and ignores the work, claiming it to be artificial and by-product of underlying chemical activities, which retains no importance. Research into the junction between the nerve and its end organ or muscle and the synapse (gap) to demonstrate whether the action potential became an electrical current to cross the gap pursues. ** AD 1936: Sir Henry Hallett Dale and Otto Loewi receive Nobel Prize in Physiology for discoveries relating to chemical transmission of nerve impulses. * AD 1940-1950: Andrew Llyod Hodgkin, Andrew Fielding Huxley, and Sir John Corew Eccles prove the outlines of the Berstein hypothesis by penetrating the nerve cell membrane with microelectrodes, demonstrating normal transmembrane potential is produced by sodium ions being excluded from the nerve cell interior, permitted only when membrane is stimulated to produce action potential. Bioelectricity is shunned from biology, except when in discussion of heat and shock, as electricity retains no role in living organisms and there is no vital force, despite strengthening supportive evidence. Semi-conductors exist but are of no practical utilization, existing only as solid, also being excluded from biology as biology is believed to be exclusively water-based to allow for chemical reactions. AD 1941: Albert Szent-Györgyi von Nagyrapolt, a Hungarian physician and biochemist who received the 1937 Nobel Prize for Physiology on his work with biological combustion processes, suggests the existence of semi-conduction in living organisms. Atomic structure of biological molecules, proteins as an example, are organized to function as a lattice of crystal, where proteins join together with common energy levels to allow semi-conduction current flow over long distance. He states his belief that biological knowledge is less complete than some believed and persuaded others, stating in his Koranyi lecture in Budapest, "it looks as if some basic fact about life is still missing, without which any real understanding is impossible". (modern concept of electrobiology extends from this) ** AD 1944: Americans Joseph Erlanger and Herbert Spencer Gasser receive Nobel Prize for work regarding differentiated functions of single nerve fibers. ** AD 1963: Hodgkin, Huxley, and Eccles receive the Nobel Prize in physiology for their work with the neural system.
* dates are generalized and are not professed to be wholly accurate: for more information regarding the time period, refer to articles specialized in such history. ** dates acknowledged for appropriate Nobel Prize recipients are not necessarily the dates on which the Prizes were acknowledged, but are the year for which the Prize was being rewarded (when the work was completed).
Anemaw [Animal Electromagnetism and Waves] © Elizabeth Gerrow 2002 . |
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