ELECTROPHYSIOLOGY

From Big Medical Encyclopedia

ELECTROPHYSIOLOGY — one of sections of physiology studying the electric phenomena in living tissues and also action on them electric current. Electrophysiologic methods of a research widely apply at diagnosis of various diseases, assessment of a functional condition of bodies, fabrics and cells (see Elektrogastrografiya, Elektrokardiografiya, the Electromyography, Elektroentsefalografiya, etc.), during the studying of the nature of the bioelectric phenomena (see Bioelectric potential, the Bioelectric phenomena) and their bonds with function and various processes of life activity (see. Electropro-water content of biological systems, Elktrotonichesky phenomena).

Existence of «animal» electricity was for the first time proved to L. Galvani in 1791. In 1837 Matteuchchi (S. of Matteucci) found demarcation currents in an alterirovanny muscle. E. Du Bois-Reymond (1848) made an attempt of theoretical justification of the bioelectric phenomena, having offered a so-called electromolecular hypothesis of emergence of the currents of rest and action currents found by it in a muscle due to existence polarly of the loaded molecules-di-water changing the orientation at excitement. The membrane theory of emergence of bioelectric potential of Bernstein (J. Bernstein, 1902) explaining emergence of biopotentials with selective permeability of biological membranes for ions became development of views of E. Du Bois-Reymond. The first comprehensive theory of the bioelectric phenomena and action on living tissue of a current was created by domestic scientific V. Yu. Chagovts believing that rest potentials and actions are diffusion, arising owing to various diffusion rates of the ions which are formed at metabolic reactions. Big contribution to development E. N. E. Vvedensky, A. F. Samoylov and other domestic scientists brought.

The end 19 — the beginning of 20 centuries were characterized by improvement used in E. devices. Considerable progresses were made in connection with achievements of the technology of strengthening of weak electric signals, in particular using electron tubes. The problem of undistorted reproduction of bioelectric signals was solved with use of electron beam oscillographs in electrophysiologic researches. In the same time electrophysiologic methods began to be applied in a wedge. practice, to what creation by V. Eyntkhoven (1903) string galvanometers and registration with his help of typical electrocardiograms, and also detection (1913) characteristic rhythms of the electroencephalogram by V. V. Pravdich-Neminsky at animals and Berger (N. of Berger, 1929) — at the person formed a basis.

A new stage in development E. studying of bioelectric activity of separate cells was. Laurent de No (R. Lorente de No, 1935) the first applied metal microelectrodes to extracellular recording of bioelectric activity of neurons (see. Microelectrode method of a research). In 1939 A. Hodzhkin and E. Huxley measured the membrane potential of a huge axon of a squid. Gerrard (R. W. Gerard, 1946) and sotr. developed the microglass electrodes which allowed to carry out direct measurement of potentials in bodies of nervous and other cells. Detection of depolarization in a myoneural synapse revealed a possibility of use of microelectrode technics for studying of synoptic processes (see the Synapse). The big role in their analysis was played by a method of a microionophoresis (see). Achievements experimental E. led to creation of the modern ionic theory of excitement (see).

For the present stage of development E. escalating use of electrophysiologic methods in clinical and experimental practice, and also their use in a complex with biochemical, immunochemical and biophysical methods is characteristic. For the analysis of results of a research in E. the electronic computer facilities are applied (see. Electronic computer). Methods E. are effectively used at diagnosis and treatment of heart troubles, nervous and muscular systems, and also in air and sports medicine. Big distribution was gained by telemetric registration of electrophysiologic indicators in the conditions of free movement of the person and animals, use of bioelectric potential as the signals managing various technical devices, active prostheses, manipulators (see Prosthetics bioelectric, Telemetry). By means of electrophysiologic methods a number of important problems of fundamental and applied character, in particular studying of the principles of the neural organization of a brain (see the Cerebral cortex), the mechanisms which are the cornerstone of processes of reception, coding, information processing in a nervous system (see), a research of molecular mechanisms of specialized activity of nervous and other cells, roles of various biologically active agents In regulation of electric and chemical excitability of cells and fabrics, in modulation of synoptic transfer is solved.

Big contribution to development E. the Soviet scientists P. K. Anokhin, I. S. Beritashvili, N. P. Bekhtereva, D. S. Vorontsov, M. N. Livanov, A. B. Kogan, P. G. Kostiuk, etc. brought.

Electrophysiologic researches in our country are widely conducted in many scientific and to lay down. - the prof. institutions. Among them it is possible to note scientific research institute of normal physiology of P. K. Anokhina USSR Academy of Medical Sciences, All-Union cardiological scientific center of the USSR Academy of Medical Sciences, All-Union center mental zdo rovya USSR Academy of Medical Sciences, Institute of physiology of I. P. Pavlov Academy of Sciences of the USSR, Institute of experimental medicine of the USSR Academy of Medical Sciences, Institute of higher nervous activity and neurophysiology Academy of Sciences of the USSR, Institute of biological physics of Academy of Sciences of the USSR, Institute of physiology to them. A. A. Bogomoltsa of AN of USSR, Lomonosov Moscow State University, etc.

See also Biophysics, Physiology.

Bibliography: Bekhtereva N. P. Healthy and sore brain of the person, D., 1980; Kogan A. B. Electrophysiology, M., 1969; General physiology of a nervous system, under the editorship of P. G. Kostiuk, L., 1979; Pervis R. D. Microelectronic methods of intracellular recording and an ionophoresis, the lane with English, M., 1983; Handbook of physiology, A critical, comprehensive presentation of physiological knowledge and concepts, ed. by J. R. Pappenheimer, sect. 1 — 2, Betbesda, 1977 — 1979.

A. I. Gromov, V. V. Sherstnev.

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