From Big Medical Encyclopedia

SETSCHENOW'S INHIBITION (I. M. Sechenov, the domestic physiologist, 1829 — 1905) — the physiological phenomenon opened by I. M. Sechenov and proving existence of the braking influences from the central nervous system. Traditionally in scientific, especially educational, literature the term «Setschenow's inhibition» call fiziol. the experiment, with the help to-rogo I. M. Sechenov proved existence in c. N of page of the process called later central braking (see).

For the first time the phenomenon of braking was revealed brothers E. E. F. W. Weber and E. F. W. Weber in 1845, to-rye observed negative other and chronotropic effects or dead stop of heart at irritation of both the most vagus nerve, and its back kernel located in a myelencephalon. In 1857 E. Pflyuger opened the braking effect of sympathetic fibers of a big celiac nerve (a big splanchnic nerve. T.) pas physical activity of intestines. These types of braking received the name of peripheral braking.

I. M. Sechenov, working in Paris in K. Bernard's laboratory, in 1862 found out that at chemical and electric irritation of area of visual hillocks the frog has an oppression of a spinal reflex of Türk (i.e. otdergivany pads of a frog at her immersion in salt brine to - you) that it was expressed in lengthening of time of stage of latency of response. After elimination of action of an irritant reflex activity of a spinal cord was completely recovered.

Existence of the phenomenon of the central braking at hematothermal animals is shown in 1866 by I. M. Sechenov's pupil of JI. N. Simonov.

Historical value of opening of I. M. Sechenov is that he for the first time paid attention to existence in a nervous system along with process excitement (see) another of active process — braking as special fiziol. process, without to-rogo it is impossible to present implementation of c. N of page of integrative function. Opening of the central braking allowed I. M. Sechenov to approach the solution of a number of the most difficult problems of neurophysiology, including regulation of coordinate acts in behavior of organisms, traffic control and interpretation of mental processes on a reflex basis (see. Reflex , Reflex theory ).

The question of the mechanism of the central braking was for the first time raised by I. M. Sechenov. At first he considered that in c. N of page along with the centers having reinforcing action on reflex activity exist also the specialized brake, «detaining» centers, the irritation to-rykh causes oppression of reflex acts of an organism. Nek-ry scientists objected to such interpretation of mechanisms of the central braking. So, I. F. Tsion (1865) suggested that lengthening * time of a reflex in I. M. Sechenov's experiences is connected not with true specific braking, and with lengthening of time of carrying out on a reflex arc. He opposed understanding of the central braking as the process other than excitement. It agrees the theory of an interference offered them, braking arises because excitation waves, coming to a nerve center from two sources, are imposed at each other and fade owing to what the reflex is not implemented. I. M. Sechenov proved insolvency of the theory of I. F. Tsion in 1875 in «A note about the mechanisms detaining reflexes».

Denied existence of the special brake center on average a brain and A. A. Herzen, to-ry, having repeated I. M. Sechenov's experiments, found out that braking of spinal reflexes can be caused irritation of various sites of a spinal cord. H. E. Vvedensky considered that S. of t. it is caused parabiotic with-stoyanivkhm (see. Parabiosis ), a cut it is created in cells of c. N of page in point of the appendix of irritation owing to excessive strengthening and increase of the irritating incentives, to-rye exceed functional lability of the excited fabric. However I. M. Sechenov claimed that in visual hillocks at irritation process of excitement initially develops, to-ry extends on c. the N of page earlier, than in general arises braking of some working effect. «Oppression of reflexes is a product of excitement — I. M. Sechenov wrote — but not overexcitation of any nervous mechanisms... From cuts of visual halls the irritation gives a diastolic stop of blood heart near oppression, i.e. clearly excites a brain».

Continuing pilot study of the mechanism of the central braking, And. M. Sechenov introduced amendments in initial representations and came to conclusion: «Oppression of reflexes at irritation of visual halls corresponds to excited state of the concluded mechanisms in them... These mechanisms, in other words, detain reflexes». Thus, the outer brake effect of reflex activity observed in experience according to I. M. Sechenov, is result of collision in c. the N of page of two vozbuzhdeniye, at Krom occurs the braking action of one excitement on another, and this action can happen at all levels ts.n.s.

The explanations of mechanisms of the central braking new offered, concerning, are received by means of a method of intracellular recording of potentials from the central neurons (see. Microelectrode method of a research ). According to modern representations S.'s emergence t., as well as other types of the central braking, is explained by action of the inhibitory neurons or synapses having the peculiar type of a metabolism allowing them to produce brake mediators (glycine, piperidic to - that), to-rye cause special type of the electric changes called brake postsynaptic potentials on a postsynaptic membrane (see. Synapse ). Thus, opening of brake cells confirms the initial assumption of I. M. Sechenov of existence in c. N of page of the specialized detaining (brake) structures.

See also Higher nervous activity , Nervous system .

Bibliography: Anokhin P. K. Biology and neurophysiology of a conditioned reflex, page 274, M., 1968; B of e r and t about in I. S. General physiology of a muscular and nervous system, t. 2, page 126, M., 1966; Vvedensky H. E. Complete works, t. 5, page 195, L., 1954; Ivan Mikhaylovich Sechenov, under the editorship of P. G. Kostiuk, etc., page 166, M., 1980; Kiselyov P. A. About participation of a cerebrospinal and sympathetic nervous system in the mechanism of Setschenow's inhibition, Uchen. zap. Le-ningr. un-that, It is gray. biol., century 22, page 253, 1950; The General and private physiology of a nervous system, under the editorship of P. G. Kostiuk, L., 1969; About r e l and L. A. Lectures on physiology of a nervous system, page 326, L., 1935; Sechenov I. M. Chosen works, t. 1 — 2, M., 1952 — 1956.

V. A. Makarov.