By Academician Konstantin SUDAKOV, RAMN, director of the P. K. Anokhin Institute of Normal Physiology, Russian Academy of Medical Sciences

Norbert Wiener, the father of cybernetics (1894 - 1964), said in one of his last interviews that the 21st century would not be a century of engineering and spaceships, it would be a century of systems. Which means: objects and phenomena of the world we live in would be approached in a systemic way, as a totality of orderly elements interacting in a hierarchical fashion. Fitting in with this approach is the theory of functional systems devised by the Russian physiologist Pyotr Anokhin (1898 - 1974)-a theory that enables a comprehensive study and evaluation of the ever increasing dataflows in biology and physiology. Furthermore, this theory makes it possible to consider many of the particular, circumstantial details involved. More than that, it may become a groundwork for the systemic theory of the human organism - a theory, now in the mainstream, that will determine in many ways the course of medicine of the 21 st century.

According to Pyotr Anokhin, the main factor orchestrating the functional systems of organisms and, if necessary, restructuring them consists in a useful adaptive result, that is in the satisfaction of needs essential to vital activity. This is manifest at quite different levels of life organization (metabolic, organic, social levels, etc.). Corresponding functional systems are formed at each of these levels. Such systems operate as dynamic self-organizing and self-regulating entities. Their components interact with one another and in concert contribute to various adaptive results.

Pyotr Anokhin outlined these ideas in the early 1930s as, together with his coworkers, he was experimenting with dogs in Gorky (now Nizhni Novgorod) by suturing together nerves responsible for different functions. For instance, the nerve regulating the locomotor activity of a fore-limb was joined to one responsible for respiration. Chimeras were thus produced-that is, monster animals whose paw could breathe, for example. However, in five or six months the vital functions of the incapacitated dogs were restored to normal. The nerve centers had to respecialize, or "learn anew", as one said then.

Studying the data thus obtained, P. Anokhin suggested: achieving a useful result could be decisive for the structuring of the organism's physiological functions. And, twelve years before N. Wiener, he pointed to the crucial role of return afferentation*

* With reference to afferent (efferent) communication when an impulse travels from body organs (glands, muscles, etc.) to the nerve center.- Ed.

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(reafferentation). The great American, who early in the 1960s visited the Normal Physiology Department at I. M. Sechenov's Medical College (First Medical Institute) in Moscow where P. Anokhin was working at the time, acknowledged his priority in using the concept of feedback relative to living organisms.

Since it is the result that evolves as the main factor of functional systems, these must be endowed with the characteristic of self-organization. What does it mean? Say, if the organism does not experience any particular need, it will persist in the "quiescent" state and will be composed of chaotic elements. But once a need arises, motivation will take body and form. It induces certain transformations in the brain, above all, changes in the properties of its neurons. These start interacting with external irritants to which they, the neurons, did not respond before. Say, whilst neurons were insensitive to flashes of light or acoustic effects before, they now begin reacting to such irritants under the effect of motivation.

Yet even more fundamental transformations occur in the brain. The chemical composition of neurons is changed, they acquire an ability to react differently to neuromediators and neuropeptides. A similar pattern applies to the organism's peripheral receptors. For instance, food-deprived animals show a dramatic increase in the sensitivity of oral receptors and, if aggressive, they develop enhanced sensitivity in the receptors of their snout. That is elements of the organism, its brain including, come to be attuned to a state enabling them to satisfy the motivation-conditioned need. Thereupon all these elements form a set which for a while will pursue no definite goal: hunger can arouse an animal, but it does not dictate the sequence of its further actions. Here a good deal depends on the ambient environment and, first of all, on the objective to be achieved. Once it is achieved, the organism develops a functional system aimed at getting the desired result. Brain characteristics develop accordingly. That is why if the same need arises in the future and if it is supported by proper motivation, the system will prod the subject (man or animal) toward goal reaching. This kind of activity stereotype fixed in the brain neurons will persist for the rest of the subject's life, even though it may change now and then (with the change in parameters of the desired result).

Functional systems thus persist in the dynamic state all the time: the state of activity (desire of need satisfaction) will give way to inhibition should motivation be absent. Should it appear again, the system will resume its activity. The dynamics and cyclic pattern of its performance

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A functional system as P. Anokhin saw it.

Functional system's central architectonics.

are described by the principle of systemic quantization of the vital activity of organisms.

Isomorphism is an important principle of the functional systems structure: no matter what the level of such systems could be (from metabolic to social), they have an essentially equal architectonics, and this is orientation to a useful adaptive result and its fixation by means of return afferentation (reafferentation). For example, the selfsame pattern holds both for arterial pressure and for the number of individuals in a population.

Yet simultaneously functional systems are capable of selectively increasing the number of component elements depending on a need to be catered to. This is because one and the same neuron can be implicated in the functioning of various systems. Various body organs "act" likewise. Say, the kidneys can sustain blood pressure, and secure defense and pain reactions alike. To achieve a required result elements of the organism should cooperate in conceited fashion, synergically.

Lately research scientists of our institute have been attacking yet another intriguing property of the functional systems-what we call the holographic principle of their activity organization. The point is that a tiny fragment of a hologram can show the entire holographic picture. In much the same manner, as we have found in the course of our experiments, definite neurons of the brain of an animal experiencing some compulsive urge (hunger, thirst, fear) "fix" it and start working toward its actualization. This is accompanied by motivation which subsides with need satisfaction. We may suggest therefore that functional systems operate by the principle of inhibiting the needs once they have been satisfied and stimulating the motivation when they arise. There is

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a special data evaluation apparatus to assess to what extent a system has achieved the necessary result at a given moment of time.

It is often said: The organism is a system. From the standpoint of P. Anokhin's theory, this is wrong because the integral organism is a totality of multiple functional systems of different levels, from metabolic to psychic and behavioral ones. The number of such systems depends on how many useful adaptive results can be identified.

Now, how do the functional systems interact? First, in keeping with the hierarchical principle. In other words, a dominant need guides the activity of the organism for any particular stretch of time.* The dominant role of such need is determined by a result preferable to the organism at this particular time. The other needs are phased down or else used for the actualization of the dominant need. Only after it has been satisfied can other needs come up, with preference given to one of the utmost significance at the time. This pattern recurs again and again.

Another, second principle of the work of the organism's functional systems consists in their multiparametric interaction. What it means is this: if one functional system changes its parameters, all the other systems will have to be restructured until a new level of interaction is achieved. But if the organism is overstrained and subjected to stress, and is unable to satisfy its bad need (be it for a while), the informational multiparametric interactions of different functional systems come to be upset in the first place. These start working on their own, something that may impair their self- regulation mechanism and, consequently, cause a dysfunction. This condition can be remedied with the aid of all the various nonmedication methods-say, by means of massage, or acupuncture.

And the third principle underlying the operation of functional systems in the organism is in their consecutive interaction. The result of the activity of one of them can "jolt" another one into action. Pyotr Anokhin called that systemic genesis (systemogenesis).

In a nutshell, any living organism incorporates a totality of numerous functional systems interacting in keeping with the above three principles. This joint orchestrated effort takes in not only physicochemical processes-it also involves psychic, behavioral and other factors working toward a useful adaptive result. An all-important role in harmonizing this interaction is played by dataflows.

* The principle of a dominant was discovered by the Russian physiologist Academician Alexei Ukhtomsky (1875 - 1942). -Ed.

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