Neuron Theory

NEURON THEORY. A neuron is commonly understood to mean a nerve cell with all its dendrites and neurite (see Nerve cells), including the endings of these processes (motor and sensory nerve endings). The neuron theory refers to the doctrine of the structure of nervous tissue that accepts the neuron as the unit in genetic, morphological, and physiological relations. The doctrine of the microscopic structure of nervous tissue, and in particular the neuron theory, was formulated later than other parts of histology (the 1870s-1890s), because only thanks to the discovery of special methods for staining nervous tissue (see), the apparent obvious real identity of the basic unit of the nervous system with the cell was revealed. By this time, facts had been obtained on the development of the nervous system in the embryo. According to the data of Biddar, Kupffer, Forel, His, Kölliker, Waldeyer, and Lenhossék (Bidder, Kupfer, Forel, W. His, Kölliker, Waldeyer, Lenhossék), the original beginning of the entire nervous system, both central and peripheral, is the embryonic neural tube (see), in which the future nerve cells - neuroblasts - are laid. His showed that the processes of neuroblasts leave the neural tube and ganglionic ridges and grow as anterior and posterior roots as processes of nerve cells. Grouping into bundles, the processes of neuroblasts form what is called a nerve, and continuing to grow, they reach various organs (muscles, glands, skin), where they form nerve endings. Of particular importance for the doctrine of the structure of nervous tissue and for the neuron theory is the so-called secondary degeneration of the nerve trunk discovered by Waller (see Wallerian degeneration) and the phenomenon of regeneration of nerve fibers (see Nerve fibers, regeneration of nerve fibers). The most essential observation for the neuron theory was that of Cajal, confirmed by a huge number of researchers, that connections between individual neurons are built on the principle of nerve endings, i.e., that a neuron connects with another neuron in the same way as a nerve connects with a muscle, a gland cell, etc. These interneuronal connections are described in the form of various types of 'pericellular baskets', terminal buttons, pericellular apparatuses, etc. All this made it possible for Waldeyer (1891) to formulate the neuron theory as follows: 'the nervous system consists of numerous units - neurons - which are neither anatomically nor genetically connected with each other.' Later this formula was refined by Martin Heidenhain and reduced to the following: 1) a neuron morphologically corresponds to one cell; 2) a neuron is a genetic unit (develops from one neuroblast during development); 3) all nervous substance is contained only in nerve cells and their processes; 4) neurons are anatomically separated from each other; they only come into contact by means of contact; 5) a neuron is a trophic unit (the peripheral segment of a nerve fiber dies without connection with a nerve cell); 6) a neuron is a functional unit. Criticism of the neuron theory. Almost simultaneously with the neuron theory, a number of theories emerged that interpret nervous tissue in terms of its genesis and structure from completely different points of view (Hensen, Balfour, Hoffmann, Bethe, Apathy, Held). The fierce polemic between supporters and critics of the neuron theory, unusually sharp, continues to this day. Three main points, most important for morphology, physiology and pathology and which are controversial, should be noted: 1) development of the nervous system, 2) regeneration and degeneration of nerve fibers, 3) connection between neurons (interneuronal connections).-The theory of Apathy and Bethe, or the neurofibrillar theory. The constructions of Apathy and Bethe are based on a very large amount of material obtained mainly from invertebrate animals. The authors paid special attention to the neurofibrillar apparatus (see Nerve cells), hence the name of the theory. Apathy and Bethe drew attention to the fact that neurofibrils, detectable in the ventral nerve chain and ganglia of invertebrates, do not coincide with individual cellular territories, and therefore with the concept of a neuron. The entire nervous system is built here in such a way that neurofibrils form a continuous network, laid both in the bodies of nerve cells and outside them. This infinite network with its peripheral parts is laid in the tissues in the form of sensory and motor endings, while in the central nervous system it represents a special neurofibrillar meshwork 'neuropil', from which individual neurofibrils enter nerve cells and leave them. Nerve cells therefore cannot be interpreted as nervous units, but play the role of certain condensations of neuroplasm, the role of trophic centers, located along the course of neurofibrils. This thereby reduces the role of nerve cells in the processes of conduction, occurrence or change of excitation to nothing. At one time, Bethe's experiment had great success, in which he managed to cut off the nerve cells from the nerve chain in a crab, and within 2 days the reflexes of the corresponding muscles remained undisturbed, carried out, in Bethe's opinion, with the help of the remaining neuropil. Since according to the neurofibrillar theory nerve cells represent only territories included along the course of neurofibrils, the fundamental difference between nerve cells and cells of the sheaths of nerve fibers disappears, since neurofibrils also pass in the protoplasm of sheath cells. Hence it inevitably follows the histogenetic concept of the neurofibrillar theory, according to which a nerve arises as a result of the differentiation of neurofibrils both in nerve cells and in the cells of the nerve sheath (Schwann cells). The sheath cells therefore receive the name of peripheral neuroblasts (O. Schultze), and the entire system - nerve cell - nerve fiber - terminal organ - develops from chains of peripheral neuroblasts (hence the term: chain theory of the development of nervous tissue - Kettentheorie). In turn, the doctrine of peripheral neuroblasts determined the position of the neurofibrillar theory with respect to the mechanism of regeneration of nerve fibers. The existence of peripheral neuroblasts had to imply the possibility of autonomous regeneration, independent of the growth of the central segment. Bethe indeed tried to prove this experimentally. According to his data, in puppies, regeneration of the peripheral segment of a nerve can be obtained without its connection with the central one. The question of interneuronal connections for the neurofibrillar theory disappears, since according to this theory neurofibrils pass without any breaks from one cell to another, and the entire nervous system represents one continuous syncytium with neurofibrils passing through it (an evaluation of this theory is given below). Nissl's theory is almost entirely speculative. Adhering in general outline to the neurofibrillar theory, Nissl placed special emphasis on the neuropil and, expanding this concept, postulated the existence of a special hypothetical 'gray' substance, which should lie outside nerve cells and have important significance in the physiology of the nervous system. Nissl's theory is currently not recognized or valued. The existence of the hypothetical 'gray substance' was never confirmed by anyone later. Due to the lack of factual material, the entire construction is purely speculative. Held's theory occupies an intermediate position between the neuron theory and the neurofibrillar theory. Held and a number of his followers (Boecke, Paton, Heringa) paid special attention to the questions of histogenesis of nervous tissue. The most difficult to understand in the development of nervous tissue is the question of the connection of neuroblasts with the terminal organ. According to the histogenetic concept of the neuronists, neuroblasts in the process of development, thanks to the active growth of their processes, connect with strictly defined muscles, glands, blood vessels, areas of skin, etc. It remains unclear what causes the correctness of such a connection. In Held's expression, this phenomenon resembles shooting a pistol with closed eyes, and the bullet surely hits the target. In his teaching, Held is based on the observations of Hensen, according to which in the primary body cavity between the individual embryonic leaves there is a large number of cellular elements connected in a continuous syncytium. According to Hensen, the primary connections of the neural tube with primitive organs are given by the system of protoplasmic processes of this syncytium. Held believes that the actively growing processes of neuroblasts use this preformed path and thus reach the final station. The entire path of neurofibrils up to the innervated organ is laid in the protoplasm of this conducting syncytium. Being mesenchymal at the beginning of development, this syncytium is later replaced by ectodermal elements (Schwann cells). Held's teaching that in the innervated organ neurofibrils are immersed in the protoplasm of the cells of this organ was developed mainly by Boeke and his students, who showed the penetration of neurofibrils into the protoplasm of epithelial cells, the sarcoplasm of muscle fibers, into the protoplasm of mesenchymal cells and other elements.

The question of the regeneration of nerve fibers is resolved by Held in the spirit of the Neuron Theory, with the only difference that according to Held, regenerating nerve fibers grow inside the protoplasm of Schwann cells of the peripheral segment. The question of interneuronal connections is resolved by Held in the sense of a continuous transition of neurofibrils from one nerve cell to another. In the very recent past, Held has described in the central nervous system something like a neuropile, but not neurofibrillar, but protoplasmic, within which neurofibrils pass. The theory of the structure of nervous tissue in the light of the latest data. The basic concept of His-Cajal on the development of the nervous system has received a number of confirmations in recent times. Of particular importance was the method of tissue cultures, which made it possible to reproduce outside the body the growth of processes of neuroblasts and the differentiation of nerve fibers (Maximov, Harrison, Levi, and others). A series of experimental works has shown that it is possible to direct nerve trunks from nerve plexuses into organs that are known not to contain nerves, and these trunks grow into the organ and innervate the skin and muscles. Hamburger removed in the frog at the neurula stage the rudiment of the lumbo-sacral plexus on one side. In a number of cases, a limb grew that did not contain a single nerve fiber. But in a number of cases, nerve trunks grew from the plexus of the unoperated side and penetrated into the denervated limb. In some cases, the nerves of the shoulder girdle, under the influence of irritation coming from the denervated hind limb, began to grow along the body toward the tail and grew into this limb. Hamburger also tried to block the path of growing nerves with the help of a mica plate; in these cases, the nerves bypassed the obstacle from both sides. These experiments refute the theory of Hensen-Held about preformed pathways (plasmodesmata). At the same time, before the researchers, the question of the nature of the substances causing growth (neurotropism) arose with all its sharpness. In the doctrine of the regeneration of nerve fibers, the numerous experiments of Cajal and Tello were of particular importance, which showed the inadequacy of the theory of autonomous peripheral regeneration and the doctrine of peripheral neuroblasts. The question of interneuronal connections has recently been subjected to a new review in a number of experimental works. Lavrentiev and his collaborators succeeded, by turning off the preganglionic fibers of the sympathetic nerve (see Vegetative Nervous System), in tracing the picture of the degeneration of the endings of the spinal neuron on the sympathetic nerve cells and the picture of the restoration of these endings (pericellular apparatuses); at the same time, the picture of restoration coincided with the physiological effect. These findings have been confirmed in the very recent past by a pupil of Cajal-de Castro. Baron in Lavrentiev's laboratory carried out heterogeneous innervation of sympathetic nerve cells, connecting the central end of the n. phrenici with the peripheral end of the cervical sympathetic trunk below the superior cervical ganglion. The regenerated fibers of the nervi phrenici formed pericellular baskets on the sympathetic nerve cells. Along with this, the corresponding physiological effect was obtained (dilation of the pupil, contraction of the nictitating membrane). Thus it was shown that the connection of a nerve cell with another nerve cell is carried out on the principle of new growth from the center, as was assumed by Cajal. Despite these latest data, confirming the factual material presented by the neuron theory, the theory itself, in the form in which it was formulated by Waldeyer and Heidenhain, cannot be accepted. The Neuron Theory has played a major role in the history of the development of histology, physiology, and neuropathology as a convenient working hypothesis, but it contains a number of premises that are incompatible with correct views on cells and tissues. The main drawback of the Neuron Theory is that it reflects the cell theory of the time of Schultze and Virchow, i.e., the cell state theory. Neurons in the formulation of the founders of the Neuron Theory are independent individuals, coming into contact with each other "at certain points, but no more. Since the establishment of the cell theory, which is a brilliant example of exclusively analytical thinking, the concepts of tissues have undergone a significant restructuring. Tissue cannot be reduced to the sum of the cellular elements that compose it. Being a new quality in the process of development of the organism, every tissue, and the nervous tissue in particular, cannot be considered and studied in isolation, outside the connection with other tissues and cellular elements. The data of Held and his followers on the intimate connection of the nerve with the innervated organ vividly show this. The nerve fiber penetrating the sarcoplasm of the muscle fiber (see Nerve endings) forms a neuromuscular apparatus, which cannot be qualitatively broken down either morphologically or physiologically into nerve plus muscle. The same applies to any innervated organ. This circumstance has exceptional importance for the correct understanding of the pathology of both the nervous system and the innervated tissues. The development of nervous tissue is closely connected with other tissues, and the developed nerve fiber represents an organic whole, into which the Schwann cells also enter and have great significance. The concept of the supporters of the Neuron Theory about Schwann elements as insulating sheaths, casings, etc., having nothing to do with the axis cylinder, cannot be accepted as obviously mechanistic. The data of Wallerian degeneration, the data of Held and Bouquet show that the Schwann syncytium is closely connected with both the metabolism and the function of the entire nerve fiber. Thus the nerve fiber must be considered as a whole, and not as an axis cylinder plus sheaths. Therefore, if the term "neuron" is to be retained, then the concept of the neuron must include not only the nerve cell with all its processes, but also the organic elements of the Schwann syncytium associated with it. Thus, most of the theses of Waldeyer-Heidenhain cannot be accepted by modern histology without very significant amendments. One of the merits of the Neuron Theory should be considered the detailed analysis of interneuronal connections. The neurofibrillar theory has gone in this question along the path of simplification. Denying the specificity of the structure of interneuronal connections, denying the functional significance of the place of connection of one neuron with another, it was ready to reduce all the complexity of the organization of the nervous system of vertebrates to the infinite neurofibrillar grid discovered in the leech. [In addition, recently published in vivo observations on the nervous system made by Bozler show that here too the questions of the continuity of the course of neurofibrils must be placed under great doubt.] Thus the questions of the significance of nerve centers, the questions of one-sided conduction, the change in the rhythm of excitation with the concept of the nervous system as a greatly expanded syncytium with a continuous course of fibrils became inaccessible to morphological analysis and lost their material substrate. This in turn gave food for a number of idealistic constructions. Ph. Stohr, denying the morphological equivalent for physiological phenomena associated with the transition of excitation from one neuron to another, speaks of the futility of attempts to find a morphological substrate for physiological phenomena, about "special" "independent" paths of morphology, etc. The "collapse" of the Neuron Theory was used in the same sense by vitalists (Pauli). Meanwhile, experimental morphological analysis has very clearly revealed that the connections between neurons are secondary connections of nerve elements with each other, built on the type of nerve endings, arising during development and becoming more complex with the growth of the organism. The specific structures found at these connections undoubtedly have great functional significance. This opens the way for the joint work of the physiologist, morphologist, and neuropathologist on the questions of conduction, excitation, and inhibition in the nervous system.

B. Lavrentiev. NEUROPATHIES, neuropathia (synonyms: neuropathic constitution, constitutional nervousness, endogenous nervousness), a term whose content lacks precision. In the second half of the 19th century, under the influence mainly of French authors (Morel, Charcot, Fere, Magnan and others), the concept of N. united a motley group of hereditary anomalies of nervous activity in the areas of sensory, motor, as well as psychic functions, in the basis of which no grossly destructive processes of nervous tissue were assumed. In this sense, the concept of N. closely approached the concept of neuropsychic degeneration, which until relatively recently played such a large role in the doctrine of the etiology of psychoses, psychoneuroses, criminality, etc. Recently, in connection with the development of the doctrine of psychopathic personalities, psychopathies (Kraepelin, Kurt Schneider, Kan, Yudin), there is a tendency to abandon the concept of N. or, in the extreme case, to limit it to the circle of functional nervous symptoms that, occurring outside direct psychic influences, depend directly on various special inadequacies in the lower parts of the nervous system (sympathetic, parasympathetic). With this understanding, N. represents, on a vegetative 'soil', what psychopathies are in the affective-volent sphere, i.e., in the sphere of human behavior as a member of society (I. H. Schultz, Reichardt). Both terms - psychopathy and neuropathy, - denoting limit concepts abstracted from the entire diversity of actual reality, thus have a conditional and purely orientational value as a terminological accent, falling in one case or another on different sides of a single and integral personality. With such essential reservations, one should proceed to the analysis of pathological phenomena united by the term neuropathy. The main features of N. reduce mainly to hyperesthesias and kinesthesias, hypo- and paresthesias and to various quantitative variants and combinations of these phenomena in the area of vegetative functions. Carriers of neuropathic signs, as a rule, show a number of other features indicating persistent anomalies in the biochemistry of tissues. The latter are expressed, among other things, in physical, chemical (for example food and medicinal) idiosyncrasies that occur in neuropaths completely independently of any moments of higher (cortical) functioning, i.e., representations, fears, etc. As a soil on which neuropathic anomalies arise, a number of primary disorders of metabolism, lesions of the endocrine system, etc., are noted. The diversity of tissues and organs showing phenomena of inadequacy and therefore being places of least resistance and greatest sensitivity creates an extremely motley picture of N. The fact of biochemical changes characteristic of neuropaths led at one time to the creation of a broad concept of 'neuro-arthritic' diathesis (diathese neuro-arthritique) with extremely diverse symptomatology. This included, for example, such phenomena as instability of thermoregulation, tendency to vasomotor diseases of the skin, to inflammations of joints, to formation of concretions, to asthmatic attacks, to migraines and to a whole series of syndromes of a neuropsychic order (irritability, anxiety, fatigue, depression, obsessive thoughts, etc.). Having played a major role in the general system of development of scientific ideas, the concept of neuro-arthritic diathesis as something whole and unified has lost its significance at the present time. It has been replaced by a whole series of other diatheses: psychocolloidoclastic diathesis of Pascal and Davesne (Pascal, Davesne), allergic diathesis of Kemmerer (Kemmerer), neuropathic diathesis of Borchardt (Borchardt), vagotonia and sympathicotonia of Eppinger and Hess, etc. (see also Diatheses, Constitution, Vegetative nervous system, Vegetative neuroses). The symptomatology of neuropathies is extremely polymorphous. We have here spontaneous and reactively arising attacks of tachycardia, sharp fluctuations of blood pressure, irregularities of pulse and distribution of blood, enhanced dermographism, dyspepsias, disorders of gastric and intestinal secretion and peristalsis, etc.; extremely numerous are various anomalies of the urogenital system in the form of inadequacy of innervation of the bladder sphincter with tendency to pollakiuria, hyper- and hyposexuality, disorder of potency¹, ejaculatio praecox, frigidity, perversions, etc.; to the symptoms of motor inadequacy belong increased patellar reflexes, trembling of eyelids, hands, tongue, fibrillary twitching of muscles, tendency to spasms of the pharynx, esophagus, pylorus, intestines, etc.; in the sphere of general sensitivity, increased susceptibility to fluctuations of t°, intolerance to irritations of sense organs and especially to various painful sensations are observed, so that with the tendency of neuropaths to headaches and neuralgias, to muscle and joint pains, this phenomenon (general hyperalgesia) often dominates the picture of the disease, being the subject of numerous subjective complaints, decrease in working capacity, source of hypochondriacal ideas and emotional reactions. When objective and subjective phenomena of pain are closely related to a certain system of organs, often showing obvious inadequacy, it is possible to speak conditionally of neuro-cardio-pathies, neuro-gastro-pathies, neuro-entero-pathies, etc., and of a whole series of other organ neuroses, among which neuropathic disorders in the sexual sphere occupy perhaps a special place as characterological factors in the psychogenesis of personality and a number of its pathological peculiar features. In all cases of such inadequacy of organs (Adler), the latter is the central core of the morbid state, around which various reactive and compensatory formations are layered. According to the scheme of Laignel-Lavastine (Laignel-Lavastine), the structure of each neuropathy (neurosis) consists of several 'zones'. We have here 1) the central core of the disease, i.e., inadequacy or disease of an organ, 2) the visceral zone, 3) the endocrine zone, 4) the nervous zone and 5) the peripheral-psychic zone. Various relationships and degree of involvement of these zones result in one or another variant of N. The scheme of the French scientist clearly illustrates the entire conditionality of the concept of N., artificially separated from the concepts of somato- and psychopathy. As for the specifically psychopathological moment in the symptomatology of neuropathies, here in the picture of the disease there is mainly a distressing experience of inadequacy, insufficiency, anxiety, compensated by means of a whole series of special mechanisms. In the vast majority of cases, carriers of neuropathic syndromes show constitutional peculiarities, most often asthenic or infantile-asthenic build, often dysplastic deviations, with the presence of so-called degenerative signs (asthenic psychopathy of K. Schneider and E. Kan). Often an anatomo-morphological inadequacy of a number of internal organs can be noted: small heart, narrow lumen of aorta and vessels, general enteroptosis (asthenic constitution of Stiller), hypoplasia of the sexual system (psychosexual infantilism of Künfeld) and etc. A special place in this list is occupied by the inadequacy of the endocrine system, which can sometimes be assigned a certain pathogenetic role in the origin of neuropathies. As for temperament and character, neuropaths often give pictures of sharply expressed hysteria with abundance of conversion symptoms, schizoid psychopathy, psychasthenia in the sense of P. Janet, etc. (see also Psychopathies). Etiology. N. in all its numerous varieties has been considered until now mainly as a congenital morbid state. Although the available genetic material is far from sufficient, however, in a whole series of cases one can note the coincidence of symptomatic pictures in ascending generations and lateral branches of families of severe neuropaths. Despite the importance of these moments, great significance is also attached to injuries of the embryo in the intrauterine period (blastophoria), caused by injuries to the mother during pregnancy, alcoholism, syphilis of parents, etc. Similar reasons affecting the child in the first years of his life, along with improper nutrition, infectious diseases, etc., can also give rise to the development of neuropathy. If one adopts the scheme of Laignel-Lavastine and Adler's theory of the influence of organ inadequacy as irritants causing pathological reactions of the organism, then the possibility of acquiring N. in subsequent periods of the individual's existence becomes understandable even in the absence of a specifically congenital predisposition. The so-called moral factors play no small role in early childhood: cruel treatment, humiliating punishments, as well as psychic traumas on a sexual basis.

The last group includes not only the banal 'seduction,' but especially untimely close familiarity with the sexual life of adults, peeping and listening in on parents' coitus, which in many cases, causing dreadful feelings, fear, sexual excitement, insomnia, leaves deep traces not only in the psyche but also in the endocrine-vegetative system of the child. We are indebted to Freud for many observations in this area, who drew attention to childhood sexuality and the evolutionary deviations of the latter in their correlation with neuroses and the formation of character (see Psychoanalysis). The course of N. is highly diverse. Many features of N. can remain hidden for a long time and be discovered only with the intervention of additional pathogenic factors—infections, intoxications, overwork, life conflicts, etc. In the cases mentioned, under the influence of sometimes completely insignificant exogenous factors, a special 'vulnerability' suddenly appears, which the neuropath shows in relation to certain ingredients of the environment. In addition to such heightened reactions, N. is also characterized by spontaneously occurring (autochthonous) symptoms, often showing a peculiar periodicity, which in all areas of pathology serves as a sign of endogenous predisposition. Such spontaneous outbreaks of neuropathic symptoms have different characteristics, thus representing, as it were, diverse equivalents of the basic inadequacy of the personality. A special case of such a 'transformation' of neuropathic symptoms is the so-called childhood somnambulism (sleepwalking), which is most often combined with nocturnal enuresis and appears as a precursor to a whole series of further neuro- and psychopathic equivalents (Epstein). Thus, in subsequent years, for example, hypersexuality, early masturbation, frequent pollutions, etc., are observed. In so-called nodal points of life (pubertal period, pre-senile and senile involution), neuropathy gives various kinds of exacerbations with the addition of special moments characteristic of this phase of development, and numerous combinations with exogenous types of reactions. In women, the course of neuropathy depends greatly on generative processes (menstruation, pregnancy, lactation, menopause). The diagnosis is established first by excluding all chronically harmful exogenous factors of physical-chemical and reactive-psychological nature, as well as excluding chronic diseases of the central nervous system and internal organs (latent syphilis, malaria, tbc, etc.). In the absence of such causes, the diagnosis of N. becomes probable, especially in those cases where the corresponding symptoms (or similar ones) can be traced back to early periods of the patient's life and even more so when the presence of similar constitutional features is found in this family. The prognosis is essentially determined by the fact that we do not have before us a disease in the exact sense of the word, but most often a chronic condition. The most favorable prediction is for neuropathic exacerbations that occur in connection with accidental infections, various exhausting factors, generative processes, situations that give rise to depressing affects (if they are removable), etc. In cases of a pronounced constitutional and hereditary type of N., the prognosis is unfavorable. The treatment of neuropathies represents one of the most difficult tasks. The theoretical plan in each case provides for 1) somatic features of the subject—inadequacy of an organ or system of organs, metabolism, endocrinological data; 2) special features of nervous excitability and intolerance (vulnerability) observed in one or another part of the nervous system; 3) the reaction of the personality to neuropathic disorders; 4) the life situation and the general purposefulness of the patient. Corresponding to all this, the treatment of N. is always combined. The complete implementation of causal-therapeutic tasks is in most cases difficult to accomplish. The possible variants of purely symptomatic treatment are so diverse that they cannot be formulated schematically. Here a combination of physiotherapy and psychotherapeutic measures is necessary. In many cases, a change of profession, place of residence, way of life, etc., is desirable. Significant improvement is achievable where neuropathic reactions are maintained by a pampering environment and excessive care from others. Sometimes an obstacle to therapy is the excessive hypochondriasis of the subject, when the latter is an expression of a more pronounced psychopathic constitution. The prevention of neuropathies should be 1) environmental and 2) genetic. The first consists in a radical improvement of living and working conditions, protection of women during pregnancy, hygiene of childhood and youth, prevention of sexual trauma, rational pedagogical measures. Genetic prevention is mainly aimed at preventing marriages between neuro- and psychopaths.

Y. Kannabikh. Neuropathy in children. Nervous-psychic anomalies in children in their nascent form contain the beginnings of neuroses and mental illnesses, which are more clearly defined only in later life, and in childhood are not yet precisely determinable. Therefore, the concept of N. as applied to children has a broader content, encompassing the most diverse forms of nervous-psychic anomalies observed in the child. The symptomatology of childhood N. is extremely diverse, manifesting itself both in anomalies of somatic and vegetative innervation and in psychic anomalies. In the sphere of somatic and vegetative innervation, the most frequent disorders are general hyperreflexia, increased mechanical excitability of the nerves (Chvostek's symptom), tics, stuttering, enuresis, vasoneurotic anomalies, tendency to vomiting (morning vomiting, periodic acetonemic), umbilical colic, enteritis membranacea, etc. In the psychic sphere, characteristic of N. in children are increased impressionability and susceptibility to events of daily life, rapid change of moods or, conversely, delay in psychic equalization: affectivity, manifesting in violent expressions of anger, joy, in frenzied play, etc.; very common in small children are hypermotoricity, restlessness and fussiness, inability to concentrate attention, morbid touchiness and tears for trivial reasons, extraordinary stubbornness and persistence. Also not uncommon are the opposite qualities, such as: general inhibition, indifference to surrounding life, absence of normal interest in games and reading, emotional dryness, habitual gloom and grumpiness: sometimes insensitivity to punishments. Both this last group of symptoms and the anomalies of primary instincts (see below) and traits of dissociality are signs of more severe neuropathy. By a whole series of characteristic symptoms, the neuropathic constitution is already revealed in infancy. In the first weeks of the child's life, these are frequent twitchings as an increased reaction to various tactile, visual and auditory irritations or to indefinite sensations originating from internal organs. A little later - disturbances of sleep in the form of excessive sensitivity or quantitative insufficiency of it (calm insomnia, as opposed to insomnia with general restlessness from local disorders); spastic phenomena in the digestive tract - habitual restlessness, crying and arching of the body with refusal to suckle every time after the first few swallows, a condition that can disrupt nutrition and normal weight gain for many months (Brustscheu, fear of the breast Schlossmann's); pathological tendency to regurgitation, from abnormally frequent regurgitation to expressed pylorospasm; increased sexual excitability (masturbation in girls and erections in boys); disturbances of the general sensory tone in the form of constant and lasting for months crying and restlessness without adequate causes (often a harbinger of more severe neuropathies).- By the end of the first year, in addition to the above, there is found abnormal affectivity in the form of general irritability, fearfulness and frequent expressions of anger with inextinguishable crying, bringing children to exhaustion; a massive sign of N. in the infant - tendency to convulsions (symptomatic, toxic and spasmophilic), in a child with a normal nervous system either not observed at all or observed only in the most severe intoxications. - In the second year, various 'negativisms' appear, either of a general nature in the form of morbid disobedience and stubbornness or specific: persistent refusal of any unfamiliar food, because of which these children abnormally long exclusively on milk and few other dishes to the detriment of the general nutritional state; refusal to chew hard food (Kaulaut, chewing laziness; 'children for a long time hold the food bolus in the mouth and finally spit it out); refusal to observe cleanliness in the performance of natural needs. A special form of negativism is delayed speech, more correctly - refusal of it with normal mental development, normal hearing and articulation. A frequent phenomenon - attacks of Wutkrampf (convulsion from anger, affective epilepsy) with rolling of the eyes, cyanosis and disturbance of consciousness; these attacks are very similar to laryngospasm (see), but have nothing in common with spasmophilia and occur only when the child's desires are not fulfilled. Familiarity with the above early signs of N. is extremely important from the point of view of correct diagnostic and preventive evaluation of them. We do not have an exact classification of childhood N. at present, but we distinguish two different inclinations. One can single out a group with a more differentiated nervous system, with a higher level of giftedness, with accelerated psychic tempo and expressed emotional hyperesthesia in the presence of harmony and general coordination of intellectual and characterological features (progenerative inclination). The degree of differentiation of the nervous system in these children, however, corresponds to the degree of its vulnerability; therefore, with general increased reactivity and excessively intense experience of what comes from the external world, they show a pathological tendency to breakdowns, either acute or prolonged. Such are acute neurasthenic states, phobias, obsessive neuroses, transient forms of stuttering, hysteroid psychogenies, acute hallucinatory delirium, etc. All these breakdowns arise from definite external causes, such as accidental general illnesses, emotional traumas, overwork, etc.; with appropriate approach these states are usually removable, but under unfavorable conditions can lead to prolonged and deep disturbances of nervous-psychic equilibrium. The vulnerability of the nervous system in these children predisposes them also to such diseases as meningitis, poliomyelitis, chorea, etc. - The opposite of the described one - degenerative inclination. Characteristic for it are anomalies of somatic innervation and distortions and deficiencies in the moral-intellectual sphere, disharmony of various aspects of mental life. Defects of somatic innervation: congenital nystagmus, congenital strabismus, persistent forms of stuttering, persistent enuresis, tic general, so-called rhythmic movements, predisposition to general convulsions, etc. Also common are physical stigmata of degeneration. To the second group of disorders belong the extreme forms of disinhibition, dissocial and antisocial character traits, anomalies of primary instincts (increased sexuality and irresistible masturbation, some forms of anorexias lasting for years and leading to general physical hypotrophy, disinclination to normal life patterns). Examples of psychic disharmony: increased sentimentality, coexisting with acts of cruelty, outstanding giftedness along with unusual emotional dryness or incompatibility, aggressiveness in the company of peers, good memory along with morbid distractibility, etc. Without sharp boundaries, the described inclination passes into states of psychopathies. On the other hand, the mentioned anomalies can be expressed moderately in quality and quantity, and from representatives of this group can develop full-fledged members of society and people of outstanding abilities. Being polar to each other, the progenerative and degenerative inclinations give countless transitional forms; this division, however, facilitates the understanding of the genesis and peculiarities of the mental structure in the various forms of N., while at the same time indicating the character of the necessary therapeutic approach. The course of N. depends above all on environmental influences. The etiology is identical with the etiology of adults. Heredity and blastophthorisms (see above) have primary importance. Along with biological factors, due to the general decreased stability of the nervous-psychic apparatus in the child and due to a number of features that distinguish the psyche of children from the psyche of adults (greater imitativeness, suggestibility and impulsiveness), in the origin of childhood N. external (social) factors lying in the environmental conditions play a particularly important role. In contrast to biological ones, they are more accessible to our influence and in many cases removable. The main ones are: 1. Induction (under the influence of suggestibility and imitativeness, psychic acts and pathological states observed in another person are unconsciously and involuntarily reproduced). The child becomes nervous in a nervous environment and, perceiving the life tempo as well as the affectivity, impulsiveness and unevenness of the persons surrounding him, reproduces - often in an exaggerated form - this abnormal reactivity, which with time becomes deeply embedded in his nature. For this reason, nervousness of parents and educators and lack of self-discipline in themselves - one of the most frequent factors causing N. in the child or aggravating the congenital one. -2. Defects in upbringing. One of the main tasks of the latter - the development in the child of the so-called 'internal inhibitions,' the basis of normal behavior and normal attitude to the surrounding world.

Insufficiency in inhibitions has as a consequence the manifestation of abnormal reactivity, emotionalism, and affects, which often take in children an unbridled, habitual, and pathological character [affective seizures (Wutkrampf), habitual fainting states, states of raptus, convulsions, etc.]. In close connection with the insufficiency of inhibitory processes as a result of incorrect educational approaches is the abnormal social orientation with antisocial actions, to which neurotics show a special predisposition. Favorable to the neuron theory are exaggerated and excessively emphasized care for the physical well-being of the child, predisposing to hypochondriasis and hysteria, as well as excessively compassionate attitude toward him and coddling, which in a debilitating-relaxing manner affects his psyche. Harm is also caused by the opposite, i.e., cruel treatment, as well as any treatment that creates in the child a conviction of his inferiority compared to others and favoring the development in him of the so-called feeling of inferiority (Minderwertigkeitsgefuhl); the latter, as is known, predisposes to various psychoneuroses and to the striving for hypercompensation, often in socially unacceptable forms. 3. Irritating factors and overloading of the nervous system. In infancy and early childhood, the nervous system is overloaded by the abundance of people surrounding the child with amusements and loud games; accelerating the pace of mental development is the constant satisfaction of excessive curiosity of many mentally gifted but psychologically unstable children by nature. In older age, constant presence among adults is harmful; from them the child adopts habits and inclinations not corresponding to his age, and from their casual conversations he perceives various things, which in the child's psyche are refracted in a distorted form. Premature visits to spectacles, unsuitable and excessive reading, as well as excessive enthusiasm for sports activities also overload and irritate the nervous system. As for school, it overloads the nervous system only in cases of irrational workload. The harm, usually apparent only in higher grades, is also caused by placement in a class not corresponding to age; capable and self-respecting adolescents in such cases overcome difficulties, but the normal stability of the nervous system and physical well-being are undermined for a long time. In individual cases, psychological trauma of a sexual nature influences the occurrence of the neuron theory (see above). However, there is no reason to attribute them an exclusive role; the latter is in most cases equivalent to the role of other, more severe psychological traumas and acquires special significance only in cases where there is constitutional hypersexuality or when the affect, like any other, is not overcome. Prevention follows from what has been said about the causes. Extremely important is the dissemination of information on eugenics among the population; of great importance is the timely early recognition of neuropathic deviations in the child, and great benefit can be brought by so-called consultations on educational issues and dispensarization at general outpatient clinics. Therapy of neuroses in children consists first of all in the application of therapeutic-pedagogical influence. With a progenerative tendency with painful impressionability and tendency to breakdowns, protection from more severe psychological trauma is indicated, and along with this, psychological hardening: physical culture, stay in a rural setting, manual labor, elimination of excessive guardianship, introduction to the children's collective and socially-labor interests. Excited children are surrounded by a calm atmosphere; at the same time, by applying a so-called passive education system, they act on the patient in an inducing manner with calm, even, and confident behavior. For the overwhelming majority of neurotics, the importance of inhibition exercises in the sense of developing self-discipline. This approach, especially with dissocial tendencies, should be carried out from early childhood and be based on attention to the rights and obligations of others, i.e., on the correct social orientation. This orientation toward sociocentrism (contrasted with egocentrism) is most successfully achieved by all types of group education, especially with the system of collective self-control, selection of an active core in it with skillful general guidance from the educator. The introduction of a certain rhythm into life in the form of a regulated daily routine, certain types of gymnastics (rhythmic), the so-called dead hour, certain games requiring endurance and self-control, excursions also provide training for inhibitory processes. In all cases, attention is paid to the general physical condition, including endocrinopathic deviations. Climatotherapeutically, a moderately humid, forest-surrounded area is recommended, which is preferred to the sea and steppe. Hydrotherapeutically, hot baths are used in states of excitement, and in torpid forms - cool rubdowns, bathing in the river, air baths. Among medicinal preparations, preparations of phosphorus, iron, arsenic, calcium and organotherapy are used.

m. iogihes.