Ultrastructural bases of the development of the neural apparatus of the heart

By means of electron microscopy developmental dynamics of the human and mammalian innervation has been studied during prenatal period of ontogenesis. Regularities in formation of the intracardiac nervous ganglia and in differentiation of nervous-muscular connections in the myocardium have been stated. Ultrastructural peculiarities of proneuroblasts and the nervous fiber terminals, growing to differentiating cardiomyocytes have been described during the premediator stage of the vegetative nervous system development. Peculiarities of synaptogenesis have been followed, among them those demonstrated as heterochromic formation of pre- and post-synaptic membrane and as uneven accumulation of synaptic vesicles. Development of the nervous-muscular connections have been studied. At the beginning of the mediator stage of the vegetative nervous system development formation of simple contacts between the nervous terminals and cardiomyocytes is intensified, and glial tunics develop rather poorly. Therefore, at the beginning the terminal parts of axons are not surrounded with processes of gliocytes. Simultaneously, formation of small intensively luminescent cells takes place. Development of afferent nervous terminals occurs not only in the myocardium, but in the intracardiac ganglia.     

Reactive changes in adrenergic innervation of the cerebral arteries after activation of the cholinergic mechanisms]

Magistral arteries of the brain and pia mater have been studied in cats 24-72 h after administration of the cholinesterase inhibitor (phosphacol, 600 mcg/kg). Cholinesterase activity in blood has been checked by means of the potentiometric titration method, and acetylcholinesterase (AChE) content in varicosities of the perivascular nervous fibers--cytophotometrically in preparations treated after Karnovsky--Roots histochemical method. Cholinesterase activity of blood homogenates in test animals is 42 +/- 10%, and acetylcholinesterase content in varicosities of the perivascular nervous fibers--23.5 +/- 2.3% in comparison to the norm. Catecholamines in adrenergic nervous elements are revealed treating them with glyoxylic acid. Distribution density (DD) of histochemically active nervous elements is determined, as well as their specific content of the mediator according to luminescent intensity (LI) of varicosities of nervous fibers. The data obtained in intact animals serve as the control. In the experiment DD and LI reach 127 +/- 9% and 154 +/- 15%, respectively, as compared to the control. Signs of the adrenergic nervous apparatus activation in the experiment reflect a compensatory reaction in response to increase of dilatatory cholinergic influences to vessels under conditions of AChE activity.     

Adrenergic innervation of the kidneys in man and various laboratory animals

By means of the neurohistochemical method for slice incubation in 2% solution of glyoxylic acid, innervation of the kidneys of a 57-year-old man after a sudden cardiac death has been investigated, as well as innervation of the kidneys in white rat, rabbit, guinea pig and cat. A rich adrenergic innervation in the organ's blood vessels has been revealed. In particular, adrenergic nervous fibers have been found along the course of afferent glomerular arterioles. Together with innervation of the proximal and distal convoluted tubules, a high density of the terminal adrenergic nervous plexus is revealed along the course of the nephron loops. Adrenergic nervous plexuses of high density are found in the area of the initial part of the urinary excretory pathways and their connection with nervous plexuses of the kidney itself.     

Reorganization of the nervous system during regeneration in Dugesia tigrina]

The normal structure of the nervous system in Dugesia tigrina Girard and the total morphodynamics of the nervous system during regeneration have been studied by means of choline esterase assay. The nervous system reacts to local damages of the planarian body; accumulations of nervous elements form in the wound region. Following the transverse cut of a planarian, the regeneration of the nervous system is not reduced to the completion of lacking parts. In this case (as well as in that of asexual reproduction) the nervous system manifests a considerable morphological lability and undergoes morphological rearrangements accompanied by the appearance of additional, frequently unpaired, nerve trunks. The data obtained are to be taken into account in neurobiological studies on planarians.     

The structure of the nervous system of the pluteus larva of Strongylocentrotus purpuratus

Summary Tissues that have the ultrastructural characteristics of nervous tissues are associated with ciliary and muscular elements of the pluteus larva of Strongylocentrotus purpuratus. The nerve cells are found along the margins of the ciliary bands, which are composed predominantly of spindle-shaped ciliated cells. The nerve cells contribute axonal processes to a tract of axons, which runs at the base of the ciliary band throughout its length. Axonal tracts, in the esophagus, lie beneath the circumesophageal muscles. Branched microvilli, which have been interpreted as sensory receptors, are located on the oral side of the main ciliary band and connect with the nerve cells in the ciliary band. The nervous structures described here, and other tissues of the pluteus that have been previously described as nervous, are compared on the basis of their association with receptor and effector organs, and their ultrastructural characteristics.     

Restoring the balance of the autonomic nervous system as an innovative approach to the treatment of rheumatoid arthritis

The immunomodulatory effect of the autonomic nervous system has raised considerable interest over the last decades. Studying the influence on the immune system and the role in inflammation of the sympathetic as well as the parasympathetic nervous system not only will increase our understanding of the mechanism of disease, but also could lead to the identification of potential new therapeutic targets for chronic immune-mediated inflammatory diseases, such as rheumatoid arthritis (RA). An imbalanced autonomic nervous system, with a reduced parasympathetic and increased sympathetic tone, has been a consistent finding in RA patients. Studies in animal models of arthritis have shown that influencing the sympathetic (via α- and β-adrenergic receptors) and the parasympathetic (via the nicotinic acetylcholine receptor α7nAChR or by electrically stimulating the vagus nerve) nervous system can have a beneficial effect on inflammation markers and arthritis. The immunosuppressive effect of the parasympathetic nervous system appears less ambiguous than the immunomodulatory effect of the sympathetic nervous system, where activation can lead to increased or decreased inflammation depending on timing, doses and kind of adrenergic agent used. In this review we will discuss the current knowledge of the role of both the sympathetic (SNS) and parasympathetic nervous system (PNS) in inflammation with a special focus on the role in RA. In addition, potential antirheumatic strategies that could be developed by targeting these autonomic pathways are discussed.     

Type II neurons in the trunk of the cockroach Periplaneta americana

Staining the nervous system by methylene blue, studies have been made on the topography and structure of type II neurones in the trunk of the cockroach. Small quantity of cells innervating various tissues was found together with 3 varieties of neurones, located near the nervous trunks, as well as 4 pairs of the abdominal stretch receptors (one pair of unicellular and one pair of bicellular receptors in tergites and sternites).     

Free amino acids in the nervous system of the amphioxus Branchiostoma lanceolatum. A comparative study

The cephalochordate amphioxus is the closest invertebrate relative to vertebrates. In this study, using HPLC technique, free L-amino acids (L-AAs) and D-aspartic acid (D-Asp) have been detected in the nervous system of the amphioxus Branchiostoma lanceolatum. Among other amino acids glutamate, aspartate, glycine, alanine and serine are the amino acids found at the greatest concentrations. As it occurs in the nervous system of other animal phyla, glutamate (L-Glu) and aspartate (L-Asp) are present at very high concentrations in the amphioxus nervous system compared to other amino acids, whereas the concentration of taurine and gamma-aminobutyric acid (GABA) is very low. Interestingly, as it is the case in vertebrates, D-aspartic acid is present as an endogenous compound in amphioxus nervous tissues. The physiological function of excitatory amino acids, and D-aspartate in particular, are discussed in terms of evolution of the nervous system under an Evo-fun (Evolution of function) perspective.     

Neural connections of the heart and superior vena cava in the rabbit and man

Innervational connections of the heart and the superior vena cava wall have been studied in the rabbit and the man. Besides, series of their embryos, impregnated with silver salts after Cajal-Favorsky have been investigated. Methods of Bielschowsky-Gros, Gomori and Karnovsky-Roots have also been applied. Adrenergic nervous elements have been revealed by means of incubation the slices in 2% solution of glyoxylic acid. Abundant cholinergic and adrenergic nervous plexuses are revealed on the wall of the superior vena cava, they are tightly connected with corresponding plexuses of the heart. Developmental of these nervous connections is followed, when embryogenesis of the cardiac nervous plexuses and large major vessels is studied in serial sections of embryos and fetuses of the rabbit and the man.     

Bioamines of the sympathetic nervous system of the normal rat thyroid and in merkazolil exposure

According to histochemical data (Falck method in modification), cytofluorimetric analysis, as well as the results of regressive modelling, localization and quantitative interaction of bioamines in the sympathetic nervous plexuses of the rat thyroid gland have been estimated. In the intact state a relatively firm correlation between serotonin and catecholamine concentrations is revealed in all parts investigated in the intraorganic nervous apparatus. Effect of thyrostatic--merkazolil--results in development of certain discrepancy between intensification of bioamines uptake and ability of thyrocytes to their functionally useful utilization. A suggestion is made that dynamic equilibrium of serotonin and catecholamines ratio in the thyroid sympathetic nervous fibers is one of the factors for maintenance of the function-proliferative balance of the gland working elements at the level, adequate to the active situation.     

神经迁移因子在血管系统中的表达与功能

神经迁移因子是近10年来在发育神经生物学中的研究热点,主要由ephrin、neuropilin、Slit和netrin四大家族成员构成,其主要功能是吸引或排斥神经元轴突的迁移,在神经系统中发挥着重要作用。现在,越来越多的实验证据表明：神经迁移因子的作用不仅仅局限在神经系统发育过程中,在血管发生或新生血管形成中同样具有不可替代的功能。     

Navigating their way to the clinic: emerging roles for axon guidance molecules in neurological disorders and injury

The mechanisms underlying formation of the basic network of the nervous system are of fundamental interest in developmental neurobiology. During the wiring of the nervous system, newborn neurons send axons that travel long distances to their targets. These axons are directed by environmental cues, known as guidance cues, to their correct destinations. Through extensive studies in vertebrates and invertebrates many of the guidance cues and their receptors have been identified. Recently, guidance molecules have been suggested to have important roles in pathological conditions of the nervous system. Mutations in guidance receptors have been associated with hereditary neurological disorders, and deregulation of guidance cues might be associated with predisposition to epilepsy. In addition, it was suggested that guidance molecules play roles in the ability of the adult nervous system to recover and repair after injury. Thus, molecules that were first discovered as "developmental cues" are now emerging as important factors in neurological disease and injury in the adult.     

Features of the motor innervation of striated muscle tissue of the esophagus

By means of neurohistological, histochemical and ultramicroscopical techniques it has been revealed that motor innervation of the oesophageal striated muscle tissue in rats and rabbits is performed by amyelinated nervous fibers, that terminate as nervous-muscle synapses. Ultrastructural peculiarities of these synapses are presented as a large amount of synaptic vesicles in the axonal terminal, as a poor ramification of secondary synaptic folds, as a considerable amount of mitochondria in the adjoining sarcoplasm. Reaction to acetylcholinesterase demonstrates that most of the motor nervous terminals belong to the racemose type. They are situated in the oesophageal musculature chaotically and have less area than synapses of the muscle of the locomotor apparatus.     

Vegetative nervous system's contribution to the development of stress induced gastric ulcers]

A vegetative nervous system contribution to the development of stress-induced gastric ulcers has been investigated. The experiments involved male Wistar rats. Vegetative nervous system activity has been assessed with acetylcholine brain and stomach tissue levels and synthesis as well as adrenaline and noradrenaline levels in adrenals and gastric wall. The results have shown, that ulcerogenic effect of stress is accompanied by the increase in both cholinergic and adrenergic activities. Moreover, it has been shown, that markedly strong stimulation of the adrenergic system in some rats, together with pharmacologic activation of alpha-adrenergic receptors, inhibits the development of stress-induced gastric ulcers.     

The interrelations of the lymphatic capillaries with the nerve structures in the wall of the small intestine]

The character of interrelations of nervous structures and the lymphatic capillary walls has been studied in cats. Under the light microscope twisted nervous fiber terminals of the intestinal neuron dendrites have been revealed around the lymphatic capillaries. Electron microscopical investigation has not revealed any specialized contacts of the nervous terminals and the lymphatic capillary walls. The receptors and terminals of axons do not situate nearer than 10 nm from the latter. According to the structure of synaptic vesicles among the axonal terminals next to the lymphatic capillary walls cholinergic, adrenergic and purinergic ones are described. The influence of the nervous system to the function of the small intestine lymphatic capillaries is mediated via the precapillary space. The neuromediators from the axonal terminals get into it owing to absence of neurolemmocytic membranes around them.     

Adrenergic and cholinergic innervation of the prostate in laboratory animals

The prostate innervation has been studied in 50 white rats, 12 rabbits, 12 guinea pigs, 6 cats and 6 dogs. Together with the impregnation techniques, Karnovsky-Roots method has been applied, for revealing cholinergic components, and the incubation method in 2% solution of glyoxylic acid, for revealing adrenergic nervous structures. Density of adrenergic and cholinergic nervous plexuses has been estimated by means of the planimetric point method. The prostate of the laboratory animals possesses well manifested adrenergic and cholinergic nervous plexuses. The organ's alveolus and ducts are covered with adrenergic and cholinergic fibers, however, the relative density of the cholinergic plexuses is less than that of the adrenergic ones. The guinea pig prostate is the most richly supplied with the adrenergic nervous plexuses, and the rabbit prostate--with the cholinergic nervous plexuses.     

Neurobiology of parasitic flatworms: how much "neuro" in the biology?

The nervous systems in the parasitic Platyhelminthes have generally been considered to be degenerate and of marginal significance, but recent studies have shown these systems to be more significant in the biology of these animals than formerly believed. There are many similarities in the construction and apparent neurochemistry of the nervous systems in the parasitic forms as well as in the free-living Turbellaria. In all forms there appears to be a large neurohormonal component. Though the nervous system appears to be important for many aspects of parasitic flatworm biology, little direct or specific information about the physiology of these systems is yet available.     

Organization of the nervous system in Opisthorchis viverrini investigated by histochemical and immunohistochemical study

The structure and organization of the nervous system has been documented for various helminth parasites. However, the neuroanatomy of the carcinogenic liver fluke, Opisthorchis viverrini has not been described. This study therefore investigated the organization of the nervous system of this fluke using cholinesterase activity, aminergic and peptidergic (FMRFamide-like peptides) immunostaining to tag major neural elements. The nervous system, as detected by acetylcholinesterase (AchE) reaction, was similar in newly excysted metacercariae, migrating juveniles and adult parasites. In these stages, there were three pairs (dorsal, ventral and lateral) of bilaterally symmetrical longitudinal nerve cords and two cerebral ganglia. The ventral nerve cords and the cerebral ganglia were well-developed and exhibited strong AchE reactivity, as well as aminergic and FMRFamide-like immunoreactivity. Numerous immunoreactive nerve cell bodies were observed around the inner surface of the ventral sucker. Fine FMRFamide-like peptides immunopositive nerve fiber was rarely observed. Overall, the organization of the nervous system of O. viverrini is similar to other trematodes.     

History of the mainstream scientific research at the Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences

The classical reflex theory of the higher nervous activity has been developed in the works of E.A. Asratyan, the first director of the Institute, and his scientific school. The novel aspects of the theory have been developed: the principle of system organization; the concept of the nervous center as a set of structures located in different areas of the central nervous system; conditioned switchover, the mechanism of conditioned connection closure; the origin and localization of conditioned inhibition; the two-way, forward and backward conditioned connections. The elaboration of physiological mechanisms of the active goal-directed motivated behavior was begun. V.S. Rusinov and his collaborates have developed the concept of the dominanta and role of the stationary excitation foci in the integrative brain activity. M.N. Livanov has created the concept of the spatio-temporal organization of bioelectric potential and systemic organization of brain activity. P.V. Simonov, beginning from 1964, has developed the need-informational theory of the human and animal higher nervous activity (behavior). As distinct from the theories that originate from a single viewpoint and reject all the others, Simonov's theory is integrative and follows the logic of development of brain science.