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Biomedical subjects

O S Sotnikov

Publications and source records attributed to O S Sotnikov.

At least 19 recordsLinked to original sources
PubMed2001

[Neuron non-electrical functions].

Classical histological preparations of the metasympathetic nervous system treated with silver salts were compared with isolated neuron cultures to study non-electrical functions of the neurons. A hypothesis of a tissue trophic effect of the nervous tissue's receptors, is advanced. Proteolytic enzymes were shown to be a growth factor for surrounding tissues and to play a role of trophic agents. A permanent restructurisation seems to occur in formed plexuses of adult healthy animals.

Afferent Pathways↗
PubMed2001

[Structural organization of the acellular region of the sinoauricular nerve plexus in the dog heart at maximal motor activity].

The reactions of the dog sinoatrial node artery under hypo- and hyperkinesia were revealed by the serial semi-thin section morphometric analysis. Single maximal physical load may be a cause of significant changes in the main source of blood supply of the dog heart sinoauricular region. During 4 weeks period hypokinezia leads to decrease of structural and functional reserve of the artery. The following physical load causes acute reduction of the blood volume in the region of the right atrium of the heart. The individual peculiarities of the artery adaptive reactions are determined by the level of the heart functional activity and by the cardiac muscle metabolism, which should be taken into account when using maximal physical loads in clinic and in experimental studies.

Animals↗
PubMed2000

[Innervation of the humerus metaepiphysis in newborn and one year old children].

Analysis of home and foreign literature on metaepiphyseal cartilage innervation and blood supply was presented, data on these organ diseases substantiate theoretical and clinical significance of the study was performed. Using macro-microscopic preparation, histological study, automatic image analyzer branches of humerus proximal metaepiphysis were shown to originate from axillary and subscapulary nerves. Nerves and vessels penetrating in the cartilaginous canals form neurovascular complexes. Cartilaginous canals are located unevenly. Nervous structures were found in the canals and their characteristics was given.

Growth Plate↗
PubMed1999

[Morphogenesis of neuronal systems in tissue culture repeats the evolution of simpler nervous systems].

Comparison of simpler nervous systems of invertebrates and plexiganglionic systems cultivated in tissue culture was conducted for the first time. Their principal resemblance was discovered. By following up the kinetics of neuronal behaviour in culture similarity between mechanisms underlying the evolution of simpler nervous systems and processes of self assembly of neuronal systems was revealed. In both cases isolated nerve cells are replaced by primitive (archaic) nervous plexus that, in turn, becomes a plexiganglionic neuronal system. Final individual architecture of ganglia and mechanisms of formation of nerve ganglia and trunks coincide. Highly specialized unipolar neurons transform into archaic unipolar cells and display signs of chemotaxis. Resemblance of stages and mechanisms of the formation of all elementary nervous systems and neuronal systems in culture is explained by integrity of the neuron properties (adhesion and mobility of neuron bodies, extrusion and retraction of their processes and autotomy of nerve endings). Similar neuron potentialities in evolution and tissue culture underly the abundance of parallelisms between nervous systems in animals of unrelated phyla. In this aspect a possibility appeared to formulate another biogenetic postulate concerning general mechanisms of neurogenesis: morphogenesis of plexiganglionic neuronal systems in tissue culture represents fast and simplified repetition of the evolution of elementary nervous system of invertebrates.

Animals↗
PubMed1998

Kinetics of the structure of neurites in mollusk brain after its dissociation.

Using phase microscopy the behaviour of living neurons directly after their enzymatic isolation from ganglia of Clione limacina and Lymnaea stagnalis was studied. Apart from single-processed unipolar neurons, numerous dipolar and unipolar ones were found in mollusc which does not conform to neuron classification generally adopted. Disrupted neurons were seen to shorten gradually in Ringer solution and -1640 medium at the rate of 0.84-0.27 mm min. Serial photomicrography revealed that the process has two stages. Neurite retraction is interrupted by the expansion stage (extrusion and urgent regeneration). Duration of retraction and extrusion stages made 22.7-3.3 and 6.6-9.1 min respectively. Retraction speed was 24-0.5 mm/min while that of extrusion was 2.8-0.4 mm/min. different processes of the same neuron contract asynchronously. Process invagination leads to its rounding. Thus the cell acquires most thermodynamically stable from which is arranged to prompt its survival. Spherical neurons lacking processes migrate and demonstrate capacity of regeneration. As the conditions somehow resembling the experimental ones (high proteolytic activity of the medium and process loss in part of neurons) arise in cerebral trauma nidus of it is suggested that viable neuron behaviour is alike in this situation.

Animals↗
PubMed1996

[The intramural neural apparatus of the mesenteric lymphangion of the small intestine].

Concentration of nerve structures in the lymphangion wall directly correlates with myocyte number in its different regions. Maximal adrenergic and cholinergic fibres concentration was defined in valvular torus muscular cuff of the lymphangion and minimal--in the valvular sinus wall. Besides, as structural organization of adrenergic plexus does not differ from that of antichollinaestherase-positive one and electron microscopic photos display diverse cholinergic and monoaminergic mediator vesicles in same fibres a suggestion is made on the mixed mediator nature of intramural plexuses of the lymphangion.

Acetylcholinesterase↗
PubMed1992

Brain neurite-stimulating protein promotes formation of mechanosensory endings in sensory neuron.

In the present study we have shown that in the organotypic culture of dorsal root ganglia (DRG) of 10-11 day-old chick embryos, the neurite-stimulating protein (NSP) from bovine brain promotes the development of branching mechanosensory endings. The light and electron microscopic observation revealed that the morphological features of these sensory endings are similar to those in vivo. A mechanical stimulation of these endings elicited bursts of impulses in the sensory neurons.

Animals↗
PubMed1991

[The autotomy process of the microcirculatory bed receptors].

Autotomy of receptors' endings in the intestine's microvascular bed was shown to entail a real breaking off of the end-plates or large fragments of receptors with their subsequent degeneration. The process of autotomy can be reproduced in the tissue culture. The TV-computer analysis revealed the autotomy both in developing structures in early ontogeny and in mature tissue receptors in adult animals. The autotomy seems to be a part of receptors recycling, the latter being associated with retractile activity of preterminals and resembling the separation of cytosomes in apical secretion, thrombo- and erythropoiesis.

Adaptation, Physiological↗
PubMed1991

[The neural apparatus of the small intestine of piglets after administration of a growth stimulator kormogrisein].

By means of classical neurohistological techniques, phase contrast microscopy and morphometry, a comparative investigation has been performed concerning the development of the intramural nervous apparatus in the small intestine, normal and at application of cormogrisine. The structural peculiarities of morphogenesis are considered together with signs of activation and inhibition of the neurons growth in tissue culture. A number of morphological criteria, demonstrating an increased extrusive activity and enhancing potensity of the neurons growth have been revealed. The number of nervous processes becomes greater; degree of their ramification increases; a part of neurons of Dogiel II type turns into multiprocessive neurons with some signs of Dogiel I type cells; growth cones and arcadian structures are present; giant processes appear; thick nervous fasciculi are formed; volume of the neuron bodies increases more intensively. After application of cormogrisine for 2 months a definite neurostimulatory effect is revealed; it demonstrates a more intensive morphogenesis of the small intestine nervous of Physiology, USSR, Academy of Medical Sciences, Leningrad.

Animal Feed↗
PubMed1990

[Autotomy of sensory nerve endings in the area of microvessels].

The phenomenon of autotomy of peripheral receptor terminals, in the area of the intestinal microvessel bed has been analysed. This phenomenon is accompanied with a real separation of the terminal patches or large fragments of receptors with their successive degeneration. The effect of the terminals autotomy is succeeded in reproducing and analysing in dynamics in tissue culture. The computer analysis of the image demonstrates that autotomy is observed not only in developing structures during early period of ontogenesis, but in well developed, as regards all morphological criteria, tissue receptors of mature animals. The investigations have been performed by means of silver nitrate impregnation after Bielschowsky--Gros, as well as using vital microscopy. An idea has been formed that autotomy is a part of the cyclic process of autotomy--regeneration of the terminals. This process is connected with retractile cytopoiesis, apocrine secretion. A high concentration of proteolytic enzymes in the amputated degrading fragment of the receptor can serve as a trophic factor, activating the local metabolic process in the area of microvessels.

Animals↗
PubMed1990

[Ultrastructural changes in the perimembranous layer of the ganglionic neurons during orthodromic pessimal stimulation].

By means of the transmissive electron microscope certain changes in ultrastructure of the perimembranous layer in the frog ganglionar neurons have been studied. They occur at an orthodromic synaptic stimulation (40 Hz for 10 and 20 min, 100 Hz for 20 min). Formation of a number of heterogenous membranes according to their electron density and thickness of submembranous aggregates is noted: sharply manifested sub-membranous thickenings, resembling postsynaptic thickenings of the synapse, thick membranes, differing from more thin membranes of glyocytes and making an image of asymmetry in the adjoining membranes. In their area a massive formation of coated vesicles, local desmosome-like junctions are noted. A reactive rearrangement of submembranous cisterns and other organelles associated with the membrane is demonstrated. The ultrastructural changes mentioned are evidently important for generation of the action potential under conditions of the pessimal stimulation.

Action Potentials↗