Individual resistance of the organism and nerve cell to hypoxia

The correlation between the pattern of a neuron's reaction to acute hypoxia and individual resistance to oxygen deficit is studied on ratsin vivo as well as on surviving slices of their cerebellumin vitro. According to the survival time in a pressure chamber simulating an altitude of 11 km all the rats were divided into groups of high resistance, medium resistance, and low resistance to hypoxia. Survival time was 4.2 times longer in the high resistance group than in the low resistance group. In the cerebellar slices of high resistance animals 61.5% high-resistance neurons and 38.5% low-resistance neurons were recorded. On the other hand, in the high resistance animals the percentage of high-resistance neurons and low-resistance neurons was 31.2 and 68.8, respectively. The period of hypoxia development was 4.32 times longer in the high-resistance neurons as compared to low-resistance neurons. It is speculated that individual differences in the resistance to O₂ deficit are of a hereditary nature and manifest themselves not only on the level of the whole organism, but also in the individual nerve cell. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 11, pp. 454–457, November, 1994     

Effect of interferon on the structural organization of rat thymus

Changes in the thymus of male Wistar rats were studied under a light microscope at various times after intranasal administration of α-interferon. The relative mass of the organ, the cortex volume, the total number of cells, the number of small and medium lymphocytes, and the number of mitoses decrease 14 days after interferon administration. At the same time, the number of macrophages, neutrophils, mature plasmacytes, eosinophils, and erythrocytes increases, and mast cells appear. Thus, α-interferon probably suppresses the formation of T cells, facilitates allergization of the organism, and increases the permeability of the vascular endothelium. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 609–612, December, 1994     

Disorders in the structural and metabolic organization of liver acini in systemic endotoxemia

Injection ofEscherichia coli lipopolysaccharide to dogs caused pronounced structural and metabolic changes of liver acini, characterized by the development of compensatory reactions to the endotoxin followed by their failure. In addition to hypoxia, depressed activity of hepatocyte dehydrogenases and diaphorases with impairment of the intraacinar gradient of their activity, leading to the development of hepatocellular insufficiency, appears to underlie the involvement of the liver in systemic endotoxemia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12, pp. 643–646, December, 1995 Presented by V. V. Kupriyanov, Member of the Russian Academy of Medical Sciences     

The target cell plasma membrane and steroid hormones: the beginning or end of the debate?

Drawing on experience gained in previous studies, the authors propose their own approach to defining the role the plasma membrane of the target cell plays in the mechanism of action of steroid hormones. The properties of membrane receptors for glucocorticoids on lymphoid cells are identified and examined, and possible ways in which the hormonal signal is transformed into a biological response of the target cell are described. The results provide a theoretical basis for the development of novel diagnostic techniques and pharmaceutical preparations. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 10, pp. 342–348, October, 1995     

Effect of monochromatic red and near-infrared light on the adhesive properties of the cell membrane: Dependence on wavelength

Changes in the adhesive properties of the cell membrane after irradiation of HeLa cells with monochromatic visible and near-infrared radiation (λ=580–860 nm, i=1.3 W/m², t=40 sec, D=52 J/m²) are assessed as the number of adherent cells. Three spectral regions (600–625 nm, 645–700 nm, and 720–860 nm) with the maximums near wave-lengths 620, 680, 750, and 825 nm are identified, where the adhesive properties of the cell membrane are observed to be enhanced. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 670–672, June, 1994 Presented by V. P. Solov'ev, Member of the Russian Academy of Medical Sciences     

Selection of intact fine nerve strands using power spectrum of their electrical noise

Experiments on narcotized cats demonstrated a decrease in noise factor determined as the ratio of power spectrum maximum of electrical noise in a fine nerve strand to the corresponding value of the equivalent resistor in neurofilaments isolated from the sciatic nerve with blocked conduction in comparison with intact control. Noise factor can be used as a criterion for selection of intact fine nerve strands. Translated fromByulleten ‘Eksperimental’ noi Biologii i Meditsiny, Vol. 130, No. 8, pp. 151–154, August, 2000     

Separation of peripheral polypeptides from soybean lipid extracts and their effects on structural organization of phospholipids

Fluorescence assay of soybean lipid extract showed the presence of polypeptides with tryptophan residues in hydrophobic and polar microenvironment. The peripheral polypeptide with polar tryptophan can be separated from phospholipids in solution with high ionic strength.³¹P nuclear magnetic resonance spectroscopy demonstrated that this polypeptide stabilized the phospholipid bilayer. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 2, pp. 159–162, February, 2000     

Subsynaptic units as a universal system-forming and regulating factor of brain synapses

Dense projections and postsynaptic density — specialized structures of the synaptic cytoskeleton — are regarded as a single functional system of subsynaptic units. From this viewpoint, interneuronal relations in health and after brain ischemia are analyzed. It is shown that hyperplasia and recombination of the system of subsynaptic units are the major mechanisms responsible for reorganization of functionally mature interneuronal junctions in the mammalian and human brain. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 7, pp. 4–12, July, 1997     

Effect of maternal aseptic inflammation on the structural organization of extraembryonal organs and on the proliferative activity of embryonic liver and lung cells in rats

After 2 days of aseptic inflammation in pregnant rats the number of hematopoietic lineage cells in the embryonic liver decreased, while proliferative activity of cells in the embryonic lung increased. Degenerative changes were noted in the placenta. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 584–587, May, 1997     

Plasticity and stability of synapse architectonics of the cerebral cortex

Changes in the interneuronal contacts and recombinant changes in the synapse architectonics play an important role in its plasticity. Along with the reorganization of the synapse architectonics, these changes are attended by an increase or decrease in the number of interneuronal contacts. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny Vol., 121, N ^o 3, pp. 321–323, March, 1996 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Effect of trifluoperazine on transmission of excitation in the rabbit brain during its prolonged administration

Cortical unit responses to electrical stimulation of neighboring areas were studied in experiments on waking rabbits treated with trifluoperazine in a dose of 1 mg/kg daily for 2 weeks. Measurement of dispersion of poststimulus histograms showed a decrease in the magnitude and duration of cortical unit responses after stimulation under the influence of trifluoperazine. The effect of trifluoperazine is examined from the point of view of impairment of impulse conduction in neuron nets.Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 8, pp. 63–66, August, 1975.     

Effect of lamotrigin on the development of neurogenic pain syndrome in rats

Analgesic activity of a new anticonvulsive agent lamotrigin was studied on the model of neurogenic pain syndrome produced in rats by penicillin applied to the dorsal surface of the spinal cord and by dissection of the sciatic nerve. Lamotrigin was shown to have a profound analgesic activity. It can be used as an efficient prophylactic agent for prevention of chronic pain syndromes by suppression of the generators of pathologically enhanced excitation in the nociceptive structures which are the pathophysiological basis of the chronic pain syndromes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 5, pp. 517–521, January, 1998.     

Study of frequency potentiation mechanisms of cAMP-dependent responses of snail neurons

Translated fromByulleten' Experimental'noi Biologii i Meditsiny, Vol. 115, No. 1, pp. 13–15, January, 1993     

Effect of ultralow doses of thyroliberin on microviscosity of lipid components of biological membranes

Effects of the regulatory peptide thyroliberin on microviscosity of lipid components of endoplasmic reticulum biological membranes in mouse hepatocytes were studied by electron paramagnetic resonance. Thyroliberin in a concentration of 10⁻³–10⁻¹⁸ M decreased microviscosity of surface layers of membrane lipids. This decrease was the most pronounced (30%) under effects of 10⁻¹⁰ and 10⁻¹⁶ M thyroliberin. Physiological effects of thyroliberin corresponded to its influence on the membrane structure. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 38–40, January, 2000     

Effect of stress on the reticular zone of the adrenal cortex

The reticular zone (RZ) of the adrenal cortex is shown to be involved in the formation of the organism's response to stress. A new scheme of physiological regulation of RZ is presented. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 7, pp. 8–10, July, 1994 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Structural organization of the bone mineral

Structural organization of the bone mineral phase formed by intra- and interfibrillar lamellar crystals is studied by scanning electron microscopy and cryofractography. Rod-shaped crystals are found only in collagen fibrils of the bone lacuna walls. Intra- and interfibrillar crystals form numerous contacts, ensuring the integrity of the bone mineral phase. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 12, pp. 687–691, December, 1996     

Bradykinin effect on conduction of rhythmic series of pulses through the neuromuscular synapse

Bradykinin did not change the amplitude and duration of growth and decrease of individual currents of the terminal plate, but potentiated the depression of amplitudes of consecutive currents during stimulation of the motor nerve at a frequency of 10–60 Hz under conditions of two-electrode fixation of potential on a frog neuromuscular preparation. The origin of this effect is presynaptic, because it does not depend on the activity of acetylcholinesterase and is associated with a longer increase in the terminal plate currents which are synchronous with the amplitude depression. The deconvolution method revealed a slower kinetics of the mediator secretion under the effect of bradykinin. Bradykinin impairs the conduction of rhythmic pulse series through the synapse by augmenting the asynchronism of the transmitter quantum secretion from the motor nerve endings, which may underlie the development of muscular asthenia observed in inflammatory and allergic reactions. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 9, pp. 256–258, September, 1998     

Characteristics of the septohippocampal cholinergic GABA-ergic neurons using retrograde marker and immunochemical tests

It is shown that a large number of immunopositive neurons possess hippocampal projections; there are many immunonegative cells on sections as well. The correlation between choline acetyltransferase-and parvalbumin-positive neurons and retrograde and double-labeled neurons is demonstrated to be much the same, thus favoring the method used. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 143–145, February, 1994 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Effect of a short-term elaboration of a local food-rewarded instrumental response on the protein content in neurons of the hippocampus

The protein content in neurons of areas CA1 and CA3 of the rat dorsal hippocampus is compared by cytointerferometry. The involvement of CA3 neurons is observed both during instrumental response conditioning and at delayed times after training, whereas neurons of the CA1 area are involved only at the earliest stages of conditioned response shaping: at the stage of formation of new motor coordination. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 6–8, January, 1994 Presented by V. S. Rusinov. Member of the Russian Academy of Medical Sciences