Двигательная активность студентов

В статье рассмотрены теоретические аспекты двигательной активности студентов, возможности увеличения ее объема. The article considers theoretical aspects of physical activity of students, the possibility of increasing its volume

Complexity of the frog intracardiac neurons. Intracellular injection study

The goal of this study was to determine the structure of intracardiac neurons in the frog Rana temporaria. Fifty-six intracardiac neurons from 8 animals were labelled ionophoretically by the intracellular markers AlexaFluor 586 and Lucifer Yellow CH. Among the labelled neurons, we found the cells of unipolar, bipolar, multipolar and pseudounipolar types. Multiple neuronal processes originated from the soma, the axon hillock and the initial segment of axon. With respect to the soma, the neuron contained (Mean ± SE) 3.5 ± 0.3 long and 5.5 ± 0.6 short processes. Most neurons had the spine, the bubble or the flake like extensions on their soma surface and were classified as Golgi I typeneurons. Few Golgi II type neurons, the presumptive interneurons, were also found. Our findings contradict to a general view that the frog intracardiac ganglia contain only the adendritic neurons of the unipolar type. Our findings demonstrate that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia

Electrophysiological effects of nicotinic and electrical stimulation of intrinsic cardiac ganglia in the absence of extrinsic autonomic nerves in the rabbit heart

BackgroundThe intrinsic cardiac nervous system is a rich network of cardiac nerves that converge to form distinct ganglia and extend across the heart and is capable of influencing cardiac function.ObjectiveThe goals of this study were to provide a complete picture of the neurotransmitter/neuromodulator profile of the rabbit intrinsic cardiac nervous system and to determine the influence of spatially divergent ganglia on cardiac electrophysiology.MethodsNicotinic or electrical stimulation was applied at discrete sites of the intrinsic cardiac nerve plexus in the Langendorff-perfused rabbit heart. Functional effects on sinus rate and atrioventricular conduction were measured. Immunohistochemistry for choline acetyltransferase (ChAT), tyrosine hydroxylase, and/or neuronal nitric oxide synthase (nNOS) was performed using whole mount preparations.ResultsStimulation within all ganglia produced either bradycardia, tachycardia, or a biphasic brady-tachycardia. Electrical stimulation of the right atrial and right neuronal cluster regions produced the largest chronotropic responses. Significant prolongation of atrioventricular conduction was predominant at the pulmonary vein-caudal vein region. Neurons immunoreactive (IR) only for ChAT, tyrosine hydroxylase, or nNOS were consistently located within the limits of the hilum and at the roots of the right cranial and right pulmonary veins. ChAT-IR neurons were most abundant (1946 ± 668 neurons). Neurons IR only for nNOS were distributed within ganglia.ConclusionStimulation of intrinsic ganglia, shown to be of phenotypic complexity but predominantly of cholinergic nature, indicates that clusters of neurons are capable of independent selective effects on cardiac electrophysiology, therefore providing a potential therapeutic target for the prevention and treatment of cardiac disease

Исследование влияния внешних факторов на изоляцию нефтепогружных кабелей

Нефтяная отрасль - это специфический пласт деятельности, требующий особого подхода к изготавливаемому оборудованию. Истощение поверхностных запасов нефти привело к тому, что процесс добычи сырья происходит на большей глубине, чем ранее, что требует использования более прочного оборудования, в том числе и кабеля для нефтяной промышленности. Цель работы: Исследование влияния механических нагрузок и времени старения на пробивное напряжение изоляционных материалов, применяемых в нефтепогружных кабелях.The oil industry is an activity where a special approach to manufactured equipment is required. Depletion of surface oil reserves has led to the fact that the process of extracting raw materials occurs at a greater depth than previously, so it is necessary to use more durable equipment, including cables for the oil industry

Nerves projecting from the intrinsic cardiac ganglia of the pulmonary veins modulate sinoatrial node pacemaker function

Rationale: Autonomic nerves from sinoatrial node (SAN) ganglia are known to regulate SAN function. However, it is unclear whether remote pulmonary vein ganglia (PVG) also modulate SAN pacemaker rhythm. Objective: To investigate whether in the mouse heart PVG modulate SAN function. Methods and Results: In hearts from 45 C57BL and 7 Connexin40+/GFP mice, we used tyrosine-hydroxylase (TH) and choline-acetyltransferase (ChAT) immunofluorescence labeling to characterize adrenergic and cholinergic elements, repectively, within the PVG and SAN. PVG project postganglionic nerves to the SAN. TH and ChAT stained nerves, enter the SAN as an extensive, dense mesh-like neural network. Neurons in PVG are biphenotypic, containing ChAT and TH positive neurons. In Langendorff-perfused hearts, we compared effects of electrical stimulation of PVG, posterior (PRCVG) and anterior right vena cava ganglia (ARCVG) using 200-2000 ms trains of pulses (300μs, 0.2-0.6mA, 200Hz). Sympathetic and/or parasympathetic blockade was achieved using 0.5μM propranolol and 1μM atropine, respectively. Epicardial optical mapping of SAN activation was performed before, during and after ganglion stimulation. PVG stimulation increased the P-P interval by 36±9%; PRCVG stimulation increased the P-P interval by 42±11%. ARCVG stimulation produced no change. Propranolol perfusion increased the PVG stimulation effect to 43±13%. Atropine caused a 5±6% decrease. In optical mapping experiments of whole hearts and isolated atrial preparations, PVG stimulation shifted the origin of SAN discharges to varying locations. Conclusions: PVG contain cholinergic, adrenergic and biphenotipic neurons whose axons project across the right atrium to richly innervate the SAN region and contribute significantly to regulation of SAN function.Zarzoso Muñoz, M.; Rysevaite, K.; Milstein, ML.; Calvo Saiz, CJ.; Kean, AC.; Atienza Fernández, F.; Pauza, DH.... (2013). Nerves projecting from the intrinsic cardiac ganglia of the pulmonary veins modulate sinoatrial node pacemaker function. Cardiovascular Research. 566-575. doi:10.1093/cvr/cvt081S566575Johnson, T. A., Gray, A. L., Lauenstein, J.-M., Newton, S. S., & Massari, V. J. (2004). Parasympathetic control of the heart. I. An interventriculo-septal ganglion is the major source of the vagal intracardiac innervation of the ventricles. Journal of Applied Physiology, 96(6), 2265-2272. doi:10.1152/japplphysiol.00620.2003Rysevaite, K., Saburkina, I., Pauziene, N., Noujaim, S. F., Jalife, J., & Pauza, D. H. (2011). Morphologic pattern of the intrinsic ganglionated nerve plexus in mouse heart. Heart Rhythm, 8(3), 448-454. doi:10.1016/j.hrthm.2010.11.019Yuan, B.-X., Ardell, J. L., Hopkins, D. A., & Armour, J. A. (1993). Differential cardiac responses induced by nicotine sensitive canine atrial and ventricular neurones. Cardiovascular Research, 27(5), 760-769. doi:10.1093/cvr/27.5.760Rysevaite, K., Saburkina, I., Pauziene, N., Vaitkevicius, R., Noujaim, S. F., Jalife, J., & Pauza, D. H. (2011). Immunohistochemical characterization of the intrinsic cardiac neural plexus in whole-mount mouse heart preparations. Heart Rhythm, 8(5), 731-738. doi:10.1016/j.hrthm.2011.01.013Pauza, D. H., Pauziene, N., Pakeltyte, G., & Stropus, R. (2002). Comparative quantitative study of the intrinsic cardiac ganglia and neurons in the rat, guinea pig, dog and human as revealed by histochemical staining for acetylcholinesterase. Annals of Anatomy - Anatomischer Anzeiger, 184(2), 125-136. doi:10.1016/s0940-9602(02)80005-xPauza, D. H., Skripka, V., & Pauziene, N. (2002). Morphology of the Intrinsic Cardiac Nervous System in the Dog: A Whole-Mount Study Employing Histochemical Staining with Acetylcholinesterase. Cells Tissues Organs, 172(4), 297-320. doi:10.1159/000067198Arora, R. C., Waldmann, M., Hopkins, D. A., & Armour, J. A. (2003). Porcine intrinsic cardiac ganglia. The Anatomical Record, 271A(1), 249-258. doi:10.1002/ar.a.10030Gatti, P. J., Johnson, T. A., & John Massari, V. (1996). Can neurons in the nucleus ambiguus selectively regulate cardiac rate and atrio-ventricular conduction? Journal of the Autonomic Nervous System, 57(1-2), 123-127. doi:10.1016/0165-1838(95)00104-2Zhuang, S., Zhang, Y., Mowrey, K. A., Li, J., Tabata, T., Wallick, D. W., … Mazgalev, T. N. (2002). Ventricular Rate Control by Selective Vagal Stimulation Is Superior to Rhythm Regularization by Atrioventricular Nodal Ablation and Pacing During Atrial Fibrillation. Circulation, 106(14), 1853-1858. doi:10.1161/01.cir.0000031802.58532.04CHEN, J., WASMUND, S. L., & HAMDAN, M. H. (2006). Back to the Future: The Role of the Autonomic Nervous System in Atrial Fibrillation. Pacing and Clinical Electrophysiology, 29(4), 413-421. doi:10.1111/j.1540-8159.2006.00362.xArmour, J. A. (2008). Potential clinical relevance of the ‘little brain’ on the mammalian heart. Experimental Physiology, 93(2), 165-176. doi:10.1113/expphysiol.2007.041178LAZZARA, R., SCHERLAG, B. J., ROBINSON, M. J., & SAMET, P. (1973). Selective In Situ Parasympathetic Control of the Canine Sinoatrial and Atrioventricular Nodes. Circulation Research, 32(3), 393-401. doi:10.1161/01.res.32.3.393Gray, A. L., Johnson, T. A., Ardell, J. L., & Massari, V. J. (2004). Parasympathetic control of the heart. II. A novel interganglionic intrinsic cardiac circuit mediates neural control of heart rate. Journal of Applied Physiology, 96(6), 2273-2278. doi:10.1152/japplphysiol.00616.2003Pappone, C., Santinelli, V., Manguso, F., Vicedomini, G., Gugliotta, F., Augello, G., … Alfieri, O. (2004). Pulmonary Vein Denervation Enhances Long-Term Benefit After Circumferential Ablation for Paroxysmal Atrial Fibrillation. Circulation, 109(3), 327-334. doi:10.1161/01.cir.0000112641.16340.c7MIQUEROL, L., MEYSEN, S., MANGONI, M., BOIS, P., VANRIJEN, H., ABRAN, P., … GROS, D. (2004). Architectural and functional asymmetry of the His–Purkinje system of the murine heart. Cardiovascular Research, 63(1), 77-86. doi:10.1016/j.cardiores.2004.03.007Jalife, J., Slenter, V. A., Salata, J. J., & Michaels, D. C. (1983). Dynamic vagal control of pacemaker activity in the mammalian sinoatrial node. Circulation Research, 52(6), 642-656. doi:10.1161/01.res.52.6.642Fedorov, V. V., Hucker, W. J., Dobrzynski, H., Rosenshtraukh, L. V., & Efimov, I. R. (2006). Postganglionic nerve stimulation induces temporal inhibition of excitability in rabbit sinoatrial node. American Journal of Physiology-Heart and Circulatory Physiology, 291(2), H612-H623. doi:10.1152/ajpheart.00022.2006Saburkina, I., & Pauza, D. H. (2006). Location and variability of epicardiac ganglia in human fetuses. Anatomy and Embryology, 211(6), 585-594. doi:10.1007/s00429-006-0110-4Slavíková, J., Kuncová, J., Reischig, J., & Dvořáková, M. (2003). Neurochemical Research, 28(3/4), 593-598. doi:10.1023/a:1022837810357Tan, A. Y., Li, H., Wachsmann-Hogiu, S., Chen, L. S., Chen, P.-S., & Fishbein, M. C. (2006). Autonomic Innervation and Segmental Muscular Disconnections at the Human Pulmonary Vein-Atrial Junction. Journal of the American College of Cardiology, 48(1), 132-143. doi:10.1016/j.jacc.2006.02.054Vaitkevicius, R., Saburkina, I., Rysevaite, K., Vaitkeviciene, I., Pauziene, N., Zaliunas, R., … Pauza, D. H. (2009). Nerve Supply of the Human Pulmonary Veins: An Anatomical Study. Heart Rhythm, 6(2), 221-228. doi:10.1016/j.hrthm.2008.10.027Mabe, A. M., & Hoover, D. B. (2009). Structural and functional cardiac cholinergic deficits in adult neurturin knockout mice. Cardiovascular Research, 82(1), 93-99. doi:10.1093/cvr/cvp029Beau, S. L., Hand, D. E., Schuessler, R. B., Bromberg, B. I., Kwon, B., Boineau, J. P., & Saffitz, J. E. (1995). Relative Densities of Muscarinic Cholinergic and β-Adrenergic Receptors in the Canine Sinoatrial Node and Their Relation to Sites of Pacemaker Activity. Circulation Research, 77(5), 957-963. doi:10.1161/01.res.77.5.957Mangoni, M. E., & Nargeot, J. (2008). Genesis and Regulation of the Heart Automaticity. Physiological Reviews, 88(3), 919-982. doi:10.1152/physrev.00018.2007Brack, K. E., Coote, J. H., & Ng, G. A. (2003). Interaction between direct sympathetic and vagus nerve stimulation on heart rate in the isolated rabbit heart. Experimental Physiology, 89(1), 128-139. doi:10.1113/expphysiol.2003.002654Levy, M. N., & Zieske, H. (1969). Autonomic control of cardiac pacemaker activity and atrioventricular transmission. Journal of Applied Physiology, 27(4), 465-470. doi:10.1152/jappl.1969.27.4.465Hartzell, H. C. (1988). Regulation of cardiac ion channels by catecholamines, acetylcholine and second messenger systems. Progress in Biophysics and Molecular Biology, 52(3), 165-247. doi:10.1016/0079-6107(88)90014-4LEVY, M. N., YANG, T., & WALLICK, D. W. (1993). Assessment of Beat-by-Beat Control of Heart Rate by the Autonomic Nervous System: Molecular Biology Techniques Are Necessary, But Not Sufficient. Journal of Cardiovascular Electrophysiology, 4(2), 183-193. doi:10.1111/j.1540-8167.1993.tb01222.xLevy, M. N. (1971). Brief Reviews. Circulation Research, 29(5), 437-445. doi:10.1161/01.res.29.5.437Ng, G. A., Brack, K. E., & Coote, J. H. (2001). Effects of Direct Sympathetic and Vagus Nerve Stimulation on the Physiology of the Whole Heart - A Novel Model of Isolated Langendorff Perfused Rabbit Heart with Intact Dual Autonomic Innervation. Experimental Physiology, 86(3), 319-329. doi:10.1113/eph8602146Goldberg, J. (1975). Intra-SA-nodal pacemaker shifts induced by autonomic nerve stimulation in the dog. American Journal of Physiology-Legacy Content, 229(4), 1116-1123. doi:10.1152/ajplegacy.1975.229.4.1116Shibata, N., Inada, S., Mitsui, K., Honjo, H., Yamamoto, M., Niwa, R., … Kodama, I. (2001). Pacemaker Shift in the Rabbit Sinoatrial Node in Response to Vagal Nerve Stimulation. Experimental Physiology, 86(2), 177-184. doi:10.1113/eph8602100Glukhov, A. V., Fedorov, V. V., Anderson, M. E., Mohler, P. J., & Efimov, I. R. (2010). Functional anatomy of the murine sinus node: high-resolution optical mapping of ankyrin-B heterozygous mice. American Journal of Physiology-Heart and Circulatory Physiology, 299(2), H482-H491. doi:10.1152/ajpheart.00756.2009Michaels, D. C., Matyas, E. P., & Jalife, J. (1987). Mechanisms of sinoatrial pacemaker synchronization: a new hypothesis. Circulation Research, 61(5), 704-714. doi:10.1161/01.res.61.5.704Boyett, M. (2000). The sinoatrial node, a heterogeneous pacemaker structure. Cardiovascular Research, 47(4), 658-687. doi:10.1016/s0008-6363(00)00135-8Lemery, R., Birnie, D., Tang, A. S. L., Green, M., & Gollob, M. (2006). Feasibility study of endocardial mapping of ganglionated plexuses during catheter ablation of atrial fibrillation. Heart Rhythm, 3(4), 387-396. doi:10.1016/j.hrthm.2006.01.009Pokushalov, E., Romanov, A., Shugayev, P., Artyomenko, S., Shirokova, N., Turov, A., & Katritsis, D. G. (2009). Selective ganglionated plexi ablation for paroxysmal atrial fibrillation. Heart Rhythm, 6(9), 1257-1264. doi:10.1016/j.hrthm.2009.05.018Scherlag, B. J., Nakagawa, H., Jackman, W. M., Yamanashi, W. S., Patterson, E., Po, S., & Lazzara, R. (2005). Electrical Stimulation to Identify Neural Elements on the Heart: Their Role in Atrial Fibrillation. Journal of Interventional Cardiac Electrophysiology, 13(S1), 37-42. doi:10.1007/s10840-005-2492-2Puodziukynas, A., Kazakevicius, T., Vaitkevicius, R., Rysevaite, K., Jokubauskas, M., Saburkina, I., … Pauza, D. H. (2012). Radiofrequency catheter ablation of pulmonary vein roots results in axonal degeneration of distal epicardial nerves. Autonomic Neuroscience, 167(1-2), 61-65. doi:10.1016/j.autneu.2012.01.001Bauer, A., Deisenhofer, I., Schneider, R., Zrenner, B., Barthel, P., Karch, M., … Schmidt, G. (2006). Effects of circumferential or segmental pulmonary vein ablation for paroxysmal atrial fibrillation on cardiac autonomic function. Heart Rhythm, 3(12), 1428-1435. doi:10.1016/j.hrthm.2006.08.025Armour, J. A. (2010). Functional anatomy of intrathoracic neurons innervating the atria and ventricles. Heart Rhythm, 7(7), 994-996. doi:10.1016/j.hrthm.2010.02.01

Morphology of human intracardiac nerves: an electron microscope study

Since many human heart diseases involve both the intrinsic cardiac neurons and nerves, their detailed normal ultrastructure was examined in material from autopsy cases without cardiac complications obtained no more than 8 h after death. Many intracardiac nerves were covered by epineurium, the thickness of which was related to nerve diameter. The perineurial sheath varied from nerve to nerve and, depending on nerve diameter, contained up to 12 layers of perineurial cells. The sheaths of the intracardiac nerves therefore become progressively attenuated during their course in the heart. The intraneural capillaries of the human heart differ from those in animals in possessing an increased number of endothelial cells. A proportion of the intraneural capillaries were fenestrated. The number of unmyelinated axons within unmyelinated nerve fibres was related to nerve diameter, thin cardiac nerves possessing fewer axons. The most distinctive feature was the presence of stacks of laminated Schwann cell processes unassociated with axons that were more frequent in older subjects. Most unmyelinated and myelinated nerve fibres showed normal ultrastructure, although a number of profiles displayed a variety of different axoplasmic contents. Collectively, the data provide baseline information on the normal structure of intracardiac nerves in healthy humans which may be useful for assessing the degree of nerve damage both in autonomic and sensory neuropathies in the human heart

Anatomy and Physiology of Intrinsic Cardiac Autonomic Nervous System: Da Vinci Anatomy Card #2.

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