Fisyunov A.I.,Bogomolets Institute of Physiology of the NAS of Ukraine
Neurophysiology | Year: 2012
Receptors of the 7-TMR group (G protein-coupled receptors, GPCRs) are uniquely important from the fundamental physiological aspect because they mediate the effects of a majority of the known neuromediators and hormones. According to a widely accepted paradigm, activation of heterotrimetric G proteins is the initial step in the process of transduction of signals from these receptors to effectors. In recent times, increasing proof of the existence of G protein-independent mechanisms providing initiation of biochemical signals by these receptors and modulation of the excitability of the neurons has been accumulated. According to these data, 7-TMRs are able to interact with a few cytoplasmic scaffold proteins and take part in various protein-to-protein interactions. Despite the fact that functional importance of many such interactions remains unknown at present, the respective results indicate that the above processes are capable not only of providing G protein-independent transmission of signals from the 7-TMRs, but also of influencing pharmacological characteristics, cellular localization, and compartmentalization of the mentioned receptors. © 2012 Springer Science+Business Media, Inc.
Maznychenko A.V.,Bogomolets Institute of Physiology of the NAS of Ukraine
Neurophysiology | Year: 2014
We detected changes in the gene c-fos expression induced by activation of muscle afferents in the rat spinal cord after systemic introduction of reserpine (irreversible suppressor of vesicular transporter of monoamines, 1.5 mg/kg, intraperitoneally) and with no action of this agent. Numbers of Fosimmunoreactive (Fos-ir) neurons were calculated in the gray matter of the lumbar spinal segments after unilateral vibrational stimulation (VS) of the Achilles tendon of the mm. gastrocnemius–soleus. In the spinal cord of rats preliminarily injected with reserpine, greater numbers of Fos-ir neurons were observed; these units were localized mostly in layers 4–7 and in the nucl. intermediolateralis (35.4 ± 1.6 and 16.7 ± 0.9 positive neurons per 40 μm-thick slice) of segments L1–L2, and also in layers 4–7 and layer 9 (Fos-ir motoneurons) of segments L4–L5 (51.7 ± 3.4 and 11.4 ± 1.5 labeled units, respectively). The numbers of activated cells in the above structures of the spinal cord after VS but without preliminary injections of reserpine were, on average, 25.6 ± 1.4 and 3.5 ± 0.5, 27.8 ± ± 0.9 and 6.9 ± 0.3 units, respectively. Most ipsilateral Fos-ir motoneurons (86%) were localized in the lateral pool of layer 9, and only 14% of labeled motoneurons were localized in its medial regions. The results obtained show that weakening of monoaminergic influences resulting from administration of reserpine is accompanied by increase in the activity of intraspinal neuronal networks activated by proprioceptive afferent volleys, and the effects of the above inputs on spinal motoneurons and sympathetic preganglionic neurons are intensified. Weakening of inhibitory control, realized by inhibitory interneurons in the pathways of transmission of excitatory influences from muscle afferents to motoneurons, which was observed in our experiments after suppression of monoaminergic modulatory systems, can be considered a significant factor responsible for the development of rigidity/spasticity of the limb muscles manifested in neurodegenerative diseases and after traumas of the spinal cord. © 2015, Springer Science+Business Media New York.
Sukhanova K.Y.,Bogomolets Institute of Physiology of the NAS of Ukraine |
Bouryi V.A.,Bogomolets Institute of Physiology of the NAS of Ukraine |
Gordienko D.V.,Bogomolets Institute of Physiology of the NAS of Ukraine |
Gordienko D.V.,Lille University of Science and Technology
Neurophysiology | Year: 2014
Ionotropic P2X receptors (P2XRs) are involved in sympathetic control of the vascular tone; they mediate entry of Ca2+ in smooth muscle cells (SMCs), which results in depolarization of the latter and activation of voltage-gated L-type calcium channels. In addition, Ca2+ ions, after their entry into the cell, trigger Ca2+ release from the sarcoplasmic reticulum (SR) of SMCs via ryanodine receptors (RyRs), and this amplifies calcium signals. We found earlier that Ca2+ release mediated by inositol triphosphate (IP3) receptors (IP3Rs) also provides a considerable contribution to P2XR-mediated calcium signaling. Thus, a metabotropic signal pathway is a component of the calcium signaling system triggered by ionotropic P2XRs. Using confocal detection of changes in the intracellular Ca2+ concentration ([Ca2+]i) and applications of the inhibitors of calcium channels (nicardipine, 5 μM), sarco-endoplasmic Ca2+ ATPase SERCA (CPA, 10 μM), IP3Rs (2-APB, 30 μM), RyRs (tetracaine, 100 μM), and phosphalipase C (PLC; U-73122, 2.5 μM), we estimated relative contributions of the above-mentioned four components to increase in the [Ca2+]i induced by the action of an agonist of P2XRs, α,β-meATP. The contributions of transmembrane Ca2+ entry via channels of P2XRs and calcium channels were comparable (11.0 ± 1.4 %, n = 14 and 8.0 ± 1.4 %, n = 14, respectively). The contribution of Ca2+ release via IP3Rs was found to be three times greater than that via RyRs (41 ± 5 %, n = 26 and 14 ± 7 %, n = 16, respectively). Blocking of calcium channels resulted in a sevenfold decrease in the contribution of IP3R-mediated Ca2+ release (from 41.0 to 5.6%); in this case, the contribution of RyR-mediated Ca2+ release underwent no significant changes. This fact allows us to suppose that there is a functional relation between activation of calcium channels and functioning of a metabotropic PLC/IP3-mediated signal cascade. The efficiency of inhibition of α,β-meATP-induced calcium responses by the blocker of PLC, on the one hand, and by the IP3R blocker and nicardipine, on the other hand, is comparable, and this fact agrees with the above hypothesis. According to our data, P2XR activation-induced increase in [Ca2+]I results not only from P2XR-mediated Ca2+ entry that triggers Ca2+ release via RyRs but also from Ca2+ release via IP3Rs. The latter process is realized due to the functioning of the PLC-mediated pathway, is in close relation with activation of calcium channels, and provides a dominant contribution in Ca2+ release from the stores after activation of the above ionotropic receptors. © 2015, Springer Science+Business Media New York.
Rybachuk O.A.,Bogomolets Institute of Physiology of the NAS of Ukraine |
Pivneva T.A.,Bogomolets Institute of Physiology of the NAS of Ukraine
Neurophysiology | Year: 2013
Mesenchymal stem cells, MSCs, were identified in the 1960s. Recently, these cells have attracted great attention from researchers because their clinical applications look rather promising. At present, MSCs are most frequently interpreted as multipotent cells characterized by fibroblast-like morphology and capable of proliferating. These are non-differentiated cells possessing a great potential for differentiation and formation of tissues of different types, including the bone, cartilage, and muscle tissues, and also of the bone marrow stroma. In accessible publications, there is information that extremely wide plasticity is typical of MSCs obtained from the bone marrow; these cells can serve as originating units for the nerve tissue, hepatocytes, cardiomyocytes, and epithelial cells of the lungs. In this review, we describe results of recent studies in the field of fundamental biology of MSCs separated from different sources, their identification, potential for differentiation, and possibilities for therapeutic use. © 2013 Springer Science+Business Media New York.
Gura Y.V.,Bogomolets Institute of Physiology of the NAS of Ukraine |
Bagatskaya Y.V.,Bogomolets Institute of Physiology of the NAS of Ukraine
Neurophysiology | Year: 2015
In experiments on male albino mice, we examined the role of the serotonergic cerebral system in analgesia induced by microwave irradiation of the acupuncture point (AP) E-36. Two modes of irradiation were used: broadband (30–300 GHz) radiation with low-frequency (0.1–100 Hz) amplitude modulation and fixed-frequency (61 ± 4 GHz) radiation. Irradiation of the AP preceded induction of visceral pain by i.p. injections of acetic acid. A blocker of serotonin (ST) synthesis, DL para-chlorophenylalanine (PCPA, 300 mg/kg), introduced 72 h before injection of acetic acid, provided significant prolongation of manifestations of the pain behavioral reaction (PBR) by 41.6 and 66.7%, respectively, as compared with the duration of this reaction in mice subjected to irradiation of the AP in the above modes but with no PCPA injection (P < 0.05 in both cases). Intensification of the PBR against the background of blockade of ST synthesis shows that the respective cerebral system is significantly involved in analgesia induced by preliminary (preceding the induction of the pain syndrome) microwave irradiation of the AP E-36. © 2015, Springer Science+Business Media New York.