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<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="research-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Russian Journal of Physiology</journal-id><journal-title-group><journal-title xml:lang="en">Russian Journal of Physiology</journal-title><trans-title-group xml:lang="ru"><trans-title>Российский физиологический журнал им. И.М. Сеченова</trans-title></trans-title-group></journal-title-group><issn publication-format="print">0869-8139</issn><issn publication-format="electronic">2658-655X</issn><publisher><publisher-name xml:lang="en">The Russian Academy of Sciences</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">651743</article-id><article-id pub-id-type="doi">10.31857/S0869813924080048</article-id><article-id pub-id-type="edn">BDCUCD</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>EXPERIMENTAL ARTICLES</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>ЭКСПЕРИМЕНТАЛЬНЫЕ СТАТЬИ</subject></subj-group><subj-group subj-group-type="article-type"><subject>Research Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">An investigation of the spontaneous tonic activity of the rat soleus muscle following hindlimb suspension, with a focus on the effects of CLP290, a novel activator of the spinal cord potassium-chloride co-transporter</article-title><trans-title-group xml:lang="ru"><trans-title>Природа спонтанной тонической активности камбаловидной мышцы крысы в условиях опорной разгрузки, выявленная при использовании CLP290, нового активатора калий-хлоридного ко-транспортера спинного мозга</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Kalashnikov</surname><given-names>V. E.</given-names></name><name xml:lang="ru"><surname>Калашников</surname><given-names>В. Е.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>vitaliy.kalasxnikov@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Sergeeva</surname><given-names>K. V.</given-names></name><name xml:lang="ru"><surname>Сергеева</surname><given-names>К. В.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>vitaliy.kalasxnikov@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Turtikova</surname><given-names>O. V.</given-names></name><name xml:lang="ru"><surname>Туртикова</surname><given-names>О. В.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>vitaliy.kalasxnikov@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Tyganov</surname><given-names>S. A.</given-names></name><name xml:lang="ru"><surname>Тыганов</surname><given-names>С. А.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>vitaliy.kalasxnikov@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Mirzoev</surname><given-names>T. M.</given-names></name><name xml:lang="ru"><surname>Мирзоев</surname><given-names>Т. М.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>vitaliy.kalasxnikov@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Shenkman</surname><given-names>B. S.</given-names></name><name xml:lang="ru"><surname>Шенкман</surname><given-names>Б. С.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>vitaliy.kalasxnikov@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Institute of Biomedical Problems, Russian Academy of Sciences</institution></aff><aff><institution xml:lang="ru">Институт медико-биологических проблем Российской академии наук</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2024-09-15" publication-format="electronic"><day>15</day><month>09</month><year>2024</year></pub-date><volume>110</volume><issue>9</issue><issue-title xml:lang="ru"/><fpage>1337</fpage><lpage>1348</lpage><history><date date-type="received" iso-8601-date="2025-02-02"><day>02</day><month>02</month><year>2025</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2024, Russian Academy of Sciences</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2024, Российская академия наук</copyright-statement><copyright-year>2024</copyright-year><copyright-holder xml:lang="en">Russian Academy of Sciences</copyright-holder><copyright-holder xml:lang="ru">Российская академия наук</copyright-holder></permissions><self-uri xlink:href="https://journals.eco-vector.com/0869-8139/article/view/651743">https://journals.eco-vector.com/0869-8139/article/view/651743</self-uri><abstract xml:lang="en"><p>The electromyographic activity of the soleus muscle is a reliable indicator of its functional status. Unloading of support causes an immediate cessation of electrical activity in the soleus muscle, which resumes upon restoration of the support load. Prolonged support unloading, however, results in the emergence of spontaneous electrical activity in the soleus muscle. Previous research has established a correlation between this activity and the presence of the potassium-chloride cotransporter (KCC2) on the membranes of spinal cord motor neurons. Additionally, it has been demonstrated that the introduction of the KCC2 activator prochlorperazine can eliminate spontaneous muscle activity. This study aimed to investigate the impact of CLP290, an alternative KCC2 activator, on the spontaneous tonic activity of the rat soleus muscle. The results indicated that daily administration of CLP290 to rats during a 14-day period of hindlimb suspension prevented the reduction in KCC2 levels in the motor neurons of the lumbar spinal cord and the increase in spontaneous tonic activity in the soleus muscle. Notably, there were no significant differences in the cross-sectional area of slow-type fibers between the antiorthostatic suspension groups with and without CLP290 administration.</p></abstract><trans-abstract xml:lang="ru"><p>Общеизвестно, что электромиографическая активность камбаловидной мышцы отражает ее функциональную активность. Опорная разгрузка приводит к моментальному устранению электрической активности в камбаловидной мышце, которая возобновляется сразу после восстановления опорной нагрузки. Однако при длительной опорной разгрузке в камбаловидной мышце наблюдается возникновение спонтанной электрической активности. В предыдущих работах нами была показана связь между этой активностью и содержанием калий-хлоридного котранспортера (KCC2) на мембранах мотонейронов спинного мозга, а также возможность устранения спонтанной активности мышцы введением активатора KCC2 прохлорперазина. Целью данной работы было изучить влияние CLP290, альтернативного активатора KCC2, на спонтанную тоническую активность камбаловидной мышцы крысы. Обнаружено, что ежедневное введение крысам CLP290 на фоне 14-суточного антиортостатического вывешивания предотвращает снижение содержания KCC2 в мотонейронах поясничного отдела спинного мозга и рост спонтанной тонической активности в камбаловидной мышце. При этом не обнаружено статистически значимых отличий площади поперечного сечения волокон медленного типа в группах антиортостатического вывешивания с введением и без введения CLP290.</p></trans-abstract><kwd-group xml:lang="en"><kwd>KCC2</kwd><kwd>prochlorperazine</kwd><kwd>CLP290</kwd><kwd>hindlimb suspension</kwd><kwd>spontaneous muscle activity</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>KCC2</kwd><kwd>прохлорперазин</kwd><kwd>CLP290</kwd><kwd>антиортостатическое вывешивание</kwd><kwd>спонтанная мышечная активность</kwd></kwd-group><funding-group><award-group><funding-source><institution-wrap><institution xml:lang="ru">Российский Научный Фонд</institution></institution-wrap><institution-wrap><institution xml:lang="en">Russian Science Foundation</institution></institution-wrap></funding-source><award-id>22-15-00151</award-id></award-group></funding-group></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Alford EK, Roy RR, Hodgson JA, Edgerton VR (1987) Electromyography of rat soleus, medial gastrocnemius, and tibialis anterior during hind limb suspension. Exp Neurol 96(3): 635–649. https://doi.org/10.1016/0014-4886(87)90225-1</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>De-Doncker L, Kasri M, Picquet F, Falempin M (2005) Physiologically adaptive changes of the L5 afferent neurogram and of the rat soleus EMG activity during 14 days of hindlimb unloading and recovery. J Exp Biol 208(Pt 24): 4585–4592. https://doi.org/10.1242/jeb.01931</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Boulenguez P, Liabeuf S, Bos R, Bras H, Jean-Xavier C, Brocard C, Stil A, Darbon P, Cattaert D, Delpire E, Marsala M, Vinay L (2010) Down-regulation of the potassium-chloride cotransporter KCC2 contributes to spasticity after spinal cord injury. Nat Med 16(3): 302–307. https://doi.org/10.1038/nm.2107</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Edgerton VR, Roy RR (2010) Spasticity: a switch from inhibition to excitation. Nat Med 16(3): 270–271. https://doi.org/10.1038/nm0310-270</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Kalashnikov VE, Tyganov SA, Turtikova OV, Kalashnikova EP, Glazova MV, Mirzoev TM, Shenkman BS (2021) Prochlorperazine Withdraws the Delayed Onset Tonic Activity of Unloaded Rat Soleus Muscle: A Pilot Study. Life 11(11): 1161. https://doi.org/10.3390/life11111161</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Сергеева КВ, Шарло КА, Калашников ВЕ, Туртикова ОВ, Тыганов СА, Шенкман БC (2023) Влияние спонтанной нервно-мышечной активности на развитие атрофии камбаловидной мышцы в условиях функциональной разгрузки. Рос физиол журн им ИМ Сеченова 109(10): 1430–1442. [Sergeeva KV, Sharlo KA, Kalashnikov VE, Turtikova OV, Tyganov SA, Shenkman BS (2023) The effect of spontaneous neuromuscular activity on the development of atrophy of the soleus muscle in conditions of functional unloading. Russ J Phisiol 109(10): 1430–1442. (In Russ)]. https://doi.org/10.31857/S0869813923100102</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Gagnon M, Bergeron MJ, Lavertu G, Castonguay A, Tripathy S, Bonin RP, Perez-Sanchez J, Boudreau D, Wang B, Dumas L, Valade I, Bachand K, Jacob-Wagner M, Tardif C, Kianicka I, Isenring P, Attardo G, Coull JA, De Koninck Y (2013) Chloride extrusion enhancers as novel therapeutics for neurological diseases. Nat Med 19(11): 1524–1528. https://doi.org/10.1038/nm.3356</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Григорьев АИ, Козловская ИБ, Шенкман БС (2004) Роль опорной афферентации в организации тонической мышечной системы. Рос физиол журн им ИМ Сеченова 90(5): 508–521. [Grigoriev AI, Kozlovskaya IB, Shenkman BS (2004) The role of supporting afferentation in the organization of the tonic muscular system. Russ J Phisiol 90(5): 508–521. (In Russ)].</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Kawano F, Ishihara A, Stevens JL, Wang XD, Ohshima S, Horisaka M, Maeda Y, Nonaka I, Ohira Y (2004) Tension- and afferent input-associated responses of neuromuscular system of rats to hindlimb unloading and/or tenotomy. Am J Physiol Regul Integr Comp Physiol 287(1): R76–R86. https://doi.org/10.1152/ajpregu.00694.2003</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Kawano F, Nomura T, Ishihara A, Nonaka I, Ohira Y (2002) Afferent input-associated reduction of muscle activity in microgravity environment. Neuroscience 114(4): 1133–1138. https://doi.org/10.1016/s0306-4522(02)00304-4</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Шенкман БС, Мирзоев ТМ, Козловская ИБ (2020) Тоническая активность и гравитационный контроль постуральной мышцы. Авиакосм и экол мед 54(6): 58–72. [Shenkman BS, Mirzoev TM, Kozlovskaya IB (2020) Tonic activity and gravitational control of the postural muscle. Aerospace and enviroment med54(6): 58–72. (In Russ). https://doi.org/10.21687/0233-528X-2020-54-6-58-72</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Blaesse P, Airaksinen MS, Rivera C, Kaila K (2009) Cation-chloride cotransporters and neuronal function. Neuron 61(6): 820–838. https://doi.org/10.1016/j.neuron.2009.03.003</mixed-citation></ref><ref id="B13"><label>13.</label><mixed-citation>Akhter ET, Griffith RW, English AW, Alvarez FJ (2019) Removal of the Potassium Chloride Co-Transporter from the Somatodendritic Membrane of Axotomized Motoneurons Is Independent of BDNF/TrkB Signaling But Is Controlled by Neuromuscular Innervation. eNeuro 6(5): 1–23. https://doi.org/10.1523/ENEURO.0172-19.2019</mixed-citation></ref><ref id="B14"><label>14.</label><mixed-citation>Lu Y, Zheng J, Xiong L, Zimmermann M, Yang J (2008) Spinal cord injury-induced attenuation of GABAergic inhibition in spinal dorsal horn circuits is associated with down-regulation of the chloride transporter KCC2 in rat. J Physiol 586(23): 5701–5715. https://doi.org/10.1113/jphysiol.2008.152348</mixed-citation></ref></ref-list></back></article>
