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https://www.readbyqxmd.com/read/28087340/electrophysiological-alterations-in-diaphragm-muscle-caused-by-abdominal-ischemia-reperfusion
#1
Seckin Tuncer, Nizamettin Dalkilic, Ilksen Burat
Ischemia-reperfusion injury is the major complication of abdominal aortic surgery, and it mainly affects the lower extremities and remote organs. In the present study, the electrophysiological alterations in diaphragm that underlie the post-operative respiratory dysfunction were investigated. Wistar Albino rats were randomly divided into two groups: SHAM (only laparotomy was performed) and IR (abdominal aorta was clamped for 30min and reperfused for 2h). Following the operational period diaphragm muscles were isolated and electrophysiological experiments were carried out in-vitro...
January 10, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28077712/changes-in-properties-of-auditory-nerve-synapses-following-conductive-hearing-loss
#2
Xiaowen Zhuang, Wei Sun, Matthew A Xu-Friedman
: Auditory activity plays an important role in the development of the auditory system. Decreased activity can result from conductive hearing loss (CHL) associated with otitis media, which may lead to long-term perceptual deficits. The effects of CHL have been mainly studied at later stages of the auditory pathway, but early stages remain less examined. However, changes in early stages could be important because they would affect how information about sounds is conveyed to higher-order areas for further processing and localization...
January 11, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28075010/stimulatory-actions-of-a-novel-thiourea-derivative-on-large-conductance-calcium-activated-potassium-channels
#3
Sheng-Nan Wu, Jyh-Haur Chern, Santai Shen, Hwei-Hisen Chen, Ying-Ting Hsu, Chih-Chin Lee, Ming-Huan Chan, Ming-Chi Lai, Feng-Shiun Shie
AIM: In this study, we examine whether an anti-inflammatory thiourea derivative, compound #326, actions on ion channels. METHODS: The effects of compound #326 on Ca(2+) -activated K(+) channels were evaluated by patch-clamp recordings obtained in cell-attached, inside-out or whole-cell configuration. RESULTS: In pituitary GH3 cells, compound #326 increased the amplitude of Ca(2+) -activated K(+) currents (IK(Ca) ) with an EC50 value of 11...
January 11, 2017: Journal of Cellular Physiology
https://www.readbyqxmd.com/read/28072605/oxytocin-alleviates-orofacial-mechanical-hypersensitivity-associated-with-infraorbital-nerve-injury-via-vasopressin-1a-receptors-of-the-rat-trigeminal-ganglia
#4
Asako Kubo, Masamichi Shinoda, Ayano Katagiri, Mamoru Takeda, Tatsuro Suzuki, Junichi Asaka, David C Yeomans, Koichi Iwata
Oxytocin (OXT) is a neuropeptide hormone synthesized and secreted by hypothalamic neurons, and has been reported to play a significant role in pain modulation. However, the mechanisms underlying OXT's antinociceptive effect on neuropathic pain are not fully understood. In the present study, we examined the peripheral effect of OXT on mechanical hypersensitivity induced by partial ligation of the infraorbital nerve (PNL) in rats. Mechanical hypersensitivity in the whisker pad skin following PNL was attenuated by the direct administration of OXT into the trigeminal ganglion (TG)...
January 7, 2017: Pain
https://www.readbyqxmd.com/read/28072464/genistein-and-tyrphostin-ag556-decrease-human-atrial-ultra-rapidly-activating-delayed-rectifier-potassium-current-by-inhibiting-egfr-tyrosine-kinase
#5
Guo-Sheng Xiao, Yan-Hui Zhang, Wei Wu, Hai-Ying Sun, Yan Wang, Gui-Rong Li
BACKGROUND AND PURPOSE: The ultra-rapidly activating delayed rectifier K(+) current IKur (encoded by Kv1.5 or KCNA5) plays an important role in human atrial repolarization. The present study investigates the regulation of this current by protein tyrosine kinases (PTKs). EXPERIMENTAL APPROACH: Whole-cell patch voltage-clamp technique, and immunoprecipitation/western blotting analysis were used to investigate whether the PTK inhibitors genistein, Tyrphostin AG556 (AG556) and PP2 regulate human atrial IKur , and hKv1...
January 10, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28070896/tiny-protein-detection-using-pressure-through-solid-state-nanopores
#6
Ji Li, Rui Hu, Xiaoqing Li, Xin Tong, Dapeng Yu, Qing Zhao
Solid-state nanopore is a promising tool to detect proteins and its complexes. Small proteins (sub-35 kDa) translocate very fast which could not be detected by normal patch-clamp recording instrument due to low temporal resolution. We firstly introduce pressure into protein study and detection. The pressure-derived force, combined with the voltage bias, makes very tiny protein (MW<6.5 kDa) detection possible. Capture rate for Aprotinin is enhanced five times more than that in traditional voltage-driven method by fine tuning of pressure and voltage...
January 9, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28069411/age-related-alterations-of-neuronal-excitability-and-voltage-dependent-ca-2-current-in-a-spontaneous-mouse-model-of-alzheimer-s-disease
#7
Hua-Long Wang, Xiao-Hui Xian, Qiao-Yun Song, Chao Pang, Jia-Lei Wang, Ming-Wei Wang, Wen-Bin Li
Alzheimer's disease (AD) is the most common age-dependent neurodegenerative disorder, characterized by a progressive dysfunction of central neurons, and senescence-accelerated mouse prone 8 (SAMP8), a spontaneous AD mouse model, appears to be an excellent model to investigate the process of AD. Previous studies have indicated that neuronal excitability is impaired in transgenic AD mice. In this study, the cognition of SAMP8 mice was tested using the passive avoidance task and Morris water maze; whole-cell current-clamp recordings were used to evaluate the neuronal excitability, including the resting membrane potential, the number of action potentials, and after-hyperpolarization; and the voltage-dependent Ca(2+) current in hippocampal slices was measured using whole-cell voltage-clamp recordings...
January 6, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28066143/acepromazine-inhibits-herg-potassium-ion-channels-expressed-in-human-embryonic-kidney-293-cells
#8
Young Shin Joo, Hong Joon Lee, Jin-Sung Choi, Ki-Wug Sung
The effects of acepromazine on human ether-à-go-go-related gene (hERG) potassium channels were investigated using whole-cell voltage-clamp technique in human embryonic kidney (HEK293) cells transfected with hERG. The hERG currents were recorded with or without acepromazine, and the steady-state and peak tail currents were analyzed for the evaluating the drug effects. Acepromazine inhibited the hERG currents in a concentration-dependent manner with an IC50 value of 1.5 µM and Hill coefficient of 1.1. Acepromazine blocked hERG currents in a voltage-dependent manner between -40 and +10 mV...
January 2017: Korean Journal of Physiology & Pharmacology
https://www.readbyqxmd.com/read/28065753/the-roles-of-conserved-aromatic-residues-tyr5-and-tyr42-in-interaction-of-scorpion-toxin-bmk-agp-sypu1-with-human-nav1-7
#9
Xiangxue Meng, Yijia Xu, Fangyang Wang, Mingyi Zhao, Xue Hou, Yuanyuan Ma, Yao Jin, Yanfeng Liu, Yongbo Song, Jinghai Zhang
Scorpion toxins are invaluable source of therapeutic leads and pharmacological tools which produce influence on the voltage gated sodium channels. In the previous study, our group has reported BmK AGP-SYPU1 (64 amino acids), one scorpion toxin with both potential α-type and β-type scorpion characteristics and analgesic activity in vivo, act as an activator to hNav1.4 and hNav1.5. Additionally, conserved aromatic amino acids Tyr5 and Tyr42 played important roles in bioactivity of BmK AGP-SYPU1 on hNav1.4 and hNav1...
January 5, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28058990/restoration-of-the-response-of-the-middle-cerebral-artery-of-the-rat-to-acidosis-in-hyposmotic-hyponatremia-by-the-opener-of-large-conductance-calcium-sensitive-potassium-channels-bkca
#10
Marta Aleksandrowicz, Beata Dworakowska, Krzysztof Dolowy, Ewa Kozniewska
Hyposmotic hyponatremia (the decrease of extracellular concentration of sodium ions from 145 to 121 mM and the decrease of hyposmolality from 300 to 250 mOsm/kg H2O) impairs response of the middle cerebral artery (MCA) to acetylcholine and NO donor (S-nitroso-N-acetyl-DL-penicillamine). Since acidosis activates a similar intracellular signaling pathway, the present study was designed to verify the hypothesis that the response of the MCA to acidosis is impaired during acute hyposmotic hyponatremia due to abnormal NO-related signal transduction in vascular smooth muscle cells...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28057491/mefloquine-inhibits-voltage-dependent-nav1-4-channel-by-overlapping-the-local-anaesthetic-binding-site
#11
Bertin Paiz-Candia, Angel A Islas, Alfredo Sánchez-Solano, Claudia Mancilla-Simbro, Thomas Scior, Lourdes Millan-PerezPeña, Eduardo M Salinas-Stefanon
Mefloquine constitutes a multitarget antimalaric that inhibits cation currents. However, the effect and the binding site of this compound on Na(+) channels is unknown. To address the mechanism of action of mefloquine, we employed two-electrode voltage clamp recordings on Xenopus laevis oocytes, site-directed mutagenesis of the rat Na(+) channel, and a combined in silico approach using Molecular Dynamics and docking protocols. We found that mefloquine: i) inhibited Nav1.4 currents (IC50 =60μM), ii) significantly delayed fast inactivation but did not affect recovery from inactivation, iii) markedly the shifted steady-state inactivation curve to more hyperpolarized potentials...
January 3, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28056022/l-type-calcium-channel-inhibition-contributes-to-the-proarrhythmic-effects-of-aconitine-in-human-cardiomyocytes
#12
Jianjun Wu, Xiangchong Wang, Ying Ying Chung, Cai Hong Koh, Zhenfeng Liu, Huicai Guo, Qiang Yuan, Chuan Wang, Suwen Su, Heming Wei
Aconitine (ACO) is well-known for causing lethal ventricular tachyarrhythmias. While cardiac Na+ channel opening during repolarization has long been documented in animal cardiac myocytes, the cellular effects and mechanism of ACO in human remain unexplored. This study aimed to assess the proarrhythmic effects of ACO in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). ACO concentration-dependently (0.3 ~ 3.0 μM) shortened the action potentials (AP) durations (APD) in ventricular-like hiPSC-CMs by > 40% and induced delayed after-depolarization...
2017: PloS One
https://www.readbyqxmd.com/read/28053245/synaptic-control-of-the-shape-of-the-motoneuron-pool-input-output-function
#13
Randall K Powers, Charles J Heckman
Although motoneurons have often been considered to be fairly linear transducers of synaptic input, recent evidence suggests that strong persistent inward currents (PICs) in motoneurons allow neuromodulatory and inhibitory synaptic inputs to induce large nonlinearities in the relation between the level of excitatory input and motor output. To try and estimate the possible extent of this nonlinearity, we developed a pool of model motoneurons designed to replicate the characteristics of motoneuron input-output properties measured in medial gastrocnemius motoneurons in the decerebrate cat using voltage-clamp and current-clamp techniques...
January 4, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28053242/nitric-oxide-promotes-gaba-release-by-activating-a-voltage-independent-ca2-influx-pathway-in-retinal-amacrine-cells
#14
John Wesley Maddox, Evanna L Gleason
Retinal amacrine cells express nitric oxide synthase and produce nitric oxide (NO), making NO available to regulate the function of amacrine cells. Here, we test the hypothesis that NO can alter the GABAergic synaptic output of amacrine cells. We investigate this using whole-cell voltage clamp recordings and Ca(2+) imaging of cultured chick retinal amacrine cells. When recording from amacrine cells receiving synaptic input from other amacrine cells, we find that NO increases GABAergic spontaneous postsynaptic current (sPSC) frequency...
January 4, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28053010/mutations-in-gabrb3-from-febrile-seizures-to-epileptic-encephalopathies
#15
Rikke S Møller, Thomas V Wuttke, Ingo Helbig, Carla Marini, Katrine M Johannesen, Eva H Brilstra, Ulvi Vaher, Ingo Borggraefe, Inga Talvik, Tiina Talvik, Gerhard Kluger, Laurence L Francois, Gaetan Lesca, Julitta de Bellescize, Susanne Blichfeldt, Nicolas Chatron, Nils Holert, Julia Jacobs, Marielle Swinkels, Cornelia Betzler, Steffen Syrbe, Marina Nikanorova, Candace T Myers, Line H G Larsen, Sabina Vejzovic, Manuela Pendziwiat, Sarah von Spiczak, Sarah Hopkins, Holly Dubbs, Yuan Mang, Konstantin Mukhin, Hans Holthausen, Koen L van Gassen, Hans A Dahl, Niels Tommerup, Heather C Mefford, Guido Rubboli, Renzo Guerrini, Johannes R Lemke, Holger Lerche, Hiltrud Muhle, Snezana Maljevic
OBJECTIVE: To examine the role of mutations in GABRB3 encoding the β3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. METHODS: We performed massive parallel sequencing of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs...
January 4, 2017: Neurology
https://www.readbyqxmd.com/read/28049780/preparing-brain-slices-to-study-basic-synaptic-properties
#16
Matthew A Xu-Friedman
This protocol describes how to prepare brain slices for electrophysiology, with an emphasis on synaptic physiology in voltage clamp. This approach remains the gold standard for understanding the properties of individual neurons, as well as the connections between neurons.
January 3, 2017: Cold Spring Harbor Protocols
https://www.readbyqxmd.com/read/28045238/secure-low-cost-technique-for-laparoscopic-hepatic-resection-using-the-crush-clamp-method-with-a-bipolar-sealer
#17
Takatsugu Yamamoto, Takahiro Uenishi, Kazuhisa Kaneda, Masato Okawa, Shogo Tanaka, Shoji Kubo
INTRODUCTION: Laparoscopic hepatectomy is difficult because surgeons must perform the transection using many (four and more) energy devices and without direct manual maneuvers. Here we introduce hepatic transection by the classical method with a few (two or three) energy devices. MATERIALS AND SURGICAL TECHNIQUE: We performed laparoscopic hepatectomy for 40 patients with hepatic tumor and liver dysfunction. For parenchymal transection, we used bipolar radiofrequency coagulation forceps connected to a voltage-controlled electrosurgical generator and ultrasonic dissector...
February 2017: Asian Journal of Endoscopic Surgery
https://www.readbyqxmd.com/read/28043879/-6-gingerol-and-6-shogaol-active-ingredients-of-the-traditional-japanese-medicine-hangeshashinto-relief-oral-ulcerative-mucositis-induced-pain-via-action-on-na-channels
#18
Suzuro Hitomi, Kentaro Ono, Kiyoshi Terawaki, Chinami Matsumoto, Keita Mizuno, Kiichiro Yamaguchi, Ryota Imai, Yuji Omiya, Tomohisa Hattori, Yoshio Kase, Kiyotoshi Inenaga
The traditional Japanese herbal medicine hangeshashinto (HST) has beneficial effects for the treatment of oral ulcerative mucositis (OUM) in cancer patients. However, the ingredient-based mechanism that underlies its pain-relieving activity remains unknown. In the present study, to clarify the analgesic mechanism of HST on OUM-induced pain, we investigated putative HST ingredients showing antagonistic effects on Na(+) channels in vitro and in vivo. A screen of 21 major ingredients using automated patch-clamp recordings in channel-expressing cells showed that [6]-gingerol and [6]-shogaol, two components of a Processed Ginger extract, considerably inhibited voltage-activated Na(+) currents...
December 30, 2016: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
https://www.readbyqxmd.com/read/28039042/role-of-low-voltage-activated-calcium-current-and-extracellular-calcium-in-controlling-the-firing-pattern-of-developing-ca1-pyramidal-neurons
#19
Alberto Sánchez-Aguilera, José Luis Sánchez-Alonso, María Ángeles Vicente-Torres, Asunción Colino
The firing pattern of individual neurons is an important element for information processing and storing. During the first weeks of development, there is a transitional period during which CA1 pyramidal neurons display burst-spiking behavior in contrast to the adult regular-firing pattern. Spike after-depolarizations (ADPs) constitute a major factor underlying burst-spiking behavior. Using current-clamp recordings, we studied ADP waveforms and firing patterns in CA1 pyramidal neurons of Wistar rats from 9 to 19 postnatal days (P9-19)...
December 28, 2016: Neuroscience
https://www.readbyqxmd.com/read/28033523/-s-5-ethynyl-anabasine-a-novel-compound-is-a-more-potent-agonist-than-other-nicotine-alkaloids-on-the-nematode-asu-acr-16-receptor
#20
Fudan Zheng, Xiangwei Du, Tsung-Han Chou, Alan P Robertson, Edward W Yu, Brett VanVeller, Richard J Martin
Nematode parasites infect ∼2 billion people world-wide. Infections are treated and prevented by anthelmintic drugs, some of which act on nicotinic acetylcholine receptors (nAChRs). There is an unmet need for novel therapeutic agents because of concerns about the development of resistance. We have selected Asu-ACR-16 from a significant nematode parasite genus, Ascaris suum, as a pharmaceutical target and nicotine as our basic moiety (EC50 6.21 ± 0.56 μM, Imax 82.39 ± 2.52%) to facilitate the development of more effective anthelmintics...
December 9, 2016: International Journal for Parasitology, Drugs and Drug Resistance
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