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Artykuły w czasopismach na temat „Biphasic stimulation”

Autor: Grafiati

Data publikacji: 4 czerwca 2021

Data aktualizacji: 12 lutego 2022

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Walsh, Paul L., Jelena Petrovic, and R. Mark Wightman. "Distinguishing splanchnic nerve and chromaffin cell stimulation in mouse adrenal slices with fast-scan cyclic voltammetry." American Journal of Physiology-Cell Physiology 300, no. 1 (January 2011): C49—C57. http://dx.doi.org/10.1152/ajpcell.00332.2010.

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Electrical stimulation is an indispensible tool in studying electrically excitable tissues in neurobiology and neuroendocrinology. In this work, the consequences of high-intensity electrical stimulation on the release of catecholamines from adrenal gland slices were examined with fast-scan cyclic voltammetry at carbon fiber microelectrodes. A biphasic signal, consisting of a fast and slow phase, was observed when electrical stimulations typically used in tissue slices (10 Hz, 350 μA biphasic, 2.0 ms/phase pulse width) were applied to bipolar tungsten-stimulating electrodes. This signal was found to be stimulation dependent, and the slow phase of the signal was abolished when smaller (≤250 μA) and shorter (1 ms/phase) stimulations were used. The slow phase of the biphasic signal was found to be tetrodotoxin and hexamethonium independent, while the fast phase was greatly reduced using these pharmacological agents. Two different types of calcium responses were observed, where the fast phase was abolished by perfusion with a low-calcium buffer while both the fast and slow phases could be modulated when Ca2+ was completely excluded from the solution using EGTA. Perfusion with nifedipine resulted in the reduction of the slow catecholamine release to 29% of the original signal, while the fast phase was only decreased to 74% of predrug values. From these results, it was determined that high-intensity stimulations of the adrenal medulla result in depolarizing not only the splanchnic nerves, but also the chromaffin cells themselves resulting in a biphasic catecholamine release.

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Hwang, Hyeoncheol, Kyu-Chang Wang, Moon Suk Bang, Hyung-Ik Shin, Seung-Ki Kim, Ji Hoon Phi, Ji Yeoun Lee, Jinwoo Choi, Seungwoo Cha, and Keewon Kim. "Optimal stimulation parameters for intraoperative bulbocavernosus reflex in infants." Journal of Neurosurgery: Pediatrics 20, no. 5 (November 2017): 464–70. http://dx.doi.org/10.3171/2017.6.peds16664.

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OBJECTIVEThe aim of this study was to establish optimal electric stimulation parameters for intraoperatively monitoring the bulbocavernosus reflexes (BCRs) in infants.METHODSThe authors retrospectively reviewed the medical records of all infants (age < 24 months) who had undergone an untethering operation for tethered cord syndrome between May 2013 and February 2014 at a single institution and whose baseline BCR had been elicited during surgery. Using different combinations of stimulation parameters—number of stimulation pulses: 4 or 8 pulses, interpulse interval: 1, 2, or 5 msec, and polarity of stimulation: biphasic or monophasic—the authors compared the relative mean amplitude of 10 BCR responses (rmaBCRs) to each combination of parameters.RESULTSThe rmaBCRs were larger with the 8-pulse stimulations than with the 4-pulse stimulations (p < 0.0001). There was a tendency, though not statistically significant, for larger rmaBCRs to be obtained with the longer interpulse interval in the 8-pulse stimulation (p = 0.1289). The biphasic stimulation produced larger rmaBCRs than the monophasic stimulation (p = 0.0005).CONCLUSIONSBiphasic 8-pulse stimulations with 5-msec or 2-msec intervals yield the largest BCR responses. Considering that an 8-pulse stimulation with 5-msec intervals may overlap the onset of the BCR, a biphasic 8-pulse stimulation with 2-msec intervals is recommended as the optimal stimulation paradigm to monitor intraoperative BCRs in infants.

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Ward, Tyler, Neil Grabham, Chris Freeman, Yang Wei, Ann-Marie Hughes, Conor Power, John Tudor, and Kai Yang. "Multichannel Biphasic Muscle Stimulation System for Post Stroke Rehabilitation." Electronics 9, no. 7 (July 17, 2020): 1156. http://dx.doi.org/10.3390/electronics9071156.

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We present biphasic stimulator electronics developed for a wearable functional electrical stimulation system. The reported stimulator electronics consist of a twenty four channel biphasic stimulator. The stimulator circuitry is physically smaller per channel and offers a greater degree of control over stimulation parameters than existing functional electrical stimulator systems. The design achieves this by using, off the shelf multichannel high voltage switch integrated circuits combined with discrete current limiting and dc blocking circuitry for the frontend, and field programmable gate array based logic to manage pulse timing. The system has been tested on both healthy adults and those with reduced upper limb function following a stroke. Initial testing on healthy users has shown the stimulator can reliably generate specific target gestures such as palm opening or pointing with an average accuracy of better than 4 degrees across all gestures. Tests on stroke survivors produced some movement but this was limited by the mechanical movement available in those users’ hands.

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Lee, Chae-Eun, Younginha Jung, and Yoon-Kyu Song. "8-Channel Biphasic Current Stimulator Optimized for Retinal Prostheses." Journal of Nanoscience and Nanotechnology 21, no. 8 (August 1, 2021): 4298–302. http://dx.doi.org/10.1166/jnn.2021.19405.

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Retinal prostheses substitute the functionality of damaged photoreceptors by electrically stimulating retinal ganglion cells (RGCs). RGCs, densely packed in a small region, needs a high spatial resolution of the microelectrode, which in turn raises its impedance. Therefore, the high output impedance circuit and the high compliance output voltage are the key characteristics of the current-source-based stimulator. Also, as the system is intended to implant in the retina, the stimulation parameter should be optimized for efficiency and safety. Here we designed 8-channel neural stimulator customized to the retinal ganglion cell. Designed IC is fabricated in the TSMC 0.18 μm 1P6M RF CMOS process with 3.3 V supply voltage, occupying the 1060 μm×950 μm area.

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Nilsson, Jan, John Ravits, and Mark Hallett. "Stimulus artifact compensation using biphasic stimulation." Muscle & Nerve 11, no. 6 (June 1988): 597–602. http://dx.doi.org/10.1002/mus.880110612.

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Arfin, Scott K., Michael A. Long, Michale S. Fee, and Rahul Sarpeshkar. "Wireless Neural Stimulation in Freely Behaving Small Animals." Journal of Neurophysiology 102, no. 1 (July 2009): 598–605. http://dx.doi.org/10.1152/jn.00017.2009.

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We introduce a novel wireless, low-power neural stimulation system for use in freely behaving animals. The system consists of an external transmitter and a miniature, implantable wireless receiver–stimulator. The implant uses a custom integrated chip to deliver biphasic current pulses to four addressable bipolar electrodes at 32 selectable current levels (10 μA to 1 mA). To achieve maximal battery life, the chip enters a sleep mode when not needed and can be awakened remotely when required. To test our device, we implanted bipolar stimulating electrodes into the songbird motor nucleus HVC (formerly called the high vocal center) of zebra finches. Single-neuron recordings revealed that wireless stimulation of HVC led to a strong increase of spiking activity in its downstream target, the robust nucleus of the arcopallium. When we used this device to deliver biphasic pulses of current randomly during singing, singing activity was prematurely terminated in all birds tested. Thus our device is highly effective for remotely modulating a neural circuit and its corresponding behavior in an untethered, freely behaving animal.

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Aiello, Orazio. "On the DC Offset Current Generated during Biphasic Stimulation: Experimental Study." Electronics 9, no. 8 (July 25, 2020): 1198. http://dx.doi.org/10.3390/electronics9081198.

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This paper deals with the DC offset currents generated by a platinum electrode matrix during biphasic stimulation. A fully automated test bench evaluates the nanoampere range DC offset currents in a realistic and comprehensive scenario by using platinum electrodes in a saline solution as a load for the stimulator. Measurements are performed on different stimulation patterns for single or dual hexagonal stimulation sites operating simultaneously and alternately. The effectiveness of the return electrode presence in reducing the DC offset current is considered. Experimental results show how for a defined nominal injected charge, the generated DC offset currents differ depending on the stimulation patterns, frequency, current amplitude, and pulse width of a biphasic signal.

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Kolbl, Florian, Yannick Bornat, Jonathan Castelli, Louis Regnacq, Gilles N’Kaoua, Sylvie Renaud, and Noëlle Lewis. "IC-Based Neuro-Stimulation Environment for Arbitrary Waveform Generation." Electronics 10, no. 15 (August 3, 2021): 1867. http://dx.doi.org/10.3390/electronics10151867.

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Electrical stimulation of the nervous system is commonly based on biphasic stimulation waveforms, which limits its relevance for some applications, such as selective stimulation. We propose in this paper a stimulator capable of delivering arbitrary waveforms to electrodes, and suitable for non-conventional stimulation strategies. Such a system enables in vivo stimulation protocols with optimized efficacy or energy efficiency. The designed system comprises a High Voltage CMOS ASIC generating a configurable stimulating current, driven by a digital circuitry implemented on a FPGA. After fabrication, the ASIC and system were characterized and tested; they successfully generated programmable waveforms with a frequential content up to 1.2 MHz and a voltage compliance between [−17.9; +18.3] V. The system is not optimum when compared to single application stimulators, but no embedded stimulator in the literature offers an equivalent bandwidth which allows the wide range of stimulation paradigms, including high-frequency blocking stimulation. We consider that this stimulator will help test unconventional stimulation waveforms and can be used to generate proof-of-concept data before designing implantable and application-dedicated implantable stimulators.

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Woods, A. J., and M. J. Stock. "Biphasic brown fat temperature responses to hypothalamic stimulation in rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 266, no. 2 (February 1, 1994): R328—R337. http://dx.doi.org/10.1152/ajpregu.1994.266.2.r328.

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Low-level electrical stimulation (monophasic square-wave pulses: 15 Hz, 7.0 microA, 0.5 ms) of the ventromedial hypothalamus (VMH) in anesthetized rats produced a decrease (phase 1) in interscapular brown adipose tissue (IBAT) temperature that was sustained for as long as the stimulus was applied (2-45 min). A rise in IBAT temperature (phase 2) occurred only after the stimulation had stopped. VMH stimulations ipsilateral and contralateral to a lateral hypothalamic (LH) lesion indicated that the phase 1 response required an intact LH, and denervation of IBAT showed that both phases required an intact sympathetic innervation. Central intracerebroventricular injections of amphetamine and dopamine produced decreases in IBAT temperature similar in magnitude to the phase 1 response to electrical stimulation of the VMH. This, as well as the observation that pimozide blocked phase 1, suggested that dopaminergic pathways were responsible for mediating the phase 1 decrease in IBAT temperature. The peripheral mechanisms responsible for phase 1 are unknown, but a vascular component might explain the unexpected decrease in IBAT temperature seen during sustained VMH stimulation.

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Field-Fote, Edelle C., Brent Anderson, Valma J. Robertson, and Neil I. Spielholz. "Monophasic and biphasic stimulation evoke different responses." Muscle & Nerve 28, no. 2 (July 14, 2003): 239–41. http://dx.doi.org/10.1002/mus.10414.

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Scheiner, Avram, J. Thomas Mortimer, and Uros Roessmann. "Imbalanced biphasic electrical stimulation: Muscle tissue damage." Annals of Biomedical Engineering 18, no. 4 (July 1990): 407–25. http://dx.doi.org/10.1007/bf02364157.

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Zhuo, M., and G. F. Gebhart. "Biphasic Modulation of Spinal Nociceptive Transmission From the Medullary Raphe Nuclei in the Rat." Journal of Neurophysiology 78, no. 2 (August 1, 1997): 746–58. http://dx.doi.org/10.1152/jn.1997.78.2.746.

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Zhuo, M. and G. F. Gebhart. Biphasic modulation of spinal nociceptive transmission from the medullary raphe nuclei in the rat. J. Neurophysiol. 78: 746–758, 1997. The modulatory effects of electrical and chemical (glutamate) stimulation in the rostral ventromedial medulla (RVM) on spinal nociceptive transmission and a spinal nociceptive reflex were studied in rats. Electrical stimulation at a total 86 sites in the RVM in the medial raphe nuclei ( n = 54) and adjacent gigantocellular areas ( n = 32) produced biphasic (facilitatory and inhibitory, n = 43) or only inhibitory ( n = 43) modulation of the tail-flick (TF) reflex. At these 43 biphasic sites in the RVM, facilitation of the TF reflex was produced at low intensities of stimulation (5–25 μA) and inhibition was produced at greater intensities of stimulation (50–200 μA). At 43 sites in the RVM, electrical stimulation only produced intensity-dependent inhibition of the TF reflex. Activation of cell bodies in the RVM by glutamate microinjection reproduced the biphasic modulatory effects of electrical stimulation. At biphasic sites previously characterized by electrical stimulation, glutamate at a low concentration (5 nmol) produced facilitation of the TF reflex; a greater concentration (50 nmol) only inhibited the TF reflex. In electrophysiological experiments, electrical stimulation at 62 sites in the RVM produced biphasic ( n = 26), only inhibitory ( n = 26), or only facilitatory ( n = 10) modulation of responses of lumbar spinal dorsal horn neurons to noxious cutaneous thermal (50°C) or mechanical (75.9 g) stimulation. Facilitatory effects were produced at lesser intensities of stimulation and inhibitory effects were produced at greater intensities of stimulation. The apparent latencies to stimulation-produced facilitation and inhibition, determined with the use of a cumulative sum method and bin-by-bin analysis of spinal neuron responses to noxious thermal stimulation of the skin, were 231 and 90 ms, respectively. The spinal pathways conveying descending facilitatory and inhibitory influences were found to be different. Descending facilitatory influences on the TF reflex were conveyed in ventral/ventrolateral funiculi, whereas inhibitory influences were conveyed in dorsolateral funiculi. The results indicate that descending inhibitory and facilitatory influences can be simultaneously engaged throughout the RVM, including nucleus raphe magnus, and that such influences are conveyed in different spinalfuniculi.

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Zorko, B., J. Rozman, and A. Seliškar. "INFLUENCE OF ELECTRICAL STIMULATION ON Regeneration of the radial nerve in dogS." Acta Veterinaria Hungarica 48, no. 1 (February 1, 2000): 99–105. http://dx.doi.org/10.1556/avet.48.2000.1.11.

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The effects of biphasic electric fields on nerve regeneration that follows injury to the left radial nerve were studied in dogs by electromyography (EMG). Left and right radial nerves were crushed with a serrated haemostat. Stimulating electrodes were positioned proximally and distally to the site of the injury. The left nerves received rectangular, biphasic and current pulses (30 µA, 0.5 Hz) through the injury for two months. The right radial nerves were treated as controls and regenerated without electrical stimulation. EMG activities were recorded intramuscularly from the left and right musculus extensor digitalis communis (MEDC). Results obtained at the end of the two-month stimulation period showed a significant difference in EMG activity between the left (stimulated) and the right (non-stimulated) MEDC, suggesting that electrical treatment enhanced nerve regeneration.

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Woodcock, Alan H., Paul N. Taylor, and David J. Ewins. "Long Pulse Biphasic Electrical Stimulation of Denervated Muscle." Artificial Organs 23, no. 5 (May 1999): 457–59. http://dx.doi.org/10.1046/j.1525-1594.1999.06366.x.

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Arifianto, Deny. "Functional Electrical Stimulation dengan Pulsa Biphasic Untuk Membantu Fungsi Ekstremitas Atas Pasien Pasca Stroke." Jurnal Biosains Pascasarjana 23, no. 1 (June 10, 2021): 40. http://dx.doi.org/10.20473/jbp.v23i1.2021.40-48.

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Abstract Stroke or nerve function disorders caused by disruption of blood flow to the brain that arises suddenly or quickly with symptoms or signs that correspond to the affected area. One of the post-stroke rehabilitation using electrical stimulation, also known as an electro stimulator. This study aims to design Functional electrical stimulation (FES), which aims to stimulate the peripheral nervous system with biphasic pulses. Stimulation for patients with MMT 1 was optimal at a frequency of 22-30 Hz. In post-stroke patients with MMT inclusion characteristics 0-3, a minimum voltage, frequency and pulse width value of 200 Vp, 22 Hz, and 20 s is required with a power of 0.00146 Watt. Studies have shown that this electro stimulator device had good accuracy and has high peak voltage values and low effective current. It can be considered because it provides comfort and safety for medical therapy equipment.

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Yang, Guangning, Zhiying Xiao, Jicheng Wang, Bing Shen, James R. Roppolo, William C. de Groat, and Changfeng Tai. "Post-stimulation block of frog sciatic nerve by high-frequency (kHz) biphasic stimulation." Medical & Biological Engineering & Computing 55, no. 4 (July 1, 2016): 585–93. http://dx.doi.org/10.1007/s11517-016-1539-0.

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Rubinstein, J. T., C. A. Miller, H. Mino, and P. J. Abbas. "Analysis of monophasic and biphasic electrical stimulation of nerve." IEEE Transactions on Biomedical Engineering 48, no. 10 (2001): 1065–70. http://dx.doi.org/10.1109/10.951508.

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McLeod, K. J., D. F. Lovely, and R. N. Scott. "A biphasic pulse burst generator for afferent nerve stimulation." Medical & Biological Engineering & Computing 25, no. 1 (January 1987): 77–80. http://dx.doi.org/10.1007/bf02442825.

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Zhang, Haosu, Petro Julkunen, Axel Schröder, Anna Kelm, Sebastian Ille, Claus Zimmer, Minna Pitkänen, Bernhard Meyer, Sandro M. Krieg, and Nico Sollmann. "Short-Interval Intracortical Facilitation Improves Efficacy in nTMS Motor Mapping of Lower Extremity Muscle Representations in Patients with Supra-Tentorial Brain Tumors." Cancers 12, no. 11 (November 2, 2020): 3233. http://dx.doi.org/10.3390/cancers12113233.

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Navigated transcranial magnetic stimulation (nTMS) is increasingly used for mapping of motor function prior to surgery in patients harboring motor-eloquent brain lesions. To date, single-pulse nTMS (sp-nTMS) has been predominantly used for this purpose, but novel paired-pulse nTMS (pp-nTMS) with biphasic pulse application has been made available recently. The purpose of this study was to systematically evaluate pp-nTMS with biphasic pulses in comparison to conventionally used sp-nTMS for preoperative motor mapping of lower extremity (lE) muscle representations. Thirty-nine patients (mean age: 56.3 ± 13.5 years, 69.2% males) harboring motor-eloquent brain lesions of different entity underwent motor mapping of lE muscle representations in lesion-affected hemispheres and nTMS-based tractography of the corticospinal tract (CST) using data from sp-nTMS and pp-nTMS with biphasic pulses, respectively. Compared to sp-nTMS, pp-nTMS enabled motor mapping with lower stimulation intensities (61.8 ± 13.8% versus 50.7 ± 11.6% of maximum stimulator output, p < 0.0001), and it provided reliable motor maps even in the most demanding cases where sp-nTMS failed (pp-nTMS was able to provide a motor map in five patients in whom sp-nTMS did not provide any motor-positive points, and pp-nTMS was the only modality to provide a motor map in one patient who also did not show motor-positive points during intraoperative stimulation). Fiber volumes of the tracked CST were slightly higher when motor maps of pp-nTMS were used, and CST tracking using pp-nTMS data was also possible in the five patients in whom sp-nTMS failed. In conclusion, application of pp-nTMS with biphasic pulses enables preoperative motor mapping of lE muscle representations even in the most challenging patients in whom the motor system is at high risk due to lesion location or resection.

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Richardson, S., S. Twente, and T. Audhya. "GHRF causes biphasic stimulation of SRIF secretion from rat hypothalamic cells." American Journal of Physiology-Endocrinology and Metabolism 255, no. 6 (December 1, 1988): E829—E832. http://dx.doi.org/10.1152/ajpendo.1988.255.6.e829.

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The complex interactions of the hypothalamic releasing peptides somatostatin (SRIF) and growth hormone (GH)-releasing hormone (GHRF), which regulate GH secretion, are still incompletely understood. To further scrutinize these interactions, we have studied the effects of GHRF on SRIF secretion from dispersed adult rat hypothalamic cells. Rat GHRF caused calcium- and dose-dependent stimulation of SRIF release in static 1-h incubations. SRIF release was stimulated by GHRF in a concentration range of 1-100 nM. However, the extended dose-response curve was biphasic in nature, with a significantly lower SRIF response in the presence of 1 microM GHRF vs. 100 nM GHRF. SRIF release, stimulated by another secretagogue (10 microM veratridine), was not affected by the presence or absence of 1 microM GHRF, suggesting the lack of toxic impairment of hypothalamic cell function by GHRF at this concentration. In conclusion, a biphasic stimulatory pattern of SRIF secretion in response to GHRF was observed in experiments employing dispersed rat hypothalamic cells. The biphasic SRIF response pattern to GHRF may be relevant in the physiological regulation of GH secretion.

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Julkunen, Petro, Gustaf Järnefelt, Petri Savolainen, Jarmo Laine, and Jari Karhu. "Facilitatory effect of paired-pulse stimulation by transcranial magnetic stimulation with biphasic wave-form." Medical Engineering & Physics 38, no. 8 (August 2016): 813–17. http://dx.doi.org/10.1016/j.medengphy.2016.04.025.

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Jones, J. L., R. E. Jones, and G. Balasky. "Improved cardiac cell excitation with symmetrical biphasic defibrillator waveforms." American Journal of Physiology-Heart and Circulatory Physiology 253, no. 6 (December 1, 1987): H1418—H1424. http://dx.doi.org/10.1152/ajpheart.1987.253.6.h1418.

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According to the most commonly accepted hypothesis, ventricular defibrillation is produced by exciting cells in a critical mass of the ventricle. For monophasic defibrillator waveforms, this hypothesis correctly predicts a direct correlation between defibrillation threshold in the transthoracic calf model and excitation threshold for extracellular field stimulation in the cultured cell model. To further test the hypothesis, we determined whether symmetrical biphasic waveforms, which reduce defibrillation threshold in the calf to approximately 65% of that of the corresponding monophasic waveform (14), decrease excitation threshold in the cultured cell model. Experiments were performed on 100- to 250-microns aggregates from 10- to 12-day-old chick embryos. Excitation threshold strength-duration curves obtained at extracellular potassium (Ko) = 6.5 mM and pacing interval of 1,000 ms showed a significant reduction for symmetrical biphasic rectangular waveforms, when compared with the corresponding monophasic waveforms for durations greater than 3 ms. At the rheobase, the threshold ratio between the biphasic and monophasic waveforms was 0.63 (SE = 0.02). Transmembrane potentials during stimulation showed that excitation takes place during the second portion of the biphasic waveform for intensities that are subthreshold for the monophasic waveform. The relative effectiveness of the biphasic waveform (5-ms duration) increases under "fibrillation conditions" of short pacing interval (300 ms) and high extracellular potassium (10.5 mM). These results show that symmetrical biphasic waveforms decrease excitation threshold in the cultured cell model and that the degree of threshold reduction is dependent on Ko and beat rate.

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Laufer, Yocheved, Julie Deanne Ries, Peter M. Leininger, and Gad Alon. "Quadriceps Femoris Muscle Torques and Fatigue Generated by Neuromuscular Electrical Stimulation With Three Different Waveforms." Physical Therapy 81, no. 7 (July 1, 2001): 1307–16. http://dx.doi.org/10.1093/ptj/81.7.1307.

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Abstract Background and Purpose. Neuromuscular electrical stimulation is used by physical therapists to improve muscle performance. Optimal forms of stimulation settings are yet to be determined, as are possible sex-related differences in responsiveness to electrical stimulation. The objectives of the study were: (1) to compare the ability of 3 different waveforms to generate isometric contractions of the quadriceps femoris muscles of individuals without known impairments, (2) to compare muscle fatigue caused by repeated contractions induced by these same waveforms, and (3) to examine the effect of sex on muscle force production and fatigue induced by electrical stimulation. Subjects. Fifteen women and 15 men (mean age=29.5 years, SD=5.4, range=22–38) participated in the study. Methods. A portable battery-operated stimulator was used to generate either a monophasic or biphasic rectangular waveform. A stimulator that was plugged into an electrical outlet was used to generate a 2,500-Hz alternating current. Phase duration, frequency, and on-off ratios were kept identical for both stimulators. Participants did not know the type of waveform being used. Torque was measured using a computerized dynamometer: a maximal voluntary isometric contraction (MVIC) of the right quadriceps femoris muscle set at 60 degrees of knee flexion was determined during the first session. In each of the 3 testing sessions, torque of contraction and fatigue elicited by one waveform were measured. Order of testing was randomized. Torque elicited by electrical stimulation was expressed as a percentage of average MVIC. A mixed-model analysis of variance was used to determine the effect of stimulation and sex on strength of contraction and fatigue. Bonferroni-corrected post hoc tests were used to further distinguish between the effects of the 3 stimulus waveforms. Results. The results indicated that the monophasic and biphasic waveforms generated contractions with greater torque than the polyphasic waveform. These 2 waveforms also were less fatiguing. The torques from the maximally tolerated electrically elicited contractions were greater for the male subjects than for the female subjects. Discussion and Conclusion. Muscle torque and fatigue of electrically induced contractions depend on the waveform used to stimulate the contraction, with monophasic and biphasic waveforms having an advantage over the polyphasic waveform. All tested waveforms elicited, on average, stronger contractions in male subjects than in female subjects when measured as a percentage of MVIC.

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Gauthier, Pierre. "Adrenomedullary pressor responses to stimulation of the rostral hypothalamus in the rat: influence of adrenaline-induced vasodilation and reflex cardioinhibition." Canadian Journal of Physiology and Pharmacology 66, no. 2 (February 1, 1988): 213–21. http://dx.doi.org/10.1139/y88-037.

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Electrical stimulation (100 Hz, 1 ms, 150 μA, 10 s) of the anterior hypothalamus in chloralose-anesthetized rats evoked a biphasic pressor response consisting of an initial sharp rise in arterial pressure at the onset of stimulation, followed by a second elevation after cessation of the stimulus. This response was accompanied by an increase in plasma noradrenaline and adrenaline levels. Peripheral sympathectomy with guanethidine selectively abolished the primary phase of the biphasic pressor response, while bilateral removal of the adrenal medulla eliminated only the secondary component. After α-adrenergic blockade with phentolamine, the primary phase of the stimulation-induced response was reduced while the secondary pressor component was blocked and replaced by a significant hypotension. The intravenous administration of sotalol enhanced the secondary pressor component without affecting the stimulation-induced plasma noradrenaline and adrenaline responses. After treatment with atropine, the secondary pressor effect was also potentiated, as the reflex bradycardia normally associated with the response was eliminated. A subsequent administration of sotalol in these rats further potentiated the secondary pressor component to stimulation. In rats treated with atropine and sotalol, the sympathetic vasomotor and the adrenomedullary pressor responses could be dissociated according to thresholds and stimulus frequency or current–response characteristics. The results suggest that in intact rats, adrenaline-induced vasodilation and reflex cardiac inhibition contribute to either reduce or mask the adrenomedullary component of the biphasic pressor response evoked by stimulation of the anterior hypothalamus. The study also raises the hypothesis of a dual regulation of both components of the sympathetic system in the anterior hypothalamic region.

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Constandinou, Timothy G., Julius Georgiou, and Christofer Toumazou. "A Partial-Current-Steering Biphasic Stimulation Driver for Vestibular Prostheses." IEEE Transactions on Biomedical Circuits and Systems 2, no. 2 (June 2008): 106–13. http://dx.doi.org/10.1109/tbcas.2008.927238.

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Florini, J. R., D. Z. Ewton, S. L. Falen, and J. J. Van Wyk. "Biphasic concentration dependency of stimulation of myoblast differentiation by somatomedins." American Journal of Physiology-Cell Physiology 250, no. 5 (May 1, 1986): C771—C778. http://dx.doi.org/10.1152/ajpcell.1986.250.5.c771.

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It is widely believed that mitogens inhibit in vitro differentiation of myoblasts to form postmitotic myotubes, but we and others have shown that the mitogenic hormones insulin and the insulin-like growth factors (IGFs) stimulate myoblast differentiation. We now report the results of concentration-dependency studies that resolve this disagreement. We found that the IGFs give a biphasic dose-response curve; at low concentrations, there is progressive stimulation of L6 myoblast differentiation; at higher concentrations, there is a progressive decrease. Similar results were obtained with IGF-II and insulin. When differentiation was maximally stimulated (by 1,280 ng/ml insulin), adding rat IGF-II gave decreases in differentiation similar to those reported for other mitogens. Two trivial explanations have been eliminated: stimulation of differentiation (at low concentrations) is not due to enhanced survival or growth of the cells, and inhibition (at higher concentrations) is not a toxic effect. In L6 cells, epidermal growth factor and fibroblast growth factor had no effect on proliferation or differentiation. We conclude that the effects of medium components on myoblast differentiation cannot be generalized to indicate inhibition by all mitogens; depending on the cell lines and concentrations used, certain mitogens may either stimulate or inhibit differentiation.

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Tai, Changfeng, Qiang Shen, and Dazong Jiang. "Selective stimulation of smaller nerve fibers using biphasic rectangular pulses." Frontiers of Medical and Biological Engineering 10, no. 4 (2000): 319–35. http://dx.doi.org/10.1163/156855700750265486.

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KAVANAGH, K. M., H. J. DUFF, R. CLARK, K. V. ROBINSON, W. R. GILES, and D. G. WYSE. "Monophasic Versus Biphasic Cardiac Stimulation: Mechanism of Decreased Energy Requirements." Pacing and Clinical Electrophysiology 13, no. 10 (October 1990): 1268–76. http://dx.doi.org/10.1111/j.1540-8159.1990.tb02026.x.

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Delvendahl, I., N. Gattinger, T. Berger, B. Gleich, H. Siebner, and V. Mall. "P 231. A physiological characterization of biphasic transcranial magnetic stimulation." Clinical Neurophysiology 124, no. 10 (October 2013): e176-e177. http://dx.doi.org/10.1016/j.clinph.2013.04.308.

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Hayashi, Naoyuki. "Exercise pressor reflex in decerebrate and anesthetized rats." American Journal of Physiology-Heart and Circulatory Physiology 284, no. 6 (June 1, 2003): H2026—H2033. http://dx.doi.org/10.1152/ajpheart.00400.2002.

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I investigated whether muscular contraction evokes cardiorespiratory increases (exercise pressor reflex) in α-chloralose- and chloral hydrate-anesthetized and precollicular, midcollicular, and postcollicular decerebrated rats. Mean arterial pressure (MAP), heart rate (HR), and minute ventilation (V˙e) were recorded before and during 1-min sciatic nerve stimulation, which induced static contraction of the triceps surae muscles, and during 1-min stretch of the calcaneal tendon, which selectively stimulated mechanosensitive receptors in the muscles. Anesthetized rats showed various patterns of MAP response to both stimuli, i.e., biphasic, depressor, pressor, and no response. Sciatic nerve stimulation to muscle in precollicular decerebrated rats always evoked spontaneous running, so the exercise pressor reflex was not determined from these preparations. None of the postcollicular decerebrated rats showed a MAP response or spontaneous running. Midcollicular decerebrated rats consistently showed biphasic blood pressure response to both stimulations. The increases in MAP, HR, and V˙e were related to the tension developed. The static contractions in midcollicular decerebrated rats (381 ± 65 g developed tension) significantly increased MAP, HR, andV˙e from 103 ± 12 to 119 ± 24 mmHg, from 386 ± 30 to 406 ± 83 beats/min, and from 122 ± 7 to 133 ± 25 ml/min, respectively. After paralysis, sciatic nerve stimulation had no effect on MAP, HR, or V˙e. These results indicate that the midcollicular decerebrated rat can be a model for the study of the exercise pressor reflex.

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Holcomb, William R., Shahin Golestani, and Shante Hill. "A Comparison of Knee-Extension Torque Production with Biphasic versus Russian Current." Journal of Sport Rehabilitation 9, no. 3 (August 2000): 229–39. http://dx.doi.org/10.1123/jsr.9.3.229.

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Context:Neuromuscular electrical stimulation (NMES) can be used to prevent the atrophy and strength loss associated with immobilization.Objective:To compare the effects of biphasic current and the modulated “Russian” current on muscular torque production during different contraction conditions.Design, Setting, and Participants:In a within-subjects design, 10 healthy subjects in an athletic training laboratory received NMES.Interventions:Isometric knee-extension torque was recorded with the Biodex™ under 4 conditions: maximum voluntary contraction (MVC; control), MVC superimposed with low-intensity stimulation (sham), MVC superimposed with high-intensity stimulation, and high-intensity stimulation only.Main Outcome Measure:Data normalized for body weight were analyzed using a 2 (current type) X 4 (condition) repeated-measures analysis of variance.Results:The main effect for current type was not significant, F1,9 = .03, P = .87.

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Araújo, Tiago, Rui Candeias, Neuza Nunes, and Hugo Gamboa. "Evaluation of Motor Neuron Excitability by CMAP Scanning with Electric Modulated Current." Neuroscience Journal 2015 (August 27, 2015): 1–5. http://dx.doi.org/10.1155/2015/360648.

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Introduction. Compound Muscle Action Potential (CMAP) scan is a noninvasive promissory technique for neurodegenerative pathologies diagnosis. In this work new CMAP scan protocols were implemented to study the influence of electrical pulse waveform on peripheral nerve excitability. Methods. A total of 13 healthy subjects were tested. Stimulation was performed with an increasing intensities range from 4 to 30 mA. The procedure was repeated 4 times per subject, using a different single pulse stimulation waveform: monophasic square and triangular and quadratic and biphasic square. Results. Different waveforms elicit different intensity-response amplitude curves. The square pulse needs less current to generate the same response amplitude regarding the other waves and this effect is gradually decreasing for the triangular, quadratic, and biphasic pulse, respectively. Conclusion. The stimulation waveform has a direct influence on the stimulus-response slope and consequently on the motoneurons excitability. This can be a new prognostic parameter for neurodegenerative disorders.

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Katsidoni, Vicky, Andreas Kastellakis та George Panagis. "Biphasic effects of Δ9-tetrahydrocannabinol on brain stimulation reward and motor activity". International Journal of Neuropsychopharmacology 16, № 10 (1 листопада 2013): 2273–84. http://dx.doi.org/10.1017/s1461145713000709.

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Abstract Δ9-tetrahydrocannabinol (Δ9-THC), the main psychoactive ingredient of marijuana, has led to equivocal results when tested with the intracranial self-stimulation (ICSS) procedure or the open-field test for motor activity, two behavioural models for evaluating the reward-facilitating and locomotor stimulating effects of drugs of abuse, respectively. Therefore, in the present study, the effects of high and low doses of Δ9-THC were compared in the ICSS procedure and the open-field test. Moreover, the involvement of CB1 receptors in tentative Δ9-THC-induced effects was investigated by pre-treating the animals with the CB1 receptor antagonist SR141716A (rimonabant). The results obtained show that low doses of Δ9-THC induce opposite effects from high doses of Δ9-THC. Specifically, 0.1 mg/kg Δ9-THC decreased ICSS thresholds and produced hyperactivity, whereas 1 mg/kg increased ICSS thresholds and produced hypoactivity. Both effects were reversed by pre-treatment with SR141716A, indicating the involvement of CB1 receptors on these actions. Altogether, our results indicate that Δ9-THC can produce acute activating effects in locomotion that coincide with its reward-facilitating effects in the ICSS paradigm. The present findings provide further support that Δ9-THC induces behaviours typical of abuse and substantiate the notion that marijuana resembles other drugs of abuse.

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Lianggang Hu, Xiaomei Xu, Yongsheng Gong, Xiaofang Fan, Liangxing Wang, Jianhua Zhang, and Yanjun Zeng. "Percutaneous Biphasic Electrical Stimulation for Treatment of Obstructive Sleep Apnea Syndrome." IEEE Transactions on Biomedical Engineering 55, no. 1 (January 2008): 181–87. http://dx.doi.org/10.1109/tbme.2007.897836.

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Siegel, David, Serapio M. Baca, David C. Thompson, Molly M. Huntsman, Morton M. Mower, and David Ross. "The effect of anodal/cathodal biphasic electrical stimulation on insulin release." Journal of Cellular Physiology 234, no. 9 (February 11, 2019): 16389–99. http://dx.doi.org/10.1002/jcp.28307.

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Arai, Noritoshi, Shingo Okabe, Takashi Ohnishi, Hitoshi Mochizuki, and Yoshikazu Ugawa. "Differences between 3 Hz monophasic and biphasic repetitive transcranial magnetic stimulation." International Congress Series 1278 (March 2005): 295–98. http://dx.doi.org/10.1016/j.ics.2004.11.143.

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Jones, J. L., and K. B. Milne. "Dysfunction and safety factor strength-duration curves for biphasic defibrillator waveforms." American Journal of Physiology-Heart and Circulatory Physiology 266, no. 1 (January 1, 1994): H263—H271. http://dx.doi.org/10.1152/ajpheart.1994.266.1.h263.

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Newly developed biphasic waveforms significantly lower defibrillation threshold in animal and clinical models. However, underlying mechanisms and optimum waveform shape are unknown. Defibrillation shocks produce dysfunction; safety factor, the ratio of shock intensity inducing dysfunction to that producing stimulation of partially refractory cells, is an important parameter for defibrillator waveforms. We determined dysfunction and safety factor strength-duration curves for symmetric and asymmetric (50% undershoot) monophasic and biphasic rectangular (0%-tilt) waveforms. Dysfunction threshold, defined as the voltage producing a 4-s postshock contractile arrest, was determined for waveforms with total durations from 1 to 40 ms. For all waveforms, dysfunction threshold decreased with waveform duration. At all durations, dysfunction threshold was similar for symmetric monophasic and biphasic waveforms with the same total duration. In contrast, asymmetric biphasic waveforms increased dysfunction threshold 14 +/- 3% (P < 0.005) compared with monophasic control waveforms. Because long-duration, low-tilt, biphasic waveforms improve excitation threshold for refractory cells, they should improve defibrillation threshold. Asymmetric waveforms have the additional advantage of improving safety factor by reducing postshock dysfunction.

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Escoubet, B., M. C. Garestier, G. Cherqui, and C. Amiel. "PKC and Pi deprivation modulate differently the ubiquitous Na-dependent Pi uptake in MDCK cells." American Journal of Physiology-Renal Physiology 260, no. 2 (February 1, 1991): F235—F242. http://dx.doi.org/10.1152/ajprenal.1991.260.2.f235.

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The role of protein kinase C (PKC) in the modulation of the ubiquitous sodium-dependent phosphate transport and in adaptation of that transport to phosphate deprivation was investigated in MDCK cells. Phorbol myristate acetate (PMA) had a biphasic effect on sodium-dependent phosphate uptake characterized by early inhibition (-25% at 1 h) followed by late stimulation (2.3-fold at 15 h). Late stimulation was related to a decreased apparent affinity (Km) with unchanged maximal velocity (Vmax). The 15-h stimulation of phosphate uptake was also induced by an initial 1-h PMA treatment followed by a 14-h washout of PMA or by R59 022. The stimulation was inhibited by PKC downregulation. PMA stimulation was dependent on protein synthesis but not on transcription, as shown by the respective effects of cycloheximide, 3'-deoxyadenosine, and actinomycin D. In phosphate-deprived cells PMA had also a biphasic effect. A potentiation of PMA stimulation of phosphate uptake with phosphate deprivation was observed. Adaptation to phosphate deprivation was not prevented by PKC downregulation. Cytosolic and membranous PKC activities were not changed by 15-h phosphate deprivation. We conclude that 1) PKC modulates sodium-dependent phosphate uptake in MDCK cells, and 2) phosphate deprivation and PKC modulation of sodium-dependent phosphate uptake involve different cellular pathways; that is, phosphate deprivation acts through gene regulation, and PKC acts through translation regulation.

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Zhuo, M., J. N. Sengupta, and G. F. Gebhart. "Biphasic Modulation of Spinal Visceral Nociceptive Transmission From the Rostroventral Medial Medulla in the Rat." Journal of Neurophysiology 87, no. 5 (May 1, 2002): 2225–36. http://dx.doi.org/10.1152/jn.2002.87.5.2225.

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Descending inhibitory and facilitatory influences from the rostroventral medulla (RVM) on responses of lumbosacral spinal neurons to noxious colorectal distension (CRD, 80 mmHg, 20 s) were studied. At 25 sites in the RVM, electrical stimulation produced biphasic effects, facilitating responses of spinal neurons to CRD at lesser intensities of stimulation (5–25 μA) and inhibiting responses of the same neurons at greater intensities of stimulation (50–100 μA). At 38 other sites in the RVM, electrical stimulation produced only intensity-dependent inhibition of neuron responses to CRD. At another 13 sites in the RVM, electrical stimulation (5–100 μA) produced only facilitatory effects on responses to CRD. Descending modulatory effects were selective for distension-evoked activity; spontaneous activities of the same spinal neurons were not significantly affected by electrical stimulation that either facilitated or inhibited neuron responses to CRD. Neuron responses to graded CRD (20–100 mmHg) were positively accelerating functions that were shifted leftward or rightward, respectively, by lesser, facilitatory intensities or greater, inhibitory intensities of RVM stimulation. l-glutamate microinjection into the RVM replicated the effects of electrical stimulation, producing similar biphasic modulatory effects as produced by electrical stimulation. Microinjection of glutamate into the RVM at a low dose (5 nmoles) facilitated responses of spinal neurons to CRD and inhibited responses of the same neurons at a greater dose (50 nmoles). In some experiments, microinjection of lidocaine (0.5 μl of 4% solution) or the neurotoxin ibotenic acid (0.5 μl, 10 μg) into the RVM produced reversible or long-lasting, respectively, decreases in spontaneous activity and responses of spinal neurons to CRD. These results reveal that spinal visceral nociceptive transmission is subject to a tonic descending excitatory influence from the RVM and that descending modulatory effects from the RVM on visceral nociceptive transmission are qualitatively similar to modulation of cutaneous nociceptive transmission.

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Nikolski, Vladimir P., Aleksandre T. Sambelashvili, and Igor R. Efimov. "Mechanisms of make and break excitation revisited: paradoxical break excitation during diastolic stimulation." American Journal of Physiology-Heart and Circulatory Physiology 282, no. 2 (February 1, 2002): H565—H575. http://dx.doi.org/10.1152/ajpheart.00544.2001.

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10.1152/ajpheart.00544.2001. Onset and termination of electric stimulation may result in “make” and “break” excitation of the heart tissue. Wikswo et al. (30) explained both types of stimulations by virtual electrode polarization. Make excitation propagates from depolarized regions (virtual cathodes). Break excitation propagates from hyperpolarized regions (virtual anodes). However, these studies were limited to strong stimulus intensities. We examined excitation during weak near-threshold diastolic stimulation. We optically mapped electrical activity from a 4 × 4-mm area of epicardium of Langendorff-perfused rabbit hearts ( n = 12) around the pacing electrode in the presence ( n = 12) and absence ( n = 2) of 15 mM 2,3-butanedione monoxime. Anodal and cathodal 2-ms stimuli of various intensities were applied. We imaged an excitation wavefront with 528-μs resolution. We found that strong stimuli (×5 threshold) result in make excitation, starting from the virtual cathodes. In contrast, near-threshold stimulation resulted in break excitation, originating from the virtual anodes. Characteristic biphasic upstrokes in the virtual cathode area were observed. Break and make excitation represent two extreme cases of near-threshold and far-above-threshold stimulations, respectively. Both mechanisms are likely to contribute during intermediate clinically relevant strengths.

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Petrossians, Artin, Navya Davuluri, John J. Whalen, Florian Mansfeld, and James D. Weiland. "Improved Biphasic Pulsing Power Efficiency with Pt-Ir Coated Microelectrodes." MRS Proceedings 1621 (2014): 249–57. http://dx.doi.org/10.1557/opl.2014.267.

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ABSTRACTNeuromodulation devices such as deep brain stimulators (DBS), spinal cord stimulators (SCS) and cochlear implants (CIs) use electrodes in contact with tissue to deliver electrical pulses to targeted cells. In general, the neuromodulation industry has been evolving towards smaller, less invasive devices. Improving power efficiency of these devices can reduce battery storage requirements. Neuromodulation devices can realize significant power savings if the impedance to charge transfer at the electrode-tissue interface can be reduced. High electrochemical impedance at the surface of stimulation microelectrodes results in larger polarization voltages. Decreasing this polarization voltage response can reduce power required to deliver the current pulse. One approach to doing this is to reduce the electrochemical impedance at the electrode surface. Previously we have reported on a novel electrochemically deposited 60:40% platinum-iridium (Pt-Ir) electrode material that lowered the electrode impedance by two orders of magnitude or more.This study compares power consumption of an electrochemically deposited Pt-Ir stimulating microelectrode to that of standard Pt-Ir probe microelectrode produced using conventional techniques. Both electrodes were tested using in-vitro in phosphate buffered saline (PBS) solution and in-vivo (live rat) models.

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Guzman, Jorge A., Ariosto E. Rosado, and James A. Kruse. "Dopamine-1 receptor stimulation impairs intestinal oxygen utilization during critical hypoperfusion." American Journal of Physiology-Heart and Circulatory Physiology 284, no. 2 (February 1, 2003): H668—H675. http://dx.doi.org/10.1152/ajpheart.00636.2002.

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Effects of a dopamine-1 (DA-1) receptor agonist on systemic and intestinal oxygen delivery (D˙o 2)-uptake relationships were studied in anesthetized dogs during sequential hemorrhage. Control ( group 1) and experimental animals ( group 2) were treated similarly except for the addition of fenoldopam (1.0 μg · kg−1 · min−1) in group 2. Both groups had comparable systemic criticalD˙o 2(D˙o 2crit), but animals in group 2 had a higher gut D˙o 2crit(1.12 ± 1.13 vs. 0.80 ± 0.09 ml · kg−1 · min−1, P < 0.05). At the mucosal level, a clear biphasic delivery-uptake relationship was not observed in group 1; thus oxygen consumption by the mucosa may be supply dependent under physiological conditions. Group 2 demonstrated higher peak mucosal blood flow and lack of supply dependency at higher mucosalD˙o 2 levels. Fenoldopam resulted in a more conspicuous biphasic relationship at the mucosa and a rightward shift of overall splanchnic D˙o 2crit despite increased splanchnic blood flow. These findings suggest that DA-1 receptor stimulation results in increased gut perfusion heterogeneity and maldistribution of perfusion, resulting in increased susceptibility to ischemia.

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Nagykaldi, Zsolt, David Kem, Ralph Lazzara та Bela Szabo. "Conditioning of β1-adrenoceptor effect via β2-subtype on L-type Ca2+ current in canine ventricular myocytes". American Journal of Physiology-Heart and Circulatory Physiology 279, № 3 (1 вересня 2000): H1329—H1337. http://dx.doi.org/10.1152/ajpheart.2000.279.3.h1329.

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We investigated the roles of β1- and β2-receptors (β-AR) in adrenergic enhancement of L-type Ca2+ current ( I CaL) in canine ventricular myocytes. Isoproterenol and l-norepinephrine produced a monophasic and a biphasic concentration- I CaL relationship (CR), respectively. α1-AR inhibition with prazosin and β2-AR stimulation with zinterol or l-epinephrine shifted the CR of l-norepinephrine leftward. Zinterol (50 nM) and l-epinephrine (10 nM), but not prazosin, altered the biphasic CR of l-norepinephrine to a monophasic CR. Zinterol and l-epinephrine applied after l-norepinephrine had no effect on I CaL. β2-AR inhibition with ICI-118551 reduced the E max of isoproterenol and l-norepinephrine by 60% and abolished the augmentation of l-norepinephrine by zinterol and l-epinephrine. Carbachol (100 nM) modestly reduced the I CaLresponse to β1-AR stimulation but abolished the enhancement via β2-AR. Zinterol augmented the enhancement of I CaL by forskolin, IBMX, and theophylline, but not in the presence of CGP-20712A. We conclude that selective β2-AR stimulation does not increase I CaL but enhances adenylyl cyclase activity when stimulated via β1-AR and with forskolin. β2-AR activity preconditions adenylyl cyclase for β1-AR stimulation.

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Arshavsky, Y. I., T. G. Deliagina, I. L. Okshtein, G. N. Orlovsky, Y. V. Panchin, and L. B. Popova. "Defense reaction in the pond snail Planorbis corneus. I. Activity of the shell-moving and respiratory systems." Journal of Neurophysiology 71, no. 3 (March 1, 1994): 882–90. http://dx.doi.org/10.1152/jn.1994.71.3.882.

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1. In the intact pond snail Planorbis corneus, tactile or electrical stimulation of the skin evoked a biphasic general defense reaction. A weak stimulation evoked only the first phase of the reaction, represented as a fast pulling of the shell towards the head. With stronger stimulation, this phase was followed by the second phase that was comprised of three components: detachment from the substrate, slow retraction of the body into the shell, and letting out of air from the lung through the pneumostome. 2. About 70 motor neurons (MNs) of the columellar muscle have been revealed in different ganglia by means of their cobalt back-filling through the cut columellar nerve. A complicated pattern of electrical coupling was found for different groups of MNs. Excitation of individual MNs, evoked by current injection, resulted in contraction of the columellar muscle (CNS-columellar muscle preparation). The strongest contraction was evoked by the cerebral MNs; fast small contraction by the parietal MNs; and slow, long-latency contraction, by the pedal MNs. 3. In the same preparation, electrical stimulation of the cutaneous (lip) nerve evoked biphasic contraction of the columellar muscle (a first phase lasting approximately 3 s, and a second phase of up to 1 min). The temporal pattern of this response was similar to that of the defense reaction in the intact animal. A weak stimulation evoked only the first phases of the reaction, while a stronger stimulation evoked both phases. The amplitude of both the first and the second phase was graded with the strength of stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

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Shan, Yi-Chia, Wei Fang, Yang-Chyuan Chang, Wen-Dien Chang, and Jih-Huah Wu. "Effect of Near-Infrared Pulsed Light on the Human Brain Using Electroencephalography." Evidence-Based Complementary and Alternative Medicine 2021 (March 5, 2021): 1–11. http://dx.doi.org/10.1155/2021/6693916.

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In our previous study, the low-level laser (LLL) stimulation at the palm with a stimulation frequency of 10 Hz was able to induce significant brain activation in normal subjects. The electroencephalography (EEG) changes caused by the stimulation of light-emitting diode (LED) in normal subjects have not been investigated. This study aimed at identifying the effects of LED stimulation on the human brain using EEG analysis. Moreover, the dosage has been raised 4 times than that in the previous LLL study. The LED array stimulator (6 pcs LEDs, central wavelength 850 nm, output power 30 mW, and operating frequency 10 Hz) was used as the stimulation source. The LED stimulation was found to induce significant variation in alpha activity in the occipital, parietal, and temporal regions of the brain. Compared to the previous low-level laser study, LED has similar effects on EEG in alpha (8–12 Hz) activity. Theta (4–7 Hz) power significantly increased in the posterior head region of the brain. The effect lasted for at least 15 minutes after stimulation ceased. Conversely, beta (13–35 Hz) intensity in the right parietal area increased significantly, and a biphasic dose response has been observed in this study.

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Segal, Joseph. "Biphasic stimulation of cellular calcium concentration by 3,5,3'-triiodothyronine in rat thymocytes." Biochemistry 27, no. 7 (April 5, 1988): 2586–90. http://dx.doi.org/10.1021/bi00407a047.

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Tanaka, Seigo, Ryo Saito, Kenji Honda, Kouichi Handa, Yukio Takano, and Hiro-o. Kamiya. "Electrical field stimulation causes biphasic relaxation in precontracted mesenteric arteries of rats." Japanese Journal of Pharmacology 73 (1997): 168. http://dx.doi.org/10.1016/s0021-5198(19)45173-1.

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Swartz, John, Janice L. Jones, and Ross Fletcher. "Symmetrical biphasic defibrillator waveforms enhance refractory period stimulation in the human heart." Journal of the American College of Cardiology 17, no. 2 (February 1991): A335. http://dx.doi.org/10.1016/0735-1097(91)92305-6.

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de Balthasar, C., C. Boëx, G. Cosendai, G. Valentini, A. Sigrist, and M. Pelizzone. "Channel interactions with high-rate biphasic electrical stimulation in cochlear implant subjects." Hearing Research 182, no. 1-2 (August 2003): 77–87. http://dx.doi.org/10.1016/s0378-5955(03)00174-6.

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Shen, Na, Qiong Liang, Yuehong Liu, Bin Lai, Wen Li, Zhengmin Wang, and Shufeng Li. "Charge-balanced biphasic electrical stimulation inhibits neurite extension of spiral ganglion neurons." Neuroscience Letters 624 (June 2016): 92–99. http://dx.doi.org/10.1016/j.neulet.2016.04.069.

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