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Journal articles on the topic 'Biphasic Electrode'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

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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2

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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3

Won, Eun-Seo, and Jong-Won Lee. "Biphasic Solid Electrolytes with Homogeneous Li-Ion Transport Pathway Enabled By Metal-Organic Frameworks." ECS Meeting Abstracts MA2022-01, no. 55 (July 7, 2022): 2248. http://dx.doi.org/10.1149/ma2022-01552248mtgabs.

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Solid-state batteries based on nonflammable inorganic solid electrolytes provide a promising technical solution that can resolve the safety issues of current lithium-ion batteries. Biphasic solid electrolytes comprising Li7La3Zr2O12 (LLZO) garnet and polymer have been attracting significant interest for solid-state Li batteries because of their mechanical robustness and enhanced Li+ conductivity, compared to conventional polymer electrolytes. Furthermore, the hybridization allows for the fabrication of thin and large-area electrolyte membranes without the need for high-temperature sintering of LLZO. However, the non-uniform distribution of LLZO particles and polymer species in biphasic electrolytes may cause uneven Li+ conduction, which results in poor interfacial stability with electrodes during repeated charge–discharge cycling. In this study, we report a biphasic solid electrolyte with homogeneous Li+ transport pathway achieved by a metal–organic framework (MOF) layer. To regulate and homogenize the Li+ flux across the interface between the electrolyte and electrode, a free-standing, biphasic solid electrolyte membrane is integrated with the MOF nanoparticle layer. A mixture of plastic crystal (PC) and polymeric phase is infused into porous networks of the MOF-integrated electrolyte membrane, producing the percolating Li+ conduction pathways. The MOF-integrated electrolyte membrane is found to form the smooth and uniform interface with nanoporous channels in contact with the electrodes, effectively facilitating homogeneous Li+ transport. A solid-state battery with the MOF-integrated electrolyte membrane shows the enhanced rate-capability and cycling stability in comparison to the battery with the unmodified biphasic electrolyte. This study demonstrates that the proposed electrolyte design provides an effective approach to improving the interfacial stability of biphasic electrolytes with electrodes for long-cycling solid-state batteries. [1] H.-S. Shin, W. Jeong, M.-H. Ryu, S.W. Lee, K.-N. Jung, J.-W. Lee, Electrode-to-electrode monolithic integration for high-voltage bipolar solid-state batteries based on plastic-crystal polymer electrolyte, Chem. Eng. J, published online. [2] T. Jiang, P. He, G. Wang, Y. Shen, C.-W. Nan, L.-Z. Fan, Solvent-free synthesis of thin, flexible, nonflammable garnet-based composite solid electrolyte for all-solid-state lithium batteries, Adv. Energy Mater. 10 (2020) 1903376.

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4

Sooksood, K., T. Stieglitz, and M. Ortmanns. "An experimental study on passive charge balancing." Advances in Radio Science 7 (May 19, 2009): 197–200. http://dx.doi.org/10.5194/ars-7-197-2009.

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Abstract. This paper presents a simplified analysis of the electrode potential upon mismatched, biphasic stimulation using passive discharge techniques, e.g. by shortening of the electrodes. It turns out that especially for microelectrodes the required shorting intervals become as large as to limit a feasible stimulation interval. If no blocking capacitors can be used due to limited space and the degree of miniaturisation, the passive discharge even imposes severe risks to the surrounding tissue and the electrode.

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5

Kriaučiūnas, K., and J. Kulys. "Macrokinetic Model of Catalase Electrode with Biphasic Enzyme Inhibition." Nonlinear Analysis: Modelling and Control 9, no. 3 (July 25, 2004): 241–46. http://dx.doi.org/10.15388/na.2004.9.3.15155.

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Macrokinetics of catalase based enzyme electrode was investigated in presence of enzyme inhibitor – hydroxylamine. The modeling of the electrode was performed using biphasic scheme of enzyme inhibition and external diffusion limitation. The maximal enzyme electrode sensitivity was indicated at transition from diffusion to kinetically controlled mode. The fitting of experimental data demonstrated that the enzyme electrode had 70% of maximal sensitivity

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6

Spitzer, Emily R., and Michelle L. Hughes. "Effect of Stimulus Polarity on Physiological Spread of Excitation in Cochlear Implants." Journal of the American Academy of Audiology 28, no. 09 (October 2017): 786–98. http://dx.doi.org/10.3766/jaaa.16144.

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AbstractContemporary cochlear implants (CIs) use cathodic-leading, symmetrical, biphasic current pulses, despite a growing body of evidence that suggests anodic-leading pulses may be more effective at stimulating the auditory system. However, since much of this research on humans has used pseudomonophasic pulses or biphasic pulses with unusually long interphase gaps, the effects of stimulus polarity are unclear for clinically relevant (i.e., symmetric biphasic) stimuli.The purpose of this study was to examine the effects of stimulus polarity on basic characteristics of physiological spread-of-excitation (SOE) measures obtained with the electrically evoked compound action potential (ECAP) in CI recipients using clinically relevant stimuli.Using a within-subjects (repeated measures) design, we examined the differences in mean amplitude, peak electrode location, area under the curve, and spatial separation between SOE curves obtained with anodic- and cathodic-leading symmetrical, biphasic pulses.Fifteen CI recipients (ages 13–77) participated in this study. All were users of Cochlear Ltd. devices.SOE functions were obtained using the standard forward-masking artifact reduction method. Probe electrodes were 5–18, and they were stimulated at an 8 (of 10) loudness rating (“loud”). Outcome measures (mean amplitude, peak electrode location, curve area, and spatial separation) for each polarity were compared within subjects.Anodic-leading current pulses produced ECAPs with larger average amplitudes, greater curve area, and less spatial separation between SOE patterns compared with that for cathodic-leading pulses. There was no effect of polarity on peak electrode location.These results indicate that for equal current levels, the anodic-leading polarity produces broader excitation patterns compared with cathodic-leading pulses, which reduces the spatial separation between functions. This result is likely due to preferential stimulation of the central axon. Further research is needed to determine whether SOE patterns obtained with anodic-leading pulses better predict pitch discrimination.

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7

Kárason, Halldór, Óskar Pilkington, and Thordur Helgason. "Selective electrical stimulation with current-field modulation." Current Directions in Biomedical Engineering 7, no. 2 (October 1, 2021): 803–6. http://dx.doi.org/10.1515/cdbme-2021-2205.

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Abstract Selective electrical stimulation using a multielectrode array is a promising technique that can potentially bring electrical stimulation treatment modalities a step forward. A microcontroller-controlled electrical stimulator system delivering a single pulse was designed, suitable for current-field modulation. The goal is to make electrical stimulation with surface electrodes more specific. A graphical user interface (GUI) was developed to control stimulation parameters and current-field within a multi-electrode array wirelessly. The stimulator generates arbitrary biphasic waveforms with a 5-bit resolution and high temporal precision (<10 μs) and was demonstrated to stimulate posterior lumbar root fibers in transcutaneous spinal cord stimulation (tSCS) treatment selectively. Current-field modulation throughout a sixteen-electrode array was achieved. The system has the goal to improve control of stimulation conditions in electrophysiological studies and time-dependent and site-specific stimulation patterns for neuromodulation applications. A novel feature is the current-field modulation ability of the stimulator for surface electrode arrays.

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8

Javel, E., Y. C. Tong, R. K. Shepherd, and G. M. Clark. "Responses of Cat Auditory Nerve Fibers to Biphasic Electrical Current Pulses." Annals of Otology, Rhinology & Laryngology 96, no. 1_suppl (January 1987): 26–30. http://dx.doi.org/10.1177/00034894870960s111.

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Discharge patterns of single auditory nerve fibers were recorded from normal-hearing cats implanted with a 12-band intracochlear electrode array. Stimuli were biphasic current pulses of specifiable width, amplitude, and rate. Acoustic tuning curves were obtained to determine the cochlear positions of the fibers. Response latencies to electrical stimuli formed two groups. Short latency (0.3 to 0.7 ms) responses were attributed to direct activation of spiral ganglion neurons. At high stimulus intensities, these often exhibited abrupt shifts toward even shorter latencies. Long latency (> 1.5 ms) responses were probably caused by electrophonic activation of functional hair cells. Response thresholds to electrical stimuli depended on a fiber's proximity to the stimulating electrodes, and they did not depend on a fiber's acoustic response threshold or spontaneous discharge rate. High intensity (> 1.5 mA) stimuli could excite fibers over a wide range of characteristic frequencies, even for the narrowest (0.45 mm) electrode separations. Response threshold was an exponentially decreasing function of pulse width for widths up to 300 μs/phase. Fiber discharges were highly phase-locked at all suprathreshold intensities, and saturation discharge rates usually equaled stimulus pulse rates for rates up to at least 800 pulses/s. Dynamic ranges were small (1 to 6 dB), increased with pulse rate, and were uncorrelated with electrical response threshold. Within the dynamic range, shapes of poststimulus time and interspike interval histograms resembled those obtained in response to acoustic stimuli. Depolarization block caused fiber activity to cease in 2 to 5 seconds for sustained stimuli presented at high (> 600 pulses/s) pulse rates and intensities.

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9

Bardy, G. H., C. Troutman, G. Johnson, R. Mehra, J. E. Poole, G. L. Dolack, P. J. Kudenchuk, and D. M. Gartman. "Electrode system influence on biphasic waveform defibrillation efficacy in humans." Circulation 84, no. 2 (August 1991): 665–71. http://dx.doi.org/10.1161/01.cir.84.2.665.

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10

Daneshvar e Asl, Shervin, and Sayed Khatiboleslam Sadrnezhaad. "Biphasic TiO2 nanoleafed nanorod electrode for dye-sensitized solar cell." Physica E: Low-dimensional Systems and Nanostructures 123 (September 2020): 114206. http://dx.doi.org/10.1016/j.physe.2020.114206.

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11

Hayashi, Hideki, Shien-Fong Lin, Boyoung Joung, Hrayr S. Karagueuzian, James N. Weiss, and Peng-Sheng Chen. "Virtual electrodes and the induction of fibrillation in Langendorff-perfused rabbit ventricles: the role of intracellular calcium." American Journal of Physiology-Heart and Circulatory Physiology 295, no. 4 (October 2008): H1422—H1428. http://dx.doi.org/10.1152/ajpheart.00001.2008.

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A strong premature electrical stimulus (S2) induces both virtual anodes and virtual cathodes. The effects of virtual electrodes on intracellular Ca2+ concentration ([Ca2+]i) transients and ventricular fibrillation thresholds (VFTs) are unclear. We studied 16 isolated, Langendorff-perfused rabbit hearts with simultaneous voltage and [Ca2+]i optical mapping and for vulnerable window determination. After baseline pacing (S1), a monophasic (10 ms anodal or cathodal) or biphasic (5 ms-5 ms) S2 was applied to the left ventricular epicardium. Virtual electrode polarizations and [Ca2+]i varied depending on the S2 polarity. Relative to the level of [Ca2+]i during the S1 beat, the [Ca2+]i level 40 ms after the onset of monophasic S2 increased by 36 ± 8% at virtual anodes and 20 ± 5% at virtual cathodes ( P < 0.01), compared with 25 ± 5% at both virtual cathode-anode and anode-cathode sites for biphasic S2. The VFT was significantly higher and the vulnerable window significantly narrower for biphasic S2 than for either anodal or cathodal S2 ( n = 7, P < 0.01). Treatment with thapsigargin and ryanodine ( n = 6) significantly prolonged the action potential duration compared with control (255 ± 22 vs. 189 ± 6 ms, P < 0.05) and eliminated the difference in VFT between monophasic and biphasic S2, although VFT was lower for both cases. We conclude that virtual anodes caused a greater increase in [Ca2+]i than virtual cathodes. Monophasic S2 is associated with lower VFT than biphasic S2, but this difference was eliminated by the inhibition of the sarcoplasmic reticulum function and the prolongation of the action potential duration. However, the inhibition of the sarcoplasmic reticulum function also reduced VFT, indicating that the [Ca2+]i dynamics modulate, but are not essential, to ventricular vulnerability.

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12

Vomero, Maria, Elena Zucchini, Emanuela Delfino, Calogero Gueli, Norma Mondragon, Stefano Carli, Luciano Fadiga, and Thomas Stieglitz. "Glassy Carbon Electrocorticography Electrodes on Ultra-Thin and Finger-Like Polyimide Substrate: Performance Evaluation Based on Different Electrode Diameters." Materials 11, no. 12 (December 7, 2018): 2486. http://dx.doi.org/10.3390/ma11122486.

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Glassy carbon (GC) has high potential to serve as a biomaterial in neural applications because it is biocompatible, electrochemically inert and can be incorporated in polyimide-based implantable devices. Miniaturization and applicability of GC is, however, thought to be partially limited by its electrical conductivity. For this study, ultra-conformable polyimide-based electrocorticography (ECoG) devices with different-diameter GC electrodes were fabricated and tested in vitro and in rat models. For achieving conformability to the rat brain, polyimide was patterned in a finger-like shape and its thickness was set to 8 µm. To investigate different electrode sizes, each ECoG device was assigned electrodes with diameters of 50, 100, 200 and 300 µm. They were electrochemically characterized and subjected to 10 million biphasic pulses—for achieving a steady-state—and to X-ray photoelectron spectroscopy, for examining their elemental composition. The electrodes were then implanted epidurally to evaluate the ability of each diameter to detect neural activity. Results show that their performance at low frequencies (up to 300 Hz) depends on the distance from the signal source rather than on the electrode diameter, while at high frequencies (above 200 Hz) small electrodes have higher background noises than large ones, unless they are coated with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS).

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13

Werginz, Paul, Andrea Corna, and Günther Zeck. "Avoidance of axonal activation in epiretinal implants using short biphasic pulses." Current Directions in Biomedical Engineering 8, no. 3 (September 1, 2022): 5–8. http://dx.doi.org/10.1515/cdbme-2022-2002.

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Abstract Retinal implants allow patients suffering from degenerative retinal diseases to regain visual percepts. Despite considerable effort in developing and improving retinal neuroprostheses in the last decades, the restored vision in patients does not achieve sufficient quality. The elicited percepts do not accurately match the stimulating pixels and therefore the formation of high acuity vision is hindered. One of the main obstacles in epiretinal implants is the concurrent activation of cells close to a stimulating electrode and cells that have their axons traversing the electrode. In this study, we use computational modeling to examine the effect of pulse duration on the selectivity of focal versus non-focal activation. Our results suggest that biphasic pulses in the range of 10-20 microseconds can prevent axonal activation while still reliably activating target neurons.

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14

Ramesh, Thimmasandra Narayan. "Effect of Substituents on the Electrochemical Reversible Discharge Capacity of Cobalt Hydroxide Electrodes." Journal of New Materials for Electrochemical Systems 18, no. 2 (May 30, 2015): 091–93. http://dx.doi.org/10.14447/jnmes.v18i2.375.

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Cobalt hydroxide, nickel hydroxide-cobalt hydroxide and zinc oxide-cobalt hydroxide biphasic mixtures were prepared by precipitation method. In spite of structural similarities exhibited by nickel hydroxide and cobalt hydroxide samples, former is a good electrode material and exchanges 1e-/Ni while latter does not show any reversibility. Presence of small amount of other metal ions such as nickel or zinc in the lattice of cobalt hydroxide or as a biphasic mixture of cobalt hydroxide-nickel hydroxide/cobalt hydroxide- zinc oxide, exchange up to 0.2 to 0.24e- exchange compared to pure cobalt hydroxide which shows 0.1 e- exchange.

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15

Neuzner, Jörg, Heinz Friedrich Pitschner, Torsten Schwarz, Martin Dürsch, and Martin Schlepper. "Effects of electrode polarity on delibrillation thresholds in biphasic endocardial defibrillation." American Journal of Cardiology 78, no. 1 (July 1996): 96–97. http://dx.doi.org/10.1016/s0002-9149(96)00234-2.

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16

Newbold, Carrie, Rachael Richardson, Rodney Millard, Christie Huang, Dusan Milojevic, Robert Shepherd, and Robert Cowan. "Changes in biphasic electrode impedance with protein adsorption and cell growth." Journal of Neural Engineering 7, no. 5 (September 14, 2010): 056011. http://dx.doi.org/10.1088/1741-2560/7/5/056011.

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17

LEONELLI, FABIO M., K. E. WANG, CHARLES KING, JAMES BREWER, ANN M. DONOHOO, and MARK W. KROLL. "Energy Steering of Biphasic Waveforms Using a Transvenous Three Electrode System." Pacing and Clinical Electrophysiology 22, no. 6 (June 1999): 849–54. http://dx.doi.org/10.1111/j.1540-8159.1999.tb06807.x.

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18

Dalrymple, Ashley N., Jordyn E. Ting, Rohit Bose, James K. Trevathan, Stephan Nieuwoudt, Scott F. Lempka, Manfred Franke, et al. "Stimulation of the dorsal root ganglion using an Injectrode^®." Journal of Neural Engineering 18, no. 5 (October 1, 2021): 056068. http://dx.doi.org/10.1088/1741-2552/ac2ffb.

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Abstract Objective. The goal of this work was to compare afferent fiber recruitment by dorsal root ganglion (DRG) stimulation using an injectable polymer electrode (Injectrode®) and a more traditional cylindrical metal electrode. Approach. We exposed the L6 and L7 DRG in four cats via a partial laminectomy or burr hole. We stimulated the DRG using an Injectrode or a stainless steel (SS) electrode using biphasic pulses at three different pulse widths (80, 150, 300 μs) and pulse amplitudes spanning the range used for clinical DRG stimulation. We recorded antidromic evoked compound action potentials (ECAPs) in the sciatic, tibial, and common peroneal nerves using nerve cuffs. We calculated the conduction velocity of the ECAPs and determined the charge-thresholds and recruitment rates for ECAPs from Aα, Aβ, and Aδ fibers. We also performed electrochemical impedance spectroscopy measurements for both electrode types. Main results. The ECAP thresholds for the Injectrode did not differ from the SS electrode across all primary afferents (Aα, Aβ, Aδ) and pulse widths; charge-thresholds increased with wider pulse widths. Thresholds for generating ECAPs from Aβ fibers were 100.0 ± 32.3 nC using the SS electrode, and 90.9 ± 42.9 nC using the Injectrode. The ECAP thresholds from the Injectrode were consistent over several hours of stimulation. The rate of recruitment was similar between the Injectrodes and SS electrode and decreased with wider pulse widths. Significance. The Injectrode can effectively excite primary afferents when used for DRG stimulation within the range of parameters used for clinical DRG stimulation. The Injectrode can be implanted through minimally invasive techniques while achieving similar neural activation to conventional electrodes, making it an excellent candidate for future DRG stimulation and neuroprosthetic applications.

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Rao, V. Bhujanga, P. Seetharamaiah, and Nukapeyi Sharmili. "Design of a Prototype for Vision Prosthesis." International Journal of Biomedical and Clinical Engineering 7, no. 2 (July 2018): 1–13. http://dx.doi.org/10.4018/ijbce.2018070101.

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This article describes how the field of vision prostheses is currently being developed around the world to restore useful vision for people suffering from retinal degenerative diseases. The vision prosthesis system (VPS) maps visual images to electrical pulses and stimulates the surviving healthy parts in the retina of the eye, i.e. ganglion cells, using electric pulses applied through an electrode array. The retinal neurons send visual information to the brain. This article presents the design of a prototype vision prosthesis system which converts images/video into biphasic electric stimulation pulses for the excitation of electrodes simulated by an LED array. The proposed prototype laboratory model has been developed for the design of flexible high-resolution 1024-electrode VPS, using an embedded computer-based efficient control algorithm for better visual prediction. The prototype design for the VPS is verified visually through a video display on an LCD/LED array. The experimental results of VPS are enumerated for the test objects, such as, palm, human face and large font characters. The results were found to be satisfactory.

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20

Danieli, Fabiana, Miguel Angelo Hyppolito, Raabid Hussain, Michel Hoen, Chadlia Karoui, and Ana Cláudia Mirândola Barbosa Reis. "The Effects of Multi-Mode Monophasic Stimulation with Capacitive Discharge on the Facial Nerve Stimulation Reduction in Young Children with Cochlear Implants: Intraoperative Recordings." Journal of Clinical Medicine 12, no. 2 (January 9, 2023): 534. http://dx.doi.org/10.3390/jcm12020534.

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Facial nerve stimulation (FNS) is a potential complication which may affect the auditory performance of children with cochlear implants (CIs). We carried out an exploratory prospective observational study to investigate the effects of the electrical stimulation pattern on FNS reduction in young children with CI. Ten ears of seven prelingually deafened children with ages up to 6 years old who undergone a unilateral or bilateral CI surgery were included in this study. Electromyographic (EMG) action potentials from orbicularis oculi muscle were recorded using monopolar biphasic stimulation (ST1) and multi-mode monophasic stimulation with capacitive discharge (ST2). Presence of EMG responses, facial nerve stimulation thresholds (T-FNS) and EMG amplitudes were compared between ST1 and ST2. Intra-cochlear electrodes placement, cochlear-nerve and electrode-nerve distances were also estimated to investigate their effects on EMG responses. The use of ST2 significantly reduced the presence of intraoperative EMG responses compared to ST1. Higher stimulation levels were required to elicit FNS with ST2, with smaller amplitudes, compared to ST1. No and weak correlation was observed between cochlea-nerve and electrode-nerve distances and EMG responses, respectively. ST2 may reduce FNS in young children with CI. Differently from the electrical stimulation pattern, the cochlea-nerve and electrode-nerve distances seem to have limited effects on FNS in this population.

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21

Schoen, Ingmar, and Peter Fromherz. "Extracellular Stimulation of Mammalian Neurons Through Repetitive Activation of Na+ Channels by Weak Capacitive Currents on a Silicon Chip." Journal of Neurophysiology 100, no. 1 (July 2008): 346–57. http://dx.doi.org/10.1152/jn.90287.2008.

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Reliable extracellular stimulation of neuronal activity is the prerequisite for electrical interfacing of cultured networks and brain slices, as well as for neural implants. Safe stimulation must be achieved without damage to the cells. With respect to a future application of highly integrated semiconductor chips, we present an electrophysiological study of capacitive stimulation of mammalian cells in the geometry of adhesion on an insulated titanium dioxide/silicon electrode. We used HEK293 cells with overexpressed NaV1.4 channels and neurons from rat hippocampus. Weak biphasic stimuli of falling and rising voltage ramps were applied in the absence of Faradaic current and electroporation. We recorded the response of the intra- and extracellular voltage and evaluated the concomitant polarization of the attached and free cell membranes. Falling ramps efficiently depolarized the central area of the attached membrane. A transient sodium inward current was activated that gave rise to a weak depolarization of the cell on the order of 1 mV. The depolarization could be enhanced step by step by a train of biphasic stimuli until self-excitation of sodium channels set in. We applied the same protocol to cultured rat neurons and found that pulse trains of weak capacitive stimuli were able to elicit action potentials. Our results provide a basis for safe extracellular stimulation not only for cultured neurons on insulated semiconductor electrodes, but also more generally for metal electrodes in cell culture and brain tissue.

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22

ANDERSON, CORY, NATALIA TRAYANOVA, and KIRILL SKOUIBINE. "Termination of Spiral Waves with Biphasic Shocks: Role of Virtual Electrode Polarization." Journal of Cardiovascular Electrophysiology 11, no. 12 (December 2000): 1386–96. http://dx.doi.org/10.1046/j.1540-8167.2000.01386.x.

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23

MARKS, MELINDA L., GEORGE JOHNSON, BRADLEY O. HOFER, and GUST H. BARDY. "Biphasic Waveform Defibrillation Using a Three-Electrode Transvenous Lead System in Humans." Journal of Cardiovascular Electrophysiology 5, no. 2 (February 1994): 103–8. http://dx.doi.org/10.1111/j.1540-8167.1994.tb01149.x.

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24

Rajbongshi, Biju Mani, and Anil Verma. "Plasmonic noble metal coupled biphasic TiO2 electrode for dye-sensitized solar cell." Materials Letters 232 (December 2018): 220–23. http://dx.doi.org/10.1016/j.matlet.2018.08.114.

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25

Franck, Kevin H., Roger R. Marsh, Udayan K. Shah, and William P. Potsic. "Effects of Clarion Electrode Design on Mapping Levels in Children." Annals of Otology, Rhinology & Laryngology 111, no. 12 (December 2002): 1128–32. http://dx.doi.org/10.1177/000348940211101212.

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The design of the placement of the Clarion cochlear implant's intracochlear electrode array has undergone 2 revisions since its introduction, each to improve modiolar proximity. Stimulation with modiolar proximity may reduce current requirements for threshold levels and most comfortable levels of stimulation. This study analyzed the effects of electrode design on programming levels for deaf children implanted with the 3 cochlear implant designs and followed at The Children's Hospital of Philadelphia. Psychophysical data were reported if measurements were taken approximately 3 months after initial activation, and programming parameters included nonsequential monopolar stimulation of 75-μs-per-phase biphasic pulses presented at 813 Hz per electrode. The threshold level and most comfortable programming level were measured by standard clinical techniques appropriate for children. The results indicate that the 2 electrode placement revisions have each significantly reduced threshold levels and most comfortable stimulation levels. These results are discussed in the context of device aesthetics, safety, and function.

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Beitel, Ralph E., Russell L. Snyder, Christoph E. Schreiner, Marcia W. Raggio, and Patricia A. Leake. "Electrical Cochlear Stimulation in the Deaf Cat: Comparisons Between Psychophysical and Central Auditory Neuronal Thresholds." Journal of Neurophysiology 83, no. 4 (April 1, 2000): 2145–62. http://dx.doi.org/10.1152/jn.2000.83.4.2145.

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Cochlear prostheses for electrical stimulation of the auditory nerve (“electrical hearing”) can provide auditory capacity for profoundly deaf adults and children, including in many cases a restored ability to perceive speech without visual cues. A fundamental challenge in auditory neuroscience is to understand the neural and perceptual mechanisms that make rehabilitation of hearing possible in these deaf humans. We have developed a feline behavioral model that allows us to study behavioral and physiological variables in the same deaf animals. Cats deafened by injection of ototoxic antibiotics were implanted with either a monopolar round window electrode or a multichannel scala tympani electrode array. To evaluate the effects of perceptually significant electrical stimulation of the auditory nerve on the central auditory system, an animal was trained to avoid a mild electrocutaneous shock when biphasic current pulses (0.2 ms/phase) were delivered to its implanted cochlea. Psychophysical detection thresholds and electrical auditory brain stem response (EABR) thresholds were estimated in each cat. At the conclusion of behavioral testing, acute physiological experiments were conducted, and threshold responses were recorded for single neurons and multineuronal clusters in the central nucleus of the inferior colliculus (ICC) and the primary auditory cortex (A1). Behavioral and neurophysiological thresholds were evaluated with reference to cochlear histopathology in the same deaf cats. The results of the present study include: 1) in the cats implanted with a scala tympani electrode array, the lowest ICC and A1 neural thresholds were virtually identical to the behavioral thresholds for intracochlear bipolar stimulation; 2) behavioral thresholds were lower than ICC and A1 neural thresholds in each of the cats implanted with a monopolar round window electrode; 3) EABR thresholds were higher than behavioral thresholds in all of the cats (mean difference = 6.5 dB); and 4) the cumulative number of action potentials for a sample of ICC neurons increased monotonically as a function of the amplitude and the number of stimulating biphasic pulses. This physiological result suggests that the output from the ICC may be integrated spatially across neurons and temporally integrated across pulses when the auditory nerve array is stimulated with a train of biphasic current pulses. Because behavioral thresholds were lower and reaction times were faster at a pulse rate of 30 pps compared with a pulse rate of 2 pps, spatial-temporal integration in the central auditory system was presumably reflected in psychophysical performance.

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Rosahl, Steffen K., Gerhard Mark, Martin Herzog, Christos Pantazis, Farnaz Gharabaghi, Cordula Matthies, Thomas Brinker, and Madjid Samii. "Far-field responses to stimulation of the cochlear nucleus by microsurgically placed penetrating and surface electrodes in the cat." Journal of Neurosurgery 95, no. 5 (November 2001): 845–52. http://dx.doi.org/10.3171/jns.2001.95.5.0845.

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Object. A new generation of penetrating electrodes for auditory brainstem implants is on the verge of being introduced into clinical practice. This study was designed to compare electrically evoked auditory brainstem responses (EABRs) to stimulation of the cochlear nucleus (CN) by microsurgically implanted surface electrodes and insertion electrodes (INSELs) with stimulation areas of identical size. Methods. Via a lateral suboccipital approach, arrays of surface and penetrating microelectrodes with geometric stimulation areas measuring 4417 µm2 (diameter 75 µm) were placed over and inserted into the CN in 10 adult cats. After recording the auditory brainstem response (ABR) at the mastoid process, the CN, and the level of the inferior colliculus, EABRs to stimulation of the CN were recorded using biphasic, charge-balanced stimuli with phase durations of 80 µsec, 160 µsec, and 240 µsec at a repetition rate of 22.3 Hz. Waveform, threshold, maximum amplitude, and the dynamic range of the responses were compared for surface and penetrating electrodes. The EABR waveforms that appeared for both types of stimulation resembled each other closely. The mean impedance was slightly lower (30 ± 3.4 kΩ compared with 31.7 ± 4.5 kΩ, at 10 kHz), but the mean EABR threshold was significantly higher (51.8 µA compared with 40.5 µA, t = 3.5, p = 0.002) for surface electrode arrays as opposed to penetrating electrode arrays. Due to lower saturation levels of the INSEL array, dynamic ranges were almost identical between the two types of stimulation. Sectioning of the eighth cranial nerve did not abolish EABRs. Conclusions. Microsurgical insertion of electrodes into the CN complex may be guided and monitored using techniques similar to those applied for implantation of surface electrodes. Lower thresholds and almost equivalent dynamic ranges indicate that a more direct access to secondary auditory neurons is achieved using penetrating electrodes.

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Yeung, Jade, Peter G. R. Burke, Fiona L. Knapman, Jessica Patti, Elizabeth C. Brown, Simon C. Gandevia, Danny J. Eckert, Jane E. Butler, and Lynne E. Bilston. "Task-dependent neural control of regions within human genioglossus." Journal of Applied Physiology 132, no. 2 (February 1, 2022): 527–40. http://dx.doi.org/10.1152/japplphysiol.00478.2021.

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During swallowing, we observed two distinct, stereotyped muscle activation patterns that define the horizontal (monophasic, maximal EMG) and oblique (biphasic, submaximal EMG) neuromuscular compartments of genioglossus. In contrast, volitional tongue protrusions produced uniform activation across compartments. This provides evidence for task-dependent, functionally discrete neuromuscular control of the oblique and horizontal compartments of genioglossus. The magnitude and temporal patterning of genioglossus EMG during swallowing may help guide electrode placement in tongue EMG studies.

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McIntyre, Cameron C., and Warren M. Grill. "Extracellular Stimulation of Central Neurons: Influence of Stimulus Waveform and Frequency on Neuronal Output." Journal of Neurophysiology 88, no. 4 (October 1, 2002): 1592–604. http://dx.doi.org/10.1152/jn.2002.88.4.1592.

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The objective of this project was to examine the influence of stimulus waveform and frequency on extracellular stimulation of neurons with their cell bodies near the electrode (local cells) and fibers of passage in the CNS. Detailed computer-based models of CNS cells and axons were developed that accurately reproduced the dynamic firing properties of mammalian motoneurons including afterpotential shape, spike-frequency adaptation, and firing frequency as a function of stimulus amplitude. The neuron models were coupled to a three-dimensional finite element model of the spinal cord that solved for the potentials generated in the tissue medium by an extracellular electrode. Extracellular stimulation of the CNS with symmetrical charge balanced biphasic stimuli resulted in activation of fibers of passage, axon terminals, and local cells around the electrode at similar thresholds. While high stimulus frequencies enhanced activation of fibers of passage, a much more robust technique to achieve selective activation of targeted neuronal populations was via alterations in the stimulus waveform. Asymmetrical charge-balanced biphasic stimuli, consisting of a long-duration low-amplitude cathodic prepulse phase followed by a short-duration high-amplitude anodic stimulus phase, enabled selective activation of local cells. Conversely, an anodic prepulse phase followed by a cathodic stimulus phase enabled selective activation of fibers of passage. The threshold for activation of axon terminals in the vicinity of the electrode was lower than the threshold for direct activation of local cells, independent of the stimulus waveform. As a result, stimulation induced trans-synaptic influences (indirect depolarization/hyperpolarization) on local cells altered their neural output, and this indirect effect was dependent on stimulus frequency. If the indirect activation of local cells was inhibitory, there was little effect on the stimulation induced neural output of the local cells. However, if the indirect activation of the local cells was excitatory, attempts to activate selectively fibers of passage over local cells was limited. These outcomes provide a biophysical basis for understanding frequency-dependent outputs during CNS stimulation and provide useful tools for selective stimulation of the CNS.

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Rector, David M., Gina R. Poe, Morten P. Kristensen, and Ronald M. Harper. "Light Scattering Changes Follow Evoked Potentials From Hippocampal Schaeffer Collateral Stimulation." Journal of Neurophysiology 78, no. 3 (September 1, 1997): 1707–13. http://dx.doi.org/10.1152/jn.1997.78.3.1707.

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Rector, David M., Gina R. Poe, Morten P. Kristensen, and Ronald M. Harper. Light scattering changes follow evoked potentials from hippocampal Schaeffer collateral stimulation. J. Neurophysiol. 78: 1707–1713, 1997. We assessed relationships of evoked electrical and light scattering changes from cat dorsal hippocampus following Schaeffer collateral stimulation. Under anesthesia, eight stimulating electrodes were placed in the left hippocampal CA1 field and an optic probe, coupled to a photodiode or a charge-coupled device camera to detect scattered light changes, was lowered to the contralateral dorsal hippocampal surface. Light at 660 ± 10 (SE) nm illuminated the tissue through optic fibers surrounding the optic probe. An attached bipolar electrode recorded evoked right hippocampal commissural potentials. Electrode recordings and photodiode output were simultaneously acquired at 2.4 kHz during single biphasic pulse stimuli 0.5 ms in duration with 0.1-Hz intervals. Camera images were digitized at 100 Hz. An average of 150 responses was calculated for each of six stimulating current levels. Stimuli elicited a complex population synaptic potential that lasted 100–200 ms depending on stimulus intensity and electrode position. Light scattering changes peaked 20 ms after stimuli and occurred simultaneously with population spikes. A long-lasting light scattering component peaked 100–500 ms after the stimulus, concurrently with larger population postsynaptic potentials. Optical signals occurred over a time course similar to that for electrical signals and increased with larger stimulation amplitude to a maximum, then decreased with further increases in stimulation current. Camera images revealed a topographic response pattern that paralleled the photodiode measurements and depended on stimulation electrode position. Light scattering changes accompanied fast electrical responses, occurred too rapidly for perfusion, and showed a stimulus intensity relationship not consistent with glial changes.

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Schmidt, Anders Sjørslev, Kasper Glerup Lauridsen, Dorthe Svenstrup Møller, Per Dahl Christensen, Karen Kaae Dodt, Hans Rickers, Bo Løfgren, and Andi Eie Albertsen. "Anterior–Lateral Versus Anterior–Posterior Electrode Position for Cardioverting Atrial Fibrillation." Circulation 144, no. 25 (December 21, 2021): 1995–2003. http://dx.doi.org/10.1161/circulationaha.121.056301.

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Background: Smaller randomized studies have reported conflicting results regarding the optimal electrode position for cardioverting atrial fibrillation. However, anterior–posterior electrode positioning is widely used as a standard and believed to be superior to anterior–lateral electrode positioning. Therefore, we aimed to compare anterior–lateral and anterior–posterior electrode positioning for cardioverting atrial fibrillation in a multicenter randomized trial. Methods: In this multicenter, investigator-initiated, open-label trial, we randomly assigned patients with atrial fibrillation scheduled for elective cardioversion to either anterior–lateral or anterior–posterior electrode positioning. The primary outcome was the proportion of patients in sinus rhythm after the first shock. The secondary outcome was the proportion of patients in sinus rhythm after up to 4 shocks escalating to maximum energy. Safety outcomes were any cases of arrhythmia during or after cardioversion, skin redness, and patient-reported periprocedural pain. Results: We randomized 468 patients. The primary outcome occurred in 126 patients (54%) assigned to the anterior–lateral electrode position and in 77 patients (33%) assigned to the anterior–posterior electrode position (risk difference, 22 percentage points [95% CI, 13–30]; P <0.001). The number of patients in sinus rhythm after the final cardioversion shock was 216 (93%) assigned to anterior–lateral electrode positioning and 200 (85%) assigned to anterior–posterior electrode positioning (risk difference, 7 percentage points [95% CI, 2–12]). There were no significant differences between groups in any safety outcomes. Conclusions: Anterior–lateral electrode positioning was more effective than anterior–posterior electrode positioning for biphasic cardioversion of atrial fibrillation. There were no significant differences in any safety outcome. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03817372.

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Krishnan, Ashwati, Mats Forssell, Zhanhong Du, X. Tracy Cui, Gary K. Fedder, and Shawn K. Kelly. "Residual voltage as an ad-hoc indicator of electrode damage in biphasic electrical stimulation." Journal of Neural Engineering 18, no. 4 (August 1, 2021): 0460c1. http://dx.doi.org/10.1088/1741-2552/ac028a.

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Karlsson, Gudjon, Yi Zhang, L. Ray Davies, William Coddington, and Richard E. Kerber. "Does electrode polarity alter the energy requirements for transthoracic biphasic waveform defibrillation? Experimental studies." Resuscitation 51, no. 1 (October 2001): 77–81. http://dx.doi.org/10.1016/s0300-9572(01)00379-3.

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Guse, Paul A., Gregory P. Walcott, Dennis L. Rollins, William M. Smith, and Raymond E. Ideker. "Defibrillation electrode configurations developed from cardiac mapping that combine biphasic shocks with sequential timing." American Heart Journal 124, no. 6 (December 1992): 1491–500. http://dx.doi.org/10.1016/0002-8703(92)90062-z.

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Mimeault, Murielle, and Robert Carpentier. "Electrochemical differentiation between photosystem I and II in thylakoid membranes." Biochemistry and Cell Biology 66, no. 5 (May 1, 1988): 436–41. http://dx.doi.org/10.1139/o88-052.

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The current–voltage relationship of a thylakoid-containing electrochemical cell of small volume (80 μL) was determined in the dark and under illumination. The photocurrent produced was dependent on pH, on the type of artificial electron acceptor or inhibitor added, and on the electrode potential. Specific monitoring of photosystem-I and -II electron-transfer activity was possible. Photosystem II produced maximal photoeffect at pH 6.0, and the photocurrent–voltage behavior was monophasic. In contrast, photocurrent induction by photosystem I was maximal at pH 8.0 and a biphasic photocurrent–voltage dependency was obtained, presumably as a result of a redox potential barrier located on the donor side of photosystem I. It was concluded that the three-electrode system used is appropriate for measurement of the partial reactions of photosynthesis as well as the coupled photoreactions I and II using the same type of experiment.

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Chung, Won-Ho, Jong-Chan Lee, Do Yeon Cho, Eun Young Won, Yang-Sun Cho, and Sung Hwa Hong. "Waveform reliability with different recording electrode placement in facial electroneuronography." Journal of Laryngology & Otology 118, no. 6 (June 2004): 421–25. http://dx.doi.org/10.1258/002221504323219527.

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Electroneuronography (ENoG) has become a useful test for estimating the degree of facial nerve degeneration and predicting the prognosis in patients with facial nerve palsy. Test results may be influenced by several factors, including the electrode positions, skin resistance, stimulus magnitude, and possible artifacts. Regarding recording electrode positions, different groups have used two different locations, the nasolabial fold and nasal ala. The authors compared the waveforms recorded from these two locations in ENoG recordings to obtain the optimal waveform. Twenty healthy volunteers and 25 patients with unilateral facial nerve palsy were included in this study. Recordings were carried out with the recording electrode placed on the nasolabial fold, followed by placement on the nasal ala after 10 minutes. The following parameters were assessed: (1) the supramaximal threshold, (2) amplitude and shape of the waveform, (3) interside difference, and (4) test-retest variability. There was no significant difference in the amplitude of the waveform, interside difference, and test-retest variability between the two groups. However, when the electrode was placed on the nasal ala, the threshold was significantly lower, an ideal biphasic configuration was present in almost all cases (97.5 per cent) of normal volunteers and it was easier to identify the waveform. Placement of the recording electrode on the nasal ala would be the preferred method.

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Asai, Satoshi, Yuji Iribe, Tadashi Kohno, and Koichi Ishikawa. "Real time monitoring of biphasic glutamate release using dialysis electrode in rat acute brain ischemia." NeuroReport 7, no. 5 (April 1996): 1092–96. http://dx.doi.org/10.1097/00001756-199604100-00028.

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Asai, Satoshi, Yuji Iribe, Tadashi Kohno, Isaburo Hosoi, and Koichi Ishikawa. "Analysis of distinct biphasic glutamate release using a dialysis electrode in rat acute brain anoxia." Japanese Journal of Pharmacology 71 (1996): 189. http://dx.doi.org/10.1016/s0021-5198(19)36994-x.

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Bardy, Gust H., Margaret D. Allen, George Johnson, Rahul Mehra, and H. Leon Greene. "The effect of electrode systems and current pathways on biphasic waveform defibrillation efficacy in man." Journal of the American College of Cardiology 15, no. 2 (February 1990): A72. http://dx.doi.org/10.1016/0735-1097(90)92006-n.

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Menezes, AS, APM Nascente, BW Calaça, GM Silveira, and HPP Gama. "Stability overlapping biphasic impulse (OLBI) to atrial pacing using floating electrode: 36 months follow-up." EP Europace 2, Supplement_1 (January 2001): A12. http://dx.doi.org/10.1016/eupace/2.supplement_1.a12-b.

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Siaplaouras, Stephanos, Axel Buob, Carsten Rötter, Michael Böhm, and Jens Jung. "Randomized comparison of anterolateral versus anteroposterior electrode position for biphasic external cardioversion of atrial fibrillation." American Heart Journal 150, no. 1 (July 2005): 150–52. http://dx.doi.org/10.1016/j.ahj.2004.08.009.

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Rieiro, Héctor, Carolina Diaz-Piedra, José Miguel Morales, Andrés Catena, Samuel Romero, Joaquin Roca-Gonzalez, Luis J. Fuentes, and Leandro L. Di Stasi. "Validation of Electroencephalographic Recordings Obtained with a Consumer-Grade, Single Dry Electrode, Low-Cost Device: A Comparative Study." Sensors 19, no. 12 (June 23, 2019): 2808. http://dx.doi.org/10.3390/s19122808.

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The functional validity of the signal obtained with low-cost electroencephalography (EEG) devices is still under debate. Here, we have conducted an in-depth comparison of the EEG-recordings obtained with a medical-grade golden-cup electrodes ambulatory device, the SOMNOwatch + EEG-6, vs those obtained with a consumer-grade, single dry electrode low-cost device, the NeuroSky MindWave, one of the most affordable devices currently available. We recorded EEG signals at Fp1 using the two different devices simultaneously on 21 participants who underwent two experimental phases: a 12-minute resting state task (alternating two cycles of closed/open eyes periods), followed by 60-minute virtual-driving task. We evaluated the EEG recording quality by comparing the similarity between the temporal data series, their spectra, their signal-to-noise ratio, the reliability of EEG measurements (comparing the closed eyes periods), as well as their blink detection rate. We found substantial agreement between signals: whereas, qualitatively, the NeuroSky MindWave presented higher levels of noise and a biphasic shape of blinks, the similarity metric indicated that signals from both recording devices were significantly correlated. While the NeuroSky MindWave was less reliable, both devices had a similar blink detection rate. Overall, the NeuroSky MindWave is noise-limited, but provides stable recordings even through long periods of time. Furthermore, its data would be of adequate quality compared to that of conventional wet electrode EEG devices, except for a potential calibration error and spectral differences at low frequencies.

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Haginomori, Shin-Ichi, Atsuko Takamaki, and Hiroshi Takenaka. "S209 – Optimal Electrode Position for ENoG for Facial Palsy." Otolaryngology–Head and Neck Surgery 139, no. 2_suppl (August 2008): P145—P146. http://dx.doi.org/10.1016/j.otohns.2008.05.384.

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Objectives To develop a more simple procedure for electroneurography (ENoG) of facial palsy for assessing prognosis, we conducted a preliminary study to examine an optimal electrode position for recording evoked compound muscle action potentials (CMAPs) of the perioral muscles. Methods We evaluated a new method called the submentall method, in which the electrode connected to the negative input (G1) was placed on the skin over the orbicularis oris muscle, and the other electrode connected to the positive input of the amplifier (G2) was placed on the mental protuberance. We compared the amplitudes and morphology between the CMAPs recorded with this method and those recorded using the standard electrode positions (G1 placed on the skin over the orbicularis oris muscle; G2 placed on the nasolabial fold, closely lateral to the ala nasi). Furthermore, the amplitudes and waveforms of CMAPs were recorded from 4 different G1 positions on the skin over the orbicularis oris muscle, with G2 set on the mental protuberance. The main trunk of the facial nerve was stimulated by percutaneous supramaximal electrical stimulation beneath the auricle. Results The submental method gave greater amplitudes and more obvious biphasic CMAPs than those produced with the standard method. In the submental method, the optimal G1 recording electrode position was on the philtrum. Conclusions This recording procedure has the potential to be a simpler and more reliable method for calculating ENoG values than the standard method. However, further studies to establish prognostic criteria of ENoG for facial palsy are needed.

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Salah, Husam M., Subodh R. Devabhaktuni, Sanjay D. Shah, Abhishek Deshmukh, Hakan Paydak, J. Paul Mounsey, and Srikanth Vallurupalli. "Meta-Analysis Comparing Anterior-Lateral Versus Anterior-Posterior Electrode Position for Biphasic Cardioversion in Atrial Fibrillation." American Journal of Cardiology 169 (April 2022): 164–65. http://dx.doi.org/10.1016/j.amjcard.2022.02.002.

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Smith, David W., and Charles C. Finley. "Effects of electrode configuration on psychophysical strength-duration functions for single biphasic electrical stimuli in cats." Journal of the Acoustical Society of America 102, no. 4 (October 1997): 2228–37. http://dx.doi.org/10.1121/1.419636.

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Schauerte, Patrick N., Kathrin Ziegert, Matthias Waldmann, Friedrich A. Schöndube, Frank Birkenhauer, Karl Mischke, Marius Grossmann, Peter Hanrath, and Christoph Stellbrink. "Effect of Biphasic Shock Duration on Defibrillation Threshold With Different Electrode Configurations and Phase 2 Capacitances." Circulation 99, no. 11 (March 23, 1999): 1516–22. http://dx.doi.org/10.1161/01.cir.99.11.1516.

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YAMANOUCHI, YOSHIO, KENT A. MOWREY, GEORGE R. NADZAM, DONALD G. HILLS, MARK W. KROLL, JAMES E. BREWER, ANN M. DONOHOO, BRUCE L. WILKOFF, and PATRICK J. TCHOU. "Effects of Polarity on Defibrillation Thresholds Using a Biphasic Waveform in a Hot Can Electrode System." Pacing and Clinical Electrophysiology 20, no. 12 (December 1997): 2911–16. http://dx.doi.org/10.1111/j.1540-8159.1997.tb05459.x.

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Tan, Zhenjun T., Matthew Ward, Robert J. Phillips, Xueguo Zhang, Deborah M. Jaffey, Logan Chesney, Bartek Rajwa, Elizabeth A. Baronowsky, Jennifer McAdams, and Terry L. Powley. "Stomach region stimulated determines effects on duodenal motility in rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 320, no. 3 (March 1, 2021): R331—R341. http://dx.doi.org/10.1152/ajpregu.00111.2020.

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Gastric electrical stimulation (GES) is used clinically to promote proximal GI emptying and motility. In acute experiments, we measured duodenal motor responses elicited by GES applied at 141 randomly chosen electrode sites on the stomach serosal surface. Overnight-fasted (H2O available) anesthetized male rats ( n = 81) received intermittent biphasic GES for 5 min (20-s-on/40-s-off cycles; I = 0.3 mA; pw = 0.2 ms; 10 Hz). A strain gauge on the serosal surface of the proximal duodenum of each animal was used to evaluate baseline motor activity and the effect of GES. Using ratios of time blocks compared with a 15-min prestimulation baseline, we evaluated the effects of the 5-min stimulation on concurrent activity, on the 10 min immediately after the stimulation, and on the 15-min period beginning with the onset of stimulation. We mapped the magnitude of the duodenal response (three different motility indices) elicited from the 141 stomach sites. Post hoc electrode site maps associated with duodenal responses suggested three zones similar to the classic regions of forestomach, corpus, and antrum. Maximal excitatory duodenal motor responses were elicited from forestomach sites, whereas inhibitory responses occurred with stimulation of the corpus. Moderate excitatory duodenal responses occurred with stimulation of the antrum. Complex, weak inhibitory/excitatory responses were produced by stimulation at boundaries between stomach regions. Patterns of GES efficacies coincided with distributions of previously mapped vagal afferents, suggesting that excitation of the duodenum is strongest when GES electrodes are situated over stomach concentrations of vagal intramuscular arrays, putative stretch receptors in the muscle wall.

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Romański, Krzysztof. "Dose-related effects of cholecystokinin octapeptide administered during various phases of the migrating motor complex on small-intestinal motility in sheep." Acta Veterinaria Hungarica 57, no. 4 (December 1, 2009): 495–508. http://dx.doi.org/10.1556/avet.57.2009.4.4.

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Cholecystokinin (CCK) may affect intestinal motility, but in ruminants its precise effects have not been entirely explored. The aim of this study was to examine the effects of CCK-octapeptide (CCK-OP) on small-intestinal myoelectric activity in rams in the course of chronic experiments. Five rams underwent implantation of bipolar platinum electrodes to the duodenal bulb, distal duodenum, and jejunum as well as a strain gauge force transducer attached near the duodenal electrode. During continuous myoelectric recordings, 0.15 M NaCl or CCK-OP were injected slowly into the jugular vein. Injections of CCK-OP at doses of 20 (over 30 s), 200 (over 30 or 60 s) and 2000 (over 30, 60 or 120 s) ng/kg of body weight were each administered 5 or 30–40 min after the onset of the duodenal phase 1 or phase 2 of the migrating myoelectric complex (MMC), respectively. Most of these CCK doses were considered physiological. Injections of the smallest dose of CCK-OP exerted a slight and mostly insignificant inhibitory effect on the duodenal bulb and the duodenal myoelectric activity index (MAI) values. In the duodenal bulb, the effects of CCK-OP on myoelectric activity were dose dependent and closely related to the phase of the MMC. In the duodenum, the high dose of the hormone evoked short stimulatory and longer inhibitory biphasic effects on the MAI. These effects were inversely related to the duration of the hormone injection. It is concluded that CCK evokes a physiological stimulatory and inhibitory (biphasic) effect on the duodenal bulb and duodenal motility in sheep, with the inhibitory effect of the hormone being more pronounced in the duodenal bulb than in the duodenum. These effects were related to the CCK dose and the MMC phase. Therefore, CCK is an important regulator of upper small bowel motility in sheep.

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Fulceri, R., G. Bellomo, A. Gamberucci, and A. Benedetti. "MgATP-dependent accumulation of calcium ions and inorganic phosphate in a liver reticular pool." Biochemical Journal 272, no. 2 (December 1, 1990): 549–52. http://dx.doi.org/10.1042/bj2720549.

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1. MgATP-dependent Ca2+ uptake by rat liver microsomal preparations and permeabilized hepatocytes was measured in the presence or absence of Pi. 2. Monitoring of free Ca2+ in incubation systems with a Ca2+ electrode in the presence of Pi (2-7 mM) revealed a biphasic Ca2+ uptake, with the onset of a second, Pi-dependent, Ca2+ accumulation. 3. Increasing Pi concentrations (up to 10 mM) caused a progressive enlargement of 45Ca2(+)-loading capacity of microsomal fractions. 4. As a result of Pi stimulation of active Ca2+ uptake, [32P]Pi and 45Ca2+ were co-accumulated. 5. Experiments with permeabilized hepatocytes revealed that the amount of Ca2+ releasable by myo-inositol 1,4,5-trisphosphate is unaffected by Pi.

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