Journal articles: 'Single channel recording'

1

Berg, H. "Single channel recording." Bioelectrochemistry and Bioenergetics 39, no. 1 (February 1996): 152. http://dx.doi.org/10.1016/s0302-4598(96)90039-2.

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Plested, Andrew J. R. "Single-Channel Recording of Ligand-Gated Ion Channels." Cold Spring Harbor Protocols 2016, no. 8 (August 2016): pdb.top087239. http://dx.doi.org/10.1101/pdb.top087239.

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Mortensen, Martin, and Trevor G. Smart. "Single-channel recording of ligand-gated ion channels." Nature Protocols 2, no. 11 (November 2007): 2826–41. http://dx.doi.org/10.1038/nprot.2007.403.

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Franciolini, F., and A. Petris. "Single channel recording and gating function of ionic channels." Experientia 44, no. 3 (March 1988): 183–88. http://dx.doi.org/10.1007/bf01941702.

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Carter, Alison A., and Robert E. Oswald. "Linear prediction and single-channel recording." Journal of Neuroscience Methods 60, no. 1-2 (August 1995): 69–78. http://dx.doi.org/10.1016/0165-0270(94)00221-2.

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Yang, Youshan, and Fred J. Sigworth. "Single-Channel Properties of IKs Potassium Channels." Journal of General Physiology 112, no. 6 (December 1, 1998): 665–78. http://dx.doi.org/10.1085/jgp.112.6.665.

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Expressed in Xenopus oocytes, KvLQT1 channel subunits yield a small, rapidly activating, voltage- dependent potassium conductance. When coexpressed with the minK gene product, a slowly activating and much larger potassium current results. Using fluctuation analysis and single-channel recordings, we have studied the currents formed by human KvLQT1 subunits alone and in conjunction with human or rat minK subunits. With low external K+, the single-channel conductances of these three channel types are estimated to be 0.7, 4.5, and 6.5 pS, respectively, based on noise analysis at 20 kHz bandwidth of currents at +50 mV. Power spectra computed over the range 0.1 Hz–20 kHz show a weak frequency dependence, consistent with current interruptions occurring on a broad range of time scales. The broad spectrum causes the apparent single-channel current value to depend on the bandwidth of the recording, and is mirrored in very “flickery” single-channel events of the channels from coexpressed KvLQT1 and human minK subunits. The increase in macroscopic current due to the presence of the minK subunit is accounted for by the increased apparent single-channel conductance it confers on the expressed channels. The rat minK subunit also confers the property that the outward single-channel current is increased by external potassium ions.

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Dynes, Joseph L., Anna Amcheslavsky, and Michael D. Cahalan. "Genetically targeted single-channel optical recording reveals multiple Orai1 gating states and oscillations in calcium influx." Proceedings of the National Academy of Sciences 113, no. 2 (December 28, 2015): 440–45. http://dx.doi.org/10.1073/pnas.1523410113.

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Orai1 comprises the pore-forming subunit of the Ca2+ release-activated Ca2+ (CRAC) channel. When bound and activated by stromal interacting molecule 1 (STIM1), an endoplasmic reticulum (ER)-resident calcium sensor, Orai1 channels possess high selectivity for calcium but extremely small conductance that has precluded direct recording of single-channel currents. We have developed an approach to visualize Orai1 activity by fusing Orai1 to fluorescent, genetically encoded calcium indicators (GECIs). The GECI–Orai1 probes reveal local Ca2+ influx at STIM1–Orai1 puncta. By whole cell recording, these fusions are fully functional as CRAC channels. When GECI–Orai1 and the CRAC-activating domain (CAD) of STIM1 were coexpressed at low levels and imaged using a total internal reflectance fluorescence microscope, cells exhibited sporadic fluorescence transients the size of diffraction-limited spots and the brightness of a few activated GECI proteins. Transients typically rose rapidly and fell into two classes according to duration: briefer “flickers” lasting only a few hundred milliseconds, and longer “pulses” lasting one to several seconds. The size, intensity, trace shape, frequency, distribution, physiological characteristics, and association with CAD binding together demonstrate that GECI–Orai1 fluorescence transients correspond to single-channel Orai1 responses. Single Orai1 channels gated by CAD, and small Orai1 puncta gated by STIM1, exhibit repetitive fluctuations in single-channel output. CAD binding supports a role in open state maintenance and reveals a second phase of CAD/STIM1 binding after channel opening. These first recordings of single-channel Orai1 currents reveal unexpected dynamics, and when paired with CAD association, support multiple single-channel states.

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Popović, Nenad B., Nadica Miljković, and Mirjana B. Popović. "Simple gastric motility assessment method with a single-channel electrogastrogram." Biomedical Engineering / Biomedizinische Technik 64, no. 2 (April 24, 2019): 177–85. http://dx.doi.org/10.1515/bmt-2017-0218.

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Abstract Surface electrogastrography (EGG) is a non-invasive technique that is used to record myoelectrical activity of the stomach using cutaneous electrodes placed on the abdomen. Gastric motility assessment by EGG is a candidate for standard clinical procedure based on the quantification of parameters characteristic of gastric motility disorders. Despite its noticeable benefits, EGG is not widely implemented in clinical practice. The main reasons are: (1) lack of standardization of electrode placement, (2) time-consuming diagnostic procedures and (3) a complex multi-channel recording setup. We proposed a methodology in which an easy-to-use single-channel EGG, with a less time-consuming protocol (<1 h), would provide sufficient information for gastric motility assessment. Recordings from the three anatomical landmarks in 20 healthy young subjects were compared under two conditions, fasting and postprandial by evaluating the dominant frequency (DF). Our results showed that there is a statistically significant increase of DF after meal ingestion (p<0.05) in each of the three channels. However, when the study group was divided into two subgroups based on body mass index (BMI), the most appropriate recording location was above the body of the stomach (according to statistical significance p=7.82×10−6). We showed that a less time-consuming recording session with light meal intake could be used for the assessment of gastric myoelectrical activity (GMA).

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Schoenfeld, R. L. "From Einthoven's galvanometer to single-channel recording." IEEE Engineering in Medicine and Biology Magazine 21, no. 3 (May 2002): 90–96. http://dx.doi.org/10.1109/memb.2002.1016853.

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Pottosin, Igor I. "Single channel recording in the chloroplast envelope." FEBS Letters 308, no. 1 (August 10, 1992): 87–90. http://dx.doi.org/10.1016/0014-5793(92)81057-s.

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Robertson, Alan P., Sreekanth Puttachary, and Richard J. Martin. "Single-channel recording from adult Brugia malayi." Invertebrate Neuroscience 11, no. 1 (May 18, 2011): 53–57. http://dx.doi.org/10.1007/s10158-011-0118-1.

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12

Zheng, Jie. "Patch Fluorometry: Shedding New Light on Ion Channels." Physiology 21, no. 1 (February 2006): 6–12. http://dx.doi.org/10.1152/physiol.00041.2005.

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Patch fluorometry has emerged as a new approach to the study of the structure-function relationship in membrane-embedded functional ion channels. Simultaneous fluorescent and electrical recordings are achieved from a small number of channels in a cell-free membrane patch, yielding high recording sensitivities. Further improvement of this approach should permit direct observation of the gating motion of a single-channel protein.

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Puthumadathil, Neethu, Poornendhu Jayasree, K. Santhosh Kumar, K. Madhavan Nampoothiri, Harsha Bajaj, and Kozhinjampara R. Mahendran. "Detecting the structural assembly pathway of human antimicrobial peptide pores at single-channel level." Biomaterials Science 7, no. 8 (2019): 3226–37. http://dx.doi.org/10.1039/c9bm00181f.

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Bruhn, Brandon R., and Michael Mayer. "Dual-Pore Glass Chips for Single-Channel Recording." Biophysical Journal 104, no. 2 (January 2013): 673a. http://dx.doi.org/10.1016/j.bpj.2012.11.3715.

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Wu, Guangyan, Shunjin Li, Guangning Zong, Xiaofen Liu, Shuang Fei, Linda Shen, Xiangchen Guan, Xue Yang, and Yuequan Shen. "Single channel recording of a mitochondrial calcium uniporter." Biochemical and Biophysical Research Communications 496, no. 1 (January 2018): 127–32. http://dx.doi.org/10.1016/j.bbrc.2018.01.010.

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ROBERTSON, A. P., R. J. MARTIN, and J. R. KUSEL. "A vesicle preparation for resolving single-channel currents in tegument of male Schistosoma mansoni." Parasitology 115, no. 2 (August 1997): 183–92. http://dx.doi.org/10.1017/s0031182097001273.

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A tegumental vesicle preparation from adult male Schistosoma mansoni was developed that allows the resolution of single ion-channel currents. Adult male schistosomes were exposed to a low pH (3·75) medium for a period of approximately 30 min at 37°C. During this period smooth vesicles formed from the tegument. Fluorescence microscopy following staining of the tegument with the dye, 5-N-[octadecanoyl]aminofluorescein (AF-18), transmission electron microscopy and scanning electron microscopy revealed that the vesicles were produced from the outer tegumental membrane. The fluorescence studies showed the presence of the double bilayer structure of the outer membrane in >41% of the vesicles. These studies suggested that the preparation is suitable for single-channel recording with the patch-clamp technique. Cell-attached and isolated inside-out patch recordings of ion-channel activity were obtained with giga-ohm resistance seals. Different types of ion-channel were recorded from tegumental vesicles from male schistosomes, illustrating the potential of the technique. The channels observed included: a non-selective cation channel (360 pS); a K+ channel (with a conductance of 115 pS in high bath-K conditions); and a Cl− selective channel (20 pS). The currents of these ion-channels may cross the double bilayer of the outer tegumental membrane.

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Gryboś, Paweł, Piotr Kmon, Robert Szczygieł, and Mirosław Żołądź. "64 Channel ASIC for Neurobiology Experiments." International Journal of Electronics and Telecommunications 56, no. 4 (November 1, 2010): 375–80. http://dx.doi.org/10.2478/v10177-010-0049-5.

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64 Channel ASIC for Neurobiology ExperimentsThis paper presents the design and measurements of 64 channel Application Specific Integrated Circuits (ASIC) for recording signals in neurobiology experiments. The ASIC is designed in 180 nm technology and operates with ± 0.9 V supply voltage. Single readout channel is built of AC coupling circuit at the input and two amplifier stages. In order to reduce the number of output lines, the 64 analogue signals from readout channels are multiplexed to a single output by an analogue multiplexer. The gain of the single channel can be set either to 350 V/V or 700 V/V. The low and the high cut-off frequencies can be tuned in 9 ÷ 90 Hz and in the 1.6 ÷ 24 kHz range respectively. The input referred noise is 7 μV rms in the bandwidth 90 Hz - 1.6 kHz and 9 μV rms in the bandwidth 9 Hz - 24 kHz. The single channel consumes 200 μW of power and this together with other parameters make the chip suitable for recording neurobiology signals.

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Rogawski, M. A. "Single voltage-dependent potassium channels in cultured rat hippocampal neurons." Journal of Neurophysiology 56, no. 2 (August 1, 1986): 481–93. http://dx.doi.org/10.1152/jn.1986.56.2.481.

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Single-channel recordings using the gigohm seal patch-clamp technique were carried out on the somatic membranes of dissociated embryonic rat hippocampal neurons grown in cell culture. The recording medium contained tetrodotoxin to block the voltage-dependent Na+ conductance and Cd2+ to block Ca2+ and Ca2+-activated conductances. In the cell-attached configuration, depolarizing voltage steps activated outward directed single-channel currents with conductance 15-20 pS. The channel openings exhibited a moderate degree of flickering. The mean burst lifetimes ranged from 5 to 13 ms with a tendency to increase slightly at more depolarized potentials (T = 21-25 degrees C). Reversal potential measurements using excised membrane patches indicated that the channels behaved as expected of a K+-selective membrane pore. Channel opening occurred in Ca2+-free EGTA-containing solutions but was never observed in the presence of tetraethylammonium (TEA; 20 mM). The frequency of channel opening increased as the membrane was depolarized by up to 50 mV from resting potential; the fraction of time spent in the open state during the first 300 ms following a step depolarization increased e-fold for a 8-25 mV change in potential. First-latency histograms and simulations of the macroscopic current based on channel data obtained during repeated depolarizing voltage steps indicated that the probability of the channel being in the open state increases gradually with time after a step depolarization. During repeated depolarizing steps the channels appeared to randomly enter and exit a long-lived inactive state. It is concluded that these channels may underly the slowly activating, very slowly inactivating, TEA-sensitive voltage-dependent K+ current (IK) in cultured hippocampal neurons.

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Worden, M. K., R. Rahamimoff, and E. A. Kravitz. "Ion channel activity in lobster skeletal muscle membrane." Journal of Experimental Biology 182, no. 1 (September 1, 1993): 113–30. http://dx.doi.org/10.1242/jeb.182.1.113.

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Ion channel activity in the sarcolemmal membrane of muscle fibers is critical for regulating the excitability, and therefore the contractility, of muscle. To begin the characterization of the biophysical properties of the sarcolemmal membrane of lobster exoskeletal muscle fibers, recordings were made from excised patches of membrane from enzymatically induced muscle fiber blebs. Blebs formed as evaginations of the muscle sarcolemmal membrane and were sufficiently free of extracellular debris to allow the formation of gigaohm seals. Under simple experimental conditions using bi-ionic symmetrical recording solutions and maintained holding potentials, a variety of single channel types with conductances in the range 32–380 pS were detected. Two of these ion channel species are described in detail, both are cation channels selective for potassium. They can be distinguished from each other on the basis of their single-channel conductance and gating properties. The results suggest that current flows through a large number of ion channels that open spontaneously in bleb membranes in the absence of exogenous metabolites or hormones.

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Vanuytsel, Steven, Christopher L. Parperis, and Mark I. Wallace. "Combined Single-Molecule FRET and Single-Channel Recording to Link Ion Channel Conformation and Function." Biophysical Journal 118, no. 3 (February 2020): 466a—467a. http://dx.doi.org/10.1016/j.bpj.2019.11.2591.

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Hirano, Minako, Daiki Yamamoto, Mami Asakura, Tohru Hayakawa, Shintaro Mise, Akinobu Matsumoto, and Toru Ide. "A Lipid Bilayer Formed on a Hydrogel Bead for Single Ion Channel Recordings." Micromachines 11, no. 12 (December 1, 2020): 1070. http://dx.doi.org/10.3390/mi11121070.

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Ion channel proteins play important roles in various cell functions, making them attractive drug targets. Artificial lipid bilayer recording is a technique used to measure the ion transport activities of channel proteins with high sensitivity and accuracy. However, the measurement efficiency is low. In order to improve the efficiency, we developed a method that allows us to form bilayers on a hydrogel bead and record channel currents promptly. We tested our system by measuring the activities of various types of channels, including gramicidin, alamethicin, α-hemolysin, a voltage-dependent anion channel 1 (VDAC1), a voltage- and calcium-activated large conductance potassium channel (BK channel), and a potassium channel from Streptomyces lividans (KcsA channel). We confirmed the ability for enhanced measurement efficiency and measurement system miniaturizion.

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Lekovic, Gregory P., John F. Kerrigan, Scott Wait, Harold L. Rekate, and Peter N. Steinmetz. "IN SITU SINGLE-UNIT RECORDING OF HYPOTHALAMIC HAMARTOMAS UNDER ENDOSCOPIC DIRECT VISUALIZATION." Neurosurgery 65, no. 6 (December 1, 2009): E1195—E1196. http://dx.doi.org/10.1227/01.neu.0000359531.45021.52.

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Abstract OBJECTIVE Hypothalamic hamartomas (HHs) are associated with refractory epilepsy and are amenable to surgical treatment. The gelastic seizures associated with HHs originate within the HH lesion, but the responsible cellular mechanisms are unknown. Microelectrode patch-clamp recordings from HH neurons in resected slice preparations show that small HH neurons spontaneously fire with intrinsic pacemaker-like activity. We questioned whether spontaneous firing of HH neurons was present in situ, and we hypothesized that single-unit field recordings from HH tissue could be obtained with instrumentation passed through the endoscope before surgical resection. TECHNIQUE After informed consent was obtained, patients undergoing transventricular, endoscopic resection of an HH for intractable epilepsy were eligible for study. After placement of the endoscope, a bundled microwire (total of 9 contacts) was placed into the HH under direct visualization. Spontaneous activity was recorded for two or three 5-minute epochs, under steady-state general anesthesia. The wire was advanced 0.5 to 1 mm within the lesion between recording epochs. RESULTS A total of thirteen 5-minute recordings were obtained from 5 patients. Noise levels were comparable to extraoperative microwire recordings for temporal lobe epilepsy. Single-neuron spike activity was isolated from a total of 5 channels obtained during recording of 3 sessions in 3 patients. CONCLUSION We have shown that single-unit recordings from HH lesions can be successfully obtained in situ under direct endoscopic visualization. We believe that this is the first report using the working channel of a neuroendoscope to make physiological recordings of deep structures in humans.

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Brown, Austin L., Zhiwen Liao, and Miriam B. Goodman. "MEC-2 and MEC-6 in the Caenorhabditis elegans Sensory Mechanotransduction Complex: Auxiliary Subunits that Enable Channel Activity." Journal of General Physiology 131, no. 6 (May 26, 2008): 605–16. http://dx.doi.org/10.1085/jgp.200709910.

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The ion channel formed by the homologous proteins MEC-4 and MEC-10 forms the core of a sensory mechanotransduction channel in Caenorhabditis elegans. Although the products of other mec genes are key players in the biophysics of transduction, the mechanism by which they contribute to the properties of the channel is unknown. Here, we investigate the role of two auxiliary channel subunits, MEC-2 (stomatin-like) and MEC-6 (paraoxonase-like), by coexpressing them with constitutively active MEC-4/MEC-10 heteromeric channels in Xenopus oocytes. This work extends prior work demonstrating that MEC-2 and MEC-6 synergistically increase macroscopic current. We use single-channel recordings and biochemistry to show that these auxiliary subunits alter function by increasing the number of channels in an active state rather than by dramatically affecting either single-channel properties or surface expression. We also use two-electrode voltage clamp and outside-out macropatch recording to examine the effects of divalent cations and proteases, known regulators of channel family members. Finally, we examine the role of cholesterol binding in the mechanism of MEC-2 action by measuring whole-cell and single-channel currents in MEC-2 mutants deficient in cholesterol binding. We suggest that MEC-2 and MEC-6 play essential roles in modulating both the local membrane environment of MEC-4/MEC-10 channels and the availability of such channels to be gated by force in vivo.

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Johnstone, Stuart J., Russell Blackman, and Jason M. Bruggemann. "EEG From a Single-Channel Dry-Sensor Recording Device." Clinical EEG and Neuroscience 43, no. 2 (March 27, 2012): 112–20. http://dx.doi.org/10.1177/1550059411435857.

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Coleman, C. H., D. A. Lindholm, D. A. Petersen, and R. Wood. "High data rate magnetic recording in a single channel." Journal of the Institution of Electronic and Radio Engineers 55, no. 6 (1985): 229. http://dx.doi.org/10.1049/jiere.1985.0075.

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Mathers, D. A. "The GABAA receptor: New insights from single-channel recording." Synapse 1, no. 1 (1987): 96–101. http://dx.doi.org/10.1002/syn.890010113.

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Mak, Don-On Daniel, Sean McBride, Viswanathan Raghuram, Yun Yue, Suresh K. Joseph, and J. Kevin Foskett. "Single-Channel Properties in Endoplasmic Reticulum Membrane of Recombinant Type 3 Inositol Trisphosphate Receptor." Journal of General Physiology 115, no. 3 (February 14, 2000): 241–56. http://dx.doi.org/10.1085/jgp.115.3.241.

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The inositol 1,4,5-trisphosphate receptor (InsP3R) is an intracellular Ca2+-release channel localized in endoplasmic reticulum (ER) with a central role in complex Ca2+ signaling in most cell types. A family of InsP3Rs encoded by several genes has been identified with different primary sequences, subcellular locations, variable ratios of expression, and heteromultimer formation. This diversity suggests that cells require distinct InsP3Rs, but the functional correlates of this diversity are largely unknown. Lacking are single-channel recordings of the recombinant type 3 receptor (InsP3R-3), a widely expressed isoform also implicated in plasma membrane Ca2+ influx and apoptosis. Here, we describe functional expression and single-channel recording of recombinant rat InsP3R-3 in its native membrane environment. The approach we describe suggests a novel strategy for expression and recording of recombinant ER-localized ion channels in the ER membrane. Ion permeation and channel gating properties of the rat InsP3R-3 are strikingly similar to those of Xenopus type 1 InsP3R in the same membrane. Using two different two-electrode voltage clamp protocols to examine calcium store-operated calcium influx, no difference in the magnitude of calcium influx was observed in oocytes injected with rat InsP3R-3 cRNA compared with control oocytes. Our results suggest that if cellular expression of multiple InsP3R isoforms is a mechanism to modify the temporal and spatial features of [Ca2+]i signals, then it must be achieved by isoform-specific regulation or localization of various types of InsP3Rs that have relatively similar Ca2+ permeation properties.

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Ball, F., R. K. Milne, and G. F. Yeo. "Multivariate semi-Markov analysis of burst properties of multiconductance single ion channels." Journal of Applied Probability 39, no. 01 (March 2002): 179–96. http://dx.doi.org/10.1017/s0021900200021598.

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Patch clamp recordings from ion channels often show periods of repetitive activity, known as bursts, which are noticeably separated from each other by periods of inactivity. Depending on the type of channel, such recordings may exhibit (conductance) levels between the closed (zero) level and the fully open level. Properties of bursts are less subject to problems that arise from recording than are properties for individual sojourns at different levels, and study of bursting behaviour provides important information about the finer structure of the underlying channel gating process. For a general finite state space continuous-time Markov chain model allowing one or more nonzero conductance levels, the present paper establishes results about the semi-Markov structure of a single burst and of a sequence of bursts, and uses this in a unified approach to properties of both theoretical and empirical bursts. The distribution and moments of particular burst properties, including the total charge transfer, the total sojourn time and the total number of visits to specified conductance levels during a burst, are derived. Various extensions are also described.

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Ball, F., R. K. Milne, and G. F. Yeo. "Multivariate semi-Markov analysis of burst properties of multiconductance single ion channels." Journal of Applied Probability 39, no. 1 (March 2002): 179–96. http://dx.doi.org/10.1239/jap/1019737996.

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Patch clamp recordings from ion channels often show periods of repetitive activity, known as bursts, which are noticeably separated from each other by periods of inactivity. Depending on the type of channel, such recordings may exhibit (conductance) levels between the closed (zero) level and the fully open level. Properties of bursts are less subject to problems that arise from recording than are properties for individual sojourns at different levels, and study of bursting behaviour provides important information about the finer structure of the underlying channel gating process. For a general finite state space continuous-time Markov chain model allowing one or more nonzero conductance levels, the present paper establishes results about the semi-Markov structure of a single burst and of a sequence of bursts, and uses this in a unified approach to properties of both theoretical and empirical bursts. The distribution and moments of particular burst properties, including the total charge transfer, the total sojourn time and the total number of visits to specified conductance levels during a burst, are derived. Various extensions are also described.

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Demuro, Angelo, and Ian Parker. "“Optical Patch-clamping”." Journal of General Physiology 126, no. 3 (August 15, 2005): 179–92. http://dx.doi.org/10.1085/jgp.200509331.

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We describe an optical technique using total internal reflection fluorescence (TIRF) microscopy to obtain simultaneous and independent recordings from numerous ion channels via imaging of single-channel Ca2+ flux. Muscle nicotinic acetylcholine (ACh) receptors made up of αβγδ subunits were expressed in Xenopus oocytes, and single channel Ca2+ fluorescence transients (SCCaFTs) were imaged using a fast (500 fps) electron-multiplied c.c.d. camera with fluo-4 as the indicator. Consistent with their arising through openings of individual nicotinic channels, SCCaFTs were seen only when a nicotinic agonist was present in the bathing solution, were blocked by curare, and increased in frequency as roughly the second power of [ACh]. Their fluorescence amplitudes varied linearly with membrane potential and extrapolated to zero at about +60 mV. The rise and fall times of fluorescence were as fast as 2 ms, providing a kinetic resolution adequate to characterize channel gating kinetics; which showed mean open times of 7.9 and 15.8 ms when activated, respectively, by ACh or suberyldicholine. Simultaneous records were obtained from >400 channels in the imaging field, and we devised a novel “channel chip” representation to depict the resultant large dataset as a single image. The positions of SCCaFTs remained fixed (<100 nm displacement) over tens of seconds, indicating that the nicotinic receptor/channels are anchored in the oocyte membrane; and the spatial distribution of channels appeared random without evidence of clustering. Our results extend single-channel TIRFM imaging to ligand-gated channels that display only partial permeability to Ca2+, and demonstrate an order-of-magnitude improvement in kinetic resolution. We believe that functional single-channel imaging opens a new approach to ion channel study, having particular advantages over patch-clamp recording in that it is massively parallel, and provides high-resolution spatial information that is inaccessible by electrophysiological techniques.

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Hagras, Shaimaa, Reham R. Mostafa, and Ahmed Abou elfetouh. "A Biometric System Based on Single-channel EEG Recording in One-second." International Journal of Intelligent Systems and Applications 12, no. 5 (October 8, 2020): 28–40. http://dx.doi.org/10.5815/ijisa.2020.05.03.

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In recent years, there are great research interests in using the Electroencephalogram (EEG) signals in biometrics applications. The strength of EEG signals as a biometric comes from its major fraud prevention capability. However, EEG signals are so sensitive, and many factors affect its usage as a biometric; two of these factors are the number of channels, and the required time for acquiring the signal; these factors affect the convenience and practicality. This study proposes a novel approach for EEG-based biometrics that optimizes the channels of acquiring data to only one channel. And the time to only one second. The results are compared against five commonly used classifiers named: KNN, Random Forest (RF), Support Vector Machine (SVM), Decision Tables (DT), and Naïve Bayes (NB). We test the approach on the public Texas data repository. The results prove the constancy of the approach for the eight minutes. The best result of the eyes-closed scenario is Average True Positive Rate (TPR) 99.1% and 98.2% for the eyes-opened. And it reaches 100% for multiple subjects.

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Jonas, P., M. E. Brau, M. Hermsteiner, and W. Vogel. "Single-channel recording in myelinated nerve fibers reveals one type of Na channel but different K channels." Proceedings of the National Academy of Sciences 86, no. 18 (September 1, 1989): 7238–42. http://dx.doi.org/10.1073/pnas.86.18.7238.

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Hoshi, T., and R. W. Aldrich. "Voltage-dependent K+ currents and underlying single K+ channels in pheochromocytoma cells." Journal of General Physiology 91, no. 1 (January 1, 1988): 73–106. http://dx.doi.org/10.1085/jgp.91.1.73.

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Properties of the whole-cell K+ currents and voltage-dependent activation and inactivation properties of single K+ channels in clonal pheochromocytoma (PC-12) cells were studied using the patch-clamp recording technique. Depolarizing pulses elicited slowly inactivating whole-cell K+ currents, which were blocked by external application of tetraethylammonium+, 4-aminopyridine, and quinidine. The amplitudes and time courses of these K+ currents were largely independent of the prepulse voltage. Although pharmacological agents and manipulation of the voltage-clamp pulse protocol failed to reveal any additional separable whole-cell currents in a majority of the cells examined, single-channel recordings showed that, in addition to the large Ca++-dependent K+ channels described previously in many other preparations, PC-12 cells had at least four distinct types of K+ channels activated by depolarization. These four types of K+ channels differed in the open-channel current-voltage relation, time course of activation and inactivation, and voltage dependence of activation and inactivation. These K+ channels were designated the Kw, Kz, Ky, and Kx channels. The typical chord conductances of these channels were 18, 12, 7, and 7 pS in the excised configuration using Na+-free saline solutions. These four types of K+ channels opened in the presence of low concentrations of internal Ca++ (1 nM). Their voltage-dependent gating properties can account for the properties of the whole-cell K+ currents in PC-12 cells.

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Schreibmayer, W., E. Hofer, P. Wolf, A. Lueger, and H. A. Tritthart. "Analysis of Single Channel Currents with a Microprocessor Based Device." Zeitschrift für Naturforschung C 42, no. 3 (March 1, 1987): 173–77. http://dx.doi.org/10.1515/znc-1987-0301.

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Data evaluation of single channel currents obtained from artificial black lipid membranes and with the patch clamp method is an important part of every single channel study, but it is a time consuming part often exceeding the time for experimentation and recording by far. We describe here a microprocessor based device, which allows the experimentator to analyse in a simple way the distribution of current levels in a single channel trace (amplitude-histogram analysis of single channel currents) either online, or offline. Current levels are sampled at a constant frequency of 6 kHz and the relative frequencies of occurrence of these current levels are displayed as a histogram on the screen of an analog or digital storage oscilloscope. The data reducing algorithm of this analyser eliminates the requirement of large amounts of mass storage that normally is needed for digital amplitude-histogram analysis of single channel recordings. Examples of evaluation for both a voltage operated cation-channel and a blockage of a potassium channel by tetraethylammoniumchloride (TEA) are given.

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35

Kerschbaum, H. H. "Single-Channel Recording of a Store-Operated Ca2+ Channel in Jurkat T Lymphocytes." Science 283, no. 5403 (February 5, 1999): 836–39. http://dx.doi.org/10.1126/science.283.5403.836.

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36

Devor, D. C., J. N. Forrest, W. K. Suggs, and R. A. Frizzell. "cAMP-activated Cl- channels in primary cultures of spiny dogfish (Squalus acanthias) rectal gland." American Journal of Physiology-Cell Physiology 268, no. 1 (January 1, 1995): C70—C79. http://dx.doi.org/10.1152/ajpcell.1995.268.1.c70.

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Whole cell and single-channel patch-clamp techniques were used to identify and characterize the Cl- currents responsible for adenosine 3',5'-cyclic monophosphate (cAMP)-mediated Cl- secretion in the rectal gland of the spiny dogfish (Squalus acanthias). During whole cell recordings, in cultured rectal gland cells forskolin (10 microM) and 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate (400 microM) stimulated a 28-fold increase in Cl- conductance (n = 10). This cAMP-activated conductance pathway had a linear current-voltage (I-V) relationship that was time and voltage independent. Substitution of 235 meq Cl- with I- in the bath inhibited the cAMP-activated current at both positive and negative voltages (64%). Glibenclamide (60 microM) abolished the cAMP-stimulated current, and its effect was irreversible (n = 3). During cell-attached recording, increased cellular cAMP activated single Cl- channels in nine previously quiet patches. These channels had a linear I-V relationship with an average single-channel conductance of 5.1 +/- 0.2 pS (n = 6). Similar properties were observed in excised inside-out patches, permitting further characterization of the single-channel properties. Excised quiescent patches could be activated by the addition of ATP and protein kinase A. Replacing bath Cl- with I- inhibited both inward and outward currents (n = 3). In three inside-out patches, glibenclamide (300 microM) reversibly reduced open probability by 74%, with no effect on single-channel current amplitude. Similar results were obtained in four outside-out recordings. These results suggest that increased cellular cAMP in dogfish rectal gland activates a small linear Cl- channel that resembles human cystic fibrosis transmembrane conductance regulator in its biophysical and pharmacological properties.

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37

Benzinger, G. Richard, Xiao-Ming Xia, and Christopher J. Lingle. "Direct Observation of a Preinactivated, Open State in BK Channels with β2 Subunits." Journal of General Physiology 127, no. 2 (January 17, 2006): 119–31. http://dx.doi.org/10.1085/jgp.200509425.

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Proteins arising from the Slo family assemble into homotetramers to form functional large-conductance, Ca2+- and voltage-activated K+ channels, or BK channels. These channels are also found in association with accessory β subunits, which modulate several aspects of channel gating and expression. Coexpression with either of two such subunits, β2 or β3b, confers time-dependent inactivation onto BK currents. mSlo1+β3b channels display inactivation that is very rapid but incomplete. Previous studies involving macroscopic recordings from these channels have argued for the existence of a second, short-lived conducting state in rapid equilibrium with the nonconducting, inactivated conformation. This state has been termed “pre-inactivated,” or O*. β2-mediated inactivation, in contrast, occurs more slowly but is virtually complete at steady state. Here we demonstrate, using both macroscopic and single channel current recordings, that a preinactivated state is also a property of mSlo1+β2 channels. Detection of this state is enhanced by a mutation (W4E) within the initial β2 NH2-terminal segment critical for inactivation. This mutation increases the rate of recovery to the preinactivated open state, yielding macroscopic inactivation properties qualitatively more similar to those of β3b. Furthermore, short-lived openings corresponding to entry into the preinactivated state can be observed directly with single-channel recording. By examining the initial openings after depolarization of a channel containing β2-W4E, we show that channels can arrive directly at the preinactivated state without passing through the usual long-lived open conformation. This final result suggests that channel opening and inactivation are at least partly separable in this channel. Mechanistically, the preinactivated and inactivated conformations may correspond to binding of the β subunit NH2 terminus in the vicinity of the cytoplasmic pore mouth, followed by definitive movement of the NH2 terminus into a position of occlusion within the ion-conducting pathway.

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38

Suzuki, K., and O. H. Petersen. "Patch-clamp study of single-channel and whole-cell K+ currents in guinea pig pancreatic acinar cells." American Journal of Physiology-Gastrointestinal and Liver Physiology 255, no. 3 (September 1, 1988): G275—G285. http://dx.doi.org/10.1152/ajpgi.1988.255.3.g275.

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K+ channels in the plasma membrane of isolated guinea pig pancreatic acini were studied by patch-clamp single-channel and whole-cell current recording techniques. Three types of K+-permeable pores were found in excised patch experiments: Ca2+-activated nonselective cation channels with a unit conductance of approximately 25 pS that could be inhibited by ATP acting on the membrane inside, and two kinds of Ca2+- and voltage-activated K+-selective channels with unit conductances (in symmetrical K+-rich solutions) of about 200 and 30 pS, respectively. In intact cells, pentagastrin activation of currents through the 30 pS K+-selective pores was demonstrated. In these experiments pentagastrin was added to the bath solution and had no direct contact with the electrically isolated membrane area from which the single-channel currents were recorded, suggesting that the activation is mediated via an intracellular messenger system. Pentagastrin stimulation of voltage-gated K+ currents was also observed in whole-cell recording experiments. Results from these experiments suggest that in the stimulated condition the membrane electrical properties were dominated by the 30 pS K+-selective channels.

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39

Stein, P., and P. Palade. "Patch clamp of sarcolemmal spheres from stretched skeletal muscle fibers." American Journal of Physiology-Cell Physiology 256, no. 2 (February 1, 1989): C434—C440. http://dx.doi.org/10.1152/ajpcell.1989.256.2.c434.

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Stretching frog skeletal muscle fibers to the breaking point results in the rapid formation of numerous large spheres of membrane (5-80 microns diam). The surface of the spheres readily forms gigaohm (G omega) seals against patch pipettes, allowing low-noise single-channel recording. Currents recorded from patches isolated from these spheres indicate that they contain a variety of channels including 1) a small Na+-selective channel seen in the presence of veratridine, 2) a K+-selective channel which is blocked by millimolar Mg-ATP, and 3) a relatively large voltage-dependent Cl- channel which is blocked by Zn2+ and limited in selectivity over other anions [PCl/PMOPS = 3.7; MOPS, 3-(N-morpholino)propanesulfonic acid]. These channels have been described previously and have been identified as markers for sarcolemmal (SL) membrane. Accordingly, this method allows rapid and direct recording of channels in the SL membrane without first having to pretreat fibers with proteolytic enzymes to render the SL accessible to patch pipettes.

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40

Ide, Toru, Yuko Takeuchi, Takaaki Aoki, and Toshio Yanagida. "Simultaneous Optical and Electrical Recording of a Single Ion-Channel." Japanese Journal of Physiology 52, no. 5 (2002): 429–34. http://dx.doi.org/10.2170/jjphysiol.52.429.

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41

Senning, Eric N., and Sharona E. Gordon. "Optical Recording of Single Channel TRPV1 Activity in Living Cells." Biophysical Journal 102, no. 3 (January 2012): 341a. http://dx.doi.org/10.1016/j.bpj.2011.11.1868.

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42

Wang, X. Y., P. J. Harris, and R. E. Kemm. "Ba(2+)-sensitive K+ channels in basal membrane of confluent Madin-Darby canine kidney cells." American Journal of Physiology-Renal Physiology 267, no. 6 (December 1, 1994): F1007—F1014. http://dx.doi.org/10.1152/ajprenal.1994.267.6.f1007.

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A method is described for gaining access to the basolateral membranes of confluent Madin-Darby canine kidney (MDCK) cells by surgical reflection of the cell layer overlying fluid-filled domes. Single-channel recordings from cell-attached inside-out and outside-out configurations revealed two K+ channels located in the basal membranes of the highly differentiated monolayers. With 140 mmol/l KCl in pipette, the intermediate-conductance K+ channel displayed outward rectification in cell-attached configuration with channel conductances of 65 pS for outward part and 17 pS for inward part. In excised-patch recording, this channel had a conductance of 92 pS with 140 mmol/l KCl on the extracellular side of the patch and 5 mmol/l KCl on the cytosolic side. The maximum conductance obtained in symmetrical KCl (140 mmol/l) solution was 140 pS. Ba2+ (1 mmol/l) and tetraethylammonium (5 mmol/l) blocked this channel reversibly. Channel open probability (Po) was reduced from 0.41 at cytosolic pH 7.4 to 0.14 at pH 6.8 and increased to 0.64 at pH 8.0. The channel activity was significantly inhibited by elevation of intracellular Ca2+. A small-conductance K+ channel was also observed mainly in excised patches with single-channel conductance of 48 pS in symmetrical KCl solutions. However, the activity of this channel was partially obscured by the intermediate-conductance K+ channel and further analysis was not possible. A physiological role of these channels in mediating K+ recycling through the monolayer is suggested.

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43

Li, Yang, Paul Langlais, Nikita Gamper, Feng Liu, and Mark S. Shapiro. "Dual Phosphorylations Underlie Modulation of Unitary KCNQ K+Channels by Src Tyrosine Kinase." Journal of Biological Chemistry 279, no. 44 (August 10, 2004): 45399–407. http://dx.doi.org/10.1074/jbc.m408410200.

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Src tyrosine kinase suppresses KCNQ (M-type) K+channels in a subunit-specific manner representing a mode of modulation distinct from that involving G protein-coupled receptors. We probed the molecular and biophysical mechanisms of this modulation using mutagenesis, biochemistry, and both whole-cell and single channel modes of patch clamp recording. Immunoprecipitation assays showed that Src associates with KCNQ2–5 subunits but phosphorylates only KCNQ3–5. Using KCNQ3 as a background, we found that mutation of a tyrosine in the amino terminus (Tyr-67) or one in the carboxyl terminus (Tyr-349) abolished Src-dependent modulation of heterologously expressed KCNQ2/3 heteromultimers. The tyrosine phosphorylation was much weaker for either the KCNQ3-Y67F or KCNQ3-Y349F mutants and wholly absent in the KCNQ3-Y67F/Y349F double mutant. Biotinylation assays showed that Src activity does not alter the membrane abundance of channels in the plasma membrane. In recordings from cell-attached patches containing a single KCNQ2/3 channel, we found that Src inhibits the open probability of the channels. Kinetic analysis was consistent with the channels having two discrete open times and three closed times. Src activity reduced the durations of the longest open time and lengthened the longest closed time of the channels. The implications for the mechanisms of channel regulation by the dual phosphorylations on both channel termini are discussed.

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44

Ide, Toru. "Simultaneous Optical and Electrical Recording of Single Molecule Bonding to Single Channel Proteins." ChemPhysChem 11, no. 16 (September 9, 2010): 3408–11. http://dx.doi.org/10.1002/cphc.201000560.

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45

van der Reijden, Christoph S., Lucas H. M. Mens, and Ad F. M. Snik. "Signal-to-Noise Ratios of the Auditory Steady-State Response from Fifty-Five EEG Derivations in Adults." Journal of the American Academy of Audiology 15, no. 10 (November 2004): 692–701. http://dx.doi.org/10.3766/jaaa.15.10.4.

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The Auditory Steady-State Response (ASSR) was recorded in 20 awake adults with normal hearing on ten EEG channels simultaneously to find derivations with the best signal-to-noise ratios (SNRs). Stimuli were 20% frequency modulated tones of 0.5 and 2 kHz at 20 dB SL, 100% amplitude modulated at 90 or 94 Hz, and presented one at a time to one ear.ASSR recordings using a set of at least three channels improved SNRs significantly by an average of between 6% (500 Hz right ear) to 118% (2 kHz right ear) above the SNRs from the conventional channels. Assuming that the recording time was proportional to 1/(SNR)2, this translates into a recording time of 89% (500 Hz right ear) to 21% (2 kHz right ear) of that for conventional single-channel recording.The three channels comprised the electrode positions inion, right mastoid, and left mastoid. All three electrode positions were referenced to Cz. Adding a fourth channel (Pz-Cz) increases the number of participants with significant responses from the 500 Hz right ear stimulus from 13 to 17. Electrode position F4 and other commonly used positions such as the forehead and right earlobe made significantly less contribution to test efficiency.

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Hayman, K. A., and R. H. Ashley. "Structural features of a multisubstate cardiac mitoplast anion channel: Inferences from single channel recording." Journal of Membrane Biology 136, no. 2 (November 1993): 191–97. http://dx.doi.org/10.1007/bf02505763.

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47

Vyssotski, Alexei L., Andrei N. Serkov, Pavel M. Itskov, Giacomo Dell'Omo, Alexander V. Latanov, David P. Wolfer, and Hans-Peter Lipp. "Miniature Neurologgers for Flying Pigeons: Multichannel EEG and Action and Field Potentials in Combination With GPS Recording." Journal of Neurophysiology 95, no. 2 (February 2006): 1263–73. http://dx.doi.org/10.1152/jn.00879.2005.

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To study the neurophysiology of large-scale spatial cognition, we analyzed the neuronal activity of navigating homing pigeons. This is not possible using conventional radio-telemetry suitable for short distances only. Therefore we developed a miniaturized data logger (“neurologger”) that can be carried by a homing pigeon on its back, in conjunction with a micro-global position system (GPS) logger recording the spatial position of the bird. In its present state, the neurologger permits recording from up to eight single-ended or differential electrodes in a walking or flying pigeon. Inputs from eight independent channels are preamplified, band-pass filtered, and directed to an eight-channel, 10-bit analog-digital converter of the microcontroller storing data on a “Multimedia” or “Secure Digital” card. For electroencephalography (EEG), the logger permits simultaneous recordings of up to eight channels during maximally 47 h, depending on memory, while single unit activity from two channels can be stored over 9 h. The logger permits single unit separation from recorded multiunit signals. The neurologger with GPS represents a better alternative to telemetry that will eventually permit to record neuronal activity during cognitive and innate behavior of many species moving freely in their habitats but will also permit automated high-throughput screening of EEG in the laboratory.

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48

Vyshnevskyi, V. V., T. N. Romanenko, and Yu O. Lugovskyi. "The validity of a person’s authentication using an electrocardiogram with a limited number of channels." Mathematical machines and systems 2 (2020): 43–50. http://dx.doi.org/10.34121/1028-9763-2020-2-43-50.

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The concept of mobile and home telemedicine for screening and early diagnostics of cardiovascular dis-eases is being expanded due to the emergence of mobile diagnostic devices and smartphones. In the course of such telemedicine consultations, the doctor must be sure that the digital electrocardiogram (ECG) be-longs to the patient who was registered. Both multi-channel and single-channel ECG-recording devices are available on the telemedicine consulting market now. Single-channel electrocardiographs are more eco-nomic feasible for home use. Previously, the authors have developed and experimentally tested the algo-rithms for patient authentication by his/her multi-channel ECG. These algorithms are based on the analysis of the shape of QRS complex in three-dimensional phase space of coordinates. Therefore, it is reasonable to adapt these algorithms to single-channel ECG. In case of multi-channel ECG, we can construct a three-dimensional phase space of coordinates by obtaining all the necessary data from the ECG leads. In a case of the single-channel ECG it is necessary to create two additional signals artificially and then it will be possible to form a synthetic phase space. In general, the question of the validity of biometric person au-thentication algorithms by his/her ECG with a limited number of channels is discussed in this paper. Be-sides the algorithms for solving the problem of authentication, the comparison of sensitivity and specificity indicators, calculated on the results of experiments for multi-channel and single-channel ECG, are also given in this paper. The results of experiments with multi-channel and single-channel ECG of a larger number of patients are given in comparison to the previous experiments. The results of the experiments for the case of recording ECG signals by different devices are given as well.

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49

Lipton, Stuart A. "GABA-activated single channel currents in outside-out membrane patches from rat retinal ganglion cells." Visual Neuroscience 3, no. 3 (September 1989): 275–79. http://dx.doi.org/10.1017/s0952523800010026.

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Abstractγ-aminobutyric acid (GABA) evokes large whole-cell currents in solitary mammalian retinal ganglion cells studied by the patch-clamp method. This evidence suggests that GABA acts directly on the retinal ganglion cells as an inhibitory transmitter as it does elsewhere in the mammalian central nervous system. Here, single-channel recordings of the currents underlying the GABA-induced responses were studied in outside-out patches of cell membrane. In some other preparations, single GABAA channels recorded in the excised patch configuration have been shown to have altered properties in comparison to responses elicited during whole-cell recording. For example, in cortical neurons single GABA-activated channels in excised patches display accelerated desensitization kinetics as well as rapid rundown of the response. Therefore, in retinal ganglion cells, responses generated by GABA in cell-free patches were compared to whole-cell responses. After determining that the responses to GABA in acutely isolated outside-out patches were indeed similar to those of the whole-cell currents in retinal ganglion cells, the unitary conductances were studied. It was determined that these single-channel events resemble those reported in other nervous tissues with 4 elementary conductances of ~10 pS, 19–22 pS, 30–33 pS, and 45–50 pS at 33–35°C.

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50

Kamouchi, M., and K. Kitamura. "Regulation of ATP-sensitive K+ channels by ATP and nucleotide diphosphate in rabbit portal vein." American Journal of Physiology-Heart and Circulatory Physiology 266, no. 5 (May 1, 1994): H1687—H1698. http://dx.doi.org/10.1152/ajpheart.1994.266.5.h1687.

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The modulation of ATP-sensitive K+ (KATP)-channel activity was investigated by recording single-channel currents in isolated smooth muscle cells from rabbit portal vein. K(+)-channel openers (KCOs; pinacidil, lemakalim, and nicorandil) induced burstlike openings of single KATP channels in the cell-attached configuration. After patch excision, KATP channels showed "run-down" phenomenon in the presence of KCOs, but subsequent application of Mg-ATP (1 mM) restored KATP-channel activity. Removal of Mg-ATP resulted in transient augmentation of KATP currents, which eventually decayed out. Nucleotide diphosphates (NDPs; GDP, ADP, UDP, IDP, and CDP) also induced channel reopening in the presence of KCOs, which was markedly enhanced by addition of Mg2+ in millimolar concentrations at the internal side of the membrane. The dose-response relation between ATP and the UDP-induced KATP-channel activity was shifted to the right in the presence of Mg2+ (2 mM). These results suggest that intracellular ATP, NDPs, and Mg2+ regulate the channel state of KATP channels (operative and inoperative states) and that KCOs open KATP channels only in the operative state.

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Journal articles on the topic 'Single channel recording'

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