The Experts below are selected from a list of 16968 Experts worldwide ranked by ideXlab platform

Minoru Onozuka - One of the best experts on this subject based on the ideXlab platform.

  • augmentation of bursting pacemaker activity by serotonin in an identified achatina fulica neurone an increase in sodium and calcium activated negative Slope Resistance via cyclic amp dependent protein phosphorylation
    The Journal of Experimental Biology, 1993
    Co-Authors: Kozo Funase, Kazuko Watanabe, Minoru Onozuka
    Abstract:

    The mechanism of serotonin (5-HT) action on bursting activity was examined in a bursting pacemaker neurone of the snail Achatina fulica. 5-HT augmented both the depolarizing and post-burst-hyperpolarizing phases of the bursting cycle in a dose-dependent manner. This biogenic amine also enhanced the negative Slope Resistance (NSR), which was normally detectable at membrane potentials between −40 and −20 mV, and produced another NSR at voltages between −20 and 0 mV. The former NSR disappeared in Na(+)-free saline and the latter was abolished by replacement with Co(2+)-substituted Ca(2+)-free saline. Both isobutylmethylxanthine, extracellular applied, and intracellularly applied cyclic AMP simulated a 5-HT effect on the current-voltage relationships. In contrast, the 5-HT effect was suppressed in a dose-dependent manner by prior treatment with a cyclic-AMP-dependent protein kinase inhibitor, isoquinoline sulphonamide. Similar suppression was observed after intracellular injection of a cyclic-AMP-dependent protein kinase inhibitor isolated from bovine muscle. These results suggest that 5-HT may augment the bursting pacemaker activity by its stimulatory effect on both the slow Na+ channels and the Ca2+ channels through cyclic-AMP-dependent protein phosphorylation.

  • cyclic amp dependent protein phosphorylation is involved in the development of negative Slope Resistance and a reduction of the potassium current induced by pentylenetetrazole in identified snail neurons
    Neuroscience Letters, 1991
    Co-Authors: Minoru Onozuka, Hiroyasu Furuichi, Yasushi Fukami
    Abstract:

    Abstract The role of cAMP-dependent protein phosphorylation in the pentylenetetrazole (PTZ)-induced bursting activity was examined in snail neurons, using the voltage clamp method in combination with the pressure injection technique. The cAMP-dependent protein kinase inhibitors, protein kinase inhibitor isolated from rabbit muscle and isoquinolinesulfonamide, inhibited the PTZ-induced negative Slope Resistance (NSR) in the steady state I – V curve. These inhibitors also suppressed the action of PTZ on the delayed outward potassium current ( I KD ). This suppression was transiently abolished by intracellular injection of the catalytic subunit of cAMP-dependent protein kinase. These findings suggest that cAMP-dependent protein phosphorylation may be involved in both the development of the NSR and a reduction of the I KD by PTZ, leading to depolarizing phase of a bursting cycle.

Yasushi Fukami - One of the best experts on this subject based on the ideXlab platform.

Kozo Funase - One of the best experts on this subject based on the ideXlab platform.

  • augmentation of bursting pacemaker activity by serotonin in an identified achatina fulica neurone an increase in sodium and calcium activated negative Slope Resistance via cyclic amp dependent protein phosphorylation
    The Journal of Experimental Biology, 1993
    Co-Authors: Kozo Funase, Kazuko Watanabe, Minoru Onozuka
    Abstract:

    The mechanism of serotonin (5-HT) action on bursting activity was examined in a bursting pacemaker neurone of the snail Achatina fulica. 5-HT augmented both the depolarizing and post-burst-hyperpolarizing phases of the bursting cycle in a dose-dependent manner. This biogenic amine also enhanced the negative Slope Resistance (NSR), which was normally detectable at membrane potentials between −40 and −20 mV, and produced another NSR at voltages between −20 and 0 mV. The former NSR disappeared in Na(+)-free saline and the latter was abolished by replacement with Co(2+)-substituted Ca(2+)-free saline. Both isobutylmethylxanthine, extracellular applied, and intracellularly applied cyclic AMP simulated a 5-HT effect on the current-voltage relationships. In contrast, the 5-HT effect was suppressed in a dose-dependent manner by prior treatment with a cyclic-AMP-dependent protein kinase inhibitor, isoquinoline sulphonamide. Similar suppression was observed after intracellular injection of a cyclic-AMP-dependent protein kinase inhibitor isolated from bovine muscle. These results suggest that 5-HT may augment the bursting pacemaker activity by its stimulatory effect on both the slow Na+ channels and the Ca2+ channels through cyclic-AMP-dependent protein phosphorylation.

Kazuko Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • augmentation of bursting pacemaker activity by serotonin in an identified achatina fulica neurone an increase in sodium and calcium activated negative Slope Resistance via cyclic amp dependent protein phosphorylation
    The Journal of Experimental Biology, 1993
    Co-Authors: Kozo Funase, Kazuko Watanabe, Minoru Onozuka
    Abstract:

    The mechanism of serotonin (5-HT) action on bursting activity was examined in a bursting pacemaker neurone of the snail Achatina fulica. 5-HT augmented both the depolarizing and post-burst-hyperpolarizing phases of the bursting cycle in a dose-dependent manner. This biogenic amine also enhanced the negative Slope Resistance (NSR), which was normally detectable at membrane potentials between −40 and −20 mV, and produced another NSR at voltages between −20 and 0 mV. The former NSR disappeared in Na(+)-free saline and the latter was abolished by replacement with Co(2+)-substituted Ca(2+)-free saline. Both isobutylmethylxanthine, extracellular applied, and intracellularly applied cyclic AMP simulated a 5-HT effect on the current-voltage relationships. In contrast, the 5-HT effect was suppressed in a dose-dependent manner by prior treatment with a cyclic-AMP-dependent protein kinase inhibitor, isoquinoline sulphonamide. Similar suppression was observed after intracellular injection of a cyclic-AMP-dependent protein kinase inhibitor isolated from bovine muscle. These results suggest that 5-HT may augment the bursting pacemaker activity by its stimulatory effect on both the slow Na+ channels and the Ca2+ channels through cyclic-AMP-dependent protein phosphorylation.

Jagadeesh V Kumar - One of the best experts on this subject based on the ideXlab platform.

  • A Novel Dual-Slope Resistance-to-Digital Converter
    IEEE Transactions on Instrumentation and Measurement, 2010
    Co-Authors: Madhu N. Mohan, Boby George, Jagadeesh V Kumar
    Abstract:

    A dual-Slope Resistance-to-digital (DSRDC) converter that accepts the Resistance of a single-element resistive-type sensor as input and provides a direct digital output proportional to the parameter being sensed by the resistive-type sensor is presented in this paper. A high level of linearity and accuracy is achieved since the output of the DSRDC is dictated only by the magnitudes of a pair of dc reference voltages and the transformation constant of the sensor. Sensitivity analysis shows that the effect of circuit parameter variations on the output is minimal. Simulation studies and test results obtained on a prototype establish the efficacy of the proposed scheme.

  • Direct digital converter for a single active element resistive sensor
    2009 IEEE Instrumentation and Measurement Technology Conference, 2009
    Co-Authors: Madhu N. Mohan, Jagadeesh V Kumar
    Abstract:

    A direct digital converter that provides a digital output, proportional to the measurand being sensed by a single active element resistive sensor is presented in this paper. To accomplish this task, the structure and the switching sequence of a conventional dual Slope, analog to digital converter (DSADC) is appropriately altered so that the altered DSADC accepts the Resistance of the sensor as an integral part and provides a digital output that is linearly proportional to the physical quantity being sensed by the resistive sensor. Since the output of the dual Slope Resistance to digital converter (DSRDC) is dictated only by the magnitudes of a pair of DC reference voltages, a fixed value resistor and the transformation constant of the sensor, the error in the output is minimal. Hence, a high level of linearity and accuracy is achieved. Simulation studies establish the efficacy of the proposed scheme.

  • Dual Slope Resistance to Digital Converter
    2007 IEEE Instrumentation & Measurement Technology Conference IMTC 2007, 2007
    Co-Authors: Madhu N. Mohan, Boby George, Jagadeesh V Kumar
    Abstract:

    A dual Slope Resistance to digital converter applicable to differential resistive sensors is presented. A dual Slope digital converter is appropriately modified so that it accepts directly the resistive elements of a differential resistive sensor and provide a digital output that is linearly proportional to the physical quantity being sensed by the sensor. High accuracy is easily obtained since the output is decided only by a pair of dc reference voltages and the transformation constant of the sensor. Sensitivity analysis shows that the effect of circuit parameter variations on the output is minimal. The efficacy of the proposed scheme is clearly demonstrated by the test results obtained on a prototype.