Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Inward rectifier current noise in frog skeletal muscle.

T E DeCoursey, J Dempster, O F Hutter

    The Journal of Physiology
    |April 1, 1984
    PubMed
    Summary

    This study investigates inwardly rectifying potassium (K+) currents in frog muscle fibers. Researchers found that current noise spectra reveal fluctuations linked to the rectification mechanism, yielding insights into channel properties.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    Voltage-gated proton channels exist in the plasma membrane of human oocytes.

    Human reproduction (Oxford, England)·2019
    Same author

    Miniature wireless recording and stimulation system for rodent behavioural testing.

    Journal of neural engineering·2015
    Same author

    On the minimum requirements for otolaryngology clinics in National Health Service hospitals.

    The Journal of laryngology and otology·2015
    Same author

    Exploration of the two-photon excitation spectrum of fluorescent dyes at wavelengths below the range of the Ti:Sapphire laser.

    Journal of microscopy·2015
    Same author

    C1 inhibitor deficiency: 2014 United Kingdom consensus document.

    Clinical and experimental immunology·2015
    Same author

    A UK national audit of hereditary and acquired angioedema.

    Clinical and experimental immunology·2013

    Area of Science:

    • Electrophysiology
    • Membrane Biophysics
    • Ion Channel Function

    Background:

    • Inwardly rectifying potassium (K+) currents play crucial roles in regulating membrane potential.
    • Understanding the biophysical properties of these currents is essential for comprehending cellular excitability.

    Purpose of the Study:

    • To characterize the noise properties of inwardly rectifying K+ currents in frog muscle fibers.
    • To elucidate the underlying mechanisms of inward rectification using noise analysis.

    Main Methods:

    • Utilized the Vaseline-gap voltage-clamp technique on cut frog muscle fibers.
    • Analyzed current noise spectra, fitting them with Lorentzian and 1/f components.
    • Investigated the effects of varying external ion concentrations (K+, tetraethylammonium, Rb+).

    Main Results:

    • Current noise spectra exhibited a Lorentzian component at small negative potentials, attributed to the rectification mechanism.
    • The time constant derived from the Lorentzian component correlated with K+ current activation kinetics.
    • Replacing external K+ with TEA+ or Rb+ abolished the Lorentzian component.
    • A model incorporating two gating parameters (ps and pf) successfully explained the macroscopic currents and noise spectra.
    • Estimated single-channel conductance (gamma) at approximately 9 pS with a channel density of about 1 micron-2.

    Conclusions:

    • The Lorentzian component of current noise directly reflects fluctuations within the inwardly rectifying K+ channel mechanism.
    • The proposed two-parameter model provides a robust framework for interpreting inwardly rectifying K+ currents and their associated noise.
    • The study determined key single-channel parameters, offering valuable data for future biophysical modeling.

    Related Experiment Videos