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Intracellular calcium ions decrease the affinity of the GABA receptor

M Inoue, Y Oomura, T Yakushiji

    Nature
    |November 13, 1986
    PubMed

    Insights

    Intracellular calcium (Ca2+) suppresses GABA-activated chloride currents in bullfrog sensory neurons. This finding reveals a novel mechanism where Ca2+ modulates GABA receptor affinity, impacting neuronal signaling.

    Area of Science:

    • Neuroscience
    • Cellular Biology
    • Neurophysiology

    Background:

    • Intracellular free calcium ions (Ca2+) are vital second messengers in signal transduction.
    • Ca2+ influences neuronal functions including synaptic transmission and receptor activation.

    Purpose of the Study:

    • To investigate the role of intracellular Ca2+ in modulating GABA receptor activity in bullfrog sensory neurons.

    Main Methods:

    • Neuronal activity recording from bullfrog sensory neurons using suction pipette method.
    • Application of gamma-aminobutyric acid (GABA) via a 'concentration clamp' technique.

    Main Results:

    • Intracellular Ca2+ was found to suppress GABA-activated chloride (Cl-) conductance.
    • This suppression occurs by reducing the apparent affinity of the GABA receptor.

    Conclusions:

    • Intracellular Ca2+ acts as a negative modulator of GABAergic transmission.
    • This study provides the first evidence for Ca2+-mediated suppression of GABA receptor function.

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