Gamma-Aminobutyric Acid Antagonism and Presynaptic Inhibition in the Frog Spinal Cord

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Science  21 Jan 1972:
Vol. 175, Issue 4019, pp. 331-333
DOI: 10.1126/science.175.4019.331


The convulsant alkaloid bicuculline blocked presynaptic inhibition, dorsal root potentials, primary afferent depolarization, and depolarizing effects of gamma-aminobutyric acid on dorsal root terminals of the amphibian spinal cord, but did not block effects of other putative amino acid transmitters. These actions of bicuculline suggest that gamma-aminobutyric acid may be the transmitter involved in spinal presynaptic inhibition.