Antagonism of GABA by picrotoxin in the feline cerebral cortex

Picrotoxin and gamma-aminobutyric acid (GABA) were applied by microiontophoresis to an unselected population of neurones in the feline cerebral cortex. Picrotoxin was shown to antagonize the depressant effects of GABA and in addition appeared free of some of the actions of bicuculline which tend to mask GABA antagonism.