gamma-Aminobutyric acid as an inhibitory neurotransmitter in the rat supraoptic nucleus: intracellular recordings in the hypothalamic slice.

Intracellular recordings have been made from rat supraoptic neurones in the hypothalamic slice preparation. Application of gamma-aminobutyric acid (GABA) caused all neurones to hyperpolarise and this was accompanied by an increase in membrane conductance. GABA application examined on a variety of cells was found to have a potent influence on patterning of electrical activity, always consistent with an inhibitory action.