Blockade of neurotransmitter-activated K+ conductance by QX-314 in the rat hippocampus.

Intracellular injection of QX-314 blocked the ability of baclofen and 5-carboxyamidotryptamine to hyperpolarize cells in the rat hippocampus. This effect was not associated with a reduction in the effects of norepinephrine on these cells nor a blockade of the potassium channels underlying the calcium-dependent afterhyperpolarization responsible or significant changes in membrane potential. These results suggest that QX-314 is an effective blocker of G-protein-gated potassium channels in this region.