Direct demonstration of sulphonylurea-sensitive KATP channels on nerve terminals of the rat motor cortex.

We examined whether ATP-sensitive potassium (KATP) channels are present on presynaptic terminals of the rat motor cortex, an area of the CNS exhibiting a high density of sulphonylurea binding. A novel fused nerve terminal preparation was developed which produced structures amenable to patch clamp methods. In inside-out recordings a K+ channel was observed which possessed all the major features of the Type 1 KATP channel, including sensitivity to ATP and the antidiabetic sulphonylureas.