Functional localization of single active ion channels can the surface of aliving cell

The spatial distribution of ion channels in the cell plasma membrane has an important role in governing regional specialization, providing a precise a nd localized control over cell function. We report here a novel technique b ased on scanning ion conductance microscopy that allows, for the first time , mapping of single active ion channels in intact cell plasma membranes. We have mapped the distribution of ATP-regulated K+ channels (K-ATP channels) in cardiac myocytes. The channels are organized in small groups and anchor ed in the Z-grooves of the sarcolemma. The distinct pattern of distribution of these channels may have important functional implications.