Electrophysiological Techniques for Mitochondrial Channels

The patch-clamp technique has revolutionized studies of ion channels in a wide variety of cells. Its development in the late 1970s and early 1980s made it possible to analyze the currents of single ion channels. However, electrophysiological recordings of these proteins were limited to the plasma-membrane of living cells: the small size and the doublemembrane organization of some cell organelles and the reduced stability of intracellular membranes precluded an implementation of this technique to investigate the properties of channels located in mitochondria, chloroplasts, the endoplasmic reticulum or lysosomes. For the last 25 years great effort has been made to implement the patch-clamp technique besides the planar lipid bilayer approach on these organelles. In this mini-review we focus on the developments and applications of the patch-clamp technique on mitochondrial and other cytosolic membranes and discuss the challenges of different, innovative approaches.