What can we learn about cell signalling by combining optical imaging and patch clamp techniques?

Optical imaging is a powerful technique with which to investigate the activity, distribution and movement of biomolecules. The increased resolution of images obtained with confocal microscopy now allows us to visualize the signalling events in individual intracellular organelles. Local photobleaching and uncaging of caged compounds enable investigators to control the activity of many biologically important molecules in small localized regions of both cytosol and internal spaces of cellular organelles. Uncaging and photobleaching conveniently complement laser scanning confocal microscopy. The whole-cell recording configuration of the patch-clamp technique has been widely used not only to measure ionic currents, but also to control the concentration of important molecules in the cytosol. The cell-attached configuration of patch clamp was utilized for local stimulation of the cell and local delivery of the second messengers. This paper describes the advantages of combining patch-clamp and optical imaging methods as well as some of the recent achievements using this approach.