Electrophysiologic Measurements of Membrane Capacitance in Hormone-Secreting Cells

Many methods have been developed for the study of exo- and endocytosis. One of the most elegant consists of cellular membrane capacitance measurements which reflect membrane area changes due to fusion or fission of secretory vesicles. This parameter can be monitored directly by the electrophysiologic patch-clamp technique developed by Erwin Neher and Bert Sakmann in 1976. It is still widely used, primarily for the study of currents across ion channels but also for measurements of membrane capacitance as introduced by Erwin Neher and Alain Marty in 1982. In this chapter we provide an overview of the patch-clamp membrane capacitance techniques used in our laboratory to study anterior pituitary hormone-secreting cells.