During the past two decades, great advances have been made in the electrophysiological and molecular identification of calcium entry pathways in non-excitable cells. The term “non-excitable” refers to a variety of cell types that are not capable of firing action potentials. Essentially, except for neurons, muscle cells, and some endocrine cells, all other cells in the body are non-excitable. For the most part, they lack the necessary levels of expression of voltage-gated Na+ channels (NaV family) and also voltage-gated Ca2+ channels (CaV family). Ca2+ influx in these cell types is therefore thought to rely on unrelated, voltage-independent channels, such as Orai (CRACM) and TRP family members. In this chapter, we will discuss direct electrophysiological methods used to record the electrical activity of these proteins, focusing on calcium-selective Orai/STIM and TRPV5/TRPV6 channels.
© 2017 by Taylor & Francis Group, LLC.