Neuronal Ca2+-sensitive Non-selective Cation Channels and TRPC5

Membrane excitability is mainly regulated by ion channels, including both voltage-gated and ligand-gated channels. In addition to these conventional types of ion channel, a new class of ionic channel is also involved in regulation of the membrane potential. Transient receptor potential (TRP) channels are expressed not only in excitable cells, such as sensory organs, neurons, and cardiac myocytes, but also in non-excitable cells such as endothelial cells, B lymphocytes, and rat basophilic leukemia mast cells. Most TRP channels are Ca2+-permeable, and some are regulated by intracellular Ca2+. The aim of this review is to provide an overview of the TRP channel superfamily, and describe the electrophysiological properties and physiological roles of the neuronal Ca2+-sensitive non-selective cation channel TRPC5.