Ca 2+ signaling by T-type Ca 2+ channels in neurons

Among the major families of voltage-gated Ca2+ channels, the low-voltage-activated channels formed by the Cav3 subunits, referred to as T-type Ca2+ channels, have recently gained increased interest in terms of the intracellular Ca2+ signals generated upon their activation. Here, we provide an overview of recent reports documenting that T-type Ca2+ channels act as an important Ca2+ source in a wide range of neuronal cell types. The work is focused on T-type Ca2+ channels in neurons, but refers to non-neuronal cells in cases where exemplary functions for Ca2+ entering through T-type Ca2+ channels have been described. Notably, Ca2+ influx through T-type Ca2+ channels is the predominant Ca2+ source in several neuronal cell types and carries out specific signaling roles. We also emphasize that Ca2+ signaling through T-type Ca2+ channels occurs often in select subcellular compartments, is mediated through strategically co-localized targets, and is exploited for unique physiological functions.