Fig. 2.
(A) The general structure of voltage-gated calcium channels, such as CaV1.3, which includes the pore-forming α1-subunit and auxiliary β, γ, and α2/δ subunits. (B) The α1-subunit is the primary component that facilitates calcium influx and is composed of four transmembrane domains (I, II, III, & IV). Commonly, these channels possess a long cytoplasmic C-terminal tail that is involved in regulating its activity (long isoform). The alternative spliced CaV1.3-short isoform lacks this region. (C) (i) Autonomous spiking is observed through whole-cell, patch-clamping recordings at the cell body (soma), where each spike indicates a neuronal action potential [4]. (ii) At distal dendritic sites, calcium concentrations spike synchronously with somatic firing. This elevated intracellular calcium concentration, but not the autonomous spiking, is blocked by the calcium channel inhibitor, isradipine, and is then restored after the washout of this agent. Fig. 2(C) sourced from [4] with permission.