Mediates the electrogenic exchange of Ca(2+) against Na(+) ions across the cell membrane, and thereby contributes to the regulation of cytoplasmic Ca(2+) levels and Ca(2+)-dependent cellular processes (PubMed:8021246, PubMed:9486131). Contributes to cellular Ca(2+) homeostasis in excitable cells (By similarity). Contributes to the rapid decrease of cytoplasmic Ca(2+) levels back to baseline after neuronal activation, and thereby contributes to modulate synaptic plasticity, learning and memory (By similarity). Plays a role in regulating urinary Ca(2+) and Na(+) excretion (By similarity). Ca(2+)(in) + 3 Na(+)(out) = Ca(2+)(out) + 3 Na(+)(in) Calcium transport is down-regulated by Na(+) and stimulated by Ca(2+). Detected in neocortex and hippocampus on pyramidal cells, astrocyte processes and dendrites (at protein level) (PubMed:16914199). Brain and skeletal muscle. The cytoplasmic Calx-beta domains bind the regulatory Ca(2+). The first Calx-beta domain can bind up to four Ca(2+) ions. The second domain can bind another two Ca(2+) ions that are essential for calcium-regulated ion exchange. Belongs to the Ca(2+):cation antiporter (CaCA) (TC 2.A.19) family. SLC8 subfamily.