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. Contributes to cellular Ca(2+ homeostasis in excitable cells. 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. Plays a role in regulating urinary Ca(2+ and Na(+ excretion.