The function of Ensembl gene identifier ENSG00000124140 (SLC12A5, solute carrier family 12 member 5) is as follows. Mediates electroneutral potassium-chloride cotransport in mature neurons and is required for neuronal Cl(-) homeostasis (PubMed:12106695). As major extruder of intracellular chloride, it establishes the low neuronal Cl(-) levels required for chloride influx after binding of GABA-A and glycine to their receptors, with subsequent hyperpolarization and neuronal inhibition (By similarity). Involved in the regulation of dendritic spine formation and maturation (PubMed:24668262). {ECO:0000250|UniProtKB:Q63633, ECO:0000269|PubMed:12106695, ECO:0000269|PubMed:24668262}.