Members of the solute carrier family 4 are classified as bicarbonate transporters, which transport chloride across membranes in order to regulate intracellular pH. SLC4A10/NCBE is predominantly distributed in the brain. Mice lacking slc4a10 have rather small brain ventricles and increased seizure threshold. In humans, disruption of the gene for SLC4A10/NCBE has been observed in a mentally retarded patient with complex partial epilepsy. Therefore, SLC4A10/NCBE may participate in the regulation of neuronal pH and neuronal excitability in the central nervous system.