Other potential pHi regulating mechanism includes the Na+/HCO3− cotransporter (NBCe1), which facilitates HCO3− outward transport (coupled with Na+ efflux) to buffer extracellular H+ loads in response to neuronal activity [64], or stimulates inwardly directed HCO3− transport (coupled with Na+ influx) in ischemic stroke conditions [65]. Here, SLC4A4 is linked to ischemic stroke.