The epithelial cells of the choroid plexuses form the major barrier between the blood and the cerebrospinal fluid (CSF. They secrete the cerebrospinal fluid in a highly regulated manner so that the concentrations of ions in the CSF are constant even when the composition of the blood plasma is perturbed. The epithelial cells also transport nutrients into the brain e.g. vitamin C, and remove by-products of neuronal activity from the CSF e.g. K+, catecholamines. My laboratory is investigating the function and regulation of the ion channels and transporters expressed in choroid plexus epithelial cells. Our aim is to gain an understanding of how the activity of the proteins is integrated in CSF secretion, and how these proteins are regulated to ensure the stable composition of the CSF.