The transport of manganese across the blood–brain barrier

The mammalian central nervous system (CNS) possesses a unique and specialized capillary adaptation, referred to as the blood–brain barrier (BBB). The BBB maintains an optimal neuronal microenvironment, regulating blood–tissue exchange of macromolecules and nutrients. The BBB is characterized by individual endothelial cells that are continuously linked by tight junctions, inhibiting the diffusion of macromolecules and solutes between adjacent endothelial cells. This review will focus on pertinent issues to BBB maintenance, and survey recent dogmas on the transport mechanisms for the essential metal, manganese, across this barrier. Specifically, putative carriers for manganese into and out of the brain will be discussed.